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. A SIMPLIFIED METHOD FOR EVALUATING THE LIQUEFACTION OF SANDY SOIL CONFINED BY A LATTICE-TYPE DEEP MIXING WALL

    NASA Astrophysics Data System (ADS)

    Ishikawa, Akira; Shamoto, Yasuhiro; Jang, Gjiho; Kimura, Takumi

    A simplified method for evaluating the liquefaction of sandy soil confined by a lattice-type deep mixing wall is proposed in this paper. The method calculates the accumulative excess pore water pressure from the initial shear strain using an equivalent shear-stiffness model by homogenization method. The method uses only parameters that are clear in their physical meaning, and can evaluate not only the effect of variations in the external forces, but also the physical properties of the ground. This paper first explains the proposed idea and then presents a specific calculation procedure using an actual site plan.

  3. 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.

  4. Deep Mixing Statistics in the Globular Cluster NGC5466

    NASA Astrophysics Data System (ADS)

    Wilkerson, Rachel

    2010-01-01

    Using VIRUS-P in conjunction with the 2.7m telescope at McDonald Observatory, we obtained a sample of red giants from the metal-poor globular cluster NGC 5466. The flux of the CN and CH absorption features was calculated using the band indices S3839 and SCH respectively. The results indicate that none of the red giants in this sample exhibit deep mixing abundances. To date all similarly surveyed globular clusters show at least some stars with deep mixing abundances. We discuss the cluster properties of NGC 5466 and how this lack of deep mixing stars makes NGC 5466 different from other metal-poor globular clusters.

  5. Maximum mixing method

    NASA Astrophysics Data System (ADS)

    Hjorth, Jens

    The unique feature of MEM is that C(-1)(z) = exp(z) amplifies all scales equally. Narayan & Nityananda (1986) have shown that this leads to Gaussian deconvolved peaks. In MMM different scales are treated differently, depending on the choice of C. This gives different peak shapes, but also allows one to experiment with the degree of peak sharpening as a function of peak height. In fact, despite its strong information-theoretic background, MEM is known to redistribute flux incorrectly during deconvolution, thus making the method problematic if the goal is to get correct intensities out. MMM could remedy this problem by using an alternative to the entropy. In conclusion, some ideas connecting the physics of blurring with a proposed reconstruction scheme, dubbed Maximum Mixing Method, have been presented. It has been shown that this physically motivated, non-information theoretic, non-probabilistic, non-Bayesian approach can be turned into a powerful deconvolution technique, competitive with, and having as a special case, the Maximum Entropy Method. Further work within the proposed framework is required to fully explore the consequences of the theory. A paper including proofs and examples is in preparation.

  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. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Mixed methods research in mental health nursing.

    PubMed

    Kettles, A M; Creswell, J W; Zhang, W

    2011-08-01

    Mixed methods research is becoming more widely used in order to answer research questions and to investigate research problems in mental health and psychiatric nursing. However, two separate literature searches, one in Scotland and one in the USA, revealed that few mental health nursing studies identified mixed methods research in their titles. Many studies used the term 'embedded' but few studies identified in the literature were mixed methods embedded studies. The history, philosophical underpinnings, definition, types of mixed methods research and associated pragmatism are discussed, as well as the need for mixed methods research. Examples of mental health nursing mixed methods research are used to illustrate the different types of mixed methods: convergent parallel, embedded, explanatory and exploratory in their sequential and concurrent combinations. Implementing mixed methods research is also discussed briefly and the problem of identifying mixed methods research in mental and psychiatric nursing are discussed with some possible solutions to the problem proposed. PMID:21749560

  15. Paleohydrological mixing portions in one deep borehole at the Swedish Aspo Hard Rock Laboratory

    SciTech Connect

    Laaksoharju, M.; Sharman, C.

    1995-12-01

    A borehole 1700.5 m deep near the AESPOE Hard Rock Laboratory represents the deepest borehole drilled for the project. In order to establish the paleohydrological mixing portions in the present water, a mixing model was constructed using Principal Component Analysis. This multivariate method used both conservative and non-conservative tracers. The mixing model can describe how large portions of a particular type of water are needed in order to explain the chemical composition of the observed water. Six end-members were identified which are believed to represent waters that interact in different degrees in the sampling area. Mixing ratios were calculated for each end-member at various borehole depths. The multivariate calculation technique established the tracers of paleohydrological water in the borehole with greater resolution than univariate analysis.

  16. 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…

  17. 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…

  18. 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.)

  19. Field testing of stiffened deep cement mixing piles under lateral cyclic loading

    NASA Astrophysics Data System (ADS)

    Raongjant, Werasak; Jing, Meng

    2013-06-01

    Construction of seaside and underground wall bracing often uses stiffened deep cement mixed columns (SDCM). This research investigates methods used to improve the level of bearing capacity of these SDCM when subjected to cyclic lateral loading via various types of stiffer cores. Eight piles, two deep cement mixed piles and six stiffened deep cement mixing piles with three different types of cores, H shape cross section prestressed concrete, steel pipe, and H-beam steel, were embedded though soft clay into medium-hard clay on site in Thailand. Cyclic horizontal loading was gradually applied until pile failure and the hysteresis loops of lateral load vs. lateral deformation were recorded. The lateral carrying capacities of the SDCM piles with an H-beam steel core increased by 3-4 times that of the DCM piles. This field research clearly shows that using H-beam steel as a stiffer core for SDCM piles is the best method to improve its lateral carrying capacity, ductility and energy dissipation capacity.

  20. 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.

  1. Effect of a deep breath on gas mixing and diffusion in the lung.

    PubMed

    Prabhu, M B; Mink, J T; Graham, B L; Cotton, D J

    1990-03-01

    We examined the effect of a previous deep breath on both inert gas mixing and the single breath diffusing capacity (DLCOSB) during submaximal single breath maneuvers in normal subjects. Single breath washouts were performed either immediately after a deep breath or after breathing tidally for 10 min. Maneuvers consisted of inhaling test gas from functional residual capacity to 50% inspiratory capacity and, after either 0 or 6 s of breath holding, exhaling slowly back to residual volume. We measured the Fowler dead space, the Phase III slope of the alveolar plateau of the He washout (delta He/L), the amplitude of the cardiogenic oscillations (Oc), closing capacity, mixing efficiency (Emix) and DLCOSB using the three equation method. For maneuvers immediately after a deep breath we found that delta He/L was steeper and the Oc were larger for washouts with 6 s but not 0 s of breath holding, while Emix was significantly lower and DLCOSB significantly higher for both the 0 s and the 6 s breath holding maneuvers. We conclude that a deep breath increases DLCOSB but simultaneously also increases convective-dependent inhomogeneity in the lung. PMID:2356360

  2. 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.

  3. 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

  4. 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…

  5. Investigation of Deep Ocean Circulation and Mixing Using Ar-39 (Invited)

    NASA Astrophysics Data System (ADS)

    Smethie, W. M.; Schlosser, P.

    2013-12-01

    are about 270, 190, and 330 years respectively. Radiocarbon also provides information on circulation and mixing in the deep ocean and thousands of measurements have been made. However, the distributions of Ar-39 and C-14 are different due to the large difference in their half-lives (269 years and 5730 years respectively). Measurement of both tracers provides information on the relative importance of advection and mixing in the deep ocean and provides more accurate transit times than can be obtained with only one of these tracers. In the Atlantic Ocean, where the deep water is roughly a two-end member mixture of northern component and southern component water, the age of the two components can be estimated from simultaneous measurement of Ar-39 and C-14. The few existing measurements suggest that the northern component water has an age range of 40-200 years and the southern component water a range of 60-600 years. Development of the ATTA method for measuring radioactive noble gases offers great potential to dramatically increase the number of samples that can be measured for Ar-39, which could greatly improve our understanding of mixing and circulation in the deep ocean.

  6. Mixed methods research for the novice researcher.

    PubMed

    Giddings, Lynne S; Grant, Barbara M

    2006-10-01

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

  7. 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.

