Science.gov

Sample records for deep mixing method

  1. Deep Mixing in Stellar Variability: Improved Method, Statistics, and Applications

    NASA Astrophysics Data System (ADS)

    Arkhypov, Oleksiy V.; Khodachenko, Maxim L.; Lammer, Helmut; Güdel, Manuel; Lüftinger, Theresa; Johnstone, Colin P.

    2016-07-01

    The preliminary results on deep-mixing manifestations in stellar variability are tested using our improved method and extended data set. We measure the timescales τ m of the stochastic change in the spectral power of rotational harmonics with numbers m ≤ 3 in the light curves of 1361 main-sequence stars from the Kepler mission archive. We find that the gradient [{log}({τ }2)-{log}({τ }1)]/[{log}(2)-{log}(1)] has a histogram maximum at ‑2/3, demonstrating agreement with Kolmogorov’s theory of turbulence and therefore confirming the manifestation of deep mixing. The squared amplitudes of the first and second rotational harmonics, corrected for integral photometry distortion, also show a quasi-Kolmogorov character with spectral index ≈‑5/3. Moreover, the reduction of τ 1 and τ 2 to the timescales τ lam1 and τ lam2 of laminar convection in the deep stellar layers reveals the proximity of both τ lam1 and τ lam2 to the turnover time τ MLT of standard mixing length theory. Considering this result, we use the obtained stellar variability timescales instead of τ MLT in our analysis of the relation between stellar activity and the Rossby number P/τ MLT. Comparison of our diagrams with previous results and theoretical expectations shows that best-fit correspondence is achieved for τ lam1, which can therefore be used as an analog of τ MLT. This means that the laminar component (giant cells) of stellar turbulent convection indeed plays an important role in the physics of stars. Additionally, we estimate the diffusivity of magnetic elements in stellar photospheres.

  2. Deep Mixing in Stellar Variability: Improved Method, Statistics, and Applications

    NASA Astrophysics Data System (ADS)

    Arkhypov, Oleksiy V.; Khodachenko, Maxim L.; Lammer, Helmut; Güdel, Manuel; Lüftinger, Theresa; Johnstone, Colin P.

    2016-07-01

    The preliminary results on deep-mixing manifestations in stellar variability are tested using our improved method and extended data set. We measure the timescales τ m of the stochastic change in the spectral power of rotational harmonics with numbers m ≤ 3 in the light curves of 1361 main-sequence stars from the Kepler mission archive. We find that the gradient [{log}({τ }2)-{log}({τ }1)]/[{log}(2)-{log}(1)] has a histogram maximum at -2/3, demonstrating agreement with Kolmogorov’s theory of turbulence and therefore confirming the manifestation of deep mixing. The squared amplitudes of the first and second rotational harmonics, corrected for integral photometry distortion, also show a quasi-Kolmogorov character with spectral index ≈-5/3. Moreover, the reduction of τ 1 and τ 2 to the timescales τ lam1 and τ lam2 of laminar convection in the deep stellar layers reveals the proximity of both τ lam1 and τ lam2 to the turnover time τ MLT of standard mixing length theory. Considering this result, we use the obtained stellar variability timescales instead of τ MLT in our analysis of the relation between stellar activity and the Rossby number P/τ MLT. Comparison of our diagrams with previous results and theoretical expectations shows that best-fit correspondence is achieved for τ lam1, which can therefore be used as an analog of τ MLT. This means that the laminar component (giant cells) of stellar turbulent convection indeed plays an important role in the physics of stars. Additionally, we estimate the diffusivity of magnetic elements in stellar photospheres.

  3. Mixed tumor of deep soft tissue.

    PubMed

    Adachi, Toshisada; Oda, Yoshinao; Sakamoto, Akio; Saito, Tsuyoshi; Tamiya, Sadafumi; Hachitanda, Yoichi; Masuda, Sachio; Tsuneyoshi, Masazumi

    2003-01-01

    Mixed tumors of the salivary gland and skin are relatively common but are quite rare in soft tissue. It is believed that, as in the salivary gland form, most of these lesions are benign, but that a small subset behave in an aggressive fashion. We report here a patient with recurrent mixed tumor of soft tissue with infiltrative growth. The primary tumor arose in deep subfascial soft tissue of the right lower leg and was adjacent to the surface of the fibula. An open biopsy and complete resection were performed. Upon histological examination of the resected specimen, neoplastic cell infiltration at the tumor/soft tissue interface was not obvious; local recurrence, however, was observed 1 year later. The patient was treated with wide resection. Histological examination confirmed that the recurrent tumor with an extensive chondroid area invaded the osseous tissue of the fibula. At present, 1 year after the second resection surgery, there is no evidence of disease.

  4. Corium quench in deep pool mixing experiments

    SciTech Connect

    Spencer, B.W.; McUmber, L.; Gregorash, D.; Aeschlimann, R.; Sienicki, J.J.

    1985-01-01

    The results of two recent corium-water thermal interaction (CWTI) tests are described in which a stream of molten corium was poured into a deep pool of water in order to determine the mixing behavior, the corium-to-water heat transfer rates, and the characteristic sizes of the quenched debris. The corium composition was 60% UO/sub 2/, 16% ZrO/sub 2/, and 24% stainless steel by weight; its initial temperature was 3080 K, approx.160 K above the oxide phase liquidus temperature. The corium pour stream was a single-phase 2.2 cm dia liquid column which entered the water pool in film boiling at approx.4 m/s. The water subcooling was 6 and 75C in the two tests. Test results showed that with low subcooling, rapid steam generation caused the pool to boil up into a high void fraction regime. In contrast, with large subcooling no net steam generation occurred, and the pool remained relatively quiescent. Breakup of the jet appeared to occur by surface stripping. In neither test was the breakup complete during transit through the 32 cm deep water pool, and molten corium channeled to the base where it formed a melt layer. The characteristic heat transfer rates measured 3.5 MJ/s and 2.7 MJ/s during the fall stage for small and large subcooling, respectively; during the initial stage of bed quench, the surface heat fluxes measured 2.4 MW/m/sup 2/ and 3.7 MW/m/sup 2/, respectively. A small mass of particles was formed in each test, measuring typically 0.1 to 1 mm and 1 to 5 mm dia for the large and small subcooling conditions, respectively. 9 refs., 13 figs., 1 tab.

  5. Method of deep drilling

    DOEpatents

    Colgate, Stirling A.

    1984-01-01

    Deep drilling is facilitated by the following steps practiced separately or in any combination: (1) Periodically and sequentially fracturing zones adjacent the bottom of the bore hole with a thixotropic fastsetting fluid that is accepted into the fracture to overstress the zone, such fracturing and injection being periodic as a function of the progression of the drill. (2) Casing the bore hole with ductile, pre-annealed casing sections, each of which is run down through the previously set casing and swaged in situ to a diameter large enough to allow the next section to run down through it. (3) Drilling the bore hole using a drill string of a low density alloy and a high density drilling mud so that the drill string is partially floated.

  6. Deep Mixing and Metallicity in Globular Cluster Red Giants

    NASA Astrophysics Data System (ADS)

    Martell, Sarah L.

    2007-12-01

    We present results from a study of carbon depletion and deep mixing in globular cluster red giants across a wide range of metallicity. CH bandstrengths are measured from low-resolution (R 1000) spectra and converted to [C/Fe] abundances by comparisons with synthetic spectra. Although some models of deep mixing predict that its efficiency will be reduced at high metallicity, no sign of such a cutoff is seen in our data, which span the range -2.29 < [Fe/H] < -1.29.

  7. 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…

  8. Deep Whole-Genome Sequencing to Detect Mixed Infection of Mycobacterium tuberculosis

    PubMed Central

    Gan, Mingyu; Liu, Qingyun; Yang, Chongguang; Gao, Qian; Luo, Tao

    2016-01-01

    Mixed infection by multiple Mycobacterium tuberculosis (MTB) strains is associated with poor treatment outcome of tuberculosis (TB). Traditional genotyping methods have been used to detect mixed infections of MTB, however, their sensitivity and resolution are limited. Deep whole-genome sequencing (WGS) has been proved highly sensitive and discriminative for studying population heterogeneity of MTB. Here, we developed a phylogenetic-based method to detect MTB mixed infections using WGS data. We collected published WGS data of 782 global MTB strains from public database. We called homogeneous and heterogeneous single nucleotide variations (SNVs) of individual strains by mapping short reads to the ancestral MTB reference genome. We constructed a phylogenomic database based on 68,639 homogeneous SNVs of 652 MTB strains. Mixed infections were determined if multiple evolutionary paths were identified by mapping the SNVs of individual samples to the phylogenomic database. By simulation, our method could specifically detect mixed infections when the sequencing depth of minor strains was as low as 1× coverage, and when the genomic distance of two mixed strains was as small as 16 SNVs. By applying our methods to all 782 samples, we detected 47 mixed infections and 45 of them were caused by locally endemic strains. The results indicate that our method is highly sensitive and discriminative for identifying mixed infections from deep WGS data of MTB isolates. PMID:27391214

  9. Deep Whole-Genome Sequencing to Detect Mixed Infection of Mycobacterium tuberculosis.

    PubMed

    Gan, Mingyu; Liu, Qingyun; Yang, Chongguang; Gao, Qian; Luo, Tao

    2016-01-01

    Mixed infection by multiple Mycobacterium tuberculosis (MTB) strains is associated with poor treatment outcome of tuberculosis (TB). Traditional genotyping methods have been used to detect mixed infections of MTB, however, their sensitivity and resolution are limited. Deep whole-genome sequencing (WGS) has been proved highly sensitive and discriminative for studying population heterogeneity of MTB. Here, we developed a phylogenetic-based method to detect MTB mixed infections using WGS data. We collected published WGS data of 782 global MTB strains from public database. We called homogeneous and heterogeneous single nucleotide variations (SNVs) of individual strains by mapping short reads to the ancestral MTB reference genome. We constructed a phylogenomic database based on 68,639 homogeneous SNVs of 652 MTB strains. Mixed infections were determined if multiple evolutionary paths were identified by mapping the SNVs of individual samples to the phylogenomic database. By simulation, our method could specifically detect mixed infections when the sequencing depth of minor strains was as low as 1× coverage, and when the genomic distance of two mixed strains was as small as 16 SNVs. By applying our methods to all 782 samples, we detected 47 mixed infections and 45 of them were caused by locally endemic strains. The results indicate that our method is highly sensitive and discriminative for identifying mixed infections from deep WGS data of MTB isolates. PMID:27391214

  10. OCEANOGRAPHY: Missing Mixing Found in the Deep Sea.

    PubMed

    Kerr, R A

    2000-06-16

    In their simulations of how the sea's ponderous flows of water and heat affect climate, including future greenhouse warming, climate modelers assumed that something evenly stirred the world ocean from top to bottom around the globe. But oceanographers gauging the tides of the world's seas from a satellite perch have found intense patches of tidally driven mixing deep within the open ocean. Once modelers include these patches, they should see some changes in model predictions of global warming. PMID:17835102

  11. Tidal Energy Available for Deep Ocean Mixing: Bounds from Altimetry Data

    NASA Technical Reports Server (NTRS)

    Ray, Richard D.; Egbert, Gary D.

    1999-01-01

    Maintenance of the large-scale thermohaline circulation has long presented an interesting problem. Observed mixing rates in the pelagic ocean are an order of magnitude too small to balance the rate at which dense bottom water is created at high latitudes. Recent observational and theoretical work suggests that much of this mixing may occur in hot spots near areas of rough topography (e.g., mid-ocean ridges and island arcs). Barotropic tidal currents provide a very plausible source of energy to maintain these mixing processes. Topex/Poseidon satellite altimetry data have made precise mapping of open ocean tidal elevations possible for the first time. We can thus obtain empirical, spatially localized, estimates of barotropic tidal dissipation. These provide an upper bound on the amount of tidal energy that is dissipated in the deep ocean, and hence is available for deep mixing. We will present and compare maps of open ocean tidal energy flux divergence, and estimates of tidal energy flux into shallow seas, derived from T/P altimetry data using both formal data assimilation methods and empirical approaches. With the data assimilation methods we can place formal error bars on the fluxes. Our results show that 20-25% of tidal energy dissipation occurs outside of the shallow seas, the traditional sink for tidal energy. This suggests that up to 1 TW of energy may be available from the tides (lunar and solar) for mixing the deep ocean. The dissipation indeed appears to be concentrated over areas of rough topography.

  12. Tidal Energy Available for Deep Ocean Mixing: Bounds From Altimetry Data

    NASA Technical Reports Server (NTRS)

    Egbert, Gary D.; Ray, Richard D.

    1999-01-01

    Maintenance of the large-scale thermohaline circulation has long presented a problem to oceanographers. Observed mixing rates in the pelagic ocean are an order of magnitude too small to balance the rate at which dense bottom water is created at high latitudes. Recent observational and theoretical work suggests that much of this mixing may occur in hot spots near areas of rough topography (e.g., mid-ocean ridges and island arcs). Barotropic tidal currents provide a very plausible source of energy to maintain these mixing processes. Topex/Poseidon satellite altimetry data have made precise mapping of open ocean tidal elevations possible for the first time. We can thus obtain empirical, spatially localized, estimates of barotropic tidal dissipation. These provide an upper bound on the amount of tidal energy that is dissipated in the deep ocean, and hence is available for deep mixing. We will present and compare maps of open ocean tidal energy flux divergence, and estimates of tidal energy flux into shallow seas, derived from T/P altimetry data using both formal data assimilation methods and empirical approaches. With the data assimilation methods we can place formal error bars on the fluxes. Our results show that 20-25% of tidal energy dissipation occurs outside of the shallow seas, the traditional sink for tidal energy. This suggests that up to 1 TW of energy may be available from the tides (lunar and solar) for mixing the deep ocean. The dissipation indeed appears to be concentrated over areas of rough topography.

  13. Deep soil mixing for reagent delivery and contaminant treatment

    SciTech Connect

    Korte, N.; Gardner, F.G.; Cline, S.R.; West, O.R.

    1997-12-31

    Deep soil mixing was evaluated for treating clay soils contaminated with TCE and its byproducts at the Department of Energy`s Kansas City Plant. The objective of the project was to evaluate the extent of limitations posed by the stiff, silty-clay soil. Three treatment approaches were tested. The first was vapor stripping. In contrast to previous work, however, laboratory treatability studies indicated that mixing saturated, clay soil was not efficient unless powdered lime was added. Thus, powder injection of lime was attempted in conjunction with the mixing/stripping operation. In separate treatment cells, potassium permanganate solution was mixed with the soil as a means of destroying contaminants in situ. Finally, microbial treatment was studied in a third treatment zone. The clay soil caused operational problems such as breakage of the shroud seal and frequent reagent blowouts. Nevertheless, treatment efficiencies of more than 70% were achieved in the saturated zone with chemical oxidation. Although expensive ($1128/yd{sup 3}), there are few alternatives for soils of this type.

  14. Implementation of deep soil mixing at the Kansas City Plant

    SciTech Connect

    Gardner, F.G.; Korte, N.; Strong-Gunderson, J.; Siegrist, R.L.; West, O.R.; Cline, S.R.; Baker, J.

    1998-11-01

    In July 1996, the US Department of Energy (DOE) Kansas City Plant (KCP), AlliedSignal Federal Manufacturing and Technologies, and Oak Ridge National Laboratory (ORNL), conducted field-scale tests of in situ soil mixing and treatment technologies within the Northeast Area (NEA) of the KCP at the Former Ponds site. This demonstration, testing, and evaluation effort was conducted as part of the implementation of a deep soil mixing (DSM) innovative remedial technology demonstration project designed to test DSM in the low-permeability clay soils at the KCP. The clay soils and groundwater beneath this area are contaminated by volatile organic compounds (VOCs), primarily trichloroethene (TCE) and 1,2-dichloroethene (1,2-DCE). The demonstration project was originally designed to evaluate TCE and 1,2-DCE removal efficiency using soil mixing coupled with vapor stripping. Treatability study results, however, indicated that mixed region vapor stripping (MRVS) coupled with calcium oxide (dry lime powder) injection would improve TCE and 1,2-DCE removal efficiency in saturated soils. The scope of the KCP DSM demonstration evolved to implement DSM with the following in situ treatment methodologies for contaminant source reduction in soil and groundwater: DSM/MRVS coupled with calcium oxide injection; DSM/bioaugmentation; and DSM/chemical oxidation using potassium permanganate. Laboratory treatability studies were started in 1995 following collection of undisturbed soil cores from the KCP. These studies were conducted at ORNL, and the results provided information on optimum reagent concentrations and mixing ratios for the three in situ treatment agents to be implemented in the field demonstration.

  15. Moments, Mixed Methods, and Paradigm Dialogs

    ERIC Educational Resources Information Center

    Denzin, Norman K.

    2010-01-01

    I reread the 50-year-old history of the qualitative inquiry that calls for triangulation and mixed methods. I briefly visit the disputes within the mixed methods community asking how did we get to where we are today, the period of mixed-multiple-methods advocacy, and Teddlie and Tashakkori's third methodological moment. (Contains 10 notes.)

  16. Pragmatism, Evidence, and Mixed Methods Evaluation

    ERIC Educational Resources Information Center

    Hall, Jori N.

    2013-01-01

    Mixed methods evaluation has a long-standing history of enhancing the credibility of evaluation findings. However, using mixed methods in a utilitarian way implicitly emphasizes convenience over engaging with its philosophical underpinnings (Denscombe, 2008). Because of this, some mixed methods evaluators and social science researchers have been…

  17. Qualitative Approaches to Mixed Methods Practice

    ERIC Educational Resources Information Center

    Hesse-Biber, Sharlene

    2010-01-01

    This article discusses how methodological practices can shape and limit how mixed methods is practiced and makes visible the current methodological assumptions embedded in mixed methods practice that can shut down a range of social inquiry. The article argues that there is a "methodological orthodoxy" in how mixed methods is practiced that…

  18. Tidal Energy Available for Deep Ocean Mixing: Bounds from Altimetry Data

    NASA Technical Reports Server (NTRS)

    Egbert, Gary D.; Ray, Richard D.

    1999-01-01

    Maintenance of the large-scale thermohaline circulation has long presented a problem to oceanographers. Observed mixing rates in the pelagic ocean are an order of magnitude too small to balance the rate at which dense bottom water is created at high latitudes. Recent observational and theoretical work suggests that much of this mixing may occur in hot spots near areas of rough topography (e.g., mid-ocean ridges and island arcs). Barotropic tidal currents provide a very plausible source of energy to maintain these mixing processes. Topex/Poseidon (T/P) satellite altimetry data have made precise mapping of open ocean tidal elevations possible for the first time. We can thus obtain empirical, spatially localized, estimates of barotropic tidal dissipation. These provide an upper bound on the amount of tidal energy that is dissipated in the deep ocean, and hence is available for deep mixing. We will present and compare maps of open ocean tidal energy flux divergence, and estimates of tidal energy flux into shallow seas, derived from T/P altimetry data using both formal data assimilation methods and empirical approaches. With the data assimilation methods we can place formal error bars on the fluxes. Our results show that 20-25% of tidal energy dissipation occurs outside of the shallow seas, the traditional sink for tidal energy. This suggests that up to 1 TW of energy may be available from the tides (lunar and solar) for mixing the deep ocean. The dissipation indeed appears to be concentrated over areas of rough topography.

  19. A survey of mixed finite element methods

    NASA Technical Reports Server (NTRS)

    Brezzi, F.

    1987-01-01

    This paper is an introduction to and an overview of mixed finite element methods. It discusses the mixed formulation of certain basic problems in elasticity and hydrodynamics. It also discusses special techniques for solving the discrete problem.

  20. Hydrothermal mixing: Fuel for life in the deep-sea

    NASA Astrophysics Data System (ADS)

    Hentscher, M.; Bach, W.; Amend, J.; McCollom, T.

    2009-04-01

    Deep-sea hydrothermal vent systems show a wide range of fluid compositions and temperatures. They reach from highly alkaline and reducing, like the Lost City hydrothermal field, to acidic and reducing conditions, (e. g., the Logatchev hydrothermal field) to acidic and oxidizing conditions (e. g., island arc hosted systems). These apparently hostile vent systems are generally accompanied by high microbial activity forming the base of a food-web that often includes higher organisms like mussels, snails, or shrimp. The primary production is boosted by mixing of chemically reduced hydrothermal vent fluids with ambient seawater, which generates redox disequilibria that serve as energy source for chemolithoautotrophic microbial life. We used geochemical reaction path models to compute the affinities of catabolic (energy-harvesting) and anabolic (biosynthesis) reactions along trajectories of batch mixing between vent fluids and 2 °C seawater. Geochemical data of endmember hydrothermal fluids from 12 different vent fields (Lost City, Rainbow, Logatchev, TAG, EPR 21 °N, Manus Basin, Mariana Arc, etc.) were included in this reconnaissance study of the variability in metabolic energetics in global submarine vent systems. The results show a distinction between ultramafic-hosted and basalt-hosted hydrothermal systems. The highest energy yield for chemolithotrophic catabolism in ultramafic-hosted hydrothermal systems is reached at low temperature and under slightly aerobic to aerobic conditions. The dominant reactions, for example at Rainbow or Lost City, are the oxidation of H2, Fe2+ and methane. At temperatures >60 °C, anaerobic metabolic reactions, e. g., sulphate reduction and methanogenesis, become more profitable. In contrast, basalt-hosted systems, such as TAG and 21 °N EPR uniformly indicate H2S oxidation to be the catabolically dominant reaction over the entire microbial-relevant temperature range. Affinities were calculated for the formation of individual cellular

  1. Mixed Methods, Triangulation, and Causal Explanation

    ERIC Educational Resources Information Center

    Howe, Kenneth R.

    2012-01-01

    This article distinguishes a disjunctive conception of mixed methods/triangulation, which brings different methods to bear on different questions, from a conjunctive conception, which brings different methods to bear on the same question. It then examines a more inclusive, holistic conception of mixed methods/triangulation that accommodates…

  2. Critical Appraisal of Mixed Methods Studies

    ERIC Educational Resources Information Center

    Heyvaert, Mieke; Hannes, Karin; Maes, Bea; Onghena, Patrick

    2013-01-01

    In several subdomains of the social, behavioral, health, and human sciences, research questions are increasingly answered through mixed methods studies, combining qualitative and quantitative evidence and research elements. Accordingly, the importance of including those primary mixed methods research articles in systematic reviews grows. It is…

  3. Mixed Methods Approaches in Family Science Research

    ERIC Educational Resources Information Center

    Plano Clark, Vicki L.; Huddleston-Casas, Catherine A.; Churchill, Susan L.; Green, Denise O'Neil; Garrett, Amanda L.

    2008-01-01

    The complex phenomena of interest to family scientists require the use of quantitative and qualitative approaches. Researchers across the social sciences are now turning to mixed methods designs that combine these two approaches. Mixed methods research has great promise for addressing family science topics, but only if researchers understand the…

  4. Quasioptimality of some spectral mixed methods

    NASA Astrophysics Data System (ADS)

    Gopalakrishnan, Jayadeep; Demkowicz, L. F. Leszek F.

    2004-05-01

    In this paper, we construct a sequence of projectors into certain polynomial spaces satisfying a commuting diagram property with norm bounds independent of the polynomial degree. Using the projectors, we obtain quasioptimality of some spectral mixed methods, including the Raviart-Thomas method and mixed formulations of Maxwell equations. We also prove some discrete Friedrichs type inequalities involving curl.

  5. Identity, Intersectionality, and Mixed-Methods Approaches

    ERIC Educational Resources Information Center

    Harper, Casandra E.

    2011-01-01

    In this article, the author argues that current strategies to study and understand students' identities fall short of fully capturing their complexity. A multi-dimensional perspective and a mixed-methods approach can reveal nuance that is missed with current approaches. The author offers an illustration of how mixed-methods research can promote a…

  6. Mixing Methods in Assessing Coaches' Decision Making

    ERIC Educational Resources Information Center

    Vergeer, Ineke; Lyle, John

    2007-01-01

    Mixing methods has recently achieved respectability as an appropriate approach to research design, offering a variety of advantages (Tashakkori & Teddlie, 2003). The purpose of this paper is to outline and evaluate a mixed methods approach within the domain of coaches' decision making. Illustrated with data from a policy-capturing study on…

  7. Mixed Method Designs in Implementation Research

    PubMed Central

    Aarons, Gregory A.; Horwitz, Sarah; Chamberlain, Patricia; Hurlburt, Michael; Landsverk, John

    2010-01-01

    This paper describes the application of mixed method designs in implementation research in 22 mental health services research studies published in peer-reviewed journals over the last 5 years. Our analyses revealed 7 different structural arrangements of qualitative and quantitative methods, 5 different functions of mixed methods, and 3 different ways of linking quantitative and qualitative data together. Complexity of design was associated with number of aims or objectives, study context, and phase of implementation examined. The findings provide suggestions for the use of mixed method designs in implementation research. PMID:20967495

  8. Mixed Methods Research in School Psychology: A Mixed Methods Investigation of Trends in the Literature

    ERIC Educational Resources Information Center

    Powell, Heather; Mihalas, Stephanie; Onwuegbuzie, Anthony J.; Suldo, Shannon; Daley, Christine E.

    2008-01-01

    This article illustrates the utility of mixed methods research (i.e., combining quantitative and qualitative techniques) to the field of school psychology. First, the use of mixed methods approaches in school psychology practice is discussed. Second, the mixed methods research process is described in terms of school psychology research. Third, the…

  9. 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…

  10. Transformative Paradigm: Mixed Methods and Social Justice

    ERIC Educational Resources Information Center

    Mertens, Donna M.

    2007-01-01

    The intersection of mixed methods and social justice has implications for the role of the researcher and choices of specific paradigmatic perspectives. The transformative paradigm with its associated philosophical assumptions provides a framework for addressing inequality and injustice in society using culturally competent, mixed methods…

  11. Increasing vertical mixing to reduce Southern Ocean deep convection in NEMO3.4

    NASA Astrophysics Data System (ADS)

    Heuzé, C.; Ridley, J. K.; Calvert, D.; Stevens, D. P.; Heywood, K. J.

    2015-10-01

    Most CMIP5 (Coupled Model Intercomparison Project Phase 5) models unrealistically form Antarctic Bottom Water by open ocean deep convection in the Weddell and Ross seas. To identify the mechanisms triggering Southern Ocean deep convection in models, we perform sensitivity experiments on the ocean model NEMO3.4 forced by prescribed atmospheric fluxes. We vary the vertical velocity scale of the Langmuir turbulence, the fraction of turbulent kinetic energy transferred below the mixed layer, and the background diffusivity and run short simulations from 1980. All experiments exhibit deep convection in the Riiser-Larsen Sea in 1987; the origin is a positive sea ice anomaly in 1985, causing a shallow anomaly in mixed layer depth, hence anomalously warm surface waters and subsequent polynya opening. Modifying the vertical mixing impacts both the climatological state and the associated surface anomalies. The experiments with enhanced mixing exhibit colder surface waters and reduced deep convection. The experiments with decreased mixing give warmer surface waters, open larger polynyas causing more saline surface waters and have deep convection across the Weddell Sea until the simulations end. Extended experiments reveal an increase in the Drake Passage transport of 4 Sv each year deep convection occurs, leading to an unrealistically large transport at the end of the simulation. North Atlantic deep convection is not significantly affected by the changes in mixing parameters. As new climate model overflow parameterisations are developed to form Antarctic Bottom Water more realistically, we argue that models would benefit from stopping Southern Ocean deep convection, for example by increasing their vertical mixing.

  12. Mixing in microfluidic devices and enhancement methods

    PubMed Central

    Ward, Kevin; Fan, Z Hugh

    2015-01-01

    Mixing in microfluidic devices presents a challenge due to laminar flows in microchannels, which result from low Reynolds numbers determined by the channel’s hydraulic diameter, flow velocity, and solution’s kinetic viscosity. To address this challenge, novel methods of mixing enhancement within microfluidic devices have been explored for a variety of applications. Passive mixing methods have been created, including those using ridges or slanted wells within the microchannels, as well as their variations with improved performance by varying geometry and patterns, by changing the properties of channel surfaces, and by optimization via simulations. In addition, active mixing methods including microstirrers, acoustic mixers, and flow pulsation have been investigated and integrated into microfluidic devices to enhance mixing in a more controllable manner. In general, passive mixers are easy to integrate, but difficult to control externally by users after fabrication. Active mixers usually take efforts to integrate within a device and they require external components (e.g. power sources) to operate. However, they can be controlled by users to a certain degree for tuned mixing. In this article, we provide a general overview of a number of passive and active mixers, discuss their advantages and disadvantages, and make suggestions on choosing a mixing method for a specific need as well as advocate possible integration of key elements of passive and active mixers to harness the advantages of both types. PMID:26549938

  13. Methods of testing parameterizations: Vertical ocean mixing

    NASA Technical Reports Server (NTRS)

    Tziperman, Eli

    1992-01-01

    The ocean's velocity field is characterized by an exceptional variety of scales. While the small-scale oceanic turbulence responsible for the vertical mixing in the ocean is of scales a few centimeters and smaller, the oceanic general circulation is characterized by horizontal scales of thousands of kilometers. In oceanic general circulation models that are typically run today, the vertical structure of the ocean is represented by a few tens of discrete grid points. Such models cannot explicitly model the small-scale mixing processes, and must, therefore, find ways to parameterize them in terms of the larger-scale fields. Finding a parameterization that is both reliable and plausible to use in ocean models is not a simple task. Vertical mixing in the ocean is the combined result of many complex processes, and, in fact, mixing is one of the less known and less understood aspects of the oceanic circulation. In present models of the oceanic circulation, the many complex processes responsible for vertical mixing are often parameterized in an oversimplified manner. Yet, finding an adequate parameterization of vertical ocean mixing is crucial to the successful application of ocean models to climate studies. The results of general circulation models for quantities that are of particular interest to climate studies, such as the meridional heat flux carried by the ocean, are quite sensitive to the strength of the vertical mixing. We try to examine the difficulties in choosing an appropriate vertical mixing parameterization, and the methods that are available for validating different parameterizations by comparing model results to oceanographic data. First, some of the physical processes responsible for vertically mixing the ocean are briefly mentioned, and some possible approaches to the parameterization of these processes in oceanographic general circulation models are described in the following section. We then discuss the role of the vertical mixing in the physics of the

  14. [Hadamard transform spectrometer mixed pixels' unmixing method].

    PubMed

    Yan, Peng; Hu, Bing-Liang; Liu, Xue-Bin; Sun, Wei; Li, Li-Bo; Feng, Yu-Tao; Liu, Yong-Zheng

    2011-10-01

    Hadamard transform imaging spectrometer is a multi-channel digital transform spectrometer detection technology, this paper based on digital micromirror array device (DMD) of the Hadamard transform spectrometer working principle and instrument structure, obtained by the imaging sensor mixed pixel were analyzed, theory derived the solution of pixel aliasing hybrid method, simulation results show that the method is simple and effective to improve the accuracy of mixed pixel spectrum more than 10% recovery. PMID:22250574

  15. Is collisional breakup an important process within mixed-phase deep convective clouds?

    NASA Astrophysics Data System (ADS)

    Seifert, A.; Khain, A.; Mayer, F.

    2003-04-01

    The microphysics of deep convective clouds determines their precipitation efficiency as well as the dynamical evolution of cloud systems and is therefore of great importance for numerical weather prediction, flood forecasting and regional climate modeling. Of all cloud systems mixed-phase deep convection is maybe the most complex and least understood. One reason is that the numerous microphysical processes taking place are highly nonlinear and strongly coupled with each other as well as with the hydrodynamics of the cloud. Collisional breakup of raindrops is one of these cloud microphysical processes, but is often neglected or not well represented in state-of-the-art cloud resolving models. The importance of collisional breakup is well known for tropical cloud systems, which are dominated by warm phase processes. In addition various studies using so-called rainshaft models showed that collisional breakup can alter the raindrop size distribution below cloud base. But what happens within the clouds and especially within strong convective updrafts? Can collisional breakup lead to a different cloud evolution by changing the drop size distribution? Using the Hebrew University Cloud Model (HUCM), which includes the most detailed spectral microphysics model available today, we performed a sensitivity study to answer these questions. Collisional breakup was therefore recently included in HUCM using Bleck's numerical method, which is standard for simulation of the breakup process. Our breakup scheme itself is mainly based on the parameterization of Low and List (1982, JAS), but includes also additional data for small raindrops by Beard and Ochs (1995, JAS). As a test case a deep convective mixed-phase cloud is simulated with initial conditions based on a sounding from 13 August 1999, Midland/Texas. We present a detailed analysis of the simulated cloud evolution with and without collisional breakup taken into account. The conclusion from our sensitivity study is that

  16. What is so new about mixed methods?

    PubMed

    Pelto, Pertti J

    2015-06-01

    In this article, I dispute claims that mixed methods research emerged only recently in the social sciences. I argue that some anthropologists and sociologists (and others) have used mixed methods in fieldwork for at least 80 years, and there are studies from early in the 20th century that clearly fall within the definition of "mixed methods." I explore some of the history of the mixing of qualitative and quantitative data in earlier ethnographic works and show that in some sectors of social science research, the "emergence" and proliferation of mixed methods were particularly notable around the middle of the 20th century. Furthermore, concerning issues about "paradigms of research" in the social sciences, I identify some of the types of research in which the mixing of QUAL and QUAN approaches was more likely to occur. I suggest that some of the literature about research paradigms has involved a certain amount of "myth-making" in connection with descriptions of qualitative and quantitative research assumptions and styles.

  17. Mixed oxide nanoparticles and method of making

    DOEpatents

    Lauf, Robert J.; Phelps, Tommy J.; Zhang, Chuanlun; Roh, Yul

    2002-09-03

    Methods and apparatus for producing mixed oxide nanoparticulates are disclosed. Selected thermophilic bacteria cultured with suitable reducible metals in the presence of an electron donor may be cultured under conditions that reduce at least one metal to form a doped crystal or mixed oxide composition. The bacteria will form nanoparticles outside the cell, allowing easy recovery. Selection of metals depends on the redox potentials of the reducing agents added to the culture. Typically hydrogen or glucose are used as electron donors.

  18. Effects of climate change on deep-water oxygen and winter mixing in a deep lake (Lake Geneva)

    NASA Astrophysics Data System (ADS)

    Schwefel, Robert; Alfred, Wüest; Damien, Bouffard

    2016-04-01

    Oxygen is the most important dissolved gas for lake ecosystems. Because low oxygen concentrations are an ongoing problem in many parts of the oceans and numerous lakes, oxygen depletion processes have been intensively studied over the last decades and were mainly attributed to high nutrient loads. Recently, climate-induced changes in stratification and mixing behavior were recognized as additional thread to hypolimnetic oxygen budgets in lakes and reservoirs [Matzinger et al., 2007; Zhang et al., 2015]. Observational data of Lake Geneva, a deep perialpine lake situated between France and Switzerland showed no decreasing trend in hypoxia over the last 43 years, despite an impressive reduction in nutrient input during this period. Instead, hypoxic conditions were predominantly controlled by deep mixing end of winter and in turn by winter temperatures. To test the sensitivity of Lake Geneva on future climate change and changes in water transparency, we simulated the hydrodynamics and temperature of Lake Geneva under varying conditions for atmospheric temperature and water clarity performed with the one-dimensional model SIMSTRAT [Goudsmit, 2002]. The results show, that the stratification in lakes is only weakly affected by changes in light absorption due to varying water quality. For conditions expected for the end of the century, a decrease in the annual mean deep convective mixing of up to 45 m is predicted. Also complete mixing events over the whole lake are less likely to occur. A change in the hypolimnetic oxygen concentration of up to 20% can thus be expected in the future. These results show, that changes in deep mixing have an equally strong impact as eutrophication on the deep-water oxygen development of oligomictic lakes and have to be considered in the prediction of the future development of lakes. References: Goudsmit, G. H., H. Burchard, F. Peeters, and A. Wüest (2002), Application of k-ɛ turbulence models to enclosed basins: The role of internal

  19. 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…

  20. 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…

  1. Applying Mixed Methods Techniques in Strategic Planning

    ERIC Educational Resources Information Center

    Voorhees, Richard A.

    2008-01-01

    In its most basic form, strategic planning is a process of anticipating change, identifying new opportunities, and executing strategy. The use of mixed methods, blending quantitative and qualitative analytical techniques and data, in the process of assembling a strategic plan can help to ensure a successful outcome. In this article, the author…

  2. 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…

  3. 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.

  4. Strong-mixing induced deep ocean heat uptake events in the North Atlantic.

    NASA Astrophysics Data System (ADS)

    Somavilla Cabrillo, Raquel; Gonzalez-Pola, Cesar; Schauer, Ursula; Budeus, Gedeon

    2015-04-01

    The deceleration of the upper ocean heat storage during the last decade has resulted in an active search for the 'missing heat' in the deep ocean. Modeling work has provided new insights into the role of the central Pacific Ocean on the present hiatus in global warming and the efficient transfer of heat to the deep ocean, but recent studies have highlighted also the large contribution of the North Atlantic basin to these processes, mainly based on ocean observations. The deep ocean heat uptake (below 300 m) in the North Atlantic is not confined to the subpolar gyre region but extends to mid-latitudes of the Eastern North Atlantic (ENA), requiring an additional process for its explanation other than deep convection considered until now. Here, using oceanographic in-situ data, we describe a mechanism of heat and salt injection to the deep ocean after years of warming and saltening at the surface occurred both in regions of mode (43°-48°N) and deep water (74°-76°N) formation in the ENA. The mechanism, although punctual meditated by strong winter mixing events, is between 2 and 6 times higher than the 2000-2010 ocean heat uptake at depths of mode (300-700m) and deep water (>2000m) formation, contributing significantly to the observed deep ocean heat uptake in the North Atlantic. Nutrient, hydrographic and reanalysis data indicate that the strong mixing-induced deep ocean heat uptake events at areas of mode and deep water formation in the North Atlantic are connected through the northward propagation of salty ENA mode waters triggered by the contraction of the subpolar gyre reinforced by the occurrences of blocking anomalies in the ENA. Such connection is not unique of the last decade but observed also during the 1960s. Natural climate variability seems the ultimate driver of the strong mixing-induced deep ocean heat uptake events, although the anthropogenic global warming and its forcing on the Arctic sea-ice retreat and frequency of extreme weather events could

  5. Long Term Deep Mixing Changes in Lakes to Climate Change. The Question of When and How?

    NASA Astrophysics Data System (ADS)

    Sahoo, G. B.; Schladow, S. G.; Reuter, J.

    2009-12-01

    Lake Tahoe (California-Nevada), an ice free warm-monomictic lake, has been warmed up over the last 35 years due to climate change. Lake Tahoe strongly stratifies during summer and its water body mixes well during winter. The last 35 years records indicate that complete lake turn over takes place once or twice in 3 to 4 years. If the lake warming trend continues, its deep mixing might be stopped at some point in the future. Since deep mixing supplies dissolved oxygen from surface to bottom, reduced mixing may result in evolution of anoxic condition near the sediment-water interface. The Intergovernmental Panel on Climate Change report (IPCC 2007) indicates continued warming over the next few decades. It is therefore important to assess mixing dynamics of the lake using predictions of the global circulation models (GCMs). The dynamic lake model (DLM), developed by University of California Davis researcher was used to estimate the mixing dynamics of the lake. The GCM-predicted trends in meteorological variables for the grid cell that includes Lake Tahoe were obtained from GCMs: (1) Model for Interdisciplinary Research on Climate V. 3.2 High Resolution (MIROC-HIRES) Japan, (2) National Center for Atmospheric Research, Community Climate Model (NCAR CCM V. 3.0), and (3) National Oceanic and Atmospheric Administration (NOAA) - Geophysical Fluid Dynamics Laboratory V CM2.1 (NOAA GFDL CM2.1). Sensitivity analysis results demonstrates that a change in longwave radiations has pronounced effect on lake warming. Results of 40-year simulations show that the lake continues to become warmer at the rate of approximately 0.013 oC per year and more stable. With continued climate change, deep mixing (full or greater than 300m) will cease after one-two decades. This indicates that Lake Tahoe is likely to transition to meromictic lake because of reduced mixing and increasing stability. This may result in major water quality problems and ecological changes over time.

  6. Deep-reaching thermocline mixing in the equatorial pacific cold tongue.

    PubMed

    Liu, Chuanyu; Köhl, Armin; Liu, Zhiyu; Wang, Fan; Stammer, Detlef

    2016-05-12

    Vertical mixing is an important factor in determining the temperature, sharpness and depth of the equatorial Pacific thermocline, which are critical to the development of El Ninõ and Southern Oscillation (ENSO). Yet, properties, dynamical causes and large-scale impacts of vertical mixing in the thermocline are much less understood than that nearer the surface. Here, based on Argo float and the Tropical Ocean and Atmosphere (TAO) mooring measurements, we identify a large number of thermocline mixing events occurring down to the lower half of the thermocline and the lower flank of the Equatorial Undercurrent (EUC), in particular in summer to winter. The deep-reaching mixing events occur more often and much deeper during periods with tropical instability waves (TIWs) than those without and under La Niña than under El Niño conditions. We demonstrate that the mixing events are caused by lower Richardson numbers resulting from shear of both TIWs and the EUC.

  7. Deep-reaching thermocline mixing in the equatorial pacific cold tongue

    NASA Astrophysics Data System (ADS)

    Liu, Chuanyu; Köhl, Armin; Liu, Zhiyu; Wang, Fan; Stammer, Detlef

    2016-05-01

    Vertical mixing is an important factor in determining the temperature, sharpness and depth of the equatorial Pacific thermocline, which are critical to the development of El Ninõ and Southern Oscillation (ENSO). Yet, properties, dynamical causes and large-scale impacts of vertical mixing in the thermocline are much less understood than that nearer the surface. Here, based on Argo float and the Tropical Ocean and Atmosphere (TAO) mooring measurements, we identify a large number of thermocline mixing events occurring down to the lower half of the thermocline and the lower flank of the Equatorial Undercurrent (EUC), in particular in summer to winter. The deep-reaching mixing events occur more often and much deeper during periods with tropical instability waves (TIWs) than those without and under La Niña than under El Niño conditions. We demonstrate that the mixing events are caused by lower Richardson numbers resulting from shear of both TIWs and the EUC.

  8. A Mixed Methods Sampling Methodology for a Multisite Case Study

    ERIC Educational Resources Information Center

    Sharp, Julia L.; Mobley, Catherine; Hammond, Cathy; Withington, Cairen; Drew, Sam; Stringfield, Sam; Stipanovic, Natalie

    2012-01-01

    The flexibility of mixed methods research strategies makes such approaches especially suitable for multisite case studies. Yet the utilization of mixed methods to select sites for these studies is rarely reported. The authors describe their pragmatic mixed methods approach to select a sample for their multisite mixed methods case study of a…

  9. Pacific deep circulation and ventilation controlled by tidal mixing away from the sea bottom.

    PubMed

    Oka, Akira; Niwa, Yoshihiro

    2013-01-01

    Vertical mixing in the ocean is a key driver of the global ocean thermohaline circulation, one of the most important factors controlling past and future climate change. Prior observational and theoretical studies have focused on intense tidal mixing near the sea bottom (near-field mixing). However, ocean general circulation models that employ a parameterization of near-field mixing significantly underestimate the strength of the Pacific thermohaline circulation. Here we demonstrate that tidally induced mixing away from the sea bottom (far-field mixing) is essential in controlling the Pacific thermohaline circulation. Via the addition of far-field mixing to a widely used tidal parameterization, we successfully simulate the Pacific thermohaline circulation. We also propose that far-field mixing is indispensable for explaining the presence of the world ocean's oldest water in the eastern North Pacific Ocean. Our findings suggest that far-field mixing controls ventilation of the deep Pacific Ocean, a process important for ocean carbon and biogeochemical cycles.

  10. Pacific deep circulation and ventilation controlled by tidal mixing away from the sea bottom.

    PubMed

    Oka, Akira; Niwa, Yoshihiro

    2013-01-01

    Vertical mixing in the ocean is a key driver of the global ocean thermohaline circulation, one of the most important factors controlling past and future climate change. Prior observational and theoretical studies have focused on intense tidal mixing near the sea bottom (near-field mixing). However, ocean general circulation models that employ a parameterization of near-field mixing significantly underestimate the strength of the Pacific thermohaline circulation. Here we demonstrate that tidally induced mixing away from the sea bottom (far-field mixing) is essential in controlling the Pacific thermohaline circulation. Via the addition of far-field mixing to a widely used tidal parameterization, we successfully simulate the Pacific thermohaline circulation. We also propose that far-field mixing is indispensable for explaining the presence of the world ocean's oldest water in the eastern North Pacific Ocean. Our findings suggest that far-field mixing controls ventilation of the deep Pacific Ocean, a process important for ocean carbon and biogeochemical cycles. PMID:24013486

  11. Method and apparatus for reducing mixed waste

    DOEpatents

    Elliott, Michael L.; Perez, Jr., Joseph M.; Chapman, Chris C.; Peters, Richard D.

    1995-01-01

    The present invention is a method and apparatus for in-can waste reduction. The method is mixing waste with combustible material prior to placing the waste into a waste reduction vessel. The combustible portion is ignited, thereby reducing combustible material to ash and non-combustible material to a slag. Further combustion or heating may be used to sinter or melt the ash. The apparatus is a waste reduction vessel having receiving canister connection means on a first end, and a waste/combustible mixture inlet on a second end. An oxygen supply is provided to support combustion of the combustible mixture.

  12. Comment on "Deep mixing of 3He: reconciling Big Bang and stellar nucleosynthesis".

    PubMed

    Balser, Dana S; Rood, Robert T; Bania, T M

    2007-08-31

    Eggleton et al. (Reports, 8 December 2006, p. 1580) reported on a deep-mixing mechanism in low-mass stars caused by a Rayleigh-Taylor instability that destroys all of the helium isotope 3He produced during the star's lifetime. Observations of 3He in planetary nebulae, however, indicate that some stars produce prodigious amounts of 3He. This is inconsistent with the claim that all low-mass stars should destroy 3He.

  13. Comment on "Deep mixing of 3He: reconciling Big Bang and stellar nucleosynthesis".

    PubMed

    Balser, Dana S; Rood, Robert T; Bania, T M

    2007-08-31

    Eggleton et al. (Reports, 8 December 2006, p. 1580) reported on a deep-mixing mechanism in low-mass stars caused by a Rayleigh-Taylor instability that destroys all of the helium isotope 3He produced during the star's lifetime. Observations of 3He in planetary nebulae, however, indicate that some stars produce prodigious amounts of 3He. This is inconsistent with the claim that all low-mass stars should destroy 3He. PMID:17761865

  14. Mixing of shallow and deep groundwater as indicated by the chemistry and age of karstic springs

    USGS Publications Warehouse

    Toth, D.J.; Katz, B.G.

    2006-01-01

    Large karstic springs in east-central Florida, USA were studied using multi-tracer and geochemical modeling techniques to better understand groundwater flow paths and mixing of shallow and deep groundwater. Spring water types included Ca-HCO3 (six), Na-Cl (four), and mixed (one). The evolution of water chemistry for Ca-HCO3 spring waters was modeled by reactions of rainwater with soil organic matter, calcite, and dolomite under oxic conditions. The Na-Cl and mixed-type springs were modeled by reactions of either rainwater or Upper Floridan aquifer water with soil organic matter, calcite, and dolomite under oxic conditions and mixed with varying proportions of saline Lower Floridan aquifer water, which represented 4-53% of the total spring discharge. Multiple-tracer data-chlorofluorocarbon CFC-113, tritium (3H), helium-3 (3Hetrit), sulfur hexafluoride (SF6) - for four Ca-HCO3 spring waters were consistent with binary mixing curves representing water recharged during 1980 or 1990 mixing with an older (recharged before 1940) tracer-free component. Young-water mixing fractions ranged from 0.3 to 0.7. Tracer concentration data for two Na-Cl spring waters appear to be consistent with binary mixtures of 1990 water with older water recharged in 1965 or 1975. Nitrate-N concentrations are inversely related to apparent ages of spring waters, which indicated that elevated nitrate-N concentrations were likely contributed from recent recharge. ?? Springer-Verlag 2006.

  15. Transformative, Mixed Methods Checklist for Psychological Research with Mexican Americans

    ERIC Educational Resources Information Center

    Canales, Genevieve

    2013-01-01

    This is a description of the creation of a research methods tool, the "Transformative, Mixed Methods Checklist for Psychological Research With Mexican Americans." For conducting literature reviews of and planning mixed methods studies with Mexican Americans, it contains evaluative criteria calling for transformative mixed methods, perspectives…

  16. Deep geologic disposal of mixed waste in bedded salt: The Waste Isolation Pilot Plant

    SciTech Connect

    Rempe, N.T.

    1993-12-01

    Mixed waste (i.e., waste that contains both chemically hazardous and radioactive components) poses a moral, political, and technical challenge to present and future generations. But an international consensus is emerging that harmful byproducts and residues can be permanently isolated from the biosphere in a safe and environmentally responsible manner by deep geologic disposal. To investigate and demonstrate such disposal for transuranic mixed waste, derived from defense-related activities, the US Department of Energy has prepared the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico. This research and development facility was excavated approximately at the center of a 600 m thick sequence of salt (halite) beds, 655 m below the surface. Proof of the long-term tectonic and hydrological stability of the region is supplied by the fact that these salt beds have remained essentially undisturbed since they were deposited during the Late Permian age, approximately 225 million years ago. Plutonium-239, the main radioactive component of transuranic mixed waste, has a half-life of 24,500 years. Even ten half-lives of this isotope - amounting to about a quarter million years, the time during which its activity will decline to background level represent only 0.11 percent of the history of the repository medium. Therefore, deep geologic disposal of transuranic mixed waste in Permian bedded salt appears eminently feasible.

  17. Deep Pacific ventilation ages during the last deglaciation: Evaluating the influence of diffusive mixing and source region reservoir age

    NASA Astrophysics Data System (ADS)

    Lund, David C.

    2013-11-01

    Enhanced ventilation of the deep ocean during the last deglaciation may have caused the rise in atmospheric carbon dioxide that drove Earth's climate from a glacial to interglacial state. Recent results based on the projection age method, however, suggest the ventilation rate of the deep Pacific slowed during the deglaciation, opposite the expected pattern (Lund et al., 2011). Because the projection age method does not account for tracer diffusion (Adkins and Boyle, 1997) it can yield spurious results and therefore requires validation with alternative techniques. Here ventilation ages are determined using the transit-time equilibration-time distribution (TTD-ETD) method which explicitly accounts for diffusive mixing in the ocean interior (DeVries and Primeau, 2010). The overall time history of deep Pacific TTD-ETD and projection ages is very similar; both show a 1000-yr increase in ventilation age during Heinrich Stadial 1 (HS1; 14.5-17.5 kyr BP) and a 500-yr increase during the Younger Dryas (YD). The similarity is due in part to the use of projection age error estimates that take into account uncertainty in both calendar age and benthic 14C age. Centennial-scale offsets between the TTD-ETD and projection ages are due primarily to the different approaches used to estimate surface ocean radiocarbon content. Both the TTD-ETD and projection age results imply that the ventilation rate of the deep Pacific decreased during the deglaciation, opposite the pattern expected if Southern Ocean upwelling and enhanced meridional overturning drove outgassing of CO2 from the abyss. Variations in surface water reservoir age could cause an apparent shift in deep Pacific ventilation age but existing proxy records from the Southern Ocean appear to be inconsistent with such a driver.

  18. A Mapping method for mixing with diffusion

    NASA Astrophysics Data System (ADS)

    Schlick, Conor P.; Christov, Ivan C.; Umbanhowar, Paul B.; Ottino, Julio M.; Lueptow, Richard M.

    2012-11-01

    We present an accurate and efficient computational method for solving the advection-diffusion equation in time-periodic chaotic flows. The method uses operator splitting which allows advection and diffusion steps to be treated independently. Taking advantage of flow periodicity, the advection step is solved with a mapping method, and diffusion is added discretely after each iteration of the advection map. This approach allows for a ``composite'' mapping matrix to be constructed for an entire period of a chaotic advection-diffusion process, which provides a natural approach to the spectral analysis of mixing. To test the approach, we consider the two-dimensional time-periodic sine flow. When compared to the exact solution for this simple velocity field, the operator splitting method exhibits qualitative agreement (overall concentration structure) for large time steps and is quantitatively accurate (average and maximum error) for small time steps. We extend the operator splitting approach to three-dimensional chaotic flows. Funded by NSF Grant CMMI-1000469. Present affiliation: Princeton University. Supported by NSF Grant DMS-1104047.

  19. 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…

  20. 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…

  1. Educational Accountability: A Qualitatively Driven Mixed-Methods Approach

    ERIC Educational Resources Information Center

    Hall, Jori N.; Ryan, Katherine E.

    2011-01-01

    This article discusses the importance of mixed-methods research, in particular the value of qualitatively driven mixed-methods research for quantitatively driven domains like educational accountability. The article demonstrates the merits of qualitative thinking by describing a mixed-methods study that focuses on a middle school's system of…

  2. 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…

  3. Impact of water mass mixing on the biogeochemistry and microbiology of the Northeast Atlantic Deep Water

    NASA Astrophysics Data System (ADS)

    Reinthaler, Thomas; Álvarez Salgado, Xosé Antón; Álvarez, Marta; Aken, Hendrik M.; Herndl, Gerhard J.

    2013-12-01

    The extent to which water mass mixing contributes to the biological activity of the dark ocean is essentially unknown. Using a multiparameter water mass analysis, we examined the impact of water mass mixing on the nutrient distribution and microbial activity of the Northeast Atlantic Deep Water (NEADW) along an 8000 km long transect extending from 62°N to 5°S. Mixing of four water types (WT) and basin scale mineralization from the site where the WT where defined to the study area explained up to 95% of the variability in the distribution of inorganic nutrients and apparent oxygen utilization. Mixing-corrected average O2:N:P mineralization ratios of 127(±11):13.0(±0.7):1 in the core of the NEADW suggested preferential utilization of phosphorus compounds while dissolved organic carbon mineralization contributed a maximum of 20% to the oxygen demand of the NEADW. In conjunction with the calculated average mineralization ratios, our results indicate a major contribution of particulate organic matter to the biological activity in the NEADW. The variability in prokaryotic abundance, high nucleic acid containing cells, and prokaryotic heterotrophic production in the NEADW was explained by large scale (64-79%) and local mineralization processes (21-36%), consistent with the idea that deep-water prokaryotic communities are controlled by substrate supply. Overall, our results suggest a major impact of mixing on the distribution of inorganic nutrients and a weaker influence on the dissolved organic matter pool supporting prokaryotic activity in the NEADW.

