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Sample records for 447-marketing mix design

  1. Mixed voltage VLSI design

    NASA Technical Reports Server (NTRS)

    Panwar, Ramesh; Rennels, David; Alkalaj, Leon

    1993-01-01

    A technique for minimizing the power dissipated in a Very Large Scale Integration (VLSI) chip by lowering the operating voltage without any significant penalty in the chip throughput even though low voltage operation results in slower circuits. Since the overall throughput of a VLSI chip depends on the speed of the critical path(s) in the chip, it may be possible to sustain the throughput rates attained at higher voltages by operating the circuits in the critical path(s) with a high voltage while operating the other circuits with a lower voltage to minimize the power dissipation. The interface between the gates which operate at different voltages is crucial for low power dissipation since the interface may possibly have high static current dissipation thus negating the gains of the low voltage operation. The design of a voltage level translator which does the interface between the low voltage and high voltage circuits without any significant static dissipation is presented. Then, the results of the mixed voltage design using a greedy algorithm on three chips for various operating voltages are presented.

  2. Defining and Designing Mixed Research Synthesis Studies

    PubMed Central

    Sandelowski, Margarete; Voils, Corrine I.; Barroso, Julie

    2009-01-01

    Mixed research synthesis is the latest addition to the repertoires of mixed methods research and systematic review. Mixed research synthesis requires that the problems generated by the methodological diversity within and between qualitative and quantitative studies be resolved. Three basic research designs accommodate this diversity, including the segregated, integrated, and contingent designs. Much work remains to be done before mixed research synthesis can secure its place in the repertoires of mixed methods research and systematic review, but the effort is well worth it as it has the potential to enhance both the significance and utility for practice of the many qualitative and quantitative studies constituting shared domains of research. PMID:20098638

  3. Mixed Methods Research Designs in Counseling Psychology

    ERIC Educational Resources Information Center

    Hanson, William E.; Creswell, John W.; Clark, Vicki L. Plano; Petska, Kelly S.; Creswell, David J.

    2005-01-01

    With the increased popularity of qualitative research, researchers in counseling psychology are expanding their methodologies to include mixed methods designs. These designs involve the collection, analysis, and integration of quantitative and qualitative data in a single or multiphase study. This article presents an overview of mixed methods…

  4. Automated mixed traffic vehicle design AMTV 2

    NASA Technical Reports Server (NTRS)

    Johnston, A. R.; Marks, R. A.; Cassell, P. L.

    1982-01-01

    The design of an improved and enclosed Automated Mixed Traffic Transit (AMTT) vehicle is described. AMTT is an innovative concept for low-speed tram-type transit in which suitable vehicles are equipped with sensors and controls to permit them to operate in an automated mode on existing road or walkway surfaces. The vehicle chassis and body design are presented in terms of sketches and photographs. The functional design of the sensing and control system is presented, and modifications which could be made to the baseline design for improved performance, in particular to incorporate a 20-mph capability, are also discussed. The vehicle system is described at the block-diagram-level of detail. Specifications and parameter values are given where available.

  5. Development of a simplified asphalt mix stability procedure for use in Superpave volumetric mix design

    NASA Astrophysics Data System (ADS)

    Hafez, Ihab Hussein Fahmy

    Over the last five decades, two common test methods (Marshall and Hveem) have evolved for the design of asphaltic mixes. These design methods have been historically found to be generally reliable and reasonable for most application in design. However, premature distress in many flexible pavements suggests that these empirical methods of design do not guarantee a stable mix. Recently, many studies have been carried out in order to develop a rational mix design procedure that accounts for both the mix volumetric properties as well as fundamental engineering properties. Among those is the Superpave design procedure, which was originally divided into three, hierarchical levels termed the volumetric mix design (level I), the abbreviated mix design (level II), and the full mix design (level III). In the volumetric design, the entire mix design process is based upon the volumetric properties and does not include a test method to evaluate the stability/strength of the mix. Although both the abbreviated level and the full level of design included test methods that considered the engineering properties in a complete and a comprehensive manner; they required the purchase of very expensive equipment and a large number of samples to be tested. The objective of this research was to develop a new rational "fundamental" mix strength (stability) test for the design of dense graded mixes to overcome the limitations of the Hveem and Marshall empirical methods and to fill the gaps and major deficiencies in the current Superpave volumetric mix design. The new procedure is based upon the Superpave volumetric design (level I) but is augmented by the simple, but fundamental mix strength (stability) test. Such a test is now currently absent in the existing Superpave approach. The new procedure introduces the flow time as a fundamental engineering design criterion in the mix design. This parameter is defined as the time (in seconds) at which plastic flow in a mix occurs under creep loading

  6. Demystifying Mixed Methods Research Design: A Review of the Literature

    ERIC Educational Resources Information Center

    Caruth, Gail D.

    2013-01-01

    Mixed methods research evolved in response to the observed limitations of both quantitative and qualitative designs and is a more complex method. The purpose of this paper was to examine mixed methods research in an attempt to demystify the design thereby allowing those less familiar with its design an opportunity to utilize it in future research.…

  7. What Can Mixed Methods Designs Offer Professional Development Program Evaluators?

    ERIC Educational Resources Information Center

    Giordano, Victoria; Nevin, Ann

    2007-01-01

    In this paper, the authors describe the benefits and pitfalls of mixed methods designs. They argue that mixed methods designs may be preferred when evaluating professional development programs for p-K-12 education given the new call for accountability in making data-driven decisions. They summarize and critique the studies in terms of limitations…

  8. Mixed Methodology Research Design in Educational Technology

    ERIC Educational Resources Information Center

    Kumar, Muthu

    2007-01-01

    In recent times many educational researchers have moved away from the traditional purist approach of strictly adopting either a qualitative or quantitative approach to conducting research. Instead they have attempted an eclectic mix of both methods in their research inquiry, combining aspects of both the traditions at various stages of their…

  9. Improvements in Mixing Time and Mixing Uniformity in Devices Designed for Studies of Protein Folding Kinetics

    SciTech Connect

    Yao, Shuhuai; Bakajin, Olgica

    2007-08-01

    Using a microfluidic laminar flow mixer designed for studies of protein folding kinetics, we demonstrate a mixing time of 1 +/- 1 micros with sample consumption on the order of femtomoles. We recognize two limitations of previously proposed designs: (1) size and shape of the mixing region, which limits mixing uniformity and (2) the formation of Dean vortices at high flow rates, which limits the mixing time. We address these limitations by using a narrow shape-optimized nozzle and by reducing the bend of the side channel streamlines. The final design, which combines both of these features, achieves the best performance. We quantified the mixing performance of the different designs by numerical simulation of coupled Navier-Stokes and convection-diffusion equations and experiments using fluorescence resonance energy-transfer (FRET)-labeled DNA.

  10. DNA microarrays: design principles for maximizing ergodic, chaotic mixing.

    PubMed

    Hertzsch, Jan-Martin; Sturman, Rob; Wiggins, Stephen

    2007-02-01

    In this article we show that models of flows in DNA microarrays generated by pulsed source-sink pairs can be studied as linked twist maps. The significance of this is that it enables us to relate the flow to mathematically precise notions of chaotic mixing that can be realized through specific design criteria. We apply these techniques to three different mixing protocols, two of which have been previously described in the literature, and we are able to isolate the features of each mixer that lead to "good" or "bad" mixing. Based on this, we propose a new design to generate a "well-mixed" flow in a DNA microarray. PMID:17262763

  11. RBCC Mixing Studies: Ejector Ramjet Design Optimization

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The research project reported herein extended over a period from October 1997 through August 1999. The research resulted in three technical papers presented at the AIAA/SAE/ASME/ASEE 35th Joint Propulsion Conference in Los Angeles in July 1999. These three papers are attached to this Executive Summary to constitute the final report. Objective: The objective of this research was to determine the mixing characteristics between the primary rocket jets and the turbine exhaust stream in a simulated Rocket Based Combined Cycle propulsion concept operating in the air augmented rocket mode.

  12. Designing, Teaching, and Evaluating Two Complementary Mixed Methods Research Courses

    ERIC Educational Resources Information Center

    Christ, Thomas W.

    2009-01-01

    Teaching mixed methods research is difficult. This longitudinal explanatory study examined how two classes were designed, taught, and evaluated. Curriculum, Research, and Teaching (EDCS-606) and Mixed Methods Research (EDCS-780) used a research proposal generation process to highlight the importance of the purpose, research question and…

  13. Mixed-Reality Prototypes to Support Early Creative Design

    NASA Astrophysics Data System (ADS)

    Safin, Stéphane; Delfosse, Vincent; Leclercq, Pierre

    The domain we address is creative design, mainly architecture. Rooted in a multidisciplinary approach as well as a deep understanding of architecture and design, our method aims at proposing adapted mixed-reality solutions to support two crucial activities: sketch-based preliminary design and distant synchronous collaboration in design. This chapter provides a summary of our work on a mixed-reality device, based on a drawing table (the Virtual Desktop), designed specifically to address real-life/business-focused issues. We explain our methodology, describe the two supported activities and the related users’ needs, detail the technological solution we have developed, and present the main results of multiple evaluation sessions. We conclude with a discussion of the usefulness of a profession-centered methodology and the relevance of mixed reality to support creative design activities.

  14. Fixed-Order Mixed Norm Designs for Building Vibration Control

    NASA Technical Reports Server (NTRS)

    Whorton, Mark S.; Calise, Anthony J.

    2000-01-01

    This study investigates the use of H2, mu-synthesis, and mixed H2/mu methods to construct full order controllers and optimized controllers of fixed dimensions. The benchmark problem definition is first extended to include uncertainty within the controller bandwidth in the form of parametric uncertainty representative of uncertainty in the natural frequencies of the design model. The sensitivity of H2 design to unmodeled dynamics and parametric uncertainty is evaluated for a range of controller levels of authority. Next, mu-synthesis methods are applied to design full order compensators that are robust to both unmodeled dynamics and to parametric uncertainty. Finally, a set of mixed H2/mu compensators are designed which are optimized for a fixed compensator dimension. These mixed norm designs recover the H2 design performance levels while providing the same levels of robust stability as the mu designs. It is shown that designing with the mixed norm approach permits higher levels of controller authority for which the H2 designs are destabilizing. The benchmark problem is that of an active tendon system. The controller designs are all based on the use of acceleration feedback.

  15. A Mixed Methods Investigation of Mixed Methods Sampling Designs in Social and Health Science Research

    ERIC Educational Resources Information Center

    Collins, Kathleen M. T.; Onwuegbuzie, Anthony J.; Jiao, Qun G.

    2007-01-01

    A sequential design utilizing identical samples was used to classify mixed methods studies via a two-dimensional model, wherein sampling designs were grouped according to the time orientation of each study's components and the relationship of the qualitative and quantitative samples. A quantitative analysis of 121 studies representing nine fields…

  16. Guidance for using mixed methods design in nursing practice research.

    PubMed

    Chiang-Hanisko, Lenny; Newman, David; Dyess, Susan; Piyakong, Duangporn; Liehr, Patricia

    2016-08-01

    The mixed methods approach purposefully combines both quantitative and qualitative techniques, enabling a multi-faceted understanding of nursing phenomena. The purpose of this article is to introduce three mixed methods designs (parallel; sequential; conversion) and highlight interpretive processes that occur with the synthesis of qualitative and quantitative findings. Real world examples of research studies conducted by the authors will demonstrate the processes leading to the merger of data. The examples include: research questions; data collection procedures and analysis with a focus on synthesizing findings. Based on experience with mixed methods studied, the authors introduce two synthesis patterns (complementary; contrasting), considering application for practice and implications for research. PMID:27397810

  17. Mixed methods research design for pragmatic psychoanalytic studies.

    PubMed

    Tillman, Jane G; Clemence, A Jill; Stevens, Jennifer L

    2011-10-01

    Calls for more rigorous psychoanalytic studies have increased over the past decade. The field has been divided by those who assert that psychoanalysis is properly a hermeneutic endeavor and those who see it as a science. A comparable debate is found in research methodology, where qualitative and quantitative methods have often been seen as occupying orthogonal positions. Recently, Mixed Methods Research (MMR) has emerged as a viable "third community" of research, pursuing a pragmatic approach to research endeavors through integrating qualitative and quantitative procedures in a single study design. Mixed Methods Research designs and the terminology associated with this emerging approach are explained, after which the methodology is explored as a potential integrative approach to a psychoanalytic human science. Both qualitative and quantitative research methods are reviewed, as well as how they may be used in Mixed Methods Research to study complex human phenomena. PMID:21880844

  18. Thermal design of multi-fluid mixed-mixed cross-flow heat exchangers

    NASA Astrophysics Data System (ADS)

    Roetzel, W.; Luo, X.

    2010-11-01

    A fast analytical calculation method is developed for the thermal design and rating of multi-fluid mixed-mixed cross-flow heat exchangers. Temperature dependent heat capacities and heat transfer coefficients can iteratively be taken into account. They are determined at one or two special reference temperatures. Examples are given for the application of the method to the rating of special multi-fluid multi-pass shell-and-tube heat exchangers and multi-fluid cross-flow plate-fin heat exchangers. The accuracy of the method is tested against numerical calculations with good results.

  19. Aerodynamic design and investigation of a mixed flow compressor stage

    NASA Astrophysics Data System (ADS)

    Eisenlohr, Gernot; Benfer, Friedrich Wilhelm

    1994-03-01

    Topic of this contribution is a single stage mixed flow compressor with 6:1 pressure ratio, which is under development as a component for a turbojet. Primary design aim for the stage was to achieve minimum frontal area at a high efficiency level. Excerpts of the considerations and calculations for determining the design rotational speed and the main dimensions of this mixed flow compressor stage are presented first. Some explanations concerning the definition of the meridional contours and the generation of the blading are given, supplemented by several results of the impeller flow calculations. After a brief description of the test rig and its instrumentation, the measured impeller characteristics are presented. They show that the impeller meets its design pressure ratio and exceeds the efficiency target. For selected operating points the measured pressure distributions along the impeller outer contour are compared with the predicted static pressure rise. The discussions of the test results closes with the measured mixed flow compressor map which reveals that the overall stage performance does not fully meet the design goals, mainly because of high losses in the diffusing system.

  20. The Mixed Waste Management Facility. Preliminary design review

    SciTech Connect

    1995-12-31

    This document presents information about the Mixed Waste Management Facility. Topics discussed include: cost and schedule baseline for the completion of the project; evaluation of alternative options; transportation of radioactive wastes to the facility; capital risk associated with incineration; radioactive waste processing; scaling of the pilot-scale system; waste streams to be processed; molten salt oxidation; feed preparation; initial operation to demonstrate selected technologies; floorplans; baseline revisions; preliminary design baseline; cost reduction; and project mission and milestones.

  1. Prevalence of Mixed-Methods Sampling Designs in Social Science Research

    ERIC Educational Resources Information Center

    Collins, Kathleen M. T.

    2006-01-01

    The purpose of this mixed-methods study was to document the prevalence of sampling designs utilised in mixed-methods research and to examine the interpretive consistency between interpretations made in mixed-methods studies and the sampling design used. Classification of studies was based on a two-dimensional mixed-methods sampling model. This…

  2. Design and calibration of the mixing layer and wind tunnel

    NASA Technical Reports Server (NTRS)

    Bell, James H.; Mehta, Rabindra D.

    1989-01-01

    A detailed account of the design, assembly and calibration of a wind tunnel specifically designed for free-shear layer research is contained. The construction of this new facility was motivated by a strong interest in the study of plane mixing layers with varying initial and operating conditions. The Mixing Layer Wind tunnel is located in the Fluid Mechanics Laboratory at NASA Ames Research Center. The tunnel consists of two separate legs which are driven independently by centrifugal blowers connected to variable speed motors. The blower/motor combinations are sized such that one is smaller than the other, giving maximum flow speeds of about 20 and 40 m/s, respectively. The blower speeds can either be set manually or via the Microvax II computer. The two streams are allowed to merge in the test section at the sharp trailing edge of a slowly tapering splitter plate. The test section is 36 cm in the cross-stream direction, 91 cm in the spanwise direction and 366 cm in length. One test section side-wall is slotted for probe access and adjustable so that the streamwise pressure gradient may be controlled. The wind tunnel is also equipped with a computer controlled, three-dimensional traversing system which is used to investigate the flow fields with pressure and hot-wire instrumentation. The wind tunnel calibration results show that the mean flow in the test section is uniform to within plus or minus 0.25 pct and the flow angularity is less than 0.25 deg. The total streamwise free-stream turbulence intensity level is approximately 0.15 pct. Currently the wind tunnel is being used in experiments designed to study the three-dimensional structure of plane mixing layers and wakes.

  3. Some design considerations for supersonic cruise mixed compression inlets

    NASA Technical Reports Server (NTRS)

    Bowditch, D. N.

    1973-01-01

    A mixed compression inlet designed for supersonic cruise has very demanding requirements for high total pressure recovery and low bleed and cowl drag. However, since the optimum inlet for supersonic cruise performance may have other undesirable characteristics, it is necessary to establish trade-offs between inlet performance and other inlet characteristics. Some of these trade-offs between the amount of internal compression, aerodynamic performance and angle-of-attack tolerance are reviewed. Techniques for analysis of boundary layer control and subsonic diffuser flow are discussed.

  4. A Preliminary Rubric Design to Evaluate Mixed Methods Research

    ERIC Educational Resources Information Center

    Burrows, Timothy J.

    2013-01-01

    With the increase in frequency of the use of mixed methods, both in research publications and in externally funded grants there are increasing calls for a set of standards to assess the quality of mixed methods research. The purpose of this mixed methods study was to conduct a multi-phase analysis to create a preliminary rubric to evaluate mixed…

  5. Interactive tools designed to study mix in inertial confinement fusion implosions

    SciTech Connect

    Welser-sherrill, Leslie; Cooley, James H; Wilson, Doug C

    2008-01-01

    Graphical user interface tools have been built in IDL to study mix in inertial confinement fusion (ICF) implosion cores. FLAME (Fall-Line Analysis Mix Evaluator), a code which investigates yield degradation due to mix , was designed to post-process 1D hydrodynamic simulation output by implementing a variety of mix models. Three of these mix models are based on the physics of the fall-line. In addition, mixing data from other sources can be incorporated into the yield degradation analysis. Two independent tools called HAME (Haan Analysis Mix Evaluator) and YAME (Youngs Analysis Mix Evaluator) were developed to calculate the spatial extent of the mix region according to the Haan saturation model and Youngs' phenomenological model, respectively. FLAME facilitates a direct comparison to experimental data. The FLAME, HAME, and YAME interfaces are user-friendly, flexible, and platform-independent.

  6. A Proposed Model of Retransformed Qualitative Data within a Mixed Methods Research Design

    ERIC Educational Resources Information Center

    Palladino, John M.

    2009-01-01

    Most models of mixed methods research design provide equal emphasis of qualitative and quantitative data analyses and interpretation. Other models stress one method more than the other. The present article is a discourse about the investigator's decision to employ a mixed method design to examine special education teachers' advocacy and…

  7. Single-Case Designs and Qualitative Methods: Applying a Mixed Methods Research Perspective

    ERIC Educational Resources Information Center

    Hitchcock, John H.; Nastasi, Bonnie K.; Summerville, Meredith

    2010-01-01

    The purpose of this conceptual paper is to describe a design that mixes single-case (sometimes referred to as single-subject) and qualitative methods, hereafter referred to as a single-case mixed methods design (SCD-MM). Minimal attention has been given to the topic of applying qualitative methods to SCD work in the literature. These two…

  8. Mixing Qualitative and Quantitative Methods: Insights into Design and Analysis Issues

    ERIC Educational Resources Information Center

    Lieber, Eli

    2009-01-01

    This article describes and discusses issues related to research design and data analysis in the mixing of qualitative and quantitative methods. It is increasingly desirable to use multiple methods in research, but questions arise as to how best to design and analyze the data generated by mixed methods projects. I offer a conceptualization for such…

  9. The Mixed Waste Management Facility. Design basis integrated operations plan (Title I design)

    SciTech Connect

    1994-12-01

    The Mixed Waste Management Facility (MWMF) will be a fully integrated, pilotscale facility for the demonstration of low-level, organic-matrix mixed waste treatment technologies. It will provide the bridge from bench-scale demonstrated technologies to the deployment and operation of full-scale treatment facilities. The MWMF is a key element in reducing the risk in deployment of effective and environmentally acceptable treatment processes for organic mixed-waste streams. The MWMF will provide the engineering test data, formal evaluation, and operating experience that will be required for these demonstration systems to become accepted by EPA and deployable in waste treatment facilities. The deployment will also demonstrate how to approach the permitting process with the regulatory agencies and how to operate and maintain the processes in a safe manner. This document describes, at a high level, how the facility will be designed and operated to achieve this mission. It frequently refers the reader to additional documentation that provides more detail in specific areas. Effective evaluation of a technology consists of a variety of informal and formal demonstrations involving individual technology systems or subsystems, integrated technology system combinations, or complete integrated treatment trains. Informal demonstrations will typically be used to gather general operating information and to establish a basis for development of formal demonstration plans. Formal demonstrations consist of a specific series of tests that are used to rigorously demonstrate the operation or performance of a specific system configuration.

  10. Engineering scale mixing system tests for MWTF title II design

    SciTech Connect

    Chang, S.C.

    1994-10-10

    Mixing tests for the Multifunction Waste Tank Facility (MWTF) were conducted in 1/25 and 1/10 scale test tanks with different slurry levels, solids concentrations, different jet mixers and with simulated in-tank structures. The same test procedure was used as in the Title I program, documented in WHC-SD-W236A-ER-005. The test results support the scaling correlation derived previously in the Title I program. The tests also concluded that a partially filled tank requires less mixing power, and horizontal and angled jets in combination (H/A mixer) are significantly more effective than the two horizontal jet mixers (H/H mixer) when used for mixing slurry with a high solids concentrations.

  11. Design and synthesis of mixed oxides nanoparticles for biofuel applications

    SciTech Connect

    Chen, Senniang

    2010-05-15

    The work in this dissertation presents the synthesis of two mixed metal oxides for biofuel applications and NMR characterization of silica materials. In the chapter 2, high catalytic efficiency of calcium silicate is synthesized for transesterfication of soybean oil to biodisels. Chapter 3 describes the synthesis of a new Rh based catalyst on mesoporous manganese oxides. The new catalyst is found to have higher activity and selectivity towards ethanol. Chapter 4 demonstrates the applications of solid-state Si NMR in the silica materials.

  12. DISTRIBUTED MIXING BURNER (DMB) ENGINEERING DESIGN FOR APPLICATION TO INDUSTRIAL AND UTILITY BOILERS

    EPA Science Inventory

    The report summarizes the design of two prototype distributed mixing burners (DMBs) for application to industrial and utility boilers. The DMB is a low-NOx pulverized-coal-fired burner in which: (1) mixing of the coal with combustion air is controlled to minimize NOx emissions, a...

  13. Advanced Off-Gas Control System Design For Radioactive And Mixed Waste Treatment

    SciTech Connect

    Nick Soelberg

    2005-09-01

    Treatment of radioactive and mixed wastes is often required to destroy or immobilize hazardous constituents, reduce waste volume, and convert the waste to a form suitable for final disposal. These kinds of treatments usually evolve off-gas. Air emission regulations have become increasingly stringent in recent years. Mixed waste thermal treatment in the United States is now generally regulated under the Hazardous Waste Combustor (HWC) Maximum Achievable Control Technology (MACT) standards. These standards impose unprecedented requirements for operation, monitoring and control, and emissions control. Off-gas control technologies and system designs that were satisfactorily proven in mixed waste operation prior to the implementation of new regulatory standards are in some cases no longer suitable in new mixed waste treatment system designs. Some mixed waste treatment facilities have been shut down rather than have excessively restrictive feed rate limits or facility upgrades to comply with the new standards. New mixed waste treatment facilities in the U. S. are being designed to operate in compliance with the HWC MACT standards. Activities have been underway for the past 10 years at the INL and elsewhere to identify, develop, demonstrate, and design technologies for enabling HWC MACT compliance for mixed waste treatment facilities. Some specific off-gas control technologies and system designs have been identified and tested to show that even the stringent HWC MACT standards can be met, while minimizing treatment facility size and cost.

  14. What Informs Practice and What Is Valued in Corporate Instructional Design? A Mixed Methods Study

    ERIC Educational Resources Information Center

    Thompson-Sellers, Ingrid N.

    2012-01-01

    This study used a two-phased explanatory mixed-methods design to explore in-depth what factors are perceived by Instructional Design and Technology (IDT) professionals as impacting instructional design practice, how these factors are valued in the field, and what differences in perspectives exist between IDT managers and non-managers. For phase 1…

  15. Interactive tools designed to study mix in inertial confinement fusion implosions

    NASA Astrophysics Data System (ADS)

    Welser-Sherrill, L.; Cooley, J. H.; Wilson, D. C.

    2009-06-01

    Graphical user interface tools have been built in IDL to study mix in inertial confinement fusion (ICF) implosion cores. FLAME, a code which investigates yield degradation due to mix, was designed to post-process 1D hydrodynamic simulation output by implementing a variety of mix models. Three of these mix models are based on the physics of the fall-line. In addition, mixing data from other sources can be incorporated into the yield degradation analysis. Two independent tools called HAME and YAME were developed to calculate the spatial extent of the mix region according to the Haan saturation model and Youngs' phenomenological model, respectively. FLAME facilitates a direct comparison to experimental data. The FLAME, HAME, and YAME interfaces are user-friendly, flexible, and platform-independent.

  16. Conflicts Management Model in School: A Mixed Design Study

    ERIC Educational Resources Information Center

    Dogan, Soner

    2016-01-01

    The object of this study is to evaluate the reasons for conflicts occurring in school according to perceptions and views of teachers and resolution strategies used for conflicts and to build a model based on the results obtained. In the research, explanatory design including quantitative and qualitative methods has been used. The quantitative part…

  17. A Study of Fixed-Order Mixed Norm Designs for a Benchmark Problem in Structural Control

    NASA Technical Reports Server (NTRS)

    Whorton, Mark S.; Calise, Anthony J.; Hsu, C. C.

    1998-01-01

    This study investigates the use of H2, p-synthesis, and mixed H2/mu methods to construct full-order controllers and optimized controllers of fixed dimensions. The benchmark problem definition is first extended to include uncertainty within the controller bandwidth in the form of parametric uncertainty representative of uncertainty in the natural frequencies of the design model. The sensitivity of H2 design to unmodelled dynamics and parametric uncertainty is evaluated for a range of controller levels of authority. Next, mu-synthesis methods are applied to design full-order compensators that are robust to both unmodelled dynamics and to parametric uncertainty. Finally, a set of mixed H2/mu compensators are designed which are optimized for a fixed compensator dimension. These mixed norm designs recover the H, design performance levels while providing the same levels of robust stability as the u designs. It is shown that designing with the mixed norm approach permits higher levels of controller authority for which the H, designs are destabilizing. The benchmark problem is that of an active tendon system. The controller designs are all based on the use of acceleration feedback.

  18. Mixing, Noise and Thrust Benefits Using Corrugated Designs

    NASA Technical Reports Server (NTRS)

    Morgan, Morris H., III; Gilinsky, Mikhail M.

    2000-01-01

    These projects are directed toward the analysis of several concepts for nozzle and inlet performance improvement and noise reduction from jet exhausts. Currently. The FM&AL also initiates new joint research between the HU/FM&AL, the Hyper-X Program Team at the LaRC, and the Central Institute of Aviation Motors (CIAM), Moscow, Russia in the field of optimization of fuel injection and mixing in air-breathing propulsion systems. The main results of theoretical, numerical simulation and experimental tests obtained in the previous research are in the papers and patents. The goals of the 14U/FM&AL programs are twofold: 1) to improve the working efficiency of the HU/FM&AL team in generating new innovative ideas and in conducting research in the field of fluid dynamics and acoustics, basically for improvement of supersonic and subsonic aircraft engines, and 2) to attract promising minority students to this research and training and, in cooperation with other HU departments, to teach them basic knowledge in Aerodynamics, Gas Dynamics, and Theoretical and Experimental Methods in Aeroacoustics and Computational Fluid Dynamics (CFD). The research at the HU/FM&AL supports reduction schemes associated with the emission of en 'ne pollutants for commercial aircraft and concepts for reduction of 91 observables for military aircraft. These research endeavors relate to the goals of the NASA Strategic Enterprise in Aeronautics concerning the development of environmentally acceptable aircraft. It is in this precise area, where the US aircraft industry, academia, and Government are in great need of trained professionals and which is a high priority goal of the Minority University Research and Education (MLTREP) Program, that the HU/FM&AL can make its most important contribution.

  19. A PET system design by using mixed detectors: resolution properties

    NASA Astrophysics Data System (ADS)

    Liu, Jingjing; Kao, Chien-Min; Gu, Shuguo; Xiao, Peng; Xie, Qingguo

    2014-07-01

    We investigate a cylindrical positron emission tomography (PET) system design strategy that employs two groups of detectors with different resolutions. The reason for considering this strategy is the observation that in many tasks one would want a higher resolution in a targeted region, which contains lesions or organs of interest, than that in the rest of the subject. Although one can design a PET system to meet the highest resolution required by the imaging task, this is not cost efficient because the superior resolution outside the target region is not needed. To address this issue, investigators have proposed the concept of an insert, in which a high-resolution detector (HRD) is inserted into a parent PET system to locally increase the image resolution. In this paper, we examine an alternative strategy in which the system is made of one arc of normal-resolution detectors with respect to, for example, whole-body imaging and one arc of HRDs. By using Monte Carlo simulations, we study the resolution properties of this system design and examine how they are affected by the location and size of the HRD arc. Our results show that the region obtained by connecting the edges of the HRD arc to the center of the field-of-view (FOV) can have significantly better resolution than that in the rest of the FOV, as well as better resolution uniformity.

  20. A PET system design by using mixed detectors: resolution properties.

    PubMed

    Liu, Jingjing; Kao, Chien-Min; Gu, Shuguo; Xiao, Peng; Xie, Qingguo

    2014-07-01

    We investigate a cylindrical positron emission tomography (PET) system design strategy that employs two groups of detectors with different resolutions. The reason for considering this strategy is the observation that in many tasks one would want a higher resolution in a targeted region, which contains lesions or organs of interest, than that in the rest of the subject. Although one can design a PET system to meet the highest resolution required by the imaging task, this is not cost efficient because the superior resolution outside the target region is not needed. To address this issue, investigators have proposed the concept of an insert, in which a high-resolution detector (HRD) is inserted into a parent PET system to locally increase the image resolution. In this paper, we examine an alternative strategy in which the system is made of one arc of normal-resolution detectors with respect to, for example, whole-body imaging and one arc of HRDs. By using Monte Carlo simulations, we study the resolution properties of this system design and examine how they are affected by the location and size of the HRD arc. Our results show that the region obtained by connecting the edges of the HRD arc to the center of the field-of-view (FOV) can have significantly better resolution than that in the rest of the FOV, as well as better resolution uniformity. PMID:24910321

  1. Design of turbulent tangential micro-mixers that mix liquids on the nanosecond time scale.

    PubMed

    Mitic, Sandra; van Nieuwkasteele, Jan W; van den Berg, Albert; de Vries, Simon

    2015-01-15

    Unravelling (bio)chemical reaction mechanisms and macromolecular folding pathways on the (sub)microsecond time scale is limited by the time resolution of kinetic instruments for mixing reactants and observation of the progress of the reaction. To improve the mixing time resolution, turbulent four- and two-jet tangential micro-mixers were designed and characterized for their mixing and (unwanted) premixing performances employing acid-base reactions monitored by a pH-sensitive fluorescent dye. The mixing performances of the micro-mixers were determined after the mixing chamber in a free-flowing jet. The premixing behavior in the vortex chamber was assessed in an optically transparent glass-silicon replica of a previously well-characterized stainless-steel four-jet tangential micro-mixer. At the highest flow rates, complete mixing was achieved in 160ns with only approximately 9% premixing of the reactants. The mixing time of 160ns is at least 50 times shorter than estimated for other fast mixing devices. Key aspects to the design of ultrafast turbulent micro-mixers are discussed. The integration of these micro-mixers with an optical flow cell would enable the study of the very onset of chemical reactions in general and of enzyme catalytic reactions in particular. PMID:25447461

  2. Design of a mixing system for simulated high-level nuclear waste melter feed slurries

    SciTech Connect

    Peterson, M.E.; McCarthy, D.; Muhlstein, K.D.

    1986-03-01

    The Nuclear Waste Treatment Program development program consists of coordinated nonradioactive and radioactive testing combined with numerical modeling of the process to provide a complete basis for design and operation of a vitrification facility. The radioactive demonstration tests of equipment and processes are conducted before incorporation in radioactive pilot-scale melter systems for final demonstration. The mixing system evaluation described in this report was conducted as part of the nonradioactive testing. The format of this report follows the sequence in which the design of a large-scale mixing system is determined. The initial program activity was concerned with gaining an understanding of the theoretical foundation of non-Newtonian mixing systems. Section 3 of this report describes the classical rheological models that are used to describe non-Newtonian mixing systems. Since the results obtained here are only valid for the slurries utilized, Section 4, Preparation of Simulated Hanford and West Valley Slurries, describes how the slurries were prepared. The laboratory-scale viscometric and physical property information is summarized in Section 5, Laboratory Rheological Evaluations. The bench-scale mixing evaluations conducted to define the effects of the independent variables described above on the degree of mixing achieved with each slurry are described in Section 6. Bench-scale results are scaled-up to establish engineering design requirements for the full-scale mixing system in Section 7. 24 refs., 37 figs., 44 tabs.

  3. A numerical study of automotive turbocharger mixed flow turbine inlet geometry for off design performance

    NASA Astrophysics Data System (ADS)

    Leonard, T.; Spence, S.; Early, J.; Filsinger, D.

    2013-12-01

    Mixed flow turbines represent a potential solution to the increasing requirement for high pressure, low velocity ratio operation in turbocharger applications. While literature exists for the use of these turbines at such operating conditions, there is a lack of detailed design guidance for defining the basic geometry of the turbine, in particular, the cone angle - the angle at which the inlet of the mixed flow turbine is inclined to the axis. This investigates the effect and interaction of such mixed flow turbine design parameters. Computational Fluids Dynamics was initially used to investigate the performance of a modern radial turbine to create a baseline for subsequent mixed flow designs. Existing experimental data was used to validate this model. Using the CFD model, a number of mixed flow turbine designs were investigated. These included studies varying the cone angle and the associated inlet blade angle. The results of this analysis provide insight into the performance of a mixed flow turbine with respect to cone and inlet blade angle.

  4. Curiosity and Pedagogy: A Mixed-Methods Study of Student Experiences in the Design Studio

    ERIC Educational Resources Information Center

    Smith, Korydon H.

    2010-01-01

    Curiosity is often considered the foundation of learning. There is, however, little understanding of how (or if) pedagogy in higher education affects student curiosity, especially in the studio setting of architecture, interior design, and landscape architecture. This study used mixed-methods to investigate curiosity among design students in the…

  5. A Typology of Mixed Methods Sampling Designs in Social Science Research

    ERIC Educational Resources Information Center

    Onwuegbuzie, Anthony J.; Collins, Kathleen M. T.

    2007-01-01

    This paper provides a framework for developing sampling designs in mixed methods research. First, we present sampling schemes that have been associated with quantitative and qualitative research. Second, we discuss sample size considerations and provide sample size recommendations for each of the major research designs for quantitative and…

  6. Establishing Interpretive Consistency When Mixing Approaches: Role of Sampling Designs in Evaluations

    ERIC Educational Resources Information Center

    Collins, Kathleen M. T.; Onwuegbuzie, Anthony J.

    2013-01-01

    The goal of this chapter is to recommend quality criteria to guide evaluators' selections of sampling designs when mixing approaches. First, we contextualize our discussion of quality criteria and sampling designs by discussing the concept of interpretive consistency and how it impacts sampling decisions. Embedded in this discussion are…

  7. Panel Design Variations in the Multistage Test Using the Mixed-Format Tests

    ERIC Educational Resources Information Center

    Kim, Jiseon; Chung, Hyewon; Dodd, Barbara G.; Park, Ryoungsun

    2012-01-01

    This study compared various panel designs of the multistage test (MST) using mixed-format tests in the context of classification testing. Simulations varied the design of the first-stage module. The first stage was constructed according to three levels of test information functions (TIFs) with three different TIF centers. Additional computerized…

  8. Design Case Summary. Production of Mixed Alcohols from Municipal Solid Waste via Gasification

    SciTech Connect

    Valkenburg, C.; Zhu, Y.; Walton, C. W.; Thompson, B. L.; Gerber, M. A.; Jones, S. B.; Stevens, D. J.

    2010-03-01

    The Biomass Program develops design cases to understand the current state of conversion technologies and to determine where improvements need to take place in the future. This design case establishes cost targets for converting MSW to ethanol and other mixed alcohols via gasification.

  9. Design Optimization of Mixed-flow Pump Impellers and Diffusers in a Fixed Meridional Shape

    NASA Astrophysics Data System (ADS)

    Kim, Sung; Choi, Young-Seok; Lee, Kyoung-Yong

    2010-06-01

    In this paper, design optimization for mixed-flow pump impellers and diffusers has been studied by using a commercial CFD code and DOE(design of experiments). We also discussed how to improve the performance of the mixed-flow pump by designing the impeller and diffuser in the mixed-flow pump. Geometric design variables were defined by the vane plane development which indicates the blade-angle distributions and length of the impeller and the diffusers. The vane plane development was controlled by using blade-angle in a fixed meridional shape. First the design optimization of the defined impeller geometric variables was done, and then the flow characteristics were analyzed in the point of incidence angle at the diffuser leading edge for the optimized impeller. Then design optimizations of the defined diffuser shape variables were performed. The importance of the geometric design variables was analyzed by using 2k factorial designs, and the design optimization of the geometric variables were determined using the response surface method. The objective functions are defined as the total head and the total efficiency at the design flow-rate. From the comparison of CFD results between optimized pump and base design model, the reason for the performance improvement was discussed.

  10. Homotopy Algorithm for Fixed Order Mixed H2/H(infinity) Design

    NASA Technical Reports Server (NTRS)

    Whorton, Mark; Buschek, Harald; Calise, Anthony J.

    1996-01-01

    Recent developments in the field of robust multivariable control have merged the theories of H-infinity and H-2 control. This mixed H-2/H-infinity compensator formulation allows design for nominal performance by H-2 norm minimization while guaranteeing robust stability to unstructured uncertainties by constraining the H-infinity norm. A key difficulty associated with mixed H-2/H-infinity compensation is compensator synthesis. A homotopy algorithm is presented for synthesis of fixed order mixed H-2/H-infinity compensators. Numerical results are presented for a four disk flexible structure to evaluate the efficiency of the algorithm.

  11. The Design of Useful Mix Characterization Experiments for the LLNL Reshock Platform

    NASA Astrophysics Data System (ADS)

    Islam, Tanim

    2015-11-01

    The NIF Re-shock platform has been extensively engineered to minimize boundary effects and polluting shocks. It is capable of comprehensively and reproducibly exploring a large parameter space important in mix experiments: strength and timing of shocks and reshocks; the amplitude and wavelength of Richtmyer-Meshkov-unstable interfaces; the Atwood number of these mixing layers; and using a technique developed with experiments at the Omega laser, the simultaneous visualization of spike and bubble fronts. In this work, I explore multimodal and roughened surface designed, and combinations of light and heavy materials, that may illuminate our understanding of mix in plasmas.

  12. Design and aerodynamic performance evaluation of a high-work mixed flow turbine stage

    NASA Technical Reports Server (NTRS)

    Neri, Remo N.; Elliott, Thomas J.; Marsh, David N.; Civinskas, Kestutis C.

    1994-01-01

    As axial and radial turbine designs have been pushed to their aerothermodynamic and mechanical limits, the mixed-flow turbine (MFT) concept has been projected to offer performance and durability improvements, especially when ceramic materials are considered. The objective of this NASA/U.S. Army sponsored mixed-flow turbine (AMFT) program was to determine the level of performance attainable with MFT technology within the mechanical constraints of 1997 projected ceramic material properties. The MFT geometry is similar to a radial turbine, exhibiting a large radius change from inlet to exit, but differing in that the inlet flowpath is not purely radial, nor axial, but mixed; it is the inlet geometry that gives rise to the name 'mixed-flow'. The 'mixed' orientation of the turbine inlet offers several advantages over radial designs by allowing a nonzero inlet blade angle yet maintaining radial-element blades. The oblique inlet not only improves the particle-impact survivability of the design, but improves the aerodynamic performance by reducing the incidence at the blade inlet. The difficulty, however, of using mixed-flow geometry lies in the scarcity of detailed data and documented design experience. This paper reports the design of a MFT stage designed with the intent to maximize aerodynamic performance by optimizing design parameters such as stage reaction, rotor incidence, flowpath shape, blade shape, vane geometry, and airfoil counts using 2-D, 3-D inviscid, and 3-D viscous computational fluid dynamics code. The aerodynamic optimization was accomplished while maintaining mechanical integrity with respect to vibration and stress levels in the rotor. A full-scale cold-flow rig test was performed with metallic hardware fabricated to the specifications of the hot ceramic geometry to evaluate the stage performance.

  13. Compound parabolic concentrator design for red, green, blue, and white LED light mixing

    NASA Astrophysics Data System (ADS)

    Wei, An-Chi; Lo, Shih-Chieh; Hung, Pei-Fang; Lee, Ju-Yi; Yeh, Hong-Yih; Huang, Hong-Cheng; Li, Chia-Ming

    2016-08-01

    A light-mixing module consisting of a compound parabolic concentrator (CPC) and a fiber for mixing light from red, green, blue, and white (RGBW) LEDs was proposed. The design principle was investigated and a design prototype was demonstrated in a simulation. The simulated results showed that the chromatic nonuniformity was reduced to 1/10 when the fiber length was 40 times the core width, and the module efficiencies were more than 80% and more than 60% when the fiber lengths were 350 mm and 5 m, respectively. The proposed module is suitable for solar lighting compensation or indoor lighting, such as plant-factory lighting.

  14. Facility design consideration for continuous mix production of class 1.3 propellant

    NASA Technical Reports Server (NTRS)

    Williamson, K. L.; Schirk, P. G.

    1994-01-01

    In November of 1989, NASA awarded the Advanced Solid Rocket Motor (ASRM) contract to Lockheed Missiles and Space Company (LMSC) for production of advanced solid rocket motors using the continuous mix process. Aerojet ASRM division (AAD) was selected as the facility operator and RUST International Corporation provided the engineering, procurement, and construction management services. The continuous mix process mandates that the mix and cast facilities be 'close-coupled' along with the premix facilities, creating unique and challenging requirements for the facility designer. The classical approach to handling energetic materials-division into manageable quantities, segregation, and isolation-was not available due to these process requirements and quantities involved. This paper provides a description of the physical facilities, the continuous mix process, and discusses the monitoring and detection techniques used to mitigate hazards and prevent an incident.

  15. [The mixed design in nursing sciences or when a question of research calls for qualitative and quantitative strategies].

    PubMed

    Bourgault, Patricia; Gallagher, Frances; Michaud, Cécile; Saint-Cyr-Tribble, Denise

    2010-12-01

    The use of a mixed method research design raises many questions, especially regarding the paradigmatic position. With this paradigm, we may consider the mixed method design as the best way of answering a research question and the latter orients to one of the different subtypes of mixed method design. To illustrate the use of this kind of design, we propose a study such as conducted in nursing sciences. In this article, the challenges raised by the mixed method design, and the place of this type of research in nursing sciences is discussed. PMID:21322192

  16. Taking Advantage of Model-Driven Engineering Foundations for Mixed Interaction Design

    NASA Astrophysics Data System (ADS)

    Gauffre, Guillaume; Dubois, Emmanuel

    New forms of interactive systems, hereafter referred to as Mixed Interactive Systems (MIS), are based on the use of physical artefacts present in the environment. Mixing the digital and physical worlds affects the development of interactive systems, especially from the point of view of the design resources which need to express new dimensions. Consequently, there is a crucial need to clearly describe the content and utility of the recent models associated to these new interaction forms. Based on existing initiatives in the field of HCI, this chapter first highlights the interest of using a Model-Driven Engineering (MDE) approach for the design of MIS. Then, this chapter retraces the application of a MDE approach on a specific Mixed Interaction design resource. The resulted contribution is a motivated, explicit, complete and standardized definition of the ASUR model, a model for mixed interaction design. This definition constitutes a basis to promote the use of this model, to support its diffusion and to derive design tools from this model. The model-driven development of a flexible ASUR editor is finally introduced, thus facilitating the insertion of model extensions and articulations.

  17. Nanohole Arrays of Mixed Designs and Microwriting for Simultaneous and Multiple Protein Binding Studies

    PubMed Central

    Ji, Jin; Yang, Jiun-Chan; Larson, Dale N.

    2009-01-01

    We demonstrate using nanohole arrays of mixed designs and a microwriting process based on dip-pen nanolithography to monitor multiple, different protein binding events simultaneously in real time based on the intensity of Extraordinary Optical Transmission of nanohole arrays. The microwriting process and small footprint of the individual nanohole arrays enabled us to observe different binding events located only 16μm apart, achieving high spatial resolution. We also present a novel concept that incorporates nanohole arrays of different designs to improve confidence and accuracy of binding studies. For proof of concept, two types of nanohole arrays, designed to exhibit opposite responses to protein bindings, were fabricated on one transducer. Initial studies indicate that the mixed designs could help to screen out artifacts such as protein intrinsic signals, providing improved accuracy of binding interpretation. PMID:19297143

  18. DESIGN AND PERFORMANCE CHARACTERISTICS OF A TURBULENT MIXING CONDENSATION NUCLEI COUNTER. (R826654)

    EPA Science Inventory

    The design and optimization of operation parameters of a Turbulent Mixing Condensation Nuclei Counter (TMCNC) are discussed as well as its performance using dibutylphthalate (DBP) as the working fluid. A detection limit of 3 nm has been achieved at a flow rate of 2.8 lmin-1<...

  19. 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…

  20. A Mixed-Methods Social Networks Study Design for Research on Transnational Families

    ERIC Educational Resources Information Center

    Bernardi, Laura

    2011-01-01

    This paper advocates the adoption of a mixed-methods research design to describe and analyze ego-centered social networks in transnational family research. Drawing on the experience of the "Social Networks Influences on Family Formation" project (2004-2005; see Bernardi, Keim, & von der Lippe, 2007a, 2007b), I show how the combined use of network…

  1. Interfacial Design of Mixed Matrix Membranes for Improved Gas Separation Performance.

    PubMed

    Wang, Zhenggong; Wang, Dong; Zhang, Shenxiang; Hu, Liang; Jin, Jian

    2016-05-01

    High-performance metal-organic framework (MOF)/polyimide (PI) mixed matrix membranes (MMMs) are fabricated by a facile strategy by designing the MOF/PI matrix interface via poly dopamine coating. The overall separation performance of the designed MMMs surpasses the state-of-the-art 2008 Robeson upper bound for the H2 /CH4 and H2 /N2 gas pairs and approaches the 2008 upper bound for the O2 /N2 gas pair. PMID:26936293

  2. A PC-based inverse design method for radial and mixed flow turbomachinery

    NASA Technical Reports Server (NTRS)

    Skoe, Ivar Helge

    1991-01-01

    An Inverse Design Method suitable for radial and mixed flow turbomachinery is presented. The codes are based on the streamline curvature concept; therefore, it is applicable for current personal computers from the 286/287 range. In addition to the imposed aerodynamic constraints, mechanical constraints are imposed during the design process to ensure that the resulting geometry satisfies production consideration and that structural considerations are taken into account. By the use of Bezier Curves in the geometric modeling, the same subroutine is used to prepare input for both aero and structural files since it is important to ensure that the geometric data is identical to both structural analysis and production. To illustrate the method, a mixed flow turbine design is shown.

  3. A reuse-based framework for the design of analog and mixed-signal ICs

    NASA Astrophysics Data System (ADS)

    Castro-Lopez, Rafael; Fernandez, Francisco V.; Rodriguez Vazquez, Angel

    2005-06-01

    Despite the spectacular breakthroughs of the semiconductor industry, the ability to design integrated circuits (ICs) under stringent time-to-market (TTM) requirements is lagging behind integration capacity, so far keeping pace with still valid Moore"s Law. The resulting gap is threatening with slowing down such a phenomenal growth. The design community believes that it is only by means of powerful CAD tools and design methodologies - and, possibly, a design paradigm shift - that this design gap can be bridged. In this sense, reuse-based design is seen as a promising solution, and concepts such as IP Block, Virtual Component, and Design Reuse have become commonplace thanks to the significant advances in the digital arena. Unfortunately, the very nature of analog and mixed-signal (AMS) design has hindered a similar level of consensus and development. This paper presents a framework for the reuse-based design of AMS circuits. The framework is founded on three key elements: (1) a CAD-supported hierarchical design flow that facilitates the incorporation of AMS reusable blocks, reduces the overall design time, and expedites the management of increasing AMS design complexity; (2) a complete, clear definition of the AMS reusable block, structured into three separate facets or views: the behavioral, structural, and layout facets, the two first for top-down electrical synthesis and bottom-up verification, the latter used during bottom-up physical synthesis; (3) the design for reusability set of tools, methods, and guidelines that, relying on intensive parameterization as well as on design knowledge capture and encapsulation, allows to produce fully reusable AMS blocks. A case study and a functional silicon prototype demonstrate the validity of the paper"s proposals.

  4. Proposed pushered single shell capsule design for the investigation of mid/high Z mix on the NIF

    NASA Astrophysics Data System (ADS)

    Sacks, Ryan; Tipton, Robert; Graziani, Frank

    2016-05-01

    The CD Mix campaign has given a detailed explination of the mix mechanics in the current ignition capsule designs by investigating the relationship between material mixing, shell-fuel interfaces, and the change in thermonuclear yield given a deuterated layer in the capsule. Alternative ignition scenarios include the use of double shell designs that incorporate high-Z material in the capsule. Simulations are conducted on a proposed capsule platform using the ARES code on a scaled capsule design using a partially reduced glass capsule design. This allows for the inclusion of deuterium on the inner surface of the pusher layer similar to the CD mix experiments. The presence of silicon dioxide allows for the investigation of the influence of higher Z material on the mixing characteristics.

  5. 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.

  6. Global Optimization Using Mixed Surrogates and Space Elimination in Computationally Intensive Engineering Designs

    NASA Astrophysics Data System (ADS)

    Younis, Adel; Dong, Zuomin

    2012-07-01

    Surrogate-based modeling is an effective search method for global design optimization over well-defined areas using complex and computationally intensive analysis and simulation tools. However, indentifying the appreciate surrogate models and their suitable areas remains a challenge that requires extensive human intervention. In this work, a new global optimization algorithm, namely Mixed Surrogate and Space Elimination (MSSE) method, is introduced. Representative surrogate models, including Quadratic Response Surface, Radial Basis function, and Kriging, are mixed with different weight ratios to form an adaptive metamodel with best tested performance. The approach divides the field of interest into several unimodal regions; identifies and ranks the regions that likely contain the global minimum; fits the weighted surrogate models over each promising region using additional design experiment data points from Latin Hypercube Designs and adjusts the weights according to the performance of each model; identifies its minimum and removes the processed region; and moves to the next most promising region until all regions are processed and the global optimum is identified. The proposed algorithm was tested using several benchmark problems for global optimization and compared with several widely used space exploration global optimization algorithms, showing reduced computation efforts, robust performance and comparable search accuracy, making the proposed method an excellent tool for computationally intensive global design optimization problems.

  7. 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.

  8. Method of analysis for compressible flow through mixed-flow centrifugal impellers of arbitrary design

    NASA Technical Reports Server (NTRS)

    Hamrick, Joseph T; Ginsburg, Ambrose; Osborn, Walter M

    1952-01-01

    A method is presented for analysis of the compressible flow between the hub and the shroud of mixed-flow impellers of arbitrary design. Axial symmetry was assumed, but the forces in the meridional (hub to shroud) plane, which are derived from tangential pressure gradients, were taken into account. The method was applied to an experimental mixed-flow impeller. The analysis of the flow in the meridional plane of the impeller showed that the rotational forces, the blade curvature, and the hub-shroud profile can introduce severe velocity gradients along the hub and the shroud surfaces. Choked flow at the impeller inlet as determined by the analysis was verified by experimental results.

  9. Design and performance of family of diffusing scrolls with mixed-flow impeller and vaneless diffuser

    NASA Technical Reports Server (NTRS)

    Brown, W Byron; Bradshaw, Guy R

    1949-01-01

    A family of diffusing scrolls was designed for use with a mixed-flow impeller and a small-diameter vaneless diffuser. The design theory, intended to maintain a uniform pressure around the scroll inlet, permits determination of the position of scroll cross sections of preassigned area by considering the radial variation in fluid density and the effects of friction along the scroll. Inasmuch as the design method leaves the cross-sectional shape undetermined, the effect of certain variations in scroll shape was investigated by studying scrolls having angles of divergence (of the scroll walls downstream of the entrance section) of 24 degrees, 40 degrees, and 80 degrees. A second 80 degree scroll was of asymmetrical construction and a third was plaster-cast instead of sand-cast. Each scroll was tested as a compressor component at actual impeller tip speeds of 700 to 1300 feet per second from full throttle to surge.

  10. Statistical efficiency and optimal design for stepped cluster studies under linear mixed effects models.

    PubMed

    Girling, Alan J; Hemming, Karla

    2016-06-15

    In stepped cluster designs the intervention is introduced into some (or all) clusters at different times and persists until the end of the study. Instances include traditional parallel cluster designs and the more recent stepped-wedge designs. We consider the precision offered by such designs under mixed-effects models with fixed time and random subject and cluster effects (including interactions with time), and explore the optimal choice of uptake times. The results apply both to cross-sectional studies where new subjects are observed at each time-point, and longitudinal studies with repeat observations on the same subjects. The efficiency of the design is expressed in terms of a 'cluster-mean correlation' which carries information about the dependency-structure of the data, and two design coefficients which reflect the pattern of uptake-times. In cross-sectional studies the cluster-mean correlation combines information about the cluster-size and the intra-cluster correlation coefficient. A formula is given for the 'design effect' in both cross-sectional and longitudinal studies. An algorithm for optimising the choice of uptake times is described and specific results obtained for the best balanced stepped designs. In large studies we show that the best design is a hybrid mixture of parallel and stepped-wedge components, with the proportion of stepped wedge clusters equal to the cluster-mean correlation. The impact of prior uncertainty in the cluster-mean correlation is considered by simulation. Some specific hybrid designs are proposed for consideration when the cluster-mean correlation cannot be reliably estimated, using a minimax principle to ensure acceptable performance across the whole range of unknown values. © 2016 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd. PMID:26748662

  11. Design considerations for an intelligent mobile robot for mixed-waste inspection

    SciTech Connect

    Sias, F.R.; Dawson, D.M.; Schalkoff, R.J.; Byrd, J.S.; Pettus, R.O.

    1993-06-01

    Large quantities of low-level radioactive waste are stored in steel drums at various Department of Energy (DOE) sites in the United States. Much of the stored waste qualifies as mixed waste and falls under Environmental Protection Agency (EPA) regulations that require periodic inspection. A semi-autonomous mobile robot is being developed during Phase 1 of a DOE contract to perform the inspection task and consequently reduce the radiation exposure of inspection personnel to ALARA (as low as reasonably achievable). The nature of the inspection process, the resulting robot design requirements, and the current status of the project are the subjects of this paper.

  12. Design and Implementation of Network Management System Based on Mixed-mode

    NASA Astrophysics Data System (ADS)

    Wei, Xianmin

    With the growth of network scale size, structure is getting more and more sophisticated, how to effectively manage the network has been increasingly paid attention to. Development of network management systems, there are mainly two system models, that is, C/S mode and B/S mode. This paper focuses on analysis of advantages and disadvantages in the C/S mode and B/S mode, design and implementation network management system based on the mixed mode with C/S mode and B/S mode.

  13. [Mixed design for the evaluation of the Mesoamerica Health 2015 initiative].

    PubMed

    Gutiérrez, Juan Pablo; Téllez-Rojo, Marta María; Torres, Pilar; Romero, Martín; Bertozzi, Stefano M

    2011-01-01

    Since the Salud Mesoamerica 2015 initiative (SM-2015) aim is to improve health and nutrition conditions of those most vulnerable in Mesoamerica, the goal of the evaluation is to generate evidence of the joint effectiveness of a package of interventions designed to improve the health conditions. We propose a mix design for the evaluation, which will allow to know the magnitude of changes attributable to the interventions, as well as the meanings of these changes for the target population, taking into account the specificities of each country. The main axis of this design is a locality panel where information about individuals, households, and health facilities (first and second level) will also be collected. The evaluation design described in this paper was developed between June and December, 2009, and it was integrated during workshops in Cuernavaca (Mexico), Managua (Nicaragua), and San Jose (Costa Rica). The proposed design will allow to generate evidence about the joint effectiveness of the package of interventions proposed for the SM-2015. The success of this design rests on the political commitment of countries and donors. PMID:22344383

  14. A New Design for Airway Management Training with Mixed Reality and High Fidelity Modeling.

    PubMed

    Shen, Yunhe; Hananel, David; Zhao, Zichen; Burke, Daniel; Ballas, Crist; Norfleet, Jack; Reihsen, Troy; Sweet, Robert

    2016-01-01

    Restoring airway function is a vital task in many medical scenarios. Although various simulation tools have been available for learning such skills, recent research indicated that fidelity in simulating airway management deserves further improvements. In this study, we designed and implemented a new prototype for practicing relevant tasks including laryngoscopy, intubation and cricothyrotomy. A large amount of anatomical details or landmarks were meticulously selected and reconstructed from medical scans, and 3D-printed or molded to the airway intervention model. This training model was augmented by virtually and physically presented interactive modules, which are interoperable with motion tracking and sensor data feedback. Implementation results showed that this design is a feasible approach to develop higher fidelity airway models that can be integrated with mixed reality interfaces. PMID:27046605

  15. Radiation hardness by design for mixed signal infrared readout circuit applications

    NASA Astrophysics Data System (ADS)

    Gaalema, Stephen; Gates, James; Dobyns, David; Pauls, Greg; Wall, Bruce

    2013-09-01

    Readout integrated circuits (ROICs) to support space-based infrared detection applications often have severe radiation tolerance requirements. Radiation hardness-by-design (RHBD) significantly enhances the radiation tolerance of commercially available CMOS and custom radiation hardened fabrication techniques are not required. The combination of application specific design techniques, enclosed gate architecture nFETs and intrinsic thin oxide radiation hardness of 180 nm process node commercial CMOS allows realization of high performance mixed signal circuits. Black Forest Engineering has used RHBD techniques to develop ROICs with integrated A/D conversion that operate over a wide range of temperatures (40K-300K) to support infrared detection. ROIC radiation tolerance capability for 256x256 LWIR area arrays and 1x128 thermopile linear arrays is presented. The use of 130 nm CMOS for future ROIC RHBD applications is discussed.

  16. Engineering design and test plan for demonstrating DETOX treatment of mixed wastes

    SciTech Connect

    Goldblatt, S.; Dhooge, P.

    1995-03-01

    DETOX is a cocatalyzed wet oxidation process in which the catalysts are a relatively great concentration of iron ions (typically as iron(III) chloride) in the presence of small amounts of platinum and ruthenium ions. Organic compounds are oxidized completely to carbon dioxide, water, and (if chlorinated) hydrogen chloride. The process has shown promise as a non-thermal alternative to incineration for treatment and/or volume reduction of hazardous, radioactive, and mixed wastes. Design and fabrication of a demonstration unit capable of destroying 25. Kg/hr of organic material is now in progress. This paper describes the Title 2 design of the demonstration unit, and the planned demonstration effort at Savannah River Site (SRS) and Weldon Spring Site Remedial Action Project (WSSRAP).

  17. Advanced Mixed Waste Treatment Project melter system preliminary design technical review meeting

    SciTech Connect

    Eddy, T.L.; Raivo, B.D.; Soelberg, N.R.; Wiersholm, O.

