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Sample records for two-part growth mixture

  1. Detection of unobserved heterogeneity with growth mixture models

    OpenAIRE

    Jost Reinecke; Luca Mariotti

    2009-01-01

    Latent growth curve models as structural equation models are extensively discussedin various research fields (Duncan et al., 2006). Recent methodological and statisticalextension are focused on the consideration of unobserved heterogeneity in empiricaldata. Muth´en extended the classical structural equation approach by mixture components,i. e. categorical latent classes (Muth´en 2002, 2004, 2007).The paper will discuss applications of growth mixture models with data from oneof the first panel...

  2. Interaction between growth and transport phenomena in living mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Grillo, A [DMFCI, Facolta di Ingegneria, Universita di Catania, Viale Andrea Doria 6, 95125 Catania (Italy); Zingali, G [Dottorato di Ricerca in Ingegneria Fisica, Universita di Catania, Viale Andrea Doria 6, 95125 Catania (Italy); Borrello, D [Dottorato di Ricerca in Ingegneria Fisica, Universita di Catania, Viale Andrea Doria 6, 95125 Catania (Italy); Federico, S [HPL - Faculty of Kinesiology, Univesity of Calgary, 2500 University Drive NW, Calgary, Alberta, T2N 1N4 (Canada); Herzog, W [HPL - Faculty of Kinesiology, Univesity of Calgary, 2500 University Drive NW, Calgary, Alberta, T2N 1N4 (Canada); Giaquinta, G [DMFCI, Facolta di Ingegneria, Universita di Catania, Viale Andrea Doria 6, 95125 Catania (Italy)

    2007-03-15

    Biological growth is regulated by the presence of several chemical substances, and is modulated by thermo-mechanical stimuli. The evolution of chemical substances is described by the advection-diffusion-reaction process of solutes dissolved in the fluid-phase of a biphasic mixture with mass exchange between phases. We present a picture in which growth, by changing material symmetries, modifies the environment in which transport processes take place, and we outline a possible interaction between growth and chemical agents. In order to study this interaction, we use averaging methods to determine the macroscopic counterparts of the transport properties defined at the microscale, and, by writing the macroscopic transport equation in material form, we illustrate how these properties are modulated by growth. In the case of anisotropic growth, such a modulation has a geometric meaning, and is related to both the change of material symmetries, and the development of material inhomogeneities. By regarding growth as a process characterized by a time-scale much slower than that of the transport process of interest, we provide an asymptotic analysis of transport in a growing porous medium based on the adiabatic approximation. We prove that the macroscopic concentration of chemical substances is 'renormalized' by the anisotropy of growth.

  3. Determining of migraine prognosis using latent growth mixture models

    Institute of Scientific and Technical Information of China (English)

    Bahar Tasdelen; Aynur Ozge; Hakan Kaleagasi; Semra Erdogan; Tufan Mengi

    2011-01-01

    Background This paper presents a retrospective study to classify patients into subtypes of the treatment according to baseline and longitudinally observed values considering heterogenity in migraine prognosis. In the classical prospective clinical studies,participants are classified with respect to baseline status and followed within a certain time period.However,latent growth mixture model is the most suitable method,which considers the population heterogenity and is not affected drop-outs if they are missing at random. Hence,we planned this comprehensive study to identify prognostic factors in migraine.Methods The study data have been based on a 10-year computer-based follow-up data of Mersin University Headache Outpatient Department. The developmental trajectories within subgroups were described for the severity,frequency,and duration of headache separately and the probabilities of each subgroup were estimated by using latent growth mixture models. SAS PROC TRAJ procedures,semiparametric and group-based mixture modeling approach,were applied to define the developmental trajectories.Results While the three-group model for the severity (mild,moderate,severe) and frequency (low,medium,high) of headache appeared to be appropriate,the four-group model for the duration (low,medium,high,extremely high) was more suitable. The severity of headache increased in the patients with nausea,vomiting,photophobia and phonophobia.The frequency of headache was especially related with increasing age and unilateral pain. Nausea and photophobia were also related with headache duration.Conclusions Nausea,vomiting and photophobia were the most significant factors to identify developmental trajectories.The remission time was not the same for the severity,frequency,and duration of headache.

  4. Two-part set systems

    CERN Document Server

    Gerbner, Dániel; Lemons, Nathan; Mubayi, Dhruv; Palmer, Cory; Patkós, Balázs

    2011-01-01

    The two part Sperner theorem of Katona and Kleitman states that if $X$ is an $n$-element set with partition $X_1 \\cup X_2$, and $\\cF$ is a family of subsets of $X$ such that no two sets $A, B \\in \\cF$ satisfy $A \\subset B$ (or $B \\subset A$) and $A \\cap X_i=B \\cap X_i$ for some $i$, then $|\\cF| \\le {n \\choose \\lfloor n/2 \\rfloor}$. We consider variations of this problem by replacing the Sperner property with the intersection property and considering families that satisfiy various combinations of these properties on one or both parts $X_1$, $X_2$. Along the way, we prove the following new result which may be of independent interest: let $\\cF, \\cG$ be families of subsets of an $n$-element set such that $\\cF$ and $\\cG$ are both intersecting and cross-Sperner, meaning that if $A \\in \\cF$ and $B \\in \\cG$, then $A \

  5. Mixture

    Directory of Open Access Journals (Sweden)

    Silva-Aguilar Martín

    2011-01-01

    Full Text Available Metals are ubiquitous pollutants present as mixtures. In particular, mixture of arsenic-cadmium-lead is among the leading toxic agents detected in the environment. These metals have carcinogenic and cell-transforming potential. In this study, we used a two step cell transformation model, to determine the role of oxidative stress in transformation induced by a mixture of arsenic-cadmium-lead. Oxidative damage and antioxidant response were determined. Metal mixture treatment induces the increase of damage markers and the antioxidant response. Loss of cell viability and increased transforming potential were observed during the promotion phase. This finding correlated significantly with generation of reactive oxygen species. Cotreatment with N-acetyl-cysteine induces effect on the transforming capacity; while a diminution was found in initiation, in promotion phase a total block of the transforming capacity was observed. Our results suggest that oxidative stress generated by metal mixture plays an important role only in promotion phase promoting transforming capacity.

  6. Biochar-compost mixtures added to simulated golf greens increase creeping bentgrass growth

    Science.gov (United States)

    Mixtures of 85% sand and 15% mixtures of peat (control), a commercial biochar, a commercial biochar-compost product (CarbonizPN), and seven biochar-commercial compost mixtures were tested on the growth of creeping bentgrass (Agrostis stolonifera L. "007") in simulated golf greens. Physical properti...

  7. Comparison of – Mixture and Minoxidil on Hair Growth Promoting Effect in Mice

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    Ki Soo Park

    2016-11-01

    Full Text Available BackgroundAlgae have traditionally been used for promotion of hair growth. Use of hair regrowth drugs, such as minoxidil, is limited due to side effects. The aim of this study was to examine a mixture of Saccharina japonica and Undaria pinnatifida (L-U mixture on hair growth and to compare the promoting effect of hair growth by a 3% minoxidil and a L-U mixture.MethodsTo evaluate the hair growth-promoting activity, saline, 50% ethanol, 3% minoxidil, and the L-U mixture were applied 2 times a day for a total of 14 days on the dorsal skin of C57BL/6 mice after depilation. Analysis was determined by using a high-resolution hair analysis system, real-time polymerase chain reaction, and H&E staining.ResultsOn day 14, the hair growth effect of the L-U mixture was the same as that of the 3% minoxidil treatment. The L-U mixture significantly (P<0.05 stimulated hair growth-promoting genes, as vascular endothelial growth factor (VEGF and insulin-like growth factor -1. Increase of VEGF was observed in the L-U mixture group compared with minoxidil and the negative control. In contrast, the L-U mixture suppressed the expression of transforming growth factor-β1, which is the hair loss-related gene. In histological examination in the L-U mixture and minoxidil groups, the induction of an anagen stage of hair follicles was faster than that of control groups.ConclusionsThis study provides evidence that the L-U mixture can promote hair growth in mice, similar to the effect from minoxidil, and suggests that there is potential application for hair loss treatments.

  8. An evaluation of microbial growth and corrosion of 316L SS in glycol/seawater mixtures

    Science.gov (United States)

    Lee, Jason S.; Ray, Richard I.; Lowe, Kristine L.; Jones-Meehan, Joanne; Little, Brenda J.

    2003-01-01

    Glycol/seawater mixtures containing > 50% glycol inhibit corrosion of 316L stainless steel and do not support bacterial growth. The results indicate bacteria are able to use low concentrations of glycol (10%) as a growth medium, but bacterial growth decreased with increasing glycol concentration. Pitting potential, determined by anodic polarization, was used to evaluate susceptibility of 316L SS to corrosion in seawater-contaminated glycol. Mixture containing a minimum concentration of 50% propylene glycol-based coolant inhibited pitting corrosion. A slightly higher minimum concentration (55%) was needed for corrosion protection in ethylene glycol mixtures.

  9. Primordial soup was edible: abiotically produced Miller-Urey mixture supports bacterial growth.

    Science.gov (United States)

    Xie, Xueshu; Backman, Daniel; Lebedev, Albert T; Artaev, Viatcheslav B; Jiang, Liying; Ilag, Leopold L; Zubarev, Roman A

    2015-09-28

    Sixty years after the seminal Miller-Urey experiment that abiotically produced a mixture of racemized amino acids, we provide a definite proof that this primordial soup, when properly cooked, was edible for primitive organisms. Direct admixture of even small amounts of Miller-Urey mixture strongly inhibits E. coli bacteria growth due to the toxicity of abundant components, such as cyanides. However, these toxic compounds are both volatile and extremely reactive, while bacteria are highly capable of adaptation. Consequently, after bacterial adaptation to a mixture of the two most abundant abiotic amino acids, glycine and racemized alanine, dried and reconstituted MU soup was found to support bacterial growth and even accelerate it compared to a simple mixture of the two amino acids. Therefore, primordial Miller-Urey soup was perfectly suitable as a growth media for early life forms.

  10. Modeling Math Growth Trajectory--An Application of Conventional Growth Curve Model and Growth Mixture Model to ECLS K-5 Data

    Science.gov (United States)

    Lu, Yi

    2016-01-01

    To model students' math growth trajectory, three conventional growth curve models and three growth mixture models are applied to the Early Childhood Longitudinal Study Kindergarten-Fifth grade (ECLS K-5) dataset in this study. The results of conventional growth curve model show gender differences on math IRT scores. When holding socio-economic…

  11. The Impact of Misspecifying Class-Specific Residual Variances in Growth Mixture Models

    Science.gov (United States)

    Enders, Craig K.; Tofighi, Davood

    2008-01-01

    The purpose of this study was to examine the impact of misspecifying a growth mixture model (GMM) by assuming that Level-1 residual variances are constant across classes, when they do, in fact, vary in each subpopulation. Misspecification produced bias in the within-class growth trajectories and variance components, and estimates were…

  12. Piecewise Linear-Linear Latent Growth Mixture Models with Unknown Knots

    Science.gov (United States)

    Kohli, Nidhi; Harring, Jeffrey R.; Hancock, Gregory R.

    2013-01-01

    Latent growth curve models with piecewise functions are flexible and useful analytic models for investigating individual behaviors that exhibit distinct phases of development in observed variables. As an extension of this framework, this study considers a piecewise linear-linear latent growth mixture model (LGMM) for describing segmented change of…

  13. Primordial soup was edible: abiotically produced Miller-Urey mixture supports bacterial growth

    OpenAIRE

    Xueshu Xie; Daniel Backman; Albert T. Lebedev; Viatcheslav B. Artaev; Liying Jiang; Leopold L. Ilag; Zubarev, Roman A.

    2015-01-01

    Sixty years after the seminal Miller-Urey experiment that abiotically produced a mixture of racemized amino acids, we provide a definite proof that this primordial soup, when properly cooked, was edible for primitive organisms. Direct admixture of even small amounts of Miller-Urey mixture strongly inhibits E. coli bacteria growth due to the toxicity of abundant components, such as cyanides. However, these toxic compounds are both volatile and extremely reactive, while bacteria are highly capa...

  14. Growth Responses of Fish During Chronic Exposure of Metal Mixture under Laboratory Conditions

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    Saima Naz and Muhammad Javed

    2013-07-01

    Full Text Available Growth responses of five fish species viz. Catla catla, Labeo rohita, Cirrhina mrigala, Ctenopharyngodon idella and Hypophthalmichthys molitrix were determined, separately, under chronic exposure of binary mixture of metals (Zn+Ni at sub-lethal concentrations (1/3rd of LC50 for 12 weeks. Randomized complete block design (RCBD was followed to conduct this research work. The groups (10 fish each of Catla catla, Labeo rohita, Cirrhina mrigala, Ctenopharyngodon idella and Hypophthalmichthys molitrix having almost similar weights were investigated for their growth responses and metals bioaccumulation patterns in their body organs during chronic exposure of Zn+Ni mixture. The bioaccumulation of metals in the fish body organs viz. gills, liver, kidney, fins, bones, muscle and skin were also determined before and after growth trails under the stress of metals mixture. The exposure of fish to sub-lethal concentrations of mixture caused significant impacts on the average wet weight increments of five fish species. Ctenopharyngodon idella and Labeo rohita attained significantly higher weights, followed by that of Hypophthalmichthys molitrix, Cirrhina mrigala and Catla catla. However, the growth of metals mixture exposed fish species was significantly lesser than that of control fish (un-stressed. Significantly variable condition factor values reflected the degree of fish well-beings that correlated directly with fish growth and metal exposure concentration. Any significant change in feed intake, due to stress, is reflected in terms of fish growth showing the impacts of metal mixture on fish growth were either additive or antagonist / synergistic. Accumulation of all the metals in fish body followed the general order: liver>kidney>gills> skin >muscle> fins >bones.

  15. Effects of Different Pot Mixtures on spathiphyllum (Spathiphyllum wallisii Regel Growth and Development

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    Fatemeh KAKOEI

    2013-06-01

    Full Text Available The growth of Spathiphyllum wallisii Regel plants was evaluated using different pot mixtures (v:v. Plant growth was measured by 11 parameters: leaf area, leaf number, mean shoot length, shoot fresh and dry weight, mean root length, root number, root fresh and dry weight, root volume and number of suckers. Parameters such as leaf area, leaf number, shoot fresh and dry weight, root fresh and dry weight and root length were higher in the media containing only perlite. Mean shoot length was higher in the medium containing 3:1 perlite: sand mixture, 1:3 perlite: sand mixture and only perlite; and root number was higher in the medium containing 3:1 perlite: sand mixture and only perlite. Furthermore, root volume was higher in the medium containing equal perlite: sand mixture and only perlite. The highest number of suckers was obtained in equal leaf-mold: sand mixture. It is concluded that these differences represent a direct effect on the rooting process and that substrate characteristics are of the utmost importance for the quality of rooted plants.

  16. Using Bayesian statistics for modeling PTSD through Latent Growth Mixture Modeling : implementation and discussion

    NARCIS (Netherlands)

    Depaoli, Sarah; van de Schoot, Rens; van Loey, Nancy; Sijbrandij, Marit

    2015-01-01

    BACKGROUND: After traumatic events, such as disaster, war trauma, and injuries including burns (which is the focus here), the risk to develop posttraumatic stress disorder (PTSD) is approximately 10% (Breslau & Davis, 1992). Latent Growth Mixture Modeling can be used to classify individuals into dis

  17. A homogenized constrained mixture (and mechanical analog) model for growth and remodeling of soft tissue.

    Science.gov (United States)

    Cyron, C J; Aydin, R C; Humphrey, J D

    2016-12-01

    Most mathematical models of the growth and remodeling of load-bearing soft tissues are based on one of two major approaches: a kinematic theory that specifies an evolution equation for the stress-free configuration of the tissue as a whole or a constrained mixture theory that specifies rates of mass production and removal of individual constituents within stressed configurations. The former is popular because of its conceptual simplicity, but relies largely on heuristic definitions of growth; the latter is based on biologically motivated micromechanical models, but suffers from higher computational costs due to the need to track all past configurations. In this paper, we present a temporally homogenized constrained mixture model that combines advantages of both classical approaches, namely a biologically motivated micromechanical foundation, a simple computational implementation, and low computational cost. As illustrative examples, we show that this approach describes well both cell-mediated remodeling of tissue equivalents in vitro and the growth and remodeling of aneurysms in vivo. We also show that this homogenized constrained mixture model suggests an intimate relationship between models of growth and remodeling and viscoelasticity. That is, important aspects of tissue adaptation can be understood in terms of a simple mechanical analog model, a Maxwell fluid (i.e., spring and dashpot in series) in parallel with a "motor element" that represents cell-mediated mechanoregulation of extracellular matrix. This analogy allows a simple implementation of homogenized constrained mixture models within commercially available simulation codes by exploiting available models of viscoelasticity.

  18. Bayesian Inference for Growth Mixture Models with Latent Class Dependent Missing Data

    Science.gov (United States)

    Lu, Zhenqiu Laura; Zhang, Zhiyong; Lubke, Gitta

    2011-01-01

    "Growth mixture models" (GMMs) with nonignorable missing data have drawn increasing attention in research communities but have not been fully studied. The goal of this article is to propose and to evaluate a Bayesian method to estimate the GMMs with latent class dependent missing data. An extended GMM is first presented in which class…

  19. Growth of Saccharomyces cerevisiae CBS 426 on mixtures of glucose and succinic acid: a model

    Energy Technology Data Exchange (ETDEWEB)

    Bonnet, J.A.B.A.F.; Koellmann, C.J.W.; Dekkers-de Kok, H.E.; Roels, J.A.

    1984-03-01

    Saccharomyces cerevisiae CBS 426 was grown in continuous culture in a defined medium with a mixture of glucose and succinic acid as the carbon source. Growth on succinic acid was possible after long adaptation periods. The flows of glucose, succinic acid, oxygen, carbon dioxide, and biomass to and from the system were measured. It proved necessary to expand our previous model to accommodate the active transport of succinic acid by the cell. The values found for the efficiency of the oxidative phosphorylation (PIO) and the amount of ATP needed for production of biomass from monomers gave the same values as found for substrate mixtures taken up passively. (Refs. 13).

  20. Plant growth and soil microbial community structure of legumes and grasses grown in monoculture or mixture

    Institute of Scientific and Technical Information of China (English)

    CHEN Meimei; CHEN Baodong; MARSCHNER Petra

    2008-01-01

    A greenhouse pot experiment was conducted to investigate the influence of soil moisture eontent on plant growth and the rhizospheremicrobial community structure of four plant species (white clover, alfalfa, sudan grass, tall fescue), grown individually or in a mixture.The soil moisture content was adjusted to 55% or 80% water holding capacity (WHC). The results indicated that the total plant biomassof one pot was lower at 55% WHC. At a given soil moisture, the total plant biomass of white clover and tall fescue in the mixture waslower than that in a monoculture, indicating their poor competitiveness. For leguminous plants, the decrease in soil moisture reducedthe total microbial biomass, bacterial biomass, fungal biomass, and fungal/baeterial ratio in soil as assessed by the phospholipid fattyacid analysis, whereas, lower soil moisture increased those parameters in the tall fescue. The microbial biomass in the soil with legumeswas higher than that in the soil with grasses and the two plant groups differed in soil microbial community composition. At high soilmoisture content, microbial communities of the plant mixture were similar to those of the legume monoculture, and the existenceof legumes in the mixture enhanced the bacterial and fungal biomass in the soil compared to the grasses grown in the monoculture,indicating that legumes played a dominant role in the soil microbial community changes in the plant mixture.

  1. Inhibition of bacterial growth by different mixtures of propofol and thiopentone

    Directory of Open Access Journals (Sweden)

    K.E. Joubert

    2005-06-01

    Full Text Available Propofol is, as a result of its formulation, an ideal bacterial and yeast culture medium. An outbreak of sepsis in humans and an increase in wound infections in dogs has been ascribed to the use of propofol. It has been previously reported that a 1:1 mixture of propofol and thiopentone has bactericidal properties. This study was undertaken to determine if further serial mixtures of propofol and thiopentone maintained the bactericidal properties. Mixtures of 1:1 (solution A, 5:1 (solution B, 10:1 (solution C, 50:1 (solution D and 100:1 (solution E of 1 % propofol to 2.5 % thiopentone, 2.5 % thiopentone (solution T, 1 % propofol (solution P and saline (solution S were prepared and inoculated with between 105 and 106 colony-forming units of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. A sample was withdrawn from each solution at 0, 1, 6, 12, 48 and 120 hours after inoculation and a bacterial count was performed. This study showed that thiopentone and solution A behaved in similar fashion by inhibiting bacterial growth and was bactericidal after 48 hours. Solution B was not bactericidal against S. aureus and C. albicans. Propofol and solutions D and E all supported growth of all the organisms tested. These data indicate that mixtures of propofol and thiopentone at a ratio less than 1:1 do not maintain the bactericidal properties.

  2. Comparison of diamond growth with different gas mixtures in microwave plasma asssited chemical vapor deposition (MWCVD

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    Corat Evaldo J.

    2003-01-01

    Full Text Available In this work we study the influence of oxygen addition to several halocarbon-hydrogen gas systems. Diamond growth have been performed in a high power density MWCVD reactor built in our laboratory. The growth experiments are monitored by argon actinometry as a reference to plasma temperature and atomic hydrogen production, and by mass spectrometry to compare the exhaust gas composition. Atomic hydrogen actinometry revealed that the halogen presence in the gas phase is responsible for a considerable increase of atomic hydrogen concentration in the gas phase. Mass spectrometry shows similar results for all gas mixtures tested. Growth studies with oxygen addition to CF4/H2, CCl4/H2, CCl2F2/H2 and CH3Cl/H2 reveals that oxygen increases the carbon solubility in the gas phase but no better diamond growth conditions were found. Halogens are not, per se, eligible for diamond growth. All the possible advantages, as the higher production of atomic hydrogen, have been suppressed by the low carbon solubility in the gas phase, even when oxygen is added. The diamond growth with small amount of CF4 added to CH4/H2 mixture is not aggressive to the apparatus but brings several advantages to the process.

  3. Performance of growth mixture models in the presence of time-varying covariates.

    Science.gov (United States)

    Diallo, Thierno M O; Morin, Alexandre J S; Lu, HuiZhong

    2016-10-31

    Growth mixture modeling is often used to identify unobserved heterogeneity in populations. Despite the usefulness of growth mixture modeling in practice, little is known about the performance of this data analysis technique in the presence of time-varying covariates. In the present simulation study, we examined the impacts of five design factors: the proportion of the total variance of the outcome explained by the time-varying covariates, the number of time points, the error structure, the sample size, and the mixing ratio. More precisely, we examined the impact of these factors on the accuracy of parameter and standard error estimates, as well as on the class enumeration accuracy. Our results showed that the consistent Akaike information criterion (CAIC), the sample-size-adjusted CAIC (SCAIC), the Bayesian information criterion (BIC), and the integrated completed likelihood criterion (ICL-BIC) proved to be highly reliable indicators of the true number of latent classes in the data, across design conditions, and that the sample-size-adjusted BIC (SBIC) also proved quite accurate, especially in larger samples. In contrast, the Akaike information criterion (AIC), the entropy, the normalized entropy criterion (NEC), and the classification likelihood criterion (CLC) proved to be unreliable indicators of the true number of latent classes in the data. Our results also showed that substantial biases in the parameter and standard error estimates tended to be associated with growth mixture models that included only four time points.

  4. Dynamics of gas bubble growth in oil-refrigerant mixtures under isothermal decompression

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Joao Paulo; Barbosa Junior, Jader R.; Prata, Alvaro T. [Federal University of Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. of Mechanical Engineering], Emails: jpdias@polo.ufsc.br, jrb@polo.ufsc.br, prata@polo.ufsc.br

    2010-07-01

    This paper proposes a numerical model to predict the growth of gaseous refrigerant bubbles in oil-refrigerant mixtures with high contents of oil subjected to isothermal decompression. The model considers an Elementary Cell (EC) in which a spherical bubble is surrounded by a concentric and spherical liquid layer containing a limited amount of dissolved liquid refrigerant. The pressure reduction in the EC generates a concentration gradient at the bubble interface and the refrigerant is transported to the bubble by molecular diffusion. After a sufficiently long period of time, the concentration gradient in the liquid layer and the bubble internal pressure reach equilibrium and the bubble stops growing, having attained its stable radius. The equations of momentum and chemical species conservation for the liquid layer, and the mass balance at the bubble interface are solved via a coupled finite difference procedure to determine the bubble internal pressure, the refrigerant radial concentration distribution and the bubble growth rate. Numerical results obtained for a mixture of ISO VG10 ester oil and refrigerant HFC-134a showed that bubble growth dynamics depends on model parameters like the initial bubble radius, initial refrigerant concentration in the liquid layer, decompression rate and EC temperature. Despite its simplicity, the model showed to be a potential tool to predict bubble growth and foaming which may result from important phenomena occurring inside refrigeration compressors such as lubrication of sliding parts and refrigerant degassing from the oil stored in oil sump during compressor start-up. (author)

  5. The Probiotic Mixture VSL#3 Accelerates Gastric Ulcer Healing by Stimulating Vascular Endothelial Growth Factor

    Science.gov (United States)

    Dharmani, Poonam; De Simone, Claudio; Chadee, Kris

    2013-01-01

    Studies assessing the effect and mechanism of probiotics on diseases of the upper gastrointestinal tract (GI) including gastric ulcers are limited despite extensive work and promising results of this therapeutic option for other GI diseases. In this study, we investigated the mechanisms by which the probiotic mixture VSL#3 (a mixture of eight probiotic bacteria including Lactobacilli, Bifidobacteria and Streptococcus species) heals acetic acid induced gastric ulcer in rats. VSL#3 was administered orally at low (6×109 bacteria) or high (1.2×1010 bacteria) dosages from day 3 after ulcer induction for 14 consecutive days. VSL#3 treatments significantly enhanced gastric ulcer healing in a dose-dependent manner. To assess the mechanism(s) whereby VSL#3 exerted its protective effects, we quantified the gene expression of several pro-inflammatory cytokines, protein and expression of stomach mucin-Muc5ac, regulatory cytokine-IL-10, COX-2 and various growth factors. Of all the components examined, only expression and protein production of VEGF was increased 332-fold on day 7 in the ulcerated tissues of animals treated with VSL#3. Predictably, animals treated with VEGF neutralizing antibody significantly delayed gastric ulcer healing in VSL#3 treated animals. This is the first report to demonstrate high efficacy of the probiotic mixture VSL#3 in enhancing gastric ulcer healing. Probiotic efficacy was effective at higher concentrations of VSL#3 by specifically increasing the expression and production of angiogenesis promoting growth factors, primarily VEGF. PMID:23484048

  6. A Systematic Investigation of Within-Subject and Between-Subject Covariance Structures in Growth Mixture Models

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    Liu, Junhui

    2012-01-01

    The current study investigated how between-subject and within-subject variance-covariance structures affected the detection of a finite mixture of unobserved subpopulations and parameter recovery of growth mixture models in the context of linear mixed-effects models. A simulation study was conducted to evaluate the impact of variance-covariance…

  7. Nonlinear Structured Growth Mixture Models in Mplus and OpenMx

    Science.gov (United States)

    Grimm, Kevin J.; Ram, Nilam; Estabrook, Ryne

    2014-01-01

    Growth mixture models (GMMs; Muthén & Muthén, 2000; Muthén & Shedden, 1999) are a combination of latent curve models (LCMs) and finite mixture models to examine the existence of latent classes that follow distinct developmental patterns. GMMs are often fit with linear, latent basis, multiphase, or polynomial change models because of their common use, flexibility in modeling many types of change patterns, the availability of statistical programs to fit such models, and the ease of programming. In this paper, we present additional ways of modeling nonlinear change patterns with GMMs. Specifically, we show how LCMs that follow specific nonlinear functions can be extended to examine the presence of multiple latent classes using the Mplus and OpenMx computer programs. These models are fit to longitudinal reading data from the Early Childhood Longitudinal Study-Kindergarten Cohort to illustrate their use. PMID:25419006

  8. Nonlinear Structured Growth Mixture Models in Mplus and OpenMx.

    Science.gov (United States)

    Grimm, Kevin J; Ram, Nilam; Estabrook, Ryne

    2010-01-01

    Growth mixture models (GMMs; Muthén & Muthén, 2000; Muthén & Shedden, 1999) are a combination of latent curve models (LCMs) and finite mixture models to examine the existence of latent classes that follow distinct developmental patterns. GMMs are often fit with linear, latent basis, multiphase, or polynomial change models because of their common use, flexibility in modeling many types of change patterns, the availability of statistical programs to fit such models, and the ease of programming. In this paper, we present additional ways of modeling nonlinear change patterns with GMMs. Specifically, we show how LCMs that follow specific nonlinear functions can be extended to examine the presence of multiple latent classes using the Mplus and OpenMx computer programs. These models are fit to longitudinal reading data from the Early Childhood Longitudinal Study-Kindergarten Cohort to illustrate their use.

  9. Reading Ability Development from Kindergarten to Junior Secondary: Latent Transition Analyses with Growth Mixture Modeling

    Directory of Open Access Journals (Sweden)

    Yuan Liu

    2016-10-01

    Full Text Available The present study examined the reading ability development of children in the large scale Early Childhood Longitudinal Study (Kindergarten Class of 1998-99 data; Tourangeau, Nord, Lê, Pollack, & Atkins-Burnett, 2006 under the dynamic systems. To depict children's growth pattern, we extended the measurement part of latent transition analysis to the growth mixture model and found that the new model fitted the data well. Results also revealed that most of the children stayed in the same ability group with few cross-level changes in their classes. After adding the environmental factors as predictors, analyses showed that children receiving higher teachers' ratings, with higher socioeconomic status, and of above average poverty status, would have higher probability to transit into the higher ability group.

  10. Growth mixture modeling as an exploratory analysis tool in longitudinal quantitative trait loci analysis.

    Science.gov (United States)

    Chang, Su-Wei; Choi, Seung Hoan; Li, Ke; Fleur, Rose Saint; Huang, Chengrui; Shen, Tong; Ahn, Kwangmi; Gordon, Derek; Kim, Wonkuk; Wu, Rongling; Mendell, Nancy R; Finch, Stephen J

    2009-12-15

    We examined the properties of growth mixture modeling in finding longitudinal quantitative trait loci in a genome-wide association study. Two software packages are commonly used in these analyses: Mplus and the SAS TRAJ procedure. We analyzed the 200 replicates of the simulated data with these programs using three tests: the likelihood-ratio test statistic, a direct test of genetic model coefficients, and the chi-square test classifying subjects based on the trajectory model's posterior Bayesian probability. The Mplus program was not effective in this application due to its computational demands. The distributions of these tests applied to genes not related to the trait were sensitive to departures from Hardy-Weinberg equilibrium. The likelihood-ratio test statistic was not usable in this application because its distribution was far from the expected asymptotic distributions when applied to markers with no genetic relation to the quantitative trait. The other two tests were satisfactory. Power was still substantial when we used markers near the gene rather than the gene itself. That is, growth mixture modeling may be useful in genome-wide association studies. For markers near the actual gene, there was somewhat greater power for the direct test of the coefficients and lesser power for the posterior Bayesian probability chi-square test.

  11. Demographic and growth responses of a guerrilla and a phalanx perennial grass in competitive mixtures

    Science.gov (United States)

    Humphrey, David L.; Pyke, David A.

    1998-01-01

    The advantages of guerrilla and phalanx growth for the guerrilla Elymus lanceolatus ssp. lanceolatus and phalanx E. l. ssp. wawawaiensis were evaluated over 2 years in two taxon mixtures with a range of densities of each subspecies and under two levels of watering. Ramet numbers and biomass of the guerrilla subspecies were higher than those of the phalanx grass in the first year but in the second year declined greatly, while the phalanx grass showed no change in biomass and an increase in ramet numbers. High neighbour densities affected the phalanx subspecies more strongly than the guerrilla subspecies in the first year, but in the second year there were few differences between subspecies. Biomass of the guerrilla grass remained greater than that of the phalanx grass but ramet numbers were similar in the second year. For both subspecies in both years, probability of flowering decreased at higher neighbour densities, indicating adaptation for competitive ability. In the first year, biomass was more strongly reduced by densities than flowering was, but in the second year, when crowding was apparently greater, flowering was more severely affected. Genet survival was high and similar for both subspecies. The presumed advantage of guerrilla subspecies in exploiting open space was supported. The guerrilla grass exploited resources more quickly in the first year by faster growth and greater ramet production, but its biomass, ramet numbers and rhizome growth, and thus its advantage, were reduced in the second year. The phalanx subspecies had slower growth, produced more ramets in later years, and delayed flowering until later years. Although less able to exploit open resources, it appeared adapted to more stressful conditions, and may be able to exploit temporal resource pulses more effectively.

  12. A parallel process growth mixture model of conduct problems and substance use with risky sexual behavior.

    Science.gov (United States)

    Wu, Johnny; Witkiewitz, Katie; McMahon, Robert J; Dodge, Kenneth A

    2010-10-01

    Conduct problems, substance use, and risky sexual behavior have been shown to coexist among adolescents, which may lead to significant health problems. The current study was designed to examine relations among these problem behaviors in a community sample of children at high risk for conduct disorder. A latent growth model of childhood conduct problems showed a decreasing trend from grades K to 5. During adolescence, four concurrent conduct problem and substance use trajectory classes were identified (high conduct problems and high substance use, increasing conduct problems and increasing substance use, minimal conduct problems and increasing substance use, and minimal conduct problems and minimal substance use) using a parallel process growth mixture model. Across all substances (tobacco, binge drinking, and marijuana use), higher levels of childhood conduct problems during kindergarten predicted a greater probability of classification into more problematic adolescent trajectory classes relative to less problematic classes. For tobacco and binge drinking models, increases in childhood conduct problems over time also predicted a greater probability of classification into more problematic classes. For all models, individuals classified into more problematic classes showed higher proportions of early sexual intercourse, infrequent condom use, receiving money for sexual services, and ever contracting an STD. Specifically, tobacco use and binge drinking during early adolescence predicted higher levels of sexual risk taking into late adolescence. Results highlight the importance of studying the conjoint relations among conduct problems, substance use, and risky sexual behavior in a unified model. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  13. Antifungal effectiveness of fungicide and peroxyacetic acid mixture on the growth of Botrytis cinerea.

    Science.gov (United States)

    Ayoub, Fatima; Ben Oujji, Najwa; Chebli, Bouchra; Ayoub, Mohamed; Hafidi, Athman; Salghi, Rachid; Jodeh, Shehdeh

    2017-04-01

    In the attempt to reduce the negative impacts of chemical pesticides on environment and consumer's health, a new plant treatment practice minimizing the amount of pesticides needed during pests and diseases treatments has been developed. Our approach is based on combining the biocide effects of fungicide with the peroxyacetic acid (PAA) one. In this paper, we focused on the in vitro study of the antifungal activity of this combination against Botrytis cinerea, the most redoubtable threat of tomatoes plants in Morocco. First, different concentrations of a peroxyacetic acid product (PERACLEAN(®)5) and two commercially available fungicides SWITCH and SIGNUM were tested separately for their inhibitory effects on the mycelial growth and spores germination of B. cinerea. 100% inhibition of fungal growth was achieved using 16.77 and 14.47 μg/ml of SIGNUM and SWITCH respectively and 1.5% of PERACLEAN(®)5. When combined with 0.5% of the peroxyacetic acid mixture (PERACLEAN(®)5), the pesticides 100% effective concentrations decreased to 0.5 μg/ml for both pesticides. Hence, this approach allowed us to suppress the pathogen while minimizing the amounts of applied fungicides by more than 95%. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Using growth mixture modeling to identify classes of sodium adherence in adults with heart failure.

    Science.gov (United States)

    Masterson Creber, Ruth; Lee, Christopher S; Lennie, Terry A; Topaz, Maxim; Riegel, Barbara

    2014-01-01

    The prevention of fluid retention is important to reduce hospitalizations in patients with heart failure (HF). Following a low-sodium diet helps to reduce fluid retention. The primary objective of this study was to use growth mixture modeling to identify distinct classes of sodium adherence-characterized by shared growth trajectories of objectively measured dietary sodium. The secondary objective was to identify patient-level determinants of the nonadherent trajectory. This was a secondary analysis of data collected from a prospective longitudinal study of 279 community-dwelling adults with previously or currently symptomatic HF. Growth mixture modeling was used to identify distinct trajectories of change in 24-hour urinary sodium excretion measured at 3 time points over 6 months. Logistic modeling was used to predict membership in observed trajectories. The sample was predominantly male (64%), had a mean age of 62 years, was functionally compromised (59% New York Heart Association class III), and had nonischemic HF etiology. Two distinct trajectories of sodium intake were identified and labeled adherent (66%) and nonadherent (34%) to low-sodium diet recommendations. Three predictors of the nonadherent trajectory were identified, confirming our previous mixed-effect analysis. Compared with being normal weight (body mass index obese was associated with a 4-fold incremental increase in the likelihood of being in the nonadherent trajectory (odds ratio [OR], 4.63; 95% confidence interval [CI], 1.66-12.91; P < .002). Being younger than 65 years (OR, 4.66; 95% CI, 1.04-20.81; P = .044) or having diabetes (OR, 4.15; 95% CI, 1.29-13.40; P = .016) were both associated with more than 4 times the odds of being in the nonadherent urine sodium trajectory compared with being older than 65 years or not having diabetes, respectively. Two distinct trajectories of sodium intake were identified in patients with HF. The nonadherent trajectory was characterized by an elevated pattern

  15. Coal slurry solids/coal fluidized bed combustion by-product mixtures as plant growth media

    Science.gov (United States)

    Darmody, R.G.; Green, W.P.; Dreher, G.B.

    1998-01-01

    Fine-textured, pyritic waste produced by coal cleaning is stored in slurry settling ponds that eventually require reclamation. Conventionally, reclamation involves covering the dewatered coal slurry solids (CSS) with 1.3 m of soil to allow plant growth and prevent acid generation by pyrite oxidation. This study was conducted to determine the feasiblity of a less costly reclamation approach that would eliminate the soil cover and allow direct seeding of plants into amended CSS materials. Potential acidity of the CSS would be neutralized by additions of fluidized-bed combustion by-product (FBCB), an alkaline by-product of coal combustion. The experiment involved two sources of CSS and FBCB materials from Illinois. Birdsfoot trefoil (Lotus corniculatus L.), tall fescue (Festuca arundinacea Schreb.), and sweet clover (Melilotus officinalis (L.) Lam.) were seeded in the greenhouse into pots containing mixtures of the materials. CSS-1 had a high CaCO3:FeS2 ratio and needed no FBCB added to compensate for its potential acidity. CSS-2 was mixed with the FBCB materials to neutralize potential acidity (labeled Mix A and B). Initial pH was 5.6, 8.8, and 9.2 for the CSS-1, Mix A, and Mix B materials, respectively. At the end of the 70-day experiment, pH was 5.9 for all mixtures. Tall fescue and sweet clover grew well in all the treatments, but birdsfoot trefoil had poor emergence and survival. Elevated tissue levels of B, Cd, and Se were found in some plants. Salinity, low moisture holding capacity, and potentially phytotoxic B may limit the efficacy of this reclamation method.

  16. Joint effects of heavy metal binary mixtures on seed germination, root and shoot growth, bacterial bioluminescence, and gene mutation

    Institute of Scientific and Technical Information of China (English)

    In Chul Kong

    2013-01-01

    This investigation was to assess the joint effects of metal binary mixtures on seed germination,root and shoot growth,bacterial bioluminescence,and gene mutation based on the one toxic unit (1 TU) approach.Different sensitivities and orders of toxicity of metal mixtures were observed among the bioassays.In general,mostly additive or antagonistic effects were observed,while almost no synergistic effects by the binary metal mixtures in all bioassays.Therefore,the combined effects of heavy metals in the different bioassays were difficult to generalize since they were dependent on both chemical type and the organism used in each bioassay.However,these results indicate that a battery of bioassays with mixture chemicals as opposed to just a single assay with single metal is a better strategy for the bioassessment of environmental pollutants.

  17. TOXIC EFFECTS OF LINEAR ALKYLBENZENE SULFONATE, ANTHRACENE AND THEIR MIXTURE ON GROWTH OF A MICROBIAL CONSORTIUM ISOLATED FROM POLLUTED SEDIMENT

    OpenAIRE

    2010-01-01

    The aim of this study was to determine the effect of linear alkylbenzene sulfonate (LAS), anthracene and a LAS-anthracene mixture on the growth of a microbial consortium isolated from polluted sediment. The microbial consortium was grown in a sterile glass bottle with mineral medium containing 1 g/L of glucose. Microbial growth inhibition produced by LAS, anthracene and combinations of LAS and anthracene was determined by viable count in nutritive agar; inhibitory concentration 50 (IC50) was ...

  18. Using Bayesian statistics for modeling PTSD through Latent Growth Mixture Modeling: implementation and discussion

    Directory of Open Access Journals (Sweden)

    Sarah Depaoli

    2015-03-01

    Full Text Available Background: After traumatic events, such as disaster, war trauma, and injuries including burns (which is the focus here, the risk to develop posttraumatic stress disorder (PTSD is approximately 10% (Breslau & Davis, 1992. Latent Growth Mixture Modeling can be used to classify individuals into distinct groups exhibiting different patterns of PTSD (Galatzer-Levy, 2015. Currently, empirical evidence points to four distinct trajectories of PTSD patterns in those who have experienced burn trauma. These trajectories are labeled as: resilient, recovery, chronic, and delayed onset trajectories (e.g., Bonanno, 2004; Bonanno, Brewin, Kaniasty, & Greca, 2010; Maercker, Gäbler, O'Neil, Schützwohl, & Müller, 2013; Pietrzak et al., 2013. The delayed onset trajectory affects only a small group of individuals, that is, about 4–5% (O'Donnell, Elliott, Lau, & Creamer, 2007. In addition to its low frequency, the later onset of this trajectory may contribute to the fact that these individuals can be easily overlooked by professionals. In this special symposium on Estimating PTSD trajectories (Van de Schoot, 2015a, we illustrate how to properly identify this small group of individuals through the Bayesian estimation framework using previous knowledge through priors (see, e.g., Depaoli & Boyajian, 2014; Van de Schoot, Broere, Perryck, Zondervan-Zwijnenburg, & Van Loey, 2015. Method: We used latent growth mixture modeling (LGMM (Van de Schoot, 2015b to estimate PTSD trajectories across 4 years that followed a traumatic burn. We demonstrate and compare results from traditional (maximum likelihood and Bayesian estimation using priors (see, Depaoli, 2012, 2013. Further, we discuss where priors come from and how to define them in the estimation process. Results: We demonstrate that only the Bayesian approach results in the desired theory-driven solution of PTSD trajectories. Since the priors are chosen subjectively, we also present a sensitivity analysis of the

  19. Patterns of Children's Adrenocortical Reactivity to Interparental Conflict and Associations with Child Adjustment: A Growth Mixture Modeling Approach

    Science.gov (United States)

    Koss, Kalsea J.; George, Melissa R. W.; Davies, Patrick T.; Cicchetti, Dante; Cummings, E. Mark; Sturge-Apple, Melissa L.