  4. Deep-reaching thermocline mixing in the equatorial pacific cold tongue.

    PubMed

    Liu, Chuanyu; Köhl, Armin; Liu, Zhiyu; Wang, Fan; Stammer, Detlef

    2016-01-01

    Vertical mixing is an important factor in determining the temperature, sharpness and depth of the equatorial Pacific thermocline, which are critical to the development of El Ninõ and Southern Oscillation (ENSO). Yet, properties, dynamical causes and large-scale impacts of vertical mixing in the thermocline are much less understood than that nearer the surface. Here, based on Argo float and the Tropical Ocean and Atmosphere (TAO) mooring measurements, we identify a large number of thermocline mixing events occurring down to the lower half of the thermocline and the lower flank of the Equatorial Undercurrent (EUC), in particular in summer to winter. The deep-reaching mixing events occur more often and much deeper during periods with tropical instability waves (TIWs) than those without and under La Niña than under El Niño conditions. We demonstrate that the mixing events are caused by lower Richardson numbers resulting from shear of both TIWs and the EUC. PMID:27175988

  5. Deep-reaching thermocline mixing in the equatorial pacific cold tongue

    PubMed Central

    Liu, Chuanyu; Köhl, Armin; Liu, Zhiyu; Wang, Fan; Stammer, Detlef

    2016-01-01

    Vertical mixing is an important factor in determining the temperature, sharpness and depth of the equatorial Pacific thermocline, which are critical to the development of El Ninõ and Southern Oscillation (ENSO). Yet, properties, dynamical causes and large-scale impacts of vertical mixing in the thermocline are much less understood than that nearer the surface. Here, based on Argo float and the Tropical Ocean and Atmosphere (TAO) mooring measurements, we identify a large number of thermocline mixing events occurring down to the lower half of the thermocline and the lower flank of the Equatorial Undercurrent (EUC), in particular in summer to winter. The deep-reaching mixing events occur more often and much deeper during periods with tropical instability waves (TIWs) than those without and under La Niña than under El Niño conditions. We demonstrate that the mixing events are caused by lower Richardson numbers resulting from shear of both TIWs and the EUC. PMID:27175988

  6. Mixing and the dynamics of the deep chlorophyll maximum in Lake Tahoe

    NASA Technical Reports Server (NTRS)

    Abbott, M. R.; Denman, K. L.; Powell, T. M.; Richerson, P. J.; Richards, R. C.; Goldman, C. R.

    1984-01-01

    Chlorophyll-temperature profiles were measured across Lake Tahoe about every 10 days from April through July 1980. Analysis of the 123 profiles and associated productivity and nutrient data identified three important processes in the formation and dynamics of the deep chlorophyll maximum (DCM): turbulent diffusion, nutrient supply rate, and light availability. Seasonal variation in these three processes resulted in three regimes: a diffusion-dominated regime with a weak DCM, a variable-mixing regime with a pronounced, nutrient supply-dominated DCM, and a stable regime with a deep, moderate light availability-dominated DCM. The transition between the first two regimes occurred in about 10 days, the transition between the last two more gradually over about 3 weeks. The degree of spatial variability of the DCM was highest in the second regime and lowest in the third. These data indicate that the DCM in Lake Tahoe is constant in neither time nor space.

  7. Discontinuous mixed covolume methods for parabolic problems.

    PubMed

    Zhu, Ailing; Jiang, Ziwen

    2014-01-01

    We present the semidiscrete and the backward Euler fully discrete discontinuous mixed covolume schemes for parabolic problems on triangular meshes. We give the error analysis of the discontinuous mixed covolume schemes and obtain optimal order error estimates in discontinuous H(div) and first-order error estimate in L(2).

  8. "Reading" Mixed Methods Research: Contexts for Criticism

    ERIC Educational Resources Information Center

    Freshwater, Dawn

    2007-01-01

    Health and social care researchers, in their haste to "belong" to academia, have adopted the system of mixed methodology research, overestimating its ability to reveal the truth and occasionally imprisoning their thought in one system. In this article, some of the assumptions underpinning mixed methodology research and its discourse are subjected…

  9. Compulsory Deep Mixing of 3He and CNO Isotopes on the First Giant Branch

    SciTech Connect

    Eggleton, P P; Dearborn, D P; Lattanzio, J

    2007-07-26

    We have found a deep-mixing process which occurs during First Giant Branch (FGB) evolution. It begins at the point in evolution where the surface convection zone (SCZ), having previously grown in size, starts to shrink, and it is driven by a local minimum that develops in the mean molecular weight as a result of the burning of {sup 3}He. This mixing can solve two important observational problems. One is why the interstellar medium (ISM) has not been considerably enriched in {sup 3}He since the Big Bang. The other is why products of nucleosynthesis such as {sup 13}C are progressively enriched on the upper FGB, when classical stellar modeling says that no further enrichment should take beyond the First Dredge-Up (FDU) episode, somewhat below the middle of the FGB.

  10. Parameterizing deep convection using the assumed probability density function method

    DOE PAGES

    Storer, R. L.; Griffin, B. M.; Höft, J.; Weber, J. K.; Raut, E.; Larson, V. E.; Wang, M.; Rasch, P. J.

    2014-06-11

    Due to their coarse horizontal resolution, present-day climate models must parameterize deep convection. This paper presents single-column simulations of deep convection using a probability density function (PDF) parameterization. The PDF parameterization predicts the PDF of subgrid variability of turbulence, clouds, and hydrometeors. That variability is interfaced to a prognostic microphysics scheme using a Monte Carlo sampling method. The PDF parameterization is used to simulate tropical deep convection, the transition from shallow to deep convection over land, and mid-latitude deep convection. These parameterized single-column simulations are compared with 3-D reference simulations. The agreement is satisfactory except when the convective forcing ismore » weak. The same PDF parameterization is also used to simulate shallow cumulus and stratocumulus layers. The PDF method is sufficiently general to adequately simulate these five deep, shallow, and stratiform cloud cases with a single equation set. This raises hopes that it may be possible in the future, with further refinements at coarse time step and grid spacing, to parameterize all cloud types in a large-scale model in a unified way.« less

  11. Parameterizing deep convection using the assumed probability density function method

    SciTech Connect

    Storer, R. L.; Griffin, B. M.; Hoft, Jan; Weber, J. K.; Raut, E.; Larson, Vincent E.; Wang, Minghuai; Rasch, Philip J.

    2015-01-06

    Due to their coarse horizontal resolution, present-day climate models must parameterize deep convection. This paper presents single-column simulations of deep convection using a probability density function (PDF) parameterization. The PDF parameterization predicts the PDF of subgrid variability of turbulence, clouds, and hydrometeors. That variability is interfaced to a prognostic microphysics scheme using a Monte Carlo sampling method.The PDF parameterization is used to simulate tropical deep convection, the transition from shallow to deep convection over land, and mid-latitude deep convection.These parameterized single-column simulations are compared with 3-D reference simulations. The agreement is satisfactory except when the convective forcing is weak. The same PDF parameterization is also used to simulate shallow cumulus and stratocumulus layers. The PDF method is sufficiently general to adequately simulate these five deep, shallow, and stratiform cloud cases with a single equation set. This raises hopes that it may be possible in the future, with further refinements at coarse time step and grid spacing, to parameterize all cloud types in a large-scale model in a unified way.

  12. Parameterizing deep convection using the assumed probability density function method

    DOE PAGES

    Storer, R. L.; Griffin, B. M.; Höft, J.; Weber, J. K.; Raut, E.; Larson, V. E.; Wang, M.; Rasch, P. J.

    2015-01-06

    Due to their coarse horizontal resolution, present-day climate models must parameterize deep convection. This paper presents single-column simulations of deep convection using a probability density function (PDF) parameterization. The PDF parameterization predicts the PDF of subgrid variability of turbulence, clouds, and hydrometeors. That variability is interfaced to a prognostic microphysics scheme using a Monte Carlo sampling method. The PDF parameterization is used to simulate tropical deep convection, the transition from shallow to deep convection over land, and midlatitude deep convection. These parameterized single-column simulations are compared with 3-D reference simulations. The agreement is satisfactory except when the convective forcing ismore » weak. The same PDF parameterization is also used to simulate shallow cumulus and stratocumulus layers. The PDF method is sufficiently general to adequately simulate these five deep, shallow, and stratiform cloud cases with a single equation set. This raises hopes that it may be possible in the future, with further refinements at coarse time step and grid spacing, to parameterize all cloud types in a large-scale model in a unified way.« less

  13. Variance reduction methods applied to deep-penetration problems

    SciTech Connect

    Cramer, S.N.

    1984-01-01

    All deep-penetration Monte Carlo calculations require variance reduction methods. Before beginning with a detailed approach to these methods, several general comments concerning deep-penetration calculations by Monte Carlo, the associated variance reduction, and the similarities and differences of these with regard to non-deep-penetration problems will be addressed. The experienced practitioner of Monte Carlo methods will easily find exceptions to any of these generalities, but it is felt that these comments will aid the novice in understanding some of the basic ideas and nomenclature. Also, from a practical point of view, the discussions and developments presented are oriented toward use of the computer codes which are presented in segments of this Monte Carlo course.

  14. Feasibility study on common methods for wave force estimation of deep water combined breakwaters

    NASA Astrophysics Data System (ADS)

    Yu, Dingyong; Tang, Peng; Song, Qingguo

    2015-08-01

    China's newly enacted Breakwater Design Specifications (JTS154-2011) explicitly state that breakwaters with water depths greater than 20 m are categorized as deep-water breakwaters, and emphasize that design principles, methods and construction requirements are different from those of common shallow water breakwaters. However, the specifications do not make any mention of how to choose wave force calculation methods of deep-water breakwaters. To study the feasibility of different formulae for wave force estimation of deep water combined breakwaters, the wave force calculated by the Sainflou's, Goda's, modified Goda's and specifications' methods are compared for various water depths and wave heights in this paper. The calculated results are also compared with experimental data. The total horizontal forcing and the pattern of pressure distributions are presented. Comparisons show that the wave pressure distributions by the four methods are similar, but the total horizontal forces are different. The results obtained by the Goda's method and the specified formulae are much closer to the experimental data. As for the wave force estimation for the deepwater mixed embankment foundation bed parapet, the Goda's formula is applied in the case with a water depth of less than 42 m. The Specifications method is suitable for standing waves. In the wave force estimates of breastworks, Sainflou's and the modified Gaoda's formulae are no longer applicable for the foundation bed of mixed embankment.

  15. A ternary age-mixing model to explain contaminant occurrence in a deep supply well.

    PubMed

    Jurgens, Bryant C; Bexfield, Laura M; Eberts, Sandra M

    2014-09-01

    The age distribution of water from a public-supply well in a deep alluvial aquifer was estimated and used to help explain arsenic variability in the water. The age distribution was computed using a ternary mixing model that combines three lumped parameter models of advection-dispersion transport of environmental tracers, which represent relatively recent recharge (post-1950s) containing volatile organic compounds (VOCs), old intermediate depth groundwater (about 6500 years) that was free of drinking-water contaminants, and very old, deep groundwater (more than 21,000 years) containing arsenic above the USEPA maximum contaminant level of 10 µg/L. The ternary mixing model was calibrated to tritium, chloroflorocarbon-113, and carbon-14 (14C) concentrations that were measured in water samples collected on multiple occasions. Variability in atmospheric 14C over the past 50,000 years was accounted for in the interpretation of (14) C as a tracer. Calibrated ternary models indicate the fraction of deep, very old groundwater entering the well varies substantially throughout the year and was highest following long periods of nonoperation or infrequent operation, which occured during the winter season when water demand was low. The fraction of young water entering the well was about 11% during the summer when pumping peaked to meet water demand and about 3% to 6% during the winter months. This paper demonstrates how collection of multiple tracers can be used in combination with simplified models of fluid flow to estimate the age distribution and thus fraction of contaminated groundwater reaching a supply well under different pumping conditions.

  16. A ternary age-mixing model to explain contaminant occurrence in a deep supply well

    USGS Publications Warehouse

    Jurgens, Bryant; Bexfield, Laura M.; Eberts, Sandra

    2014-01-01

    The age distribution of water from a public-supply well in a deep alluvial aquifer was estimated and used to help explain arsenic variability in the water. The age distribution was computed using a ternary mixing model that combines three lumped parameter models of advection-dispersion transport of environmental tracers, which represent relatively recent recharge (post- 1950s) containing volatile organic compounds (VOCs), old intermediate depth groundwater (about 6500 years) that was free of drinking-water contaminants, and very old, deep groundwater (more than 21,000 years) containing arsenic above the USEPA maximum contaminant level of 10 µg/L. The ternary mixing model was calibrated to tritium, chloroflorocarbon-113, and carbon-14 (14C) concentrations that were measured in water samples collected on multiple occasions. Variability in atmospheric 14C over the past 50,000 years was accounted for in the interpretation of 14C as a tracer. Calibrated ternary models indicate the fraction of deep, very old groundwater entering the well varies substantially throughout the year and was highest following long periods of nonoperation or infrequent operation, which occured during the winter season when water demand was low. The fraction of young water entering the well was about 11% during the summer when pumping peaked to meet water demand and about 3% to 6% during the winter months. This paper demonstrates how collection of multiple tracers can be used in combination with simplified models of fluid flow to estimate the age distribution and thus fraction of contaminated groundwater reaching a supply well under different pumping conditions.

  17. A Ternary Age-Mixing Model to Explain Contaminant Occurrence in a Deep Supply Well

    PubMed Central

    Jurgens, Bryant C; Bexfield, Laura M; Eberts, Sandra M

    2014-01-01

    The age distribution of water from a public-supply well in a deep alluvial aquifer was estimated and used to help explain arsenic variability in the water. The age distribution was computed using a ternary mixing model that combines three lumped parameter models of advection-dispersion transport of environmental tracers, which represent relatively recent recharge (post-1950s) containing volatile organic compounds (VOCs), old intermediate depth groundwater (about 6500 years) that was free of drinking-water contaminants, and very old, deep groundwater (more than 21,000 years) containing arsenic above the USEPA maximum contaminant level of 10 µg/L. The ternary mixing model was calibrated to tritium, chloroflorocarbon-113, and carbon-14 (14C) concentrations that were measured in water samples collected on multiple occasions. Variability in atmospheric 14C over the past 50,000 years was accounted for in the interpretation of 14C as a tracer. Calibrated ternary models indicate the fraction of deep, very old groundwater entering the well varies substantially throughout the year and was highest following long periods of nonoperation or infrequent operation, which occured during the winter season when water demand was low. The fraction of young water entering the well was about 11% during the summer when pumping peaked to meet water demand and about 3% to 6% during the winter months. This paper demonstrates how collection of multiple tracers can be used in combination with simplified models of fluid flow to estimate the age distribution and thus fraction of contaminated groundwater reaching a supply well under different pumping conditions. PMID:24597520

  18. Mixed quantum classical calculation of proton transfer reaction rates: From deep tunneling to over the barrier regimes

    SciTech Connect

    Xie, Weiwei; Xu, Yang; Zhu, Lili; Shi, Qiang

    2014-05-07

    We present mixed quantum classical calculations of the proton transfer (PT) reaction rates represented by a double well system coupled to a dissipative bath. The rate constants are calculated within the so called nontraditional view of the PT reaction, where the proton motion is quantized and the solvent polarization is used as the reaction coordinate. Quantization of the proton degree of freedom results in a problem of non-adiabatic dynamics. By employing the reactive flux formulation of the rate constant, the initial sampling starts from the transition state defined using the collective reaction coordinate. Dynamics of the collective reaction coordinate is treated classically as over damped diffusive motion, for which the equation of motion can be derived using the path integral, or the mixed quantum classical Liouville equation methods. The calculated mixed quantum classical rate constants agree well with the results from the numerically exact hierarchical equation of motion approach for a broad range of model parameters. Moreover, we are able to obtain contributions from each vibrational state to the total reaction rate, which helps to understand the reaction mechanism from the deep tunneling to over the barrier regimes. The numerical results are also compared with those from existing approximate theories based on calculations of the non-adiabatic transmission coefficients. It is found that the two-surface Landau-Zener formula works well in calculating the transmission coefficients in the deep tunneling regime, where the crossing point between the two lowest vibrational states dominates the total reaction rate. When multiple vibrational levels are involved, including additional crossing points on the free energy surfaces is important to obtain the correct reaction rate using the Landau-Zener formula.

  19. 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.…

  20. Reflections on Mixing Methods in Applied Linguistics Research

    ERIC Educational Resources Information Center

    Hashemi, Mohammad R.

    2012-01-01

    This commentary advocates the use of mixed methods research--that is the integration of qualitative and quantitative methods in a single study--in applied linguistics. Based on preliminary findings from a research project in progress, some reflections on the current practice of mixing methods as a new trend in applied linguistics are put forward.…

  1. Method of chaotic mixing and improved stirred tank reactors

    DOEpatents

    Muzzio, Fernando J.; Lamberto, David J.

    1999-01-01

    The invention provides a method and apparatus for efficiently achieving a homogeneous mixture of fluid components by introducing said components having a Reynolds number of between about .ltoreq.1 to about 500 into a vessel and continuously perturbing the mixing flow by altering the flow speed and mixing time until homogeniety is reached. This method prevents the components from aggregating into non-homogeneous segregated regions within said vessel during mixing and substantially reduces the time the admixed components reach homogeneity.

  2. Method of chaotic mixing and improved stirred tank reactors

    DOEpatents

    Muzzio, F.J.; Lamberto, D.J.

    1999-07-13

    The invention provides a method and apparatus for efficiently achieving a homogeneous mixture of fluid components by introducing said components having a Reynolds number of between about [le]1 to about 500 into a vessel and continuously perturbing the mixing flow by altering the flow speed and mixing time until homogeneity is reached. This method prevents the components from aggregating into non-homogeneous segregated regions within said vessel during mixing and substantially reduces the time the admixed components reach homogeneity. 19 figs.

  3. 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

  4. 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…

  5. Grounded Theory in Practice: Is It Inherently a Mixed Method?

    ERIC Educational Resources Information Center

    Johnson, R. B.; McGowan, M. W.; Turner, L. A.

    2010-01-01

    We address 2 key points of contention in this article. First, we engage the debate concerning whether particular methods are necessarily linked to particular research paradigms. Second, we briefly describe a mixed methods version of grounded theory (MM-GT). Grounded theory can be tailored to work well in any of the 3 major forms of mixed methods…

  6. 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…

  7. Teacher Professionalism and Team Performance Pay: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Wells, Pamela; Combs, Julie P.; Bustamante, Rebecca M.

    2012-01-01

    The purpose of this mixed methods research study was to explore teachers' perceptions of their professional behaviors when they worked in schools that awarded team performance pay. Teachers' archival responses from two questionnaires were analyzed using mixed methods data analysis techniques (Year 1, n = 368; Year 2, n = 649). Most teachers had…

  8. Mixed Methods in VET Research: Usage and Quality

    ERIC Educational Resources Information Center

    Cameron, Roslyn

    2010-01-01

    Mixed methods had been heralded as the third methodological movement with several authorities from across an array of discipline fields contributing to a growing body of literature and theoretical developments. The discipline fields which are showing high levels of acceptance for mixed methods are those related to education, health and nursing,…

  9. Commentary: Using Mixed Methods to Transform Special Education Research

    ERIC Educational Resources Information Center

    Trainor, Audrey A.

    2011-01-01

    Klingner and Boardman (this issue) offer a cogent and compelling argument for opening the door for the acceptance and use of mixed methods in special education research. Self-identifying as pragmatists, they embody this paradigmatic view by focusing on the utility, efficacy, and accuracy of mixed methods, an argument that should appeal to the…

  10. 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…

  11. Water mass structure and deep mixing processes in the Tyrrhenian Sea: Results from the VECTOR project

    NASA Astrophysics Data System (ADS)

    Falco, Pierpaolo; Trani, Marilisa; Zambianchi, Enrico

    2016-07-01

    In this study, we analyze data from observations conducted in the southern Tyrrhenian Sea, within the framework of the VECTOR project, initiated in 2006. In the six cruises organized as part of the project, in November 2006, in February, April and June 2007, in February 2008 and in January 2009, repeated hydrological measurements were collected along a transect. Data collected at the same stations in a subsequent cruise in November 2010 were also incorporated into the study. The main Tyrrhenian water masses were clearly identified in vertical sections. In particular, a positive salinity anomaly, observed both in the first (late autumn) and second (winter) cruise, associated with an anti-cyclonic structure, characterized the surface layer. The intermediate layer revealed salinity values higher than the climatological salinities, continuing the rising trend observed in the previous works, because of the influence of the Eastern Mediterranean Transient on the western basin hydrology. At the bottom, both temperature and salinity showed higher values with respect to the historical data, but were nearly constant during the study period. However, the water column between 600 m and 2500 m exhibited a trend of increases in temperature and salinity at a mean rate of 0.025°/y and 0.0075/y, higher than the findings in earlier studies. This discrepancy is likely due to the downward transfer of excess heat and salt from the intermediate depths. In the Tyrrhenian Sea, one of the main mechanisms responsible for transferring heat and salt in the deep layers is double diffusion, which is particularly active here. Double diffusion forms 'staircase' structures that are better developed and more stable than in other areas of the world's oceans. Such structures are clearly seen in the analysis of the CTD data collected at an offshore station. These features occur at depths below 600 m, where the Levantine Intermediate Water (LIW) encounters the Tyrrhenian Dense Water, and mixing

  12. Sunspot drawings handwritten character recognition method based on deep learning

    NASA Astrophysics Data System (ADS)

    Zheng, Sheng; Zeng, Xiangyun; Lin, Ganghua; Zhao, Cui; Feng, Yongli; Tao, Jinping; Zhu, Daoyuan; Xiong, Li

    2016-05-01

    High accuracy scanned sunspot drawings handwritten characters recognition is an issue of critical importance to analyze sunspots movement and store them in the database. This paper presents a robust deep learning method for scanned sunspot drawings handwritten characters recognition. The convolution neural network (CNN) is one algorithm of deep learning which is truly successful in training of multi-layer network structure. CNN is used to train recognition model of handwritten character images which are extracted from the original sunspot drawings. We demonstrate the advantages of the proposed method on sunspot drawings provided by Chinese Academy Yunnan Observatory and obtain the daily full-disc sunspot numbers and sunspot areas from the sunspot drawings. The experimental results show that the proposed method achieves a high recognition accurate rate.

  13. Deep Atmosphere Ammonia Mixing Ratio at Jupiter from the Galileo Probe Mass Spectrometer

    NASA Technical Reports Server (NTRS)

    Mahaffy, P. R.; Niemann, H. B.; Demick, J. E.

    1999-01-01

    New laboratory studies employing the Engineering Unit (EU) of the Galileo Probe Mass Spectrometer (GPMS) have resulted in a substantial reduction in the previously reported upper limit on the ammonia mixing ratio derived from the GPMS experiment at Jupiter. This measurement is complicated by background ammonia contributions in the GPMS during direct atmospheric sampling produced from the preceding gas enrichment experiments. These backgrounds can be quantified with the data from the EU studies when they are carried out in a manner that duplicates the descent profile of pressure and enrichment cell loading. This background is due to the tendency of ammonia to interact strongly with the walls of the mass spectrometer and on release to contribute to the gas being directly directed into the ion source from the atmosphere through a capillary pressure reduction leak. It is evident from the GPMS and other observations that the mixing ratio of ammonia at Jupiter reaches the deep atmosphere value at substantially higher pressures than previously assumed. This is a likely explanation for the previously perceived discrepancy between ammonia values derived from ground based microwave observations and those obtained from attenuation of the Galileo Probe radio signal.

  14. Method for gasification of deep, thin coal seams. [DOE patent

    DOEpatents

    Gregg, D.W.

    1980-08-29

    A method of gasification of coal in deep, thin seams by using controlled bending subsidence to confine gas flow to a region close to the unconsumed coal face is given. The injection point is moved sequentially around the perimeter of a coal removal area from a production well to sweep out the area to cause the controlled bending subsidence. The injection holes are drilled vertically into the coal seam through the overburden or horizontally into the seam from an exposed coal face. The method is particularly applicable to deep, thin seams found in the eastern United States and at abandoned strip mines where thin seams were surface mined into a hillside or down a modest dip until the overburden became too thick for further mining.

  15. Method for gasification of deep, thin coal seams

    DOEpatents

    Gregg, David W.

    1982-01-01

    A method of gasification of coal in deep, thin seams by using controlled bending subsidence to confine gas flow to a region close to the unconsumed coal face. The injection point is moved sequentially around the perimeter of a coal removal area from a production well to sweep out the area to cause the controlled bending subsidence. The injection holes are drilled vertically into the coal seam through the overburden or horizontally into the seam from an exposed coal face. The method is particularly applicable to deep, thin seams found in the eastern United States and at abandoned strip mines where thin seams were surface mined into a hillside or down a modest dip until the overburden became too thick for further mining.

  16. 10 best resources on ... mixed methods research in health systems.

    PubMed

    Ozawa, Sachiko; Pongpirul, Krit

    2014-05-01

    Mixed methods research has become increasingly popular in health systems. Qualitative approaches are often used to explain quantitative results and help to develop interventions or survey instruments. Mixed methods research is especially important in low- and middle-income country (LMIC) settings, where understanding social, economic and cultural contexts are essential to assess health systems performance. To provide researchers and programme managers with a guide to mixed methods research in health systems, we review the best resources with a focus on LMICs. We selected 10 best resources (eight peer-reviewed articles and two textbooks) based on their importance and frequency of use (number of citations), comprehensiveness of content, usefulness to readers and relevance to health systems research in resource-limited contexts. We start with an overview on mixed methods research and discuss resources that are useful for a better understanding of the design and conduct of mixed methods research. To illustrate its practical applications, we provide examples from various countries (China, Vietnam, Kenya, Tanzania, Zambia and India) across different health topics (tuberculosis, malaria, HIV testing and healthcare costs). We conclude with some toolkits which suggest what to do when mixed methods findings conflict and provide guidelines for evaluating the quality of mixed methods research.

  17. A Rationale for Mixed Methods (Integrative) Research Programmes in Education

    ERIC Educational Resources Information Center

    Niaz, Mansoor

    2008-01-01

    Recent research shows that research programmes (quantitative, qualitative and mixed) in education are not displaced (as suggested by Kuhn) but rather lead to integration. The objective of this study is to present a rationale for mixed methods (integrative) research programs based on contemporary philosophy of science (Lakatos, Giere, Cartwright,…

  18. 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

  19. Multidimensional resonance raman spectroscopy by six-wave mixing in the deep UV

    SciTech Connect

    Molesky, Brian P.; Giokas, Paul G.; Guo, Zhenkun; Moran, Andrew M.

    2014-09-21

    Two-dimensional (2D) resonance Raman spectroscopies hold great potential for uncovering photoinduced relaxation processes in molecules but are not yet widely applied because of technical challenges. Here, we describe a newly developed 2D resonance Raman experiment operational at the third-harmonic of a Titanium-Sapphire laser. High-sensitivity and rapid data acquisition are achieved by combining spectral interferometry with a background-free (six-pulse) laser beam geometry. The third-harmonic laser pulses are generated in a filament produced by the fundamental and second-harmonic pulses in neon gas at pressures up to 35 atm. The capabilities of the setup are demonstrated by probing ground-state wavepacket motions in triiodide. The information provided by the experiment is explored with two different representations of the signal. In one representation, Fourier transforms are carried out with respect to the two experimentally controlled delay times to obtain a 2D Raman spectrum. Further insights are derived in a second representation by dispersing the signal pulse in a spectrometer. It is shown that, as in traditional pump-probe experiments, the six-wave mixing signal spectrum encodes the wavepacket's position by way of the (time-evolving) emission frequency. Anharmonicity additionally induces dynamics in the vibrational resonance frequency. In all cases, the experimental signals are compared to model calculations based on a cumulant expansion approach. This study suggests that multi-dimensional resonance Raman spectroscopies conducted on systems with Franck-Condon active modes are fairly immune to many of the technical issues that challenge off-resonant 2D Raman spectroscopies (e.g., third-order cascades) and photon-echo experiments in the deep UV (e.g., coherence spikes). The development of higher-order nonlinear spectroscopies operational in the deep UV is motivated by studies of biological systems and elementary organic photochemistries.

  20. Multidimensional resonance Raman spectroscopy by six-wave mixing in the deep UV.

    PubMed

    Molesky, Brian P; Giokas, Paul G; Guo, Zhenkun; Moran, Andrew M

    2014-09-21

    Two-dimensional (2D) resonance Raman spectroscopies hold great potential for uncovering photoinduced relaxation processes in molecules but are not yet widely applied because of technical challenges. Here, we describe a newly developed 2D resonance Raman experiment operational at the third-harmonic of a Titanium-Sapphire laser. High-sensitivity and rapid data acquisition are achieved by combining spectral interferometry with a background-free (six-pulse) laser beam geometry. The third-harmonic laser pulses are generated in a filament produced by the fundamental and second-harmonic pulses in neon gas at pressures up to 35 atm. The capabilities of the setup are demonstrated by probing ground-state wavepacket motions in triiodide. The information provided by the experiment is explored with two different representations of the signal. In one representation, Fourier transforms are carried out with respect to the two experimentally controlled delay times to obtain a 2D Raman spectrum. Further insights are derived in a second representation by dispersing the signal pulse in a spectrometer. It is shown that, as in traditional pump-probe experiments, the six-wave mixing signal spectrum encodes the wavepacket's position by way of the (time-evolving) emission frequency. Anharmonicity additionally induces dynamics in the vibrational resonance frequency. In all cases, the experimental signals are compared to model calculations based on a cumulant expansion approach. This study suggests that multi-dimensional resonance Raman spectroscopies conducted on systems with Franck-Condon active modes are fairly immune to many of the technical issues that challenge off-resonant 2D Raman spectroscopies (e.g., third-order cascades) and photon-echo experiments in the deep UV (e.g., coherence spikes). The development of higher-order nonlinear spectroscopies operational in the deep UV is motivated by studies of biological systems and elementary organic photochemistries. PMID:25240351

  1. Accurate and computationally efficient mixing models for the simulation of turbulent mixing with PDF methods

    NASA Astrophysics Data System (ADS)

    Meyer, Daniel W.; Jenny, Patrick

    2013-08-01

    Different simulation methods are applicable to study turbulent mixing. When applying probability density function (PDF) methods, turbulent transport, and chemical reactions appear in closed form, which is not the case in second moment closure methods (RANS). Moreover, PDF methods provide the entire joint velocity-scalar PDF instead of a limited set of moments. In PDF methods, however, a mixing model is required to account for molecular diffusion. In joint velocity-scalar PDF methods, mixing models should also account for the joint velocity-scalar statistics, which is often under appreciated in applications. The interaction by exchange with the conditional mean (IECM) model accounts for these joint statistics, but requires velocity-conditional scalar means that are expensive to compute in spatially three dimensional settings. In this work, two alternative mixing models are presented that provide more accurate PDF predictions at reduced computational cost compared to the IECM model, since no conditional moments have to be computed. All models are tested for different mixing benchmark cases and their computational efficiencies are inspected thoroughly. The benchmark cases involve statistically homogeneous and inhomogeneous settings dealing with three streams that are characterized by two passive scalars. The inhomogeneous case clearly illustrates the importance of accounting for joint velocity-scalar statistics in the mixing model. Failure to do so leads to significant errors in the resulting scalar means, variances and other statistics.

  2. Mixed time integration methods for transient thermal analysis of structures

    NASA Technical Reports Server (NTRS)

    Liu, W. K.

    1982-01-01

    The computational methods used to predict and optimize the thermal structural behavior of aerospace vehicle structures are reviewed. In general, two classes of algorithms, implicit and explicit, are used in transient thermal analysis of structures. Each of these two methods has its own merits. Due to the different time scales of the mechanical and thermal responses, the selection of a time integration method can be a different yet critical factor in the efficient solution of such problems. Therefore mixed time integration methods for transient thermal analysis of structures are being developed. The computer implementation aspects and numerical evaluation of these mixed time implicit-explicit algorithms in thermal analysis of structures are presented. A computationally useful method of estimating the critical time step for linear quadrilateral element is also given. Numerical tests confirm the stability criterion and accuracy characteristics of the methods. The superiority of these mixed time methods to the fully implicit method or the fully explicit method is also demonstrated.

  3. [Mixed methods research in public health: issues and illustration].

    PubMed

    Guével, Marie-Renée; Pommier, Jeanine

    2012-01-01

    For many years, researchers in a range of fields have combined quantitative and qualitative methods. However, the combined use of quantitative and qualitative methods has only recently been conceptualized and defined as mixed methods research. Some authors have described the emerging field as a third methodological tradition (in addition to the qualitative and quantitative traditions). Mixed methods research combines different perspectives and facilitates the study of complex interventions or programs, particularly in public health, an area where interdisciplinarity is critical. However, the existing literature is primarily in English. By contrast, the literature in French remains limited. The purpose of this paper is to present the emergence of mixed methods research for francophone public health specialists. A literature review was conducted to identify the main characteristics of mixed methods research. The results provide an overall picture of the mixed methods approach through its history, definitions, and applications, and highlight the tools developed to clarify the approach (typologies) and to implement it (integration of results and quality standards). The tools highlighted in the literature review are illustrated by a study conducted in France. Mixed methods research opens new possibilities for examining complex research questions and provides relevant and promising opportunities for addressing current public health issues in France.

  4. On Hybrid and mixed finite element methods

    NASA Technical Reports Server (NTRS)

    Pian, T. H. H.

    1981-01-01

    Three versions of the assumed stress hybrid model in finite element methods and the corresponding variational principles for the formulation are presented. Examples of rank deficiency for stiffness matrices by the hybrid stress model are given and their corresponding kinematic deformation modes are identified. A discussion of the derivation of general semi-Loof elements for plates and shells by the hybrid stress method is given. It is shown that the equilibrium model by Fraeijs de Veubeke can be derived by the approach of the hybrid stress model as a special case of semi-Loof elements.

  5. Applying Mixed Methods Research at the Synthesis Level: An Overview

    ERIC Educational Resources Information Center

    Heyvaert, Mieke; Maes, Bea; Onghena, Patrick

    2011-01-01

    Historically, qualitative and quantitative approaches have been applied relatively separately in synthesizing qualitative and quantitative evidence, respectively, in several research domains. However, mixed methods approaches are becoming increasingly popular nowadays, and practices of combining qualitative and quantitative research components at…

  6. Analytical chemistry methods for mixed oxide fuel, March 1985

    SciTech Connect

    Not Available

    1985-03-01

    This standard provides analytical chemistry methods for the analysis of materials used to produce mixed oxide fuel. These materials are ceramic fuel and insulator pellets and the plutonium and uranium oxides and nitrates used to fabricate these pellets.

  7. 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.

  8. Mixed methods research: a design for emergency care research?

    PubMed

    Cooper, Simon; Porter, Jo; Endacott, Ruth

    2011-08-01

    This paper follows previous publications on generic qualitative approaches, qualitative designs and action research in emergency care by this group of authors. Contemporary views on mixed methods approaches are considered, with a particular focus on the design choice and the amalgamation of qualitative and quantitative data emphasising the timing of data collection for each approach, their relative 'weight' and how they will be mixed. Mixed methods studies in emergency care are reviewed before the variety of methodological approaches and best practice considerations are presented. The use of mixed methods in clinical studies is increasing, aiming to answer questions such as 'how many' and 'why' in the same study, and as such are an important and useful approach to many key questions in emergency care.

  9. Approaches to Mixed Methods Dissemination and Implementation Research: Methods, Strengths, Caveats, and Opportunities

    PubMed Central

    Green, Carla A.; Duan, Naihua; Gibbons, Robert D.; Hoagwood, Kimberly E.; Palinkas, Lawrence A.; Wisdom, Jennifer P.

    2015-01-01

    Limited translation of research into practice has prompted study of diffusion and implementation, and development of effective methods of encouraging adoption, dissemination and implementation. Mixed methods techniques offer approaches for assessing and addressing processes affecting implementation of evidence-based interventions. We describe common mixed methods approaches used in dissemination and implementation research, discuss strengths and limitations of mixed methods approaches to data collection, and suggest promising methods not yet widely used in implementation research. We review qualitative, quantitative, and hybrid approaches to mixed methods dissemination and implementation studies, and describe methods for integrating multiple methods to increase depth of understanding while improving reliability and validity of findings. PMID:24722814

  10. Approaches to Mixed Methods Dissemination and Implementation Research: Methods, Strengths, Caveats, and Opportunities.

    PubMed

    Green, Carla A; Duan, Naihua; Gibbons, Robert D; Hoagwood, Kimberly E; Palinkas, Lawrence A; Wisdom, Jennifer P

    2015-09-01

    Limited translation of research into practice has prompted study of diffusion and implementation, and development of effective methods of encouraging adoption, dissemination and implementation. Mixed methods techniques offer approaches for assessing and addressing processes affecting implementation of evidence-based interventions. We describe common mixed methods approaches used in dissemination and implementation research, discuss strengths and limitations of mixed methods approaches to data collection, and suggest promising methods not yet widely used in implementation research. We review qualitative, quantitative, and hybrid approaches to mixed methods dissemination and implementation studies, and describe methods for integrating multiple methods to increase depth of understanding while improving reliability and validity of findings.

  11. Non-local ocean mixing model and a new plume model for deep convection

    NASA Astrophysics Data System (ADS)

    Canuto, V. M.; Cheng, Y.; Howard, A. M.

    Turbulent fluxes can be represented by a diffusivity tensor, the symmetric part of which describes " turbulent diffusion" while the anti-symmetric part describes " advection". Diffusion is a local process in the sense that it depends only on the local gradients of the mean fields while advection is non-local for it is represented by an integral over all length scales (all eddies) that can "fit" from say the bottom of the physical domain to the z where the fluxes are computed. In the ocean, there are two main regimes where non-local transport is important. One regime is where storms release a sudden burst of mechanical energy to the ocean surface that is then transported downward by energetic eddies that deepen the mixed layer. Even relatively simple non-local models yield results considerably more realistic than those of local models. The second regime is deep convection (DC) caused by loss of surface buoyancy, the description of which is required for a reliable assessment of water masses formation. At present, there is no reliable model for either of these non-local regimes individually or much less a formalism capable of accounting for both regimes simultaneously. The goal of this paper is to present a formalism that provides the expressions for the non-local fluxes for momentum, heat and salinity encompassing both cases. Since the resulting number of dynamic equations involves is however large, we work out two sub-models, one when only shear must be treated non-locally (e.g., when storms release mechanical energy) and one when only buoyancy is to be treated non-locally (the DC case). We employ the Reynolds Stress formalism in which non-locality is represented by the third-order moments which in turn depend on the fourth-order moments for which we employ a new model that has been tested against LES data, aircraft data and a full PBL simulation. For the DC case, we rewrite the non-local model in terms of Plumes since thus far the only non-local model used to treat

  12. Concrete Mixing Methods and Concrete Mixers: State of the Art.

    PubMed

    Ferraris, C F

    2001-01-01

    As for all materials, the performance of concrete is determined by its microstructure. Its microstructure is determined by its composition, its curing conditions, and also by the mixing method and mixer conditions used to process the concrete. This paper gives an overview of the various types of mixing methods and concrete mixers commercially available used by the concrete industry. There are two main types of mixers used: batch mixers and continuous mixers. Batch mixers are the most common. To determine the mixing method best suited for a specific application, factors to be considered include: location of the construction site (distance from the batching plant), the amount of concrete needed, the construction schedule (volume of concrete needed per hour), and the cost. Ultimately, the quality of the concrete produced determines its performance after placement. An important measure of the quality is the homogeneity of the material after mixing. This paper will review mixing methods in regards to the quality of the concrete produced. Some procedures used to determine the effectiveness of the mixing will be examined.

  13. Concrete Mixing Methods and Concrete Mixers: State of the Art

    PubMed Central

    Ferraris, Chiara F.

    2001-01-01

    As for all materials, the performance of concrete is determined by its microstructure. Its microstructure is determined by its composition, its curing conditions, and also by the mixing method and mixer conditions used to process the concrete. This paper gives an overview of the various types of mixing methods and concrete mixers commercially available used by the concrete industry. There are two main types of mixers used: batch mixers and continuous mixers. Batch mixers are the most common. To determine the mixing method best suited for a specific application, factors to be considered include: location of the construction site (distance from the batching plant), the amount of concrete needed, the construction schedule (volume of concrete needed per hour), and the cost. Ultimately, the quality of the concrete produced determines its performance after placement. An important measure of the quality is the homogeneity of the material after mixing. This paper will review mixing methods in regards to the quality of the concrete produced. Some procedures used to determine the effectiveness of the mixing will be examined. PMID:27500029

  14. Assessing and evaluating multidisciplinary translational teams: a mixed methods approach.

    PubMed

    Wooten, Kevin C; Rose, Robert M; Ostir, Glenn V; Calhoun, William J; Ameredes, Bill T; Brasier, Allan R

    2014-03-01

    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.

  15. 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.

  16. Detecting plastic strain distribution by a nonlinear wave mixing method

    NASA Astrophysics Data System (ADS)

    Tang, Guangxin; Liu, Minghe; Jacobs, Laurence J.; Qu, Jianmin

    2013-01-01

    A nonlinear wave mixing method is used to measure the plastic strain distribution in polycrystalline materials. A pair of collinear longitudinal and shear waves is generated. Under the phase matching condition, a resonant shear wave with a difference frequency is generated and propagates towards the shear wave transducer. The amplitude of this resonant shear wave is proportional to the acoustic nonlinearity parameter β, which is known to be related to plastic deformation. By adjusting the two primary waves so that they mix at different locations, the distribution of β can be obtained. This study demonstrates the feasibility of detecting plastic strain distribution in polycrystalline materials by the nonlinear wave mixing technique.

  17. Using Mixed Methods in Health Information Technology Evaluation.

    PubMed

    Sockolow, Paulina; Dowding, Dawn; Randell, Rebecca; Favela, Jesus

    2016-01-01

    With the increasing adoption of interactive systems in healthcare, there is a need to ensure that the benefits of such systems are formally evaluated. Traditionally quantitative research approaches have been used to gather evidence on measurable outcomes of health technology. Qualitative approaches have also been used to analyze how or why particular interventions did or did not work in specific healthcare contexts. Mixed methods research provides a framework for carrying out both quantitative and qualitative approaches within a single research study. In this paper an international group of four informatics scholars illustrate some of the benefits and challenges of using mixed methods in evaluation. The diversity of the research experience provides a broad overview of approaches in combining robust analysis of outcome data with qualitative methods that provide an understanding of the processes through which, and the contexts in which, those outcomes are achieved. This paper discussed the benefits that mixed methods brought to each study. PMID:27332167

  18. Dual Formulations of Mixed Finite Element Methods with Applications.

    PubMed

    Gillette, Andrew; Bajaj, Chandrajit

    2011-10-01

    Mixed finite element methods solve a PDE using two or more variables. The theory of Discrete Exterior Calculus explains why the degrees of freedom associated to the different variables should be stored on both primal and dual domain meshes with a discrete Hodge star used to transfer information between the meshes. We show through analysis and examples that the choice of discrete Hodge star is essential to the numerical stability of the method. Additionally, we define interpolation functions and discrete Hodge stars on dual meshes which can be used to create previously unconsidered mixed methods. Examples from magnetostatics and Darcy flow are examined in detail.

  19. Symmetry conserving configuration mixing method with cranked states

    NASA Astrophysics Data System (ADS)

    Borrajo, Marta; Rodríguez, Tomás R.; Luis Egido, J.

    2015-06-01

    We present the first calculations of a symmetry conserving configuration mixing method (SCCM) using time-reversal symmetry breaking Hartree-Fock-Bogoliubov (HFB) states with the Gogny D1S interaction. The method includes particle number and tridimensional angular momentum symmetry restorations as well as configuration mixing within the generator coordinate method (GCM) framework. The nucleus 32Mg is chosen to show the performance and reliability of the calculations. Additionally, 01+, 21+ and 41+ states are computed for the magnesium isotopic chain, where a noticeable compression of the spectrum is obtained by including cranked states, leading to a very good agreement with the known experimental data.

  20. Studying Participation Networks in Collaboration Using Mixed Methods

    ERIC Educational Resources Information Center

    Martinez, Alejandra; Dimitriadis, Yannis; Gomez-Sanchez, Eduardo; Rubia-Avi, Bartolome; Jorrin-Abellan, Ivan; Marcos, Jose A.

    2006-01-01

    This paper describes the application of a mixed-evaluation method, published elsewhere, to three different learning scenarios. The method defines how to combine social network analysis with qualitative and quantitative analysis in order to study participatory aspects of learning in CSCL contexts. The three case studies include a course-long,…

  1. Mixed exhaust flow supersonic jet engine and method

    SciTech Connect

    Klees, G.W.

    1993-06-08

    A method of operating a supersonic jet engine installation is described comprising (a) providing an engine having a variable area air inlet means and an outlet to discharge engine exhaust; (b) providing a secondary air passageway means; (c) receiving ambient air in the air inlet means and providing the ambient air as primary air to the engine inlet and secondary air to the secondary air passageway means; (d) providing a mixing section having an inlet portion and an exit portion, utilizing the mixing section in directing the exhaust from the engine to primary convergent/divergent exit passageway segments, where the exhaust is discharged at supersonic velocity as primary flow components, and directing secondary air flow from the secondary air passageway means to secondary exit passageway segments which are interspersed with the primary segments and from which the secondary air is discharged at subsonic velocity as secondary flow components; and (e) providing an exhaust section to receive the primary and secondary flow components in a mixing region and causing the primary and secondary flow components to mix to create a supersonic mixed flow, the exhaust section having a variable area final nozzle through which the mixed flow is discharged.

  2. 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…

  3. Creating and Supporting a Mixed Methods Health Services Research Team

    PubMed Central

    Bowers, Barbara; Cohen, Lauren W; Elliot, Amy E; Grabowski, David C; Fishman, Nancy W; Sharkey, Siobhan S; Zimmerman, Sheryl; Horn, Susan D; Kemper, Peter

    2013-01-01

    Objective. To use the experience from a health services research evaluation to provide guidance in team development for mixed methods research. Methods. The Research Initiative Valuing Eldercare (THRIVE) team was organized by the Robert Wood Johnson Foundation to evaluate The Green House nursing home culture change program. This article describes the development of the research team and provides insights into how funders might engage with mixed methods research teams to maximize the value of the team. Results. Like many mixed methods collaborations, the THRIVE team consisted of researchers from diverse disciplines, embracing diverse methodologies, and operating under a framework of nonhierarchical, shared leadership that required new collaborations, engagement, and commitment in the context of finite resources. Strategies to overcome these potential obstacles and achieve success included implementation of a Coordinating Center, dedicated time for planning and collaborating across researchers and methodologies, funded support for in-person meetings, and creative optimization of resources. Conclusions. Challenges are inevitably present in the formation and operation of effective mixed methods research teams. However, funders and research teams can implement strategies to promote success. PMID:24138774

  4. Achieving Integration in Mixed Methods Designs—Principles and Practices

    PubMed Central

    Fetters, Michael D; Curry, Leslie A; Creswell, John W

    2013-01-01

    Mixed methods research offers powerful tools for investigating complex processes and systems in health and health care. This article describes integration principles and practices at three levels in mixed methods research and provides illustrative examples. Integration at the study design level occurs through three basic mixed method designs—exploratory sequential, explanatory sequential, and convergent—and through four advanced frameworks—multistage, intervention, case study, and participatory. Integration at the methods level occurs through four approaches. In connecting, one database links to the other through sampling. With building, one database informs the data collection approach of the other. When merging, the two databases are brought together for analysis. With embedding, data collection and analysis link at multiple points. Integration at the interpretation and reporting level occurs through narrative, data transformation, and joint display. The fit of integration describes the extent the qualitative and quantitative findings cohere. Understanding these principles and practices of integration can help health services researchers leverage the strengths of mixed methods. PMID:24279835

  5. Mixed time integration methods for transient thermal analysis of structures

    NASA Technical Reports Server (NTRS)

    Liu, W. K.

    1983-01-01

    The computational methods used to predict and optimize the thermal-structural behavior of aerospace vehicle structures are reviewed. In general, two classes of algorithms, implicit and explicit, are used in transient thermal analysis of structures. Each of these two methods has its own merits. Due to the different time scales of the mechanical and thermal responses, the selection of a time integration method can be a difficult yet critical factor in the efficient solution of such problems. Therefore mixed time integration methods for transient thermal analysis of structures are being developed. The computer implementation aspects and numerical evaluation of these mixed time implicit-explicit algorithms in thermal analysis of structures are presented. A computationally-useful method of estimating the critical time step for linear quadrilateral element is also given. Numerical tests confirm the stability criterion and accuracy characteristics of the methods. The superiority of these mixed time methods to the fully implicit method or the fully explicit method is also demonstrated.

  6. Near-surface mixing and pronounced deep-water stratification in a compartmentalised, human-disturbed atoll lagoon system

    NASA Astrophysics Data System (ADS)

    Gardner, J. P. A.; Garton, D. W.; Collen, J. D.

    2011-03-01

    Palmyra Atoll has four partially isolated lagoons up to 50 m in depth, each with complex and variable bottom topographies. Measurements of depth, temperature, salinity, turbidity and dissolved oxygen (DO) revealed a well-mixed shallow surface layer (0-10 m depth) and below that pronounced stratification of DO in the absence of a pycnocline. Turbidity increased in a step-like manner at ~25 m depth, at the oxycline. For all deep sections of the lagoon (>30 m), DO declined uniformly to 0% saturation. As determined from filtration, mass of particulates was independent of depth. Surface mixing and deep-water stratification are both stable at different temporal scales, including day versus night, daily, weekly and annually. We suggest that lagoon circulation is represented by a shallow, westward-moving surface layer of well-to-partially mixed water with high DO and low turbidity, underlain by a relatively static and temporally stable layer with low to zero DO and elevated turbidity. This is the first report of such conditions within a deep lagoon system, and only the second report of anoxic conditions in any such system. In deep-water, stable euxinic conditions reflect bottom topography, with dysoxic and anoxic water being constrained within silled basins. The occurrence and depth of large volumes of sediment-laden and dysoxic/anoxic water need to be considered in management proposals designed to increase water flow through the lagoon. These novel water column conditions most probably arose as a consequence of military construction work, consistent with published reports of profound changes to the atoll during 1940-1945. If so, they highlight the need to better understand the possible consequences of cutting channels and modification of lagoon flow at many atolls across the central Pacific Ocean.

  7. 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.

  8. Libraries in Online Elementary Schools: A Mixed-Methods Study

    ERIC Educational Resources Information Center

    Hibbard, Laura; Franklin, Teresa

    2015-01-01

    School libraries serve an important role; however, elementary students who attend schools online typically do not have a school library. This study followed an online school's inaugural year in instituting a library. A mixed methods approach examined data from focus groups, interviews, surveys, library-use records and oral reading fluency scores.…

  9. 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…

  10. Consent, Informal Organization and Job Rewards: A Mixed Methods Analysis

    ERIC Educational Resources Information Center

    Laubach, Marty

    2005-01-01

    This study uses a mixed methods approach to workplace dynamics. Ethnographic observations show that the consent deal underlies an informal stratification that divides the workplace into an "informal periphery," a "conventional core" and an "administrative clan." The "consent deal" is defined as an exchange of autonomy, voice and schedule…

  11. Linking Research Questions to Mixed Methods Data Analysis Procedures

    ERIC Educational Resources Information Center

    Onwuegbuzie, Anthony J.; Leech, Nancy L.

    2006-01-01

    The purpose of this paper is to discuss the development of research questions in mixed methods studies. First, we discuss the ways that the goal of the study, the research objective(s), and the research purpose shape the formation of research questions. Second, we compare and contrast quantitative research questions and qualitative research…

  12. First Generation College Student Leadership Potential: A Mixed Methods Analysis

    ERIC Educational Resources Information Center

    Hojan-Clark, Jane M.

    2010-01-01

    This mixed methods research compared the leadership potential of traditionally aged first generation college students to that of college students whose parents are college educated. A college education provides advantages to those who can obtain it (Baum & Payea, 2004; Black Issues in Higher Education, 2005; Education and the Value of Knowledge,…

  13. College Students; Justification for Digital Piracy: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Yu, Szde

    2012-01-01

    A mixed methods project was devoted to understanding college students' justification for digital piracy. The project consisted of two studies, a qualitative one and a quantitative one. Qualitative interviews were conducted to identify main themes in students' justification for digital piracy, and then the findings were tested in a quantitative…

  14. A Method To Ensure Heterogeneous Mixing of Grade 9 Classes.

    ERIC Educational Resources Information Center

    Brydges, Bruce

    This paper presents outcomes of a practicum that was designed to address a need that was created when the Ministry of Education in Ontario, Canada, mandated that all grade 9 classes be "destreamed." A review of educational literature found no methods for ensuring that classes are truly heterogeneously mixed. The practicum was designed to gather…

  15. Is Mixed Methods Research Used in Australian Career Development Research?

    ERIC Educational Resources Information Center

    Cameron, Roslyn

    2010-01-01

    Mixed methods research has become a substantive and growing methodological force that is growing in popularity within the human and social sciences. This article reports the findings of a study that has systematically reviewed articles from the "Australian Journal of Career Development" from 2004 to 2009. The aim of the study was to provide a…

  16. 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…

  17. Prevalence of Mixed Methods Research in Mathematics Education

    ERIC Educational Resources Information Center

    Ross, Amanda A.; Onwuegbuzie, Anthony J.

    2012-01-01

    In wake of federal legislation such as the No Child Left Behind Act of 2001 that have called for "scientifically based research in education," this study examined the possible trends in mixed methods research articles published in 2 peer-reviewed mathematics education journals (n = 87) from 2002 to 2006. The study also illustrates how the…

  18. A multigrid solution method for mixed hybrid finite elements

    SciTech Connect

    Schmid, W.

    1996-12-31

    We consider the multigrid solution of linear equations arising within the discretization of elliptic second order boundary value problems of the form by mixed hybrid finite elements. Using the equivalence of mixed hybrid finite elements and non-conforming nodal finite elements, we construct a multigrid scheme for the corresponding non-conforming finite elements, and, by this equivalence, for the mixed hybrid finite elements, following guidelines from Arbogast/Chen. For a rectangular triangulation of the computational domain, this non-conforming schemes are the so-called nodal finite elements. We explicitly construct prolongation and restriction operators for this type of non-conforming finite elements. We discuss the use of plain multigrid and the multilevel-preconditioned cg-method and compare their efficiency in numerical tests.