    1995-02-01

    The Idaho National Engineering Laboratory Advanced Mixed Waste Treatment Project sponsored a plasma are melter technical design review meeting to evaluate high-temperature melter system configurations for processing heterogeneous alpha-contaminated low-level radioactive waste (ALLW). Thermal processing experts representing Department of Energy contractors, the Environmental Protection Agency, and private sector companies participated in the review. The participants discussed issues and evaluated alternative configurations for three areas of the melter system design: plasma torch melters and graphite arc melters, offgas treatment options, and overall system configuration considerations. The Technical Advisory Committee for the review concluded that graphite arc melters are preferred over plasma torch melters for processing ALLW. Initiating involvement of stakeholders was considered essential at this stage of the design. For the offgas treatment system, the advisory committee raised the question whether to a use wet-dry or a dry-wet system. The committee recommended that the waste stream characterization, feed preparation, and the control system are essential design tasks for the high-temperature melter treatment system. The participants strongly recommended that a complete melter treatment system be assembled to conduct tests with nonradioactive surrogate waste material. A nonradioactive test bed would allow for inexpensive design and operational changes prior to assembling a system for radioactive waste treatment operations.

  18. Optimal design of mixed-effects PK/PD models based on differential equations.

    PubMed

    Wang, Yi; Eskridge, Kent M; Nadarajah, Saralees

    2012-01-01

    There is a vast literature on the analysis of optimal design of nonlinear mixed-effects models (NLMMs) described by ordinary differential equations (ODEs) with analytic solution. However, much less has been published on the design of trials to fit such models with nonanalytic solution. In this article, we use the "direct" method to find parameter sensitivities, which are required during the optimization of models defined as ODEs, and apply them to find D-optimal designs for various specific situations relevant to population pharmacokinetic studies using a particular model with first-order absorption and elimination. In addition, we perform two simulation studies. The first one aims to show that the criterion computed from the development of the Fisher information matrix expression is a good measure to compare and optimize population designs, thus avoiding a large number of simulations; In the second one, a sensitivity analysis with respect to parameter misspecification allows us to compare the robustness of different population designs constructed in this article. PMID:22204534

  19. Design and Performance of South Ukraine Nuclear Power Plant Mixed Cores

    SciTech Connect

    Abdullayev, A. M.; Baydulin, V.; Zhukov, A. I.; Latorre, Richard

    2011-09-24

    In 2010, 42 Westinghouse fuel assemblies (WFAs) were loaded into the core of South Ukraine Nuclear Power Plant (SUNPP) Unit 3 after four successful cycles with 6 Westinghouse Lead Test Assemblies. The scope of safety substantiating documents required for the regulatory approval of this mixed core was extended considerably, particularly with development and implementation of new methodologies and 3-D kinetic codes. Additional verification for all employed codes was also performed. Despite the inherent hydraulic non-uniformity of a mixed core, it was possible to demonstrate that all design and operating restrictions for three different types of fuel (TVS-M, TVSA and WFA) loaded in the core were conservatively met. This paper provides the main results from the first year of operation of the core loaded with 42 WFAs, the predicted parameters for the transition and equilibrium cycles with WFAs, comparisons of predicted versus measured core parameters, as well as the acceptable margin evaluation results for reactivity accidents using the 3-D kinetic codes. To date WFA design parameters have been confirmed by operation experience.

  20. Comparing the efficiency of supersonic oxygen-iodine laser with different mixing designs

    NASA Astrophysics Data System (ADS)

    Vyskubenko, Boris A.; Adamenkov, A. A.; Bakshin, V. V.; Efremov, V. I.; Ilyin, S. P.; Kolobyanin, Yu. V.; Krukovsky, I. M.; Kudryashov, E. A.; Moiseyev, V. B.

    2003-11-01

    The paper presents experimental studies of supersonic oxygen-iodine laser (OIL) using twisted-flow singlet oxygen generator (SOG) over a wide range of the singlet oxygen pressures and the buffer gas flow rates. The experiments used different designs of the nozzle unit and mixing system for singlet oxygen and iodine gas with the carrier gas (such as nitrogen or helium). For a wide range of the key parameters, the study looked at the efficiency of supersonic OIL with variation of the singlet oxygen pressure. The measurements were made for different positions of the iodine injection plane with respect to the critical cross-section (both in the subsonic part of the nozzle and in the supersonic flow). The gas pressure at the nozzle unit entry was varied from 50 to 250 Torr. The total pressure loss have been found for different mixing designs. Experimental curves are given for energy performance and chemical efficiency of the supersonic OIL as a function of the key parameters. Comparison is made between the calculated and experimental data. For the optimum conditions of OIL operation, chemical efficiency of 25-30% has been achieved.

  1. A proposed through-flow inverse method for the design of mixed-flow pumps

    NASA Technical Reports Server (NTRS)

    Borges, Joao Eduardo

    1991-01-01

    A through-flow (hub-to-shroud) truly inverse method is proposed and described. It uses an imposition of mean swirl, i.e., radius times mean tangential velocity, given throughout the meridional section of the turbomachine as an initial design specification. In the present implementation, it is assumed that the fluid is inviscid, incompressible, and irrotational at inlet and that the blades are supposed to have zero thickness. Only blade rows that impart to the fluid a constant work along the space are considered. An application of this procedure to design the rotor of a mixed-flow pump is described in detail. The strategy used to find a suitable mean swirl distribution and the other design inputs is also described. The final blade shape and pressure distributions on the blade surface are presented, showing that it is possible to obtain feasible designs using this technique. Another advantage of this technique is the fact that it does not require large amounts of CPU time.

  2. Automatic design of synthetic gene circuits through mixed integer non-linear programming.

    PubMed

    Huynh, Linh; Kececioglu, John; Köppe, Matthias; Tagkopoulos, Ilias

    2012-01-01

    Automatic design of synthetic gene circuits poses a significant challenge to synthetic biology, primarily due to the complexity of biological systems, and the lack of rigorous optimization methods that can cope with the combinatorial explosion as the number of biological parts increases. Current optimization methods for synthetic gene design rely on heuristic algorithms that are usually not deterministic, deliver sub-optimal solutions, and provide no guaranties on convergence or error bounds. Here, we introduce an optimization framework for the problem of part selection in synthetic gene circuits that is based on mixed integer non-linear programming (MINLP), which is a deterministic method that finds the globally optimal solution and guarantees convergence in finite time. Given a synthetic gene circuit, a library of characterized parts, and user-defined constraints, our method can find the optimal selection of parts that satisfy the constraints and best approximates the objective function given by the user. We evaluated the proposed method in the design of three synthetic circuits (a toggle switch, a transcriptional cascade, and a band detector), with both experimentally constructed and synthetic promoter libraries. Scalability and robustness analysis shows that the proposed framework scales well with the library size and the solution space. The work described here is a step towards a unifying, realistic framework for the automated design of biological circuits. PMID:22536398

  3. Optimal design of mixed-media packet-switching networks - Routing and capacity assignment

    NASA Technical Reports Server (NTRS)

    Huynh, D.; Kuo, F. F.; Kobayashi, H.

    1977-01-01

    This paper considers a mixed-media packet-switched computer communication network which consists of a low-delay terrestrial store-and-forward subnet combined with a low-cost high-bandwidth satellite subnet. We show how to route traffic via ground and/or satellite links by means of static, deterministic procedures and assign capacities to channels subject to a given linear cost such that the network average delay is minimized. Two operational schemes for this network model are investigated: one is a scheme in which the satellite channel is used as a slotted ALOHA channel; the other is a new multiaccess scheme we propose in which whenever a channel collision occurs, retransmission of the involved packets will route through ground links to their destinations. The performance of both schemes is evaluated and compared in terms of cost and average packet delay tradeoffs for some examples. The results offer guidelines for the design and optimal utilization of mixed-media networks.

  4. Design, implementation and testing of extended and mixed precisionBLAS

    SciTech Connect

    Li, X.S.; Demmel, J.W.; Bailey, D.H.; Henry, G.; Hida, Y.; Iskandar, J.; Kahan, W.; Kapur, A.; Martin, M.C.; Tung, T.; Yoo, D.J.

    2000-10-20

    This article describes the design rationale, a C implementation, and conformance testing of a subset of the new Standard for the BLAS (Basic Linear Algebra Subroutines): Extended and Mixed Precision BLAS. Permitting higher internal precision and mixed input/output types and precisions allows us to implement some algorithms that are simpler, more accurate, and sometimes faster than possible without these features. The new BLAS are challenging to implement and test because there are many more subroutines than in the existing Standard, and because we must be able to assess whether a higher precision is used for internal computations than is used for either input or output variables. We have therefore developed an automated process of generating and systematically testing these routines. Our methodology is applicable to languages besides C. In particular, our algorithms used in the testing code will be valuable to all other BLAS implementors. Our extra precision routines achieve excellent performance--close to half of the machine peak Megaflop rate even for the Level 2 BLAS, when the data access is stride one.

  5. Rational design of metallic nanocavities for resonantly enhanced four-wave mixing

    PubMed Central

    Almeida, Euclides; Prior, Yehiam

    2015-01-01

    Optimizing the shape of nanostructures and nano-antennas for specific optical properties has evolved to be a very fruitful activity. With modern fabrication tools a large variety of possibilities is available for shaping both nanoparticles and nanocavities; in particular nanocavities in thin metal films have emerged as attractive candidates for new metamaterials and strong linear and nonlinear optical systems. Here we rationally design metallic nanocavities to boost their Four-Wave Mixing response by resonating the optical plasmonic resonances with the incoming and generated beams. The linear and nonlinear optical responses as well as the propagation of the electric fields inside the cavities are derived from the solution of Maxwell’s equations by using the 3D finite-differences time domain method. The observed conversion-efficiency of near-infrared to visible light equals or surpasses that of BBO of equivalent thickness. Implications to further optimization for efficient and broadband ultrathin nonlinear optical materials are discussed. PMID:25974175

  6. Mixed culture optimization for marigold flower ensilage via experimental design and response surface methodology.

    PubMed

    Navarrete-Bolaños, José Luis; Jiménez-Islas, Hugo; Botello-Alvarez, Enrique; Rico-Martínez, Ramiro

    2003-04-01

    Endogenous microorganisms isolated from the marigold flower (Tagetes erecta) were studied to understand the events taking place during its ensilage. Studies of the cellulase enzymatic activity and the ensilage process were undertaken. In both studies, the use of approximate second-order models and multiple lineal regression, within the context of an experimental mixture design using the response surface methodology as optimization strategy, determined that the microorganisms Flavobacterium IIb, Acinetobacter anitratus, and Rhizopus nigricans are the most significant in marigold flower ensilage and exhibit high cellulase activity. A mixed culture comprised of 9.8% Flavobacterium IIb, 41% A. anitratus, and 49.2% R. nigricans used during ensilage resulted in an increased yield of total xanthophylls extracted of 24.94 g/kg of dry weight compared with 12.92 for the uninoculated control ensilage. PMID:12670157

  7. Groundwater Remediation Design Using a Three-Dimensional Simulation Model and Mixed-Integer Programming

    NASA Astrophysics Data System (ADS)

    Sawyer, Charles S.; Ahlfeld, David P.; King, Alan J.

    1995-05-01

    A three-dimensional groundwater flow management model for making decisions on the design of hydrodynamic control of a groundwater flow system using a combination of extraction and/or injection wells is developed. The model takes into account constraints imposed on the system to stop the horizontal spread of contaminants and to ensure a net upward flow in areas where downward vertical gradients exist. The mathematical formulation of the groundwater remediation problem as a mixed-integer model and the strategy for solving the model are presented. Numerical results are presented for the Toms River Plant site, which is modeled as a five-layer aquifer system with interconnecting aquitards. A sensitivity analysis on the relative magnitude of the continuous operating costs and the fixed-charge costs is also presented.

  8. Freely designable optical frequency conversion in Raman-resonant four-wave-mixing process.

    PubMed

    Zheng, Jian; Katsuragawa, Masayuki

    2015-01-01

    Nonlinear optical processes are governed by the relative-phase relationships among the relevant electromagnetic fields in these processes. In this Report, we describe the physics of arbitrary manipulation of Raman-resonant four-wave-mixing process by artificial control of relative phases. As a typical example, we show freely designable optical-frequency conversions to extreme spectral regions, mid-infrared and vacuum-ultraviolet, with near-unity quantum efficiencies. Furthermore, we show that such optical-frequency conversions can be realized by using a surprisingly simple technology where transparent plates are placed in a nonlinear optical medium and their positions and thicknesses are adjusted precisely. In a numerical simulation assuming practically applicable parameters in detail, we demonstrate a single-frequency tunable laser that covers the whole vacuum-ultraviolet spectral range of 120 to 200 nm. PMID:25748023

  9. Mixed logic style adder circuit designed and fabricated using SOI substrate for irradiation-hardened experiment

    NASA Astrophysics Data System (ADS)

    Yuan, Shoucai; Liu, Yamei

    2016-08-01

    This paper proposed a rail to rail swing, mixed logic style 28-transistor 1-bit full adder circuit which is designed and fabricated using silicon-on-insulator (SOI) substrate with 90 nm gate length technology. The main goal of our design is space application where circuits may be damaged by outer space radiation; so the irradiation-hardened technique such as SOI structure should be used. The circuit's delay, power and power-delay product (PDP) of our proposed gate diffusion input (GDI)-based adder are HSPICE simulated and compared with other reported high-performance 1-bit adder. The GDI-based 1-bit adder has 21.61% improvement in delay and 18.85% improvement in PDP, over the reported 1-bit adder. However, its power dissipation is larger than that reported with 3.56% increased but is still comparable. The worst case performance of proposed 1-bit adder circuit is also seen to be less sensitive to variations in power supply voltage (VDD) and capacitance load (CL), over a wide range from 0.6 to 1.8 V and 0 to 200 fF, respectively. The proposed and reported 1-bit full adders are all layout designed and wafer fabricated with other circuits/systems together on one chip. The chip measurement and analysis has been done at VDD = 1.2 V, CL = 20 fF, and 200 MHz maximum input signal frequency with temperature of 300 K.

  10. Development of ORIGEN Libraries for Mixed Oxide (MOX) Fuel Assembly Designs

    DOE PAGESBeta

    Mertyurek, Ugur; Gauld, Ian C.

    2015-12-24

    In this research, ORIGEN cross section libraries for reactor-grade mixed oxide (MOX) fuel assembly designs have been developed to provide fast and accurate depletion calculations to predict nuclide inventories, radiation sources and thermal decay heat information needed in safety evaluations and safeguards verification measurements of spent nuclear fuel. These ORIGEN libraries are generated using two-dimensional lattice physics assembly models that include enrichment zoning and cross section data based on ENDF/B-VII.0 evaluations. Using the SCALE depletion sequence, burnup-dependent cross sections are created for selected commercial reactor assembly designs and a representative range of reactor operating conditions, fuel enrichments, and fuel burnup.more » The burnup dependent cross sections are then interpolated to provide problem-dependent cross sections for ORIGEN, avoiding the need for time-consuming lattice physics calculations. The ORIGEN libraries for MOX assembly designs are validated against destructive radiochemical assay measurements of MOX fuel from the MALIBU international experimental program. This program included measurements of MOX fuel from a 15 × 15 pressurized water reactor assembly and a 9 × 9 boiling water reactor assembly. The ORIGEN MOX libraries are also compared against detailed assembly calculations from the Phase IV-B numerical MOX fuel burnup credit benchmark coordinated by the Nuclear Energy Agency within the Organization for Economic Cooperation and Development. Finally, the nuclide compositions calculated by ORIGEN using the MOX libraries are shown to be in good agreement with other physics codes and with experimental data.« less

  11. Development of ORIGEN Libraries for Mixed Oxide (MOX) Fuel Assembly Designs

    SciTech Connect

    Mertyurek, Ugur; Gauld, Ian C.

    2015-12-24

    In this research, ORIGEN cross section libraries for reactor-grade mixed oxide (MOX) fuel assembly designs have been developed to provide fast and accurate depletion calculations to predict nuclide inventories, radiation sources and thermal decay heat information needed in safety evaluations and safeguards verification measurements of spent nuclear fuel. These ORIGEN libraries are generated using two-dimensional lattice physics assembly models that include enrichment zoning and cross section data based on ENDF/B-VII.0 evaluations. Using the SCALE depletion sequence, burnup-dependent cross sections are created for selected commercial reactor assembly designs and a representative range of reactor operating conditions, fuel enrichments, and fuel burnup. The burnup dependent cross sections are then interpolated to provide problem-dependent cross sections for ORIGEN, avoiding the need for time-consuming lattice physics calculations. The ORIGEN libraries for MOX assembly designs are validated against destructive radiochemical assay measurements of MOX fuel from the MALIBU international experimental program. This program included measurements of MOX fuel from a 15 × 15 pressurized water reactor assembly and a 9 × 9 boiling water reactor assembly. The ORIGEN MOX libraries are also compared against detailed assembly calculations from the Phase IV-B numerical MOX fuel burnup credit benchmark coordinated by the Nuclear Energy Agency within the Organization for Economic Cooperation and Development. Finally, the nuclide compositions calculated by ORIGEN using the MOX libraries are shown to be in good agreement with other physics codes and with experimental data.

  12. Interdisciplinary concepts for design and implementation of mixed reality interactive neurorehabilitation systems for stroke.

    PubMed

    Baran, Michael; Lehrer, Nicole; Duff, Margaret; Venkataraman, Vinay; Turaga, Pavan; Ingalls, Todd; Rymer, W Zev; Wolf, Steven L; Rikakis, Thanassis

    2015-03-01

    Interactive neurorehabilitation (INR) systems provide therapy that can evaluate and deliver feedback on a patient's movement computationally. There are currently many approaches to INR design and implementation, without a clear indication of which methods to utilize best. This article presents key interactive computing, motor learning, and media arts concepts utilized by an interdisciplinary group to develop adaptive, mixed reality INR systems for upper extremity therapy of patients with stroke. Two INR systems are used as examples to show how the concepts can be applied within: (1) a small-scale INR clinical study that achieved integrated improvement of movement quality and functionality through continuously supervised therapy and (2) a pilot study that achieved improvement of clinical scores with minimal supervision. The notion is proposed that some of the successful approaches developed and tested within these systems can form the basis of a scalable design methodology for other INR systems. A coherent approach to INR design is needed to facilitate the use of the systems by physical therapists, increase the number of successful INR studies, and generate rich clinical data that can inform the development of best practices for use of INR in physical therapy. PMID:25425694

  13. Interdisciplinary Concepts for Design and Implementation of Mixed Reality Interactive Neurorehabilitation Systems for Stroke

    PubMed Central

    Lehrer, Nicole; Duff, Margaret; Venkataraman, Vinay; Turaga, Pavan; Ingalls, Todd; Rymer, W. Zev; Wolf, Steven L.; Rikakis, Thanassis

    2015-01-01

    Interactive neurorehabilitation (INR) systems provide therapy that can evaluate and deliver feedback on a patient's movement computationally. There are currently many approaches to INR design and implementation, without a clear indication of which methods to utilize best. This article presents key interactive computing, motor learning, and media arts concepts utilized by an interdisciplinary group to develop adaptive, mixed reality INR systems for upper extremity therapy of patients with stroke. Two INR systems are used as examples to show how the concepts can be applied within: (1) a small-scale INR clinical study that achieved integrated improvement of movement quality and functionality through continuously supervised therapy and (2) a pilot study that achieved improvement of clinical scores with minimal supervision. The notion is proposed that some of the successful approaches developed and tested within these systems can form the basis of a scalable design methodology for other INR systems. A coherent approach to INR design is needed to facilitate the use of the systems by physical therapists, increase the number of successful INR studies, and generate rich clinical data that can inform the development of best practices for use of INR in physical therapy. PMID:25425694

  14. "Vogue," 1892-1928: An Historical Look at the Evolution of One Magazine's Editorial-Advertising-Design Mix.

    ERIC Educational Resources Information Center

    Prior, Marcia R.

    The careful integration of editorial content, graphic design, and advertising to create a successful magazine package is not a phenomenon of the last half of the twentieth century. As early as the 1890s, the first publishers of "Vogue" magazine had established an editorial-advertising-design mix in the fashion magazine that was calculated to…

  15. Mixed waste landfill monitoring prototype test design for Los Alamos National Laboratory. Final report

    SciTech Connect

    Keller, C.

    1994-09-01

    The purpose of this contract is to design the prototype tests necessary for the verification of the measurement methods proposed for the Mixed Waste Disposal Facility. The design is limited to the hydrological performance of the measurement methods. It does not include the mechanical testing of the methods proposed. The test site is to be selected and when approved, construction drawings provided. The contract also includes testing of vitrified clay pipe as the liner of choice for the passages under the landfill. The tests are to be done of both he hydrologic and the mechanical capability of the pipe. The test bed construction is to be supervised as it is being done by the construction contractor monitored by LANL. This contract does not include the logical subsequent work of performance of the measurements in the test bed. Since this contract was received by September 15, with the work to be completed by September 30, only that work possible in the short time was performed. That included the design of the test bed, the purchase of the vitrified clay pipe and the mechanical tests of the pipe, and the purchase of the SEAMIST systems for testing in the clay pipe. None of those could be delivered in time for flow tests to be done on the clay pipe. The mechanical tests were done as part of the pipe purchase and are reported here. The contract was not extended beyond September 30 for lack of funds. This report is therefore limited to the preliminary design of the test bed and to the specification of the orders for the materials. The hope is that funding will be restored to the program for the completion of the design and measurement effort.

  16. Lessons from a Mixed-Methods Approach to Evaluating Active Living by Design

    PubMed Central

    Brownson, Ross C.; Brennan, Laura K.; Evenson, Kelly R.; Leviton, Laura C.

    2016-01-01

    Background Beginning in 2003, Active Living by Design (ALbD) established innovative approaches across 25 communities to increase physical activity through community design, public policies, programming, and communication strategies. Purpose The complexity of the ALbD projects called for a mixed-methods evaluation to understand implementation as well as perceived and actual impacts of these efforts. Methods Six primary evaluation methods addressed three primary aims: (1) to assess impacts of physical projects and policy changes on community environments; (2) to document intervention strategies implemented, as well as intended and unintended consequences; and (3) to identify strengths and challenges in planning, developing, and implementing interventions. The ALbD evaluation included cross-site comparisons and more in-depth case studies. This article describes the methods used to address the three aims. Results Analysis of the strengths and challenges associated with the different methods, including partnership capacity surveys, Concept Mapping, an online Progress Reporting System (PRS), key informant interviews, focus groups, and photos and videos. Additional methods, including environmental audits and direct observation, were explored to specifically assess environmental changes. Several important challenges included the lack of baseline data, difficulty in evaluating natural experiments, the need for ongoing policy surveillance, and the need to capture longer-term endpoints. Conclusions The mixed-methods evaluation of ALbD advances implementation and evaluation science related to community-based efforts for promoting active living through identification of methods and measures to capture multicomponent and complex interventions as well as translation of a range of approaches to create community change across a variety of populations and settings. PMID:23079259

  17. The use of designed experiments in the process development of continuous propellant mixing

    NASA Technical Reports Server (NTRS)

    Campbell, J. A.; Clemons, K. T.; Wong, M. K.

    1993-01-01

    A continuous mix pilot plant was constructed at Aerojet Propulsion Division in Sacramento, California to develop a robust propellant mixing process for the full scale plant that was to be built at the NASA Advanced Solid Rocket Motor facility Yellow Creek, Mississippi. The plant was used to conduct dozens of subsystem and full system mixing tests for evaluation of equipment, processing methods, and control schemes for later use at the production plant. As a culmination to this work, a series of designed experiments were conducted using an eight run Taguchi analysis with four factors at two levels each to determine the primary effect of processing parameters on propellant ballistic and mechanical properties. The factors examined in these runs included the propellant production rate (454 (1000) and 622 kg/hr (1371 Ib/hr)), the product temperature out of the mixer (49 (120) and 63 deg C (145 deg F)), mixer screw speed (75 and 90 rpm), and the deaerator excess capacity (20 and 80 percent). Measured response variables included the uncured and cured density, Crawford Bomb liquid strand burning rates, and selected mechanical properties. The experiment revealed that several of the response variables displayed significant changes from run-to-run with the product temperature being the single most important factor. After concluding this experiment, a twenty-six hour confirmation run was conducted to verify the conclusions reached in the designed experiment. The extended run produced over 12,250 kgs (27,000 lbs) of propellant meeting all of the pre-run targeted properties including density (1.803 g/cc (0.065 lb/in(exp 3)) with a 0.12 percent coefficient of variation (CV) at 25 deg C (77 deg F)), liquid strand burn rate (0.889 cm/s (0.350 in/s) with a 0.69 percent CV at 4210 KPa (610 psig), 15.6 deg C (60 deg F)), nominal maximum stress (828 KPa (120 psig) with a 2.84 percent CV, S&E at 25 deg C (77 deg F), 5.08 cm/min (2 in/min)), strain at nominal maximum (47.4 percent with a

  18. Investigating Appropriate Sampling Design for Estimating Above-Ground Biomass in Bruneian Lowland Mixed Dipterocarp Forest

    NASA Astrophysics Data System (ADS)

    Lee, S.; Lee, D.; Abu Salim, K.; Yun, H. M.; Han, S.; Lee, W. K.; Davies, S. J.; Son, Y.

    2014-12-01

    Mixed tropical forest structure is highly heterogeneous unlike plantation or mixed temperate forest structure, and therefore, different sampling approaches are required. However, the appropriate sampling design for estimating the above-ground biomass (AGB) in Bruneian lowland mixed dipterocarp forest (MDF) has not yet been fully clarified. The aim of this study was to provide supportive information in sampling design for Bruneian forest carbon inventory. The study site was located at Kuala Belalong lowland MDF, which is part of the Ulu Tembulong National Park, Brunei Darussalam. Six 60 m × 60 m quadrats were established, separated by a distance of approximately 100 m and each was subdivided into quadrats of 10 m × 10 m, at an elevation between 200 and 300 m above sea level. At each plot all free-standing trees with diameter at breast height (dbh) ≥ 1 cm were measured. The AGB for all trees with dbh ≥ 10 cm was estimated by allometric models. In order to analyze changes in the diameter-dependent parameters used for estimating the AGB, different quadrat areas, ranging from 10 m × 10 m to 60 m × 60 m, were used across the study area, starting at the South-West end and moving towards the North-East end. The derived result was as follows: (a) Big trees (dbh ≥ 70 cm) with sparse distribution have remarkable contribution to the total AGB in Bruneian lowland MDF, and therefore, special consideration is required when estimating the AGB of big trees. Stem number of trees with dbh ≥ 70 cm comprised only 2.7% of all trees with dbh ≥ 10 cm, but 38.5% of the total AGB. (b) For estimating the AGB of big trees at the given acceptable limit of precision (p), it is more efficient to use large quadrats than to use small quadrats, because the total sampling area decreases with the former. Our result showed that 239 20 m × 20 m quadrats (9.6 ha in total) were required, while 15 60 m × 60 m quadrats (5.4 ha in total) were required when estimating the AGB of the trees

  19. Prioritizing the mHealth Design Space: A Mixed-Methods Analysis of Smokers’ Perspectives

    PubMed Central

    BlueSpruce, June; Catz, Sheryl L; McClure, Jennifer B

    2016-01-01

    Background Smoking remains the leading cause of preventable disease and death in the United States. Therefore, researchers are constantly exploring new ways to promote smoking cessation. Mobile health (mHealth) technologies could be effective cessation tools. Despite the availability of commercial quit-smoking apps, little research to date has examined smokers’ preferred treatment intervention components (ie, design features). Honoring these preferences is important for designing programs that are appealing to smokers and may be more likely to be adopted and used. Objective The aim of this study was to understand smokers’ preferred design features of mHealth quit-smoking tools. Methods We used a mixed-methods approach consisting of focus groups and written surveys to understand the design preferences of adult smokers who were interested in quitting smoking (N=40). Focus groups were stratified by age to allow differing perspectives to emerge between older (>40 years) and younger (<40 years) participants. Focus group discussion included a “blue-sky” brainstorming exercise followed by participant reactions to contrasting design options for communicating with smokers, providing social support, and incentivizing program use. Participants rated the importance of preselected design features on an exit survey. Qualitative analyses examined emergent discussion themes and quantitative analyses compared feature ratings to determine which were perceived as most important. Results Participants preferred a highly personalized and adaptive mHealth experience. Their ideal mHealth quit-smoking tool would allow personalized tracking of their progress, adaptively tailored feedback, and real-time peer support to help manage smoking cravings. Based on qualitative analysis of focus group discussion, participants preferred pull messages (ie, delivered upon request) over push messages (ie, sent automatically) and preferred interaction with other smokers through closed social

  20. Conceptual Design Report: Nevada Test Site Mixed Waste Disposal Facility Project

    SciTech Connect

    NSTec Environmental Management

    2009-01-31

    Environmental cleanup of contaminated nuclear weapons manufacturing and test sites generates radioactive waste that must be disposed. Site cleanup activities throughout the U.S. Department of Energy (DOE) complex are projected to continue through 2050. Some of this waste is mixed waste (MW), containing both hazardous and radioactive components. In addition, there is a need for MW disposal from other mission activities. The Waste Management Programmatic Environmental Impact Statement Record of Decision designates the Nevada Test Site (NTS) as a regional MW disposal site. The NTS has a facility that is permitted to dispose of onsite- and offsite-generated MW until November 30, 2010. There is not a DOE waste management facility that is currently permitted to dispose of offsite-generated MW after 2010, jeopardizing the DOE environmental cleanup mission and other MW-generating mission-related activities. A mission needs document (CD-0) has been prepared for a newly permitted MW disposal facility at the NTS that would provide the needed capability to support DOE's environmental cleanup mission and other MW-generating mission-related activities. This report presents a conceptual engineering design for a MW facility that is fully compliant with Resource Conservation and Recovery Act (RCRA) and DOE O 435.1, 'Radioactive Waste Management'. The facility, which will be located within the Area 5 Radioactive Waste Management Site (RWMS) at the NTS, will provide an approximately 20,000-cubic yard waste disposal capacity. The facility will be licensed by the Nevada Division of Environmental Protection (NDEP).

  1. Fault Protection Design and Testing for the Cassini Spacecraft in a "Mixed" Thruster Configuration

    NASA Technical Reports Server (NTRS)

    Bates, David; Lee, Allan; Meakin, Peter; Weitl, Raquel

    2013-01-01

    NASA's Cassini Spacecraft, launched on October 15th, 1997 and arrived at Saturn on June 30th, 2004, is the largest and most ambitious interplanetary spacecraft in history. In order to meet the challenging attitude control and navigation requirements of the orbit profile at Saturn, Cassini is equipped with a monopropellant thruster based Reaction Control System (RCS), a bipropellant Main Engine Assembly (MEA) and a Reaction Wheel Assembly (RWA). In 2008, after 11 years of reliable service, several RCS thrusters began to show signs of end of life degradation, which led the operations team to successfully perform the swap from the A-branch to the B-branch RCS system. If similar degradation begins to occur on any of the B-branch thrusters, Cassini might have to assume a "mixed" thruster configuration, where a subset of both A and B branch thrusters will be designated as prime. The Cassini Fault Protection FSW was recently updated to handle this scenario. The design, implementation, and testing of this update is described in this paper.

  2. Mixed-Fidelity Approach for Design of Low-Boom Supersonic Aircraft

    NASA Technical Reports Server (NTRS)

    Li, Wu; Shields, Elwood; Geiselhart, Karl

    2011-01-01

    This paper documents a mixed-fidelity approach for the design of low-boom supersonic aircraft with a focus on fuselage shaping.A low-boom configuration that is based on low-fidelity analysis is used as the baseline. The fuselage shape is modified iteratively to obtain a configuration with an equivalent-area distribution derived from computational fluid dynamics analysis that attempts to match a predetermined low-boom target area distribution and also yields a low-boom ground signature. The ground signature of the final configuration is calculated by using a state-of-the-art computational-fluid-dynamics-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 computational fluid dynamics equivalent-area distribution. This result supports the validity of 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.

  3. Mix design and pollution control potential of pervious concrete with non-compliant waste fly ash.

    PubMed

    Soto-Pérez, Linoshka; Hwang, Sangchul

    2016-07-01

    Pervious concrete mix was optimized for the maximum compressive strength and the desired permeability at 7 mm/s with varying percentages of water-to-binder (W/B), fly ash-to-binder (FA/B), nano-iron oxide-to-binder (NI/B) and water reducer-to-binder (WR/B). The mass ratio of coarse aggregates in sizes of 4.75-9.5 mm to the binder was fixed at 4:1. Waste FA used in the study was not compliant with a standard specification for use as a mineral admixture in concrete. One optimum pervious concrete (Opt A) targeting high volume FA utilization had a 28-day compressive strength of 22.8 MPa and a permeability of 5.6 mm/s with a mix design at 36% W/B, 35% FA/B, 6% NI/B and 1.2% WR/B. The other (Opt B) targeting a less use of admixtures had a 28-day compressive strength and a permeability of 21.4 MPa and 7.6 mm/s, respectively, at 32% W/B, 10% FA/B, 0.5% NI/B and 0.8% WR/B. During 10 loads at a 2-h contact time each, the Opt A and Opt B achieved the average fecal coliform removals of 72.4% and 77.9% and phosphorus removals of 49.8% and 40.5%, respectively. Therefore, non-compliant waste FA could be utilized for a cleaner production of pervious concrete possessing a greater structural strength and compatible hydrological property and pollution control potential, compared to the ordinary pervious concrete. PMID:27042974

  4. The Design and Construction of the Advanced Mixed Waste Treatment Facility

    SciTech Connect

    Harrop, G.

    2003-02-27

    The Advanced Mixed Treatment Project (AMWTP) privatized contract was awarded to BNFL Inc. in December 1996 and construction of the main facility commenced in August 2000. The purpose of the advanced mixed waste treatment facility is to safely treat plutonium contaminated waste, currently stored in drums and boxes, for final disposal at the Waste Isolation Pilot Plant (WIPP). The plant is being built at the Idaho National Engineering and Environmental Laboratory. Construction was completed in 28 months, to satisfy the Settlement Agreement milestone of December 2002. Commissioning of the related retrieval and characterization facilities is currently underway. The first shipment of pre-characterized waste is scheduled for March 2003, with AMWTP characterized and certified waste shipments from June 2003. To accommodate these challenging delivery targets BNFL adopted a systematic and focused construction program that included the use of a temporary structure to allow winter working, proven design and engineering principles and international procurement policies to help achieve quality and schedule. The technology involved in achieving the AMWTP functional requirements is primarily based upon a BNFL established pedigree of plant and equipment; applied in a manner that suits the process and waste. This technology includes the use of remotely controlled floor mounted and overhead power manipulators, a high power shredder and a 2000-ton force supercompactor with the attendant glove box suite, interconnections and automated material handling. The characterization equipment includes real-time radiography (RTR) units, drum and box assay measurement systems, drum head space gas sampling / analysis and drum venting, drum coring and sampling capabilities. The project adopted a particularly stringent and intensive pre-installation testing philosophy to ensure that equipment would work safely and reliably at the required throughput. This testing included the complete off site

  5. H-infinity mix sensitivity controller design based on GIMC for electro-optical stabilization and tracking system

    NASA Astrophysics Data System (ADS)

    Liu, Zi-dong; Bao, Qi-liang; Xia, Yunxia; Liu, Xiang

    2013-08-01

    Electro-optical stabilization and tracking system is critical and difficult issue in satellite laser communication. Moreover, line-of-sight stabilized system is the kernel of implementing electro-optical stabilization and tracking system, which can be used to isolate the vibration of the moving platform of the satellite and the disturbance of the space environment. In this paper, we propose a new method, which using H∞ mix sensitivity based on generalized internal model controller (GIMC), to design the control system of the electro-optical stabilized platform. It is well known that there is an intrinsic conflict between performance and robustness in the standard feedback framework. Generalized internal model controller is a new architecture which can separate the performance and robustness design in controller design. This architecture has two parts: a high performance controller, say K0,which is designed by PI controller in this paper, and then a robustification controller, say Q, which is designed to improve the ability of the anti disturbance by using H-infinity mix sensitivity controller design method. In this paper, we also present the steps of controller design by using this method to make it easier to use. Based on the proposed method, numerical simulation and experiment are both carried out for a gyro stabilized platform of electro-optical tacking system. Both the numerical simulated and the experimental results show that the electro-optical stabilized platform using the H-infinity mix sensitivity controller design method based on GIMC is accurate and effective. Comparing with the same PI controller in standard feedback framework, the proposed method can guarantee the high tracking performance as same as the PI controller and improve the external disturbance restraining ability a lot. In conclusion, H-infinity mix sensitivity controller design method based on GIMC is a new approach for gyro stabilized platform of electro-optical stabilization and tracking

  6. Porous mixed metal oxides: design, formation mechanism, and application in lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Wu, Fangfang; Bai, Jing; Feng, Jinkui; Xiong, Shenglin

    2015-10-01

    The relentless pursuit of new electrode materials for lithium ion batteries (LIBs) has been conducted for decades. Structures with either porous or nanostructure configurations have been confirmed as advantageous candidates for energy storage/conversion applications. The integration of the two features into one structure can provide another chance to improve the electroactivities. Recently, single-phased mixed metal oxides (MMOs) containing different metal cations, in particular, have confirmed high electrochemical activities because of their complex chemical composition, interfacial effects, and the synergic effects of the multiple metal species. In this review, we will focus on recent research advances of MMOs with porous architectures as anode materials in the matter of structural arrangement and compositional manipulation. Moreover, the application of self-supported MMO-based porous structures as LIB anodes is also explained herein. More importantly, investigations on the synthetic system and formation mechanism of porous MMOs will be highlighted. Some future trends for the innovative design of new electrode materials are also discussed in this review. The challenges and prospects will draw many researchers' attention.

  7. Designing a solidification/stabilization process for a fine powder mixed radioactive waste

    SciTech Connect

    Artates, L.M.

    1994-12-31

    A fine powder radioactive mixed waste was generated during cleanup of the Colonie Interim Storage Site (CISS) near Albany, New York. This site is being remediated by Bechtel National as part of the Formerly Utilized Sites Remedial Action Program for the U.S. Department of Energy. The waste, high-efficiency particulate air (HEPA) vacuum dust, must be treated before disposal at Envirocare, Utah. The treated waste must pass the toxicity characteristic leaching procedure (TCLP) test in order to meet treatment standards for land disposal. The primary contaminants of concern are lead and cadmium. Portland cement, portland cement/silica fume, portland cement/soluble sodium silicate, Envirostone{reg_sign} gypsum cement, Fluid Tech{reg_sign} materials, sulfur cement, and vinyl ester resin were all examined and tested as potential solidification/stabilization agents. Bench-scale test results are presented, and a process design using portland cement with silica fume and water reducing admixtures is recommended for a small-scale application.

  8. Design of mixed-solvent processes for chemisorption with ultrahigh recovery

    SciTech Connect

    Shethna, H.K.; Towler, G.P.

    1997-12-01

    The variation of the phase-equilibrium behavior of chemisorbed gases with solvent concentration in mixed-solvent systems and resulting effects on the design of split-loop chemisorption processes are studied. Split-loop absorption as currently practiced is thermodynamically inefficient due to variations in solvent concentration during stripping. Adding equipment to enable better control of solvent composition results in improved process economics relative to single-loop absorption. Examination of concentration-enthalpy plots identifies the supply of stripping vapor as the main thermodynamic bottleneck of absorption-stripping processes. This suggests an alternative split-loop flow sheet in which the solvent for gas polishing is regenerated using a small fraction of the clean processed gas. This novel recycle arrangement has lower energy and capital costs and can be further integrated with other gas-processing technology. The new processes are illustrated with the example of hydrogen sulfide (H{sub 2}S) and carbon dioxide (CO{sub 2}) removal from hydrocarbons using aqueous methyldiethanolamine. Ultrahigh separation of H{sub 2}S at much-reduced energy use is possible, either selectively or nonselectively with respect to CO{sub 2}.

  9. Designing mixed metal halide ammines for ammonia storage using density functional theory and genetic algorithms.

    PubMed

    Jensen, Peter Bjerre; Lysgaard, Steen; Quaade, Ulrich J; Vegge, Tejs

    2014-09-28

    Metal halide ammines have great potential as a future, high-density energy carrier in vehicles. So far known materials, e.g. Mg(NH3)6Cl2 and Sr(NH3)8Cl2, are not suitable for automotive, fuel cell applications, because the release of ammonia is a multi-step reaction, requiring too much heat to be supplied, making the total efficiency lower. Here, we apply density functional theory (DFT) calculations to predict new mixed metal halide ammines with improved storage capacities and the ability to release the stored ammonia in one step, at temperatures suitable for system integration with polymer electrolyte membrane fuel cells (PEMFC). We use genetic algorithms (GAs) to search for materials containing up to three different metals (alkaline-earth, 3d and 4d) and two different halides (Cl, Br and I) - almost 27,000 combinations, and have identified novel mixtures, with significantly improved storage capacities. The size of the search space and the chosen fitness function make it possible to verify that the found candidates are the best possible candidates in the search space, proving that the GA implementation is ideal for this kind of computational materials design, requiring calculations on less than two percent of the candidates to identify the global optimum. PMID:25115581

  10. Probing the Chemical Stability of Mixed Ferrites: Implications for MR Contrast Agent Design

    PubMed Central

    Schultz-Sikma, Elise A.; Joshi, Hrushikesh M.; Ma, Qing; MacRenaris, Keith W.; Eckermann, Amanda L.; Dravid, Vinayak P.; Meade, Thomas J.

    2011-01-01

    Nanomaterials with mixed composition, in particular magnetic spinel ferrites, are emerging as efficient contrast agents for magnetic resonance imaging (MRI). Many factors, including size, composition, atomic structure, and surface properties are crucial in the design of such nanoparticle-based probes due to their influence on the magnetic properties. Silica-coated iron oxide (IO-SiO2) and cobalt ferrite (CoIO-SiO2) nanoparticles were synthesized using standard high temperature thermal decomposition and base-catalyzed water-in-oil microemulsion techniques. Under neutral aqueous conditions, it was found that 50–75% of the cobalt content in the CoIO-SiO2 nanoparticles leached out of the core structure. Leaching caused a 7.2-fold increase in longitudinal relaxivity and an increase in the saturation magnetization from ~48 emu/g core to ~65 emu/g core. X-ray absorption fine structure studies confirmed that the atomic structure of the ferrite core was altered following leaching, while TEM and DLS confirmed that the morphology and size of the nanoparticle remained unchanged. The CoIO-SiO2 nanoparticles converted from a partially inverted spinel cation arrangement (unleached state) to an inverse spinel arrangement (leached state). The control IO-SiO2 nanoparticles remained stable with no change in structure and negligible changes in magnetic behavior. This detailed analysis highlights how important understanding the properties of nanomaterials is in the development of reliable agents for diagnostic and therapeutic applications. PMID:21603070

  11. The Design, Synthesis and Structure-Activity Relationship of Mixed Serotonin, Norepinephrine and Dopamine Uptake Inhibitors

    NASA Astrophysics Data System (ADS)

    Chen, Zhengming; Yang, Ji; Skolnick, Phil

    The evolution of antidepressants over the past four decades has involved the replacement of drugs with a multiplicity of effects (e.g., TCAs) by those with selective actions (i.e., SSRIs). This strategy was employed to reduce the adverse effects of TCAs, largely by eliminating interactions with certain neurotransmitters or receptors. Although these more selective compounds may be better tolerated by patients, selective drugs, specifically SSRIs, are not superior to older drugs in treating depressed patients as measured by response and remission rates. It may be an advantage to increase synaptic levels of both serotonin and norepinephrine, as in the case of dual uptake inhibitors like duloxetine and venlafaxine. An important recent development has been the emergence of the triple-uptake inhibitors (TUIs/SNDRIs), which inhibit the uptake of the three neurotransmitters most closely linked to depression: serotonin, norepinephrine, and dopamine. Preclinical studies and clinical trials indicate that a drug inhibiting the reuptake of all three of these neurotransmitters could produce more rapid onset of action and greater efficacy than traditional antidepressants. This review will detail the medicinal chemistry involved in the design, synthesis and discovery of mixed serotonin, norepinephrine and dopamine transporter uptake inhibitors.

  12. Effects of auditing patient safety in hospital care: design of a mixed-method evaluation

    PubMed Central

    2013-01-01

    Background Auditing of patient safety aims at early detection of risks of adverse events and is intended to encourage the continuous improvement of patient safety. The auditing should be an independent, objective assurance and consulting system. Auditing helps an organisation accomplish its objectives by bringing a systematic, disciplined approach to evaluating and improving the effectiveness of risk management, control, and governance. Audits are broadly conducted in hospitals, but little is known about their effects on the behaviour of healthcare professionals and patient safety outcomes. This study was initiated to evaluate the effects of patient safety auditing in hospital care and to explore the processes and mechanisms underlying these effects. Methods and design Our study aims to evaluate an audit system to monitor and improve patient safety in a hospital setting. We are using a mixed-method evaluation with a before-and-after study design in eight departments of one university hospital in the period October 2011–July 2014. We measure several outcomes 3 months before the audit and 15 months after the audit. The primary outcomes are adverse events and complications. The secondary outcomes are experiences of patients, the standardised mortality ratio, prolonged hospital stay, patient safety culture, and team climate. We use medical record reviews, questionnaires, hospital administrative data, and observations to assess the outcomes. A process evaluation will be used to find out which components of internal auditing determine the effects. Discussion We report a study protocol of an effect and process evaluation to determine whether auditing improves patient safety in hospital care. Because auditing is a complex intervention targeted on several levels, we are using a combination of methods to collect qualitative and quantitative data about patient safety at the patient, professional, and department levels. This study is relevant for hospitals that want to

  13. Designing cost-effective biopharmaceutical facilities using mixed-integer optimization.

    PubMed

    Liu, Songsong; Simaria, Ana S; Farid, Suzanne S; Papageorgiou, Lazaros G

    2013-01-01

    Chromatography operations are identified as critical steps in a monoclonal antibody (mAb) purification process and can represent a significant proportion of the purification material costs. This becomes even more critical with increasing product titers that result in higher mass loads onto chromatography columns, potentially causing capacity bottlenecks. In this work, a mixed-integer nonlinear programming (MINLP) model was created and applied to an industrially relevant case study to optimize the design of a facility by determining the most cost-effective chromatography equipment sizing strategies for the production of mAbs. Furthermore, the model was extended to evaluate the ability of a fixed facility to cope with higher product titers up to 15 g/L. Examination of the characteristics of the optimal chromatography sizing strategies across different titer values enabled the identification of the maximum titer that the facility could handle using a sequence of single column chromatography steps as well as multi-column steps. The critical titer levels for different ratios of upstream to dowstream trains where multiple parallel columns per step resulted in the removal of facility bottlenecks were identified. Different facility configurations in terms of number of upstream trains were considered and the trade-off between their cost and ability to handle higher titers was analyzed. The case study insights demonstrate that the proposed modeling approach, combining MINLP models with visualization tools, is a valuable decision-support tool for the design of cost-effective facility configurations and to aid facility fit decisions. 2013. PMID:23956206

  14. Development of high-strength concrete mix designs in support of the prestressed concrete reactor vessel design for a HTGR steam cycle/cogeneration plant

    SciTech Connect

    Naus, D.J.; Oland, C.B.

    1985-01-01

    Design optimization studies indicate that a significant reduction in the size of the PCRV for a 2240 MW(t) HTGR plant can be effected through utilization of high-strength concrete in conjunction with large capacity prestressing systems. A three-phase test program to develop and evaluate high-strength concretes (>63.4 MPa) is described. Results obtained under Phase I of the investigation related to materials selection-evaluation and mix design development are presented. 3 refs., 4 figs.

  15. Probing the Chemical Stability of Mixed Ferrites: Implications for Magnetic Resonance Contrast Agent Design

    SciTech Connect

    Schultz-Sikma, Elise A.; Joshi, Hrushikesh M.; Ma, Qing; MacRenaris, Keith W.; Eckermann, Amanda L.; Dravid, Vinayak P.; Meade, Thomas J.

    2011-09-16

    Nanomaterials with mixed composition, in particular magnetic spinel ferrites, are emerging as efficient contrast agents for magnetic resonance imaging. Many factors, including size, composition, atomic structure, and surface properties, are crucial in the design of such nanoparticle-based probes because of their influence on the magnetic properties. Silica-coated iron oxide (IO-SiO{sub 2}) and cobalt ferrite (CoIO-SiO{sub 2}) nanoparticles were synthesized using standard high-temperature thermal decomposition and base-catalyzed water-in-oil microemulsion techniques. Under neutral aqueous conditions, it was found that 50-75% of the cobalt content in the CoIO-SiO{sub 2} nanoparticles leached out of the core structure. Leaching caused a 7.2-fold increase in the longitudinal relaxivity and an increase in the saturation magnetization from {approx}48 to {approx}65 emu/g of the core. X-ray absorption fine structure studies confirmed that the atomic structure of the ferrite core was altered following leaching, while transmission electron microscopy and dynamic light scattering confirmed that the morphology and size of the nanoparticle remained unchanged. The CoIO-SiO{sub 2} nanoparticles converted from a partially inverted spinel cation arrangement (unleached state) to an inverse spinel arrangement (leached state). The control IO-SiO{sub 2} nanoparticles remained stable with no change in the structure and negligible changes in the magnetic behavior. This detailed analysis highlights how important understanding the properties of nanomaterials is in the development of reliable agents for diagnostic and therapeutic applications.

  16. Mixed enrichment core design for the NC State University PULSTAR Reactor

    SciTech Connect

    Mayo, C.W.; Verghese, K.; Huo, Y.G.

    1997-12-01

    The North Carolina State University PULSTAR Reactor license was renewed for an additional 20 years of operation on April 30, 1997. The relicensing period added additional years to the facility operating time through the end of the second license period, increasing the excess reactivity needs as projected in 1988. In 1995, the Nuclear Reactor Program developed a strategic plan that addressed the future maintenance, development, and utilization of the facility. Goals resulting from this plan included increased academic utilization of the facility in accordance with its role as a university research facility, and increased industrial service use in accordance with the mission of a land grant university. The strategic plan was accepted, and it is the intent of the College of Engineering to operate the PULSTAR Reactor as a going concern through at least the end of the current license period. In order to reach the next relicensing review without prejudice due to low excess reactivity, it is desired to maintain sufficient excess reactivity so that, if relicensed again, the facility could continue to operate without affecting users until new fuel assistance was provided. During the NC State University license renewal, the operation of the PULSTAR Reactor at the State University of New York at Buffalo (SUNY Buffalo) was terminated. At that time, the SUNY Buffalo facility had about 240 unused PULSTAR Reactor fuel pins with 6% enrichment. The objective of the work reported here was to develop a mixed enrichment core design for the NC State University PULSTAR reactor which would: (1) demonstrate that 6% enriched SUNY buffalo fuel could be used in the NC State University PULSTAR Reactor within the existing technical specification safety limits for core physics parameters; (2) show that use of this fuel could permit operating the NC State University PULSTAR Reactor to 2017 with increased utilization; and (3) assure that the decision whether or not to relicense the facility would

  17. African American Organ Donor Registration: A Mixed Methods Design using the Theory of Planned Behavior

    PubMed Central

    DuBay, Derek A.; Ivankova, Nataliya; Herby, Ivan; Wynn, Theresa A.; Kohler, Connie; Berry, Beverly; Foushee, Herman; Carson, April; Redden, David T.; Holt, Cheryl; Siminoff, Laura; Fouad, Mona; Martin, Michelle Y.

    2015-01-01

    Context A large racial disparity exists in organ donation. Objective The purpose of this study was to identify factors associated with becoming a registered organ donor in among African Americans in Alabama. Methods The study utilized a concurrent mixed methods design guided by the Theory of Planned Behavior to analyze African American’s decisions to become a registered organ donor using both qualitative (focus groups) and quantitative (survey) methods. Results The sample consisted of 22 registered organ donors (ROD) and 65 non-registered participants (NRP) from six focus groups completed in urban (n=3) and rural (n=3) areas. Participants emphasized the importance of the autonomy to make one’s own organ donation decision and have this decision honored posthumously. One novel barrier to becoming a ROD was the perception that organs from African Americans were often unusable due to high prevalence of chronic medical conditions such as diabetes and hypertension. Another novel theme discussed as an advantage to becoming a ROD was the subsequent motivation to take responsibility for one’s health. Family and friends were the most common groups of persons identified as approving and disapproving of the decision to become a ROD. The most common facilitator to becoming a ROD was information, while fear and the lack of information were the most common barriers. In contrast, religious beliefs, mistrust and social justice themes were infrequently referenced as barriers to becoming a ROD. Discussion Findings from this study may be useful for prioritizing organ donation community-based educational interventions in campaigns to increase donor registration. PMID:25193729

  18. Evaluation of tubular reactor designs for supercritical water oxidation of U.S. Department of Energy mixed waste

    SciTech Connect

    Barnes, C.M.

    1994-12-01

    Supercritical water oxidation (SCWO) is an emerging technology for industrial waste treatment and is being developed for treatment of the US Department of Energy (DOE) mixed hazardous and radioactive wastes. In the SCWO process, wastes containing organic material are oxidized in the presence of water at conditions of temperature and pressure above the critical point of water, 374 C and 22.1 MPa. DOE mixed wastes consist of a broad spectrum of liquids, sludges, and solids containing a wide variety of organic components plus inorganic components including radionuclides. This report is a review and evaluation of tubular reactor designs for supercritical water oxidation of US Department of Energy mixed waste. Tubular reactors are evaluated against requirements for treatment of US Department of Energy mixed waste. Requirements that play major roles in the evaluation include achieving acceptable corrosion, deposition, and heat removal rates. A general evaluation is made of tubular reactors and specific reactors are discussed. Based on the evaluations, recommendations are made regarding continued development of supercritical water oxidation reactors for US Department of Energy mixed waste.

  19. Earth Science Learning in SMALLab: A Design Experiment for Mixed Reality

    ERIC Educational Resources Information Center

    Birchfield, David; Megowan-Romanowicz, Colleen

    2009-01-01

    Conversational technologies such as email, chat rooms, and blogs have made the transition from novel communication technologies to powerful tools for learning. Currently virtual worlds are undergoing the same transition. We argue that the next wave of innovation is at the level of the computer interface, and that mixed-reality environments offer…

  20. Using Mixed-Method Design and Network Analysis to Measure Development of Interagency Collaboration

    ERIC Educational Resources Information Center

    Cross, Jennifer Eileen; Dickmann, Ellyn; Newman-Gonchar, Rebecca; Fagan, Jesse Michael

    2009-01-01

    In recent years, there has been increasing attention to the importance of interagency collaboration for improving community well-being, environmental and public health, and educational outcomes. This article uses a mixed-methods approach including network analysis to examine the changes in interagency collaboration in one site funded by the Safe…

  1. Innovative Mixed-Methods Research: Moving beyond Design Technicalities to Epistemological and Methodological Realizations

    ERIC Educational Resources Information Center

    Riazi, A. Mehdi

    2016-01-01

    Mixed-methods research (MMR), as an inter-discourse (quantitative and qualitative) methodology, can provide applied linguistics researchers the opportunity to draw on and integrate the strengths of the two research methodological approaches in favour of making more rigorous inferences about research problems. In this article, the argument is made…

  2. Triangulation and Mixed Methods Designs: Data Integration with New Research Technologies

    ERIC Educational Resources Information Center

    Fielding, Nigel G.

    2012-01-01

    Data integration is a crucial element in mixed methods analysis and conceptualization. It has three principal purposes: illustration, convergent validation (triangulation), and the development of analytic density or "richness." This article discusses such applications in relation to new technologies for social research, looking at three innovative…

  3. Quasi-three dimensional hydraulic design and performance calculation of high specific speed mixed-flow pump

    NASA Astrophysics Data System (ADS)

    Su, M.; Zhang, Y. X.; Zhang, J. Y.; Hou, H. C.

    2016-05-01

    According to the basic parameters of 211-80 high specific speed mixed-flow pump, based on the quasi-three dimensional flow theory, the hydraulic design of impeller and its matching spaced guide vanes for high specific speed mixed flow pump was completed, in which the iterative calculation of S 1, S 2 stream surfaces was employed to obtain meridional flow fields and the point-by-point integration method was employed to draw blade camber lines. Blades are thickened as well as blade leading edges are smoothed in the conformal mapping surface. Subsequently the internal fields of the whole flow passage of the designed pump were simulated by using RANS equations with RNG k-ε two-equation turbulent model. The results show that, compared with the 211-80 model, the hydraulic efficiency of the designed pump at the optimal flow rate increases 9.1%. The hydraulic efficiency of designed pump in low flow rate condition (78% designed flow rate) increases 6.46%. The hydraulic efficiency in high flow rate areas increases obviously and there is no bad phenomenon of suddenly decrease of hydraulic efficiency in model pump. From the distributions of velocity and pressure fields, it can be seen that the flow in impeller is uniform and the increase of pressure is gentle. There are no obvious impact phenomenon on impeller inlet and obvious wake shedding vortex phenomenon from impeller outlet to guide vanes inlet.

  4. Orthogonal decomposition as a design tool: With application to a mixing impeller

    SciTech Connect

    Sloan, Benjamin

    2013-01-01

    Digital manufacturing eliminates the expense and time required to develop custom products. By utilizing this technology, designers can quickly create a customized product specifically for their performance needs. But the timescale and expense from the engineering design workflows used to develop these customized products have not been adapted from the workflows used in mass production. In many cases these customized designs build upon already successful mass-produced products that were developed using conventional engineering design workflows. Many times as part of this conventional design process significant time is spent creating and validating high fidelity models that accurately predict the performance of the final design. These existing validated high fidelity models used for the mass-produced design can be reused for analysis and design of unknown products. This thesis explores the integration of reduced order modeling and detailed analysis into the engineering design workflow developing a customized design using digital manufacturing. Specifically, detailed analysis is coupled with proper orthogonal decomposition to enable the exploration of the design space while simultaneously shaping the model representing the design. This revised workflow is examined using the design of a laboratory scale overhead mixer impeller. The case study presented here is compared with the design of the Kar Dynamic Mixer impeller developed by The Dow Chemical Company. The result of which is a customized design for a refined set of operating conditions with improved performance.

  5. Characterizing Design Learning through the Use of Language: A Mixed-Methods Study of Engineering Designers. Research Brief

    ERIC Educational Resources Information Center

    Atman, Cindy; Kilgore, Deborah; McKenna, Ann

    2009-01-01

    This analysis, that utilizes data from part of the Academic Pathways Study (APS) of the Center for the Advancement of Engineering Education (CAEE), found that as a result of taking a course in engineering design and/or studying engineering for four years, students acquire engineering design language that is common to a larger community of practice…

  6. Optimization of long circulating mixed polymeric micelles containing vinpocetine using simple lattice mixture design, in vitro and in vivo characterization.