    2013-01-01

    Examining children's physiological functioning is an important direction for understanding the links between interparental conflict and child adjustment. Utilizing growth mixture modeling, the present study examined children's cortisol reactivity patterns in response to a marital dispute. Analyses revealed three different patterns of cortisol…

  20. Patterns of Children's Adrenocortical Reactivity to Interparental Conflict and Associations with Child Adjustment: A Growth Mixture Modeling Approach

    Science.gov (United States)

    Koss, Kalsea J.; George, Melissa R. W.; Davies, Patrick T.; Cicchetti, Dante; Cummings, E. Mark; Sturge-Apple, Melissa L.

    2013-01-01

    Examining children's physiological functioning is an important direction for understanding the links between interparental conflict and child adjustment. Utilizing growth mixture modeling, the present study examined children's cortisol reactivity patterns in response to a marital dispute. Analyses revealed three different patterns of cortisol…

  1. An Investigation of Growth Mixture Models for Studying the Flynn Effect

    Directory of Open Access Journals (Sweden)

    Grant B. Morgan

    2014-10-01

    Full Text Available The Flynn effect (FE is the well-documented generational increase of mean IQ scores over time, but a methodological issue that has not received much attention in the FE literature is the heterogeneity in change patterns across time. Growth mixture models (GMMs offer researchers a flexible latent variable framework for examining the potential heterogeneity of change patterns. The article presents: (1 a Monte Carlo investigation of the performance of the various measures of model fit for GMMs in data that resemble previous FE studies; and (2 an application of GMM to the National Intelligence Tests. The Monte Carlo study supported the use of the Bayesian information criterion (BIC and consistent Akaike information criterion (CAIC for model selection. The GMM application study resulted in the identification of two classes of participants that had unique change patterns across three time periods. Our studies show that GMMs, when applied carefully, are likely to identify homogeneous subpopulations in FE studies, which may aid in further understanding of the FE.

  2. Approximation of the two-part MDL code

    NARCIS (Netherlands)

    Adriaans, P.; Vitányi, P.M.B.

    2009-01-01

    Approximation of the optimal two-part minimum description length (MDL) code for given data, through successive monotonically length-decreasing two-part MDL codes, has the following properties: (i) computation of each step may take arbitrarily long; (ii) we may not know when we reach the optimum, or

  3. Approximation of the two-part MDL code

    NARCIS (Netherlands)

    P. Adriaans; P.M.B. Vitányi (Paul)

    2009-01-01

    htmlabstractApproximation of the optimal two-part minimum description length (MDL) code for given data, through successive monotonically length-decreasing two-part MDL codes, has the following properties: (i) computation of each step may take arbitrarily long; (ii) we may not know when we reach the

  4. Estimation of the minimum and maximum substrate temperatures for diamond growth from hydrogen-hydrocarbon gas mixtures

    Science.gov (United States)

    Zhang, Yafei; Zhang, Fangqing; Chen, Guanghua

    1994-12-01

    It is proposed in this paper that the minimum substrate temperature for diamond growth from hydrogen-hydrocarbon gas mixtures be determined by the packing arrangements of hydrocarbon fragments at the surface, and the maximum substrate temperature be limited by the diamond growth surface reconstruction, which can be prevented by saturating the surface dangling bonds with atomic hydrogen. Theoretical calculations have been done by a formula proposed by Dryburgh [J. Crystal Growth 130 (1993) 305], and the results show that diamond can be deposited at the substrate temperatures ranging from ≈ 400 to ≈ 1200°C by low pressure chemical vapor deposition. This is consistent with experimental observations.

  5. Applications of Latent Growth Mixture Modeling and allied methods to posttraumatic stress response data

    Directory of Open Access Journals (Sweden)

    Isaac R. Galatzer-Levy

    2015-03-01

    Full Text Available Background: Scientific research into mental health outcomes following trauma is undergoing a revolution as scientists refocus their efforts to identify underlying dimensions of health and psychopathology. This effort is in stark contrast to the previous focus which was to characterize individuals based on Diagnostic and Statistical Manual of Mental Disorders (DSM diagnostic status (Insel et al., 2010. A significant unresolved issue underlying this shift is how to characterize clinically relevant populations without reliance on the categorical definitions provided by the DSM. Classifying individuals based on their pattern of stress adaptation over time holds significant promise for capturing inherent inter-individual heterogeneity as responses including chronicity, recovery, delayed onset, and resilience can only be determined longitudinally (Galatzer-Levy & Bryant, 2013 and then characterizing these patterns for future research (Depaoli, Van de Schoot, Van Loey, & Sijbrandij, 2015. Such an approach allows for the identification of phenominologically similar patterns of response to diverse extreme environmental stressors (Bonanno, Kennedy, Galatzer-Levy, Lude, & Elfstom, 2012; Galatzer-Levy & Bonanno, 2012; Galatzer-Levy, Brown, et al., 2013; Galatzer-Levy, Burton, & Bonanno, 2012 including translational animal models of stress adaptation (Galatzer-Levy, Bonanno, Bush, & LeDoux, 2013; Galatzer-Levy, Moscarello, et al., 2014. The empirical identification of heterogeneous stress response patterns can increase the identification of mechanisms (Galatzer-Levy, Steenkamp, et al., 2014, consequences (Galatzer-Levy & Bonanno, 2014, treatment effects (Galatzer-Levy, Ankri, et al., 2013, and prediction (Galatzer-Levy, Karstoft, Statnikov, & Shalev, 2014 of individual differences in response to trauma. Method: Methodological and theoretical considerations for the application of Latent Growth Mixture Modeling (LGMM and allied methods such as Latent Class

  6. Experimental mixture design as a tool to optimize the growth of various Ganoderma species cultivated on media with different sugars

    Directory of Open Access Journals (Sweden)

    Yit Kheng Goh

    2016-01-01

    Full Text Available The influence of different medium components (glucose, sucrose, and fructose on the growth of different Ganoderma isolates and species was investigated using mixture design. Ten sugar combinations based on three simple sugars were generated with two different concentrations, namely 3.3% and 16.7%, which represented low and high sugar levels, respectively. The media were adjusted to either pH 5 or 8. Ganoderma isolates (two G. boninense from oil palm, one Ganoderma species from coconut palm, G. lingzhi, and G. australe from tower tree grew faster at pH 8. Ganoderma lingzhi proliferated at the slowest rate compared to all other tested Ganoderma species in all the media studied. However, G. boninense isolates grew the fastest. Different Ganoderma species were found to have different sugar preferences. This study illustrated that the mixture design can be used to determine the optimal combinations of sugar or other nutrient/chemical components of media for fungal growth.

  7. Effect of Organic Manure Mixture on growth and yield of Radish (RaphanusSativus L

    Directory of Open Access Journals (Sweden)

    M. Etesami

    2016-02-01

    Full Text Available Introduction: Today, production of organic farming and gardening is rising. The use of organic fertilizers such as animal manure has a long history. In recent years, the use of fertilizers and manure for providing the nutritional needs of plants, improve soil physical and chemical structure and reduce the environmental issues have been observed. Animal manures can increase soil organic matter and nutrients, improve soil structure and water-holding capacity which in turn increase the quality and quantity of the product to follow. Manure is a valuable source of biological, ecological and environmental benefits is positive and its main use is for agricultural use. Radish is an important root vegetable that belongs to the cruciferous (Brassicaceae. Value radish on high levels of dietary is related to soluble fiber and antioxidants. Radish is a native plant to Asia, China and Europe. The oral part of the botanical garden radish is important and that kind of traditional varieties have long hypocotyls include root and hypocotyls made.The purpose of this test is to evaluate the different mixture amount of animal fertilizers on the growth and yield of radish plants and compare them to each other. Materials and Methods: In order to study of different manure effect on radish growth and yield, an experiment carried out in 2012-2013 in the greenhouse of Gonbad- Kavos University with geographical characteristics 37.16 degrees north, 55.12 ° east and with a height of 45 meters above sea level in a completely randomized design with four replications. Soil and fertilizers used to this experiment were made of the soil and livestock of Gonbad- Kavos University. Soil texture was Clay loam and pH was 7.7 obtained from soil analysis. To obtain the required levels of fertilizer treatments (25, 50, 75, 100, a measure was considered as the basis of each treatment on the basis of the ratio were calculated. The treatments included control (soil, 25 percent cow manure+ 75

  8. Roles of Ⅴ/Ⅲ ratio and mixture degree in GaN growth: CFD and MD simulation study

    Institute of Scientific and Technical Information of China (English)

    Zhou An; Xiu Xiang-Qian; Zhang Rong; Xie Zi-Li; Hua Xue-Mei; Liu Bin; Han Ping

    2013-01-01

    To understand the mechanism of Gallium nitride (GaN) film growth is of great importance for their potential applications.In this paper,we investigate the growth behavior of the GaN film by combining computational fluid dynamics (CFD) and molecular dynamics (MD) simulations.Both of the simulations show that Ⅴ/Ⅲ mixture degree can have important impacts on the deposition behavior,and it is found that the more uniform the mixture is,the better the growth is.Besides,by using MD simulations,we illustrate the whole process of the GaN growth.Furthermore,we also find that the Ⅴ/Ⅲ ratio can affect the final roughness of the GaN film.When the Ⅴ/Ⅲ ratio is high,the surface of final GaN film is smooth.The present study provides insights into GaN growth from the macroscopic and microscopic views,which may provide some suggestions on better experimental GaN preparation.

  9. Neck/shoulder and back pain in new graduate nurses: A growth mixture modeling analysis.

    Science.gov (United States)

    Lövgren, Malin; Gustavsson, Petter; Melin, Bo; Rudman, Ann

    2014-04-01

    Although it is well known that musculoskeletal disorders are common among registered nurses, little longitudinal research has been conducted to examine this problem from nursing education to working life. The aim was to investigate the prevalence and incidence of neck/shoulder and back pain in nursing students in their final semester, and one and two years after graduation. Furthermore, to identify common trajectories of neck/shoulder and back pain, and explore sociodemographic and lifestyle-related factors, contextual factors and health outcome that might be characteristic of individuals in the various trajectories. Longitudinal study following nursing students from their final year of studies, with follow-ups one and two years after graduation. Nursing students who graduated from the 26 universities providing undergraduate nursing education in Sweden 2002 were invited to participate (N=1700). Of those asked, 1153 gave their informed consent. The participants answered postal surveys at yearly intervals. Descriptive statistics were used to analyze prevalence and incidence of pain, and growth mixture modeling was applied to identify different homogeneous clusters of individuals following similar trajectories in pain development across time. The prevalence of neck/shoulder and back pain remained constant over time (around 50% for neck/shoulder pain and just over 40% for back pain). Six different development trajectories for each symptom were found, reflecting patterns of stable pain levels or variation in levels over time: one symptom-free group, two decreasing pain groups, two increasing pain groups, and one chronic pain group. With few exceptions, the same factors (sex, children, chronic disease, working overtime, work absence, sickness presence, physical load, depression, self-rated health, sleep quality and muscular tension) were associated with neck/shoulder and back pain trajectories. Different types of physical load characterized new nurses with neck

  10. Astragalus Extract Mixture HT042 Increases Longitudinal Bone Growth Rate by Upregulating Circulatory IGF-1 in Rats

    Directory of Open Access Journals (Sweden)

    Donghun Lee

    2017-01-01

    Full Text Available Astragalus extract mixture HT042 is a standardized ingredient of health functional food approved by Korean FDA with a claim of “height growth of children.” HT042 stimulates bone growth rate and increases local IGF-1 expression in growth plate of rats which can be considered as direct stimulation of GH and its paracrine/autocrine actions. However, it remains unclear whether HT042 stimulates circulatory IGF-1 which also plays a major role to stimulate bone growth. To determine the effects on circulatory IGF-1, IGF-1 and IGFBP-3 expressions and phosphorylation of JAK2/STAT5 were evaluated in the liver after 10 days of HT042 administration. HT042 upregulated liver IGF-1 and IGFBP-3 mRNA expression, IGF-1 protein expression, and phosphorylation of JAK2/STAT5. HT042 also increased bone growth rate and proliferative zonal height in growth plate. In conclusion, HT042 stimulates bone growth rate via increment of proliferative rate by upregulation of liver IGF-1 and IGFBP-3 mRNA followed by IGF-1 protein expression through phosphorylation of JAK2/STAT5, which can be regarded as normal functioning of GH-dependent endocrine pathway.

  11. A two-part model for censored medical cost data.

    Science.gov (United States)

    Tian, Lu; Huang, Jie

    2007-10-15

    The two-part model is often used to analyse medical cost data which contain a large proportion of zero cost and are highly skewed with some large costs. The total medical costs over a period of time are often censored due to incomplete follow-up, making the analysis difficult as the censoring can be informative. We propose to apply the inverse probability weighting method on a two-part model to analyse right-censored cumulative medical costs with informative censoring. We also introduce a set of simple functionals based on the intermediate cost history to be applied with the efficiency augmentation technique. In addition, we propose a practical model-checking technique based on the cumulative residuals. Simulation studies are conducted to evaluate the finite sample performance of the proposed method. We use a data set on the cardiovascular disease (CVD)-related Medicare costs to illustrate our proposed method.

  12. Solvent and stabilizer free growth of Ag and Pd nanoparticles using metallic salts/cyclotriphosphazenes mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Díaz Valenzuela, C. [Departamento de Química, Facultad de Química, Universidad de Chile, La Palmeras 3425, Nuñoa, Casilla 653, Santiago de Chile (Chile); Valenzuela, M.L., E-mail: mlvalenzuela@unab.cl [Universidad Andres Bello, Departamento de Ciencias Química, Facultad de Ciencias Exactas, Av. Republica 275, Santiago (Chile); Caceres, S.; Diaz, R. [Departamento de Química, Facultad de Química, Universidad de Chile, La Palmeras 3425, Nuñoa, Casilla 653, Santiago de Chile (Chile); O' Dwyer, C. [Applied Nanoscience Group, Department of Chemistry, University College Cork, Cork (Ireland); Micro and Nanoelectronics Centre, Tyndall National Institute, Lee Maltings, Cork (Ireland)

    2013-12-16

    Cyclotriphosphazene is used as a sacrificial solid-state template to synthesize a range of Ag and Pd nanoparticles with diverse geometries by thermal treatment using MLn/N{sub 3}P{sub 3}(O{sub 2}C{sub 12}H{sub 8}){sub 3} mixtures. The Pd and Ag nanoparticles are synthesized by solid-state pyrolysis of AgPPh{sub 3}[CF{sub 3}SO{sub 3}]/N{sub 3}P{sub 3}(O{sub 2}C{sub 12}H{sub 8}){sub 3} and PdCl{sub 2}/N{sub 3}P{sub 3}(O{sub 2}C{sub 12}H{sub 8}){sub 3} mixtures with molar relationships of 1:1, 1:5 and 1:10 respectively, in air and at 800 °C. The morphology of the as-prepared nanoparticles is found to depend on the molar ratio of the precursor mixture, the preparation method and of the nature of the metal. Ag and Pd, microcrystals were thermally grown on Si from the respective 1:1 precursors while that metal foams were grown from 1:5 ratios precursors on SiO{sub 2} wafers. High resolution transmission electron microscopy investigations reveal in most cases small crystals of Pd. HRSTEM measurements indicate that the formation of the Pd and Ag nanoparticles occurs through a phase demixing and dewetting mechanism. This approach has potential to be a useful and facile method to prepare metallic nanoparticles without requiring solutions or surfactants for application in electronic, catalytic and sensor materials and devices. - Highlights: • Pyrolysis MLn/N{sub 3}P{sub 3}(O{sub 2}C{sub 12}H{sub 8}){sub 3} mixtures under air, give Pd and Ag nanoparticles. • AgPPh{sub 3}[CF{sub 3}SO{sub 3}] and PdCl{sub 2} in molar ratios 1:1 and 1:5 were used. • Metal foams were obtained from 1:5 ratios when deposited on SiO{sub 2.} • Using crucible supporting in 1:1 metal/trimer <2 nm Pd nanoparticles were obtained. • The probable mechanism involves a dewetting, nucleation and ripening crystallization.

  13. Growth Dynamics of Celosia cristata Grown in Cocopeat, Burnt Rice Hull and Kenaf Core Fiber Mixtures

    Directory of Open Access Journals (Sweden)

    Yahya Awang

    2010-01-01

    Full Text Available Problem statement: Understanding the growth dynamics of short-lived plant could be critical as it would complete its life cycle in a short time period. It does not normally has much time to adjust to hostile environmental condition. This study provides a detail account on growth dynamics of Celosia cristata grown in five growing media for the production of high quality flowers. Approach: Celosia cristata plants were grown on five growing media (v/v: 100% Cocopeat (CP; 70% CP: 30% Burnt Rice Hull (BRH; 70% CP: 30% perlite; 70% CP: 30% Kenaf Core Fiber (KCF and 40% CP: 60% KCF. To explore the dynamics of plant growth and development, data on plant height and canopy diameter were regressed against Days After Transplanting (DAT by using the equation y = A/(1+be-cx while its derivative [dy/dx = (Abce-cx/(1+be-cx2] was used to estimate the growth rate of the parameter. The variation in leaf number, flower length and flower diameter were modeled using an exponential function of y = Aebx and their rate of change was derived using dx/dy = Abebx. Results: The growth rates of plant height, canopy diameter and leaf number of plants grown in media containing 100% CP, 70% CP: 30% BRH, 70% CP: 30% perlite, 70% CP: 30% KCF were higher than those grown on media containing 40% CP: 60% KCF. The growth rates of stem and canopy of the plants grown in the later media tended to be higher at the end of the growth cycle. This, however would not be sufficient to compensate their early losses, since the rate of growth in leaf number did not increase concurrently. Negative effects of media containing KCF were also detected in flower size. Conclusion: Overall results showed that CP is an excellent growing media for the production of Celosia cristata. Replacing 30% of CP with BRH, perlite and KCF did not affect the growth and flowering of the plants.

  14. A generalized longitudinal mixture IRT model for measuring differential growth in learning environments.

    Science.gov (United States)

    Kadengye, Damazo T; Ceulemans, Eva; Van den Noortgate, Wim

    2014-09-01

    This article describes a generalized longitudinal mixture item response theory (IRT) model that allows for detecting latent group differences in item response data obtained from electronic learning (e-learning) environments or other learning environments that result in large numbers of items. The described model can be viewed as a combination of a longitudinal Rasch model, a mixture Rasch model, and a random-item IRT model, and it includes some features of the explanatory IRT modeling framework. The model assumes the possible presence of latent classes in item response patterns, due to initial person-level differences before learning takes place, to latent class-specific learning trajectories, or to a combination of both. Moreover, it allows for differential item functioning over the classes. A Bayesian model estimation procedure is described, and the results of a simulation study are presented that indicate that the parameters are recovered well, particularly for conditions with large item sample sizes. The model is also illustrated with an empirical sample data set from a Web-based e-learning environment.

  15. Phase transitions and hygroscopic growth of aerosol particles containing humic acid and mixtures of humic acid and ammonium sulphate

    Directory of Open Access Journals (Sweden)

    C. L. Badger

    2006-01-01

    Full Text Available The phase transitions and hygroscopic growth of two humic acid aerosols (Aldrich sodium salt and Leonardite Standard (IHSS and their mixtures with ammonium sulphate have been investigated using a combination of two techniques, Fourier transform infra-red (FTIR spectroscopy and tandem differential mobility analysis (TDMA. A growth factor of 1.16 at 85% relative humidity (RH was found for the Aldrich humic acid which can be regarded as an upper limit for growth factors of humic-like substances (HULIS found in atmospheric aerosol and is significantly smaller than that of typical atmospheric inorganics. We find that the humic acid aerosols exhibit water uptake over all relative humidities with no apparent phase changes, suggesting that these aerosols readily form supersaturated droplets. In the mixed particles, the humic acid component decreases the deliquescence relative humidity (DRH and increases the efflorescence relative humidity (ERH of the ammonium sulphate component, and there is some degree of water uptake prior to ammonium sulphate deliquescence. In addition, at low RH, the FTIR spectra show that the ammonium is present in a different chemical environment in the mixed aerosols than in crystalline ammonium sulphate, perhaps existing as a complex with the humic materials. The growth factors of the mixed aerosols are intermediate between those of the single-component aerosols and can be predicted assuming that the inorganic and organic fractions take up water independently.

  16. Two-dimensional electrophoresis analysis of protein production during growth of Pseudomonas putida F1 on toluene, phenol, and their mixture.

    Science.gov (United States)

    Reardon, Kenneth F; Kim, Kee-Hong

    2002-07-01

    The protein profiles of Pseudomonas putida F1 during growth on toluene, phenol, and their mixture were examined by two-dimensional polyacrylamide gel electrophoresis. Although this bacterium uses the same catabolic pathway for both substrates, P. putida F1 produced specific sets of proteins in response to toluene and phenol as single or mixed substrates. Proteins associated with growth on these substrates could be classified into three categories: ten Group T proteins were associated with the degradation of toluene, seventeen Group P proteins were associated with the degradation of phenol, and one Group M protein was observed to be associated only with toluene-phenol mixture degradation. During growth on the mixture, the protein profile of the cells shifted from Group T proteins to Group P proteins. This correlated well with the substrate consumption pattern, in which toluene was consumed first and growth on phenol did not begin until the medium was nearly depleted of toluene. Individual Group T and Group P protein intracellular concentrations had different transients as the cells grew on the mixture; seven protein levels increased, four decreased, and sixteen reached a maximum and then declined. The Group M protein reached a concentration maximum near the time when growth on phenol began. Variations in the maintenance of these proteins were also noted. These results demonstrate that cells growing on a mixture of substrates undergo significant physiological changes. Further investigation of these changes is expected to shed light on the unusual biodegradation kinetics previously observed with this mixed-substrate system.

  17. Grazing and nitrogen on the growth of roots in the mixture of oat and ryegrass

    Directory of Open Access Journals (Sweden)

    Hugo von Linsingen Piazzetta

    2014-09-01

    Full Text Available This study evaluated the effect of grazing and its absence, and the nitrogen on the morphology of roots of black oat (Avena strigosa Schreb. mixed with Italian ryegrass (Lolium multiflorum Lam.. The experimental design was a randomized block design in split-split, the main portion was study the effects of grazing and its absence, in the subplots the nitrogen doses of 75 and 150 kg ha-1 and in the sub-subplots were at sampling period. There was used the cylinder method to collect the root, being measured the length, surface area, mean diameter and volume by image analysis system Win / MacRizho (4.1c. Determined the dry mass of roots and shoot, and estimated the density of the root tissue and shoot:root ratio. From these results we determined the rate of root growth relative (RGR, relative root expansion rate (RRER and rate of accumulation of dry matter daily (RADM. In the first period, was higher RGR, RRER, the second period there was a reduction of the same, probably due to the period of drought and plant senescence. There was also reduced due to grazing RADM. With grazing, the length, surface area, mean diameter and root volume were higher, indicating that there was greater root growth of plants grazed compared to ungrazed. The systems studied had no effect on the dry weight of roots. There were found greater specific mass and shot:root ratio in the system without grazing. There was no significant difference between the nitrogen studied. At mixed of black oat and ryegrass, the grazing and nitrogen dose until 150 kg ha-1 little affect root growth. The nitrogen dose changed a little the growth rates and expansion of the roots. On the other hand, the grazing favored the length, area, volume and root diameter.

  18. Study of various NH4+/NO3- mixtures for enhancing growth of potatoes

    Science.gov (United States)

    Cao, W.; Tibbitts, T. W.

    1993-01-01

    Two experiments were conducted to determine the effects of various NH4(+)-N/NO3(-)-N percentages on growth and mineral concentrations in potato (Solanum tuberosum L.) plants using a non-recirculating nutrient film system in a controlled environment. The first experiment included six NH4(+)-N/NO3(-)-N percentages at 0/100, 20/80, 40/60, 60/40, 80/20, and 100/0 with the same total N concentration of 4 mM. The second experiment included six NH4(+)-N/NO3(-)-N percentages at 0/100, 4/96, 8/92, 12/88, 16/84, and 20/80 again with the same total N of 4 mM. In each experiment, plants were harvested 35 days after transplanting when tubers had been initiated and started to enlarge. Dry weights of shoots, tubers, and whole plant at the harvest were increased significantly with all mixed nitrogen treatments as compared with single NH4+ or NO3- form. The enhanced growth with mixed nitrogen was greatest at 8% to 20% NH4(+)-N. Also, the concentrations and accumulation of total N in the shoots and roots were greater with mixed nitrogen than with separate NH4+ or NO3- nutrition. With NH4+ present in the solutions, the concentrations of P and Cl in the shoots were increased compared to NO3- alone, whereas the tissue concentrations of Ca and Mg were decreased. It was concluded that nitrogen fertilization provided with combined NH4+ and NO3- forms, even at small proportions of NH4+, can enhance nitrogen uptake and productivity in potato plants.

  19. Effect of Sugar Cane Extract, Commercial Probiotic and their Mixture on Growth Performance and Intestinal Histology in Broiler Chickens

    Directory of Open Access Journals (Sweden)

    Oraya Khambualai

    2010-01-01

    Full Text Available Problem statement: As the intestinal function is intimately affected by fed diets, many kinds of natural substances and probiotics have been supplemented to broilers to raise poultry productivity due to activating intestinal function. Besides, the intestinal histology is clearly altered by intestinal functions. The aim of this study was to investigate whether Sugar Cane Extract (SCE and commercial probiotic (SPB, either alone or in combination, could improve growth performance and how intestinal histological alterations would be observed in these birds. Approach: A total of 64, 7-d-old male broiler chicks were randomly assigned to 4 treatment groups, consisting of 4 replicates of 4 birds each. Commercial mash starter and finisher diets were supplemented with 0.05% SCE, 0.4% SPB, or a mixture of 0.05% SCE and 0.4% SPB (SCE + SPB. Results: Body weight gain was better in all the experimental groups than the control. The greatest improvement was observed in the SCE + SPB group. Most values of villus height, villus area, cell area and cell mitosis in all intestinal segments were higher (pConclusion: The present results of enhanced light microscopic parameters and protuberant epithelial cells in SCE and SPB groups suggest that the intestinal villi and epithelial cells might be hypertrophied by SCE and SPB. The fact that a synergistic effect was observed with regard to growth performance and intestinal histology in the SCE + SPB group suggests that SCE is a good supplement to probiotics.

  20. Biosorption and growth inhibition of wetland plants in water contaminated with a mixture of arsenic and heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Park, Soyoung [Department of Ocean Engineering, Pukyong National University, Busan (Korea, Republic of); Kang, Daeseok; Kim, Youngyun; Lee, Suk Mo; Chung, Yonghyun; Sung, Kijune [Department of Ecological Engineering, Pukyong National University, Busan (Korea, Republic of)

    2011-02-15

    The potential of wetland plants as an onsite biosorbent and a biomonitor for combined pollution of arsenic and four heavy metals from non-point sources was investigated in this study. Ceratophyllum demersum, Hydrilla verticillata, Hydrocharis dubia, and Salvinia natans were exposed to a water containing mixture of As, Cr, Cu, Pb, and Zn. Growth inhibition and biosorption potential of the wetland plants in artificially contaminated conditions were studied. These contaminants significantly reduced the growth of the plants. The tested wetland plants accumulated appreciable amounts of the contaminants in the following order: Pb>Cr>Cu>Zn>As. H. verticillata showed distinct visual change and a high biosorption factor (BSF) rank for As and heavy metals among the plants used in the study. As an unspecific collector of contaminants, it might be useful as a biomonitor and biosorbent in the As and heavy metal-contaminated aquatic system. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. The impact of total and partial inclusion or exclusion of active and inactive time invariant covariates in growth mixture models.

    Science.gov (United States)

    Diallo, Thierno M O; Morin, Alexandre J S; Lu, HuiZhong

    2017-03-01

    This article evaluates the impact of partial or total covariate inclusion or exclusion on the class enumeration performance of growth mixture models (GMMs). Study 1 examines the effect of including an inactive covariate when the population model is specified without covariates. Study 2 examines the case in which the population model is specified with 2 covariates influencing only the class membership. Study 3 examines a population model including 2 covariates influencing the class membership and the growth factors. In all studies, we contrast the accuracy of various indicators to correctly identify the number of latent classes as a function of different design conditions (sample size, mixing ratio, invariance or noninvariance of the variance-covariance matrix, class separation, and correlations between the covariates in Studies 2 and 3) and covariate specification (exclusion, partial or total inclusion as influencing class membership, partial or total inclusion as influencing class membership, and the growth factors in a class-invariant or class-varying manner). The accuracy of the indicators shows important variation across studies, indicators, design conditions, and specification of the covariates effects. However, the results suggest that the GMM class enumeration process should be conducted without covariates, and should rely mostly on the Bayesian information criterion (BIC) and consistent Akaike information criterion (CAIC) as the most reliable indicators under conditions of high class separation (as indicated by higher entropy), versus the sample size adjusted BIC or CAIC (SBIC, SCAIC) and bootstrapped likelihood ratio test (BLRT) under conditions of low class separation (indicated by lower entropy). (PsycINFO Database Record

  2. Effect of BMP-2 and BMP-7 homodimers and a mixture of BMP-2/BMP-7 homodimers on osteoblast adhesion and growth following culture on a collagen scaffold

    Energy Technology Data Exchange (ETDEWEB)

    Laflamme, Claude; Rouabhia, Mahmoud [Groupe de recherche en ecologie buccale, Faculte de medecine dentaire, Universite Laval, Quebec City, Quebec G1K 7P4 (Canada)], E-mail: Mahmoud.rouabhia@fmd.ulaval.ca

    2008-03-01

    In the present study, we studied the involvement of BMP-2 and BMP-7 as homodimers and as a mixture of homodimers in bone regeneration using an engineered bone model. The engineered bone model consisted of a collagen scaffold populated with osteoblasts that acted as a carrier for the BMPs. BMP-2, BMP-7 and a mixture of BMP-2/BMP-7 were used at final concentrations of 10 and 100 ng ml{sup -1}. Osteoblasts seeded onto a collagen scaffold were cultured for 24 h before being stimulated with the BMPs. Four days later, osteoblast adhesion to and growth on the scaffold were assessed. Osteocalcin, IL-6, metalloproteinase (MMP-2 and MMP-9) and protease inhibitor (TIMP-1 and TIMP-2) mRNA and protein levels were measured. Our results showed that the BMP-2, BMP-7 and a mixture of BMP-2/BMP-7 all promoted osteoblast growth on the collagen scaffold, with the mixture of BMP-2/BMP-7 enhancing the most growth. BMP-2 and the mixture of BMP-2/BMP-7 enhanced osteocalcin (an osteoblast differentiation marker) mRNA expression and protein secretion, likely via the IL-6 pathway given that IL-6 secretion was upregulated by BMP-7 and a mixture of BMP-2/BMP-7. BMPs promote extracellular matrix production by inhibiting MMP-2 mRNA and increasing TIMP-1 and TIMP-2 mRNA expressions and protein secretions. BMP-2, BMP-7 and the mixture of BMP-2/BMP-7 could promote bone regeneration via different mechanisms involving IL-6 and MMP inhibitors.

  3. Toxicity of cadmium, anthracene, and their mixture to Desmodesmus subspicatus estimated by algal growth-inhibition ISO standard test.

    Science.gov (United States)

    Baścik-Remisiewicz, Agnieszka; Aksmann, Anna; Żak, Adam; Kowalska, Maja; Tukaj, Zbigniew

    2011-05-01

    Cells of Desmodesmus subspicatus 86.81 were used to examine the toxicity of cadmium chloride (CdCl(2)) and anthracene (ANT) applied individually and in combination. The experiments were performed according to standardized ISO (International Organization for Standardization) 8692 protocol (2004). Parameters measured were the number of cells and chlorophyll a fluorescence parameters. E(r)C(10) and E(r)C(50) values (growth rate [r] inhibition by 10% and 50%, respectively) for single toxicants were determined separately. The effect of mixtures of the substances (Cd + ANT) at concentrations corresponding to E(r)C(10) (E(r)C(10) + E(r)C(10)) and E(r)C(50) (E(r)C(50) + E(r)C(50)) values was characterized. The toxicity of individual chemicals after a 72-h exposure was as follows: ANT (E(r)C(10) = 0.06; E(r)C(50) = 0.26 mg l(-1)) and CdCl(2) (E(r)C(10) = 0.12; E(r)C(50) = 0.30 mg l(-1)). The combination Cd + ANT decreased the population growth rate more strongly than the substances applied individually. Cadmium at a concentration corresponding to E(r)C(10) slightly influenced the parameters of chlorophyll a fluorescence as measured by the OJIP test (O, J, I, and P are the different steps of fluorescence induction curve), whereas the influence of ANT was not statistically significant. In Cd + ANT-treated samples, the photosynthetic "vitality" (PI), the maximum quantum yield of primary photochemistry (φ(Po)), and the fraction of active PS II reaction centre (RC) decreased, but the values of ABS/RC, TR(0)/RC, and DI(0)/RC increased. The type of interaction between Cd and ANT depended on the concentration of chemicals used. When the substances were applied at concentrations of E(r)C(10), synergistic effects were observed, whereas the mixture of chemicals used at an E(r)C(50) concentration showed an antagonistic interaction.

  4. Effect of supplementation of prebiotic mannan-oligosaccharides and probiotic mixture on growth performance of broilers subjected to chronic heat stress

    Science.gov (United States)

    The present study was aimed at elucidating the effects of supplementing mannan-oligosaccharides (MOS) and probiotic mixture (PM) on growth performance, intestinal histology, and corticosterone concentrations in broilers kept under chronic heat stress (HS). Four hundred and fifty day-old chicks were...

  5. Pyrosequencing investigation into the influence of Cu2+, Zn2+, Fe2+ and I− mixtures on fungal diversity and toxigenic fungal growth in a fermented liquid feed

    Directory of Open Access Journals (Sweden)

    Yuyong He

    2016-03-01

    Full Text Available A L9(34 orthogonal experiment was conducted to evaluate the influence of 9 mixtures which consisted of Cu2+, Zn2+, Fe2+ and I− ions at different ion concentrations on fungal diversity and toxigenic fungal growth in a Bacillus subtilis-fermented liquid feed (FLF using pyrosequencing. The maximal Chao estimator and Shannon index were achieved in the FLF with a mixture of Cu2+ (200 mg/kg, Zn2+ (160 mg/kg, Fe2+ (150 mg/kg and I− (2.4 mg/kg. The minimal relative abundance of Aspergillus was achieved when a mixture of Cu2+ (200 mg/kg, Zn2+, Fe2+ and I− was added to the FLF. Compared with Zn2+, Fe2+ and I−, Cu2+ was the most important ion in inhibiting Aspergillus growth. Adding Zn2+ (160 mg/kg, Cu2+, Fe2+ and I− to the FLF minimized the relative abundance of Fusarium. It was Zn2+ instead of Cu2+ played a critical role in suppressing the growth of Fusarium. The proper use of the mixture of Cu2+, Zn2+, Fe2+ and I− in FLF contributes to inhibit the growth of mycotoxin-producing fungi during storage. The new findings of this study help farmers properly use the mixture of Cu2+, Zn2+, Fe2+ and I− to inhibit the growth of mycotoxin-producing fungi in the production of high quality FLF and alleviate mycotoxins damages to animals and humans.

  6. Quantitative analysis of liver GST-P foci promoted by a chemical mixture of hexachlorobenzene and PCB 126: implication of size-dependent cellular growth kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yasong [Colorado State University, Quantitative and Computational Toxicology Group, Department of Environmental and Radiological Health Sciences, Fort Collins, CO (United States); Translational Pharmacology Group, PDM, Pfizer Inc, Groton, CT (United States); Lohitnavy, Manupat; Lohitnavy, Ornrat; Eickman, Elizabeth; Gerjevic, Lisa; Yang, Raymond S.H. [Colorado State University, Quantitative and Computational Toxicology Group, Department of Environmental and Radiological Health Sciences, Fort Collins, CO (United States); Reddy, Micaela [DMPK Group, Preclinical Sciences, Roche Palo Alto LLC, CA (United States); Ashley, Amanda [Colorado State University, Department of Cell and Molecular Biology, Fort Collins, CO (United States); Xu, Yihua [University of Wisconsin, McArdle Laboratory for Cancer Research, Madison, WI (United States); Conolly, Rory B. [USEPA, National Center for Computational Toxicology, Research Triangle Park, NC (United States)

    2008-02-15

    The objectives of this study were twofold: (1) evaluating the carcinogenic potential of the mixture of two persistent environmental pollutants, hexachlorobenzene (HCB) and 3,3',4,4',5-pentachlorobiphenyl (PCB 126), in an initiation-promotion bioassay involving the development of {pi} glutathione S-transferase (GST-P) liver foci, and (2) analyzing the GST-P foci data using a biologically-based computer model (i.e., clonal growth model) with an emphasis on the effect of focal size on the growth kinetics of initiated cells. The 8-week bioassay involved a series of treatments of initiator, two-thirds partial hepatectomy, and daily oral gavage of the mixture of two doses in male F344 rats. The mixture treatment significantly increased liver GST-P foci development, indicating carcinogenic potential of this mixture. Our clonal growth model was developed to simulate the appearance and development of initiated GST-P cells in the liver over time. In the model, the initiated cells were partitioned into two subpopulations with the same division rate but different death rates. Each subpopulation was further categorized into single cells, mini- (2-11 cells), medium- (12-399 cells), and large-foci (>399 cells) with different growth kinetics. Our modeling suggested that the growth of GST-P foci is size-dependent; in general, the larger the foci, the higher the rate constants of division and death. In addition, the modeling implied that the two doses promoted foci development in different manners even though the experimental foci data appeared to be similar between the two doses. This study further illustrated how clonal growth modeling may facilitate our understanding in chemical carcinogenic process. (orig.)

  7. Identifying Latent Trajectories of Personality Disorder Symptom Change: Growth Mixture Modeling in the Longitudinal Study of Personality Disorders

    Science.gov (United States)

    Hallquist, Michael N.; Lenzenweger, Mark F.

    2013-01-01

    Although previous reports have documented mean-level declines in personality disorder (PD) symptoms over time, little is known about whether personality pathology sometimes emerges among nonsymptomatic adults, or whether rates of change differ qualitatively among symptomatic persons. Our study sought to characterize heterogeneity in the longitudinal course of PD symptoms with the goal of testing for and describing latent trajectories. Participants were 250 young adults selected into two groups using a PD screening measure: those who met diagnostic criteria for a DSM-III-R PD (PPD, n = 129), and those with few PD symptoms (NoPD, n = 121). PD symptoms were assessed three times over a four-year study using semistructured interviews. Total PD symptom counts and symptoms of each DSM-III-R PD were analyzed using growth mixture modeling. In the NoPD group, latent trajectories were characterized by stable, minor symptoms; the rapid or gradual remission of subclinical symptoms; or the emergence of symptoms of Avoidant, Obsessive-Compulsive, or Paranoid PD. In the PPD group, three latent trajectories were evident: rapid symptom remission, slow symptom decline, or a relative absence of symptoms. Rapid remission of PD symptoms was associated with fewer comorbid disorders, lower negative emotionality, and greater positive emotionality and constraint, whereas emergent personality dysfunction was associated with comorbid PD symptoms and lower positive emotionality. In most cases, symptom change for one PD was associated with concomitant changes in other PDs, depressive symptoms, and anxiety. These results indicate that the longitudinal course of PD symptoms is heterogeneous, with distinct trajectories evident for both symptomatic and nonsymptomatic individuals. The prognosis of PD symptoms may be informed by an assessment of personality and comorbid psychopathology. PMID:23231459

  8. Trajectory Pathways for Depressive Symptoms and Their Associated Factors in a Chinese Primary Care Cohort by Growth Mixture Modelling.

    Directory of Open Access Journals (Sweden)

    Weng Yee Chin

    Full Text Available The naturalistic course for patients suffering from depressive disorders can be quite varied. Whilst some remit with little or no intervention, others may suffer a more prolonged course of symptoms. The aim of this study was to identify trajectory patterns for depressive symptoms in a Chinese primary care cohort and their associated factors.A 12-month cohort study was conducted. Patients recruited from 59 primary care clinics across Hong Kong were screened for depressive symptoms using the Centre for Epidemiologic Studies Depression Scale (CES-D and monitored over 12 months using the Patient Health Questionnaire-9 items (PHQ-9 administered at 12, 26 and 52 weeks. 721 subjects were included for growth mixture modelling analysis. Using Akaike Information Criterion, Bayesian Information Criterion, Entropy and Lo-Mendell-Rubin adjusted likelihood ratio test, a seven-class trajectory path model was identified. Over 12 months, three trajectory groups showed improvement in depressive symptoms, three remained static, whilst one deteriorated. A mild severity of depressive symptoms with gradual improvement was the most prevalent trajectory identified. Multivariate, multinomial regression analysis was used to identify factors associated with each trajectory. Risk factors associated with chronicity included: female gender; not married; not in active employment; presence of multiple chronic disease co-morbidities; poor self-rated general health; and infrequent health service use.Whilst many primary care patients may initially present with a similar severity of depressive symptoms, their course over 12 months can be quite heterogeneous. Although most primary care patients improve naturalistically over 12 months, many do not remit and it is important for doctors to be able to identify those who are at risk of chronicity. Regular follow-up and greater treatment attention is recommended for patients at risk of chronicity.

  9. Identifying latent trajectories of personality disorder symptom change: growth mixture modeling in the longitudinal study of personality disorders.