  19. Fluid mixing and the deep biosphere of a fossil Lost City-type hydrothermal system at the Iberia Margin.

    PubMed

    Klein, Frieder; Humphris, Susan E; Guo, Weifu; Schubotz, Florence; Schwarzenbach, Esther M; Orsi, William D

    2015-09-29

    Subseafloor mixing of reduced hydrothermal fluids with seawater is believed to provide the energy and substrates needed to support deep chemolithoautotrophic life in the hydrated oceanic mantle (i.e., serpentinite). However, geosphere-biosphere interactions in serpentinite-hosted subseafloor mixing zones remain poorly constrained. Here we examine fossil microbial communities and fluid mixing processes in the subseafloor of a Cretaceous Lost City-type hydrothermal system at the magma-poor passive Iberia Margin (Ocean Drilling Program Leg 149, Hole 897D). Brucite-calcite mineral assemblages precipitated from mixed fluids ca. 65 m below the Cretaceous paleo-seafloor at temperatures of 31.7 ± 4.3 °C within steep chemical gradients between weathered, carbonate-rich serpentinite breccia and serpentinite. Mixing of oxidized seawater and strongly reducing hydrothermal fluid at moderate temperatures created conditions capable of supporting microbial activity. Dense microbial colonies are fossilized in brucite-calcite veins that are strongly enriched in organic carbon (up to 0.5 wt.% of the total carbon) but depleted in (13)C (δ(13)C(TOC) = -19.4‰). We detected a combination of bacterial diether lipid biomarkers, archaeol, and archaeal tetraethers analogous to those found in carbonate chimneys at the active Lost City hydrothermal field. The exposure of mantle rocks to seawater during the breakup of Pangaea fueled chemolithoautotrophic microbial communities at the Iberia Margin, possibly before the onset of seafloor spreading. Lost City-type serpentinization systems have been discovered at midocean ridges, in forearc settings of subduction zones, and at continental margins. It appears that, wherever they occur, they can support microbial life, even in deep subseafloor environments.

  20. Fluid mixing and the deep biosphere of a fossil Lost City-type hydrothermal system at the Iberia Margin.

    PubMed

    Klein, Frieder; Humphris, Susan E; Guo, Weifu; Schubotz, Florence; Schwarzenbach, Esther M; Orsi, William D

    2015-09-29

    Subseafloor mixing of reduced hydrothermal fluids with seawater is believed to provide the energy and substrates needed to support deep chemolithoautotrophic life in the hydrated oceanic mantle (i.e., serpentinite). However, geosphere-biosphere interactions in serpentinite-hosted subseafloor mixing zones remain poorly constrained. Here we examine fossil microbial communities and fluid mixing processes in the subseafloor of a Cretaceous Lost City-type hydrothermal system at the magma-poor passive Iberia Margin (Ocean Drilling Program Leg 149, Hole 897D). Brucite-calcite mineral assemblages precipitated from mixed fluids ca. 65 m below the Cretaceous paleo-seafloor at temperatures of 31.7 ± 4.3 °C within steep chemical gradients between weathered, carbonate-rich serpentinite breccia and serpentinite. Mixing of oxidized seawater and strongly reducing hydrothermal fluid at moderate temperatures created conditions capable of supporting microbial activity. Dense microbial colonies are fossilized in brucite-calcite veins that are strongly enriched in organic carbon (up to 0.5 wt.% of the total carbon) but depleted in (13)C (δ(13)C(TOC) = -19.4‰). We detected a combination of bacterial diether lipid biomarkers, archaeol, and archaeal tetraethers analogous to those found in carbonate chimneys at the active Lost City hydrothermal field. The exposure of mantle rocks to seawater during the breakup of Pangaea fueled chemolithoautotrophic microbial communities at the Iberia Margin, possibly before the onset of seafloor spreading. Lost City-type serpentinization systems have been discovered at midocean ridges, in forearc settings of subduction zones, and at continental margins. It appears that, wherever they occur, they can support microbial life, even in deep subseafloor environments. PMID:26324888

  1. Fluid mixing and the deep biosphere of a fossil Lost City-type hydrothermal system at the Iberia Margin

    PubMed Central

    Klein, Frieder; Humphris, Susan E.; Guo, Weifu; Schubotz, Florence; Schwarzenbach, Esther M.; Orsi, William D.

    2015-01-01

    Subseafloor mixing of reduced hydrothermal fluids with seawater is believed to provide the energy and substrates needed to support deep chemolithoautotrophic life in the hydrated oceanic mantle (i.e., serpentinite). However, geosphere-biosphere interactions in serpentinite-hosted subseafloor mixing zones remain poorly constrained. Here we examine fossil microbial communities and fluid mixing processes in the subseafloor of a Cretaceous Lost City-type hydrothermal system at the magma-poor passive Iberia Margin (Ocean Drilling Program Leg 149, Hole 897D). Brucite−calcite mineral assemblages precipitated from mixed fluids ca. 65 m below the Cretaceous paleo-seafloor at temperatures of 31.7 ± 4.3 °C within steep chemical gradients between weathered, carbonate-rich serpentinite breccia and serpentinite. Mixing of oxidized seawater and strongly reducing hydrothermal fluid at moderate temperatures created conditions capable of supporting microbial activity. Dense microbial colonies are fossilized in brucite−calcite veins that are strongly enriched in organic carbon (up to 0.5 wt.% of the total carbon) but depleted in 13C (δ13CTOC = −19.4‰). We detected a combination of bacterial diether lipid biomarkers, archaeol, and archaeal tetraethers analogous to those found in carbonate chimneys at the active Lost City hydrothermal field. The exposure of mantle rocks to seawater during the breakup of Pangaea fueled chemolithoautotrophic microbial communities at the Iberia Margin, possibly before the onset of seafloor spreading. Lost City-type serpentinization systems have been discovered at midocean ridges, in forearc settings of subduction zones, and at continental margins. It appears that, wherever they occur, they can support microbial life, even in deep subseafloor environments. PMID:26324888

  2. The role of mixed methods in improved cookstove research.

    PubMed

    Stanistreet, Debbi; Hyseni, Lirije; Bashin, Michelle; Sadumah, Ibrahim; Pope, Daniel; Sage, Michael; Bruce, Nigel

    2015-01-01

    The challenge of promoting access to clean and efficient household energy for cooking and heating is a critical issue facing low- and middle-income countries today. Along with clean fuels, improved cookstoves (ICSs) continue to play an important part in efforts to reduce the 4 million annual premature deaths attributed to household air pollution. Although a range of ICSs are available, there is little empirical evidence on appropriate behavior change approaches to inform adoption and sustained used at scale. Specifically, evaluations using either quantitative or qualitative methods provide an incomplete picture of the challenges in facilitating ICS adoption. This article examines how studies that use the strengths of both these approaches can offer important insights into behavior change in relation to ICS uptake and scale-up. Epistemological approaches, study design frameworks, methods of data collection, analytical approaches, and issues of validity and reliability in the context of mixed methods ICS research are examined, and the article presents an example study design from an evaluation study in Kenya incorporating a nested approach and a convergent case oriented design. The authors discuss the benefits and methodological challenges of mixed-methods approaches in the context of researching behavior change and ICS use recognizing that such methods represent relatively uncharted territory. The authors propose that more published examples are needed to provide frameworks for other researchers seeking to apply mixed methods in this context and suggest a comprehensive research agenda is required that incorporates integrated mixed-methods approaches, to provide best evidence for future scale-up.

  3. Pragmatism in practice: mixed methods research for physiotherapy.

    PubMed

    Shaw, James A; Connelly, Denise M; Zecevic, Aleksandra A

    2010-11-01

    The purpose of this paper is to provide an argument for the place of mixed methods research across practice settings as an effective means of supporting evidence-based practice in physiotherapy. Physiotherapy practitioners use both qualitative and quantitative methods throughout the process of patient care-from history taking, assessment, and intervention to evaluation of outcomes. Research on practice paradigms demonstrates the importance of mixing qualitative and quantitative methods to achieve 'expert practice' that is concerned with optimizing outcomes and incorporating patient beliefs and values. Research paradigms that relate to this model of practice would integrate qualitative and quantitative types of knowledge and inquiry, while maintaining a prioritized focus on patient outcomes. Pragmatism is an emerging research paradigm where practical consequences and the effects of concepts and behaviors are vital components of meaning and truth. This research paradigm supports the simultaneous use of qualitative and quantitative methods of inquiry to generate evidence to support best practice. This paper demonstrates that mixed methods research with a pragmatist view provides evidence that embraces and addresses the multiple practice concerns of practitioners better than either qualitative or quantitative research approaches in isolation.

  4. Logically rectangular mixed methods for Darcy flow on general geometry

    SciTech Connect

    Arbogast, T.; Keenan, P.T.; Wheeler, M.F.; Yotov, I.

    1995-12-31

    The authors consider an expanded mixed finite element formulation (cell centered finite difference) for Darcy flow with a tensor absolute permeability. The reservoir can be geometrically general with internal features, but the computational domain is rectangular. The method is defined on a curvilinear grid that need not be orthogonal, obtained by mapping the rectangular, computational grid. The original flow problem becomes a similar problem with a modified permeability on the computational grid. Quadrature rules turn the mixed method into a cell-centered finite difference method with a 9 point stencil in 2-D and 19 in 3-D. As shown by theory and experiment, if the modified permeability on the computational domain is smooth, then the convergence rate is optimal and both pressure and velocity are superconvergent at certain points. If not, Lagrange multiplier pressures can be introduced on boundaries of elements so that optimal convergence is retained. This modification presents only small changes in the solution process; in fact, the same parallel domain decomposition algorithms can be applied with little or no change to the code if the modified permeability is smooth over the subdomains. This Lagrange multiplier procedure can be used to extend the difference scheme to multi-block domains, and to give a coupling with unstructured grids. In all cases, the mixed formulation is locally conservative. Computational results illustrate the advantage and convergence of this method.

  5. Laminated microchannel devices, mixing units and method of making same

    DOEpatents

    Bennett, Wendy D [Kennewick, WA; Hammerstrom, Donald J [West Richland, WA; Martin, Peter M [Kennewick, WA; Matson, Dean W [Kennewick, WA

    2002-10-17

    A laminated microchannel device is described in which there is a unit operation process layer that has longitudinal channel. The longitudinal channel is cut completely through the layer in which the unit process operation resides. Both the device structure and method of making the device provide significant advantages in terms of simplicity and efficiency. A static mixing unit that can be incorporated in the laminated microchannel device is also described.

  6. Compulsory Deep Mixing of 3He and CNO Isotopes in the Envelopes of low-mass Red Giants

    SciTech Connect

    Eggleton, P P; Dearborn, D P; Lattanzio, J C

    2007-03-20

    Three-dimensional stellar modeling has enabled us to identify a deep-mixing mechanism that must operate in all low mass giants. This mixing process is not optional, and is driven by a molecular weight inversion created by the {sup 3}He({sup 3}He,2p){sup 4}He reaction. In this paper we characterize the behavior of this mixing, and study its impact on the envelope abundances. It not only eliminates the problem of {sup 3}He overproduction, reconciling stellar and big bang nucleosynthesis with observations, but solves the discrepancy between observed and calculated CNO isotope ratios in low mass giants, a problem of more than 3 decades standing. This mixing mechanism operates rapidly once the hydrogen burning shell approaches the material homogenized by the surface convection zone. In agreement with observations, Pop I stars between 0.8 and 2.0 M{sub {circle_dot}} develop {sup 12}C/{sup 13}C ratios of 14.5 {+-} 1.5, while Pop II stars process the carbon to ratios of 4.0 {+-} 0.5. In stars less than 1.25 M{sub {circle_dot}}, this mechanism also destroys 90% to 95% of the {sup 3}He produced on the main sequence.

  7. Preconditioned Mixed Spectral Element Methods for Elasticity and Stokes Problems

    NASA Technical Reports Server (NTRS)

    Pavarino, Luca F.

    1996-01-01

    Preconditioned iterative methods for the indefinite systems obtained by discretizing the linear elasticity and Stokes problems with mixed spectral elements in three dimensions are introduced and analyzed. The resulting stiffness matrices have the structure of saddle point problems with a penalty term, which is associated with the Poisson ratio for elasticity problems or with stabilization techniques for Stokes problems. The main results of this paper show that the convergence rate of the resulting algorithms is independent of the penalty parameter, the number of spectral elements Nu and mildly dependent on the spectral degree eta via the inf-sup constant. The preconditioners proposed for the whole indefinite system are block-diagonal and block-triangular. Numerical experiments presented in the final section show that these algorithms are a practical and efficient strategy for the iterative solution of the indefinite problems arising from mixed spectral element discretizations of elliptic systems.

  8. Elliptic interface problem solved using the mixed finite element method

    NASA Astrophysics Data System (ADS)

    Wang, Shuqiang

    2007-05-01

    The elliptic boundary value/interface problem is very important in many applications, for example, in incompressible flow and MHD. Many methods are used to solve these problems in a complex domain, including the finite volume method, the finite element method and the boundary element method. For a complex computational domain, the better choice of the partition of the computational domain is to use an unstructured grid. However, it is not a straight forward task to implement a mesh generation program. Such a program requires extra computing time and resources (such as computer memory). Thus people like to use a structured mesh if possible, especially a cartesian mesh. Popular methods using structured cartesian grids for the elliptic boundary value/interface problem include the immersed boundary method, the immersed interface method, the ghost fluid method, and the embedded boundary method. This thesis solves the elliptic problem using several versions of the mixed nite element method on an unstructured mesh. The results are compared for speed and accuracy to the embedded boundary method. A ghost fluid method for elliptic boundary value/interface problems is also investigated. Finally, a simple test of the 2D Rayleigh-Taylor instability is performed using the FronTier-Lite package. Key Words. Elliptic Boundary Value, Interface, Mesh Generation, Quadtree, Octree, Front Tracking.

  9. Comparison of three screening methods to select mixed-microbial inoculum for mixed-acid fermentations.

    PubMed

    Golub, Kristina W; Forrest, Andrea K; Wales, Melinda E; Hammett, Amy Jo M; Cope, Julia L; Wilkinson, Heather H; Holtzapple, Mark T

    2013-02-01

    Using a mixed culture of microorganisms, the carboxylate platform converts biomass into hydrocarbons and chemicals. To develop a method that identifies the highest performing inoculum for carboxylate fermentations, five bacterial communities were screened and ranked by three fermentation performance tests: (1) 30-day batch screen, (2) 28-day continuum particle distribution model (CPDM), and (3) 5-month continuous countercurrent fermentation trains. To screen numerous inocula sources, these tests were used sequentially in an aseptic environment. For the batch-fermentation screen, Inoculum 1 achieved the highest conversion. For the CPDM evaluation, the operating map for Inoculum 1 had the highest performance. For the continuous countercurrent fermentation, the train resulting from Inoculum 1 was among the best performers. This study suggests that the three screens are a useful and predictive method for choosing optimal inocula sources. The bacterial community with optimal performance in these three screens could be considered for use in commercial-scale fermentations. PMID:23334035

  10. [A new method for deep reflex muscular massage].

    PubMed

    Aksenova, A M

    1997-01-01

    The idea of deep reflex muscular massage rests on the existence of a strong relationship between structural and functional changes in the skeletal muscles and visceral condition. The massage can be used for management of acute states in combination with herbs, food additives, reduced drug dosages, exercises, thermotherapy.

  11. Combining sources in stable isotope mixing models: alternative methods.

    PubMed

    Phillips, Donald L; Newsome, Seth D; Gregg, Jillian W

    2005-08-01

    Stable isotope mixing models are often used to quantify source contributions to a mixture. Examples include pollution source identification; trophic web studies; analysis of water sources for soils, plants; or water bodies, and many others. A common problem is having too many sources to allow a unique solution. We discuss two alternative procedures for addressing this problem. One option is a priori to combine sources with similar signatures so the number of sources is small enough to provide a unique solution. Aggregation should be considered only when isotopic signatures of clustered sources are not significantly different, and sources are related so the combined source group has some functional significance. For example, in a food web analysis, lumping several species within a trophic guild allows more interpretable results than lumping disparate food sources, even if they have similar isotopic signatures. One result of combining mixing model sources is increased uncertainty of the combined end-member isotopic signatures and consequently the source contribution estimates; this effect can be quantified using the IsoError model (http://www.epa.gov/wed/pages/models/isotopes/isoerror1_04.htm). As an alternative to lumping sources before a mixing analysis, the IsoSource mixing model (http://www.epa.gov/wed/pages/models/isosource/isosource.htm) can be used to find all feasible solutions of source contributions consistent with isotopic mass balance. While ranges of feasible contributions for each individual source can often be quite broad, contributions from functionally related groups of sources can be summed a posteriori, producing a range of solutions for the aggregate source that may be considerably narrower. A paleo-human dietary analysis example illustrates this method, which involves a terrestrial meat food source, a combination of three terrestrial plant foods, and a combination of three marine foods. In this case, a posteriori aggregation of sources allowed

  12. Magnetohydrodynamics and deep mixing in evolved stars. I. Two- and three-dimensional analytical models for the asymptotic giant branch

    SciTech Connect

    Nucci, M. C.; Busso, M. E-mail: busso@fisica.unipg.it

    2014-06-01

    The advection of thermonuclear ashes by magnetized domains emerging near the H shell was suggested to explain asymptotic giant branch (AGB) star abundances. Here we verify this idea quantitatively through exact MHD models. Starting with a simple two-dimensional (2D) geometry and in an inertia frame, we study plasma equilibria avoiding the complications of numerical simulations. We show that below the convective envelope of an AGB star, variable magnetic fields induce a natural expansion, permitted by the almost ideal MHD conditions, in which the radial velocity grows as the second power of the radius. We then study the convective envelope, where the complexity of macroturbulence allows only for a schematic analytical treatment. Here the radial velocity depends on the square root of the radius. We then verify the robustness of our results with 3D calculations for the velocity, showing that for both studied regions the solution previously found can be seen as a planar section of a more complex behavior, in which the average radial velocity retains the same dependency on the radius found in 2D. As a final check, we compare our results to approximate descriptions of buoyant magnetic structures. For realistic boundary conditions, the envelope crossing times are sufficient to disperse in the huge convective zone any material transported, suggesting magnetic advection as a promising mechanism for deep mixing. The mixing velocities are smaller than for convection but larger than for diffusion and adequate for extra mixing in red giants.

  13. Contribution of hydraulically lifted deep moisture to the water budget in a Southern California mixed forest

    NASA Astrophysics Data System (ADS)

    Kitajima, Kuni; Allen, Michael F.; Goulden, Michael L.

    2013-12-01

    and shrubs growing in California's mountains rely on deep roots to survive the hot and dry Mediterranean climate summer. The shallow montane soil cannot hold enough water to support summer transpiration, and plants must access deeper moisture from the weathered bedrock. We used the HYDRUS-1D model to simulate the moisture flux through the soil-plant continuum in Southern California's San Jacinto Mountains. The mechanisms facilitating deep water access are poorly understood, and it is possible that either or both hydraulic lift and capillary rise contribute to the survival and activity of trees and soil microorganisms. We modified HYDRUS to incorporate hydraulic lift and drove it with meteorological and physiological data. The modeled quantity of water lifted hydraulically ranged from near zero during the wet months to ~28 mm month-1 in midsummer. Likewise, modeled capillary rise was negligible during the winter and averaged ~15 mm month-1 during June through November. Both mechanisms provided water to support evapotranspiration during the dry months. Isotopic measurements of xylem water for eight shrub and tree species confirmed the importance of a deep source of water. Conventional and automated minirhizotron observations showed that fine-root and rhizomorph biomass remained relatively constant year-round, while mycorrhizal hyphae biomass varied markedly, peaking in the wet season and declining by ~70% in the dry season. Model results predict that hydraulic lift and capillary rise play key roles in Southern California's mountains: they support evapotranspiration and photosynthesis during the summer drought; they contribute to the year-round survival of fine roots and soil microorganisms.

  14. Networks of informal caring: a mixed-methods approach.

    PubMed

    Rutherford, Alasdair; Bowes, Alison

    2014-12-01

    Care for older people is a complex phenomenon, and is an area of pressing policy concern. Bringing together literature on care from social gerontology and economics, we report the findings of a mixed-methods project exploring networks of informal caring. Using quantitative data from the British Household Panel Survey (official survey of British households), together with qualitative interviews with older people and informal carers, we describe differences in formal care networks, and the factors and decision-making processes that have contributed to the formation of the networks. A network approach to care permits both quantitative and qualitative study, and the approach can be used to explore many important questions.

  15. A mixed methods assessment of coping with pediatric cancer

    PubMed Central

    Alderfer, Melissa A.; Deatrick, Janet A.; Marsac, Meghan L.

    2014-01-01

    The purpose of this study was to describe child coping and parent coping assistance with cancer-related stressors during treatment. Fifteen children (aged 6-12) with cancer and their parents (N = 17) completed semi-structured interviews and self-report measures to assess coping and coping assistance. Results suggest families utilized a broad array of approach and avoidance strategies to manage cancer and its treatment. Quantitative and qualitative assessments provided complementary and unique contributions to understanding coping among children with cancer and their parents. Using a mixed methods approach to assess coping provides a richer understanding of families’ experiences, which can better inform clinical practice. PMID:24428250

  16. Mixed mode control method and engine using same

    DOEpatents

    Kesse, Mary L.; Duffy, Kevin P.

    2007-04-10

    A method of mixed mode operation of an internal combustion engine includes the steps of controlling a homogeneous charge combustion event timing in a given engine cycle, and controlling a conventional charge injection event to be at least a predetermined time after the homogeneous charge combustion event. An internal combustion engine is provided, including an electronic controller having a computer readable medium with a combustion timing control algorithm recorded thereon, the control algorithm including means for controlling a homogeneous charge combustion event timing and means for controlling a conventional injection event timing to be at least a predetermined time from the homogeneous charge combustion event.

  17. Mixing methods to explore appearance in dementia care.

    PubMed

    Ward, Richard; Campbell, Sarah

    2013-05-01

    This paper considers approaches to investigating appearance and the work invested in maintaining it within dementia care. Our focus is upon methodological and methods-related issues associated with the challenge of generating knowledge of the embodied worlds of people with dementia. We begin with a brief overview of the literature on appearance and dementia, and consider what it teaches us about the nature of appearance and ways of understanding it. We describe and discuss the mixing of methods for an on-going investigation into hairdressing in dementia care: The Hair and Care project. Based upon the experience of research in care-based hair salons, we argue for a creative use of methods in dementia studies as an avenue to better engaging with the embodied experiences of people with dementia and, as a result, understanding how people use their bodies and senses to create meaningful worlds. PMID:24336856

  18. Mixing methods to explore appearance in dementia care.

    PubMed

    Ward, Richard; Campbell, Sarah

    2013-05-01

    This paper considers approaches to investigating appearance and the work invested in maintaining it within dementia care. Our focus is upon methodological and methods-related issues associated with the challenge of generating knowledge of the embodied worlds of people with dementia. We begin with a brief overview of the literature on appearance and dementia, and consider what it teaches us about the nature of appearance and ways of understanding it. We describe and discuss the mixing of methods for an on-going investigation into hairdressing in dementia care: The Hair and Care project. Based upon the experience of research in care-based hair salons, we argue for a creative use of methods in dementia studies as an avenue to better engaging with the embodied experiences of people with dementia and, as a result, understanding how people use their bodies and senses to create meaningful worlds.

  19. Deep mixing of 3He: reconciling Big Bang and stellar nucleosynthesis.

    PubMed

    Eggleton, Peter P; Dearborn, David S P; Lattanzio, John C

    2006-12-01

    Low-mass stars, approximately 1 to 2 solar masses, near the Main Sequence are efficient at producing the helium isotope 3He, which they mix into the convective envelope on the giant branch and should distribute into the Galaxy by way of envelope loss. This process is so efficient that it is difficult to reconcile the low observed cosmic abundance of 3He with the predictions of both stellar and Big Bang nucleosynthesis. Here we find, by modeling a red giant with a fully three-dimensional hydrodynamic code and a full nucleosynthetic network, that mixing arises in the supposedly stable and radiative zone between the hydrogen-burning shell and the base of the convective envelope. This mixing is due to Rayleigh-Taylor instability within a zone just above the hydrogen-burning shell, where a nuclear reaction lowers the mean molecular weight slightly. Thus, we are able to remove the threat that 3He production in low-mass stars poses to the Big Bang nucleosynthesis of 3He.

  20. Deep Mixing of 3He: Reconciling Big Bang and Stellar Nucleosynthesis

    SciTech Connect

    Eggleton, P P; Dearborn, D P; Lattanzio, J

    2006-07-26

    Low-mass stars, {approx} 1-2 solar masses, near the Main Sequence are efficient at producing {sup 3}He, which they mix into the convective envelope on the giant branch and should distribute into the Galaxy by way of envelope loss. This process is so efficient that it is difficult to reconcile the low observed cosmic abundance of {sup 3}He with the predictions of both stellar and Big Bang nucleosynthesis. In this paper we find, by modeling a red giant with a fully three-dimensional hydrodynamic code and a full nucleosynthetic network, that mixing arises in the supposedly stable and radiative zone between the hydrogen-burning shell and the base of the convective envelope. This mixing is due to Rayleigh-Taylor instability within a zone just above the hydrogen-burning shell, where a nuclear reaction lowers the mean molecular weight slightly. Thus we are able to remove the threat that {sup 3}He production in low-mass stars poses to the Big Bang nucleosynthesis of {sup 3}He.

  1. Mixing length and opacity effects - Deep convective envelopes on the asymptotic giant branch

    NASA Astrophysics Data System (ADS)

    Sackmann, I.-Juliana; Boothroyd, Arnold I.

    1991-01-01

    We constructed detailed envelopes appropriate to stars on the asymptotic giant branch (AGB) for a wide range of mixing length parameter values alpha, considering different opacities, stellar masses, luminosities, and chemical compositions. Due to the molecular opacities present in the new LAOL opacity tables, a given AGB effective temperature Te requires a mixing length parameter α more than twice as large as that necessary with the older Cox and Stewart opacities. For any set of molecular opacity tables, authors should normalize their value for α by matching observations of the Sun (radius and luminosity at the solar age) or by matching the observed positions of the lower main sequence and red giant branch in the H-R diagram. (For our LAOL opacities, our normalized value turned out to be α ≍ 2.1.) Although this normalization of the mixing length results in a solar convective envelope essentially independent of molecular opacities, this is not true on the AGB: different opacities result in different conditions at the base of the convective envelope on the AGB, even after this normalization. Reliable molecular opacities are imperative for stellar models on the AGB. The temperature TCE at the base of the convective envelope is strongly dependent on the envelope mass and on the luminosity, ranging between 105 K and 107 K for our normalized value of α ≍ 2.1: hot-bottom envelope burning seems not to be totally out of reach. The effect of the chemical composition on TCE is surprisingly small: changes in helium abundance Y have a completely negligible effect, and even a large change in metallicity from Z = 0.02 to 0.001 increases TCE by only a factor of 2. On the AGB, we find that Te ∝ α1/2and R ∝ 1/α.

  2. Effects of water stratification and mixing on microbial community structure in a subtropical deep reservoir.

    PubMed

    Yu, Zheng; Yang, Jun; Amalfitano, Stefano; Yu, Xiaoqing; Liu, Lemian

    2014-07-25

    Microorganisms play pivotal roles within aquatic ecosystems, affecting their structure, functioning and services. However, little is known about the effects of water stratification and mixing on the aquatic microbial community dynamics in subtropical reservoirs. In this study, we explored vertical and seasonal patterns of microbial diversity in the Dongzhen Reservoir (southeast China). Quantitative PCR, quantitative RT-PCR, and 454 pyrosequencing were used for an in-depth characterization of the bacterial community across time (every three months for one year) and space (five different water depths). Our results indicated that thermal and oxygen stratification shaped the phylogenetic composition of microbial communities in the reservoir. There were significant differences in physical, chemical and microbiological parameters between epilimnion and hypolimnion (P < 0.05). The RNA: DNA ratios were significantly lower in epilimnion and metalimnion but rapidly increased in hypolimnion (P < 0.05), suggesting that microorganisms were more active at low temperatures, low dissolved oxygen concentrations and high TN/TP ratios. Redundancy analysis and pathway analysis revealed a complex interplay of various environmental and biological factors by explaining the spatiotemporal variations in bacterial communities. Adaptive reservoir management strategies should consider carefully the effects of water stratification and mixing, together with the distribution patterns of aquatic microorganisms.

  3. Spectral phase transfer from near IR to deep UV by broadband phase-matched four-wave mixing in an argon-filled hollow core waveguide

    NASA Astrophysics Data System (ADS)

    Siqueira, J. P.; Mendonça, C. R.; Zilio, S. C.; Misoguti, L.

    2016-10-01

    We report on the implementation of a spectral phase transfer scheme from near IR to deep UV, in which the frequency conversion step is based on the broadband phase-matched four-wave mixing in a gas-filled hollow core waveguide. Micro joule level femtosecond pulses at 260 nm were generated by nonlinear mixing of a Ti:sapphire laser and its second-harmonic. The transfer of a π-step phase in a controllable manner was proposed and confirmed by a modulation observed in the generated deep UV femtosecond pulse spectrum due to an interference process. Numerical simulations confirmed our results.

  4. High-Resolution Hepatitis C Virus Subtyping Using NS5B Deep Sequencing and Phylogeny, an Alternative to Current Methods

    PubMed Central

    Gregori, Josep; Rodríguez-Frias, Francisco; Buti, Maria; Madejon, Antonio; Perez-del-Pulgar, Sofia; Garcia-Cehic, Damir; Casillas, Rosario; Blasi, Maria; Homs, Maria; Tabernero, David; Alvarez-Tejado, Miguel; Muñoz, Jose Manuel; Cubero, Maria; Caballero, Andrea; delCampo, Jose Antonio; Domingo, Esteban; Belmonte, Irene; Nieto, Leonardo; Lens, Sabela; Muñoz-de-Rueda, Paloma; Sanz-Cameno, Paloma; Sauleda, Silvia; Bes, Marta; Gomez, Jordi; Briones, Carlos; Perales, Celia; Sheldon, Julie; Castells, Lluis; Viladomiu, Lluis; Salmeron, Javier; Ruiz-Extremera, Angela; Quiles-Pérez, Rosa; Moreno-Otero, Ricardo; López-Rodríguez, Rosario; Allende, Helena; Romero-Gómez, Manuel; Guardia, Jaume; Esteban, Rafael; Garcia-Samaniego, Javier; Forns, Xavier

    2014-01-01

    Hepatitis C virus (HCV) is classified into seven major genotypes and 67 subtypes. Recent studies have shown that in HCV genotype 1-infected patients, response rates to regimens containing direct-acting antivirals (DAAs) are subtype dependent. Currently available genotyping methods have limited subtyping accuracy. We have evaluated the performance of a deep-sequencing-based HCV subtyping assay, developed for the 454/GS-Junior platform, in comparison with those of two commercial assays (Versant HCV genotype 2.0 and Abbott Real-time HCV Genotype II) and using direct NS5B sequencing as a gold standard (direct sequencing), in 114 clinical specimens previously tested by first-generation hybridization assay (82 genotype 1 and 32 with uninterpretable results). Phylogenetic analysis of deep-sequencing reads matched subtype 1 calling by population Sanger sequencing (69% 1b, 31% 1a) in 81 specimens and identified a mixed-subtype infection (1b/3a/1a) in one sample. Similarly, among the 32 previously indeterminate specimens, identical genotype and subtype results were obtained by direct and deep sequencing in all but four samples with dual infection. In contrast, both Versant HCV Genotype 2.0 and Abbott Real-time HCV Genotype II failed subtype 1 calling in 13 (16%) samples each and were unable to identify the HCV genotype and/or subtype in more than half of the non-genotype 1 samples. We concluded that deep sequencing is more efficient for HCV subtyping than currently available methods and allows qualitative identification of mixed infections and may be more helpful with respect to informing treatment strategies with new DAA-containing regimens across all HCV subtypes. PMID:25378574

  5. More than Method?: A Discussion of Paradigm Differences within Mixed Methods Research

    ERIC Educational Resources Information Center

    Harrits, Gitte Sommer

    2011-01-01

    This article challenges the idea that mixed methods research (MMR) constitutes a coherent research paradigm and explores how different research paradigms exist within MMR. Tracing paradigmatic differences at the level of methods, ontology, and epistemology, two MMR strategies are discussed: nested analysis, recently presented by the American…

  6. Physical Parameters of Hot Horizontal-Branch Stars in NGC 6752: Deep Mixing and Radiative Levitation

    NASA Technical Reports Server (NTRS)

    Moehler, S.; Sweigart, A. V.; Landsman, W. B.; Heber, U.; Catelan, M.

    1999-01-01

    Atmospheric parameters (T(sub eff), log g and log n(sub He)/n(sub H-dot)) are derived for 42 hot horizontal branch (HB) stars in the globular cluster NGC 6752. For 19 stars Mg II and Fe II lines are detected indicating an iron enrichment by a factor 50 on average with respect to the cluster abundance whereas the magnesium abundances are consistent with the cluster metallicity. This finding adds to the growing evidence that radiative levitation plays a significant role in determining the physical parameters of blue HB stars. Indeed, we find that iron enrichment can explain part, but not all, of the problem of anomalously low gravities along the blue HB. Thus the physical parameters of horizontal branch stars hotter than about 11,500 K in NGC 6752, as derived in this paper, are best explained by a combination of helium mixing and radiative levitation effects.

  7. Bay Ridge Gardens - Mixed Humid Affordable Multifamily Housing Deep Energy Retrofit

    SciTech Connect

    Lyons, James; Moore, Mike; Thompson, Margo

    2013-08-01

    Under this project, Newport Partners (as part of the BA-PIRC research team) evaluated the installation, measured performance, and cost effectiveness of efficiency upgrade measures for a tenant-in-place deep energy retrofit (DER) at the Bay Ridge multifamily development in Annapolis, Maryland. This report summarizes system commissioning, short-term test results, utility bill data analysis, and analysis of real-time data collected over a one-year period after the retrofit was complete. The Bay Ridge project is comprised of a "base scope" retrofit which was estimated to achieve a 30%+ savings (relative to pre-retrofit) on 186 apartments, and a "DER scope" which was estimated to achieve 50% savings (relative to pre-retrofit) on a 12-unit building. A wide range of efficiency measures was applied to pursue this savings target for the DER building, including improvements/replacements of mechanical equipment and distribution systems, appliances, lighting and lighting controls, the building envelope, hot water conservation measures, and resident education. The results of this research build upon the current body of knowledge of multifamily retrofits. Towards this end, the research team has collected and generated data on the selection of measures, their estimated performance, their measured performance, and risk factors and their impact on potential measures.

  8. The puzzling MgAl anticorrelation in globular-cluster red giants: primordial plus deep mixing scenario?

    NASA Astrophysics Data System (ADS)

    Denissenkov, P. A.; Da Costa, G. S.; Norris, J. E.; Weiss, A.

    1998-05-01

    Star-to-star abundance variations of C, N, O, Na and Al in globular-cluster red giants have been recently supplemented by the finding that [Mg/Fe] is depleted in stars with extremely large [Al/Fe] (Shetrone 1996a). To find out which of the magnesium isotopes is responsible for the observed depletion of [Mg/Fe] Shetrone (1996b) also undertook an isotopic analysis of Mg and found that it is (24) Mg which is depleted in Al-rich giants. On the other hand, Norris & Da Costa (1995) demonstrated that even in the massive globular cluster omega Cen which has intrinsic spreads in both [Fe/H] and the abundances of the s-process elements, [O/Fe] anticorrelates with [Na/Fe] and [Al/Fe] as in ``normal'' monometallic clusters. These new spectroscopic results allow us to test current models of stellar evolution and nucleosynthesis, as well as those of the formation and chemical enrichment of globular clusters. In an effort to explain self-consistently these observations we have considered two possibilities: (1) a deep mixing scenario which assumes that in red giants some kind of (extra)mixing transports products of nuclear reactions from the hydrogen burning shell (HBS) to the base of the convective envelope; and (2) a combination of primordial and deep mixing scenarios. It is shown that (1) cannot account for the anticorrelation of [Mg/Fe] vs. [Al/Fe] without additional ad hoc assumptions, among which we identify a strong but still undetected low energy resonance in the reaction (24) Mg(p,gamma )(25) Al, and episodical increases of the HBS temperature up to the value T~ 7410(6) K. In (2) intermediate mass AGB stars are assumed to produce the decreased (24) Mg and increased (25) Mg initial abundances in some globular-cluster low mass stars and Al is synthesized at the expense of (25) Mg in the HBS and transported to the surface of the red giant by extramixing. We discuss advantages and deficiencies of both scenarios and propose some observational tests.

  9. Bisexuality, poverty and mental health: A mixed methods analysis.

    PubMed

    Ross, Lori E; O'Gorman, Laurel; MacLeod, Melissa A; Bauer, Greta R; MacKay, Jenna; Robinson, Margaret

    2016-05-01

    Bisexuality is consistently associated with poor mental health outcomes. In population-based data, this is partially explained by income differences between bisexual people and lesbian, gay, and/or heterosexual individuals. However, the interrelationships between bisexuality, poverty, and mental health are poorly understood. In this paper, we examine the relationships between these variables using a mixed methods study of 302 adult bisexuals from Ontario, Canada. Participants were recruited using respondent-driven sampling to complete an internet-based survey including measures of psychological distress and minority stress. A subset of participants completed a semi-structured qualitative interview to contextualize their mental health experiences. Using information regarding household income, number of individuals supported by the income and geographic location, participants were categorized as living below or above the Canadian Low Income Cut Off (LICO). Accounting for the networked nature of the sample, participants living below the LICO had significantly higher mean scores for depression and posttraumatic stress disorder symptoms and reported significantly more perceived discrimination compared to individuals living above the LICO. Grounded theory analysis of the qualitative interviews suggested four pathways through which bisexuality and poverty may intersect to impact mental health: through early life experiences linked to bisexuality or poverty that impacted future financial stability; through effects of bisexual identity on employment and earning potential; through the impact of class and sexual orientation discrimination on access to communities of support; and through lack of access to mental health services that could provide culturally competent care. These mixed methods data help us understand the income disparities associated with bisexual identity in population-based data, and suggest points of intervention to address their impact on bisexual mental

  10. Bisexuality, poverty and mental health: A mixed methods analysis.

    PubMed

    Ross, Lori E; O'Gorman, Laurel; MacLeod, Melissa A; Bauer, Greta R; MacKay, Jenna; Robinson, Margaret

    2016-05-01

    Bisexuality is consistently associated with poor mental health outcomes. In population-based data, this is partially explained by income differences between bisexual people and lesbian, gay, and/or heterosexual individuals. However, the interrelationships between bisexuality, poverty, and mental health are poorly understood. In this paper, we examine the relationships between these variables using a mixed methods study of 302 adult bisexuals from Ontario, Canada. Participants were recruited using respondent-driven sampling to complete an internet-based survey including measures of psychological distress and minority stress. A subset of participants completed a semi-structured qualitative interview to contextualize their mental health experiences. Using information regarding household income, number of individuals supported by the income and geographic location, participants were categorized as living below or above the Canadian Low Income Cut Off (LICO). Accounting for the networked nature of the sample, participants living below the LICO had significantly higher mean scores for depression and posttraumatic stress disorder symptoms and reported significantly more perceived discrimination compared to individuals living above the LICO. Grounded theory analysis of the qualitative interviews suggested four pathways through which bisexuality and poverty may intersect to impact mental health: through early life experiences linked to bisexuality or poverty that impacted future financial stability; through effects of bisexual identity on employment and earning potential; through the impact of class and sexual orientation discrimination on access to communities of support; and through lack of access to mental health services that could provide culturally competent care. These mixed methods data help us understand the income disparities associated with bisexual identity in population-based data, and suggest points of intervention to address their impact on bisexual mental

  11. Multi-platform observation of submesoscale vortices formed by deep vertical mixing: characterization and role for the general circulation of the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Bosse, Anthony; Testor, Pierre; Mortier, Laurent; Houpert, Loïc

    2015-04-01

    Since 2010, an intense effort in the collection of in-situ observations has been carried out in the Northwestern Mediterranean Sea thanks to gliders, regular cruises and a highly instrumented mooring line. This integrated observing system enabled a year-to-year monitoring of the deep water formation that occurred in the Gulf of Lions area during the 4 consecutive winters of the study period (2010-2013). Vortical structures remnant of wintertime deep vertical mixing events were regularly sampled by different platforms. They are isolated Submesoscale Coherent Vortices (SCVs) characterized by a small radius (~5km), strong depth-intensified azimutal velocities (~10-15cm/s) with a weaker surface signature, high Rossby (~0.5) and Burger (~1) numbers. Anticyclones are found to transport mode and newly formed deep waters resulting from vertical mixing characterized by intermediate (~300-500m) to deep (~2000m) mixing. Cyclones are characterized by a weakly stratified core of newly formed Western Mediterranean Deep Waters (or Dense Shelf Waters that cascaded from the shelf of the Gulf of Lions in 2012) extending from ~500-1000m depth to the bottom (~2300m). The formation of the cyclones might be favoured by bottom-reaching convection or cascading events reaching the abyssal plain. This study confirms the prominent role anticyclonic SCVs and shed light into the role of cyclonic SCVs in the spreading of newly formed deep waters out of an open-ocean deep convection area. They could also potentially impact vertical mixing during the the following winter through a local preconditioning effect.

  12. 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…

  13. 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…

  14. Integrative Mixed Methods Data Analytic Strategies in Research on School Success in Challenging Circumstances

    ERIC Educational Resources Information Center

    Jang, Eunice E.; McDougall, Douglas E.; Pollon, Dawn; Herbert, Monique; Russell, Pia

    2008-01-01

    There are both conceptual and practical challenges in dealing with data from mixed methods research studies. There is a need for discussion about various integrative strategies for mixed methods data analyses. This article illustrates integrative analytic strategies for a mixed methods study focusing on improving urban schools facing challenging…

  15. A Case Study of a Mixed Methods Study Engaged in Integrated Data Analysis

    ERIC Educational Resources Information Center

    Schiazza, Daniela Marie

    2013-01-01

    The nascent field of mixed methods research has yet to develop a cohesive framework of guidelines and procedures for mixed methods data analysis (Greene, 2008). To support the field's development of analytical frameworks, this case study reflects on the development and implementation of a mixed methods study engaged in integrated data analysis.…

  16. METHODS FOR DETERMINING AGITATOR MIXING REQUIREMENTS FOR A MIXING & SAMPLING FACILITY TO FEED WTP (WASTE TREATMENT PLANT)

    SciTech Connect

    GRIFFIN PW

    2009-08-27

    The following report is a summary of work conducted to evaluate the ability of existing correlative techniques and alternative methods to accurately estimate impeller speed and power requirements for mechanical mixers proposed for use in a mixing and sampling facility (MSF). The proposed facility would accept high level waste sludges from Hanford double-shell tanks and feed uniformly mixed high level waste to the Waste Treatment Plant. Numerous methods are evaluated and discussed, and resulting recommendations provided.

  17. Deep deuterium retention and Be/W mixing at tungsten coated surfaces in the JET divertor

    NASA Astrophysics Data System (ADS)

    Bergsåker, H.; Bykov, I.; Zhou, Y.; Petersson, P.; Possnert, G.; Likonen, J.; Pettersson, J.; Koivuranta, S.; Widdowson, A. M.; contributors, JET

    2016-02-01

    Surface samples from a full poloidal set of divertor tiles exposed in JET through operations 2010-2012 with ITER-like wall have been investigated using SEM, SIMS, ICP-AES analysis and micro beam nuclear reaction analysis (μ-NRA). Deposition of Be and retention of D is microscopically inhomogeneous. With careful overlaying of μ-NRA elemental maps with SEM images, it is possible to separate surface roughness effects from depth profiles at microscopically flat surface regions, without pits. With (3He, p) μ-NRA at 3-5 MeV beam energy the accessible depth for D analysis in W is about 9 μm, sufficient to access the W/Mo and Mo/W interfaces in the coatings and beyond, while for Be in W it is about 6 μm. In these conditions, at all plasma wetted surfaces, D was found throughout the whole accessible depth at concentrations in the range 0.2-0.7 at% in W. Deuterium was found to be preferentially trapped at the W/Mo and Mo/W interfaces. Comparison is made with SIMS profiling, which also shows significant D trapping at the W/Mo interface. Mixing of Be and W occurs mainly in deposited layers.

  18. A mixed RKPM/RBF immersed method for FSI simulations

    NASA Astrophysics Data System (ADS)

    Giometto, M.; Fang, J.; Putti, M.; Saetta, A.; Lanzoni, S.; Parlange, M. B.

    2012-04-01

    Simulating fluid-structure interaction still represents a challenging multiphysics application in the framework of Civil and Environmental Engineering. Techniques to couple in an efficient way the two continua have become more and more sophisticated and they all aim to find an efficient way to deal with the two different frames of reference and to avoid the need to re-mesh when the element aspect ratio has become unacceptable (e.g. large deformations). To overcome such problems we propose a mixed RKPM / RBF immersed method in which a Lagrangian meshless solid domain moves on top of a background Eulerian fluid mesh that spans over the entire computational domain. This method is similar to the original Immersed Boundary Method introduced by C.Peskin, except that the structure has the same spatial dimension of the fluid domain and therefore the effects of the fluid-embedded bodies are summarized into a volumetric source term. The governing equations for the viscous fluid are discretized and solved on a regular, Cartesian mesh using a pseudo-spectral approach, while the solid equations are solved by means of RKPM basis functions. The use of a Reproducing Kernel Particle Method for the solid domain enables us to easily handle large deformations without the typical mesh distortion of Finite-Element-Methods while still providing sufficient accuracy in the solution. At the moment we're validating the code by running simple-geometry, low-Reynolds DNS simulations; a further step will be including a subgrid-scale model in the fluid formulation and run simulations with turbulent flows at high-Reynolds numbers, to study the effects of flexible structures (e.g. trees, bridges, towers) on the Atmospheric Boundary Layer.

  19. Some aspects of integral transport method for deep penetration problem

    SciTech Connect

    Takahashi, H.

    1982-01-01

    An analytical expression of the integral transport method for an experimental hole in fission reactors has been developed. This analytical method might still be useful for designing a fusion reactor without using large computer machine time.

  20. A method of face detection with deep models for patrol videos

    NASA Astrophysics Data System (ADS)

    Jia, Baozhi; Zhu, Ming

    2015-07-01

    Common face detection methods may fail in videos captured by patrol cars for the low resolution and uncooperative situation. We proposed a method to handle this problem with a parts-based deep model. Different parts of human bodies are detected for improving the accuracy of face detection in this method. A deep neural network is used for combining the detections of different parts. Experiments were conducted on two different datasets. The results demonstrate that the proposed method outperforms existing common face detection methods.

  1. Obesity in social media: a mixed methods analysis.

    PubMed

    Chou, Wen-Ying Sylvia; Prestin, Abby; Kunath, Stephen

    2014-09-01

    The escalating obesity rate in the USA has made obesity prevention a top public health priority. Recent interventions have tapped into the social media (SM) landscape. To leverage SM in obesity prevention, we must understand user-generated discourse surrounding the topic. This study was conducted to describe SM interactions about weight through a mixed methods analysis. Data were collected across 60 days through SM monitoring services, yielding 2.2 million posts. Data were cleaned and coded through Natural Language Processing (NLP) techniques, yielding popular themes and the most retweeted content. Qualitative analyses of selected posts add insight into the nature of the public dialogue and motivations for participation. Twitter represented the most common channel. Twitter and Facebook were dominated by derogatory and misogynist sentiment, pointing to weight stigmatization, whereas blogs and forums contained more nuanced comments. Other themes included humor, education, and positive sentiment countering weight-based stereotypes. This study documented weight-related attitudes and perceptions. This knowledge will inform public health/obesity prevention practice.

  2. Active Semi-Supervised Learning Method with Hybrid Deep Belief Networks

    PubMed Central

    Zhou, Shusen; Chen, Qingcai; Wang, Xiaolong

    2014-01-01

    In this paper, we develop a novel semi-supervised learning algorithm called active hybrid deep belief networks (AHD), to address the semi-supervised sentiment classification problem with deep learning. First, we construct the previous several hidden layers using restricted Boltzmann machines (RBM), which can reduce the dimension and abstract the information of the reviews quickly. Second, we construct the following hidden layers using convolutional restricted Boltzmann machines (CRBM), which can abstract the information of reviews effectively. Third, the constructed deep architecture is fine-tuned by gradient-descent based supervised learning with an exponential loss function. Finally, active learning method is combined based on the proposed deep architecture. We did several experiments on five sentiment classification datasets, and show that AHD is competitive with previous semi-supervised learning algorithm. Experiments are also conducted to verify the effectiveness of our proposed method with different number of labeled reviews and unlabeled reviews respectively. PMID:25208128

  3. Active semi-supervised learning method with hybrid deep belief networks.

    PubMed

    Zhou, Shusen; Chen, Qingcai; Wang, Xiaolong

    2014-01-01

    In this paper, we develop a novel semi-supervised learning algorithm called active hybrid deep belief networks (AHD), to address the semi-supervised sentiment classification problem with deep learning. First, we construct the previous several hidden layers using restricted Boltzmann machines (RBM), which can reduce the dimension and abstract the information of the reviews quickly. Second, we construct the following hidden layers using convolutional restricted Boltzmann machines (CRBM), which can abstract the information of reviews effectively. Third, the constructed deep architecture is fine-tuned by gradient-descent based supervised learning with an exponential loss function. Finally, active learning method is combined based on the proposed deep architecture. We did several experiments on five sentiment classification datasets, and show that AHD is competitive with previous semi-supervised learning algorithm. Experiments are also conducted to verify the effectiveness of our proposed method with different number of labeled reviews and unlabeled reviews respectively. PMID:25208128

  4. Evaluating outpatient transition clinics: a mixed-methods study protocol

    PubMed Central

    Sattoe, Jane N T; Peeters, Mariëlle A C; Hilberink, Sander R; Ista, Erwin; van Staa, AnneLoes

    2016-01-01

    Introduction To support young people in their transition to adulthood and transfer to adult care, a number of interventions have been developed. One particularly important intervention is the transition clinic (TC), where paediatric and adult providers collaborate. TCs are often advocated as best practices in transition care for young people with chronic conditions, but little is known about TC models and effects. The proposed study aims to gain insight into the added value of a TC compared with usual care (without a TC). Methods and analysis We propose a mixed-methods study with a retrospective controlled design consisting of semistructured interviews among healthcare professionals, observations of consultations with young people, chart reviews of young people transferred 2–4 years prior to data collection and questionnaires among the young people included in the chart reviews. Qualitative data will be analysed through thematic analysis and results will provide insights into structures and daily routines of TCs, and experienced barriers and facilitators in transitional care. Quantitatively, within-group differences on clinical outcomes and healthcare use will be studied over the four measurement moments. Subsequently, comparisons will be made between intervention and control groups on all outcomes at all measurement moments. Primary outcomes are ‘no-show after transfer’ (process outcome) and ‘experiences and satisfaction with the transfer’ (patient-reported outcome). Secondary outcomes consider clinical outcomes, healthcare usage, self-management outcomes and perceived quality of care. Ethics The Medical Ethical Committee of the Erasmus Medical Centre approved the study protocol (MEC-2014-246). Dissemination Study results will be disseminated through peer-reviewed journals and conferences. The study started in September 2014 and will continue until December 2016. The same study design will be used in a national study in 20 diabetes settings (2016

  5. Mixed-bed affinity chromatography: principles and methods.

    PubMed

    Boschetti, Egisto; Righetti, Pier Giorgio

    2015-01-01

    Mixed-bed chromatography is far from being a well-established technology within the panoply of bioseparation tools. Composed of an assembly of distinct sorbents that are mixed in a single bed, they have been mostly developed in the last decade for the reduction of dynamic concentration range where they allowed discovering many low-copy proteins within very complex proteomes. Other interesting preparative applications of mixed-bed chromatography have since been developed. In this chapter the basic concepts first and then detailed application recipes are described for (1) the reduction of protein dynamic concentration range, (2) the removal of impurity traces at the last stage of a biopurification process, and (3) the selection and use of sorbents as mixed bed in protein purification. PMID:25749952

  6. 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.

  7. Mixed Methods in CAM Research: A Systematic Review of Studies Published in 2012

    PubMed Central

    Bishop, Felicity L.; Holmes, Michelle M.

    2013-01-01

    Background. Mixed methods research uses qualitative and quantitative methods together in a single study or a series of related studies. Objectives. To review the prevalence and quality of mixed methods studies in complementary medicine. Methods. All studies published in the top 10 integrative and complementary medicine journals in 2012 were screened. The quality of mixed methods studies was appraised using a published tool designed for mixed methods studies. Results. 4% of papers (95 out of 2349) reported mixed methods studies, 80 of which met criteria for applying the quality appraisal tool. The most popular formal mixed methods design was triangulation (used by 74% of studies), followed by embedded (14%), sequential explanatory (8%), and finally sequential exploratory (5%). Quantitative components were generally of higher quality than qualitative components; when quantitative components involved RCTs they were of particularly high quality. Common methodological limitations were identified. Most strikingly, none of the 80 mixed methods studies addressed the philosophical tensions inherent in mixing qualitative and quantitative methods. Conclusions and Implications. The quality of mixed methods research in CAM can be enhanced by addressing philosophical tensions and improving reporting of (a) analytic methods and reflexivity (in qualitative components) and (b) sampling and recruitment-related procedures (in all components). PMID:24454489

  8. Engaging patients through open notes: an evaluation using mixed methods

    PubMed Central

    Esch, Tobias; Mejilla, Roanne; Anselmo, Melissa; Podtschaske, Beatrice; Delbanco, Tom; Walker, Jan

    2016-01-01

    Objectives (A) To gain insights into the experiences of patients invited to view their doctors’ visit notes, with a focus on those who review multiple notes; (B) to examine the relationships among fully transparent electronic medical records and quality of care, the patient-doctor relationship, patient engagement, self-care, self-management skills and clinical outcomes. Design Mixed methods qualitative study: analyses of survey data, including content analysis of free-text answers, and quantitative-descriptive measures combined with semistructured individual interviews, patient activation measures, and member checks. Setting Greater Boston, USA. Participants Patients cared for by primary care physicians (PCPs) at the Beth Israel Deaconess Medical Center who had electronic access to their PCP visit notes. Among those submitting surveys, 576 free-text answers were identified and analysed (414 from female patients, 162 from male patients; 23–88 years). In addition, 13 patients (9 female, 4 male; 58–87 years) were interviewed. Results Patient experiences indicate improved understanding (of health information), better relationships (with doctors), better quality (adherence and compliance; keeping track) and improved self-care (patient-centredness, empowerment). Patients want more doctors to offer access to their notes, and some wish to contribute to their generation. Those patients with repeated experience reviewing notes express fewer concerns and more perceived benefits. Conclusions As the use of fully transparent medical records spreads, it is important to gain a deeper understanding of possible benefits or harms, and to characterise target populations that may require varying modes of delivery. Patient desires for expansion of this practice extend to specialty care and settings beyond the physician's office. Patients are also interested in becoming involved actively in the generation of their medical records. The OpenNotes movement may increase patient

  9. A Method for Studying the Electric Field Enhanced Emission of Carriers from Deep Levels

    NASA Astrophysics Data System (ADS)

    Hwang, In Duk; Choe, Byungdoo

    1986-11-01

    A spectroscopic method is proposed for studying the electric field enhanced emission of trapped carriers from deep levels. The resulting spectrum directly represents the effect of the electric field enhanced emission only, thus removing the intrinsic difficulty in treating the electric field enhanced emission from deep levels of large concentration. This method involves two steps of measurements of the ionized trap densities; in the first step the electric field pulse is applied to induce an enhanced emission, and in the second without the electric field pulse. Experimental results by this method have been given for the DX center in LPE Al068Ga0.32As:Sn.