    PubMed

    El-Dahmy, Rania Moataz; Elsayed, Ibrahim; Elshafeey, Ahmed Hassen; Gawad, Nabaweya Abdelaziz Abd El; El-Gazayerly, Omaima Naim

    2014-12-30

    The aim of this study was to increase the in vivo mean residence time of vinpocetine after IV injection utilizing long circulating mixed micellar systems. Mixed micelles were prepared using Pluronics L121, P123 and F127. The systems were characterized by testing their entrapment efficiency, particle size, polydispersity index, zeta potential, transmission electron microscopy and in vitro drug release. Simple lattice mixture design was planned for the optimization using Design-Expert(®) software. The optimized formula was lyophilized, sterilized and imaged by scanning electron microscope. Moreover, the in vivo behavior of the optimized formula was evaluated after IV injection in rabbits. The optimized formula, containing 68% w/w Pluronic L121 and 32% w/w Pluronic F127, had the highest desirability value (0.621). Entrapment efficiency, particle size, polydispersity index and zeta potential of the optimized formula were 50.74 ± 3.26%, 161.50 ± 7.39 nm, 0.21 ± 0.03 and -22.42 ± 1.72 mV, respectively. Lyophilization and sterilization did not affect the characteristics of the optimized formula. Upon in vivo investigation in rabbits, the optimized formula showed a significantly higher elimination half-life and mean residence time than the market product. Finally, mixed micelles could be considered as a promising long circulating nanocarrier for lipophilic drugs. PMID:25290813

  7. Visual perception and mixed-initiative interaction for assisted visualization design.

    PubMed

    Healey, Christopher; Kocherlakota, Sarat; Rao, Vivek; Mehta, Reshma; St Amant, Robert

    2008-01-01

    This paper describes the integration of perceptual guidelines from human vision with an AI-based mixed-initiative search strategy. The result is a visualization assistant called ViA, a system that collaborates with its users to identify perceptually salient visualizations for large, multidimensional datasets. ViA applies knowledge of low-level human vision to: (1) evaluate the effectiveness of a particular visualization for a given dataset and analysis tasks; and (2) rapidly direct its search towards new visualizations that are most likely to offer improvements over those seen to date. Context, domain expertise, and a high-level understanding of a dataset are critical to identifying effective visualizations. We apply a mixed-initiative strategy that allows ViA and its users to share their different strengths and continually improve ViA's understanding of a user's preferences. We visualize historical weather conditions to compare ViA's search strategy to exhaustive analysis, simulated annealing, and reactive tabu search, and to measure the improvement provided by mixed-initiative interaction. We also visualize intelligent agents competing in a simulated online auction to evaluate ViA's perceptual guidelines. Results from each study are positive, suggesting that ViA can construct high-quality visualizations for a range of real-world datasets. PMID:18192718

  8. How and Why Do IT Entrepreneurs Leave Their Salaried Employment to Start a SME? A Mixed Methods Research Design

    NASA Astrophysics Data System (ADS)

    Mourmant, Gaëtan

    This method paper addresses an untapped but important type of IT turnover: IT entrepreneurship. We seek to develop a mixed methods research (MMR) design to understand the factors and processes that influence turnover behavior of prospective (nascent) IT entrepreneurs. To do this, we review two prior streams of research: the entrepreneurship literature and IT employee turnover. We incorporate the results of this literature review into a conceptual framework describing how the relevant factors leading to entrepreneurial and turnover behavior change over time, either gradually or suddenly, in response to specific events. In addition, we also contribute to the research by arguing that mixed methods research (MMR) is appropriate to bridge the gap between entrepreneurial literature and the IT turnover literature. A third important contribution is the design of the MMR, combining a longitudinal approach with a retrospective approach; a qualitative with a quantitative approach and, the exploratory design with the triangulation design [1]. Finally, we discuss practical implications for IT managers and IT entrepreneurs.

  9. Design a freeform microlens array module for any arbitrary-shape collimated beam shaping and color mixing

    NASA Astrophysics Data System (ADS)

    Chen, Enguo; Wu, Rengmao; Guo, Tailiang

    2014-06-01

    Collimated beam shaping with freeform surface usually employs a predefined mapping to tailor one or multiple freeform surfaces. Limitation on those designs is that the source, the freeform optics and the target are in fixed one-to-one correspondence with each other. To overcome this drawback, this paper presents a kind of freeform microlens array module integrated with an ultra-thin freeform microlens array and a condenser lens to reshape any arbitrary-shape collimated beam into a prescribed uniform rectangular illumination and achieve color mixing. The design theory is explicitly given, and some key issues are addressed. Several different application examples are given, and the target is obtained with high uniformity and energy efficiency. This freeform microlens array module, which shows better flexibility and practicality than the regular designs, can be used not only to reshape any arbitrary-shape collimated beam (or a collimated beam integrated with several sub-collimated beams), but also most importantly to achieve color mixing. With excellent optical performance and ultra-compact volume, this optical module together with the design theory can be further introduced into other applications and will have a huge market potential in the near future.

  10. The eXperience Induction Machine: A New Paradigm for Mixed-Reality Interaction Design and Psychological Experimentation

    NASA Astrophysics Data System (ADS)

    Bernardet, Ulysses; Bermúdez I Badia, Sergi; Duff, Armin; Inderbitzin, Martin; Le Groux, Sylvain; Manzolli, Jônatas; Mathews, Zenon; Mura, Anna; Väljamäe, Aleksander; Verschure, Paul F. M. J.

    The eXperience Induction Machine (XIM) is one of the most advanced mixed-reality spaces available today. XIM is an immersive space that consists of physical sensors and effectors and which is conceptualized as a general-purpose infrastructure for research in the field of psychology and human-artifact interaction. In this chapter, we set out the epistemological rational behind XIM by putting the installation in the context of psychological research. The design and implementation of XIM are based on principles and technologies of neuromorphic control. We give a detailed description of the hardware infrastructure and software architecture, including the logic of the overall behavioral control. To illustrate the approach toward psychological experimentation, we discuss a number of practical applications of XIM. These include the so-called, persistent virtual community, the application in the research of the relationship between human experience and multi-modal stimulation, and an investigation of a mixed-reality social interaction paradigm.

  11. Supplemental design requirements document enhanced radioactive and mixed waste storage: Phase 5, Project W-113

    SciTech Connect

    Ocampo, V.P.

    1994-11-01

    This Supplemental Design Requirements Document (SDRD) is used to communicate Project W-113 specific plant design information from Westinghouse Hanford Company (WHC) to the United States Department of Energy (DOE) and the cognizant Architect Engineer (A/E). The SDRD is prepared after the completion of the project Conceptual Design report (CDR) and prior to the initiation of definitive design. Information in the SDRD serves two purposes: to convey design requirements that are too detailed for inclusion in the Functional Design Criteria (FDC) report and to serve as a means of change control for design commitments in the Title I and Title II design. The Solid Waste Retrieval Project (W-113) SDRD has been restructured from the equipment based outline used in previous SDRDs to a functional systems outline. This was done to facilitate identification of deficiencies in the information provided in the initial draft SDRD and aid design confirmation. The format and content of this SDRD adhere as closely as practicable to the requirements of WHC-CM-6-1, Standard Engineering Practices for Functional Design Criteria.

  12. Integrated model for assessing the cost and CO2 emission (IMACC) for sustainable structural design in ready-mix concrete.

    PubMed

    Hong, Taehoon; Ji, Changyoon; Park, Hyoseon

    2012-07-30

    Cost has traditionally been considered the most important factor in the decision-making process. Recently, along with the consistent interest in environmental problems, environmental impact has also become a key factor. Accordingly, there is a need to develop a method that simultaneously reflects the cost and environmental impact in the decision-making process. This study proposed an integrated model for assessing the cost and CO(2) emission (IMACC) at the same time. IMACC is a model that assesses the cost and CO(2) emission of the various structural-design alternatives proposed in the structural-design process. To develop the IMACC, a standard on assessing the cost and CO(2) emission generated in the construction stage was proposed, along with the CO(2) emission factors in the structural materials, based on such materials' strengths. Moreover, using the economic and environmental scores that signify the cost and CO(2) emission reduction ratios, respectively, a method of selecting the best design alternative was proposed. To verify the applicability of IMACC, practical application was carried out. Structural designs were assessed, each of which used 21, 24, 27, and 30 MPa ready-mix concrete (RMC). The use of IMACC makes it easy to verify what the best design is. Results show the one that used 27 MPa RMC was the best design. Therefore, the proposed IMACC can be used as a tool for supporting the decision-making process in selecting the best design alternative. PMID:22436837

  13. CFSpro: ray tracing for design and optimization of complex fenestration systems using mixed dimensionality approach.

    PubMed

    Kostro, André; Geiger, Mario; Scartezzini, Jean-Louis; Schüler, Andreas

    2016-07-01

    Advanced optical ray tracing software, CFSpro, was developed for the study and optimization of complex fenestration systems (CFSs). Using an algorithm mixing 2D and 3D approaches, accurate computation of large numbers of rays in extruded geometries can be performed and visualized in real time. A thin film model was included to assess the spectral control provided by coatings. In this paper, the ray tracing model is described and validated. A novel glazing, engineered with this simulation tool, is presented. It combines the functions of daylight provision, glare protection, and seasonal thermal control while conserving a view to the outside at near normal incidence. PMID:27409200

  14. A mixed molecular building block strategy for the design of nested polyhedron metal-organic frameworks.

    PubMed

    Tian, Dan; Chen, Qiang; Li, Yue; Zhang, Ying-Hui; Chang, Ze; Bu, Xian-He

    2014-01-13

    A mixed molecular building block (MBB) strategy for the synthesis of double-walled cage-based porous metal-organic frameworks (MOFs) is presented. By means of this method, two isostructural porous MOFs built from unprecedented double-walled metal-organic octahedron were obtained by introducing two size-matching C3 -symmetric molecular building blocks with different rigidities. With their unique framework structures, these MOFs provide, to the best of our knowledge, the first examples of double-walled octahedron-based MOFs. PMID:24282117

  15. Energy Design Guidelines for High Performance Schools: Temperate and Mixed Climates.

    ERIC Educational Resources Information Center

    National Renewable Energy Lab. (DOE), Golden, CO.

    The U.S. Department of Energy's EnergySmart Schools provides school boards, administrators, and design staff with guidance to help them make informed decisions about energy and environmental issues important to school systems and communities. The design guidelines presented in this document outline high performance principles for the new or…

  16. Comparisons among Designs for Equating Mixed-Format Tests in Large-Scale Assessments

    ERIC Educational Resources Information Center

    Kim, Sooyeon; Walker, Michael E.; McHale, Frederick

    2010-01-01

    In this study we examined variations of the nonequivalent groups equating design for tests containing both multiple-choice (MC) and constructed-response (CR) items to determine which design was most effective in producing equivalent scores across the two tests to be equated. Using data from a large-scale exam, this study investigated the use of…

  17. Implementing Quality Criteria in Designing and Conducting a Sequential Quan [right arrow] Qual Mixed Methods Study of Student Engagement with Learning Applied Research Methods Online

    ERIC Educational Resources Information Center

    Ivankova, Nataliya V.

    2014-01-01

    In spite of recent methodological developments related to quality assurance in mixed methods research, practical examples of how to implement quality criteria in designing and conducting sequential QUAN [right arrow] QUAL mixed methods studies to ensure the process is systematic and rigorous remain scarce. This article discusses a three-step…

  18. Quantifying suspended sediment flux in a mixed-land-use urbanizing watershed using a nested-scale study design.

    PubMed

    Zeiger, Sean; Hubbart, Jason A

    2016-01-15

    Suspended sediment (SS) remains the most pervasive water quality problem globally and yet, despite progress, SS process understanding remains relatively poor in watersheds with mixed-land-use practices. The main objective of the current work was to investigate relationships between suspended sediment and land use types at multiple spatial scales (n=5) using four years of suspended sediment data collected in a representative urbanized mixed-land-use (forest, agriculture, urban) watershed. Water samples were analyzed for SS using a nested-scale experimental watershed study design (n=836 samples×5 gauging sites). Kruskal-Wallis and Dunn's post-hoc multiple comparison tests were used to test for significant differences (CI=95%, p<0.05) in SS levels between gauging sites. Climate extremes (high precipitation/drought) were observed during the study period. Annual maximum SS concentrations exceeded 2387.6 mg/L. Median SS concentrations decreased by 60% from the agricultural headwaters to the rural/urban interface, and increased by 98% as urban land use increased. Multiple linear regression analysis results showed significant relationships between SS, annual total precipitation (positive correlate), forested land use (negative correlate), agricultural land use (negative correlate), and urban land use (negative correlate). Estimated annual SS yields ranged from 16.1 to 313.0 t km(-2) year(-1) mainly due to differences in annual total precipitation. Results highlight the need for additional studies, and point to the need for improved best management practices designed to reduce anthropogenic SS loading in mixed-land-use watersheds. PMID:26519591

  19. Definitive design report: Design report project W-025, Radioactive Mixed Waste (RMW) Land Disposal Facility NON-DRAG-OFF. Revision 1, Volume 1 and 2

    SciTech Connect

    Roscha, V.

    1994-11-29

    The purpose of this report is to describe the definitive design of the Radioactive Mixed Waste (RMW) Non-Drag-Off disposal facility, Project W-025. This report presents a n of the major landfill design features and a discussion of how each of the criteria is addressed in the design. The appendices include laboratory test results, design drawings, and individual analyses that were conducted in support of the design. Revision 1 of this document incorporates design changes resulting from an increase in the required operating life of the W-025 landfill from 2 to 20 years. The rationale for these design changes is described in Golder Associates Inc. 1991a. These changes include (1) adding a 1.5-foot-thick layer of compacted admix directory-under the primary FML on the floor of the landfill to mitigate the effects of possible stress cracking in the primary flexible membrane liner (FML), and (2) increasing the operations layer thickness from two to three feet over the entire landfill area, to provide additional protection for the secondary admix layer against mechanical damage and the effects of freezing and desiccation. The design of the W-025 Landfill has also been modified in response to the results of the EPA Method 9090 chemical compatibility testing program (Golder Associates Inc. 1991b and 1991c), which was completed after the original design was prepared. This program consisted of testing geosynthetic materials and soil/bentonite admix with synthetic leachate having the composition expected during the life of the W-025 Landfill., The results of this program indicated that the polyester geotextile originally specified for the landfill might be susceptible to deterioration. On this basis, polypropylene geotextiles were substituted as a more chemically-resistant alternative. In addition, the percentage of bentonite in the admix was increased to provide sufficiently low permeability to the expected leachate.

  20. Toward compositional design of reticular type porous films by mixing and coating titania-based frameworks with silica

    NASA Astrophysics Data System (ADS)

    Kimura, T.

    2015-12-01

    A recently developed reticular type porous structure, which can be fabricated as the film through the soft colloidal block copolymer (e.g., PS-b-PEO) templating, is very promising as the porous platform showing high-performance based on its high surface area as well as high diffusivity of targeted organic molecules and effective accommodation of bulky molecules, but the compositional design of oxide frameworks has not been developed so enough to date. Here, I report reliable synthetic methods of the reticular type porous structure toward simple compositional variations. Due to the reproducibility of reticular type porous titania films from titanium alkoxide (e.g., TTIP; titanium tetraisopropoxide), a titania-silica film having similar porous structure was obtained by mixing silicon alkoxide (e.g., tetraethoxysilane) and TTIP followed by their pre-hydrolysis, and the mixing ratio of Ti to Si composition was easily reached to 1.0. For further compositional design, a concept of surface coating was widely applicable; the reticular type porous titania surfaces can be coated with other oxides such as silica. Here, a silica coating was successfully achieved by the simple chemical vapor deposition of silicon alkoxide (e.g., tetramethoxysilane) without water (with water at the humidity level), which was also utilized for pore filling with silica by the similar process with water.

  1. Energy Design Guidelines for High Performance Schools: Temperate and Mixed Climates

    SciTech Connect

    Not Available

    2002-06-01

    School districts around the country are finding that the smart energy choices can help them save money and provide healthier, more effective learning environments. By incorporating energy improvements into their construction or renovation plans, schools can significantly reduce energy consumption and costs. These savings can be redirected to educational needs such as additional teachers, instructional materials, or new computers. These design guidelines outline high performance principles for the new or retrofit design of your K-12 school. By incorporating these principles, you can create and exemplary building that is both energy and resource efficient.

  2. Design and Testing of a Boron Carbide Capsule for Spectral Tailoring in Mixed-Spectrum Reactors

    SciTech Connect

    Greenwood, Lawrence R.; Wittman, Richard S.; Pierson, Bruce D.; Metz, Lori A.; Payne, Rosara F.; Finn, Erin C.; Friese, Judah I.

    2012-03-01

    A boron carbide capsule has been designed and used for spectral-tailoring experiments at the TRIGA reactor at Washington State University. Irradiations were conducted in pulsed mode and in continuous operation for up to 4 hours. A cadmium cover was used to reduce thermal heating. The neutron spectrum calculated with MCNP was found to be in good agreement with reactor dosimetry measurements using the STAY'SL computer code. The neutron spectrum resembles that of a fast reactor. Design of a capsule using boron carbide enriched in {sup 10}B shows that it is possible to produce a neutron spectrum similar to {sup 235}U fission.

  3. Model of Values-Based Management Process in Schools: A Mixed Design Study

    ERIC Educational Resources Information Center

    Dogan, Soner

    2016-01-01

    The aim of this paper is to evaluate the school administrators' values-based management behaviours according to the teachers' perceptions and opinions and, accordingly, to build a model of values-based management process in schools. The study was conducted using explanatory design which is inclusive of both quantitative and qualitative methods.…

  4. Internet, Phone, Mail, and Mixed-Mode Surveys: The Tailored Design Method, 4th Edition

    ERIC Educational Resources Information Center

    Dillman, Don A.; Smyth, Jolene D.; Christian, Lean Melani

    2014-01-01

    For over two decades, Dillman's classic text on survey design has aided both students and professionals in effectively planning and conducting mail, telephone, and, more recently, Internet surveys. The new edition is thoroughly updated and revised, and covers all aspects of survey research. It features expanded coverage of mobile phones, tablets,…

  5. Path programmable logic: A structured design method for digital and/or mixed analog integrated circuits

    NASA Technical Reports Server (NTRS)

    Taylor, B.

    1990-01-01

    The design of Integrated Circuits has evolved past the black art practiced by a few semiconductor companies to a world wide community of users. This was basically accomplished by the development of computer aided design tools which were made available to this community. As the tools matured into different components of the design task they were accepted into the community at large. However, the next step in this evolution is being ignored by the large tool vendors hindering the continuation of this process. With system level definition and simulation through the logic specification well understood, why is the physical generation so blatantly ignored. This portion of the development is still treated as an isolated task with information being passed from the designer to the layout function. Some form of result given back but it severely lacks full definition of what has transpired. The level of integration in I.C.'s for tomorrow, whether through new processes or applications will require higher speeds, increased transistor density, and non-digital performance which can only be achieved through attention to the physical implementation.

  6. Mixing console design for telematic applications in live performance and remote recording

    NASA Astrophysics Data System (ADS)

    Samson, David J.

    The development of a telematic mixing console addresses audio engineers' need for a fully integrated system architecture that improves efficiency and control for applications such as distributed performance and remote recording. Current systems used in state of the art telematic performance rely on software-based interconnections with complex routing schemes that offer minimal flexibility or control over key parameters needed to achieve a professional workflow. The lack of hardware-based control in the current model limits the full potential of both the engineer and the system. The new architecture provides a full-featured platform that, alongside customary features, integrates (1) surround panning capability for motorized, binaural manikin heads, as well as all sources in the included auralization module, (2) self-labelling channel strips, responsive to change at all remote sites, (3) onboard roundtrip latency monitoring, (4) synchronized remote audio recording and monitoring, and (5) flexible routing. These features combined with robust parameter automation and precise analog control will raise the standard for telematic systems as well as advance the development of networked audio systems for both research and professional audio markets.

  7. Designing Health Websites Based on Users’ Web-Based Information-Seeking Behaviors: A Mixed-Method Observational Study

    PubMed Central

    Pang, Patrick Cheong-Iao; Verspoor, Karin; Pearce, Jon

    2016-01-01

    Background Laypeople increasingly use the Internet as a source of health information, but finding and discovering the right information remains problematic. These issues are partially due to the mismatch between the design of consumer health websites and the needs of health information seekers, particularly the lack of support for “exploring” health information. Objective The aim of this research was to create a design for consumer health websites by supporting different health information–seeking behaviors. We created a website called Better Health Explorer with the new design. Through the evaluation of this new design, we derive design implications for future implementations. Methods Better Health Explorer was designed using a user-centered approach. The design was implemented and assessed through a laboratory-based observational study. Participants tried to use Better Health Explorer and another live health website. Both websites contained the same content. A mixed-method approach was adopted to analyze multiple types of data collected in the experiment, including screen recordings, activity logs, Web browsing histories, and audiotaped interviews. Results Overall, 31 participants took part in the observational study. Our new design showed a positive result for improving the experience of health information seeking, by providing a wide range of information and an engaging environment. The results showed better knowledge acquisition, a higher number of page reads, and more query reformulations in both focused and exploratory search tasks. In addition, participants spent more time to discover health information with our design in exploratory search tasks, indicating higher engagement with the website. Finally, we identify 4 design considerations for designing consumer health websites and health information–seeking apps: (1) providing a dynamic information scope; (2) supporting serendipity; (3) considering trust implications; and (4) enhancing interactivity

  8. Design and Test of Mixed-flow Impellers III : Design and Experimental Results for Impeller Model MFI-2A and Comparison with Impeller Model MFI-1A

    NASA Technical Reports Server (NTRS)

    Hamrick, Joseph T; Osborn, Walter M; Beede, William L

    1953-01-01

    A mixed-flow impeller was designed to give a prescribed blade-surface velocity distribution at mean blade height for a given hub-shroud profile. The blade shape at mean blade height, which was produced by the prescribed velocity distribution, was extended by means of radial lines to form the composite blade shape from hub to shroud. The resulting blade was relatively thick; therefore, it was necessary to retain the inverse blade taper which resulted from extension of the radial lines in order to prevent merging or near merging of the separate blades near the hub. For the first test version of the impeller, designated the MFI-2A, the blade height was arbitrarily made greater than that for the basic impeller (the MFI-2) to allow for viscous effects. At design equivalent speed of 1400 feet per second the peak pressure ratio and maximum adiabatic efficiency were 3.95 and 79 percent, respectively. The adiabatic efficiency of the MFI-2A is four points lower than that for impeller model MFI-1A, but because of the higher slip factor for the MFI-2A, the pressure ratios are approximately equal. The procedures followed in the design of the MFI-1A and MFI-2A were, in general, the same; and, although the prescribed initial condition resulted in geometrical configurations that were quite dissimilar, the resulting performance characteristics compare favorably with designs for which considerable development work has been necessary.

  9. Image processing algorithm design and implementation for real-time autonomous inspection of mixed waste

    SciTech Connect

    Schalkoff, R.J.; Shaaban, K.M.; Carver, A.E.

    1996-12-31

    The ARIES {number_sign}1 (Autonomous Robotic Inspection Experimental System) vision system is used to acquire drum surface images under controlled conditions and subsequently perform autonomous visual inspection leading to a classification as `acceptable` or `suspect`. Specific topics described include vision system design methodology, algorithmic structure,hardware processing structure, and image acquisition hardware. Most of these capabilities were demonstrated at the ARIES Phase II Demo held on Nov. 30, 1995. Finally, Phase III efforts are briefly addressed.

  10. Crested wheatgrass-cheatgrass seedling competition in a mixed-density design

    USGS Publications Warehouse

    Francis, Mark G.; Pyke, David A.

    1996-01-01

    Plant competition experiments have historically used designs that are difficult to interpret due to confounding problems. Recently, designs based on a 'response function' approach have been proposed and tested in various plant mixture settings. For this study, 3 species were used that are important in current revegetation practices in the Intermountain West. 'Nordan' (Agropyron desertorum [Fish. ex Link] Shult.) and 'Hycrest' (A. cristatum [L.] Gaertn. x desertorum) crested wheatgrass are commonly-used revegetation species on rangelands susceptible to cheatgrass (Bromus tectorum L.) invasion, although little quantitative data exist that compare their competitive abilities. We evaluated the competitive ability of Hycrest and Nordan seedlings in 2-species mixtures with cheatgrass in a greenhouse study. Linear and nonlinear models were developed for a range of densities (130- 520 seeds m-2) for each species to predict median above-ground biomass and tiller numbers and to further test the usefulness of this design for evaluating species to rehabilitate rangelands. In both experiments, increasing Hycrest and Nordan densities reduced their own biomass and tiller production while increasing Hycrest densities reduced cheatgrass biomass and tiller production. Nordan did not affect cheatgrass biomass and tiller production. However, increasing cheatgrass densities reduced Hycrest and Nordan biomass and tiller production, and its own biomass and tiller production. The competition index i.e. substitution rate, indicated that Hycrest seedlings were better competitors with cheatgrass than Nordan, although in all mixtures, cheatgrass plants were the superior competitors. Further field research using this design, where environmental inputs are less optimal and diverse, is needed to validate these results and to further evaluate the use of this approach in examining effects of intra- and interspecific competition.

  11. Greenhouse gas emissions from concrete can be reduced by using mix proportions, geometric aspects, and age as design factors

    NASA Astrophysics Data System (ADS)

    Miller, Sabbie A.; Horvath, Arpad; Monteiro, Paulo J. M.; Ostertag, Claudia P.

    2015-11-01

    With increased awareness of the emissions of greenhouse gases (GHGs) and the significant contribution from the cement industry, research efforts are being advanced to reduce the impacts associated with concrete production and consumption. A variety of methods have been proposed, one of the most common being the replacement of cement as a binder in concrete with supplementary cementitious materials, such as fly ash (FA), which can have lower environmental effects. The use of FA can change the kinetics of the hydration reactions and, consequently, modify the evolution of the concrete strength over time. Yet the influence of designing structural elements to obtain the required strength at later ages has not been examined in terms of their influence on global warming potential (GWP) of concrete. This research investigates the influence of design age, in addition to mix proportions and geometric aspects, on the GWP associated with making beams, columns, and a concrete building frame. Findings suggest that while the GWP for beams is not highly dependent on concrete mixture strength, the GWP for columns is dependent on strength, thus the influence of required strength at later ages influences GWP of making columns more so than beams. For the concrete frame analyzed, a potential 45% reduction in GWP, depending on mix proportions and design age, was found. Using the findings from this research, the GWP associated with production of concrete in California could be reduced by approximately 1.8 million metric tons of CO2-eq emissions, equivalent to approximately 2% of all industrial GHG emissions in California.

  12. Mixing design for enzymatic hydrolysis of sugarcane bagasse: methodology for selection of impeller configuration.

    PubMed

    Corrêa, Luciano Jacob; Badino, Alberto Colli; Cruz, Antonio José Gonçalves

    2016-02-01

    One of the major process bottlenecks for viable industrial production of second generation ethanol is related with technical-economic difficulties in the hydrolysis step. The development of a methodology to choose the best configuration of impellers towards improving mass transfer and hydrolysis yield together with a low power consumption is important to make the process cost-effective. In this work, four dual impeller configurations (DICs) were evaluated during hydrolysis of sugarcane bagasse (SCB) experiments in a stirred tank reactor (3 L). The systems tested were dual Rushton turbine impellers (DIC1), Rushton and elephant ear (down-pumping) turbines (DIC2), Rushton and elephant ear (up-pumping) turbines (DIC3), and down-pumping and up-pumping elephant ear turbines (DIC4). The experiments were conducted during 96 h, using 10 % (m/v) SCB, pH 4.8, 50 °C, 10 FPU/g biomass, 470 rpm. The mixing time was successfully used as the characteristic parameter to select the best impeller configuration. Rheological parameters were determined using a rotational rheometer, and the power consumptions of the four DICs were on-line measured with a dynamometer. The values obtained for the energetic efficiency (the ratio between the cellulose to glucose conversion and the total energy) showed that the proposed methodology was successful in choosing a suitable configuration of impellers, wherein the DIC4 obtained approximately three times higher energetic efficiency than DIC1. Furthermore a scale-up protocol (factor scale-up 1000) for the enzymatic hydrolysis reactor was proposed. PMID:26650719

  13. Large-eddy simulations of a mixed-flow pump at off-design conditions

    NASA Astrophysics Data System (ADS)

    Posa, Antonio; Lippolis, Antonio; Balaras, Elias

    2014-11-01

    Reduced flow-rates in turbopumps produce significant unsteady phenomena, characterized by separation and back-flow. In this study an LES approach coupled with an immersed-boundary methodology is utilized to investigate the changes in the flow physics, when compared to nominal flow-rates. The present methodology has been already validated for the design case through comparison with PIV experiments in the literature. It will be shown that for a reduced flow rate (40% of the design one) separation phenomena are generated on the suction side of the rotor blades and on the pressure side of the stator ones. Significant spanwise non-uniformity is produced in the diffuser channels, with a displacement of the flow towards the hub side and back-flow on the shroud side. The values of turbulent kinetic energy are increased by an order of magnitude at off-design conditions and the main source of turbulence is not anymore the flow from the suction side and the trailing edge of the rotor blades: most turbulence is generated now at the leading edge of the diffuser blades. The increased interaction between rotating and stationary parts implies also a stronger dependence of the flow features on the relative position between impeller and diffuser blades.

  14. A Comparison of Student Teachers' Beliefs from Four Different Science Teaching Domains Using a Mixed Methods Design

    NASA Astrophysics Data System (ADS)

    Markic, Silvija; Eilks, Ingo

    2012-03-01

    The study presented in this paper integrates data from four combined research studies, which are both qualitative and quantitative in nature. The studies describe freshman science student teachers' beliefs about teaching and learning. These freshmen intend to become teachers in Germany in one of four science teaching domains (secondary biology, chemistry, and physics, respectively, as well as primary school science). The qualitative data from the first study are based on student teachers' drawings of themselves in teaching situations. It was formulated using Grounded Theory to test three scales: Beliefs about Classroom Organisation, Beliefs about Teaching Objectives, and Epistemological Beliefs. Three further quantitative studies give insight into student teachers' curricular beliefs, their beliefs about the nature of science itself, and about the student- and/or teacher-centredness of science teaching. This paper describes a design to integrate all these data within a mixed methods framework. The aim of the current study is to describe a broad, triangulated picture of freshman science student teachers' beliefs about teaching and learning within their respective science teaching domain. The study reveals clear tendencies between the sub-groups. The results suggest that freshman chemistry and-even more pronouncedly-freshman physics student teachers profess quite traditional beliefs about science teaching and learning. Biology and primary school student teachers express beliefs about their subjects which are more in line with modern educational theory. The mixed methods approach towards the student teachers' beliefs is reflected upon and implications for science education and science teacher education are discussed.

  15. Dry anaerobic digestion in batch mode: design and operation of a laboratory-scale, completely mixed reactor.

    PubMed

    Guendouz, J; Buffière, P; Cacho, J; Carrère, M; Delgenes, J-P

    2010-10-01

    A laboratory-scale (40 l) reactor was designed to investigate dry anaerobic digestion. The reactor is equipped with an intermittent paddle mixer, enabling complete mixing in the reactor. Three consecutive batch dry digestion tests of municipal solid waste were performed under mesophilic conditions and compared to operation results obtained on a pilot-scale (21 m(3)) with the same feedstock. Biogas and methane production at the end of the tests were similar (around 200 m(3) CH(4)STP/tVS), and the dynamics of methane production and VFA accumulation concurred. However, the maximal levels of VFA transitory accumulation varied between reactors and between runs in a same reactor. Ammonia levels were similar in both reactors. These results show that the new reactor accurately imitates the conditions found in larger ones. Adaptation of micro-organisms to the waste and operating conditions was also pointed out along the consecutive batches. PMID:20096555

  16. Free-Electron Laser Design for Four-Wave Mixing Experiments with Soft-X-Ray Pulses

    NASA Astrophysics Data System (ADS)

    Marcus, G.; Penn, G.; Zholents, A. A.

    2014-07-01

    We present the design of a single-pass free-electron laser amplifier suitable for enabling four-wave mixing x-ray spectroscopic investigations. The production of longitudinally coherent, single-spike pulses of light from a single electron beam in this scenario relies on a process of selective amplification where a strong undulator taper compensates for a large energy chirp only for a short region of the electron beam. This proposed scheme offers improved flexibility of operation and allows for independent control of the color, timing, and angle of incidence of the individual pulses of light at an end user station. Detailed numerical simulations are used to illustrate the more impressive characteristics of this scheme.

  17. A two-reservoir, hollow-fiber bioreactor for the study of mixed-population dynamics: design aspects and validation of the approach.

    PubMed

    Manjarrez, E S; Albasi, C; Riba, J P

    2000-08-20

    A two-reservoir, membrane bioreactor for carrying out studies of mixed-population dynamics in batch fermentations is presented. Mixing requirements and design aspects for the validity of the approach are given and discussed. Equations describing mixing times between the reservoirs are presented and compared to the experimental results. The validity of the approach is demonstrated by the study of an amensalistic-type interaction, the protein-mediated killer phenomenon between two Saccharomyces cerevisiae strains. The validation consisted in the comparison between the results obtained in actual mixed culture and the results obtained by keeping the strains separated. A good agreement was found which demonstrates the viability of the designed bioreactor. PMID:10862678

  18. Augmented paper maps: Exploring the design space of a mixed reality system

    NASA Astrophysics Data System (ADS)

    Paelke, Volker; Sester, Monika

    Paper maps and mobile electronic devices have complementary strengths and shortcomings in outdoor use. In many scenarios, like small craft sailing or cross-country trekking, a complete replacement of maps is neither useful nor desirable. Paper maps are fail-safe, relatively cheap, offer superior resolution and provide large scale overview. In uses like open-water sailing it is therefore mandatory to carry adequate maps/charts. GPS based mobile devices, on the other hand, offer useful features like automatic positioning and plotting, real-time information update and dynamic adaptation to user requirements. While paper maps are now commonly used in combination with mobile GPS devices, there is no meaningful integration between the two, and the combined use leads to a number of interaction problems and potential safety issues. In this paper we explore the design space of augmented paper maps in which maps are augmented with additional functionality through a mobile device to achieve a meaningful integration between device and map that combines their respective strengths.

  19. Design of Mixed Batch Reactor and Column Studies at Oak Ridge National Laboratory

    SciTech Connect

    Wu, Weimin; Criddle, Craig S.

    2015-11-16

    We (the Stanford research team) were invited as external collaborators to contribute expertise in environmental engineering and field research at the ORNL IFRC, Oak Ridge, TN, for projects carried out at the Argonne National Laboratory and funded by US DOE. Specifically, we assisted in the design of batch and column reactors using ORNL IFRC materials to ensure the experiments were relevant to field conditions. During the funded research period, we characterized ORNL IFRC groundwater and sediments in batch microcosm and column experiments conducted at ANL, and we communicated with ANL team members through email and conference calls and face-to-face meetings at the annual ERSP PI meeting and national meetings. Microcosm test results demonstrated that U(VI) in sediments was reduced to U(IV) when amended with ethanol. The reduced products were not uraninite but unknown U(IV) complexes associated with Fe. Fe(III) in solid phase was only partially reduced. Due to budget reductions at ANL, Stanford contributions ended in 2011.

  20. Mixed matrix membrane application for olive oil wastewater treatment: process optimization based on Taguchi design method.

    PubMed

    Zirehpour, Alireza; Rahimpour, Ahmad; Jahanshahi, Mohsen; Peyravi, Majid

    2014-01-01

    Olive oil mill wastewater (OMW) is a concentrated effluent with a high organic load. It has high levels of organic chemical oxygen demand (COD) and phenolic compounds. This study presents a unique process to treat OMW. The process uses ultrafiltration (UF) membranes modified by a functionalized multi wall carbon nano-tube (F-MWCNT). The modified tube has an inner diameter of 15-30 nm and is added to the OMW treatment process to improve performance of the membrane. Tests were done to evaluate the following operating parameters of the UF system; pressure, pH and temperature; also evaluated parameters of permeate flux, flux decline, COD removal and total phenol rejection. The Taguchi robust design method was applied for an optimization evaluation of the experiments. Variance (ANOVA) analysis was used to determine the most significant parameters affecting permeate flux, flux decline, COD removal and total phenols rejection. Results demonstrated coagulation and pH as the most important factors affecting permeate flux of the UF. Moreover, pH and F-MWCNT UF had significant positive effects on flux decline, COD removal and total phenols rejection. Based on the optimum conditions determined by the Taguchi method, evaluations for permeate flux tests; flux decline, COD removal and total phenols rejection were about 21.2 (kg/m(2) h), 12.6%, 72.6% and 89.5%, respectively. These results were in good agreement with those predicted by the Taguchi method (i.e.; 22.8 (kg/m(2) h), 11.9%, 75.8 and 94.7%, respectively). Mechanical performance of the membrane and its application for high organic wastewater treatment were determined as strong. PMID:24291584

  1. Performance of a low cost interdigitated flow design on a 1 kW class all vanadium mixed acid redox flow battery

    NASA Astrophysics Data System (ADS)

    Reed, David; Thomsen, Edwin; Li, Bin; Wang, Wei; Nie, Zimin; Koeppel, Brian; Sprenkle, Vincent

    2016-02-01

    Three flow designs were operated in a 3-cell 1 kW class all vanadium mixed acid redox flow battery. The influence of electrode surface area and flow rate on the coulombic, voltage, and energy efficiency and the pressure drop in the flow circuit will be discussed and correlated to the flow design. Material cost associated with each flow design will also be discussed.

  2. Reliable Attention Network Scores and Mutually Inhibited Inter-network Relationships Revealed by Mixed Design and Non-orthogonal Method

    PubMed Central

    Wang, Yi-Feng; Jing, Xiu-Juan; Liu, Feng; Li, Mei-Ling; Long, Zhi-Liang; Yan, Jin H.; Chen, Hua-Fu

    2015-01-01

    The attention system can be divided into alerting, orienting, and executive control networks. The efficiency and independence of attention networks have been widely tested with the attention network test (ANT) and its revised versions. However, many studies have failed to find effects of attention network scores (ANSs) and inter-network relationships (INRs). Moreover, the low reliability of ANSs can not meet the demands of theoretical and empirical investigations. Two methodological factors (the inter-trial influence in the event-related design and the inter-network interference in orthogonal contrast) may be responsible for the unreliability of ANT. In this study, we combined the mixed design and non-orthogonal method to explore ANSs and directional INRs. With a small number of trials, we obtained reliable and independent ANSs (split-half reliability of alerting: 0.684; orienting: 0.588; and executive control: 0.616), suggesting an individual and specific attention system. Furthermore, mutual inhibition was observed when two networks were operated simultaneously, indicating a differentiated but integrated attention system. Overall, the reliable and individual specific ANSs and mutually inhibited INRs provide novel insight into the understanding of the developmental, physiological and pathological mechanisms of attention networks, and can benefit future experimental and clinical investigations of attention using ANT. PMID:25997025

  3. Social cohesion through football: a quasi-experimental mixed methods design to evaluate a complex health promotion program

    PubMed Central

    2010-01-01

    The complexity of the Football United program poses challenges for measurement, and requires the study design to be responsive to the dynamic nature of the program and context. Assessment of change is needed at multiple levels, drawing on mixed methods and multidisciplinary approaches in implementation and evaluation. Attention to these challenges has underpinned the design and methods in the Social Cohesion through Football study, which will use a unique and innovative combination of measures that have not been applied together previously in social inclusion/cohesion and sport and social inclusion/cohesion program research. PMID:20920361

  4. Maximizing Data Quality using Mode Switching in Mixed-Device Survey Design: Nonresponse Bias and Models of Demographic Behavior

    PubMed Central

    Axinn, William G.; Gatny, Heather H.; Wagner, James

    2016-01-01

    Conducting survey interviews on the internet has become an attractive method for lowering data collection costs and increasing the frequency of interviewing, especially in longitudinal studies. However, the advantages of the web mode for studies with frequent re-interviews can be offset by the serious disadvantage of low response rates and the potential for nonresponse bias to mislead investigators. Important life events, such as changes in employment status, relationship changes, or moving can cause attrition from longitudinal studies, producing the possibility of attrition bias. The potential extent of such bias in longitudinal web surveys is not well understood. We use data from the Relationship Dynamics and Social Life (RDSL) study to examine the potential for a mixed-device approach with active mode switching to reduce attrition bias. The RDSL design allows panel members to switch modes by integrating telephone interviewing into a longitudinal web survey with the objective of collecting weekly reports. We found that in this design allowing panel members to switch modes kept more participants in the study compared to a web only approach. The characteristics of persons who ever switched modes are different than those who did not – including not only demographic characteristics, but also baseline characteristics related to pregnancy and time-varying characteristics that were collected after the baseline interview. This was true in multivariate models that control for multiple of these dimensions simultaneously. We conclude that mode options and mode switching is important for the success of longitudinal web surveys to maximize participation and minimize attrition. PMID:26865882

  5. A Comparison of the Bootstrap-F, Improved General Approximation, and Brown-Forsythe Multivariate Approaches in a Mixed Repeated Measures Design

    ERIC Educational Resources Information Center

    Seco, Guillermo Vallejo; Izquierdo, Marcelino Cuesta; Garcia, M. Paula Fernandez; Diez, F. Javier Herrero

    2006-01-01

    The authors compare the operating characteristics of the bootstrap-F approach, a direct extension of the work of Berkovits, Hancock, and Nevitt, with Huynh's improved general approximation (IGA) and the Brown-Forsythe (BF) multivariate approach in a mixed repeated measures design when normality and multisample sphericity assumptions do not hold.…

  6. Using Interpretative Phenomenological Analysis in a Mixed Methods Research Design to Explore Music in the Lives of Mature Age Amateur Keyboard Players

    ERIC Educational Resources Information Center

    Taylor, Angela

    2015-01-01

    This article discusses the use of interpretative phenomenological analysis (IPA) in a mixed methods research design with reference to five recent publications about music in the lives of mature age amateur keyboard players. It explores the links between IPA and the data-gathering methods of "Rivers of Musical Experience",…

  7. Benefits of Incentives for Breastfeeding and Smoking cessation in pregnancy (BIBS): a mixed-methods study to inform trial design.

    PubMed Central

    Morgan, Heather; Hoddinott, Pat; Thomson, Gill; Crossland, Nicola; Farrar, Shelley; Yi, Deokhee; Hislop, Jenni; Moran, Victoria Hall; MacLennan, Graeme; Dombrowski, Stephan U; Rothnie, Kieran; Stewart, Fiona; Bauld, Linda; Ludbrook, Anne; Dykes, Fiona; Sniehotta, Falko F; Tappin, David; Campbell, Marion

    2015-01-01

    BACKGROUND Smoking in pregnancy and/or not breastfeeding have considerable negative health outcomes for mother and baby. AIM To understand incentive mechanisms of action for smoking cessation in pregnancy and breastfeeding, develop a taxonomy and identify promising, acceptable and feasible interventions to inform trial design. DESIGN Evidence syntheses, primary qualitative survey, and discrete choice experiment (DCE) research using multidisciplinary, mixed methods. Two mother-and-baby groups in disadvantaged areas collaborated throughout. SETTING UK. PARTICIPANTS The qualitative study included 88 pregnant women/recent mothers/partners, 53 service providers, 24 experts/decision-makers and 63 conference attendees. The surveys included 1144 members of the general public and 497 health professionals. The DCE study included 320 women with a history of smoking. METHODS (1) Evidence syntheses: incentive effectiveness (including meta-analysis and effect size estimates), delivery processes, barriers to and facilitators of smoking cessation in pregnancy and/or breastfeeding, scoping review of incentives for lifestyle behaviours; (2) qualitative research: grounded theory to understand incentive mechanisms of action and a framework approach for trial design; (3) survey: multivariable ordered logit models; (4) DCE: conditional logit regression and the log-likelihood ratio test. RESULTS Out of 1469 smoking cessation and 5408 breastfeeding multicomponent studies identified, 23 smoking cessation and 19 breastfeeding studies were included in the review. Vouchers contingent on biochemically proven smoking cessation in pregnancy were effective, with a relative risk of 2.58 (95% confidence interval 1.63 to 4.07) compared with non-contingent incentives for participation (four studies, 344 participants). Effects continued until 3 months post partum. Inconclusive effects were found for breastfeeding incentives compared with no/smaller incentives (13 studies) but provider commitment

  8. Evaluation and improvement of micro-surfacing mix design method and modelling of asphalt emulsion mastic in terms of filler-emulsion interaction

    NASA Astrophysics Data System (ADS)

    Robati, Masoud

    This Doctorate program focuses on the evaluation and improving the rutting resistance of micro-surfacing mixtures. There are many research problems related to the rutting resistance of micro-surfacing mixtures that still require further research to be solved. The main objective of this Ph.D. program is to experimentally and analytically study and improve rutting resistance of micro-surfacing mixtures. During this Ph.D. program major aspects related to the rutting resistance of micro-surfacing mixtures are investigated and presented as follow: 1) evaluation of a modification of current micro-surfacing mix design procedures: On the basis of this effort, a new mix design procedure is proposed for type III micro-surfacing mixtures as rut-fill materials on the road surface. Unlike the current mix design guidelines and specification, the new mix design is capable of selecting the optimum mix proportions for micro-surfacing mixtures; 2) evaluation of test methods and selection of aggregate grading for type III application of micro-surfacing: Within the term of this study, a new specification for selection of aggregate grading for type III application of micro-surfacing is proposed; 3) evaluation of repeatability and reproducibility of micro-surfacing mixture design tests: In this study, limits for repeatability and reproducibility of micro-surfacing mix design tests are presented; 4) a new conceptual model for filler stiffening effect on asphalt mastic of micro-surfacing: A new model is proposed, which is able to establish limits for minimum and maximum filler concentrations in the micro-surfacing mixture base on only the filler important physical and chemical properties; 5) incorporation of reclaimed asphalt pavement and post-fabrication asphalt shingles in micro-surfacing mixture: The effectiveness of newly developed mix design procedure for micro-surfacing mixtures is further validated using recycled materials. The results present the limits for the use of RAP and RAS

  9. Investigating the effect of mixing ratio on molar mass distributions of synthetic polymers determined by MALDI-TOF mass spectrometry using design of experiments.

    PubMed

    Brandt, Heike; Ehmann, Thomas; Otto, Matthias

    2010-11-01

    It is well known that the mixing ratio affects the molar mass distribution of synthetic polymers determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Surely, the molar mixing ratio determines whether a mass spectrum will be obtained or not. However, depending on the mass range, several effects such as multimer formation occur, which might be a source of errors in molar mass distribution calculations. In this study, the effect of mixing ratio was investigated for several synthetic polymers, including polystyrene (PS), poly(dimethylsiloxane) (PDMS), poly(ethylene glycol) (PEG), and poly(methyl methacrylate) (PMMA) using statistical designs of experiments. The 2(3) full factorial design was found to be suitable in the study of more than 1000 samples. The obtained MALDI mass spectra as well as the ANOVA statistics show that the mixing ratio affects the molar mass distribution. The optimal mixing ratio for a defined synthetic polymer depends on the studied combination (matrix, cationization reagent, solvent). PMID:20685132

  10. Describing the Situational Contexts of Sweetened Product Consumption in a Middle Eastern Canadian Community: Application of a Mixed Method Design

    PubMed Central

    Moubarac, Jean-Claude; Cargo, Margaret; Receveur, Olivier; Daniel, Mark

    2012-01-01

    Little is known about the situational contexts in which individuals consume processed sources of dietary sugars. This study aimed to describe the situational contexts associated with the consumption of sweetened food and drink products in a Catholic Middle Eastern Canadian community. A two-stage exploratory sequential mixed-method design was employed with a rationale of triangulation. In stage 1 (n = 62), items and themes describing the situational contexts of sweetened food and drink product consumption were identified from semi-structured interviews and were used to develop the content for the Situational Context Instrument for Sweetened Product Consumption (SCISPC). Face validity, readability and cultural relevance of the instrument were assessed. In stage 2 (n = 192), a cross-sectional study was conducted and exploratory factor analysis was used to examine the structure of themes that emerged from the qualitative analysis as a means of furthering construct validation. The SCISPC reliability and predictive validity on the daily consumption of sweetened products were also assessed. In stage 1, six themes and 40-items describing the situational contexts of sweetened product consumption emerged from the qualitative analysis and were used to construct the first draft of the SCISPC. In stage 2, factor analysis enabled the clarification and/or expansion of the instrument's initial thematic structure. The revised SCISPC has seven factors and 31 items describing the situational contexts of sweetened product consumption. Initial validation of the instrument indicated it has excellent internal consistency and adequate test-retest reliability. Two factors of the SCISPC had predictive validity for the daily consumption of total sugar from sweetened products (Snacking and Energy demands) while the other factors (Socialization, Indulgence, Constraints, Visual Stimuli and Emotional needs) were rather associated to occasional consumption of these products. PMID:23028597

  11. The German Young Olympic Athletes' Lifestyle and Health Management Study (GOAL Study): design of a mixed-method study

    PubMed Central

    2011-01-01

    Background In order to perform at top levels, elite athletes have to both protect and risk their health at the same time. Adolescent elite athletes have the additional challenge of coping with substantial physical, psychological and social transformations. The contradictory phenomenon of protecting and risking the adolescent athletes' health in sports challenges the development of health promotion and protection strategies. The GOAL Study (German Young Olympic Athletes' Lifestyle and Health Management Study) analyzes the individual and organizational management of health in adolescent elite sports. Methods/design We combine quantitative and qualitative approaches in a mixed-method study. This allows us to gather a broad range of representative information on squad athletes from all Olympic disciplines as well as in-depth information on four selected Olympic disciplines (artistic gymnastics, biathlon, handball and wrestling). Within the quantitative section we attempt to identify the young athletes' health and nutrition behavior, their subjective health state and their lay health representations, health-related social networks, and structures of medical attendance. 1138 national team level athletes born between 1992 and 1995 from 51 Olympic disciplines responded to the questionnaire (response rate: 61,75%). The qualitative section investigates the meaning and relevance of health and nutrition within the athletes' sports specific surroundings, the impact of biographic backgrounds on individual health behavior, and sports specific cultures of health, nutrition and risk. We interviewed 24 athletes and 28 coaching and medical experts, and carried out 14 multi-day participant observations at training sessions and competitions. Conclusions The studies' results will serve as the basis for developing tailored health promotion strategies to be in cooperation with German elite sports associations. PMID:21627777

  12. Equipment Design and Cost Estimation for Small Modular Biomass Systems, Synthesis Gas Cleanup, and Oxygen Separation Equipment; Task 9: Mixed Alcohols From Syngas -- State of Technology

    SciTech Connect

    Nexant Inc.

    2006-05-01

    This deliverable is for Task 9, Mixed Alcohols from Syngas: State of Technology, as part of National Renewable Energy Laboratory (NREL) Award ACO-5-44027, ''Equipment Design and Cost Estimation for Small Modular Biomass Systems, Synthesis Gas Cleanup and Oxygen Separation Equipment''. Task 9 supplements the work previously done by NREL in the mixed alcohols section of the 2003 technical report Preliminary Screening--Technical and Economic Assessment of Synthesis Gas to Fuels and Chemicals with Emphasis on the Potential for Biomass-Derived Syngas.

  13. Hydraulic performance numerical simulation of high specific speed mixed-flow pump based on quasi three-dimensional hydraulic design method

    NASA Astrophysics Data System (ADS)

    Zhang, Y. X.; Su, M.; Hou, H. C.; Song, P. F.

    2013-12-01

    This research adopts the quasi three-dimensional hydraulic design method for the impeller of high specific speed mixed-flow pump to achieve the purpose of verifying the hydraulic design method and improving hydraulic performance. Based on the two families of stream surface theory, the direct problem is completed when the meridional flow field of impeller is obtained by employing iterative calculation to settle the continuity and momentum equation of fluid. The inverse problem is completed by using the meridional flow field calculated in the direct problem. After several iterations of the direct and inverse problem, the shape of impeller and flow field information can be obtained finally when the result of iteration satisfies the convergent criteria. Subsequently the internal flow field of the designed pump are simulated by using RANS equations with RNG k-ε two-equation turbulence model. The static pressure and streamline distributions at the symmetrical cross-section, the vector velocity distribution around blades and the reflux phenomenon are analyzed. The numerical results show that the quasi three-dimensional hydraulic design method for high specific speed mixed-flow pump improves the hydraulic performance and reveal main characteristics of the internal flow of mixed-flow pump as well as provide basis for judging the rationality of the hydraulic design, improvement and optimization of hydraulic model.

  14. Designing for chaos: applications of chaotic advection at the microscale: One contribution of 11 to a Theme 'Transport and mixing at the microscale'

    NASA Astrophysics Data System (ADS)

    Stremler, Mark A.; Haselton, F. R.; Aref, Hassan

    2004-05-01

    Chaotic advection can play an important role in efficient microfluidic mixers. We discuss a design paradigm that exploits chaotic advection and illustrate by two recent examples, namely enhancing gene expression profiling and constructing an in-line microfluidic mixing channel, how application of this paradigm has led to successful micromixers. We suggest that 'designing for chaos', that is, basing practical mixer design on chaotic advection analysis, is a promising approach to adopt in this developing field which otherwise has little to guide it and is constrained by issues of scale and manufacturability.

  15. Is it possible to predict improved diabetes outcomes following diabetes self-management education: a mixed-methods longitudinal design

    PubMed Central

    Huxley, Caroline; Sturt, Jackie; Dale, Jeremy; Walker, Rosie; Caramlau, Isabela; O'Hare, Joseph P; Griffiths, Frances

    2015-01-01

    Objective To predict the diabetes-related outcomes of people undertaking a type 2 Diabetes Self-Management Education (DSME) programme from their baseline data. Design A mixed-methods longitudinal experimental study. 6 practice nurses and 2 clinical academics undertook blind assessments of all baseline and process data to predict clinical, behavioural and psychological outcomes at 6 months post-DSME programme. Setting Primary care. Participants –31 people with type 2 diabetes who had not previously undertaken DSME. Intervention All participants undertook the Diabetes Manual 1:1 self-directed learning 12-week DSME programme supported by practice nurses trained as Diabetes Manual facilitators. Outcome variables Glycated haemoglobin (HbA1c), diabetes knowledge, physical activity, waist circumference, self-efficacy, diabetes distress, anxiety, depression, demographics, change talk and treatment satisfaction. These variables were chosen because they are known to influence self-management behaviour or to have been influenced by a DSME programme in empirical evidence. Results Baseline and 6-month follow-up data were available for 27 participants of which 13 (48%) were male, 22 (82%) white British, mean age 59 years and mean duration of type 2 diabetes 9.1 years. Significant reductions were found in HbA1c t(26)=2.35, p=0.03, and diabetes distress t(26)=2.30, p=0.03, and a significant increase in knowledge t(26)=−2.06, p=0.05 between baseline and 6 months. No significant changes were found in waist circumference, physical activity, anxiety, depression or self-efficacy. Accuracy of predictions varied little between clinical academics and practice nurses but greatly between outcome (0–100%). The median and mode accuracy of predicted outcome was 66.67%. Accuracy of prediction for the key outcome of HbA1c was 44.44%. Diabetes distress had the highest prediction accuracy (81.48%). Conclusions Clinicians in this small study were unable to identify individuals likely

  16. Asymmetric antiproton debuncher: No bad mixing, more good mixing

    SciTech Connect

    Visnjic, V.

    1994-07-01

    An asymmetric lattice for the Fermilab Antiproton Debuncher is designed. The lattice has zero mixing between the pickups and the kickers (bad mixing) while the mixing in the rest of the machine (good mixing) can be varied (even during the operation of the machine) in order to optimize the stochastic cooling. As an example, a lattice with zero bad mixing and twice the good mixing is presented. The betatron cooling rate in this lattice is twice its present value.

  17. Winchester/Camberley Homes New Construction Test House Design, Construction, and Short-Term Testing in a Mixed-Humid Climate

    SciTech Connect

    Mallay, D.; Wiehagen, J.; Wood, A.

    2012-10-01

    The NAHB Research Center partnered with production builder Winchester/Camberley Homes to build a new construction test house in the mixed-humid climate zone of Silver Spring, MD in June 2011. The goal for this house was to improve energy efficiency by 30% over the Building America B10 benchmark through an optimized energy solutions package design that could be constructed on a production basis. This report outlines the features of this house, discusses the energy efficient design, and reports on short-term testing results.

  18. Data Collection Design for Equivalent Groups Equating: Using a Matrix Stratification Framework for Mixed-Format Assessment

    ERIC Educational Resources Information Center

    Mbella, Kinge Keka

    2012-01-01

    Mixed-format assessments are increasingly being used in large scale standardized assessments to measure a continuum of skills ranging from basic recall to higher order thinking skills. These assessments are usually comprised of a combination of (a) multiple-choice items which can be efficiently scored, have stable psychometric properties, and…

  19. Evaluation and performance based mix design of rubber modified mixtures: Laboratory evaluation of asphalt concrete mixtures using waste tires. Final report

    SciTech Connect

    Goulias, D.G.; Ali, A.H.M.

    1997-02-01

    New Jersey Department of Transportation has been investigating the use of rubber modified materials over the last few years with the design and use of dense and gap graded mixtures, and in some cases the incorporation of RAP materials, in selected projects. While the short term field performance of these materials is satisfactory, their long term performance is unknown. These mixtures were designed with the traditional Marshall mixture design method, and thus is was not considered design criteria related to mixture behavior and performance into mixture selection. The main objective of this study is the development of a mixture design methodology for rubber modified materials that considers mixture behavior and performance. In order to achieve this objective researchers conducted a laboratory investigation which was able to evaluate mixture properties that can be related to mixture performance, (in terms of rutting, low temperature cracking, and fatigue), and simulating the actual field loading conditions that the material is being exposed to. The possibility of coupling the traditional Marshall mix design method with parameters related to mixture behavior and performance was investigated since this technique has been used over the years by the agency, and the necessary testing apparatus is available to both the agency and material laboratories. The SHRP SUPERPAVE mix design methodology was reviewed and considered in this study for the development of an integrated performance based design procedure. However, its applicability and use on routine bases was not considered at this time since it requires specific equipment with ongoing evaluation for its repeatability and precision. Finally, for the conduct of this investigation materials and mixtures used by NJDOT in rubber modified paving projects were used.

  20. Development of Design Technology on Thermal-Hydraulic Performance in Tight-Lattice Rod Bundles: III - Numerical Evaluation of Fluid Mixing Phenomena using Advanced Interface-Tracking Method -

    NASA Astrophysics Data System (ADS)

    Yoshida, Hiroyuki; Nagayoshi, Takuji; Takase, Kazuyuki; Akimoto, Hajime

    Thermal-hydraulic design of the current boiling water reactor (BWR) is performed by correlations with empirical results of actual-size tests. However, for the Innovative Water Reactor for Flexible Fuel Cycle (FLWR) core, an actual size test of an embodiment of its design is required to confirm or modify such correlations. Development of a method that enables the thermal-hydraulic design of nuclear reactors without these actual size tests is desired, because these tests take a long time and entail great cost. For this reason we developed an advanced thermal-hydraulic design method for FLWRs using innovative two-phase flow simulation technology. In this study, detailed Two-Phase Flow simulation code using advanced Interface Tracking method: TPFIT is developed to calculate the detailed information of the two-phase flow. We tried to verify the TPFIT code by comparing it with the 2-channel air-water and steam-water mixing experimental results. The predicted result agrees well the observed results and bubble dynamics through the gap and cross flow behavior could be effectively predicted by the TPFIT code, and pressure difference between fluid channels is responsible for the fluid mixing.

  1. Design and Synthesis of Heterocyclic Cations for Specific DNA Recognition: From AT-Rich to Mixed-Base-Pair DNA Sequences

    PubMed Central

    2015-01-01

    The compounds synthesized in this research were designed with the goal of establishing a new paradigm for mixed-base-pair DNA sequence-specific recognition. The design scheme starts with a cell-permeable heterocyclic cation that binds to AT base pair sites in the DNA minor groove. Modifications were introduced in the original compound to include an H-bond accepting group to specifically recognize the G-NH that projects into the minor groove. Therefore, a series of heterocyclic cations substituted with an azabenzimidazole ring has been designed and synthesized for mixed-base-pair DNA recognition. The most successful compound, 12a, had an azabenzimidazole to recognize G and additional modifications for general minor groove interactions. It binds to the DNA site −AAAGTTT– more strongly than the −AAATTT– site without GC and indicates the design success. Structural modifications of 12a generally weakened binding. The interactions of the new compound with a variety of DNA sequences with and without GC base pairs were evaluated by thermal melting analysis, circular dichroism, fluorescence emission spectroscopy, surface plasmon resonance, and molecular modeling. PMID:24422528

  2. Foundations of chaotic mixing.

    PubMed

    Wiggins, Stephen; Ottino, Julio M

    2004-05-15

    The simplest mixing problem corresponds to the mixing of a fluid with itself; this case provides a foundation on which the subject rests. The objective here is to study mixing independently of the mechanisms used to create the motion and review elements of theory focusing mostly on mathematical foundations and minimal models. The flows under consideration will be of two types: two-dimensional (2D) 'blinking flows', or three-dimensional (3D) duct flows. Given that mixing in continuous 3D duct flows depends critically on cross-sectional mixing, and that many microfluidic applications involve continuous flows, we focus on the essential aspects of mixing in 2D flows, as they provide a foundation from which to base our understanding of more complex cases. The baker's transformation is taken as the centrepiece for describing the dynamical systems framework. In particular, a hierarchy of characterizations of mixing exist, Bernoulli --> mixing --> ergodic, ordered according to the quality of mixing (the strongest first). Most importantly for the design process, we show how the so-called linked twist maps function as a minimal picture of mixing, provide a mathematical structure for understanding the type of 2D flows that arise in many micromixers already built, and give conditions guaranteeing the best quality mixing. Extensions of these concepts lead to first-principle-based designs without resorting to lengthy computations. PMID:15306478

  3. A Bayesian adaptive phase 1 design to determine the optimal dose and schedule of an adoptive T-cell therapy in a mixed patient population.