  8. 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…

  9. 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…

  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. 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…

  12. Two-phase convective mixing under a buoyant plume of CO2 in deep saline aquifers

    NASA Astrophysics Data System (ADS)

    Emami-Meybodi, Hamid; Hassanzadeh, Hassan

    2015-02-01

    The storage of carbon dioxide (CO2) in deep saline aquifers has been suggested as a promising method for stabilizing the atmospheric concentration of CO2. An accurate evaluation of the CO2 trapping mechanisms, such as convective mixing, is crucial for estimates of storage capacity and security. We recently investigated the gravitational stability of the diffusive boundary layer underneath a capillary transition zone by performing a linear stability analysis, which provides a quantitative description of the onset of convection for the two-phase, buoyancy-driven flow in the presence of the capillary transition zone (Emami-Meybodi and Hassanzadeh, 2013). In this paper, we further examine the effect of the capillary transition zone on the onset of convection and subsequent convective mixing using direct numerical simulations. We describe key features of the two-phase convective mixing for systems with low Rayleigh numbers (Ra ≤ 1000) and the measurement of several global quantities, such as the total CO2 dissolution, Sherwood number, swelling factor, and interface velocity. We show that the commonly used assumption of a sharp CO2-brine interface with constant CO2 concentration at the top of an aquifer (i.e. single-phase system) may lead to erroneous estimates of not only the onset of convection, but also of the rate and magnitude of CO2 dissolution. The significant effect of the capillary transition zone on the dissolution of CO2 under a buoyant plume in saline aquifers is explained; and, the link between the capillary transition zone and the volume change, due to CO2 dissolution and the interface velocity over the mixing process, is demonstrated. Compared to the single-phase system, a crossflow through the interface of the diffusive boundary layer with the capillary transition zone, as well as the upward advance of the interface motion, may enhance the convective mixing early in the period of natural convection. The decrease in the onset time and stronger mass flux

  13. 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

  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. 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

  16. 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

  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. 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…

  19. Mixed Method Research in Special Education.

    ERIC Educational Resources Information Center

    McWilliam, R. A.

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

  20. 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…

  1. 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…

  2. 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.

  3. A Methodology for Conducting Integrative Mixed Methods Research and Data Analyses

    PubMed Central

    Castro, Felipe González; Kellison, Joshua G.; Boyd, Stephen J.; Kopak, Albert

    2011-01-01

    Mixed methods research has gained visibility within the last few years, although limitations persist regarding the scientific caliber of certain mixed methods research designs and methods. The need exists for rigorous mixed methods designs that integrate various data analytic procedures for a seamless transfer of evidence across qualitative and quantitative modalities. Such designs can offer the strength of confirmatory results drawn from quantitative multivariate analyses, along with “deep structure” explanatory descriptions as drawn from qualitative analyses. This article presents evidence generated from over a decade of pilot research in developing an integrative mixed methods methodology. It presents a conceptual framework and methodological and data analytic procedures for conducting mixed methods research studies, and it also presents illustrative examples from the authors' ongoing integrative mixed methods research studies. PMID:22167325

  4. Use of deep soil mixing as an alternate verticle barrier to slurry walls

    SciTech Connect

    Miller, A.D.

    1997-12-31

    Slurry walls have become an accepted subsurface remediation technique to contain contaminated zones. However, situations develop where conventional slurry wall excavation techniques are not suitable. The use of conventional containment wall construction methods may involve removal and disposal of contaminated soils, stability concerns and the risk of open excavations. For these reasons, other installation techniques have received further consideration. Deep Soil Mixing (DSM) has emerged as a viable alternative to conventional slurry wall techniques. In situations dictating limited soil removal for contamination or stability concerns, or where space is a limitation, DSM can be used for installation of the barrier. Proper installation of a DSM wall requires sufficient monitoring and sampling to evaluate the continuity, mixing effectiveness, permeability and key into the confining layer. This paper describes a case study where DSM was used to cross major highways to avoid open excavation, and along slopes to reduce stability concerns. The DSM barrier was tied to an existing conventional slurry wall that had been installed in more stable areas without highway traffic.

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

    ERIC Educational Resources Information Center

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

    1999-01-01

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

  6. Thermobaric control of gravitational potential energy generation by diapycnal mixing in the deep ocean

    NASA Astrophysics Data System (ADS)

    Oliver, K. I. C.; Tailleux, R.

    2013-01-01

    Sources and sinks of gravitational potential energy (GPE) play a rate-limiting role in the large-scale ocean circulation. A key source is turbulent diapycnal mixing, whereby irreversible mixing across isoneutral surfaces is enhanced by turbulent straining of these surfaces. This has motivated international observational efforts to map diapycnal mixing in the global ocean. However, in order to accurately relate the GPE supplied to the large-scale circulation by diapycnal mixing to the mixing energy source, it is first necessary to determine the ratio, ξ, of the GPE generation rate to the available potential energy dissipation rate associated with turbulent mixing. Here the link between GPE and hydrostatic pressure is used to derive the GPE budget for a compressible ocean with a nonlinear equation of state. The role of diapycnal mixing is isolated and from this a global climatological distribution of ξ is calculated. It is shown that, for a given source of mixing energy, typically three times as much GPE is generated if the mixing takes place in bottom waters rather than in the pycnocline. This is due to GPE destruction by cabbelling in the pycnocline, as opposed to thermobaric enhancement of GPE generation by diapycnal mixing in the deep ocean.

  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. PMID:24013486

  10. Iterative methods for mixed finite element equations

    NASA Technical Reports Server (NTRS)

    Nakazawa, S.; Nagtegaal, J. C.; Zienkiewicz, O. C.

    1985-01-01

    Iterative strategies for the solution of indefinite system of equations arising from the mixed finite element method are investigated in this paper with application to linear and nonlinear problems in solid and structural mechanics. The augmented Hu-Washizu form is derived, which is then utilized to construct a family of iterative algorithms using the displacement method as the preconditioner. Two types of iterative algorithms are implemented. Those are: constant metric iterations which does not involve the update of preconditioner; variable metric iterations, in which the inverse of the preconditioning matrix is updated. A series of numerical experiments is conducted to evaluate the numerical performance with application to linear and nonlinear model problems.

  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. Mixed Finite Element Method for Melt Migration

    NASA Astrophysics Data System (ADS)

    Taicher, A. L.; Hesse, M. A.; Arbogast, T.

    2012-12-01

    Multi-phase flow arises during partial melting in the earth mantle, where the porosity is small and material has the characteristics of a compacting porous medium. The equations governing multi-phase flow have been specialized to partially molten materials by McKenzie and Fowler. Their model, also called a Darcy-Stokes system, is highly coupled and non-linear. Melt flow is governed by Darcy's Law while the high temperature, ductile creep of the solid matrix is modeled using viscous non-Newtonian Stokes rheology. In addition, the melt and solid pressures are related through a compaction relation. This nearly elliptic mechanical problem is then coupled with both solute transport and thermal evolution according to the enthalpy method developed by Katz. A suitable numerical method must solve the Darcy-Stokes problem in a manner compatible with the transport problem. Moreover, unlike most porous media problems, partially molten materials transition dynamically from non-porous solid to porous medium. Therefore, a numerical method must also carefully account for the limit of zero porosity. The Darcy-Stokes system for modeling partial melting in the mantle is a novel problem. As far as we know, there currently does not exist a finite element solution in the literature solving these coupled equations. The finite element framework provides support for additional analysis of error and convergence. Moreover, both mesh refinement and anisotropy are naturally incorporated into finite elements. In particular, the mixed finite element method presents a good candidate because it works in both limiting cases: Darcy and incompressible Stokes flow. Mixed methods also produce discretely conservative fluxes that are required for the transport problem to remains stable without violating conservation of mass. Based preliminary investigations in 1D and derived energy estimates, we present a mixed formulation for the Darcy-Stokes system. Next, using novel elements of lowest order and

  13. Mixed Finite Element Methods for Melt Migration

    NASA Astrophysics Data System (ADS)

    Taicher, A. L.