  10. EFFECTS OF A DEEP MIXED SHELL ON SOLAR g-MODES, p-MODES, AND NEUTRINO FLUX

    SciTech Connect

    Wolff, Charles L.

    2009-08-10

    A mixed-shell model that reflects g-modes away from the Sun's center is developed further by calibrating its parameters and evaluating a mixing mechanism: buoyancy. The shell roughly doubles g-mode oscillation periods and would explain why there is no definitive detection of their periods. But the shell has only minor effects on most p-modes. The model provides a mechanism for causing short-term fluctuations in neutrino flux and makes plausible the correlations between this flux and solar activity levels. Relations are derived for a shell heated asymmetrically by transient increases in nuclear burning in small 'hot spots'. The size of these spots and the timing of a heating event are governed by sets(l) of standing asymptotic g-modes, coupled by a maximal principle that greatly enhances their excitation and concentrates power toward the equator, assisting the detection of higher-l sets. Signals from all sets, except one, in the range 2 {<=} l {<=} 8 are identified by difference periods between consecutive radial states using the method of Garcia et al. and reinterpreting their latest spectrum. This confirms two detections of sets in a similar range of l by their rotation rates. The mean radius of shell mixing is r{sub m} = 0.16 R{sub sun}, which improves an earlier independent estimate of 0.18 by the author. The shell may cause the unexplained dip in measured sound speed at its location. Another sound speed error, centered near 0.67 R{sub sun}, and reversing flows in the same place with a period originally near 1.3 yr suggest that the g-modes are depositing there about 3% of the solar luminosity. That implies the shell at r{sub m} is receiving a similar magnitude of power, which would be enough energy to mix the corresponding shell in a standard solar model in <<10{sup 7} yr.

  11. Clustering Methods with Qualitative Data: a Mixed-Methods Approach for Prevention Research with Small Samples.

    PubMed

    Henry, David; Dymnicki, Allison B; Mohatt, Nathaniel; Allen, James; Kelly, James G

    2015-10-01

    Qualitative methods potentially add depth to prevention research but can produce large amounts of complex data even with small samples. Studies conducted with culturally distinct samples often produce voluminous qualitative data but may lack sufficient sample sizes for sophisticated quantitative analysis. Currently lacking in mixed-methods research are methods allowing for more fully integrating qualitative and quantitative analysis techniques. Cluster analysis can be applied to coded qualitative data to clarify the findings of prevention studies by aiding efforts to reveal such things as the motives of participants for their actions and the reasons behind counterintuitive findings. By clustering groups of participants with similar profiles of codes in a quantitative analysis, cluster analysis can serve as a key component in mixed-methods research. This article reports two studies. In the first study, we conduct simulations to test the accuracy of cluster assignment using three different clustering methods with binary data as produced when coding qualitative interviews. Results indicated that hierarchical clustering, K-means clustering, and latent class analysis produced similar levels of accuracy with binary data and that the accuracy of these methods did not decrease with samples as small as 50. Whereas the first study explores the feasibility of using common clustering methods with binary data, the second study provides a "real-world" example using data from a qualitative study of community leadership connected with a drug abuse prevention project. We discuss the implications of this approach for conducting prevention research, especially with small samples and culturally distinct communities.

  12. Clustering Methods with Qualitative Data: A Mixed Methods Approach for Prevention Research with Small Samples

    PubMed Central

    Henry, David; Dymnicki, Allison B.; Mohatt, Nathaniel; Allen, James; Kelly, James G.

    2016-01-01

    Qualitative methods potentially add depth to prevention research, but can produce large amounts of complex data even with small samples. Studies conducted with culturally distinct samples often produce voluminous qualitative data, but may lack sufficient sample sizes for sophisticated quantitative analysis. Currently lacking in mixed methods research are methods allowing for more fully integrating qualitative and quantitative analysis techniques. Cluster analysis can be applied to coded qualitative data to clarify the findings of prevention studies by aiding efforts to reveal such things as the motives of participants for their actions and the reasons behind counterintuitive findings. By clustering groups of participants with similar profiles of codes in a quantitative analysis, cluster analysis can serve as a key component in mixed methods research. This article reports two studies. In the first study, we conduct simulations to test the accuracy of cluster assignment using three different clustering methods with binary data as produced when coding qualitative interviews. Results indicated that hierarchical clustering, K-Means clustering, and latent class analysis produced similar levels of accuracy with binary data, and that the accuracy of these methods did not decrease with samples as small as 50. Whereas the first study explores the feasibility of using common clustering methods with binary data, the second study provides a “real-world” example using data from a qualitative study of community leadership connected with a drug abuse prevention project. We discuss the implications of this approach for conducting prevention research, especially with small samples and culturally distinct communities. PMID:25946969

  13. Methods of deep dives in whole ice cover conditions

    NASA Astrophysics Data System (ADS)

    Sagalevich, A. M.

    2016-05-01

    The essence of methodological and engineering questions solved during the preparation and implementation of historic dives of the manned submersibles Mir-1 and Mir-2, allowing humans to see the bottom of the North Pole at a depth of 4300 m, are described together with innovative developments in underwater navigation, as well as the Mir's propulsion, ballast, and other systems that ensured the safety of the dives. These innovative methods have opened up the Arctic's underice space for scientific research and practical exploration for minerals with the direct participation of scientists and specialists.

  14. Methods, systems, and devices for deep desulfurization of fuel gases

    DOEpatents

    Li, Liyu; King, David L.; Liu, Jun; Huo, Qisheng

    2012-04-17

    A highly effective and regenerable method, system and device that enables the desulfurization of warm fuel gases by passing these warm gasses over metal-based sorbents arranged in a mesoporous substrate. This technology will protect Fischer-Tropsch synthesis catalysts and other sulfur sensitive catalysts, without drastic cooling of the fuel gases. This invention can be utilized in a process either alone or alongside other separation processes, and allows the total sulfur in such a gas to be reduced to less than 500 ppb and in some instances as low as 50 ppb.

  15. Invisible nursing research: thoughts about mixed methods research and nursing practice.

    PubMed

    Fawcett, Jacqueline

    2015-04-01

    In this this essay, the author addresses the close connection between mixed methods research and nursing practice. If the assertion that research and practice are parallel processes is accepted, then nursing practice may be considered "invisible mixed methods research," in that almost every encounter between a nurse and a patient involves collection and integration of qualitative (word) and quantitative (number) information that actually is single-case mixed methods research.

  16. Purists need not apply: the case for pragmatism in mixed methods research.

    PubMed

    Florczak, Kristine L

    2014-10-01

    The purpose of this column is to describe several different ways of conducting mixed method research. The paradigms that underpin both qualitative and quantitative research are also considered along with a cursory review of classical pragmatism as it relates conducting mixed methods studies. Finally, the idea of loosely coupled systems as a means to support mixed methods studies is proposed along with several caveats to researchers who desire to use this new way of obtaining knowledge.

  17. The roles of deep convection and extratropical mixing in the tropical tropopause layer: An in situ measurement perspective

    NASA Astrophysics Data System (ADS)

    Sargent, Maryann R.; Smith, Jessica B.; Sayres, David S.; Anderson, James G.

    2014-11-01

    The majority of air which enters the stratosphere passes through the tropical tropopause layer (TTL), where the temperature profile and amount of deep convection set the entry level for stratospheric water vapor. We use simultaneous in situ measurements of ozone, carbon monoxide, carbon dioxide, water vapor, and heavy water vapor (HDO) from the 2006 Costa Rica Aura Validation Experiment and 2007 Tropical Composition, Cloud, and Climate Coupling campaigns in a one-dimensional mixing model to investigate how different transport pathways in the TTL impact the amount of water vapor which enters the stratosphere. We focused on four main pathways: (1) slow upward ascent, (2) isentropic transport from the midlatitude lowermost stratosphere, (3) convective injection, and (4) descent within the TTL coupled to convection. Each pathway brings air into the TTL with a specific chemical signature, such that anomalies in simultaneously measured tracer concentrations can be used to identify the source of the air mass. We found that isentropic transport from the midlatitude lowermost stratosphere accounted for 20-60% of the air in the lower TTL and 20-40% of air above the tropopause, bringing elevated ozone concentrations which radiatively warm the TTL, impacting the amount of dehydration which takes place. Convective input accounted for on average ~30% of the air measured below 370 K potential temperature, and ~10% of air above the tropopause in both summer and winter, increasing water vapor concentrations above the tropopause by 0.3 ppmv on average and by up to 1.6 ppmv in some air masses.

  18. 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…

  19. 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…

  20. Validating for Use and Interpretation: A Mixed Methods Contribution Illustrated

    ERIC Educational Resources Information Center

    Morell, Linda; Tan, Rachael Jin Bee

    2009-01-01

    Researchers in the areas of psychology and education strive to understand the intersections among validity, educational measurement, and cognitive theory. Guided by a mixed model conceptual framework, this study investigates how respondents' opinions inform the validation argument. Validity evidence for a science assessment was collected through…

  1. COMBINING SOURCES IN STABLE ISOTOPE MIXING MODELS: ALTERNATIVE METHODS

    EPA Science Inventory

    Stable isotope mixing models are often used to quantify source contributions to a mixture. Examples include pollution source identification; trophic web studies; analysis of water sources for soils, plants, or water bodies; and many others. A common problem is having too many s...

  2. Team Performance Pay and Motivation Theory: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Wells, Pamela; Combs, Julie P.; Bustamante, Rebecca M.

    2013-01-01

    This study was conducted to explore teachers' perceptions of a team performance pay program in a large suburban school district through the lens of motivation theories. Mixed data analysis was used to analyze teacher responses from two archival questionnaires (Year 1, n = 368; Year 2, n = 649). Responses from teachers who participated in the team…

  3. Transient 3d contact problems—NTS method: mixed methods and conserving integration

    NASA Astrophysics Data System (ADS)

    Hesch, Christian; Betsch, Peter

    2011-10-01

    The present work deals with a new formulation for transient large deformation contact problems. It is well known, that one-step implicit time integration schemes for highly non-linear systems fail to conserve the total energy of the system. To deal with this drawback, a mixed method is newly proposed in conjunction with the concept of a discrete gradient. In particular, we reformulate the well known and widely-used node-to-segment methods and establish an energy-momentum scheme. The advocated approach ensures robustness and enhanced numerical stability, demonstrated in several three-dimensional applications of the proposed algorithm.

  4. The Multilevel Mixed Intact Group Analysis: A Mixed Method to Seek, Detect, Describe, and Explain Differences Among Intact Groups

    ERIC Educational Resources Information Center

    Schoonenboom, Judith

    2016-01-01

    Educational innovations often involve intact subgroups, such as school classes or university departments. In small-scale educational evaluation research, typically involving 1 to 20 subgroups, differences among these subgroups are often neglected. This article presents a mixed method from a qualitative perspective, in which differences among…

  5. Biofilm development in a hotspot of mixing between shallow and deep groundwater in a fractured aquifer: field evidence from joint flow, chemical and microbiological measurements

    NASA Astrophysics Data System (ADS)

    Bochet, O.; Dufresne, A.; Pédrot, M.; Chatton, E.; Labasque, T.; Ben Maamar, S.; Burté, L.; de la Bernardie, J.; Guihéneuf, N.; Lavenant, N.; Petton, C.; Bour, O.; Aquilina, L.; Le Borgne, T.

    2015-12-01

    Biofilms play a major role in controlling the fluxes and reactivity of chemical species transported in hydro-logical systems. Micro-organisms require both electron donors and electron acceptors for cellular growth, proliferation and maintenance of their metabolic functions. The mechanisms controlling these reactions derive from the interactions occurring at the micro-scale that depend on mineral compositions, the biota of subsurface environment, but also fluid mixing, which determines the local concentrations of nutriments, electron donors and electron acceptors. Hence, mixing zones between oxygen and nutriment rich shallow groundwater and mineralized deep groundwater are often considered as potential hotspots of microbial activity, although relatively few field data document flow distributions, transport properties, chemical gradients and micro-organisms distributions across these mixing interfaces. Here we investigate the origin of a localized biofilm development observed in the fractured granite aquifer at the Ploemeur observatory (H+ network hplus.ore.fr).This biofilm composed of ferro-oxidizing bacteria is observed in an 130m deep artesian well. Borehole video logs show an important colonization of the well by the biofilm in the shallower part (0 to 60m), while it is inexistent in the deeper part (60 to 130m). As flow is localized in a few deep and shallow fractures, we presume that the spatial distribution of biofilm is controlled by mixing between shallow and deep groundwater. To verify this hypothesis we conducted a field campaign with joint characterization of the flow and chemical composition of water flowing from the different fractures, as well as the microbiological composition of the biofilm at different depth, using pyrosequencing techniques. We will discuss in this presentation the results of this interdisciplinary dataset and their implications for the occurrence of hotspots of microbiological activity in the subsurface.

  6. Eutectic self-mixing method for the preparation of LiMn 2O 4 without any artificial mixing procedures

    NASA Astrophysics Data System (ADS)

    Kang, Hyun-Koo; Ahn, Wook; Lee, Seung-Goo; Han, Kyoo-Seung; Song, Jun-Ho; Kwon, Oh-Heon; Kang, Eun-Young

    Spinel LiMn 2O 4 as a cathode material for lithium rechargeable batteries is economically prepared by a novel eutectic self-mixing method without any artificial mixing procedures of reactants. The phase transitions of lithium manganese oxide are found three times on the preparation. Thus, those process controls are discussed and emphasized. The prepared LiMn 2O 4 exhibits the initial discharge capacity of 124.8 mAh g -1 and the discharge capacity retention of 98.2% after 20 cycles.

  7. Transient three-dimensional contact problems: mortar method. Mixed methods and conserving integration

    NASA Astrophysics Data System (ADS)

    Hesch, Christian; Betsch, Peter

    2011-10-01

    The present work deals with the development of an energy-momentum conserving method to unilateral contact constraints and is a direct continuation of a previous work (Hesch and Betsch in Comput Mech 2011, doi: 10.1007/s00466-011-0597-2) dealing with the NTS method. In this work, we introduce the mortar method and a newly developed segmentation process for the consistent integration of the contact interface. For the application of the energy-momentum approach to mortar constraints, we extend an approach based on a mixed formulation to the segment definition of the mortar constraints. The enhanced numerical stability of the newly proposed discretization method will be shown in several examples.

  8. Development of a new method for the noninvasive measurement of deep body temperature without a heater.

    PubMed

    Kitamura, Kei-Ichiro; Zhu, Xin; Chen, Wenxi; Nemoto, Tetsu

    2010-01-01

    The conventional zero-heat-flow thermometer, which measures the deep body temperature from the skin surface, is widely used at present. However, this thermometer requires considerable electricity to power the electric heater that compensates for heat loss from the probe; thus, AC power is indispensable for its use. Therefore, this conventional thermometer is inconvenient for unconstrained monitoring. We have developed a new dual-heat-flux method that can measure the deep body temperature from the skin surface without a heater. Our method is convenient for unconstrained and long-term measurement because the instrument is driven by a battery and its design promotes energy conservation. Its probe consists of dual-heat-flow channels with different thermal resistances, and each heat-flow-channel has a pair of IC sensors attached on its top and bottom. The average deep body temperature measurements taken using both the dual-heat-flux and then the zero-heat-flow thermometers from the foreheads of 17 healthy subjects were 37.08 degrees C and 37.02 degrees C, respectively. In addition, the correlation coefficient between the values obtained by the 2 methods was 0.970 (p<0.001). These results show that our method can be used for monitoring the deep body temperature as accurately as the conventional method, and it overcomes the disadvantage of the necessity of AC power supply.

  9. Direct numerical simulations of a reacting turbulent mixing layer by a pseudospectral-spectral element method

    NASA Technical Reports Server (NTRS)

    Mcmurtry, Patrick A.; Givi, Peyman

    1992-01-01

    An account is given of the implementation of the spectral-element technique for simulating a chemically reacting, spatially developing turbulent mixing layer. Attention is given to experimental and numerical studies that have investigated the development, evolution, and mixing characteristics of shear flows. A mathematical formulation is presented of the physical configuration of the spatially developing reacting mixing layer, in conjunction with a detailed representation of the spectral-element method's application to the numerical simulation of mixing layers. Results from 2D and 3D calculations of chemically reacting mixing layers are given.

  10. Deep learning for image classification

    NASA Astrophysics Data System (ADS)

    McCoppin, Ryan; Rizki, Mateen

    2014-06-01

    This paper provides an overview of deep learning and introduces the several subfields of deep learning including a specific tutorial of convolutional neural networks. Traditional methods for learning image features are compared to deep learning techniques. In addition, we present our preliminary classification results, our basic implementation of a convolutional restricted Boltzmann machine on the Mixed National Institute of Standards and Technology database (MNIST), and we explain how to use deep learning networks to assist in our development of a robust gender classification system.

  11. Mixed-methods research in pharmacy practice: recommendations for quality reporting. Part 2.

    PubMed

    Hadi, Muhammad Abdul; Alldred, David Phillip; Closs, S José; Briggs, Michelle

    2014-02-01

    This is the second of two papers that explore the use of mixed-methods research in pharmacy practice. This paper discusses the rationale, applications, limitations and challenges of conducting mixed-methods research. As with other research methods, the choice of mixed-methods should always be justified because not all research questions require a mixed-methods approach. Mixed-methods research is particularly suitable when one dataset may be inadequate in answering the research question, an explanation of initial results is required, generalizability of qualitative findings is desired or broader and deeper understanding of a research problem is necessary. Mixed-methods research has its own challenges and limitations, which should be considered carefully while designing the study. There is a need to improve the quality of reporting of mixed-methods research. A framework for reporting mixed-methods research is proposed, for researchers and reviewers, with the intention of improving its quality. Pharmacy practice research can benefit from research that uses both 'numbers' (quantitative) and 'words' (qualitative) to develop a strong evidence base to support pharmacy-led services.

  12. A Mixed Methods Approach to Understanding School Counseling Program Evaluation: High School Counselors' Methods and Perceptions

    ERIC Educational Resources Information Center

    Aucoin, Jennifer Mangrum

    2013-01-01

    The purpose of this mixed methods concurrent triangulation study was to examine the program evaluation practices of high school counselors. A total of 294 high school counselors in Texas were assessed using a mixed methods concurrent triangulation design. A researcher-developed survey, the School Counseling Program Evaluation Questionnaire…

  13. Biofilm development in a hotspot of mixing between shallow and deep groundwater in a fractured aquifer: field evidence from joint flow, chemical and microbiological characterization

    NASA Astrophysics Data System (ADS)

    Bochet, Olivier; Le Borgne, Tanguy; Pédrot, Mathieu; Labasque, Thierry; Lavenant, Nicolas; Petton, Christophe; Dufresne, Alexis; Ben Maamar, Sarah; Chatton, Eliot; De la Bernardie, Jérôme; Aquilina, Luc

    2015-04-01

    Biofilm development in a hotspot of mixing between shallow and deep groundwater in a fractured aquifer: field evidence from joint flow, chemical and microbiological characterization Olivier Bochet1, Tanguy Le Borgne1, Mathieu Pédrot1, Thierry Labasque1, Nicolas Lavenant1, Christophe Petton1, Alexis Dufresne2,Sarah Ben Maamar1-2, Eliot Chatton1, Jérôme de la Bernardie1, Luc Aquilina1 1: Géosciences Rennes, CNRS UMR 6118, Université de Rennes 1, Campus de Beaulieu bât 14B, Rennes, France 2: Ecobio, CNRS UMR 6553, Université de Rennes 1, Campus de Beaulieu, bât 14, Rennes, France Biofilms play a major role in controlling the fluxes and reactivity of chemical species transported in hydrological systems. Their development can have either positive impacts on groundwater quality (e.g. attenuation of contaminants under natural or stimulated conditions), or possible negative effects on subsurface operations (e.g. bio-clogging of geothermal dipoles or artificial recharge systems). Micro-organisms require both electron donors and electron acceptors for cellular growth, proliferation and maintenance of their metabolic functions. The mechanisms controlling these reactions derive from the interactions occurring at the micro-scale that depend on mineral compositions, the biota of subsurface environment, but also fluid mixing, which determines the local concentrations of nutriments, electron donors and electron acceptors. Hence, mixing zones between oxygen and nutriment rich shallow groundwater and mineralized deep groundwater are often considered as potential hotspots of microbial activity, although relatively few field data document flow distributions, transport properties, chemical gradients and micro-organisms distributions across these mixing interfaces. Here we investigate the origin of a localized biofilm development observed in the fractured granite aquifer at the Ploemeur observatory (H+ network hplus.ore.fr).This biofilm composed of ferro-oxidizing bacteria is

  14. Mixing Research Methods in Health Professional Degrees: Thoughts for Undergraduate Students and Supervisors

    ERIC Educational Resources Information Center

    Anaf, Sophie; Sheppard, Lorraine A.

    2007-01-01

    This commentary considers some of the challenges of applying mixed methods research in undergraduate research degrees, especially in professions with a clinical health focus. Our experience in physiotherapy academia is used as an example. Mixed methods research is increasingly appreciated in its own right as a "third paradigm," however the success…

  15. Mixed ionic-electronic conductor-based radiation detectors and methods of fabrication

    DOEpatents

    Conway, Adam; Beck, Patrick R; Graff, Robert T; Nelson, Art; Nikolic, Rebecca J; Payne, Stephen A; Voss, Lars; Kim, Hadong

    2015-04-07

    A method of fabricating a mixed ionic-electronic conductor (e.g. TlBr)-based radiation detector having halide-treated surfaces and associated methods of fabrication, which controls polarization of the mixed ionic-electronic MIEC material to improve stability and operational lifetime.

  16. 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…

  17. A Mixed-Methods Exploration of an Environment for Learning Computer Programming

    ERIC Educational Resources Information Center

    Mather, Richard

    2015-01-01

    A mixed-methods approach is evaluated for exploring collaborative behaviour, acceptance and progress surrounding an interactive technology for learning computer programming. A review of literature reveals a compelling case for using mixed-methods approaches when evaluating technology-enhanced-learning environments. Here, ethnographic approaches…

  18. Internet-Mediated Technologies and Mixed Methods Research: Problems and Prospects

    ERIC Educational Resources Information Center

    Hesse-Biber, Sharlene; Griffin, Amy J.

    2013-01-01

    This article provides an examination of a range of mixed methods research projects that employ Internet-mediated technologies (IMT) for data collection. Using a case study approach, this article allows for the uncovering of a process by which IMT are used as a data collection medium in mixed methods praxis. Under the theoretical position of medium…

  19. Progress Monitoring for the Gifted and Talented: A Mixed Methods Examination of Response to Intervention

    ERIC Educational Resources Information Center

    Eckberg, Lynn Ann

    2013-01-01

    The mixed methods correlational study examined the problem that AYP of Pennsylvania gifted middle school students who have met state-mandated proficiency requirements under No Child Left Behind (NCLB) has been reliant upon minimum proficiency tests. The purpose of the mixed methods study was to examine the correlations between the current measure…

  20. Efficient calculation method for realistic deep 3D scene hologram using orthographic projection

    NASA Astrophysics Data System (ADS)

    Igarashi, Shunsuke; Nakamura, Tomoya; Matsushima, Kyoji; Yamaguchi, Masahiro

    2016-03-01

    We propose a fast calculation method to synthesize a computer-generated hologram (CGH) of realistic deep three-dimensional (3D) scene. In our previous study, we have proposed a calculation method of CGH for reproducing such scene called ray-sampling-plane (RSP) method, in which light-ray information of a scene is converted to wavefront, and the wavefront is numerically propagated based on diffraction theory. In this paper, we introduce orthographic projection to the RSP method for accelerating calculation time. By numerical experiments, we verified the accelerated calculation with the ratio of 28-times compared to the conventional RSP method. The calculated CGH was fabricated by the printing system using laser lithography and demonstrated deep 3D image reconstruction in 52mm×52mm with realistic appearance effect such as gloss and translucent effect.

  1. Higher order temporal finite element methods through mixed formalisms.

    PubMed

    Kim, Jinkyu

    2014-01-01

    The extended framework of Hamilton's principle and the mixed convolved action principle provide new rigorous weak variational formalism for a broad range of initial boundary value problems in mathematical physics and mechanics. In this paper, their potential when adopting temporally higher order approximations is investigated. The classical single-degree-of-freedom dynamical systems are primarily considered to validate and to investigate the performance of the numerical algorithms developed from both formulations. For the undamped system, all the algorithms are symplectic and unconditionally stable with respect to the time step. For the damped system, they are shown to be accurate with good convergence characteristics. PMID:25210664

  2. Higher order temporal finite element methods through mixed formalisms.

    PubMed

    Kim, Jinkyu

    2014-01-01

    The extended framework of Hamilton's principle and the mixed convolved action principle provide new rigorous weak variational formalism for a broad range of initial boundary value problems in mathematical physics and mechanics. In this paper, their potential when adopting temporally higher order approximations is investigated. The classical single-degree-of-freedom dynamical systems are primarily considered to validate and to investigate the performance of the numerical algorithms developed from both formulations. For the undamped system, all the algorithms are symplectic and unconditionally stable with respect to the time step. For the damped system, they are shown to be accurate with good convergence characteristics.

  3. A Modularity-Based Method Reveals Mixed Modules from Chemical-Gene Heterogeneous Network

    PubMed Central

    Song, Jianglong; Tang, Shihuan; Liu, Xi; Gao, Yibo; Yang, Hongjun; Lu, Peng

    2015-01-01

    For a multicomponent therapy, molecular network is essential to uncover its specific mode of action from a holistic perspective. The molecular system of a Traditional Chinese Medicine (TCM) formula can be represented by a 2-class heterogeneous network (2-HN), which typically includes chemical similarities, chemical-target interactions and gene interactions. An important premise of uncovering the molecular mechanism is to identify mixed modules from complex chemical-gene heterogeneous network of a TCM formula. We thus proposed a novel method (MixMod) based on mixed modularity to detect accurate mixed modules from 2-HNs. At first, we compared MixMod with Clauset-Newman-Moore algorithm (CNM), Markov Cluster algorithm (MCL), Infomap and Louvain on benchmark 2-HNs with known module structure. Results showed that MixMod was superior to other methods when 2-HNs had promiscuous module structure. Then these methods were tested on a real drug-target network, in which 88 disease clusters were regarded as real modules. MixMod could identify the most accurate mixed modules from the drug-target 2-HN (normalized mutual information 0.62 and classification accuracy 0.4524). In the end, MixMod was applied to the 2-HN of Buchang naoxintong capsule (BNC) and detected 49 mixed modules. By using enrichment analysis, we investigated five mixed modules that contained primary constituents of BNC intestinal absorption liquid. As a matter of fact, the findings of in vitro experiments using BNC intestinal absorption liquid were found to highly accord with previous analysis. Therefore, MixMod is an effective method to detect accurate mixed modules from chemical-gene heterogeneous networks and further uncover the molecular mechanism of multicomponent therapies, especially TCM formulae. PMID:25927435

  4. Investigation of deep levels in porous silicon by photoconductivity decay and thermally stimulated depolarization current methods

    NASA Astrophysics Data System (ADS)

    Borowski, P.; Bratkowski, A.; Bala, Waclaw; Bartkiewicz, K.

    2003-10-01

    The photoconductivity measurements of porous silicon were made using the visible light in wavelength range of 450 nm - 1200 nm. Obtained photoconductivity spectra were decomposed as a sum of Gaussian. The deep level energies are calculated for these peaks at about 1.24 eV, 1.33 eV, 1.55 eV, 1.84 eV, 2.17 eV and 2.54 eV at room temperature. To characterizing the deep levels we used also thermally stimulated depolarizaton current method (TSDC). In this case we used a thermal stimulation in temperature range of about 90 K - 300 K in vaccuum. After multigaussian decomposing of the current-temperature characteristic we calculated the thermal deep levels energies (0.4 eV and 0.8 eV). From the voltage-current measurements ideality factor was also calculated.

  5. THE DEEP2 GALAXY REDSHIFT SURVEY: THE VORONOI-DELAUNAY METHOD CATALOG OF GALAXY GROUPS

    SciTech Connect

    Gerke, Brian F.; Newman, Jeffrey A.; Davis, Marc; Coil, Alison L.; Cooper, Michael C.; Dutton, Aaron A.; Faber, S. M.; Guhathakurta, Puragra; Koo, David C.; Phillips, Andrew C.; Noeske, Kai; Rosario, David J.; Weiner, Benjamin J.; Willmer, Christopher N. A.; Yan, Renbin

    2012-05-20

    We present a public catalog of galaxy groups constructed from the spectroscopic sample of galaxies in the fourth data release from the Deep Extragalactic Evolutionary Probe 2 (DEEP2) Galaxy Redshift Survey, including the Extended Groth Strip (EGS). The catalog contains 1165 groups with two or more members in the EGS over the redshift range 0 < z < 1.5 and 1295 groups at z > 0.6 in the rest of DEEP2. Twenty-five percent of EGS galaxies and fourteen percent of high-z DEEP2 galaxies are assigned to galaxy groups. The groups were detected using the Voronoi-Delaunay method (VDM) after it has been optimized on mock DEEP2 catalogs following similar methods to those employed in Gerke et al. In the optimization effort, we have taken particular care to ensure that the mock catalogs resemble the data as closely as possible, and we have fine-tuned our methods separately on mocks constructed for the EGS and the rest of DEEP2. We have also probed the effect of the assumed cosmology on our inferred group-finding efficiency by performing our optimization on three different mock catalogs with different background cosmologies, finding large differences in the group-finding success we can achieve for these different mocks. Using the mock catalog whose background cosmology is most consistent with current data, we estimate that the DEEP2 group catalog is 72% complete and 61% pure (74% and 67% for the EGS) and that the group finder correctly classifies 70% of galaxies that truly belong to groups, with an additional 46% of interloper galaxies contaminating the catalog (66% and 43% for the EGS). We also confirm that the VDM catalog reconstructs the abundance of galaxy groups with velocity dispersions above {approx}300 km s{sup -1} to an accuracy better than the sample variance, and this successful reconstruction is not strongly dependent on cosmology. This makes the DEEP2 group catalog a promising probe of the growth of cosmic structure that can potentially be used for cosmological tests.

  6. The existence results and Tikhonov regularization method for generalized mixed variational inequalities in Banach spaces

    NASA Astrophysics Data System (ADS)

    Wang, Min

    2016-04-01

    This paper aims to establish the Tikhonov regularization method for generalized mixed variational inequalities in Banach spaces. For this purpose, we firstly prove a very general existence result for generalized mixed variational inequalities, provided that the mapping involved has the so-called mixed variational inequality property and satisfies a rather weak coercivity condition. Finally, we establish the Tikhonov regularization method for generalized mixed variational inequalities. Our findings extended the results for the generalized variational inequality problem (for short, GVIP(F, K)) in R^n spaces (He in Abstr Appl Anal, 2012) to the generalized mixed variational inequality problem (for short, GMVIP(F,φ , K) ) in reflexive Banach spaces. On the other hand, we generalized the corresponding results for the generalized mixed variational inequality problem (for short, GMVIP(F,φ ,K) ) in R^n spaces (Fu and He in J Sichuan Norm Univ (Nat Sci) 37:12-17, 2014) to reflexive Banach spaces.

  7. The influence of different black carbon and sulfate mixing methods on their optical and radiative properties

    NASA Astrophysics Data System (ADS)

    Zhang, Hua; Zhou, Chen; Wang, Zhili; Zhao, Shuyun; Li, Jiangnan

    2015-08-01

    Three different internal mixing methods (Core-Shell, Maxwell-Garnett, and Bruggeman) and one external mixing method are used to study the impact of mixing methods of black carbon (BC) with sulfate aerosol on their optical properties, radiative flux, and heating rate. The optical properties of a mixture of BC and sulfate aerosol particles are considered for three typical bands. The results show that mixing methods, the volume ratio of BC to sulfate, and relative humidity have a strong influence on the optical properties of mixed aerosols. Compared to internal mixing, external mixing underestimates the particle mass absorption coefficient by 20-70% and the particle mass scattering coefficient by up to 50%, whereas it overestimates the particle single scattering albedo by 20-50% in most cases. However, the asymmetry parameter is strongly sensitive to the equivalent particle radius, but is only weakly sensitive to the different mixing methods. Of the internal methods, there is less than 2% difference in all optical properties between the Maxwell-Garnett and Bruggeman methods in all bands; however, the differences between the Core-Shell and Maxwell-Garnett/Bruggeman methods are usually larger than 15% in the ultraviolet and visible bands. A sensitivity test is conducted with the Beijing Climate Center Radiation transfer model (BCC-RAD) using a simulated BC concentration that is typical of east-central China and a sulfate volume ratio of 75%. The results show that the internal mixing methods could reduce the radiative flux more effectively because they produce a higher absorption. The annual mean instantaneous radiative force due to BC-sulfate aerosol is about -3.18 W/m2 for the external method and -6.91 W/m2 for the internal methods at the surface, and -3.03/-1.56/-1.85 W/m2 for the external/Core-Shell/(Maxwell-Garnett/Bruggeman) methods, respectively, at the tropopause.

  8. Development of a Hybrid RANS/LES Method for Compressible Mixing Layer Simulations

    NASA Technical Reports Server (NTRS)

    Georgiadis, Nicholas J.; Alexander, J. Iwan D.; Reshotko, Eli

    2001-01-01

    A hybrid method has been developed for simulations of compressible turbulent mixing layers. Such mixing layers dominate the flows in exhaust systems of modem day aircraft and also those of hypersonic vehicles currently under development. The hybrid method uses a Reynolds-averaged Navier-Stokes (RANS) procedure to calculate wall bounded regions entering a mixing section, and a Large Eddy Simulation (LES) procedure to calculate the mixing dominated regions. A numerical technique was developed to enable the use of the hybrid RANS/LES method on stretched, non-Cartesian grids. The hybrid RANS/LES method is applied to a benchmark compressible mixing layer experiment. Preliminary two-dimensional calculations are used to investigate the effects of axial grid density and boundary conditions. Actual LES calculations, performed in three spatial directions, indicated an initial vortex shedding followed by rapid transition to turbulence, which is in agreement with experimental observations.

  9. Mixed Methods: Incorporating multiple learning styles into a measurements course

    NASA Astrophysics Data System (ADS)

    Pallone, Arthur

    2010-03-01

    The best scientists and engineers regularly combine creative and critical skill sets. As faculty, we are responsible to provide future scientists and engineers with those skills sets. EGR 390: Engineering Measurements at Murray State University is structured to actively engage students in the processes that develop and enhance those skills. Students learn through a mix of traditional lecture and homework, active discussion of open-ended questions, small group activities, structured laboratory exercises, oral and written communications exercises, student chosen team projects, and peer evaluations. Examples of each of these activities, the skill set addressed by each activity, outcomes from and effectiveness of each activity and recommendations for future directions in the EGR 390 course as designed will be presented.

  10. Method for producing a compressed body of mix-powder for ceramic

    NASA Technical Reports Server (NTRS)

    Okawa, K.

    1983-01-01

    Under the invented method, a compressed body of mix powder for ceramic is produced by mixing and stirring several raw powder materials with mixing liquid such as water, and, in the process of sending the resulted viscous material pressurized at 5 kg/cm to 7 kg/cm, using 1.5 to 2 times the pressure to filter and dehydrate, adjusting the water content to 10 to 20%.

  11. A brief measure of attitudes toward mixed methods research in psychology

    PubMed Central

    Roberts, Lynne D.; Povee, Kate

    2014-01-01

    The adoption of mixed methods research in psychology has trailed behind other social science disciplines. Teaching psychology students, academics, and practitioners about mixed methodologies may increase the use of mixed methods within the discipline. However, tailoring and evaluating education and training in mixed methodologies requires an understanding of, and way of measuring, attitudes toward mixed methods research in psychology. To date, no such measure exists. In this article we present the development and initial validation of a new measure: Attitudes toward Mixed Methods Research in Psychology. A pool of 42 items developed from previous qualitative research on attitudes toward mixed methods research along with validation measures was administered via an online survey to a convenience sample of 274 psychology students, academics and psychologists. Principal axis factoring with varimax rotation on a subset of the sample produced a four-factor, 12-item solution. Confirmatory factor analysis on a separate subset of the sample indicated that a higher order four factor model provided the best fit to the data. The four factors; ‘Limited Exposure,’ ‘(in)Compatibility,’ ‘Validity,’ and ‘Tokenistic Qualitative Component’; each have acceptable internal reliability. Known groups validity analyses based on preferred research orientation and self-rated mixed methods research skills, and convergent and divergent validity analyses based on measures of attitudes toward psychology as a science and scientist and practitioner orientation, provide initial validation of the measure. This brief, internally reliable measure can be used in assessing attitudes toward mixed methods research in psychology, measuring change in attitudes as part of the evaluation of mixed methods education, and in larger research programs. PMID:25429281

  12. ADVANCING THE STUDY OF VIOLENCE AGAINST WOMEN USING MIXED METHODS: INTEGRATING QUALITATIVE METHODS INTO A QUANTITATIVE RESEARCH PROGRAM

    PubMed Central

    Testa, Maria; Livingston, Jennifer A.; VanZile-Tamsen, Carol

    2011-01-01

    A mixed methods approach, combining quantitative with qualitative data methods and analysis, offers a promising means of advancing the study of violence. Integrating semi-structured interviews and qualitative analysis into a quantitative program of research on women’s sexual victimization has resulted in valuable scientific insight and generation of novel hypotheses for testing. This mixed methods approach is described and recommendations for integrating qualitative data into quantitative research are provided. PMID:21307032

  13. Advancing the study of violence against women using mixed methods: integrating qualitative methods into a quantitative research program.

    PubMed

    Testa, Maria; Livingston, Jennifer A; VanZile-Tamsen, Carol

    2011-02-01

    A mixed methods approach, combining quantitative with qualitative data methods and analysis, offers a promising means of advancing the study of violence. Integrating semi-structured interviews and qualitative analysis into a quantitative program of research on women's sexual victimization has resulted in valuable scientific insight and generation of novel hypotheses for testing. This mixed methods approach is described and recommendations for integrating qualitative data into quantitative research are provided.

  14. Mixed-methods research in pharmacy practice: basics and beyond (part 1).

    PubMed

    Hadi, Muhammad Abdul; Alldred, David Phillip; Closs, S José; Briggs, Michelle

    2013-10-01

    This is the first of two papers which explore the use of mixed-methods research in pharmacy practice. In an era of evidence-based medicine and policy, high-quality research evidence is essential for the development of effective pharmacist-led services. Over the past decade, the use of mixed-methods research has become increasingly common in healthcare, although to date its use has been relatively limited in pharmacy practice research. In this article, the basic concepts of mixed-methods research including its definition, typologies and advantages in relation to pharmacy practice research are discussed. Mixed-methods research brings together qualitative and quantitative methodologies within a single study to answer or understand a research problem. There are a number of mixed-methods designs available, but the selection of an appropriate design must always be dictated by the research question. Importantly, mixed-methods research should not be seen as a 'tool' to collect qualitative and quantitative data, rather there should be some degree of 'integration' between the two data sets. If conducted appropriately, mixed-methods research has the potential to generate quality research evidence by combining strengths and overcoming the respective limitations of qualitative and quantitative methodologies.

  15. Simple parameterized coordinate transformation method for deep- and smooth-profile gratings.

    PubMed

    Xu, Xihong; Li, Lifeng

    2014-12-01

    A simple variable transformation that consists of two joined straight-line segments per grating period is proposed for the parameterized coordinate transformation method (the C method). With this bilinear parameterization, the C method can produce convergent numerical results for gratings of deep and smooth profiles with a groove depth-to-period ratio as high as 10, which to date has been far out of reach of the C method. The danger of getting divergent results due to inadvertently using an overly large truncation number is also practically eliminated.

  16. Methods for collecting individual components of mixed saliva: the relevance to clinical pharmacology.

    PubMed

    Stephen, K W; Speirs, C F

    1976-04-01

    Methods are described for collecting constituents of mixed saliva, viz. parotid, submandibular, monor gland and sublingual saliva and gingival fluid. Literature is cited which showed that using these techniques, few antibiotics could be found in mixed saliva or its main components but all were detected in gingival fluid. Rifamicin and clindamycin were found in all components.

  17. Mixed time integration methods for transient thermal analysis of structures, appendix 5

    NASA Technical Reports Server (NTRS)

    Liu, W. K.

    1982-01-01

    Mixed time integration methods for transient thermal analysis of structures are studied. An efficient solution procedure for predicting the thermal behavior of aerospace vehicle structures was developed. A 2D finite element computer program incorporating these methodologies is being implemented. The performance of these mixed time finite element algorithms can then be evaluated employing the proposed example problem.

  18. A mixed finite element domain decomposition method for nearly elastic wave equations in the frequency domain

    SciTech Connect

    Feng, Xiaobing

    1996-12-31

    A non-overlapping domain decomposition iterative method is proposed and analyzed for mixed finite element methods for a sequence of noncoercive elliptic systems with radiation boundary conditions. These differential systems describe the motion of a nearly elastic solid in the frequency domain. The convergence of the iterative procedure is demonstrated and the rate of convergence is derived for the case when the domain is decomposed into subdomains in which each subdomain consists of an individual element associated with the mixed finite elements. The hybridization of mixed finite element methods plays a important role in the construction of the discrete procedure.

  19. Efficient Methods For Object Searching In LSST And Pan-STARRS "Deep Stacks"

    NASA Astrophysics Data System (ADS)

    Myers, Jonathan Ashley; Pierfederici, F.; Axelrod, T.; Kubica, J.; Jedicke, R.; Denneau, L.

    2008-09-01

    The Moving Object Pipeline System (MOPS) is the solar system object search and discovery system designed for the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) and the Large Synoptic Survey Telescope (LSST). While the observational schedules of the two telescopes are designed with solar system object search in mind, other science objectives result in some schedules which prove challenging for existing MOPS algorithms. In particular, we focus on the "deep stack" schedules in which a single area of the sky is imaged many times in rapid succession. These "deep stack" collections are a poor match for existing algorithms used in MOPS, resulting in long computation times and unacceptably large memory usage. We present and compare two new methods for efficiently extracting useful data from detections in "deep stack" images and integrating it into the existing MOPS system and we report our experiences with each. One is a modified intra-nightly linking algorithm which uses a partial Hough transform method for quickly identifying multiple detections which follow similar linear motion using data local to each detection. The other is a new post-processing step for intra-nightly linking which uses a KD-Tree of physically plausible pairs of detections to identify pairs with similar vectors of linear motion. Both methods have greatly reduced memory requirements compared to the existing methods, and have been successful in simulations of MOPS using both Pan-STARRS and LSST parameters.

  20. Interannual control of plankton communities by deep winter mixing and prey/predator interactions in the NW Mediterranean: Results from a 30-year 3D modeling study

    NASA Astrophysics Data System (ADS)

    Auger, P. A.; Ulses, C.; Estournel, C.; Stemmann, L.; Somot, S.; Diaz, F.

    2014-05-01

    A realistic modeling approach is designed to address the role of winter mixing on the interannual variability of plankton dynamics in the north-western (NW) Mediterranean basin. For the first time, a high-resolution coupled hydrodynamic-biogeochemical model (Eco3m-S) covering a 30-year period (1976-2005) is validated on available in situ and satellite data for the NW Mediterranean. In this region, cold, dry winds in winter often lead to deep convection and strong upwelling of nutrients into the euphotic layer. High nutrient contents at the end of winter then support the development of a strong spring bloom of phytoplankton. Model results indicate that annual primary production is not affected by winter mixing due to seasonal balance (minimum in winter and maximum in spring). However, the total annual water column-integrated phytoplankton biomass appears to be favored by winter mixing because zooplankton grazing activity is low in winter and early spring. This reduced grazing is explained here by the rarefaction of prey due to both light limitation and the effect of mixing-induced dilution on prey/predator interactions. A negative impact of winter mixing on winter zooplankton biomass is generally simulated except for mesozooplankton. This difference is assumed to stem from the lower parameterized mortality, top trophic position and detritivorous diet of mesozooplankton in the model. Moreover, model suggests that the variability of annual mesozooplankton biomass is principally modulated by the effects of winter mixing on winter biomass. Thus, interannual variability of winter nutrient contents in the euphotic layer, resulting from winter mixing, would control spring primary production and thus annual mesozooplankton biomass. Our results show a bottom-up control of mesozooplankton communities, as observed at a coastal location of the Ligurian Sea.

  1. Magma mixing in the Kalaqin core complex, northern North China Craton: Linking deep lithospheric destruction and shallow extension

    NASA Astrophysics Data System (ADS)

    Fu, Lebing; Wei, Junhao; Tan, Jun; Santosh, M.; Zhang, Daohan; Chen, Jiajie; Li, Yanjun; Zhao, Shaoqing; Peng, Lina

    2016-09-01

    .4, T2DM(Nd)Group 1 = 1705-1775 Ma, (87Sr/86Sr)iGroup 2 = 0.70586-0.70587, εNd(t)Group 2 = - 0.6 to - 0.7, T2DM(Nd)Group 2 = 971-978 Ma, and εHf(t)Group 2 = - 4.5 to - 10.0. The mineralogical and geochemical features suggest that the host Jiguanzi adamellite and Group 2 enclaves were generated through synchronous mixing and fractional crystallization accompanied by mechanical and chemical exchanges. The Group 1 enclaves showing cogenetic affinity with their felsic host represent the mechanical concentrations of mafic minerals and accessory phases from evolved hybrid host magma. Magma sources of the host Jiguanzi adamellite and its Group 1 enclaves are dominated by lower crust (LCC) components, whereas those for the Group 2 enclaves are dominated by metasomatized lithospheric mantle. The magma genesis involved complex multi-stage crust-mantle interaction processes including: (1) lithospheric mantle modification induced by Triassic subduction of the Paleo-Asian Ocean slab and/or Triassic-Cretaceous asthenospheric melt underplating; and (2) melting of the ancient LCC and lithospheric mantle, and hybridization of mantle- and crust-derived melts. In conjunction with regional geological and geochemical data, we argue that the Late Jurassic-Early Cretaceous shallow extension events represented by the Kalaqin MCC triggered deep-seated multi-stage magmatism and lithospheric destruction, and the continuous generation of magma further strengthened the extension and result in more extensive lithospheric thinning.

  2. Method for the discrimination of superficial and deep absorption variations by time domain fNIRS.

    PubMed

    Zucchelli, Lucia; Contini, Davide; Re, Rebecca; Torricelli, Alessandro; Spinelli, Lorenzo

    2013-01-01

    A method for the discrimination of superficial and deep absorption variations by time domain functional near infrared spectroscopy is presented. The method exploits the estimate of the photon time-dependent pathlength in different domains of the sampled medium and makes use of an approach based on time-gating of the photon distribution of time-of-flights. Validation of the method is performed in the two-layer geometry to focus on muscle and head applications. Numerical simulations varied the thickness of the upper layer, the interfiber distance, the shape of the instrument response function and the photon counts. Preliminary results from in vivo data are also shown.

  3. Method for the discrimination of superficial and deep absorption variations by time domain fNIRS

    PubMed Central

    Zucchelli, Lucia; Contini, Davide; Re, Rebecca; Torricelli, Alessandro; Spinelli, Lorenzo

    2013-01-01

    A method for the discrimination of superficial and deep absorption variations by time domain functional near infrared spectroscopy is presented. The method exploits the estimate of the photon time-dependent pathlength in different domains of the sampled medium and makes use of an approach based on time-gating of the photon distribution of time-of-flights. Validation of the method is performed in the two-layer geometry to focus on muscle and head applications. Numerical simulations varied the thickness of the upper layer, the interfiber distance, the shape of the instrument response function and the photon counts. Preliminary results from in vivo data are also shown. PMID:24409389

  4. 300-mW narrow-linewidth deep-ultraviolet light generation at 193 nm by frequency mixing between Yb-hybrid and Er-fiber lasers.

    PubMed

    Xuan, Hongwen; Zhao, Zhigang; Igarashi, Hironori; Ito, Shinji; Kakizaki, Kouji; Kobayashi, Yohei

    2015-04-20

    A narrow-linewidth, high average power deep-ultraviolet (DUV) coherent laser emitting at 193 nm is demonstrated by frequency mixing a Yb-hybrid laser with an Er-fiber laser. The Yb-hybrid laser consists of Yb-fiber lasers and an Yb:YAG amplifier. The average output power of the 193 nm laser is 310 mW at 6 kHz, which corresponds to a pulse energy of 51 μJ. To the best of our knowledge, this is the highest average power and pulse energy ever reported for a narrow-linewidth 193 nm light generated by a combination of solid-state and fiber lasers with frequency mixing. We believe this laser will be beneficial for the application of interference lithography by seeding an injection-locking ArF eximer laser. PMID:25969096

  5. 300-mW narrow-linewidth deep-ultraviolet light generation at 193 nm by frequency mixing between Yb-hybrid and Er-fiber lasers.

    PubMed

    Xuan, Hongwen; Zhao, Zhigang; Igarashi, Hironori; Ito, Shinji; Kakizaki, Kouji; Kobayashi, Yohei

    2015-04-20

    A narrow-linewidth, high average power deep-ultraviolet (DUV) coherent laser emitting at 193 nm is demonstrated by frequency mixing a Yb-hybrid laser with an Er-fiber laser. The Yb-hybrid laser consists of Yb-fiber lasers and an Yb:YAG amplifier. The average output power of the 193 nm laser is 310 mW at 6 kHz, which corresponds to a pulse energy of 51 μJ. To the best of our knowledge, this is the highest average power and pulse energy ever reported for a narrow-linewidth 193 nm light generated by a combination of solid-state and fiber lasers with frequency mixing. We believe this laser will be beneficial for the application of interference lithography by seeding an injection-locking ArF eximer laser.

  6. Using Mixed Methods to Interpret Differential Item Functioning

    ERIC Educational Resources Information Center

    Benítez, Isabel; Padilla, José-Luis; Hidalgo Montesinos, María Dolores; Sireci, Stephen G.

    2016-01-01

    Analysis of differential item functioning (DIF) is often used to determine if cross-lingual assessments are equivalent across languages. However, evidence on the causes of cross-lingual DIF is still evasive. Expert appraisal is a qualitative method useful for obtaining detailed information about problematic elements in the different linguistic…

  7. 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…

  8. SPRUCE Deep Peat Heating Manipulations: in situ Methods to Characterize the Response of Deep Peat to Warming

    NASA Astrophysics Data System (ADS)

    Hanson, P. J.; Riggs, J. S.; Barbier, C. N.; Nettles, W. R., IV; Phillips, J. R.; Hook, L.

    2014-12-01

    Deep soil heating infrastructure was completed in 2014 for a peatland whole-ecosystem warming study that will include air warming starting in 2015 (SPRUCE; http://mnspruce.ornl.gov). In June 2014, we initiated deep soil heating to test the responsiveness of deep peat carbon stocks, microbial communities and biogeochemical cycling processes to heating at 4 warming levels (+2.25, +4.5, +6.75 and +9 °C; 2 replicate plots) compared to fully-constructed control plots (+0 °C; 2 replicate plots). The warming treatments were deployed over eight 113 m2 areas using circular arrays of low-wattage (W) electrical resistance heaters. Perimeter heating was achieved by an exterior circle of 48 100W heaters that apply heat from the surface to a depth of 3 meters. Heating within the study area was accomplished utilizing three zones of 100W "deep only" heaters: an intermediate circle of 12 units, an interior circle of 6 units and one unit placed at the plot center. Heating elements inside the study area apply heat only from -2 to -3 m to keep active heater surfaces away from measured peat volumes. With an average peat depth of 2.5 meters this system was able to warm approximately 113 of the 282 m3 of peat within each target plot. In the absence of the air warming cap, in situ deep peat heating is only effective at sustaining warming in the deep peat layers. Warming levels at depth were achieved over a 25-day (+ 2.25 °C) to a 60-day (+9 °C) period depending on the target treatment temperatures in agreement with a priori energy balance model simulations. Homogeneous temperature distributions between heaters at a given depth interval continued to develop after these targets were reached. Biological and biogeochemical responses to these manipulations are being actively assessed. After one month of transient heating, data for ground-level surface flux of CO2 and CH4 had not shown changes from deep peat heating, but they continue to be tracked and will be summarized in this and related

  9. Using Mixed Methods and Collaboration to Evaluate an Education and Public Outreach Program (Invited)

    NASA Astrophysics Data System (ADS)

    Shebby, S.; Shipp, S. S.