    PubMed

    Quintana, Melanie; Li, Daniel H; Albertson, Tina M; Connor, Jason T

    2016-05-01

    We present a novel Bayesian adaptive phase 1 design to determine the optimal dosing regimen for an adoptive T-cell therapy in a mixed patient population. Our design is motivated by a B-cell Non-Hodgkin Lymphoma trial evaluating multiple dosing regimens within multiple disease subtypes. A utility score is calculated from both safety and efficacy utility functions and used to guide dose-escalation decisions. We pool safety data across disease subtypes and use a single dose-toxicity model while sharing efficacy information between disease subtypes using a hierarchical dose-response model. In addition, an adaptive randomization approach is applied to dynamically assign patients to a regimen when more than one regimen is open for enrollment. We illustrate this study design through a simulated trial example, and we investigate the operating characteristics using simulation studies. PMID:27109037

  4. Mixed-linker approach in designing porous zirconium-based metal-organic frameworks with high hydrogen storage capacity.

    PubMed

    Naeem, Ayesha; Ting, Valeska P; Hintermair, Ulrich; Tian, Mi; Telford, Richard; Halim, Saaiba; Nowell, Harriott; Hołyńska, Małgorzata; Teat, Simon J; Scowen, Ian J; Nayak, Sanjit

    2016-06-14

    Three highly porous Zr(iv)-based metal-organic frameworks, UBMOF-8, UBMOF-9, and UBMOF-31, were synthesized by using 2,2'-diamino-4,4'-stilbenedicarboxylic acid, 4,4'-stilbenedicarboxylic acid, and combination of both linkers, respectively. The mixed-linker UBMOF-31 showed excellent hydrogen uptake of 4.9 wt% and high selectivity for adsorption of CO2 over N2 with high thermal stability and moderate water stability with permanent porosity and surface area of 2552 m(2) g(-1). PMID:27242066

  5. The Obstacles for the Teaching of 8th Grade TR History of Revolution and Kemalism Course According to the Constructivist Approach (An Example of Exploratory Sequential Mixed Method Design)

    ERIC Educational Resources Information Center

    Karademir, Yavuz; Demir, Selcuk Besir

    2015-01-01

    The aim of this study is to ascertain the problems social studies teachers face in the teaching of topics covered in 8th grade TRHRK Course. The study was conducted in line with explanatory sequential mixed method design, which is one of the mixed research method, was used. The study involves three phases. In the first step, exploratory process…

  6. Ligand Symmetry Modulation for Designing Mixed-Ligand Metal-Organic Frameworks: Gas Sorption and Luminescence Sensing Properties.

    PubMed

    Chen, Di-Ming; Tian, Jia-Yue; Liu, Chun-Sen

    2016-09-01

    Herein, we report the synthesis of a new mixed-linker Zn(II)-based metal-organic framework (MOF), {[Zn2(atz)2(bpydb)](DMA)8}n (1) (atz = deprotonated 3-amino-1,2,4-triazole, bpydb = deprotonated 4,4'-(4,4'-bipyridine-2,6-diyl) dibenzoic acid, DMA = N,N-dimethylacetamide), through symmetry modulation of a triazole ligand. The desymmetrized triazole linkers not only bond to the Zn(II) ions to result in a new helical Zn-triazolate chain building unit but also lead to the formation of a highly porous framework (N2 uptake: 617 cm(3)/g; BET surface area: 2393 m(2)/g) with 1D helical channels. The adsorption properties of desolved 1 were investigated by H2, C2H2, CO2, and CH4 sorption experiments, which showed that 1 exhibited high uptake capacity for H2 at 77 K and C2H2 around room temperature. More importantly, the high C2H2 uptake capacity but low binding energy makes this MOF a promising candidate for effective C2H2 capture from C2H2/CO2 and C2H2/CH4 mixed gases with low regenerative energy cost. In addition, 1 shows potential application for the luminescence sensing of small aromatic molecules picric acid (PA) and p-xylene (PX). PMID:27494087

  7. Mixed Ising system designed with integer and half-integer spins: dynamic behaviors under oscillating magnetic field

    NASA Astrophysics Data System (ADS)

    Ertaş, Mehmet

    2016-06-01

    By using the simplified effective-field theory based on Glauber-type stochastic dynamics, namely the dynamic simplified effective-field theory, the dynamic phase diagrams of a two-dimensional mixed spin-1 and spin-3/2 Blume-Capel model are studied in an oscillating external magnetic field. The dynamic equations are derived for two interpenetrating square lattices. The time variations of average magnetizations and the temperature dependence of the dynamic magnetizations are examined, and the dynamic phase diagrams are presented in the two different planes. The dynamic phase diagrams illustrate several ordered phases, the coexistence phase region and critical points as well as a re-entrant behavior depending on the interaction parameters. Finally, the discussion and comparison of the dynamic phase diagrams are given briefly.

  8. The design and testing of a cooling system using mixed solid cryogen for a portable superconducting magnetic energy storage system

    NASA Astrophysics Data System (ADS)

    Kim, K. L.; Song, J. B.; Choi, J. H.; Kim, S. H.; Y Koh, D.; Seong, K. C.; Chang, H. M.; Lee, H. G.

    2010-12-01

    A cooling system that uses solid nitrogen (SN2) as an effective heat capacity enhancer was recently introduced to enhance the thermal stability of the HTS SMES. Since SN2 has a large enthalpy with minimal weight, it enables a portable system by increasing the recooling to recooling time period (RRTP). However, contact between the SN2 and HTS SMES magnet can be broken by repeated thermal disturbances (thermal 'dry-out' phenomena). Therefore, it is essential to improve thermal contact to allow full use of the heat capacity of SN2. This study evaluated the effect of using a mixture containing SN2 and a small amount of a liquid cryogen as a cooling system in the HTS SMES system. The performance of the cooling system was evaluated using the mixed cryogen and compared with that of SN2 alone. In addition, the role of liquid neon (Ne) as a heat exchanger between SN2 and the HTS SMES magnet is discussed.

  9. Designing Mixed Species Tree Plantations for the Tropics: Balancing Ecological Attributes of Species with Landholder Preferences in the Philippines

    PubMed Central

    Nguyen, Huong; Lamb, David; Herbohn, John; Firn, Jennifer

    2014-01-01

    A mixed species reforestation program known as the Rainforestation Farming system was undertaken in the Philippines to develop forms of farm forestry more suitable for smallholders than the simple monocultural plantations commonly used then. In this study, we describe the subsequent changes in stand structure and floristic composition of these plantations in order to learn from the experience and develop improved prescriptions for reforestation systems likely to be attractive to smallholders. We investigated stands aged from 6 to 11 years old on three successive occasions over a 6 year period. We found the number of species originally present in the plots as trees >5 cm dbh decreased from an initial total of 76 species to 65 species at the end of study period. But, at the same time, some new species reached the size class threshold and were recruited into the canopy layer. There was a substantial decline in tree density from an estimated stocking of about 5000 trees per ha at the time of planting to 1380 trees per ha at the time of the first measurement; the density declined by a further 4.9% per year. Changes in composition and stand structure were indicated by a marked shift in the Importance Value Index of species. Over six years, shade-intolerant species became less important and the native shade-tolerant species (often Dipterocarps) increased in importance. Based on how the Rainforestation Farming plantations developed in these early years, we suggest that mixed-species plantations elsewhere in the humid tropics should be around 1000 trees per ha or less, that the proportion of fast growing (and hence early maturing) trees should be about 30–40% of this initial density and that any fruit tree component should only be planted on the plantation margin where more light and space are available for crowns to develop. PMID:24751720

  10. Designing mixed species tree plantations for the tropics: balancing ecological attributes of species with landholder preferences in the Philippines.

    PubMed

    Nguyen, Huong; Lamb, David; Herbohn, John; Firn, Jennifer

    2014-01-01

    A mixed species reforestation program known as the Rainforestation Farming system was undertaken in the Philippines to develop forms of farm forestry more suitable for smallholders than the simple monocultural plantations commonly used then. In this study, we describe the subsequent changes in stand structure and floristic composition of these plantations in order to learn from the experience and develop improved prescriptions for reforestation systems likely to be attractive to smallholders. We investigated stands aged from 6 to 11 years old on three successive occasions over a 6 year period. We found the number of species originally present in the plots as trees >5 cm dbh decreased from an initial total of 76 species to 65 species at the end of study period. But, at the same time, some new species reached the size class threshold and were recruited into the canopy layer. There was a substantial decline in tree density from an estimated stocking of about 5000 trees per ha at the time of planting to 1380 trees per ha at the time of the first measurement; the density declined by a further 4.9% per year. Changes in composition and stand structure were indicated by a marked shift in the Importance Value Index of species. Over six years, shade-intolerant species became less important and the native shade-tolerant species (often Dipterocarps) increased in importance. Based on how the Rainforestation Farming plantations developed in these early years, we suggest that mixed-species plantations elsewhere in the humid tropics should be around 1000 trees per ha or less, that the proportion of fast growing (and hence early maturing) trees should be about 30-40% of this initial density and that any fruit tree component should only be planted on the plantation margin where more light and space are available for crowns to develop. PMID:24751720

  11. Process Design and Economics for Conversion of Lignocellulosic Biomass to Ethanol: Thermochemical Pathway by Indirect Gasification and Mixed Alcohol Synthesis

    SciTech Connect

    Dutta, A.; Talmadge, M.; Hensley, J.; Worley, M.; Dudgeon, D.; Barton, D.; Groendijk, P.; Ferrari, D.; Stears, B.; Searcy, E. M.; Wright, C. T.; Hess, J. R.

    2011-05-01

    This design report describes an up-to-date benchmark thermochemical conversion process that incorporates the latest research from NREL and other sources. Building on a design report published in 2007, NREL and its subcontractor Harris Group Inc. performed a complete review of the process design and economic model for a biomass-to-ethanol process via indirect gasification. The conceptual design presented herein considers the economics of ethanol production, assuming the achievement of internal research targets for 2012 and nth-plant costs and financing. The design features a processing capacity of 2,205 U.S. tons (2,000 metric tonnes) of dry biomass per day and an ethanol yield of 83.8 gallons per dry U.S. ton of feedstock. The ethanol selling price corresponding to this design is $2.05 per gallon in 2007 dollars, assuming a 30-year plant life and 40% equity financing with a 10% internal rate of return and the remaining 60% debt financed at 8% interest. This ethanol selling price corresponds to a gasoline equivalent price of $3.11 per gallon based on the relative volumetric energy contents of ethanol and gasoline.

  12. The effect of passive mixing on pressure drop and oxygen mass fraction using opposing channel flow field design in a Proton Exchange Membrane Fuel Cell

    NASA Astrophysics Data System (ADS)

    Singh, Anant Bir

    This study investigates a flow field with opposing channel design. Previous studies on flow field designs have been focused on improving fuel utilization which often leads to increased pressure drop. This increased pressure drop is typical because standard designs employ either a single flow channel to clear blockages or dead end condition to force the flow through the gas diffusion layer. The disadvantage with these designs is the increased resistance to the flow which requires higher pressure, which becomes a parasitic loss that lowers the system efficiency. For this study the focus was to reduce the pressure drop by providing a less resistive path to the flow. To achieve a less resistive path, the inlet channel was split into two opposing channels. These channels are then recombined only to be split again for the next leg. Therefore, the split channel design should reduce the pressure drop which reduces the parasitic load and ultimately contributes to higher system efficiency. In addition the recombining of the streams at each leg should induce mixing. Having opposing channels should also increase cross flow under the lands to reduce mass transfer loses. The cathode side of the fuel cell is especially sensitive to the mass transport losses since air (oxygen mixed with nitrogen) is used for supplying oxygen unlike the anode side which uses pure hydrogen. To test the hypothesis of having benefits from an opposing channel design, both an experimental and analytical approach was taken. For the experiment, a serpentine flow field and opposing channel flow field plates were compared over several flow rates with compressed air. To test the hypothesis of increased mass transfer, the two flow fields were modeled using a CFD software package, COMSOL. It was found that the opposing channel configuration for high flow rate with multiple entry and exit conditions exhibited significant improvement over the single serpentine channel. Pressure drop was ⅓ less than the

  13. The Mixed Proportion of Business Knowledge Courses and English Language Courses in Business English Curriculum Design in China

    ERIC Educational Resources Information Center

    Zhu, Wenzhong; Liu, Xuyang

    2014-01-01

    Business English in China has evolved into a degree programme from an ESP teaching programme in the past decades. The degree programme of Business English major intends to cultivate multi-skilled talents of foreign language to better satisfy the real needs of society and economy through curriculum design and teaching method innovation activities.…

  14. An Indirect Mixed-Sensitivity Approach to Microgravity Vibration Isolation: The Exploitation of Kinematic Coupling In Frequency-weighting Design-Filter Selections

    NASA Technical Reports Server (NTRS)

    Hampton, R. David; Whorton, Mark S.

    2000-01-01

    Many space-science experiments need an active isolation system to provide them with the requisite microgravity environment. The isolation systems planned for use with the International Space Station have been appropriately modeled using relative position relative velocity, and acceleration states. In theory, frequency-weighting design filters can be applied to these state-space models, in order to develop optimal H2 or mixed-norm controllers with desired stability and performance characteristics. In practice, however, the kinematic coupling among the various states can lead, through the associated frequency-weighting-filters, to conflicting demands on the Riccati design "machinery." The results can be numerically ill-conditioned regulator and estimator Riccati equations and/or reduced intuition in the design process. In addition, kinematic coupling can result in a redundancy in the demands imposed by the frequency weights. Failure properly to account for this type of coupling can lead to an unnecessary increase in controller dimensionality and, in turn, controller complexity. This paper suggests a rational approach to the assignment of frequency-weighting design filters, in the presence of the kinematic coupling among states that exists in the microgravity vibration isolation problem.

  15. An Indirect Mixed-Sensitivity Approach to Microgravity Vibration Isolation: The Exploitation of Kinematic Coupling In Frequency-Weighting Design-Filter Selections

    NASA Technical Reports Server (NTRS)

    Hampton, R. David; Whorton, Mark S.

    2000-01-01

    Many space science experiments need an active isolation system to provide them with the requisite microgravity environment. The isolation systems planned for use with the International Space Station have been appropriately modeled using relative position, relative velocity, and acceleration states. In theory, frequency design filters can be applied to these state-space models, in order to develop optimal H, or mixed-norm controllers with desired stability- and performance characteristics. In practice. however, the kinematic coupling among the various states can lead, through the associated frequency-weighting-filters, to conflicting demands on the Riccati design "machinery." The results can be numerically ill-conditioned regulator and estimator Riccati equations and/or reduced intuition in the design process. In addition, kinematic coupling can result in a redundancy in the demands imposed by the frequency weights. Failure properly to account for this type of coupling can lead to an unnecessary increase in controller dimensionality and, in turn, controller complexity. This paper suggests a rational approach to the assignment of frequency weighting design filters, in the presence of the kinematic coupling among states that exists in the microgravity vibration isolation problem.

  16. Winchester/Camberley Homes New Construction Test House Design, Construction, and Short-Term Testing in a Mixed-Humid Climate

    SciTech Connect

    Mallav, D.; Wiehagen, J.; Wood, A.

    2012-10-01

    The NAHB Research Center partnered with production builder Winchester/Camberley Homes to build a DOE Building America New Construction Test House (NCTH). This single family, detached house, located in the mixed-humid climate zone of Silver Spring, MD, was completed in June 2011. The primary goal for this house was to improve energy efficiency by 30% over the Building America B10 benchmark by developing and implementing an optimized energy solutions package design that could be cost effectively and reliably constructed on a production basis using quality management practices. The intent of this report is to outline the features of this house, discuss the implementation of the energy efficient design, and report on short-term testing results. During the interactive design process of this project, numerous iterations of the framing, air sealing, insulation, and space conditioning systems were evaluated for energy performance, cost, and practical implementation. The final design featured numerous advanced framing techniques, high levels of insulation, and the HVAC system entirely within conditioned space. Short-term testing confirmed a very tight thermal envelope and efficient and effective heating and cooling. In addition, relevant heating, cooling, humidity, energy, and wall cavity moisture data will be collected and presented in a future long-term report.

  17. Design and testing of a boron carbide capsule for spectral-tailoring in mixed-spectrum reactors

    SciTech Connect

    Greenwood, L.R.; Wittman, R.; Pierson, B.P.; Metz, L.A.; Payne, R.; Finn, E.C.; Friese, J.I.

    2011-07-01

    A boron carbide capsule has been designed and used for spectral-tailoring experiments at the TRIGA reactor at Washington State Univ.. Irradiations were conducted in pulsed mode and in continuous operation for up to 4 h. A cadmium cover was used to reduce thermal heating. The neutron spectrum calculated with the Monte Carlo N-particle transport code was found to be in good agreement with reactor dosimetry measurements using the STAY'SL computer code. The neutron spectrum resembles that of a fast reactor. The design of a capsule using boron carbide fully enriched in {sup 10}B shows that it is possible to produce a neutron spectrum similar to that of {sup 235}U fission. (authors)

  18. User-generated quality standards for youth mental health in primary care: a participatory research design using mixed methods

    PubMed Central

    Graham, Tanya; Rose, Diana; Murray, Joanna; Ashworth, Mark; Tylee, André

    2014-01-01

    Objectives To develop user-generated quality standards for young people with mental health problems in primary care using a participatory research model. Methods 50 young people aged 16–25 from community settings and primary care participated in focus groups and interviews about their views and experiences of seeking help for mental health problems in primary care, cofacilitated by young service users and repeated to ensure respondent validation. A second group of young people also aged 16–25 who had sought help for any mental health problem from primary care or secondary care within the last 5 years were trained as focus groups cofacilitators (n=12) developed the quality standards from the qualitative data and participated in four nominal groups (n=28). Results 46 quality standards were developed and ranked by young service users. Agreement was defined as 100% of scores within a two-point region. Group consensus existed for 16 quality standards representing the following aspects of primary care: better advertising and information (three); improved competence through mental health training and skill mix within the practice (two); alternatives to medication (three); improved referral protocol (three); and specific questions and reassurances (five). Alternatives to medication and specific questions and reassurances are aspects of quality which have not been previously reported. Conclusions We have demonstrated the feasibility of using participatory research methods in order to develop user-generated quality standards. The development of patient-generated quality standards may offer a more formal method of incorporating the views of service users into quality improvement initiatives. This method can be adapted for generating quality standards applicable to other patient groups. PMID:24920648

  19. Recognition of mixed-sequence DNA duplexes: Design guidelines for Invaders based on 2′-O-(pyren-1-yl)methyl-RNA monomers

    PubMed Central

    Karmakar, Saswata; Guenther, Dale C.; Hrdlicka*, Patrick J.

    2013-01-01

    Development of agents that recognize mixed-sequence double-stranded DNA (dsDNA) is desirable due to their potential as tools for detection, regulation and modification of genes. Despite progress with triplex-forming oligonucleotides, peptide nucleic acids, polyamides and other approaches, recognition of mixed-sequence dsDNA targets remains challenging. Our laboratory studies Invaders as an alternative approach toward this end. These double-stranded oligonucleotide probes are activated for recognition of mixed-sequence dsDNA through modification with +1 interstrand zippers of intercalator-functionalized nucleotides such as 2′-O-(pyren-1-yl)methyl-RNA monomers and have been recently shown to recognize linear dsDNA, DNA hairpins and chromosomal DNA. In the present work, we systematically study the role that the nucleobase moieties of the 2′-O-(pyren-1-yl)methyl-RNA monomers have on recognition efficiency of Invader duplexes. Results from thermal denaturation, binding energy, and recognition experiments using Invader duplexes with +1 interstrand zippers of the four canonical 2′-O-(pyren-1-yl)methyl-RNA A/C/G/U monomers, show that incorporation of these motifs is a general strategy for activation of probes for recognition of dsDNA. Probe duplexes with interstrand zippers comprised of C and/or U monomers result in the most efficient recognition of dsDNA. The insight gained from this study will drive the design of effective Invaders for applications in molecular biology, nucleic acid diagnostics and biotechnology. PMID:24195730

  20. TElehealth in CHronic disease: mixed-methods study to develop the TECH conceptual model for intervention design and evaluation

    PubMed Central

    Thomas, Clare; O'Cathain, Alicia; Rogers, Anne; Pope, Catherine; Yardley, Lucy; Fahey, Tom; Lewis, Glyn; Large, Shirley; Edwards, Louisa; Rowsell, Alison; Segar, Julia; Brownsell, Simon; Montgomery, Alan A

    2015-01-01

    Objective To develop a conceptual model for effective use of telehealth in the management of chronic health conditions, and to use this to develop and evaluate an intervention for people with two exemplar conditions: raised cardiovascular disease risk and depression. Design The model was based on several strands of evidence: a metareview and realist synthesis of quantitative and qualitative evidence on telehealth for chronic conditions; a qualitative study of patients’ and health professionals’ experience of telehealth; a quantitative survey of patients’ interest in using telehealth; and review of existing models of chronic condition management and evidence-based treatment guidelines. Based on these evidence strands, a model was developed and then refined at a stakeholder workshop. Then a telehealth intervention (‘Healthlines’) was designed by incorporating strategies to address each of the model components. The model also provided a framework for evaluation of this intervention within parallel randomised controlled trials in the two exemplar conditions, and the accompanying process evaluations and economic evaluations. Setting Primary care. Results The TElehealth in CHronic Disease (TECH) model proposes that attention to four components will offer interventions the best chance of success: (1) engagement of patients and health professionals, (2) effective chronic disease management (including subcomponents of self-management, optimisation of treatment, care coordination), (3) partnership between providers and (4) patient, social and health system context. Key intended outcomes are improved health, access to care, patient experience and cost-effective care. Conclusions A conceptual model has been developed based on multiple sources of evidence which articulates how telehealth may best provide benefits for patients with chronic health conditions. It can be used to structure the design and evaluation of telehealth programmes which aim to be acceptable to

  1. Research design for hydrologic response to watershed treatments in the mixed conifer zone of California's Sierra Nevada

    NASA Astrophysics Data System (ADS)

    Battles, J.; Bales, R.; Conklin, M.; Saksa, P.; Martin, S.

    2008-12-01

    Water quantity response to forest management is of great interest in California's Sierra Nevada, owing to shifts in the rain-snow transition elevation associated with climate change, increasing value of hydropower from high-elevation dams, and the re-examination of adaptive management strategies for wildfire mitigation. In 2006 we initiated a multi-disciplinary research program to inform adaptive management for Forest Service lands in the Sierra Nevada. The forest treatment approach is based on disconnected, overlapping fuel treatment patches (forest thinning) to reduce the rate and intensity of fire. As little as 30% of the area in a given catchment will be treated. Controlling for confounding influences is particularly challenging when the experimental unit is a whole landscape and the inferential reference is an entire region. To isolate water and ecosystem impacts related to forest thinning, we are using a Before After Control Impact (BACI) design in conjunction with mechanistic modeling. BACI compensates for the sparse replication (2 sites) and the non- random assignment of the treatments by providing robust longitudinal controls. BACI design defines two treatments, a control and an impact. For modeling fire and wildlife response we chose subdivided the region into two 40-km2 sub-firesheds; within each is a 1-km2 hydrologic study catchment. The control site in this a measure of natural variation rather than a true control. Meta-replication using parallel studies in the Sierra Nevada with different approaches is also an important component and involves a creative combination of data from multiple sources. Rather than statistical comparisons or traditional hypothesis testing, we will measure the support in the data for our a priori expectations using mechanistic models. We are currently evaluating how to extend this research design to private forest lands with a wider range of management options.

  2. Design and testing of a 10B4C capsule for spectral-tailoring in mixed-spectrum reactors

    NASA Astrophysics Data System (ADS)

    Greenwood, L. R.; Wittman, R.; Metz, L. A.; Finn, E. C.; Friese, J. I.

    2014-04-01

    A boron carbide capsule highly enriched in 10B has been designed and used for spectral-tailoring experiments at the TRIGA reactor at Washington State University. New experiments show that enriching the boron to 96% B-10 results in additional absorption of neutrons in the resonance region thereby producing a neutron spectrum that is much closer to a pure 235U fission spectrum than measured previously with a natural boron carbide capsule. A cadmium outer cover was used to reduce thermal alpha heating. The neutron spectrum calculated with MCNP was found to be in very good agreement with measured activation rates from neutron fluence monitors.

  3. Design and Testing of a 10B4C Capsule for Spectral-Tailoring in Mixed-Spectrum Reactors

    SciTech Connect

    Greenwood, Lawrence R.; Wittman, Richard S.; Metz, Lori A.; Finn, Erin C.; Friese, Judah I.

    2014-04-11

    A boron carbide capsule highly enriched in 10B has been designed and used for spectral-tailoring experiments at the TRIGA reactor at Washington State University. New experiments show that enriching the boron to 96% B-10 results in additional absorption of neutrons in the resonance region thereby producing a neutron spectrum that is much closer to a pure 235U fission spectrum. A cadmium outer cover was used to reduce thermal heating. The neutron spectrum calculated with MCNP was found to be in very good agreement with measured activation rates from neutron fluence monitors.

  4. Mesoscopic spatial designs of nano- and microfiber meshes for tissue-engineering matrix and scaffold based on newly devised multilayering and mixing electrospinning techniques.

    PubMed

    Kidoaki, Satoru; Kwon, Il Kuen; Matsuda, Takehisa

    2005-01-01

    To design a mesoscopically ordered structure of the matrices and scaffolds composed of nano- and microscale fiber meshes for artificial and tissue-engineering devices, two new electrospinning techniques are proposed: multilayering electrospinning and mixing electrospinning. First, the following four kinds of component polymers were individually electrospun to determine the conditions for producing stable nano- and microfibers by optimizing the formulation parameters (solvent and polymer concentration) and operation parameters (voltage, air gap, and flow rate) for each polymer: (a) type I collagen, (b) styrenated gelatin (ST-gelatin), (c) segmented polyurethane (SPU), and (d) poly(ethylene oxide). A trilayered electrospun mesh, in which individual fiber meshes (type I collagen, ST-gelatin, and SPU) were deposited layer by layer, was formed by sequential electrospinning; this was clearly visualized by confocal laser scanning microscopy. The mixed electrospun-fiber mesh composed of SPU and PEO was prepared by simultaneous electrospinning on a stainless-steel mandrel with high-speed rotation and traverse movement. A bilayered tubular construct composed of a thick SPU microfiber mesh as an outer layer and a thin type I collagen nanofiber mesh as an inner layer was fabricated as a prototype scaffold of artificial grafts, and visualized by scanning electron microscopy. PMID:15193879

  5. Mixing and compaction temperatures for Superpave mixes

    NASA Astrophysics Data System (ADS)

    Yildirim, Yetkin

    According to Superpave mixture design, gyratory specimens are mixed and compacted at equiviscous binder temperatures corresponding to viscosities of 0.17 and 0.28 Pa.s. respectively. These were the values previously used in the Marshal mix design method to determine optimal mixing and compaction temperatures. In order to estimate the appropriate mixing and compaction temperatures for Superpave mixture design, a temperature-viscosity relationship for the binder needs to be developed (ASTM D 2493, Calculation of Mixing and Compaction Temperatures). The current approach is simple and provides reasonable temperatures for unmodified binders. However, some modified binders have exhibited unreasonably high temperatures for mixing and compaction using this technique. These high temperatures can result in construction problems, damage of asphalt, and production of fumes. Heating asphalt binder to very high temperatures during construction oxidizes the binder and separates the polymer from asphalt binder. It is known that polymer modified asphalt binders have many benefits to the roads, such as; increasing rutting resistance, enhancing low temperature cracking resistance, improving traction, better adhesion and cohesion, elevating tensile strength which are directly related to the service life of the pavement. Therefore, oxidation and separation of the polymer from the asphalt binder results in reduction of the service life. ASTM D 2493 was established for unmodified asphalt binders which are Newtonian fluids at high temperatures. For these materials, viscosity does not depend on shear rate. However, most of the modified asphalt binders exhibit a phenomenon known as pseudoplasticity, where viscosity does depend on shear rate. Thus, at the high shear rates occurring during mixing and compaction, it is not necessary to go to very high temperatures. This research was undertaken to determine the shear rate during compaction such that the effect of this parameter could be

  6. Effect of mixed convection and u-bends on the design of double-pipe heat exchangers

    SciTech Connect

    Abdelmessih, A.N.; Bell, K.J.

    1999-09-01

    For horizontal flow in the laminar flow regimen, the interaction between natural and forced convection and the effect of the secondary flow induced by an unheated U-bend were considered in developing an empirical correlation for the nearly uniform heat flux condition. The correlation predicts the local peripheral average heat transfer coefficient with an absolute average deviation of 9.9%. In this article the mechanisms involved in laminar flow with the presence of a U-bend are explained. The realistic behavior of the correlation is illustrated. Also, a brief discussion of some of the existing correlations for laminar flow is presented. Four cases showing the practicality of using the correlation in the design of horizontal double-pipe heat exchangers are demonstrated.

  7. Modeling and design of lossy waveguide structures for generation of broadband terahertz pulses through difference frequency mixing

    NASA Astrophysics Data System (ADS)

    Vallejo Monsalve, Felipe Antonio

    We present an integral coupled mode theory (CMT), suited to account for high optical losses, to model ultra-broadband terahertz (THz) waveguide emitters (0.1- 20 THz) based on difference frequency generation (DFG) pumped by femtosecond infrared (IR) optical pulses. This integral model works even in the situation where the DFG occurs between several IR and THz modes. We also present a simplified CMT approximation that reproduces the results of the rigorous integral CMT for situations where the THz generation is mediated through single-IR-mode to single-THz-mode interactions. Using the simplified approach we derive a new expression that incorporates loss effects into the coherence length for optical rectification (OR). The expression that we derived for the coherence length can be adapted to describe other second order nonlinear processes such as second harmonic generation. We apply both models to study waveguide emitters whose nonlinear cores are composed of poled guest-host electro-optic (EO) polymer composites, which belong to the 1mm symmetry class and have high nonlinearities. We apply the models to a generic, symmetric, five-layer, metal/cladding/core waveguide structure and provide design strategies for efficient ultra-broadband THz emitters. Two different design strategies are analyzed, one in which the waveguides are designed to have a single-IR-mode and a single-THz-mode guided within the structure, and other where the waveguide is made with a single-THz-mode but admits several IR guided modes. In both strategies the waveguide geometric parameters are optimized to obtain the highest THz conversion efficiencies and broader output bandwidth. The simplified CMT approach is much faster to implement than the integral CMT. Thus, we use the simplified approach to perform a parametric study for different waveguide parameters and pumping wavelengths, in the telecom and short wavelength infrared region, to establish under what conditions the five-layered structure

  8. Atomically mixed Fe-group nanoalloys: catalyst design for the selective electrooxidation of ethylene glycol to oxalic acid.

    PubMed

    Matsumoto, Takeshi; Sadakiyo, Masaaki; Ooi, Mei Lee; Yamamoto, Tomokazu; Matsumura, Syo; Kato, Kenichi; Takeguchi, Tatsuya; Ozawa, Nobuki; Kubo, Momoji; Yamauchi, Miho

    2015-05-01

    We demonstrate electric power generation via the electrooxidation of ethylene glycol (EG) on a series of Fe-group nanoalloy (NA) catalysts in alkaline media. A series of Fe-group binary NA catalysts supported on carbon (FeCo/C, FeNi/C, and CoNi/C) and monometallic analogues (Fe/C, Co/C, and Ni/C) were synthesized. Catalytic activities and product distributions on the prepared Fe-group NA catalysts in the EG electrooxidation were investigated by cyclic voltammetry and chronoamperometry, and compared with those of the previously reported FeCoNi/C, which clarified the contributory factors of the metal components for the EG electrooxidation activity, C2 product selectivity, and catalyst durability. The Co-containing catalysts, such as Co/C, FeCo/C, and FeCoNi/C, exhibit relatively high catalytic activities for EG electrooxidation, whereas the catalytic performances of Ni-containing catalysts are relatively low. However, we found that the inclusion of Ni is a requisite for the prevention of rapid degradation due to surface modification of the catalyst. Notably, FeCoNi/C shows the highest selectivity for oxalic acid production without CO2 generation at 0.4 V vs. the reversible hydrogen electrode (RHE), resulting from the synergetic contribution of all of the component elements. Finally, we performed power generation using the direct EG alkaline fuel cell in the presence of the Fe-group catalysts. The power density obtained on each catalyst directly reflected the catalytic performances elucidated in the electrochemical experiments for the corresponding catalyst. The catalytic roles and alloying effects disclosed herein provide information on the design of highly efficient electrocatalysts containing Fe-group metals. PMID:25848911

  9. Why peer assessment helps to improve clinical performance in undergraduate physical therapy education: a mixed methods design

    PubMed Central

    2014-01-01

    Background Peer Assessment (PA) in health professions education encourages students to develop a critical attitude towards their own and their peers’ performance. We designed a PA task to assess students’ clinical skills (including reasoning, communication, physical examination and treatment skills) in a role-play that simulated physical therapy (PT) practice. Students alternately performed in the role of PT, assessor, and patient. Oral face-to-face feedback was provided as well as written feedback and scores. This study aims to explore the impact of PA on the improvement of clinical performance of undergraduate PT students. Methods The PA task was analyzed and decomposed into task elements. A qualitative approach was used to explore students’ perceptions of the task and the task elements. Semi-structured interviews with second year students were conducted to explore the perceived impact of these task elements on performance improvement. Students were asked to select the elements perceived valuable, to rank them from highest to lowest learning value, and to motivate their choices. Interviews were transcribed verbatim and analyzed, using a phenomenographical approach and following template analysis guidelines. A quantitative approach was used to describe the ranking results. Results Quantitative analyses showed that the perceived impact on learning varied widely. Performing the clinical task in the PT role, was assigned to the first place (1), followed by receiving expert feedback (2), and observing peer performance (3). Receiving peer feedback was not perceived the most powerful task element. Qualitative analyses resulted in three emerging themes: pre-performance, true-performance, and post-performance triggers for improvement. Each theme contained three categories: learning activities, outcomes, and conditions for learning. Intended learning activities were reported, such as transferring prior learning to a new application context and unintended learning

  10. Microfluidic Mixing: A Review

    PubMed Central

    Lee, Chia-Yen; Chang, Chin-Lung; Wang, Yao-Nan; Fu, Lung-Ming

    2011-01-01

    The aim of microfluidic mixing is to achieve a thorough and rapid mixing of multiple samples in microscale devices. In such devices, sample mixing is essentially achieved by enhancing the diffusion effect between the different species flows. Broadly speaking, microfluidic mixing schemes can be categorized as either “active”, where an external energy force is applied to perturb the sample species, or “passive”, where the contact area and contact time of the species samples are increased through specially-designed microchannel configurations. Many mixers have been proposed to facilitate this task over the past 10 years. Accordingly, this paper commences by providing a high level overview of the field of microfluidic mixing devices before describing some of the more significant proposals for active and passive mixers. PMID:21686184

  11. Multi-objective Mixed Integer Programming approach for facility layout design by considering closeness ratings, material handling, and re-layout cost

    NASA Astrophysics Data System (ADS)

    Purnomo, Muhammad Ridwan Andi; Satrio Wiwoho, Yoga

    2016-01-01

    Facility layout becomes one of production system factor that should be managed well, as it is designated for the location of production. In managing the layout, designing the layout by considering the optimal layout condition that supports the work condition is essential. One of the method for facility layout optimization is Mixed Integer Programming (MIP). In this study, the MIP is solved using Lingo 9.0 software and considering quantitative and qualitative objectives to be achieved simultaneously: minimizing material handling cost, maximizing closeness rating, and minimizing re-layout cost. The research took place in Rekayasa Wangdi as a make to order company, focusing on the making of concrete brick dough stirring machine with 10 departments involved. The result shows an improvement in the new layout for 333,72 points of objective value compared with the initial layout. As the conclusion, the proposed MIP is proven to be used to model facility layout problem under multi objective consideration for a more realistic look.

  12. SNP Design from 454 Sequencing of Podosphaera plantaginis Transcriptome Reveals a Genetically Diverse Pathogen Metapopulation with High Levels of Mixed-Genotype Infection

    PubMed Central

    Tollenaere, Charlotte; Susi, Hanna; Nokso-Koivisto, Jussi; Koskinen, Patrik; Tack, Ayco; Auvinen, Petri; Paulin, Lars; Frilander, Mikko J.; Lehtonen, Rainer; Laine, Anna-Liisa

    2012-01-01

    Background Molecular tools may greatly improve our understanding of pathogen evolution and epidemiology but technical constraints have hindered the development of genetic resources for parasites compared to free-living organisms. This study aims at developing molecular tools for Podosphaera plantaginis, an obligate fungal pathogen of Plantago lanceolata. This interaction has been intensively studied in the Åland archipelago of Finland with epidemiological data collected from over 4,000 host populations annually since year 2001. Principal Findings A cDNA library of a pooled sample of fungal conidia was sequenced on the 454 GS-FLX platform. Over 549,411 reads were obtained and annotated into 45,245 contigs. Annotation data was acquired for 65.2% of the assembled sequences. The transcriptome assembly was screened for SNP loci, as well as for functionally important genes (mating-type genes and potential effector proteins). A genotyping assay of 27 SNP loci was designed and tested on 380 infected leaf samples from 80 populations within the Åland archipelago. With this panel we identified 85 multilocus genotypes (MLG) with uneven frequencies across the pathogen metapopulation. Approximately half of the sampled populations contain polymorphism. Our genotyping protocol revealed mixed-genotype infection within a single host leaf to be common. Mixed infection has been proposed as one of the main drivers of pathogen evolution, and hence may be an important process in this pathosystem. Significance The developed SNP panel offers exciting research perspectives for future studies in this well-characterized pathosystem. Also, the transcriptome provides an invaluable novel genomic resource for powdery mildews, which cause significant yield losses on commercially important crops annually. Furthermore, the features that render genetic studies in this system a challenge are shared with the majority of obligate parasitic species, and hence our results provide methodological insights

  13. Pre-Test CFD for the Design and Execution of the Enhanced Injection and Mixing Project at NASA Langley Research Center

    NASA Technical Reports Server (NTRS)

    Drozda, Tomasz G.; Axdahl, Erik L.; Cabell, Karen F.

    2014-01-01

    With the increasing costs of physics experiments and simultaneous increase in availability and maturity of computational tools it is not surprising that computational fluid dynamics (CFD) is playing an increasingly important role, not only in post-test investigations, but also in the early stages of experimental planning. This paper describes a CFD-based effort executed in close collaboration between computational fluid dynamicists and experimentalists to develop a virtual experiment during the early planning stages of the Enhanced Injection and Mixing project at NASA Langley Research Center. This projects aims to investigate supersonic combustion ramjet (scramjet) fuel injection and mixing physics, improve the understanding of underlying physical processes, and develop enhancement strategies and functional relationships relevant to flight Mach numbers greater than 8. The purpose of the virtual experiment was to provide flow field data to aid in the design of the experimental apparatus and the in-stream rake probes, to verify the nonintrusive measurements based on NO-PLIF, and to perform pre-test analysis of quantities obtainable from the experiment and CFD. The approach also allowed for the joint team to develop common data processing and analysis tools, and to test research ideas. The virtual experiment consisted of a series of Reynolds-averaged simulations (RAS). These simulations included the facility nozzle, the experimental apparatus with a baseline strut injector, and the test cabin. Pure helium and helium-air mixtures were used to determine the efficacy of different inert gases to model hydrogen injection. The results of the simulations were analyzed by computing mixing efficiency, total pressure recovery, and stream thrust potential. As the experimental effort progresses, the simulation results will be compared with the experimental data to calibrate the modeling constants present in the CFD and validate simulation fidelity. CFD will also be used to

  14. Atomization and Mixing Study

    NASA Technical Reports Server (NTRS)

    Ferrenberg, A.; Hunt, K.; Duesberg, J.

    1985-01-01

    The primary objective was the obtainment of atomization and mixing performance data for a variety of typical liquid oxygen/hydrocarbon injector element designs. Such data are required to establish injector design criteria and to provide critical inputs to liquid rocket engine combustor performance and stability analysis, and computational codes and methods. Deficiencies and problems with the atomization test equipment were identified, and action initiated to resolve them. Test results of the gas/liquid mixing tests indicated that an assessment of test methods was required. A series of 71 liquid/liquid tests were performed.

  15. Thermal and fluid mixing in a 1/2-scale test facility. Volume 1. Facility and test design report. Final report

    SciTech Connect

    Dolan, F.X.; Valenzuela, J.A.

    1985-07-01

    This report describes the test facility and program designed to measure fluid mixing and heat transfer in a 1/2-scale model of the cold leg downcomer and lower plenum of a pressurized water reactor under conditions of interest to the issue of pressurized thermal shock. Several cold leg assemblies are modeled and the downcomer arrangement can be altered to match vendor-specific configurations. The facility can be operated to model flow rates based on Froude number of the injected flow in the cold leg and with steady or transient inlet boundary conditions. Extensive instrumentation is provided to measure flow rates, temperatures and pressure at the facility boundaries and for detailed measurements of temperature, velocity and heat transfer data in the cold leg and downcomer models. The test data are monitored and recorded by a computer data acquisition system that is also used for post-test data reduction and plotting. The planned test matrix includes 75 tests with variations in cold leg and downcomer geometries, loop and HPI flow rates, cold leg Froude number and loop to HPI density difference. Test results will be reported in a series of quick look and final report.

  16. Design, Development, and Optimization of Sterculia Gum-Based Tablet Coated with Chitosan/Eudragit RLPO Mixed Blend Polymers for Possible Colonic Drug Delivery

    PubMed Central

    Nath, Bipul; Nath, Lila Kanta

    2013-01-01

    The purpose of this study is to explore the possible applicability of Sterculia urens gum as a novel carrier for colonic delivery system of a sparingly soluble drug, azathioprine. The study involves designing a microflora triggered colon-targeted drug delivery system (MCDDS) which consists of a central polysaccharide core and is coated to different film thicknesses with blends of chitosan/Eudragit RLPO, and is overcoated with Eudragit L00 to provide acid and intestinal resistance. The microflora degradation property of gum was investigated in rat caecal medium. Drug release study in simulated colonic fluid revealed that swelling force of the gum could concurrently drive the drug out of the polysaccharide core due to the rupture of the chitosan/Eudargit coating in microflora-activated environment. Chitosan in the mixed film coat was found to be degraded by enzymatic action of the microflora in the colon. Release kinetic data revealed that the optimized MCDDS was fitted well into first-order model, and apparent lag time was found to be 6 hours, followed by Higuchi release kinetics. In vivo study in rabbits shows delayed Tmax, prolonged absorption time, decreased Cmax, and absorption rate constant (Ka), indicating a reduced systemic toxicity of the drug as compared to other dosage forms. PMID:26555985

  17. Mixed Dementia

    MedlinePlus

    ... bodies , What Is Alzheimer's? NIA-Funded Memory & Aging Project Reveals Mixed Dementia Common Data from the first ... disease. For example, in the Memory and Aging Project study involving long-term cognitive assessments followed by ...

  18. Examining the pathways for young people with drug and alcohol dependence: a mixed-method design to examine the role of a treatment programme

    PubMed Central

    Nathan, Sally; Rawstorne, Patrick; Hayen, Andrew; Bryant, Joanne; Baldry, Eileen; Ferry, Mark; Williams, Megan; Shanahan, Marian; Jayasinha, Ranmalie

    2016-01-01

    Introduction Young people with drug and alcohol problems are likely to have poorer health and other psychosocial outcomes than other young people. Residential treatment programmes have been shown to lead to improved health and related outcomes for young people in the short term. There is very little robust research showing longer term outcomes or benefits of such programmes. This paper describes an innovative protocol to examine the longer term outcomes and experiences of young people referred to a residential life management and treatment programme in Australia designed to address alcohol and drug issues in a holistic manner. Methods and analysis This is a mixed-methods study that will retrospectively and prospectively examine young people's pathways into and out of a residential life management programme. The study involves 3 components: (1) retrospective data linkage of programme data to health and criminal justice administrative data sets, (2) prospective cohort (using existing programme baseline data and a follow-up survey) and (3) qualitative in-depth interviews with a subsample of the prospective cohort. The study will compare findings among young people who are referred and (a) stay 30 days or more in the programme (including those who go on to continuing care and those who do not); (b) start, but stay fewer than 30 days in the programme; (c) are assessed, but do not start the programme. Ethics and dissemination Ethics approval has been sought from several ethics committees including a university ethics committee, state health departments and an Aboriginal-specific ethics committee. The results of the study will be published in peer-reviewed journals, presented at research conferences, disseminated via a report for the general public and through Facebook communications. The study will inform the field more broadly about the value of different methods in evaluating programmes and examining the pathways and trajectories of vulnerable young people. PMID

  19. Inference of Mix from Experimental Data and Theoretical Mix Models

    SciTech Connect

    Welser-Sherrill, L.; Haynes, D. A.; Cooley, J. H.; Mancini, R. C.; Haan, S. W.; Golovkin, I. E.

    2007-08-02

    The mixing between fuel and shell materials in Inertial Confinement Fusion implosion cores is a topic of great interest. Mixing due to hydrodynamic instabilities can affect implosion dynamics and could also go so far as to prevent ignition. We have demonstrated that it is possible to extract information on mixing directly from experimental data using spectroscopic arguments. In order to compare this data-driven analysis to a theoretical framework, two independent mix models, Youngs' phenomenological model and the Haan saturation model, have been implemented in conjunction with a series of clean hydrodynamic simulations that model the experiments. The first tests of these methods were carried out based on a set of indirect drive implosions at the OMEGA laser. We now focus on direct drive experiments, and endeavor to approach the problem from another perspective. In the current work, we use Youngs' and Haan's mix models in conjunction with hydrodynamic simulations in order to design experimental platforms that exhibit measurably different levels of mix. Once the experiments are completed based on these designs, the results of a data-driven mix analysis will be compared to the levels of mix predicted by the simulations. In this way, we aim to increase our confidence in the methods used to extract mixing information from the experimental data, as well as to study sensitivities and the range of validity of the mix models.

  20. Evaluating the Usability and Perceived Impact of an Electronic Medical Record Toolkit for Atrial Fibrillation Management in Primary Care: A Mixed-Methods Study Incorporating Human Factors Design

    PubMed Central

    Leblanc, Kori; Valentinis, Alissia; Kavanagh, Doug; Zahr, Nina; Ivers, Noah M

    2016-01-01

    Background Atrial fibrillation (AF) is a common and preventable cause of stroke. Barriers to reducing stroke risk through appropriate prescribing have been identified at the system, provider, and patient levels. To ensure a multifaceted initiative to address these barriers is effective, it is essential to incorporate user-centered design to ensure all intervention components are optimized for users. Objective To test the usability of an electronic medical record (EMR) toolkit for AF in primary care with the goal of further refining the intervention to meet the needs of primary care clinicians. Methods An EMR-based toolkit for AF was created and optimized through usability testing and iterative redesign incorporating a human factors approach. A mixed-methods pilot study consisting of observations, semi-structured interviews, and surveys was conducted to examine usability and perceived impact on patient care and workflow. Results A total of 14 clinicians (13 family physicians and 1 nurse practitioner) participated in the study. Nine iterations of the toolkit were created in response to feedback from clinicians and the research team; interface-related changes were made, additional AF-related resources were added, and functionality issues were fixed to make the toolkit more effective. After improvements were made, clinicians expressed that the toolkit improved accessibility to AF-related information and resources, served as a reminder for guideline-concordant AF management, and was easy to use. Most clinicians intended to continue using the toolkit for patient care. With respect to impact on care, clinicians believed the toolkit increased the thoroughness of their assessments for patients with AF and improved the quality of AF-related care received by their patients. Conclusions The positive feedback surrounding the EMR toolkit for AF and its perceived impact on patient care can be attributed to the adoption of a user-centered design that merged clinically important

  1. Mixed-Methods Research Methodologies

    ERIC Educational Resources Information Center

    Terrell, Steven R.

    2012-01-01

    Mixed-Method studies have emerged from the paradigm wars between qualitative and quantitative research approaches to become a widely used mode of inquiry. Depending on choices made across four dimensions, mixed-methods can provide an investigator with many design choices which involve a range of sequential and concurrent strategies. Defining…

  2. Understanding the link between leadership style, employee satisfaction, and absenteeism: a mixed methods design study in a mental health care institution

    PubMed Central

    Elshout, Rachelle; Scherp, Evelien; van der Feltz-Cornelis, Christina M

    2013-01-01

    Background In service oriented industries, such as the health care sector, leadership styles have been suggested to influence employee satisfaction as well as outcomes in terms of service delivery. However, how this influence comes into effect has not been widely explored. Absenteeism may be a factor in this association; however, no studies are available on this subject in the mental health care setting, although this setting has been under a lot of strain lately to provide their services at lower costs. This may have an impact on employers, employees, and the delivery of services, and absenteeism due to illness of employees tends to already be rather high in this particular industry. This study explores the association between leadership style, absenteeism, and employee satisfaction in a stressful work environment, namely a post-merger specialty mental health care institution (MHCI) in a country where MHCIs are under governmental pressure to lower their costs (The Netherlands). Methods We used a mixed methods design with quantitative as well as qualitative research to explore the association between leadership style, sickness absence rates, and employee satisfaction levels in a specialty MHCI. In depth, semi-structured interviews were conducted with ten key informants and triangulated with documented research and a contrast between four departments provided by a factor analysis of the data from the employee satisfaction surveys and sickness rates. Data was analyzed thematically by means of coding and subsequent exploration of patterns. Data analysis was facilitated by qualitative analysis software. Results Quantitative analysis revealed sickness rates of 5.7% in 2010, which is slightly higher than the 5.2% average national sickness rate in The Netherlands in 2010. A general pattern of association between low employee satisfaction, high sickness rates, and transactional leadership style in contrast to transformational leadership style was established. The

  3. [Mixed marriages].

    PubMed

    Harmsen, C N

    1998-08-01

    The author examines the extent and characteristics of mixed marriages in the Netherlands. "Nine out of ten married persons born in Turkey or Morocco have a partner who was born in the same country. The majority of married Surinamese also have a partner originating from the same country. Those who spend (a part of) their youth in Indonesia (the former Dutch East Indies), on the other hand, are mostly married to someone born in the Netherlands." (EXCERPT) PMID:12294179

  4. Mixed results with mixed disulfides.

    PubMed

    Brigelius-Flohé, Regina

    2016-04-01

    A period of research with Helmut Sies in the 1980s is recalled. Our experiments aimed at an in-depth understanding of metabolic changes due to oxidative challenges under near-physiological conditions, i.e. perfused organs. A major focus were alterations of the glutathione and the NADPH/NADP(+) system by different kinds of oxidants, in particular formation of glutathione mixed disulfides with proteins. To analyze mixed disulfides, a test was adapted which is widely used until today. The observations in perfused rat livers let us believe that glutathione-6-phosphate dehydrogenase (G6PDH), i.a. might be activated by glutathionylation. Although we did not succeed to verify this hypothesis for the special case of G6PDH, the regulation of enzyme/protein activities by glutathionylation today is an accepted posttranslational mechanism in redox biology in general. Our early experimental approaches are discussed in the context of present knowledge. PMID:27095221

  5. Using Multimedia Records To Support Mixed-Method Evaluation.

    ERIC Educational Resources Information Center

    Bennington, Tammy L.; Jones, Michael L. W.; Gay, Geri

    1999-01-01

    Explores how multimedia records, especially digital video, can enhance the analysis and presentation of research findings and can facilitate mixed-method research designs. Draws analogies between mixing methods and mixing technologies. (Author/SLD)

  6. The Constructivist Approach? I Have Heard about It but I Have Never Seen It "An Example of Exploratory Sequential Mixed Design Study"

    ERIC Educational Resources Information Center

    Polat, Ahmet; Dogan, Soner; Demir, Selçuk Besir

    2016-01-01

    The present study was undertaken to investigate the quality of education based on the views of the students attending social studies education departments at the Faculties of Education and to determine the existing problems and present suggestions for their solutions. The study was conducted according to exploratory sequential mixed method. In…

  7. The Constructivist Approach? I Have Heard about It but I Have Never Seen It: "An Example of Exploratory Sequential Mixed Design Study"

    ERIC Educational Resources Information Center

    Polat, Ahmet; Dogan, Soner; Demir, Selçuk Besir

    2016-01-01

    The present study was undertaken to investigate the quality of education based on the views of the students attending social studies education departments at the Faculties of Education and to determine the existing problems and present suggestions for their solutions. The study was conducted according to exploratory sequential mixed method. In…

  8. Bottom-up design and synthesis of limit size lipid nanoparticle systems with aqueous and triglyceride cores using millisecond microfluidic mixing.

    PubMed

    Zhigaltsev, Igor V; Belliveau, Nathan; Hafez, Ismail; Leung, Alex K K; Huft, Jens; Hansen, Carl; Cullis, Pieter R

    2012-02-21

    Limit size systems are defined as the smallest achievable aggregates compatible with the packing of the molecular constituents in a defined and energetically stable structure. Here we report the use of rapid microfluidic mixing for the controlled synthesis of two types of limit size lipid nanoparticle (LNP) systems, having either polar or nonpolar cores. Specifically, limit size LNP consisting of 1-palmitoyl, 2-oleoyl phosphatidylcholine (POPC), cholesterol and the triglyceride triolein were synthesized by mixing a stream of ethanol containing dissolved lipid with an aqueous stream, employing a staggered herringbone micromixer. Millisecond mixing of aqueous and ethanol streams at high flow rate ratios (FRR) was used to rapidly increase the polarity of the medium, driving bottom-up synthesis of limit size LNP systems by spontaneous assembly. For POPC/triolein systems the limit size structures consisted of a hydrophobic core of triolein surrounded by a monolayer of POPC where the diameter could be rationally engineered over the range 20-80 nm by varying the POPC/triolein ratio. In the case of POPC and POPC/cholesterol (55/45; mol/mol) the limit size systems achieved were bilayer vesicles of approximately 20 and 40 nm diameter, respectively. We further show that doxorubicin, a representative weak base drug, can be efficiently loaded and retained in limit size POPC LNP, establishing potential utility as drug delivery systems. To our knowledge this is the first report of stable triglyceride emulsions in the 20-50 nm size range, and the first time vesicular systems in the 20-50 nm size range have been generated by a scalable manufacturing method. These results establish microfluidic mixing as a powerful and general approach to access novel LNP systems, with both polar or nonpolar core structures, in the sub-100 nm size range. PMID:22268499

  9. MIXING PHENOMENA IN INDUSTRIAL FUME AFTERBURNER SYSTEMS

    EPA Science Inventory

    The report reviews the physical-mixing phenomena involved in the reactions that occur in afterburners or fume incinerators. It considers mixing in after-burners from three points of view. It first covers typical designs of afterburner components that are involved in the mixing ph...

  10. Toward rational design of protein detergent complexes: determinants of mixed micelles that are critical for the in vitro stabilization of a G-protein coupled receptor.

    PubMed

    O'Malley, Michelle A; Helgeson, Matthew E; Wagner, Norman J; Robinson, Anne S

    2011-10-19

    Although reconstitution of membrane proteins within protein detergent complexes is often used to enable their structural or biophysical characterization, it is unclear how one should rationally choose the appropriate micellar environment to preserve native protein folding. Here, we investigated model mixed micelles consisting of a nonionic glucosylated alkane surfactant from the maltoside and thiomaltoside families, bile salt surfactant, and the steryl derivative cholesteryl hemisuccinate. We correlated several key attributes of these micelles with the in vitro ligand-binding activity of hA(2)aR in these systems. Through small-angle neutron scattering and radioligand-binding analysis, we found several key aspects of mixed micellar systems that preserve the activity of hA(2)aR, including a critical amount of cholesteryl hemisuccinate per micelle, and an optimal hydrophobic thickness of the micelle that is analogous to the thickness of native mammalian bilayers. These features are closely linked to the headgroup chemistry of the surfactant and the hydrocarbon chain length, which influence both the morphology and composition of resulting micelles. This study should serve as a general guide for selecting the appropriate mixed surfactant systems to stabilize membrane proteins for biophysical analysis. PMID:22004748

  11. Design of an impact evaluation using a mixed methods model – an explanatory assessment of the effects of results-based financing mechanisms on maternal healthcare services in Malawi

    PubMed Central

    2014-01-01

    Background In this article we present a study design to evaluate the causal impact of providing supply-side performance-based financing incentives in combination with a demand-side cash transfer component on equitable access to and quality of maternal and neonatal healthcare services. This intervention is introduced to selected emergency obstetric care facilities and catchment area populations in four districts in Malawi. We here describe and discuss our study protocol with regard to the research aims, the local implementation context, and our rationale for selecting a mixed methods explanatory design with a quasi-experimental quantitative component. Design The quantitative research component consists of a controlled pre- and post-test design with multiple post-test measurements. This allows us to quantitatively measure ‘equitable access to healthcare services’ at the community level and ‘healthcare quality’ at the health facility level. Guided by a theoretical framework of causal relationships, we determined a number of input, process, and output indicators to evaluate both intended and unintended effects of the intervention. Overall causal impact estimates will result from a difference-in-difference analysis comparing selected indicators across intervention and control facilities/catchment populations over time. To further explain heterogeneity of quantitatively observed effects and to understand the experiential dimensions of financial incentives on clients and providers, we designed a qualitative component in line with the overall explanatory mixed methods approach. This component consists of in-depth interviews and focus group discussions with providers, service user, non-users, and policy stakeholders. In this explanatory design comprehensive understanding of expected and unexpected effects of the intervention on both access and quality will emerge through careful triangulation at two levels: across multiple quantitative elements and across

  12. [Mixed approaches in nursing science].

    PubMed

    Dupin, Cécile-Marie

    2015-06-01

    Mixed methods research uses methodologies from quantitative and qualitative approaches in a single project. Thanks to the integration of the results of the studies, complex phenomena can be explored. The designs are based on specific criteria of rigour. Strategies exist for the design of this type of research. PMID:26146330

  13. Design

    ERIC Educational Resources Information Center

    Buchanan, Richard; Cross, Nigel; Durling, David; Nelson, Harold; Owen, Charles; Valtonen, Anna; Boling, Elizabeth; Gibbons, Andrew; Visscher-Voerman, Irene

    2013-01-01

    Scholars representing the field of design were asked to identify what they considered to be the most exciting and imaginative work currently being done in their field, as well as how that work might change our understanding. The scholars included Richard Buchanan, Nigel Cross, David Durling, Harold Nelson, Charles Owen, and Anna Valtonen. Scholars…

  14. 50-200 GHz Silicon-Germanium Heterojunction Bipolar Transistor BICMOS Technology and a Computer-Aided Design Environment for 2--50+ GHz Very Large-Scale Integration Mixed-Signal ICs

    NASA Astrophysics Data System (ADS)

    Subbanna, Seshadri; Freeman, Gregory; Rieh, Jae-Sung; Ahlgren, David; Stein, Kenneth; Dickey, Carl; Mecke, James; Bacon, Peter; Groves, Robert; Meghelli, Mounir; Soyuer, Mehmet; Jagannathan, Basanth; Schonenberg, Kathryn; Jeng, Shwu-Jen; Joseph, Alvin; Coolbaugh, Douglas; Volant, Richard; Greenberg, David; Chen, Huajie; Brelsford, Kevin; Harame, David; Dunn, James; Larson, Lawrence; Herman, Dean; Meyerson, Bernard

    2002-02-01

    Silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) BICMOS technology is a stable, ultra-high performance, semiconductor technology capable of supporting mixed-signal, very large-scale integration (VLSI) circuit designs for a variety of emerging communication applications. This technology is supported by a computer-aided design (CAD) system that supports a variety of high-performance circuit designs, mixed-signal circuit block reuse, and the ability to accurately predict circuit performance at the highest frequencies. This paper summarizes the progress this technology has made in recent years in moving from the research laboratory to a production environment. We also specifically address performance, operating voltage, reliability and integration considerations for using 100--200 GHz SiGe HBTs in high-speed (10--40 Gb/s) network ICs, an application space previously only addressed by InP technology. All indications are that SiGe will be very successful at addressing this new application space, and all facets of the networking IC market.