    2013-12-01

    Multi-phase flow arises during partial melting in the earth mantle, where the porosity is small and material has the characteristics of a compacting porous medium. The equations governing multi-phase flow have been specialized to partially molten materials by McKenzie and Fowler. Their model, also called a Darcy-Stokes system, is highly coupled and non-linear. Melt flow is governed by Darcy's Law while the high temperature, ductile creep of the solid matrix is modeled using viscous non-Newtonian Stokes rheology. In addition, the melt and solid pressures are related through a compaction relation. This nearly elliptic mechanical problem is then coupled with both solute transport and thermal evolution according to the enthalpy method developed by Katz. A suitable numerical method must solve the Darcy-Stokes problem in a manner compatible with the transport problem. Moreover, unlike most porous media problems, partially molten materials transition dynamically from non-porous solid to porous medium so must carefully account for the limit of zero porosity. The Darcy-Stokes system for modeling partial melting in the mantle is a novel problem. As far as we know, there currently does not exist a finite element solution in the literature solving these coupled equations. In particular, the mixed finite element method presents a good candidate because it works in both limiting cases: Darcy and incompressible Stokes flow. We present a mixed formulation for the Darcy-Stokes system. Next, we present novel elements of lowest order and compatible with both Darcy and Stokes flow Finally, we present our 2D mixed FEM code result for solving Stokes and Darcy flow as well as the coupled Darcy-Stokes system the mid-ocean ridge or corner flow problem.

  14. 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

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

    ERIC Educational Resources Information Center

    Johnson, R. Burke; Onwuegbuzie, Anthony J.

    2004-01-01

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

  16. Evaluating Mixed Research Studies: A Mixed Methods Approach

    ERIC Educational Resources Information Center

    Leech, Nancy L.; Dellinger, Amy B.; Brannagan, Kim B.; Tanaka, Hideyuki

    2010-01-01

    The purpose of this article is to demonstrate application of a new framework, the validation framework (VF), to assist researchers in evaluating mixed research studies. Based on an earlier work by Dellinger and Leech, a description of the VF is delineated. Using the VF, three studies from education, health care, and counseling fields are…

  17. 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…

  18. 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…

  19. 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…

  20. 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…

  1. 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.

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

    PubMed Central

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

    2014-01-01

    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. PMID:24683294

  3. 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

  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. 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.

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

    PubMed

    Hesse-Biber, Sharlene

    2015-06-01

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

  7. 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.

  8. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

    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 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.

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

    DOE PAGESBeta

    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

    DOE PAGESBeta

    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

  12. Discontinuous Mixed Covolume Methods for Parabolic Problems

    PubMed Central

    Zhu, Ailing

    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 L2. PMID:24983008

  13. "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…

  14. 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.

  15. 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

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

    PubMed

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

    2014-05-01

    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. PMID:24811623

  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. Deep Dive: Evaluation Methods for Electronic Health Records.

    PubMed

    Collins, Sarah

    2016-01-01

    Clinicians currently use electronic health records (EHR) which have often not been designed with the user in mind. Participatory design requires a thorough evaluation of the system using mixed methods. When different methods yield conflicting results, synthesis is challenging. This panel will present four cases of triangulation approaches to evaluate EHR usability and usage in multiple institutions. The audience will have a better idea how to triangulate results from multiple innovative methods such as the use of eye-tracking techniques and mixed methods approaches to evaluation. PMID:27332332

  20. 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.…

  1. 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.…

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. A Mixed Methods Portrait of Urban Instrumental Music Teaching

    ERIC Educational Resources Information Center

    Fitzpatrick, Kate R.

    2011-01-01

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

  7. 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…

  8. 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…

  9. 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,…

  10. Use of the Transformative Framework in Mixed Methods Studies

    ERIC Educational Resources Information Center

    Sweetman, David; Badiee, Manijeh; Creswell, John W.

    2010-01-01

    A concern exists that mixed methods studies do not contain advocacy stances. Preliminary evidence suggests that this is not the case, but to address this issue in more depth the authors examined 13 mixed methods studies that contained an advocacy, transformative lens. Such a lens consisted of incorporating intent to advocate for an improvement in…

  11. 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…

  12. 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…

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

    ERIC Educational Resources Information Center

    Palak, Deniz; Walls, Richard T.

    2009-01-01

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

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. Small RNA deep sequencing revealed that mixed infection of known and unknown viruses were common in field collected vegetable samples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In an effort to characterize the causal agents for plant diseases in field collected samples using the small RNA deep sequencing technology, numerous known or novel viruses and viroids were identified. In many cases, a mixed infection with multiple pathogen species was common. Such situation compl...

  19. 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

  20. 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.

  1. 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,…

  2. 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

  3. Why, and how, mixed methods research is undertaken in health services research in England: a mixed methods study

    PubMed Central

    O'Cathain, Alicia; Murphy, Elizabeth; Nicholl, Jon

    2007-01-01

    Background Recently, there has been a surge of international interest in combining qualitative and quantitative methods in a single study – often called mixed methods research. It is timely to consider why and how mixed methods research is used in health services research (HSR). Methods Documentary analysis of proposals and reports of 75 mixed methods studies funded by a research commissioner of HSR in England between 1994 and 2004. Face-to-face semi-structured interviews with 20 researchers sampled from these studies. Results 18% (119/647) of HSR studies were classified as mixed methods research. In the documentation, comprehensiveness was the main driver for using mixed methods research, with researchers wanting to address a wider range of questions than quantitative methods alone would allow. Interviewees elaborated on this, identifying the need for qualitative research to engage with the complexity of health, health care interventions, and the environment in which studies took place. Motivations for adopting a mixed methods approach were not always based on the intrinsic value of mixed methods research for addressing the research question; they could be strategic, for example, to obtain funding. Mixed methods research was used in the context of evaluation, including randomised and non-randomised designs; survey and fieldwork exploratory studies; and instrument development. Studies drew on a limited number of methods – particularly surveys and individual interviews – but used methods in a wide range of roles. Conclusion Mixed methods research is common in HSR in the UK. Its use is driven by pragmatism rather than principle, motivated by the perceived deficit of quantitative methods alone to address the complexity of research in health care, as well as other more strategic gains. Methods are combined in a range of contexts, yet the emerging methodological contributions from HSR to the field of mixed methods research are currently limited to the single

  4. 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.

  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. 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.

  7. Can loss of balance from mesoscale eddies adequately power deep ocean mixing?

    NASA Astrophysics Data System (ADS)

    Williams, P. D.; Haine, T. W.; Read, P. L.

    2009-12-01

    The global ocean thermohaline circulation is partly composed of the sinking of dense surface waters at high latitudes. But in order to close the circulation and maintain the abyssal stratification, the dense waters must rise up again through vertical mixing. This process requires a source of energy roughly estimated to be 2 TW. Previous work has concluded that tides and winds may adequately supply the required power, but the conceivable role of loss of balance from mesoscale eddies, resulting in the generation of internal inertia-gravity waves and associated vertical mixing, has hitherto been considered to be 'of unknown importance' (Wunsch and Ferrari, 2004). We investigate the potential role of loss of balance, by studying the generation of internal inertia-gravity waves by balanced flow in a rotating two-layer annulus laboratory experiment (Williams et al., 2008). A photograph from the experiment is shown in the figure. As the Rossby number of the balanced flow decreases, the amplitude of the emitted inertia-gravity waves also decreases, but much less rapidly than is predicted by several dynamical theories. This finding suggests that inertia-gravity waves might be far more energised than previously thought. The balanced flow leaks roughly one per cent of its energy each rotation period into internal inertia-gravity waves at the peak of their generation. Crude extrapolation of this result to the global ocean suggests that the flux of energy from mesoscale eddies into internal waves may be as large as 1.5 TW. We claim no accuracy for this figure which is only indicative. Nevertheless, we are persuaded that generation of inertia-gravity waves from the balanced mesoscale flow may be an important source of energy for deep interior mixing, and deserves further study. Reference Williams, PD, Haine, TWN and Read, PL (2008) Inertia-Gravity Waves Emitted from Balanced Flow: Observations, Properties, and Consequences. Journal of the Atmospheric Sciences, 65(11), pp 3543

  8. Mixed Methods: A Paradigm for Holistic Evaluation of Health IT.

    PubMed

    Scott, Philip J

    2016-01-01

    This contribution offers an overview of the 'third research paradigm', its historical roots and its relevance for health informatics. Using illustrative studies, we explore the concepts of triangulation and integration of quantitative and qualitative data and refute common philosophical objections to mixing different types of knowledge. We consider how the mixed method paradigm relates to two programme design and evaluation frameworks that are important for health informatics: realist evaluation and Theory of Change. We discuss how to manage practical challenges to this approach and explain how mixed method studies support an evidence-based approach to real world policy, planning and investment decisions. PMID:27198096

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

    PubMed

    Hadi, Muhammad Abdul; Closs, S José

    2016-06-01

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

  10. 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

  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 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.