    2013-12-01

    Traditional indicators (such as the number of participants or Likert-type ratings of participant perceptions) are often used to provide stakeholders with basic information about program outputs and to justify funding decisions. However, use of qualitative methods can strengthen the reliability of these data and provide stakeholders with more meaningful information about program challenges, successes, and ultimate impacts (Stern, Stame, Mayne, Forss, David & Befani, 2012). In this session, presenters will discuss how they used a mixed methods evaluation to determine the impact of an education and public outreach (EPO) program. EPO efforts were intended to foster more effective, sustainable, and efficient utilization of science discoveries and learning experiences through three main goals 1) increase engagement and support by leveraging of resources, expertise, and best practices; 2) organize a portfolio of resources for accessibility, connectivity, and strategic growth; and 3) develop an infrastructure to support coordination. The evaluation team used a mixed methods design to conduct the evaluation. Presenters will first discuss five potential benefits of mixed methods designs: triangulation of findings, development, complementarity, initiation, and value diversity (Greene, Caracelli & Graham, 2005). They will next demonstrate how a 'mix' of methods, including artifact collection, surveys, interviews, focus groups, and vignettes, was included in the EPO project's evaluation design, providing specific examples of how alignment between the program theory and the evaluation plan was best achieved with a mixed methods approach. The presentation will also include an overview of different mixed methods approaches and information about important considerations when using a mixed methods design, such as selection of data collection methods and sources, and the timing and weighting of quantitative and qualitative methods (Creswell, 2003). Ultimately, this presentation will

  10. Updating and testing of a Finnish method for mixed municipal solid waste composition studies.

    PubMed

    Liikanen, M; Sahimaa, O; Hupponen, M; Havukainen, J; Sorvari, J; Horttanainen, M

    2016-06-01

    More efficient recycling of municipal solid waste (MSW) is an essential precondition for turning Europe into a circular economy. Thus, the recycling of MSW must increase significantly in several member states, including Finland. This has increased the interest in the composition of mixed MSW. Due to increased information needs, a method for mixed MSW composition studies was introduced in Finland in order to improve the national comparability of composition study results. The aim of this study was to further develop the method so that it corresponds to the information needed about the composition of mixed MSW and still works in practice. A survey and two mixed MSW composition studies were carried out in the study. According to the responses of the survey, the intensification of recycling, the landfill ban on organic waste and the producer responsibility for packaging waste have particularly influenced the need for information about the composition of mixed MSW. The share of biowaste in mixed MSW interested the respondents most. Additionally, biowaste proved to be the largest waste fraction in mixed MSW in the composition studies. It constituted over 40% of mixed MSW in both composition studies. For these reasons, the classification system of the method was updated by further defining the classifications of biowaste. The classifications of paper as well as paperboard and cardboard were also updated. The updated classification system provides more information on the share of avoidable food waste and waste materials suitable for recycling in mixed MSW. The updated method and the information gained from the composition studies are important in ensuring that the method will be adopted by municipal waste management companies and thus used widely in Finland.

  11. Updating and testing of a Finnish method for mixed municipal solid waste composition studies.

    PubMed

    Liikanen, M; Sahimaa, O; Hupponen, M; Havukainen, J; Sorvari, J; Horttanainen, M

    2016-06-01

    More efficient recycling of municipal solid waste (MSW) is an essential precondition for turning Europe into a circular economy. Thus, the recycling of MSW must increase significantly in several member states, including Finland. This has increased the interest in the composition of mixed MSW. Due to increased information needs, a method for mixed MSW composition studies was introduced in Finland in order to improve the national comparability of composition study results. The aim of this study was to further develop the method so that it corresponds to the information needed about the composition of mixed MSW and still works in practice. A survey and two mixed MSW composition studies were carried out in the study. According to the responses of the survey, the intensification of recycling, the landfill ban on organic waste and the producer responsibility for packaging waste have particularly influenced the need for information about the composition of mixed MSW. The share of biowaste in mixed MSW interested the respondents most. Additionally, biowaste proved to be the largest waste fraction in mixed MSW in the composition studies. It constituted over 40% of mixed MSW in both composition studies. For these reasons, the classification system of the method was updated by further defining the classifications of biowaste. The classifications of paper as well as paperboard and cardboard were also updated. The updated classification system provides more information on the share of avoidable food waste and waste materials suitable for recycling in mixed MSW. The updated method and the information gained from the composition studies are important in ensuring that the method will be adopted by municipal waste management companies and thus used widely in Finland. PMID:27021698

  12. Criteria for quantitative and qualitative data integration: mixed-methods research methodology.

    PubMed

    Lee, Seonah; Smith, Carrol A M

    2012-05-01

    Many studies have emphasized the need and importance of a mixed-methods approach for evaluation of clinical information systems. However, those studies had no criteria to guide integration of multiple data sets. Integrating different data sets serves to actualize the paradigm that a mixed-methods approach argues; thus, we require criteria that provide the right direction to integrate quantitative and qualitative data. The first author used a set of criteria organized from a literature search for integration of multiple data sets from mixed-methods research. The purpose of this article was to reorganize the identified criteria. Through critical appraisal of the reasons for designing mixed-methods research, three criteria resulted: validation, complementarity, and discrepancy. In applying the criteria to empirical data of a previous mixed methods study, integration of quantitative and qualitative data was achieved in a systematic manner. It helped us obtain a better organized understanding of the results. The criteria of this article offer the potential to produce insightful analyses of mixed-methods evaluations of health information systems.

  13. Counseling About IUDs: A Mixed-Methods Analysis

    PubMed Central

    Dehlendorf, Christine; Tharayil, Mithu; Anderson, Nora; Gbenedio, Kessy; Wittman, Allen; Steinauer, Jody

    2014-01-01

    CONTEXT IUDs are infrequently used in the United States. Assessing how counseling about this method is delivered can help identify barriers to IUD use that might be overcome by improving services. METHODS A sample of 342 family planning visits at six clinics in the San Francisco Bay Area in 2009–2012 were audio-recorded, and patients completed surveys both before and after their visits. Descriptive quantitative analyses of counseling were performed, and correlates of IUDs’ being mentioned during counseling were investigated using logistic regression. Qualitative analyses investigated the counseling women received about IUDs generally (in a subset of 42 visits), as well as counseling for women who already had an IUD in place (13 visits) or who felt their provider inappropriately expressed a preference for IUDs (five visits). RESULTS IUDs were mentioned in 75% of visits. Patient-initiated mention of IUDs was more likely in visits by women aged 35 or older than in those by women younger than 20 (odds ratio, 6.4); provider-initiated discussion of this method was less common if the provider was older than 55 than if he or she was younger than 46 (0.3). Providers more often discussed potential adverse effects of IUD use than benefits; counseling often was noninteractive and did not address how patient preferences related to characteristics of IUDs. Counseling was frequently fragmented by the need for return visits or referral elsewhere for insertion. CONCLUSIONS IUD counseling may be improved by enhancing comprehensiveness and patient-centeredness, and by decreasing fragmentation of care. PMID:24628710

  14. Modeling BOD removal in constructed wetlands with mixing cell method

    SciTech Connect

    Chen, S.; Wang, G.T.; Xue, S.K.

    1999-01-01

    A new concept, transport detention time, is proposed in this paper to describe solute-transport processes. Using this concept, a new mathematical model was developed to describe biochemical oxygen demand removal in constructed wetlands. By treating a constructed wetland as a series of continuous stir tank reactors, an nth-order ordinary differential equation was derived based on the principle of mass balance and convective-dispersive equation and by introducing transfer function and Laplace transform. The number of continuous stir tank reactors of a particular wetland was determined by the parameters, such as dispersion coefficient and flow velocity, occurring in the wetland. Two examples were presented to illustrate the applications of the model. Moment method and a combination of moment and optimization methods were used to estimate the model parameters from tracer experiment data. A comparison between the model presented in this paper and the currently used plug-flow-constructed wetland model indicated that the former was more accurate. Additionally, this model can be applied to transient conditions, is theoretically sound, and represents a theoretical advance in constructed wetland research.

  15. A time-dependent Mixing Model for PDF Methods in Heterogeneous Aquifers

    NASA Astrophysics Data System (ADS)

    Schüler, Lennart; Suciu, Nicolae; Knabner, Peter; Attinger, Sabine

    2016-04-01

    Predicting the transport of groundwater contaminations remains a demanding task, especially with respect to the heterogeneity of the subsurface and the large measurement uncertainties. A risk analysis also includes the quantification of the uncertainty in order to evaluate how accurate the predictions are. Probability density function (PDF) methods are a promising alternative to predicting the transport of solutes in groundwater under uncertainty. They make it possible to derive the evolution equations of the mean concentration and the concentration variance, which can be used as a first measure of uncertainty. A mixing model, also known as a dissipation model, is essential for both methods. Finding a satisfactory mixing model is still an open question and due to the rather elaborate PDF methods, a difficult undertaking. Both the PDF equation and the concentration variance equation depend on the same mixing model. This connection is used to find and test an improved mixing model for the much easier to handle concentration variance. Subsequently, this mixing model is transferred to the PDF equation and tested. The newly proposed mixing model yields significantly improved results for both variance modelling and PDF modelling. The implications of the new mixing model for different kinds of flow conditions are discussed and some comments are made on efficiently handling spatially resolved higher moments.

  16. Evaluating a physician leadership development program - a mixed methods approach.

    PubMed

    Throgmorton, Cheryl; Mitchell, Trey; Morley, Tom; Snyder, Marijo

    2016-05-16

    Purpose - With the extent of change in healthcare today, organizations need strong physician leaders. To compensate for the lack of physician leadership education, many organizations are sending physicians to external leadership programs or developing in-house leadership programs targeted specifically to physicians. The purpose of this paper is to outline the evaluation strategy and outcomes of the inaugural year of a Physician Leadership Academy (PLA) developed and implemented at a Michigan-based regional healthcare system. Design/methodology/approach - The authors applied the theoretical framework of Kirkpatrick's four levels of evaluation and used surveys, observations, activity tracking, and interviews to evaluate the program outcomes. The authors applied grounded theory techniques to the interview data. Findings - The program met targeted outcomes across all four levels of evaluation. Interview themes focused on the significance of increasing self-awareness, building relationships, applying new skills, and building confidence. Research limitations/implications - While only one example, this study illustrates the importance of developing the evaluation strategy as part of the program design. Qualitative research methods, often lacking from learning evaluation design, uncover rich themes of impact. The study supports how a PLA program can enhance physician learning, engagement, and relationship building throughout and after the program. Physician leaders' partnership with organization development and learning professionals yield results with impact to individuals, groups, and the organization. Originality/value - Few studies provide an in-depth review of evaluation methods and outcomes of physician leadership development programs. Healthcare organizations seeking to develop similar in-house programs may benefit applying the evaluation strategy outlined in this study. PMID:27119393

  17. Evaluating a physician leadership development program - a mixed methods approach.

    PubMed

    Throgmorton, Cheryl; Mitchell, Trey; Morley, Tom; Snyder, Marijo

    2016-05-16

    Purpose - With the extent of change in healthcare today, organizations need strong physician leaders. To compensate for the lack of physician leadership education, many organizations are sending physicians to external leadership programs or developing in-house leadership programs targeted specifically to physicians. The purpose of this paper is to outline the evaluation strategy and outcomes of the inaugural year of a Physician Leadership Academy (PLA) developed and implemented at a Michigan-based regional healthcare system. Design/methodology/approach - The authors applied the theoretical framework of Kirkpatrick's four levels of evaluation and used surveys, observations, activity tracking, and interviews to evaluate the program outcomes. The authors applied grounded theory techniques to the interview data. Findings - The program met targeted outcomes across all four levels of evaluation. Interview themes focused on the significance of increasing self-awareness, building relationships, applying new skills, and building confidence. Research limitations/implications - While only one example, this study illustrates the importance of developing the evaluation strategy as part of the program design. Qualitative research methods, often lacking from learning evaluation design, uncover rich themes of impact. The study supports how a PLA program can enhance physician learning, engagement, and relationship building throughout and after the program. Physician leaders' partnership with organization development and learning professionals yield results with impact to individuals, groups, and the organization. Originality/value - Few studies provide an in-depth review of evaluation methods and outcomes of physician leadership development programs. Healthcare organizations seeking to develop similar in-house programs may benefit applying the evaluation strategy outlined in this study.

  18. The advantages and disadvantages of mixing methods: an analysis of combining traditional and autoethnographic approaches.

    PubMed

    O'Byrne, Patrick

    2007-12-01

    Although mixed- and multiple-method research designs are currently gaining momentum and popularity, it is essential that researchers undertake a critical analysis of the process of mixing "mainstream" research designs with newer methods before commencing. In ethnography, not only are there multiple approaches to data collection, but each approach also spans the competing paradigms, thus making the term mainstream ambiguous because these mainstream techniques are reasonably different from one another. When critically appraising the combination of ethnography and autoethnography, researchers must evaluate paradigmatic philosophies and methods of inquiry for commensurability and delineate the advantages and disadvantages of combining methods as they relate to each paradigm. The author's goal in this article is to demarcate the methodologies of both ethnography and autoethnography and then to identify the (dis)advantages that might arise from undertaking multiple-method and/or mixed-method research that uses these approaches concurrently. PMID:18000077

  19. The advantages and disadvantages of mixing methods: an analysis of combining traditional and autoethnographic approaches.

    PubMed

    O'Byrne, Patrick

    2007-12-01

    Although mixed- and multiple-method research designs are currently gaining momentum and popularity, it is essential that researchers undertake a critical analysis of the process of mixing "mainstream" research designs with newer methods before commencing. In ethnography, not only are there multiple approaches to data collection, but each approach also spans the competing paradigms, thus making the term mainstream ambiguous because these mainstream techniques are reasonably different from one another. When critically appraising the combination of ethnography and autoethnography, researchers must evaluate paradigmatic philosophies and methods of inquiry for commensurability and delineate the advantages and disadvantages of combining methods as they relate to each paradigm. The author's goal in this article is to demarcate the methodologies of both ethnography and autoethnography and then to identify the (dis)advantages that might arise from undertaking multiple-method and/or mixed-method research that uses these approaches concurrently.

  20. Food Environments around American Indian Reservations: A Mixed Methods Study

    PubMed Central

    Kodish, Stephen; Oddo, Vanessa M.; Antiporta, Daniel A.; Jock, Brittany; Jones-Smith, Jessica C.

    2016-01-01

    Objectives To describe the food environments experienced by American Indians living on tribal lands in California. Methods Geocoded statewide food business data were used to define and categorize existing food vendors into healthy, unhealthy, and intermediate composite categories. Distance to and density of each of the composite food vendor categories for tribal lands and nontribal lands were compared using multivariate linear regression. Quantitative results were concurrently triangulated with qualitative data from in-depth interviews with tribal members (n = 24). Results After adjusting for census tract-level urbanicity and per capita income, results indicate there were significantly fewer healthy food outlets per square mile for tribal areas compared to non-tribal areas. Density of unhealthy outlets was not significantly different for tribal versus non-tribal areas. Tribal members perceived their food environment negatively and reported barriers to the acquisition of healthy food. Conclusions Urbanicity and per capita income do not completely account for disparities in food environments among American Indians tribal lands compared to nontribal lands. This disparity in access to healthy food may present a barrier to acting on the intention to consume healthy food. PMID:27560132

  1. Control method for mixed refrigerant based natural gas liquefier

    DOEpatents

    Kountz, Kenneth J.; Bishop, Patrick M.

    2003-01-01

    In a natural gas liquefaction system having a refrigerant storage circuit, a refrigerant circulation circuit in fluid communication with the refrigerant storage circuit, and a natural gas liquefaction circuit in thermal communication with the refrigerant circulation circuit, a method for liquefaction of natural gas in which pressure in the refrigerant circulation circuit is adjusted to below about 175 psig by exchange of refrigerant with the refrigerant storage circuit. A variable speed motor is started whereby operation of a compressor is initiated. The compressor is operated at full discharge capacity. Operation of an expansion valve is initiated whereby suction pressure at the suction pressure port of the compressor is maintained below about 30 psig and discharge pressure at the discharge pressure port of the compressor is maintained below about 350 psig. Refrigerant vapor is introduced from the refrigerant holding tank into the refrigerant circulation circuit until the suction pressure is reduced to below about 15 psig, after which flow of the refrigerant vapor from the refrigerant holding tank is terminated. Natural gas is then introduced into a natural gas liquefier, resulting in liquefaction of the natural gas.

  2. Integrating Quantitative and Qualitative Results in Health Science Mixed Methods Research Through Joint Displays

    PubMed Central

    Guetterman, Timothy C.; Fetters, Michael D.; Creswell, John W.

    2015-01-01

    PURPOSE Mixed methods research is becoming an important methodology to investigate complex health-related topics, yet the meaningful integration of qualitative and quantitative data remains elusive and needs further development. A promising innovation to facilitate integration is the use of visual joint displays that bring data together visually to draw out new insights. The purpose of this study was to identify exemplar joint displays by analyzing the various types of joint displays being used in published articles. METHODS We searched for empirical articles that included joint displays in 3 journals that publish state-of-the-art mixed methods research. We analyzed each of 19 identified joint displays to extract the type of display, mixed methods design, purpose, rationale, qualitative and quantitative data sources, integration approaches, and analytic strategies. Our analysis focused on what each display communicated and its representation of mixed methods analysis. RESULTS The most prevalent types of joint displays were statistics-by-themes and side-by-side comparisons. Innovative joint displays connected findings to theoretical frameworks or recommendations. Researchers used joint displays for convergent, explanatory sequential, exploratory sequential, and intervention designs. We identified exemplars for each of these designs by analyzing the inferences gained through using the joint display. Exemplars represented mixed methods integration, presented integrated results, and yielded new insights. CONCLUSIONS Joint displays appear to provide a structure to discuss the integrated analysis and assist both researchers and readers in understanding how mixed methods provides new insights. We encourage researchers to use joint displays to integrate and represent mixed methods analysis and discuss their value. PMID:26553895

  3. Individualized feedback during simulated laparoscopic training: a mixed methods study

    PubMed Central

    Weurlander, Maria; Hedman, Leif; Nisell, Henry; Lindqvist, Pelle G.; Felländer-Tsai, Li; Enochsson, Lars

    2015-01-01

    Objectives This study aimed to explore the value of indi-vidualized feedback on performance, flow and self-efficacy during simulated laparoscopy. Furthermore, we wished to explore attitudes towards feedback and simulator training among medical students. Methods Sixteen medical students were included in the study and randomized to laparoscopic simulator training with or without feedback. A teacher provided individualized feedback continuously throughout the procedures to the target group. Validated questionnaires and scales were used to evaluate self-efficacy and flow. The Mann-Whitney U test was used to evaluate differences between groups regarding laparoscopic performance (instrument path length), self-efficacy and flow. Qualitative data was collected by group interviews and interpreted using inductive thematic analyses. Results Sixteen students completed the simulator training and questionnaires. Instrument path length was shorter in the feedback group (median 3.9 m; IQR: 3.3-4.9) as com-pared to the control group (median 5.9 m; IQR: 5.0-8.1), p<0.05. Self-efficacy improved in both groups. Eleven students participated in the focus interviews. Participants in the control group expressed that they had fun, whereas participants in the feedback group were more concentrated on the task and also more anxious. Both groups had high ambitions to succeed and also expressed the importance of getting feedback. The authenticity of the training scenario was important for the learning process. Conclusions This study highlights the importance of individualized feedback during simulated laparoscopy training. The next step is to further optimize feedback and to transfer standardized and individualized feedback from the simulated setting to the operating room. PMID:26223033

  4. A Model Incorporating the Rationale and Purpose for Conducting Mixed-Methods Research in Special Education and beyond

    ERIC Educational Resources Information Center

    Collins, Kathleen M. T.; Onwuegbuzie, Anthony J.; Sutton, Ida L.

    2006-01-01

    This article provides a typology of reasons for conducting mixed-methods research in special education. The mixed-methods research process is described along with the role of the rationale and purpose of study. The reasons given in the literature for utilizing mixed-methods research are explicated, and the limitations of these reason frameworks…

  5. Importance of mixed methods in pragmatic trials and dissemination and implementation research.

    PubMed

    Albright, Karen; Gechter, Katherine; Kempe, Allison

    2013-01-01

    With increased attention to the importance of translating research to clinical practice and policy, recent years have seen a proliferation of particular types of research, including pragmatic trials and dissemination and implementation research. Such research seeks to understand how and why interventions function in real-world settings, as opposed to highly controlled settings involving conditions not likely to be repeated outside the research study. Because understanding the context in which interventions are implemented is imperative for effective pragmatic trials and dissemination and implementation research, the use of mixed methods is critical to understanding trial results and the success or failure of implementation efforts. This article discusses a number of dimensions of mixed methods research, utilizing at least one qualitative method and at least one quantitative method, that may be helpful when designing projects or preparing grant proposals. Although the strengths and emphases of qualitative and quantitative approaches differ substantially, methods may be combined in a variety of ways to achieve a deeper level of understanding than can be achieved by one method alone. However, researchers must understand when and how to integrate the data as well as the appropriate order, priority, and purpose of each method. The ability to demonstrate an understanding of the rationale for and benefits of mixed methods research is increasingly important in today's competitive funding environment, and many funding agencies now expect applicants to include mixed methods in proposals. The increasing demand for mixed methods research necessitates broader methodological training and deepened collaboration between medical, clinical, and social scientists. Although a number of challenges to conducting and disseminating mixed methods research remain, the potential for insight generated by such work is substantial.

  6. Qualitative and mixed methods research in dissemination and implementation science: introduction to the special issue.

    PubMed

    Southam-Gerow, Michael A; Dorsey, Shannon

    2014-01-01

    This special issue provides examples of how qualitative and mixed methods research approaches can be used in dissemination and implementation science. In this introductory article, we provide a brief rationale for why and how qualitative and mixed methods approaches can be useful in moving the field forward. Specifically, we provide a brief primer on common qualitative methods, including a review of guidelines provided by the National Institutes of Health. Next, we introduce the six articles in the issue. The first of the articles by Palinkas represents a more thorough and authoritative discussion related to qualitative methods, using the other five articles in the issue (and other published works) as examples. The remaining five articles are empirical and/or descriptive articles of recently completed or ongoing qualitative or mixed methods studies related to dissemination and implementation of evidence-based practices for children and adolescents.

  7. An equivalent domain integral method for three-dimensional mixed-mode fracture problems

    NASA Technical Reports Server (NTRS)

    Shivakumar, K. N.; Raju, I. S.

    1991-01-01

    A general formulation of the equivalent domain integral (EDI) method for mixed mode fracture problems in cracked solids is presented. The method is discussed in the context of a 3-D finite element analysis. The J integral consists of two parts: the volume integral of the crack front potential over a torus enclosing the crack front and the crack surface integral due to the crack front potential plus the crack face loading. In mixed mode crack problems the total J integral is split into J sub I, J sub II, and J sub III representing the severity of the crack front in three modes of deformations. The direct and decomposition methods are used to separate the modes. These two methods were applied to several mixed mode fracture problems, were analyzed, and results were found to agree well with those available in the literature. The method lends itself to be used as a post-processing subroutine in a general purpose finite element program.

  8. The DEEP2 Galaxy Redshift Survey: The Voronoi-Delaunay Method Catalog of Galaxy Groups

    SciTech Connect

    Gerke, Brian F.; Newman, Jeffrey A.; Davis, Marc; Marinoni, Christian; Yan, Renbin; Coil, Alison L.; Conroy, Charlie; Cooper, Michael C.; Faber, S.M.; Finkbeiner, Douglas P.; Guhathakurta, Puragra; Kaiser, Nick; Koo, David C.; Phillips, Andrew C.; Weiner, Benjamin J.; /Maryland U.

    2012-02-14

    We use the first 25% of the DEEP2 Galaxy Redshift Survey spectroscopic data to identify groups and clusters of galaxies in redshift space. The data set contains 8370 galaxies with confirmed redshifts in the range 0.7 {<=} z {<=} 1.4, over one square degree on the sky. Groups are identified using an algorithm (the Voronoi-Delaunay Method) that has been shown to accurately reproduce the statistics of groups in simulated DEEP2-like samples. We optimize this algorithm for the DEEP2 survey by applying it to realistic mock galaxy catalogs and assessing the results using a stringent set of criteria for measuring group-finding success, which we develop and describe in detail here. We find in particular that the group-finder can successfully identify {approx}78% of real groups and that {approx}79% of the galaxies that are true members of groups can be identified as such. Conversely, we estimate that {approx}55% of the groups we find can be definitively identified with real groups and that {approx}46% of the galaxies we place into groups are interloper field galaxies. Most importantly, we find that it is possible to measure the distribution of groups in redshift and velocity dispersion, n({sigma}, z), to an accuracy limited by cosmic variance, for dispersions greater than 350 km s{sup -1}. We anticipate that such measurements will allow strong constraints to be placed on the equation of state of the dark energy in the future. Finally, we present the first DEEP2 group catalog, which assigns 32% of the galaxies to 899 distinct groups with two or more members, 153 of which have velocity dispersions above 350 km s{sup -1}. We provide locations, redshifts and properties for this high-dispersion subsample. This catalog represents the largest sample to date of spectroscopically detected groups at z {approx} 1.

  9. Residual glasses and melt inclusions in basalts from DSDP Legs 45 and 46 - Evidence for magma mixing. [Deep Sea Drilling Project

    NASA Technical Reports Server (NTRS)

    Dungan, M. A.; Rhodes, J. M.

    1978-01-01

    Microprobe analyses of natural glasses in basalts recovered by Legs 45 and 46 of the Deep Sea Drilling Project are reported and interpreted in the context of other geochemical, petrographic and experimental data on the same rocks (Rhodes et al., 1978). Residual glass compositions in the moderately evolved aphyritic and abundantly phyric basalts within each site indicate that none of the units is related to any other or to a common parent by simple fractional crystallization. The compositional trends, extensive disequilibrium textures in the plagioclase phenocrysts and the presence in evolved lavas of refractory plagioclase and olivine phenocrysts bearing primitive melt inclusions provide evidence that magma mixing had a major role in the genesis of the Leg 45 and 46 basalts. The magma parental to these basalts was most likely characterized by high Mg/(Mg + Fe/+2/), CaO/Al2O3, CaO/Na2O and low lithophile concentrations. A mixing model involving incremental enrichment of magmaphile elements by repeated episodes of mixing of relatively primitive and moderately evolved magmas, followed by a small amount of fractionation is consistent with the characteristics of the basalts studied.

  10. A New Mixed Element Method for a Class of Time-Fractional Partial Differential Equations

    PubMed Central

    Li, Hong; Gao, Wei; He, Siriguleng; Fang, Zhichao

    2014-01-01

    A kind of new mixed element method for time-fractional partial differential equations is studied. The Caputo-fractional derivative of time direction is approximated by two-step difference method and the spatial direction is discretized by a new mixed element method, whose gradient belongs to the simple (L2(Ω)2) space replacing the complex H(div; Ω) space. Some a priori error estimates in L2-norm for the scalar unknown u and in (L2)2-norm for its gradient σ. Moreover, we also discuss a priori error estimates in H1-norm for the scalar unknown u. PMID:24737957

  11. A mixed methods contribution to the study of health public policies: complementarities and difficulties

    PubMed Central

    2015-01-01

    The use of mixed methods (combining quantitative and qualitative data) is developing in a variety of forms, especially in the health field. Our own research has adopted this perspective from the outset. We have sought all along to innovate in various ways and especially to develop an equal partnership, in the sense of not allowing any single approach to dominate. After briefly describing mixed methods, in this article we explain and illustrate how we have exploited both qualitative and quantitative methods to answer our research questions, ending with a reflective analysis of our experiment. PMID:26559730

  12. Existing Whole-House Solutions Case Study: Bay Ridge Gardens - Mixed Humid Affordable Multifamily Housing Deep Energy Retrofit, Annapolis, Maryland

    SciTech Connect

    2013-10-01

    Under this project, the BA-PIRC research team evaluated the installation, measured performance, and cost-effectiveness of efficiency upgrade measures for a tenant-in-place deep energy retrofit at the Bay Ridge multifamily development in Annapolis, Maryland. The design and construction phase of the Bay Ridge project was completed in August 2012. This case study summarizes system commissioning, short-term test results, utility bill data analysis, and analysis of real-time data collected over a one-year period after the retrofit was complete.

  13. A systematic review of mixed methods research on human factors and ergonomics in health care.

    PubMed

    Carayon, Pascale; Kianfar, Sarah; Li, Yaqiong; Xie, Anping; Alyousef, Bashar; Wooldridge, Abigail

    2015-11-01

    This systematic literature review provides information on the use of mixed methods research in human factors and ergonomics (HFE) research in health care. Using the PRISMA methodology, we searched four databases (PubMed, PsycInfo, Web of Science, and Engineering Village) for studies that met the following inclusion criteria: (1) field study in health care, (2) mixing of qualitative and quantitative data, (3) HFE issues, and (4) empirical evidence. Using an iterative and collaborative process supported by a structured data collection form, the six authors identified a total of 58 studies that primarily address HFE issues in health information technology (e.g., usability) and in the work of healthcare workers. About two-thirds of the mixed methods studies used the convergent parallel study design where quantitative and qualitative data were collected simultaneously. A variety of methods were used for collecting data, including interview, survey and observation. The most frequent combination involved interview for qualitative data and survey for quantitative data. The use of mixed methods in healthcare HFE research has increased over time. However, increasing attention should be paid to the formal literature on mixed methods research to enhance the depth and breadth of this research.

  14. A Systematic Review of Mixed Methods Research on Human Factors and Ergonomics in Health Care

    PubMed Central

    Carayon, Pascale; Kianfar, Sarah; Li, Yaqiong; Xie, Anping; Alyousef, Bashar; Wooldridge, Abigail

    2016-01-01

    This systematic literature review provides information on the use of mixed methods research in human factors and ergonomics (HFE) research in health care. Using the PRISMA methodology, we searched four databases (PubMed, PsycInfo, Web of Science, and Engineering Village) for studies that met the following inclusion criteria: (1) field study in health care, (2) mixing of qualitative and quantitative data, (3) HFE issues, and (4) empirical evidence. Using an iterative and collaborative process supported by a structured data collection form, the six authors identified a total of 58 studies that primarily address HFE issues in health information technology (e.g., usability) and in the work of healthcare workers. About two-thirds of the mixed methods studies used the convergent parallel study design where quantitative and qualitative data were collected simultaneously. A variety of methods were used for collecting data, including interview, survey and observation. The most frequent combination involved interview for qualitative data and survey for quantitative data. The use of mixed methods in healthcare HFE research has increased over time. However, increasing attention should be paid to the formal literature on mixed methods research to enhance the depth and breadth of this research. PMID:26154228

  15. A new method to manipulate broiler chicken growth and metabolism: Response to mixed LED light system.

    PubMed

    Yang, Yefeng; Yu, Yonghua; Pan, Jinming; Ying, Yibin; Zhou, Hong

    2016-01-01

    Present study introduced a new method to manipulate broiler chicken growth and metabolism by mixing the growth-advantage LED. We found that the green/blue LED mixed light system (G-B and G × B) have the similar stimulatory effect on chick body weight with single green light and single blue light (G and B), compared with normal artificial light (P = 0.028). Moreover, the percentage of carcass was significantly greater in the mixed light (G × B) when compared with the single light (P = 0.003). Synchronized with body weight, the mixed light (G-B and G × B) had a significant improved influence on the feed conversion of birds compared with normal light (P = 0.002). A significant improvement in feed conversion were found in mixed light (G × B) compared with single LED light (P = 0.037). G group resulted in a greater high-density lipoprotein cholesterol level than B group (P = 0.002), whereas B group resulted in a greater low-density lipoprotein cholesterol level than G group (P = 0.017). The mixed light significantly increased the birds' glucose level in comparison with the single light (P = 0.003). This study might establish an effective strategy for maximizing growth of chickens by mixed LED technology. PMID:27170597

  16. A new method to manipulate broiler chicken growth and metabolism: Response to mixed LED light system

    PubMed Central

    Yang, Yefeng; Yu, Yonghua; Pan, Jinming; Ying, Yibin; Zhou, Hong

    2016-01-01

    Present study introduced a new method to manipulate broiler chicken growth and metabolism by mixing the growth-advantage LED. We found that the green/blue LED mixed light system (G-B and G × B) have the similar stimulatory effect on chick body weight with single green light and single blue light (G and B), compared with normal artificial light (P = 0.028). Moreover, the percentage of carcass was significantly greater in the mixed light (G × B) when compared with the single light (P = 0.003). Synchronized with body weight, the mixed light (G-B and G × B) had a significant improved influence on the feed conversion of birds compared with normal light (P = 0.002). A significant improvement in feed conversion were found in mixed light (G × B) compared with single LED light (P = 0.037). G group resulted in a greater high-density lipoprotein cholesterol level than B group (P = 0.002), whereas B group resulted in a greater low-density lipoprotein cholesterol level than G group (P = 0.017). The mixed light significantly increased the birds’ glucose level in comparison with the single light (P = 0.003). This study might establish an effective strategy for maximizing growth of chickens by mixed LED technology. PMID:27170597

  17. A new method to manipulate broiler chicken growth and metabolism: Response to mixed LED light system

    NASA Astrophysics Data System (ADS)

    Yang, Yefeng; Yu, Yonghua; Pan, Jinming; Ying, Yibin; Zhou, Hong

    2016-05-01

    Present study introduced a new method to manipulate broiler chicken growth and metabolism by mixing the growth-advantage LED. We found that the green/blue LED mixed light system (G-B and G × B) have the similar stimulatory effect on chick body weight with single green light and single blue light (G and B), compared with normal artificial light (P = 0.028). Moreover, the percentage of carcass was significantly greater in the mixed light (G × B) when compared with the single light (P = 0.003). Synchronized with body weight, the mixed light (G-B and G × B) had a significant improved influence on the feed conversion of birds compared with normal light (P = 0.002). A significant improvement in feed conversion were found in mixed light (G × B) compared with single LED light (P = 0.037). G group resulted in a greater high-density lipoprotein cholesterol level than B group (P = 0.002), whereas B group resulted in a greater low-density lipoprotein cholesterol level than G group (P = 0.017). The mixed light significantly increased the birds’ glucose level in comparison with the single light (P = 0.003). This study might establish an effective strategy for maximizing growth of chickens by mixed LED technology.

  18. A Hybrid Numerical Method for Turbulent Mixing Layers. Degree awarded by Case Western Reserve Univ.

    NASA Technical Reports Server (NTRS)

    Georgiadis, Nicholas J.

    2001-01-01

    A hybrid method has been developed for simulations of compressible turbulent mixing layers. Such mixing layers dominate the flows in exhaust systems of modern day aircraft and also those of hypersonic vehicles currently under development. The method configurations in which a dominant structural feature provides an unsteady mechanism to drive the turbulent development in the mixing layer. The hybrid method uses a Reynolds-averaged Navier-Stokes (RANS) procedure to calculate wall bounded regions entering a mixing section, and a Large Eddy Simulation (LES) procedure to calculate the mixing dominated regions. A numerical technique was developed to enable the use of the hybrid RANS-LES method on stretched, non-Cartesian grids. Closure for the RANS equations was obtained using the Cebeci-Smith algebraic turbulence model in conjunction with the wall-function approach of Ota and Goldberg. The wall-function approach enabled a continuous computational grid from the RANS regions to the LES region. The LES equations were closed using the Smagorinsky subgrid scale model. The hybrid RANS-LES method is applied to a benchmark compressible mixing layer experiment. Preliminary two dimensional calculations are used to investigate the effects of axial grid density and boundary conditions. Vortex shedding from the base region of a splitter plate separating the upstream flows was observed to eventually transition to turbulence. The location of the transition, however, was much further downstream than indicated by experiments. Actual LES calculations, performed in three spatial directions, also indicated vortex shedding, but the transition to turbulence was found to occur much closer to the beginning of the mixing section. which is in agreement with experimental observations. These calculations demonstrated that LES simulations must be performed in three dimensions. Comparisons of time-averaged axial velocities and turbulence intensities indicated reasonable agreement with experimental

  19. Mixed-Methods and Mixed-Worlds: Engaging Globally Distributed User Groups for Extended Evaluation and Studies

    NASA Astrophysics Data System (ADS)

    Livingstone, Daniel; Bloomfield, Peter R.

    At first glance, the goal of the SLOODLE (Simulation Linked Object Oriented Dynamic Learning Environment) project is to develop educational technology - specifically, software for integrating web-based virtual learning environments and 3D multi-user virtual worlds being used for educational purposes. However, a second goal is to research how such integration might best be achieved - and to understand what users might want from such technology. And both goals rely in part on a third - to develop an active and involved community engaged in a participatory design process. This paper reviews the mixed-methods approaches that have been employed to support research as the project principals have been working to engage with users world-wide through a range of activities held in the virtual world of Second LifeTM (SL), on the world-wide web and at demonstration workshops conducted in-person.

  20. A Mixed-Methods Study Investigating the Relationship between Media Multitasking Orientation and Grade Point Average

    ERIC Educational Resources Information Center

    Lee, Jennifer

    2012-01-01

    The intent of this study was to examine the relationship between media multitasking orientation and grade point average. The study utilized a mixed-methods approach to investigate the research questions. In the quantitative section of the study, the primary method of statistical analyses was multiple regression. The independent variables for the…

  1. A Mixed Methods Content Analysis of the Research Literature in Science Education

    ERIC Educational Resources Information Center

    Schram, Asta B.

    2014-01-01

    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…

  2. Enhancing Learning Outcomes through Evaluation of Serious Gaming: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Douglas, Kerrie Anna

    2012-01-01

    This study compared the change in counseling student's self-efficacy and skill related to suicide assessment and intervention through the use of a novel intervention-oriented evaluation method, evaluation focused discussion groups, in an experimental embedded mixed methods design. An innovation counselor pedagogical tool, Suicide Risk…

  3. A Health Website Recommendation from Gold Coast General Practitioners to Their Patients: A Mixed Method Approach

    ERIC Educational Resources Information Center

    Usher, Wayne

    2011-01-01

    Introduction: To identify health website recommendation trends by Gold Coast (Australia) general practitioners (GPs) to their patients. Method: A mixed method approach to data collection and analysis was employed. Quantitative data were collected using a prepaid postal survey, consisting of 17 questions, mailed to 250 (61 per cent) of 410 GPs on…

  4. Telling It All : A Story of Women's Social Capital Using a Mixed Methods Approach

    ERIC Educational Resources Information Center

    Hodgkin, Suzanne

    2008-01-01

    The aim of this article is to demonstrate how quantitative and qualitative methods can be us together in feminist research. Despite an increasing number of texts and journal articles detailing mixed methods research, there are relatively few published reports of its use in feminist study. This article draws on a study conducted in regional…

  5. Searching for Rigour in the Reporting of Mixed Methods Population Health Research: A Methodological Review

    ERIC Educational Resources Information Center

    Brown, K. M.; Elliott, S. J.; Leatherdale, S. T.; Robertson-Wilson, J.

    2015-01-01

    The environments in which population health interventions occur shape both their implementation and outcomes. Hence, when evaluating these interventions, we must explore both intervention content and context. Mixed methods (integrating quantitative and qualitative methods) provide this opportunity. However, although criteria exist for establishing…

  6. A Review of Mixed Methods Research on Bullying and Peer Victimization in School

    ERIC Educational Resources Information Center

    Hong, Jun Sung; Espelage, Dorothy L.

    2012-01-01

    Recognizing the negative outcomes associated with experiences in bullying at school, educational researchers, school officials, and policy-makers have called for more rigorous research on bullying in school. Research on bullying behavior in school has primarily been examined using quantitative methods. Mixed methods research in the field of…

  7. Adolescent (Mis)Perceptions about Nicotine Addiction: Results from a Mixed-Methods Study

    ERIC Educational Resources Information Center

    Roditis, Maria; Lee, Joann; Halpern-Felsher, Bonnie L.

    2016-01-01

    Purpose: Despite evidence that adolescents become addicted to nicotine even after limited use, adolescents believe they can experiment with or smoke cigarettes for a few years and easily quit. The goal of this study was to examine adolescents' understanding of the definition and process of nicotine addiction using a mixed-methods approach. Method:…

  8. The Presentation of Self in Letters of Application: A Mixed-Method Approach

    ERIC Educational Resources Information Center

    Soroko, Emilia

    2012-01-01

    The application letter, as the first phase of employment-seeking, is an opportunity for a job applicant to make a favorable impression on a potential employer. In the current study, the author used a mixed-method approach to empirically explore strategies for self-presentation in job application letters and determine the methods used in the…

  9. Speckle contrast optical tomography: A new method for deep tissue three-dimensional tomography of blood flow

    PubMed Central

    Varma, Hari M.; Valdes, Claudia P.; Kristoffersen, Anna K.; Culver, Joseph P.; Durduran, Turgut

    2014-01-01

    A novel tomographic method based on the laser speckle contrast, speckle contrast optical tomography (SCOT) is introduced that allows us to reconstruct three dimensional distribution of blood flow in deep tissues. This method is analogous to the diffuse optical tomography (DOT) but for deep tissue blood flow. We develop a reconstruction algorithm based on first Born approximation to generate three dimensional distribution of flow using the experimental data obtained from tissue simulating phantoms. PMID:24761306

  10. Method for the fabrication of three-dimensional microstructures by deep X-ray lithography

    DOEpatents

    Sweatt, William C.; Christenson, Todd R.

    2005-04-05

    A method for the fabrication of three-dimensional microstructures by deep X-ray lithography (DXRL) comprises a masking process that uses a patterned mask with inclined mask holes and off-normal exposures with a DXRL beam aligned with the inclined mask holes. Microstructural features that are oriented in different directions can be obtained by using multiple off-normal exposures through additional mask holes having different orientations. Various methods can be used to block the non-aligned mask holes from the beam when using multiple exposures. A method for fabricating a precision 3D X-ray mask comprises forming an intermediate mask and a master mask on a common support membrane.

  11. Experimental Validation of Methods for Prophylaxis against Deep Venous Thrombosis: A Review and Proposal

    PubMed Central

    Agutter, Paul S.; Malone, P. Colm; Silver, Ian A.

    2012-01-01

    The experimental procedure by which the valve cusp hypoxia (VCH) hypothesis of the etiology of deep venous thrombosis (DVT) was confirmed lends itself to testing of methods of prophylaxis. Similar animal experiments could end the present exclusive reliance on statistical analysis of data from large patient cohorts to evaluate prophylactic regimes. The reduction of need for such (usually retrospective) analyses could enable rationally-based clinical trials of prophylactic methods to be conducted more rapidly, and the success of such trials would lead to decreased incidences of DVT-related mortality and morbidity. This paper reviews the VCH hypothesis (“VCH thesis”, following its corroboration) and its implications for understanding DVT and its sequelae, and outlines the experimental protocol for testing prophylactic methods. The advantages and limitations of the protocol are briefly discussed. PMID:22567254

  12. Experimental Validation of Methods for Prophylaxis against Deep Venous Thrombosis: A Review and Proposal.

    PubMed

    Agutter, Paul S; Malone, P Colm; Silver, Ian A

    2012-01-01

    The experimental procedure by which the valve cusp hypoxia (VCH) hypothesis of the etiology of deep venous thrombosis (DVT) was confirmed lends itself to testing of methods of prophylaxis. Similar animal experiments could end the present exclusive reliance on statistical analysis of data from large patient cohorts to evaluate prophylactic regimes. The reduction of need for such (usually retrospective) analyses could enable rationally-based clinical trials of prophylactic methods to be conducted more rapidly, and the success of such trials would lead to decreased incidences of DVT-related mortality and morbidity. This paper reviews the VCH hypothesis ("VCH thesis", following its corroboration) and its implications for understanding DVT and its sequelae, and outlines the experimental protocol for testing prophylactic methods. The advantages and limitations of the protocol are briefly discussed.

  13. Explicating Metatheory for Mixed Methods Research in Educational Leadership: An Application of Habermas's "Theory of Communicative Action"

    ERIC Educational Resources Information Center

    Whiteman, Rodney S.

    2015-01-01

    Purpose: Mixed methods research can provide a fruitful line of inquiry for educational leadership, program evaluation, and policy analysis; however, mixed methods research requires a metatheory that allows for mixing what have traditionally been considered incompatible qualitative and quantitative inquiry. The purpose of this paper is to apply…

  14. Points of Convergence in Music Education: The Use of Data Labels as a Strategy for Mixed Methods Integration

    ERIC Educational Resources Information Center

    Fitzpatrick, Kate R.

    2016-01-01

    Although the mixing of quantitative and qualitative data is an essential component of mixed methods research, the process of integrating both types of data in meaningful ways can be challenging. The purpose of this article is to describe the use of data labels in mixed methods research as a technique for the integration of qualitative and…

  15. Development of an Empirical Methods for Predicting Jet Mixing Noise of Cold Flow Rectangular Jets

    NASA Technical Reports Server (NTRS)

    Russell, James W.

    1999-01-01

    This report presents an empirical method for predicting the jet mixing noise levels of cold flow rectangular jets. The report presents a detailed analysis of the methodology used in development of the prediction method. The empirical correlations used are based on narrow band acoustic data for cold flow rectangular model nozzle tests conducted in the NASA Langley Jet Noise Laboratory. There were 20 separate nozzle test operating conditions. For each operating condition 60 Hz bandwidth microphone measurements were made over a frequency range from 0 to 60,000 Hz. Measurements were performed at 16 polar directivity angles ranging from 45 degrees to 157.5 degrees. At each polar directivity angle, measurements were made at 9 azimuth directivity angles. The report shows the methods employed to remove screech tones and shock noise from the data in order to obtain the jet mixing noise component. The jet mixing noise was defined in terms of one third octave band spectral content, polar and azimuth directivity, and overall power level. Empirical correlations were performed over the range of test conditions to define each of these jet mixing noise parameters as a function of aspect ratio, jet velocity, and polar and azimuth directivity angles. The report presents the method for predicting the overall power level, the average polar directivity, the azimuth directivity and the location and shape of the spectra for jet mixing noise of cold flow rectangular jets.

  16. Method for stabilizing low-level mixed wastes at room temperature

    DOEpatents

    Wagh, Arun S.; Singh, Dileep

    1997-01-01

    A method to stabilize solid and liquid waste at room temperature is provided comprising combining solid waste with a starter oxide to obtain a powder, contacting the powder with an acid solution to create a slurry, said acid solution containing the liquid waste, shaping the now-mixed slurry into a predetermined form, and allowing the now-formed slurry to set. The invention also provides for a method to encapsulate and stabilize waste containing cesium comprising combining the waste with Zr(OH).sub.4 to create a solid-phase mixture, mixing phosphoric acid with the solid-phase mixture to create a slurry, subjecting the slurry to pressure; and allowing the now pressurized slurry to set. Lastly, the invention provides for a method to stabilize liquid waste, comprising supplying a powder containing magnesium, sodium and phosphate in predetermined proportions, mixing said powder with the liquid waste, such as tritium, and allowing the resulting slurry to set.

  17. Method for stabilizing low-level mixed wastes at room temperature

    DOEpatents

    Wagh, A.S.; Singh, D.

    1997-07-08

    A method to stabilize solid and liquid waste at room temperature is provided comprising combining solid waste with a starter oxide to obtain a powder, contacting the powder with an acid solution to create a slurry, said acid solution containing the liquid waste, shaping the now-mixed slurry into a predetermined form, and allowing the now-formed slurry to set. The invention also provides for a method to encapsulate and stabilize waste containing cesium comprising combining the waste with Zr(OH){sub 4} to create a solid-phase mixture, mixing phosphoric acid with the solid-phase mixture to create a slurry, subjecting the slurry to pressure; and allowing the now pressurized slurry to set. Lastly, the invention provides for a method to stabilize liquid waste, comprising supplying a powder containing magnesium, sodium and phosphate in predetermined proportions, mixing said powder with the liquid waste, such as tritium, and allowing the resulting slurry to set. 4 figs.

  18. Application of the control volume mixed finite element method to a triangular discretization

    USGS Publications Warehouse

    Naff, R.L.

    2012-01-01

    A two-dimensional control volume mixed finite element method is applied to the elliptic equation. Discretization of the computational domain is based in triangular elements. Shape functions and test functions are formulated on the basis of an equilateral reference triangle with unit edges. A pressure support based on the linear interpolation of elemental edge pressures is used in this formulation. Comparisons are made between results from the standard mixed finite element method and this control volume mixed finite element method. Published 2011. This article is a US Government work and is in the public domain in the USA. ?? 2012 John Wiley & Sons, Ltd. This article is a US Government work and is in the public domain in the USA.

  19. A novel method of microneedle array fabrication using inclined deep x-ray exposure

    NASA Astrophysics Data System (ADS)

    Moon, Sang Jun; Jin, Chun Yan; Lee, Seung S.

    2006-04-01

    We report a novel fabrication method for the microneedle array with a 3-dimentional feature and its replication method; ''Hot-pressing'' process with bio-compatible material, PLLA (Poly L-LActide). Using inclined deep X-ray exposure technique, we fabricate a band type microneedle array with a single body on the same material basement. Since the single body feature does not make adhesion problem with the microneedle shank and basement during peel-off step of a mold, the PMMA (Poly-Methyl-MethAcrylate) microneedle array mold insert can be used for mold process which is used with the soft material mold, PDMS (Poly-Di- Methyl-Siloxane). The side inclined deep X-ray exposure also makes complex 3-dimentional features by the regions which are not exposed during twice successive exposure steps. In addition, the successive exposure does not need an additional mask alignment after the first side exposure. The fabricated band type microneedle array mold inserts are assembled for large area patch type out-of-plane microneedle array. The bio-compatible microneedle array can be fabricated to the laboratory scale mass production by the single body PMMA mold insert and ''Hot-pressing'' process.

  20. Shear wave velocity analysis of a deep seated gravel landslide structure using the microtremor survey method

    NASA Astrophysics Data System (ADS)

    Su, L.; Xu, X.; Liao, H.; Geng, X.-Y.

    2015-09-01

    The depth and geometry of potential failure surface is the fundamental for evaluating the mechanisms of a landslide. Traditional techniques to acquire information on potential sliding surface are mainly drilling, pitting, and trenching, but these techniques are time consuming and expensive. In this study, microtremor signals and the dispersion curves of surface wave are extracted from the vertical component of microtremor records using the spatial autocorrelation (SPAC) method to estimate shear wave velocity structure. The results suggest that the buried depth of phyllite bedrock is approximately 47.4m, and the thickness of weathered bedrock layer is about 9.9m at about 57.3m deep, which could be interpreted as the potential sliding surface of this landslide, in accordance with borehole data. The microtremor survey method (MSM) is flexible, non-invasive, relatively quick and deployable on the landslide. It clearly demonstrat that it is an effective tool to improve the drilling success rate, and hence allow a large scale and high density investigation of structure characteristics of a deep seated landslide.

  1. Qualitative and mixed methods in mental health services and implementation research.

    PubMed

    Palinkas, Lawrence A

    2014-01-01

    Qualitative and mixed methods play a prominent role in mental health services research. However, the standards for their use are not always evident, especially for those not trained in such methods. This article reviews the rationale and common approaches to using qualitative and mixed methods in mental health services and implementation research based on a review of the articles included in this special series along with representative examples from the literature. Qualitative methods are used to provide a "thick description" or depth of understanding to complement breadth of understanding afforded by quantitative methods, elicit the perspective of those being studied, explore issues that have not been well studied, develop conceptual theories or test hypotheses, or evaluate the process of a phenomenon or intervention. Qualitative methods adhere to many of the same principles of scientific rigor as quantitative methods but often differ with respect to study design, data collection, and data analysis strategies. For instance, participants for qualitative studies are usually sampled purposefully rather than at random and the design usually reflects an iterative process alternating between data collection and analysis. The most common techniques for data collection are individual semistructured interviews, focus groups, document reviews, and participant observation. Strategies for analysis are usually inductive, based on principles of grounded theory or phenomenology. Qualitative methods are also used in combination with quantitative methods in mixed-method designs for convergence, complementarity, expansion, development, and sampling. Rigorously applied qualitative methods offer great potential in contributing to the scientific foundation of mental health services research.

  2. Reactive Transport Modelling By Using Euleria-Lagrangian Methods Based on Mixing

    NASA Astrophysics Data System (ADS)

    soler Sagarra, J.; Nardi, A.; Saaltink, M.; Carrera, J.

    2014-12-01

    Reactive transport use to be a complicated problem by the difficulty of finding a universal numerical method, which reproduces the natural behaviour. Eulerian methods provide accurate results, since they give second order convergence, but they require meeting stability conditions that restrict their actual applicability. Eulerian - Lagrangian methods overcome these limitations, but often cause additional mixing by numerical dispersion. This is a particularly serious problem when transport is coupled to fast chemical reactions, whose rate is controlled by mixing. This work proposes an Eulerian-Lagrangià method without numerical dispersion for solving reactive transport based on mixing. The method consists on the construction of a streamline oriented grid such that the transit time between sequential cells remains constant (isochronal mesh). We have tested the method performances in two different cases: 1) Instantaneous point injection with analytical solution and 2) considering an isolated fracture. In both we have compared the proposed method against existing Eulerian and Eulerian-Lagrangian methods. The results confirm that the proposed method is superior to the two existing cases where dispersivities are medium and low, although the method needs additional refinements in mediums with great heterogeneous. In addition, a new reactive transport method has been obtained.

  3. Prospects of electromagnetic methods application for evaluation of deep geothermal resources of intraplate regions

    NASA Astrophysics Data System (ADS)

    Pushkarev, P.; Khmelevskoy, V.; Golubtsova, N.