  15. Perspectives On Dilution Jet Mixing

    NASA Technical Reports Server (NTRS)

    Holdeman, J. D.; Srinivasan, R.

    1990-01-01

    NASA recently completed program of measurements and modeling of mixing of transverse jets with ducted crossflow, motivated by need to design or tailor temperature pattern at combustor exit in gas turbine engines. Objectives of program to identify dominant physical mechanisms governing mixing, extend empirical models to provide near-term predictive capability, and compare numerical code calculations with data to guide future analysis improvement efforts.

  16. Nanofluidic mixing via hybrid surface

    SciTech Connect

    Ye, Ziran; Li, Shunbo; Zhou, Bingpu; Hui, Yu Sanna; Shen, Rong; Wen, Weijia

    2014-10-20

    We report the design and fabrication of the nanofluidic mixer comprising hybrid hydrophobic/hydrophilic micro-patterns on the top and bottom walls of the nanochannel. The unique feature of such mixer is that, without any geometric structure inside the nanochannel, the mixing can be realized solely by the hybrid surfaces. Besides, the mixing length in nanomixer has been significantly shortened comparing to micromixer. We attribute the mixing achievement to be caused by the convection and chaotic flows of two fluids along the hybrid surface due to the large surface-to-volume ratio of the nanochannel.

  17. Mixed methods research for the novice researcher.

    PubMed

    Giddings, Lynne S; Grant, Barbara M

    2006-10-01

    Mixed methods research is becoming increasingly popular in the health and social science disciplines. The aim of this article is to give an overview of the varieties of mixed methods designs. We begin by situating mixed methods research in the context of a paradigmatic framework which assists a researcher in making decisions concerning the design of their study. Although the most commonly used mixed methods designs are underpinned by positivist/postpositivist assumptions, the combination of qualitative and quantitative methods can be used within any research paradigm. PMID:17083315

  18. Program to design, fabricate, test, and deliver a thermal control-mixing control device for the George C. Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    Thurston, T. S.; Larson, R. H.

    1976-01-01

    The development and testing of a temperature sensor and pulse duration modulation (PDM) diverter valve for a thermal control-mixing control device are described. The temperature sensor selected for use uses a fluidic pin amplifier in conjunction with an expansion device. This device can sense changes of less than 0.25 F with greater than 15:1 signal to noise ratio when operating with a typical Freon pump supplied pressure. The pressure sensitivity of the sensor is approximately 0.0019 F/kPa. The valve which was selected was tested and performed with 100% flow diversion. In addition, the valve operates with a flow efficiency of at least 95%, with the possibility of attaining 100% if the vent flow of the PDM can be channeled through the last stage of the diverter valve. A temperature sensor which utilized an orifice bridge circuit and proportional-vortex combination mixing valve were also evaluated, but the concepts were rejected due to various problems.

  19. Rational chemical design of the next generation of molecular imaging probes based on physics and biology: mixing modalities, colors and signals

    PubMed Central

    Longmire, Michelle R.; Ogawa, Mikako; Choyke, Peter L.

    2012-01-01

    In recent years, numerous in vivo molecular imaging probes have been developed. As a consequence, much has been published on the design and synthesis of molecular imaging probes focusing on each modality, each type of material, or each target disease. More recently, second generation molecular imaging probes with unique, multi-functional, or multiplexed characteristics have been designed. This critical review focuses on (i) molecular imaging using combinations of modalities and signals that employ the full range of the electromagnetic spectra, (ii) optimized chemical design of molecular imaging probes for in vivo kinetics based on biology and physiology across a range of physical sizes, (iii) practical examples of second generation molecular imaging probes designed to extract complementary data from targets using multiple modalities, color, and comprehensive signals (277 references). PMID:21607237

  20. In Silico Design of Highly Selective Mo-V-Te-Nb-O Mixed Metal Oxide Catalysts for Ammoxidation and Oxidative Dehydrogenation of Propane and Ethane.

    PubMed

    Cheng, Mu-Jeng; Goddard, William A

    2015-10-21

    We used density functional theory quantum mechanics with periodic boundary conditions to determine the atomistic mechanism underlying catalytic activation of propane by the M1 phase of Mo-V-Nb-Te-O mixed metal oxides. We find that propane is activated by Te═O through our recently established reduction-coupled oxo activation mechanism. More importantly, we find that the C-H activation activity of Te═O is controlled by the distribution of nearby V atoms, leading to a range of activation barriers from 34 to 23 kcal/mol. On the basis of the new insight into this mechanism, we propose a synthesis strategy that we expect to form a much more selective single-phase Mo-V-Nb-Te-O catalyst. PMID:26423704

  1. Housing Mix, School Mix: Barriers to Success

    ERIC Educational Resources Information Center

    Camina, M. M.; Iannone, P.

    2014-01-01

    Recent UK policy has emphasised both the development of socially mixed communities and the creation of balanced school intakes. In this paper, we use a case study of an area of mixed tenure in eastern England to explore policy in practice and the extent to which mechanisms of segregation impact on both the creation of socially mixed neighbourhoods…

  2. Reconsidering the Utility of Case Study Designs for Researching School Reform in a Neo-Scientific Era: Insights from a Multiyear, Mixed-Methods Study

    ERIC Educational Resources Information Center

    Donmoyer, Robert; Galloway, Fred

    2010-01-01

    In recent years, policy makers and researchers once again have embraced the traditional idea that quasi-experimental research designs (or reasonable facsimiles) can provide the sort of valid and generalizable knowledge about "what works" that educational researchers had promised--but never really produced--during the previous century. Although…

  3. Chromatographic evaluation of a newly designed peptide-silica stationary phase in reverse phase liquid chromatography and hydrophilic interaction liquid chromatography: mixed mode behavior.

    PubMed

    Ray, Sudipta; Takafuji, Makoto; Ihara, Hirotaka

    2012-11-30

    The short peptide Boc-Phe-Aib-Phe-OH was synthesized and immobilized onto porous silica using grafting methodology. The resulting peptide-bonded silica was characterized using DRIFT-mode FT-IR, elemental analysis, thermogravimetric analysis, solid state C(13) NMR spectroscopy and the successful immobilization of the peptide on the silica support was confirmed. This grafted phase was packed into a stainless steel column and used for mixed-mode chromatography such as reversed-phase high-performance liquid chromatography and hydrophilic interaction liquid chromatography for the efficient separation of hydrophobic compounds, small polar molecules, and drug molecules. Compared with ODS and phenyl columns, this new stationary phase shows considerably higher molecular-planarity selectivity towards polyaromatic hydrocarbons and also available for separation of nucleo-analytes and sulfa-drug molecules in a hydrophilic interaction liquid chromatography mode. The multiple interactions induced by polar carbonyl group and hydrophobic phenyl group allow this peptide-modified silica to serve as a multi-mode stationary phase in high performance liquid chromatography. PMID:23116801

  4. Inference of ICF Implosion Core Mix using Experimental Data and Theoretical Mix Modeling

    SciTech Connect

    Welser-Sherrill, L; Haynes, D A; Mancini, R C; Cooley, J H; Tommasini, R; Golovkin, I E; Sherrill, M E; Haan, S W

    2008-04-30

    The mixing between fuel and shell materials in Inertial Confinement Fusion (ICF) implosion cores is a current topic of interest. The goal of this work was to design direct-drive ICF experiments which have varying levels of mix, and subsequently to extract information on mixing directly from the experimental data using spectroscopic techniques. The experimental design was accomplished using hydrodynamic simulations in conjunction with Haan's saturation model, which was used to predict the mix levels of candidate experimental configurations. These theoretical predictions were then compared to the mixing information which was extracted from the experimental data, and it was found that Haan's mix model performed well in predicting trends in the width of the mix layer. With these results, we have contributed to an assessment of the range of validity and predictive capability of the Haan saturation model, as well as increased our confidence in the methods used to extract mixing information from experimental data.

  5. Inference of ICF implosion core mix using experimental data and theoretical mix modeling

    SciTech Connect

    Sherrill, Leslie Welser; Haynes, Donald A; Cooley, James H; Sherrill, Manolo E; Mancini, Roberto C; Tommasini, Riccardo; Golovkin, Igor E; Haan, Steven W

    2009-01-01

    The mixing between fuel and shell materials in Inertial Confinement Fusion (lCF) implosion cores is a current topic of interest. The goal of this work was to design direct-drive ICF experiments which have varying levels of mix, and subsequently to extract information on mixing directly from the experimental data using spectroscopic techniques. The experimental design was accomplished using hydrodynamic simulations in conjunction with Haan's saturation model, which was used to predict the mix levels of candidate experimental configurations. These theoretical predictions were then compared to the mixing information which was extracted from the experimental data, and it was found that Haan's mix model predicted trends in the width of the mix layer as a function of initial shell thickness. These results contribute to an assessment of the range of validity and predictive capability of the Haan saturation model, as well as increasing confidence in the methods used to extract mixing information from experimental data.

  6. Mixing and Transport.

    PubMed

    Chang, Chein-Chi; Chapman, Tom; Siverts-Wong, Elena; Wei, Li; Mei, Ying

    2016-10-01

    This section covers research published during the calendar year 2015 on mixing and transport processes. The review covers mixing of anaerobic digesters, mixing of heat transfer, and environmental fate and transport. PMID:27620101

  7. Mixed Methods Research: A Research Paradigm Whose Time Has Come

    ERIC Educational Resources Information Center

    Johnson, R. Burke; Onwuegbuzie, Anthony J.

    2004-01-01

    The purposes of this article are to position mixed methods research ("mixed research" is a synonym) as the natural complement to traditional qualitative and quantitative research, to present pragmatism as offering an attractive philosophical partner for mixed methods research, and to provide a framework for designing and conducting mixed methods…

  8. Design and Test of Mixed-flow Impellers IV : Experimental Results for Impeller Models MFI-1 and MFI-2 with Changes in Blade Height

    NASA Technical Reports Server (NTRS)

    Hamrick, Joseph T; Beede, William L; Withee, Joseph R JR

    1954-01-01

    Modifications A and B of impeller model MFI-1 and A, B, and C of impeller model MFI-2 were investigated experimentally in an attempt to determine what allowance in blade height should be made for boundary layer and viscous losses in an impeller designed for isentropic compressible flow. A gradual increase in blade height was arbitrarily made from inlet to outlet in anticipation of a gradual build-up of boundary layer. Apparently there was a rapid build-up of boundary layer near the inlet in the experimental case rather than a gradual one. Therefore, the proper allowance for boundary layer cannot be described from the data obtained. Decreasing the pressure gradient along the shroud by reducing the blade height allowance apparently did little to increase the overall efficiency. At the design speed of 1400 feet per second, the overall adiabatic efficiency was increased from 0.83 for the MFI-1A to 0.85 for the MFI-1B with reduction in height; however, it is indicated from the theoretical velocity distribution and outlet surveys that the increase was due to a change from decelerating to accelerating flow along the hub rather than from any change along the shroud. It is further indicated that the consequences of a thickened or separated boundary layer depend not only on the design velocity gradients but also on the shape of the passage.

  9. Design and characterization of a mixed-signal PCB for digital-to-analog conversion in a modular and scalable infrared scene projector

    NASA Astrophysics Data System (ADS)

    Benedict, Jacob

    Infra-red (IR) sensors have proven instrumental in a wide variety of fields from military to industrial applications. The proliferation of IR sensors has spawned an intense push for technologies that can test and calibrate the multitudes of IR sensors. One such technology, IR scene projection (IRSP), provides an inexpensive and safe method for the testing of IR sensor devices. Previous efforts have been conducted to develop IRSPs based on super-lattice light emitting diodes (SLEDS). A single-color 512x512 SLEDs system has been developed, produced, and tested as documented in Corey Lange's Master's thesis, and a GOMAC paper by Rodney McGee [1][2]. Current efforts are being undergone to develop a two-color 512x512 SLEDs system designated (TCSA). The following thesis discusses the design and implementation of a custom printed circuit board (PCB), known as the FMC 4DAC, that contains both analog and digital signals. Utilizing two 16-bit digital-to-analog converters (DAC) the purpose of the board is to provide four analog current output channels for driving the TCSA system to a maximum frame rate of 1 kHz. In addition, the board supports a scalable TCSA system architecture. Several copies of the board can be run in parallel to achieve a range of analog channels between 4 and 32.

  10. A STATISTICAL INTELLIGENCE (STI) APPROACH TO DISCOVERING SPURIOUS CORRELATION IN A PHYSICAL MODEL AND RESOLVING THE PROBLEM WITH AN EXAMPLE OF DESIGNING A PULSE JET MIXING SYSTEM AT HANFORD

    SciTech Connect

    Amidan, Brett G.; Piepel, Gregory F.; Heredia-Langner, Alejandro; Meyer, Perry A.; Wells, Beric E.; Fort, James A.; Bamberger, Judith A.; Kuhn, William L.

    2010-07-23

    Pulse jet mixing tests were conducted to support the design of mixing systems for the Hanford Waste Treatment and Immobilization Plant. A physical approach (based on hydro-dynamic behavior) and two semi-empirical (SE) approaches were applied to the data to develop models for predicting two response variables (critical-suspension velocity and cloud height). Tests were conducted at three geometric scales using multiple noncohesive simulants and levels of possibly influential factors. The physical modeling approach based on hydro- dynamic behavior was first attempted, but this approach can yield models with spurious correlation. To overcome this dilemma, two semi-empirical (SE) models were developed by generalizing the form of the physical model using dimensional and/or nondimensional (ND) variables. The results of applying statistical intelligence (STI) tools to resolve the spurious correlation problem via fitting the physical and SE models are presented and compared. Considering goodness-of-fit, prediction performance, spurious correlation, and the need to extrapolate, the SE models based on ND variables are recommended.

  11. Monitoring Uranium Transformations Determined by the Evolution of Biogeochemical Processes: Design of Mixed Batch Reactor and Column Studies at Oak Ridge National Laboratory

    SciTech Connect

    Criddle, Craig S.; Wu, Weimin

    2013-04-17

    With funds provided by the US DOE, Argonne National Laboratory subcontracted the design of batch and column studies to a Stanford University team with field experience at the ORNL IFRC, Oak Ridge, TN. The contribution of the Stanford group ended in 2011 due to budget reduction in ANL. Over the funded research period, the Stanford research team characterized ORNL IFRC groundwater and sediments and set up microcosm reactors and columns at ANL to ensure that experiments were relevant to field conditions at Oak Ridge. The results of microcosm testing demonstrated that U(VI) in sediments was reduced to U(IV) with the addition of ethanol. The reduced products were not uraninite but were instead U(IV) complexes associated with Fe. Fe(III) in solid phase was only partially reduced. The Stanford team communicated with the ANL team members through email and conference calls and face to face at the annual ERSP PI meeting and national meetings.

  12. Studying feasibility and effects of a two-stage nursing staff training in residential geriatric care using a 30 month mixed-methods design [ISRCTN24344776

    PubMed Central

    2011-01-01

    Background Transfer techniques and lifting weights often cause back pain and disorders for nurses in geriatric care. The Kinaesthetics care conception claims to be an alternative, yielding benefits for nurses as well as for clients. Starting a multi-step research program on the effects of Kinaesthetics, we assess the feasibility of a two-stage nursing staff training and a pre-post research design. Using quantitative and qualitative success criteria, we address mobilisation from the bed to a chair and backwards, walking with aid and positioning in bed on the staff level as well as on the resident level. In addition, effect estimates should help to decide on and to prepare a controlled trial. Methods/Design Standard basic and advanced Kinaesthetics courses (each comprising four subsequent days and an additional counselling day during the following four months) are offered to n = 36 out of 60 nurses in a residential geriatric care home, who are in charge of 76 residents. N = 22 residents needing movement support are participating to this study. On the staff level, measurements include focus group discussions, questionnaires, physical strain self-assessment (Borg scale), video recordings and external observation of patient assistance skills using a specialised instrument (SOPMAS). Questionnaires used on the resident level include safety, comfort, pain, and level of own participation during mobilisation. A functional mobility profile is assessed using a specialised test procedure (MOTPA). Measurements will take place at baseline (T0), after basic training (T1), and after the advanced course (T2). Follow-up focus groups will be offered at T1 and 10 months later (T3). Discussion Ten criteria for feasibility success are established before the trial, assigned to resources (missing data), processes (drop-out of nurses and residents) and science (minimum effects) criteria. This will help to make rational decision on entering the next stage of the research program. Trial

  13. The design and use of a simple System Suitability Test Mix for generic reverse phase high performance liquid chromatography-mass spectrometry systems and the implications for automated system monitoring using global software tracking.

    PubMed

    Mutton, Ian; Boughtflower, Bob; Taylor, Nick; Brooke, Daniel

    2011-06-10

    The development of a seven-component test mixture designed for use with a generic gradient and a reversed-phase high performance liquid chromatography-mass spectrometry (RP-HPLC-MS) system is discussed. Unlike many test mixtures formulated in order to characterise column quality at neutral pH, the test mixture reported here was designed to permit an overall suitability assessment of the whole liquid chromatography-mass spectrometry (LCMS) system. The mixture is designed to test the chromatographic performance of the column as well as certain aspects of the performance of the individual instrumental components of the system. The System Suitability Test Mix can be used for low and high pH generic reverse phase LCMS analysis. Four phthalates are used: diethyl phthalate (DEP), diamyl phthalate (DAP), di-n-hexyl phthalate (DHP) and dioctyl phthalate (DOP). Three other probes are employed: 8-bromoguanosine (8-BG), amitryptyline (Ami), and 4-chlorocinnamic acid (4-CCA). We show that analysis of this test mixture can alert the user when any part of the system (instrument or column) contributes to loss of overall performance and may require remedial action and demonstrate that it can provide information that enables us to document data quality control. PMID:21543072

  14. A modelling study and optimization of catalytic reduction of NO over CeO2-MnOx (0.25)-Ba mixed oxide catalyst using design of experiments.

    PubMed

    Mousavi, Seyed Mahdi; Salari, Dariush; Niaei, Aligholi; Panahi, Parvaneh Nakhostin; Shafiei, Sirous

    2014-01-01

    In this study, the effects of operation variables on catalytic performance of CeO2-MnOx (0.25)-Ba mixed oxide in catalytic reduction of NO with ammonia are investigated by using design of experiments. A response surface methodology (RSM) combined with the central composite design (CCD) is used to model and optimize the process variables, including concentration of 02 (vol.%), NH3/NO ratio in the gas feed, gas hourly space velocity (GHSV) and reaction temperature (degrees C) on the NO conversion and N2 selectivity as responses. The R2 values for both generated models were greater than 0.9, confirming the capability of quadratic RSM model in fitting the obtained experimental data. According to the results, GHSV had the largest and negative effect on the NO conversion, while it was an insignificant parameter on the N2 selectivity in the design space. Also, NH3/NO ratio was the most effective parameter on the N2 selectivity. Under the optimum conditions: 4.75 vol.% O2, NH3/NO ratio of 0.9, GHSV of 12,000 h(-1) and 197.5 degrees C, the predicted values for NO conversion and N2 selectivity were 96.47% and 93.96%, respectively. The obtained experimental values in optimum condition agreed with those predicted, indicating suitability of the RSM model to estimate the values of the responses. PMID:24645437

  15. CORNELL MIXING ZONE EXPERT SYSTEM (CORMIX)

    EPA Science Inventory

    Cornell mixing zone expert system (CORMIX) can be used for the analysis, prediction, and design of aqueous toxic or conventional pollutant discharges into diverse water bodies. The major emphasis is on the geometry and dilution characteristics of the initial mixing zone -- includ...

  16. Degradation of mix hydrocarbons by immobilized cells of mix culture using a trickle fluidized bed reactor

    SciTech Connect

    Chapatwala, K.D.

    1993-01-01

    The microorganisms, capable of degrading mix hydrocarbons were isolated from the soil samples collected from the hydrocarbon contaminated sites. The mix cultures were immobilized in calcium alginate solution in the form of beads. A trickle fluidized bed air-uplift-type reactor designed to study the degradation of mix hydrocarbons was filled with 0.85% normal saline containing the immobilized cells of mix culture. The immobilized beads were aerated with CO[sub 2]-free air at 200 ml/min. The degradation of different concentrations of hydrocarbons in the presence/absence of commercially available fertilizers by the immobilized cells of mix culture is now in progress.

  17. Click “Like” to Change Your Behavior: A Mixed Methods Study of College Students’ Exposure to and Engagement With Facebook Content Designed for Weight Loss

    PubMed Central

    Weibel, Nadir; Patrick, Kevin; Fowler, James H; Norman, Greg J; Gupta, Anjali; Servetas, Christina; Calfas, Karen; Raste, Ketaki; Pina, Laura; Donohue, Mike; Griswold, William G; Marshall, Simon

    2014-01-01

    Background Overweight or obesity is prevalent among college students and many gain weight during this time. Traditional face-to-face weight loss interventions have not worked well in this population. Facebook is an attractive tool for delivering weight loss interventions for college students because of its popularity, potential to deliver strategies found in successful weight loss interventions, and ability to support ongoing adaptation of intervention content. Objective The objective of this study was to describe participant exposure to a Facebook page designed to deliver content to overweight/obese college students in a weight loss randomized controlled trial (N=404) and examine participant engagement with behavior change campaigns for weight loss delivered via Facebook. Methods The basis of the intervention campaign model were 5 self-regulatory techniques: intention formation, action planning, feedback, goal review, and self-monitoring. Participants were encouraged to engage their existing social network to meet their weight loss goals. A health coach moderated the page and modified content based on usage patterns and user feedback. Quantitative analyses were conducted at the Facebook post- and participant-level of analysis. Participant engagement was quantified by Facebook post type (eg, status update) and interaction (eg, like) and stratified by weight loss campaign (sequenced vs nonsequenced). A subset of participants were interviewed to evaluate the presence of passive online engagement or “lurking.” Results The health coach posted 1816 unique messages to the study’s Facebook page over 21 months, averaging 3.45 posts per day (SD 1.96, range 1-13). In all, 72.96% (1325/1816) of the posts were interacted with at least once (eg, liked). Of these, approximately 24.75% (328/1325) had 1-2 interactions, 23.39% (310/1325) had 3-5 interactions, 25.13% (333/1325) had 6-8 interactions, and 41 posts had 20 or more interactions (3.09%, 41/1325). There was

  18. Efficient Research Design: Using Value-of-Information Analysis to Estimate the Optimal Mix of Top-down and Bottom-up Costing Approaches in an Economic Evaluation alongside a Clinical Trial.

    PubMed

    Wilson, Edward C F; Mugford, Miranda; Barton, Garry; Shepstone, Lee

    2016-04-01

    In designing economic evaluations alongside clinical trials, analysts are frequently faced with alternative methods of collecting the same data, the extremes being top-down ("gross costing") and bottom-up ("micro-costing") approaches. A priori, bottom-up approaches may be considered superior to top-down approaches but are also more expensive to collect and analyze. In this article, we use value-of-information analysis to estimate the efficient mix of observations on each method in a proposed clinical trial. By assigning a prior bivariate distribution to the 2 data collection processes, the predicted posterior (i.e., preposterior) mean and variance of the superior process can be calculated from proposed samples using either process. This is then used to calculate the preposterior mean and variance of incremental net benefit and hence the expected net gain of sampling. We apply this method to a previously collected data set to estimate the value of conducting a further trial and identifying the optimal mix of observations on drug costs at 2 levels: by individual item (process A) and by drug class (process B). We find that substituting a number of observations on process A for process B leads to a modest £ 35,000 increase in expected net gain of sampling. Drivers of the results are the correlation between the 2 processes and their relative cost. This method has potential use following a pilot study to inform efficient data collection approaches for a subsequent full-scale trial. It provides a formal quantitative approach to inform trialists whether it is efficient to collect resource use data on all patients in a trial or on a subset of patients only or to collect limited data on most and detailed data on a subset. PMID:26762649

  19. Microgravity acoustic mixing for particle cloud combustors

    NASA Technical Reports Server (NTRS)

    Pla, Frederic; Rubinstein, Robert I.

    1990-01-01

    Experimental and theoretical investigations of acoustic mixing procedures designed to uniformly distribute fuel particles in a combustion tube for application in the proposed Particle Cloud Combustion Experiment (PCCE) are described. Two acoustic mixing methods are investigated: mixing in a cylindrical tube using high frequency spinning modes generated by suitably phased, or quadrature speakers, and acoustic premixing in a sphere. Quadrature mixing leads to rapid circumferential circulation of the powder around the tube. Good mixing is observed in the circulating regions. However, because axial inhomogeneities are necessarily present in the acoustic field, this circulation does not extend throughout the tube. Simultaneous operation of the quadrature-speaker set and the axial-speaker was observed to produce considerably enhanced mixing compared to operation of the quadrature-speaker set alone. Mixing experiments using both types of speakers were free of the longitudinal powder drift observed using axial-speakers alone. Vigorous powder mixing was obtained in the sphere for many normal modes: however, in no case was the powder observed to fill the sphere entirely. Theoretical analysis indicated that mixing under steady conditions cannot fill more than a hemisphere except under very unusual conditions. Premixing in a hemisphere may be satisfactory; otherwise, complete mixing in microgravity might be possible by operating the speaker in short bursts. A general conclusion is that acoustic transients are more likely to produce good mixing than steady state conditions. The reason is that in steady conditions, flow structures like nodal planes are possible and often even unavoidable. These tend to separate the mixing region into cells across which powder cannot be transferred. In contrast, transients not only are free of such structures, they also have the characteristics, desirable for mixing, of randomness and disorder. This conclusion is corroborated by mixing

  20. Mixing in explosions

    SciTech Connect

    Kuhl, A.L.

    1993-12-01

    Explosions always contain embedded turbulent mixing regions, for example: boundary layers, shear layers, wall jets, and unstable interfaces. Described here is one particular example of the latter, namely, the turbulent mixing occurring in the fireball of an HE-driven blast wave. The evolution of the turbulent mixing was studied via two-dimensional numerical simulations of the convective mixing processes on an adaptive mesh. Vorticity was generated on the fireball interface by baroclinic effects. The interface was unstable, and rapidly evolved into a turbulent mixing layer. Four phases of mixing were observed: (1) a strong blast wave phase; (2) and implosion phase; (3) a reshocking phase; and (4) an asymptotic mixing phase. The flowfield was azimuthally averaged to evaluate the mean and r.m.s. fluctuation profiles across the mixing layer. The vorticity decayed due to a cascade process. This caused the corresponding enstrophy parameter to increase linearly with time -- in agreement with homogeneous turbulence calculations of G.K. Batchelor.

  1. Mixing in astrophysics

    SciTech Connect

    Fryer, Christopher Lee

    2011-01-07

    Turbulent mixing plays a vital role in many fields in astronomy. Here I review a few of these sites, discuss the importance of this turbulent mixing and the techniques used by astrophysicists to solve these problems.

  2. Investigating Turbulent Mix in HEDLP Experiments

    NASA Astrophysics Data System (ADS)

    Flippo, K. A.; Doss, F. W.; Devolder, B.; Fincke, J. R.; Loomis, E. N.; Kline, J. L.; Welser-Sherrill, L.

    2016-03-01

    Mix is an important issue in High Energy Density Laboratory Plasmas (HEDLP), specifically Inertial Confinement Fusion (ICF) implosions. In ICF, shock waves traverse fuel capsule defects and material interfaces, and due to hydrodynamic instabilities transitioning into turbulence, these shocks can initiate mix between shell and fuel, degrading yield. To this end, a series of laser-driven mix experiments has been designed for the OMEGA and NIF laser facilities to investigate the turbulent mixing of materials proceeded by reshock and shear, which initiates Richtmyer-Meshkov and\\or Kelvin-Helmholtz instabilities on a tracer layer. The experiments are designed to understand if the Besnard-Harlow-Rauenzahn (BHR) mix model that has been implemented in LANL's RAGE hydrodynamics code has coefficients that are properly determined for an HEDLP environment.

  3. Rationale, design and baseline data of a mixed methods study examining the clinical impact of a brief transition programme for young people with juvenile idiopathic arthritis: the DON'T RETARD project

    PubMed Central

    Hilderson, Deborah; Westhovens, Rene; Wouters, Carine; Van der Elst, Kristien; Goossens, Eva; Moons, Philip

    2013-01-01

    Objectives To describe (1) the content of a transition programme for young people with juvenile idiopathic arthritis (JIA) designed as a brief intervention, (2) the rationale and design of a mixed-methods study evaluating the clinical impact of this transition programme and (3) to provide baseline data of the intervention group. Design An ‘embedded experimental’ design is used for the evaluation of the transition programme. A ‘one-group pretest-posttest, with a non-equivalent posttest-only comparison group design’ is used to quantitatively evaluate the impact of the transition programme, applying both longitudinal and comparative analyses. Subsequently, experiences of adolescents and their parents who participated in the experimental group will be analysed qualitatively using content analysis. Setting Participants in the intervention are recruited at a tertiary care centre in Belgium. The comparison group participants are recruited from one tertiary and three secondary care centres in Belgium. Participants The intervention group consists of 33 young people (25 females; 8 males) with a median age of 16 years. Main diagnoses are persistent or extended oligoarticular JIA (33%), polyarticular JIA (30%), enthesitis-related JIA (21%) or systemic arthritis (15%). Intervention The transition programme comprises eight key components: (1) transition coordinator; (2) providing information and education; (3) availability by telephone; (4) information about and contact with an adult care programme; (5) guidance of parents; (6) meeting with peers; (7) transfer plan; and (8) actual transfer to adult care. Primary and secondary outcomes The primary outcome is health status, as perceived by the adolescents. Secondary outcomes are health status, as perceived by the parents; medication adherence; illness-related knowledge; quality of life; fatigue; promotion of independence; support of autonomy; behavioural control and psychological control. Results At baseline, the median

  4. Conversion of mixed plutonium-uranium oxides. [COPRECAL

    SciTech Connect

    Thomas, L.L.

    1980-04-01

    Coprocessing is among the several reprocessing schemes being considered to improve the proliferation resistance of the back end of the nuclear fuel cycle. Coconversion of mixed oxides has been developed but not demonstrated on a production scale. AGNS developed a preliminary conceptual design for a production scale facility to convert mixed plutonium-uranium nitrate to the mixed oxide.

  5. Writing a Mixed Methods Report in Social Work Research

    ERIC Educational Resources Information Center

    Bronstein, Laura R.; Kovacs, Pamela J.

    2013-01-01

    This article briefly chronicles the development of mixed methods research and its use in social work. We then move onto a discussion of terms and designs, reasons for (and for not) using mixed methods. Drawing upon exemplars, we address how to write up a mixed methods study when (1) the sample is single; single for one part, with a subset for the…

  6. RAPP, a systematic e-assessment of postoperative recovery in patients undergoing day surgery: study protocol for a mixed-methods study design including a multicentre, two-group, parallel, single-blind randomised controlled trial and qualitative interview studies

    PubMed Central

    Dahlberg, K; Odencrants, S; Hagberg, L

    2016-01-01

    Introduction Day surgery is a well-established practice in many European countries, but only limited information is available regarding postoperative recovery at home though there is a current lack of a standard procedure regarding postoperative follow-up. Furthermore, there is also a need for improvement of modern technology in assessing patient-related outcomes such as mobile applications. This article describes the Recovery Assessment by Phone Points (RAPP) study protocol, a mixed-methods study to evaluate if a systematic e-assessment follow-up in patients undergoing day surgery is cost-effective and improves postoperative recovery, health and quality of life. Methods and analysis This study has a mixed-methods study design that includes a multicentre, two-group, parallel, single-blind randomised controlled trial and qualitative interview studies. 1000 patients >17 years of age who are undergoing day surgery will be randomly assigned to either e-assessed postoperative recovery follow-up daily in 14 days measured via smartphone app including the Swedish web-version of Quality of Recovery (SwQoR) or to standard care (ie, no follow-up). The primary aim is cost-effectiveness. Secondary aims are (A) to explore whether a systematic e-assessment follow-up after day surgery has a positive effect on postoperative recovery, health-related quality of life (QoL) and overall health; (B) to determine whether differences in postoperative recovery have an association with patient characteristic, type of surgery and anaesthesia; (C) to determine whether differences in health literacy have a substantial and distinct effect on postoperative recovery, health and QoL; and (D) to describe day surgery patient and staff experiences with a systematic e-assessment follow-up after day surgery. The primary aim will be measured at 2 weeks postoperatively and secondary outcomes (A–C) at 1 and 2 weeks and (D) at 1 and 4 months. Trial registration number NCT02492191; Pre

  7. Advances in compressible turbulent mixing

    SciTech Connect

    Dannevik, W.P.; Buckingham, A.C.; Leith, C.E.

    1992-01-01

    This volume includes some recent additions to original material prepared for the Princeton International Workshop on the Physics of Compressible Turbulent Mixing, held in 1988. Workshop participants were asked to emphasize the physics of the compressible mixing process rather than measurement techniques or computational methods. Actual experimental results and their meaning were given precedence over discussions of new diagnostic developments. Theoretical interpretations and understanding were stressed rather than the exposition of new analytical model developments or advances in numerical procedures. By design, compressibility influences on turbulent mixing were discussed--almost exclusively--from the perspective of supersonic flow field studies. The papers are arranged in three topical categories: Foundations, Vortical Domination, and Strongly Coupled Compressibility. The Foundations category is a collection of seminal studies that connect current study in compressible turbulent mixing with compressible, high-speed turbulent flow research that almost vanished about two decades ago. A number of contributions are included on flow instability initiation, evolution, and transition between the states of unstable flow onset through those descriptive of fully developed turbulence. The Vortical Domination category includes theoretical and experimental studies of coherent structures, vortex pairing, vortex-dynamics-influenced pressure focusing. In the Strongly Coupled Compressibility category the organizers included the high-speed turbulent flow investigations in which the interaction of shock waves could be considered an important source for production of new turbulence or for the enhancement of pre-existing turbulence. Individual papers are processed separately.

  8. Mixed oxide solid solutions

    DOEpatents

    Magno, Scott; Wang, Ruiping; Derouane, Eric

    2003-01-01

    The present invention is a mixed oxide solid solution containing a tetravalent and a pentavalent cation that can be used as a support for a metal combustion catalyst. The invention is furthermore a combustion catalyst containing the mixed oxide solid solution and a method of making the mixed oxide solid solution. The tetravalent cation is zirconium(+4), hafnium(+4) or thorium(+4). In one embodiment, the pentavalent cation is tantalum(+5), niobium(+5) or bismuth(+5). Mixed oxide solid solutions of the present invention exhibit enhanced thermal stability, maintaining relatively high surface areas at high temperatures in the presence of water vapor.

  9. Heterogeneous Reburning By Mixed Fuels

    SciTech Connect

    Anderson Hall

    2009-03-31

    Recent studies of heterogeneous reburning, i.e., reburning involving a coal-derived char, have elucidated its variables, kinetics and mechanisms that are valuable to the development of a highly efficient reburning process. Young lignite chars contain catalysts that not only reduce NO, but they also reduce HCN that is an important intermediate that recycles to NO in the burnout zone. Gaseous CO scavenges the surface oxides that are formed during NO reduction, regenerating the active sites on the char surface. Based on this mechanistic information, cost-effective mixed fuels containing these multiple features has been designed and tested in a simulated reburning apparatus. Remarkably high reduction of NO and HCN has been observed and it is anticipated that mixed fuel will remove 85% of NO in a three-stage reburning process.

  10. HETEROGENEOUS REBURNING BY MIXED FUELS

    SciTech Connect

    Wei-Yin Chen; Benson B. Gathitu

    2005-01-14

    Recent studies of heterogeneous reburning, i.e., reburning involving a coal-derived char, have elucidated its variables, kinetics and mechanisms that are valuable to the development of a highly efficient reburning process. Young lignite chars contain catalysts that not only reduce NO, but they also reduce HCN that is an important intermediate that recycles to NO in the burnout zone. Gaseous CO scavenges the surface oxides that are formed during NO reduction, regenerating the active sites on the char surface. Based on this mechanistic information, cost-effective mixed fuels containing these multiple features has been designed and tested in a simulated reburning apparatus. Remarkably high reduction of NO and HCN has been observed and it is anticipated that mixed fuel will remove 85% of NO in a three-stage reburning process.

  11. Theory for Neutrino Mixing

    NASA Astrophysics Data System (ADS)

    He, Xiao-Gang

    2016-07-01

    Since the discovery of neutrino oscillations, for which Takaaki Kajita and Arthur B. McDonald were awarded the 2015 Nobel prize in physics, tremendous progresses have been made in measuring the mixing angles which determine the oscillation pattern. A lot of theoretical efforts have been made to understand how neutrinos mix with each other. Present data show that in the standard parameterization of the mixing matrix, θ23 is close to π/4 and the CP violating phase is close to ‑ π/2. In this talk I report results obtained in arXiv:1505.01932 (Phys. Lett. B750(2015)620) and arXive:1404.01560 (Chin. J. Phys.53(2015)100101) and discuss some implications for theoretical model buildings for such mixing pattern. Specific examples for neutrino mixing based on A4 family symmetry are given.

  12. High-mix insulins

    PubMed Central

    Kalra, Sanjay; Farooqi, Mohammad Hamed; El-Houni, Ali E.

    2015-01-01

    Premix insulins are commonly used insulin preparations, which are available in varying ratios of different molecules. These drugs contain one short- or rapid-acting, and one intermediate- or long-acting insulin. High-mix insulins are mixtures of insulins that contain 50% or more than 50% of short-acting insulin. This review describes the clinical pharmacology of high-mix insulins, including data from randomized controlled trials. It suggests various ways, in which high-mix insulin can be used, including once daily, twice daily, thrice daily, hetero-mix, and reverse regimes. The authors provide a rational framework to help diabetes care professionals, identify indications for pragmatic high-mix use. PMID:26425485

  13. A Mixed Methods Portrait of Urban Instrumental Music Teaching

    ERIC Educational Resources Information Center

    Fitzpatrick, Kate R.

    2011-01-01

    The purpose of this mixed methods study was to learn about the ways that instrumental music teachers in Chicago navigated the urban landscape. The design of the study most closely resembles Creswell and Plano Clark's (2007) two-part Triangulation Convergence Mixed Methods Design, with the addition of an initial exploratory focus group component.…

  14. ADVANCED MIXING MODELS

    SciTech Connect

    Lee, S; Dimenna, R; Tamburello, D

    2011-02-14

    The process of recovering and processing High Level Waste (HLW) the waste in storage tanks at the Savannah River Site (SRS) typically requires mixing the contents of the tank with one to four mixers (pumps) located within the tank. The typical criteria to establish a mixed condition in a tank are based on the number of pumps in operation and the time duration of operation. To ensure that a mixed condition is achieved, operating times are typically set conservatively long. This approach results in high operational costs because of the long mixing times and high maintenance and repair costs for the same reason. A significant reduction in both of these costs might be realized by reducing the required mixing time based on calculating a reliable indicator of mixing with a suitably validated computer code. The focus of the present work is to establish mixing criteria applicable to miscible fluids, with an ultimate goal of addressing waste processing in HLW tanks at SRS and quantifying the mixing time required to suspend sludge particles with the submersible jet pump. A single-phase computational fluid dynamics (CFD) approach was taken for the analysis of jet flow patterns with an emphasis on the velocity decay and the turbulent flow evolution for the farfield region from the pump. Literature results for a turbulent jet flow are reviewed, since the decay of the axial jet velocity and the evolution of the jet flow patterns are important phenomena affecting sludge suspension and mixing operations. The work described in this report suggests a basis for further development of the theory leading to the identified mixing indicators, with benchmark analyses demonstrating their consistency with widely accepted correlations. Although the indicators are somewhat generic in nature, they are applied to Savannah River Site (SRS) waste tanks to provide a better, physically based estimate of the required mixing time. Waste storage tanks at SRS contain settled sludge which varies in

  15. Remotely controllable mixing system

    NASA Technical Reports Server (NTRS)

    Belew, R. R. (Inventor)

    1986-01-01

    This invention relates to a remotely controllable mixing system in which a plurality of mixing assemblies are arranged in an annular configuration, and wherein each assembly employs a central chamber and two outer, upper and lower chambers. Valves are positioned between chambers, and these valves for a given mixing assembly are operated by upper and lower control rotors, which in turn are driven by upper and lower drive rotors. Additionally, a hoop is compressed around upper control rotors and a hoop is compressed around lower control rotors to thus insure constant frictional engagement between all control rotors and drive rotors. The drive rollers are driven by a motor.

  16. Guidelines for mixed waste minimization

    SciTech Connect

    Owens, C.

    1992-02-01

    Currently, there is no commercial mixed waste disposal available in the United States. Storage and treatment for commercial mixed waste is limited. Host States and compacts region officials are encouraging their mixed waste generators to minimize their mixed wastes because of management limitations. This document provides a guide to mixed waste minimization.

  17. Launch site integration for mixed fleet operations

    NASA Technical Reports Server (NTRS)

    Scott, L. P.

    1990-01-01

    Launch site impacts and integration planning issues are presented to support launch operations for a mixed vehicle fleet (manned and cargo). Proposed ground systems and launch site configurations are described. Prelaunch processing scenarios and schedules are developed for candidate launch vehicles. Earth-to-orbit (ETO) vehicle architectures are presented to meet future launch requirements, including the Space Exploration Initiative (SEI). Flight vehicle design recommendations to enhance launch processing are discussed. The significance of operational designs for future launch vehicles is shown to be a critical factor in planning for mixed fleet launch site operations.

  18. Mixed-Media Owls

    ERIC Educational Resources Information Center

    Schultz, Kathy

    2010-01-01

    The fun of creating collages is there are unlimited possibilities for the different kinds of materials one can use. In this article, the author describes how her eighth-grade students created an owl using mixed media.

  19. Detection and evaluation of mixed pixels in Landsat agricultural scenes

    NASA Technical Reports Server (NTRS)

    Merickel, M. B.; Lundgren, J. C.; Lennington, R. K.

    1982-01-01

    A major problem area encountered in the identification and estimation of agricultural crop proportions in Landsat imagery involves the large proportion of the pixels which are mixed pixels, whose spectral response is influenced by more than one ground cover type. The development of methods for the detection and estimation of crop proportions in mixed pixels is presently reported. The procedure designated CASCADE, based on the estimation of the gradient image for the detection of mixed pixels, considers the consequences of a linear mixing model and is found to provide a method for the allocation of mixed pixels to the surrounding homogeneous region.

  20. Laboratory studies of ocean mixing by microorganisms

    NASA Astrophysics Data System (ADS)

    Martinez-Ortiz, Monica; Dabiri, John O.

    2011-11-01

    Ocean mixing plays a major role in nutrient and energy transport and is an important input to climate models. Recent studies suggest that the contribution of fluid transport by swimming microorganisms to ocean mixing may be of the same order of magnitude as winds and tides. An experimental setup has been designed in order to study the mixing efficiency of vertical migration of plankton. To this end, a stratified water column is created to model the ocean's density gradient. The vertical migration of Artemia Salina (brine shrimp) within the water column is controlled via luminescent signals on the top and bottom of the column. By fluorescently labelling portions of the water column, the stirring of the density gradient by the animals is visualized and quantified. Preliminary results show that the vertical movement of these organisms produces enhanced mixing relative to control cases in which only buoyancy forces and diffusion are present.

  1. Pulse Jet Mixing Tests With Noncohesive Solids

    SciTech Connect

    Meyer, Perry A.; Bamberger, Judith A.; Enderlin, Carl W.; Fort, James A.; Wells, Beric E.; Sundaram, S. K.; Scott, Paul A.; Minette, Michael J.; Smith, Gary L.; Burns, Carolyn A.; Greenwood, Margaret S.; Morgen, Gerald P.; Baer, Ellen BK; Snyder, Sandra F.; White, Michael K.; Piepel, Gregory F.; Amidan, Brett G.; Heredia-Langner, Alejandro

    2012-02-17

    This report summarizes results from pulse jet mixing (PJM) tests with noncohesive solids in Newtonian liquid. The tests were conducted during FY 2007 and 2008 to support the design of mixing systems for the Hanford Waste Treatment and Immobilization Plant (WTP). Tests were conducted at three geometric scales using noncohesive simulants, and the test data were used to develop models predicting two measures of mixing performance for full-scale WTP vessels. The models predict the cloud height (the height to which solids will be lifted by the PJM action) and the critical suspension velocity (the minimum velocity needed to ensure all solids are suspended off the floor, though not fully mixed). From the cloud height, the concentration of solids at the pump inlet can be estimated. The predicted critical suspension velocity for lifting all solids is not precisely the same as the mixing requirement for 'disturbing' a sufficient volume of solids, but the values will be similar and closely related. These predictive models were successfully benchmarked against larger scale tests and compared well with results from computational fluid dynamics simulations. The application of the models to assess mixing in WTP vessels is illustrated in examples for 13 distinct designs and selected operational conditions. The values selected for these examples are not final; thus, the estimates of performance should not be interpreted as final conclusions of design adequacy or inadequacy. However, this work does reveal that several vessels may require adjustments to design, operating features, or waste feed properties to ensure confidence in operation. The models described in this report will prove to be valuable engineering tools to evaluate options as designs are finalized for the WTP. Revision 1 refines data sets used for model development and summarizes models developed since the completion of Revision 0.

  2. Quick-Mixing Studies Under Reacting Conditions

    NASA Technical Reports Server (NTRS)

    Leong, May Y.; Samuelsen, G. S.

    1996-01-01

    The low-NO(x) emitting potential of rich-burn/quick-mix/lean-burn )RQL) combustion makes it an attractive option for engines of future stratospheric aircraft. Because NO(x) formation is exponentially dependent on temperature, the success of the RQL combustor depends on minimizing high temperature stoichiometric pocket formation in the quick-mixing section. An experiment was designed and built, and tests were performed to characterize reaction and mixing properties of jets issuing from round orifices into a hot, fuel-rich crossflow confined in a cylindrical duct. The reactor operates on propane and presents a uniform, non-swirling mixture to the mixing modules. Modules consisting of round orifice configurations of 8, 9, 10, 12, 14, and 18 holes were evaluated at a momentum-flux ratio of 57 and jet-to-mainstream mass-flaw ratio of 2.5. Temperatures and concentrations of O2, CO2, CO, HC, and NO(x) were obtained upstream, down-stream, and within the orifice plane to determine jet penetration as well as reaction processes. Jet penetration was a function of the number of orifices and affected the mixing in the reacting system. Of the six configurations tested, the 14-hole module produced jet penetration close to the module half-radius and yielded the best mixing and most complete combustion at a plane one duct diameter from the orifice leading edge. The results reveal that substantial reaction and heat release occur in the jet mixing zone when the entering effluent is hot and rich, and that the experiment as designed will serve to explore satisfactorily jet mixing behavior under realistic reacting conditions in future studies.

  3. Scoping Study of Airlift Circulation Technologies for Supplemental Mixing in Pulse Jet Mixed Vessels

    SciTech Connect

    Schonewill, Philip P.; Berglin, Eric J.; Boeringa, Gregory K.; Buchmiller, William C.; Burns, Carolyn A.; Minette, Michael J.

    2015-04-07

    At the request of the U.S. Department of Energy Office of River Protection, Pacific Northwest National Laboratory (PNNL) conducted a scoping study to investigate supplemental technologies for supplying vertical fluid motion and enhanced mixing in Waste Treatment and Immobilization Plant (WTP) vessels designed for high solids processing. The study assumed that the pulse jet mixers adequately mix and shear the bottom portion of a vessel. Given that, the primary function of a supplemental technology should be to provide mixing and shearing in the upper region of a vessel. The objective of the study was to recommend a mixing technology and configuration that could be implemented in the 8-ft test vessel located at Mid-Columbia Engineering (MCE). Several mixing technologies, primarily airlift circulator (ALC) systems, were evaluated in the study. This technical report contains a review of ALC technologies, a description of the PNNL testing and accompanying results, and recommended features of an ALC system for further study.

  4. Mixing of Supersonic Streams

    NASA Technical Reports Server (NTRS)

    Hawk, C. W.; Landrum, D. B.; Muller, S.; Turner, M.; Parkinson, D.

    1998-01-01

    The Strutjet approach to Rocket Based Combined Cycle (RBCC) propulsion depends upon fuel-rich flows from the rocket nozzles and turbine exhaust products mixing with the ingested air for successful operation in the ramjet and scramjet modes. It is desirable to delay this mixing process in the air-augmented mode of operation present during low speed flight. A model of the Strutjet device has been built and is undergoing test to investigate the mixing of the streams as a function of distance from the Strutjet exit plane during simulated low speed flight conditions. Cold flow testing of a 1/6 scale Strutjet model is underway and nearing completion. Planar Laser Induced Fluorescence (PLIF) diagnostic methods are being employed to observe the mixing of the turbine exhaust gas with the gases from both the primary rockets and the ingested air simulating low speed, air augmented operation of the RBCC. The ratio of the pressure in the turbine exhaust duct to that in the rocket nozzle wall at the point of their intersection is the independent variable in these experiments. Tests were accomplished at values of 1.0, 1.5 and 2.0 for this parameter. Qualitative results illustrate the development of the mixing zone from the exit plane of the model to a distance of about 10 rocket nozzle exit diameters downstream. These data show the mixing to be confined in the vertical plane for all cases, The lateral expansion is more pronounced at a pressure ratio of 1.0 and suggests that mixing with the ingested flow would be likely beginning at a distance of 7 nozzle exit diameters downstream of the nozzle exit plane.

  5. Mixing of Supersonic Streams

    NASA Technical Reports Server (NTRS)

    Hawk, C. W.; Landrum, D. B.; Muller, S.; Turner, M.; Parkinson, D.

    1998-01-01

    The Strutjet approach to Rocket Based Combined Cycle (RBCC) propulsion depends upon fuel-rich flows from the rocket nozzles and turbine exhaust products mixing with the ingested air for successful operation in the ramjet and scramjet modes. It is desirable to delay this mixing process in the air-augmented mode of operation present during low speed flight. A model of the Strutjet device has been built and is undergoing test to investigate the mixing of the streams as a function of distance from the Strutjet exit plane during simulated low speed flight conditions. Cold flow testing of a 1/6 scale Strutjet model is underway and nearing completion. Planar Laser Induced Fluorescence (PLIF) diagnostic methods are being employed to observe the mixing of the turbine exhaust gas with the gases from both the primary rockets and the ingested air simulating low speed, air augmented operation of the RBCC. The ratio of the pressure in the turbine exhaust duct to that in the rocket nozzle wall at the point of their intersection is the independent variable in these experiments. Tests were accomplished at values of 1.0, 1.5 and 2.0 for this parameter. Qualitative results illustrate the development of the mixing zone from the exit plane of the model to a distance of about 19 equivalent rocket nozzle exit diameters downstream. These data show the mixing to be confined in the vertical plane for all cases, The lateral expansion is more pronounced at a pressure ratio of 1.0 and suggests that mixing with the ingested flow would be likely beginning at a distance of 7 nozzle exit diameters downstream of the nozzle exit plane.

  6. ADVANCED MIXING MODELS

    SciTech Connect

    Lee, S; Richard Dimenna, R; David Tamburello, D

    2008-11-13

    The process of recovering the waste in storage tanks at the Savannah River Site (SRS) typically requires mixing the contents of the tank with one to four dual-nozzle jet mixers located within the tank. The typical criteria to establish a mixed condition in a tank are based on the number of pumps in operation and the time duration of operation. To ensure that a mixed condition is achieved, operating times are set conservatively long. This approach results in high operational costs because of the long mixing times and high maintenance and repair costs for the same reason. A significant reduction in both of these costs might be realized by reducing the required mixing time based on calculating a reliable indicator of mixing with a suitably validated computer code. The work described in this report establishes the basis for further development of the theory leading to the identified mixing indicators, the benchmark analyses demonstrating their consistency with widely accepted correlations, and the application of those indicators to SRS waste tanks to provide a better, physically based estimate of the required mixing time. Waste storage tanks at SRS contain settled sludge which varies in height from zero to 10 ft. The sludge has been characterized and modeled as micron-sized solids, typically 1 to 5 microns, at weight fractions as high as 20 to 30 wt%, specific gravities to 1.4, and viscosities up to 64 cp during motion. The sludge is suspended and mixed through the use of submersible slurry jet pumps. To suspend settled sludge, water is added to the tank as a slurry medium and stirred with the jet pump. Although there is considerable technical literature on mixing and solid suspension in agitated tanks, very little literature has been published on jet mixing in a large-scale tank. If shorter mixing times can be shown to support Defense Waste Processing Facility (DWPF) or other feed requirements, longer pump lifetimes can be achieved with associated operational cost and

  7. Hawaii Ocean Mixing Experiment: Program Summary

    NASA Technical Reports Server (NTRS)

    Ray, Richard D.; Chao, Benjamin F. (Technical Monitor)

    2002-01-01

    It is becoming apparent that insufficient mixing occurs in the pelagic ocean to maintain the large scale thermohaline circulation. Observed mixing rates fall a factor of ten short of classical indices such as Munk's "Abyssal Recipe." The growing suspicion is that most of the mixing in the sea occurs near topography. Exciting recent observations by Polzin et al., among others, fuel this speculation. If topographic mixing is indeed important, it must be acknowledged that its geographic distribution, both laterally and vertically, is presently unknown. The vertical distribution of mixing plays a critical role in the Stommel Arons model of the ocean interior circulation. In recent numerical studies, Samelson demonstrates the extreme sensitivity of flow in the abyssal ocean to the spatial distribution of mixing. We propose to study the topographic mixing problem through an integrated program of modeling and observation. We focus on tidally forced mixing as the global energetics of this process have received (and are receiving) considerable study. Also, the well defined frequency of the forcing and the unique geometry of tidal scattering serve to focus the experiment design. The Hawaiian Ridge is selected as a study site. Strong interaction between the barotropic tide and the Ridge is known to take place. The goals of the Hawaiian Ocean Mixing Experiment (HOME) are to quantify the rate of tidal energy loss to mixing at the Ridge and to identify the mechanisms by which energy is lost and mixing generated. We are challenged to develop a sufficiently comprehensive picture that results can be generalized from Hawaii to the global ocean. To achieve these goals, investigators from five institutions have designed HOME, a program of historic data analysis, modeling and field observation. The Analysis and Modeling efforts support the design of the field experiments. As the program progresses, a global model of the barotropic (depth independent) tide, and two models of the

  8. Mixed waste management options

    SciTech Connect

    Owens, C.B.; Kirner, N.P.

    1991-12-31

    Disposal fees for mixed waste at proposed commercial disposal sites have been estimated to be $15,000 to $40,000 per cubit foot. If such high disposal fees are imposed, generators may be willing to apply extraordinary treatment or regulatory approaches to properly dispose of their mixed waste. This paper explores the feasibility of several waste management scenarios and attempts to answer the question: Can mixed waste be managed out of existence? Existing data on commercially generated mixed waste streams are used to identify the realm of mixed waste known to be generated. Each waste stream is evaluated from both a regulatory and technical perspective in order to convert the waste into a strictly low-level radioactive or a hazardous waste. Alternative regulatory approaches evaluated in this paper include a delisting petition, no migration petition, and a treatability variance. For each waste stream, potentially available treatment options are identified that could lead to these variances. Waste minimization methodology and storage for decay are also considered. Economic feasibility of each option is discussed broadly.

  9. [Mixed states and schizophrenia].

    PubMed

    Fakra, E; Belzeaux, R; Pringuey, D; Cermolacce, M; Corréard, N; Micoulaud-Franchi, J-A; Azorin, J-M

    2013-12-01

    Because of their compilation of contrasted symptoms and their variable clinical presentation, mixed episodes have been withdrawn from the DSM. However, mixed states question not only the bonds between depression and mania, but also the distinction between bipolar disorders and schizophrenia. Indeed, doubts about the dichotomy introduced by Kraepelin between bipolar disorders and schizophrenia is as old as the nosolgy itself, as attest the later works of this author revealing his hesitations on his own classification. But findings here reviewed issued from recent technical advances, particularly in the imaging and genetic fields, offer a better understanding of the boundaries between these two disorders. Yet, when confronted to an acute episode, clinicians may find it challenging to distinguish a mixed state from a schizophrenic relapse. Indeed, there is no pathognomonic manifestation allowing to retain a diagnosis with confidence. The physician will therefore have to identify a pattern of signs, which will orient his assessment with no certainty. Thus, negative rather than affective or psychotic symptomatology appears to be useful in discriminating schizophrenia (or schizoaffective) disorders from mixed mania. However, a conclusion during this acute stage appears in definitive a formal exercise, first because the final diagnosis will only be ascertained once the symptoms are amended, and second because, according to our classifications, a mood episode, including mania and mixed mania, can be observed without ruling out the diagnosis of schizophrenia. PMID:24359851

  10. Using a Mixed Methods Sequential Design to Identify Factors Associated with African American Mothers' Intention to Vaccinate Their Daughters Aged 9 to 12 for HPV with a Purpose of Informing a Culturally-Relevant, Theory-Based Intervention

    ERIC Educational Resources Information Center

    Cunningham, Jennifer L.

    2013-01-01

    The purpose of this sequential, explanatory mixed methods research study was to understand what factors influenced African American maternal intentions to get their daughters aged 9 years to 12 years vaccinated in Alabama. In the first, quantitative phase of the study, the research questions focused on identifying the predictive power of eleven…

  11. Performance of a mixed filter to identify relevant studies for mixed studies reviews

    PubMed Central

    El Sherif, Reem; Pluye, Pierre; Gore, Genevieve; Granikov, Vera; Hong, Quan Nha

    2016-01-01

    Objective Mixed studies reviews include empirical studies with diverse designs. Given that identifying relevant studies for such reviews is time consuming, a mixed filter was developed. Methods The filter was used for six journals from three disciplines. For each journal, database records were coded “empirical” (relevant) when they mentioned a research question or objective, data collection, analysis, and results. We measured precision (proportion of retrieved documents being relevant), sensitivity (proportion of relevant documents retrieved), and specificity (proportion of nonrelevant documents not retrieved). Results Records were coded with and without the filter, and descriptive statistics were performed, suggesting the mixed filter has high sensitivity. PMID:26807052

  12. Enhanced Mixing in a Rectangular Duct

    NASA Technical Reports Server (NTRS)

    Liscinsky, D. S.; True, B.

    2003-01-01

    An experimental investigation of the mixing of non-reacting opposed rows of jets injected normal to a confined rectangular crossflow has been conducted. Planar Mie-scattering was used to measure the time-average concentration distribution of the jet fluid in planes perpendicular to the duct axis. Particular emphasis was placed on the study of closely spaced orifice configurations applicable to the mixing zone of an RQL combustor. Baseline studies were performed of mixing under "ideal" conditions, i.e., plenum fed jets injecting into a crossflow uniform in velocity and turbulence intensity. In addition, more practical ("non-ideal") issues encountered during hardware design were also studied. As in other studies, mixing effectiveness, determined using a spatial unmixedness parameter based on the variance of mean jet concentration distributions, was found to be optimum when the spacing-to-duct-height ratio was inversely proportional to the square root of the jet-to-mainstream momentum-flux ratio. This relationship is suitable for design under ideal flow conditions. Inlet flow boundary conditions of the jet and approach flow (mainstream) were found to strongly influence mixing performance, but no attempt was made to determine optimum performance under non-ideal conditions. The tests performed do offer some guidance as to expected mixing behavior for several common variables likely to be imposed by hardware constraints. Additionally, in this study it was found that for rows of orifices with opposite centerlines inline, mixing was similar for blockages up to 89 percent (previous crossflow mixing studies concerned with dilution zone configurations, blockages were typically less than 50 percent). Lower levels of unmixedness were obtained as a function of downstream location when axial injection length was minimized. Mixing may be enhanced if orifice centerlines of opposed rows are staggered, but blockage must be =50 percent in this configuration. Round hole and "square

  13. Mixed Stream Test Rig (MISTER) Startup Report

    SciTech Connect

    Charles Park

    2011-02-01

    This report describes the work accomplished to date to design, procure, assemble, authorize, and startup the Mixed Stream Test Rig (MISTER) at the Idaho National Laboratory (INL). It describes the reasons for establishing this capability, physical configuration of the test equipment, operations methodology, initial success, and plans for completing the initial 1,000 hour test.