    Science.gov (United States)

    Hallquist, Michael N; Lenzenweger, Mark F

    2013-02-01

    Although previous reports have documented mean-level declines in personality disorder (PD) symptoms over time, little is known about whether personality pathology sometimes emerges among nonsymptomatic adults, or whether rates of change differ qualitatively among symptomatic persons. Our study sought to characterize heterogeneity in the longitudinal course of PD symptoms with the goal of testing for and describing latent trajectories. Participants were 250 young adults selected into two groups using a PD screening measure: those who met diagnostic criteria for a DSM-III-R PD (PPD, n = 129), and those with few PD symptoms (NoPD, n = 121). PD symptoms were assessed three times over a 4-year study using semistructured interviews. Total PD symptom counts and symptoms of each DSM-III-R PD were analyzed using growth mixture modeling. In the NoPD group, latent trajectories were characterized by stable, minor symptoms; the rapid or gradual remission of subclinical symptoms; or the emergence of symptoms of avoidant, obsessive-compulsive, or paranoid PD. In the PPD group, three latent trajectories were evident: rapid symptom remission, slow symptom decline, or a relative absence of symptoms. Rapid remission of PD symptoms was associated with fewer comorbid disorders, lower Negative Emotionality, and greater Positive Emotionality and Constraint, whereas emergent personality dysfunction was associated with comorbid PD symptoms and lower Positive Emotionality. In most cases, symptom change for one PD was associated with concomitant changes in other PDs, depressive symptoms, and anxiety. These results indicate that the longitudinal course of PD symptoms is heterogeneous, with distinct trajectories evident for both symptomatic and nonsymptomatic individuals. The prognosis of PD symptoms may be informed by an assessment of personality and comorbid psychopathology.

  10. Effect of Antioxidant Mixtures on Growth and Ochratoxin A Production of Aspergillus Section Nigri Species under Different Water Activity Conditions on Peanut Meal Extract Agar

    Directory of Open Access Journals (Sweden)

    Carla Barberis

    2010-06-01

    Full Text Available The effect of mixtures of antioxidants butylated hydroxyanisol (BHA and propyl paraben (PP on lag phase, growth rate and ochratoxin A (OTA production by four Aspergillus section Nigri strains was evaluated on peanut meal extract agar (PMEA under different water activities (aw. The antioxidant mixtures used were: BHA + PP (mM, M1 (0.5 + 0.5, M2 (1.0 + 0.5, M3 (2.5 + 0.5, M4 (0.5 + 1.0, M5 (1.0 + 1.0, M6 (2.5 + 1.0, M7 (5.0 + 2.5 and M8 (10 + 2.5. The mixture M8 completely suppressed mycelial growth for all strains. A significant stimulation in OTA production was observed with mixtures M1 to M5 mainly at the highest aw; whereas M6, M7 and M8 completely inhibited OTA production in all strains assayed; except M6 in A. carbonarius strain (RCP G. These results could enable a future intervention strategy to minimize OTA contamination.

  11. Daphnia growth on microcystin-producing and microcystin-free Microcystis aeruginosa in different mixtures with the green alga Scenedesmus obliquus

    OpenAIRE

    Lürling, M.F.L.L.W.

    2003-01-01

    The hypothesis that negative effects of Microcystis on Daphnia growth and reproduction can be explained from the presence of microcystin in the Microcystis cells was tested by comparing the effects on Daphnia life history characteristics of a microcystin-free mutant strain and microcystin-containing strain of the cyanobacterium Microcystis aeruginosa PCC7806. To avoid nutritional deficiency, Microcystis was offered to Daphnia alone and in various mixtures with the high-quality green alga Scen...

  12. Effect of long-term feeding with a plant protein mixture based diet on growth and body/fillet quality traits of large rainbow trout (Oncorhynchus mykiss)

    OpenAIRE

    De Francesco, Matilde; Parisi, Giuliana; Medale, Francoise; Lupi, Paola; Kaushik, Sadasivam; Poli, Bianca

    2004-01-01

    Two diets based oil fish meal (FM) or oil a mixture of plant protein sources supplemented with free amino acids (PP) were fed to rainbow trout having a mean initial body weight of 162.5 g reared at 17 +/- 1 degreesC for 24 weeks to evaluate the effect of plant protein sources oil fish growth, morphological and body quality traits. At the end of the growth study, samples were withdrawn for chemical analyses as well as measurements of different parameters of quality. Compared to the FM gro...

  13. A Specific Mixture of Nutrients Suppresses Ovarian Cancer A-2780 Tumor Incidence, Growth, and Metastasis to Lungs

    Directory of Open Access Journals (Sweden)

    Mohd Waheed Roomi

    2017-03-01

    Full Text Available Ovarian cancer is the deadliest gynecological malignancy in women, and fifth leading cause of death. Despite advances made in chemotherapy and surgery, the average time of clinical remission is approximately 2 years and the 5-year survival rate is 45%. Thus, there is an urgent need for the development of a novel therapeutic approach to ovarian cancer treatment. We investigated the effect of a specific nutrient mixture (EPQ containing ascorbic acid, lysine, proline, green tea extract, and quercetin on human ovarian cancer cell A-2780 in vivo and in vitro. Athymic female nude mice (n = 12 were all inoculated intraperitoneally (IP with 2 × 106 cells in 0.1 mL of phosphate buffered saline (PBS and randomly divided into two groups. Upon injection, the Control group (n = 6 was fed a regular diet and the EPQ group (n = 6 a regular diet supplemented with 0.5% EPQ. Four weeks later, the mice were sacrificed and tumors that developed in the ovary were excised, weighed, and processed for histology. Lungs were inspected for metastasis. In vitro, A-2780 cells were cultured in Dulbecco modified Eagle medium supplemented with 10% FBS and antibiotics. At near confluence, cells were treated with EPQ in triplicate at concentrations between 0 and 1000 μg/mL. Cell proliferation was measured via MTT assay, MMP-9 secretion via gelatinase zymography, invasion through Matrigel and morphology via hematoxylin and eosin (H & E staining. All Control mice developed large ovarian tumors, whereas 5 out of 6 mice in the EPQ group developed no tumors, and one, a small tumor. Control mice also showed lung metastasis in 6 out of 6 mice, while no lung metastasis was evident in EPQ mice. Zymography demonstrated only MMP-9 expression, which EPQ inhibited in a dose-dependent fashion, with virtual total block at 250 μg/mL concentration. EPQ significantly inhibited invasion through Matrigel with total block at 250 μg/mL concentration. MTT showed dose-dependent inhibition of cell

  14. Growth of n-type ZnO thin films by using mixture gas of hydrogen and argon

    Institute of Scientific and Technical Information of China (English)

    Zhou Xin; Wang Shi-Qi; Lian Gui-Jun; Xiong Guang-Cheng

    2006-01-01

    High-quality oxide semiconductor ZnO thin films were prepared on single-crystal sapphire and LaAlO3 substrates by pulsed laser deposition (PLD) in the mixture gas of hydrogen and argon. Low resistivity n-type ZnO thin films with smoother surface were achieved by deposition at 600℃ in 1Pa of the mixture gas. In addition, ferromagnetism was observed in Co-doped ZnO thin films and rectification Ⅰ-Ⅴ curves were found in p-GaN/n-ZnO and p-CdTe/n-ZnO heterostructure junctions. The results indicated that using mixture gas of hydrogen and argon in PLD technique was a flexible method for depositing high-quality n-type oxide semiconductor films, especially for the multilayer thin film devices.

  15. Growth and wood properties of Sitka spruce (Picea sitchensis (Bong.) Carr.) in nursing mixtures established on nitrogen-deficient mineral soils

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, A.D.; Watson, B.A. [Aberdeen Univ. (United Kingdom). Dept. of Forestry

    2000-07-01

    Rate of growth and wood properties of Sitka spruce (Picea sitchensis (Bong.) Carr.) were investigated in triplet mixtures with lodgepole pine (Pinus contorta Loud.) (Alaskan provenance) and Japanese larch (Larix kaempferi (Lamb.) Carr.), established on nitrogen-deficient, iron pan soils. These 'nursing' mixtures were compared with pure stands of Sitka spruce that had been either regularly or periodically fertilized with nitrogen. Japanese larch promoted a growth rate in Sitka spruce greater than that achieved in the lodgepole pine-nursed spruce and equivalent to the two pure spruce treatments over the duration of the experiment (current age 28 yrs). Growth of regularly fertilized pure Sitka spruce was not significantly greater than that of periodically fertilized pure spruce. Alaskan lodgepole pine controlled branch size on the lower part of the spruce stems more effectively than the other treatments, although this may have been a function of tree size. Branch characteristics of Japanese larch-nursed spruce, however, were similar to those of the pure spruce treatments. Japanese larch caused an imbalance in crown development in the spruce, although it is unclear from the present study whether this will have an influence on stem and wood quality by the end of the rotation. Overall, the evidence from this study suggests that Japanese larch is an effective nurse of Sitka spruce on nitrogen-deficient iron pans, maintaining a rate of growth similar to that of pure Sitka spruce periodically fertilized with nitrogen and higher than that observed in spruce nursed by Alaskan lodgepole pine.

  16. Nucleation, growth and habit modification of n-alkanes and homologous mixtures in the absence and presence of flow improving additives

    CERN Document Server

    Taggart, A M

    1996-01-01

    A detailed study has been performed on the nucleation, growth and habit modification of n-alkanes and homologous mixtures in the absence and presence of flow improving additives in an attempt to gain a clearer appreciation of the interaction mechanisms behind wax / additive crystallisation. Kinetic and structural assessment of melt phase n-alkanes illustrate the different crystallographic forms present within the homologous series. Studies demonstrate the alternating behaviour of the even and odd numbered homologues which converges as a function of increasing molecular weight. Greater crystal lattice stabilities were found for those n-alkanes which have an even carbon number and which crystallise into the triclinic crystal structure. Solid state phase behaviour of the n-alkanes was found to vary depending on the number and parity of n. Nucleation kinetic studies of n-alkanes and homologous mixtures from model diesel fuel solvents (dodecane, m-xylene, decalin, pristane and a dewaxed fuel) are assessed using tu...

  17. Effects of microcystin-LR, cylindrospermopsin and a microcystin-LR/cylindrospermopsin mixture on growth, oxidative stress and mineral content in lettuce plants (Lactuca sativa L.).

    Science.gov (United States)

    Freitas, Marisa; Azevedo, Joana; Pinto, Edgar; Neves, Joana; Campos, Alexandre; Vasconcelos, Vitor

    2015-06-01

    Toxic cyanobacterial blooms are documented worldwide as an emerging environmental concern. Recent studies support the hypothesis that microcystin-LR (MC-LR) and cylindrospermopsin (CYN) produce toxic effects in crop plants. Lettuce (Lactuca sativa L.) is an important commercial leafy vegetable that supplies essential elements for human nutrition; thus, the study of its sensitivity to MC-LR, CYN and a MC-LR/CYN mixture is of major relevance. This study aimed to assess the effects of environmentally relevant concentrations (1, 10 and 100 µg/L) of MC-LR, CYN and a MC-LR/CYN mixture on growth, antioxidant defense system and mineral content in lettuce plants. In almost all treatments, an increase in root fresh weight was obtained; however, the fresh weight of leaves was significantly decreased in plants exposed to 100 µg/L concentrations of each toxin and the toxin mixture. Overall, GST activity was significantly increased in roots, contrary to GPx activity, which decreased in roots and leaves. The mineral content in lettuce leaves changed due to its exposure to cyanotoxins; in general, the mineral content decreased with MC-LR and increased with CYN, and apparently these effects are time and concentration-dependent. The effects of the MC-LR/CYN mixture were almost always similar to the single cyanotoxins, although MC-LR seems to be more toxic than CYN. Our results suggest that lettuce plants in non-early stages of development are able to cope with lower concentrations of MC-LR, CYN and the MC-LR/CYN mixture; however, higher concentrations (100 µg/L) can affect both lettuce yield and nutritional quality.

  18. Discarded oranges and brewer's spent grains as promoting ingredients for microbial growth by submerged and solid state fermentation of agro-industrial waste mixtures.

    Science.gov (United States)

    Aggelopoulos, Theodoros; Bekatorou, Argyro; Pandey, Ashok; Kanellaki, Maria; Koutinas, Athanasios A

    2013-08-01

    The exploitation of various agro-industrial wastes for microbial cell mass production of Kluyveromyces marxianus, kefir, and Saccharomyces cerevisiae is reported in the present investigation. Specifically, the promotional effect of whole orange pulp on cell growth in mixtures consisting of cheese whey, molasses, and potato pulp in submerged fermentation processes was examined. A 2- to 3-fold increase of cell mass was observed in the presence of orange pulp. Likewise, the promotional effect of brewer's spent grains on cell growth in solid state fermentation of mixtures of whey, molasses, potato pulp, malt spent rootlets, and orange pulp was examined. The cell mass was increased by 3-fold for K. marxianus and 2-fold for S. cerevisiae in the presence of these substrates, proving their suitability for single-cell protein production without the need for extra nutrients. Cell growth kinetics were also studied by measurements of cell counts at various time intervals at different concentrations of added orange pulp. The protein content of the fermented substrates was increased substantially, indicating potential use of mixed agro-industrial wastes of negligible cost, as protein-enriched livestock feed, achieving at the same time creation of added value and waste minimization.

  19. Marijuana Use among Juvenile Arrestees: A Two-Part Growth Model Analysis

    Science.gov (United States)

    Dembo, Richard; Wareham, Jennifer; Greenbaum, Paul E.; Childs, Kristina; Schmeidler, James

    2009-01-01

    This article examines the impact of sociodemographic characteristics and psychosocial factors on the probability and frequency of marijuana use and, for youths initiating use, on their frequency of use over four time points. The sample consists of 278 justice-involved youths completing at least one of three follow-up interviews as part of a…

  20. Marijuana Use among Juvenile Arrestees: A Two-Part Growth Model Analysis

    Science.gov (United States)

    Dembo, Richard; Wareham, Jennifer; Greenbaum, Paul E.; Childs, Kristina; Schmeidler, James

    2009-01-01

    This article examines the impact of sociodemographic characteristics and psychosocial factors on the probability and frequency of marijuana use and, for youths initiating use, on their frequency of use over four time points. The sample consists of 278 justice-involved youths completing at least one of three follow-up interviews as part of a…

  1. Growth characteristic, guest distribution, guest ordering and the stability of urea inclusion compounds with 1-decene, n-decane and mixture of 1-decene and n-decane

    Science.gov (United States)

    Wang, Yan; Ge, Xihui; Zhang, Minqing; Zhu, Huaigong; Zhang, Zijian; Wang, Ming

    2014-01-01

    Growth characteristics of urea inclusion compounds with 1-decene, n-decane and mixture of 1-decene and n-decane (relative mass ratio = 1:1) were studied by CCD high-speed Camera. The present studies show that the speed of UICs growth in tunnel direction is faster than in vertical direction and the length of UICs with 1-decene is shorter than UICs with n-decane, and the length of UICs with mixture is between them due to the influence of the vinyl in 1-decene. The value of R = I(CH2)/I(CH3) and M = I(CHCH2)/I(CH3) in FTIR spectrum of UICs increasing with growth time demonstrates that urea prefers to include n-decane than 1-decene. 13C CP/MAS NMR studies of UICs indicate that the arrangement of 1-decene in UICs is CH3⋯CH3 and CHCH2⋯CH2CH. The arrangement of 1-decene in UICs leads to short chain of UICs with 1-decene in tunnel direction. The 13C CP/MAS NMR spectra of UICs with MIX reveal that there are three different types of arrangement: CH3⋯CH3, CHCH2⋯CH3 and CHCH2⋯CH2CH. The methods of FTIR and DSC were used to test the stability of UICs with different guests. The result shows that UICs with n-decane are stable than UICs with 1-decene. And the stability of UICs with mixture is in the middle.

  2. Screening probiotic candidates for a mixture of probiotics to enhance the growth performance, immunity, and disease resistance of Asian seabass, Lates calcarifer (Bloch), against Aeromonas hydrophila.

    Science.gov (United States)

    Lin, Hsueh-Li; Shiu, Ya-Li; Chiu, Chiu-Shia; Huang, Shih-Ling; Liu, Chun-Hung

    2017-01-01

    Six bacteria, including, Lactobacillus casei M15, Lac. plantarum D8, Lac. pentosus BD6, Lac. fermentum LW2, Enterococcus faecium 10-10, and Bacillus subtilis E20, and one yeast, Saccharomyces cerevisiae P13 were selected as probiotics for Asian seabass, Lates calcarifer, by tracking the growth performance and disease resistance of fish against Aeromonas hydrophila in the first trial. The probiotic efficiency screening results showed that B. subtilis E20 and Lac. pentosus BD6, and S. cerevisiae P13 and Lac. fermentum LW2 respectively improved either the growth performance or disease resistance. Therefore, these four probiotics were then selected to prepare a probiotics mixture, and this was incorporated in equal proportions into diets for Asian seabass at levels of 0 (control), and 10(6) (MD6), 10(7) (MD7), 10(8) (MD8), and 10(9) (MD9) colony-forming units (cfu) (kg diet)(-1). A synergistic effect of the combined probiotics was investigated in this study, and the probiotics mixture was able to improve both the growth performance and health status of fish. After 56 days of feeding, fish fed the MD9 diet had a higher final weight and percentage of weight gain. In addition, protein contents in the dorsal muscle of fish fed the MD8 and MD9 diets were significantly higher compared to the control. For the pathogen challenge test, fish fed the MD7, MD8, and MD9 diets had significantly lower cumulative mortalities after A. hydrophila infection compared to those of fish fed the control and MD6 diets, which might have been due to increased respiratory bursts, decreased superoxide dismutase activity in leucocytes, and increased phagocytic activity. Therefore, we considered that the probiotics mixture could adequately provide probiotic efficiency for Asian seabass, and the diet containing 10(9) cfu (kg diet)(-1) probiotic mixture is recommended to improve the growth and health status of Asian seabass. Copyright © 2016. Published by Elsevier Ltd.

  3. Mixture Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Piepel, Gregory F.

    2007-12-01

    A mixture experiment involves combining two or more components in various proportions or amounts and then measuring one or more responses for the resulting end products. Other factors that affect the response(s), such as process variables and/or the total amount of the mixture, may also be studied in the experiment. A mixture experiment design specifies the combinations of mixture components and other experimental factors (if any) to be studied and the response variable(s) to be measured. Mixture experiment data analyses are then used to achieve the desired goals, which may include (i) understanding the effects of components and other factors on the response(s), (ii) identifying components and other factors with significant and nonsignificant effects on the response(s), (iii) developing models for predicting the response(s) as functions of the mixture components and any other factors, and (iv) developing end-products with desired values and uncertainties of the response(s). Given a mixture experiment problem, a practitioner must consider the possible approaches for designing the experiment and analyzing the data, and then select the approach best suited to the problem. Eight possible approaches include 1) component proportions, 2) mathematically independent variables, 3) slack variable, 4) mixture amount, 5) component amounts, 6) mixture process variable, 7) mixture of mixtures, and 8) multi-factor mixture. The article provides an overview of the mixture experiment designs, models, and data analyses for these approaches.

  4. Clustering asian and north african countries according to trend of colon and rectum cancer mortality rates: an application of growth mixture models.

    Science.gov (United States)

    Zayeri, Farid; Sheidaei, Ali; Mansouri, Anita

    2015-01-01

    Colorectal cancer is the second most common cause of cancer death with half a million deaths per year. Incidence and mortality rates have demonstrated notable changes in Asian and African countries during the last few decades. In this study, we first aimed to determine the trend of colorectal cancer mortality rate in each Institute for Health Metrics and Evaluation (IHME) region, and then re-classify them to find more homogenous classes. Our study population consisted of 52 countries of Asia and North Africa in six IHME pre-defined regions for both genders and age-standardized groups from 1990 to 2010.We first applied simple growth models for pre-defined IHME regions to estimate the intercepts and slopes of mortality rate trends. Then, we clustered the 52 described countries using the latent growth mixture modeling approach for classifying them based on their colorectal mortality rates over time. Statistical analysis revealed that males and people in high income Asia pacific and East Asia countries were at greater risk of death from colon and rectum cancer. In addition, South Asia region had the lowest rates of mortality due to this cancer. Simple growth modeling showed that majority of IHME regions had decreasing trend in mortality rate of colorectal cancer. However, re-classification these countries based on their mortality trend using the latent growth mixture model resulted in more homogeneous classes according to colorectal mortality trend. In general, our statistical analyses showed that most Asian and North African countries had upward trend in their colorectal cancer mortality. We therefore urge the health policy makers in these countries to evaluate the causes of growing mortality and study the interventional programs of successful countries in managing the consequences of this cancer.

  5. Effects of crude oil and oil/dispersant mixture on growth and expression of vitellogenin and heat shock protein 90 in blue crab, Callinectes sapidus, juveniles.

    Science.gov (United States)

    Chiasson, Susan C; Taylor, Caz M

    2017-06-30

    The 2010 Deepwater Horizon (DWH) oil spill in the northern Gulf of Mexico (NGOM) resulted in over 780million liters of crude oil spilling into Gulf waters. In an effort to disperse the oil, nearly 7.6million liters of dispersant was applied. Many commercially and recreationally important species reside in or near the area of the spill. The blue crab, Callinectes sapidus, is common in the NGOM and is both economically and ecologically important in this region. In this study, after exposing juvenile blue crabs to oil or a mixture of oil and dispersant we tested for relative expression of heat shock protein 90 (hsp90) and vitellogenin (vtg) by measuring their corresponding mRNA expression. We also monitored crabs over two molts to test for effects on growth. Expression of hsp90 was significantly downregulated, and we did not detect any effects of exposure to oil or oil/dispersant mixture on growth or vtg expression. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Inhibitory Effect of a γ-Tocopherol-Rich Mixture of Tocopherols on the Formation and Growth of LNCaP Prostate Tumors in Immunodeficient Mice

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Xi, E-mail: xizheng@rci.rutgers.edu [Susan Lehman Cullman Laboratory for Cancer Research, Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, 164 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Cancer Institute of New Jersey, New Brunswick, NJ 08903 (United States); Cui, Xiao-Xing [Susan Lehman Cullman Laboratory for Cancer Research, Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, 164 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Khor, Tin Oo; Huang, Ying [Department of Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (United States); DiPaola, Robert S; Goodin, Susan [Cancer Institute of New Jersey, New Brunswick, NJ 08903 (United States); Lee, Mao-Jung [Susan Lehman Cullman Laboratory for Cancer Research, Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, 164 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Yang, Chung S [Susan Lehman Cullman Laboratory for Cancer Research, Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, 164 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Cancer Institute of New Jersey, New Brunswick, NJ 08903 (United States); Kong, Ah-Ng [Cancer Institute of New Jersey, New Brunswick, NJ 08903 (United States); Department of Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (United States); Allan H, Conney [Susan Lehman Cullman Laboratory for Cancer Research, Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, 164 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Cancer Institute of New Jersey, New Brunswick, NJ 08903 (United States)

    2011-09-28

    In the present study, we determined the effects of a γ-tocopherol-rich mixture of tocopherols (γ-TmT) on the growth and apoptosis of cultured human prostate cancer LNCaP cells. We also determined the effects of dietary γ-TmT on the formation and growth of LNCaP tumors in immunodeficient mice. In the in vitro study, we found that the activity of γ-TmT was stronger than α-tocopherol for inhibiting the growth and stimulating apoptosis in LNCaP cells. In the animal study, treatment of severe combined immunodeficient (SCID) mice with dietary γ-TmT inhibited the formation and growth of LNCaP xenograft tumors in a dose-dependent manner. Mechanistic studies showed that γ-TmT administration inhibited proliferation as reflected by decreased mitosis and stimulated apoptosis as reflected by increased caspase-3 (active form) expression in LNCaP tumors. In addition, dietary administration of γ-TmT increased the levels of α-, γ- and δ- tocopherol in plasma, and increased levels of γ- and δ- tocopherol were also observed in the prostate and in tumors. The present study demonstrated that γ-TmT had strong anticancer activity both in vitro and in vivo. Additional studies are needed to determine the potential preventive effect of γ-TmT for prostate cancer in humans.

  7. A Functional Tricarboxylic Acid Cycle Operates during Growth of Bordetella pertussis on Amino Acid Mixtures as Sole Carbon Substrates.

    Science.gov (United States)

    Izac, Marie; Garnier, Dominique; Speck, Denis; Lindley, Nic D

    2015-01-01

    It has been claimed that citrate synthase, aconitase and isocitrate dehydrogenase activities are non-functional in Bordetella pertussis and that this might explain why this bacterium's growth is sometimes associated with accumulation of polyhydroxybutyrate (PHB) and/or free fatty acids. However, the sequenced genome includes the entire citric acid pathway genes. Furthermore, these genes were expressed and the corresponding enzyme activities detected at high levels for the pathway when grown on a defined medium imitating the amino acid content of complex media often used for growth of this pathogenic microorganism. In addition, no significant PHB or fatty acids could be detected. Analysis of the carbon balance and stoichiometric flux analysis based on specific rates of amino acid consumption, and estimated biomass requirements coherent with the observed growth rate, clearly indicate that a fully functional tricarboxylic acid cycle operates in contrast to previous reports.

  8. A Functional Tricarboxylic Acid Cycle Operates during Growth of Bordetella pertussis on Amino Acid Mixtures as Sole Carbon Substrates.

    Directory of Open Access Journals (Sweden)

    Marie Izac

    Full Text Available It has been claimed that citrate synthase, aconitase and isocitrate dehydrogenase activities are non-functional in Bordetella pertussis and that this might explain why this bacterium's growth is sometimes associated with accumulation of polyhydroxybutyrate (PHB and/or free fatty acids. However, the sequenced genome includes the entire citric acid pathway genes. Furthermore, these genes were expressed and the corresponding enzyme activities detected at high levels for the pathway when grown on a defined medium imitating the amino acid content of complex media often used for growth of this pathogenic microorganism. In addition, no significant PHB or fatty acids could be detected. Analysis of the carbon balance and stoichiometric flux analysis based on specific rates of amino acid consumption, and estimated biomass requirements coherent with the observed growth rate, clearly indicate that a fully functional tricarboxylic acid cycle operates in contrast to previous reports.

  9. Growth of the calcium carbonate polymorph vaterite in mixtures of water and ethylene glycol at conditions of gas processing

    Science.gov (United States)

    Flaten, Ellen Marie; Seiersten, Marion; Andreassen, Jens-Petter

    2010-03-01

    Long subsea tie-ins for transportation of moist gas and condensate require corrosion and hydrate control. The combination of alkalinity for corrosion mitigation and monoethylene glycol (MEG) for hydrate inhibition strongly affects the tolerance for produced formation water. The elevated alkalinity downstream of the injection point increases the risk of carbonate formation. Calcium carbonate is the most common precipitate at such conditions. Our previous findings (Flaten et al., 2009) [1] show that MEG governs calcium carbonate precipitation and promotes formation of the metastable polymorph vaterite. This paper describes crystal growth of vaterite in mixed MEG water solvent with 0-70 wt% MEG at temperatures of 40 and 70 °C in solutions with high calcium to carbonate ratios representative of the production conditions. Results of some experiments in solutions with stoichiometric amounts of the reactants are included for comparison. The growth rate of vaterite can be described by second-order kinetics in most of the investigated supersaturation range. The growth order is lower at high MEG contents and high calcium concentrations when the carbonate activity is reduced in order to maintain comparable supersaturation values. It is then probable that the low carbonate activity makes the reaction diffusion limited. MEG reduces the growth rate constant of vaterite when the reaction is second order. Increasing the MEG concentration from 0 to 50 wt%, decreases the growth rate constant kr from 1.9 to 0.7 nm/s at 40 °C and from 2.6 to 1.2 nm/s at 70 °C. The growth reduction can be explained by a change of either de-hydration or diffusion rate along the surface when the ions are incorporated into the crystal lattice. Further investigations into which of the two mechanisms that is rate determining is outside the scope of this work.

  10. Influence of dietary prebiotic mixture (α-mune on growth performance, haematology and innate immunity of Beluga sturgeon (Huso huso juvenile

    Directory of Open Access Journals (Sweden)

    Ahmad Gharaei

    2016-09-01

    Full Text Available The present study investigated the effects of prebiotic (α-mune, a mixture of mannan oligosaccharide, β-1,3 and β-1,6 glucan, on the growth performance, haematology and innate immunity of beluga sturgeon (Huso huso juvenile. Fish (46±3 g were allocated into 12 tanks (15 fish per tank and triplicate groups were fed a control diet or diets containing 1.5, 3.0 and 4.5 g kg-1 prebiotic for 46 days. Fish fed 1.5 g kg-1 prebiotic displayed significantly higher final weight, specific growth rate and feed conversion ratio. WBC, RBC, MCV, MCH, haemoglobin, haematocrit and lymphocyte levels were also significantly higher in the fish fed 1.5 g kg-1 prebiotic. Furthermore, the highest haematocrit content and lymphocyte level were found in the fish fed a diet containing 1.5 g kg-1 prebiotic. Alternative complement activity (ACH50, lysozyme activity and Ig concentration were significantly higher in the fed 1.5 g kg-1 prebiotic. These results indicate that α-mune can be considered as a beneficial dietary supplement for improving the growth performance, haematological and immunological parameters of beluga sturgeon juvenile.

  11. The developmental impact of two first grade preventive interventions on aggressive/disruptive behavior in childhood and adolescence: an application of latent transition growth mixture modeling.

    Science.gov (United States)

    Petras, Hanno; Masyn, Katherine; Ialongo, Nick

    2011-09-01

    We examine the impact of two universal preventive interventions in first grade on the growth of aggressive/disruptive behavior in grades 1-3 and 6-12 through the application of a latent transition growth mixture model (LT-GMM). Both the classroom-centered and family-centered interventions were designed to reduce the risk for later conduct problems by enhancing the child behavior management practices of teachers and parents, respectively. We first modeled growth trajectories in each of the two time periods with separate GMMs. We then associated latent trajectory classes of aggressive/disruptive behavior across the two time periods using a transition model for the corresponding latent class variables. Subsequently, we tested whether the interventions had direct effects on trajectory class membership in grades 1-3 and 6-12. For males, both the classroom-centered and family-centered interventions had significant direct effects on trajectory class membership in grades 6-12, whereas only the classroom-centered intervention had a significant effect on class membership in grades 1-3. Significant direct effects for females were confined to grades 1-3 for the classroom-centered intervention. Further analyses revealed that both the classroom-centered and family-centered intervention males were significantly more likely than control males to transition from the high trajectory class in grades 1-3 to a low class in grades 6-12. Effects for females in classroom-centered interventions went in the hypothesized direction but did not reach significance. © Society for Prevention Research 2011

  12. Sample selection versus two-part models revisited: the case of female smoking and drinking.

    Science.gov (United States)

    Madden, David

    2008-03-01

    There is a well-established debate between Heckman sample selection and two-part models in health econometrics, particularly when no obvious exclusion restrictions are available. Most of this debate has focussed on the application of these models to health care expenditure. This paper revisits the debate in the context of female smoking and drinking, and evaluates the two approaches on three grounds: theoretical, practical and statistical. The two-part model is generally favoured but it is stressed that this comparison should be carried out on a case-by-case basis.

  13. A Study on Digital Analysis of Bach’s “Two-Part Inventions”

    Directory of Open Access Journals (Sweden)

    Xiao-Yi Song

    2015-01-01

    Full Text Available In the field of music composition, creating polyphony is relatively one of the most difficult parts. Among them, the basis of multivoice polyphonic composition is two-part counterpoint. The main purpose of this paper is, through the computer technology, conducting a series of studies on “Two-Part Inventions” of Bach, a Baroque polyphony master. Based on digitalization, visualization and mathematical methods, data mining algorithm has been applied to identify bipartite characteristics and rules of counterpoint polyphony. We hope that the conclusions drawn from the article could be applied to the digital creation of polyphony.

  14. Determination of water absorption and water holding capacities of different soil mixtures with MINIDRAIN system to enhance the plant growth

    Science.gov (United States)

    Sudan Acharya, Madhu; Rauchecker, Markus; Wu, Wei

    2014-05-01

    Soil water holding capacity is the amount of water that a given soil can hold against the force of gravity. Soil texture and organic matter are the key components that determine soil water holding capacity. Soils with smaller particle sizes, such as silt and clay have larger surface area can hold more water compared to sand which has large particle sizes which results in smaller surface area. A study report showed that 1% increase in soil humus will result in a 4% increase in stored soil water (Morris, 2004) and 1 part humus holds 4 parts of water (Wheeler and Ward, 1998). Therefore, the more humus that can be added to the soil, the greater the water holding capacity of the soil. As the level of organic matter increases in a soil, the water holding capacity also increases due to the affinity of organic matter for water. The water holding capacity of the soil is determined by the amount of water held in the soil sample vs. the dry weight of the sample. MINIDRAIN is a patented system made of geo-fabric (fleece) or combination of geosynthetics and humus. MINIDRAIN and vegetation nets developed by the company ÖKO-TEX (Linz, Austria) will improve the distribution of water and air in the soils, increase the growth of vegetation and reduce the soil erosion. Depending on the physical configuration, there are four different combinations of MINIDRAIN systems developed by ÖKO-TEX. a) Geotextile (fleece) strips of different sizes (e.g. 5x10x250 mm) b) Net formed strips (drainage nets) of different sizes c) Multilayer geotextile mats with humus, seeds or compost of different sizes (e.g. 10x30x200 mm) d) Multilayer geotextile net formed mats with humus, seeds or compost This paper describes the experimental results of the water absorption and water holding capacity of different forms of MINIDRAIN under different soil mixes. In this experiment, potting soil, coarse sand and LECA (Light weight clay aggregates) balls are mixed with different proportion of MINIDRAIN systems and

  15. Changes in nutritive value and herbage yield during extended growth intervals in grass-legume mixtures: effects of species, maturity at harvest, and relationships between productivity and components of feed quality

    DEFF Research Database (Denmark)

    Elgersma, Anjo; Søegaard, Karen

    2017-01-01

    There is a lack of information on the effects of companion species in grass–legume mixtures on herbage yield and quality changes during prolonged growth. Such information is relevant for harvest planning and estimation of consequences for feeding value of conserved feed when harvesting is delayed...

  16. A Cost-Effective Two-Part Experiment for Teaching Introductory Organic Chemistry Techniques

    Science.gov (United States)

    Sadek, Christopher M.; Brown, Brenna A.; Wan, Hayley

    2011-01-01

    This two-part laboratory experiment is designed to be a cost-effective method for teaching basic organic laboratory techniques (recrystallization, thin-layer chromatography, column chromatography, vacuum filtration, and melting point determination) to large classes of introductory organic chemistry students. Students are exposed to different…

  17. Long-term effects of dietary supplementation with an essential oil mixture on the growth and laying performance of two layer strains

    Directory of Open Access Journals (Sweden)

    Abdullah U. Çatli

    2012-01-01

    Full Text Available One thousand two hundred 1-day-old Lohmann LSL white and Lohmann Brown layer chickens were fed diets supplemented with either an antibiotic growth promoter (AGP or an herbal essential oil mixture (EOM till 58 wk of age to reveal the long-term effects of those additives on growth, performance and wholesome egg quality parameters. The study was arranged in a 2x3 factorial design with two layer strains and three feed additive regimens. Thus, the layer birds of both strains were randomly assigned to the three dietary treatments, i.e., standard basal diet (control, control with AGP (specifically, avilamycin, 10 mg/kg diet and control with EOM (24 mg/kg diet. The data regarding egg production were recorded between 22 to 58 weeks of age. Neither the dietary treatments nor the bird strain influenced the body weight and mortality of the birds in both the growing and laying period. AGP or EOM supplementation to the laying hen diet significantly increased the egg production rate and egg weight as compared to the control  diet alone, but egg mass output, feed consumption, and feed conversion ratio were not effected  by the dietary treatments. Neither dietary treatment created any statistically significantly differences in egg quality parameters with the exception of Haugh unit. The research findings have confirmed the beneficial effects of supplementation with feed-grade EOM on the laying rate and egg weight of both white and brown layers. Indeed, EOM, being a novel feed additive natural origin, proved to be as efficacious as AGP in promoting egg yield.

  18. Effect of adding crushed Pimpinella anisum, Nigella sativa seeds and Thymus vulgaris mixture to antibiotics-free rations of vaccinated and non-vaccinated male broilers on growth performance, antibody titer and haematological profile

    Directory of Open Access Journals (Sweden)

    Mamoun Z. Athamneh

    2010-04-01

    Full Text Available This research explores an experimental study conducted to investigate the effect of crushed Pimpinella anisum (PA, Nigella sativa (NS seeds and Thymus vulgaris (TV mixture as a feed additive on growth performance and mortality rate (MR, selected antibodies titer (Ab’s and blood hematological profile of vaccinated and non-vaccinated Lohman male broiler chicks fed free-antibiotics ration. A total of 400 one-day old chicks were distributed into 16 groups (4 treatment x 4 replicates x 25chicks. The experiment lasted from one to 42 days of age. The statistical findings of this experiment prove that the use of medicinal plants mixture improves live body weight, body weight gain, feed conversion ratio and MR of vaccinated male broilers at 21 and 42 days of age. antibodies titer against infectious bronchitis and infectious bursal disease of non-vaccinated and vaccinated male broilers were significantly improved at 21 and 42 days as a result of the addition of medicinal plant mixture to the basal ration. Concerning Newcastle disease, the use of PA, NS and TV mixture did not reflect in any additional improvement of Ab's than vaccines did. The addition of medicinal plants mixture increases WBC's, RBC's, thrombocytes count and Hb concentration of vaccinated and non-vaccinated male broilers at 21 days of age. Meanwhile, heterophils, lymphocytes and monocytes of vaccinated male broilers (VMB were significantly improved by adding medicinal plant mixture to their basal diet. Moreover, at 42 days of age the use of PA, NS seeds and TV mixture indicate significant increase in total WBC’s, lymphocytes and monocytes and monocytes count of VMB and non-vaccinated male broiler (NVMB. No significant differences were noticed in RBC’s and Hct as a result of feeding crushed medicinal plants mixture.

  19. Chemical and Physical Characteristics of Cocopeat-Based Media Mixtures and Their Effects on the Growth and Development of Celosia cristata

    Directory of Open Access Journals (Sweden)

    Yahya Awang

    2009-01-01

    Full Text Available Problem statement: Cocopeat is considered as a good growing media component with acceptable pH, electrical conductivity and other chemical attributes but it has been recognized to have high water holding capacity which causes poor air-water relationship, leading to low aeration within the medium, thus affecting the oxygen diffusion to the roots. Incorporation of coarser materials into cocopeat could improve the aeration status of the media. Approach: Selected chemical and physical characteristics of five types of growing media comprising of (v/v 100% cocopeat, 70% cocopeat: 30% burnt rice hull, 70% cocopeat: 30% perlite, 70% cocopeat: 30% kenaf core fiber and 40% cocopeat: 60% kenaf core fiber were determined and their suitability as growing media was tested using Celosia cristata. Data on pH, Electrical Conductivity (EC and various aspects of air-water relationships of the media, as well on growth and flowering of test plant and leaf nutrient contents were collected. Results: Initial pH for 100% cocopeat and 70% cocopeat: 30% kenaf core fiber was higher than the other media but the values were eventually similar by the end of the study. The bulk density and EC of media containing burnt rice hull was markedly higher than the other media (0.12 g cm3 and 0.48 mS cm-1, respectively. Media comprising of 70% cocopeat: 30% burnt rice hull and 70% cocopeat: 30% perlite contained higher air content. The former held the highest volume of available water. Incorporation of burnt rice hull and perlite into cocopeat increased water absorption ability of the media which reached saturation earlier than the other media. Addition of burnt rice hull (30%, perlite (30% and kenaf core fiber (30% to cocopeat elevated the Air-Filled Porosity (AFP of the media. The growth and flowering of Celosia cristata were the greatest when grown in a mixture of 70% cocopeat: 30% burnt rice hull and perhaps linked with a good balance

  20. Development of the two-part pattern during regeneration of the head in hydra

    DEFF Research Database (Denmark)

    Bode, Matthias; Awad, T A; Koizumi, O;

    1988-01-01

    The head of a hydra is composed of two parts, a domed hypostome with a mouth at the top and a ring of tentacles below. When animals are decapitated a new head regenerates. During the process of regeneration the apical tip passes through a transient stage in which it exhibits tentacle...... began evaginating in a ring, both the TS-19 antigen and RLI+ ganglion cells gradually disappeared from the presumptive hypostome area and RLI+ sensory cells appeared at the apex. By tracking tissue movements during morphogenesis it became clear that the apical cap, in which these changes took place, did...... not undergo tissue turnover. The implications of this tentacle-like stage for patterning the two-part head are discussed....

  1. Much ado about two: reconsidering retransformation and the two-part model in health econometrics.

    Science.gov (United States)

    Mullahy, J

    1998-06-01

    In health economics applications involving outcomes (y) and covariates (x), it is often the case that the central inferential problems of interest involve E[y/x] and its associated partial effects or elasticities. Many such outcomes have two fundamental statistical properties: y > or = 0; and the outcome y = 0 is observed with sufficient frequency that the zeros cannot be ignored econometrically. This paper (1) describes circumstances where the standard two-part model with homoskedastic retransformation will fail to provide consistent inferences about important policy parameters; and (2) demonstrates some alternative approaches that are likely to prove helpful in applications.

  2. Physical activity versus cardiorespiratory fitness: two (partly) distinct components of cardiovascular health?

    Science.gov (United States)

    DeFina, Laura F; Haskell, William L; Willis, Benjamin L; Barlow, Carolyn E; Finley, Carrie E; Levine, Benjamin D; Cooper, Kenneth H

    2015-01-01

    Physical activity (PA) and cardiorespiratory fitness (CRF) both have inverse relationships to cardiovascular (CV) morbidity and mortality. Recent position papers and guidelines have identified the important role of both of these factors in CV health. The benefits of PA and CRF in the prevention of CV disease and risk factors are reviewed. In addition, assessment methodology and utilization in the research and clinical arenas are discussed. Finally, the benefits, methodology, and utilization are compared and contrasted to better understand the two (partly) distinct components and their impact on CV health.