    2013-12-01

    Due to increase of demand for energy resources and development of technologies of their extraction, the number of regions, where geothermal resources are used, is growing. These resources were used in the areas with surface indications of geothermal activity, but now geothermal energy is exploited in the regions with no such indications and, which is more important, where deep temperatures are lower in most cases. Hereafter, usage of the Earth's deep heat may become effective everywhere, including intraplate regions and, in particular, cratons. However, here the depth of boreholes, required to reach temperatures 250 - 350 0C, making electricity production possible, should be about 10 km. Geothermal resources can be divided to hydrothermal and petrothermal. The former are connected with thermal groundwater. As soon as some groundwater deposits were depleted, recharge of reservoirs using reinjection boreholes was applied. Petrothermal resources are connected with deep hot dry rocks of intraplate regions, for their exploitation closed-loop petrothermal circulation systems (PCS) can be used. In such a system water is pumped into injecting well(s), gets hot in the reservoir, created by means of hydrofracturing, and is pumped out from exploitation well(s). When choosing a location for a PCS, the main criterion is proximity to a consumer of energy and, especially, of hot water for heating. However, efficiency of choice depends on structure, state and thermal regime of the interiors and can be increased by application of geophysical methods, including electromagnetic (EM). In general, application of EM methods is possible at three stages: 1) Regional studies, when zones of probable increase of deep temperatures are revealed; 2) Detailed explorations, near-surface and deep, in the area, selected for PCS construction; 3) Monitoring, for imaging of the reservoir during its creation and exploitation. Here we will concentrate on the first stage. The depth range of our interest

  4. Connecting the Dots and Merging Meaning: Using Mixed Methods to Study Primary Care Delivery Transformation

    PubMed Central

    Scammon, Debra L; Tomoaia-Cotisel, Andrada; Day, Rachel L; Day, Julie; Kim, Jaewhan; Waitzman, Norman J; Farrell, Timothy W; Magill, Michael K

    2013-01-01

    Objective. To demonstrate the value of mixed methods in the study of practice transformation and illustrate procedures for connecting methods and for merging findings to enhance the meaning derived. Data Source/Study Setting. An integrated network of university-owned, primary care practices at the University of Utah (Community Clinics or CCs). CC has adopted Care by Design, its version of the Patient Centered Medical Home. Study Design. Convergent case study mixed methods design. Data Collection/Extraction Methods. Analysis of archival documents, internal operational reports, in-clinic observations, chart audits, surveys, semistructured interviews, focus groups, Centers for Medicare and Medicaid Services database, and the Utah All Payer Claims Database. Principal Findings. Each data source enriched our understanding of the change process and understanding of reasons that certain changes were more difficult than others both in general and for particular clinics. Mixed methods enabled generation and testing of hypotheses about change and led to a comprehensive understanding of practice change. Conclusions. Mixed methods are useful in studying practice transformation. Challenges exist but can be overcome with careful planning and persistence. PMID:24279836

  5. Students awareness of learning styles and their perceptions to a mixed method approach for learning

    PubMed Central

    Bhagat, Anumeha; Vyas, Rashmi; Singh, Tejinder

    2015-01-01

    Background: Individualization of instructional method does not contribute significantly to learning outcomes although it is known that students have differing learning styles (LSs). Hence, in order to maximally enhance learning, one must try to use a mixed method approach. Hypothesis: Our hypothesis was that awareness of preferred LS and motivation to incorporate multiple learning strategies might enhance learning outcomes. Aim: Our aim was to determine the impact of awareness of LS among medical undergraduates and motivating students to use mixed methods of learning. Materials and Methods: Before awareness lecture, LS preferences were determined using Visual, Aural, Read/Write, and Kinesthetic (VARK) questionnaire. Awareness of LS was assessed using a validated questionnaire. Through a lecture, students were oriented to various LSs, impact of LS on their performance, and benefit of using mixed method approach for learning. Subsequently, group discussions were organized. After 3 months, VARK preferences and awareness of LSs were reassessed. Student narratives were collected. Qualitative analysis of the data was done. Results: There was a significant increase in the number of students who were aware of LS. The number of participants showing a change in VARK scores for various modalities of learning was also significant (P < 0.001). Conclusion: Thus, awareness of LSs motivated students to adapt other learning strategies and use mixed methods for learning. PMID:26380214

  6. Origin of the Apollo 14, 15, and 17 yellow ultramafic glasses by mixing of deep cumulate remelts

    NASA Astrophysics Data System (ADS)

    Brown, S. M.; Grove, T. L.

    2015-12-01

    We examine the fO2-dependent melting conditions of the Apollo 14 yellow intermediate-Ti ultramafic glasses and the melting processes that formed the full suite of lunar yellow ultramafic glasses. Multiple saturation experiments indicate that the Apollo 14 yellow glass would have been in equilibrium with residual olivine and low-Ca pyroxene near 1530 °C and 2.4 GPa at ΔIW = +2. At ΔIW = -2, the multiple saturation point moves to greater depth and higher temperature to 1580 °C and 3.0 GPa. Combining the results of this study with that of Krawczynski and Grove (2012) on more Ti-rich Apollo orange and red glass indicates that the fO2-induced change in multiple saturation pressure correlates with the Fe-Ti# (molar (FeO + TiO2*)/(MgO + FeO + TiO2*), where TiO2* = all Ti calculated as Ti4+) of the liquid. Further, a decrease in the olivine Fe-Mg exchange coefficient at lower fO2 suggests that Fe2+ is complexing more efficiently with Ti3+ at the expense of Mg in the melt than it did with Ti4+ at higher fO2. Processes involving assimilation and/or fractionation and/or melt-wall rock reaction all fail to produce the within-suite compositional variability observed in the Apollo 14, 15, and 17 yellow glasses. Mixing of remelted source cumulates, combined with small amounts of olivine fractionation, are the only mechanisms that can reproduce all three trends. We present a quantitative model of the mixing process with simultaneous olivine fractionation. Remarkably, the trends can be explained by mixing melts of an ultramafic source (olivine + pigeonite or orthopyroxene), a clinopyroxene + ilmenite bearing cumulate, and KREEP. Lunar mantle overturn is the most likely process that can reconcile the observed major and trace element compositional characteristics and the experimental results. These two constraints are consistent with different models of lunar magma ocean crystallization (Snyder et al., 1992; Eklins-Tanton et al., 2011). A complex, hot thermal history is necessary

  7. An Improved Method for Predicting Linear B-cell Epitope Using Deep Maxout Networks.

    PubMed

    Lian, Yao; Huang, Ze Chi; Ge, Meng; Pan, Xian Ming

    2015-06-01

    To establish a relation between an protein amino acid sequence and its tendencies to generate antibody response, and to investigate an improved in silico method for linear B-cell epitope (LBE) prediction. We present a sequence-based LBE predictor developed using deep maxout network (DMN) with dropout training techniques. A graphics processing unit (GPU) was used to reduce the training time of the model. A 10-fold cross-validation test on a large, non-redundant and experimentally verified dataset (Lbtope_Fixed_ non_redundant) was performed to evaluate the performance. DMN-LBE achieved an accuracy of 68.33% and an area under the receiver operating characteristic curve (AUC) of 0.743, outperforming other prediction methods in the field. A web server, DMN-LBE, of the improved prediction model has been provided for public free use. We anticipate that DMN-LBE will be beneficial to vaccine development, antibody production, disease diagnosis, and therapy.

  8. Texture-depending performance of an in situ method assessing deep seepage

    NASA Astrophysics Data System (ADS)

    Hohenbrink, Tobias L.; Lischeid, Gunnar

    2014-04-01

    Deep seepage estimation is important for water balance investigations of groundwater and the vadose zone. A simplified Buckingham-Darcy method to assess time series of deep seepage fluxes was proposed by Schindler and Müller (1998). In the method dynamics of water fluxes are calculated by a soil hydraulic conductivity function. Measured soil moistures and matric heads are used as input data. Resulting time series of flux dynamics are scaled to realistic absolute levels by calibrating the method with the areal water balance. An assumption of the method is that water fluxes at different positions exhibit identical dynamics although their absolute values can differ. The aim of this study was to investigate uncertainties of that method depending on the particle size distribution and textural heterogeneity in non-layered soils. We performed a numerical experiment using the two-dimensional Richards Equation. A basic model of transient water fluxes beneath the root and capillary zone was setup and used to simulate time series of soil moisture, matric head, and seepage fluxes for 4221 different cases of particle size distribution and intensities of textural heterogeneity. Soil hydraulic parameters were predicted by the pedotransfer function Rosetta. Textural heterogeneity was modeled with Miller and Miller scaling factors arranged in spatial random fields. Seepage fluxes were calculated with the Buckingham-Darcy method from simulated soil moisture and matric head time series and compared with simulated reference fluxes. The median of Root Mean Square Error was about 0.026 cm d-1 and the median of maximum cross correlation was 0.96 when the method was calibrated adequately. The method's performance was mainly influenced by (i) the soil textural class and (ii) the time period used for flux calibration. It performed best in sandy loam while hotspots of errors occurred in sand and silty texture. Calibrating the method with time periods that exhibit high variance of seepage

  9. Transient modeling/analysis of hyperbolic heat conduction problems employing mixed implicit-explicit alpha method

    NASA Technical Reports Server (NTRS)

    Tamma, Kumar K.; D'Costa, Joseph F.

    1991-01-01

    This paper describes the evaluation of mixed implicit-explicit finite element formulations for hyperbolic heat conduction problems involving non-Fourier effects. In particular, mixed implicit-explicit formulations employing the alpha method proposed by Hughes et al. (1987, 1990) are described for the numerical simulation of hyperbolic heat conduction models, which involves time-dependent relaxation effects. Existing analytical approaches for modeling/analysis of such models involve complex mathematical formulations for obtaining closed-form solutions, while in certain numerical formulations the difficulties include severe oscillatory solution behavior (which often disguises the true response) in the vicinity of the thermal disturbances, which propagate with finite velocities. In view of these factors, the alpha method is evaluated to assess the control of the amount of numerical dissipation for predicting the transient propagating thermal disturbances. Numerical test models are presented, and pertinent conclusions are drawn for the mixed-time integration simulation of hyperbolic heat conduction models involving non-Fourier effects.

  10. Assessment of condensation of water vapor in the mixing chamber by CFD method

    NASA Astrophysics Data System (ADS)

    Vojkůvková, Petra; Šikula, Ondřej; Weyr, Jan

    2015-05-01

    The analyzed topic belongs to the field of design and operation of HVAC systems, focusing mainly on mixing chambers. The paper deals with problems of condensation and freezing of water vapour on walls of mixing chambers in a special case, when the partial pressure of the final resulting state of the mixture of warm moist air and colder air is located above the saturation limit. Experimental in situ methods and computer computational fluid dynamics (CFD) modelling method were used for processing. The main contribution of this work is the finding that partial condensation and freezing of water vapour may occur in local parts of the mixing chamber. It causes problems in terms of hygienic safety and service life of these devices. In particular it has been found that condensation and freezing of water vapour may occur even if relative humidity of the resulting mixture is about 70 %.

  11. Evaluation of Listeria monocytogenes survival in ice cream mixes flavored with herbal tea using Taguchi method.

    PubMed

    Ozturk, Ismet; Golec, Adem; Karaman, Safa; Sagdic, Osman; Kayacier, Ahmed

    2010-10-01

    In this study, the effects of the incorporation of some herbal teas at different concentrations into the ice cream mix on the population of Listeria monocytogenes were studied using Taguchi method. The ice cream mix samples flavored with herbal teas were prepared using green tea and sage at different concentrations. Afterward, fresh culture of L. monocytogenes was inoculated into the samples and the L. monocytogenes was counted at different storage periods. Taguchi method was used for experimental design and analysis. In addition, some physicochemical properties of samples were examined. Results suggested that there was some effect, although little, on the population of L. monocytogenes when herbal tea was incorporated into the ice cream mix. Additionally, the use of herbal tea caused a decrease in the pH values of the samples and significant changes in the color values.

  12. A Software Engineering Method for the Design of Mixed Reality Systems

    NASA Astrophysics Data System (ADS)

    Dupuy-Chessa, S.; Godet-Bar, G.; Pérez-Medina, J.-L.; Rieu, D.; Juras, D.

    The domain of mixed reality systems is currently making decisive advances on a daily basis. However, the knowledge and know-how of HCI scientists and interaction engineers, used in the design of such systems, are not well understood. This chapter addresses this issue by proposing a software engineering method that couples a process for designing mixed reality interaction with a process for developing the functional core. Our development method features a Y-shaped development cycle that separates the description of functional requirements and their analysis from the study of technical requirements of the application. These sub-processes produce Business Objects and Interactional Objects, which are connected to produce a complete mixed reality system. The whole process is presented via a case study, with a particular emphasis on the design of the interactive solution.

  13. Examining mixing methods in an evaluation of a smoking cessation program.

    PubMed

    Betzner, Anne; Lawrenz, Frances P; Thao, Mao

    2016-02-01

    Three different methods were used in an evaluation of a smoking cessation study: surveys, focus groups, and phenomenological interviews. The results of each method were analyzed separately and then combined using both a pragmatic and dialectic stance to examine the effects of different approaches to mixing methods. Results show that the further apart the methods are philosophically, the more diverse the findings. Comparisons of decision maker opinions and costs of the different methods are provided along with recommendations for evaluators' uses of different methods.

  14. Probability density function method for variable-density pressure-gradient-driven turbulence and mixing

    SciTech Connect

    Bakosi, Jozsef; Ristorcelli, Raymond J

    2010-01-01

    Probability density function (PDF) methods are extended to variable-density pressure-gradient-driven turbulence. We apply the new method to compute the joint PDF of density and velocity in a non-premixed binary mixture of different-density molecularly mixing fluids under gravity. The full time-evolution of the joint PDF is captured in the highly non-equilibrium flow: starting from a quiescent state, transitioning to fully developed turbulence and finally dissipated by molecular diffusion. High-Atwood-number effects (as distinguished from the Boussinesq case) are accounted for: both hydrodynamic turbulence and material mixing are treated at arbitrary density ratios, with the specific volume, mass flux and all their correlations in closed form. An extension of the generalized Langevin model, originally developed for the Lagrangian fluid particle velocity in constant-density shear-driven turbulence, is constructed for variable-density pressure-gradient-driven flows. The persistent small-scale anisotropy, a fundamentally 'non-Kolmogorovian' feature of flows under external acceleration forces, is captured by a tensorial diffusion term based on the external body force. The material mixing model for the fluid density, an active scalar, is developed based on the beta distribution. The beta-PDF is shown to be capable of capturing the mixing asymmetry and that it can accurately represent the density through transition, in fully developed turbulence and in the decay process. The joint model for hydrodynamics and active material mixing yields a time-accurate evolution of the turbulent kinetic energy and Reynolds stress anisotropy without resorting to gradient diffusion hypotheses, and represents the mixing state by the density PDF itself, eliminating the need for dubious mixing measures. Direct numerical simulations of the homogeneous Rayleigh-Taylor instability are used for model validation.

  15. Residual Stress Analysis in Deep Drawn Twinning Induced Plasticity (TWIP) Steels Using Neutron Diffraction Method

    NASA Astrophysics Data System (ADS)

    Hong, Seokmin; Lee, Junghoon; Lee, Sunghak; Woo, Wanchuck; Kim, Sung-Kyu; Kim, Hyoung Seop

    2014-04-01

    In Twinning Induced Plasticity (TWIP) steels, delayed fracture occurs due to residual stresses induced during deep drawing. In order to investigate the relation between residual stresses and delayed fracture, in the present study, residual stresses of deep drawn TWIP steels (22Mn-0.6C and 18Mn-2Al-0.6C steels) were investigated using the finite element method (FEM) and neutron diffraction measurements. In addition, the delayed fracture properties were examined by dipping tests of cup specimens in the boiled water. In the FEM analysis, the hoop direction residual stress was highly tensile at cup edge, and the delayed fracture was initiated by the separation of hoop direction and propagated in an axial direction. According to the neutron diffraction analysis, residual stresses in 18Mn-2Al-0.6C steel were about half the residual stresses in 22Mn-0.6C steel. From the residual strain measurement using electron back-scatter diffraction, formation of deformation twins caused a lot of grain rotation and local strain at the grain boundaries and twin boundaries. These local residual strains induce residual stress at boundaries. Al addition in TWIP steels restrained the formation of deformation twins and dynamic strain aging, resulting in more homogeneous stress and strain distributions in cup specimens. Thus, in Al-added TWIP steels, residual stress of cup specimen considerably decreased, and delayed fracture resistance was remarkably improved by the addition of Al in TWIP steels.

  16. Deep crustal anatexis, magma mixing, and the generation of epizonal plutons in the Southern Rocky Mountains, Colorado

    NASA Astrophysics Data System (ADS)

    Jacob, Kristin H.; Farmer, G. Lang; Buchwaldt, Robert; Bowring, Samuel A.

    2015-01-01

    The Never Summer Mountains in north-central Colorado, USA, are cored by two Oligocene, epizonal granitic plutons originally emplaced in the shallow levels of a short-lived (~1 m.y.), small-volume continental magmatic system. The younger Mt. Cumulus stock (28.015 ± 0.012 Ma) is a syenogranite equivalent compositionally to topaz rhyolites. A comparison to the chemical and isotopic composition of crustal xenoliths entrained in nearby Devonian kimberlites demonstrates that the silicic melts parental to the stock were likely derived from anatexis of local Paleoproterozoic, garnet-absent, mafic lower continental crust. In contrast, the older Mt. Richthofen stock is compositionally heterogeneous and ranges from monzodiorite to monzogranite. Major and trace element abundances and Sr, Nd and Pb isotopic ratios in this stock vary regularly with increasing whole rock wt% SiO2. These data suggest that the Mt. Richthofen stock was constructed from mixed mafic and felsic magmas, the former corresponding to lithosphere-derived basaltic magmas similar isotopically to mafic enclaves entrained in the eastern portions of the stock and the latter corresponding to less differentiated versions of the silicic melts parental to the Mt. Cumulus stock. Zircon U-Pb geochronology further reveals that the Mt. Richthofen stock was incrementally emplaced over a time interval from at least 28.975 ± 0.020 to 28.742 ± 0.053 Ma. Magma mixing could have occurred either in situ in the upper crust during basaltic underplating and remelting of an antecedent, incrementally emplaced, silicic intrusive body, or at depth in the lower crust prior to periodic magma ascent and emplacement in the shallow crust. Overall, the two stocks demonstrate that magmatism associated with the Never Summer igneous complex was fundamentally bimodal in composition. Highly silicic anatectic melts of the mafic lower crust and basaltic, mantle-derived magmas were the primary melts in the magma system, with mixing of the two

  17. Development of a Hybrid RANS/LES Method for Turbulent Mixing Layers

    NASA Technical Reports Server (NTRS)

    Georgiadis, Nicholas J.; Alexander, J. Iwan D.; Reshotko, Eli

    2001-01-01

    Significant research has been underway for several years in NASA Glenn Research Center's nozzle branch to develop advanced computational methods for simulating turbulent flows in exhaust nozzles. The primary efforts of this research have concentrated on improving our ability to calculate the turbulent mixing layers that dominate flows both in the exhaust systems of modern-day aircraft and in those of hypersonic vehicles under development. As part of these efforts, a hybrid numerical method was recently developed to simulate such turbulent mixing layers. The method developed here is intended for configurations in which a dominant structural feature provides an unsteady mechanism to drive the turbulent development in the mixing layer. Interest in Large Eddy Simulation (LES) methods have increased in recent years, but applying an LES method to calculate the wide range of turbulent scales from small eddies in the wall-bounded regions to large eddies in the mixing region is not yet possible with current computers. As a result, the hybrid method developed here uses a Reynolds-averaged Navier-Stokes (RANS) procedure to calculate wall-bounded regions entering a mixing section and uses a LES procedure to calculate the mixing-dominated regions. A numerical technique was developed to enable the use of the hybrid RANS-LES method on stretched, non-Cartesian grids. With this technique, closure for the RANS equations is obtained by using the Cebeci-Smith algebraic turbulence model in conjunction with the wall-function approach of Ota and Goldberg. The LES equations are closed using the Smagorinsky subgrid scale model. Although the function of the Cebeci-Smith model to replace all of the turbulent stresses is quite different from that of the Smagorinsky subgrid model, which only replaces the small subgrid turbulent stresses, both are eddy viscosity models and both are derived at least in part from mixing-length theory. The similar formulation of these two models enables the RANS

  18. A comparison of the atmospheres of Jupiter and Saturn: deep atmospheric composition, cloud structure, vertical mixing, and origin.

    PubMed

    Atreya, S K; Wong, M H; Owen, T C; Mahaffy, P R; Niemann, H B; de Pater, I; Drossart, P; Encrenaz, T h

    1999-01-01

    We present our current understanding of the composition, vertical mixing, cloud structure and the origin of the atmospheres of Jupiter and Saturn. Available observations point to a much more vigorous vertical mixing in Saturn's middle-upper atmosphere than in Jupiter's. The nearly cloud-free nature of the Galileo probe entry site, a 5-micron hotspot, is consistent with the depletion of condensable volatiles to great depths, which is attributed to local meteorology. Somewhat similar depletion of water may be present in the 5-micron bright regions of Saturn also. The supersolar abundances of heavy elements, particularly C and S in Jupiter's atmosphere and C in Saturn's, as well as the progressive increase of C from Jupiter to Saturn and beyond, tend to support the icy planetesimal model of the formation of the giant planets and their atmospheres. However, much work remains to be done, especially in the area of laboratory studies, including identification of possible new microwave absorbers, and modelling, in order to resolve the controversy surrounding the large discrepancy between Jupiter's global ammonia abundance, hence the nitrogen elemental ratio, derived from the earth-based microwave observations and that inferred from the analysis of the Galileo probe-orbiter radio attenuation data for the hotspot. We look forward to the observations from Cassini-Huygens spacecraft which are expected to result not only in a rich harvest of information for Saturn, but a better understanding of the formation of the giant planets and their atmospheres when these data are combined with those that exist for Jupiter.

  19. Deep seismic soundings on the 1-AP profile in the Barents Sea: Methods and results

    NASA Astrophysics Data System (ADS)

    Sakoulina, T. S.; Kashubin, S. N.; Pavlenkova, G. A.

    2016-07-01

    Profile 1-AP with a length of 1300 km intersects the Barents Sea from The Kola Peninsula to Franz Josef Land. The combined Common Depth Point (CDP) and Deep Seismic Sounding (DSS) seismic studies were carried out on this profile. The DSS measurements were conducted with the standalone bottom seismic stations with an interval of 5-20 km between them. The stations recorded the signals generated by the large air guns with a step of 250 m. Based on these data, the detailed P-velocity section of the Earth's crust and uppermost mantle have been constructed for the entire profile and the S-velocity section for its southern part. The use of a variety of methods for constructing the velocity sections enabled us to assess the capabilities of each method from the standpoint of the highest reliability and informativity of the models. The ray tracing method yielded the best results. The 1-PR profile crosses two large basins—the South Barents and North Barents ones, with the thickness of the sediments increasing from 8 to 10 km in the south to 12-15 km in the north. The Earth's crust pertains to the continental type along the entire profile. Its thickness averages 32 to 36 km and only increases to 43 km at the boundary between the two basins. The distinct change in the wave field at this boundary suggests the presence of a large deep fault in this zone. The high-velocity blocks are revealed in the crust of the South Barents basin, whereas the North Barents crust is characterized by relatively low velocities.

  20. A Lagrangian parcel based mixing plane method for calculating water based mixed phase particle flows in turbo-machinery

    NASA Astrophysics Data System (ADS)

    Bidwell, Colin S.

    2015-05-01

    A method for calculating particle transport through turbo-machinery using the mixing plane analogy was developed and used to analyze the energy efficient engine . This method allows the prediction of temperature and phase change of water based particles along their path and the impingement efficiency and particle impact property data on various components in the engine. This methodology was incorporated into the LEWICE3D V3.5 software. The method was used to predict particle transport in the low pressure compressor of the . The was developed by NASA and GE in the early 1980s as a technology demonstrator and is representative of a modern high bypass turbofan engine. The flow field was calculated using the NASA Glenn ADPAC turbo-machinery flow solver. Computations were performed for a Mach 0.8 cruise condition at 11,887 m assuming a standard warm day for ice particle sizes of 5, 20 and 100 microns and a free stream particle concentration of . The impingement efficiency results showed that as particle size increased average impingement efficiencies and scoop factors increased for the various components. The particle analysis also showed that the amount of mass entering the inner core decreased with increased particle size because the larger particles were less able to negotiate the turn into the inner core due to particle inertia. The particle phase change analysis results showed that the larger particles warmed less as they were transported through the low pressure compressor. Only the smallest 5 micron particles were warmed enough to produce melting with a maximum average melting fraction of 0.18. The results also showed an appreciable amount of particle sublimation and evaporation for the 5 micron particles entering the engine core (22.6 %).

  1. Studying the Impact of Academic Mobility on Intercultural Competence: A Mixed-Methods Perspective

    ERIC Educational Resources Information Center

    Cots, Josep M.; Aguilar, Marta; Mas-Alcolea, Sònia; Llanes, Àngels

    2016-01-01

    This paper contributes to the study of the impact of academic mobility on the development of students' intercultural competence (IC). Following Byram, IC is seen as comprising the three components of knowledge, behaviour and attitude. The study adopts a mixed-methods approach, analysing the results of a quantitative pre-stay post-stay survey…

  2. Teacher Perceptions of Principals' Leadership Qualities: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Hauserman, Cal P.; Ivankova, Nataliya V.; Stick, Sheldon L.

    2013-01-01

    This mixed methods sequential explanatory study utilized the Multi-factor Leadership Questionnaire, responses to open-ended questions, and in-depth interviews to identify transformational leadership qualities that were present among principals in Alberta, Canada. The first quantitative phase consisted of a random sample of 135 schools (with…

  3. Technology-Enhanced Multimedia Instruction in Foreign Language Classrooms: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Ketsman, Olha

    2012-01-01

    Technology-enhanced multimedia instruction in grades 6 through 12 foreign language classrooms was the focus of this study. The study's findings fill a gap in the literature through the report of how technology-enhanced multimedia instruction was successfully implemented in foreign language classrooms. Convergent parallel mixed methods study…

  4. Exploring and Testing the Predictors of New Faculty Success: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Stupnisky, R. H.; Weaver-Hightower, M. B.; Kartoshkina, Y.

    2015-01-01

    The purpose of this mixed methods study was to investigate and test the factors contributing to new faculty members' success. In the first phase, qualitative analysis of focus groups revealed four prominent themes affecting new faculty members: expectations, collegiality, balance, and location. In the second phase, new faculty members…

  5. The Promise of Mixed-Methods for Advancing Latino Health Research

    PubMed Central

    Apesoa-Varano, Ester Carolina; Hinton, Ladson

    2015-01-01

    Mixed-methods research in the social sciences has been conducted for quite some time. More recently, mixed-methods have become popular in health research, with the National Institutes of Health leading the impetus to fund studies that implement such an approach. The public health issues facing us today are great and they range from policy and other macro-level issues, to systems level problems to individuals' health behaviors. For Latinos, who are projected to become the largest minority group bearing a great deal of the burden of social inequality in the U.S., it is important to understand the deeply-rooted nature of these health disparities in order to close the gap in health outcomes. Mixed-methodology thus holds promise for advancing research on Latino heath by tackling health disparities from a variety of standpoints and approaches. The aim of this manuscript is to provide two examples of mixed methods research, each of which addresses a health topic of considerable importance to older Latinos and their families. These two examples will illustrate a) the complementary use of qualitative and quantitative methods to advance health of older Latinos in an area that is important from a public health perspective, and b) the “translation” of findings from observational studies (informed by social science and medicine) to the development and testing of interventions. PMID:23996325

  6. Promise for Enhancing Children's Reading Attitudes through Peer Reading: A Mixed Method Approach

    ERIC Educational Resources Information Center

    Lee, Youngju

    2014-01-01

    Peer-Assisted Learning Strategies (PALS) was implemented for supplementary reading classes in a Korean elementary school. The treatment group children were exposed to PALS during 20 min sessions, 4 times a week, for 8 weeks. The impacts of PALS were investigated in 3 aspects using a mixed-methods approach: improvement in reading attitudes, reading…

  7. Mixed Methods Research with Internally Displaced Colombian Gay and Bisexual Men and Transwomen

    ERIC Educational Resources Information Center

    Zea, Maria Cecilia; Aguilar-Pardo, Marcela; Betancourt, Fabian; Reisen, Carol A.; Gonzales, Felisa

    2014-01-01

    We discuss the use of mixed methods research to further understanding of displaced Colombian gay and bisexual men and transwomen, a marginalized population at risk. Within the framework of communicative action, which calls for social change through egalitarian dialog, we describe how our multinational, interdisciplinary research team explored the…

  8. Understanding Succession Planning and Management Efforts at Midwestern University: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Mateso, Peter E. E.

    2010-01-01

    The purpose of this concurrent triangulation mixed methods study was to understand the status of succession planning and management (SPM) efforts of the subject university as perceived by the fulltime academic and fulltime administrative staff. Four research questions guided this study: (1) how do fulltime academic staff and fulltime…

  9. Mindful Leaders in Highly Effective Schools: A Mixed-Method Application of Hoy's M-Scale

    ERIC Educational Resources Information Center

    Kearney, W. Sean; Kelsey, Cheryl; Herrington, David

    2013-01-01

    This article presents a mixed-method study utilizing teacher ratings of principal mindfulness from 149 public schools in Texas and follow-up qualitative data analysis through semi-structured interviews conducted with the top 10 percent of princeipals identified as mindful. This research is based on the theoretical framework of mindfulness as…

  10. Educating Linguistically Diverse Students: A Mixed Methods Study of Elementary Teachers' Coursework, Attitudes, and Practice

    ERIC Educational Resources Information Center

    Greenfield, Renée A.

    2016-01-01

    This study followed a mixed-methods sequential explanatory design. Phase I involved the collection of quantitative data to examine inservice teachers' (N = 69) attitudes about language and linguistic diversity as well as their teacher education coursework. All participants were graduates from the same teacher education program. Phase II included…

  11. A Mixed-Methods Assessment of Using an Online Commercial Tutoring System to Teach Introductory Statistics

    ERIC Educational Resources Information Center

    Xu, Yonghong Jade; Meyer, Katrina A.; Morgan, Dianne D.

    2009-01-01

    This study used a mixed-methods approach to evaluate a hybrid teaching format that incorporated an online tutoring system, ALEKS, to address students' learning needs in a graduate-level introductory statistics course. Student performance in the hybrid course with ALEKS was found to be no different from that in a course taught in a traditional…

  12. 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…

  13. Engineers' Perceptions of Diversity and the Learning Environment at Work: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Firestone, Brenda L.

    2012-01-01

    The purpose of this dissertation research study was to investigate engineers' perceptions of diversity and the workplace learning environment surrounding diversity education efforts in engineering occupations. The study made use of a mixed methods methodology and was theoretically framed using a critical feminist adult education lens and…

  14. 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…

  15. Exploration of Undergraduate Preservice Teachers' Experiences Learning Advocacy: A Mixed-Methods Study

    ERIC Educational Resources Information Center

    Massengale, Kelley; Childers-McKee, Cherese; Benavides, Aerin

    2014-01-01

    Applying transformational critical advocacy research in college instruction can be a powerful way to engage students in challenging inequity in society and promoting positive changes. Few studies systematically measure the impact of such pedagogy on the development of college students' beliefs about advocacy. In this mixed methods study, we…

  16. Exploring Dual Identification among Muslim-American Emerging Adults: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Sirin, Selcuk R.; Bikmen, Nida; Mir, Madeeha; Fine, Michelle; Zaal, Mayida; Katsiaficas, Dalal

    2008-01-01

    This mixed methods study explored dual identification among Muslim-American emerging adults of immigrant origin. A closer look was taken at the relationship between American and Muslim identifications and how this relationship was influenced by experiences of discrimination, acculturative and religious practices, and whether it varied by gender.…

  17. Teacher Support and Adolescents' Subjective Well-Being: A Mixed-Methods Investigation

    ERIC Educational Resources Information Center

    Suldo, Shannon M.; Friedrich, Allison A.; White, Tiffany; Farmer, Jennie; Minch, Devon; Michalowski, Jessica

    2009-01-01

    Adolescents' subjective well-being (SWB) is associated with a variety of schooling experiences, particularly their perceptions of teacher support. This article presents results of a mixed-methods study conducted to identify which types of perceived social support enacted by teachers are most strongly associated with middle school students' SWB…

  18. Development of Academic Self-Efficacy in Women during College: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Smith, Savala

    2013-01-01

    Although women account for more than 50% of the college degrees awarded nationally, The College of Idaho has had a challenge retaining female students. There are any number of reasons for women's struggle to persist at the college, but one of the most basic may be a matter of self-efficacy. This mixed methods study used a combination of…

  19. Behavioral Changes Based on a Course in Agroecology: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Harms, Kristyn; King, James; Francis, Charles

    2009-01-01

    This study evaluated and described student perceptions of a course in agroecology to determine if participants experienced changed perceptions and behaviors resulting from the Agroecosystems Analysis course. A triangulation validating quantitative data mixed methods approach included a written survey comprised of both quantitative and open-ended…

  20. Key Competencies and Characteristics for Innovative Teaching among Secondary School Teachers: A Mixed-Methods Research

    ERIC Educational Resources Information Center

    Zhu, Chang; Wang, Di

    2014-01-01

    This research aims to understand the key competencies and characteristics for innovative teaching as perceived by Chinese secondary teachers. A mixed-methods research was used to investigate secondary teachers' views. First, a qualitative study was conducted with interviews of teachers to understand the perceived key competencies and…

  1. A Mixed-Method Exploration of Functioning in Safe Schools/Healthy Students Partnerships

    ERIC Educational Resources Information Center

    Merrill, Marina L.; Taylor, Nicole L.; Martin, Alison J.; Maxim, Lauren A.; D'Ambrosio, Ryan; Gabriel, Roy M.; Wendt, Staci J.; Mannix, Danyelle; Wells, Michael E.

    2012-01-01

    This paper presents a mixed-method approach to measuring the functioning of Safe Schools/Healthy Students (SS/HS) Initiative partnerships. The SS/HS national evaluation team developed a survey to collect partners' perceptions of functioning within SS/HS partnerships. Average partnership functioning scores were used to rank each site from lowest to…

  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. Translating Basic Behavioral and Social Science Research to Clinical Application: The EVOLVE Mixed Methods Approach

    ERIC Educational Resources Information Center

    Peterson, Janey C.; Czajkowski, Susan; Charlson, Mary E.; Link, Alissa R.; Wells, Martin T.; Isen, Alice M.; Mancuso, Carol A.; Allegrante, John P.; Boutin-Foster, Carla; Ogedegbe, Gbenga; Jobe, Jared B.

    2013-01-01

    Objective: To describe a mixed-methods approach to develop and test a basic behavioral science-informed intervention to motivate behavior change in 3 high-risk clinical populations. Our theoretically derived intervention comprised a combination of positive affect and self-affirmation (PA/SA), which we applied to 3 clinical chronic disease…

  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. How L2 Legal Writers Use Strategies for Scholarly Writing: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Bain Butler, Donna

    2010-01-01

    This dissertation research fills existing gaps regarding the practices and processes of teaching second language (L2) writers at higher ranges of proficiency in law school context. It is a mixed methods, longitudinal, descriptive, writer-centered study. The research purpose was to explore strategic competence as a catalyst for professional…

  6. Perceptions of Organizational Culture of a Multi-Campus Community College District: Mixed Methods in Concert

    ERIC Educational Resources Information Center

    Kuster Dale, Kimberly

    2012-01-01

    This concurrent, mixed-methods case study analyzed perceptions of current and preferred organizational culture within a rural, multi-campus community college district. This phenomenon was examined by analyzing and comparing data collected by surveying all full-time employees utilizing the Organizational Culture Assessment Instrument (OCAI) and…

  7. Beginning Secondary Science Teacher Induction: A Two-Year Mixed Methods Study

    ERIC Educational Resources Information Center

    Luft, Julie A.; Firestone, Jonah B.; Wong, Sissy S.; Ortega, Ira; Adams, Krista; Bang, EunJin

    2011-01-01

    Those who study secondary science teachers are often concerned with preservice or in-service teacher development. Science teacher educators have acknowledged that this focus is limited, as the induction years of beginning teachers are an important component of teacher development. This mixed methods study focuses on the induction years of…

  8. Understanding the Impact of School Factors on School Counselor Burnout: A Mixed-Methods Study

    ERIC Educational Resources Information Center

    Bardhoshi, Gerta; Schweinle, Amy; Duncan, Kelly

    2014-01-01

    This mixed-methods study investigated the relationship between burnout and performing noncounseling duties among a national sample of professional school counselors, while identifying school factors that could attenuate this relationship. Results of regression analyses indicate that performing noncounseling duties significantly predicted burnout…

  9. The Performance of a Method for the Long-Term Equating of Mixed-Format Assessment

    ERIC Educational Resources Information Center

    Kamata, Akihito; Tate, Richard

    2005-01-01

    The goal of this study was the development of a procedure to predict the equating error associated with the long-term equating method of Tate (2003) for mixed-format tests. An expression for the determination of the error of an equating based on multiple links using the error for the component links was derived and illustrated with simulated data.…

  10. A Mixed-Methods Study Comparing the Perceived Spiritual Benefits of Topical and Extended Scripture Memorization

    ERIC Educational Resources Information Center

    Johnson, Andy

    2010-01-01

    The purpose of this mixed-methods study is to compare the perceived benefits of topical Scripture memorization (TSM) with the perceived benefits of extended Scripture memorization (ESM) to explore if one strategy fosters more perceived spiritual growth than the other. A baseline for the study is established by investigating the historical,…

  11. Originality Detection Software in a Graduate Policy Course: A Mixed-Methods Evaluation of Plagiarism

    ERIC Educational Resources Information Center

    Dreuth Zeman, Laura; Steen, Julie A.; Metz Zeman, Natalie

    2011-01-01

    The authors used a mixed-methods approach to evaluate the use of Turnitin originality detection software in a graduate social work course. Qualitative analysis of student responses revealed positive and negative spent completing assignments, and the tone of the class. Quantitative analysis of students' originality scores indicated a short-term…

  12. Support, Belonging, Motivation, and Engagement in the College Classroom: A Mixed Method Study

    ERIC Educational Resources Information Center

    Zumbrunn, Sharon; McKim, Courtney; Buhs, Eric; Hawley, Leslie R.

    2014-01-01

    This explanatory sequential mixed methods study examined how belonging perceptions, academic motivation, and engagement might mediate the relationship between academic contextual characteristics and achievement using structural equation modeling and qualitative follow-up interviews with college students from a large, Midwestern university. In the…

  13. Expanding the Family Economic Stress Model: Insights from a Mixed-Methods Approach

    ERIC Educational Resources Information Center

    Mistry, Rashmita S.; Lowe, Edward D.; Benner, Aprile D.; Chien, Nina

    2008-01-01

    The current study used a mixed-methods approach to examine how low-income mothers managed their household economies, their experiences of economic pressure, and the consequences for family and child functioning. Qualitative analyses (N = 32 families) revealed that experiences of economic pressure were associated with an inability to afford "both"…

  14. Intercultural Competence and Student Engagement of U.S. Community College Students: A Mixed Method Study

    ERIC Educational Resources Information Center

    Riley, Rebecca L.; Bustamante, Rebecca M.; Edmonson, Stacey L.

    2016-01-01

    In a culturally diverse society, United States community colleges are ideally positioned to develop intercultural competence in students. This mixed method study focused on the relationship between student engagement, as measured by the Community College Survey of Student Engagement (CCSSE) (2005), and intercultural competence, as assessed by the…

  15. Motivation Beliefs of Secondary School Teachers in Canada and Singapore: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Klassen, Robert M.; Chong, Wan Har; Huan, Vivien S.; Wong, Isabella; Kates, Allison; Hannok, Wanwisa

    2008-01-01

    A mixed methods approach was used to explore secondary teachers' motivation beliefs in Canada and Singapore. Results from Study 1 revealed that socio-economic status (SES) was the strongest predictor of school climate in Canada, and that collective efficacy mediated the effect of SES on school climate in Singapore, but not in Canada. In Study 2,…

  16. Associations between Children's Physical Activities, Sedentary Behaviours and Family Structure: A Sequential Mixed Methods Approach

    ERIC Educational Resources Information Center

    Quarmby, T.; Dagkas, S.; Bridge, M.

    2011-01-01

    This mixed method paper explored the effect of family structure on children's physical activities and sedentary pursuits. It furthers the limited understanding of how family structure impacts on children's time in, and reasons behind engaging in, certain physical activities. Children from three inner city comprehensive schools in the Midlands,…

  17. Mixed Methods Analysis of Multicultural Identity and Psychological Help Seeking Beliefs in College Students

    ERIC Educational Resources Information Center

    Walter, Jeffrey P.

    2012-01-01

    Research on the psychological help-seeking beliefs and behaviors of college students has provided evidence for differences among students based on demographic factors, with different variables being salient for different cultural groups. This mixed methods study focuses on understanding how common psychological help-seeking variables, including…

  18. School Resource Officers for Bullying Interventions: A Mixed-Methods Analysis

    ERIC Educational Resources Information Center

    Robles-Pina, Rebecca A.; Denham, Magdalena A.

    2012-01-01

    The number of school police officers, School Resource Officers (SROs), is increasing on school campuses to assist in preventing school violence, and in particular bullying. This mixed-methods study was conducted to compare the knowledge and perceptions of SROs (N = 184) hired by independent school districts (ISD SROs) and those contracted from law…

  19. Social Influences on Fertility: A Comparative Mixed Methods Study in Eastern and Western Germany

    ERIC Educational Resources Information Center

    Bernardi, Laura; Keim, Sylvia; von der Lippe, Holger

    2007-01-01

    This article uses a mixed methods design to investigate the effects of social influence on family formation in a sample of eastern and western German young adults at an early stage of their family formation. Theoretical propositions on the importance of informal interaction for fertility and family behavior are still rarely supported by systematic…

  20. Asian International Students' Willingness to Seek Counseling: A Mixed-Methods Study

    ERIC Educational Resources Information Center

    Li, Peiwei; Wong, Y. Joel; Toth, Paul

    2013-01-01

    Using a mixed-methods survey design that was predominantly quantitative, this study explored Asian international students' willingness to seek counseling. Participants were 177 Asian international students recruited from a U.S. Midwestern University. After controlling for attitudes toward psychological help-seeking and past counseling experience,…

  1. Students' Attitudes toward Statistics across the Disciplines: A Mixed-Methods Approach

    ERIC Educational Resources Information Center

    Griffith, James D.; Adams, Lea T.; Gu, Lucy L.; Hart, Christian L.; Nichols-Whitehead, Penney

    2012-01-01

    Students' attitudes toward statistics were investigated using a mixed-methods approach including a discovery-oriented qualitative methodology among 684 undergraduate students across business, criminal justice, and psychology majors where at least one course in statistics was required. Students were asked about their attitudes toward statistics and…

  2. Monogamy on the Street: A Mixed Methods Study of Homeless Men

    ERIC Educational Resources Information Center

    Brown, Ryan A.; Kennedy, David P.; Tucker, Joan S.; Golinelli, Daniela; Wenzel, Suzanne L.

    2013-01-01

    In this study, we used a mixed methods approach to explore the determinants of relationship patterns and risky sex among homeless men living in downtown Los Angeles. This involved analysis of qualitative interviews focused on gender ideology and sexual events ("n" = 30) as well as structured interviews ("n" = 305) focused on…

  3. A Mixed Methods Explanatory Study of Intermediate School Collaboration and Inclusion

    ERIC Educational Resources Information Center

    Sanchez, Sandra J.

    2012-01-01

    This mixed methods explanatory study addressed the problem of continuing disparity in achievement between students with special needs and their peers in the educational setting, despite mandates requiring schools to educate these students in the least restrictive environment. The purpose of this study was to determine the types and extent of…

  4. Mixed Methods Case Study of Generational Patterns in Responses to Shame and Guilt

    ERIC Educational Resources Information Center

    Ng, Tony

    2013-01-01

    Moral socialization and moral learning are antecedents of moral motivation. As many as 4 generations interact in workplace and education settings; hence, a deeper understanding of the moral motivation of members of those generations is needed. The purpose of this convergent mixed methods case study was to understand the moral motivation of 5…

  5. Feminist Approaches to Triangulation: Uncovering Subjugated Knowledge and Fostering Social Change in Mixed Methods Research

    ERIC Educational Resources Information Center

    Hesse-Biber, Sharlene

    2012-01-01

    This article explores the deployment of triangulation in the service of uncovering subjugated knowledge and promoting social change for women and other oppressed groups. Feminist approaches to mixed methods praxis create a tight link between the research problem and the research design. An analysis of selected case studies of feminist praxis…

  6. Broadening Horizons in a Shrinking World: A Mixed Method Study on Foreign Language Learning

    ERIC Educational Resources Information Center

    Miranda-Aldaco, Citlali

    2012-01-01

    This study examined the effectiveness of a bilingual/bicultural technology intervention on beginning learners of Spanish at a public university in the United States and intermediate learners of English at a public university in Mexico. This study used a quasi-experimental mixed method design and compared gains in grammar, listening, and reading…

  7. Family Functioning in Families with a Child with Down Syndrome: A Mixed Methods Approach

    ERIC Educational Resources Information Center

    Povee, K.; Roberts, L.; Bourke, J.; Leonard, H.

    2012-01-01

    Background: This study aimed to explore the factors that predict functioning in families with a child with Down syndrome using a mixed methods design. The quantitative component examined the effect of maladaptive and autism-spectrum behaviours on the functioning of the family while the qualitative component explored the impact of having a child…

  8. Why Did They Stay? A Mixed Methods Approach to Understand Student Persistence

    ERIC Educational Resources Information Center

    Banks, Hardil Kay

    2012-01-01

    This study utilizes Pierre Bourdieu's concept of cultural and social capital as a theoretical framework to understand student persistence. The research design is a mixed-methods approach, using data collected through the "Social and Cultural Capital Questionnaire" and interviews with select survey participants. The sample includes…

  9. Relationship between Educational Resources and School Achievement: A Mixed Method Intra-District Analysis

    ERIC Educational Resources Information Center

    Jimenez-Castellanos, Oscar

    2010-01-01

    This study examines the relationship between educational resources (fiscal, personnel and facilities) and school achievement within a large urban/suburban elementary school district. A sequential mixed methods approach reveals inequitable resource allocation trends and patterns between schools within a school district by producing different…

  10. Understanding Perspectives of English Language Learning and Assessment Practices: A Mixed-Method Embedded Study

    ERIC Educational Resources Information Center

    Bailey, Angela Christine

    2013-01-01

    This study contributed to the continuing dialogue of quality language programs and student outcomes for classroom language learning and assessments within the standardized testing era to language learning programs within Colombia. The particular purpose of this one-phase, embedded, mixed-method study examined students' and teachers' beliefs about…

  11. 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…

  12. Mixed Methods Analysis and Information Visualization: Graphical Display for Effective Communication of Research Results

    ERIC Educational Resources Information Center

    Onwuegbuzie, Anthony J.; Dickinson, Wendy B.

    2008-01-01

    In this paper, we introduce various graphical methods that can be used to represent data in mixed research. First, we present a broad taxonomy of visual representation. Next, we use this taxonomy to provide an overview of visual techniques for quantitative data display and qualitative data display. Then, we propose what we call "crossover" visual…

  13. The Health Role of Local Area Coordinators in Scotland: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Brown, Michael; Karatzias, Thanos; O'Leary, Lisa

    2013-01-01

    The study set out to explore whether local area coordinators (LACs) and their managers view the health role of LACs as an essential component of their work and identify the health-related activities undertaken by LACs in Scotland. A mixed methods cross-sectional phenomenological study involving local authority service managers (n = 25) and LACs (n…

  14. Caregiver Grief in Terminal Illness and Bereavement: A Mixed-Methods Study

    ERIC Educational Resources Information Center

    Waldrop, Deborah P.

    2007-01-01

    Caregivers experience multiple losses during the downhill trajectory of a loved one's terminal illness. Using mixed methods, this two-stage study explored caregiver grief during a terminal illness and after the care recipient's death. Caregiver grief was a state of heightened responsiveness during end-stage care: anxiety, hostility, depression,…

  15. A Mixed-Method Evaluation of a Strength-Based Bullying Prevention Program

    ERIC Educational Resources Information Center

    Rawana, Jennine S.; Norwood, Sarah Jane; Whitley, Jessica

    2011-01-01

    The goal of this study was to describe the strength-based bullying prevention program, "Strengths in Motion," and to evaluate the program utilizing a mixed-method design. Participants included students in Grades 4 to 8 from an intervention (n = 50) and a comparison (n = 53) school in Northern Ontario. Measures of bullying, strengths, and classroom…

  16. Do Zoo Visitors Come to Learn? An Internationally Comparative, Mixed-Methods Study

    ERIC Educational Resources Information Center

    Roe, Katie; McConney, Andrew

    2015-01-01

    Zoo visitors go to see animals, but are they there to learn? This mixed-methods study examines visitor learning from both zoos' and visitors' perspectives using qualitative and quantitative data. Five hundred and forty zoo visitor interviews from nine case studies provide insight into visitor intentions, which indicate that the majority of…

  17. Exploring Top-Rated MBA Programs for Best Practices in Internationalizing Curricula: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Flores, Kelly A.

    2010-01-01

    To investigate if, and how, curriculum developers are incorporating opportunities to develop global competence into business curricula, the Exploratory Design: Taxonomy Development Model (Qualitative Emphasized) was conducted on top-rated MBA programs. This three-phase mixed methods approach revealed 11 global competencies (or taxonomies) and 84…

  18. A Mixed-Methods Analysis of Reading Intervention Effectiveness in the Community College

    ERIC Educational Resources Information Center

    Dreyer, Melissa

    2012-01-01

    The purpose of this mixed-methods study was to determine if, when implemented at one two-year post-secondary institution, such K-12 reading comprehension strategies as concept mapping, think-aloud protocols, and Question-Answer Relationships (QAR) elicit change in COMPASS reading test scores of adult readers. Data was collected over four academic…

  19. Secondary Science Teachers' Beliefs and Persistence: A Longitudinal Mixed-Methods Study

    ERIC Educational Resources Information Center

    Wong, Sissy S.; Luft, Julie A.

    2015-01-01

    While many studies focus on why teachers leave the classroom, there remains a need to study why teachers persist in teaching. One area to study is the beliefs of teachers, which may impact persistence in the field. This 5-year mixed-methods study explored whether 35 beginning secondary science teachers' beliefs were related to their persistence in…

  20. Creating Rich Portraits: A Mixed-Methods Approach to Understanding Profiles of Intrinsic and Extrinsic Motivations

    ERIC Educational Resources Information Center

    Corpus, Jennifer Henderlong; Wormington, Stephanie V.; Haimovitz, Kyla

    2016-01-01

    A person-centered, mixed-methods approach (self-report surveys, semistructured interviews, school records) was used to characterize and evaluate profiles of intrinsic and extrinsic motivations among 243 third- through eighth-grade students. Cluster analysis suggested four distinct profiles: high quantity (high intrinsic, high extrinsic), primarily…

  1. A Mixed-Method Study of Language-Learning Motivation and Intercultural Contact of International Students

    ERIC Educational Resources Information Center

    Kormos, Judit; Csizér, Kata; Iwaniec, Janina

    2014-01-01

    The mixed-method study presented in this paper investigates the changes in direct and indirect intercultural contact and language-learning attitudes and effort of international students in the United Kingdom. Seventy international learners of English were asked to fill in a questionnaire three times during one academic year in an international…

  2. Education Student Research Paradigms and Emerging Scholar Identities: A Mixed-Methods Study

    ERIC Educational Resources Information Center

    Hales, Patrick D.; Croxton, Rebecca A.; Kirkman, Christopher J.

    2016-01-01

    Using a mixed-methods approach, this study sought to understand a general sense of paradigm confidence and to see how this confidence relates to doctoral student identities as emerging scholars. Identity development was explored among 46 education doctoral students at a midsized public university in the Southeast. Researchers examined students'…

  3. Mixed Methods in Indigenous Research: Building Relationships for Sustainable Intervention Outcomes

    ERIC Educational Resources Information Center

    Chilisa, Bagele; Tsheko, Gaelebale N.

    2014-01-01

    Indigenous communities raise concerns that they are overresearched and tired of research always asking the same questions and reproducing the same answers, thus pressuring researchers to open the discourse on mixed methods research so as to enable new debates and approaches to emerge. A postcolonial indigenous paradigm provides a theoretical…

  4. What We Learned about Mentoring Research Assistants Employed in a Complex, Mixed-Methods Health Study

    ERIC Educational Resources Information Center

    Weeks, Lori E.; Villeneuve, Michelle A.; Hutchinson, Susan; Roger, Kerstin; Versnel, Joan; Packer, Tanya

    2015-01-01

    We investigated the experiences of research assistants in their dual role as both employees and trainees, when they were employed in a complex, mixed-methods, Canadian study on the everyday experience of living with and managing a chronic condition. A total of 13 research assistants participated in one or more components of this study: a survey (n…

  5. Learning and Study Strategies of Students with Traumatic Brain Injury: A Mixed Method Study

    ERIC Educational Resources Information Center

    Bush, Erin; Hux, Karen; Zickefoose, Samantha; Simanek, Gina; Holmberg, Michelle; Henderson, Ambyr

    2011-01-01

    The purpose of this research was to explore the perceptions of four college students with severe traumatic brain injury and people associated with them regarding the use of learning skills and study strategies. The researchers employed a concurrent mixed method design using descriptive quantitative data as well as qualitative multiple case study…

  6. Scaffolding Argumentation about Water Quality: A Mixed-Method Study in a Rural Middle School

    ERIC Educational Resources Information Center

    Belland, Brian R.; Gu, Jiangyue; Armbrust, Sara; Cook, Brant

    2015-01-01

    A common way for students to develop scientific argumentation abilities is through argumentation about socioscientific issues, defined as scientific problems with social, ethical, and moral aspects. Computer-based scaffolding can support students in this process. In this mixed method study, we examined the use and impact of computer based…

  7. The Relationship between Task Difficulty and Second Language Fluency in French: A Mixed Methods Approach

    ERIC Educational Resources Information Center

    Préfontaine, Yvonne; Kormos, Judit

    2015-01-01

    While there exists a considerable body of literature on task-based difficulty and second language (L2) fluency in English as a second language (ESL), there has been little investigation with French learners. This mixed methods study examines learner appraisals of task difficulty and their relationship to automated utterance fluency measures in…

  8. Asian American College Students' Suicide Ideation: A Mixed-Methods Study

    ERIC Educational Resources Information Center

    Wong, Y. Joel; Koo, Kelly; Tran, Kimberly K.; Chiu, Yu-Chen; Mok, Yvonne

    2011-01-01

    The purpose of this mixed-methods study was to explore the phenomenon of suicide ideation among 293 Asian American college students. Guided by T. Joiner's (2005) interpersonal-psychological theory of suicidal behavior, the authors examined the relationships among perceived burdensomeness, thwarted belongingness, self-construals, and suicide…

  9. Good Practices for Student Learning: Mixed-Method Evidence from the Wabash National Study

    ERIC Educational Resources Information Center

    Goodman, Kathleen M.; Magolda, Marcia Baxter; Seifert, Tricia A.; King, Patricia M.

    2011-01-01

    Since 2006, 19 institutions across the United States have been trying to figure out how to work smarter through their participation in the Wabash National Study of Liberal Arts Education. Drawing on data from the first year of the study, the robust, mixed-methods study the authors report in this article evaluated growth in the first year of…

  10. Perceived Barriers and Facilitators to School Social Work Practice: A Mixed-Methods Study

    ERIC Educational Resources Information Center

    Teasley, Martell; Canifield, James P.; Archuleta, Adrian J.; Crutchfield, Jandel; Chavis, Annie McCullough

    2012-01-01

    Understanding barriers to practice is a growing area within school social work research. Using a convenience sample of 284 school social workers, this study replicates the efforts of a mixed-method investigation designed to identify barriers and facilitators to school social work practice within different geographic locations. Time constraints and…

  11. Exploring Writing of English Language Learners in Middle School: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Danzak, Robin L.