  14. Instructor Technology Use: A Mixed Methods Investigation

    ERIC Educational Resources Information Center

    Becking, Suzanne K.

    2011-01-01

    This mixed methods concurrent triangulation study was designed to examine instructional leaders' descriptions of their experience with integrating technology into their teaching. Seminal studies from the 1990s were found to remain true today--that teachers are not ready to incorporate technology into their teaching (Becker, 1999; Ertmer, 1999). In…

  15. Introduction to Studies in Granular Mixing

    ERIC Educational Resources Information Center

    Llusa, Marcos; Muzzio, Fernando

    2008-01-01

    This article describes a hands-on educational activity designed to introduce students (or industrial employees) in the pharmaceutical arena to some of the most common problems in the mixing of solids: Active Pharmaceutical Ingredient (API) and lubricant (i.e. magnesium stearate) homogenization, characterization of segregation tendencies, and…

  16. Mixed Method Research in Special Education.

    ERIC Educational Resources Information Center

    McWilliam, R. A.

    This paper addresses the conditions under which quantitative and qualitative research methods could be combined in special education. The paper asserts that qualitative designs have not had a significant effect on special education research and speculates that mixed-method research might be more acceptable to special education researchers or…

  17. Mixed Methods Sampling: A Typology with Examples

    ERIC Educational Resources Information Center

    Teddlie, Charles; Yu, Fen

    2007-01-01

    This article presents a discussion of mixed methods (MM) sampling techniques. MM sampling involves combining well-established qualitative and quantitative techniques in creative ways to answer research questions posed by MM research designs. Several issues germane to MM sampling are presented including the differences between probability and…

  18. A Parametric Numerical Study of Mixing in a Cylindrical Duct

    NASA Technical Reports Server (NTRS)

    Oechsle, V. L.; Mongia, H. C.; Holdeman, J. D.

    1992-01-01

    The interaction is described of some of the important parameters affecting the mixing process in a quick mixing region of a rich burn/quick mix/lean burn (RQL) combustor. The performance of the quick mixing region is significantly affected by the geometric designs of both the mixing domain and the jet inlet orifices. Several of the important geometric parameters and operating conditions affecting the mixing process were analytically studied. Parameters such as jet-to-mainstream momentum flux ratio (J), mass flow ratio (MR), orifice geometry, orifice orientation, and number of orifices/row (equally spaced) around the circumferential direction were analyzed. Three different sets of orifice shapes were studied: (1) square, (2) elongated slots, and (3) equilateral triangles. Based on the analytical results, the best mixing configuration depends significantly on the penetration depth of the jet to prevent the hot mainstream flow from being entrained behind the orifice. The structure in a circular mixing section is highly weighted toward the outer wall and any mixing structure affecting this area significantly affects the overall results. The increase in the number of orifices per row increases the mixing at higher J conditions. Higher slot slant angles and aspect ratios are generally the best mixing configurations at higher momentum flux ratio (J) conditions. However, the square and triangular shaped orifices were more effective mixing configurations at lower J conditions.

  19. Dilution jet mixing program

    NASA Technical Reports Server (NTRS)

    Srinivasan, R.; Coleman, E.; Johnson, K.

    1984-01-01

    Parametric tests were conducted to quantify the mixing of opposed rows of jets (two-sided injection) in a confined cross flow. Results show that jet penetrations for two sided injections are less than that for single-sided injections, but the jet spreading rates are faster for a given momentum ratio and orifice plate. Flow area convergence generally enhances mixing. Mixing characteristics with asymmetric and symmetric convergence are similar. For constant momentum ratio, the optimum S/H(0) with in-line injections is one half the optimum value for single sided injections. For staggered injections, the optimum S/H(0) is twice the optimum value for single-sided injection. The correlations developed predicted the temperature distributions within first order accuracy and provide a useful tool for predicting jet trajectory and temperature profiles in the dilution zone with two-sided injections.

  20. Mixed waste: Proceedings

    SciTech Connect

    Moghissi, A.A.; Blauvelt, R.K.; Benda, G.A.; Rothermich, N.E.

    1993-12-31

    This volume contains the peer-reviewed and edited versions of papers submitted for presentation a the Second International Mixed Waste Symposium. Following the tradition of the First International Mixed Waste Symposium, these proceedings were prepared in advance of the meeting for distribution to participants. The symposium was organized by the Mixed Waste Committee of the American Society of Mechanical Engineers. The topics discussed at the symposium include: stabilization technologies, alternative treatment technologies, regulatory issues, vitrification technologies, characterization of wastes, thermal technologies, laboratory and analytical issues, waste storage and disposal, organic treatment technologies, waste minimization, packaging and transportation, treatment of mercury contaminated wastes and bioprocessing, and environmental restoration. Individual abstracts are catalogued separately for the data base.

  1. Rapid mixing kinetic techniques.

    PubMed

    Martin, Stephen R; Schilstra, Maria J

    2013-01-01

    Almost all of the elementary steps in a biochemical reaction scheme are either unimolecular or bimolecular processes that frequently occur on sub-second, often sub-millisecond, time scales. The traditional approach in kinetic studies is to mix two or more reagents and monitor the changes in concentrations with time. Conventional spectrophotometers cannot generally be used to study reactions that are complete within less than about 20 s, as it takes that amount of time to manually mix the reagents and activate the instrument. Rapid mixing techniques, which generally achieve mixing in less than 2 ms, overcome this limitation. This chapter is concerned with the use of these techniques in the study of reactions which reach equilibrium; the application of these methods to the study of enzyme kinetics is described in several excellent texts (Cornish-Bowden, Fundamentals of enzyme kinetics. Portland Press, 1995; Gutfreund, Kinetics for the life sciences. Receptors, transmitters and catalysis. Cambridge University Press, 1995).There are various ways to monitor changes in concentration of reactants, intermediates and products after mixing, but the most common way is to use changes in optical signals (absorbance or fluorescence) which often accompany reactions. Although absorbance can sometimes be used, fluorescence is often preferred because of its greater sensitivity, particularly in monitoring conformational changes. Such methods are continuous with good time resolution but they seldom permit the direct determination of the concentrations of individual species. Alternatively, samples may be taken from the reaction volume, mixed with a chemical quenching agent to stop the reaction, and their contents assessed by techniques such as HPLC. These methods can directly determine the concentrations of different species, but are discontinuous and have a limited time resolution. PMID:23729251

  2. Atomization and mixing study

    NASA Technical Reports Server (NTRS)

    Ferrenberg, A.; Jaqua, V. W.

    1983-01-01

    The state of the art in atomization and mixing for triplet, pentad, and coaxial injectors is described. Injectors that are applicable for LOX/hydrocarbon propellants and main chamber and fuel rich preburner/gas generator mixture ratios are of special interest. Various applicable correlating equations and parameters as well as test data found in the literature are presented. The validity, utility, and important aspects of these data and correlations are discussed and the measurement techniques used are evaluated. Propellant mixing tests performed are described and summarized, results are reported, and tentative conclusions are included.

  3. Mixed crystal organic scintillators

    DOEpatents

    Zaitseva, Natalia P; Carman, M Leslie; Glenn, Andrew M; Hamel, Sebastien; Hatarik, Robert; Payne, Stephen A; Stoeffl, Wolfgang

    2014-09-16

    A mixed organic crystal according to one embodiment includes a single mixed crystal having two compounds with different bandgap energies, the organic crystal having a physical property of exhibiting a signal response signature for neutrons from a radioactive source, wherein the signal response signature does not include a significantly-delayed luminescence characteristic of neutrons interacting with the organic crystal relative to a luminescence characteristic of gamma rays interacting with the organic crystal. According to one embodiment, an organic crystal includes bibenzyl and stilbene or a stilbene derivative, the organic crystal having a physical property of exhibiting a signal response signature for neutrons from a radioactive source.

  4. Mixed waste characterization strategy

    SciTech Connect

    Baldwin, C.E.; Stakebake, J.; Peters, M.

    1992-01-01

    Radioactive mixed wastes containing a radioactive component subject to the Atomic Energy Act (AEA) and hazardous waste subject to resource Conservation and Recovery Act (RCRA) are generated, treated, and stored at the Rocky Flats Plant (RFP) and are subject to federal and state statutory and regulatory requirements. The US Environmental Protection Agency (EPA) and the Colorado Department of Health (CDH) are the two primary regulatory agencies which enforce these requirements. This paper describes the mechanism by which RFP will characterize mixed wastes within the LDR provisions of RCRA and the LDR FFCA as well as for meeting the waste acceptance criteria for disposal.

  5. Mixed waste characterization strategy

    SciTech Connect

    Baldwin, C.E.; Stakebake, J.; Peters, M.

    1992-08-01

    Radioactive mixed wastes containing a radioactive component subject to the Atomic Energy Act (AEA) and hazardous waste subject to resource Conservation and Recovery Act (RCRA) are generated, treated, and stored at the Rocky Flats Plant (RFP) and are subject to federal and state statutory and regulatory requirements. The US Environmental Protection Agency (EPA) and the Colorado Department of Health (CDH) are the two primary regulatory agencies which enforce these requirements. This paper describes the mechanism by which RFP will characterize mixed wastes within the LDR provisions of RCRA and the LDR FFCA as well as for meeting the waste acceptance criteria for disposal.

  6. MixDown

    2010-01-01

    MixDown is a meta-build tool that orchestrates and manages the building of multiple 3rd party libraries. It can manage the downloading, uncompressing, unpacking, patching, configuration, build, and installation of 3rd party libraries using a variety of configuration and build tools. As a meta-build tool, it relies on 3rd party tools such as GNU Autotools, make, Cmake, scons, etc. to actually confugure and build libraries. MixDown includes an extensive database of settings to be used formore » general machines and specific leadership class computing resources.« less

  7. Turbulence and Interfacial Mixing

    SciTech Connect

    Glimm, James; Li, Xiaolin

    2005-03-15

    The authors study mix from analytical and numerical points of view. These investigations are linked. The analytical studies (in addition to laboratory experiments) provide bench marks for the direct simulation of mix. However, direct simulation is too detailed to be useful and to expensive to be practical. They also consider averaged equations. Here the major issue is the validation of the closure assumptions. They appeal to the direct simulation methods for this step. They have collaborated with several NNSA teams; moreover, Stony Brook alumni (former students, faculty and research collaborators) presently hold staff positions in NNSA laboratories.

  8. Mixed Methods Research: The "Thing-ness" Problem.

    PubMed

    Hesse-Biber, Sharlene

    2015-06-01

    Contemporary mixed methods research (MMR) veers away from a "loosely bounded" to a "bounded" concept that has important negative implications for how qualitatively driven mixed methods approaches are positioned in the field of mixed methods and overall innovation in the praxis of MMR. I deploy the concept of reification defined as taking an object/abstraction and treating it as if it were real such that it takes on the quality of "thing-ness," having a concrete independent existence. I argue that the contemporary reification of mixed methods as a "thing" is fueled by three interrelated factors: (a) the growing formalization of mixed methods as design, (b) the unexamined belief in the "synergy" of mixed methods and, (c) the deployment of a "practical pragmatism" as the "philosophical partner" for mixed methods inquiry. PMID:25888694

  9. Visualizing turbulent mixing of gases and particles

    NASA Technical Reports Server (NTRS)

    Ma, Kwan-Liu; Smith, Philip J.; Jain, Sandeep

    1995-01-01

    A physical model and interactive computer graphics techniques have been developed for the visualization of the basic physical process of stochastic dispersion and mixing from steady-state CFD calculations. The mixing of massless particles and inertial particles is visualized by transforming the vector field from a traditionally Eulerian reference frame into a Lagrangian reference frame. Groups of particles are traced through the vector field for the mean path as well as their statistical dispersion about the mean position by using added scalar information about the root mean square value of the vector field and its Lagrangian time scale. In this way, clouds of particles in a turbulent environment are traced, not just mean paths. In combustion simulations of many industrial processes, good mixing is required to achieve a sufficient degree of combustion efficiency. The ability to visualize this multiphase mixing can not only help identify poor mixing but also explain the mechanism for poor mixing. The information gained from the visualization can be used to improve the overall combustion efficiency in utility boilers or propulsion devices. We have used this technique to visualize steady-state simulations of the combustion performance in several furnace designs.

  10. Sylgard® Mixing Study

    SciTech Connect

    Bello, Mollie; Welch, Cynthia F.; Goodwin, Lynne Alese; Keller, Jennie

    2014-08-22

    Sylgard® 184 and Sylgard® 186 silicone elastomers form Dow Corning® are used as potting agents across the Nuclear Weapons Complex. A standardized mixing procedure is required for filled versions of these products. The present study is a follow-up to a mixing study performed by MST-7 which established the best mixing procedure to use when adding filler to either 184 or 186 base resins. The most effective and consistent method of mixing resin and curing agent for three modified silicone elastomer recipes is outlined in this report. For each recipe, sample size, mixing type, and mixing time was varied over 10 separate runs. The results show that the THINKY™ Mixer gives reliable mixing over varying batch sizes and mixing times. Hand Mixing can give improved mixing, as indicated by reduced initial viscosity; however, this method is not consistent.

  11. True Anonymity Without Mixes

    NASA Astrophysics Data System (ADS)

    Molina-Jimenez, C.; Marshall, L.

    2002-04-01

    Anonymizers based on mix computers interposed between the sender and the receiver of an e-mail message have been used in the Internet for several years by senders of e-mail messages who do not wish to disclose their identity. Unfortunately, the degree of anonymity provided by this paradigm is limited and fragile. First, the messages sent are not truly anonymous but pseudo-anonymous since one of the mixes, at least, always knows the sender's identity. Secondly, the strength of the system to protect the sender's identity depends on the ability and the willingness of the mixes to keep the secret. If the mixes fail, the sender/'s anonymity is reduced to pieces. In this paper, we propose a novel approach for sending truly anonymous messages over the Internet where the anonymous message is sent from a PDA which uses dynamically assigned temporary, non-personal, random IP and MAC addresses. Anonymous E-cash is used to pay for the service.

  12. Josephson junction mixing.

    NASA Technical Reports Server (NTRS)

    Thompson, E. D.

    1973-01-01

    A theory is presented which, though too simple to explain quantitative details in the Josephson junction mixing response, is sufficient for explaining qualitatively the results observed. Crucial to the theory presented, and that which differentiates it from earlier ones, is the inclusion of harmonic voltages across the ideal Josephson element.

  13. Mixed valent metals.

    PubMed

    Riseborough, P S; Lawrence, J M

    2016-08-01

    We review the theory of mixed-valent metals and make comparison with experiments. A single-impurity description of the mixed-valent state is discussed alongside the description of the nearly-integer valent or Kondo limit. The degeneracy N of the f-shell plays an important role in the description of the low-temperature Fermi-liquid state. In particular, for large N, there is a rapid cross-over between the mixed-valent and the Kondo limit when the number of f electrons is changed. We discuss the limitations on the application of the single-impurity description to concentrated compounds such as those caused by the saturation of the Kondo effect and those due to the presence of magnetic interactions between the impurities. This discussion is followed by a description of a periodic lattice of mixed-valent ions, including the role of the degeneracy N. The article concludes with a comparison of theory and experiment. Topics covered include the single-impurity Anderson model, Luttinger's theorem, the Friedel sum rule, the Schrieffer-Wolff transformation, the single-impurity Kondo model, Kondo screening, the Wilson ratio, local Fermi-liquids, Fermi-liquid sum rules, the Noziéres exhaustion principle, Doniach's diagram, the Anderson lattice model, the Slave-Boson method, etc. PMID:27376888

  14. Stabilizer for mixed fuels

    SciTech Connect

    Yamamura, M.; Igarashi, T.; Ukigai, T.

    1984-03-13

    A stabilizer for mixed fuels containing a reaction product obtained by reacting (1) a polyol having at least 3 hydroxyl groups in the molecule and a molecular weight of 400-10,000 with (2) an epihalohydrin, as the principal component.

  15. Progress in mix modeling

    SciTech Connect

    Harrison, A.K.

    1997-03-14

    We have identified the Cranfill multifluid turbulence model (Cranfill, 1992) as a starting point for development of subgrid models of instability, turbulent and mixing processes. We have differenced the closed system of equations in conservation form, and coded them in the object-oriented hydrodynamics code FLAG, which is to be used as a testbed for such models.

  16. Mixed-Initiative Clustering

    ERIC Educational Resources Information Center

    Huang, Yifen

    2010-01-01

    Mixed-initiative clustering is a task where a user and a machine work collaboratively to analyze a large set of documents. We hypothesize that a user and a machine can both learn better clustering models through enriched communication and interactive learning from each other. The first contribution or this thesis is providing a framework of…

  17. Mixed valent metals

    NASA Astrophysics Data System (ADS)

    Riseborough, P. S.; Lawrence, J. M.

    2016-08-01

    We review the theory of mixed-valent metals and make comparison with experiments. A single-impurity description of the mixed-valent state is discussed alongside the description of the nearly-integer valent or Kondo limit. The degeneracy N of the f-shell plays an important role in the description of the low-temperature Fermi-liquid state. In particular, for large N, there is a rapid cross-over between the mixed-valent and the Kondo limit when the number of f electrons is changed. We discuss the limitations on the application of the single-impurity description to concentrated compounds such as those caused by the saturation of the Kondo effect and those due to the presence of magnetic interactions between the impurities. This discussion is followed by a description of a periodic lattice of mixed-valent ions, including the role of the degeneracy N. The article concludes with a comparison of theory and experiment. Topics covered include the single-impurity Anderson model, Luttinger’s theorem, the Friedel sum rule, the Schrieffer–Wolff transformation, the single-impurity Kondo model, Kondo screening, the Wilson ratio, local Fermi-liquids, Fermi-liquid sum rules, the Noziéres exhaustion principle, Doniach’s diagram, the Anderson lattice model, the Slave-Boson method, etc.

  18. Mixing of Supersonic Streams

    NASA Technical Reports Server (NTRS)

    Hawk, Clark W.; Landrum, D. Brian; Turner, Matthew; Wagner, David K.; Lambert, James

    1998-01-01

    The Strutjet approach to Rocket Based Combined Cycle (RBCC) propulsion depends upon fuel-rich flows from the rocket nozzles and turbine exhaust products mixing with the ingested air for successful operation in the ramjet and scramjet modes. A model of the Strutjet device has been built and is undergoing test to investigate the mixing of the streams as a function of distance from the Strutjet exit plane. Initial cold flow testing of the model is underway to determine both, the behavior of the ingested air in the duct and to validate the mixing diagnostics. During the tests, each of the two rocket nozzles ejected up to two pounds mass per second into the 13.6 square inch duct. The tests showed that the mass flow of the rockets was great enough to cause the entrained air to go sonic at the strut, which is the location of the rocket nozzles. More tests are necessary to determine whether the entrained air chokes due to the reduction in the area of the duct at the strut (a physical choke), or because of the addition of mass inside the duct at the nozzle exit (a Fabri choke). The initial tests of the mixing diagnostics are showing promise.

  19. Mixed Markov models

    PubMed Central

    Fridman, Arthur

    2003-01-01

    Markov random fields can encode complex probabilistic relationships involving multiple variables and admit efficient procedures for probabilistic inference. However, from a knowledge engineering point of view, these models suffer from a serious limitation. The graph of a Markov field must connect all pairs of variables that are conditionally dependent even for a single choice of values of the other variables. This makes it hard to encode interactions that occur only in a certain context and are absent in all others. Furthermore, the requirement that two variables be connected unless always conditionally independent may lead to excessively dense graphs, obscuring the independencies present among the variables and leading to computationally prohibitive inference algorithms. Mumford [Mumford, D. (1996) in ICIAM 95, eds. Kirchgassner, K., Marenholtz, O. & Mennicken, R. (Akademie Verlag, Berlin), pp. 233–256] proposed an alternative modeling framework where the graph need not be rigid and completely determined a priori. Mixed Markov models contain node-valued random variables that, when instantiated, augment the graph by a set of transient edges. A single joint probability distribution relates the values of regular and node-valued variables. In this article, we study the analytical and computational properties of mixed Markov models. In particular, we show that positive mixed models have a local Markov property that is equivalent to their global factorization. We also describe a computationally efficient procedure for answering probabilistic queries in mixed Markov models. PMID:12829802

  20. Color mixing models

    NASA Astrophysics Data System (ADS)

    Harrington, Steven J.

    1992-05-01

    In black-and-white printing the page image can be represented within a computer as an array of binary values indicating whether or not pixels should be inked. The Boolean operators of AND, OR, and EXCLUSIVE-OR are often used when adding new objects to the image array. For color printing the page may be represented as an array of continuous tone color values, and the generalization of these logic functions to gray-scale or full-color images is, in general, not defined or understood. When incrementally composing a page image new colors can replace old in an image buffer, or new colors and old can be combined according to some mixing function to form a composite color which is stored. This paper examines the properties of the Boolean operations and suggests full-color mixing functions which preserve the desired properties. These functions can be used to combine colored images, giving various transparency effects. The relationships between the mixing functions and physical models of color mixing are also discussed.

  1. Mixing and Transport.

    ERIC Educational Resources Information Center

    Ditmars, John D.

    1978-01-01

    Presents a literature review of longitudinal dispersion, mixing and transport in streams, rivers, lakes, reservoirs, estuaries, and oceans. This review covers also: (1) fluid-solid mixtures and (2) oil spill behavior. A list of 189 references published in 1976 and 1977 is presented. (HM)

  2. Pulse Jet Mixing Tests With Noncohesive Solids

    SciTech Connect

    Meyer, Perry A.; Bamberger, Judith A.; Enderlin, Carl W.; Fort, James A.; Wells, Beric E.; Sundaram, S. K.; Scott, Paul A.; Minette, Michael J.; Smith, Gary L.; Burns, Carolyn A.; Greenwood, Margaret S.; Morgen, Gerald P.; Baer, Ellen BK; Snyder, Sandra F.; White, Michael; Piepel, Gregory F.; Amidan, Brett G.; Heredia-Langner, Alejandro; Bailey, Sharon A.; Bower, John C.; Denslow, Kayte M.; Eakin, David E.; Elmore, Monte R.; Gauglitz, Phillip A.; Guzman, Anthony D.; Hatchell, Brian K.; Hopkins, Derek F.; Hurley, David E.; Johnson, Michael D.; Kirihara, Leslie J.; Lawler, Bruce D.; Loveland, Jesse S.; Mullen, O Dennis; Pekour, Mikhail S.; Peters, Timothy J.; Robinson, Peter J.; Russcher, Michael S.; Sande, Susan; Santoso, Christian; Shoemaker, Steven V.; Silva, Steve M.; Smith, Devin E.; Su, Yin-Fong; Toth, James J.; Wiberg, John D.; Yu, Xiao-Ying; Zuljevic, Nino

    2009-05-11

    This report summarizes results from pulse jet mixing (PJM) tests with noncohesive solids in Newtonian liquid conducted during FY 2007 and 2008 to support the design of mixing systems for the Hanford Waste Treatment and Immobilization Plant (WTP). Tests were conducted at three geometric scales using noncohesive simulants. The test data were used to independently develop mixing models that can be used to predict full-scale WTP vessel performance and to rate current WTP mixing system designs against two specific performance requirements. One requirement is to ensure that all solids have been disturbed during the mixing action, which is important to release gas from the solids. The second requirement is to maintain a suspended solids concentration below 20 weight percent at the pump inlet. The models predict the height to which solids will be lifted by the PJM action, and the minimum velocity needed to ensure all solids have been lifted from the floor. From the cloud height estimate we can calculate the concentration of solids at the pump inlet. The velocity needed to lift the solids is slightly more demanding than "disturbing" the solids, and is used as a surrogate for this metric. We applied the models to assess WTP mixing vessel performance with respect to the two perform¬ance requirements. Each mixing vessel was evaluated against these two criteria for two defined waste conditions. One of the wastes was defined by design limits and one was derived from Hanford waste characterization reports. The assessment predicts that three vessel types will satisfy the design criteria for all conditions evaluated. Seven vessel types will not satisfy the performance criteria used for any of the conditions evaluated. The remaining three vessel types provide varying assessments when the different particle characteristics are evaluated. The assessment predicts that three vessel types will satisfy the design criteria for all conditions evaluated. Seven vessel types will not satisfy

  3. Mix experiments with the NOVA laser

    SciTech Connect

    Rupert, V.C.; Kilkenny, J.D.; Skokowski, P.G.

    1988-10-01

    The NOVA mix experiments are designed to study mix between two dissimilar materials subjected to strong (M/approximately/50) shocks and variable accelerations in a direction normal to their common boundary. The main purpose of the experiments is to provide a data base with which predictive models can be compared and normalized. Together with shock tube experiments, which explore a different regime, the current NOVA tests investigate the shock induced source terms in our model and the evolution of both Rayleigh-Taylor stable and unstable interfaces. 3 refs., 9 figs.

  4. Mapping Mixed Methods Research: Methods, Measures, and Meaning

    ERIC Educational Resources Information Center

    Wheeldon, J.

    2010-01-01

    This article explores how concept maps and mind maps can be used as data collection tools in mixed methods research to combine the clarity of quantitative counts with the nuance of qualitative reflections. Based on more traditional mixed methods approaches, this article details how the use of pre/post concept maps can be used to design qualitative…

  5. Triangulation, Respondent Validation, and Democratic Participation in Mixed Methods Research

    ERIC Educational Resources Information Center

    Torrance, Harry

    2012-01-01

    Over the past 10 years or so the "Field" of "Mixed Methods Research" (MMR) has increasingly been exerting itself as something separate, novel, and significant, with some advocates claiming paradigmatic status. Triangulation is an important component of mixed methods designs. Triangulation has its origins in attempts to validate research findings…

  6. Teachers' Beliefs and Technology Practices: A Mixed-Methods Approach

    ERIC Educational Resources Information Center

    Palak, Deniz; Walls, Richard T.

    2009-01-01

    In a sequential mixed methods design, we sought to examine the relationship between teachers' beliefs and their instructional technology practices among technology-using teachers who worked at technology-rich schools to ultimately describe if change in practice toward a student-centered paradigm occurred. The integrated mixed-methods results…

  7. Unitarity constraints on trimaximal mixing

    SciTech Connect

    Kumar, Sanjeev

    2010-07-01

    When the neutrino mass eigenstate {nu}{sub 2} is trimaximally mixed, the mixing matrix is called trimaximal. The middle column of the trimaximal mixing matrix is identical to tribimaximal mixing and the other two columns are subject to unitarity constraints. This corresponds to a mixing matrix with four independent parameters in the most general case. Apart from the two Majorana phases, the mixing matrix has only one free parameter in the CP conserving limit. Trimaximality results in interesting interplay between mixing angles and CP violation. A notion of maximal CP violation naturally emerges here: CP violation is maximal for maximal 2-3 mixing. Similarly, there is a natural constraint on the deviation from maximal 2-3 mixing which takes its maximal value in the CP conserving limit.

  8. The mixed waste management facility

    SciTech Connect

    Streit, R.D.

    1995-10-01

    During FY96, the Mixed Waste Management Facility (MWMF) Project has the following major objectives: (1) Complete Project Preliminary Design Review (PDR). (2) Complete final design (Title II) of MWMF major systems. (3) Coordinate all final interfaces with the Decontamination and Waste Treatment Facility (DWTF) for facility utilities and facility integration. (4) Begin long-lead procurements. (5) Issue Project Baseline Revision 2-Preliminary Design (PB2), modifying previous baselines per DOE-requested budget profiles and cost reduction. Delete Mediated Electrochemical Oxidation (MEO) as a treatment process for initial demonstration. (6) Complete submittal of, and ongoing support for, applications for air permit. (7) Begin detailed planning for start-up, activation, and operational interfaces with the Laboratory`s Hazardous Waste Management Division (HWM). In achieving these objectives during FY96, the Project will incorporate and implement recent DOE directives to maximize the cost savings associated with the DWTF/MWMF integration (initiated in PB1.2); to reduce FY96 new Budget Authority to {approximately}$10M (reduced from FY97 Validation of $15.3M); and to keep Project fiscal year funding requirements largely uniform at {approximately}$10M/yr. A revised Project Baseline (i.e., PB2), to be issued during the second quarter of FY96, will address the implementation and impact of this guidance from an overall Project viewpoint. For FY96, the impact of this guidance is that completion of final design has been delayed relative to previous baselines (resulting from the delay in the completion of preliminary design); ramp-up in staffing has been essentially eliminated; and procurements have been balanced through the Project to help balance budget needs to funding availability.

  9. Applications of mixed-methods methodology in clinical pharmacy research.

    PubMed

    Hadi, Muhammad Abdul; Closs, S José

    2016-06-01

    Introduction Mixed-methods methodology, as the name suggests refers to mixing of elements of both qualitative and quantitative methodologies in a single study. In the past decade, mixed-methods methodology has gained popularity among healthcare researchers as it promises to bring together the strengths of both qualitative and quantitative approaches. Methodology A number of mixed-methods designs are available in the literature and the four most commonly used designs in healthcare research are: the convergent parallel design, the embedded design, the exploratory design, and the explanatory design. Each has its own unique advantages, challenges and procedures and selection of a particular design should be guided by the research question. Guidance on designing, conducting and reporting mixed-methods research is available in the literature, so it is advisable to adhere to this to ensure methodological rigour. When to use it is best suited when the research questions require: triangulating findings from different methodologies to explain a single phenomenon; clarifying the results of one method using another method; informing the design of one method based on the findings of another method, development of a scale/questionnaire and answering different research questions within a single study. Two case studies have been presented to illustrate possible applications of mixed-methods methodology. Limitations Possessing the necessary knowledge and skills to undertake qualitative and quantitative data collection, analysis, interpretation and integration remains the biggest challenge for researchers conducting mixed-methods studies. Sequential study designs are often time consuming, being in two (or more) phases whereas concurrent study designs may require more than one data collector to collect both qualitative and quantitative data at the same time. PMID:26659085

  10. [Mixed leg ulcers].

    PubMed

    Willenberg, Torsten

    2011-03-01

    Coexisting peripheral arterial disease is not uncommon (15 - 21 %) in patients with ulcera cruris primarily based on a venous etiology. Patient's history, clinical examination and detection of ABI as well as duplex scan will establish diagnosis of mixed arterial-venous ulcera. Clinical significance of coexisting arterial disease is often difficult to define and should be evaluated by a vascular specialist. The concept of treatment of mixed ulcers should always include the arterial component. Frequently peripheral arterial perfusion and healing can be improved by minimal invasive, endovascular revascularization. Compression therapy is the corner stone in treatment of venous disease and should be complemented by contemporary two piece graduated compression systems if ulcera are present. According to circumstances ablation of varicose veins must be considered. PMID:21360460

  11. Nozzle mixing apparatus

    SciTech Connect

    Mensink, D.L.

    1992-12-31

    This invention is comprised of a nozzle device for causing two fluids to mix together. In particular, a spray nozzle comprise two hollow, concentric housings, an inner housing and an outer housing. The inner housing has a channel formed therethrough for a first fluid. Its outer surface cooperates with the interior surface of the outer housing to define the second channel for a second fluid. The outer surface of the inner housing and the inner surface of the outer housing each carry a plurality of vanes that interleave but do not touch, each vane of one housing being between two vanes of the other housing. The vanes are curved and the inner surface of the outer housing and the outer surface of the inner housing converge to narrow the second channel. The shape of second channel results in a swirling, accelerating second fluid that will impact the first fluid just past the end of the nozzle where mixing will take place.

  12. Experiments in mixed reality

    NASA Astrophysics Data System (ADS)

    Krum, David M.; Sadek, Ramy; Kohli, Luv; Olson, Logan; Bolas, Mark

    2010-01-01

    As part of the Institute for Creative Technologies and the School of Cinematic Arts at the University of Southern California, the Mixed Reality lab develops technologies and techniques for presenting realistic immersive training experiences. Such experiences typically place users within a complex ecology of social actors, physical objects, and collections of intents, motivations, relationships, and other psychological constructs. Currently, it remains infeasible to completely synthesize the interactivity and sensory signatures of such ecologies. For this reason, the lab advocates mixed reality methods for training and conducts experiments exploring such methods. Currently, the lab focuses on understanding and exploiting the elasticity of human perception with respect to representational differences between real and virtual environments. This paper presents an overview of three projects: techniques for redirected walking, displays for the representation of virtual humans, and audio processing to increase stress.

  13. Mixing by individual swimmers

    NASA Astrophysics Data System (ADS)

    Pushkin, Dmitri; Shum, Henry; Yeomans, Julia

    2012-11-01

    Despite their evolutionary and technological importance, different biomixing mechanisms, their effectiveness and universality remain poorly understood. In this talk we focus on the Lagrangian transport of the surrounding fluid by swimmers. Low Re passive tracers advected by swimmers move in loops that are, in general, almost closed. We analyze the reasons for this behavior and, as non-closedness of the loops is a natural requirement for an efficient mixing, propose a classification of possible mechanisms for biogenic mixing. Next, we discuss the universal (common to all swimmers) and the swimmer-dependent features of the resulting tracer displacements and analyze the Darwin drift, the total fluid volume displaced by a swimmer passing from and to infinity. We show that the Darwin drift is finite for force-free swimmers and can be decomposed into a universal and a swimmer-dependent part. We illustrate our consideration with examples for model swimmers and biological data.

  14. Turbulent mixing and beyond.

    PubMed

    Abarzhi, S I; Sreenivasan, K R

    2010-04-13

    Turbulence is a supermixer. Turbulent mixing has immense consequences for physical phenomena spanning astrophysical to atomistic scales under both high- and low-energy-density conditions. It influences thermonuclear fusion in inertial and magnetic confinement systems; governs dynamics of supernovae, accretion disks and explosions; dominates stellar convection, planetary interiors and mantle-lithosphere tectonics; affects premixed and non-premixed combustion; controls standard turbulent flows (wall-bounded and free-subsonic, supersonic as well as hypersonic); as well as atmospheric and oceanic phenomena (which themselves have important effects on climate). In most of these circumstances, the mixing phenomena are driven by non-equilibrium dynamics. While each article in this collection dwells on a specific problem, the purpose here is to seek a few unified themes amongst diverse phenomena. PMID:20211872

  15. First mix experiments at Nova, the LoRo series

    SciTech Connect

    Rupert, V.C.

    1991-09-12

    The first series of experiments using the Nova laser to investigate mix at an interface between different materials has been completed. Mix was induced by a shock crossing the interface and initiating a Richtmyer-Meshkov instability. Both low and high Atwood number targets were used and the results compare favorably with simulations using a k{var epsilon} mix model. These experiments pave the way for new designs which should provide data needed to develop mix models with predictive capabilities. 9 refs., 8 figs.

  16. Supersonic Jet Mixing Enhancement due to Natural and Induced Screech

    NASA Technical Reports Server (NTRS)

    Rice, E. J.; Raman, G.

    1999-01-01

    Outline of presentation are: (1) Review of experimental apparatus. (2) Effect of natural screech of jet mixing; converging nozzle, underexpanded jet and converging-diverging nozzle, design pressure.(3) Effect of induced screech on jet mixing: produced by paddles in shear layers, similar to edge tones, and converging-diverging nozzle, design pressure. (4) Effect of paddles on near-field jet noise. and (5) Concluding remarks.

  17. Effect of mix parameters on longevity of bituminous mixtures

    NASA Astrophysics Data System (ADS)

    Reichle, Clayton Matthew

    This study was performed to evaluate the effects of varying aggregate sources, aggregate gradations on the stripping and rutting potential of bituminous based plant mixes specified by the Missouri Department of Transportation. The different aggregate combinations included two different aggregate sources (Potosi Dolomite and Jefferson City Dolomite) including two variations for the Jefferson City Dolomite mix to simulate a marginally in-specification mix and an out-of-specification but in-field tolerance mix. The "field" mix simulated the marginal mix where field tolerance of high dust and low binder content were maximized. All three mixes were evaluated for stripping susceptibility using the Tensile Strength Ratio (TSR) test and the Hamburg Wheel Tracking Device (HWTD). The mix characteristics (unit weight, effective binder content, and air voids) were used for a Level 3 analysis in the Mechanistic-Empirical Pavement Design Guide (MEPDG) to determine long term pavement distress conditions such as fatigue cracking, rutting, and IRI (smoothness). The Potosi mix exhibited the best resistance to rutting and stripping during both the TSR testing as well as the Hamburg testing. The Jefferson City In-Spec and Out-of-Spec mixes showed less resistance to rutting and stripping in order, respectively. This was expected for the Jefferson City mixes where the aggregate was of lower quality (higher Los Angeles Abrasion, Micro Deval loss, absorption, and deleterious materials). Also, in the case of the Jefferson City Out-of-Spec mix, the binder content was lower. Upon evaluating the mixes using the MEPDG software, it was shown that mix characteristics such as air voids, VMA, and VFA influenced the fatigue cracking, rutting, and IRI predictions to a minor degree.

  18. Quantifying mixing using magnetic resonance imaging.

    PubMed

    Tozzi, Emilio J; McCarthy, Kathryn L; Bacca, Lori A; Hartt, William H; McCarthy, Michael J

    2012-01-01

    Mixing is a unit operation that combines two or more components into a homogeneous mixture. This work involves mixing two viscous liquid streams using an in-line static mixer. The mixer is a split-and-recombine design that employs shear and extensional flow to increase the interfacial contact between the components. A prototype split-and-recombine (SAR) mixer was constructed by aligning a series of thin laser-cut Poly (methyl methacrylate) (PMMA) plates held in place in a PVC pipe. Mixing in this device is illustrated in the photograph in Fig. 1. Red dye was added to a portion of the test fluid and used as the minor component being mixed into the major (undyed) component. At the inlet of the mixer, the injected layer of tracer fluid is split into two layers as it flows through the mixing section. On each subsequent mixing section, the number of horizontal layers is duplicated. Ultimately, the single stream of dye is uniformly dispersed throughout the cross section of the device. Using a non-Newtonian test fluid of 0.2% Carbopol and a doped tracer fluid of similar composition, mixing in the unit is visualized using magnetic resonance imaging (MRI). MRI is a very powerful experimental probe of molecular chemical and physical environment as well as sample structure on the length scales from microns to centimeters. This sensitivity has resulted in broad application of these techniques to characterize physical, chemical and/or biological properties of materials ranging from humans to foods to porous media (1, 2). The equipment and conditions used here are suitable for imaging liquids containing substantial amounts of NMR mobile (1)H such as ordinary water and organic liquids including oils. Traditionally MRI has utilized super conducting magnets which are not suitable for industrial environments and not portable within a laboratory (Fig. 2). Recent advances in magnet technology have permitted the construction of large volume industrially compatible magnets suitable for

  19. Quantifying Mixing using Magnetic Resonance Imaging

    PubMed Central

    Tozzi, Emilio J.; McCarthy, Kathryn L.; Bacca, Lori A.; Hartt, William H.; McCarthy, Michael J.

    2012-01-01

    Mixing is a unit operation that combines two or more components into a homogeneous mixture. This work involves mixing two viscous liquid streams using an in-line static mixer. The mixer is a split-and-recombine design that employs shear and extensional flow to increase the interfacial contact between the components. A prototype split-and-recombine (SAR) mixer was constructed by aligning a series of thin laser-cut Poly (methyl methacrylate) (PMMA) plates held in place in a PVC pipe. Mixing in this device is illustrated in the photograph in Fig. 1. Red dye was added to a portion of the test fluid and used as the minor component being mixed into the major (undyed) component. At the inlet of the mixer, the injected layer of tracer fluid is split into two layers as it flows through the mixing section. On each subsequent mixing section, the number of horizontal layers is duplicated. Ultimately, the single stream of dye is uniformly dispersed throughout the cross section of the device. Using a non-Newtonian test fluid of 0.2% Carbopol and a doped tracer fluid of similar composition, mixing in the unit is visualized using magnetic resonance imaging (MRI). MRI is a very powerful experimental probe of molecular chemical and physical environment as well as sample structure on the length scales from microns to centimeters. This sensitivity has resulted in broad application of these techniques to characterize physical, chemical and/or biological properties of materials ranging from humans to foods to porous media 1, 2. The equipment and conditions used here are suitable for imaging liquids containing substantial amounts of NMR mobile 1H such as ordinary water and organic liquids including oils. Traditionally MRI has utilized super conducting magnets which are not suitable for industrial environments and not portable within a laboratory (Fig. 2). Recent advances in magnet technology have permitted the construction of large volume industrially compatible magnets suitable for

  20. Mixing in suspensions of active particles

    NASA Astrophysics Data System (ADS)

    Pushkin, Dmitri O.; Yeomans, Julia M.

    2014-03-01

    Microscopic active particles self-propelling in the surrounding fluid create flows that eventually lead to emergence of non-equilibrium states with long-ranged fluctuations. One of the technologically important consequences of these fluctuations is enhanced mixing of the surrounding fluid. It is also critical for understanding the ecology of a particular type of biological active systems, bacterial suspension, as the enhanced mixing strongly alters the fluxes of nutrients. We consider the theoretical foundations of fluid mixing enhancement in dilute suspensions of active force-free swimmers. We describe the impediments to fluid mixing imposed by the physical nature of fluid flows created by swimmers, and different ways of overcoming them. We show that fluid mixing in 3D suspensions of force-free (dipolar) swimmers is dominated by the effect of curvature of their trajectories, and obtain an exact analytical expression for the corresponding effective diffusion coefficient. Our results highlight limitations of alternative ``effective temperature'' approaches and may serve as a quantitative tool for designing technological applications.

  1. Chaotic mixing by microswimmers moving on quasiperiodic orbits

    NASA Astrophysics Data System (ADS)

    Jalali, Mir Abbas; Khoshnood, Atefeh; Alam, Mohammad-Reza

    2015-11-01

    Life on the Earth is strongly dependent upon mixing across a vast range of scales. For example, mixing distributes nutrients for microorganisms in aquatic environments, and balances the spatial energy distribution in the oceans and the atmosphere. From industrial point of view, mixing is essential in many microfluidic processes and lab-on-a-chip operations, polymer engineering, pharmaceutics, food engineering, petroleum engineering, and biotechnology. Efficient mixing, typically characterized by chaotic advection, is hard to achieve in low Reynolds number conditions because of the linear nature of the Stokes equation that governs the motion. We report the first demonstration of chaotic mixing induced by a microswimmer that strokes on quasiperiodic orbits with multi-loop turning paths. Our findings can be utilized to understand the interactions of microorganisms with their environments, and to design autonomous robotic mixers that can sweep and mix an entire volume of complex-geometry containers.

  2. The Iterative Design of a Virtual Design Studio

    ERIC Educational Resources Information Center

    Blevis, Eli; Lim, Youn-kyung; Stolterman, Erik; Makice, Kevin

    2008-01-01

    In this article, the authors explain how they implemented Design eXchange as a shared collaborative online and physical space for design for their students. Their notion for Design eXchange favors a complex mix of key elements namely: (1) a virtual online studio; (2) a forum for review of all things related to design, especially design with the…

  3. Mixed integer evolution strategies for parameter optimization.

    PubMed

    Li, Rui; Emmerich, Michael T M; Eggermont, Jeroen; Bäck, Thomas; Schütz, M; Dijkstra, J; Reiber, J H C

    2013-01-01

    Evolution strategies (ESs) are powerful probabilistic search and optimization algorithms gleaned from biological evolution theory. They have been successfully applied to a wide range of real world applications. The modern ESs are mainly designed for solving continuous parameter optimization problems. Their ability to adapt the parameters of the multivariate normal distribution used for mutation during the optimization run makes them well suited for this domain. In this article we describe and study mixed integer evolution strategies (MIES), which are natural extensions of ES for mixed integer optimization problems. MIES can deal with parameter vectors consisting not only of continuous variables but also with nominal discrete and integer variables. Following the design principles of the canonical evolution strategies, they use specialized mutation operators tailored for the aforementioned mixed parameter classes. For each type of variable, the choice of mutation operators is governed by a natural metric for this variable type, maximal entropy, and symmetry considerations. All distributions used for mutation can be controlled in their shape by means of scaling parameters, allowing self-adaptation to be implemented. After introducing and motivating the conceptual design of the MIES, we study the optimality of the self-adaptation of step sizes and mutation rates on a generalized (weighted) sphere model. Moreover, we prove global convergence of the MIES on a very general class of problems. The remainder of the article is devoted to performance studies on artificial landscapes (barrier functions and mixed integer NK landscapes), and a case study in the optimization of medical image analysis systems. In addition, we show that with proper constraint handling techniques, MIES can also be applied to classical mixed integer nonlinear programming problems. PMID:22122384

  4. Control of Jet Noise Through Mixing Enhancement

    NASA Technical Reports Server (NTRS)

    Bridges, James; Wernet, Mark; Brown, Cliff

    2003-01-01

    The idea of using mixing enhancement to reduce jet noise is not new. Lobed mixers have been around since shortly after jet noise became a problem. However, these designs were often a post-design fix that rarely was worth its weight and thrust loss from a system perspective. Recent advances in CFD and some inspired concepts involving chevrons have shown how mixing enhancement can be successfully employed in noise reduction by subtle manipulation of the nozzle geometry. At NASA Glenn Research Center, this recent success has provided an opportunity to explore our paradigms of jet noise understanding, prediction, and reduction. Recent advances in turbulence measurement technology for hot jets have also greatly aided our ability to explore the cause and effect relationships of nozzle geometry, plume turbulence, and acoustic far field. By studying the flow and sound fields of jets with various degrees of mixing enhancement and subsequent noise manipulation, we are able to explore our intuition regarding how jets make noise, test our prediction codes, and pursue advanced noise reduction concepts. The paper will cover some of the existing paradigms of jet noise as they relate to mixing enhancement for jet noise reduction, and present experimental and analytical observations that support these paradigms.

  5. 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

  6. CFD simulation of mixing for high-solids anaerobic digestion.

    PubMed

    Wu, Binxin

    2012-08-01

    A computational fluid dynamics (CFD) model that simulates mechanical mixing for high-solids anaerobic digestion was developed. Numerical simulations of mixing manure slurry which exhibits non-Newtonian pseudo-plastic fluid behavior were performed for six designs: (i) one helical ribbon impeller; (ii) one anchor impeller; (iii) one curtain-type impeller; (iv) three counterflow (CF-2) impellers; (v) two modified high solidity (MHS 3/39°) impellers; and (vi) two pitched blade turbine impellers. The CFD model was validated against measurements for mixing a Herschel-Bulkley fluid by ribbon and anchor impellers. Based on mixing time with respect to mixing energy level, three impeller types (ribbon, CF-2, and MHS 3/39°) stand out when agitating highly viscous fluids, of these mixing with two MHS 3/39° impellers requires the lowest power input to homogenize the manure slurry. A comparison of digestion material demonstrates that the mixing energy varies with manure type and total solids concentration to obtain a given mixing time. Moreover, an in-depth discussion about the CFD strategy, the influences of flow regime and impeller type on mixing characteristics, and the intrinsic relation between mixing and flow field is included. PMID:22422446

  7. Magnetically coupled system for mixing

    SciTech Connect

    Miller, III, Harlan; Meichel, George; Legere, Edward; Malkiel, Edwin; Woods, Robert Paul; Ashley, Oliver; Katz, Joseph; Ward, Jason; Petersen, Paul

    2014-04-01

    The invention provides a mixing system comprising a magnetically coupled drive system and a foil for cultivating algae, or cyanobacteria, in an open or enclosed vessel. The invention provides effective mixing, low energy usage, low capital expenditure, and ease of drive system component maintenance while maintaining the integrity of a sealed mixing vessel.

  8. Mix/Cast Contamination Control

    NASA Technical Reports Server (NTRS)

    Wallentine, M.

    2005-01-01

    Presented is a training handbook for Mix/Cast Contamination Control; a part of a series of training courses to qualify access to Mix/Cast facilities. Contents: List Contamination Control Requirements; Identify foreign objects debris (FOD), Control Areas and their guidelines; Describe environmental monitoring; List Contamination Control Initiatives; Describe concern for Controlled Materials; Identify FOD Controlled Areas in Mix/Cast.

  9. Magnetically coupled system for mixing

    SciTech Connect

    Miller, III, Harlan; Meichel, George; Legere, Edward; Malkiel, Edwin; Woods, Robert Paul; Ashley, Oliver; Katz, Joseph; Ward, Jason; Petersen, Paul

    2015-09-22

    The invention provides a mixing system comprising a magnetically coupled drive system and a foil for cultivating algae, or cyanobacteria, in an open or enclosed vessel. The invention provides effective mixing, low energy usage, low capital expenditure, and ease of drive system component maintenance while maintaining the integrity of a sealed mixing vessel.

  10. A new unsteady mixing model to predict NO(x) production during rapid mixing in a dual-stage combustor

    NASA Technical Reports Server (NTRS)

    Menon, Suresh

    1992-01-01

    An advanced gas turbine engine to power supersonic transport aircraft is currently under study. In addition to high combustion efficiency requirements, environmental concerns have placed stringent restrictions on the pollutant emissions from these engines. A combustor design with the potential for minimizing pollutants such as NO(x) emissions is undergoing experimental evaluation. A major technical issue in the design of this combustor is how to rapidly mix the hot, fuel-rich primary zone product with the secondary diluent air to obtain a fuel-lean mixture for combustion in the second stage. Numerical predictions using steady-state methods cannot account for the unsteady phenomena in the mixing region. Therefore, to evaluate the effect of unsteady mixing and combustion processes, a novel unsteady mixing model is demonstrated here. This model has been used to study multispecies mixing as well as propane-air and hydrogen-air jet nonpremixed flames, and has been used to predict NO(x) production in the mixing region. Comparison with available experimental data show good agreement, thereby providing validation of the mixing model. With this demonstration, this mixing model is ready to be implemented in conjunction with steady-state prediction methods and provide an improved engineering design analysis tool.

  11. RO1 Funding for Mixed Methods Research: Lessons learned from the Mixed-Method Analysis of Japanese Depression Project

    PubMed Central

    Arnault, Denise Saint; Fetters, Michael D.

    2013-01-01

    Mixed methods research has made significant in-roads in the effort to examine complex health related phenomenon. However, little has been published on the funding of mixed methods research projects. This paper addresses that gap by presenting an example of an NIMH funded project using a mixed methods QUAL-QUAN triangulation design entitled “The Mixed-Method Analysis of Japanese Depression.” We present the Cultural Determinants of Health Seeking model that framed the study, the specific aims, the quantitative and qualitative data sources informing the study, and overview of the mixing of the two studies. Finally, we examine reviewer's comments and our insights related to writing mixed method proposal successful for achieving RO1 level funding. PMID:25419196

  12. 26 CFR 1.1092(b)-4T - Mixed straddles; mixed straddle account (temporary).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... second mixed straddle account, which has an annual account net loss of $20,000 of long-term capital loss... account for determining gains and losses from all positions held as capital assets in a designated class... year, and that gain or loss from the positions is treated as gain or loss from a capital asset....

  13. Wave mixing spectroscopy

    SciTech Connect

    Smith, R.W.

    1980-08-01

    Several new aspects of nonlinear or wave mixing spectroscopy were investigated utilizing the polarization properties of the nonlinear output field and the dependence of this field upon the occurrence of multiple resonances in the nonlinear susceptibility. First, it is shown theoretically that polarization-sensitive detection may be used to either eliminate or controllably reduce the nonresonant background in coherent anti-Stokes Raman spectroscopy, allowing weaker Raman resonances to be studied. The features of multi-resonant four-wave mixing are examined in the case of an inhomogeneously broadened medium. It is found that the linewidth of the nonlinear output narrows considerably (approaching the homogeneous width) when the quantum mechanical expressions for the doubly- and triply-resonant susceptibilities are averaged over a Doppler or strain broadened profile. Experimental studies of nonlinear processes in Pr/sup +3/:LaF/sub 3/ verify this linewidth narrowing, but indicate that this strain broadened system cannot be treated with a single broadening parameter as in the case of Doppler broadening in a gas. Several susceptibilities are measured from which are deduced dipole matrix elements and Raman polarizabilities related to the /sup 3/H/sub 4/, /sup 3/H/sub 6/, and /sup 3/P/sub 0/ levels of the praseodymium ions.

  14. Transition mixing study

    NASA Technical Reports Server (NTRS)

    Reynolds, R.; White, C.

    1986-01-01

    A computer model capable of analyzing the flow field in the transition liner of small gas turbine engines is developed. A FORTRAN code has been assembled from existing codes and physical submodels and used to predict the flow in several test geometries which contain characteristics similar to transition liners, and for which experimental data was available. Comparisons between the predictions and measurements indicate that the code produces qualitative results but that the turbulence models, both K-E and algebraic Reynolds Stress, underestimate the cross-stream diffusion. The code has also been used to perform a numerical experiment to examine the effect of a variety of parameters on the mixing process in transition liners. Comparisons illustrate that geometries with significant curvature show a drift of the jet trajectory toward the convex wall and weaker wake region vortices and decreased penetration for jets located on the convex wall of the liner, when compared to jets located on concave walls. Also shown were the approximate equivalency of angled slots and round holes and a technique by which jet mixing correlations developed for rectangular channels can be used for can geometries.

  15. Correlating lepton mixing angles and mixing maxtrix with Wolfenstein parameters

    NASA Astrophysics Data System (ADS)

    Zhang, Xinyi; Ma, Bo-Qiang

    2012-11-01

    Inspired by a new relation θ13PMNS=θC/2 observed from the relatively large θ13PMNS, we find that the combination of this relation with the quark-lepton complementarity and the self-complementarity results in correlations of the lepton mixing angles with the quark mixing angles. We find that the three mixing angles in the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrix are all related to the Wolfenstein parameter λ in the quark mixing, so they are also correlated. Consequently, the PMNS matrix can be parameterized by λ, A, and a Dirac CP-violating phase δ. Such parametrizations for the PMNS matrix have the same explicitly hierarchical structure as the Wolfenstein parametrization for the Cabibbo-Kobayashi-Maskawa matrix in the quark mixing, and the bimaximal mixing pattern is deduced at the leading order. We also discuss implications of these phenomenological relations in parametrizations.

  16. The Structure of Mixed Method Studies in Educational Research: A Content Analysis

    ERIC Educational Resources Information Center

    Bryant, Lauren H.

    2011-01-01

    Educational researchers are beginning to use mixed methods designs to answer complex research questions. This content analysis investigates the structure and use of mixed methods in educational research in order to work toward a more standardized presentation. I used a concurrent mixed methods approach to analyze 30 studies from three prominent…

  17. Mixed Methods in Emerging Academic Subdisciplines: The Case of Sport Management

    ERIC Educational Resources Information Center

    van der Roest, Jan-Willem; Spaaij, Ramón; van Bottenburg, Maarten

    2015-01-01

    This article examines the prevalence and characteristics of mixed methods research in the relatively new subdiscipline of sport management. A mixed methods study is undertaken to evaluate the epistemological/philosophical, methodological, and technical levels of mixed methods design in sport management research. The results indicate that mixed…

  18. Nation's water picture mixed

    NASA Astrophysics Data System (ADS)

    The nation's water picture for April showed mixed trends: More than half of the index gaging stations reported normal streamflow conditions during the month, while the spring snowmelt boosted streamflow in the Northeast and Northwest to well above normal levels. Parts of the Southeast, however, from West Virginia south to the Carolinas, reported well-below normal streamflow conditions, according to a month-end check on water resources conditions by the U.S. Geological Survey, Department of the Interior.After nearly 2 years of drought conditions the three major reservoirs supplying New York City reached full storage capacity and were spilling during April. Combined contents of the three reservoirs on May 1, 1982, was 272 billion gallons, 101% of their full usable capacity. The full reservoirs and the generally good surface and groundwater conditions throughout the Delaware River basin allowed the Delaware River Basin Commission to lift its drought emergency warning on April 27.

  19. Holographic mixing quantified

    SciTech Connect

    Batell, Brian; Gherghetta, Tony

    2007-08-15

    We compute the precise elementary/composite field content of mass eigenstates in holographic duals of warped models in a slice of AdS{sub 5}. This is accomplished by decomposing the bulk fields not in the usual Kaluza-Klein basis, but rather into a holographic basis of 4D fields, corresponding to purely elementary source or conformal field theory (CFT) composite fields. Generically, this decomposition yields kinetic and mass mixing between the elementary and composite sectors of the holographic theory. Depending on where the bulk zero mode is localized, the elementary/composite content may differ radically, which we show explicitly for several examples including the bulk Randall-Sundrum graviton, bulk gauge boson, and Higgs boson.

  20. Mixed Mode Matrix Multiplication

    SciTech Connect

    Meng-Shiou Wu; Srinivas Aluru; Ricky A. Kendall

    2004-09-30

    In modern clustering environments where the memory hierarchy has many layers (distributed memory, shared memory layer, cache,...), an important question is how to fully utilize all available resources and identify the most dominant layer in certain computations. When combining algorithms on all layers together, what would be the best method to get the best performance out of all the resources we have? Mixed mode programming model that uses thread programming on the shared memory layer and message passing programming on the distributed memory layer is a method that many researchers are using to utilize the memory resources. In this paper, they take an algorithmic approach that uses matrix multiplication as a tool to show how cache algorithms affect the performance of both shared memory and distributed memory algorithms. They show that with good underlying cache algorithm, overall performance is stable. When underlying cache algorithm is bad, superlinear speedup may occur, and an increasing number of threads may also improve performance.

  1. Radioactive mixed waste disposal

    SciTech Connect

    Jasen, W.G.; Erpenbeck, E.G.

    1993-02-01

    Various types of waste have been generated during the 50-year history of the Hanford Site. Regulatory changes in the last 20 years have provided the emphasis for better management of these wastes. Interpretations of the Atomic Energy Act of 1954 (AEA), the Resource Conservation and Recovery Act of 1976 (RCRA), and the Hazardous and Solid Waste Amendments (HSWA) have led to the definition of radioactive mixed wastes (RMW). The radioactive and hazardous properties of these wastes have resulted in the initiation of special projects for the management of these wastes. Other solid wastes at the Hanford Site include low-level wastes, transuranic (TRU), and nonradioactive hazardous wastes. This paper describes a system for the treatment, storage, and disposal (TSD) of solid radioactive waste.

  2. Enhanced mixing in laminar flows using ultrahydrophobic surfaces.

    PubMed

    Ou, Jia; Moss, Geoffrey R; Rothstein, Jonathan P

    2007-07-01

    Under laminar, microscale flow conditions, rapid mixing can be difficult to achieve. In these low Reynolds number flows, mixing rates are governed by molecular diffusion, and in the absence of enhanced mixing techniques, mixing lengths and residence times can be much longer than most applications will allow. A number of active mixing techniques have been developed to improve mixing; however, they can be complex to implement and expensive to fabricate. In this paper, we describe a passive mixing method that utilizes a series of ultrahydrophobic surfaces. Our previous experiments have demonstrated that a shear-free air-water interface supported between hydrophobic microridges results in large slip velocities along these ultrahydrophobic surfaces, and significant drag reduction. By aligning the microridges and therefore the air-water interface at an oblique angle to the flow direction, a secondary flow is generated, which is shown to efficiently stretch and fold the fluid elements and reduce the mixing length by more than an order of magnitude compared to that of a smooth microchannel. The designs of the ultrahydrophobic surfaces were optimized through experiments and numerical simulations. A Y-shaped channel was used to bring two streams of water together, one tagged with a fluorescent dye. A confocal microscope was used to measure fluorescence intensity and dye concentration. Quantitative agreement between the experiments and the numerical simulations was achieved for both the flow patterns and degree of mixing. Increasing the angle of the microridges was found to reduce the mixing length up to a critical angle of about 60 degrees , beyond which the mixing length was found to increase with further increases to the angle of the microridge. The mixing enhancement was found to be much less sensitive to changes in microridge width or separation. PMID:17677560

  3. Jet mixing in a reacting cylindrical crossflow

    NASA Technical Reports Server (NTRS)

    Leong, M. Y.; Samuelsen, G. S.; Holdeman, J. D.