  3. Two-part silicone mold. A new tool for flexible ureteroscopy surgical training

    Directory of Open Access Journals (Sweden)

    Bruno Marroig

    Full Text Available ABSTRACT Introduction and objectives: Flexible ureteroscopy is a common procedure nowadays. Most of the training programs use virtual reality simulators. The aim of this study was to standardize the building of a three-dimensional silicone mold (cavity of the collecting system, on the basis of polyester resin endocasts, which can be used in surgical training programs. Materials and Methods: A yellow polyester resin was injected into the ureter to fill the collecting system of 24 cadaveric fresh human kidneys. After setting off the resin, the kidneys were immersed in hydrochloric acid until total corrosion of the organic matter was achieved and the collecting system endocasts obtained. The endocasts were used to prepare white color two-part silicone molds, which after endocasts withdrawn, enabled a ureteroscope insertion into the collecting system molds (cavities. Also, the minor calices were painted with different colors in order to map the access to the different caliceal groups. The cost of the materials used in the molds is $30.00 and two days are needed to build them. Results: Flexible ureteroscope could be inserted into all molds and the entire collecting system could be examined. Since some anatomical features, as infundular length, acute angle, and perpendicular minor calices may difficult the access to some minor calices, especially in the lower caliceal group, surgical training in models leads to better surgical results. Conclusions: The two-part silicone mold is feasible, cheap and allows its use for flexible ureteroscopy surgical training.

  4. New Classification Methods for Hiding Information into Two Parts: Multimedia Files and Non Multimedia Files

    CERN Document Server

    Alanazi, Hamdan O; Zaidan, B B; Jalab, Hamid A; AL-Ani, Zaidoon Kh

    2010-01-01

    With the rapid development of various multimedia technologies, more and more multimedia data are generated and transmitted in the medical, commercial, and military fields, which may include some sensitive information which should not be accessed by or can only be partially exposed to the general users. Therefore, security and privacy has become an important, Another problem with digital document and video is that undetectable modifications can be made with very simple and widely available equipment, which put the digital material for evidential purposes under question .With the large flood of information and the development of the digital format Information hiding considers one of the techniques which used to protect the important information. The main goals for this paper, provides a general overview of the New Classification Methods for Hiding Information into Two Parts: Multimedia Files and Non Multimedia Files.

  5. Growth of Cymbopogon citratus and Vetiveria zizanioides on Cu mine tailings amended with chicken manure and manure-soil mixtures: a pot scale study.

    Science.gov (United States)

    Das, Manab; Maiti, Subodh Kumar

    2009-01-01

    The Rakha Cu mines are located at East Singhbhum, Jharkhand, India and their activities ceased in 2001. The tailings (residue) were permanently stored in tailings ponds that require vegetation to reduce their impact on the environment. A pot scale study was conducted to evaluate the suitability of Cymbopogon citratus (DC.) Ex Nees and Vetiveria zizanioides (L) Nash for the reclamation of Cu tailings and to evaluate the effects of chicken manure and soil-manure mixtures on the revegetation of such tailings. Application of manure and soil-manure mixtures resulted in significant increase in pH, EC, OC, CEC and nutritional status of Cu tailings. The environmentally available and DTPA extractable Cu and Ni concentration reduced in amended tailings, while Mn and Zn content increased significantly. Plants grown on amended tailings accumulated lesser Cu and Ni but higher Mn and Zn. Plant biomass increased proportionally to manure and soil-manure mixtures application rates. Lemon grass produced more biomass than vetiver grass in either of the amended tailings. From the pot experiment, it can be suggested that application of chicken manure @ 5% (w/w) and in combination with lemon grass, could be a viable option for reclamation (phytostabilization) of toxic tailings.

  6. Mixture Density Mercer Kernels

    Data.gov (United States)

    National Aeronautics and Space Administration — We present a method of generating Mercer Kernels from an ensemble of probabilistic mixture models, where each mixture model is generated from a Bayesian mixture...

  7. Differential effects of Th1, monocyte/macrophage and Th2 cytokine mixtures on early gene expression for glial and neural-related molecules in central nervous system mixed glial cell cultures: neurotrophins, growth factors and structural proteins

    Directory of Open Access Journals (Sweden)

    Nedelkoska Liljana

    2007-12-01

    Full Text Available Abstract Background In multiple sclerosis, inflammatory cells are found in both active and chronic lesions, and it is increasingly clear that cytokines are involved directly and indirectly in both formation and inhibition of lesions. We propose that cytokine mixtures typical of Th1 or Th2 lymphocytes, or monocyte/macrophages each induce unique molecular changes in glial cells. Methods To examine changes in gene expression that might occur in glial cells exposed to the secreted products of immune cells, we have used gene array analysis to assess the early effects of different cytokine mixtures on mixed CNS glia in culture. We compared the effects of cytokines typical of Th1 and Th2 lymphocytes and monocyte/macrophages (M/M on CNS glia after 6 hours of treatment. Results In this paper we focus on changes with potential relevance for neuroprotection and axon/glial interactions. Each mixture of cytokines induced a unique pattern of changes in genes for neurotrophins, growth and maturation factors and related receptors; most notably an alternatively spliced form of trkC was markedly downregulated by Th1 and M/M cytokines, while Th2 cytokines upregulated BDNF. Genes for molecules of potential importance in axon/glial interactions, including cell adhesion molecules, connexins, and some molecules traditionally associated with neurons showed significant changes, while no genes for myelin-associated genes were regulated at this early time point. Unexpectedly, changes occurred in several genes for proteins initially associated with retina, cancer or bone development, and not previously reported in glial cells. Conclusion Each of the three cytokine mixtures induced specific changes in gene expression that could be altered by pharmacologic strategies to promote protection of the central nervous system.

  8. Mixture Modeling: Applications in Educational Psychology

    Science.gov (United States)

    Harring, Jeffrey R.; Hodis, Flaviu A.

    2016-01-01

    Model-based clustering methods, commonly referred to as finite mixture modeling, have been applied to a wide variety of cross-sectional and longitudinal data to account for heterogeneity in population characteristics. In this article, we elucidate 2 such approaches: growth mixture modeling and latent profile analysis. Both techniques are…

  9. Daphnia growth on microcystin-producing and microcystin-free Microcystis aeruginosa in different mixtures with the green alga Scenedesmus obliquues

    NARCIS (Netherlands)

    Lürling, M.

    2003-01-01

    The hypothesis that negative effects of Microcystis on Daphnia growth and reproduction can be explained from the presence of microcystin in the Microcystis cells was tested by comparing the effects on Daphnia life history characteristics of a microcystin-free mutant strain and microcystin-containing

  10. Regulation of Autotrophic and Heterotrophic Metabolism in Pseudomonas oxalaticus OX1. Growth on Fructose and on Mixtures of Fructose and Formate in Batch and Continuous Cultures

    NARCIS (Netherlands)

    Dijkhuizen, L.; Harder, W.

    1984-01-01

    In Pseudomonas oxalaticus the synthesis of enzymes involved in autotrophic CO2 fixation via the Calvin cycle is regulated by repression/derepression. During growth of the organism on fructose alone, the synthesis of ribulosebisphosphate carboxylase (RuBPCase) remained fully repressed, both in batch

  11. Daphnia growth on microcystin-producing and microcystin-free Microcystis aeruginosa in different mixtures with the green alga Scenedesmus obliquues

    NARCIS (Netherlands)

    Lürling, M.

    2003-01-01

    The hypothesis that negative effects of Microcystis on Daphnia growth and reproduction can be explained from the presence of microcystin in the Microcystis cells was tested by comparing the effects on Daphnia life history characteristics of a microcystin-free mutant strain and microcystin-containing

  12. Daphnia growth on microcystin-producing and microcystin-free Microcystis aeruginosa in different mixtures with the green alga Scenedesmus obliquus

    NARCIS (Netherlands)

    Lürling, M.F.L.L.W.

    2003-01-01

    The hypothesis that negative effects of Microcystis on Daphnia growth and reproduction can be explained from the presence of microcystin in the Microcystis cells was tested by comparing the effects on Daphnia life history characteristics of a microcystin-free mutant strain and microcystin-containing

  13. Optimal mixture experiments

    CERN Document Server

    Sinha, B K; Pal, Manisha; Das, P

    2014-01-01

    The book dwells mainly on the optimality aspects of mixture designs. As mixture models are a special case of regression models, a general discussion on regression designs has been presented, which includes topics like continuous designs, de la Garza phenomenon, Loewner order domination, Equivalence theorems for different optimality criteria and standard optimality results for single variable polynomial regression and multivariate linear and quadratic regression models. This is followed by a review of the available literature on estimation of parameters in mixture models. Based on recent research findings, the volume also introduces optimal mixture designs for estimation of optimum mixing proportions in different mixture models, which include Scheffé’s quadratic model, Darroch-Waller model, log- contrast model, mixture-amount models, random coefficient models and multi-response model.  Robust mixture designs and mixture designs in blocks have been also reviewed. Moreover, some applications of mixture desig...

  14. Study of the micellization and micellar growth in pure alkanediyl-alpha-omega-bis(dodecyldimethylammonium) bromide and MEGA10 surfactant solutions and their mixtures. Influence of the spacer on the enthalpy change accompanying sphere-to-rod transitions.

    Science.gov (United States)

    Martín, Victoria Isabel; Rodríguez, Amalia; Graciani, María del Mar; Robina, Inmaculada; Moyá, María Luisa

    2010-06-17

    The micellization and micellar growth in pure aqueous alkanediyl-alpha-omega-bis(dodecyldimethylammonium) bromide, 12-s-12,2Br(-) (with s = 2,5,6,8,10,12), and N-decanoyl-N-methylglucamide MEGA10 solutions and their mixtures are investigated at 303 K. Application of different theoretical approaches to the binary mixtures shows a nonideal behavior. It also shows that the spacer length does not play an important role in the attractive interactions shown by the mixed systems. The sphere-to-rod morphological transition in the pure dimeric micellar solutions is studied at 303 K. From comparison of these results with those at 298 K the key role played by the spacer in the micellar growth is shown. The spacer length controls not only the surfactant concentration at which the morphological transition happens but also the sign of the enthalpy change accompanying the sphere-to-rod equilibrium. Spacers with an even number of methylenes show smaller C* values than those with an odd number of -CH(2)- units. An endothermic enthalpy change is found for even spacers whereas an exothermic enthalpy change is found for odd spacers. To the authors knowledge, this is the first time this experimental trend has been shown. Addition of MEGA10 diminishes the tendency of the aggregates to grow. An increment in the solution mole fraction of MEGA10 makes the formation of elongated micelles difficult. Microviscosity measurements provide additional information about the influence of the MEGA10 content on the sphere-to-rod transition.

  15. 多阶段混合增长模型的影响因素:距离与形态%Factors of Piecewise Growth Mixture Model:Distance and Pattern

    Institute of Scientific and Technical Information of China (English)

    刘源; 骆方; 刘红云

    2014-01-01

    The piecewise growth mixture model (PGMM) has been a very popular analytical approach in recent studies of longitudinal data. PGMM builds on the piecewise growth model (PGM) and the growth mixture model (GMM). It is used to locate the turning point of growth trajectory as well as to identify the latent class of the population. It is particularly useful in detecting the non-continuous growing trend in a heterogeneous population. A simplified version of the model, the latent class growth analysis (LCGA), has also been often used with a restriction on the variance of PGMM. Understandably, factors affecting PGM and GMM will affect the estimates and performance of PGMM. These factors may include the change of the slope, the distance of latent classes, and the sample size. PGMM being developed from the two growth-related models (PGM, GMM) also attempts to analyze the growth pattern in latent growth trajectory as a special and newly emerged issue. Even for models with the same distance, their different slopes can be combined to form different patterns. This issue has not been fully explored in previous literature. Yet in empirical studies, factors such as the distance of the latent classes, the growth pattern, the existing criteria of model fit indices, and the precision of parameter estimates are well worth examining issues. In the present simulation study, a two-class-two-period model was adopted. The three simulation conditions being considered were:the sample size, the distance of latent class, and the pattern of the growth trajectory. The sample size was set to be 100, 200 and 500. The distance of the latent classes was defined as the squared Mahalanobis distance (SMD), with 1.5, 3 and 5 being used to represent the small, medium and large distance of latent classes respectively. Four different types of growth pattern were selected to represent one parallel and three non-parallel patterns. Finally, the LCGA was selected as the reference model to see whether PGMM

  16. Low temperature asphalt mixtures

    OpenAIRE

    Modrijan, Damjan

    2006-01-01

    This thesis presents the problem of manufacturing and building in the asphalt mixtures produced by the classical hot procedure and the possibility of manufacturing low temperature asphalt mixtures.We will see the main advantages of low temperature asphalt mixtures prepared with bitumen with organic addition Sasobit and compare it to the classical asphalt mixtures. The advantages and disadvantages of that are valued in the practical example in the conclusion.

  17. Liquids and liquid mixtures

    CERN Document Server

    Rowlinson, J S; Baldwin, J E; Buckingham, A D; Danishefsky, S

    2013-01-01

    Liquids and Liquid Mixtures, Third Edition explores the equilibrium properties of liquids and liquid mixtures and relates them to the properties of the constituent molecules using the methods of statistical thermodynamics. Topics covered include the critical state, fluid mixtures at high pressures, and the statistical thermodynamics of fluids and mixtures. This book consists of eight chapters and begins with an overview of the liquid state and the thermodynamic properties of liquids and liquid mixtures, including vapor pressure and heat capacities. The discussion then turns to the thermodynami

  18. Effects of heavy metals contained in soil irrigated with a mixture of sewage sludge and effluent for thirty years on soil microbial biomass and plant growth

    Science.gov (United States)

    Katanda, Y.; Mushonga, C.; Banganayi, F.; Nyamangara, J.

    The use of sewage effluent as a source of nutrients and water in peri-urban crop production is widespread in developing countries. A study was conducted in 2005 at Crowborough and Firle farms (near Harare) to assess effect of Cd on microbial biomass and activity, effect of sewage sludge and effluent on soybean (Glycine max L (Merr)) nodulation, and uptake of Zn and Cu by lettuce ( Lactuca sativa L.), mustard rape ( Brassica juncea L.), covo ( Brassica napus) and star grass ( Cynodon nlemfuensis). The soil that was used had been irrigated with sewage sludge and effluent for 30 years. Soil collected from Crowborough farm was enriched with Cd to different concentrations (0.4-5 mg Cd kg -1 soil) using Cd(NO 3) 2 and microbial biomass C and N (chloroform-incubation extraction) and respiration rates (CO 2 evolution) determined. A similar experiment to determine the effect of repeated addition of small amounts of Cd to soil over time on the same parameters was conducted. Three vegetables and star grass were grown in a pot experiment and harvested at six weeks after transplanting for the determination of above ground dry matter yield, and Zn and Cu, uptake. In another pot experiment, two soybean varieties, Magoye and Solitaire, were harvested after eight weeks and nodule number and effectiveness, and above ground dry matter yield were then determined. Cd significantly decreased biomass C (68%) and N (73%). Microbial respiration also significantly decreased. It was concluded that long-term application of sewage sludge and effluent to soil has negative effects on soil micro organisms, including Rhizobia. These micro organisms are essential for N-fixation. The damage to Rhizobia, caused diminished nodulation of soybean. Mustard rape and lettuce can accumulate Zn and Cu beyond toxic limits without apparent reduction in growth thereby posing a serious concern to the food chain. The consumption of mustard rape and lettuce grown on soil amended with sewage sludge and effluent at

  19. Effect of Inoculants Mixture on Nutrient Uptake and Growth in Cucumber (Cucumis sativus L.) Seedlings%混合菌液对黄瓜幼苗营养吸收和生长的影响

    Institute of Scientific and Technical Information of China (English)

    邵双; 郭晓雷

    2010-01-01

    [目的]考查三种促生菌的不同比例混合菌液对黄瓜幼苗生长的影响,以确定最佳混菌配比比例.[方法]菌株为同氮菌沼泽红假单胞菌SH2、解磷菌巨大芽胞杆菌SHⅡ3和解钾菌胶质芽胞杆菌SHI,设置7个浓度配比处理,盆栽黄瓜,以不同比例的混合菌液等量浇灌处理28天.[结果]三种菌液的浓度配比为2∶1∶2的处理对NPK吸收及其在土壤中含量、根茎Fe和Zn含量及株高、茎粗、干重、叶绿素含量有最强提高效果,1∶1∶2和1∶1∶1处理次之,1∶2∶2、2∶2∶1和1∶2∶1效果最差.[结论]2∶1∶2是三种菌液促进黄瓜生长的最佳混合比例.%[Objective] we checked the role of various proportion of three growth promoting bacteria to determine the optimum proportion with greater symbiosis in cucumber seedlings.[Method]Three strains of Rhodopseudomonas palustrisSH2,Bacillus megateriumSHII3,Bacillus mucilaginosusSH1 were applied in this study.Cucumber were cultured in plastic pot,inoculating mixture with seven different proportion for 28 days.tion uptake and growth of cucumber seedlings.

  20. Influences of an essential oil mixture supplementation to corn versus wheat-based practical diets on growth, organ size, intestinal morphology and immune response of male and female broilers

    Directory of Open Access Journals (Sweden)

    Fethiye Coven

    2012-07-01

    Full Text Available The aim of this study was to investigate the effect of diet type, supplementation diet with an essential oil mixture (EOM, and bird gender on the growth performance, carcass yield, internal organ weight, immune response, and small intestine histology of broiler chickens. To do this, a 2x2x2 factorial arrangement was designed. The variables used were: two diet types (based on either wheat or corn, 2 feed additives (with or without EOM, and gender (male or female. EOM supplementation in the diet decreased body weight in corn-fed male birds at Days 21 and 42, but not in those fed the wheat-based diet, signifying a diet x EOM x gender interaction. Cumulative feed intake was not influenced by either the diet type or EOM. The feed conversion ratio was not affected by diet type, whereas EOM improved feed conversion ratio over the 42-day growth period. Feeding birds on wheat decreased the carcass yield while it increased relative small intestine and large intestine weight. Relative weights of liver, bursa fabricius and serum infectious bursal disease (IBD and Newcastle disease (ND titers were not affected by any of the variables studied. EOM supplementation and feeding birds on corn increased jejunal villus height at both 21 and 42 days of age, while bird gender showed no effect. In general, EOM positively influenced body weight gain and efficiency of feed conversion in broiler chickens. Birds receiving the corn-based diet were more efficient in converting feed to body mass as compared to those fed on the wheat-based diet.

  1. Drug price regulation under consumer moral hazard. Two-part tariffs, uniform price or third-degree price discrimination?

    Science.gov (United States)

    Felder, Stefan

    2004-12-01

    Drug price differences across national markets as they exist in the EU are often justified by the concept of Ramsey prices: with fixed costs for R&D, the optimal mark-ups on marginal costs are inversely related to the price elasticity in the individual markets. This well-known result prevails if consumer moral hazard is taken into account. Contrary to the situation without moral hazard, the uniform price does not necessarily dominate discriminatory pricing in welfare terms. The two-part tariff is a better alternative as it allows governments to address moral hazard. A uniform price combined with lump-payments reflecting differences in the willingness to pay and the moral hazard in member states appears to be an attractive option for a common EU drug market.

  2. Perception of trigeminal mixtures.

    Science.gov (United States)

    Filiou, Renée-Pier; Lepore, Franco; Bryant, Bruce; Lundström, Johan N; Frasnelli, Johannes

    2015-01-01

    The trigeminal system is a chemical sense allowing for the perception of chemosensory information in our environment. However, contrary to smell and taste, we lack a thorough understanding of the trigeminal processing of mixtures. We, therefore, investigated trigeminal perception using mixtures of 3 relatively receptor-specific agonists together with one control odor in different proportions to determine basic perceptual dimensions of trigeminal perception. We found that 4 main dimensions were linked to trigeminal perception: sensations of intensity, warmth, coldness, and pain. We subsequently investigated perception of binary mixtures of trigeminal stimuli by means of these 4 perceptual dimensions using different concentrations of a cooling stimulus (eucalyptol) mixed with a stimulus that evokes warmth perception (cinnamaldehyde). To determine if sensory interactions are mainly of central or peripheral origin, we presented stimuli in a physical "mixture" or as a "combination" presented separately to individual nostrils. Results showed that mixtures generally yielded higher ratings than combinations on the trigeminal dimensions "intensity," "warm," and "painful," whereas combinations yielded higher ratings than mixtures on the trigeminal dimension "cold." These results suggest dimension-specific interactions in the perception of trigeminal mixtures, which may be explained by particular interactions that may take place on peripheral or central levels.

  3. A sealing mixture

    Energy Technology Data Exchange (ETDEWEB)

    Khayrullin, S.R.; Firsov, I.A.; Ongoyev, V.M.; Shekhtman, E.N.; Taskarin, B.T.

    1983-01-01

    A plugging mixture is proposed which contains triethanolamine, caustic soda, water and an additive. It is distinguished by the fact that in order to reduce the cost of the mixture while preserving its operational qualities, it additionally contains clay powder and as the additive, ground limestone with the following component ratio in percent by mass: ground limestone, 50 to 60; triethanolamine, 0.1 to 0.15; caustic soda, 2 to 3; clay powder, 8 to 10 and water the remainder. The mixture is distinguished by the fact that the ground limestone has a specific surface of 2,000 to 3,000 square centimeters per gram.

  4. Reverse Revenue Sharing Contract versus Two-Part Tariff Contract under a Closed-Loop Supply Chain System

    Directory of Open Access Journals (Sweden)

    Zunya Shi

    2016-01-01

    Full Text Available The importance of remanufacturing has been recognized in research and practice. The integrated system, combining the forward and reverse activities of supply chains, is called closed-loop supply chain (CLSC system. By coordination in the CLSC system, players will get economic improvement. This paper studies different coordination performances of two types of contracts, two-part tariff (TTC and reverse revenue sharing contract (RRSC, in a closed-loop system. Through mathematical analysis based on Stackelberg Game Theory, we find that it is easy for manufacturer to improve more profits and retailer’s collection effects by adjusting the ratio of transfer collection price through RRSC, and we also give the function to calculate the best ratio of transfer collection price, which may be a valuable reference for the decision maker in practice. Besides, our results also suggest that although the profits of the coordinated CLSC system are always higher than the contradictory scenario, the RRSC is more favorable to the manufacturer than to the retailer, as results show that the manufacturer will share more profits from the system through RRSC. Therefore, RRSC has attracted the manufacturers more to closing the supply chain for economic consideration.

  5. A Bayesian two part model applied to analyze risk factors of adult mortality with application to data from Namibia.

    Directory of Open Access Journals (Sweden)

    Lawrence N Kazembe

    Full Text Available Despite remarkable gains in life expectancy and declining mortality in the 21st century, in many places mostly in developing countries, adult mortality has increased in part due to HIV/AIDS or continued abject poverty levels. Moreover many factors including behavioural, socio-economic and demographic variables work simultaneously to impact on risk of mortality. Understanding risk factors of adult mortality is crucial towards designing appropriate public health interventions. In this paper we proposed a structured additive two-part random effects regression model for adult mortality data. Our proposal assumed two processes: (i whether death occurred in the household (prevalence part, and (ii number of reported deaths, if death did occur (severity part. The proposed model specification therefore consisted of two generalized linear mixed models (GLMM with correlated random effects that permitted structured and unstructured spatial components at regional level. Specifically, the first part assumed a GLMM with a logistic link and the second part explored a count model following either a Poisson or negative binomial distribution. The model was used to analyse adult mortality data of 25,793 individuals from the 2006/2007 Namibian DHS data. Inference is based on the Bayesian framework with appropriate priors discussed.

  6. Multilevel Mixture Kalman Filter

    Directory of Open Access Journals (Sweden)

    Xiaodong Wang

    2004-11-01

    Full Text Available The mixture Kalman filter is a general sequential Monte Carlo technique for conditional linear dynamic systems. It generates samples of some indicator variables recursively based on sequential importance sampling (SIS and integrates out the linear and Gaussian state variables conditioned on these indicators. Due to the marginalization process, the complexity of the mixture Kalman filter is quite high if the dimension of the indicator sampling space is high. In this paper, we address this difficulty by developing a new Monte Carlo sampling scheme, namely, the multilevel mixture Kalman filter. The basic idea is to make use of the multilevel or hierarchical structure of the space from which the indicator variables take values. That is, we draw samples in a multilevel fashion, beginning with sampling from the highest-level sampling space and then draw samples from the associate subspace of the newly drawn samples in a lower-level sampling space, until reaching the desired sampling space. Such a multilevel sampling scheme can be used in conjunction with the delayed estimation method, such as the delayed-sample method, resulting in delayed multilevel mixture Kalman filter. Examples in wireless communication, specifically the coherent and noncoherent 16-QAM over flat-fading channels, are provided to demonstrate the performance of the proposed multilevel mixture Kalman filter.

  7. Uniform designs for mixture-amount experiments and for mixture experiments under order restrictions

    Institute of Scientific and Technical Information of China (English)

    田国梁; 方开泰

    1999-01-01

    With order statistics of the uniform distribution on [0, 1], exponential and beta distributions, a stochastic representation is obtained for the uniform distribution over various domains, where A-type domains are closely associated with reliability growth analysis, order restricted statistical inference and isotonic regression theory, V-type domains are connected with the mixture-amount experiments, and T-type domains are well related to mixture experiments. With these stochastic representations, the corresponding uniform distribution and number-theoretic nets can be generated. This approach seems to be new and is called order statistics method. Some examples on reliability growth analysis and experimental design are presented.

  8. Delirium, sedation and analgesia in the intensive care unit: a multinational, two-part survey among intensivists.

    Directory of Open Access Journals (Sweden)

    Alawi Luetz

    Full Text Available Analgesia, sedation and delirium management are important parts of intensive care treatment as they are relevant for patients' clinical and functional long-term outcome. Previous surveys showed that despite this fact implementation rates are still low. The primary aim of the prospective, observational multicenter study was to investigate the implementation rate of delirium monitoring among intensivists. Secondly, current practice concerning analgesia and sedation monitoring as well as treatment strategies for patients with delirium were assesed. In addition, this study compares perceived and actual practice regarding delirium, sedation and analgesia management. Data were obtained with a two-part, anonymous survey, containing general data from intensive care units in a first part and data referring to individual patients in a second part. Questionnaires from 101 hospitals (part 1 and 868 patients (part 2 were included in data analysis. Fifty-six percent of the intensive care units reported to monitor for delirium in clinical routine. Fourty-four percent reported the use of a validated delirium score. In this respect, the survey suggests an increasing use of delirium assessment tools compared to previous surveys. Nevertheless, part two of the survey revealed that in actual practice 73% of included patients were not monitored with a validated score. Furthermore, we observed a trend towards moderate or deep sedation which is contradicting to guideline-recommendations. Every fifth patient was suffering from pain. The implementation rate of adequate pain-assessment tools for mechanically ventilated and sedated patients was low (30%. In conclusion, further efforts are necessary to implement guideline recommendations into clinical practice. The study was registered (ClinicalTrials.gov identifier: NCT01278524 and approved by the ethical committee.

  9. The U. S. transportation sector in the year 2030: results of a two-part Delphi survey.

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, G.; Stephens, T.S. (Energy Systems); (Univ. of California at Davis); (ES)

    2011-10-11

    A two-part Delphi Survey was given to transportation experts attending the Asilomar Conference on Transportation and Energy in August, 2011. The survey asked respondents about trends in the US transportation sector in 2030. Topics included: alternative vehicles, high speed rail construction, rail freight transportation, average vehicle miles traveled, truck versus passenger car shares, vehicle fuel economy, and biofuels in different modes. The survey consisted of two rounds -- both asked the same set of seven questions. In the first round, respondents were given a short introductory paragraph about the topic and asked to use their own judgment in their responses. In the second round, the respondents were asked the same questions, but were also given results from the first round as guidance. The survey was sponsored by Argonne National Lab (ANL), the National Renewable Energy Lab (NREL), and implemented by University of California at Davis, Institute of Transportation Studies. The survey was part of the larger Transportation Energy Futures (TEF) project run by the Department of Energy, Office of Energy Efficiency and Renewable Energy. Of the 206 invitation letters sent, 94 answered all questions in the first round (105 answered at least one question), and 23 of those answered all questions in the second round. 10 of the 23 second round responses were at a discussion section at Asilomar, while the remaining were online. Means and standard deviations of responses from Round One and Two are given in Table 1 below. One main purpose of Delphi surveys is to reduce the variance in opinions through successive rounds of questioning. As shown in Table 1, the standard deviations of 25 of the 30 individual sub-questions decreased between Round One and Round Two, but the decrease was slight in most cases.

  10. Mixtures Estimation and Applications

    CERN Document Server

    Mengersen, Kerrie; Titterington, Mike

    2011-01-01

    This book uses the EM (expectation maximization) algorithm to simultaneously estimate the missing data and unknown parameter(s) associated with a data set. The parameters describe the component distributions of the mixture; the distributions may be continuous or discrete. The editors provide a complete account of the applications, mathematical structure and statistical analysis of finite mixture distributions along with MCMC computational methods, together with a range of detailed discussions covering the applications of the methods and features chapters from the leading experts on the subject

  11. A new decomposition-based computer-aided molecular/mixture design methodology for the design of optimal solvents and solvent mixtures

    DEFF Research Database (Denmark)

    Karunanithi, A.T.; Achenie, L.E.K.; Gani, Rafiqul

    2005-01-01

    This paper presents a novel computer-aided molecular/mixture design (CAMD) methodology for the design of optimal solvents and solvent mixtures. The molecular/mixture design problem is formulated as a mixed integer nonlinear programming (MINLP) model in which a performance objective...... is to be optimized subject to structural, property, and process constraints. The general molecular/mixture design problem is divided into two parts. For optimal single-compound design, the first part is solved. For mixture design, the single-compound design is first carried out to identify candidates...... the design of an optimal extractant for the separation of acetic acid from water by liquid-liquid extraction. The results suggest that the new extractant would be able to perform better than the extractant being widely used for this separation. The second case study is an industrial problem involving...

  12. Mixtures and interactions

    NARCIS (Netherlands)

    Groten, J.P.

    2000-01-01

    Drinking water can be considered as a complex mixture that consists of tens, hundreds or thousands of chemicals of which the composition is qualitatively and quantitatively not fully known. From a public health point of view it is most relevant to answer the question of whether chemicals in drinking

  13. Pointer Sentinel Mixture Models

    OpenAIRE

    Merity, Stephen; Xiong, Caiming; Bradbury, James; Socher, Richard

    2016-01-01

    Recent neural network sequence models with softmax classifiers have achieved their best language modeling performance only with very large hidden states and large vocabularies. Even then they struggle to predict rare or unseen words even if the context makes the prediction unambiguous. We introduce the pointer sentinel mixture architecture for neural sequence models which has the ability to either reproduce a word from the recent context or produce a word from a standard softmax classifier. O...

  14. Population mixture model for nonlinear telomere dynamics

    Science.gov (United States)

    Itzkovitz, Shalev; Shlush, Liran I.; Gluck, Dan; Skorecki, Karl

    2008-12-01

    Telomeres are DNA repeats protecting chromosomal ends which shorten with each cell division, eventually leading to cessation of cell growth. We present a population mixture model that predicts an exponential decrease in telomere length with time. We analytically solve the dynamics of the telomere length distribution. The model provides an excellent fit to available telomere data and accounts for the previously unexplained observation of telomere elongation following stress and bone marrow transplantation, thereby providing insight into the nature of the telomere clock.

  15. Essays on Finite Mixture Models

    NARCIS (Netherlands)

    A. van Dijk (Bram)

    2009-01-01

    textabstractFinite mixture distributions are a weighted average of a ¯nite number of distributions. The latter are usually called the mixture components. The weights are usually described by a multinomial distribution and are sometimes called mixing proportions. The mixture components may be the

  16. Essays on Finite Mixture Models

    NARCIS (Netherlands)

    A. van Dijk (Bram)

    2009-01-01

    textabstractFinite mixture distributions are a weighted average of a ¯nite number of distributions. The latter are usually called the mixture components. The weights are usually described by a multinomial distribution and are sometimes called mixing proportions. The mixture components may be the sam

  17. Mixtures of truncated basis functions

    DEFF Research Database (Denmark)

    Langseth, Helge; Nielsen, Thomas Dyhre; Rumí, Rafael

    2012-01-01

    In this paper we propose a framework, called mixtures of truncated basis functions (MoTBFs), for representing general hybrid Bayesian networks. The proposed framework generalizes both the mixture of truncated exponentials (MTEs) framework and the mixture of polynomials (MoPs) framework. Similar...

  18. Separating Underdetermined Convolutive Speech Mixtures

    DEFF Research Database (Denmark)

    Pedersen, Michael Syskind; Wang, DeLiang; Larsen, Jan

    2006-01-01

    a method for underdetermined blind source separation of convolutive mixtures. The proposed framework is applicable for separation of instantaneous as well as convolutive speech mixtures. It is possible to iteratively extract each speech signal from the mixture by combining blind source separation...

  19. Toxicological evaluation of chemical mixtures

    NARCIS (Netherlands)

    Feron, V.J.; Groten, J.P.

    2002-01-01

    This paper addresses major developments in the safety evaluation of chemical mixtures during the past 15 years, reviews today's state of the art of mixture toxicology, and discusses challenges ahead. Well-thought-out tailor-made mechanistic and empirical designs for studying the toxicity of mixtures

  20. Mixture Based Outlier Filtration

    Directory of Open Access Journals (Sweden)

    P. Pecherková

    2006-01-01

    Full Text Available Success/failure of adaptive control algorithms – especially those designed using the Linear Quadratic Gaussian criterion – depends on the quality of the process data used for model identification. One of the most harmful types of process data corruptions are outliers, i.e. ‘wrong data’ lying far away from the range of real data. The presence of outliers in the data negatively affects an estimation of the dynamics of the system. This effect is magnified when the outliers are grouped into blocks. In this paper, we propose an algorithm for outlier detection and removal. It is based on modelling the corrupted data by a two-component probabilistic mixture. The first component of the mixture models uncorrupted process data, while the second models outliers. When the outlier component is detected to be active, a prediction from the uncorrupted data component is computed and used as a reconstruction of the observed data. The resulting reconstruction filter is compared to standard methods on simulated and real data. The filter exhibits excellent properties, especially in the case of blocks of outliers. 

  1. Realistic environmental mixtures of micropollutants in surface, drinking, and recycled water: herbicides dominate the mixture toxicity toward algae.

    Science.gov (United States)

    Tang, Janet Y M; Escher, Beate I

    2014-06-01

    Mixture toxicity studies with herbicides have focused on a few priority components that are most likely to cause environmental impacts, and experimental mixtures were often designed as equipotent mixtures; however, real-world mixtures are made up of chemicals with different modes of toxic action at arbitrary concentration ratios. The toxicological significance of environmentally realistic mixtures has only been scarcely studied. Few studies have simultaneously compared the mixture effect of water samples with designed reference mixtures comprised of the ratios of analytically detected concentrations in toxicity tests. In the present study, the authors address the effect of herbicides and other chemicals on inhibition of photosynthesis and algal growth rate. The authors tested water samples including secondary treated wastewater effluent, recycled water, drinking water, and storm water in the combined algae assay. The detected chemicals were mixed in the concentration ratios detected, and the biological effects of the water samples were compared with the designed mixtures of individual detected chemicals to quantify the fraction of effect caused by unknown chemicals. The results showed that herbicides dominated the algal toxicity in these environmentally realistic mixtures, and the contribution by the non-herbicides was negligible. A 2-stage model, which used concentration addition within the groups of herbicides and non-herbicides followed by the model of independent action to predict the mixture effect of the two groups, could predict the experimental mixture toxicity effectively, but the concentration addition model for herbicides was robust and sufficient for complex mixtures. Therefore, the authors used the bioanalytical equivalency concept to derive effect-based trigger values for algal toxicity for monitoring water quality in recycled and surface water. All water samples tested would be compliant with the proposed trigger values associated with the

  2. From binder to mixture: experimental programme on permanent deformation behaviour

    OpenAIRE

    2015-01-01

    Asphalt mixture, the most common road construction material, comprises bitumen, filler, fine and coarse aggregates, and air voids. Traditionally and for simplification, the mixture is treated as a continuous and homogenous material confined in the domain of linear behaviour. The demand for more durable roads, particularly with the progressive growth in traffic volumes and loads, has raised the requirement for improved design methods. Wisely, before the complex adoption of the nonlinear behavi...

  3. Concomitant variables in finite mixture models

    NARCIS (Netherlands)

    Wedel, M

    The standard mixture model, the concomitant variable mixture model, the mixture regression model and the concomitant variable mixture regression model all enable simultaneous identification and description of groups of observations. This study reviews the different ways in which dependencies among

  4. Protein mixtures: interactions and gelation

    OpenAIRE

    Ersch, C.

    2015-01-01

    Gelation is a ubiquitous process in the preparation of foods. As most foods are multi constituent mixtures, understanding gelation in mixtures is an important goal in food science. Here we presented a systematic investigation on the influence of molecular interactions on the gelation in protein mixtures. Gelatin gels with added globular protein and globular protein gels with added gelatin were analyzed for their gel microstructure and rheological properties. Mixed gels with altered microstruc...

  5. Use of two-part regression calibration model to correct for measurement error in episodically consumed foods in a single-replicate study design: EPIC case study.

    Directory of Open Access Journals (Sweden)

    George O Agogo

    Full Text Available In epidemiologic studies, measurement error in dietary variables often attenuates association between dietary intake and disease occurrence. To adjust for the attenuation caused by error in dietary intake, regression calibration is commonly used. To apply regression calibration, unbiased reference measurements are required. Short-term reference measurements for foods that are not consumed daily contain excess zeroes that pose challenges in the calibration model. We adapted two-part regression calibration model, initially developed for multiple replicates of reference measurements per individual to a single-replicate setting. We showed how to handle excess zero reference measurements by two-step modeling approach, how to explore heteroscedasticity in the consumed amount with variance-mean graph, how to explore nonlinearity with the generalized additive modeling (GAM and the empirical logit approaches, and how to select covariates in the calibration model. The performance of two-part calibration model was compared with the one-part counterpart. We used vegetable intake and mortality data from European Prospective Investigation on Cancer and Nutrition (EPIC study. In the EPIC, reference measurements were taken with 24-hour recalls. For each of the three vegetable subgroups assessed separately, correcting for error with an appropriately specified two-part calibration model resulted in about three fold increase in the strength of association with all-cause mortality, as measured by the log hazard ratio. Further found is that the standard way of including covariates in the calibration model can lead to over fitting the two-part calibration model. Moreover, the extent of adjusting for error is influenced by the number and forms of covariates in the calibration model. For episodically consumed foods, we advise researchers to pay special attention to response distribution, nonlinearity, and covariate inclusion in specifying the calibration model.

  6. Research on Estimates of Xi’an City Life Garbage Pay-As-You-Throw Based on Two-part Tariff method

    Science.gov (United States)

    Yaobo, Shi; Xinxin, Zhao; Fuli, Zheng

    2017-05-01

    Domestic waste whose pricing can’t be separated from the pricing of public economics category is quasi public goods. Based on Two-part Tariff method on urban public utilities, this paper designs the pricing model in order to match the charging method and estimates the standard of pay-as-you-throw using data of the past five years in Xi’an. Finally, this paper summarizes the main results and proposes corresponding policy recommendations.

  7. Neurotoxicity of Metal Mixtures.

    Science.gov (United States)

    Andrade, V M; Aschner, M; Marreilha Dos Santos, A P

    2017-01-01

    Metals are the oldest toxins known to humans. Metals differ from other toxic substances in that they are neither created nor destroyed by humans (Casarett and Doull's, Toxicology: the basic science of poisons, 8th edn. McGraw-Hill, London, 2013). Metals are of great importance in our daily life and their frequent use makes their omnipresence and a constant source of human exposure. Metals such as arsenic [As], lead [Pb], mercury [Hg], aluminum [Al] and cadmium [Cd] do not have any specific role in an organism and can be toxic even at low levels. The Substance Priority List of Agency for Toxic Substances and Disease Registry (ATSDR) ranked substances based on a combination of their frequency, toxicity, and potential for human exposure. In this list, As, Pb, Hg, and Cd occupy the first, second, third, and seventh positions, respectively (ATSDR, Priority list of hazardous substances. U.S. Department of Health and Human Services, Public Health Service, Atlanta, 2016). Besides existing individually, these metals are also (or mainly) found as mixtures in various parts of the ecosystem (Cobbina SJ, Chen Y, Zhou Z, Wub X, Feng W, Wang W, Mao G, Xu H, Zhang Z, Wua X, Yang L, Chemosphere 132:79-86, 2015). Interactions among components of a mixture may change toxicokinetics and toxicodynamics (Spurgeon DJ, Jones OAH, Dorne J-L, Svendsen C, Swain S, Stürzenbaum SR, Sci Total Environ 408:3725-3734, 2010) and may result in greater (synergistic) toxicity (Lister LJ, Svendsen C, Wright J, Hooper HL, Spurgeon DJ, Environ Int 37:663-670, 2011). This is particularly worrisome when the components of the mixture individually attack the same organs. On the other hand, metals such as manganese [Mn], iron [Fe], copper [Cu], and zinc [Zn] are essential metals, and their presence in the body below or above homeostatic levels can also lead to disease states (Annangi B, Bonassi S, Marcos R, Hernández A, Mutat Res 770(Pt A):140-161, 2016). Pb, As, Cd, and Hg can induce Fe, Cu, and Zn

  8. Spinodal Decomposition in Mixtures Containing Surfactants

    Science.gov (United States)

    Melenekvitz, J.

    1998-03-01

    Spinodal decomposition in mixtures containing two immiscible liquids (A and B) plus surfactant was investigated using a recently developed (J. Melenkevitz and S. H. Javadpour, J. Chem. Phys., 107, 623 (1997).) 3-component Ginzburg-Landau model. The time dependent Ginzburg-Landau (TDGL) equations governing the evolution of structure were numerically integrated in 2-dimensions. We found the growth rate of the average domain size, R(t), decreased with increasing surfactant concentration over a wide range of relative amounts of A and B. This can be attributed to the surfactant accumulating at the growing interface between the immiscible liquids, which leads to a reduction in the surface tension. At late times, the growth rate was noticeably altered when thermal fluctuations were added to the numerical simulations. In this case, power law behavior was observed for R(t) at late times, R(t) ~ t^α, with the exponent α decreasing as the amount of surfactant increased. The dynamics at early times were determined by linearizing the TDGL equations about a uniformly mixed state. The growth rate at ealry times was found to be strongly dependent on the model parameters describing the surfactant miscibility in A and B and the surfactant strength. Comparison with recent measurements on SBR / PB mixtures with added PB-SBR diblock copolymer will also be presented.