  13. 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. PMID:27500029

  14. Assessing and Evaluating Multidisciplinary Translational Teams: A Mixed Methods Approach

    PubMed Central

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

    2014-01-01

    A case report illustrates how multidisciplinary translational teams can be assessed using outcome, process, and developmental types of evaluation using a mixed methods approach. Types of evaluation appropriate for teams are considered in relation to relevant research questions and assessment methods. Logic models are applied to scientific projects and team development to inform choices between methods within a mixed methods design. Use of an expert panel is reviewed, culminating in consensus ratings of 11 multidisciplinary teams and a final evaluation within a team type taxonomy. Based on team maturation and scientific progress, teams were designated as: a) early in development, b) traditional, c) process focused, or d) exemplary. Lessons learned from data reduction, use of mixed methods, and use of expert panels are explored. PMID:24064432

  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. PMID:21880844

  16. Material nonlinear analysis via mixed-iterative finite element method

    NASA Technical Reports Server (NTRS)

    Sutjahjo, Edhi; Chamis, Christos C.

    1992-01-01

    The performance of elastic-plastic mixed-iterative analysis is examined through a set of convergence studies. Membrane and bending behaviors are tested using 4-node quadrilateral finite elements. The membrane result is excellent, which indicates the implementation of elastic-plastic mixed-iterative analysis is appropriate. On the other hand, further research to improve bending performance of the method seems to be warranted.

  17. Dual Formulations of Mixed Finite Element Methods with Applications

    PubMed Central

    Gillette, Andrew; Bajaj, Chandrajit

    2011-01-01

    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. PMID:21984841

  18. 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,…

  19. Magnetic nanoparticles colourization by a mixing-frequency method

    NASA Astrophysics Data System (ADS)

    Tu, Liang; Wu, Kai; Klein, Todd; Wang, Jian-Ping

    2014-04-01

    Brownian and Néel relaxation of magnetic nanoparticles (MNPs) can be characterized by a highly sensitive mixing-frequency method using a search-coil based detection system. The unique magnetic properties of MNPs have been used for biomarkers detection. In this paper, we present a theory and implement an experimental detection scheme using the mixing-frequency method to identify different MNPs simultaneously. A low-frequency sinusoidal magnetic field is applied to saturate the MNPs periodically. A high-frequency sinusoidal magnetic field is then applied to generate mixing-frequency signals that are highly specific to the magnetization of MNPs. The spectra of each MNP can be defined as the complex magnetization of the MNPs over the field frequency. The magnetic spectra of various MNPs and magnetic beads have been characterized and compared. The differences between the MNPs spectra enable us to identify the individual MNPs at the same time. A test has been done to verify the ratio of two different MNPs in mixed samples based on the proposed theory. The experimental results show that the mixing-frequency method is a promising method for MNPs colourization.

  20. 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…

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. Child Geopolitical Agency: A Mixed Methods Case Study

    ERIC Educational Resources Information Center

    Habashi, Janette; Worley, Jody

    2009-01-01

    This study examines the geopolitical agency of Palestinian children. Mixed methodology was used to identify the etiologies contributing to processes of political socialization. Both qualitative and qualitative methods are equally distributed throughout this research. Focus groups and interviews with 12 Palestinian children, aged 10 to 13 years,…

  7. 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…

  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. 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,…

  10. Mixed Methods and Credibility of Evidence in Evaluation

    ERIC Educational Resources Information Center

    Mertens, Donna M.; Hesse-Biber, Sharlene

    2013-01-01

    We argue for a view of credible evidence that is multidimensional in philosophical and methodological terms. We advocate for the importance of deepening the meaning of credible evaluation practice and findings by bringing multiple philosophical and theoretical lenses to the evaluation process as a basis for the use of mixed methods in evaluation,…

  11. 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…

  12. 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…

  13. 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…

  14. 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…

  15. 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…

  16. Toward a Unified Validation Framework in Mixed Methods Research

    ERIC Educational Resources Information Center

    Dellinger, Amy B.; Leech, Nancy L.

    2007-01-01

    The primary purpose of this article is to further discussions of validity in mixed methods research by introducing a validation framework to guide thinking about validity in this area. To justify the use of this framework, the authors discuss traditional terminology and validity criteria for quantitative and qualitative research, as well as…

  17. 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…

  18. An improved simulation of the deep Pacific Ocean using optimally estimated vertical diffusivity based on the Green's function method

    NASA Astrophysics Data System (ADS)

    Toyoda, Takahiro; Sugiura, Nozomi; Masuda, Shuhei; Sasaki, Yuji; Igarashi, Hiromichi; Ishikawa, Yoichi; Hatayama, Takaki; Kawano, Takeshi; Kawai, Yoshimi; Kouketsu, Shinya; Katsumata, Katsuro; Uchida, Hiroshi; Doi, Toshimasa; Fukasawa, Masao; Awaji, Toshiyuki

    2015-11-01

    An improved vertical diffusivity scheme is introduced into an ocean general circulation model to better reproduce the observed features of water property distribution inherent in the deep Pacific Ocean structure. The scheme incorporates (a) a horizontally uniform background profile, (b) a parameterization depending on the local static stability, and (c) a parameterization depending on the bottom topography. Weighting factors for these parameterizations are optimally estimated based on the Green's function method. The optimized values indicate an important role of both the intense vertical diffusivity near rough topography and the background vertical diffusivity. This is consistent with recent reports that indicate the presence of significant vertical mixing associated with finite-amplitude internal wave breaking along the bottom slope and its remote effect. The robust simulation with less artificial trend of water properties in the deep Pacific Ocean illustrates that our approach offers a better modeling analysis for the deep ocean variability.

  19. 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.

  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. PMID:25839206

  3. Deep water geomorphology of the mixed siliciclastic-carbonate system, Gulf of Papua

    NASA Astrophysics Data System (ADS)

    Francis, Jason M.; Daniell, James J.; Droxler, André W.; Dickens, Gerald R.; Bentley, Samuel J.; Peterson, Larry C.; Opdyke, Bradley N.; Beaufort, Luc

    2008-03-01

    Trough contains a large axial submarine channel that extends almost the entire length of the intraslope basin. In addition, an extensive system of canyons lines the NE margin of Moresby Trough. Mass-transport deposits have been fed from the canyons and in one case deposited a large (˜2000 km2) mass-transport complex. Fold-and-thrust-belt ridges also extend into Moresby Trough. Here they trend perpendicular to slope and catch gravity flow deposits on their updip side. GoP carbonate platforms/atolls all display very pronounced scalloped-margin morphology, which may indicate pervasive mass-wasting processes on carbonate margins. Northwest Eastern Plateau is dominantly carbonate and displays the characteristic scalloped margin morphology; however, most of the plateau is characterized by parallel seismic reflectors. These seismic observations in conjunction with core data indicate that accumulation on Eastern Plateau is primarily mixed pelagic and hemipelagic sediment. Observations and interpretations of the bathymetry have revealed the deep water GoP to contain very diverse geomorphology and suggest it is a dynamic system influenced by a variety of sediment transport processes, particularly mass wasting and other gravity flow processes.