    1995-01-01

    This paper addresses the mixing of air jets into the hot, fuel-rich products of a gas turbine primary zone. The mixing, as a result, occurs in a reacting environment with chemical conversion and substantial heat release. The geometry is a crossflow confined in a cylindrical duct with side-wall injection of jets issuing from round orifices. A specially designed reactor, operating on propane, presents a uniform mixture without swirl to mixing modules consisting of 8, 9, 10, and 12 holes at a momentum-flux ratio of 57 and a jet-to-mainstream mass-flow ratio of 2.5. Concentrations of O2, CO2, CO, and HC are obtained upstream, downstream, and within the orifice plane. O2 profiles indicate jet penetration while CO2, CO, and HC profiles depict the extent of reaction. Jet penetration is observed to be a function of the number of orifices and is found to affect the mixing in the reacting system. The results demonstrate that one module (the 12-hole) produces near-optimal penetration defined here as a jet penetration closest to the module half-radius, and hence the best uniform mixture at a plane one duct radius from the orifice leading edge.

  4. Methodology to remediate a mixed waste site

    SciTech Connect

    Berry, J.B.

    1994-08-01

    In response to the need for a comprehensive and consistent approach to the complex issue of mixed waste management, a generalized methodology for remediation of a mixed waste site has been developed. The methodology is based on requirements set forth in the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and the Resource Conservation and Recovery Act (RCRA) and incorporates ``lessons learned`` from process design, remediation methodologies, and remediation projects. The methodology is applied to the treatment of 32,000 drums of mixed waste sludge at the Oak Ridge K-25 Site. Process technology options are developed and evaluated, first with regard to meeting system requirements and then with regard to CERCLA performance criteria. The following process technology options are investigated: (1) no action, (2) separation of hazardous and radioactive species, (3) dewatering, (4) drying, and (5) solidification/stabilization. The first two options were eliminated from detailed consideration because they did not meet the system requirements. A quantitative evaluation clearly showed that, based on system constraints and project objectives, either dewatering or drying the mixed waste sludge was superior to the solidification/stabilization process option. The ultimate choice between the drying and the dewatering options will be made on the basis of a technical evaluation of the relative merits of proposals submitted by potential subcontractors.

  5. Mixing entropy in Dean flows

    NASA Astrophysics Data System (ADS)

    Fodor, Petru; Vyhnalek, Brian; Kaufman, Miron

    2013-03-01

    We investigate mixing in Dean flows by solving numerically the Navier-Stokes equation for a circular channel. Tracers of two chemical species are carried by the fluid. The centrifugal forces, experienced as the fluid travels along a curved trajectory, coupled with the fluid incompressibility induce cross-sectional rotating flows (Dean vortices). These transversal flows promote the mixing of the chemical species. We generate images for different cross sections along the trajectory. The mixing efficiency is evaluated using the Shannon entropy. Previously we have found, P. S. Fodor and M. Kaufman, Modern Physics Letters B 25, 1111 (2011), this measure to be useful in understanding mixing in the staggered herringbone mixer. The mixing entropy is determined as function of the Reynolds number, the angle of the cross section and the observation scale (number of bins). Quantitative comparison of the mixing in the Dean micromixer and in the staggered herringbone mixer is attempted.

  6. Estimating beta-mixing coefficients

    PubMed Central

    McDonald, Daniel J.; Shalizi, Cosma Rohilla; Schervish, Mark

    2015-01-01

    The literature on statistical learning for time series assumes the asymptotic independence or “mixing” of the data-generating process. These mixing assumptions are never tested, and there are no methods for estimating mixing rates from data. We give an estimator for the beta-mixing rate based on a single stationary sample path and show it is L1-risk consistent. PMID:26279742

  7. Coolant mixing in LMFBR rod bundles and outlet plenum mixing transients. Final report

    SciTech Connect

    Todreas, N.E.; Cheng, S.K.; Basehore, K.

    1984-08-01

    This project principally undertook the investigation of the thermal hydraulic performance of wire wrapped fuel bundles of LMFBR configuration. Results obtained included phenomenological models for friction factors, flow split and mixing characteristics; correlations for predicting these characteristics suitable for insertion in design codes; numerical codes for analyzing bundle behavior both of the lumped subchannel and distributed parameter categories and experimental techniques for pressure velocity, flow split, salt conductivity and temperature measurement in water cooled mockups of bundles and subchannels. Flow regimes investigated included laminar, transition and turbulent flow under forced convection and mixed convection conditions. Forced convections conditions were emphasized. Continuing efforts are underway at MIT to complete the investigation of the mixed convection regime initiated here. A number of investigations on outlet plenum behavior were also made. The reports of these investigations are identified.

  8. Nursing Home Quality, Cost, Staffing, and Staff Mix

    ERIC Educational Resources Information Center

    Rantz, Marilyn J.; Hicks, Lanis; Grando, Victoria; Petroski, Gregory F.; Madsen, Richard W.; Mehr, David R.; Conn, Vicki; Zwygart-Staffacher, Mary; Scott, Jill; Flesner, Marcia; Bostick, Jane; Porter, Rose; Maas, Meridean

    2004-01-01

    Purpose: The purpose of this study was to describe the processes of care, organizational attributes, cost of care, staffing level, and staff mix in a sample of Missouri homes with good, average, and poor resident outcomes. Design and Methods: A three-group exploratory study design was used, with 92 nursing homes randomly selected from all nursing…

  9. Investigation of fatigue failure in bituminous base mixes

    NASA Astrophysics Data System (ADS)

    Maupin, G. W., Jr.

    1980-02-01

    A correlation between the results obtained with the fatigue test and those from the indirect tensile test on two base mixes was attempted in anticipation of the possible use of the latter test to design base mixes for maximum fatigue life. Two base mixes at several asphalt contents were tested at two test temperatures. Flexural fatigue tests and indirect tensile tests were performed for each mix and temperature condition. The asphalt content corresponding to the maximum fatigue life agreed generally with the asphalt content corresponding to maximum work in the indirect tensile test. The work computed from the indirect tensile test is useful in selecting the asphalt content for the maximum fatigue life of base mixes.

  10. Computer modeling of jet mixing in INEL waste tanks

    SciTech Connect

    Meyer, P.A.

    1994-01-01

    The objective of this study is to examine the feasibility of using submerged jet mixing pumps to mobilize and suspend settled sludge materials in INEL High Level Radioactive Waste Tanks. Scenarios include removing the heel (a shallow liquid and sludge layer remaining after tank emptying processes) and mobilizing and suspending solids in full or partially full tanks. The approach used was to (1) briefly review jet mixing theory, (2) review erosion literature in order to identify and estimate important sludge characterization parameters (3) perform computer modeling of submerged liquid mixing jets in INEL tank geometries, (4) develop analytical models from which pump operating conditions and mixing times can be estimated, and (5) analyze model results to determine overall feasibility of using jet mixing pumps and make design recommendations.

  11. Overview of Neutrino Mixing Models and Their Mixing Angle Predictions

    SciTech Connect

    Albright, Carl H.

    2009-11-01

    An overview of neutrino-mixing models is presented with emphasis on the types of horizontal flavor and vertical family symmetries that have been invoked. Distributions for the mixing angles of many models are displayed. Ways to differentiate among the models and to narrow the list of viable models are discussed.

  12. Tank Pressure Control Experiment - A low-g mixing investigation

    NASA Technical Reports Server (NTRS)

    Bentz, M. D.; Meserole, J. S.; Knoll, R. L.

    1990-01-01

    The Tank Pressure Control Experiment (TPCE) was conceived to meet the need for an aspect of cryogenic fluid management technology that is critical to several future national space missions: control of cryogenic storage tank pressures by active mixing. In-space testing is the only means of obtaining the fluid dynamic data necessary to develop and test predictive models of mixing. These models, when validated, will allow future cryogenic systems to be designed with more efficient and reliable pressure control systems. The objectives of the TPCE project are to characterize the fluid dynamics of jet-induced mixing in low gravity, evaluate the validity of empirical models and correlations, and provide data for use in developing and validating computational fluid dynamic models. This paper discusses prior studies of low-g mixing, the objectives and benefits of TPCE, the design and status of the payload, and preliminary results obtained from low-g aircraft testing.

  13. Enhancement of Mixing and Heat Transfer by Corrugated Permeable Walls

    NASA Technical Reports Server (NTRS)

    Gilinsky, M.; Sinkine, N.; Akyurtlu, J.; Akyurtlu, A.; Blankson, I. M.; Maron, V. I.

    2003-01-01

    A re-circulation method that is based on the static pressure recovery in the divergent part of a converging-diverging flow channel is discussed. This method can be used to design a static device that can be used to increase the residence time of the fluid and the mixing in the transverse and/or flow directions in compressible and incompressible fluids flowing at subsonic velocities. The device with external reverse flow channels will produce mixing in both transverse and flow directions. If mixing in the flow direction is not desired, the concept can be used to design an insert to provide only transverse mixing. Theoretical relationships for a re-circulating one-dimensional incompressible flow around a converging-diverging channel were obtained. Attempts at numerical simulation of re-circulation in compressible fluids were not successful. Qualitative experimental verification of re-circulating flows for incompressible and compressible fluids were obtained.

  14. Mixing Study in a Multi-dimensional Motion Mixer

    NASA Astrophysics Data System (ADS)

    Shah, R.; Manickam, S. S.; Tomei, J.; Bergman, T. L.; Chaudhuri, B.

    2009-06-01

    Mixing is an important but poorly understood aspect in petrochemical, food, ceramics, fertilizer and pharmaceutical processing and manufacturing. Deliberate mixing of granular solids is an essential operation in the production of industrial powder products usually constituted from different ingredients. The knowledge of particle flow and mixing in a blender is critical to optimize the design and operation. Since performance of the product depends on blend homogeneity, the consequence of variability can be detrimental. A common approach to powder mixing is to use a tumbling blender, which is essentially a hollow vessel horizontally attached to a rotating shaft. This single axis rotary blender is one of the most common batch mixers among in industry, and also finds use in myriad of application as dryers, kilns, coaters, mills and granulators. In most of the rotary mixers the radial convection is faster than axial dispersion transport. This slow dispersive process hinders mixing performance in many blending, drying and coating applications. A double cone mixer is designed and fabricated which rotates around two axes, causing axial mixing competitive to its radial counterpart. Discrete Element Method (DEM) based numerical model is developed to simulate the granular flow within the mixer. Digitally recorded mixing states from experiments are used to fine tune the numerical model. Discrete pocket samplers are also used in the experiments to quantify the characteristics of mixing. A parametric study of the effect of vessel speeds, relative rotational speed (between two axes of rotation), on the granular mixing is investigated by experiments and numerical simulation. Incorporation of dual axis rotation enhances axial mixing by 60 to 85% in comparison to single axis rotation.

  15. CORMIX MIXING ZONE MODELS

    EPA Science Inventory

    Resource Purpose:CORMIX is a software system for the analysis, prediction, and design of aqueous toxics or conventional pollutant discharges to surface waters. CORMIX consists of three subsystems which are: (1) CORMIX 1, for the analysis of submerged single port discharges...

  16. Mixed additive models

    NASA Astrophysics Data System (ADS)

    Carvalho, Francisco; Covas, Ricardo

    2016-06-01

    We consider mixed models y =∑i =0 w Xiβi with V (y )=∑i =1 w θiMi Where Mi=XiXi⊤ , i = 1, . . ., w, and µ = X0β0. For these we will estimate the variance components θ1, . . ., θw, aswell estimable vectors through the decomposition of the initial model into sub-models y(h), h ∈ Γ, with V (y (h ))=γ (h )Ig (h )h ∈Γ . Moreover we will consider L extensions of these models, i.e., y˚=Ly+ɛ, where L=D (1n1, . . ., 1nw) and ɛ, independent of y, has null mean vector and variance covariance matrix θw+1Iw, where w =∑i =1 n wi .

  17. Mixed waste analysis

    SciTech Connect

    Reynolds, J.J.; Turner, C.A.

    1993-12-31

    Improved superpower relations followed by the Soviet Union`s collapse acted as catalysts for changing the mission at Rocky Flats. Now, environmental concerns command as much attention as production capability. As a result, laboratory instruments once dedicated to plutonium production have a new purpose - the analysis of mixed wastes. Waste drums destined for WIPP require headspace analysis by GS/MS (gas chromatography/mass spectrometry) for volatile and semi-volatile organic compounds (VOC and SVOC). Flame AA analysis provides information on inorganic constituents. EPA guidelines for waste analysis (SW-846) overlook the obstacles of glove box manipulations. Sometimes, SW-846 guidelines conflict with the Rocky Flats waste minimization effort. However, the EPA encourages SW-846 adaptations if experimental data confirms the results. For water and soil samples, AA analysis of laboratory control samples show method capability inside a glove box. Non-radioactive drum headspace samples use a revised version of USEPA compendium method TO-14. Radioactive drum headspace samples require new instrumentation and change to SW-846 methods.

  18. Maximum mixing method

    NASA Astrophysics Data System (ADS)

    Hjorth, Jens

    The unique feature of MEM is that C(-1)(z) = exp(z) amplifies all scales equally. Narayan & Nityananda (1986) have shown that this leads to Gaussian deconvolved peaks. In MMM different scales are treated differently, depending on the choice of C. This gives different peak shapes, but also allows one to experiment with the degree of peak sharpening as a function of peak height. In fact, despite its strong information-theoretic background, MEM is known to redistribute flux incorrectly during deconvolution, thus making the method problematic if the goal is to get correct intensities out. MMM could remedy this problem by using an alternative to the entropy. In conclusion, some ideas connecting the physics of blurring with a proposed reconstruction scheme, dubbed Maximum Mixing Method, have been presented. It has been shown that this physically motivated, non-information theoretic, non-probabilistic, non-Bayesian approach can be turned into a powerful deconvolution technique, competitive with, and having as a special case, the Maximum Entropy Method. Further work within the proposed framework is required to fully explore the consequences of the theory. A paper including proofs and examples is in preparation.

  19. Measures on mixing angles

    SciTech Connect

    Gibbons, Gary W.; Gielen, Steffen; Pope, C. N.; Turok, Neil

    2009-01-01

    We address the problem of the apparently very small magnitude of CP violation in the standard model, measured by the Jarlskog invariant J. In order to make statements about probabilities for certain values of J, we seek to find a natural measure on the space of Kobayashi-Maskawa matrices, the double quotient U(1){sup 2}/SU(3)/U(1){sup 2}. We review several possible, geometrically motivated choices of the measure, and compute expectation values for powers of J for these measures. We find that different choices of the measure generically make the observed magnitude of CP violation appear finely tuned. Since the quark masses and the mixing angles are determined by the same set of Yukawa couplings, we then do a second calculation in which we take the known quark mass hierarchy into account. We construct the simplest measure on the space of 3x3 Hermitian matrices which reproduces this known hierarchy. Calculating expectation values for powers of J in this second approach, we find that values of J close to the observed value are now rather likely, and there does not seem to be any fine-tuning. Our results suggest that the choice of Kobayashi-Maskawa angles is closely linked to the observed mass hierarchy. We close by discussing the corresponding case of neutrinos.

  20. Degradation of mix hydrocarbons by immobilized cells of mix culture using a trickle fluidized bed reactor. Annual progress report, June 1992--May 1993

    SciTech Connect

    Chapatwala, K.D.

    1993-06-01

    The microorganisms, capable of degrading mix hydrocarbons were isolated from the soil samples collected from the hydrocarbon contaminated sites. The mix cultures were immobilized in calcium alginate solution in the form of beads. A trickle fluidized bed air-uplift-type reactor designed to study the degradation of mix hydrocarbons was filled with 0.85% normal saline containing the immobilized cells of mix culture. The immobilized beads were aerated with CO{sub 2}-free air at 200 ml/min. The degradation of different concentrations of hydrocarbons in the presence/absence of commercially available fertilizers by the immobilized cells of mix culture is now in progress.

  1. Mixing in polymeric microfluidic devices.

    SciTech Connect

    Schunk, Peter Randall; Sun, Amy Cha-Tien; Davis, Robert H.; Brotherton, Christopher M. (University of Colorado at Boulder, Boulder, CO)

    2006-04-01

    This SAND report describes progress made during a Sandia National Laboratories sponsored graduate fellowship. The fellowship was funded through an LDRD proposal. The goal of this project is development and characterization of mixing strategies for polymeric microfluidic devices. The mixing strategies under investigation include electroosmotic flow focusing, hydrodynamic focusing, physical constrictions and porous polymer monoliths. For electroosmotic flow focusing, simulations were performed to determine the effect of electroosmotic flow in a microchannel with heterogeneous surface potential. The heterogeneous surface potential caused recirculations to form within the microchannel. These recirculations could then be used to restrict two mixing streams and reduce the characteristic diffusion length. Maximum mixing occurred when the ratio of the mixing region surface potential to the average channel surface potential was made large in magnitude and negative in sign, and when the ratio of the characteristic convection time to the characteristic diffusion time was minimized. Based on these results, experiments were performed to evaluate the manipulation of surface potential using living-radical photopolymerization. The material chosen to manipulate typically exhibits a negative surface potential. Using living-radical surface grafting, a positive surface potential was produced using 2-(Dimethylamino)ethyl methacrylate and a neutral surface was produced using a poly(ethylene glycol) surface graft. Simulations investigating hydrodynamic focusing were also performed. For this technique, mixing is enhanced by using a tertiary fluid stream to constrict the two mixing streams and reduce the characteristic diffusion length. Maximum mixing occurred when the ratio of the tertiary flow stream flow-rate to the mixing streams flow-rate was maximized. Also, like the electroosmotic focusing mixer, mixing was also maximized when the ratio of the characteristic convection time to the

  2. Mixing in a liquid metal electrode

    SciTech Connect

    Kelley, DH; Sadoway, DR

    2014-05-01

    Fluid mixing has first-order importance for many engineering problems in mass transport, including design and optimization of liquid-phase energy storage devices. Liquid metal batteries are currently being commercialized as a promising and economically viable technology for large-scale energy storage on worldwide electrical grids. But because these batteries are entirely liquid, fluid flow and instabilities may affect battery robustness and performance. Here we present estimates of flow magnitude and ultrasound measurements of the flow in a realistic liquid metal electrode. We find that flow does substantially affect mass transport by altering the electrode mixing time. Above a critical electrical current density, the convective flow organizes and gains speed, which promotes transport and would yield improved battery efficiency. (C) 2014 AIP Publishing LLC.

  3. Magnetoplasmonic RF mixing and nonlinear frequency generation

    NASA Astrophysics Data System (ADS)

    Firby, C. J.; Elezzabi, A. Y.

    2016-07-01

    We present the design of a magnetoplasmonic Mach-Zehnder interferometer (MZI) modulator facilitating radio-frequency (RF) mixing and nonlinear frequency generation. This is achieved by forming the MZI arms from long-range dielectric-loaded plasmonic waveguides containing bismuth-substituted yttrium iron garnet (Bi:YIG). The magnetization of the Bi:YIG can be driven in the nonlinear regime by RF magnetic fields produced around adjacent transmission lines. Correspondingly, the nonlinear temporal dynamics of the transverse magnetization component are mapped onto the nonreciprocal phase shift in the MZI arms, and onto the output optical intensity signal. We show that this tunable mechanism can generate harmonics, frequency splitting, and frequency down-conversion with a single RF excitation, as well as RF mixing when driven by two RF signals. This magnetoplasmonic component can reduce the number of electrical sources required to generate distinct optical modulation frequencies and is anticipated to satisfy important applications in integrated optics.

  4. Nonblocking space wavelength networks with wave-mixing frequency conversion

    NASA Astrophysics Data System (ADS)

    Dasylva, Abel Clement; Montuno, Delfin Y.; Kodaypak, Prasad

    2002-06-01

    We describe what we believe to be new designs for all-optical cross connects, capable of wavelength conversion. They are based on two-dimensional, space-wavelength, Benes or Cantor topologies, and they exploit cascaded wave-mixing bulk frequency conversion. In these cross connects many channels at distinct frequencies can be simultaneously frequency translated in a common wave-mixing device, and a given lightpath may be converted many times between its input and output. The new wavelength-interchanging cross connects are nonblocking and require O{F log2 W[log2(FW)]n} wave-mixing converters, where n = 0, 1.

  5. Mixed Methods: A Paradigm for Holistic Evaluation of Health IT.

    PubMed

    Scott, Philip J

    2016-01-01

    This contribution offers an overview of the 'third research paradigm', its historical roots and its relevance for health informatics. Using illustrative studies, we explore the concepts of triangulation and integration of quantitative and qualitative data and refute common philosophical objections to mixing different types of knowledge. We consider how the mixed method paradigm relates to two programme design and evaluation frameworks that are important for health informatics: realist evaluation and Theory of Change. We discuss how to manage practical challenges to this approach and explain how mixed method studies support an evidence-based approach to real world policy, planning and investment decisions. PMID:27198096

  6. Mixed Waste Working Group report

    SciTech Connect

    Not Available

    1993-11-09

    The treatment of mixed waste remains one of this country`s most vexing environmental problems. Mixed waste is the combination of radioactive waste and hazardous waste, as defined by the Resource Conservation and Recovery Act (RCRA). The Department of Energy (DOE), as the country`s largest mixed waste generator, responsible for 95 percent of the Nation`s mixed waste volume, is now required to address a strict set of milestones under the Federal Facility Compliance Act of 1992. DOE`s earlier failure to adequately address the storage and treatment issues associated with mixed waste has led to a significant backlog of temporarily stored waste, significant quantities of buried waste, limited permanent disposal options, and inadequate treatment solutions. Between May and November of 1993, the Mixed Waste Working Group brought together stakeholders from around the Nation. Scientists, citizens, entrepreneurs, and bureaucrats convened in a series of forums to chart a course for accelerated testing of innovative mixed waste technologies. For the first time, a wide range of stakeholders were asked to examine new technologies that, if given the chance to be tested and evaluated, offer the prospect for better, safer, cheaper, and faster solutions to the mixed waste problem. In a matter of months, the Working Group has managed to bridge a gap between science and perception, engineer and citizen, and has developed a shared program for testing new technologies.

  7. SOURCE ASSESSMENT: ASPHALT HOT MIX

    EPA Science Inventory

    This report summarizes data on air emissions from the asphalt hot mix industry. A representative asphalt hot mix plant was defined, based on the results of an industrial survey, to assess the severity of emissions from this industry. Source severity was defined as the ratio of th...

  8. Mixed connective tissue disease.

    PubMed

    Gunnarsson, Ragnar; Hetlevik, Siri Opsahl; Lilleby, Vibke; Molberg, Øyvind

    2016-02-01

    The concept of mixed connective tissue disease (MCTD) as a separate connective tissue disease (CTD) has persisted for more than four decades. High titers of antibodies targeting the U1 small nuclear ribonucleoprotein particle (U1 snRNP) in peripheral blood are a sine qua non for the diagnosis of MCTD, in addition to distinct clinical features including Raynaud's phenomenon (RP), "puffy hands," arthritis, myositis, pleuritis, pericarditis, interstitial lung disease (ILD), and pulmonary hypertension (PH). Recently, population-based epidemiology data from Norway estimated the point prevalence of adult-onset MCTD to be 3.8 per 100,000 and the mean annual incidence to be 2.1 per million per year, supporting the notion that MCTD is the least common CTD. Little is known about the etiology of MCTD, but recent genetic studies have confirmed that MCTD is a strongly HLA (​human leukocyte antigen)-linked disease, as the HLA profiles of MCTD differ distinctly from the corresponding profiles of ethnically matched healthy controls and other CTDs. In the first section of this review, we provide an update on the clinical, immunological, and genetic features of MCTD and discuss the relationship between MCTD and the other CTDs. Then we proceed to discuss the recent advances in therapy and our current understanding of prognosis and prognostic factors, especially those that are associated with the more serious pulmonary and cardiovascular complications of the disease. In the final section, we discuss some of the key, unresolved questions related to anti-RNP-associated diseases and indicate how these questions may be approached in future studies. PMID:27421219

  9. CHARACTERIZING PULSATING MIXING OF SLURRIES

    SciTech Connect

    Bamberger, Judith A.; Meyer, Perry A.

    2007-12-01

    This paper describes the physical properties for defining the operation of a pulse jet mixing system. Pulse jet mixing operates with no moving parts located in the vessel to be mixed. Pulse tubes submerged in the vessel provide a pulsating flow due to a controlled combination of applied pressure to expel the fluid from the pulse tube nozzle followed by suction to refill the pulse tube through the same nozzle. For mixing slurries nondimensional parameters to define mixing operation include slurry properties, geometric properties and operational parameters. Primary parameters include jet Reynolds number and Froude number; alternate parameters may include particle Galileo number, particle Reynolds number, settling velocity ratio, and hindered settling velocity ratio. Rating metrics for system performance include just suspended velocity, concentration distribution as a function of elevation, and blend time.

  10. Hanford Site annual dangerous waste report: Volume 2, Generator dangerous waste report, radioactive mixed waste

    SciTech Connect

    1994-12-31

    This report contains information on radioactive mixed wastes at the Hanford Site. Information consists of shipment date, physical state, chemical nature, waste description, waste number, waste designation, weight, and waste designation.

  11. Turbidity Current Head Mixing

    NASA Astrophysics Data System (ADS)

    Hernandez, David; Sanchez, Miguel Angel; Medina, Pablo

    2010-05-01

    coastal diffusion using image analysis. Applied Scientific Research 59,.191-204. 1998. [5] J.M. Redondo. Turbulent mixing in the Atmosphere and Ocean. Fluid Physics. 584-597. World Scientific. New York. 1994

  12. Fuel-Air Mixing and Combustion in Scramjets

    NASA Technical Reports Server (NTRS)

    Drummond, J. P.; Diskin, Glenn S.; Cutler, A. D.

    2002-01-01

    Activities in the area of scramjet fuel-air mixing and combustion associated with the Research and Technology Organization Working Group on Technologies for Propelled Hypersonic Flight are described. Work discussed in this paper has centered on the design of two basic experiments for studying the mixing and combustion of fuel and air in a scramjet. Simulations were conducted to aid in the design of these experiments. The experimental models were then constructed, and data were collected in the laboratory. Comparison of the data from a coaxial jet mixing experiment and a supersonic combustor experiment with a combustor code were then made and described. This work was conducted by NATO to validate combustion codes currently employed in scramjet design and to aid in the development of improved turbulence and combustion models employed by the codes.

  13. Mapping the Mixed Methods–Mixed Research Synthesis Terrain

    PubMed Central

    Sandelowski, Margarete; Voils, Corrine I.; Leeman, Jennifer; Crandell, Jamie L.

    2012-01-01

    Mixed methods–mixed research synthesis is a form of systematic review in which the findings of qualitative and quantitative studies are integrated via qualitative and/or quantitative methods. Although methodological advances have been made, efforts to differentiate research synthesis methods have been too focused on methods and not focused enough on the defining logics of research synthesis—each of which may be operationalized in different ways—or on the research findings themselves that are targeted for synthesis. The conduct of mixed methods–mixed research synthesis studies may more usefully be understood in terms of the logics of aggregation and configuration. Neither logic is preferable to the other nor tied exclusively to any one method or to any one side of the qualitative/quantitative binary. PMID:23066379

  14. Fluid mixing in stratified gravity currents: the Prandtl mixing length.

    PubMed

    Odier, P; Chen, J; Rivera, M K; Ecke, R E

    2009-04-01

    Shear-induced vertical mixing in a stratified flow is a key ingredient of thermohaline circulation. We experimentally determine the vertical flux of momentum and density of a forced gravity current using high-resolution velocity and density measurements. A constant eddy-viscosity model provides a poor description of the physics of mixing, but a Prandtl mixing length model relating momentum and density fluxes to mean velocity and density gradients works well. For the average gradient Richardson number Ri(g) approximately 0.08 and a Taylor Reynolds number Re(lambda) approximately 100, the mixing lengths are fairly constant, about the same magnitude, comparable to the turbulent shear length. PMID:19392360

  15. [Marketing mix in health service].

    PubMed

    Ameri, Cinzia; Fiorini, Fulvio

    2015-01-01

    The marketing mix is the combination of the marketing variables that a firm employs with the purpose to achieve the expected volume of business within its market. In the sale of goods, four variables compose the marketing mix (4 Ps): Product, Price, Point of sale and Promotion. In the case of providing services, three further elements play a role: Personnel, Physical Evidence and Processes (7 Ps). The marketing mix must be addressed to the consumers as well as to the employees of the providing firm. Furthermore, it must be interpreted as employees ability to satisfy customers (interactive marketing). PMID:26093140

  16. Thermal processing systems for TRU mixed waste

    SciTech Connect

    Eddy, T.L.; Raivo, B.D.; Anderson, G.L.

    1992-08-01

    This paper presents preliminary ex situ thermal processing system concepts and related processing considerations for remediation of transuranic (TRU)-contaminated wastes (TRUW) buried at the Radioactive Waste Management Complex (RWMC) of the Idaho National Engineering Laboratory (INEL). Anticipated waste stream components and problems are considered. Thermal processing conditions required to obtain a high-integrity, low-leachability glass/ceramic final waste form are considered. Five practical thermal process system designs are compared. Thermal processing of mixed waste and soils with essentially no presorting and using incineration followed by high temperature melting is recommended. Applied research and development necessary for demonstration is also recommended.

  17. Thermal processing systems for TRU mixed waste

    SciTech Connect

    Eddy, T.L.; Raivo, B.D.; Anderson, G.L.

    1992-01-01

    This paper presents preliminary ex situ thermal processing system concepts and related processing considerations for remediation of transuranic (TRU)-contaminated wastes (TRUW) buried at the Radioactive Waste Management Complex (RWMC) of the Idaho National Engineering Laboratory (INEL). Anticipated waste stream components and problems are considered. Thermal processing conditions required to obtain a high-integrity, low-leachability glass/ceramic final waste form are considered. Five practical thermal process system designs are compared. Thermal processing of mixed waste and soils with essentially no presorting and using incineration followed by high temperature melting is recommended. Applied research and development necessary for demonstration is also recommended.

  18. Bioprocessing of a stored mixed liquid waste

    SciTech Connect

    Wolfram, J.H.; Rogers, R.D.; Finney, R.

    1995-12-31

    This paper describes the development and results of a demonstration for a continuous bioprocess for mixed waste treatment. A key element of the process is an unique microbial strain which tolerates high levels of aromatic solvents and surfactants. This microorganism is the biocatalysis of the continuous flow system designed for the processing of stored liquid scintillation wastes. During the past year a process demonstration has been conducted on commercial formulation of liquid scintillation cocktails (LSC). Based on data obtained from this demonstration, the Ohio EPA granted the Mound Applied Technologies Lab a treatability permit allowing the limited processing of actual mixed waste. Since August 1994, the system has been successfully processing stored, {open_quotes}hot{close_quotes} LSC waste. The initial LSC waste fed into the system contained 11% pseudocumene and detectable quantities of plutonium. Another treated waste stream contained pseudocumene and tritium. Data from this initial work shows that the hazardous organic solvent, and pseudocumene have been removed due to processing, leaving the aqueous low level radioactive waste. Results to date have shown that living cells are not affected by the dissolved plutonium and that 95% of the plutonium was sorbed to the biomass. This paper discusses the bioprocess, rates of processing, effluent, and the implications of bioprocessing for mixed waste management.

  19. Fuel-Air Mixing and Combustion in Scramjets. Chapter 6

    NASA Technical Reports Server (NTRS)

    Drummond, J. Philip; Diskin, Glenn S.; Cutler, Andrew D.

    2006-01-01

    At flight speeds, the residence time for atmospheric air ingested into a scramjet inlet and exiting from the engine nozzle is on the order of a millisecond. Therefore, fuel injected into the air must efficiently mix within tens of microseconds and react to release its energy in the combustor. The overall combustion process should be mixing controlled to provide a stable operating environment; in reality, however, combustion in the upstream portion of the combustor, particularly at higher Mach numbers, is kinetically controlled where ignition delay times are on the same order as the fluid scale. Both mixing and combustion time scales must be considered in a detailed study of mixing and reaction in a scramjet to understand the flow processes and to ultimately achieve a successful design. Although the geometric configuration of a scramjet is relatively simple compared to a turbomachinery design, the flow physics associated with the simultaneous injection of fuel from multiple injector configurations, and the mixing and combustion of that fuel downstream of the injectors is still quite complex. For this reason, many researchers have considered the more tractable problem of a spatially developing, primarily supersonic, chemically reacting mixing layer or jet that relaxes only the complexities introduced by engine geometry. All of the difficulties introduced by the fluid mechanics, combustion chemistry, and interactions between these phenomena can be retained in the reacting mixing layer, making it an ideal problem for the detailed study of supersonic reacting flow in a scramjet. With a good understanding of the physics of the scramjet internal flowfield, the designer can then return to the actual scramjet geometry with this knowledge and apply engineering design tools that more properly account for the complex physics. This approach will guide the discussion in the remainder of this section.

  20. Injector Mixing Efficiency Experiments

    NASA Technical Reports Server (NTRS)

    Moser, Marlow D.

    1998-01-01

    Various optical diagnostic techniques such as laser induce fluorescence, Raman spectroscopy, laser Doppler velocimetry, and laser light scattering have been employed to study the flowfield downstream of a single injector element in a optically accessible rocket chamber at Penn State for a number o years. These techniques have been used with both liquid and gaseous oxygen at pressures up to 1000 psia which is the limit of the facility. The purpose of the test programs at Penn State were to develop the techniques and to study the flow field from various injector designs. To extend these studies to higher pressure and ultimately to multiple injectors require the capabilities of the Marshall Space Flight Center. These studies will extend the data base available for the various injector designs to higher pressure as well as to determine the interaction between multiple injectors. During this effort the Princeton Instruments ICCD camera was set up and checked out. The functionality of the system has been thoroughly checked and the shutter compensation time was found to be not working. The controller was returned to the manufacturer for warranty repair. The sensitivity has been measured and found to be approximately 60 counts per photon at maximum gain which agrees with the test data supplied by the manufacturer. The actual value depends on wavelength. The Princeton Instruments camera was been installed in a explosion proof tube for use with the rocket combustor. A 35 mm camera was also made ready for taking still photos inside the combustor. A fiber optic was used to transmit the laser light from an argon-ion laser to the rocket combustor for the light scattering images. This images were obtained for a LOX-hydrogen swirl coax injector. Several still photos were also obtained with the 35 mm camera for these firings.

  1. A Methodology for Conducting Integrative Mixed Methods Research and Data Analyses

    PubMed Central

    Castro, Felipe González; Kellison, Joshua G.; Boyd, Stephen J.; Kopak, Albert

    2011-01-01

    Mixed methods research has gained visibility within the last few years, although limitations persist regarding the scientific caliber of certain mixed methods research designs and methods. The need exists for rigorous mixed methods designs that integrate various data analytic procedures for a seamless transfer of evidence across qualitative and quantitative modalities. Such designs can offer the strength of confirmatory results drawn from quantitative multivariate analyses, along with “deep structure” explanatory descriptions as drawn from qualitative analyses. This article presents evidence generated from over a decade of pilot research in developing an integrative mixed methods methodology. It presents a conceptual framework and methodological and data analytic procedures for conducting mixed methods research studies, and it also presents illustrative examples from the authors' ongoing integrative mixed methods research studies. PMID:22167325

  2. Mixed-mu superconducting bearings

    DOEpatents

    Hull, J.R.; Mulcahy, T.M.

    1998-03-03

    A mixed-mu superconducting bearing is disclosed including a ferrite structure disposed for rotation adjacent a stationary superconductor material structure and a stationary permanent magnet structure. The ferrite structure is levitated by said stationary permanent magnet structure. 9 figs.

  3. Mixed-mu superconducting bearings

    DOEpatents

    Hull, John R.; Mulcahy, Thomas M.

    1998-01-01

    A mixed-mu superconducting bearing including a ferrite structure disposed for rotation adjacent a stationary superconductor material structure and a stationary permanent magnet structure. The ferrite structure is levitated by said stationary permanent magnet structure.

  4. Crossflow Mixing of Noncircular Jets

    NASA Technical Reports Server (NTRS)

    Liscinsky, D. S.; True, B.; Holdeman, J. D.

    1995-01-01

    An experimental investigation has been conducted of the isothermal mixing of a turbulent jet injected perpendicular to a uniform crossflow through several different types of sharp-edged orifices. Jet penetration and mixing was studied using planar Mie scattering to measure time-averaged mixture fraction distributions of circular, square, elliptical, and rectangular orifices of equal geometric area injected into a constant velocity crossflow. Hot-wire anemometry was also used to measure streamwise turbulence intensity distributions at several downstream planes. Mixing effectiveness was determined using (1) a spatial unmixedness parameter based on the variance of the mean jet concentration distributions and (2) by direct comparison of the planar distributions of concentration and of turbulence intensity. No significant difference in mixing performance was observed for the six configurations based on comparison of the mean properties.

  5. Is the tribimaximal mixing accidental?

    SciTech Connect

    Abbas, Mohammed; Smirnov, A. Yu.

    2010-07-01

    The tribimaximal (TBM) mixing is not accidental if structures of the corresponding leptonic mass matrices follow immediately from certain (residual or broken) flavor symmetry. We develop a simple formalism which allows one to analyze effects of deviations of the lepton mixing from TBM on the structure of the neutrino mass matrix and on the underlying flavor symmetry. We show that possible deviations from the TBM mixing can lead to strong modifications of the mass matrix and strong violation of the TBM-mass relations. As a result, the mass matrix may have an 'anarchical' structure with random values of elements or it may have some symmetry that differs from the TBM symmetry. Interesting examples include matrices with texture zeros, matrices with certain 'flavor alignment' as well as hierarchical matrices with a two-component structure, where the dominant and subdominant contributions have different symmetries. This opens up new approaches to understanding the lepton mixing.

  6. Mixed and Low-Level Treatment Facility Project

    SciTech Connect

    Not Available

    1992-04-01

    This appendix contains the mixed and low-level waste engineering design files (EDFS) documenting each low-level and mixed waste stream investigated during preengineering studies for Mixed and Low-Level Waste Treatment Facility Project. The EDFs provide background information on mixed and low-level waste generated at the Idaho National Engineering Laboratory. They identify, characterize, and provide treatment strategies for the waste streams. Mixed waste is waste containing both radioactive and hazardous components as defined by the Atomic Energy Act and the Resource Conservation and Recovery Act, respectively. Low-level waste is waste that contains radioactivity and is not classified as high-level waste, transuranic waste, spent nuclear fuel, or 11e(2) byproduct material as defined by DOE 5820.2A. Test specimens of fissionable material irradiated for research and development only, and not for the production of power or plutonium, may be classified as low-level waste, provided the concentration of transuranic is less than 100 nCi/g. This appendix is a tool that clarifies presentation format for the EDFS. The EDFs contain waste stream characterization data and potential treatment strategies that will facilitate system tradeoff studies and conceptual design development. A total of 43 mixed waste and 55 low-level waste EDFs are provided.

  7. The Miniature X-ray Spectrograph (MiXS)

    NASA Astrophysics Data System (ADS)

    Martinez Oliveros, Juan Carlos; Glesener, Lindsay; Saint Hilaire, Pascal; Sundkvist, David; Hurford, Gordon; Bain, Hazel; Bale, Stuart D.; Krucker, Sam

    2015-04-01

    The Miniature X-ray Spectrograph (MiXS) is an innovative, small, and fully functional solar X-ray observatory concept designed to fit within a 6U CubeSat platform. MiXS will provide the community with X-ray spectroscopy up to 100 keV of solar flares at a small fraction of the cost of a conventional mission. It includes layered Si/CdTe detectors, providing routine observations of both soft and hard X-ray emission with low background. If selected for funding, MiXS will provide hard X-ray (HXR) spectroscopy throughout the declining phase of this solar cycle allowing continuous solar observations while new generation HXR instrumentation put in orbit. MiXS is the first stage of a much ambitious cube design the Miniature Xray Imager (MiXI), which can provide to the community X-ray imaging up to 40 - 50 keV. In the next solar cycle, coordinated observations between Solar Orbiter’s STIX instrument and future MiXS or MiXI iterations will enable solar flare observation from two vantage points, while new observatories will be commissioned. This will provide new insight into the directivity of flare HXR emission and will allow detailed study of both coronal and footpoint sources within the same flare. These results may have profound implications for theories of flare acceleration processes. We describe here the MiXS concept and its usefulness to the solar and heliophysics communities.

  8. Perspectives on dilution jet mixing

    NASA Technical Reports Server (NTRS)

    Holdeman, J. D.

    1986-01-01

    A microcomputer code which displays 3-D oblique and 2-D plots of the temperature distribution downstream of jets mixing with a confined crossflow has been used to investigate the effects of varying the several independent flow and geometric parameters on the mixing. Temperature profiles calculated with this empirical model are presented to show the effects of orifice size and spacing, momentum flux ratio, density ratio, variable temperature mainstream, flow area convergence, orifice aspect ratio, and opposed and axially staged rows of jets.

  9. An Overview of Neutrino Mixing

    NASA Astrophysics Data System (ADS)

    Altarelli, G.

    2013-08-01

    We present a concise review of the recent important experimental developments on neutrino mixing (hints for sterile neutrinos, large θ13, possible non maximal θ23, approaching sensitivity on δ) and their implications on models of neutrino mixing. The new data disfavour many models but the surviving ones still span a wide range going from Anarchy (no structure, no symmetry in the lepton sector) to a maximum of symmetry, as for the models based on discrete non-abelian flavour groups.

  10. Analysis of stratified flow mixing

    NASA Astrophysics Data System (ADS)

    Soo, S. L.; Lyczkowski, R. W.

    1985-06-01

    The Creare 1/5-scale Phase II experiments which model fluid and thermal mixing of relatively cold high pressure injection (PHI) water into a cold leg of a full-scale pressurized water reactor (PWR) having loop flow are analyzed and found that they cannot achieve complete similarity with respect to characteristic Reynolds and Froude numbers and developing hydrodynamic entry length. Several analyses show that these experiments fall into two distinct regimes of mixing: momentum controlled and gravity controlled (stratification).

  11. Analysis of stratified flow mixing

    SciTech Connect

    Soo, S.L.; Lyckowski, R.W.

    1985-11-01

    The Creare one-fifth-scale Phase II experiments which model fluid and thermal mixing of relatively cold high-pressure injection water into a cold leg of a full-scale pressurized water reactor having loop flow, are analyzed. It is found that they cannot achieve complete similarity with respect to characteristic Reynolds and Froude numbers and developing hydrodynamic entry length. Several analyses show that these experiments fall into two distinct regimes of mixing: momentum and gravity controlled (stratification).

  12. On Infinite-Volume Mixing

    NASA Astrophysics Data System (ADS)

    Lenci, Marco

    2010-09-01

    In the context of the long-standing issue of mixing in infinite ergodic theory, we introduce the idea of mixing for observables possessing an infinite-volume average. The idea is borrowed from statistical mechanics and appears to be relevant, at least for extended systems with a direct physical interpretation. We discuss the pros and cons of a few mathematical definitions that can be devised, testing them on a prototypical class of infinite measure-preserving dynamical systems, namely, the random walks.

  13. On the shock enhancement of confined supersonic mixing flows

    NASA Astrophysics Data System (ADS)

    Lu, P. J.; Wu, K. C.

    1991-12-01

    Direct numerical simulations using high-resolution total variation diminishing (TVD) scheme are performed for studying the shock enhancement of two-dimensional confined (spatially growing) supersonic mixing flows. Several specially designed mixing enhancement schemes are examined with emphasis placed on the study of the fundamental aspects involved in the shock-induced mixing enhancement process. The merits associated with these mixing enhancement schemes are evaluated based on a cost/effectiveness criterion, in which the cost paid for the total pressure loss encountered and the improvement in mixing gained are considered together. The results suggest that mixing enhancement using shock waves can only be effective if the stimulation is spatially persistent, and begins from the very upstream. Being motivated by this observation, an idea of using wavy-wall configuration to generate the desirable periodic shock stimulation is proposed and investigated. The computed results show that, by an appropriate manipulation of the parameters including wall wavelength, relative phase shift between the top and bottom walls, as well as the amplitude of the waviness, considerable improvement in mixing efficiency can be achieved.

  14. Mixing of discontinuously deforming media

    NASA Astrophysics Data System (ADS)

    Smith, L. D.; Rudman, M.; Lester, D. R.; Metcalfe, G.

    2016-02-01

    Mixing of materials is fundamental to many natural phenomena and engineering applications. The presence of discontinuous deformations—such as shear banding or wall slip—creates new mechanisms for mixing and transport beyond those predicted by classical dynamical systems theory. Here, we show how a novel mixing mechanism combining stretching with cutting and shuffling yields exponential mixing rates, quantified by a positive Lyapunov exponent, an impossibility for systems with cutting and shuffling alone or bounded systems with stretching alone, and demonstrate it in a fluid flow. While dynamical systems theory provides a framework for understanding mixing in smoothly deforming media, a theory of discontinuous mixing is yet to be fully developed. New methods are needed to systematize, explain, and extrapolate measurements on systems with discontinuous deformations. Here, we investigate "webs" of Lagrangian discontinuities and show that they provide a template for the overall transport dynamics. Considering slip deformations as the asymptotic limit of increasingly localised smooth shear, we also demonstrate exactly how some of the new structures introduced by discontinuous deformations are analogous to structures in smoothly deforming systems.

  15. Mixing of discontinuously deforming media.

    PubMed

    Smith, L D; Rudman, M; Lester, D R; Metcalfe, G

    2016-02-01

    Mixing of materials is fundamental to many natural phenomena and engineering applications. The presence of discontinuous deformations-such as shear banding or wall slip-creates new mechanisms for mixing and transport beyond those predicted by classical dynamical systems theory. Here, we show how a novel mixing mechanism combining stretching with cutting and shuffling yields exponential mixing rates, quantified by a positive Lyapunov exponent, an impossibility for systems with cutting and shuffling alone or bounded systems with stretching alone, and demonstrate it in a fluid flow. While dynamical systems theory provides a framework for understanding mixing in smoothly deforming media, a theory of discontinuous mixing is yet to be fully developed. New methods are needed to systematize, explain, and extrapolate measurements on systems with discontinuous deformations. Here, we investigate "webs" of Lagrangian discontinuities and show that they provide a template for the overall transport dynamics. Considering slip deformations as the asymptotic limit of increasingly localised smooth shear, we also demonstrate exactly how some of the new structures introduced by discontinuous deformations are analogous to structures in smoothly deforming systems. PMID:26931594

  16. Synthetic-wavelength self-mixing interferometry for displacement measurement

    NASA Astrophysics Data System (ADS)

    Chen, Junbao; Zhu, Hongbin; Xia, Wei; Guo, Dongmei; Hao, Hui; Wang, Ming

    2016-06-01

    A simple synthetic-wavelength self-mixing interferometer is proposed for precision displacement measurement. Choosing the frequency difference of the orthogonally polarized dual frequency He-Ne laser appropriately, we introduce synthetic wavelength theory into self-mixing interference principle and demonstrate a feasible optical configuration by simply adjusting the optical design of self-mixing interferometer. The phase difference between the two orthogonally polarized feedback fringes is observed, and the tiny displacement of the object can be measured through the phase change of the synthetic signal. Since the virtual synthetic wavelength is 106 times larger than the operating wavelength, sub-nanometer displacement of the object can be obtained in millimeter criterion measurement without modulation, demodulation and complicated electrical circuits. Experimental results verifies the synthetic wavelength self-mixing interferometer's ability of measuring nanoscale displacement, which provides a potential approach for contactless precision displacement measurement in a number of scientific and industrial applications.

  17. Elastic properties of fly ash-stabilized mixes

    PubMed Central

    Dimter, Sanja; Rukavina, Tatjana; Minažek, Krunoslav

    2015-01-01

    Stabilized mixes are used in the construction of bearing layers in asphalt and concrete pavement structures. Two nondestructive methods: resonant frequency method and ultrasonic pulse velocity method, were used for estimation of elastic properties of fly ash–stabilized mixes. Stabilized mixes were designed containing sand from the river Drava and binder composed of different share of cement and fly ash. The aim of the research was to analyze the relationship between the dynamic modulus of elasticity determined by different nondestructive methods. Data showed that average value of elasticity modulus obtained by the ultrasound velocity method is lower than the values of elasticity modulus obtained by resonant frequency method. For further analysis and enhanced discussion of elastic properties of fly ash stabilized mixes, see Dimter et al. [1]. PMID:26702415

  18. Elastic properties of fly ash-stabilized mixes.

    PubMed

    Dimter, Sanja; Rukavina, Tatjana; Minažek, Krunoslav

    2015-12-01

    Stabilized mixes are used in the construction of bearing layers in asphalt and concrete pavement structures. Two nondestructive methods: resonant frequency method and ultrasonic pulse velocity method, were used for estimation of elastic properties of fly ash-stabilized mixes. Stabilized mixes were designed containing sand from the river Drava and binder composed of different share of cement and fly ash. The aim of the research was to analyze the relationship between the dynamic modulus of elasticity determined by different nondestructive methods. Data showed that average value of elasticity modulus obtained by the ultrasound velocity method is lower than the values of elasticity modulus obtained by resonant frequency method. For further analysis and enhanced discussion of elastic properties of fly ash stabilized mixes, see Dimter et al. [1]. PMID:26702415

  19. Computer modeling of forced mixing in waste storage tanks

    SciTech Connect

    Eyler, L.L.; Michener, T.E.

    1992-04-01

    Numerical simulation results of fluid dynamic and physical processes in radioactive waste storage tanks are presented. Investigations include simulation of jet mixing pump induced flows intended to mix and maintain particulate material uniformly distributed throughout the liquid volume. Physical effects of solids are included in the code. These are particle size through a settling velocity and mixture properties through density and viscosity. Calculations have been accomplished for a centrally located, rotationally-oscillating, horizontally-directed jet mixing pump for two cases. One case is with low jet velocity and high settling velocity. It results in nonuniform distribution. The other case is with high jet velocity and low settling velocity. It results in uniform conditions. Results are being used to aid in experiment design and to understand mixing in the waste tanks. These results are to be used in conjunction with scaled experiments to define limits of pump operation to maintain uniformity of the mixture in the storage tanks during waste retrieval operations.

  20. A new unsteady mixing model to predict NO(x) production during rapid mixing in a dual-stage combustor

    NASA Technical Reports Server (NTRS)

    Menon, Suresh; Mcmurtry, Patrick A.; Kerstein, Alan R.; Chen, J.-Y.

    1992-01-01

    An advanced gas turbine engine to power supersonic transport aircraft is currently under study. In addition to high combustion efficiency requirements, environmental concerns have placed stringent restrictions on the pollutant emissions from these engines. A dual-stage combustor with the potential for minimizing pollutants such as NO(x) emissions is undergoing experimental evaluation. A major technical issue in the design of this combustor is how to rapidly mix the hot, fuel-rich primary stage product with the secondary diluent air to obtain a fuel-lean mixture for combustion in the secondary stage. Numerical design studies using steady-state methods cannot account for the unsteady phenomena in the mixing region. Therefore, to evaluate the effect of unsteady mixing and combustion processes, a novel unsteady mixing model is demonstrated here. This model has been used in a stand-alone mode to study mixing and combustion in hydrogen-air nonpremixed jet flames. NO(x) production in these jet flames was also predicted. Comparison of the computed results with experimental data show good agreement thereby providing validation of the mixing model.

  1. Mixed and Low-Level Treatment Facility Project. Appendix B, Waste stream engineering files, Part 1, Mixed waste streams

    SciTech Connect

    Not Available

    1992-04-01

    This appendix contains the mixed and low-level waste engineering design files (EDFS) documenting each low-level and mixed waste stream investigated during preengineering studies for Mixed and Low-Level Waste Treatment Facility Project. The EDFs provide background information on mixed and low-level waste generated at the Idaho National Engineering Laboratory. They identify, characterize, and provide treatment strategies for the waste streams. Mixed waste is waste containing both radioactive and hazardous components as defined by the Atomic Energy Act and the Resource Conservation and Recovery Act, respectively. Low-level waste is waste that contains radioactivity and is not classified as high-level waste, transuranic waste, spent nuclear fuel, or 11e(2) byproduct material as defined by DOE 5820.2A. Test specimens of fissionable material irradiated for research and development only, and not for the production of power or plutonium, may be classified as low-level waste, provided the concentration of transuranic is less than 100 nCi/g. This appendix is a tool that clarifies presentation format for the EDFS. The EDFs contain waste stream characterization data and potential treatment strategies that will facilitate system tradeoff studies and conceptual design development. A total of 43 mixed waste and 55 low-level waste EDFs are provided.

  2. [Particle dispersion by order motion in mixing layers

    SciTech Connect

    Troutt, T.R.

    1993-09-01

    Multiphase mixing in turbulent flows is a key element in many energy conversion and chemical processes. There is considerable need for improving the design and control of these processes. Free turbulent shear flows are the primary agents for particle mixing in these systems. Previous studies by this research group have shown that, if particle coupling effects are neglected, the organized vortex structures generated by these shear flows control the character of the particle mixing process. A coordinated experimental and numerical study is proposed to investigate the coupled effects of droplet mass and energy transfer on the turbulent multiphase mixing process in free shear flows. This study has important implications concerning the design of reacting flow systems. Experimental visualizations of the multiphase flow will be carried out using laser-sheet lighting and high speed photography. Local measurements of droplet size, velocity and concentration diagnostics, will be made with laser anemometry and phase Doppler diagnostics. Complementary analytical and numerical analyses will be carried out to assess the effect of coupling on vortex structure, stability and growth. The results of the proposed research will provide basic understanding concerning the coupled effects of particle concentration on the rate of multiphase mixing in turbulent flows. Information of this nature is essential to the improved designs of engineering systems with particulate or droplet flows.

  3. Allergen extracts for immunotherapy: to mix or not to mix?

    PubMed

    Nony, Emmanuel; Martelet, Armelle; Jain, Karine; Moingeon, Philippe

    2016-03-01

    Allergen immunotherapy (AIT) is established as a curative treatment for allergic rhinitis, asthma, as well as insect venom allergy. AIT is based on the administration of natural allergen extracts via the subcutaneous or sublingual routes to reorient the immune system towards tolerogenic mechanisms. In this regard, since many patients are poly-allergic, mixtures of allergen extracts are often used with a potential risk to cause allergen degradation, thereby affecting treatment efficacy. Herein, we discuss the advantages and drawbacks of mixing homologous (i.e., related) or heterogeneous (i.e., unrelated) allergen extracts. We provide evidence for incompatibilities between mixes of grass pollen and house dust mite extracts containing bodies and feces, and summarize critical points to consider when mixing allergen extracts for AIT. PMID:26652799

  4. Bubble-induced acoustic mixing in a microfluidic device

    NASA Astrophysics Data System (ADS)

    Chen, Huaying; Petkovic-Duran, Karolina; Best, Michael; Zhu, Yonggang

    2015-12-01

    Homogeneous and fast mixing of samples at microscale is a critical requirement for successful applications of microfluidics in biochemical analysis, chemical synthesis, drug delivery and nanomaterial synthesis. This paper reports the optimisation of bubble-induced mixing in a microfluidic device in terms of voltage, driving frequency, piezo transducer position and PDMS thickness. The microfluidic device consists of a microwell (with the diameter of 1mm and volume of ~95 nL) with two rectangular bubble traps (400×400μm) on both sides of the well. After the injection of liquid, air bubbles were spontaneously trapped in two rectangular traps. When the frequency of a piezo was equal to the resonance frequency of air bubbles, strong liquid recirculation formed (so called acoustic microstreaming) in the vicinity of the interface of air bubbles and water. The acoustic induced flow of microbeads and mixing of water and fluorescence dye were imaged to study the mixing efficiency. For a given voltage and PDMS thickness, when the piezo was placed on top of the well, the mixing was most vigorous. For a given frequency, the mixing efficiency was directly proportional to the voltage (4-20V) and inversely proportional to the PDMS thickness (0.3-2mm). When the frequency driving the piezo was approaching the resonance frequency of air bubbles, the mixing efficiency was maximal, while when it was far away from the resonance frequency of air bubbles, the mixing efficiency was much lower. This work provides guidance to the design and the application of bubble-induced acoustic mixing in microfluidics.

  5. Mixed consortia in bioprocesses: role of microbial interactions.

    PubMed

    Ghosh, Shiladitya; Chowdhury, Ranjana; Bhattacharya, Pinaki

    2016-05-01

    The utilization of mixed consortia or mixed culture has become a current research trend of applied microbiology, bioprocess engineering and biotechnology. The constituent microorganisms of such mixed cultures can jointly perform complex processes efficiently, yielding the desired product at an augmented rate, in comparison to monocultures. It is understandable that the interactions between the microbial partners in these mixed cultures are expected to have a significant impact on the combined performance of the microorganisms and the bioprocess as a whole. Prevalence of positive interactions (commensalism or mutualism) among microbial members of a mixed culture or consortia can significantly enhance the product outcome of the bioprocess, ensuring their industrial application and long-term stability. On the contrary, negative interaction (parasitism, predation or ammensalism) leads to elimination of microbial members from the consortia causing the destruction of community structure as well as disruption of cumulative performance. Therefore, a priori knowledge on the type of interaction between the microorganisms is also essential for the optimization of the performance of the designed consortia. This could only be achieved through the study of inter-microbial interaction prevailing in a mixed culture. In the present article, different bioprocess applications of mixed cultures, currently in practice along with types of positive microbial interactions involved, have been reviewed. Complexity of mixed cultures from the perspective of multiple types of intra-culture relationships has been explained in detail. Overall, the necessity for more in-depth research studies on "microbial interaction" in mixed culture bioprocesses has been stressed in the article. PMID:27037693

  6. Assessing and Evaluating Multidisciplinary Translational Teams: A Mixed Methods Approach

    PubMed Central

    Wooten, Kevin C.; Rose, Robert M.; Ostir, Glenn V.; Calhoun, William J.; Ameredes, Bill T.; Brasier, Allan R.

    2014-01-01

    A case report illustrates how multidisciplinary translational teams can be assessed using outcome, process, and developmental types of evaluation using a mixed methods approach. Types of evaluation appropriate for teams are considered in relation to relevant research questions and assessment methods. Logic models are applied to scientific projects and team development to inform choices between methods within a mixed methods design. Use of an expert panel is reviewed, culminating in consensus ratings of 11 multidisciplinary teams and a final evaluation within a team type taxonomy. Based on team maturation and scientific progress, teams were designated as: a) early in development, b) traditional, c) process focused, or d) exemplary. Lessons learned from data reduction, use of mixed methods, and use of expert panels are explored. PMID:24064432

  7. Birth of Lepton Flavor Mixing

    NASA Astrophysics Data System (ADS)

    Kobayashi, Makoto

    The history of the lepton flavor mixing could be traced back to the early 60s, when Maki, Nakagawa and Sakata (MNS) discussed the neutrino mixing. Their work emerged in the course of the developments of the composite model of elementary particles which was initiated by Sakata. In Sakata's model, the weak interaction of the hadrons can be described by two types of transitions among the fundamental triplet baryons. This pattern of the weak interaction of the hadrons is similar to that of leptons provided that the neutrino consists of a single species. From this similarity, Maki, Nakagawa, Ohnuki and Sakata proposed the so-called Nagoya model, in which the fundamental triplet baryons are regarded as composite states of the leptons and a hypothetical object called B-matter. Although the Nagoya model did not make a remarkable success, when existence of two kinds of neutrinos was discovered in 1962, Maki, Nakagawa and Sakata precisely formulated lepton flavor mixing to associate leptons with the fundamental baryons in the framework of the Nagoya model. To recognize their contributions, the flavor mixing matrix of the lepton sector is called the MNS matrix. See also: M. Kobayashi, "Neutrino mass and mixing -- The beginning and future", Nucl. Phys. B (Proc. Suppl.) Vol. 235-236, (2013), pp. 4-7.

  8. Mix and Switch Effects in Bilingual Language Processing

    ERIC Educational Resources Information Center

    Koeth, Joel T.

    2012-01-01

    This study utilized a novel task design in an effort to identify the source of the second language processing advantage commonly reported in mixed language conditions, investigate switch cost asymmetry in non-balanced bilinguals, and identify task-related variables that potentially contribute to inconsistent results across studies with similar…

  9. Teaching Service Modelling to a Mixed Class: An Integrated Approach

    ERIC Educational Resources Information Center

    Deng, Jeremiah D.; Purvis, Martin K.