  9. Thermophysical Properties of Hydrocarbon Mixtures

    Science.gov (United States)

    SRD 4 NIST Thermophysical Properties of Hydrocarbon Mixtures (PC database for purchase)   Interactive computer program for predicting thermodynamic and transport properties of pure fluids and fluid mixtures containing up to 20 components. The components are selected from a database of 196 components, mostly hydrocarbons.

  10. Evaporating Drops of Alkane Mixtures

    OpenAIRE

    Guéna, Geoffroy; Poulard, Christophe; Cazabat, Anne-Marie

    2005-01-01

    22 pages 9 figures; Alkane mixtures are model systems where the influence of surface tension gradients during the spreading and the evaporation of wetting drops can be easily studied. The surface tension gradients are mainly induced by concentration gradients, mass diffusion being a stabilising process. Depending on the relative concentration of the mixture, a rich pattern of behaviours is obtained.

  11. Protein mixtures: interactions and gelation

    NARCIS (Netherlands)

    Ersch, C.

    2015-01-01

    Gelation is a ubiquitous process in the preparation of foods. As most foods are multi constituent mixtures, understanding gelation in mixtures is an important goal in food science. Here we presented a systematic investigation on the influence of molecular interactions on the gelation in protein mixt

  12. Evaporating Drops of Alkane Mixtures

    CERN Document Server

    Gu'ena, G; Poulard, C; Cazabat, Anne-Marie; Gu\\'{e}na, Geoffroy; Poulard, Christophe

    2005-01-01

    Alkane mixtures are model systems where the influence of surface tension gradients during the spreading and the evaporation of wetting drops can be easily studied. The surface tension gradients are mainly induced by concentration gradients, mass diffusion being a stabilising process. Depending on the relative concentration of the mixture, a rich pattern of behaviours is obtained.

  13. Protein mixtures: interactions and gelation

    NARCIS (Netherlands)

    Ersch, C.

    2015-01-01

    Gelation is a ubiquitous process in the preparation of foods. As most foods are multi constituent mixtures, understanding gelation in mixtures is an important goal in food science. Here we presented a systematic investigation on the influence of molecular interactions on the gelation in protein mixt

  14. Easy and flexible mixture distributions

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; Mabit, Stefan L.

    2013-01-01

    We propose a method to generate flexible mixture distributions that are useful for estimating models such as the mixed logit model using simulation. The method is easy to implement, yet it can approximate essentially any mixture distribution. We test it with good results in a simulation study...

  15. Sensitivity of Some Explosive/Brine Mixtures

    Science.gov (United States)

    1980-08-01

    concentration in brine mixtures. 3 Friction test results of brine mixtures. 10 4 Thermal test results of brine mixtures. 11 Li 71 - INTRODUCTION A...also carried out on these impact insensitive mixtures. Of the seven mixtures only the 15% M28-Comp. B sample passed the thermal test , since smoking

  16. Compatibilidade e efeito da mistura de isolados de rizobactérias na indução do enraizamento e crescimento de clones de eucalipto Compatibility among rhizobacteria isolates and effect of mixture of isolates in inducing rooting and growth of eucalyptus clones

    Directory of Open Access Journals (Sweden)

    Reginaldo Gonçalves Mafia

    2007-08-01

    Full Text Available Com vistas ao desenvolvimento de um produto biológico à base de rizobactérias promotoras do crescimento de plantas, este trabalho objetivou avaliar a compatibilidade e o efeito da mistura de isolados de rizobactérias pré-selecionados na indução do enraizamento e crescimento de clones de eucalipto. A compatibilidade entre os isolados de rizobactérias foi determinada por antibiograma nos meios de cultivo de Kado e Heskett e em meio B de King, enquanto o efeito da mistura de isolados foi avaliado por meio da aplicação dos isolados, individualmente ou em misturas, em substrato de enraizamento, empregando-se a mesma proporção de inóculo dos co-inoculantes. Em 64% das possíveis combinações entre dois isolados, não se constataram reações de incompatibilidade. Os isolados VC2 e CIIb foram os mais compatíveis. De forma geral, não se observou sinergia entre misturas de isolados compatíveis, assim como também não ocorreu, geralmente, redução na eficiência da mistura de isolados incompatíveis.Isolates of rhizobacteria that induced both rooting and growth of eucalyptus clones were previously selected. To assist developing a biological product based on those isolates, the compatibility among them and the effect of mixture of isolates were evaluated. The compatibility among rhizobacteria isolates was assessed by antibiograms in both Kado & Heskett and King B culture media, whereas the effect of isolate mixtures was evaluated by applying the isolates, either alone or mixed but always in the same proportions, in rooting substrate. No antagonism between isolates was observed in 64% of the possible combinations of two isolates. Isolates VC2 and CIIb were the most compatible. In general, it was observed no synergistic interaction in mixture of compatible isolates, as well as no efficiency reduction in mixture of incompatible isolates.

  17. Optimal Parameters Multicomponent Mixtures Extruding

    Directory of Open Access Journals (Sweden)

    Ramil F. Sagitov

    2013-01-01

    Full Text Available Experimental research of multicomponent mixtures extruding from production wastes are carried out, unit for production of composites from different types of waste is presented. Having analyzed dependence of multicomponent mixtures extruding energy requirements on die length and components content at three values of angular rate of screw rotation, we received the values of energy requirements at optimal length of the die, angular speed and percent of binding additives.

  18. Gaussian-mixture umbrella sampling

    OpenAIRE

    Maragakis, Paul; van der Vaart, Arjan; Karplus, Martin

    2009-01-01

    We introduce the Gaussian-mixture umbrella sampling method (GAMUS), a biased molecular dynamics technique based on adaptive umbrella sampling that efficiently escapes free energy minima in multi-dimensional problems. The prior simulation data are reweighted with a maximum likelihood formulation, and the new approximate probability density is fit to a Gaussian-mixture model, augmented by information about the unsampled areas. The method can be used to identify free energy minima in multi-dimen...

  19. The effects of mixture commercial live bakers’ yeast and probiotic bacillus on growth and feeding performance and survival rate of silver carp (Hypophthalmichthys molitrix larvae via bioencapsulated Artemia urmiana nauplii

    Directory of Open Access Journals (Sweden)

    Hossein Adineh

    2011-07-01

    Full Text Available Hypophthalmichthys molitrix (Valenciennes, 1844 larvae is an important species forfreshwater aquaculture. This study evaluated the effects of feeding a blend of probiotic bacilli bacteria(B. polymixa, B. licheniformis, B. circulans and baker´s yeast (Saccharomyces cerevisiae on growth and feeding parameters and survival rate of Silver carp larvae. Artemia urmiana (Gǘnther, 1899 nauplii is an important live food that was used as a vector to carry probiotic bacillus to digestive tract of silver carp larvae. The fish larvae were fed at a level of 10 percent body weight at 4 times a day for 30 days. Fish larvae in experimental treatments were fed A. urmiana nauplii that were enriched by blend of 50 percent of Bacillus spp. with concentrations of 1×105, 2×105, 3×105 and 4×105 CFU mL-1 and 50 percent of baker´s yeast with concentrations of 1×105, 2×105, 3×105 and 4×105 cellsmL-1 (T1, T2, T3, T4, respectively and were compared to fish larvae fed control diets of unbioencapsulated A. urmiananauplii. The experiment indicated that feeding and growth parameters in fish fed experimental treatments were significantly higher than fish fed control diets (P<0.05 but survival rate did not significantly differ. Overall, the best group was fed the highest level of yeast and probiotic.

  20. Analysis of asphalt mixtures on town roads

    OpenAIRE

    Glavica, Primož

    2006-01-01

    Asphalt mixtures are most commonly used composite for construction of top layers of different drive ways. By definition asphalt mixtures are composed of crushed rock, fill, bitumen and additives. Percentage of individual components wary according to the purpose asphalt mixture is to be used for. Asphalt mixtures must be capable of enduring different types of load. According to the type of load asphalt mixtures are divided into asphalt mixtures used for supporting layers and asp...

  1. Genetic mixture of multiple source populations accelerates invasive range expansion.

    Science.gov (United States)

    Wagner, Natalie K; Ochocki, Brad M; Crawford, Kerri M; Compagnoni, Aldo; Miller, Tom E X

    2017-01-01

    population growth) during the initial stages of invasion but no consistent effects on dispersal ability. Our work is the first to demonstrate that genetic mixture can alter the course of spatial expansion, the stage of invasion typically associated with the greatest ecological and economic impacts. We suggest that similar effects of genetic mixture may be a common feature of biological invasions in nature, but that these effects can easily go undetected.

  2. Chemical mixtures: considering the evolution of toxicology and chemical assessment.

    Science.gov (United States)

    Monosson, Emily

    2005-04-01

    The assessment of chemical mixtures is a complex topic for toxicologists, regulators, and the public. In this article the linkage between the science of toxicology and the needs of governmental regulatory agencies in the United States is explored through an overview of environmental regulations enacted over the past century and a brief history of modern toxicology. One of the goals of this overview is to encourage both regulators and scientists to consider the benefits and limitations of this science-regulatory relationship as they tackle existing issues such as chemical mixtures. It is clear that a) over the past 100 years chemical regulation and toxicologic research, have in large part, shared a common emphasis on characterization and regulation of individual chemicals. But chemical mixtures have been, and continue to be, evaluated at hazardous waste sites around the United States. For this reason the current U.S. Environmental Protection Agency guidelines for chemical mixtures assessment are also reviewed. These guidelines highlight the current practice of mixtures assessment, which relies primarily on the existing single-chemical database. It is also clear that b) the science and assessment of chemical mixtures are moving forward through the combined efforts of regulatory agencies and scientists from a broad range of disciplines, including toxicology. Because toxicology is at this exciting crossroads, particular attention should be paid to the forces (e.g., public demands, regulatory needs, funding, academic interests) that both promote and limit the growth of this expanding discipline.

  3. Overview to the two-part series: Measurement equivalence of the Patient Reported Outcomes Measurement Information System® (PROMIS® short forms

    Directory of Open Access Journals (Sweden)

    Bryce B. Reeve

    2016-03-01

    Full Text Available Measurement equivalence across differing socio-demographic groups is essential for valid assessment. This is one of two issues of Psychological Test and Assessment Modeling that contains articles describing methods and substantive findings related to establishing measurement equivalence in self-reported health, mental health and social functioning measures. The articles in this two part series describe analyses of items assessing eight domains: fatigue, depression, anxiety, sleep, pain, physical function, cognitive concerns and social function. Additionally, two overview articles describe the methods and sample characteristics of the data set used in these analyses. An additional article describes the important topic of assessing magnitude and impact of differential item functioning. These articles provide the first strong evidence supporting the measurement equivalence of the Patient Reported Outcomes Measurement Information System® (PROMIS® short form measures in ethnically, socio-demographically diverse groups, and is a beginning step in meeting the international call for further study of their performance in such groups.

  4. Marangoni Convection in Binary Mixtures

    CERN Document Server

    Zhang, J; Oron, A; Behringer, Robert P.; Oron, Alexander; Zhang, Jie

    2006-01-01

    Marangoni instabilities in binary mixtures are different from those in pure liquids. In contrast to a large amount of experimental work on Marangoni convection in pure liquids, such experiments in binary mixtures are not available in the literature, to our knowledge. Using binary mixtures of sodium chloride/water, we have systematically investigated the pattern formation for a set of substrate temperatures and solute concentrations in an open system. The flow patterns evolve with time, driven by surface-tension fluctuations due to evaporation and the Soret effect, while the air-liquid interface does not deform. A shadowgraph method is used to follow the pattern formation in time. The patterns are mainly composed of polygons and rolls. The mean pattern size first decreases slightly, and then gradually increases during the evolution. Evaporation affects the pattern formation mainly at the early stage and the local evaporation rate tends to become spatially uniform at the film surface. The Soret effect becomes i...

  5. Mixtures of skewed Kalman filters

    KAUST Repository

    Kim, Hyoungmoon

    2014-01-01

    Normal state-space models are prevalent, but to increase the applicability of the Kalman filter, we propose mixtures of skewed, and extended skewed, Kalman filters. To do so, the closed skew-normal distribution is extended to a scale mixture class of closed skew-normal distributions. Some basic properties are derived and a class of closed skew. t distributions is obtained. Our suggested family of distributions is skewed and has heavy tails too, so it is appropriate for robust analysis. Our proposed special sequential Monte Carlo methods use a random mixture of the closed skew-normal distributions to approximate a target distribution. Hence it is possible to handle skewed and heavy tailed data simultaneously. These methods are illustrated with numerical experiments. © 2013 Elsevier Inc.

  6. Taylor dispersion analysis of mixtures.

    Science.gov (United States)

    Cottet, Hervé; Biron, Jean-Philippe; Martin, Michel

    2007-12-01

    Taylor dispersion analysis (TDA) is a fast and simple method for determining hydrodynamic radii. In the case of sample mixtures, TDA, as the other nonseparative methods, leads to an average diffusion coefficient on the different molecules constituting the mixture. We set in this work the equations giving, on a consistent basis, the average values obtained by TDA with detectors with linear response functions. These equations confronted TDA experiments of sample mixtures containing different proportions of a small molecule and a polymer standard. Very good agreement between theory and experiment was obtained. In a second part of this work, on the basis of monomodal or bimodal molar mass distributions of polymers, the different average diffusion coefficients corresponding to TDA were compared to the z-average diffusion coefficient (D(z)) obtained from dynamic light scattering (DLS) experiments and to the weight average diffusion coefficient (D(w)). This latter value is sometimes considered as the most representative of the sample mixture. From these results, it appears that, for monomodal distribution and relatively low polydispersity (I = 1.15), the average diffusion coefficient generally derived from TDA is very close to Dw. However, for highly polydisperse samples (e.g., bimodal polydisperse distributions), important differences could be obtained (up to 35% between TDA and D(w)). In all the cases, the average diffusion coefficient obtained by TDA for a mass concentration detector was closer to the Dw value than the z-average obtained by DLS.

  7. Theoretical and experimental comparison of the Soret coefficient for water-methanol and water-ethanol binary mixtures

    DEFF Research Database (Denmark)

    Saghir, MZ; Jiang, CG; Derawi, Samer

    2004-01-01

    by concentration gradients. Because natural convection, molecular diffusion, and thermal conduction have different relaxation time scales, a wide variety of resulting convective motions and heat, and mass distributions might occur. In some fluid mixtures such as water-ethanol system, for instance, ethanol diffuses......In multicomponent. mixtures, a much richer variety of phenomena can occur than in Simple (single-component) fluids. Natural convection in single-component. fluids is due to buoyancy forces caused by temperature gradients. In multicomponent mixtures, buoyancy forces may also be caused...... much more slowly than heat, and because of this difference in time scales oscillatory convection might occur. In a multocomponent mixture, the total molar flux consists of two parts: the convective molar flux and the diffusive molar flux (resulting from the difference between the component, velocity...

  8. 基于二部制的价格歧视方法%Price Discrimination Method Based on Two-parts Tariff

    Institute of Scientific and Technical Information of China (English)

    彭云飞

    2012-01-01

    产品实施价格二部制的企业大量采用二级价格歧视、三级价格歧视方法外,还存在混合价格歧视.研究表明:企业收益最大化目标下实施这些价格歧视方法时,固定价格和从量价格的需求弹性、用户数、单位时间里的收益以及用户区间、资费区间分别需要满足不同的条件.这些结论为企业实施二部价格歧视提供了理论依据和决策参考.%Second-degree and third-degree price discriminaions are widely adopted in he product pricing. Research shows: under the constraints of income maximization, some con-ditions for the fixed fee of service packages and the demand elasticity of the quantity rate of bundled services, the number of users, the income per unit time, the users; and price's intervals should be meet in order to implement these price discrimination decision-making methods. These conclusions provide the theoretical and decision-making bases when the enterprises carry out two parts price discrimination

  9. Predicting toxicity of aromatic ternary mixtures to algae

    Institute of Scientific and Technical Information of China (English)

    LU GuangHua; WANG Chao; WANG PeiFang; YANG ChengZhi

    2009-01-01

    Aquatic ecosystems are often polluted with more than one type of contaminant, and information on the combined toxic effects of mixed pollutants on aquatic organisms is scarce at present. Acute toxicity of aromatic compounds and their ternary mixtures to the alga (Scenedesmus obliquus) was determined by the algae growth inhibition test. The median effective concentration (EC_(50)) value for a single aromatic compound and EC_(50mix) values for mixtures were obtained, the logarithm of n-octanol/water partition coefficient (logP_(mix)) and the frontier orbital energy gap (△E_(mix) for mixtures were calculated. Based on the quantitative structure-activity relationship model for single chemical toxicity log(1/EC_(50)) =0.426logP-1.150△E+12.61 (n=15, R~2=0.917 and Q~2=0.878), the following two-descriptor model was developed for the ternary mixture toxicity of aromatic compounds: log(1/EC_(50mix))=O.68210gP_(mix)-O.367△E_(mix)+ 4.971 (n=44, R~2-0.869 and Q~2=0.843). This model can be used to predict the combined toxicity of mixtures containing toxicants with different mechanisms of action.

  10. Local fluctuations in solution mixtures

    Science.gov (United States)

    Ploetz, Elizabeth A.; Smith, Paul E.

    2011-01-01

    An extension of the traditional Kirkwood-Buff (KB) theory of solutions is outlined which provides additional fluctuating quantities that can be used to characterize and probe the behavior of solution mixtures. Particle-energy and energy-energy fluctuations for local regions of any multicomponent solution are expressed in terms of experimentally obtainable quantities, thereby supplementing the usual particle-particle fluctuations provided by the established KB inversion approach. The expressions are then used to analyze experimental data for pure water over a range of temperatures and pressures, a variety of pure liquids, and three binary solution mixtures – methanol and water, benzene and methanol, and aqueous sodium chloride. In addition to providing information on local properties of solutions it is argued that the particle-energy and energy-energy fluctuations can also be used to test and refine solute and solvent force fields for use in computer simulation studies. PMID:21806137

  11. Binary mixtures of chiral gases

    CERN Document Server

    Presilla, Carlo

    2015-01-01

    A possible solution of the well known paradox of chiral molecules is based on the idea of spontaneous symmetry breaking. At low pressure the molecules are delocalized between the two minima of a given molecular potential while at higher pressure they become localized in one minimum due to the intermolecular dipole-dipole interactions. Evidence for such a phase transition is provided by measurements of the inversion spectrum of ammonia and deuterated ammonia at different pressures. In particular, at pressure greater than a critical value no inversion line is observed. These data are well accounted for by a model previously developed and recently extended to mixtures. In the present paper, we discuss the variation of the critical pressure in binary mixtures as a function of the fractions of the constituents.

  12. Modelling asymmetric growth in crowded plant communities

    DEFF Research Database (Denmark)

    Damgaard, Christian

    2010-01-01

    A class of models that may be used to quantify the effect of size-asymmetric competition in crowded plant communities by estimating a community specific degree of size-asymmetric growth for each species in the community is suggested. The model consists of two parts: an individual size-asymmetric ......A class of models that may be used to quantify the effect of size-asymmetric competition in crowded plant communities by estimating a community specific degree of size-asymmetric growth for each species in the community is suggested. The model consists of two parts: an individual size...

  13. Atomistic Simulations of Bicelle Mixtures

    OpenAIRE

    Jiang, Yong; Wang, Hao; Kindt, James T.

    2010-01-01

    Mixtures of long- and short-tail phosphatidylcholine lipids are known to self-assemble into a variety of aggregates combining flat bilayerlike and curved micellelike features, commonly called bicelles. Atomistic simulations of bilayer ribbons and perforated bilayers containing dimyristoylphosphatidylcholine (DMPC, di-C14 tails) and dihexanoylphosphatidylcholine (DHPC, di-C6 tails) have been carried out to investigate the partitioning of these components between flat and curved microenvironmen...

  14. Atomistic Simulations of Bicelle Mixtures

    OpenAIRE

    Jiang, Yong; WANG, HAO; Kindt, James T.

    2010-01-01

    Mixtures of long- and short-tail phosphatidylcholine lipids are known to self-assemble into a variety of aggregates combining flat bilayerlike and curved micellelike features, commonly called bicelles. Atomistic simulations of bilayer ribbons and perforated bilayers containing dimyristoylphosphatidylcholine (DMPC, di-C14 tails) and dihexanoylphosphatidylcholine (DHPC, di-C6 tails) have been carried out to investigate the partitioning of these components between flat and curved microenvironmen...

  15. FRACTIONAL TRANSPORT OF SEDIMENT MIXTURES

    Institute of Scientific and Technical Information of China (English)

    Baosheng WU; Albert MOLINAS; Anping SHU

    2003-01-01

    A new method based on the Transport Capacity Fraction (TCF) concept is proposed to compute the fractional transport rates for nonuniform sediment mixtures in sand-bed channels. The TCF concept is derived from the understanding that the measurements and predictions of bed-material load are more accurate and reliable than the measurements and predictions of fractional loads. First the bed-material load is computed using an appropriate equation, then the fractional transport rates are determined by distributing the bed-material load into size groups through a transport capacity distribution function. For the computation of bed-material loads, the Aekers and White, Engelund and Hansen, and Yang equations are used in this study. Two new transport capacity distribution functions are developed for flows in sand-bed channels. The new expressions presented in this paper account for the sheltering and exposure effects that exist in mixtures. Comparisons with measured data show that the proposed method can significantly improve the predictions of fractional transport rates for nonuniform sediment mixtures.

  16. 21 CFR 82.6 - Certifiable mixtures.

    Science.gov (United States)

    2010-04-01

    ... mixture is harmless and suitable for use therein; and (3) No diluent (except resins, natural gum, pectin... mixture is for external application to shell eggs, or for use in coloring a food specified in the...

  17. Assessment of solid reactive mixtures for the development of biological permeable reactive barriers.

    Science.gov (United States)

    Pagnanelli, Francesca; Viggi, Carolina Cruz; Mainelli, Sara; Toro, Luigi

    2009-10-30

    Solid reactive mixtures were tested as filling material for the development of biological permeable reactive barriers for the treatment of heavy metals contaminated waters. Mixture selection was performed by taking into account the different mechanisms operating in sulphate and cadmium removal with particular attention to bioprecipitation and sorption onto the organic matrices in the mixtures. Suspensions of eight reactive mixtures were tested for sulphate removal (initial concentration 3 g L(-1)). Each mixture was made up of four main functional components: a mix of organic sources for bacterial growth, a neutralizing agent, a porous medium and zero-valent iron. The best mixture among the tested ones (M8: 6% leaves, 9% compost, 3% zero-valent iron, 30% silica sand, 30% perlite, 22% limestone) presented optimal conditions for SRB growth (pH 7.8 +/- 0.1; E(h)= -410 +/- 5 mV) and 83% sulphate removal in 22 days (25% due to bioreduction, 32% due to sorption onto compost and 20% onto leaves). M8 mixture allowed the complete abatement of cadmium with a significant contribution of sorption over bioprecipitation (6% Cd removal due to SRB activity). Sorption properties, characterised by potentiometric titrations and related modelling, were mainly due to carboxylic sites of organic components used in reactive mixtures.

  18. Structural Differences in Economic Growth

    NARCIS (Netherlands)

    N. Basturk (Nalan); R. Paap (Richard); D.J.C. van Dijk (Dick)

    2008-01-01

    textabstractThis paper addresses heterogeneity in determinants of economic growth in a data-driven way. Instead of defining groups of countries with different growth characteristics a priori, based on, for example, geographical location, we use a finite mixture panel model and endogenous clustering

  19. Low Mach number fluctuating hydrodynamics of multispecies liquid mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Donev, Aleksandar, E-mail: donev@courant.nyu.edu; Bhattacharjee, Amit Kumar [Courant Institute of Mathematical Sciences, New York University, New York, New York 10012 (United States); Nonaka, Andy; Bell, John B. [Center for Computational Science and Engineering, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Garcia, Alejandro L. [Department of Physics and Astronomy, San Jose State University, San Jose, California 95192 (United States)

    2015-03-15

    We develop a low Mach number formulation of the hydrodynamic equations describing transport of mass and momentum in a multispecies mixture of incompressible miscible liquids at specified temperature and pressure, which generalizes our prior work on ideal mixtures of ideal gases [Balakrishnan et al., “Fluctuating hydrodynamics of multispecies nonreactive mixtures,” Phys. Rev. E 89 013017 (2014)] and binary liquid mixtures [Donev et al., “Low mach number fluctuating hydrodynamics of diffusively mixing fluids,” Commun. Appl. Math. Comput. Sci. 9(1), 47-105 (2014)]. In this formulation, we combine and extend a number of existing descriptions of multispecies transport available in the literature. The formulation applies to non-ideal mixtures of arbitrary number of species, without the need to single out a “solvent” species, and includes contributions to the diffusive mass flux due to gradients of composition, temperature, and pressure. Momentum transport and advective mass transport are handled using a low Mach number approach that eliminates fast sound waves (pressure fluctuations) from the full compressible system of equations and leads to a quasi-incompressible formulation. Thermal fluctuations are included in our fluctuating hydrodynamics description following the principles of nonequilibrium thermodynamics. We extend the semi-implicit staggered-grid finite-volume numerical method developed in our prior work on binary liquid mixtures [Nonaka et al., “Low mach number fluctuating hydrodynamics of binary liquid mixtures,” http://arxiv.org/abs/1410.2300 (2015)] and use it to study the development of giant nonequilibrium concentration fluctuations in a ternary mixture subjected to a steady concentration gradient. We also numerically study the development of diffusion-driven gravitational instabilities in a ternary mixture and compare our numerical results to recent experimental measurements [Carballido-Landeira et al., “Mixed-mode instability of a

  20. Psychophysical studies of mixtures of tastants

    NARCIS (Netherlands)

    Graaf, de C.

    1988-01-01

    The human perception of mixtures of tastante was studied with reference to three central issues, i.e., 1) the paradigma of equiratio taste substance mixtures. as an instrument to manipulate the physical composition of tastant mixtures. This paradiama also enables the construction of psychophysical

  1. Do cover crop mixtures have the same ability to suppress weeds as competitive monoculture cover crops?

    Directory of Open Access Journals (Sweden)

    Brust, Jochen

    2014-02-01

    Full Text Available An increasing number of farmers use cover crop mixtures instead of monoculture cover crops to improve soil and crop quality. However, only little information is available about the weed suppression ability of cover crop mixtures. Therefore, two field experiments were conducted in Baden-Württemberg between 2010 and 2012, to compare growth and weed suppression of monoculture cover crops and cover crop mixtures. In the first experiment, heterogeneous results between yellow mustard and the cover crop mixture occurred. For further research, a field experiment was conducted in 2012 to compare monocultures of yellow mustard and hemp with three cover crop mixtures. The evaluated mixtures were: “MELO”: for soil melioration; “BETA”: includes only plant species with no close relation to main cash crops in Central Europe and “GPS”: for usage as energy substrate in spring. Yellow mustard, MELO, BETA and GPS covered 90% of the soil in less than 42 days and were able to reduce photosynthetically active radiation (PAR on soil surface by more than 96% after 52 days. Hemp covered 90% of the soil after 47 days and reduced PAR by 91% after 52 days. Eight weeks after planting, only BETA showed similar growth to yellow mustard which produced the highest dry matter. The GPS mixture had comparatively poor growth, while MELO produced similar dry matter to hemp. Yellow mustard, MELO and BETA reduced weed growth by 96% compared with a no cover crop control, while hemp and GPS reduced weeds by 85% and 79%. In spring, weed dry matter was reduced by more than 94% in plots with yellow mustard and all mixtures, while in hemp plots weeds were only reduced by 71%. The results suggest that the tested cover crop mixtures offer similar weed suppression ability until spring as the monoculture of the competitive yellow mustard.

  2. Crystallization kinetics of polydisperse colloidal hard spheres. II. Binary mixtures.

    Science.gov (United States)

    Martin, S; Bryant, G; van Megen, W

    2005-02-01

    In this paper we present measurements of the crystallization kinetics of binary mixtures of two different sized hard sphere particles. The growth of the Bragg reflections over time were analyzed to yield the crystallite scattering vector, the total amount of crystal, and the average linear crystal size. It was observed that a particle size distribution skewed to higher sized particles has a less detrimental effect on the crystal structure than a skew to smaller sized particles. In the latter case we observe that initial crystallite growth occurs at only a small number of sites, with further crystallization sites developing at later times. Based on these measurements we elaborate further on the previously proposed growth mechanism whereby crystallization occurs in conjunction with a local fractionation process in the fluid, which significantly affects the kinetic growth of crystallites in polydisperse systems.

  3. Epilogue to the two-part series: Measurement equivalence of the Patient Reported Outcomes Measurement Information System® (PROMIS® short forms

    Directory of Open Access Journals (Sweden)

    Jeanne A. Teresi

    2016-06-01

    Full Text Available The articles in this two-part series of Psychological Test and Assessment Modeling describe the psychometric performance and measurement equivalence of the Patient Reported Outcomes Measurement Information System® (PROMIS® short form measures in ethnically, socio-demographically diverse groups of cancer patients. Measures in eight health-related quality of life domains were evaluated: fatigue, depression, anxiety, cognition, pain, sleep, and physical and social function. State-of-the-art latent variable methods, most based on item response theory, and described in two methods overview articles in this series were used to examine differential item functioning (DIF. Findings were generally supportive of the performance of the PROMIS measures. Although use of powerful methods and large samples resulted in the identification of many items with DIF, practi-cally none were identified with high magnitude. The aggregate level impact of DIF was small, and minimal individual impact was detected. Some methodological challenges were encountered in-volving positively and negatively worded items, but most were resolved through modest item removal. Sensitivity analyses showed minimal impact of model assumption violation on the results presented. A cautionary note is the observance of a few instances of individual-level impact of DIF in the analyses of depression, anxiety, and pain, and one instance of aggregate level impact just below threshold in the analyses of physical function. Although this sample of over 5,000 individuals was diverse, ethnically, a limitation was the lack of ability to examine language groups other than Spanish and English and specific ethnic subgroups within Hispanic, Asian/Pacific Islander, and Black subsamples. Extensive qualitative and quantitative analyses were performed in the development of PROMIS item banks. These sets of analyses, performed by several teams of psychometricians, statisticians, and qualitative experts, were the

  4. Poly (ε-caprolactone nanofibrous ring surrounding a polyvinyl alcohol hydrogel for the development of a biocompatible two-part artificial cornea

    Directory of Open Access Journals (Sweden)

    Bakhshandeh H

    2011-07-01

    % when measured in the 400–800 nm wavelength range. The plasma-treated PCL nanofibrous scaffold promoted limbal stem cell adhesion and proliferation within 10 days. These results confirmed that the polymeric artificial cornea showed suitable physical properties and good biocompatibility and epithelialization ability.Keywords: two part artificial cornea, nanofibers, electrospun, poly (ε-caprolactone, polyvinyl alcohol hydrogel, limbal stem cells

  5. Carbohydrate intake, obesity, metabolic syndrome and cancer risk? A two-part systematic review and meta-analysis protocol to estimate attributability.

    Science.gov (United States)

    Sartorius, B; Sartorius, K; Aldous, C; Madiba, T E; Stefan, C; Noakes, T

    2016-01-04

    required. The final results of this two part systematic review (plus multiplicative calculations) will be published in a relevant international peer-reviewed journal. PROSPERO CRD42015023257. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  6. Urban growth management

    DEFF Research Database (Denmark)

    Jørgensen, Gertrud; Alexander Sick Nielsen, Thomas; Grünfelder, Julien

    2011-01-01

    , and finally urban attractivity policies. Effective regional bodies are needed to deal with urban expansion and peri-urbanisation at a relevant scale; European rural and agricultural policies makes up the main ‘policy complex’ targeting the non-urban area including its land uses; while lastly leverage of urban...... urban growth and curb urban sprawl in a wider sense. Methodology The main methodology of the paper is a desk-research based review of policy options supplemented with field study and interviews in selected cased study regions. This paper consists of two parts. The first part is based on literature...... there are contradictions in the evidence presented in the literature, we believe that it may be safely said that urban growth management policies have an influence on urban growth under certain preconditions including: sufficient time for implementation and continuity of efforts; choice of appropriate policy measures...

  7. Supercritical Water Mixture (SCWM) Experiment

    Science.gov (United States)

    Hicks, Michael C.; Hegde, Uday G.

    2012-01-01

    The subject presentation, entitled, Supercritical Water Mixture (SCWM) Experiment, was presented at the International Space Station (ISS) Increment 33/34 Science Symposium. This presentation provides an overview of an international collaboration between NASA and CNES to study the behavior of a dilute aqueous solution of Na2SO4 (5% w) at near-critical conditions. The Supercritical Water Mixture (SCWM) investigation, serves as important precursor work for subsequent Supercritical Water Oxidation (SCWO) experiments. The SCWM investigation will be performed in DECLICs High Temperature Insert (HTI) for the purpose of studying critical fluid phenomena at high temperatures and pressures. The HTI includes a completely sealed and integrated test cell (i.e., Sample Cell Unit SCU) that will contain approximately 0.3 ml of the aqueous test solution. During the sequence of tests, scheduled to be performed in FY13, temperatures and pressures will be elevated to critical conditions (i.e., Tc = 374C and Pc = 22 MPa) in order to observe salt precipitation, precipitate agglomeration and precipitate transport in the presence of a temperature gradient without the influences of gravitational forces. This presentation provides an overview of the motivation for this work, a description of the DECLIC HTI hardware, the proposed test sequences, and a brief discussion of the scientific research objectives.

  8. Atomistic simulations of bicelle mixtures.

    Science.gov (United States)

    Jiang, Yong; Wang, Hao; Kindt, James T

    2010-06-16

    Mixtures of long- and short-tail phosphatidylcholine lipids are known to self-assemble into a variety of aggregates combining flat bilayerlike and curved micellelike features, commonly called bicelles. Atomistic simulations of bilayer ribbons and perforated bilayers containing dimyristoylphosphatidylcholine (DMPC, di-C(14) tails) and dihexanoylphosphatidylcholine (DHPC, di-C(6) tails) have been carried out to investigate the partitioning of these components between flat and curved microenvironments and the stabilization of the bilayer edge by DHPC. To approach equilibrium partitioning of lipids on an achievable simulation timescale, configuration-bias Monte Carlo mutation moves were used to allow individual lipids to change tail length within a semigrand-canonical ensemble. Since acceptance probabilities for direct transitions between DMPC and DHPC were negligible, a third component with intermediate tail length (didecanoylphosphatidylcholine, di-C(10) tails) was included at a low concentration to serve as an intermediate for transitions between DMPC and DHPC. Strong enrichment of DHPC is seen at ribbon and pore edges, with an excess linear density of approximately 3 nm(-1). The simulation model yields estimates for the onset of edge stability with increasing bilayer DHPC content between 5% and 15% DHPC at 300 K and between 7% and 17% DHPC at 323 K, higher than experimental estimates. Local structure and composition at points of close contact between pores suggest a possible mechanism for effective attractions between pores, providing a rationalization for the tendency of bicelle mixtures to aggregate into perforated vesicles and perforated sheets.

  9. The Kinetics of Enzyme Mixtures

    Directory of Open Access Journals (Sweden)

    Simon Brown

    2014-03-01

    Full Text Available Even purified enzyme preparations are often heterogeneous. For example, preparations of aspartate aminotransferase or cytochrome oxidase can consist of several different forms of the enzyme. For this reason we consider how different the kinetics of the reactions catalysed by a mixture of forms of an enzyme must be to provide some indication of the characteristics of the species present. Based on the standard Michaelis-Menten model, we show that if the Michaelis constants (Km of two isoforms differ by a factor of at least 20 the steady-state kinetics can be used to characterise the mixture. However, even if heterogeneity is reflected in the kinetic data, the proportions of the different forms of the enzyme cannot be estimated from the kinetic data alone. Consequently, the heterogeneity of enzyme preparations is rarely reflected in measurements of their steady-state kinetics unless the species present have significantly different kinetic properties. This has two implications: (1 it is difficult, but not impossible, to detect molecular heterogeneity using kinetic data and (2 even when it is possible, a considerable quantity of high quality data is required.

  10. Effect of Mixture Pressure and Equivalence Ratio on Detonation Cell Size for Hydrogen-Air Mixtures

    Science.gov (United States)

    2015-06-01

    EFFECT OF MIXTURE PRESSURE AND EQUIVALENCE RATIO ON DETONATION CELL SIZE FOR HYDROGEN -AIR MIXTURES...protection in the United States. AFIT-ENY-MS-15-J-045 EFFECT OF MIXTURE PRESSURE AND EQUIVALENCE RATIO ON DETONATION CELL SIZE FOR HYDROGEN -AIR...DISTRIBUTION UNLIMITED. AFIT-ENY-MS-15-J-045 EFFECT OF MIXTURE PRESSURE AND EQUIVALENCE RATIO ON DETONATION CELL SIZE FOR HYDROGEN -AIR MIXTURES

  11. Optimization of prebiotics in soybean milk using mixture experiments

    Directory of Open Access Journals (Sweden)

    Kongkarn Kijroongrojana

    2009-11-01

    Full Text Available A mixture experiment was used to optimize prebiotic mixtures in soybean milk formulation. Inulin (I, galactooligosaccharides(GOS, and isomalto-oligosaccharides (IMO were the prebiotic ingredients added (4% w/v to soybean milk. Thirteen formulations of soybean milk were compared using the general descriptive analysis and the growth of probiotics(Bifidobacterium bifidum DSM 20456, Lactobacillus plantarum TISTR 875, and Lactobacillus acidophilus TISTR 1034. There were no significant differences (p>0.05 in all sensory attributes (color, thickness, beany flavor, sweetness, viscosity, sweetness aftertaste among the samples. Various mixtures of the prebiotics had only a slight effect on the soybean milk color and viscosity (p0.05. The soybean milk supplemented with the optimized prebiotic mixture had higher (p<0.05carbohydrates, total soluble solid, total solid content, and viscosity than the control (without prebiotic. However, it had a lower L* value (lightness and a higher a* value (redness than the control (p<0.05.

  12. Inhibition of surface crystallisation of amorphous indomethacin particles in physical drug-polymer mixtures

    DEFF Research Database (Denmark)

    Priemel, Petra A; Laitinen, Riikka; Barthold, Sarah

    2013-01-01

    Surface coverage may affect the crystallisation behaviour of amorphous materials. This study investigates crystallisation inhibition in powder mixtures of amorphous drug and pharmaceutical excipients. Pure amorphous indomethacin (IMC) powder and physical mixtures thereof with Eudragit(®) E...... stability than pure IMC whereas IMC Soluplus(®) mixtures did not. Water uptake was higher for mixtures containing Soluplus(®) than for amorphous IMC or IMC Eudragit(®) mixtures. However, the Tg of amorphous IMC was unaffected by the presence (and nature) of polymer. SEM revealed that Eudragit(®) particles...... through reduced IMC surface molecular mobility. Polymer particles may also mechanically hinder crystal growth outwards from the surface. This work highlights the importance of microparticulate surface coverage of amorphous drug particles on their stability....

  13. Afrikaner spirituality: A complex mixture

    Directory of Open Access Journals (Sweden)

    Erna Olivier

    2006-10-01

    Full Text Available The article argues that the perception that Afrikaner spirituality is and has always been founded mainly or only upon the Calvinistic tradition is a misconception. Nineteenth century Afrikaner spiritualism consisted of a mixture of theology, philosophy and a way of adapting to extreme living conditions. These factors, although with different contents, are also the determinant issues that made 21st century Afrikaner spirituality such a complex phenomenon. The article postulates that the Afrikaner nation’s current identity crisis can be resolved by closely looking at the different influences on the spirituality of the nation and by carefully guiding the people through the complex set of multiple choices to a fresh relation with Christ in a new found Christian identity to confirm our Christian foundation.

  14. Differential effects of a complex organochlorine mixture on the proliferation of breast cancer cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Aube, Michel, E-mail: 4aubem@videotron.ca [Axe de recherche en sante des populations et environnementale, Centre de recherche du Centre hospitalier universitaire de Quebec and Universite Laval, 2875 Boulevard Laurier, Edifice Delta 2, bureau 600, Quebec, QC, Canada G1V 2M2 (Canada); Larochelle, Christian, E-mail: christian.larochelle@inspq.qc.ca [Axe de recherche en sante des populations et environnementale, Centre de recherche du Centre hospitalier universitaire de Quebec and Universite Laval, 2875 Boulevard Laurier, Edifice Delta 2, bureau 600, Quebec, QC, Canada G1V 2M2 (Canada); Ayotte, Pierre, E-mail: pierre.ayotte@inspq.qc.ca [Axe de recherche en sante des populations et environnementale, Centre de recherche du Centre hospitalier universitaire de Quebec and Universite Laval, 2875 Boulevard Laurier, Edifice Delta 2, bureau 600, Quebec, QC, Canada G1V 2M2 (Canada); Laboratoire de Toxicologie, Institut national de sante publique du Quebec, 945 avenue Wolfe, Quebec, QC, Canada G1V 5B3 (Canada)

    2011-04-15

    proliferative effect of the mixture on CAMA-1 cells in the presence of sex steroids appears mostly due to the antiandrogenic properties of p,p'-DDE, a major constituent of the mixture. Other mixtures of contaminants that include emerging compounds of interest such as brominated flame retardants and perfluoroalkyl compounds should be tested for their capacity to induce breast cancer cell proliferation. - Research highlights: {yields} We studied effects of a complex organochlorine mixture on breast cancer cell growth. {yields} Weak xenoestrogens in the mixture stimulated the proliferation of MCF-7 cells. {yields} Antiandrogens increased the proliferation CAMA-1 cells grown with sex steroids. {yields} High concentrations of the mixture decreased the proliferation of all cell lines.

  15. Bayesian mixture models for spectral density estimation

    OpenAIRE

    Cadonna, Annalisa

    2017-01-01

    We introduce a novel Bayesian modeling approach to spectral density estimation for multiple time series. Considering first the case of non-stationary timeseries, the log-periodogram of each series is modeled as a mixture of Gaussiandistributions with frequency-dependent weights and mean functions. The implied model for the log-spectral density is a mixture of linear mean functionswith frequency-dependent weights. The mixture weights are built throughsuccessive differences of a logit-normal di...

  16. Thermodynamic Calculations for Complex Chemical Mixtures

    Science.gov (United States)

    Mcbride, B. J.