  4. 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. PMID:20649500

  5. 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.

  6. The Use of Mixed Methods for Therapeutic Massage Research

    PubMed Central

    Porcino, Antony Joseph; Verhoef, Marja J.

    2010-01-01

    Mixed methods research is the integration of quantitative and qualitative components in a research project. Whether you are reading or designing a mixed methods research project, it is important to be familiar with both qualitative and quantitative research methods and the specific purposes for which they are brought together in a study: triangulation, complementarity, expansion, initiation, or development. In addition, decisions need to be made about the sequencing and the priority or importance of each qualitative and quantitative component relative to the other components, and the point or points at which the various qualitative and quantitative components will be integrated. Mixed methods research is increasingly being recognized for its ability to bring multiple points of view to a research project, taking advantage of the strengths of each of the quantitative and qualitative components to explain or resolve complex phenomena or results. This ability becomes critical when complex healing systems such as therapeutic massage are being studied. Complex healing systems may have multiple physiologic effects, often reflected in changes throughout the patient’s body. Additionally, the patient’s experience of the treatment may be an important outcome. PMID:21589698

  7. Generation of 12 fs deep-ultraviolet pulses by four-wave mixing through filamentation in neon gas.

    PubMed

    Fuji, Takao; Horio, Takuya; Suzuki, Toshinori

    2007-09-01

    Generation of deep-ultraviolet femtosecond pulses by four-wave mixing through filamentation in neon gas was demonstrated. Fundamental (omega) and second-harmonic (2omega) pulses of 25 fs Ti:sapphire amplifier output were focused into neon gas, and 20 microJ pulses with the center wavelength of 260 nm were produced by a four-wave mixing process, 2omega+2omega-omega?3omega through an ~15 cm filament. Additionally, pulses with an energy of 2 microJ at 200 nm were generated, probably by a cascaded process, 3omega+2omega-omega?4omega. The 260 nm pulses were compressed by a grating-based compressor and characterized by a dispersion-free transient grating frequency-resolved optical gating. The estimated pulse width was 12 fs. PMID:17767278

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

    ERIC Educational Resources Information Center

    Collins, Kathleen M. T.

    2006-01-01

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

  9. A Mixed Methods Approach to Network Data Collection

    PubMed Central

    Rice, Eric; Holloway, Ian W.; Barman-Adhikari, Anamika; Fuentes, Dahlia; Brown, C. Hendricks; Palinkas, Lawrence A.

    2013-01-01

    There is a growing interest in examining network processes with a mix of qualitative and quantitative network data. Research has consistently shown that free recall name generators entail recall bias and result in missing data that affects the quality of social network data. This study describes a mixed methods approach for collecting social network data, combining a free recall name generator in the context of an online survey with network relations data coded from transcripts of semi-structured qualitative interviews. The combined network provides substantially more information about the network space, both quantitatively and qualitatively. While network density was relatively stable across networks generated from different data collection methodologies, there were noticeable differences in centrality and component structure across networks. The approach presented here involved limited participant burden and generated more complete data than either technique alone could provide. We make suggestions for further development of this method. PMID:25285047

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Generation of deep-UV sources (160-250 nm) by frequency mixing in lithium-triborate crystal

    NASA Astrophysics Data System (ADS)

    Lin, Jui T.; Kato, Kiyoshi

    1990-05-01

    The newly discovered nonlinear crystal of lithium triborate, LiB3O5 (LBO), has several advantages over another borate family, 8-BaB2O4.13 These include nonhydroscopic, wide transparency (0.16-2.6 sm), high damage threshold and may be temperature-tuned for noncritical phase-matching (NPCM). NCPM using LBO (temperature-tuned) for the second harmonic generation (SHG) and sum frequency mixing (SFM) of N&YAG laser and YAG-laser-pumped Raman cell in H2 gas was reported.4 In this paper we present the phase-matching curves of LBO for the generation of UV-sources (160-250 nm), where 160 nm is the absorption edge of LBO crystal (see Fig. 1). In Section 2, we analyze the phasematching conditions for second harmonic generation (SHG), third harmonic generation (THG) and sum-frequency- mixing (SFM) and provide the general guidance for achieving phase-matchable shortest wavelengths. Section 3 shows the numerical results based on the Seilmeir equations of LBO, where UV and IR sources are mixed for deep-UV sources. Schematics of proposed experimental setups are also shown.

  15. 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.

  16. 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

  17. 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

  18. 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

  19. 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.

  20. The use of mixed methods in studying a chronic illness

    PubMed Central

    Jason, Leonard A.; Reed, Jordan

    2016-01-01

    This article explores mixed methods approaches with an illness called Myalgic Encephalomyelitis (ME) and Chronic Fatigue Syndrome (CFS). Qualitative and Quantitative data were used to investigate the epidemiology of this illness, as well as explore attributions based on the name of the illness, and finally treatment approaches. In each of the domains within the ME and CFS research reviewed, our analyses were richer and our findings ultimately more impactful when we integrated qualitative and quantitative research methods. The use of a multiphase mixed methods research program provided our team unique vantage points for better understanding social and community issues involving this controversial chronic illness. Further, this approach allowed us to implement the insights gained through an advocacy lens to change policy, recommend and evaluate treatments, and amplify voices within the patient population. In this way, we believe that the practice of methodological pluralism is especially applicable and effective to the study of chronic illness, and believe other investigators will benefit from the use of these approaches with similar disenfranchised and unfairly treated populations. PMID:27088060

  1. 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

  2. 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. PMID:17068226

  3. A two-moment cloud microphysics parameterization for mixed-phase clouds. Part 2: Maritime vs. continental deep convective storms

    NASA Astrophysics Data System (ADS)

    Seifert, A.; Beheng, K. D.

    2006-02-01

    A systematic modeling study investigates the effects of cloud condensation nuclei (CCNs) on the evolution of mixed-phase deep convective storms. Following previous studies the environmental conditions like buoyancy and vertical wind shear are varied to simulate different storm types like ordinary single cells, multicells and supercells. In addition, the CCN characteristics are changed from maritime to continental conditions. The results reveal very different effects of continentality on the cloud microphysics and dynamics of the different storms. While a negative feedback on total precipitation and maximum updraft velocity is found for ordinary single cells and supercell storms, a positive feedback exists for multicell cloud systems. The most important link between CCN properties, microphysics and dynamics is the release of latent heat of freezing.

  4. 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.

  5. 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

  6. The impact of overshooting deep convection on local transport and mixing in the tropical upper troposphere/lower stratosphere (UTLS)

    NASA Astrophysics Data System (ADS)

    Frey, W.; Schofield, R.; Hoor, P.; Kunkel, D.; Ravegnani, F.; Ulanovsky, A.; Viciani, S.; D'Amato, F.; Lane, T. P.

    2015-06-01

    In this study we examine the simulated downward transport and mixing of stratospheric air into the upper tropical troposphere as observed on a research flight during the SCOUT-O3 campaign in connection with a deep convective system. We use the Advanced Research Weather and Research Forecasting (WRF-ARW) model with a horizontal resolution of 333 m to examine this downward transport. The simulation reproduces the deep convective system, its timing and overshooting altitudes reasonably well compared to radar and aircraft observations. Passive tracers initialised at pre-storm times indicate the downward transport of air from the stratosphere to the upper troposphere as well as upward transport from the boundary layer into the cloud anvils and overshooting tops. For example, a passive ozone tracer (i.e. a tracer not undergoing chemical processing) shows an enhancement in the upper troposphere of up to about 30 ppbv locally in the cloud, while the in situ measurements show an increase of 50 ppbv. However, the passive carbon monoxide tracer exhibits an increase, while the observations show a decrease of about 10 ppbv, indicative of an erroneous model representation of the transport processes in the tropical tropopause layer. Furthermore, it could point to insufficient entrainment and detrainment in the model. The simulation shows a general moistening of air in the lower stratosphere, but it also exhibits local dehydration features. Here we use the model to explain the processes causing the transport and also expose areas of inconsistencies between the model and observations.