    2009-01-01

    The study's purpose was to assess, through mixed methods, written linguistic features of 20 Spanish-speaking English language learners (ELLs) in middle school. Students came from Mexico, Puerto Rico, and the Dominican Republic. Participants wrote two expository and two narrative formal texts, each in Spanish and English, for a total of eight…

  12. Toward a Better Understanding of Student Perceptions of Writing Feedback: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Zumbrunn, Sharon; Marrs, Sarah; Mewborn, Caitlin

    2016-01-01

    This explanatory sequential mixed methods study investigated the writing feedback perceptions of middle and high school students (N = 598). The predictive and mediational roles of writing self-efficacy and perceptions of writing feedback on student writing self-regulation aptitude were examined using mediation regression analysis. To augment the…

  13. Integrating Quantitative and Qualitative Data in Mixed Methods Research--Challenges and Benefits

    ERIC Educational Resources Information Center

    Almalki, Sami

    2016-01-01

    This paper is concerned with investigating the integration of quantitative and qualitative data in mixed methods research and whether, in spite of its challenges, it can be of positive benefit to many investigative studies. The paper introduces the topic, defines the terms with which this subject deals and undertakes a literature review to outline…

  14. Validity Argument for Assessing L2 Pragmatics in Interaction Using Mixed Methods

    ERIC Educational Resources Information Center

    Youn, Soo Jung

    2015-01-01

    This study investigates the validity of assessing L2 pragmatics in interaction using mixed methods, focusing on the evaluation inference. Open role-plays that are meaningful and relevant to the stakeholders in an English for Academic Purposes context were developed for classroom assessment. For meaningful score interpretations and accurate…

  15. Examination of a Dispositional System in a Teacher Education Program: A Mixed Methods Case Study

    ERIC Educational Resources Information Center

    Van Prooyen, Traci L.

    2013-01-01

    This mixed methods, case study research examined the teacher education program at Illinois State University (ISU-Normal, Illinois) as related to the views and assessment practices of the dispositions of its teacher candidates. Five years of quantitative and qualitative data from ISU's Disposition Concern form was collected and analyzed currently…

  16. Understanding Student Stress and Coping in Elementary School: A Mixed-Method, Longitudinal Study

    ERIC Educational Resources Information Center

    Sotardi, Valerie A.

    2016-01-01

    This mixed-method, longitudinal study examined daily school stress and coping strategies of elementary schoolchildren in the United States. Students (n = 65) between the ages of 7 and 11 years reported daily school stress measures for 8 weeks and completed individual stress and coping interviews. Results highlight critical relations between…

  17. 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…

  18. Mixed-Methods Resistance Training Increases Power and Strength of Young and Older Men.

    ERIC Educational Resources Information Center

    Newton, Robert U.; Hakkinen, Keijo; Hakkinen, Arja; McCormick, Matt; Volek, Jeff; Kraemer, William J.

    2002-01-01

    Examined the effects of a 10-week, mixed-methods resistance training program on young and older men. Although results confirmed some age-related reductions in muscle strength and power, the older men demonstrated similar capacity to the younger men for increases in muscle strength and power via an appropriate, periodized resistance training…

  19. Conditions That Facilitate Music Learning among Students with Special Needs: A Mixed-Methods Inquiry

    ERIC Educational Resources Information Center

    Gerrity, Kevin W.; Hourigan, Ryan M.; Horton, Patrick W.

    2013-01-01

    The purpose of this mixed-methods study was to identify and define the conditions that facilitate learning in music among students with special needs. Children with special needs met once a week for 10 consecutive weeks and received instruction in primarily music as well as the other arts. The children completed pre- and posttest evaluations that…

  20. Being Outside Learning about Science Is Amazing: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Weibel, Michelle L.

    2011-01-01

    This study used a convergent parallel mixed methods design to examine teachers' environmental attitudes and concerns about an outdoor educational field trip. Converging both quantitative data (Environmental Attitudes Scale and teacher demographics) and qualitative data (Open-Ended Statements of Concern and interviews) facilitated interpretation.…

  1. Meeting the Mixed Methods Challenge of Integration in a Sociological Study of Structure and Agency

    ERIC Educational Resources Information Center

    Woolley, Claire M.

    2009-01-01

    Substantial integration of quantitative and qualitative data and findings in mixed methods studies is seldom seen, although maximizing the potential of the approach depends on this. An absence of exemplars has been identified as among a number of factors that currently impede integration in studies carried out by researchers using the approach.…

  2. 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…

  3. Using Mixed Methods to Study First-Year College Impact on Liberal Arts Learning Outcomes

    ERIC Educational Resources Information Center

    Seifert, Tricia A.; Goodman, Kathleen; King, Patricia M.; Baxter Magolda, Marcia B.

    2010-01-01

    This study details the collection, analysis, and interpretation of data from a national multi-institutional longitudinal mixed methods study of college impact and student development of liberal arts outcomes. The authors found three sets of practices in the quantitative data that corroborated with the themes that emerged from the qualitative data:…

  4. Linking Faculty Development to Community College Student Achievement: A Mixed Methods Approach

    ERIC Educational Resources Information Center

    Elliott, Robert W.; Oliver, Diane E.

    2016-01-01

    Using a mixed methods, multilevel research design, this pilot inquiry explored the relationship between college faculty professional development and the academic achievement of diverse students by coupling two separate links: (a) the effects that professional development activities have on improving teaching strategies, and (b) the effects these…

  5. Procrastination and Motivation of Undergraduates with Learning Disabilities: A Mixed-Methods Inquiry

    ERIC Educational Resources Information Center

    Klassen, Robert M.; Krawchuk, Lindsey L.; Lynch, Shane L.; Rajani, Sukaina

    2008-01-01

    The purpose of this mixed-methods article was to report two studies exploring the relationships between academic procrastination and motivation in 208 undergraduates with (n = 101) and without (n = 107) learning disabilities (LD). In Study 1, the results from self-report surveys found that individuals with LD reported significantly higher levels…

  6. Rating Scale Impact on EFL Essay Marking: A Mixed-Method Study

    ERIC Educational Resources Information Center

    Barkaoui, Khaled

    2007-01-01

    Educators often have to choose among different types of rating scales to assess second-language (L2) writing performance. There is little research, however, on how different rating scales affect rater performance. This study employed a mixed-method approach to investigate the effects of two different rating scales on EFL essay scores, rating…

  7. A Combined Social Action, Mixed Methods Approach to Vocational Guidance Efficacy Research

    ERIC Educational Resources Information Center

    Perry, Justin C.

    2009-01-01

    This article proposes a social action, mixed methods approach to verifying the efficacy of vocational guidance programs. Research strategies are discussed in the context of how the processes and purposes of efficacy research have been conceptualized and studied in vocational psychology. Examples of how to implement this approach in future efficacy…

  8. A Mixed-Methods Investigation of Instructional Coaching for Teachers of Diverse Learners

    ERIC Educational Resources Information Center

    Teemant, Annela

    2014-01-01

    This longitudinal mixed-methods study investigates the efficacy and sustainability of instructional coaching outcomes among urban elementary teachers (N = 36) using focus group and quantitative pre-, post-, and 1 year-after intervention data. Coached teachers participated in a 30-hr workshop and then seven cycles of coaching (15 hr) targeting use…

  9. A Mixed Method Study on Freshman Students' Writing Performance as Addressed by Postsecondary Professors

    ERIC Educational Resources Information Center

    Hughes, Susan M.

    2009-01-01

    Research indicates that difficulty in general education classes significantly contributes to attrition among college freshmen. Accordingly, this mixed-method study sought to address the related problem of high school students' preparation for freshman composition or English classes. The purpose of the sequential explanatory study was to identify…

  10. Predicting High School Completion Using Student Performance in High School Algebra: A Mixed Methods Research Study

    ERIC Educational Resources Information Center

    Chiado, Wendy S.

    2012-01-01

    Too many of our nation's youth have failed to complete high school. Determining why so many of our nation's students fail to graduate is a complex, multi-faceted problem and beyond the scope of any one study. The study presented herein utilized a thirteen-step mixed methods model developed by Leech and Onwuegbuzie (2007) to demonstrate…

  11. An Exploration of a Collaborative Blogging Approach to Literacy and Learning: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Zawilinski, Lisa Marie

    2012-01-01

    The purpose of this study was to explore young students' use of a blog to communicate and share information. A mixed methods study was conducted to explore blogging skill gains at each of grades one and five, between classrooms that engaged in a collaborative blog activity and classrooms that did not. In addition, a new assessment of online…

  12. A Mixed Methods Investigation of Maternal Perspectives on Transition Experiences in Early Care and Education

    ERIC Educational Resources Information Center

    Swartz, Rebecca Anne; Speirs, Katherine Elizabeth; Encinger, Amy Johnson; McElwain, Nancy L.

    2016-01-01

    Research Findings: Strong relationships among children, families, and early care and education (ECE) providers are key to quality infant-toddler care. These relationships are shaped during the initial transition period to group care. We used a mixed methods approach to (a) assess maternal perspectives on the transition to group care, (b) explore…

  13. A Mixed-Methods Study of Mid-Career Science Teachers: The Growth of Professional Empowerment

    ERIC Educational Resources Information Center

    Moreland, Amy Laphelia

    2011-01-01

    The purpose of this concurrent, mixed-methods study was to examine the professional empowerment qualities of mid-career (years 4-8), science teachers. I used the construct of professional empowerment as the theoretical frame to explore K-12 mid-career science teachers' career trajectories and consider how they can be supported professionally and…

  14. Novel DNA Extraction Method Unveiled the Ancient Hot Deep Biosphere Concealed in Terrestrial Sedimentary Rocks

    NASA Astrophysics Data System (ADS)

    Kouduka, M.; Suko, T.; Okuzawa, K.; Fukuda, A.; Nanba, K.; Yamamoto, M.; Sakata, S.; Ito, K.; Suzuki, Y.

    2009-12-01

    It has been proposed that the hot deep biosphere is distributed deeply in the crust of the Earth. Below the upper limit of life, prokaryotic habitats extend at a depth of 4 km within a typical range of thermal gradients (2.5-3°C/100m). In contrary, large geothermal gradients allow the hot deep biosphere approaching to the Earth’s surface. We conducted aseptic and deoxygenated drilling targeting Miocene marine siliceous rocks in a tectonically stable inland fore-arc basin in central Japan. Although the in-situ groundwater temperature was 30.2°C at a maximum drilling depth of 352 mbgl, opal-CT and clinoptilolite, which commonly form as a result of progressive burial at 30-60°C and over 70°C, respectively, were detected by XRD analysis. However, burial-driven degradation and transformation of sterols (sterene to sterane) was not evident in the core samples. As presented by Y. Suzuki et al. in this meeting, extant microbial populations were dominated by Pseudomonas spp. and Flavobacterium spp. with cell numbers ranging ~107-108 cells/cm3 rock. Despite the abundance of microbial cells, DNA were not extracted from the core samples by conventional methods. We developed a DNA extraction method to avoid binding of DNA onto the siliceous mineral matrix by heating under alkaline conditions, which resulted in the successful retrieval of PCR-amplifiable DNA. Unexpectedly, 16S rRNA gene sequences closely related thermophilic Geobacillus stearothermophilus and Thermus thermophilus were dominant in the clone libraries from 300- and 350-m deep core samples, while those almost identical to the Pseudomonas spp. were minor. Based on the correlation between the GC contents of 16S rRNA gene sequences and growth temperatures of prokaryotes, the estimated growth temperatures were 90.0°C (G+C=66.3%) and 67.5°C (G+C=61.3%) for G. stearothermophilus and T. thermophilus, respectively. From these results, it is implied that temperature rise in the past led to the colonization of

  15. Numerical Evaluation of Fluid Mixing Phenomena in Boiling Water Reactor Using Advanced Interface Tracking Method

    NASA Astrophysics Data System (ADS)

    Yoshida, Hiroyuki; Takase, Kazuyuki

    Thermal-hydraulic design of the current boiling water reactor (BWR) is performed with the subchannel analysis codes which incorporated the correlations based on empirical results including actual-size tests. Then, 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. In this situation, 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, a detailed Two-Phase Flow simulation code using advanced Interface Tracking method: TPFIT is developed to calculate the detailed information of the two-phase flow. In this paper, firstly, we tried to verify the TPFIT code by comparing it with the existing 2-channel air-water mixing experimental results. Secondary, the TPFIT code was applied to simulation of steam-water two-phase flow in a model of two subchannels of a current BWRs and FLWRs rod bundle. The fluid mixing was observed at a gap between the subchannels. The existing two-phase flow correlation for fluid mixing is evaluated using detailed numerical simulation data. This data indicates that pressure difference between fluid channels is responsible for the fluid mixing, and thus the effects of the time average pressure difference and fluctuations must be incorporated in the two-phase flow correlation for fluid mixing. When inlet quality ratio of subchannels is relatively large, it is understood that evaluation precision of the existing two-phase flow correlations for fluid mixing are relatively low.

  16. A simple method for migrating narrow aperture, noisy seismic reflection data and application to Project INDEPTH (International Deep Profiling of Tibet and the Himalaya) deep seismic profiles

    NASA Astrophysics Data System (ADS)

    Alsdorf, Doug

    1997-08-01

    Migration of deep seismic data is often hindered by a narrow recording aperture (line length by record length) and a low signal-to-noise ratio. The severity of typical migration artifacts (e.g., lateral smearing of discontinuous reflections into synforms, "smiles") increases with travel time such that interpreters of deep seismic data have often substituted migrated line drawings for the actual sections. As part of Project INDEPTH (International Deep Profiling of Tibet and the Himalaya), a new migration method was developed to address both the noise and migration issues. The method works in the time-space domain and uses the simple, constant velocity, straight ray path to perform the migration. First, only amplitudes within a given range are retained for migration, thus avoiding high-amplitude noise bursts and low-amplitude background noise. Then, the local dip of a reflection is found by automatically fitting a straight line to the highest amplitudes within a small window (several time samples by several traces) and calculating the dip of the line using a constant velocity. Finally, using this dip, the method migrates a selected amplitude value. The dips, lateral positions, and depths of the migrated events compare very well with output from more conventional algorithms (e.g.,fk-Stolt, finite difference, etc.). The advantages of the new method include fewer artifacts, fast computer run times, low memory use and the ability to migrate long profiles and travel times (e.g., 50 s). The output of the method is a grid of migrated amplitudes (not wavelets) or dip values which is particularly effective for making small figures, such as those needed for publication. The principal disadvantage is the use of a constant migration velocity.

  17. Centrifugal contactor with liquid mixing and flow control vanes and method of mixing liquids of different phases

    DOEpatents

    Jubin, Robert T.; Randolph, John D.

    1991-01-01

    The invention is directed to a centrifugal contactor for solvent extraction systems. The centrifugal contactor is provided with an annular vertically oriented mixing chamber between the rotor housing and the rotor for mixing process liquids such as the aqueous and organic phases of the solvent extraction process used for nuclear fuel reprocessing. A set of stationary helically disposed vanes carried by the housing is in the lower region of the mixing chamber at a location below the process-liquid inlets for the purpose of urging the liquids in an upward direction toward the inlets and enhancing the mixing of the liquids and mass transfer between the liquids. The upper region of the mixing vessel above the inlets for the process liquids is also provided with a set helically disposed vanes carried by the housing for urging the process liquids in a downward direction when the liquid flow rates through the inlets are relatively high and the liquids contact the vane set in the upper region. The use of these opposing vane sets in the mixing zone maintains the liquid in the mixing zone at suitable levels.

  18. Advancing Methods for Hydrogeological Characterization of Deep Aquifers in Sedimentary Basins

    NASA Astrophysics Data System (ADS)

    Singh, A.; Palombi, D.

    2014-12-01

    The Groundwater Program at the Alberta Geological Survey is focused on identifying, characterizing and quantifying Alberta's groundwater resources. Characterization of deep groundwater resources is becoming increasingly important as the Government of Alberta implements its Water Conservation Policy seeking to minimize freshwater use. Conducting an inventory of saline water (non-traditional) resources for source water in various energy development scenarios, at basin scales, pose significant challenges given the potential competing uses and demand for groundwater resources. Current research activities are seeking to improve our methods to characterize deep aquifers in data-rich sedimentary basins. Two methods are discussed here: 1) identifying production/injection influenced Drill Stem Test (DST) measurements for mapping distributions of hydraulic heads (both present-day and prior to development) in deep units; and 2) analyzing variable density flow effects. DSTs are transient pressure tests usually performed for assessing potential oil and gas productivity. These tests measure pressures using gauges at the surface and down-hole. The measured pressures can be strongly influenced in cases where the test interval is located in the vicinity of a production or injection well, which generally happens in mature sedimentary basins such as the Alberta basin. To identify production influences this study utilized a cumulative inference index (CII) based approach. A new application was developed in C-code to implement the CII and will be demonstrated on a sample DST dataset from the Western Canada Sedimentary Basin. Fluid flow in sedimentary basins is often inferred using freshwater hydraulic heads, reference formation water densities and pressure-depth plots. Previous studies in the Alberta basin have often neglected density variations. Effects of density driven flow needs to be taken into account in cases where dense brines are present, a large aquifer dip or small hydraulic

  19. Alternate scenarios for population control in Pakistan: the issue of contraceptive method mix.

    PubMed

    Ahmed, T; Ali, S M

    1992-01-01

    The authors review Pakistan's population program, with a focus on the ideal mix of contraceptive methods needed to slow population growth. "Our objective in this exercise is to estimate the extent of services required to achieve a certain level of the Contraceptive Prevalence Rate (CPR) necessary to bring fertility down to a level desired by women." Comparison is made between single- and multiple-method approaches.

  20. Close encounters of the infectious kind: methods to measure social mixing behaviour

    PubMed Central

    READ, J. M.; EDMUNDS, W. J.; RILEY, S.; LESSLER, J.; CUMMINGS, D. A. T.

    2014-01-01

    SUMMARY A central tenet of close-contact or respiratory infection epidemiology is that infection patterns within human populations are related to underlying patterns of social interaction. Until recently, few researchers had attempted to quantify potentially infectious encounters made between people. Now, however, several studies have quantified social mixing behaviour, using a variety of methods. Here, we review the methodologies employed, suggest other appropriate methods and technologies, and outline future research challenges for this rapidly advancing field of research. PMID:22687447

  1. Thermodynamic properties of mixed-spin chains in magnetic field by the transfer matrix method

    NASA Astrophysics Data System (ADS)

    Fu, H. H.; Yao, K. L.; Liu, Z. L.

    2006-10-01

    Motivated by recent experimental synthesis of molecule-based ferrimagnetics, we have investigated the thermodynamic properties of one-dimensional antiferromagnetic-ferromagnetic mixed spin- {1}/{2} lozenge chain in external magnetic fields at low temperature, using the transfer matrix method. The magnetization and the specific heat of the spin system have been evaluated numerically from the free energy. The magnetization as a function of the magnetic field at low temperature shows step-like plateau characterized by three critical magnetic fields, which reflects the competing effect of magnetic interactions and thermal fluctuations. The double-peak structure in the curves of the specific heat is also found, which comes from the huge variation of the long-range order parameters. Our results show that the thermodynamic properties of the mixed spin- {1}/{2} molecule-based ferrimagnetics are very analogous to the behaviors of the spin-1 and spin- {1}/{2} mixed antiferromagentic chain.

  2. Menopause and Crisis? Fake or Real: Comprehensive Search to The Depth of Crisis Experienced: A Mixed-method Study

    PubMed Central

    avar, Nehle Parand; Mosalanejad, Leili; Ramezanli, Somaye; Ghavi, Fatemeh

    2014-01-01

    Introduction: Menopause is beyond the lack of menstruation and fertility decline in estrogen. Menopause is associated with at least three types of crisis: Biological, psychological and social. The aim of this study was to investigate psychiatric problems related to menopausal stress and experiences about psychological conditions related to menopause as a developmental crisis. Material and Methods: This mixed-method study (by triangulation approach) was done on 300 women in menopause age (44-54 years) by consensus sampling. Data gathering was from questionnaire conclude psychosomatic listed and hypochondria’s criterion that has been specified by DSMIV. The severity of the disorder was also collected by self-reported question. In the qualitative part, as a phenomenology study, data were gathered with Purposive sampling by a deep semi-structured interview. Data analysis was from content analysis). Results: Results showed that most of the disorders from psychosomatic listed experienced by women conclude: sexual problems 101(33.7%), hypertension 39(13%), and constipation 30(10%); 2.9% had experienced hypochondrias disorder. In the qualitative part, 5 themes were driven from the results of this study which described the structures of psychological experiences of the menopause as follows: change in emotion and mood, change in attitude, change in self-concept and change in interpersonal relationships. Conclusion: Menopause is a physiological process in women’s life, but due to many symptoms and complications, it requires culturally appropriate education, appropriate coping with problems and mental health promotion in this sexual crisis. PMID:24576387

  3. Adding Qualitative and Mixed Methods Research to Health Intervention Studies: Interacting With Differences.

    PubMed

    Johnson, R Burke; Schoonenboom, Judith

    2016-04-01

    The purpose of this article is to explain how to improve intervention designs, such as randomized controlled trials (RCTs), in health science research using a process philosophy and theory known as dialectical pluralism (DP). DP views reality as plural and uses dialectical, dialogical, and hermeneutical approaches to knowledge construction. Using DP and its "both/and" logic, and its attempt to produce new creative syntheses, researchers on heterogeneous teams can better dialogue with qualitative and mixed methods approaches, concepts, paradigms, methodologies, and methods to improve their intervention research studies. The concept of reflexivity is utilized but is expanded when it is a component of DP. Examples of strategies for identifying, inviting, and creating divergence and integrative strategies for producing strong mixed methods intervention studies are provided and illustrated using real-life examples.

  4. Comparison of Vibroseis and explosive source methods for deep crustal seismic reflection profiling in the Basin and Range province

    USGS Publications Warehouse

    Brocher, T.M.; Hart, P.E.

    1991-01-01

    Direct comparison of low-fold, high-energy explosive and high-fold, lower-energy Vibroseis methods for acquiring deep crustal seismic reflection data in the Basin and Range Province suggests that the high-fold common midpoint (CMP) method there does not provide the best possible image of lower crustal structure. -from Authors

  5. Deep-sequencing method for quantifying background abundances of symbiodinium types: exploring the rare symbiodinium biosphere in reef-building corals.

    PubMed

    Quigley, Kate M; Davies, Sarah W; Kenkel, Carly D; Willis, Bette L; Matz, Mikhail V; Bay, Line K

    2014-01-01

    The capacity of reef-building corals to associate with environmentally-appropriate types of endosymbionts from the dinoflagellate genus Symbiodinium contributes significantly to their success at local scales. Additionally, some corals are able to acclimatize to environmental perturbations by shuffling the relative proportions of different Symbiodinium types hosted. Understanding the dynamics of these symbioses requires a sensitive and quantitative method of Symbiodinium genotyping. Electrophoresis methods, still widely utilized for this purpose, are predominantly qualitative and cannot guarantee detection of a background type below 10% of the total Symbiodinium population. Here, the relative abundances of four Symbiodinium types (A13, C1, C3, and D1) in mixed samples of known composition were quantified using deep sequencing of the internal transcribed spacer of the ribosomal RNA gene (ITS-2) by means of Next Generation Sequencing (NGS) using Roche 454. In samples dominated by each of the four Symbiodinium types tested, background levels of the other three types were detected when present at 5%, 1%, and 0.1% levels, and their relative abundances were quantified with high (A13, C1, D1) to variable (C3) accuracy. The potential of this deep sequencing method for resolving fine-scale genetic diversity within a symbiont type was further demonstrated in a natural symbiosis using ITS-1, and uncovered reef-specific differences in the composition of Symbiodinium microadriaticum in two species of acroporid corals (Acropora digitifera and A. hyacinthus) from Palau. The ability of deep sequencing of the ITS locus (1 and 2) to detect and quantify low-abundant Symbiodinium types, as well as finer-scale diversity below the type level, will enable more robust quantification of local genetic diversity in Symbiodinium populations. This method will help to elucidate the role that background types have in maximizing coral fitness across diverse environments and in response to

  6. Deep-Sequencing Method for Quantifying Background Abundances of Symbiodinium Types: Exploring the Rare Symbiodinium Biosphere in Reef-Building Corals

    PubMed Central

    Quigley, Kate M.; Davies, Sarah W.; Kenkel, Carly D.; Willis, Bette L.; Matz, Mikhail V.; Bay, Line K.

    2014-01-01

    The capacity of reef-building corals to associate with environmentally-appropriate types of endosymbionts from the dinoflagellate genus Symbiodinium contributes significantly to their success at local scales. Additionally, some corals are able to acclimatize to environmental perturbations by shuffling the relative proportions of different Symbiodinium types hosted. Understanding the dynamics of these symbioses requires a sensitive and quantitative method of Symbiodinium genotyping. Electrophoresis methods, still widely utilized for this purpose, are predominantly qualitative and cannot guarantee detection of a background type below 10% of the total Symbiodinium population. Here, the relative abundances of four Symbiodinium types (A13, C1, C3, and D1) in mixed samples of known composition were quantified using deep sequencing of the internal transcribed spacer of the ribosomal RNA gene (ITS-2) by means of Next Generation Sequencing (NGS) using Roche 454. In samples dominated by each of the four Symbiodinium types tested, background levels of the other three types were detected when present at 5%, 1%, and 0.1% levels, and their relative abundances were quantified with high (A13, C1, D1) to variable (C3) accuracy. The potential of this deep sequencing method for resolving fine-scale genetic diversity within a symbiont type was further demonstrated in a natural symbiosis using ITS-1, and uncovered reef-specific differences in the composition of Symbiodinium microadriaticum in two species of acroporid corals (Acropora digitifera and A. hyacinthus) from Palau. The ability of deep sequencing of the ITS locus (1 and 2) to detect and quantify low-abundant Symbiodinium types, as well as finer-scale diversity below the type level, will enable more robust quantification of local genetic diversity in Symbiodinium populations. This method will help to elucidate the role that background types have in maximizing coral fitness across diverse environments and in response to

  7. Estimating internal P loading in a deep water reservoir of northern China using three different methods.

    PubMed

    Qin, Lihuan; Zeng, Qinghui; Zhang, Wangshou; Li, Xuyong; Steinman, Alan D; Du, Xinzhong

    2016-09-01

    Much attention had been paid to reducing external loading of nutrients to improve water quality, while internal loading from sediment, which has been largely neglected, is also an important source for water eutrophication. The internal load in deep lakes or reservoirs is not easy to be detected and be quantified. In this study, three different methods (mass balance method, Fick's law, and regression equation) were combined to calculate the gross or/and net P release from sediment using limited data. Our results indicated that (1) the methods of mass balance and regression equation give similar results of sediment P release rate, with values of 0.889 and 0.902 mg m(2) d(-1), respectively, while the result of Fick's law was much lower (0.400 mg m(2) d(-1)); (2) Hot periods of sediment releasing were suggested to occur from March to April and from August to September, which correspond to periods of high risks of algae blooms. The remaining months of the year were shown as net nutrient retention; (3) for the whole region, Baihedam and Chaohekuqu were identified as zones with a higher possibility to release P from sediment. (4) P loading to the Miyun Reservoir was greater in the inflow than in the outflow, suggesting a portion of the inflow P load was retained in the water or sediment; hence, release of sediment P may continue to be a major source of phosphorus in the future. PMID:27289374

  8. Estimating internal P loading in a deep water reservoir of northern China using three different methods.

    PubMed

    Qin, Lihuan; Zeng, Qinghui; Zhang, Wangshou; Li, Xuyong; Steinman, Alan D; Du, Xinzhong

    2016-09-01

    Much attention had been paid to reducing external loading of nutrients to improve water quality, while internal loading from sediment, which has been largely neglected, is also an important source for water eutrophication. The internal load in deep lakes or reservoirs is not easy to be detected and be quantified. In this study, three different methods (mass balance method, Fick's law, and regression equation) were combined to calculate the gross or/and net P release from sediment using limited data. Our results indicated that (1) the methods of mass balance and regression equation give similar results of sediment P release rate, with values of 0.889 and 0.902 mg m(2) d(-1), respectively, while the result of Fick's law was much lower (0.400 mg m(2) d(-1)); (2) Hot periods of sediment releasing were suggested to occur from March to April and from August to September, which correspond to periods of high risks of algae blooms. The remaining months of the year were shown as net nutrient retention; (3) for the whole region, Baihedam and Chaohekuqu were identified as zones with a higher possibility to release P from sediment. (4) P loading to the Miyun Reservoir was greater in the inflow than in the outflow, suggesting a portion of the inflow P load was retained in the water or sediment; hence, release of sediment P may continue to be a major source of phosphorus in the future.

  9. Sexual Pleasure and Sexual Risk among Women who Use Methamphetamine: A Mixed Methods Study

    PubMed Central

    Lorvick, Jennifer; Bourgois, Philippe; Wenger, Lynn D.; Arreola, Sonya G.; Lutnick, Alexandra; Wechsberg, Wendee M.; Kral, Alex H.

    2012-01-01

    Background The intersection of drug use, sexual pleasure and sexual risk behavior is rarely explored when it comes to poor women who use drugs. This paper explores the relationship between sexual behavior and methamphetamine use in a community-based sample of women, exploring not only risk, but also desire, pleasure and the challenges of overcoming trauma. Methods Quantitative data were collected using standard epidemiological methods (N=322) for community-based studies. In addition, using purposive sampling, qualitative data were collected among a subset of participants (n=34). Data were integrated for mixed methods analysis. Results While many participants reported sexual risk behavior (unprotected vaginal or anal intercourse) in the quantitative survey, sexual risk was not the central narrative pertaining to sexual behavior and methamphetamine use in qualitative findings. Rather, desire, pleasure and disinhibition arose as central themes. Women described feelings of power and agency related to sexual behavior while high on methamphetamine. Findings were mixed on whether methamphetamine use increased sexual risk behavior. Conclusion The use of mixed methods afforded important insights into the sexual behavior and priorities of methamphetamine-using women. Efforts to reduce sexual risk should recognize and valorize the positive aspects of methamphetamine use for some women, building on positive feelings of power and agency as an approach to harm minimization. PMID:22954501

  10. Thriving, Managing, and Struggling: A Mixed Methods Study of Adolescent African Refugees’ Psychosocial Adjustment

    PubMed Central

    Weine, Stevan Merrill; Ware, Norma; Tugenberg, Toni; Hakizimana, Leonce; Dahnweih, Gonwo; Currie, Madeleine; Wagner, Maureen; Levin, Elise

    2013-01-01

    Objectives The purpose of this mixed method study was to characterize the patterns of psychosocial adjustment among adolescent African refugees in U.S. resettlement. Methods A purposive sample of 73 recently resettled refugee adolescents from Burundi and Liberia were followed for two years and qualitative and quantitative data was analyzed using a mixed methods exploratory design. Results Protective resources identified were the family and community capacities that can promote youth psychosocial adjustment through: 1) Finances for necessities; 2) English proficiency; 3) Social support networks; 4) Engaged parenting; 5) Family cohesion; 6) Cultural adherence and guidance; 7) Educational support; and, 8) Faith and religious involvement. The researchers first inductively identified 19 thriving, 29 managing, and 25 struggling youths based on review of cases. Univariate analyses then indicated significant associations with country of origin, parental education, and parental employment. Multiple regressions indicated that better psychosocial adjustment was associated with Liberians and living with both parents. Logistic regressions showed that thriving was associated with Liberians and higher parental education, managing with more parental education, and struggling with Burundians and living parents. Qualitative analysis identified how these factors were proxy indicators for protective resources in families and communities. Conclusion These three trajectories of psychosocial adjustment and six domains of protective resources could assist in developing targeted prevention programs and policies for refugee youth. Further rigorous longitudinal mixed-methods study of adolescent refugees in U.S. resettlement are needed. PMID:24205467

  11. Approaching Etuaptmumk – introducing a consensus-based mixed method for health services research

    PubMed Central

    Chatwood, Susan; Paulette, Francois; Baker, Ross; Eriksen, Astrid; Hansen, Ketil Lenert; Eriksen, Heidi; Hiratsuka, Vanessa; Lavoie, Josée; Lou, Wendy; Mauro, Ian; Orbinski, James; Pabrum, Nathalie; Retallack, Hanna; Brown, Adalsteinn

    2015-01-01

    With the recognized need for health systems’ improvements in the circumpolar and indigenous context, there has been a call to expand the research agenda across all sectors influencing wellness and to recognize academic and indigenous knowledge through the research process. Despite being recognized as a distinct body of knowledge in international forums and across indigenous groups, examples of methods and theories based on indigenous knowledge are not well documented in academic texts or peer-reviewed literature on health systems. This paper describes the use of a consensus-based, mixed method with indigenous knowledge by an experienced group of researchers and indigenous knowledge holders who collaborated on a study that explored indigenous values underlying health systems stewardship. The method is built on the principles of Etuaptmumk or two-eyed seeing, which aim to respond to and resolve the inherent conflicts between indigenous ways of knowing and the scientific inquiry that informs the evidence base in health care. Mixed methods’ frameworks appear to provide a framing suitable for research questions that require data from indigenous knowledge sources and western knowledge. The nominal consensus method, as a western paradigm, was found to be responsive to embedding of indigenous knowledge and allowed space to express multiple perspectives and reach consensus on the question at hand. Further utilization and critical evaluation of this mixed methodology with indigenous knowledge are required. PMID:26004427

  12. [A new method for the transcutaneous measurement of deep body temperature during anaesthesia and intensive care (author's transl)].

    PubMed

    Jost, U; Hanf, K; Köhler, C O; Just, O H

    1978-04-01

    A new method for monitoring deep body temperature is described. It is based on the establishment, by means of electronic appliances, of a zone without heatflow from the deep tissues. The method is simple and the results compare favourably with those obtained by other procedures for measuring core temperature. The uses of this transcutaneous mehtod are discussed and its advantages and reliability in the operating theatre and intensive care unit are emphasized. It becomes less reliable if it is employed during and after extracorporeal circulation in hypothermia on account of the temperature gradient.

  13. A Simplified Direct Lipid Mixing Lipoplex Preparation: Comparison of Liposomal-, Dimethylsulfoxide-, and Ethanol-Based Methods

    PubMed Central

    Meisel, Joseph W.; Gokel, George W.

    2016-01-01

    Established transfection methodology often uses commercial reagents, which must be formed into liposomes in a sequence of about half a dozen steps. The simplified method reported here is a direct lipid mixing approach that requires fewer steps, less manipulation, and is less time-consuming. Results are comparable to those obtained with more commonly used methods, as judged by a variety of analytical techniques and by comparisons of transfection results. The method reported here may be applied to non-liposome-forming compounds, thereby greatly expanding the range of structures that can be tested for transfection ability. PMID:27323668

  14. A Simplified Direct Lipid Mixing Lipoplex Preparation: Comparison of Liposomal-, Dimethylsulfoxide-, and Ethanol-Based Methods.

    PubMed

    Meisel, Joseph W; Gokel, George W

    2016-01-01

    Established transfection methodology often uses commercial reagents, which must be formed into liposomes in a sequence of about half a dozen steps. The simplified method reported here is a direct lipid mixing approach that requires fewer steps, less manipulation, and is less time-consuming. Results are comparable to those obtained with more commonly used methods, as judged by a variety of analytical techniques and by comparisons of transfection results. The method reported here may be applied to non-liposome-forming compounds, thereby greatly expanding the range of structures that can be tested for transfection ability. PMID:27323668

  15. Mixed methods immigrant mental health research in Canada: a systematic review.

    PubMed

    Islam, Farah; Oremus, Mark

    2014-12-01

    Canada is home to a growing immigrant population. However, immigrant mental health declines over time following arrival in Canada. Canada's Mental Health Strategy emphasizes the importance of research that gathers information from multiple sources of knowledge to identify the mental health challenges faced by diverse immigrant populations. Mixed methods research (MMR) is well suited for this task. However, a dearth of research exists on the application of MMR to the study of immigrant mental health. A systematic review of the published MMR literature in Canadian immigrant mental health was carried out. Overall, existing MMR studies failed to incorporate correct mixed methods terminology and fully integrate the quantitative and qualitative components of the research. A checklist of important elements to include in MMR studies is offered.

  16. Mixed Methods Research With Internally Displaced Colombian Gay and Bisexual Men and Transwomen

    PubMed Central

    Zea, Maria Cecilia; Aguilar-Pardo, Marcela; Betancourt, Fabian; Reisen, Carol A.; Gonzales, Felisa

    2014-01-01

    We discuss the use of mixed methods research to further understanding of displaced Colombian gay and bisexual men and transwomen, a marginalized population at risk. Within the framework of communicative action, which calls for social change through egalitarian dialog, we describe how our multinational, interdisciplinary research team explored the subjective, objective, and social worlds of participants through life history interviews and surveys. We also describe the unique Colombian context, conscious efforts to establish egalitarian relationships among research team members, and efforts to disseminate and reflect on findings. Through discussion of our research process and results, we aim to demonstrate how mixed methods research can be utilized to facilitate noncoercive discourse and contribute to social change. PMID:24926225

  17. Systems and methods for thermal imaging technique for measuring mixing of fluids

    DOEpatents

    Booten, Charles; Tomerlin, Jeff; Winkler, Jon

    2016-06-14

    Systems and methods for thermal imaging for measuring mixing of fluids are provided. In one embodiment, a method for measuring mixing of gaseous fluids using thermal imaging comprises: positioning a thermal test medium parallel to a direction gaseous fluid flow from an outlet vent of a momentum source, wherein when the source is operating, the fluid flows across a surface of the medium; obtaining an ambient temperature value from a baseline thermal image of the surface; obtaining at least one operational thermal image of the surface when the fluid is flowing from the outlet vent across the surface, wherein the fluid has a temperature different than the ambient temperature; and calculating at least one temperature-difference fraction associated with at least a first position on the surface based on a difference between temperature measurements obtained from the at least one operational thermal image and the ambient temperature value.

  18. Mixed Methods Research With Internally Displaced Colombian Gay and Bisexual Men and Transwomen.

    PubMed

    Zea, Maria Cecilia; Aguilar-Pardo, Marcela; Betancourt, Fabian; Reisen, Carol A; Gonzales, Felisa

    2014-07-01

    We discuss the use of mixed methods research to further understanding of displaced Colombian gay and bisexual men and transwomen, a marginalized population at risk. Within the framework of communicative action, which calls for social change through egalitarian dialog, we describe how our multinational, interdisciplinary research team explored the subjective, objective, and social worlds of participants through life history interviews and surveys. We also describe the unique Colombian context, conscious efforts to establish egalitarian relationships among research team members, and efforts to disseminate and reflect on findings. Through discussion of our research process and results, we aim to demonstrate how mixed methods research can be utilized to facilitate noncoercive discourse and contribute to social change.

  19. Technical Efficiency and Organ Transplant Performance: A Mixed-Method Approach

    PubMed Central

    de-Pablos-Heredero, Carmen; Fernández-Renedo, Carlos; Medina-Merodio, Jose-Amelio

    2015-01-01

    Mixed methods research is interesting to understand complex processes. Organ transplants are complex processes in need of improved final performance in times of budgetary restrictions. As the main objective a mixed method approach is used in this article to quantify the technical efficiency and the excellence achieved in organ transplant systems and to prove the influence of organizational structures and internal processes in the observed technical efficiency. The results show that it is possible to implement mechanisms for the measurement of the different components by making use of quantitative and qualitative methodologies. The analysis show a positive relationship between the levels related to the Baldrige indicators and the observed technical efficiency in the donation and transplant units of the 11 analyzed hospitals. Therefore it is possible to conclude that high levels in the Baldrige indexes are a necessary condition to reach an increased level of the service offered. PMID:25950653

  20. 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.

  1. A mixed methods approach for measuring the impact of delivery-centric interventions on clinician workflow.

    PubMed

    Cady, Rhonda G; Finkelstein, Stanley M

    2012-01-01

    Health interventions vary widely. Pharmaceuticals, medical devices and wellness promotion are defined as 'outcome-centric.' They are implemented by clinicians for the use and benefit of consumers, and intervention effectiveness is measured by a change in health outcome. Electronic health records, computerized physician order entry systems and telehealth technologies are defined as 'delivery-centric.' They are implemented by organizations for use by clinicians to manage and facilitate consumer health, and the impact of these interventions on clinician workflow has become increasingly important. The methodological framework introduced in this paper uses a two-phase sequential mixed methods design that qualitatively explores clinician workflow before and after implementation of a delivery-centric intervention, and uses this information to quantitatively measure changes to workflow activities. The mixed methods protocol provides a standardized approach for understanding and determining the impact of delivery-centric interventions on clinician workflow. PMID:23304393

  2. Deep neural nets as a method for quantitative structure-activity relationships.

    PubMed

    Ma, Junshui; Sheridan, Robert P; Liaw, Andy; Dahl, George E; Svetnik, Vladimir

    2015-02-23

    Neural networks were widely used for quantitative structure-activity relationships (QSAR) in the 1990s. Because of various practical issues (e.g., slow on large problems, difficult to train, prone to overfitting, etc.), they were superseded by more robust methods like support vector machine (SVM) and random forest (RF), which arose in the early 2000s. The last 10 years has witnessed a revival of neural networks in the machine learning community thanks to new methods for preventing overfitting, more efficient training algorithms, and advancements in computer hardware. In particular, deep neural nets (DNNs), i.e. neural nets with more than one hidden layer, have found great successes in many applications, such as computer vision and natural language processing. Here we show that DNNs can routinely make better prospective predictions than RF on a set of large diverse QSAR data sets that are taken from Merck's drug discovery effort. The number of adjustable parameters needed for DNNs is fairly large, but our results show that it is not necessary to optimize them for individual data sets, and a single set of recommended parameters can achieve better performance than RF for most of the data sets we studied. The usefulness of the parameters is demonstrated on additional data sets not used in the calibration. Although training DNNs is still computationally intensive, using graphical processing units (GPUs) can make this issue manageable.

  3. Deep neural nets as a method for quantitative structure-activity relationships.

    PubMed

    Ma, Junshui; Sheridan, Robert P; Liaw, Andy; Dahl, George E; Svetnik, Vladimir

    2015-02-23

    Neural networks were widely used for quantitative structure-activity relationships (QSAR) in the 1990s. Because of various practical issues (e.g., slow on large problems, difficult to train, prone to overfitting, etc.), they were superseded by more robust methods like support vector machine (SVM) and random forest (RF), which arose in the early 2000s. The last 10 years has witnessed a revival of neural networks in the machine learning community thanks to new methods for preventing overfitting, more efficient training algorithms, and advancements in computer hardware. In particular, deep neural nets (DNNs), i.e. neural nets with more than one hidden layer, have found great successes in many applications, such as computer vision and natural language processing. Here we show that DNNs can routinely make better prospective predictions than RF on a set of large diverse QSAR data sets that are taken from Merck's drug discovery effort. The number of adjustable parameters needed for DNNs is fairly large, but our results show that it is not necessary to optimize them for individual data sets, and a single set of recommended parameters can achieve better performance than RF for most of the data sets we studied. The usefulness of the parameters is demonstrated on additional data sets not used in the calibration. Although training DNNs is still computationally intensive, using graphical processing units (GPUs) can make this issue manageable. PMID:25635324

  4. DL-PRO: A Novel Deep Learning Method for Protein Model Quality Assessment

    PubMed Central

    Nguyen, Son P.; Shang, Yi; Xu, Dong

    2014-01-01

    Computational protein structure prediction is very important for many applications in bioinformatics. In the process of predicting protein structures, it is essential to accurately assess the quality of generated models. Although many single-model quality assessment (QA) methods have been developed, their accuracy is not high enough for most real applications. In this paper, a new approach based on C-α atoms distance matrix and machine learning methods is proposed for single-model QA and the identification of native-like models. Different from existing energy/scoring functions and consensus approaches, this new approach is purely geometry based. Furthermore, a novel algorithm based on deep learning techniques, called DL-Pro, is proposed. For a protein model, DL-Pro uses its distance matrix that contains pairwise distances between two residues’ C-α atoms in the model, which sometimes is also called contact map, as an orientation-independent representation. From training examples of distance matrices corresponding to good and bad models, DL-Pro learns a stacked autoencoder network as a classifier. In experiments on selected targets from the Critical Assessment of Structure Prediction (CASP) competition, DL-Pro obtained promising results, outperforming state-of-the-art energy/scoring functions, including OPUS-CA, DOPE, DFIRE, and RW. PMID:25392745

  5. DL-PRO: A Novel Deep Learning Method for Protein Model Quality Assessment.

    PubMed

    Nguyen, Son P; Shang, Yi; Xu, Dong

    2014-07-01

    Computational protein structure prediction is very important for many applications in bioinformatics. In the process of predicting protein structures, it is essential to accurately assess the quality of generated models. Although many single-model quality assessment (QA) methods have been developed, their accuracy is not high enough for most real applications. In this paper, a new approach based on C-α atoms distance matrix and machine learning methods is proposed for single-model QA and the identification of native-like models. Different from existing energy/scoring functions and consensus approaches, this new approach is purely geometry based. Furthermore, a novel algorithm based on deep learning techniques, called DL-Pro, is proposed. For a protein model, DL-Pro uses its distance matrix that contains pairwise distances between two residues' C-α atoms in the model, which sometimes is also called contact map, as an orientation-independent representation. From training examples of distance matrices corresponding to good and bad models, DL-Pro learns a stacked autoencoder network as a classifier. In experiments on selected targets from the Critical Assessment of Structure Prediction (CASP) competition, DL-Pro obtained promising results, outperforming state-of-the-art energy/scoring functions, including OPUS-CA, DOPE, DFIRE, and RW.

  6. Does mode mixing matter in EMD-based highlight volume methods for hydrocarbon detection? Experimental evidence

    NASA Astrophysics Data System (ADS)

    Xue, Ya-juan; Cao, Jun-xing; Du, Hao-kun; Zhang, Gu-lan; Yao, Yao

    2016-09-01

    Empirical mode decomposition (EMD)-based spectral decomposition methods have been successfully used for hydrocarbon detection. However, mode mixing that occurs during the sifting process of EMD causes the 'true' intrinsic mode function (IMF) to be extracted incorrectly and blurs the physical meaning of the IMF. We address the issue of how the mode mixing influences the EMD-based methods for hydrocarbon detection by introducing mode-mixing elimination methods, specifically ensemble EMD (EEMD) and complete ensemble EMD (CEEMD)-based highlight volumes, as feasible tools that can identify the peak amplitude above average volume and the peak frequency volume. Three schemes, that is, using all IMFs, selected IMFs or weighted IMFs, are employed in the EMD-, EEMD- and CEEMD-based highlight volume methods. When these methods were applied to seismic data from a tight sandstone gas field in Central Sichuan, China, the results demonstrated that the amplitude anomaly in the peak amplitude above average volume captured by EMD, EEMD and CEEMD combined with Hilbert transforms, whether using all IMFs, selected IMFs or weighted IMFs, are almost identical to each other. However, clear distinctions can be found in the peak frequency volume when comparing results generated using all IMFs, selected IMFs, or weighted IMFs. If all IMFs are used, the influence of mode mixing on the peak frequency volume is not readily discernable. However, using selected IMFs or a weighted IMFs' scheme affects the peak frequency in relation to the reservoir thickness in the EMD-based method. Significant improvement in the peak frequency volume can be achieved in EEMD-based highlight volumes using selected IMFs. However, if the weighted IMFs' scheme is adopted (i.e., if the undesired IMFs are included with reduced weights rather than excluded from the analysis entirely), the CEEMD-based peak frequency volume provides a more accurate reservoir thickness estimate compared with the other two methods. This

  7. When practice precedes theory - A mixed methods evaluation of students' learning experiences in an undergraduate study program in nursing.

    PubMed

    Falk, Kristin; Falk, Hanna; Jakobsson Ung, Eva

    2016-01-01

    A key area for consideration is determining how optimal conditions for learning can be created. Higher education in nursing aims to prepare students to develop their capabilities to become independent professionals. The aim of this study was to evaluate the effects of sequencing clinical practice prior to theoretical studies on student's experiences of self-directed learning readiness and students' approach to learning in the second year of a three-year undergraduate study program in nursing. 123 nursing students was included in the study and divided in two groups. In group A (n = 60) clinical practice preceded theoretical studies. In group (n = 63) theoretical studies preceded clinical practice. Learning readiness was measured using the Directed Learning Readiness Scale for Nursing Education (SDLRSNE), and learning process was measured using the revised two-factor version of the Study Process Questionnaire (R-SPQ-2F). Students were also asked to write down their personal reflections throughout the course. By using a mixed method design, the qualitative component focused on the students' personal experiences in relation to the sequencing of theoretical studies and clinical practice. The quantitative component provided information about learning readiness before and after the intervention. Our findings confirm that students are sensitive and adaptable to their learning contexts, and that the sequencing of courses is subordinate to a pedagogical style enhancing students' deep learning approaches, which needs to be incorporated in the development of undergraduate nursing programs.

  8. Catalyst support of mixed cerium zirconium titanium oxide, including use and method of making

    DOEpatents

    Willigan, Rhonda R.; Vanderspurt, Thomas Henry; Tulyani, Sonia; Radhakrishnan, Rakesh; Opalka, Susanne Marie; Emerson, Sean C.

    2011-01-18

    A durable catalyst support/catalyst is capable of extended water gas shift operation under conditions of high temperature, pressure, and sulfur levels. The support is a homogeneous, nanocrystalline, mixed metal oxide of at least three metals, the first being cerium, the second being Zr, and/or Hf, and the third importantly being Ti, the three metals comprising at least 80% of the metal constituents of the mixed metal oxide and the Ti being present in a range of 5% to 45% by metals-only atomic percent of the mixed metal oxide. The mixed metal oxide has an average crystallite size less than 6 nm and forms a skeletal structure with pores whose diameters are in the range of 4-9 nm and normally greater than the average crystallite size. The surface area of the skeletal structure per volume of the material of the structure is greater than about 240 m.sup.2/cm.sup.3. The method of making and use are also described.

  9. Mixing a grounded theory approach with a randomized controlled trial related to intimate partner violence: what challenges arise for mixed methods research?

    PubMed

    Catallo, Cristina; Jack, Susan M; Ciliska, Donna; Macmillan, Harriet L

    2013-01-01

    Little is known about how to systematically integrate complex qualitative studies within the context of randomized controlled trials. A two-phase sequential explanatory mixed methods study was conducted in Canada to understand how women decide to disclose intimate partner violence in emergency department settings. Mixing a RCT (with a subanalysis of data) with a grounded theory approach required methodological modifications to maintain the overall rigour of this mixed methods study. Modifications were made to the following areas of the grounded theory approach to support the overall integrity of the mixed methods study design: recruitment of participants, maximum variation and negative case sampling, data collection, and analysis methods. Recommendations for future studies include: (1) planning at the outset to incorporate a qualitative approach with a RCT and to determine logical points during the RCT to integrate the qualitative component and (2) consideration for the time needed to carry out a RCT and a grounded theory approach, especially to support recruitment, data collection, and analysis. Data mixing strategies should be considered during early stages of the study, so that appropriate measures can be developed and used in the RCT to support initial coding structures and data analysis needs of the grounded theory phase.

  10. Mixed-RKDG Finite Element Methods for the 2-D Hydrodynamic Model for Semiconductor Device Simulation

    DOE PAGES

    Chen, Zhangxin; Cockburn, Bernardo; Jerome, Joseph W.; Shu, Chi-Wang

    1995-01-01

    In this paper we introduce a new method for numerically solving the equations of the hydrodynamic model for semiconductor devices in two space dimensions. The method combines a standard mixed finite element method, used to obtain directly an approximation to the electric field, with the so-called Runge-Kutta Discontinuous Galerkin (RKDG) method, originally devised for numerically solving multi-dimensional hyperbolic systems of conservation laws, which is applied here to the convective part of the equations. Numerical simulations showing the performance of the new method are displayed, and the results compared with those obtained by using Essentially Nonoscillatory (ENO) finite difference schemes. Frommore » the perspective of device modeling, these methods are robust, since they are capable of encompassing broad parameter ranges, including those for which shock formation is possible. The simulations presented here are for Gallium Arsenide at room temperature, but we have tested them much more generally with considerable success.« less

  11. The Contribution of Mixed Methods Research to the Field of Childhood Trauma: A Narrative Review Focused on Data Integration

    ERIC Educational Resources Information Center

    Boeije, Hennie; Slagt, Meike; van Wesel, Floryt

    2013-01-01

    In mixed methods research (MMR), integrating the quantitative and the qualitative components of a study is assumed to result in additional knowledge (or "yield"). This narrative review examines the extent to which MMR is used in the field of childhood trauma and provides directions for improving mixed methods studies in this field. A…

  12. Trends in the contraceptive method mix in low- and middle-income countries: analysis using a new "average deviation" measure.

    PubMed

    Ross, John; Keesbury, Jill; Hardee, Karen

    2015-02-25

    The method mix of contraceptive use is severely unbalanced in many countries, with over half of all use provided by just 1 or 2 methods. That tends to limit the range of user options and constrains the total prevalence of use, leading to unplanned pregnancies and births or abortions. Previous analyses of method mix distortions focused on countries where a single method accounted for more than half of all use (the 50% rule). We introduce a new measure that uses the average deviation (AD) of method shares around their own mean and apply that to a secondary analysis of method mix data for 8 contraceptive methods from 666 national surveys in 123 countries. A high AD value indicates a skewed method mix while a low AD value indicates a more uniform pattern across methods; the values can range from 0 to 21.9. Most AD values ranged from 6 to 19, with an interquartile range of 8.6 to 12.2. Using the AD measure, we identified 15 countries where the method mix has evolved from a distorted one to a better balanced one, with AD values declining, on average, by 35% over time. Countries show disparate paths in method gains and losses toward a balanced mix, but 4 patterns are suggested: (1) rise of one method partially offset by changes in other methods, (2) replacement of traditional with modern methods, (3) continued but declining domination by a single method, and (4) declines in dominant methods with increases in other methods toward a balanced mix. Regions differ markedly in their method mix profiles and preferences, raising the question of whether programmatic resources are best devoted to better provision of the well-accepted methods or to deploying neglected or new ones, or to a combination of both approaches.

  13. The influence of mixing methods and disinfectant on the physical properties of alginate impression materials.

    PubMed

    Dreesen, Karoline; Kellens, Annelies; Wevers, Martine; Thilakarathne, Pushpike J; Willems, Guy

    2013-06-01

    The aims of this in vitro study were to quantify the effect of manual versus automatic mixing and of using a disinfectant on mechanical properties of three different alginate impression materials. Two of the three alginates tested were especially developed for orthodontic use: Orthotrace® and Orthofine® while the third was a conventional alginate CA37FS®. Alginates were mixed by hand or automatically using a Cavex alginate mixer II®. Mixing was performed at room temperature using tap water. The material was allowed to set in a water bath at 35°C (±1°C), simulating intra-oral setting conditions, and half of the samples were disinfected before testing. For each tested material, 10 standardized samples were used. The disinfectant used was the CavexImpreSafe® that has a bactericide, virucide, and fungicide function. The specimens were exposed for 3 minutes in a 3% solution and were then tested according to the ISO 1563: 1990 (E) standard specifications. Descriptive statistics and three-way analysis of variance were performed, and a 5% significance level was used for statistical analysis. Evaluation of tensile strength and elastic recovery of different alginate samples, hand versus automatical mixing or disinfected versus not disinfected, resulted in significant differences for all materials except for Orthofine®. Considering detail reproduction, all three alginates evaluated reproduced the 50-μm line successfully without interruption. The mixing method can significantly affect the elastic recovery and tensile strength of the alginates tested while the effect of using a disinfectant is less explicit.