    1986-01-01

    General computer program, CECTRP, developed for calculation of thermodynamic properties of complex mixtures with option to calculate transport properties of these mixtures. Free-energy minimization technique used in equilibrium calculation. Rigorous equations used in transport calculations. Program calculates equilibrium compositions and corresponding thermodynamic and transport properties of mixtures. CECTRP accommodates up to 24 reactants, 20 elements, and 600 products, 400 of which are condensed. Written in FORTRAN IV for any large computer system.

  17. Shear viscosity of liquid mixtures Mass dependence

    CERN Document Server

    Kaushal, R

    2002-01-01

    Expressions for zeroth, second, and fourth sum rules of transverse stress autocorrelation function of two component fluid have been derived. These sum rules and Mori's memory function formalism have been used to study shear viscosity of Ar-Kr and isotopic mixtures. It has been found that theoretical result is in good agreement with the computer simulation result for the Ar-Kr mixture. The mass dependence of shear viscosity for different mole fraction shows that deviation from ideal linear model comes even from mass difference in two species of fluid mixture. At higher mass ratio shear viscosity of mixture is not explained by any of the emperical model.

  18. Empirical profile mixture models for phylogenetic reconstruction

    National Research Council Canada - National Science Library

    Si Quang, Le; Gascuel, Olivier; Lartillot, Nicolas

    2008-01-01

    Motivation: Previous studies have shown that accounting for site-specific amino acid replacement patterns using mixtures of stationary probability profiles offers a promising approach for improving...

  19. GROWTH INHIBITION OF FUSARIUM SP. IN LIVESTOCK FEED

    Directory of Open Access Journals (Sweden)

    Gabriella Kanižai Šarić

    2011-12-01

    Full Text Available Contamination with phytopathogenic forms of Fusarium, besides field crops, may also occur in stored products. Addition of antifungal substances to stored livestock feed is therefore common. This paper examined the effectiveness of a mixture of synthetic and natural antioxidants against the growth of Fusarium graminearum and F. verticillioides in a concentrate mixture. The most effective inhibition of growth was achieved with a mixture of butylated hydroxyanisole, propyl paraben and thymol.

  20. Simulation of mixture microstructures via particle packing models and their direct comparison with real mixtures

    Science.gov (United States)

    Gulliver, Eric A.

    The objective of this thesis to identify and develop techniques providing direct comparison between simulated and real packed particle mixture microstructures containing submicron-sized particles. This entailed devising techniques for simulating powder mixtures, producing real mixtures with known powder characteristics, sectioning real mixtures, interrogating mixture cross-sections, evaluating and quantifying the mixture interrogation process and for comparing interrogation results between mixtures. A drop and roll-type particle-packing model was used to generate simulations of random mixtures. The simulated mixtures were then evaluated to establish that they were not segregated and free from gross defects. A powder processing protocol was established to provide real mixtures for direct comparison and for use in evaluating the simulation. The powder processing protocol was designed to minimize differences between measured particle size distributions and the particle size distributions in the mixture. A sectioning technique was developed that was capable of producing distortion free cross-sections of fine scale particulate mixtures. Tessellation analysis was used to interrogate mixture cross sections and statistical quality control charts were used to evaluate different types of tessellation analysis and to establish the importance of differences between simulated and real mixtures. The particle-packing program generated crescent shaped pores below large particles but realistic looking mixture microstructures otherwise. Focused ion beam milling was the only technique capable of sectioning particle compacts in a manner suitable for stereological analysis. Johnson-Mehl and Voronoi tessellation of the same cross-sections produced tessellation tiles with different the-area populations. Control charts analysis showed Johnson-Mehl tessellation measurements are superior to Voronoi tessellation measurements for detecting variations in mixture microstructure, such as altered

  1. Thermodynamics of mixtures containing amines

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Juan Antonio [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain)], E-mail: jagl@termo.uva.es; Mozo, Ismael; Garcia de la Fuente, Isaias; Cobos, Jose Carlos [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain); Riesco, Nicolas [Department of Chemical Engineering, Loughborough University, Loughborough, LE113TU Leicestershire (United Kingdom)

    2008-01-30

    Mixtures with dimethyl or trimethylpyridines and alkane, aromatic compound or 1-alkanol have been examined using different theories: DISQUAC, Flory, the concentration-concentration structure factor, S{sub CC}(0), or the Kirkwood-Buff formalism. DISQUAC represents fairly well the available experimental data, and improves theoretical calculations from Dortmund UNIFAC. Two important effects have been investigated: (i) the effect of increasing the number of methyl groups attached to the aromatic ring of the amine; (ii) the effect of modifying the position of the methyl groups in this ring. The molar excess enthalpy, H{sup E}, and the molar excess volume, V{sup E}, decrease in systems with alkane or methanol as follows: pyridine > 3-methylpyridine > 3,5-dimethylpyridine and pyridine > 2-methylpyridine > 2,4-dimethylpyridine > 2,4,6-trimethylpyridine, which has been attributed to a weakening of the amine-amine interactions in the same sequences. This is in agreement with the relative variation of the effective dipole moment, {mu}-bar, and of the differences between the boiling temperature of a pyridine base and that of the homomorphic alkane. For heptane solutions, the observed H{sup E} variation, H{sup E} (3,5-dimethylpyridine) > H{sup E} (2,4-dimethylpyridine) > H{sup E} (2,6-dimethylpyridine), is explained similarly. Calculations on the basis of the Flory model confirm that orientational effects become weaker in systems with alkane in the order: pyridine > methylpyridine > dimethylpyridine > trimethylpyridine. S{sub CC}(0) calculations show that steric effects increase with the number of CH{sub 3}- groups in the pyridine base, and that the steric effects exerted by methyl groups in positions 2 and 6 are higher than when they are placed in positions 3 and 5. The hydrogen bond energy in methanol mixtures is independent of the pyridine base, and it is estimated to be -35.2 kJ mol{sup -1}. Heterocoordination in these solutions is due in part to size effects. Their

  2. Time-dependence in mixture toxicity prediction.

    Science.gov (United States)

    Dawson, Douglas A; Allen, Erin M G; Allen, Joshua L; Baumann, Hannah J; Bensinger, Heather M; Genco, Nicole; Guinn, Daphne; Hull, Michael W; Il'Giovine, Zachary J; Kaminski, Chelsea M; Peyton, Jennifer R; Schultz, T Wayne; Pöch, Gerald

    2014-12-04

    The value of time-dependent toxicity (TDT) data in predicting mixture toxicity was examined. Single chemical (A and B) and mixture (A+B) toxicity tests using Microtox(®) were conducted with inhibition of bioluminescence (Vibrio fischeri) being quantified after 15, 30 and 45-min of exposure. Single chemical and mixture tests for 25 sham (A1:A2) and 125 true (A:B) combinations had a minimum of seven duplicated concentrations with a duplicated control treatment for each test. Concentration/response (x/y) data were fitted to sigmoid curves using the five-parameter logistic minus one parameter (5PL-1P) function, from which slope, EC25, EC50, EC75, asymmetry, maximum effect, and r(2) values were obtained for each chemical and mixture at each exposure duration. Toxicity data were used to calculate percentage-based TDT values for each individual chemical and mixture of each combination. Predicted TDT values for each mixture were calculated by averaging the TDT values of the individual components and regressed against the observed TDT values obtained in testing, resulting in strong correlations for both sham (r(2)=0.989, n=25) and true mixtures (r(2)=0.944, n=125). Additionally, regression analyses confirmed that observed mixture TDT values calculated for the 50% effect level were somewhat better correlated with predicted mixture TDT values than at the 25 and 75% effect levels. Single chemical and mixture TDT values were classified into five levels in order to discern trends. The results suggested that the ability to predict mixture TDT by averaging the TDT of the single agents was modestly reduced when one agent of the combination had a positive TDT value and the other had a minimal or negative TDT value. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  3. Two-microphone Separation of Speech Mixtures

    DEFF Research Database (Denmark)

    2006-01-01

    Matlab source code for underdetermined separation of instaneous speech mixtures. The algorithm is described in [1] Michael Syskind Pedersen, DeLiang Wang, Jan Larsen and Ulrik Kjems: ''Two-microphone Separation of Speech Mixtures,'' 2006, submitted for journal publoication. See also, [2] Michael...

  4. Fibril assembly in whey protein mixtures

    NARCIS (Netherlands)

    Bolder, S.G.

    2007-01-01

    The objective of this thesis was to study fibril assembly in mixtures of whey proteins. The effect of the composition of the protein mixture on the structures and the resulting phase behaviour was investigated. The current work has shown that beta-lactoglobulin is responsible for the fibril assembly

  5. Supercritical separation process for complex organic mixtures

    Science.gov (United States)

    Chum, Helena L.; Filardo, Giuseppe

    1990-01-01

    A process is disclosed for separating low molecular weight components from complex aqueous organic mixtures. The process includes preparing a separation solution of supercritical carbon dioxide with an effective amount of an entrainer to modify the solvation power of the supercritical carbon dioxide and extract preselected low molecular weight components. The separation solution is maintained at a temperature of at least about 70.degree. C. and a pressure of at least about 1,500 psi. The separation solution is then contacted with the organic mixtures while maintaining the temperature and pressure as above until the mixtures and solution reach equilibrium to extract the preselected low molecular weight components from the organic mixtures. Finally, the entrainer/extracted components portion of the equilibrium mixture is isolated from the separation solution.

  6. Phase equilibria in DOPC/DPPC: Conversion from gel to subgel in two component mixtures.

    Science.gov (United States)

    Schmidt, Miranda L; Ziani, Latifa; Boudreau, Michelle; Davis, James H

    2009-11-07

    Biological membranes contain a mixture of phospholipids with varying degrees of hydrocarbon chain unsaturation. Mixtures of long chain saturated and unsaturated lipids with cholesterol have attracted a lot of attention because of the formation of two coexisting fluid bilayer phases in such systems over a broad range of temperature and composition. Interpretation of the phase behavior of such ternary mixtures must be based on a thorough understanding of the phase behavior of the binary mixtures formed with the same components. This article describes the phase behavior of mixtures of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) with 1,2-di-d(31)-palmitoyl-sn-glycero-3-phosphocholine (DPPC) between -20 and 50 degrees C. Particular attention has been paid to the phase coexistence below about 16 degrees C where the subgel phase appears. The changes in the shape of the spectrum (and its spectral moments) during the slow transformation process leads to the conclusion that below 16 degrees C the gel phase is metastable and the gel component of the two-phase mixture slowly transforms to the subgel phase with a slightly different composition. This results in a line of three-phase coexistence near 16 degrees C. Analysis of the transformation of the metastable gel domains into the subgel phase using the nucleation and growth model shows that the subgel domain growth is a two dimensional process.

  7. Inhibition of surface crystallisation of amorphous indomethacin particles in physical drug-polymer mixtures.

    Science.gov (United States)

    Priemel, Petra A; Laitinen, Riikka; Barthold, Sarah; Grohganz, Holger; Lehto, Vesa-Pekka; Rades, Thomas; Strachan, Clare J

    2013-11-18

    Surface coverage may affect the crystallisation behaviour of amorphous materials. This study investigates crystallisation inhibition in powder mixtures of amorphous drug and pharmaceutical excipients. Pure amorphous indomethacin (IMC) powder and physical mixtures thereof with Eudragit(®) E or Soluplus(®) in 3:1, 1:1 and 1:3 (w/w) ratios were stored at 30 °C and 23 or 42% RH. Samples were analysed during storage by X-ray powder diffraction, thermogravimetric analysis, differential scanning calorimetry, and scanning electron microscopy (SEM). IMC Eudragit(®) mixtures showed higher physical stability than pure IMC whereas IMC Soluplus(®) mixtures did not. Water uptake was higher for mixtures containing Soluplus(®) than for amorphous IMC or IMC Eudragit(®) mixtures. However, the Tg of amorphous IMC was unaffected by the presence (and nature) of polymer. SEM revealed that Eudragit(®) particles aggregated on the surface of IMC particles, whereas Soluplus(®) particles did not. The drug particles developed multiple crystallites at their surface with subsequent crystal growth. The intimate contact between the surface agglomerated Eudragit(®) particles and drug is believed to inhibit crystallisation through reduced IMC surface molecular mobility. Polymer particles may also mechanically hinder crystal growth outwards from the surface. This work highlights the importance of microparticulate surface coverage of amorphous drug particles on their stability.

  8. Phenol and cresol mixture degradation by the yeast Trichosporon cutaneum.

    Science.gov (United States)

    Alexieva, Z; Gerginova, M; Manasiev, J; Zlateva, P; Shivarova, N; Krastanov, A

    2008-11-01

    Most industrial wastes contain different organic mixtures, making important the investigation on the microbial destruction of composite substrates. The capability of microbes to remove harmful chemicals from polluted environments strongly depends on the presence of other carbon and energy substrates. The effect of mixtures of phenol- and methyl-substituted phenols (o-, m-, p-cresol) on the growth behaviour and degradation capacity of Trichosporon cutaneum strain was investigated. The cell-free supernatants were analysed by HPLC. It was established that the presence of o-, m- and p- cresol has not prevented complete phenol assimilation but had significant delaying effect on the phenol degradation dynamics. The mutual influence of phenol and p-cresol was investigated. We developed the kinetic model on the basis of Haldane kinetics, which used model parameters from single-substrate experiments to predict the outcome of the two-substrate mixture experiment. The interaction coefficients indicating the degree to which phenol affects the biodegradation of p-cresol and vice versa were estimated. Quantitative estimation of interaction parameters is essential to facilitate the application of single or mixed cultures to the bio-treatment of hazardous compounds.

  9. Confinement-Driven Phase Separation of Quantum Liquid Mixtures

    Science.gov (United States)

    Prisk, T. R.; Pantalei, C.; Kaiser, H.; Sokol, P. E.

    2012-08-01

    We report small-angle neutron scattering studies of liquid helium mixtures confined in Mobil Crystalline Material-41 (MCM-41), a porous silica glass with narrow cylindrical nanopores (d=3.4nm). MCM-41 is an ideal model adsorbent for fundamental studies of gas sorption in porous media because its monodisperse pores are arranged in a 2D triangular lattice. The small-angle scattering consists of a series of diffraction peaks whose intensities are determined by how the imbibed liquid fills the pores. Pure He4 adsorbed in the pores show classic, layer-by-layer film growth as a function of pore filling, leaving the long range symmetry of the system intact. In contrast, the adsorption of He3-He4 mixtures produces a structure incommensurate with the pore lattice. Neither capillary condensation nor preferential adsorption of one helium isotope to the pore walls can provide the symmetry-breaking mechanism. The scattering is consistent with the formation of randomly distributed liquid-liquid microdomains ˜2.3nm in size, providing evidence that confinement in a nanometer scale capillary can drive local phase separation in quantum liquid mixtures.

  10. Toxicity of natural mixtures of organic pollutants in temperate and polar marine phytoplankton

    KAUST Repository

    Echeveste, Pedro

    2016-07-26

    Semivolatile and persistent organic pollutants (POPs) undergo atmospheric transport before being deposited to the oceans, where they partition to phytoplankton organic matter. The goal of this study was to determine the toxicity of naturally occurring complex mixtures of organic pollutants to temperate and polar phytoplankton communities from the Mediterranean Sea, the North East (NE) Atlantic, and Southern Oceans. The cell abundance of the different phytoplankton groups, chlorophyll a concentrations, viability of the cells, and growth and decay constants were monitored in response to addition of a range of concentrations of mixtures of organic pollutants obtained from seawater extracts. Almost all of the phytoplankton groups were significantly affected by the complex mixtures of non-polar and polar organic pollutants, with toxicity being greater for these mixtures than for single POPs or simple POP mixtures. Cocktails\\' toxicity arose at concentrations as low as tenfold the field oceanic levels, probably due to a higher chemical activity of the mixture than of simple POPs mixtures. Overall, smaller cells were the most affected, although Mediterranean picophytoplankton was significantly more tolerant to non-polar POPs than picophytoplankton from the Atlantic Ocean or the Bellingshausen Sea microphytoplankton. © 2016 Elsevier B.V.

  11. A computational investigation on random packings of sphere-spherocylinder mixtures

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Random packings of binary mixtures of spheres and spherocylinders with the same volume and the same diameter were simulated by a sphere assembly model and relaxation algorithm. Simulation results show that, independently of the component volume fraction, the mixture packing density increases and then decreases with the growth of the aspect ratio of spherocylinders, and the packing density reaches its maximum at the aspect ratio of 0.35. With the same volume particles, results show that the dependence of the mixture packing density on the volume fraction of spherocylinders is approximately linear. With the same diameter particles, the relationship between the mixture packing density and component volume fraction is also roughly linear for short spherocylinders, but when the aspect ratio of spherocylinders is greater than 1.6, the curves turn convex which means the packing of the mixture can be denser than either the sphere or spherocylinder packing alone. To validate the sphere assembly model and relaxation algorithm, binary mixtures of spheres and random packings of spherocylinders were also simulated. Simulation results show the packing densities of sphere mixtures agree with previous prediction models and the results of spherocylinders correspond with the simulation results in literature.

  12. Influence of microwave heating on liquid-liquid phase inversion and temperature rates for immiscible mixtures.

    Science.gov (United States)

    Kennedy, Alvin; Tadesse, Solomon; Nunes, Janine; Reznik, Aron

    2011-01-01

    Time dependencies of component temperatures for mixtures of immiscible liquids during microwave heating were studied for acetonitrile-cyclohexane and water-toluene. For the first time, we report microwave induced liquid-liquid phase inversion for acetonitrile-cyclohexane mixture: acetonitrile layer was initially at the bottom of the mixture, after 10 sec of microwave heating its density decreased and it inverted to the top of the mixture for the remainder of the microwave heating. This phase inversion could not be achieved by conventional radiant heating. The maximum rate of temperature growth for the polar component of the mixtures was 2 - 5 times larger than for the non-polar component. This suggests that microwave energy is absorbed by polar liquids (water or acetonitrile) and heat is transferred into the non-polar liquid (toluene or cyclohexane) in the mixture by conduction (in case of cyclohexane) or conduction and convection (in case of toluene). Comparison between experimental data and semi-empirical mathematical models, proposed in [Kennedy et at., 2009] showed good correlation. Average relative error between theoretical and experimental results did not exceed 7%. These results can be used to model the temperature kinetics of components for other multiphase mixtures.

  13. Perinatal exposure to mixtures of anti-androgenic chemicals causes proliferative lesions in rat prostate

    DEFF Research Database (Denmark)

    Boberg, Julie; Johansson, Hanna Katarina Lilith; Hadrup, Niels

    2015-01-01

    BACKGROUND: Elevated levels of endogenous or exogenous estrogens during fetal life can induce permanent disturbances in prostate growth and predispose to precancerous lesions. Recent studies have indicated that also early anti-androgen exposure may affect prostate cancer risk. METHODS: We examined...... disrupters relevant for human exposure was found to elicit persistent effects on the rat prostate following perinatal exposure, suggesting that human perinatal exposure to environmental chemicals may increase the risk of prostate cancer later in life. Prostate....... the influence of perinatal exposure to mixtures of anti-androgenic and estrogenic chemicals on prostate development. Wistar rats were exposed from gestation day 7 to postnatal day 22 to a mixture of 8 anti-androgenic compounds (AAMix), a mixture of four estrogenic compounds (EMix), or paracetamol or a mixture...

  14. On the mixture model for multiphase flow

    Energy Technology Data Exchange (ETDEWEB)

    Manninen, M.; Taivassalo, V. [VTT Energy, Espoo (Finland). Nuclear Energy; Kallio, S. [Aabo Akademi, Turku (Finland)

    1996-12-31

    Numerical flow simulation utilising a full multiphase model is impractical for a suspension possessing wide distributions in the particle size or density. Various approximations are usually made to simplify the computational task. In the simplest approach, the suspension is represented by a homogeneous single-phase system and the influence of the particles is taken into account in the values of the physical properties. This study concentrates on the derivation and closing of the model equations. The validity of the mixture model is also carefully analysed. Starting from the continuity and momentum equations written for each phase in a multiphase system, the field equations for the mixture are derived. The mixture equations largely resemble those for a single-phase flow but are represented in terms of the mixture density and velocity. The volume fraction for each dispersed phase is solved from a phase continuity equation. Various approaches applied in closing the mixture model equations are reviewed. An algebraic equation is derived for the velocity of a dispersed phase relative to the continuous phase. Simplifications made in calculating the relative velocity restrict the applicability of the mixture model to cases in which the particles reach the terminal velocity in a short time period compared to the characteristic time scale of the flow of the mixture. (75 refs.)

  15. Foaming of mixtures of pure hydrocarbons

    Science.gov (United States)

    Robinson, J. V.; Woods, W. W.

    1950-01-01

    Mixtures of pure liquid hydrocarbons are capable of foaming. Nine hydrocarbons were mixed in pairs, in all possible combinations, and four proportions of each combination. These mixtures were sealed in glass tubes, and the foaming was tested by shaking. Mixtures of aliphatic with other aliphatic hydrocarbons, or of alkyl benzenes with other alkyl benzenes, did not foam. Mixtures of aliphatic hydrocarbons with alkyl benzenes did foam. The proportions of the mixtures greatly affected the foaming, the maximum foaming of 12 of 20 pairs being at the composition 20 percent aliphatic hydrocarbon, 80 percent alkyl benzene. Six seconds was the maximum foam lifetime of any of these mixtures. Aeroshell 120 lubricating oil was fractionated into 52 fractions and a residue by extraction with acetone in a fractionating extractor. The index of refraction, foam lifetime, color, and viscosity of these fractions were measured. Low viscosity and high index fractions were extracted first. The viscosity of the fractions extracted rose and the index decreased as fractionation proceeded. Foam lifetimes and color were lowest in the middle fractions. Significance is attached to the observation that none of the foam lifetimes of the fractions or residue is as high as the foam lifetime of the original Aeroshell, indicating that the foaming is not due to a particular foaming constituent, but rather to the entire mixture.

  16. Coking technology using packed coal mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Kuznichenko, V.M.; Shteinberg, Eh.A.; Tolstoi, A.P. (Khar' kovskii Nauchno-Issledovatel' skii Uglekhimicheskii Institut, Kharkov (Ukrainian SSR))

    1991-08-01

    Discusses coking of packed coal charges in the FRG, USSR, France, India, Poland and Czechoslovakia. The following aspects are evaluated: types of weakly caking coals that are used as components of packed mixtures, energy consumption of packing, effects of coal mixture packing on coke oven design, number of coke ovens in a battery, heating temperature, coking time, coke properties, investment and operating cost. Statistical data that characterize the Saarberg packing process used in the FRG are analyzed. Packing coal mixtures for coking improves coke quality and reduces environmental pollution. 4 refs.

  17. Quantiles for Finite Mixtures of Normal Distributions

    Science.gov (United States)

    Rahman, Mezbahur; Rahman, Rumanur; Pearson, Larry M.

    2006-01-01

    Quantiles for finite mixtures of normal distributions are computed. The difference between a linear combination of independent normal random variables and a linear combination of independent normal densities is emphasized. (Contains 3 tables and 1 figure.)

  18. A mixture theory for geophysical fluids

    Directory of Open Access Journals (Sweden)

    A. C. Eringen

    2004-01-01

    Full Text Available A continuum theory is developed for a geophysical fluid consisting of two species. Balance laws are given for the individual components of the mixture, modeled as micropolar viscous fluids. The continua allow independent rotational degrees of freedom, so that the fluids can exhibit couple stresses and a non-symmetric stress tensor. The second law of thermodynamics is used to develop constitutive equations. Linear constitutive equations are constituted for a heat conducting mixture, each species possessing separate viscosities. Field equations are obtained and boundary and initial conditions are stated. This theory is relevant to an atmospheric mixture consisting of any two species from rain, snow and/or sand. Also, this is a continuum theory for oceanic mixtures, such as water and silt, or water and oil spills, etc.

  19. The disentangling number for phylogenetic mixtures

    CERN Document Server

    Sullivant, Seth

    2011-01-01

    We provide a logarithmic upper bound for the disentangling number on unordered lists of leaf labeled trees. This results is useful for analyzing phylogenetic mixture models. The proof depends on interpreting multisets of trees as high dimensional contingency tables.

  20. Mapping the jamming transition of bidisperse mixtures

    Science.gov (United States)

    Koeze, D. J.; Vågberg, D.; Tjoa, B. B. T.; Tighe, B. P.

    2016-03-01

    We systematically map out the jamming transition of all 2D bidisperse mixtures of frictionless disks in the hard-particle limit. The critical volume fraction, mean coordination number, number of rattlers, structural order parameters, and bulk modulus each show a rich variation with mixture composition and particle size ratio, and can therefore be tuned by choosing certain mixtures. We identify two local minima in the critical volume fraction, both of which have low structural order; one minimum is close to the widely studied 50 : 50 mixture of particles with a ratio of radii of 1 : 1.4. We also identify a region at low size ratios characterized by increased structural order and high rattler fractions, with a corresponding enhancement in the stiffness.

  1. Ultrafiltration of a polymer-electrolyte mixture

    NARCIS (Netherlands)

    Vonk, P; Noordman, T.R; Schippers, D; Tilstra, B; Wesselingh, J.A

    1997-01-01

    We present a mathematical model to describe the ultrafiltration behaviour of polymer-electrolyte mixtures. The model combines the proper thermodynamic forces (pressure, chemical potential and electrical potential differences) with multicomponent diffusion theory. The model is verified with experimen

  2. Model structure selection in convolutive mixtures

    DEFF Research Database (Denmark)

    Dyrholm, Mads; Makeig, Scott; Hansen, Lars Kai

    2006-01-01

    The CICAAR algorithm (convolutive independent component analysis with an auto-regressive inverse model) allows separation of white (i.i.d) source signals from convolutive mixtures. We introduce a source color model as a simple extension to the CICAAR which allows for a more parsimoneous represent......The CICAAR algorithm (convolutive independent component analysis with an auto-regressive inverse model) allows separation of white (i.i.d) source signals from convolutive mixtures. We introduce a source color model as a simple extension to the CICAAR which allows for a more parsimoneous...... representation in many practical mixtures. The new filter-CICAAR allows Bayesian model selection and can help answer questions like: 'Are we actually dealing with a convolutive mixture?'. We try to answer this question for EEG data....

  3. Model structure selection in convolutive mixtures

    DEFF Research Database (Denmark)

    Dyrholm, Mads; Makeig, S.; Hansen, Lars Kai

    2006-01-01

    The CICAAR algorithm (convolutive independent component analysis with an auto-regressive inverse model) allows separation of white (i.i.d) source signals from convolutive mixtures. We introduce a source color model as a simple extension to the CICAAR which allows for a more parsimonious represent......The CICAAR algorithm (convolutive independent component analysis with an auto-regressive inverse model) allows separation of white (i.i.d) source signals from convolutive mixtures. We introduce a source color model as a simple extension to the CICAAR which allows for a more parsimonious...... representation in many practical mixtures. The new filter-CICAAR allows Bayesian model selection and can help answer questions like: ’Are we actually dealing with a convolutive mixture?’. We try to answer this question for EEG data....

  4. Boundary integral approach for propagating interfaces in a binary non-isothermal mixture

    Science.gov (United States)

    Alexandrov, D. V.; Galenko, P. K.

    2017-03-01

    A method based on boundary integral approach to the propagation of curved phase interface in a binary non-isothermal mixture is developed. Previously known equations and solutions for thermally controlled growth and needle-like dendrites follow from the obtained boundary integral equations as limiting cases.

  5. Single and mixture toxicity of pharmaceuticals and chlorophenols to freshwater algae Chlorella vulgaris.

    Science.gov (United States)

    Geiger, Elisabeth; Hornek-Gausterer, Romana; Saçan, Melek Türker

    2016-07-01

    Organisms in the aquatic environment are exposed to a variety of substances of numerous chemical classes. The unintentional co-occurrence of pharmaceuticals and other contaminants of emerging concern may pose risk to non-target organisms. In this study, individual and binary mixture toxicity experiments of selected pharmaceuticals (ibuprofen and ciprofloxacin) and chlorophenols (2.4-dichlorophenol (2,4-DCP) and 3-chlorophenol (3-CP)) have been performed with freshwater algae Chlorella vulgaris. All experiments have been carried out according to the 96-h algal growth inhibition test OECD No. 201. Binary mixture tests were conducted using proportions of the respective IC50s in terms of toxic unit (TU). The mixture concentration-response curve was compared to predicted effects based on both the concentration addition (CA) and the independent action (IA) model. Additionally, the Combination Index (CI)-isobologram equation method was used to assess toxicological interactions of the binary mixtures. All substances individually tested had a significant effect on C. vulgaris population density and revealed IC50 values ciprofloxacin>3-CP>ibuprofen. Generally, it can be concluded from this study that toxic mixture effects of all tested chemicals to C. vulgaris are higher than the individual effect of each mixture component. It could be demonstrated that IC50 values of the tested mixtures predominately lead to additive effects. The CA model is appropriate to estimate mixture toxicity, while the IA model tends to underestimate the joint effect. The CI-isobologram equation method predicted the mixtures accurately and elicited synergism at low effect levels for the majority of tested combinations.

  6. Laboratory performance of asphalt rubber mixtures

    OpenAIRE

    Fontes, Liseane; Trichês, Glicério; Pais, Jorge; Pereira, Paulo; Minhoto, Manuel

    2009-01-01

    Asphalt rubber mixtures are one of the most promising techniques to extend the service life of asphalt pavement overlays. Asphalt rubber binder is composed of crumb rubber from reclaimed tires and conventional asphalt. The asphalt rubber binder can be obtained through wet process in two different systems: tire rubber modified asphalt binder (produced at industrial plants) and continuous blending (produced in asphalt plants). This study presents a laboratory evaluation of asphalt rubber mixtur...

  7. Assessing sanitary mixtures in East African cities

    OpenAIRE

    Letema, S.C.

    2012-01-01

    The urbanisation of poverty and informality in East African cities poses a threat to environmental health, perpetuates social exclusion and inequalities, and creates service gaps (UN-Habitat, 2008). This makes conventional sanitation provision untenable citywide, giving rise to the emergence of sanitation mixtures. Sanitation mixtures have different scales, institutional arrangements, user groups, and rationalities for their establishment, location, and management. For assessing the performan...

  8. Fitting mixture distributions to phenylthiocarbamide (PTC) sensitivity.

    OpenAIRE

    Jones, P N; G.J. McLachlan

    1991-01-01

    A technique for fitting mixture distributions to phenylthiocarbamide (PTC) sensitivity is described. Under the assumptions of Hardy-Weinberg equilibrium, a mixture of three normal components is postulated for the observed distribution, with the mixing parameters corresponding to the proportions of the three genotypes associated with two alleles A and a acting at a single locus. The corresponding genotypes AA, Aa, and aa are then considered to have separate means and variances. This paper is c...

  9. Using Big Data Analytics to Address Mixtures Exposure

    Science.gov (United States)

    The assessment of chemical mixtures is a complex issue for regulators and health scientists. We propose that assessing chemical co-occurrence patterns and prevalence rates is a relatively simple yet powerful approach in characterizing environmental mixtures and mixtures exposure...

  10. Catalyst mixture for aromatic hydrocarbon synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Minderhoud, J.K.; Huizinga, T.; Sie, S.T.

    1989-06-06

    The present invention is concerned with catalyst mixtures consisting of two catalysts, characterized in that one, which is based on zinc, is capable of catalysing the conversion of a H/sub 2//CO mixture into oxygen-containing organic compounds, and the other is a crystalline iron/boron silicate which, after one hour's calcination in air at 500/sup 0/C, has the following properties: a certain X-ray powder diffraction pattern and, in the formula that represents the composition of the silicate, expressed in moles of the oxides, a SiO/sub 2//Fe/sub 2/O/sub 3 molar ratio that is 20-2000, a SiO/sub 2//B/sub 2/O/sub 3/ molar ratio 50-5000, and a Fe/sub 2/O/sub 3//B/sub 2/O/sub 3/ molar ratio higher than 1.0. Said catalyst mixtures show higher aromatics selectivity in the preparation of hydrocarbon mixtures from H/sub 2//CO mixtures than such a mixture comprising an iron silicate instead of the above iron/boron silicates. 3 tabs.

  11. Homogeneous cooling of mixtures of particle shapes

    Science.gov (United States)

    Hidalgo, R. C.; Serero, D.; Pöschel, T.

    2016-07-01

    In this work, we examine theoretically the cooling dynamics of binary mixtures of spheres and rods. To this end, we introduce a generalized mean field analytical theory, which describes the free cooling behavior of the mixture. The relevant characteristic time scale for the cooling process is derived, depending on the mixture composition and the aspect ratio of the rods. We simulate mixtures of spherocylinders and spheres using a molecular dynamics algorithm implemented on graphics processing unit (GPU) architecture. We systematically study mixtures composed of spheres and rods with several aspect ratios and varying the mixture composition. A homogeneous cooling state, where the time dependence of the system's intensive variables occurs only through a global granular temperature, is identified. We find cooling dynamics in excellent agreement with Haff's law, when using an adequate time scale. Using the scaling properties of the homogeneous cooling dynamics, we estimated numerically the efficiency of the energy interchange between rotational and translational degrees of freedom for collisions between spheres and rods.

  12. When mixtures of hard-sphere-like colloids do not behave as mixtures of hard spheres.

    Science.gov (United States)

    Germain, Ph; Malherbe, J G; Amokrane, S

    2004-10-01

    The validity of the concept of "hard-sphere-like" particles for mixtures of colloids is questioned from a theoretical point of view. This concerns the class of pseudobinary mixtures in which the nonsteric interactions between the colloids are "residual" (with very small range and moderate strength). It is shown that contrary to common expectation, such interactions may have unexpected consequences on the theoretical phase diagram. The distinction between this situation and true solute-solvent mixtures is emphasized.

  13. Growth Hormone

    Science.gov (United States)

    ... AACC products and services. Advertising & Sponsorship: Policy | Opportunities Growth Hormone Share this page: Was this page helpful? Also known as: GH; Human Growth Hormone; HGH; Somatotropin; Growth Hormone Stimulation Test; Growth ...

  14. Urban growth management

    DEFF Research Database (Denmark)

    Jørgensen, Gertrud; Alexander Sick Nielsen, Thomas; Grünfelder, Julien

    2011-01-01

    urban growth and curb urban sprawl in a wider sense. Methodology The main methodology of the paper is a desk-research based review of policy options supplemented with field study and interviews in selected cased study regions. This paper consists of two parts. The first part is based on literature......; clarity of visions and goals; coordination with other policies including economic incentives; rural policies providing incentives to maintain agricultural activities; political commitment and acceptance; support/framing from higher level policies; and finally economic incentives and de......-incentives. The evidence from the case studies generally confirm the role of national planning levels as well as the need for clear visions and strategies, and policy integration. Additional topics highlighted in the case studies include the existence and mandate of regional bodies, the role of European rural policies...

  15. Intracellular storage of acetate/starch mixture by fast growing microbial culture in sequencing batch reactor under continuous feeding.

    Science.gov (United States)

    Ciggin, Asli Seyhan; Majone, Mauro; Orhon, Derin

    2012-09-01

    The paper evaluated intracellular storage formation in fast growing microbial culture fed with acetate/starch mixture under continuous feeding. Three parallel laboratory-scale sequencing batch reactors (SBRs) were operated at a sludge age of 2 days: one of the SBRs was fed with acetate/starch mixture and the other two with acetate and starch, respectively, for comparing the results with single substrate systems. Despite continuous feeding, both acetate and starch components in the substrate mixture were partially converted to storage biopolymers. Poly-hydroxybutyrate (PHB) and glycogen pools were formed during SBR operation at steady state. Only a limited fraction of 12% of the acetate fed during each cycle generated PHB storage while the rest was directly utilized for microbial growth. Around half of the starch fraction of the substrate mixture was converted to glycogen. Increasing the sludge age to 8 days did not affect storage stoichiometry both for acetate and starch in the mixture.

  16. Configuration-specific kinetic theory applied to an ideal binary gas mixture.

    Science.gov (United States)

    Wiseman, Floyd L

    2006-10-05

    This paper is the second in a two-part series dealing with the configuration-specific analyses for molecular collision events of hard, spherical molecules at thermal equilibrium. The first paper analyzed a single-component system, and the reader is referred to it for the fundamental concepts. In this paper, the expressions for the configuration-specific collision frequencies and the average line-of-centers collision angles and speeds are derived for an ideal binary gas mixture. The analyses show that the average line-of-centers quantities are all dependent upon the ratio of the masses of the two components, but not upon molecular size. Of course, the configuration-specific collision frequencies do depend on molecular size. The expression for the overall binary collision frequency is a simple sum of the configuration-specific collision frequencies and is identical to the conventional expression.

  17. Sharp separation of C2/C3 hydrocarbon mixtures by zeolitic imidazolate framework-8 (ZIF-8) membranes synthesized in aqueous solutions

    KAUST Repository

    Pan, Yichang

    2011-01-01

    Exceptional high quality ZIF-8 membranes prepared through a novel seeded growth method in aqueous solutions at near room temperature exhibit excellent separation performance for C2/C3 hydrocarbon mixtures. The separation factors for mixtures of ethane/propane, ethylene/propylene and ethylene/propane are ∼80, ∼10 and ∼167, respectively. © 2011 The Royal Society of Chemistry.

  18. Identifiability of large phylogenetic mixture models.

    Science.gov (United States)

    Rhodes, John A; Sullivant, Seth

    2012-01-01

    Phylogenetic mixture models are statistical models of character evolution allowing for heterogeneity. Each of the classes in some unknown partition of the characters may evolve by different processes, or even along different trees. Such models are of increasing interest for data analysis, as they can capture the variety of evolutionary processes that may be occurring across long sequences of DNA or proteins. The fundamental question of whether parameters of such a model are identifiable is difficult to address, due to the complexity of the parameterization. Identifiability is, however, essential to their use for statistical inference.We analyze mixture models on large trees, with many mixture components, showing that both numerical and tree parameters are indeed identifiable in these models when all trees are the same. This provides a theoretical justification for some current empirical studies, and indicates that extensions to even more mixture components should be theoretically well behaved. We also extend our results to certain mixtures on different trees, using the same algebraic techniques.

  19. Relativistic mixtures of charged and uncharged particles

    Energy Technology Data Exchange (ETDEWEB)

    Kremer, Gilberto M. [Departamento de Física, Universidade Federal do Paraná, Curitiba (Brazil)

    2014-01-14

    Mixtures of relativistic gases within the framework of Boltzmann equation are analyzed. Three systems are considered. The first one refers to a mixture of uncharged particles by using Grad’s moment method, where the relativistic mixture is characterized by the moments of the distribution functions: particle four-flows, energy-momentum tensors, and third-order moment tensors. In the second Fick’s law for a mixture of relativistic gases of non-disparate rest masses in a Schwarzschild metric are derived from an extension of Marle and McCormack model equations applied to a relativistic truncated Grad’s distribution function, where it is shown the dependence of the diffusion coefficient on the gravitational potential. The third one consists in the derivation of the relativistic laws of Ohm and Fourier for a binary mixtures of electrons with protons and electrons with photons subjected to external electromagnetic fields and in presence of gravitational fields by using the Anderson and Witting model of the Boltzmann equation.

  20. Microsiemens or Milligrams: Measures of Ionic Mixtures ...

    Science.gov (United States)

    In December of 2016, EPA released the Draft Field-Based Methods for Developing Aquatic Life Criteria for Specific Conductivity for public comment. Once final, states and authorized tribes may use these methods to derive field-based ecoregional ambient Aquatic Life Ambient Water Quality Criteria (AWQC) for specific conductivity (SC) in flowing waters. The methods provide flexible approaches for developing science-based SC criteria that reflect ecoregional or state specific factors. The concentration of a dissolved salt mixture can be measured in a number of ways including measurement of total dissolved solids, freezing point depression, refractive index, density, or the sum of the concentrations of individually measured ions. For the draft method, SC was selected as the measure because SC is a measure of all ions in the mixture; the measurement technology is fast, inexpensive, and accurate, and it measures only dissolved ions. When developing water quality criteria for major ions, some stakeholders may prefer to identify the ionic constituents as a measure of exposure instead of SC. A field-based method was used to derive example chronic and acute water quality criteria for SC and two anions a common mixture of ions (bicarbonate plus sulfate, [HCO3−] + [SO42−] in mg/L) that represent common mixtures in streams. These two anions are sufficient to model the ion mixture and SC (R2 = 0.94). Using [HCO3−] + [SO42−] does not imply that these two anions are the

  1. ASPECTS OF THERMODYNAMICS OF POLYMER MIXTURES

    Institute of Scientific and Technical Information of China (English)

    CHAI Zhikuan

    1987-01-01

    In this brief review article some aspects of the thermodynamics of polymer mixtures are discussed,mainly based on the author's research. The studies of poly (methyl methacrylate)/chlorinated polyethylene (CPE), poly (butyl acrylate)/CPE and CPE/CPE (different chlorine content) mixture verify the "dissimilarity" and "similarity" principles for predicting miscibility of polymer mixtures. The sign of heat of mixing of oligomeric analogues is not sufficient in predicting the miscibility. The Flory equation of state theory has been applied to simulate the phase boundaries of polymer mixtures. The empirical entropy parameter Q12 plays an important role in the calculation, this reduces the usefulness of the theory. With energy parameter X12 ≠ 0 and Q12 ≠ 0 the spinodals so calculated are reasonable compared to experiments.A hole model was suggested for the statistics of polymer mixtures. The new hole theory combines the features of both the Flory equation of state theory and the Sanchez lattice fluid theory and can be reduced to them under some conditions.

  2. A constitutive theory of reacting electrolyte mixtures

    Science.gov (United States)

    Costa Reis, Martina; Wang, Yongqi; Bono Maurizio Sacchi Bassi, Adalberto

    2013-11-01

    A constitutive theory of reacting electrolyte mixtures is formulated. The intermolecular interactions among the constituents of the mixture are accounted for through additional freedom degrees to each constituent of the mixture. Balance equations for polar reacting continuum mixtures are accordingly formulated and a proper set of constitutive equations is derived with basis in the Müller-Liu formulation of the second law of thermodynamics. Moreover, the non-equilibrium and equilibrium responses of the reacting mixture are investigated in detail by emphasizing the inner and reactive structures of the medium. From the balance laws and constitutive relations, the effects of molecular structure of constituents upon the fluid flow are studied. It is also demonstrated that the local thermodynamic equilibrium state can be reached without imposing that the set of independent constitutive variables is time independent, neither spatially homogeneous nor null. The resulting constitutive relations presented throughout this work are of relevance to many practical applications, such as swelling of clays, developing of bio and polymeric membranes, and use of electrorheological fluids in industrial processes. The first author acknowledges financial support from National Counsel of Technological and Scientific Development (CNPq) and German Academic Exchange Service (DAAD).