  7. The impact of overshooting deep convection on local transport and mixing in the tropical upper troposphere/lower stratosphere (UTLS)

    NASA Astrophysics Data System (ADS)

    Frey, W.; Schofield, R.; Hoor, P.; Kunkel, D.; Ravegnani, F.; Ulanovsky, A.; Viciani, S.; D'Amato, F.; Lane, T. P.

    2015-01-01

    In this study we examine the simulated downward transport and mixing of stratospheric air into the upper tropical troposphere as observed on a research flight during the SCOUT-O3 campaign in connection to a deep convective system. We use the Advanced Research Weather and Research Forecasting (WRF-ARW) model with a horizontal resolution of 333 m to examine this downward transport. The simulation reproduces the deep convective system, its timing and overshooting altitudes reasonably well compared to radar and aircraft observations. Passive tracers initialised at pre-storm times indicate the downward transport of air from the stratosphere to the upper troposphere as well as upward transport from the boundary layer into the cloud anvils and overshooting tops. For example, a passive ozone tracer (i.e. a tracer not undergoing chemical processing) shows an enhancement in the upper troposphere of up to about 30 ppbv locally in the cloud, while the in situ measurements show an increase of 50 ppbv. However, the passive carbon monoxide tracer exhibits an increase, while the observations show a decrease of about 10 ppbv, indicative of an erroneous model representation of the transport processes in the tropical tropopause layer. Furthermore, it could point to insufficient entrainment and detrainment in the model. The simulation shows a general moistening of air in the lower stratosphere but it also exhibits local dehydration features. Here we use the model to explain the processes causing the transport and also expose areas of inconsistencies between the model and observations.

  8. Simplified method of deep-tow seismic profiling

    USGS Publications Warehouse

    Robb, James M.; Sylwester, Richard E.; Penton, Ronald

    1981-01-01

    To improve resolution of seismic-reflection profiles in continental slope water depths of 900 to 1500 m, a single hydrophone was towed about 150 m off the bottom to receive reflected signals from a surface-towed sparker sound source. That deep-towed hydrophone data show that valleys which appear V-shaped in records from a surface-towed hydrophone are flat-bottomed, and that subbottom reflections from an erosional unconformity can be much better resolved. The data produced by this technique are very hepful when used in conjunction with records from conventional surface-towed seismic-profiling equipment.

  9. 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…

  10. 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.

  11. 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.

  12. 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.

  13. Evaluating the Senior Companion Program: a mixed-method approach.

    PubMed

    Butler, Sandra S

    2006-01-01

    This article reports on a mixed-method assessment of the Senior Companion Program (SCP), a federal program which provides volunteer opportunities with small stipends to low-income older adults, 60 years of age and older, who provide companionship and offer assistance to frail community elders. Through four standardized scales and open-ended questions regarding the impact of the SCP in their lives, 34 Senior Companion volunteers and 32 of their clients were interviewed. Informants reported relatively large social networks and low levels of depression and loneliness. Thematic analysis of the qualitative data revealed the benefits of the program for both volunteers and their clients. Themes emerging from the rich narratives included: companionship, independence, reduced anxiety, giving, and rewards. The article concludes with a suggested brief evaluation instrument that directors of SCP programs, and other similar programs, can use to collect data on the impact of their program--something that is required, but often difficult to do. PMID:16901877

  14. Traditions and Alcohol Use: A Mixed-Methods Analysis

    PubMed Central

    Castro, Felipe González; Coe, Kathryn

    2011-01-01

    An integrative mixed-methods analysis examined traditional beliefs as associated with beliefs about self-care during pregnancy and with alcohol abstinence among young adult women from two rural U.S.–Mexico border communities. Quantitative (measured scale) variables and qualitative thematic variables generated from open-ended responses served as within-time predictors of these health-related outcomes. A weaker belief that life is better in big cities was associated with stronger self-care beliefs during pregnancy. Also, a weaker belief that small towns offer tranquil environments was associated with total abstinence from alcohol. Regarding the Hispanic Paradox, these results suggest that a critical appreciation of cultural traditions can be protective, as this avoids stereotypical or idyllic views of urban or rural lifeways, and promotes self-protective beliefs and behaviors. PMID:17967095

  15. Evaluation of videodisc modules: a mixed method approach.

    PubMed Central

    Parkhurst, P. E.; Lovell, K. L.; Sprafka, S. A.; Hodgins, M.

    1991-01-01

    The purpose of this study was to evaluate the design and implementation of 10 neuropathology interactive videodisc instructional (IVI) modules used by Michigan State University medical students in the College of Osteopathic Medicine and the College of Human Medicine. The evaluation strategy incorporated a mixed method approach using qualitative and quantitative data to examine levels of student acceptance for the modules; ways in which IVI modules accommodate different learner styles; and to what extent the modules facilitate the attainment of higher level learning objectives. Students rated the units highly for learning effectiveness; many students reported group interaction as beneficial; and students expressed a desire for more IVI in the curriculum. The paper concludes with recommendations for future use of interactive videodisc technology in the teaching/learning process. PMID:1807704

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

    ERIC Educational Resources Information Center

    Bryant, Lauren H.

    2011-01-01

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

  17. 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…

  18. 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…

  19. 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.…

  20. 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

  1. 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.

  2. 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.

  3. Mixed methods in gerontological research: Do the qualitative and quantitative data “touch”?

    PubMed Central

    Happ, Mary Beth

    2010-01-01

    This paper distinguishes between parallel and integrated mixed methods research approaches. Barriers to integrated mixed methods approaches in gerontological research are discussed and critiqued. The author presents examples of mixed methods gerontological research to illustrate approaches to data integration at the levels of data analysis, interpretation, and research reporting. As a summary of the methodological literature, four basic levels of mixed methods data combination are proposed. Opportunities for mixing qualitative and quantitative data are explored using contemporary examples from published studies. Data transformation and visual display, judiciously applied, are proposed as pathways to fuller mixed methods data integration and analysis. Finally, practical strategies for mixing qualitative and quantitative data types are explicated as gerontological research moves beyond parallel mixed methods approaches to achieve data integration. PMID:20077973

  4. 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.

  5. Contraceptive method-mix and family planning program in Vietnam.

    PubMed

    Hardjanti, K

    1995-01-01

    In Vietnam between 1989 and 1993, the modern contraceptive prevalence rate stopped at 38%. In 1984, the government implemented economic renovation (Doi Moi). This closed agricultural cooperatives which had supported commune health centers. Health workers received either low or no wages, resulting in low morale, absenteeism, and moving to the private sector or agriculture. Most women began using the IUD because it was low cost and easy to monitor, provided long-term protection against pregnancy, and there was a limited supply of oral contraceptives (OCs) and condoms. Condom use fell from 13% in 1984 to 1.4% in 1993. More than 80% of contraceptive users used the IUD. The IUD is not appropriate for many women because of health problems: 60-70% of pregnant women and 80% of parturient women have anemia, 40-60% of women have reproductive tract infections, and sexually transmitted diseases are rising. Vietnam's Prime Minister and the Communist Party are committed to expanding the range of the contraceptive method-mix and choice. Limited method choice is especially a problem in rural areas. It increases the abortion rate. About 38% of abortions supplant modern and traditional family planning methods. Improper counseling, insufficient knowledge, and low promotion of OCs account for the low use of OCs. Inferior quality, aversion by couples, and inaccessibility in most rural areas limit condom use. Women's fear and husband's objection outweigh the government's promotion of sterilization. Providers have limited comprehensive accurate and current knowledge of contraceptives. Health service facilities are concentrated in urban and semiurban areas. The quality of care in rural areas, where there is no clean water supply, is inferior. An annual target used to forecast contraceptive needs risks contraceptive stocks expiring during storage and/or disruptions in supply of users. Consecutive actions to eliminate constraints to use of other methods, developing a community level service