  14. Preliminary investigation of an ultrasound method for estimating pressure changes in deep-positioned vessels

    NASA Astrophysics Data System (ADS)

    Olesen, Jacob Bjerring; Villagomez-Hoyos, Carlos Armando; Traberg, Marie Sand; Chee, Adrian J. Y.; Yiu, Billy Y. S.; Ho, Chung Kit; Yu, Alfred C. H.; Jensen, Jørgen Arendt

    2016-04-01

    This paper presents a method for measuring pressure changes in deep-tissue vessels using vector velocity ultrasound data. The large penetration depth is ensured by acquiring data using a low frequency phased array transducer. Vascular pressure changes are then calculated from 2-D angle-independent vector velocity fields using a model based on the Navier-Stokes equations. Experimental scans are performed on a fabricated flow phantom having a constriction of 36% at a depth of 100 mm. Scans are carried out using a phased array transducer connected to the experimental scanner, SARUS. 2-D fields of angle-independent vector velocities are acquired using directional synthetic aperture vector flow imaging. The obtained results are evaluated by comparison to a 3-D numerical simulation model with equivalent geometry as the designed phantom. The study showed pressure drops across the constricted phantom varying from -40 Pa to 15 Pa with a standard deviation of 32%, and a bias of 25% found relative to the peak simulated pressure drop. This preliminary study shows that pressure can be estimated non-invasively to a depth that enables cardiac scans, and thereby, the possibility of detecting the pressure drops across the mitral valve.

  15. Prediction of free turbulent mixing using a turbulent kinetic energy method

    NASA Technical Reports Server (NTRS)

    Harsha, P. T.

    1973-01-01

    Free turbulent mixing of two-dimensional and axisymmetric one- and two-stream flows is analyzed by a relatively simple turbulent kinetic energy method. This method incorporates a linear relationship between the turbulent shear and the turbulent kinetic energy and an algebraic relationship for the length scale appearing in the turbulent kinetic energy equation. Good results are obtained for a wide variety of flows. The technique is shown to be especially applicable to flows with heat and mass transfer, for which nonunity Prandtl and Schmidt numbers may be assumed.

  16. Determination of Al in cake mix: Method validation and estimation of measurement uncertainty

    NASA Astrophysics Data System (ADS)

    Andrade, G.; Rocha, O.; Junqueira, R.

    2016-07-01

    An analytical method for the determination of Al in cake mix was developed. Acceptable values were obtained for the following parameters: linearity, detection limit - LOD (5.00 mg-kg-1) quantification limit - LOQ (12.5 mg-kg-1), the recovery assays values (between 91 and 102%), the relative standard deviation under repeatability and within-reproducibility conditions (<20.0%) and measurement uncertainty tests (<10.0%) The results of the validation process showed that the proposed method is fitness for purpose.

  17. High order Godunov mixed methods on tetrahedral meshes for density driven flow simulations in porous media

    NASA Astrophysics Data System (ADS)

    Mazzia, Annamaria; Putti, Mario

    2005-09-01

    Two-dimensional Godunov mixed methods have been shown to be effective for the numerical solution of density-dependent flow and transport problems in groundwater even when concentration gradients are high and the process is dominated by density effects. This class of discretization approaches solves the flow equation by means of the mixed finite element method, thus guaranteeing mass conserving velocity fields, and discretizes the transport equation by mixed finite element and finite volumes techniques combined together via appropriate time splitting. In this paper, we extend this approach to three dimensions employing tetrahedral meshes and introduce a spatially variable time stepping procedure that improves computational efficiency while preserving accuracy by adapting the time step size according to the local Courant-Friedrichs-Lewy (CFL) constraint. Careful attention is devoted to the choice of a truly three-dimensional limiter for the advection equation in the time-splitting technique, so that to preserve second order accuracy in space (in the sense that linear functions are exactly interpolated). The three-dimensional Elder problem and the saltpool problem, recently introduced as a new benchmark for testing three-dimensional density models, provide assessments with respect to accuracy and reliability of this numerical approach.

  18. Developing a methodology to assess the impact of research grant funding: a mixed methods approach.

    PubMed

    Bloch, Carter; Sørensen, Mads P; Graversen, Ebbe K; Schneider, Jesper W; Schmidt, Evanthia Kalpazidou; Aagaard, Kaare; Mejlgaard, Niels

    2014-04-01

    This paper discusses the development of a mixed methods approach to analyse research funding. Research policy has taken on an increasingly prominent role in the broader political scene, where research is seen as a critical factor in maintaining and improving growth, welfare and international competitiveness. This has motivated growing emphasis on the impacts of science funding, and how funding can best be designed to promote socio-economic progress. Meeting these demands for impact assessment involves a number of complex issues that are difficult to fully address in a single study or in the design of a single methodology. However, they point to some general principles that can be explored in methodological design. We draw on a recent evaluation of the impacts of research grant funding, discussing both key issues in developing a methodology for the analysis and subsequent results. The case of research grant funding, involving a complex mix of direct and intermediate effects that contribute to the overall impact of funding on research performance, illustrates the value of a mixed methods approach to provide a more robust and complete analysis of policy impacts. Reflections on the strengths and weaknesses of the methodology are used to examine refinements for future work.

  19. The arbitrary order mixed mimetic finite difference method for the diffusion equation

    DOE PAGES

    Gyrya, Vitaliy; Lipnikov, Konstantin; Manzini, Gianmarco

    2016-05-01

    Here, we propose an arbitrary-order accurate mimetic finite difference (MFD) method for the approximation of diffusion problems in mixed form on unstructured polygonal and polyhedral meshes. As usual in the mimetic numerical technology, the method satisfies local consistency and stability conditions, which determines the accuracy and the well-posedness of the resulting approximation. The method also requires the definition of a high-order discrete divergence operator that is the discrete analog of the divergence operator and is acting on the degrees of freedom. The new family of mimetic methods is proved theoretically to be convergent and optimal error estimates for flux andmore » scalar variable are derived from the convergence analysis. A numerical experiment confirms the high-order accuracy of the method in solving diffusion problems with variable diffusion tensor. It is worth mentioning that the approximation of the scalar variable presents a superconvergence effect.« less

  20. Connecting Past with Present: A Mixed-Methods Science Ethics Course and its Evaluation.

    PubMed

    Semendeferi, Ioanna; Tsiamyrtzis, Panagiotis; Dcosta, Malcolm; Pavlidis, Ioannis

    2016-02-01

    We present a graduate science ethics course that connects cases from the historical record to present realities and practices in the areas of social responsibility, authorship, and human/animal experimentation. This content is delivered with mixed methods, including films, debates, blogging, and practicum; even the instructional team is mixed, including a historian of science and a research scientist. What really unites all of the course's components is the experiential aspect: from acting in historical debates to participating in the current scientific enterprise. The course aims to change the students' culture into one deeply devoted to the science ethics cause. To measure the sought after cultural change, we developed and validated a relevant questionnaire. Results of this questionnaire from students who took the course, demonstrate that the course had the intended effect on them. Furthermore, results of this questionnaire from controls indicate the need for cultural change in that cohort. All these quantitative results are reinforced by qualitative outcomes.

  1. Dramatic activity of mixed-phase TiO2 photocatalyst synthesized by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Li, Huiquan; Xu, Bolian; Fan, Yining

    2013-02-01

    The mixed-phase TiO2 photocatalysts with different anatase/rutile/brookite ratios and high specific surface area (157-218 m2/g) were prepared by hydrothermal method at 100 °C and the effect of rutile content in TiO2 on the BET surface area, light absorption and separation efficiency of photogenerated charge carriers was studied and correlated to the photocatalytic activity of TiO2. Rutile content increased from 0% to 100% by increasing the amount of TiCl4 in aqueous phase and the initial pH value of reaction solution played an important role in the phase composition of TiO2. The photocatalytic mechanism of mixed-phase TiO2 was discussed.

  2. Method and apparatus for the control of fluid dynamic mixing in pulse combustors

    DOEpatents

    Bramlette, T.T.; Keller, J.O.

    1992-06-02

    In a method and apparatus for controlling total ignition delay time in a pulse combustor, and thus controlling the mixing characteristics of the combustion reactants and the combustion products in the combustor, the total ignition delay time is controlled by adjusting the inlet geometry of the inlet to the combustion chamber. The inlet geometry may be fixed or variable for controlling the mixing characteristics. A feedback loop may be employed to sense actual combustion characteristics, and, in response to the sensed combustion characteristics, the inlet geometry may be varied to obtain the total ignition delay time necessary to achieve the desired combustion characteristics. Various embodiments relate to the varying of the mass flow rate of reactants while holding the radius/velocity ratio constant. 10 figs.

  3. Method and apparatus for the control of fluid dynamic mixing in pulse combustors

    DOEpatents

    Bramlette, T. Tazwell; Keller, Jay O.

    1992-06-02

    In a method and apparatus for controlling total ignition delay time in a pulse combustor, and thus controlling the mixing characteristics of the combustion reactants and the combustion products in the combustor, the total ignition delay time is controlled by adjusting the inlet geometry of the inlet to the combustion chamber. The inlet geometry may be fixed or variable for controlling the mixing characteristics. A feedback loop may be employed to sense actual combustion characteristics, and, in response to the sensed combustion characteristics, the inlet geometry may be varied to obtain the total ignition delay time necessary to achieve the desired combustion characteristics. Various embodiments relate to the varying of the mass flow rate of reactants while holding the radius/velocity ratio constant.

  4. Connecting Past with Present: A Mixed-Methods Science Ethics Course and its Evaluation.

    PubMed

    Semendeferi, Ioanna; Tsiamyrtzis, Panagiotis; Dcosta, Malcolm; Pavlidis, Ioannis

    2016-02-01

    We present a graduate science ethics course that connects cases from the historical record to present realities and practices in the areas of social responsibility, authorship, and human/animal experimentation. This content is delivered with mixed methods, including films, debates, blogging, and practicum; even the instructional team is mixed, including a historian of science and a research scientist. What really unites all of the course's components is the experiential aspect: from acting in historical debates to participating in the current scientific enterprise. The course aims to change the students' culture into one deeply devoted to the science ethics cause. To measure the sought after cultural change, we developed and validated a relevant questionnaire. Results of this questionnaire from students who took the course, demonstrate that the course had the intended effect on them. Furthermore, results of this questionnaire from controls indicate the need for cultural change in that cohort. All these quantitative results are reinforced by qualitative outcomes. PMID:25688028

  5. Novel method to determine capture cross-section activation energies by deep-level transient spectroscopy techniques

    NASA Astrophysics Data System (ADS)

    Criado, J.; Gomez, A.; Calleja, E.; Muñoz, E.

    1988-02-01

    Deep-center characterization by deep-level transient spectroscopy (DLTS) allows a direct determination of the trap thermal emission activation energy. However, capture barrier energy measurements, based on trap partial filling by pulses of increasing width, require a quite different experimental processing and pose some hardware difficulties. In this letter we present a new method to determine the trap capture barrier energy, one that requires constant-width filling pulses and obtains capture information from standard DLTS data. This technique has been applied to Te-, Sn-, and Si-related DX centers in AlGaAs alloys.

  6. [THE CHOICE OF SURGICAL TREATMENT METHOD FOR THE DEEP VEINS THROMBOSIS IN SYSTEM OF VENA CAVA INFERIOR].

    PubMed

    Rusyn, V I; Korsak, V V; Popovych, Ya M; Boyko, S O

    2015-05-01

    There were analyzed the results of examination and treatment of 455 patients, suffering deep veins thrombosis in a system of vena cava inferior, of whom 175 (38.5%) were operated on. Inclusion of ultrasound duplex scanning, roentgencontrast phlebography, multispiral computer tomography with intravenous contrasting, radionuclide phleboscintigraphy into complex of clinic-instrumental examination of the patients gives possibility to estimate the disorders of the main trunk and collateral venous blood flow in the deep veins thrombosis, as well as to substantiate indications and choice of the operative treatment method.

  7. The Unintended Consequences of Computerized Provider Order Entry: Findings From a Mixed Methods Exploration*

    PubMed Central

    Ash, Joan S.; Sittig, Dean F.; Dykstra, Richard; Campbell, Emily; Guappone, Kenneth

    2009-01-01

    Objective To describe the foci, activities, methods, and results of a four-year research project identifying the unintended consequences of computerized provider order entry (CPOE). Methods Using a mixed methods approach, we identified and categorized into nine types 380 examples of the unintended consequences of CPOE gleaned from fieldwork data and a conference of experts. We then conducted a national survey in the U.S.A. to discover how hospitals with varying levels of infusion, a measure of CPOE sophistication, recognize and deal with unintended consequences. The research team, with assistance from experts, identified strategies for managing the nine types of unintended adverse consequences and developed and disseminated tools for CPOE implementers to help in addressing these consequences. Results Hospitals reported that levels of infusion are quite high and that these types of unintended consequences are common. Strategies for avoiding or managing the unintended consequences are similar to best practices for CPOE success published in the literature. Conclusion Development of a taxonomy of types of unintended adverse consequences of CPOE using qualitative methods allowed us to craft a national survey and discover how widespread these consequences are. Using mixed methods, we were able to structure an approach for addressing the skillful management of unintended consequences as well. PMID:18786852

  8. A Rapid Radiocarbon Method for Age Surveys of Southern Ocean Deep-sea Corals

    NASA Astrophysics Data System (ADS)

    Burke, A.; Robinson, L. F.; Gerlach, D. S.; Jenkins, W. J.; McNichol, A. P.

    2008-12-01

    Deep-sea corals provide a unique archive of past ocean radiocarbon because they are sessile and can be dated independently using U-series nuclides. One difficulty, however, is that using current techniques it is impractical to date large numbers of corals in order to determine which specimens have the appropriate ages for radiocarbon reconstructions. Here we present results from a quick method of making graphite for radiocarbon dating that reduces the amount of sample preparation time, thus allowing us to date a greater number of corals. In addition, these rapid age surveys provide important information on coral age populations, allowing us to examine coral distributions through time. The corals used in this study come from a sample set of about 6,000 specimens of Flabellum, Balanophyllia and Desmophyllum spp. collected from the Drake Passage area (50S -70S, 120 m-1700 m depth). Replicate samples from a single coral yielded a standard deviation of 81 years (n=9). Variations in sample mass (3 to 85 mg) have no clear effect on the Fm and furthermore, a simple cleaning using methanol yields the same results as a more involved cleaning procedure that includes an oxidizing solution and perchloric acid rinse. To improve the efficiency of the method, we assumed a delta13C = 0 per mil. This assumption is likely our largest source of uncertainty, resulting in offsets of up to 200 radiocarbon years over a reasonable range of delta13C. This level of uncertainty is sufficiently low to allow distinction between corals from different time periods over the past 35 ky (e.g. Last Glacial Maximum, Younger Dryas, etc.). To date, we have found corals from Burdwood Bank dating from the modern to the Younger Dryas and corals from the Drake Passage dating from the modern to Heinrich Event 1, which will be used in future paleo-climatic reconstructions in this important part of the ocean.

  9. [A quickly atmospheric correction method for HJ-1 CCD with deep blue algorithm].

    PubMed

    Wang, Zhong-Ting; Wang, Hong-Mei; Li, Qing; Zhao, Shao-Hua; Li, Shen-Shen; Chen, Liang-Fu

    2014-03-01

    In the present, for the characteristic of HJ-1 CCD camera, after receiving aerosol optical depth (AOD) from deep blue algorithm which was developed by Hsu et al. assisted by MODerate-resolution imaging spectroradiometer (MODIS) surface reflectance database, bidirectional reflectance distribution function (BRDF) correction with Kernel-Driven Model, and the calculation of viewing geometry with auxiliary data, a new atmospheric correction method of HJ-1 CCD was developed which can be used over vegetation, soil and so on. And, when the CCD data is processed to correct atmospheric influence, with look up table (LUT) and bilinear interpolation, atmospheric correction of HJ-1 CCD is completed quickly by grid calculation of atmospheric parameters and matrix operations of interface define language (IDL). The experiment over China North Plain on July 3rd, 2012 shows that by our method, the atmospheric influence was corrected well and quickly (one CCD image of 1 GB can be corrected in eight minutes), and the reflectance after correction over vegetation and soil was close to the spectrum of vegetation and soil. The comparison with MODIS reflectance product shows that for the advantage of high resolution, the corrected reflectance image of HJ-1 is finer than that of MODIS, and the correlation coefficient of the reflectance over typical surface is greater than 0.9. Error analysis shows that the recognition error of aerosol type leads to 0. 05 absolute error of surface reflectance in near infrared band, which is larger than that in visual bands, and the 0. 02 error of reflectance database leads to 0.01 absolute error of surface reflectance of atmospheric correction in green and red bands. PMID:25208402

  10. 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…

  11. Mixed Triple: Allied Viruses in Unique Recent Isolates of Highly Virulent Type 2 Bovine Viral Diarrhea Virus Detected by Deep Sequencing

    PubMed Central

    Jenckel, Maria; Höper, Dirk; Schirrmeier, Horst; Reimann, Ilona; Goller, Katja V.; Hoffmann, Bernd

    2014-01-01

    ABSTRACT In February 2013, very severe acute clinical symptoms were observed in calves, heifers, and dairy cattle in several farms in North Rhine Westphalia and Lower Saxony, Germany. Deep sequencing revealed the coexistence of three distinct genome variants within recent highly virulent bovine viral diarrhea virus type 2 (BVDV-2) isolates. While the major portion (ca. 95%) of the population harbored a duplication of a 222-nucleotide (nt) segment within the p7-NS2-encoding region, the minority reflected the standard structure of a BVDV-2 genome. Additionally, unusual mutations were found in both variants, within the highly conserved p7 protein and close to the p7-NS2 cleavage site. Using a reverse genetic system with a BVDV-2a strain harboring a similar duplication, it could be demonstrated that during replication, genomes without duplication are generated de novo from genomes with duplication. The major variant with duplication is compulsorily escorted by the minor variant without duplication. RNA secondary structure prediction allowed the analysis of the unique but stable mixture of three BVDV variants and also provided the explanation for their generation. Finally, our results suggest that the variant with duplication plays the major role in the highly virulent phenotype. IMPORTANCE This study emphasizes the importance of full-genome deep sequencing in combination with manual in-depth data analysis for the investigation of viruses in basic research and diagnostics. Here we investigated recent highly virulent bovine viral diarrhea virus isolates from a 2013 series of outbreaks. We discovered a unique special feature of the viral genome, an unstable duplication of 222 nucleotides which is eventually deleted by viral polymerase activity, leading to an unexpectedly mixed population of viral genomes for all investigated isolates. Our study is of high importance to the field because we demonstrate that these insertion/deletion events allow another level of genome

  12. Detection of plant viruses in mixed infection by a macroarray-assisted method.

    PubMed

    Shimura, Hanako; Furuta, Kazuyoshi; Masuta, Chikara

    2015-01-01

    The protocol for a simple, sensitive, and specific method using a cDNA macroarray to detect multiple viruses is provided. The method can be used even at the production sites for crops, which need a reliable routine diagnosis for mixed infection of plant viruses. The method consists of three steps: RNA extraction, duplex RT-PCR, and "microtube hybridization" (MTH). Biotinylated cDNA probes are prepared using RT-PCR and used to hybridize a nylon membrane containing target viral cDNAs by MTH. Positive signals can be visualized by colorimetric reaction and judged by eyes. We here demonstrate this method to detect asparagus viruses (Asparagus virus 1 and Asparagus virus 2) from latently infected asparagus plants. PMID:25287491

  13. Mixed Methods for the Interpretation of Longitudinal Gerontologic Data: Insights From Philosophical Hermeneutics

    PubMed Central

    Van Ness, Peter H.; Fried, Terri R.; Gill, Thomas M.

    2012-01-01

    This article’s main objective is to demonstrate that data analysis, including quantitative data analysis, is a process of interpretation involving basic hermeneutic principles that philosophers have identified in the interpretive process as applied to other, mainly literary, creations. Such principles include a version of the hermeneutic circle, an insistence on interpretive presuppositions, and a resistance to reducing the discovery of truth to the application of inductive methods. The importance of interpretation becomes especially evident when qualitative and quantitative methods are combined in a single clinical research project and when the data being analyzed are longitudinal. Study objectives will be accomplished by showing that three major hermeneutic principles make practical methodological contributions to an insightful, illustrative mixed methods analysis of a qualitative study of changes in functional disability over time embedded in the Precipitating Events Project—a major longitudinal, quantitative study of functional disability among older persons. Mixed methods, especially as shaped by hermeneutic insights such as the importance of empathetic understanding, are potentially valuable resources for scientific investigations of the experience of aging: a practical aim of this article is to articulate and demonstrate this contention. PMID:22582035

  14. Mixed-norm estimates for the M/EEG inverse problem using accelerated gradient methods

    PubMed Central

    Gramfort, Alexandre; Kowalski, Matthieu; Hämäläinen, Matti

    2012-01-01

    Magneto- and electroencephalography (M/EEG) measure the electromagnetic fields produced by the neural electrical currents. Given a conductor model for the head, and the distribution of source currents in the brain, Maxwell’s equations allow one to compute the ensuing M/EEG signals. Given the actual M/EEG measurements and the solution of this forward problem, one can localize, in space and in time, the brain regions than have produced the recorded data. However, due to the physics of the problem, the limited number of sensors compared to the number of possible source locations, and measurement noise, this inverse problem is ill-posed. Consequently, additional constraints are needed. Classical inverse solvers, often called Minimum Norm Estimates (MNE), promote source estimates with a small ℓ2 norm. Here, we consider a more general class of priors based on mixed-norms. Such norms have the ability to structure the prior in order to incorporate some additional assumptions about the sources. We refer to such solvers as Mixed-Norm Estimates (MxNE). In the context of M/EEG, MxNE can promote spatially focal sources with smooth temporal estimates with a two-level ℓ1/ℓ2 mixed-norm, while a three-level mixed-norm can be used to promote spatially non-overlapping sources between different experimental conditions. In order to efficiently solve the optimization problems of MxNE, we introduce fast first-order iterative schemes that for the ℓ1/ℓ2 norm give solutions in a few seconds making such a prior as convenient as the simple MNE. Furhermore, thanks to the convexity of the optimization problem, we can provide optimality conditions that guarantee global convergence. The utility of the methods is demonstrated both with simulations and experimental MEG data. PMID:22421459

  15. Mixed-norm estimates for the M/EEG inverse problem using accelerated gradient methods

    NASA Astrophysics Data System (ADS)

    Gramfort, Alexandre; Kowalski, Matthieu; Hämäläinen, Matti

    2012-04-01

    Magneto- and electroencephalography (M/EEG) measure the electromagnetic fields produced by the neural electrical currents. Given a conductor model for the head, and the distribution of source currents in the brain, Maxwell's equations allow one to compute the ensuing M/EEG signals. Given the actual M/EEG measurements and the solution of this forward problem, one can localize, in space and in time, the brain regions that have produced the recorded data. However, due to the physics of the problem, the limited number of sensors compared to the number of possible source locations, and measurement noise, this inverse problem is ill-posed. Consequently, additional constraints are needed. Classical inverse solvers, often called minimum norm estimates (MNE), promote source estimates with a small ℓ2 norm. Here, we consider a more general class of priors based on mixed norms. Such norms have the ability to structure the prior in order to incorporate some additional assumptions about the sources. We refer to such solvers as mixed-norm estimates (MxNE). In the context of M/EEG, MxNE can promote spatially focal sources with smooth temporal estimates with a two-level ℓ1/ℓ2 mixed-norm, while a three-level mixed-norm can be used to promote spatially non-overlapping sources between different experimental conditions. In order to efficiently solve the optimization problems of MxNE, we introduce fast first-order iterative schemes that for the ℓ1/ℓ2 norm give solutions in a few seconds making such a prior as convenient as the simple MNE. Furthermore, thanks to the convexity of the optimization problem, we can provide optimality conditions that guarantee global convergence. The utility of the methods is demonstrated both with simulations and experimental MEG data.

  16. Xenoliths in ultrapotassic volcanic rocks in the Lhasa block: direct evidence for crust-mantle mixing and metamorphism in the deep crust

    NASA Astrophysics Data System (ADS)

    Wang, Rui; Collins, William J.; Weinberg, Roberto F.; Li, Jin-xiang; Li, Qiu-yun; He, Wen-yan; Richards, Jeremy P.; Hou, Zengqian; Zhou, Li-min; Stern, Richard A.

    2016-07-01

    δ18O (+6 to 7.5 ‰), intermediate (δ18O +8.5 to 9.0 ‰), and high δ18O (+11.0 to 12.0 ‰). The fourth is almost pure andradite with δ18O 10-12 ‰. Both the low and intermediate δ18O groups show significant variation in Fe content, whereas the two high δ18O groups are compositionally homogeneous. We interpret these features to indicate that the low and intermediate δ18O group garnets grew in separate fractionating magmas that were brought together through magma mixing, whereas the high δ18O groups formed under high-grade metamorphic conditions accompanied by metasomatic exchange. The garnets record complex, open-system magmatic and metamorphic processes in a single rock. Based on these features, we consider that ultrapotassic magmas interacted with juvenile 35-20 Ma crust after they intruded in the deep crust (>50 km) at ~13 Ma to form hybridized Miocene granitoid magmas, leaving a refractory residue. The ~13 Ma zircons retain the original, evolved isotopic character of the ultrapotassic magmas, and the garnets record successive stages of the melting and mixing process, along with subsequent high-grade metamorphism followed by low-temperature alteration and brecciation during entrainment and ascent in a late UPV dyke. This is an excellent example of in situ crust-mantle hybridization in the deep Tibetan crust.

  17. Enhancing Science Education Instruction: A Mixed-Methods Study on University and Middle School Collaborations

    NASA Astrophysics Data System (ADS)

    Owen-Stone, Deborah S.

    The purpose of this concurrent mixed methods study was to examine the collaborative relationship between scientists and science teachers and to incorporate and advocate scientific literacy based on past and current educational theories such as inquiry based teaching. The scope of this study included archived student standardized test scores, semi-structured interviews, and a Likert scale survey to include open-ended comments. The methodology was based on the guiding research question: To what extent and in what ways does the collaboration and inquiry methodology, with GTF and PT teams, serve toward contributing to a more comprehensive and nuanced understanding of this predicting relationship between student PASS scores, inquiry skills, and increased scientific literacy for GTF's, PT's, and students via an integrative mixed methods analysis? The data analysis considerations were derived from the qualitative data collected from the three GTF/PT teams by the use of recorded interviews and text answered survey comments. The quantitative data of archived student Palmetto Assessment of State Standards (PASS) scores on scientific literacy and inquiry tests and the Likert-scale portion of the survey were support data to the aforementioned qualitative data findings. Limitations of the study were (1) the population of only the GK-12 teachers and their students versus the inclusion of participants that did not experience the GK-12 Fellow partnerships within their classrooms, should they be considered as participants, (2) involved the researcher as a participant for two years of the program and objectivity remained through interpretation and well documented personal reflections and experiences to inform accuracy, and (3) cultural diversity contributed to the relationship formed between the research Fellow and science educator and communication and scientific language did form a barrier between the Fellow, educator, and student rapport within the classroom. This study

  18. A harmonic pulse testing method for leakage detection in deep subsurface storage formations

    NASA Astrophysics Data System (ADS)

    Sun, Alexander Y.; Lu, Jiemin; Hovorka, Susan

    2015-06-01

    Detection of leakage in deep geologic storage formations (e.g., carbon sequestration sites) is a challenging problem. This study investigates an easy-to-implement frequency domain leakage detection technology based on harmonic pulse testing (HPT). Unlike conventional constant-rate pressure interference tests, HPT stimulates a reservoir using periodic injection rates. The fundamental principle underlying HPT-based leakage detection is that leakage modifies a storage system's frequency response function, thus providing clues of system malfunction. During operations, routine HPTs can be conducted at multiple pulsing frequencies to obtain experimental frequency response functions, using which the possible time-lapse changes are examined. In this work, a set of analytical frequency response solutions is derived for predicting system responses with and without leaks for single-phase flow systems. Sensitivity studies show that HPT can effectively reveal the presence of leaks. A search procedure is then prescribed for locating the actual leaks using amplitude and phase information obtained from HPT, and the resulting optimization problem is solved using the genetic algorithm. For multiphase flows, the applicability of HPT-based leakage detection procedure is exemplified numerically using a carbon sequestration problem. Results show that the detection procedure is applicable if the average reservoir conditions in the testing zone stay relatively constant during the tests, which is a working assumption under many other interpretation methods for pressure interference tests. HPT is a cost-effective tool that only requires periodic modification of the nominal injection rate. Thus it can be incorporated into existing monitoring plans with little additional investment.

  19. Biophotonics of skin: method for correction of deep Raman spectra distorted by elastic scattering

    NASA Astrophysics Data System (ADS)

    Roig, Blandine; Koenig, Anne; Perraut, François; Piot, Olivier; Gobinet, Cyril; Manfait, Michel; Dinten, Jean-Marc

    2015-03-01

    Confocal Raman microspectroscopy allows in-depth molecular and conformational characterization of biological tissues non-invasively. Unfortunately, spectral distortions occur due to elastic scattering. Our objective is to correct the attenuation of in-depth Raman peaks intensity by considering this phenomenon, enabling thus quantitative diagnosis. In this purpose, we developed PDMS phantoms mimicking skin optical properties used as tools for instrument calibration and data processing method validation. An optical system based on a fibers bundle has been previously developed for in vivo skin characterization with Diffuse Reflectance Spectroscopy (DRS). Used on our phantoms, this technique allows checking their optical properties: the targeted ones were retrieved. Raman microspectroscopy was performed using a commercial confocal microscope. Depth profiles were constructed from integrated intensity of some specific PDMS Raman vibrations. Acquired on monolayer phantoms, they display a decline which is increasing with the scattering coefficient. Furthermore, when acquiring Raman spectra on multilayered phantoms, the signal attenuation through each single layer is directly dependent on its own scattering property. Therefore, determining the optical properties of any biological sample, obtained with DRS for example, is crucial to correct properly Raman depth profiles. A model, inspired from S.L. Jacques's expression for Confocal Reflectance Microscopy and modified at some points, is proposed and tested to fit the depth profiles obtained on the phantoms as function of the reduced scattering coefficient. Consequently, once the optical properties of a biological sample are known, the intensity of deep Raman spectra distorted by elastic scattering can be corrected with our reliable model, permitting thus to consider quantitative studies for purposes of characterization or diagnosis.

  20. Modeling foam delivery mechanisms in deep vadose-zone remediation using method of characteristics.

    PubMed

    Roostapour, A; Kam, S I

    2012-12-01

    This study investigates foam delivery mechanisms in vadose-zone remediation by using Method of Characteristics (MoC), a mathematical tool long been used for the analysis of miscible and immiscible flooding in porous media in petroleum industry. MoC converts the governing material-balance partial differential equations into a series of ordinary differential equations, and the resulting solutions are in a form of wave propagation (more specifically, for chemical species and phase saturations) through the system as a function of time and space. Deep vadose-zone remediation has special features compared to other conventional remediation applications. They include, not limited to, a high level of heterogeneity, a very dry initial condition with low water saturation (S(w)), pollutants such as metals and radionuclides fully dissolved in groundwater, and a serious concern about downward migration during the remediation treatments. For the vadose-zone remediation processes to be successful, the injected aqueous phase should carry chemicals to react with pollutants and precipitate them for immobilization and stabilization purposes. As a result, foams are believed to be an effective means, and understanding foam flow mechanism in situ is a key to the optimal design of field applications. Results show that foam delivery mechanism is indeed very complicated, making the optimum injection condition field-specific. The five major parameters selected (i.e., initial saturation of the medium, injection foam quality, surfactant adsorption, foam strength, and foam stability) are shown to be all important, interacting with each other. Results also imply that although dry foam injection is generally recommended, too dry injection condition is found to hurt this process due to slow foam propagation.

  1. Provider payment methods and health worker motivation in community-based health insurance: a mixed-methods study.

    PubMed

    Robyn, Paul Jacob; Bärnighausen, Till; Souares, Aurélia; Traoré, Adama; Bicaba, Brice; Sié, Ali; Sauerborn, Rainer

    2014-05-01

    In a community-based health insurance (CBHI) introduced in 2004 in Nouna health district, Burkina Faso, poor perceived quality of care by CBHI enrollees has been a key factor in observed high drop-out rates. The poor quality perceptions have been previously attributed to health worker dissatisfaction with the provider payment method used by the scheme and the resulting financial risk of health centers. This study applied a mixed-methods approach to investigate how health workers working in facilities contracted by the CBHI view the methods of provider payment used by the CBHI. In order to analyze these relationships, we conducted 23 in-depth interviews and a quantitative survey with 98 health workers working in the CBHI intervention zone. The qualitative in-depth interviews identified that insufficient levels of capitation payments, the infrequent schedule of capitation payment, and lack of a payment mechanism for reimbursing service fees were perceived as significant sources of health worker dissatisfaction and loss of work-related motivation. Combining qualitative interview and quantitative survey data in a mixed-methods analysis, this study identified that the declining quality of care due to the CBHI provider payment method was a source of significant professional stress and role strain for health workers. Health workers felt that the following five changes due to the provider payment methods introduced by the CBHI impeded their ability to fulfill professional roles and responsibilities: (i) increased financial volatility of health facilities, (ii) dissatisfaction with eligible costs to be covered by capitation; (iii) increased pharmacy stock-outs; (iv) limited financial and material support from the CBHI; and (v) the lack of mechanisms to increase provider motivation to support the CBHI. To address these challenges and improve CBHI uptake and health outcomes in the targeted populations, the health care financing and delivery model in the study zone should be

  2. Innovative method and apparatus for the deep cleaning of soluble salts from mortars and lithic materials

    NASA Astrophysics Data System (ADS)

    Gaggero, Laura; Ferretti, Maurizio; Torrielli, Giulia; Caratto, Valentina

    2016-04-01

    Porous materials (e.g. plasters, mortars, concrete, and the like) used in the building industry or in artworks fail to develop, after their genesis, salts such as nitrates, carbonates (e.g. potassium carbonate, magnesium carbonate, calcium carbonate), chlorides (e.g. sodium chloride) and/or others, which are a concurrent cause of material deterioration phenomena. In the case of ancient or cultural heritage buildings, severe damage to structures and works of art, such as fresco paintings are possible. In general, in situ alteration pattern in mortars and frescoes by crystallization of soluble salts from solutions is caused by capillar rise or circulation in damp walls. Older buildings can be more subject to capillary rise of ion-rich waters, which, as water evaporates, create salt crystals inside the walls. If this pattern reveals overwhelming upon other environmental decay factors, the extraction of salts is the first restoration to recover the artpiece after the preliminary assessment and mitigation of the causes of soaking. A new method and apparatus, patented by University of Genoa [1] improves the quality and durability of decontamination by soluble salts, compared with conventional application of sepiolite or cellulose wraps. The conventional application of cellulose or sepiolite requires casting a more or less thick layer of wrap on the mortar, soaking with distilled water, and waiting until dry. The soluble salts result trapped within the wrap. A set of artificial samples reproducing the stratigraphy of frescoes was contaminated with saline solution of known concentration. The higher quality of the extraction was demonstrated by trapping the salts within layers of Japanese paper juxtaposed to the mortar; the extraction with the dedicated apparatus was operated in a significantly shorter time than with wraps (some hours vs. several days). Two cycles of about 15 minutes are effective in the deep cleaning from contaminant salts. The decontamination was

  3. Applying a Mixed-Methods Evaluation to Healthy Kids, Healthy Communities

    PubMed Central

    Brownson, Ross C.; Kemner, Allison L.; Brennan, Laura K.

    2016-01-01

    From 2008 to 2014, the Healthy Kids, Healthy Communities (HKHC) national program funded 49 communities across the United States and Puerto Rico to implement healthy eating and active living policy, system, and environmental changes to support healthier communities for children and families, with special emphasis on reaching children at highest risk for obesity on the basis of race, ethnicity, income, or geographic location. Evaluators designed a mixed-methods evaluation to capture the complexity of the HKHC projects, understand implementation, and document perceived and actual impacts of these efforts. PMID:25828217

  4. A numerical method for systems of conservation laws of mixed type admitting hyperbolic flux splitting

    NASA Technical Reports Server (NTRS)

    Shu, Chi-Wang

    1992-01-01

    The present treatment of elliptic regions via hyperbolic flux-splitting and high order methods proposes a flux splitting in which the corresponding Jacobians have real and positive/negative eigenvalues. While resembling the flux splitting used in hyperbolic systems, the present generalization of such splitting to elliptic regions allows the handling of mixed-type systems in a unified and heuristically stable fashion. The van der Waals fluid-dynamics equation is used. Convergence with good resolution to weak solutions for various Riemann problems are observed.

  5. Primary health care experiences of hispanics with serious mental illness: a mixed-methods study.

    PubMed

    Cabassa, Leopoldo J; Gomes, Arminda P; Meyreles, Quisqueya; Capitelli, Lucia; Younge, Richard; Dragatsi, Dianna; Alvarez, Juana; Nicasio, Andel; Druss, Benjamin; Lewis-Fernández, Roberto

    2014-11-01

    This mixed-methods study examines the primary health care experiences of Hispanic patients with serious mental illness. Forty patients were recruited from an outpatient mental health clinic. Participants reported a combination of perceived discrimination and stigmatization when receiving medical care. They rated the quality of chronic illness care as poor and reported low levels of self-efficacy and patient activation. These indicators were positively associated with how patients viewed their relationships with primary care providers. A grounded model was developed to describe the structural, social, and interpersonal processes that shaped participants' primary care experiences.

  6. Domain decomposition for a mixed finite element method in three dimensions

    USGS Publications Warehouse

    Cai, Z.; Parashkevov, R.R.; Russell, T.F.; Wilson, J.D.; Ye, X.

    2003-01-01

    We consider the solution of the discrete linear system resulting from a mixed finite element discretization applied to a second-order elliptic boundary value problem in three dimensions. Based on a decomposition of the velocity space, these equations can be reduced to a discrete elliptic problem by eliminating the pressure through the use of substructures of the domain. The practicality of the reduction relies on a local basis, presented here, for the divergence-free subspace of the velocity space. We consider additive and multiplicative domain decomposition methods for solving the reduced elliptic problem, and their uniform convergence is established.

  7. Primary Health Care Experiences of Hispanics with Serious Mental Illness: A Mixed-Methods Study

    PubMed Central

    Cabassa, Leopoldo J.; Gomes, Arminda P.; Meyreles, Quisqueya; Capitelli, Lucia; Younge, Richard; Dragatsi, Dianna; Alvarez, Juana; Nicasio, Andel; Druss, Benjamin; Lewis-Fernández, Roberto

    2013-01-01

    This mixed-methods study examines the primary health care experiences of Hispanic patients with serious mental illness. Forty patients were recruited from an outpatient mental health clinic. Participants reported a combination of perceived discrimination and stigmatization when receiving medical care. They rated the quality of chronic illness care as poor and reported low levels of self-efficacy and patient activation. These indicators were positively associated with how patients viewed their relationships with primary care providers. A grounded model was developed to describe the structural, social, and interpersonal processes that shaped participants’ primary care experiences. PMID:24162079

  8. Eclecticism as the foundation of meta-theoretical, mixed methods and interdisciplinary research in social sciences.

    PubMed

    Kroos, Karmo

    2012-03-01

    This article examines the value of "eclecticism" as the foundation of meta-theoretical, mixed methods and interdisciplinary research in social sciences. On the basis of the analysis of the historical background of the concept, it is first suggested that eclecticism-based theoretical scholarship in social sciences could benefit from the more systematic research method that has been developed for synthesizing theoretical works under the name metatheorizing. Second, it is suggested that the mixed methods community could base its research approach on philosophical eclecticism instead of pragmatism because the basic idea of eclecticism is much more in sync with the nature of the combined research tradition. Finally, the Kuhnian frame is used to support the argument for interdisciplinary research and, hence, eclecticism in social sciences (rather than making an argument against multiple paradigms). More particularly, it is suggested that integrating the different (inter)disciplinary traditions and schools into one is not necessarily desirable at all in social sciences because of the complexity and openness of the research field. If it is nevertheless attempted, experience in economics suggests that paradigmatic unification comes at a high price. PMID:22076693

  9. A continuous-flow capillary mixing method to monitor reactions on the microsecond time scale.

    PubMed

    Shastry, M C; Luck, S D; Roder, H

    1998-05-01

    A continuous-flow capillary mixing apparatus, based on the original design of Regenfuss et al. (Regenfuss, P., R. M. Clegg, M. J. Fulwyler, F. J. Barrantes, and T. M. Jovin. 1985. Rev. Sci. Instrum. 56:283-290), has been developed with significant advances in mixer design, detection method and data analysis. To overcome the problems associated with the free-flowing jet used for observation in the original design (instability, optical artifacts due to scattering, poor definition of the geometry), the solution emerging from the capillary is injected directly into a flow-cell joined to the tip of the outer capillary via a ground-glass joint. The reaction kinetics are followed by measuring fluorescence versus distance downstream from the mixer, using an Hg(Xe) arc lamp for excitation and a digital camera with a UV-sensitized CCD detector for detection. Test reactions involving fluorescent dyes indicate that mixing is completed within 15 micros of its initiation and that the dead time of the measurement is 45 +/- 5 micros, which represents a >30-fold improvement in time resolution over conventional stopped-flow instruments. The high sensitivity and linearity of the CCD camera have been instrumental in obtaining artifact-free kinetic data over the time window from approximately 45 micros to a few milliseconds with signal-to-noise levels comparable to those of conventional methods. The scope of the method is discussed and illustrated with an example of a protein folding reaction.

  10. Mixed direct-iterative methods for boundary integral formulations of continuum dielectric solvation models

    SciTech Connect

    Corcelli, S.A.; Kress, J.D.; Pratt, L.R.

    1995-08-07

    This paper develops and characterizes mixed direct-iterative methods for boundary integral formulations of continuum dielectric solvation models. We give an example, the Ca{sup ++}{hor_ellipsis}Cl{sup {minus}} pair potential of mean force in aqueous solution, for which a direct solution at thermal accuracy is difficult and, thus for which mixed direct-iterative methods seem necessary to obtain the required high resolution. For the simplest such formulations, Gauss-Seidel iteration diverges in rare cases. This difficulty is analyzed by obtaining the eigenvalues and the spectral radius of the non-symmetric iteration matrix. This establishes that those divergences are due to inaccuracies of the asymptotic approximations used in evaluation of the matrix elements corresponding to accidental close encounters of boundary elements on different atomic spheres. The spectral radii are then greater than one for those diverging cases. This problem is cured by checking for boundary element pairs closer than the typical spatial extent of the boundary elements and for those cases performing an ``in-line`` Monte Carlo integration to evaluate the required matrix elements. These difficulties are not expected and have not been observed for the thoroughly coarsened equations obtained when only a direct solution is sought. Finally, we give an example application of hybrid quantum-classical methods to deprotonation of orthosilicic acid in water.

  11. Method of estimating the amount of in situ gas hydrates in deep marine sediments

    USGS Publications Warehouse

    Lee, M.W.; Hutchinson, D.R.; Dillon, William P.; Miller, J.J.; Agena, W.F.; Swift, B.A.

    1993-01-01

    The bulk volume of gas hydrates in marine sediments can be estimated by measuring interval velocities and amplitude blanking of hydrated zones from true amplitude processed multichannel seismic reflection data. In general, neither velocity nor amplitude information is adequate to independently estimate hydrate concentration. A method is proposed that uses amplitude blanking calibrated by interval velocity information to quantify hydrate concentrations in the Blake Ridge area of the US Atlantic continental margin. On the Blake Ridge, blanking occurs in conjunction with relatively low interval velocities. The model that best explains this relation linearly mixes two end-member sediments: hydrated and unhydrated sediment. Hydrate concentration in the hydrate end-member can be calculated from a weighted equation that uses velocity estimated from the seismic data, known properties of the pure hydrate, and porosity inferred from a velocity-porosity relationship. Amplitude blanking can be predicted as the proportions of hydrated and unhydrated sediment change across a reflection boundary. Our analysis of a small area near DSDP 533 indicates that the amount of gas hydrates is about 6% in total volume when the interval velocity is used as a criterion and about 9.5% when amplitude information is used. This compares with a calculated value of about 8% derived from the only available measurement in DSDP 533. ?? 1993.

  12. Preparation of mixed metal thin films by a PVD method using several kinds of powder targets

    NASA Astrophysics Data System (ADS)

    Suda, Yoshiaki; Kawasaki, Hiroharu; Ohshima, Tamiko; Yagyu, Yoshihito; Ihara, Takeshi; Yamauchi, Makiko; Plasma process; application Team

    2015-09-01

    Bismuth iron garnet (Bi3Fe5O12) and aluminum doped zinc oxide (AZO) thin films were prepared by a physical vapor deposition method using mixed metal powder targets. The X-ray powder diffraction and X-ray photoelectron spectroscopy results suggest that crystalline thin films can be prepared using powder targets with quality similar to that of the films prepared using bulk targets. Bi3Fe5O12 films prepared using the pulsed laser deposition method were Bi rich, which may be due to the lower melting temperature of Bi (544 K) compared with that of Fe (1811 K). The mean transparency and resistivity of the AZO films prepared by the sputtering method were approximately 79%-84% and 0.5 - 1.4 ohm/cm, respectively.

  13. Study on Compressibility Control of Hyperelastic Material for Homogenization Method Using Mixed Finite Element Analysis

    NASA Astrophysics Data System (ADS)

    Okada, Jun-Ichi; Hisada, Toshiaki

    It is well known that the compressibility or incompressibility of biological tissue stems from its microscopic structure, which is generally composed of material with varied compressibility, including incompressibility. This paper proposes a framework for a homogenization method in which the compressibility/incompressibility of the macrostructure properly reflects that of the microstructure. The formulation is based on the mixed variational principle with a perturbed Lagrange-multiplier. It is shown that the rate of volumetric change of the macrostructure can be controlled through the homogenization procedure by introducing the constraint on the microstructure only. A couple of numerical examples are given to demonstrate the validity of the proposed method. By comparing the numerical results with theoretical solutions, the method is also confirmed to be free from locking.

  14. A solution of the Navier-Stokes equations by a mixed finite element method

    NASA Astrophysics Data System (ADS)

    Bredif, M.

    1981-09-01

    The numerical treatment of steady state, two-dimensional Navier-Stokes equations in the incompressible case is studied. The approximation method retained is the mixed finite element method, as regards stream function and vortex function. The improvements to this formulation are: possibility of choice of boundary conditions of various types; introduction of a finite element formulation of the stagnation pressure calculation; definition of a corrected formulation with a view to studying laminar flows in the case of large Reynolds numbers. The chosen formulation is discussed theoretically, encompassing the aspects mentioned. A solution algorithm is presented, based on a general conjugate gradient method; numerical results are presented for various cases of viscous, incompressible, laminar flows: (1) in a square cavity; (2) around a circular cylinder: and (3) around a NACA 0018 profile at zero angle of attack for Reynolds numbers up to 5000.

  15. A solution of the Navier-Stokes equations by a mixed finite element method

    NASA Astrophysics Data System (ADS)

    Bredif, M.

    The numerical treatment of steady state, two-dimensional Navier-Stokes equations in the incompressible case is studied. The approximation method retained is the "mixed" finite element method, as regards stream function and vortex function. The improvements to this formulation are: possibility of choice of boundary conditions of various types; introduction of a finite element formulation of the stagnation pressure calculation; definition of a corrected formulation with a view to studying laminar flows in the case of large Reynolds numbers. The chosen formulation is discussed theoretically, encompassing the aspects mentioned. A solution algorithm is presented, based on a general conjugate gradient method; numerical results are presented for various cases of viscous, incompressible, laminar flows: (1) in a square cavity; (2) around a circular cylinder; and (3) around a NACA 0018 profile at zero angle of attack for Reynolds numbers up to 5000.

  16. New method for isolating barophiles from intestinal contents of deep-sea fishes retrieved from the abyssal zone.

    PubMed

    Nakayama, A; Yano, Y; Yoshida, K

    1994-11-01

    We devised a new method (the dorayaki method) using marine agar under in situ pressures to isolate barophilic bacteria from the intestinal contents of three deep-sea fishes (two Coryphaenoides yaquinae samples and one Ilyophis sp. sample) retrieved from depths of 4,700 to 6,100 m in the Northwest Pacific Ocean. All 10 strains isolated from one sample (C. yaquinae) were obligately barophilic. One of the 10 strains did not grow at atmospheric pressure and 103.4 MPa but did grow well between 20.7 and 82.7 MPa, with optimal growth at 41.4 MPa. This method is useful for isolating psychrophilic and barophilic deep-sea bacteria. PMID:16349450

  17. Effects of planting method and seed mix richness on the early stages of tallgrass prairie restoration

    USGS Publications Warehouse

    Larson, D.L.; Bright, J.B.; Drobney, P.; Larson, J.L.; Palaia, N.; Rabie, P.A.; Vacek, S.; Wells, D.

    2011-01-01

    Tallgrass prairie restoration has been practiced for more than 75. years, yet few studies have systematically tested restoration methods over large geographic regions with the intent of refining methodology. In this study, we used three planting methods (dormant-season broadcast, growing-season broadcast and growing-season drill) fully crossed with three levels of seed species richness (10, 20, and 34 spp). We replicated the study on nine former agricultural fields located from east-central Iowa (Neal Smith National Wildlife Refuge) to northwestern Minnesota (Litchfield, Fergus Falls and Morris Wetland Management Districts), USA, within the northern tallgrass prairie biome. Objectives were to evaluate the relative influences of planting method, seed mix richness, and their interactions, on (1) planted cover (both total and by guild) and richness, (2) exotic species cover, and (3) non-planted native species cover. Optimal techniques varied between the two study areas: the dormant broadcast method produced greater cover of planted species at the Minnesota sites and the growing-season drill method produced greater cover of planted species at Iowa sites. The dormant broadcast method strongly favored establishment of perennial forbs while the growing-season drill favored warm-season grasses. Although increasing richness of the seed mix produced greater planted species richness, this did not result in greater resistance to exotic invasion. We conclude that, if planting during the growing season, drilling seed is preferable to broadcasting, but if the choice is between broadcasting seed in the dormant or growing season, the dormant season is preferred. ?? 2011.

  18. Dynamic reflexivity in action: an armchair walkthrough of a qualitatively driven mixed-method and multiple methods study of mindfulness training in schoolchildren.

    PubMed

    Cheek, Julianne; Lipschitz, David L; Abrams, Elizabeth M; Vago, David R; Nakamura, Yoshio

    2015-06-01

    Dynamic reflexivity is central to enabling flexible and emergent qualitatively driven inductive mixed-method and multiple methods research designs. Yet too often, such reflexivity, and how it is used at various points of a study, is absent when we write our research reports. Instead, reports of mixed-method and multiple methods research focus on what was done rather than how it came to be done. This article seeks to redress this absence of emphasis on the reflexive thinking underpinning the way that mixed- and multiple methods, qualitatively driven research approaches are thought about and subsequently used throughout a project. Using Morse's notion of an armchair walkthrough, we excavate and explore the layers of decisions we made about how, and why, to use qualitatively driven mixed-method and multiple methods research in a study of mindfulness training (MT) in schoolchildren.

  19. Characterization of mixed waste for sorting and inspection using non-intrusive methods

    SciTech Connect

    Roberson, G.P.; Ryon, R.W.; Bull, N.L.

    1994-12-01

    Characterization of mixed wastes (that is, radioactive and otherwise hazardous) requires that all hazardous, non-conforming, and radioactive materials be identified, localized, and quantified. With such information, decisions can be made regarding whether the item is treatable or has been adequately treated. Much of the required information can be gained without taking representative samples and analyzing them in a chemistry laboratory. Non-intrusive methods can be used to provide this information on-line at the waste treatment facility. Ideally, the characterization would be done robotically, and either automatically or semi-automatically in order to improve efficiency and safety. For the FY94 Mixed Waste Operations (MWO) project, a treatable waste item is defined as a homogeneous metal object that has external radioactive or heavy metal hazardous contamination. Surface treatment of some kind would therefore be the treatment method to be investigated. The authors developed sorting and inspection requirements, and assessed viable non-intrusive techniques to meet these requirements. They selected radiography, computed tomography and X-ray fluorescence. They have characterized selected mock waste items, and determined minimum detectable amounts of materials. They have demonstrated the efficiency possible by integrating radiographic with tomographic data. Here, they developed a technique to only use radiographic data where the material is homogeneous (fast), and then switching to tomography in those areas where heterogeneity is detected (slower). They also developed a tomographic technique to quantify the volume of each component of a mixed material. This is useful for such things as determining ash content. Lastly, they have developed a document in MOSAIC, an Internet multi-media browser. This document is used to demonstrate the ability to share data and information world-wide.

  20. The evaluation of student-centredness of teaching and learning: a new mixed-methods approach

    PubMed Central

    Lemos, Ana R.; Sandars, John E.; Alves, Palmira

    2014-01-01

    Objectives The aim of the study was to develop and consider the usefulness of a new mixed-methods approach to evaluate the student-centredness of teaching and learning on undergraduate medical courses. An essential paradigm for the evaluation was the coherence between how teachers conceptualise their practice (espoused theories) and their actual practice (theories-in-use). Methods The context was a module within an integrated basic sciences course in an undergraduate medical degree programme. The programme had an explicit intention of providing a student-centred curriculum. A content analysis framework based on Weimer’s dimensions of student-centred teaching was used to analyze data collected from individual interviews with seven teachers to identify espoused theories and 34h of classroom observations and one student focus group to identify theories-in-use. The interviewees were identified by purposeful sampling. The findings from the three methods were triangulated to evaluate the student-centredness of teaching and learning on the course. Results Different, but complementary, perspectives of the student-centredness of teaching and learning were identified by each method. The triangulation of the findings revealed coherence between the teachers’ espoused theories and theories-in-use. Conclusions A mixed-methods approach that combined classroom observations with interviews from a purposeful sample of teachers and students offered a useful evaluation of the extent of student-centredness of teaching and learning of this basic science course. Our case study suggests that this new approach is applicable to other courses in medical education. PMID:25341225