  3. Asbestos Tailings as Aggregates for Asphalt Mixture

    Institute of Scientific and Technical Information of China (English)

    LIU Xinoming; XU Linrong

    2011-01-01

    To use many asbestos tailings collected in Ya-Lu highway, and to explore the feasibility of using asbestos tailings as aggregates in common asphalt mixtures, and properties of some asphalt mixtures were evaluated as well. X-ray diffraction (XRD), X-ray fluorescent (XRF), and atomic absorption spectrophotometry (AAS) were employed to determine the solid waste content of copper, zinc, lead, and cadmium. Volume properties and pavement performances of AC-25 asphalt mixture with asbestos tailings were also evaluated compared with those with basalt as aggregates.XRD and XRF measurement results infer that asbestos tailing is an excellent road material. Volume properties of AC-25 asphalt mixture with asbestos tailings satisfied the related specifications. No heavy metals and toxic pollution were detected in AAS test and the value of pH test is 8.23, which is help to the adhesion with asphalt in the asphalt concrete. When compared with basalt, high temperature property and the resistance to low temperature cracking of AC-25 asphalt mixture was improved by using asbestos tailings as aggregates. In-service AC-25 asphalt pavement with asbestos tailings also presented excellent performance and British Pendulum Number (BPN) coefficient of surface.

  4. A cold energy mixture theory for the equation of state in solid and porous metal mixtures

    Science.gov (United States)

    Zhang, X. F.; Qiao, L.; Shi, A. S.; Zhang, J.; Guan, Z. W.

    2011-07-01

    Porous or solid multi-component mixtures are ubiquitous in nature and extensively used as industrial materials such as multifunctional energetic structural materials (MESMs), metallic and ceramic powder for shock consolidation, and porous armor materials. In order to analyze the dynamic behavior of a particular solid or porous metal mixture in any given situation, a model is developed to calculate the Hugoniot data for solid or porous mixtures using only static thermodynamic properties of the components. The model applies the cold energy mixture theory to calculate the isotherm of the components to avoid temperature effects on the mixtures. The isobaric contribution from the thermodynamic equation of state is used to describe the porous material Hugoniot. Dynamic shock responses of solid or porous powder mixtures compacted by shock waves have been analyzed based on the mixture theory and Hugoniot for porous materials. The model is tested on both single-component porous materials such as aluminum 2024, copper, and iron; and on multi-component mixtures such as W/Cu, Fe/Ni, and Al/Ni. The theoretical calculations agree well with the corresponding experimental and simulation results. The present model produces satisfactory correlation with the experimentally obtained Hugoniot data for solid porous materials over a wide pressure range.

  5. Presence of Trifolium repens promotes complementarity of water use and N facilitation in diverse grass mixtures

    Directory of Open Access Journals (Sweden)

    Pauline eHernandez

    2016-04-01

    Full Text Available Legume species promote productivity and increase the digestibility of herbage in grasslands. Considerable experimental data also indicate that communities with legumes produce more above-ground biomass than is expected from monocultures. While it has been attributed to N facilitation, evidence to identify the mechanisms involved is still lacking and the role of complementarity in soil water acquisition by vertical root differentiation remains unclear. We used a 20-month mesocosm experiment to investigate the effects of species richness (single species, two- and five-species mixtures and functional diversity (presence of the legume Trifolium repens on a set of traits related to light, N and water use and measured at community level. We found a positive effect of Trifolium presence and abundance on biomass production and complementarity effects in the two-species mixtures from the second year. In addition the community traits related to water and N acquisition and use (leaf area, N, water-use efficiency and deep root growth were higher in the presence of Trifolium. With a multiple regression approach, we showed that the traits related to water acquisition and use were with N the main determinants of biomass production and complementarity effects in diverse mixtures. At shallow soil layers, lower root mass of Trifolium and higher soil moisture should increase soil water availability for the associated grass species. Conversely at deep soil layer, higher root growth and lower soil moisture mirror soil resource use increase of mixtures. Altogether, these results highlight N facilitation but almost soil vertical differentiation and thus complementarity for water acquisition and use in mixtures with Trifolium. Contrary to grass-Trifolium mixtures, no significant over-yielding was measured for grass mixtures even those having complementary traits (short and shallow vs tall and deep. Thus, vertical complementarity for soil resources uptake in mixtures

  6. Effect of feeding Cuminum cyminum fruits, Thymus vulgaris leaves or their mixture to rats.

    Science.gov (United States)

    Haroun, E M; Mahmoud, O M; Adam, S E I

    2002-04-01

    Cuminum cyminum fruits and T. vulgaris leaves were fed to male Wistar rats at 2% or 10% of standard diet for 6 w. A mixture (5% +5%) of the 2 plants was also fed to rats for a similar period. Diets containing 2% C. cyminum fruits, 2% or 10% T. vulgaris leaves were not toxic to rats. Impairment of growth and enterohepatonephropathy were observed in the rats fed a diet containing 10% C. cyminum fruits. These changes were also seen in the rats fed the mixture of the 2 plants and were accompanied by leukopenia, anemia and increases in serum AST activity and urea and by decreased total protein and albumin levels.

  7. Adaptive Mixture Methods Based on Bregman Divergences

    CERN Document Server

    Donmez, Mehmet A; Kozat, Suleyman S

    2012-01-01

    We investigate adaptive mixture methods that linearly combine outputs of $m$ constituent filters running in parallel to model a desired signal. We use "Bregman divergences" and obtain certain multiplicative updates to train the linear combination weights under an affine constraint or without any constraints. We use unnormalized relative entropy and relative entropy to define two different Bregman divergences that produce an unnormalized exponentiated gradient update and a normalized exponentiated gradient update on the mixture weights, respectively. We then carry out the mean and the mean-square transient analysis of these adaptive algorithms when they are used to combine outputs of $m$ constituent filters. We illustrate the accuracy of our results and demonstrate the effectiveness of these updates for sparse mixture systems.

  8. Computer simulation of rod-sphere mixtures

    CERN Document Server

    Antypov, D

    2003-01-01

    Results are presented from a series of simulations undertaken to investigate the effect of adding small spherical particles to a fluid of rods which would otherwise represent a liquid crystalline (LC) substance. Firstly, a bulk mixture of Hard Gaussian Overlap particles with an aspect ratio of 3:1 and hard spheres with diameters equal to the breadth of the rods is simulated at various sphere concentrations. Both mixing-demixing and isotropic-nematic transition are studied using Monte Carlo techniques. Secondly, the effect of adding Lennard-Jones particles to an LC system modelled using the well established Gay-Berne potential is investigated. These rod-sphere mixtures are simulated using both the original set of interaction parameters and a modified version of the rod-sphere potential proposed in this work. The subject of interest is the internal structure of the binary mixture and its dependence on density, temperature, concentration and various parameters characterising the intermolecular interactions. Both...

  9. Quasi-chemical approximation for polyatomic mixtures

    CERN Document Server

    Dávila, M V; Matoz-Fernandez, D A; Ramirez-Pastor, A J

    2016-01-01

    The statistical thermodynamics of binary mixtures of polyatomic species was developed on a generalization in the spirit of the lattice-gas model and the quasi-chemical approximation (QCA). The new theoretical framework is obtained by combining: (i) the exact analytical expression for the partition function of non-interacting mixtures of linear $k$-mers and $l$-mers (species occupying $k$ sites and $l$ sites, respectively) adsorbed in one dimension, and its extension to higher dimensions; and (ii) a generalization of the classical QCA for multicomponent adsorbates and multisite-occupancy adsorption. The process is analyzed through the partial adsorption isotherms corresponding to both species of the mixture. Comparisons with analytical data from Bragg-Williams approximation (BWA) and Monte Carlo simulations are performed in order to test the validity of the theoretical model. Even though a good fitting is obtained from BWA, it is found that QCA provides a more accurate description of the phenomenon of adsorpti...

  10. Efficient radiative transfer in dust grain mixtures

    CERN Document Server

    Wolf, S

    2003-01-01

    The influence of a dust grain mixture consisting of spherical dust grains with different radii and/or chemical composition on the resulting temperature structure and spectral energy distribution of a circumstellar shell is investigated. The comparison with the results based on an approximation of dust grain parameters representing the mean optical properties of the corresponding dust grain mixture reveal that (1) the temperature dispersion of a real dust grain mixture decreases substantially with increasing optical depth, converging towards the temperature distribution resulting from the approximation of mean dust grain parameters, and (2) the resulting spectral energy distributions do not differ by more than 10% if >= 2^5 grain sizes are considered which justifies the mean parameter approximation and the many results obtained under its assumption so far. Nevertheless, the dust grain temperature dispersion at the inner boundary of a dust shell may amount to >>100K and has therefore to be considered in the cor...

  11. Two-Microphone Separation of Speech Mixtures

    DEFF Research Database (Denmark)

    Pedersen, Michael Syskind; Wang, DeLiang; Larsen, Jan

    2008-01-01

    Separation of speech mixtures, often referred to as the cocktail party problem, has been studied for decades. In many source separation tasks, the separation method is limited by the assumption of at least as many sensors as sources. Further, many methods require that the number of signals within...... the recorded mixtures be known in advance. In many real-world applications, these limitations are too restrictive. We propose a novel method for underdetermined blind source separation using an instantaneous mixing model which assumes closely spaced microphones. Two source separation techniques have been...... similar signals. Using two microphones, we can separate, in principle, an arbitrary number of mixed speech signals. We show separation results for mixtures with as many as seven speech signals under instantaneous conditions. We also show that the proposed method is applicable to segregate speech signals...

  12. Modeling methods for mixture-of-mixtures experiments applied to a tablet formulation problem.

    Science.gov (United States)

    Piepel, G F

    1999-01-01

    During the past few years, statistical methods for the experimental design, modeling, and optimization of mixture experiments have been widely applied to drug formulation problems. Different methods are required for mixture-of-mixtures (MoM) experiments in which a formulation is a mixture of two or more "major" components, each of which is a mixture of one or more "minor" components. Two types of MoM experiments are briefly described. A tablet formulation optimization example from a 1997 article in this journal is used to illustrate one type of MoM experiment and corresponding empirical modeling methods. Literature references that discuss other methods for MoM experiments are also provided.

  13. Mutation spectra of complex environmental mixtures

    Energy Technology Data Exchange (ETDEWEB)

    DeMarini, D.M. [EPA, Research Triangle Park, NC (United States)

    1997-10-01

    Bioassay-directed chemical analysis of complex environmental mixtures has indicated that much of the genotoxic activity of mixtures is due to the presence of one or a few classes or chemicals within the mixture. We have extended this observation to the molecular level by using colony probe hybridization and PCR/DNA sequence analysis to determine the mutation spectra of {approximately}8,000 revertants induced by a variety of complex mixtures and their chemical fractions in TA100 and TA98 of Salmonella. For urban air, >80% of mutagenic activity was due to a base/neutral fraction that contained primarily PAHs. The mutation spectrum induced by unfractionated urban air was not significantly different from that produced by a model PAH, B(a)P. The mutation spectrum induced by organic extracts of chlorinated drinking water were similar to those produced by the chlorinated furanone MX, which accounted for {approximately}20% of the mutagenic activity of the samples. The base/neutral fraction of municipal waste incinerator emissions accounted for the primary class of mutations induced by the emissions, and a polar neutral fraction accounted for the secondary class of mutations induced by the emissions. The primary class of mutations induced by cigarette smoke condensate in TA100 (GC {yields} TA) is also the primary class of mutations in the p53 gene of lung tumors of cigarette smokers. These results confirm at the molecular level that the mutations induced by a complex mixture reflect the dominance of one or a few classes of chemicals within the mixture.

  14. Thermophysical Properties of Fluids and Fluid Mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Sengers, Jan V.; Anisimov, Mikhail A.

    2004-05-03

    The major goal of the project was to study the effect of critical fluctuations on the thermophysical properties and phase behavior of fluids and fluid mixtures. Long-range fluctuations appear because of the presence of critical phase transitions. A global theory of critical fluctuations was developed and applied to represent thermodynamic properties and transport properties of molecular fluids and fluid mixtures. In the second phase of the project, the theory was extended to deal with critical fluctuations in complex fluids such as polymer solutions and electrolyte solutions. The theoretical predictions have been confirmed by computer simulations and by light-scattering experiments. Fluctuations in fluids in nonequilibrium states have also been investigated.

  15. Paternity testing that involves a DNA mixture.

    Science.gov (United States)

    Mortera, Julia; Vecchiotti, Carla; Zoppis, Silvia; Merigioli, Sara

    2016-07-01

    Here we analyse a complex disputed paternity case, where the DNA of the putative father was extracted from his corpse that had been inhumed for over 20 years. This DNA was contaminated and appears to be a mixture of at least two individuals. Furthermore, the mother's DNA was not available. The DNA mixture was analysed so as to predict the most probable genotypes of each contributor. The major contributor's profile was then used to compute the likelihood ratio for paternity. We also show how to take into account a dropout allele and the possibility of mutation in paternity testing.

  16. Mixture Distribution Approach In Financial Risk Analysis

    OpenAIRE

    Kocak, Keziban; Calis, Nazif; Unal, Deniz

    2014-01-01

    In recent years, major changes occurred in the prices of stock exchange appeared the necessity of measuring the financial risk. Nowadays, Value-atRisk (VaR) is often used to calculate the financial risk. Parametric methods which need normality are mostly used in the calculation of VaR.If the financial data does not fit the normal distribution, mixture of normal distribution models can be fitted to this data. In this study, the financial risk is calculated by using normal mixture distribution ...

  17. Boiler derating for coal-water mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Horney, F.A.; Nolte, F.S.

    1983-11-01

    The authors demonstrated a method for approximating the derating required when converting an oil or natural gas fired unit to a coal-water mixture. If the results show that a retrofit to coal-water mixture appears economically reasonable, then a more detailed analysis should be made by the boiler manufacturer whose methods are more precise than the methods of this paper. The expense of having the boiler manufacturer make a precise analysis can be avoided if the results of the analysis of this paper show conversion not to be viable.

  18. Conditional Density Approximations with Mixtures of Polynomials

    DEFF Research Database (Denmark)

    Varando, Gherardo; López-Cruz, Pedro L.; Nielsen, Thomas Dyhre

    2015-01-01

    Mixtures of polynomials (MoPs) are a non-parametric density estimation technique especially designed for hybrid Bayesian networks with continuous and discrete variables. Algorithms to learn one- and multi-dimensional (marginal) MoPs from data have recently been proposed. In this paper we introduce...... is found. We illustrate and study the methods using data sampled from known parametric distributions, and we demonstrate their applicability by learning models based on real neuroscience data. Finally, we compare the performance of the proposed methods with an approach for learning mixtures of truncated...

  19. Flows and chemical reactions in homogeneous mixtures

    CERN Document Server

    Prud'homme, Roger

    2013-01-01

    Flows with chemical reactions can occur in various fields such as combustion, process engineering, aeronautics, the atmospheric environment and aquatics. The examples of application chosen in this book mainly concern homogeneous reactive mixtures that can occur in propellers within the fields of process engineering and combustion: - propagation of sound and monodimensional flows in nozzles, which may include disequilibria of the internal modes of the energy of molecules; - ideal chemical reactors, stabilization of their steady operation points in the homogeneous case of a perfect mixture and c

  20. Mixture for removing tar and paraffin deposits

    Energy Technology Data Exchange (ETDEWEB)

    kamenshchikov, F.A.; Frolov, M.A.; Golovin, I.N.; Khusainov, Z.M.; Smirnov, Ya.L.; Suchkov, B.M.

    1981-05-23

    Mixture is claimed for removing tar and paraffin deposits (TPD) on the basis of the butyl-benzene fraction (BBF), which is intended to more efficiently remove TPD from the surface of refinery equipment, additionally has piperylene, isoprene and isoamine with the following ratio of the components: piperylene, 19-31%; isoprene, 8-12%; isoamines, 8-12%, while BBF, the rest. The efficiency of the given compositions was assessed by the rate at which the plates were cleaned of TPD and pure commercial paraffin. It has been shown that BBF dissolves 4-6 times faster in the given mixture than in BBF and pyperylene.

  1. Viscosity of oil and water mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Corlett, A.E.; Hall, A.R.W. [National Engineering Laboratory, Glasgow (United Kingdom)

    1999-07-01

    A study was performed to investigate the apparent viscosity of oil and water mixtures using the pressure loss along a horizontal pipe. Water fractions between 100% to 5% were examined at three flow velocities and three temperatures. Four combinations of crude oil and saline solution were used. Tests found that the mixture viscosity exhibited a peak at the position of phase inversion. The value of this maximum viscosity depended upon the temperature and fluid combination used, but not the velocity. Physical properties of the fluids were important factors in the viscosity/water fraction behaviour. (author)

  2. Methodological issues in examining measurement equivalence in patient reported outcomes measures: Methods overview to the two-part series, “Measurement equivalence of the Patient Reported Outcomes Measurement Information System® (PROMIS® short forms”

    Directory of Open Access Journals (Sweden)

    Jeanne A. Teresi

    2016-03-01

    Full Text Available The purpose of this article is to introduce the methods used and challenges confronted by the authors of this two-part series of articles describing the results of analyses of measurement equivalence of the short form scales from the Patient Reported Outcomes Measurement Information System® (PROMIS®. Qualitative and quantitative approaches used to examine differential item functioning (DIF are reviewed briefly. Qualitative methods focused on generation of DIF hypotheses. The basic quantitative approaches used all rely on a latent variable model, and examine parameters either derived directly from item response theory (IRT or from structural equation models (SEM. A key methods focus of these articles is to describe state-of-the art approaches to examination of measurement equivalence in eight domains: physical health, pain, fatigue, sleep, depression, anxiety, cognition, and social function. These articles represent the first time that DIF has been examined systematically in the PROMIS short form measures, particularly among ethnically diverse groups. This is also the first set of analyses to examine the performance of PROMIS short forms in patients with cancer. Latent variable model state-of-the-art methods for examining measurement equivalence are introduced briefly in this paper to orient readers to the approaches adopted in this set of papers. Several methodological challenges underlying (DIF-free anchor item selection and model assumption violations are presented as a backdrop for the articles in this two-part series on measurement equivalence of PROMIS measures.

  3. Evaluation of yielding of mixtures of Pisum sativum L. with Triticum aestivum L. grown in organic farming

    Directory of Open Access Journals (Sweden)

    Jerzy Księżak

    2016-09-01

    Full Text Available The aim of this study was to determine the productivity and quality of feed obtained from the mixtures of field pea (Pisum sativum L. with spring wheat (Triticum aestivum L., depending on the pea cultivar and its percentage in the weight of sown seeds under the conditions of organic farming. A field experiment was carried out in the years 2011–2013 in a randomized split-plot design with four replications. The first factor was a pea ‘Wiato’ or ‘Tarchalska’. The secondary factor was density of a pea mixture sown: 40, 60, and 80%. The yield of mixture seeds as well as the yield and structure of individual components were evaluated. The contents of crude protein and crude fiber, fat, ash, phosphorus, and potassium were determined in cereal grain and pea seeds. The examined factors and weather conditions during the growing season had a significant impact on the growth and yield of pea–spring wheat mixtures. The seed yields of the mixtures with the semi-leafless ‘Tarchalska’ were lower than with ‘Wiato’ (with bipinnate leaves. Increasing the pea percentage in seed material resulted in lower mixture yields. The percentage of pea seeds (regardless of foliage type in the mixture yields was significantly lower than the weight of sown seeds. Increasing the pea percentage in the mixture yield positively influenced the contents of protein, fat, and ash but it caused a decrease in the content of fiber. The pea percentage at sowing had little influence on the content of phosphorus in the mixture seed yields, but it slightly increased the content of potassium, regardless of the pea cultivar. The mixtures with the ‘Wiato’ and ‘Tarchalska’ cultivars contained a similar amount of protein, fiber, and fat, while the mixtures with ‘Tarchalska’ accumulated more ash.

  4. MixtureTree annotator: a program for automatic colorization and visual annotation of MixtureTree.

    Directory of Open Access Journals (Sweden)

    Shu-Chuan Chen

    Full Text Available The MixtureTree Annotator, written in JAVA, allows the user to automatically color any phylogenetic tree in Newick format generated from any phylogeny reconstruction program and output the Nexus file. By providing the ability to automatically color the tree by sequence name, the MixtureTree Annotator provides a unique advantage over any other programs which perform a similar function. In addition, the MixtureTree Annotator is the only package that can efficiently annotate the output produced by MixtureTree with mutation information and coalescent time information. In order to visualize the resulting output file, a modified version of FigTree is used. Certain popular methods, which lack good built-in visualization tools, for example, MEGA, Mesquite, PHY-FI, TreeView, treeGraph and Geneious, may give results with human errors due to either manually adding colors to each node or with other limitations, for example only using color based on a number, such as branch length, or by taxonomy. In addition to allowing the user to automatically color any given Newick tree by sequence name, the MixtureTree Annotator is the only method that allows the user to automatically annotate the resulting tree created by the MixtureTree program. The MixtureTree Annotator is fast and easy-to-use, while still allowing the user full control over the coloring and annotating process.

  5. MixtureTree annotator: a program for automatic colorization and visual annotation of MixtureTree.

    Science.gov (United States)

    Chen, Shu-Chuan; Ogata, Aaron

    2015-01-01

    The MixtureTree Annotator, written in JAVA, allows the user to automatically color any phylogenetic tree in Newick format generated from any phylogeny reconstruction program and output the Nexus file. By providing the ability to automatically color the tree by sequence name, the MixtureTree Annotator provides a unique advantage over any other programs which perform a similar function. In addition, the MixtureTree Annotator is the only package that can efficiently annotate the output produced by MixtureTree with mutation information and coalescent time information. In order to visualize the resulting output file, a modified version of FigTree is used. Certain popular methods, which lack good built-in visualization tools, for example, MEGA, Mesquite, PHY-FI, TreeView, treeGraph and Geneious, may give results with human errors due to either manually adding colors to each node or with other limitations, for example only using color based on a number, such as branch length, or by taxonomy. In addition to allowing the user to automatically color any given Newick tree by sequence name, the MixtureTree Annotator is the only method that allows the user to automatically annotate the resulting tree created by the MixtureTree program. The MixtureTree Annotator is fast and easy-to-use, while still allowing the user full control over the coloring and annotating process.

  6. A Skew-Normal Mixture Regression Model

    Science.gov (United States)

    Liu, Min; Lin, Tsung-I

    2014-01-01

    A challenge associated with traditional mixture regression models (MRMs), which rest on the assumption of normally distributed errors, is determining the number of unobserved groups. Specifically, even slight deviations from normality can lead to the detection of spurious classes. The current work aims to (a) examine how sensitive the commonly…

  7. Uniform design of experiments with mixtures

    Institute of Scientific and Technical Information of China (English)

    王元; 方开泰

    1996-01-01

    Consider a design of experiments with mixtures:0≤ai

  8. Modeling text with generalizable Gaussian mixtures

    DEFF Research Database (Denmark)

    Hansen, Lars Kai; Sigurdsson, Sigurdur; Kolenda, Thomas

    2000-01-01

    We apply and discuss generalizable Gaussian mixture (GGM) models for text mining. The model automatically adapts model complexity for a given text representation. We show that the generalizability of these models depends on the dimensionality of the representation and the sample size. We discuss...

  9. The Coffee-Milk Mixture Problem Revisited

    Science.gov (United States)

    Marion, Charles F.

    2015-01-01

    This analysis of a problem that is frequently posed at professional development workshops, in print, and on the Web--the coffee-milk mixture riddle--illustrates the timeless advice of George Pólya's masterpiece on problem solving in mathematics, "How to Solve It." In his book, Pólya recommends that problems previously solved and put…

  10. Quantification of complex mixtures by NMR

    NARCIS (Netherlands)

    Duynhoven, van J.P.M.; Velzen, van E.; Jacobs, D.M.

    2013-01-01

    NMR has firmly established itself as an analytical tool that can quantify analyte concentrations in complex mixtures in a rapid, cost-effective, accurate and precise manner. Here, the technological advances with respect to instrumentation, sample preparation, data acquisition and data processing ove

  11. Toxicology of chemical mixtures: International perspective

    NARCIS (Netherlands)

    Feron, V.J.; Cassee, F.R.; Groten, J.P.

    1998-01-01

    This paper reviews major activities outside the United States on human health issues related to chemical mixtures. In Europe an international study group on combination effects has been formed and has started by defining synergism and antagonism. Successful research programs in Europe include the de

  12. Mixture toxicity of PBT-like chemicals

    DEFF Research Database (Denmark)

    Syberg, Kristian; Dai, Lina; Ramskov, Tina

    beyond that of the individual components. Firstly, the effects of three chemicals with PBT-like properties (acetyl cedrene, pyrene and triclosan) was examined on the freshwater snail, Potamopyrgus antipodarum. Secondly, mixture bioaccumulation of the same three chemicals were assessed experimentally...

  13. Concrete mixture characterization. Cementitious barriers partnership

    Energy Technology Data Exchange (ETDEWEB)

    Langton, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Protiere, Yannick [SIMCO Technologies, Inc., Quebec (Canada)

    2014-12-01

    This report summarizes the characterization study performed on two concrete mixtures used for radioactive waste storage. Both mixtures were prepared with approximately 425 kg of binder. The testing protocol mostly focused on determining the transport properties of the mixtures; volume of permeable voids (porosity), diffusion coefficients, and water permeability were evaluated. Tests were performed after different curing durations. In order to obtain data on the statistical distribution of transport properties, the measurements after 2 years of curing were performed on 10+ samples. Overall, both mixtures exhibited very low tortuosities and permeabilities, a direct consequence of their low water-to-binder ratio and the use of supplementary cementitious materials. The data generated on 2-year old samples showed that porosity, tortuosity and permeability follow a normal distribution. Chloride ponding tests were also performed on test samples. They showed limited chloride ingress, in line with measured transport properties. These test results also showed that both materials react differently with chloride, a consequence of the differences in the binder chemical compositions.

  14. Predicting diffusivities in dense fluid mixtures

    Directory of Open Access Journals (Sweden)

    C. DARIVA

    1999-09-01

    Full Text Available In this work the Enskog solution of the Boltzmann equation, as corrected by Speedy, together with the Weeks-Chandler-Andersen (WCA perturbation theory of liquids is employed in correlating and predicting self-diffusivities of dense fluids. Afterwards this theory is used to estimate mutual diffusion coefficients of solutes at infinite dilution in sub and supercritical solvents. We have also investigated the behavior of Fick diffusion coefficients in the proximity of a binary vapor-liquid critical point since this subject is of great interest for extraction purposes. The approach presented here, which makes use of a density and temperature dependent hard-sphere diameter, is shown to be excellent for predicting diffusivities in dense pure fluids and fluid mixtures. The calculations involved highly nonideal mixtures as well as systems with high molecular asymmetry. The predicted diffusivities are in good agreement with the experimental data for the pure and binary systems. The methodology proposed here makes only use of pure component information and density of mixtures. The simple algebraic relations are proposed without any binary adjustable parameters and can be readily used for estimating diffusivities in multicomponent mixtures.

  15. Self-assembly models for lipid mixtures

    Science.gov (United States)

    Singh, Divya; Porcar, Lionel; Butler, Paul; Perez-Salas, Ursula

    2006-03-01

    Solutions of mixed long and short (detergent-like) phospholipids referred to as ``bicelle'' mixtures in the literature, are known to form a variety of different morphologies based on their total lipid composition and temperature in a complex phase diagram. Some of these morphologies have been found to orient in a magnetic field, and consequently bicelle mixtures are widely used to study the structure of soluble as well as membrane embedded proteins using NMR. In this work, we report on the low temperature phase of the DMPC and DHPC bicelle mixture, where there is agreement on the discoid structures but where molecular packing models are still being contested. The most widely accepted packing arrangement, first proposed by Vold and Prosser had the lipids completely segregated in the disk: DHPC in the rim and DMPC in the disk. Using data from small angle neutron scattering (SANS) experiments, we show how radius of the planar domain of the disks is governed by the effective molar ratio qeff of lipids in aggregate and not the molar ratio q (q = [DMPC]/[DHPC] ) as has been understood previously. We propose a new quantitative (packing) model and show that in this self assembly scheme, qeff is the real determinant of disk sizes. Based on qeff , a master equation can then scale the radii of disks from mixtures with varying q and total lipid concentration.

  16. Flexible Rasch Mixture Models with Package psychomix

    Directory of Open Access Journals (Sweden)

    Hannah Frick

    2012-05-01

    Full Text Available Measurement invariance is an important assumption in the Rasch model and mixture models constitute a flexible way of checking for a violation of this assumption by detecting unobserved heterogeneity in item response data. Here, a general class of Rasch mixture models is established and implemented in R, using conditional maximum likelihood estimation of the item parameters (given the raw scores along with flexible specification of two model building blocks: (1 Mixture weights for the unobserved classes can be treated as model parameters or based on covariates in a concomitant variable model. (2 The distribution of raw score probabilities can be parametrized in two possible ways, either using a saturated model or a specification through mean and variance. The function raschmix( in the R package psychomix provides these models, leveraging the general infrastructure for fitting mixture models in the flexmix package. Usage of the function and its associated methods is illustrated on artificial data as well as empirical data from a study of verbally aggressive behavior.

  17. Spinodal decomposition of chemically reactive binary mixtures

    Science.gov (United States)

    Lamorgese, A.; Mauri, R.

    2016-08-01

    We simulate the influence of a reversible isomerization reaction on the phase segregation process occurring after spinodal decomposition of a deeply quenched regular binary mixture, restricting attention to systems wherein material transport occurs solely by diffusion. Our theoretical approach follows a diffuse-interface model of partially miscible binary mixtures wherein the coupling between reaction and diffusion is addressed within the frame of nonequilibrium thermodynamics, leading to a linear dependence of the reaction rate on the chemical affinity. Ultimately, the rate for an elementary reaction depends on the local part of the chemical potential difference since reaction is an inherently local phenomenon. Based on two-dimensional simulation results, we express the competition between segregation and reaction as a function of the Damköhler number. For a phase-separating mixture with components having different physical properties, a skewed phase diagram leads, at large times, to a system converging to a single-phase equilibrium state, corresponding to the absolute minimum of the Gibbs free energy. This conclusion continues to hold for the critical phase separation of an ideally perfectly symmetric binary mixture, where the choice of final equilibrium state at large times depends on the initial mean concentration being slightly larger or less than the critical concentration.

  18. Toxicity of metal mixtures to chick embryos

    Energy Technology Data Exchange (ETDEWEB)

    Birge, W.J.; Roberts, O.W.; Black, J.A.

    1976-09-01

    The toxic effects of mercury/selenium and certain other metal mixtures on the chick embryo are examined to determine whether antagonistic, additive or synergistic interactions occur. White Plymouth Rock chicken eggs were treated by yolk injection with cadmium chloride, mercuric chloride, zinc chloride and sodium selenate. Test aliquots were injected prior to incubation using the needle track procedure. Using a sample size of 200, percent survival was determined as hatchability of experimental eggs/controls. Metal mixtures used included mercury/cadmium, mercury/selenium, mercury/zinc, cadmium/selenium, and cadmium/zinc. Except for mercury/selenium, all other metal mixtures gave actual values that were within 5% of those for additive toxic effects. Actual hatchability frequencies for test concentrations of mercury/selenium indicated a moderate degree of synergism. Results indicate that the strong mercury/selenium synergism which affects embryonic development in the carp does not apply for the chick embryo; that most two-way combinations of cadmium, mercury, selenium and zinc exert purely additive effects on chick hatchability; and that these metal mixtures give no discernible antagonistic interactions which affect survival of chick embryos. (MFB)

  19. Using Regression Mixture Analysis in Educational Research

    Directory of Open Access Journals (Sweden)

    Cody S. Ding

    2006-11-01

    Full Text Available Conventional regression analysis is typically used in educational research. Usually such an analysis implicitly assumes that a common set of regression parameter estimates captures the population characteristics represented in the sample. In some situations, however, this implicit assumption may not be realistic, and the sample may contain several subpopulations such as high math achievers and low math achievers. In these cases, conventional regression models may provide biased estimates since the parameter estimates are constrained to be the same across subpopulations. This paper advocates the applications of regression mixture models, also known as latent class regression analysis, in educational research. Regression mixture analysis is more flexible than conventional regression analysis in that latent classes in the data can be identified and regression parameter estimates can vary within each latent class. An illustration of regression mixture analysis is provided based on a dataset of authentic data. The strengths and limitations of the regression mixture models are discussed in the context of educational research.

  20. Two-microphone Separation of Speech Mixtures

    DEFF Research Database (Denmark)

    2006-01-01

    of Speech Mixtures," 2006, submited for journal publication. See also, [2] Michael Syskind Pedersen, DeLiang Wang, Jan Larsen and Ulrik Kjems: "Overcomplete Blind Source Separation by Combining ICA and Binary Time-Frequency Masking," in proceedings of IEEE International workshop on Machine Learning...

  1. Structure of cholesterol/ceramide monolayer mixtures

    DEFF Research Database (Denmark)

    Scheffer, L.; Solomonov, I.; Weygand, M.J.

    2005-01-01

    The structure of monolayers of cholesterol/ ceramide mixtures was investigated using grazing incidence x-ray diffraction, immunofluorescence, and atomic force microscopy techniques. Grazing incidence x-ray diffraction measurements showed the existence of a crystalline mixed phase of the two...

  2. Mixture model analysis of complex samples

    NARCIS (Netherlands)

    Wedel, M; ter Hofstede, F; Steenkamp, JBEM

    1998-01-01

    We investigate the effects of a complex sampling design on the estimation of mixture models. An approximate or pseudo likelihood approach is proposed to obtain consistent estimates of class-specific parameters when the sample arises from such a complex design. The effects of ignoring the sample desi

  3. Numerical Solution of Hard-Core Mixtures

    OpenAIRE

    Buhot, Arnaud; Krauth, Werner

    1997-01-01

    We study the equilibrium phase diagram of binary mixtures of hard spheres as well as of parallel hard cubes. A superior cluster algorithm allows us to establish and to access the demixed phase for both systems and to investigate the subtle interplay between short-range depletion and long-range demixing.

  4. Pool Boiling of Hydrocarbon Mixtures on Water

    Energy Technology Data Exchange (ETDEWEB)

    Boee, R.

    1996-09-01

    In maritime transport of liquefied natural gas (LNG) there is a risk of spilling cryogenic liquid onto water. The present doctoral thesis discusses transient boiling experiments in which liquid hydrocarbons were poured onto water and left to boil off. Composition changes during boiling are believed to be connected with the initiation of rapid phase transition in LNG spilled on water. 64 experimental runs were carried out, 14 using pure liquid methane, 36 using methane-ethane, and 14 using methane-propane binary mixtures of different composition. The water surface was open to the atmosphere and covered an area of 200 cm{sup 2} at 25 - 40{sup o}C. The heat flux was obtained by monitoring the change of mass vs time. The void fraction in the boiling layer was measured with a gamma densitometer, and a method for adapting this measurement concept to the case of a boiling cryogenic liquid mixture is suggested. Significant differences in the boil-off characteristics between pure methane and binary mixtures revealed by previous studies are confirmed. Pure methane is in film boiling, whereas the mixtures appear to enter the transitional boiling regime with only small amounts of the second component added. The results indicate that the common assumption that LNG will be in film boiling on water because of the high temperature difference, may be questioned. Comparison with previous work shows that at this small scale the results are influenced by the experimental apparatus and procedures. 66 refs., 76 figs., 28 tabs.

  5. Mixtures of Ultracold Fermions with Unequal Masses

    Science.gov (United States)

    de Melo, Carlos A. R. Sa

    2008-05-01

    The quantum phases of ultracold fermions with unequal masses are discussed in continuum and lattice models for a wide variety of mixtures which exhibit Feshbach resonances, e.g., mixtures of ^6Li and ^40K. The evolution of superfluidity from the Bardeen-Cooper-Schrieffer (BCS) to the Bose-Einstein condensation (BEC) regime in the continuum is analyzed as a function of scattering parameter, population imbalance and mass anisotropy. In the continuum case, regions corresponding to normal, phase-separated or coexisting uniform-superfluid/excess-fermion phases are identified and the possibility of topological phase transitions is discussed [1]. For optical lattices, the phase diagrams as a function of interaction strength, population imbalance, filling fraction and tunneling parameters are presented [2]. In addition to the characteristic phases of the continuum, a series of insulating phases emerge in the phase diagrams of optical lattices, including a Bose-Mott insulator (BMI), a Fermi-Pauli insulator (FPI), a phase-separated BMI/FPI mixture, and a Bose-Fermi checkerboard (BFC) phase. Lastly, the effects of harmonic traps and the emergence of unusual shell structures are discussed for mixtures of fermions with unequal masses. [1] M. Iskin, and C. A. R. S' a de Melo, Phys. Rev. Lett 97, 100404 (2006); [2] M. Iskin, and C. A. R. S' a de Melo, Phys. Rev. Lett. 99, 080403 (2007).

  6. Cementitious barriers partnership concrete mixture characterization

    Energy Technology Data Exchange (ETDEWEB)

    Langton, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Protiere, Yannick [SIMCO Technologies, Inc., Quebec (Canada)

    2014-12-01

    This report summarizes the characterization study performed on two concrete mixtures used for radioactive waste storage. Both mixtures were prepared with approximately 425 kg of binder. The testing protocol mostly focused on determining the transport properties of the mixtures; volume of permeable voids (porosity), diffusion coefficients, and water permeability were evaluated. Tests were performed after different curing durations. In order to obtain data on the statistical distribution of transport properties, the measurements after 2 years of curing were performed on 10+ samples. Overall, both mixtures exhibited very low tortuosities and permeabilities, a direct consequence of their low water-to-binder ratio and the use of supplementary cementitious materials. The data generated on 2-year old samples showed that porosity, tortuosity and permeability follow a normal distribution. Chloride ponding tests were also performed on test samples. They showed limited chloride ingress, in line with measured transport properties. These test results also showed that both materials react differently with chloride, a consequence of the differences in the binder chemical compositions.

  7. Some aspects of symmetric Gamma process mixtures

    OpenAIRE

    Naulet, Zacharie; Barat, Eric

    2015-01-01

    In this article, we present some specific aspects of symmetric Gamma process mixtures for use in regression models. We propose a new Gibbs sampler for simulating the posterior and we establish adaptive posterior rates of convergence related to the Gaussian mean regression problem.

  8. The Coffee-Milk Mixture Problem Revisited

    Science.gov (United States)

    Marion, Charles F.

    2015-01-01

    This analysis of a problem that is frequently posed at professional development workshops, in print, and on the Web--the coffee-milk mixture riddle--illustrates the timeless advice of George Pólya's masterpiece on problem solving in mathematics, "How to Solve It." In his book, Pólya recommends that problems previously solved and put…

  9. Theory of dynamic arrest in colloidal mixtures.

    Science.gov (United States)

    Juárez-Maldonado, R; Medina-Noyola, M

    2008-05-01

    We present a first-principles theory of dynamic arrest in colloidal mixtures based on the multicomponent self-consistent generalized Langevin equation theory of colloid dynamics [M. A. Chávez-Rojo and M. Medina-Noyola, Phys. Rev. E 72, 031107 (2005); M. A. Chávez-Rojo and M. Medina-Noyola, Phys. Rev. E76, 039902 (2007)]. We illustrate its application with a description of dynamic arrest in two simple model colloidal mixtures: namely, hard-sphere and repulsive Yukawa binary mixtures. Our results include observation of the two patterns of dynamic arrest, one in which both species become simultaneously arrested and the other involving the sequential arrest of the two species. The latter case gives rise to mixed states in which one species is arrested while the other species remains mobile. We also derive the ("bifurcation" or fixed-point") equations for the nonergodic parameters of the system, which takes the surprisingly simple form of a system of coupled equations for the localization length of the particles of each species. The solution of this system of equations indicates unambiguously which species is arrested (finite localization length) and which species remains ergodic (infinite localization length). As a result, we are able to draw the entire ergodic-nonergodic phase diagram of the binary hard-sphere mixture.

  10. Toxicology of chemical mixtures: International perspective

    NARCIS (Netherlands)

    Feron, V.J.; Cassee, F.R.; Groten, J.P.

    1998-01-01

    This paper reviews major activities outside the United States on human health issues related to chemical mixtures. In Europe an international study group on combination effects has been formed and has started by defining synergism and antagonism. Successful research programs in Europe include the

  11. Nucleate Pool Boiling of Pure Liquids and Binary Mixtures:part II—Analytical Model for Boiling Heat Transfer of Binary Mixtures on Smooth Tubes and Comparison of Analytical Models for both Pure Liqu

    Institute of Scientific and Technical Information of China (English)

    GuoqingWang; YingkeTan

    1996-01-01

    A combined physical model of bubbel growth is propsed along with a corresponding bubble growth model for binary mixtures on smooth tubes.Using the general model of Wang et al.[1].and the bubble growth model for binary mixtures,an analytical model for nucleate pool boiling heat transfer of binary mixtures on smooth tubes is developed.In addition,nucleate pool boiling heat transfer of pure liquids and binary mixtrues on a horizontal smooth tube was studied experimentally.The pure liquids and binary mixtures included water methanol,ehanol,and their binary mixtures.The analytical models for both pure liquids and binary mixtures are in good agreement with the experimental data.

  12. Tolerance to SO2, NO2 and their mixture in Plantago major L. populations.

    Science.gov (United States)

    Taylor, H J; Bell, J N

    1992-01-01

    The possible evolution of tolerance to NO2, alone or in combination with SO2 was investigated in three populations of Plantago major L., originating from Hyde Park in central London (polluted site), Ascot (clean site) and The Netherlands. Screening for sensitivity to the pollutants was carried out by means of chronic fumigations with NO2 or NO2 plus SO2 and acute fumigations with SO2, NO2 or their mixture. The Hyde Park population showed smaller growth reductions induced by the pollutant mixture, than did the other populations. In contrast no differential response in terms of foliar injury was observed after an acute fumigation with SO2+ NO2, but the Hyde Park population was the most sensitive to NO2 alone. The results indicate that selection for tolerance to SO2 does not confer tolerance to NO2 alone or the pollutant mixture.