  6. 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

  7. 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

  8. Examining Nurse Consultant connectivity: An Australian mixed method study.

    PubMed

    Giles, Michelle; Parker, Vicki; Mitchell, Rebecca

    2016-06-01

    The nurse consultant (NC) role in Australia is a senior classification of advanced practice nurse has been described as enhancing health care outcomes largely through extensive collaboration with consumers, nurses, and other health professionals. However, little is known about the actual nature, amount, and quality of NC interactions. This study examines the connectivity of the NC role across metropolitan and rural contexts, using a mixed method sequential design with an online survey and focus groups with NCs and other stakeholders. Results demonstrated that NCs most commonly have high density connectivity patterns with other nursing colleagues, medical staff, patients/clients, and administrative staff. Position grade (1, 2 or 3) influences density of connectivity, as does location, with those based in metropolitan roles engaging significantly less with other clinicians. Findings demonstrate that many NCs are highly collaborative and predominantly embedded into interprofessional practice models. This study provides valuable insight into the diverse and often complex NC role and the way in which NC expertise and influence is deployed and integrated across a large local health district. PMID:26305104

  9. 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. PMID:25264470

  10. Evaluating nursing outcomes: a mixed-methods approach.

    PubMed

    Lane-Tillerson, Crystal; Davis, Bertha L; Killion, Cheryl M; Baker, Spencer

    2005-12-01

    Being overweight is regarded as the most common nutritional disorder of children and adolescents in the United States. The escalating problem of being overweight or being obese in our society indicates the need for treatment strategies that encompass an all-inclusive approach. Moreover, these strategies need to be comprehensively evaluated for their effectiveness. Nurses are in an excellent position to ensure that this occurs. The purpose of this study was to determine whether using a mixed-methods approach was an efficacious way to provide a comprehensive evaluation of the behavior modification benefits of a weight loss/weight management nursing intervention in African-American adolescent girls (13-17 years of age). The overall effectiveness of the intervention was evaluated by analyzing pre- and post-program measures of weight, body mass index, cholesterol, blood pressure, self-esteem, depression, and body image (quantitative data); conducting focus groups with mothers of the participants; and administering open-ended, written questionnaires to the participants (qualitative data). Findings from the quantitative data indicated favorable outcomes in weight, blood pressure, cholesterol, body mass index, self-esteem, and body image, indicating that progress had been made over the course of the program. Furthermore, qualitative data indicated that mothers of the participants observed positive behavioral changes related to eating and exercise patterns and participants demonstrated perception of these changes as well. PMID:16570643

  11. 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

  12. 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

  13. 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.

  14. 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

  15. Tweets about hospital quality: a mixed methods study

    PubMed Central

    Greaves, Felix; Laverty, Antony A; Cano, Daniel Ramirez; Moilanen, Karo; Pulman, Stephen; Darzi, Ara; Millett, Christopher

    2014-01-01

    Background Twitter is increasingly being used by patients to comment on their experience of healthcare. This may provide information for understanding the quality of healthcare providers and improving services. Objective To examine whether tweets sent to hospitals in the English National Health Service contain information about quality of care. To compare sentiment on Twitter about hospitals with established survey measures of patient experience and standardised mortality rates. Design A mixed methods study including a quantitative analysis of all 198 499 tweets sent to English hospitals over a year and a qualitative directed content analysis of 1000 random tweets. Twitter sentiment and conventional quality metrics were compared using Spearman's rank correlation coefficient. Key results 11% of tweets to hospitals contained information about care quality, with the most frequent topic being patient experience (8%). Comments on effectiveness or safety of care were present, but less common (3%). 77% of tweets about care quality were positive in tone. Other topics mentioned in tweets included messages of support to patients, fundraising activity, self-promotion and dissemination of health information. No associations were observed between Twitter sentiment and conventional quality metrics. Conclusions Only a small proportion of tweets directed at hospitals discuss quality of care and there was no clear relationship between Twitter sentiment and other measures of quality, potentially limiting Twitter as a medium for quality monitoring. However, tweets did contain information useful to target quality improvement activity. Recent enthusiasm by policy makers to use social media as a quality monitoring and improvement tool needs to be carefully considered and subjected to formal evaluation. PMID:24748372

  16. 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.

  17. 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.

  18. 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.

  19. 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. PMID:25946969

  20. 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. PMID:25248767

  1. 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.

  2. 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…

  3. A Mixed Method Approach to Quality of Life Research: A Case Study Approach

    ERIC Educational Resources Information Center

    Dunning, Heather; Williams, Allison; Abonyi, Sylvia; Crooks, Valorie

    2008-01-01

    Increased use of qualitative and quantitative methods in quality of life projects necessitates an examination of how to effectively work within a mixed method framework. The research objectives of this paper are to (1) operationalize the two goals of mixed method research (confirmation and comprehension) and (2) develop a strategy for using mixed…

  4. 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…

  5. Problematic Preferences? A Mixed Method Examination of Principals' Preferences for Teacher Characteristics in Chicago

    ERIC Educational Resources Information Center

    Engel, Mimi

    2013-01-01

    Purpose: Relatively little is known about how principals make decisions about teacher hiring. This article uses mixed methods to examine what characteristics principals look for in teachers. Research Methods: Data were gathered using a mixed method approach, including in-depth interviews with a representative sample of 31 principals as well as an…

  6. 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.

  7. 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.

  8. 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...

  9. 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…

  10. 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…

  11. 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…

  12. [Study on key physical properties of granulated products of Andrographis mixed powder by high-speed mixing wet method].

    PubMed

    Liao, Zheng-Gen; Li, Zhe; Ming, Liang-Shan; Luo, Juan; Jiang, Qie-Ying; Zhao, Guo-Wei; Liang, Xin-Li

    2014-10-01

    The impact of key physical properties on granulated products by the high-speed mixing wet method was studied. Andrographis extracts were utilized as the model drug. Four processing methods were adopted to prepare mixed powder of microcrystalline cellulose (MCC) and starch with the mass ratio 1:0.5, 1:1 and 1:2 by the high-speed mixing wet method. The properties of the prepared granules were evaluated with such indexes as granule yield, the ratio of lumps and fine powder, granule-AOR and granule-HR. The impact of key physical properties on granulated products was analyzed through stepwise regression analysis. The results showed that angle of repose, moisture content, pore volume, density and contact angle with water were key physical properties of the powder. The key physical properties of Chinese medical extracts powder are the important factor impacting granulated products made by the high-speed mixing wet method. In this study, the impact of key physical properties on granulated products of Chinese medical extracts was analyzed from the physical angle. PMID:25612432

  13. Transparent conductive oxide films mixed with gallium oxide nanoparticle/single-walled carbon nanotube layer for deep ultraviolet light-emitting diodes

    PubMed Central

    2013-01-01

    We propose a transparent conductive oxide electrode scheme of gallium oxide nanoparticle mixed with a single-walled carbon nanotube (Ga2O3 NP/SWNT) layer for deep ultraviolet light-emitting diodes using spin and dipping methods. We investigated the electrical, optical and morphological properties of the Ga2O3 NP/SWNT layers by increasing the thickness of SWNTs via multiple dipping processes. Compared with the undoped Ga2O3 films (current level 9.9 × 10-9 A @ 1 V, transmittance 68% @ 280 nm), the current level flowing in the Ga2O3 NP/SWNT increased by approximately 4 × 105 times and the transmittance improved by 9% after 15 times dip-coating (current level 4 × 10-4 A at 1 V; transmittance 77.0% at 280 nm). These improvements result from both native high transparency of Ga2O3 NPs and high conductivity and effective current spreading of SWNTs. PMID:24295342

  14. 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.

  15. 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.