    2015-01-01

    Service modelling has become an increasingly important area in today's telecommunications and information systems practice. We have adapted a Network Design course in order to teach service modelling to a mixed class of both the telecommunication engineering and information systems backgrounds. An integrated approach engaging mathematics teaching…

  10. Measurement of resistance of amalgam mixes to condensation.

    PubMed

    Ogura, H; Hadavi, F; Asgar, K

    1983-08-01

    A method was designed to evaluate the resistance of amalgam mixes to condensation forces. For the purpose of classification with respect to the plasticity of amalgam, the optimum test condition was to apply 40 or 50 lb of static load at 30 sec after trituration. PMID:6575043

  11. Evaluation of User Acceptance of Mixed Reality Technology

    ERIC Educational Resources Information Center

    Yusoff, Rasimah Che Mohd; Zaman, Halimah Badioze; Ahmad, Azlina

    2011-01-01

    This study investigates users' perception and acceptance of mixed reality (MR) technology. Acceptance of new information technologies has been important research area since 1990s. It is important to understand the reasons why people accept information technologies, as this can help to improve design, evaluation and prediction how users will…

  12. Mixed Stream Test Rig Winter FY-2011 Report

    SciTech Connect

    Chalres Park; Tedd Lister; Kevin DeWall

    2011-04-01

    This report describes the data and analysis of the initial testing campaign of the Mixed Stream Test Rig (MISTER) at Idaho National Laboratory (INL). It describes the test specimen selection, physical configuration of the test equipment, operations methodology, and data and analysis of specimens exposed in two environments designed to represent those expected for high temperature steam electrolysis (HTSE).

  13. Motivational Engagement and Video Gaming: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Hoffman, Bobby; Nadelson, Louis

    2010-01-01

    A mixed methods design was used to identify factors associated with motivational engagement in video gaming. Self-report instruments were administered to 189 video game players to assess goal orientations, affect, need for cognition, and perceptions of engagement and flow. Simultaneously, a sub-set of 25 participants were interviewed and results…

  14. Mixed finite element formulation applied to shape optimization

    NASA Technical Reports Server (NTRS)

    Rodrigues, Helder; Taylor, John E.; Kikuchi, Noboru

    1988-01-01

    The development presented introduces a general form of mixed formulation for the optimal shape design problem. The associated optimality conditions are easily obtained without resorting to highly elaborate mathematical developments. Also, the physical significance of the adjoint problem is clearly defined with this formulation.

  15. Assessing Affective Constructs in Reading: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Conradi, Kristin

    2011-01-01

    Research investigating affective dimensions in reading has long been plagued by vaguely defined constructs and, consequently, by an array of potentially problematic instruments designed to measure them. This mixed-methods study investigated the relationship among three popular group-administered instruments intended to tap affective constructs in…

  16. Investigation of Turbulent Mixing Processes

    NASA Technical Reports Server (NTRS)

    Viktorin, K.

    1946-01-01

    With water as driving medium and delivered medium in a device similar to a simple jet apparatus, the pressure and velocity fields of the mixing zone were explored with a pitot bar; the ratio of delivered to driving volume ranged between the values 0, 1, 2, and 4. An attempt was also made to analyze the mixing flow mathematically by integration of the equation of motion, with the aid of conventional formulas for the turbulent shearing stress, but this succeeded only approximately for the very simplified case that a driving jet is introduced in an unlimited parallel flow, while the pressure over the whole mixing field is assumed to be constant. In spite of these dissimilar assumptions for the theory and the experiment, the form of the measured and the computed velocity profiles indicates a very high degree of approximation. The pressure rise, which was approximated by Flugel's formulas, disclosed good agreement with the measured values.

  17. Fluid mixing from viscous fingering.

    PubMed

    Jha, Birendra; Cueto-Felgueroso, Luis; Juanes, Ruben

    2011-05-13

    Mixing efficiency at low Reynolds numbers can be enhanced by exploiting hydrodynamic instabilities that induce heterogeneity and disorder in the flow. The unstable displacement of fluids with different viscosities, or viscous fingering, provides a powerful mechanism to increase fluid-fluid interfacial area and enhance mixing. Here we describe the dissipative structure of miscible viscous fingering, and propose a two-equation model for the scalar variance and its dissipation rate. Our analysis predicts the optimum range of viscosity contrasts that, for a given Péclet number, maximizes interfacial area and minimizes mixing time. In the spirit of turbulence modeling, the proposed two-equation model permits upscaling dissipation due to fingering at unresolved scales. PMID:21668165

  18. The Use of Hermeneutics in a Mixed Methods Design

    ERIC Educational Resources Information Center

    von Zweck, Claudia; Paterson, Margo; Pentland, Wendy

    2008-01-01

    Combining methods in a single study is becoming a more common practice because of the limitations of using only one approach to fully address all aspects of a research question. Hermeneutics in this paper is discussed in relation to a large national study that investigated issues influencing the ability of international graduates to work as…

  19. Mixing, Noise and Thrust Benefits Using Corrugated Designs

    NASA Technical Reports Server (NTRS)

    White, Samuel G.; Gilinsky, Mikhail M.

    1998-01-01

    This project was conducted as a support for effective research, training and teaching of Hampton University students in Fluid Mechanics and Acoustics. Basically, this work is organized and implemented by the new Fluid Mechanics and Acoustics Laboratory (FM & AL) which was established at Hampton University in the School of Engineering and Technology (E & T) in 1996. In addition, FM & AL in cooperation with NASA LaRC jointly conducts research with the Central AeroHydrodynamics Institute (TSAGI, Moscow) in Russia under a 2 year Civilian Research and Development Foundation (CRDF). This project is also conducted under control of NASA HQ. For fulfillment of the current project, several researchers were involved as was shown in the proposal to NASA in 1996. This work is the development and support for projects solve problems with the goal of reducing jet noise and increasing nozzle thrust.

  20. Designing Mixed Reality Mobile Games for Crisis Management Training

    ERIC Educational Resources Information Center

    Di Loreto, Ines; Mora, Simone; Divitini, Monica

    2013-01-01

    Games for crisis management offer an interesting complement to traditional training. Experiments on their usage show that games can be promising tools able to address some of the limitations of traditional training. Also our first assessment with a board game for panic management shows that this particular kind of game could be useful for soft…

  1. The Mixed Waste Management Facility monthly report August 1995

    SciTech Connect

    Streit, R.D.

    1995-09-01

    The project is concerned with the design of a mixed waste facility to prepare solid and liquid wastes for processing by electrochemical oxidation, molten salt oxidation, wet oxidation, or UV photolysis. The facility will have a receiving and shipping unit, preparation and processing units, off-gas scrubbing, analytical services, water treatment, and transport and storage facilities. This monthly report give task summaries for 25 tasks which are part of the overall design effort.

  2. Mixing in magnetized turbulent media

    SciTech Connect

    Sur, Sharanya; Scannapieco, Evan; Pan, Liubin E-mail: evan.scannapieco@asu.edu

    2014-04-01

    Turbulent motions are essential to the mixing of entrained fluids and are also capable of amplifying weak initial magnetic fields by small-scale dynamo action. Here we perform a systematic study of turbulent mixing in magnetized media, using three-dimensional magnetohydrodynamic simulations that include a scalar concentration field. We focus on how mixing depends on the magnetic Prandtl number, Pm, from 1 to 4 and the Mach number, M, from 0.3 to 2.4. For all subsonic flows, we find that the velocity power spectrum has a k {sup –5/3} slope in the early kinematic phase, but steepens due to magnetic back reactions as the field saturates. The scalar power spectrum, on the other hand, flattens compared to k {sup –5/3} at late times, consistent with the Obukohov-Corrsin picture of mixing as a cascade process. At higher Mach numbers, the velocity power spectrum also steepens due to the presence of shocks, and the scalar power spectrum again flattens accordingly. Scalar structures are more intermittent than velocity structures in subsonic turbulence, whereas for supersonic turbulence, velocity structures appear more intermittent than the scalars only in the kinematic phase. Independent of the Mach number of the flow, scalar structures are arranged in sheets in both the kinematic and saturated phases of the magnetic field evolution. For subsonic turbulence, scalar dissipation is hindered in the strong magnetic field regions, probably due to Lorentz forces suppressing the buildup of scalar gradients, whereas for supersonic turbulence, scalar dissipation increases monotonically with increasing magnetic field strength. At all Mach numbers, mixing is significantly slowed by the presence of dynamically important small-scale magnetic fields, implying that mixing in the interstellar medium and in galaxy clusters is less efficient than modeled in hydrodynamic simulations.

  3. Nonideal Rayleigh-Taylor mixing

    SciTech Connect

    Sharp, David Howland; Lin, Hyun K; Iwerks, Justin G; Gliman, James G

    2009-01-01

    Rayleigh-Taylor mixing is a classical hydrodynamic Instability, which occurs when a light fluid pushes against a heavy fluid. The two main sources of nonideal behavior in Rayleigh-Taylor (RT) mixing are regularizations (physical and numerical) which produce deviations from a pure Euler equation, scale Invariant formulation, and non Ideal (i.e. experimental) initial conditions. The Kolmogorov theory of turbulence predicts stirring at all length scales for the Euler fluid equations without regularization. We Interpret mathematical theories of existence and non-uniqueness in this context, and we provide numerical evidence for dependence of the RT mixing rate on nonideal regularizations, in other words indeterminacy when modeled by Euler equations. Operationally, indeterminacy shows up as non unique solutions for RT mixing, parametrized by Schmidt and Prandtl numbers, In the large Reynolds number (Euler equation) limit. Verification and validation evidence is presented for the large eddy simulation algorithm used here. Mesh convergence depends on breaking the nonuniqueness with explicit use of the laminar Schmidt and PrandtJ numbers and their turbulent counterparts, defined in terms of subgrid scale models. The dependence of the mixing rate on the Schmidt and Prandtl numbers and other physical parameters will be illustrated. We demonstrate numerically the influence of initial conditions on the mixing rate. Both the dominant short wavelength Initial conditions and long wavelength perturbations are observed to playa role. By examination of two classes of experiments, we observe the absence of a single universal explanation, with long and short wavelength initial conditions, and the various physical and numerical regularizations contributing In different proportions In these two different contexts.

  4. Nonideal Rayleigh–Taylor mixing

    PubMed Central

    Lim, Hyunkyung; Iwerks, Justin; Glimm, James; Sharp, David H.

    2010-01-01

    Rayleigh–Taylor mixing is a classical hydrodynamic instability that occurs when a light fluid pushes against a heavy fluid. The two main sources of nonideal behavior in Rayleigh–Taylor (RT) mixing are regularizations (physical and numerical), which produce deviations from a pure Euler equation, scale invariant formulation, and nonideal (i.e., experimental) initial conditions. The Kolmogorov theory of turbulence predicts stirring at all length scales for the Euler fluid equations without regularization. We interpret mathematical theories of existence and nonuniqueness in this context, and we provide numerical evidence for dependence of the RT mixing rate on nonideal regularizations; in other words, indeterminacy when modeled by Euler equations. Operationally, indeterminacy shows up as nonunique solutions for RT mixing, parametrized by Schmidt and Prandtl numbers, in the large Reynolds number (Euler equation) limit. Verification and validation evidence is presented for the large eddy simulation algorithm used here. Mesh convergence depends on breaking the nonuniqueness with explicit use of the laminar Schmidt and Prandtl numbers and their turbulent counterparts, defined in terms of subgrid scale models. The dependence of the mixing rate on the Schmidt and Prandtl numbers and other physical parameters will be illustrated. We demonstrate numerically the influence of initial conditions on the mixing rate. Both the dominant short wavelength initial conditions and long wavelength perturbations are observed to play a role. By examination of two classes of experiments, we observe the absence of a single universal explanation, with long and short wavelength initial conditions, and the various physical and numerical regularizations contributing in different proportions in these two different contexts. PMID:20615983

  5. Ion mixing of semiconductor superlattices

    SciTech Connect

    Xia, W.; Hsu, S.N.; Han, C.C.; Pappert, S.A.; Zhu, B.; Cozzolino, C.; Yu, P.K.L.; Lau, S.S. . Dept. of Electrical and Computer Engineering); Poker, D.B.; White, C.W. ); Schwarz, S.A. )

    1990-01-01

    Compositional disordering of III-V compound superlattice structures has received considerable attention recently due to its potential application for photonic devices. The conventional method in induce compositional disorder is to implant a moderate dose of impurity ions ({approximately} 10 {sup 15} /cm{sup 2}) into the structure at room temperature, followed by a high-temperature annealing step (this process is referred to as IA here). Ion irradiation at room temperature alone does not cause any significant intermixing of layers. The subsequent high-temperature annealing step tends to restrict device processing flexibility. Ion mixing (IM) is capable of enhancing compositional disordering of layers at a rate which increases exponentially with the ion irradiation temperature. As a processing technique to planarize devices, ion mixing appears to be an attractive technology. In this work, we investigate compositional disordering in the AlGaAs/GaAs and the InGaAs/InP systems using ion mixing. We found that the ion mixing behavior of these two systems shows a thermally activated regime as well as an athermal regime, similar to that observed for metal-metal and metal-semiconductor systems. Ion mixing is observed to induce compositional disordering at significantly lower temperatures than that for the IA process. We have compared the two processes in terms of five parameters (1) irradiation temperature, (2) dose dependence (3) annealing, and (4) electrically active ions. We found that the IM process is more efficient in utilizing the defects generated by ion irradiation to cause disordering. Both the physical mechanism of ion mixing and possible device implications will be discussed. 49 refs., 6 figs.

  6. Use and abuse of mixing models (MixSIAR)

    EPA Science Inventory

    Background/Question/MethodsCharacterizing trophic links in food webs is a fundamental ecological question. In our efforts to quantify energy flow through food webs, ecologists have increasingly used mixing models to analyze biological tracer data, often from stable isotopes. Whil...

  7. Evaluating Mixed Research Studies: A Mixed Methods Approach

    ERIC Educational Resources Information Center

    Leech, Nancy L.; Dellinger, Amy B.; Brannagan, Kim B.; Tanaka, Hideyuki

    2010-01-01

    The purpose of this article is to demonstrate application of a new framework, the validation framework (VF), to assist researchers in evaluating mixed research studies. Based on an earlier work by Dellinger and Leech, a description of the VF is delineated. Using the VF, three studies from education, health care, and counseling fields are…

  8. Mixe de Tlahuitoltepec, Oaxaca (Mixe of Tlahuitoltepec, Oaxaca).

    ERIC Educational Resources Information Center

    Mexico Coll. (Mexico City)

    This document is one of 17 volumes on indigenous Mexican languages and is the result of a project undertaken by the Archivo de Lenguas Indigenas de Mexico. This volume contains information on Mixe, an indigenous language of Mexico spoken in Tlahuitoltepec, in the state of Oaxaca. The objective of collecting such a representative sampling of the…

  9. Mixed ternary heterojunction solar cell

    DOEpatents

    Chen, Wen S.; Stewart, John M.

    1992-08-25

    A thin film heterojunction solar cell and a method of making it has a p-type layer of mixed ternary I-III-VI.sub.2 semiconductor material in contact with an n-type layer of mixed binary II-VI semiconductor material. The p-type semiconductor material includes a low resistivity copper-rich region adjacent the back metal contact of the cell and a composition gradient providing a minority carrier mirror that improves the photovoltaic performance of the cell. The p-type semiconductor material preferably is CuInGaSe.sub.2 or CuIn(SSe).sub.2.

  10. Bs Mixing at the Tevatron

    SciTech Connect

    Gomez-Ceballos, Guillelmo; /Cantabria Inst. of Phys.

    2006-04-01

    The Tevatron collider at Fermilab provides a very rich environment for the study of B{sub s} mesons. B{sub s} Mixing is the most important analysis within the B Physics program of both experiments. In this paper they summarize the most recent results on this topic from both D0 and CDF experiments. There were very important updates in both experiments after his last talk, hence the organizers warmly recommended me to include the latest available results on B{sub s} mixing, instead of what he presents there.

  11. Analysis of stratified flow mixing

    SciTech Connect

    Soo, S.L.; Lyczkowski, R.W.

    1985-01-01

    The Creare 1/5-scale Phase II experiments which model fluid and thermal mixing of relatively cold high pressure injection (HPI) water into a cold leg of a full-scale pressurized water reactor (PWR) having loop flow are analyzed and found that they cannot achieve complete similarity with respect to characteristic Reynolds and Froude numbers and developing hydrodynamic entry length. Several analyses show that these experiments fall into two distinct regimes of mixing: momentum controlled and gravity controlled (stratification). 18 refs., 9 figs.

  12. Impacts of Mixing on Acceptable Indoor Air Quality in Homes

    SciTech Connect

    Sherman, Max H.; Walker, Iain I.

    2010-01-01

    Ventilation reduces occupant exposure to indoor contaminants by diluting or removing them. In a multi-zone environment such as a house, every zone will have different dilution rates and contaminant source strengths. The total ventilation rate is the most important factor in determining occupant exposure to given contaminant sources, but the zone-specific distribution of exhaust and supply air and the mixing of ventilation air can play significant roles. Different types of ventilation systems will provide different amounts of mixing depending on several factors such as air leakage, air distribution system, and contaminant source and occupant locations. Most U.S. and Canadian homes have central heating, ventilation, and air conditioning systems, which tend to mix the air; thus, the indoor air in different zones tends to be well mixed for significant fractions of the year. This article reports recent results of investigations to determine the impact of air mixing on exposures of residential occupants to prototypical contaminants of concern. We summarize existing literature and extend past analyses to determine the parameters than affect air mixing as well as the impacts of mixing on occupant exposure, and to draw conclusions that are relevant for standards development and for practitioners designing and installing home ventilation systems. The primary conclusion is that mixing will not substantially affect the mean indoor air quality across a broad population of occupants, homes, and ventilation systems, but it can reduce the number of occupants who are exposed to extreme pollutant levels. If the policy objective is to minimize the number of people exposed above a given pollutant threshold, some amount of mixing will be of net benefit even though it does not benefit average exposure. If the policy is to minimize exposure on average, then mixing air in homes is detrimental and should not be encouraged. We also conclude that most homes in the US have adequate mixing

  13. In-line mixing states monitoring of suspensions using ultrasonic reflection technique.

    PubMed

    Zhan, Xiaobin; Yang, Yili; Liang, Jian; Zou, Dajun; Zhang, Jiaqi; Feng, Luyi; Shi, Tielin; Li, Xiwen

    2016-02-01

    Based on the measurement of echo signal changes caused by different concentration distributions in the mixing process, a simple ultrasonic reflection technique is proposed for in-line monitoring of the mixing states of suspensions in an agitated tank in this study. The relation between the echo signals and the concentration of suspensions is studied, and the mixing process of suspensions is tracked by in-line measurement of ultrasonic echo signals using two ultrasonic sensors. Through the analysis of echo signals over time, the mixing states of suspensions are obtained, and the homogeneity of suspensions is quantified. With the proposed technique, the effects of impeller diameter and agitation speed on the mixing process are studied, and the optimal agitation speed and the minimum mixing time to achieve the maximum homogeneity are acquired under different operating conditions and design parameters. The proposed technique is stable and feasible and shows great potential for in-line monitoring of mixing states of suspensions. PMID:26548526

  14. Experimental study on mixing efficiency in water supply rectangular tanks

    NASA Astrophysics Data System (ADS)

    Bateman, A.; Medina, V.; Mujal, A.

    2009-04-01

    Phenomenon of mixing in drinking water storage tanks and reservoirs has a direct effect on the quality of water. Creation of poor mixing zones and volume stratification can have negative effects in public health. The design of a storage tank must consider the conditions of the inlet and outlets, and also their orientation (vertical or horizontal) to prevent the formation of these zones. Experiments done in a reduced scaled-model with a rectangular base and three different inlets (two waterfalls and a pipe inlet) had the objective to decide which of these inlets achieved the best mixing efficiency. Four situations were considered while three entrances, two unsteady: filling and drawing, and two steady with different outlets. Moreover the effects of columns that support the roof of the tank were studied by running the three entrances with and without columns in the four situations. Neglecting the viscous scale effects, the time taken to mix the volume stored depends on the distance between the inlet and the opposite wall as though as its orientation. Taking into account the whole tank columns have a negative effect on mixing efficiency although they divide the flux and create local zones of turbulence around them, increasing local mixing. Using a digital treating image technique the results are found in a quantitative way.

  15. A phaseguided passive batch microfluidic mixing chamber for isothermal amplification.

    PubMed

    Hakenberg, Sydney; Hügle, Matthias; Weidmann, Manfred; Hufert, Frank; Dame, Gregory; Urban, Gerald A

    2012-11-01

    With a view to developing a rapid pathogen detection system utilizing isothermal nucleic acid amplification, the necessary micro-mixing step is innovatively implemented on a chip. Passive laminar flow mixing of two 6.5 μl batches differing in viscosity is performed within a microfluidic chamber. This is achieved with a novel chip space-saving phaseguide design which allows, for the first time, the complete integration of a passive mixing structure into a target chamber. Sequential filling of batches prior to mixing is demonstrated. Simulation predicts a reduction of diffusive mixing time from hours down to one minute. A simple and low-cost fabrication method is used which combines dry film resist technology and direct wafer bonding. Finally, an isothermal nucleic acid detection assay is successfully implemented where fluorescence results are measured directly from the chip after a one minute mixing sequence. In combination with our previous work, this opens up the way towards a fully integrated pathogen detection system in a lab-on-a-chip format. PMID:22952055

  16. Optimization of soil mixing technology through metallic iron addition.

    SciTech Connect

    Moos, L. P.

    1999-01-15

    Enhanced soil mixing is a process used to remove volatile organic compounds (VOCs) from soil. In this process, also known as soil mixing with thermally enhanced soil vapor extraction, or SM/TESVE, a soil mixing apparatus breaks up and mixes a column of soil up to 9 m (30 ft) deep; simultaneously, hot air is blown through the soil. The hot air carries the VOCs to the surface where they are collected and safely disposed of. This technology is cost effective at high VOC concentrations, but it becomes cost prohibitive at low concentrations. Argonne National Laboratory-East conducted a project to evaluate ways of improving the effectiveness of this system. The project investigated the feasibility of integrating the SM/TESVE process with three soil treatment processes--soil vapor extraction, augmented indigenous biodegradation, and zero-valent iron addition. Each of these technologies was considered a polishing treatment designed to remove the contaminants left behind by enhanced soil mixing. The experiment was designed to determine if the overall VOC removal effectiveness and cost-effectiveness of the SM/TESVE process could be improved by integrating this approach with one of the polishing treatment systems.

  17. Microfluidic Mixing Technology for a Universal Health Sensor

    NASA Technical Reports Server (NTRS)

    Chan, Eugene Y.; Bae, Candice

    2009-01-01

    A highly efficient means of microfluidic mixing has been created for use with the rHEALTH sensor an elliptical mixer and passive curvilinear mixing patterns. The rHEALTH sensor provides rapid, handheld, complete blood count, cell differential counts, electrolyte measurements, and other lab tests based on a reusable, flow-based microfluidic platform. These geometries allow for cleaning in a reusable manner, and also allow for complete mixing of fluid streams. The microfluidic mixing is performed by flowing two streams of fluid into an elliptical or curvilinear design that allows the combination of the flows into one channel. The mixing is accomplished by either chaotic advection around micro - fluidic loops. All components of the microfluidic chip are flow-through, meaning that cleaning solution can be introduced into the chip to flush out cells, plasma proteins, and dye. Tests were performed on multiple chip geometries to show that cleaning is efficient in any flowthrough design. The conclusion from these experiments is that the chip can indeed be flushed out with microliter volumes of solution and biological samples are cleaned readily from the chip with minimal effort. The technology can be applied in real-time health monitoring at patient s bedside or in a doctor s office, and real-time clinical intervention in acute situations. It also can be used for daily measurement of hematocrit for patients on anticoagulant drugs, or to detect acute myocardial damage outside a hospital.

  18. Chaotic mixing in a planar, curved channel using periodic slip

    SciTech Connect

    Garg, P.; Picardo, J. R.; Pushpavanam, S.

    2015-03-15

    We propose a novel strategy for designing chaotic micromixers using curved channels confined between two flat planes. The location of the separatrix between the Dean vortices, induced by centrifugal forces, is dependent on the location of the maxima of axial velocity. An asymmetry in the axial velocity profile can change the location of the separatrix. This is achieved physically by introducing slip alternatingly at the top and bottom walls. This leads to streamline crossing and Lagrangian chaos. An approximate analytical solution of the velocity field is obtained using perturbation theory. This is used to find the Lagrangian trajectories of fluid particles. Poincare sections taken at periodic locations in the axial direction are used to study the extent of chaos. We study two microchannel designs, called circlet and serpentine, in which the Dean vortices in adjacent half cells are co-rotating and counter-rotating, respectively. The extent of mixing, at low Re and low slip length, is shown to be greater in the serpentine case. Wide channels are observed to have much better mixing than tall channels; an important observation not made for separatrix flows till now. Eulerian indicators are used to gauge the extent of mixing, with varying slip length, and it is shown that an optimum slip length exists which maximizes the mixing in a particular geometry. Once the parameter space of relatively high mixing is identified, detailed variance computations are carried out to identify the detailed features.

  19. Scalar entrainment in the mixing layer

    NASA Technical Reports Server (NTRS)

    Sandham, N. D.; Mungal, M. G.; Broadwell, J. E.; Reynolds, W. C.

    1988-01-01

    New definitions of entrainment and mixing based on the passive scalar field in the plane mixing layer are proposed. The definitions distinguish clearly between three fluid states: (1) unmixed fluid, (2) fluid engulfed in the mixing layer, trapped between two scalar contours, and (3) mixed fluid. The difference betwen (2) and (3) is the amount of fluid which has been engulfed during the pairing process, but has not yet mixed. Trends are identified from direct numerical simulations and extensions to high Reynolds number mixing layers are made in terms of the Broadwell-Breidenthal mixing model. In the limit of high Peclet number (Pe = ReSc) it is speculated that engulfed fluid rises in steps associated with pairings, introducing unmixed fluid into the large scale structures, where it is eventually mixed at the Kolmogorov scale. From this viewpoint, pairing is a prerequisite for mixing in the turbulent plane mixing layer.

  20. Turbulent Mixing Chemistry in Disks

    NASA Astrophysics Data System (ADS)

    Semenov, D.; Wiebe, D.

    2006-11-01

    A gas-grain chemical model with surface reaction and 1D/2D turbulent mixing is available for protoplanetary disks and molecular clouds. Current version is based on the updated UMIST'95 database with gas-grain interactions (accretion, desorption, photoevaporation, etc.) and modified rate equation approach to surface chemistry (see also abstract for the static chemistry code).

  1. The Mystery of Neutrino Mixings

    NASA Astrophysics Data System (ADS)

    Altarelli, Guido

    2013-07-01

    In the last years we have learnt a lot about neutrino masses and mixings. Neutrinos are not all massless but their masses are very small. Probably masses are small because neutrinos are Majorana particles with masses inversely proportional to the large scale M of lepton number (L) violation, which turns out to be compatible with the GUT scale. We have understood that there is no contradiction between large neutrino mixings and small quark mixings, even in the context of GUTs and that neutrino masses fit well in the SUSY GUT picture. Out of equilibrium decays with CP and L violation of heavy RH neutrinos can produce a B-L asymmetry, then converted near the weak scale by instantons into an amount of B asymmetry compatible with observations (baryogenesis via leptogenesis). It appears that active neutrinos are not a significant component of Dark Matter in the Universe. A long list of models have been formulated over the years to understand neutrino masses and mixings. With the continuous improvement of the data most of the models have been discarded by experiment. The surviving models still span a wide range going from a maximum of symmetry, with discrete non-abelian flavour groups, to the opposite extreme of anarchy.

  2. Racially Mixed People in America.

    ERIC Educational Resources Information Center

    Root, Maria P. P., Ed.

    This book offers a comprehensive look at the social and psychological adjustment of multiracial people, models for identity development, contemporary immigration and marriage patterns, and methodological issues involved in conducting research with mixed-race people, all in the context of America's multiracial past and present. The following 26…

  3. Colour Mixing Based on Daylight

    ERIC Educational Resources Information Center

    Meyn, Jan-Peter

    2008-01-01

    Colour science is based on the sensation of monochromatic light. In contrast to that, surface colours are caused by reflection of wide sections of the daylight spectrum. Non-spectral colours like magenta and purple appear homologous to colours with spectral hue, if the approach of mixing monochromatic light is abandoned. It is shown that a large…

  4. VLSI mixed signal processing system

    NASA Technical Reports Server (NTRS)

    Alvarez, A.; Premkumar, A. B.

    1993-01-01

    An economical and efficient VLSI implementation of a mixed signal processing system (MSP) is presented in this paper. The MSP concept is investigated and the functional blocks of the proposed MSP are described. The requirements of each of the blocks are discussed in detail. A sample application using active acoustic cancellation technique is described to demonstrate the power of the MSP approach.

  5. Mixing It Up with Acrylics.

    ERIC Educational Resources Information Center

    Laird, Shirley

    1999-01-01

    Presents an art activity for fifth-grade students in which they learn about basic shapes and what happens when shapes overlap, draw seven overlapping geometric shapes, review the use of acrylic paint and mixing colors, and finally paint with primary colors. (CMK)

  6. Bayesian stable isotope mixing models

    EPA Science Inventory

    In this paper we review recent advances in Stable Isotope Mixing Models (SIMMs) and place them into an over-arching Bayesian statistical framework which allows for several useful extensions. SIMMs are used to quantify the proportional contributions of various sources to a mixtur...

  7. Chaotic mixing across oceanic jets

    SciTech Connect

    Miller, P.; Jones, C.K.; Haller, G.; Pratt, L. |

    1996-06-01

    The perspective of geometric dynamical systems is used to study the transport of fluid across oceanic jets. We study the mixing associated with the simplest analytical models for jets, namely, neutral modes superimposed on a base mean flow, where the base flow and the neutral modes are approximately potential vorticity conserving. The base jet plus a single neutral mode is an integrable flow in the appropriate moving frame, and heteroclinic orbits act as impenetrable boundaries separating different regions of phase space. Superimposing more than one neutral mode results in the breakup of these heteroclinic orbits and associated chaotic mixing. Using a cusped jet model we study the case where the perturbation is periodic in time. We present numerical simulations of the Poincar{acute e} map along with calculations of the Melnikov integral which characterizes the exchange rate across such boundaries. The analytical and numerical results show that these models explain mixing along the edges of the jet, but do not appear to explain mixing across the body of the jet. {copyright} {ital 1996 American Institute of Physics.}

  8. Generalized perturbations in neutrino mixing

    NASA Astrophysics Data System (ADS)

    Liao, Jiajun; Marfatia, D.; Whisnant, K.

    2015-10-01

    We derive expressions for the neutrino mixing parameters that result from complex perturbations on (1) the Majorana neutrino mass matrix (in the basis of charged lepton mass eigenstates) and on (2) the charged lepton mass matrix, for arbitrary initial (unperturbed) mixing matrices. In the first case, we find that the phases of the elements of the perturbation matrix, and the initial values of the Dirac and Majorana phases, strongly impact the leading-order corrections to the neutrino mixing parameters and phases. For experimentally compatible scenarios wherein the initial neutrino mass matrix has μ -τ symmetry, we find that the Dirac phase can take any value under small perturbations. Similarly, in the second case, perturbations to the charged lepton mass matrix can generate large corrections to the mixing angles and phases of the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrix. As an illustration of our generalized procedure, we apply it to a situation in which nonstandard scalar and nonstandard vector interactions simultaneously affect neutrino oscillations.

  9. Mixing and transport. [Water pollution

    SciTech Connect

    Roberts, P.J.W.

    1982-06-01

    The mixing and transport of water pollution is the subject of this literature review with 110 references. The environmental transport of pollutants is examined in streams, rivers, reservoirs, ponds, estuaries, salt marshes and coastal waters. The dynamics of fluid flow, and the physical properties of jets, plumes, and stratified fluids are discussed. (KRM)

  10. Reductant injection and mixing system

    DOEpatents

    Reeves, Matt; Henry, Cary A.; Ruth, Michael J.

    2016-02-16

    A gaseous reductant injection and mixing system is described herein. The system includes an injector for injecting a gaseous reductant into an exhaust gas stream, and a mixer attached to a surface of the injector. The injector includes a plurality of apertures through which the gaseous reductant is injected into an exhaust gas stream. The mixer includes a plurality of fluid deflecting elements.

  11. A Mixed Methods Content Analysis of the Research Literature in Science Education

    NASA Astrophysics Data System (ADS)

    Schram, Asta B.

    2014-10-01

    In recent years, more and more researchers in science education have been turning to the practice of combining qualitative and quantitative methods in the same study. This approach of using mixed methods creates possibilities to study the various issues that science educators encounter in more depth. In this content analysis, I evaluated 18 studies from science education journals as they relate to the definition, design, and overall practice of using mixed methods. I scrutinized a purposeful sample, derived from 3 journals (the International Journal of Science Education, the Journal of Research in Science Teaching, and the Research in Science Education) in terms of the type of data collected, timing, priority, design, the mixing of the 2 data strands in the studies, and the justifications authors provide for using mixed methods. Furthermore, the articles were evaluated in terms of how well they met contemporary definitions for mixed methods research. The studies varied considerably in the use and understanding of mixed methods. A systematic evaluation of the employment of mixed methods methodology was used to identify the studies that best reflected contemporary definitions. A comparison to earlier content analyses of mixed methods research indicates that researchers' knowledge of mixed methods methodology may be increasing. The use of this strategy in science education research calls, however, for an improved methodology, especially concerning the practice of mixing. Suggestions are given on how to best use this approach.

  12. JET MIXING ANALYSIS FOR SRS HIGH-LEVEL WASTE RECOVERY

    SciTech Connect

    Lee, S.

    2011-07-05

    The process of recovering the waste in storage tanks at the Savannah River Site (SRS) typically requires mixing the contents of the tank to ensure uniformity of the discharge stream. Mixing is accomplished with one to four slurry pumps located within the tank liquid. The slurry pump may be fixed in position or they may rotate depending on the specific mixing requirements. The high-level waste in Tank 48 contains insoluble solids in the form of potassium tetraphenyl borate compounds (KTPB), monosodium titanate (MST), and sludge. Tank 48 is equipped with 4 slurry pumps, which are intended to suspend the insoluble solids prior to transfer of the waste to the Fluidized Bed Steam Reformer (FBSR) process. The FBSR process is being designed for a normal feed of 3.05 wt% insoluble solids. A chemical characterization study has shown the insoluble solids concentration is approximately 3.05 wt% when well-mixed. The project is requesting a Computational Fluid Dynamics (CFD) mixing study from SRNL to determine the solids behavior with 2, 3, and 4 slurry pumps in operation and an estimate of the insoluble solids concentration at the suction of the transfer pump to the FBSR process. The impact of cooling coils is not considered in the current work. The work consists of two principal objectives by taking a CFD approach: (1) To estimate insoluble solids concentration transferred from Tank 48 to the Waste Feed Tank in the FBSR process and (2) To assess the impact of different combinations of four slurry pumps on insoluble solids suspension and mixing in Tank 48. For this work, several different combinations of a maximum of four pumps are considered to determine the resulting flow patterns and local flow velocities which are thought to be associated with sludge particle mixing. Two different elevations of pump nozzles are used for an assessment of the flow patterns on the tank mixing. Pump design and operating parameters used for the analysis are summarized in Table 1. The baseline

  13. Forced mixer lobes in ejector designs

    NASA Technical Reports Server (NTRS)

    Presz, W. M., Jr.; Morin, B. L.; Gousy, R. G.

    1986-01-01

    Forced mixer lobes in augmentor primary ejectors obtain a 100-percent increase in pumping over conventional design, together with nearly complete mixing in very short mixing ducts, through the generation of large scale axial vorticity in the mixing duct. The vorticity causes rapid mixing of the primary and secondary flows with low losses; since mixing length is minimized, wall friction losses are reduced, allowing more secondary flow to be pumped for a given total pressure in the primary flow. Analytical results are presented that are judged to have significant implications for future ejector test work.

  14. A mixed relaxed clock model

    PubMed Central

    2016-01-01

    Over recent years, several alternative relaxed clock models have been proposed in the context of Bayesian dating. These models fall in two distinct categories: uncorrelated and autocorrelated across branches. The choice between these two classes of relaxed clocks is still an open question. More fundamentally, the true process of rate variation may have both long-term trends and short-term fluctuations, suggesting that more sophisticated clock models unfolding over multiple time scales should ultimately be developed. Here, a mixed relaxed clock model is introduced, which can be mechanistically interpreted as a rate variation process undergoing short-term fluctuations on the top of Brownian long-term trends. Statistically, this mixed clock represents an alternative solution to the problem of choosing between autocorrelated and uncorrelated relaxed clocks, by proposing instead to combine their respective merits. Fitting this model on a dataset of 105 placental mammals, using both node-dating and tip-dating approaches, suggests that the two pure clocks, Brownian and white noise, are rejected in favour of a mixed model with approximately equal contributions for its uncorrelated and autocorrelated components. The tip-dating analysis is particularly sensitive to the choice of the relaxed clock model. In this context, the classical pure Brownian relaxed clock appears to be overly rigid, leading to biases in divergence time estimation. By contrast, the use of a mixed clock leads to more recent and more reasonable estimates for the crown ages of placental orders and superorders. Altogether, the mixed clock introduced here represents a first step towards empirically more adequate models of the patterns of rate variation across phylogenetic trees. This article is part of the themed issue ‘Dating species divergences using rocks and clocks’. PMID:27325829

  15. A mixed relaxed clock model.

    PubMed

    Lartillot, Nicolas; Phillips, Matthew J; Ronquist, Fredrik

    2016-07-19

    Over recent years, several alternative relaxed clock models have been proposed in the context of Bayesian dating. These models fall in two distinct categories: uncorrelated and autocorrelated across branches. The choice between these two classes of relaxed clocks is still an open question. More fundamentally, the true process of rate variation may have both long-term trends and short-term fluctuations, suggesting that more sophisticated clock models unfolding over multiple time scales should ultimately be developed. Here, a mixed relaxed clock model is introduced, which can be mechanistically interpreted as a rate variation process undergoing short-term fluctuations on the top of Brownian long-term trends. Statistically, this mixed clock represents an alternative solution to the problem of choosing between autocorrelated and uncorrelated relaxed clocks, by proposing instead to combine their respective merits. Fitting this model on a dataset of 105 placental mammals, using both node-dating and tip-dating approaches, suggests that the two pure clocks, Brownian and white noise, are rejected in favour of a mixed model with approximately equal contributions for its uncorrelated and autocorrelated components. The tip-dating analysis is particularly sensitive to the choice of the relaxed clock model. In this context, the classical pure Brownian relaxed clock appears to be overly rigid, leading to biases in divergence time estimation. By contrast, the use of a mixed clock leads to more recent and more reasonable estimates for the crown ages of placental orders and superorders. Altogether, the mixed clock introduced here represents a first step towards empirically more adequate models of the patterns of rate variation across phylogenetic trees.This article is part of the themed issue 'Dating species divergences using rocks and clocks'. PMID:27325829

  16. Mixing it up for Protein Crystallization

    NASA Astrophysics Data System (ADS)

    Hansen, Carl; Sommer, Morten; Berger, James; Quake, Stephen

    2005-03-01

    In the post-genomic era, X-ray crystallography has emerged as the workhorse of large-scale structural biology initiatives that seek to understand protein function and interaction at the atomic scale. Despite impressive technological advances in X-ray sources, phasing techniques, and computing power, the determination of protein structure continues to be severely hampered by the difficulties in obtaining high-quality protein crystals. Emergent technologies utilizing microfluidics now have the potential to solve these problems on several levels. We will present two microfluidic devices that have been shown to dramatically improve protein crystallization. The first is a formulation device which allows for the rapid combinatorial mixing of reagents to systematically explore protein solubility behavior. A priori solubility mapping allows for the rational design of optimal crystallization screens that are tailored to a specific target. A second screening device allows for massively parallel sample processing while exploiting the properties of mass transport manifest at the micron scale to ensure slow and efficient mixing kinetics that are difficult to achieve in macroscopic reactors.

  17. Pile mixing increases greenhouse gas emissions during composting of dairy manure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of pile mixing on greenhouse gas (GHG) emissions from stored dairy manure was determined using large flux chambers designed to completely cover pilot-scale manure piles. GHG emissions from piles that were mixed four times during the 80 day trial were about 20% higher than unmixed piles. ...

  18. Mixed Methods Research of Adult Family Care Home Residents and Informal Caregivers

    ERIC Educational Resources Information Center

    Jeanty, Guy C.; Hibel, James

    2011-01-01

    This article describes a mixed methods approach used to explore the experiences of adult family care home (AFCH) residents and informal caregivers (IC). A rationale is presented for using a mixed methods approach employing the sequential exploratory design with this poorly researched population. The unique challenges attendant to the sampling…

  19. Mixed Heritage College Student Experiences of Race-Oriented Student Services

    ERIC Educational Resources Information Center

    Cabinte, Desiree C.

    2013-01-01

    The mixed heritage population is one of the fastest growing in the United States. With mixed heritage youth doubling in the past ten years, higher education institutions can expect an increase of this minority group. Historically higher education has responded to underrepresented student needs and designed student services for monoracial students…

  20. Mixed Ability Teaching: Meeting Learners' Needs. Netword 3: Teaching Languages to Adults.

    ERIC Educational Resources Information Center

    Ainslie, Susan

    This guide, designed for teachers of second languages to adults, discusses instruction for student groups of mixed abilities. The first chapter examines the factors that determine mixed ability, including: student motivation, interests, and needs; linguistic ability; general educational background; learning style; age; external pressures and time…

  1. Greenhouse gas emissions during composting of dairy manure: Delaying pile mixing does not reduce overall emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of the timing of pile mixing on greenhouse gas (GHG) emissions during dairy manure composting was determined using large flux chambers designed to completely cover replicate pilot-scale compost piles. GHG emissions from compost piles that were mixed at 2, 3, 4, or 5 weeks after initial c...

  2. Unmixing the Mixing Cost: Contributions from Dimensional Relevance and Stimulus-Response Suppression

    ERIC Educational Resources Information Center

    Mari-Beffa, Paloma; Cooper, Stephen; Houghton, George

    2012-01-01

    When participants repeat the same task in a context in which the task may also switch (a mixed block), performance deteriorates compared to when there is only one task repeating (a pure block). Three experiments were designed to assess how perceptual and motor transitions influenced this mixing cost. Experiment 1 provided three pure block…

  3. Intravenous Fluid Mixing in Normal Gravity, Partial Gravity, and Microgravity: Down-Selection of Mixing Methods

    NASA Technical Reports Server (NTRS)

    Niederhaus, Charles E.; Miller, Fletcher J.

    2008-01-01

    The missions envisioned under the Vision for Space Exploration will require development of new methods to handle crew medical care. Medications and intravenous (IV) fluids have been identified as one area needing development. Storing certain medications and solutions as powders or concentrates can both increase the shelf life and reduce the overall mass and volume of medical supplies. The powders or concentrates would then be mixed in an IV bag with Sterile Water for Injection produced in situ from the potable water supply. Fluid handling in microgravity is different than terrestrial settings, and requires special consideration in the design of equipment. This document describes the analyses and down-select activities used to identify the IV mixing method to be developed that is suitable for ISS and exploration missions. The chosen method is compatible with both normal gravity and microgravity, maintains sterility of the solution, and has low mass and power requirements. The method will undergo further development, including reduced gravity aircraft experiments and computations, in order to fully develop the mixing method and associated operational parameters.

  4. New mixing system in dissolution isoperibol microcalorimeter.

    PubMed

    Moreno-Piraján, Juan Carlos; Giraldo-Gutierréz, Liliana

    2007-04-01

    In order to determine dissolution enthalpies of small amounts of easily or slightly soluble solids, a new cell for batch isoperibolic microcalorimetry was developed at the Universities of the Andes and the National of Colombia. An innovative mixing system for avoiding error due to the common effect of the brittle point breakage has been designed for this cell. The cell has a capacity of 40 ml and the sample holder can bear solid samples between 10.0 and 30.0 mg. The high stability of the base line allows solution experiments to be extended over several hours. All measurements reported were conducted at 298.15 K using water as solvent. PMID:17477696

  5. Giant exchange interaction in mixed lanthanides

    PubMed Central

    Vieru, Veacheslav; Iwahara, Naoya; Ungur, Liviu; Chibotaru, Liviu F.

    2016-01-01

    Combining strong magnetic anisotropy with strong exchange interaction is a long standing goal in the design of quantum magnets. The lanthanide complexes, while exhibiting a very strong ionic anisotropy, usually display a weak exchange coupling, amounting to only a few wavenumbers. Recently, an isostructural series of mixed (Ln = Gd, Tb, Dy, Ho, Er) have been reported, in which the exchange splitting is estimated to reach hundreds wavenumbers. The microscopic mechanism governing the unusual exchange interaction in these compounds is revealed here by combining detailed modeling with density-functional theory and ab initio calculations. We find it to be basically kinetic and highly complex, involving non-negligible contributions up to seventh power of total angular momentum of each lanthanide site. The performed analysis also elucidates the origin of magnetization blocking in these compounds. Contrary to general expectations the latter is not always favored by strong exchange interaction. PMID:27087470

  6. Giant exchange interaction in mixed lanthanides

    NASA Astrophysics Data System (ADS)

    Vieru, Veacheslav; Iwahara, Naoya; Ungur, Liviu; Chibotaru, Liviu F.

    2016-04-01

    Combining strong magnetic anisotropy with strong exchange interaction is a long standing goal in the design of quantum magnets. The lanthanide complexes, while exhibiting a very strong ionic anisotropy, usually display a weak exchange coupling, amounting to only a few wavenumbers. Recently, an isostructural series of mixed (Ln = Gd, Tb, Dy, Ho, Er) have been reported, in which the exchange splitting is estimated to reach hundreds wavenumbers. The microscopic mechanism governing the unusual exchange interaction in these compounds is revealed here by combining detailed modeling with density-functional theory and ab initio calculations. We find it to be basically kinetic and highly complex, involving non-negligible contributions up to seventh power of total angular momentum of each lanthanide site. The performed analysis also elucidates the origin of magnetization blocking in these compounds. Contrary to general expectations the latter is not always favored by strong exchange interaction.

  7. Giant exchange interaction in mixed lanthanides.

    PubMed

    Vieru, Veacheslav; Iwahara, Naoya; Ungur, Liviu; Chibotaru, Liviu F

    2016-01-01

    Combining strong magnetic anisotropy with strong exchange interaction is a long standing goal in the design of quantum magnets. The lanthanide complexes, while exhibiting a very strong ionic anisotropy, usually display a weak exchange coupling, amounting to only a few wavenumbers. Recently, an isostructural series of mixed (Ln = Gd, Tb, Dy, Ho, Er) have been reported, in which the exchange splitting is estimated to reach hundreds wavenumbers. The microscopic mechanism governing the unusual exchange interaction in these compounds is revealed here by combining detailed modeling with density-functional theory and ab initio calculations. We find it to be basically kinetic and highly complex, involving non-negligible contributions up to seventh power of total angular momentum of each lanthanide site. The performed analysis also elucidates the origin of magnetization blocking in these compounds. Contrary to general expectations the latter is not always favored by strong exchange interaction. PMID:27087470

  8. Mixed methods research in mental health nursing.

    PubMed

    Kettles, A M; Creswell, J W; Zhang, W

    2011-08-01

    Mixed methods research is becoming more widely used in order to answer research questions and to investigate research problems in mental health and psychiatric nursing. However, two separate literature searches, one in Scotland and one in the USA, revealed that few mental health nursing studies identified mixed methods research in their titles. Many studies used the term 'embedded' but few studies identified in the literature were mixed methods embedded studies. The history, philosophical underpinnings, definition, types of mixed methods research and associated pragmatism are discussed, as well as the need for mixed methods research. Examples of mental health nursing mixed methods research are used to illustrate the different types of mixed methods: convergent parallel, embedded, explanatory and exploratory in their sequential and concurrent combinations. Implementing mixed methods research is also discussed briefly and the problem of identifying mixed methods research in mental and psychiatric nursing are discussed with some possible solutions to the problem proposed. PMID:21749560

  9. Mixed Oxide Fresh Fuel Package Auxiliary Equipment

    SciTech Connect

    Yapuncich, F.; Ross, A.; Clark, R.H.; Ammerman, D.

    2008-07-01

    The United States Department of Energy's National Nuclear Security Administration (NNSA) is overseeing the construction the Mixed Oxide (MOX) Fuel Fabrication Facility (MFFF) on the Savannah River Site. The new facility, being constructed by NNSA's contractor Shaw AREVA MOX Services, will fabricate fuel assemblies utilizing surplus plutonium as feedstock. The fuel will be used in designated commercial nuclear reactors. The MOX Fresh Fuel Package (MFFP), which has recently been licensed by the Nuclear Regulatory Commission (NRC) as a type B package (USA/9295/B(U)F-96), will be utilized to transport the fabricated fuel assemblies from the MFFF to the nuclear reactors. It was necessary to develop auxiliary equipment that would be able to efficiently handle the high precision fuel assemblies. Also, the physical constraints of the MFFF and the nuclear power plants require that the equipment be capable of loading and unloading the fuel assemblies both vertically and horizontally. The ability to reconfigure the load/unload evolution builds in a large degree of flexibility for the MFFP for the handling of many types of both fuel and non fuel payloads. The design and analysis met various technical specifications including dynamic and static seismic criteria. The fabrication was completed by three major fabrication facilities within the United States. The testing was conducted by Sandia National Laboratories. The unique design specifications and successful testing sequences will be discussed. (authors)

  10. Optimized Mixing in Microchannels with Integrated Microactuators

    NASA Astrophysics Data System (ADS)

    Folk, Christopher Richard

    Microscale valves and pumps have been designed and fabricated for integration into a microfluidic circuit. Furthermore, a micromixer for this circuit has been designed and optimized. N-isopropylacrylamide (NIPA) gels have been fabricated and actuated directly with heat and indirectly by laser. A new method for photopatterning these gels based on photoinitiation has been used to fabricate hydrogel valves down to 50 mum in diameter. Hydrogel valves have been fabricated in situ in a microfluidic network. The valves open in 27 seconds and close via diffusion of water into the gel in 128 seconds, which is faster than other optically-driven polymers used for large displacements. In this research, azobis-isobutyronitrile (AIBN) is incorporated into a variety of polydimethylsiloxane (PDMS) pump chambers. The AIBN is heated via integrated resistive heaters and decomposes to release nitrogen gas. The nitrogen gas provides impulse power to a PDMS diaphragm to displace the fluid. The pump devices have been built and characterized. Lastly, in this work, we describe the use of combined fluid dynamic and diffusion modeling to simulate a micromixer based on the elements above. The micromixer is optimized via Design of Experiments to produce an optimized geometry for mixing. The optimization is validated via comparison to previous work through the Strouhal number.

  11. A Library of Rad Hard Mixed-Voltage/Mixed-Signal Building Blocks for Integration of Avionics Systems for Deep Space

    NASA Technical Reports Server (NTRS)

    Mojarradi, M. M.; Blaes, B.; Kolawa, E. A.; Blalock, B. J.; Li, H. W.; Buck, K.; Houge, D.

    2001-01-01

    To build the sensor intensive system-on-a-chip for the next generation spacecrafts for deep space, Center for Integration of Space Microsystems at JPL (CISM) takes advantage of the lower power rating and inherent radiation resistance of Silicon on Insulator technology (SOI). We are developing a suite of mixed-voltage and mixed-signal building blocks in Honeywell's SOI process that can enable the rapid integration of the next generation avionics systems with lower power rating, higher reliability, longer life, and enhanced radiation tolerance for spacecrafts such as the Europa Orbiter and Europa Lander. The mixed-voltage building blocks are predominantly for design of adaptive power management systems. Their design centers around an LDMOS structure that is being developed by Honeywell, Boeing Corp, and the University of Idaho. The mixed-signal building blocks are designed to meet the low power, extreme radiation requirement of deep space applications. These building blocks are predominantly used to interface analog sensors to the digital CPU of the next generation avionics system on a chip. Additional information is contained in the original extended abstract.

  12. PREFACE: Turbulent Mixing and Beyond Turbulent Mixing and Beyond

    NASA Astrophysics Data System (ADS)

    Abarzhi, Snezhana I.; Gauthier, Serge; Rosner, Robert

    2008-10-01

    The goals of the International Conference `Turbulent Mixing and Beyond' are to expose the generic problem of Turbulence and Turbulent Mixing in Unsteady Flows to a wide scientific community, to promote the development of new ideas in tackling the fundamental aspects of the problem, to assist in the application of novel approaches in a broad range of phenomena, where the non-canonical turbulent processes occur, and to have a potential impact on technology. The Conference provides the opportunity to bring together scientists from the areas which include, but are not limited to, high energy density physics, plasmas, fluid dynamics, turbulence, combustion, material science, geophysics, astrophysics, optics and telecommunications, applied mathematics, probability and statistics, and to have their attention focused on the long-standing formidable task. The Turbulent Mixing and Turbulence in Unsteady Flows, including multiphase flows, plays a key role in a wide variety of phenomena, ranging from astrophysical to nano-scales, under either high or low energy density conditions. Inertial confinement and magnetic fusion, light-matter interaction and non-equilibrium heat transfer, properties of materials under high strain rates, strong shocks, explosions, blast waves, supernovae and accretion disks, stellar non-Boussinesq and magneto-convection, planetary interiors and mantle-lithosphere tectonics, premixed and non-premixed combustion, oceanography, atmospheric flows, unsteady boundary layers, hypersonic and supersonic flows, are a few examples to list. A grip on unsteady turbulent processes is crucial for cutting-edge technology such as laser-micromachining and free-space optical telecommunications, and for industrial applications in aeronautics. Unsteady Turbulent Processes are anisotropic, non-local and multi-scale, and their fundamental scaling, spectral and invariant properties depart from the classical Kolmogorov scenario. The singular aspects and similarity of the

  13. Why, and how, mixed methods research is undertaken in health services research in England: a mixed methods study

    PubMed Central

    O'Cathain, Alicia; Murphy, Elizabeth; Nicholl, Jon

    2007-01-01

    Background Recently, there has been a surge of international interest in combining qualitative and quantitative methods in a single study – often called mixed methods research. It is timely to consider why and how mixed methods research is used in health services research (HSR). Methods Documentary analysis of proposals and reports of 75 mixed methods studies funded by a research commissioner of HSR in England between 1994 and 2004. Face-to-face semi-structured interviews with 20 researchers sampled from these studies. Results 18% (119/647) of HSR studies were classified as mixed methods research. In the documentation, comprehensiveness was the main driver for using mixed methods research, with researchers wanting to address a wider range of questions than quantitative methods alone would allow. Interviewees elaborated on this, identifying the need for qualitative research to engage with the complexity of health, health care interventions, and the environment in which studies took place. Motivations for adopting a mixed methods approach were not always based on the intrinsic value of mixed methods research for addressing the research question; they could be strategic, for example, to obtain funding. Mixed methods research was used in the context of evaluation, including randomised and non-randomised designs; survey and fieldwork exploratory studies; and instrument development. Studies drew on a limited number of methods – particularly surveys and individual interviews – but used methods in a wide range of roles. Conclusion Mixed methods research is common in HSR in the UK. Its use is driven by pragmatism rather than principle, motivated by the perceived deficit of quantitative methods alone to address the complexity of research in health care, as well as other more strategic gains. Methods are combined in a range of contexts, yet the emerging methodological contributions from HSR to the field of mixed methods research are currently limited to the single

  14. Mixed states in ferromagnetic superconductors

    SciTech Connect

    Matsumoto, H.; Teshima, R.; Umezawa, H.; Tachiki, M.

    1983-01-01

    A detailed study of the mixed state of the ferromagnetic rare-earth compounds RRh/sub 4/B/sub 4/, R/sub x/Mo/sub 6/S/sub 8/, and R/sub x/Mo/sub 6/Se/sub 6/ is presented. The saturation effect of the magnetic moments is taken into account. Depending on the parameters, there are many types of phase transitions between the type-II/2, type-II/1, and type-I mixed states and the paramagnetic Meissner state, ferromagnetic Meissner state, spin-periodic Meissner state, and the self-induced vortex state. It is predicted that the magnetization can exhibit a variety of unusual modes.

  15. Mixing enhancement using axial flow

    NASA Technical Reports Server (NTRS)

    Papamoschou, Dimitri (Inventor)

    2003-01-01

    A method and an apparatus for enhancing fluid mixing. The method comprises the following: (a) configuring a duct to have an effective outer wall, an effective inner wall, a cross-sectional shape, a first cross-sectional area and an exit area, the first cross-sectional area and the exit area being different in size; (b) generating a first flow at the first cross-sectional area, the first flow having a total pressure and a speed equal to or greater than a local speed of sound; and (c) generating a positive streamwise pressure gradient in a second flow in proximity of the exit area. The second flow results from the first flow. Fluid mixing is enhanced downstream from the duct exit area.

  16. Pediatric Mixed Connective Tissue Disease.

    PubMed

    Berard, Roberta A; Laxer, Ronald M

    2016-05-01

    Pediatric-onset mixed connective tissue disease is among the rare disease entities in pediatric rheumatology and includes features of arthritis, polymyositis/dermatomyositis, systemic lupus erythematosus, and systemic sclerosis. Accurate recognition and diagnosis of the disease is paramount to prevent long-term morbidity. Advances in the genetic and immunologic understanding of the factors involved in the etiopathogenesis provide an opportunity for improvements in prognostication and targeted therapy. The development of a multinational cohort of patients with mixed connective tissue disease would be invaluable to provide more updated data regarding the clinical presentation, to develop a standardized treatment approach, disease activity and outcome tools, and to provide data on long-term outcomes and comorbidities. PMID:27032791

  17. The evolution of mantle mixing.

    PubMed

    Allègre, Claude J

    2002-11-15

    We present a geochemical overview of the canonic model that suggests a two-layer mantle for most of the Earth's history. A change in the Rayleigh number may have modified the convection and now allows the subduction of oceanic plates into the lower mantle, which was not the case in the past. The measurement of stirring time in the source of mid-ocean-ridge basalt, together with Xe- and Pb-isotopic ratios in the mid-ocean-ridge-basalt source, suggests that the upper mantle is separated into two domains, one above the 400 km discontinuity (asthenosphere) with rapid mixing and short residence time, and another between the 400 and 670 km discontinuities with sluggish mixing and a residence time of ca. 1.5 x 10(9) yr. PMID:12460474

  18. Canine Mammary Mixed Tumours: A Review

    PubMed Central

    Dantas Cassali, Geovanni; Cavalheiro Bertagnolli, Angélica; Ferreira, Enio; Araújo Damasceno, Karine; de Oliveira Gamba, Conrado; Bonolo de Campos, Cecília

    2012-01-01

    Mammary mixed tumours are the most frequent neoplasias in female dogs. In humans, mixed tumours are frequently found in the salivary glands and are known as pleomorphic adenomas. In addition to their histomorphologic similarities, mixed tumours and pleomorphic adenomas have the potential to become malignant and give rise to carcinomas in mixed tumours and carcinomas ex-pleomorphic adenoma, respectively. The factors associated with malignant transformation are still poorly known in the case of canine mixed tumours. However, this form of neoplasia tends to be associated with a better prognosis than other malignant histological types. This paper discusses the main features associated with female canine mammary mixed tumours. PMID:23193497

  19. Hanford Site annual dangerous waste report: Volume 4, Waste Management Facility report, Radioactive mixed waste

    SciTech Connect

    1994-12-31

    This report contains information on radioactive mixed wastes at the Hanford Site. Information consists of shipment date, physical state, chemical nature, waste description, handling method and containment vessel, waste number, waste designation and amount of waste.

  20. Reliability and paste process optimization of eutectic and lead-free for mixed packaging

    NASA Technical Reports Server (NTRS)

    Ramkumar, S. M.; Ganeshan, V.; Thenalur, K.; Ghaffarian, R.

    2002-01-01

    This paper reports the results of an experiment that utilized the JPL's area array consortium test vehicle design, containing a myriad of mixed technology components with an OSP finish. The details of the reliability study are presented in this paper.