  16. Developing Critical Understanding in HRM Students: Using Innovative Teaching Methods to Encourage Deep Approaches to Study

    ERIC Educational Resources Information Center

    Butler, Michael J. R.; Reddy, Peter

    2010-01-01

    Purpose: This paper aims to focus on developing critical understanding in human resource management (HRM) students in Aston Business School, UK. The paper reveals that innovative teaching methods encourage deep approaches to study, an indicator of students reaching their own understanding of material and ideas. This improves student employability…

  17. 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.

  18. 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…

  19. 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

  20. Integration and Publications as Indicators of "Yield" from Mixed Methods Studies

    ERIC Educational Resources Information Center

    O'Cathain, Alicia; Murphy, Elizabeth; Nicholl, Jon

    2007-01-01

    A mixed methods study has the potential to produce knowledge that is unavailable to a qualitative study and a quantitative study undertaken independently. Any unique insight or "yield" from a mixed methods study may be difficult to assess in practice. However, given that integration of data or findings from different components of a study is a…

  1. 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…

  2. 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…

  3. Using Mixed Methods to Analyze Video Data: A Mathematics Teacher Professional Development Example

    ERIC Educational Resources Information Center

    DeCuir-Gunby, Jessica T.; Marshall, Patricia L.; McCulloch, Allison W.

    2012-01-01

    This article uses data from 65 teachers participating in a K-2 mathematics professional development research project as an example of how to analyze video recordings of teachers' classroom lessons using mixed methods. Through their discussion, the authors demonstrate how using a mixed methods approach to classroom video analysis allows researchers…

  4. 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…

  5. 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…

  6. 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…

  7. 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.

  8. 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.

  9. A Strategy to Identify Critical Appraisal Criteria for Primary Mixed-Method Studies

    PubMed Central

    Sale, Joanna E. M.; Brazil, Kevin

    2015-01-01

    The practice of mixed-methods research has increased considerably over the last 10 years. While these studies have been criticized for violating quantitative and qualitative paradigmatic assumptions, the methodological quality of mixed-method studies has not been addressed. The purpose of this paper is to identify criteria to critically appraise the quality of mixed-method studies in the health literature. Criteria for critically appraising quantitative and qualitative studies were generated from a review of the literature. These criteria were organized according to a cross-paradigm framework. We recommend that these criteria be applied to a sample of mixed-method studies which are judged to be exemplary. With the consultation of critical appraisal experts and experienced qualitative, quantitative, and mixed-method researchers, further efforts are required to revise and prioritize the criteria according to importance. PMID:26526412

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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%.

  16. 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

  17. 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.

  18. A STUDY ON APPLICABILITY OF GROUND RESPONSE ACCELERATION METHOD TO DEEP VERTICAL UNDERGROUND STRUCTURES

    NASA Astrophysics Data System (ADS)

    Matsumoto, Mai; Shiba, Yukio; Watanabe, Kazuaki

    This paper discusses the applicability of ground response acceleration method to seismic analysis for deep vertical underground structures. To examine the applicability, an analysis of relationships between response of ground and the shaft was conducted. It was found from the analysis that vertical axial stress of the shaft was not correspond with shear stress of ground. Accordingly, it was concluded that the axial stress was not evaluated correctly by the existing method. Therefore, to extend the applicability of the method, ground responses correlated with the axial stress were analyzed and a new method using these ground responses was proposed.

  19. 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.

  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. 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

  3. Robustness to Format Effects of IRT Linking Methods for Mixed-Format Tests

    ERIC Educational Resources Information Center

    Kim, Seonghoon; Kolen, Michael J.

    2006-01-01

    Four item response theory linking methods (2 moment methods and 2 characteristic curve methods) were compared to concurrent (CO) calibration with the focus on the degree of robustness to format effects (FEs) when applying the methods to multidimensional data that reflected the FEs associated with mixed-format tests. Based on the quantification of…

  4. A method of mixed dentition analysis in the mandible.

    PubMed

    Motokawa, W; Ozaki, M; Soejima, Y; Yoshida, Y

    1987-01-01

    We developed a method of space analysis based on the fact that the measurement between the distal surfaces of the mandibular permanent lateral incisors was approximately equal to that of the combined widths of the mandibular permanent canine and premolars. This method is referred to as Interlateral Incisor Width (I.L.I.W.) Analysis. One hundred and nineteen Japanese children, without malocclusion, were selected for the study. Various measurements of teeth were taken in their mouths with a modified, fine-tipped, electrical, digital caliper and recorded in a Handheld Computer by connecting it to the caliper. Statistical analyses were conducted to compare the accuracy of the I.L.I.W., Ono, Moyers, and Ballard and Wylie analyses in the mandibular arch. The summary of the results were: Correlation coefficients for the sum of the actual mesiodistal dimensions of the canine and premolars with their predicted values obtained by each of the four analyses revealed r = 0.63 for I.L.I.W., r = 0.55 for Ono, r = 0.57 for Moyers, and r - 0.55 for Ballard and Wylie. Our I.L.I.W. method presented the best correlation of the four analyses, although each indicated a relatively low correlation. This method does appear to be clinically valid, since it is simple enough to enable the practitioner to estimate the combined dimension of the unerupted canine and premolars by measurement, in the mouth, of the distance between the distal surfaces of both mandibular permanent lateral incisors, instead of on study casts. It is recommended that a radiographic method be used in conjunction with our method to obtain a more accurate estimate.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3470327

  5. Improving Mandatory Tutoring: A Mixed-Methods Program Evaluation

    ERIC Educational Resources Information Center

    Baggett, Brooks

    2009-01-01

    In recent years, the local school leadership in a suburban southern U.S. high school adopted innovative academic intervention programs to assist underperforming students but did not develop formal methods to evaluate program effectiveness. This gap in the professional practice continued with the inception of mandatory tutoring (MT), an…

  6. The mixed finite element multigrid method for stokes equations.

    PubMed

    Muzhinji, K; Shateyi, S; Motsa, S S

    2015-01-01

    The stable finite element discretization of the Stokes problem produces a symmetric indefinite system of linear algebraic equations. A variety of iterative solvers have been proposed for such systems in an attempt to construct efficient, fast, and robust solution techniques. This paper investigates one of such iterative solvers, the geometric multigrid solver, to find the approximate solution of the indefinite systems. The main ingredient of the multigrid method is the choice of an appropriate smoothing strategy. This study considers the application of different smoothers and compares their effects in the overall performance of the multigrid solver. We study the multigrid method with the following smoothers: distributed Gauss Seidel, inexact Uzawa, preconditioned MINRES, and Braess-Sarazin type smoothers. A comparative study of the smoothers shows that the Braess-Sarazin smoothers enhance good performance of the multigrid method. We study the problem in a two-dimensional domain using stable Hood-Taylor Q2-Q1 pair of finite rectangular elements. We also give the main theoretical convergence results. We present the numerical results to demonstrate the efficiency and robustness of the multigrid method and confirm the theoretical results. PMID:25945361

  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. 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…

  9. The Mixed Finite Element Multigrid Method for Stokes Equations

    PubMed Central

    Muzhinji, K.; Shateyi, S.; Motsa, S. S.

    2015-01-01

    The stable finite element discretization of the Stokes problem produces a symmetric indefinite system of linear algebraic equations. A variety of iterative solvers have been proposed for such systems in an attempt to construct efficient, fast, and robust solution techniques. This paper investigates one of such iterative solvers, the geometric multigrid solver, to find the approximate solution of the indefinite systems. The main ingredient of the multigrid method is the choice of an appropriate smoothing strategy. This study considers the application of different smoothers and compares their effects in the overall performance of the multigrid solver. We study the multigrid method with the following smoothers: distributed Gauss Seidel, inexact Uzawa, preconditioned MINRES, and Braess-Sarazin type smoothers. A comparative study of the smoothers shows that the Braess-Sarazin smoothers enhance good performance of the multigrid method. We study the problem in a two-dimensional domain using stable Hood-Taylor Q2-Q1 pair of finite rectangular elements. We also give the main theoretical convergence results. We present the numerical results to demonstrate the efficiency and robustness of the multigrid method and confirm the theoretical results. PMID:25945361

  10. 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