  13. Effects of Nutrition Relevant Mixtures of Phytoestrogens on Steroidogenesis, Aromatase, Estrogen, and Androgen Activity

    DEFF Research Database (Denmark)

    Taxvig, Camilla; Engell-Kofoed, Anders Elleby; Sonne-Hansen, Katrine;

    2010-01-01

    Phytoestrogens (PEs) are naturally occurring plant components produced in a large range of plants. They can induce biologic responses in vertebrates by mimicking or modulating the action or production of endogenous hormones. This study examined mixtures of 12 food relevant PEs for effects...... on steroid hormone production, aromatase activity, estrogenic activity, and for interaction with the androgen receptor. The results show that a mixture of all tested PEs increased estradiol production and decreased testosterone production in H295R human adrenal corticocarcinoma cells, indicating an induced...... aromatase activity. Furthermore, exposure of the H295R cells to isoflavonoids caused a decrease in testosterone production, and various mixtures of PEs significantly stimulated MCF-7 human breast adenocarcinoma cell growth and induced aromatase activity in JEG-3 choriocarcinoma cells. The estrogenic effect...

  14. Thermodynamic coarsening arrested by viscous fingering in partially miscible binary mixtures

    Science.gov (United States)

    Fu, Xiaojing; Cueto-Felgueroso, Luis; Juanes, Ruben

    2016-09-01

    We study the evolution of binary mixtures far from equilibrium, and show that the interplay between phase separation and hydrodynamic instability can arrest the Ostwald ripening process characteristic of nonflowing mixtures. We describe a model binary system in a Hele-Shaw cell using a phase-field approach with explicit dependence of both phase fraction and mass concentration. When the viscosity contrast between phases is large (as is the case for gas and liquid phases), an imposed background flow leads to viscous fingering, phase branching, and pinch off. This dynamic flow disorder limits phase growth and arrests thermodynamic coarsening. As a result, the system reaches a regime of statistical steady state in which the binary mixture is permanently driven away from equilibrium.

  15. Growth Disorders

    Science.gov (United States)

    ... because their parents are. But some children have growth disorders. Growth disorders are problems that prevent children from developing ... or other features. Very slow or very fast growth can sometimes signal a gland problem or disease. ...

  16. Computer simulation of rod-sphere mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Antypov, Dmytro

    2003-07-01

    Results are presented from a series of simulations undertaken to investigate the effect of adding small spherical particles to a fluid of rods which would otherwise represent a liquid crystalline (LC) substance. Firstly, a bulk mixture of Hard Gaussian Overlap particles with an aspect ratio of 3:1 and hard spheres with diameters equal to the breadth of the rods is simulated at various sphere concentrations. Both mixing-demixing and isotropic-nematic transition are studied using Monte Carlo techniques. Secondly, the effect of adding Lennard-Jones particles to an LC system modelled using the well established Gay-Berne potential is investigated. These rod-sphere mixtures are simulated using both the original set of interaction parameters and a modified version of the rod-sphere potential proposed in this work. The subject of interest is the internal structure of the binary mixture and its dependence on density, temperature, concentration and various parameters characterising the intermolecular interactions. Both the mixing-demixing behaviour and the transitions between the isotropic and any LC phases have been studied for four systems which differ in the interaction potential between unlike particles. A range of contrasting microphase separated structures including bicontinuous, cubic, and micelle-like arrangement have been observed in bulk. Thirdly, the four types of mixtures previously studied in bulk are subjected to a static magnetic field. A variety of novel phases are observed for the cases of positive and negative anisotropy in the magnetic susceptibility. These include a lamellar structure, in which layers of rods are separated by layers of spheres, and a configuration with a self-assembling hexagonal array of spheres. Finally, two new models are presented to study liquid crystal mixtures in the presence of curved substrates. These are implemented for the cases of convex and concave spherical surfaces. The simulation results obtained in these geometries

  17. Experiments with Mixtures Designs, Models, and the Analysis of Mixture Data

    CERN Document Server

    Cornell, John A

    2011-01-01

    The most comprehensive, single-volume guide to conducting experiments with mixtures"If one is involved, or heavily interested, in experiments on mixtures of ingredients, one must obtain this book. It is, as was the first edition, the definitive work."-Short Book Reviews (Publication of the International Statistical Institute)"The text contains many examples with worked solutions and with its extensive coverage of the subject matter will prove invaluable to those in the industrial and educational sectors whose work involves the design and analysis of mixture experiments."-Journal of the Royal S

  18. Growth, yield and NPK uptake by maize with complementary organic ...

    African Journals Online (AJOL)

    Growth, yield and NPK uptake by maize with complementary organic and inorganic fertilizers. ... African Journal of Food, Agriculture, Nutrition and Development ... The mixture of organic and inorganic fertilizer treatment consisted of half the ...

  19. Properties of Direct Coal Liquefaction Residue Modified Asphalt Mixture

    Directory of Open Access Journals (Sweden)

    Jie Ji

    2017-01-01

    Full Text Available The objectives of this paper are to use Direct Coal Liquefaction Residue (DLCR to modify the asphalt binders and mixtures and to evaluate the performance of modified asphalt mixtures. The dynamic modulus and phase angle of DCLR and DCLR-composite modified asphalt mixture were analyzed, and the viscoelastic properties of these modified asphalt mixtures were compared to the base asphalt binder SK-90 and Styrene-Butadiene-Styrene (SBS modified asphalt mixtures. The master curves of the asphalt mixtures were shown, and dynamic and viscoelastic behaviors of asphalt mixtures were described using the Christensen-Anderson-Marasteanu (CAM model. The test results show that the dynamic moduli of DCLR and DCLR-composite asphalt mixtures are higher than those of the SK-90 and SBS modified asphalt mixtures. Based on the viscoelastic parameters of CAM models of the asphalt mixtures, the high- and low-temperature performance of DLCR and DCLR-composite modified asphalt mixtures are obviously better than the SK-90 and SBS modified asphalt mixtures. In addition, the DCLR and DCLR-composite modified asphalt mixtures are more insensitive to the frequency compared to SK-90 and SBS modified asphalt mixtures.

  20. Thermodiffusion in binary and ternary nonpolar hydrocarbon + alcohol mixtures

    Science.gov (United States)

    Eslamian, Morteza; Saghir, M. Ziad

    2012-12-01

    Thermodiffusion in complex mixtures, such as associating, molten metal, and polymer mixtures is difficult to model usually owing to the occurrence of a sign change in the thermodiffusion coefficient when the mixture concentration and temperature change. A mixture comprised of a nonpolar hydrocarbon and an alcohol is a complex and highly non-ideal mixture. In this paper an existing binary non-equilibrium thermodynamics model (Eslamian and Saghir, Physical Review E 80, 061201, 2009) developed for aqueous mixtures of alcohols is examined against the experimental data of binary nonpolar hydrocarbon and alcohol mixtures. For ternary mixtures, non-equilibrium thermodynamic expressions developed by the authors for aqueous mixtures of alcohols (Eslamian and Saghir, Canadian Journal of Chemical Engineering, DOI 10.1002/cjce.20581) is used to predict thermodiffusion coefficients of ternary nonpolar hydrocarbon and alcohol mixtures. The rationale behind the sign change is elucidated and attributed to an anomalous change in the molecular structure and therefore viscosity of such mixtures. Model predictions of thermodiffusion coefficients of binary mixtures predict a sign change consistent with the experimental data although the model is still too primitive to capture all structural complexities. For instance, in the methanol-benzene mixture where the model predictions are poorest, the viscosity data show that when concentration varies, the mixture's molecular structure experiences a severe change twice, the first major change leading to a maximum in the thermodiffusion coefficient, whereas the second change causes a sign change.

  1. Flow regimes in wet conical spouted beds using glass bead mixtures

    Institute of Scientific and Technical Information of China (English)

    Marcelo S. Bacelos; José Teixeira Freire

    2008-01-01

    Using a high-viscosity Newtonian fluid, glycerol, an experimental investigation was carried out to evaluate the stable spouting regime in conical spouted beds using four particle mixtures: a reference (monoparticles), a binary mixture, two ternary mixtures with flat and Gaussian distributions respectively. The mixtures were selected for particle diameters (dp) ranging from 1.09 to 4.98 mm and particle diameter ratios (dpL/dps) ranging from 1.98 to 4.0. Experimental data show that pressure fluctuation signals of the bed, as indicated by changes in their standard deviations, provide suitable information to identify the range of operational conditions for stable spouting. However, the analysis of skewness of curves of pressure fluctuation as a function of air velocity appears not sufficient to identify a particular flow regime. For glycerol in the spouting regime, the standard deviation is noted to increase with increasing glycerol concentration due to the growth of interparticle forces. The implications of these research findings on the drying of suspensions in conical spouted beds using glass bead mixtures are also discussed.

  2. Effects of nutrition relevant mixtures of phytoestrogens on steroidogenesis, aromatase, estrogen, and androgen activity.

    Science.gov (United States)

    Taxvig, Camilla; Elleby, Anders; Sonne-Hansen, Katrine; Bonefeld-Jørgensen, Eva C; Vinggaard, Anne Marie; Lykkesfeldt, Anne E; Nellemann, Christine

    2010-01-01

    Phytoestrogens (PEs) are naturally occurring plant components produced in a large range of plants. They can induce biologic responses in vertebrates by mimicking or modulating the action or production of endogenous hormones. This study examined mixtures of 12 food relevant PEs for effects on steroid hormone production, aromatase activity, estrogenic activity, and for interaction with the androgen receptor. The results show that a mixture of all tested PEs increased estradiol production and decreased testosterone production in H295R human adrenal corticocarcinoma cells, indicating an induced aromatase activity. Furthermore, exposure of the H295R cells to isoflavonoids caused a decrease in testosterone production, and various mixtures of PEs significantly stimulated MCF-7 human breast adenocarcinoma cell growth and induced aromatase activity in JEG-3 choriocarcinoma cells. The estrogenic effect in the MCF7 cells of the isoflavonoid mixture and coumestrol was supported by an observed increase in progesterone receptor protein expression as well as a decreased ERalpha expression. Overall, the results support that nutrition-relevant concentrations of PEs both alone and in mixtures possess various endocrine disrupting effects, all of which need to be considered when assessing the effects on human health.

  3. Toxic effect of metal cation binary mixtures to the seaweed Gracilaria domingensis (Gracilariales, Rhodophyta).

    Science.gov (United States)

    Mendes, Luiz Fernando; Stevani, Cassius Vinicius; Zambotti-Villela, Leonardo; Yokoya, Nair Sumie; Colepicolo, Pio

    2014-01-01

    The macroalga Gracilaria domingensis is an important resource for the food, pharmaceutical, cosmetic, and biotechnology industries. G. domingensis is at a part of the food web foundation, providing nutrients and microelements to upper levels. As seaweed storage metals in the vacuoles, they are considered the main vectors to magnify these toxic elements. This work describes the evaluation of the toxicity of binary mixtures of available metal cations based on the growth rates of G. domingensis over a 48-h exposure. The interactive effects of each binary mixture were determined using a toxic unit (TU) concept that was the sum of the relative contribution of each toxicant and calculated using the ratio between the toxicant concentration and its endpoint. Mixtures of Cd(II)/Cu(II) and Zn(II)/Ca(II) demonstrated to be additive; Cu(II)/Zn(II), Cu(II)/Mg(II), Cu(II)/Ca(II), Zn(II)/Mg(II), and Ca(II)/Mg(II) mixtures were synergistic, and all interactions studied with Cd(II) were antagonistic. Hypotheses that explain the toxicity of binary mixtures at the molecular level are also suggested. These results represent the first effort to characterize the combined effect of available metal cations, based on the TU concept on seaweed in a total controlled medium. The results presented here are invaluable to the understanding of seaweed metal cation toxicity in the marine environment, the mechanism of toxicity action and how the tolerance of the organism.

  4. Mixture design approach for early stage formulation development of a transdermal delivery system.

    Science.gov (United States)

    Michaelis, M; Leopold, C S

    2015-01-01

    Transdermal delivery systems (TDS) consisting of mixtures of adhesives also named multiple polymer adhesive systems are rarely found in the market and research has only been performed on a few of them. Following the principles of ICH Q8, a Design of Experiments (DOE) approach was selected for the formulation development. For evaluation of the statistical method of "mixture design", blends of silicon adhesive, acrylic adhesive, oleyl alcohol as a surfactant and ibuprofen as a model drug were considered to be combined at different concentrations. A randomized design of 16 runs with five replicates and five runs to estimate the lack of fit (LOF) was generated. Samples were tested for adhesion properties, stability of the wet mixes, solubility of the API in the matrix and appearance of the matrix. After performing an ANOVA with the results, response surfaces of tack, shear adhesion, extent of creaming, crystallization behavior, droplet size and droplet size range were derived as contour plots. It could be shown that crystal growth of ibuprofen correlates well with droplet size and droplet size range, where lowest values for crystallization were found with mixtures containing small droplets. However, it was observed that oleyl alcohol showed no positive effect on the miscibility of the polymers and no improvement of the solubility of ibuprofen in the mixtures. With a reasonable number of experiments, the development of a design space for a TDS via mixture design gave valuable information on the product as well as on the interactions of the components.

  5. Solubility and cation exchange in phosphate rock and saturated clinoptilolite mixtures

    Science.gov (United States)

    Allen, E. R.; Hossner, L. R.; Ming, D. W.; Henninger, D. L.

    1993-01-01

    Mixtures of zeolite and phosphate rock (PR) have the potential to provide slow-release fertilization of plants in synthetic soils by dissolution and ion-exchange reactions. This study was conducted to examine solubility and cation-exchange relationships in mixtures of PR and NH4- and K-saturated clinoptilolite (Cp). Batch-equilibration experiments were designed to investigate the effect of PR source, the proportion of exchangeable K and NH4, and the Cp to PR ratio on solution N, P, K, and Ca concentrations. The dissolution and cation-exchange reactions that occurred after mixing NH4- and K-saturated Cp with PR increased the solubility of the PR and simultaneously released NH4 and K into solution. The more reactive North Carolina (NC) PR rendered higher solution concentrations of NH4 and K when mixed with Cp than did Tennessee (TN) PR. Solution P concentrations for the Cp-NC PR mixture and the Cp-TN PR mixture were similar. Solution concentrations of N, P, K, and Ca and the ratios of these nutrients in solution varied predictably with the type of PR, the Cp/PR ratio, and the proportions of exchangeable K and NH4 on the Cp. Our research indicated that slow-release fertilization using Cp/PR media may provide adequate levels of N, P, and K to support plant growth. Solution Ca concentrations were lower than optimum for plant growth.

  6. Effects of mixture of pharmaceuticals on early life stages of tench (Tinca tinca).

    Science.gov (United States)

    Stancova, Vlasta; Plhalova, Lucie; Bartoskova, Marta; Zivna, Dana; Prokes, Miroslav; Marsalek, Petr; Blahova, Jana; Skoric, Misa; Svobodova, Zdenka

    2014-01-01

    Ubiquitous occurrence of pharmaceuticals in aquatic environment results in concern about potential adverse the effects on nontarget organisms. In water, drugs are present in complex mixtures, in which complicated interactions affect toxicity of single components. The purpose of this study was to examine effect of 35-day-long exposure to mixture of ibuprofen, diclofenac, and carbamazepine on the mortality, growth, early ontogeny, and histopathological changes in tench (Tinca tinca). Early life stage toxicity test was carried out using a modified protocol according to OECD guideline 210. Exposure to mixture of pharmaceuticals at concentration of 60 μg · L(-1) for each substance was associated with significant increase in mortality, as well as significant increase in growth and elevated incidence of malformations. Any of the tested concentrations resulted in histopathological changes of liver, kidney, skin, or gill. After fourteen days of exposure there was short-term delay of development related to increased concentrations of pharmaceuticals in the mixture (2, 20, and 60 μg · L(-1)). Environmentally relevant concentrations (0.02; and 0.2 μg · L(-1)) used in this experiment did not result in toxic impairment of tench.

  7. Effects of Mixture of Pharmaceuticals on Early Life Stages of Tench (Tinca tinca

    Directory of Open Access Journals (Sweden)

    Vlasta Stancova

    2014-01-01

    Full Text Available Ubiquitous occurrence of pharmaceuticals in aquatic environment results in concern about potential adverse the effects on nontarget organisms. In water, drugs are present in complex mixtures, in which complicated interactions affect toxicity of single components. The purpose of this study was to examine effect of 35-day-long exposure to mixture of ibuprofen, diclofenac, and carbamazepine on the mortality, growth, early ontogeny, and histopathological changes in tench (Tinca tinca. Early life stage toxicity test was carried out using a modified protocol according to OECD guideline 210. Exposure to mixture of pharmaceuticals at concentration of 60 μg·L−1 for each substance was associated with significant increase in mortality, as well as significant increase in growth and elevated incidence of malformations. Any of the tested concentrations resulted in histopathological changes of liver, kidney, skin, or gill. After fourteen days of exposure there was short-term delay of development related to increased concentrations of pharmaceuticals in the mixture (2, 20, and 60 μg·L−1. Environmentally relevant concentrations (0.02; and 0.2 μg·L−1 used in this experiment did not result in toxic impairment of tench.

  8. Complex mixtures, complex responses: Assessing pharmaceutical mixtures using field and laboratory approaches

    Science.gov (United States)

    Schoenfuss, Heiko L.; Furlong, Edward T.; Phillips, Patrick J.; Scott, Tia-Marie; Kolpin, Dana W.; Cetkovic-Cvrlje, Marina; Lesteberg, Kelsey E.; Rearick, Daniel C.

    2016-01-01

    Pharmaceuticals are present in low concentrations (tramadol), a muscle relaxant (methocarbamol), a simple antidepressant mixture (fluoxetine, paroxetine, venlafaxine), a sleep aid (temazepam), or a complex mixture of all compounds. Larval minnow response to effluent exposure was not consistent. The 2010 exposures resulted in shorter exposed minnow larvae, whereas the larvae exposed in 2012 exhibited altered escape behavior. Mature minnows exhibited altered hepatosomatic indices, with the strongest effects in females and in mixture exposures. In addition, laboratory-exposed, mature male minnows exposed to all pharmaceuticals (except the selective serotonin reuptake inhibitor mixture) defended nest sites less rigorously than fish in the control group. Tramadol or antidepressant mixture exposure resulted in increased splenic T lymphocytes. Only male minnows exposed to whole effluent responded with increased plasma vitellogenin concentrations. Female minnows exposed to pharmaceuticals (except the opioid mixture) had larger livers, likely as a compensatory result of greater prominence of vacuoles in liver hepatocytes. The observed alteration of apical endpoints central to sustaining fish populations confirms that effluents containing waste streams from pharmaceutical formulation facilities can adversely impact fish populations but that the effects may not be temporally consistent. The present study highlights the importance of including diverse biological endpoints spanning levels of biological organization and life stages when assessing contaminant interactions.

  9. Two-component mixture model: Application to palm oil and exchange rate

    Science.gov (United States)

    Phoong, Seuk-Yen; Ismail, Mohd Tahir; Hamzah, Firdaus Mohamad

    2014-12-01

    Palm oil is a seed crop which is widely adopt for food and non-food products such as cookie, vegetable oil, cosmetics, household products and others. Palm oil is majority growth in Malaysia and Indonesia. However, the demand for palm oil is getting growth and rapidly running out over the years. This phenomenal cause illegal logging of trees and destroy the natural habitat. Hence, the present paper investigates the relationship between exchange rate and palm oil price in Malaysia by using Maximum Likelihood Estimation via Newton-Raphson algorithm to fit a two components mixture model. Besides, this paper proposes a mixture of normal distribution to accommodate with asymmetry characteristics and platykurtic time series data.

  10. Phase structure of liposome in lipid mixtures.

    Science.gov (United States)

    Zhang, Tianxi; Li, Yuzhuo; Mueller, Anja

    2011-11-01

    Gas microbubbles present in ultrasound imaging contrast agents are stabilized by lipid aggregates that typically contain a mixture of lipids. In this study, the phase structure of the lipid mixtures that contained two or three lipids was investigated using three different methods: dynamic light scattering, (1)H NMR, and microfluidity measurements with fluorescence probes. Three lipids that are commonly present in imaging agents (DPPC, DPPE-PEG, and DPPA) were used. Two types of systems, two-lipid model systems and simulated imaging systems were investigated. The results show that liposomes were the dominant aggregates in all the samples studied. The polar PEG side chains from the PEGylated lipid lead to the formation of micelles and micellar aggregates in small sizes. In the ternary lipid systems, almost all the lipids were present in bilayers with micelles absent and free lipids at very low concentration. These results suggest that liposomes, not micelles, contribute to the stabilization of microbubbles in an ultrasound imaging contrast agent.

  11. Molecular thermodiffusion (thermophoresis) in liquid mixtures.

    Science.gov (United States)

    Semenov, Semen N; Schimpf, Martin E

    2005-10-01

    Thermodiffusion (thermophoresis) in liquid mixtures is theoretically examined using a hydrodynamic approach. Thermodiffusion is related to the local temperature-induced pressure gradient in the liquid layer surrounding the selected molecule and to the secondary macroscopic pressure gradient established in the system. The local pressure gradient is produced by excess pressure due to the asymmetry of interactions with surrounding molecules in a nonuniform temperature field. The secondary pressure gradient is considered an independent parameter related to the concentration gradient formed by volume forces, calculated from the generalized equations for mass transfer. Values of Soret coefficients for mixtures of toluene and -hexane are calculated using parameters in the literature. When the molecules are assumed to be similar in shape, the calculated Soret coefficients are lower than the empirical values found in the literature. However, by introducing an asymmetry parameter, which is calculated from independent measurements of component diffusion in the literature, very good agreement is obtained.

  12. Quantum state smoothing for classical mixtures

    CERN Document Server

    Tan, D; Mølmer, K; Murch, K W

    2016-01-01

    In quantum mechanics, wave functions and density matrices represent our knowledge about a quantum system and give probabilities for the outcomes of measurements. If the combined dynamics and measurements on a system lead to a density matrix $\\rho(t)$ with only diagonal elements in a given basis $\\{|n\\rangle\\}$, it may be treated as a classical mixture, i.e., a system which randomly occupies the basis states $|n\\rangle$ with probabilities $\\rho_{nn}(t)$. Fully equivalent to so-called smoothing in classical probability theory, subsequent probing of the occupation of the states $|n\\rangle$ improves our ability to retrodict what was the outcome of a projective state measurement at time $t$. Here, we show with experiments on a superconducting qubit that the smoothed probabilities do not, in the same way as the diagonal elements of $\\rho$, permit a classical mixture interpretation of the state of the system at the past time $t$.

  13. Excess compressibility in binary liquid mixtures.

    Science.gov (United States)

    Aliotta, F; Gapiński, J; Pochylski, M; Ponterio, R C; Saija, F; Salvato, G

    2007-06-14

    Brillouin scattering experiments have been carried out on some mixtures of molecular liquids. From the measurement of the hypersonic velocities we have evaluated the adiabatic compressibility as a function of the volume fraction. We show how the quadratic form of the excess compressibility dependence on the solute volume fraction can be derived by simple statistical effects and does not imply any interaction among the components of the system other than excluded volume effects. This idea is supported by the comparison of the experimental results with a well-established prototype model, consisting of a binary mixture of hard spheres with a nonadditive interaction potential. This naive model turns out to be able to produce a very wide spectrum of structural and thermodynamic features depending on values of its parameters. An attempt has made to understand what kind of structural information can be gained through the analysis of the volume fraction dependence of the compressibility.

  14. The Supervised Learning Gaussian Mixture Model

    Institute of Scientific and Technical Information of China (English)

    马继涌; 高文

    1998-01-01

    The traditional Gaussian Mixture Model(GMM)for pattern recognition is an unsupervised learning method.The parameters in the model are derived only by the training samples in one class without taking into account the effect of sample distributions of other classes,hence,its recognition accuracy is not ideal sometimes.This paper introduces an approach for estimating the parameters in GMM in a supervising way.The Supervised Learning Gaussian Mixture Model(SLGMM)improves the recognition accuracy of the GMM.An experimental example has shown its effectiveness.The experimental results have shown that the recognition accuracy derived by the approach is higher than those obtained by the Vector Quantization(VQ)approach,the Radial Basis Function (RBF) network model,the Learning Vector Quantization (LVQ) approach and the GMM.In addition,the training time of the approach is less than that of Multilayer Perceptrom(MLP).

  15. Sum of Bernoulli Mixtures: Beyond Conditional Independence

    Directory of Open Access Journals (Sweden)

    Taehan Bae

    2014-01-01

    Full Text Available We consider the distribution of the sum of Bernoulli mixtures under a general dependence structure. The level of dependence is measured in terms of a limiting conditional correlation between two of the Bernoulli random variables. The conditioning event is that the mixing random variable is larger than a threshold and the limit is with respect to the threshold tending to one. The large-sample distribution of the empirical frequency and its use in approximating the risk measures, value at risk and conditional tail expectation, are presented for a new class of models which we call double mixtures. Several illustrative examples with a Beta mixing distribution, are given. As well, some data from the area of credit risk are fit with the models, and comparisons are made between the new models and also the classical Beta-binomial model.

  16. Robust classification using mixtures of dependency networks

    DEFF Research Database (Denmark)

    Gámez, José A.; Mateo, Juan L.; Nielsen, Thomas Dyhre

    2008-01-01

    Dependency networks have previously been proposed as alternatives to e.g. Bayesian networks by supporting fast algorithms for automatic learning. Recently dependency networks have also been proposed as classification models, but as with e.g. general probabilistic inference, the reported speed......-ups are often obtained at the expense of accuracy. In this paper we try to address this issue through the use of mixtures of dependency networks. To reduce learning time and improve robustness when dealing with data sparse classes, we outline methods for reusing calculations across mixture components. Finally......, the proposed model is empirically compared to other state-of-the-art classifiers, both in terms of accuracy and learning time....

  17. Lattice Model for water-solute mixtures

    OpenAIRE

    Furlan, A. P.; Almarza, N. G.; M. C. Barbosa

    2016-01-01

    A lattice model for the study of mixtures of associating liquids is proposed. Solvent and solute are modeled by adapting the associating lattice gas (ALG) model. The nature of interaction solute/solvent is controlled by tuning the energy interactions between the patches of ALG model. We have studied three set of parameters, resulting on, hydrophilic, inert and hydrophobic interactions. Extensive Monte Carlo simulations were carried out and the behavior of pure components and the excess proper...

  18. Fluorous Mixture Synthesis of Asymmetric Dendrimers

    Science.gov (United States)

    Jiang, Zhong-Xing; Yu, Yihua Bruce

    2010-01-01

    A divergent fluorous mixture synthesis (FMS) of asymmetric fluorinated dendrimers has been developed. Four generations of fluorinated dendrimers with the same fluorinated moiety were prepared with high efficiency, yield and purity. Comparison of the physicochemical properties of these dendrimers provided valuable information for their application and future optimization. This strategy has not only provided a practical method for the synthesis and purification of dendrimers, but also established the possibility of utilizing the same fluorinated moiety for FMS. PMID:20170088

  19. Nitrocarburising in ammonia-hydrocarbon gas mixtures

    DEFF Research Database (Denmark)

    Pedersen, Hanne; Christiansen, Thomas; Somers, Marcel A. J.

    2010-01-01

    The present work investigates the possibility of nitrocarburising in ammonia-acetylene-hydrogen and ammoniapropene- hydrogen gas mixtures, where unsaturated hydrocarbon gas is the carbon source during nitrocarburising. Consequently, nitrocarburising is carried out in a reducing atmosphere...... microscopy and X-ray diffraction analysis. It is shown that the use of unsaturated hydrocarbon gas in nitrocarburising processes is a viable alternative to traditional nitrocarburising methods....

  20. Nitrocarburizing in ammonia-hydrocarbon gas mixtures

    DEFF Research Database (Denmark)

    Pedersen, Hanne; Christiansen, Thomas; Somers, Marcel A. J.

    2011-01-01

    The present work investigates the possibility of nitrocarburising in ammonia-acetylene-hydrogen and ammonia-propene-hydrogen gas mixtures, where unsaturated hydrocarbon gas is the carbon source during nitrocarburising. Consequently, nitrocarburising is carried out in a reducing atmosphere...... microscopy and X-ray diffraction analysis. It is shown that the use of unsaturated hydrocarbon gas in nitrocarburising processes is a viable alternative to traditional nitrocarburising methods....

  1. Endocrine activity of mycotoxins and mycotoxin mixtures.

    Science.gov (United States)

    Demaegdt, Heidi; Daminet, Britt; Evrard, Annick; Scippo, Marie-Louise; Muller, Marc; Pussemier, Luc; Callebaut, Alfons; Vandermeiren, Karine

    2016-10-01

    Reporter gene assays incorporating nuclear receptors (estrogen, androgen, thyroid β and PPARγ2) have been implemented to assess the endocrine activity of 13 mycotoxins and their mixtures. As expected, zearalenone and its metabolites α-zearalenol and β- zearalenol turned out to have the strongest estrogenic potency (EC50 8,7 10-10 ± 0,8; 3,1 10-11 ± 0,5 and 1,3 10-8 ± 0,3 M respectively). The metabolite of deoxynivalenol, 3-acetyl-deoxynivalenol also had estrogenic activity (EC50 3,8 10-7 ± 1,1 M). Furthermore, most of the mycotoxins (and their mixtures) showed anti-androgenic effects (15-acetyldeoxynivalenol, 3-acetyl-deoxynivalenol and α-zearalenol with potencies within one order of magnitude of that of the reference compound flutamide). In particular, deoxynivalenol and 15-acetyl-deoxynivalenol acted as antagonists for the PPARy2 receptor. When testing mixtures of mycotoxins on the same cell systems, we showed that most of the mixtures reacted as predicted by the concentration addition (CA) theory. Generally, the CA was within the 95% confidence interval of the observed ones, only minor deviations were detected. Although these reporter gene tests cannot be directly extrapolated in vivo, they can be the basis for further research. Especially the additive effects of ZEN and its metabolites are of importance and could have repercussions in vivo.

  2. Method for Predicting Hypergolic Mixture Flammability Limits

    Science.gov (United States)

    2017-02-01

    AFRL-AFOSR-UK-TR-2017-0003 Method for Predicting Hypergolic Mixture Flammability Limits Laurent Catoire Ecole Nat Sup De Techniques Avancees Final...TASK NUMBER 5f.  WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Ecole Nat Sup De Techniques Avancees 828, Boulevard Des Marechaux...provides a mitigation strategy to reduce the risk of failure for the insertion of IL fuel technology into the small satellite market as AFRL/RQRP

  3. Hierarchical mixture models for assessing fingerprint individuality

    OpenAIRE

    Dass, Sarat C.; Li, Mingfei

    2009-01-01

    The study of fingerprint individuality aims to determine to what extent a fingerprint uniquely identifies an individual. Recent court cases have highlighted the need for measures of fingerprint individuality when a person is identified based on fingerprint evidence. The main challenge in studies of fingerprint individuality is to adequately capture the variability of fingerprint features in a population. In this paper hierarchical mixture models are introduced to infer the extent of individua...

  4. Statistical mechanical theory of fluid mixtures

    Science.gov (United States)

    Zhao, Yueqiang; Wu, Zhengming; Liu, Weiwei

    2014-01-01

    A general statistical mechanical theory of fluid mixtures (liquid mixtures and gas mixtures) is developed based on the statistical mechanical expression of chemical potential of components in the grand canonical ensemble, which gives some new relationships between thermodynamic quantities (equilibrium ratio Ki, separation factor α and activity coefficient γi) and ensemble average potential energy u for one molecule. The statistical mechanical expressions of separation factor α and activity coefficient γi derived in this work make the fluid phase equilibrium calculations can be performed by molecular simulation simply and efficiently, or by the statistical thermodynamic approach (based on the saturated-vapor pressure of pure substance) that does not need microscopic intermolecular pair potential functions. The physical meaning of activity coefficient γi in the liquid phase is discussed in detail from a viewpoint of molecular thermodynamics. The calculated Vapor-Liquid Equilibrium (VLE) properties of argon-methane, methanol-water and n-hexane-benzene systems by this model fit well with experimental data in references, which indicates that this model is accurate and reliable in the prediction of VLE properties for small, large and strongly associating molecules; furthermore the statistical mechanical expressions of separation factor α and activity coefficient γi have good compatibility with classical thermodynamic equations and quantum mechanical COSMO-SAC approach.

  5. Familial searching on DNA mixtures with dropout.

    Science.gov (United States)

    Slooten, K

    2016-05-01

    Familial searching, the act of searching a database for a relative of an unknown individual whose DNA profile has been obtained, is usually restricted to cases where the DNA profile of that person has been unambiguously determined. Therefore, it is normally applied only with a good quality single source profile as starting point. In this article we investigate the performance of the method if applied to mixtures with and without allelic dropout, when likelihood ratios are computed with a semi-continuous (binary) model. We show that mixtures with dropout do not necessarily perform worse than mixtures without, especially if some separation between the donors is possible due to their different dropout probabilities. The familial searching true and false positive rates of mixed profiles on 15 loci are in some cases better than those of single source profiles on 10 loci. Thus, the information loss due to the fact that the person of interest's DNA has been mixed with that of other, and is affected by dropout, can be less than the loss of information corresponding to having 5 fewer loci available for a single source trace. Profiles typed on 10 autosomal loci are often involved in familial searching casework since many databases, including the Dutch one, in part consist of such profiles. Therefore, from this point of view, there seems to be no objection to extend familial searching to mixed or degraded profiles.

  6. Ethane-xenon mixtures under shock conditions

    Science.gov (United States)

    Flicker, Dawn; Magyar, Rudolph; Root, Seth; Cochrane, Kyle; Mattsson, Thomas

    2015-06-01

    Mixtures of light and heavy elements arise in inertial confinement fusion and planetary science. We present results on the physics of molecular scale mixing through a validation study of equation of state (EOS) properties. Density functional theory molecular dynamics (DFT/QMD) at elevated-temperature and pressure is used to obtain the properties of pure xenon, ethane, and various compressed mixture compositions along their principal Hugoniots. To validate the QMD simulations, we performed high-precision shock compression experiments using Sandia's Z-Machine. A bond tracking analysis of the simulations correlates the sharp rise in the Hugoniot curve with completion of dissociation in ethane. DFT-based simulation results compare well with experimental data and are used to provide insight into the dissociation as a function of mixture composition. Interestingly, we find that the compression ratio for complete dissociation is similar for ethane, Xe-ethane, polymethyl-pentene, and polystyrene, suggesting that a limiting compression exists for C-C bonded systems. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, Security Administration under contract DE-AC04-94AL85000.

  7. Crowding in polymer-nanoparticle mixtures.

    Science.gov (United States)

    Denton, Alan R

    2014-01-01

    The cell nucleus is a highly crowded environment, filled with a multicomponent, polydisperse mixture of biopolymers and nuclear bodies dispersed in a viscous solvent. With volume fractions approaching 20%, excluded-volume interactions play a key role in determining the structure, dynamics, and function of macromolecules in vivo. Under such constraints, the ensembles of macromolecular conformations can differ substantially from those prevailing in dilute solutions. Crowding thus can affect protein and RNA folding, conformational stability, and reaction kinetics, as well as phase stability of macromolecular mixtures. From the perspective of soft matter physics, this chapter reviews recent studies on crowding in polymer-nanoparticle mixtures, seeking to demonstrate the utility of simple physical models for addressing challenging issues in cell biology. The focus is on applications of free-volume theory and Monte Carlo simulation, based on geometrical models of polymers as fluctuating spheres or ellipsoids. Ideal polymer coils respond to hard-sphere crowding agents by compactifying, reducing their radius of gyration, and becoming more spherical. At sufficiently high concentrations, polymers and crowders phase-separate. The goal of this review is to identify universal principles governing macromolecular crowding and to establish a general framework for future explorations of more realistic models that may include nonsteric (e.g., electrostatic) interactions. © 2014 Elsevier Inc. All rights reserved.

  8. Tandem mass spectrometry: analysis of complex mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Singleton, K.E.

    1985-01-01

    Applications of tandem mass spectrometry (MS/MS) for the analysis of complex mixtures results in increased specificity and selectivity by using a variety of reagent gases in both negative and positive ion modes. Natural isotopic abundance ratios were examined in both simple and complex mixtures using parent, daughter and neutral loss scans. MS/MS was also used to discover new compounds. Daughter scans were used to identify seven new alkaloids in a cactus species. Three of these alkaloids were novel compounds, and included the first simple, fully aromatic isoquinoline alkaloids reported in Cactaceae. MS/MS was used to characterize the chemical reaction products of coal in studies designed to probe its macromolecular structure. Negative ion chemical ionization was utilized to study reaction products resulting from the oxidation of coal. Possible structural units in the precursor coal were predicted based on the reaction products identified, aliphatic and aromatic acids and their anhydrides. The MS/MS method was also used to characterize reaction products resulting from coal liquefaction and/or extraction. These studies illustrate the types of problems for which MS/MS is useful. Emphasis has been placed on characterization of complex mixtures by selecting experimental parameters which enhance the information obtained. The value of using MS/MS in conjunction with other analytical techniques as well as the chemical pretreatment is demonstrated.

  9. Confusion of concepts in mixture toxicology.

    Science.gov (United States)

    Könemann, W H; Pieters, M N

    1996-01-01

    Regulatory limit values are generally set for single compounds. However, humans are exposed both simultaneously and sequentially to a wide variety of compounds. Some concepts on mixture toxicology are discussed in this introduction to the European Conference on Combination Toxicology. Studies on mixtures are often accompanied by statements about the type of combined action, which can be, for example, additive, synergistic or antagonistic. Unfortunately, comparison of results is hardly possible for various reasons. First, the terminology for indicating combined action is far from consistent. Bearing this in mind, researchers should be explicit in the definitions of terms. Secondly, depending on the model, different conclusions may be drawn from the same results. It is therefore important to provide clear definitions of the null hypothesis. Thirdly, adequate statistical methods should be used for testing the null hypothesis. In the past, many mixtures studies either used no statistics or used statistics incorrectly. Last, but not least, the study should be designed in such a way that it should be possible to obtain clear answers. In this introduction, it is stressed that environmental toxicologists should focus on the low-dose region of the dose-effect curves. It appears that interactions are less plausible at low doses. Dose additivity, however, cannot be excluded.

  10. Mixture risk assessment: a case study of Monsanto experiences.

    Science.gov (United States)

    Nair, R S; Dudek, B R; Grothe, D R; Johannsen, F R; Lamb, I C; Martens, M A; Sherman, J H; Stevens, M W

    1996-01-01

    Monsanto employs several pragmatic approaches for evaluating the toxicity of mixtures. These approaches are similar to those recommended by many national and international agencies. When conducting hazard and risk assessments, priority is always given to using data collected directly on the mixture of concern. To provide an example of the first tier of evaluation, actual data on acute respiratory irritation studies on mixtures were evaluated to determine whether the principle of additivity was applicable to the mixture evaluated. If actual data on the mixture are unavailable, extrapolation across similar mixtures is considered. Because many formulations are quite similar in composition, the toxicity data from one mixture can be extended to a closely related mixture in a scientifically justifiable manner. An example of a family of products where such extrapolations have been made is presented to exemplify this second approach. Lastly, if data on similar mixtures are unavailable, data on component fractions are used to predict the toxicity of the mixture. In this third approach, process knowledge and scientific judgement are used to determine how the known toxicological properties of the individual fractions affect toxicity of the mixture. Three examples of plant effluents where toxicological data on fractions were used to predict the toxicity of the mixture are discussed. The results of the analysis are used to discuss the predictive value of each of the above mentioned toxicological approaches for evaluating chemical mixtures.

  11. Statistical analysis of joint toxicity in biological growth experiments

    DEFF Research Database (Denmark)

    Spliid, Henrik; Tørslev, J.

    1994-01-01

    The authors formulate a model for the analysis of designed biological growth experiments where a mixture of toxicants is applied to biological target organisms. The purpose of such experiments is to assess the toxicity of the mixture in comparison with the toxicity observed when the toxicants...... are applied individually to the organisms. The analysis is based on a random differential equation describing the growth of the organisms. This model yields a natural measure of interaction between toxicants and the hypothesis of independent action from a mixture of toxicants can be tested. The proposed model...

  12. Response of brown hisex chicks to low levels of Jatropha curcas, Ricinus communis or their mixture.

    Science.gov (United States)

    el Badwi, S M; Mousa, H M; Adam, S E; Hapke, H J

    1992-08-01

    Feeding Jatropha curcas seed at 0.5% of the basic diet for 2 w was not lethal to chicks. In chicks fed 0.5% Ricinus communis seed or a mixture of 0.5% J curcas + 0.5% R communis for 2 w, there was dullness, poor growth, locomotor disturbance and death. Pathological changes were correlated with alterations in clinical chemistry and hematology.

  13. Study on the toxic effect of the mixture of organophosphorus pesticide on perinatal rats

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective To observe the toxic effect of the mixture of organophosphorus pesticide (MOP) on maternal rats and on the growth and development of their offspring. Methods Totally 40 Sprague-Dawley pregnant rats were randomly divided into three MOP dose groups and one control to which their offspring would be assigned. The experimental dosage of MOP and distilled water were administered orally starting on gestation day 15 and continued for 35 days. The physical development indices and the learning ability of F1...

  14. Physical Compatibility of Propofol-Sufentanil Mixtures.

    Science.gov (United States)

    Zbytovská, Jarmila; Gallusová, Jana; Vidlářová, Lucie; Procházková, Kamila; Šimek, Jan; Štěpánek, František

    2017-03-01

    Combined infusions of propofol and sufentanil preparations are frequently used in clinical practice to induce anesthesia and analgesia. However, the stability of propofol emulsions can be affected by dilution with another preparation, sometimes leading to particle coalescence and enlargement. Such unwanted effects can lead to fat embolism syndrome after intravenous application. This study describes the physical stability of 5 commercially available propofol preparations mixed with sufentanil citrate solutions. Two common markers of emulsion stability were used in this study; namely, the zeta potential and size distribution of the emulsion droplets. Both were measured using dynamic light scattering. The data for the pure propofol preparations and their mixtures with sufentanil citrate solution were compared. The absolute value of zeta potential decreased in 4 of the 5 propofol preparations after they had been mixed with sufentanil citrate. This effect indicates a lowering of repulsive interactions between the emulsion droplets. Although this phenomenon tends to cause agglomeration, none of the studied mixtures displayed a substantial increase in droplet size within 24 hours of blending. However, our long-term stability study revealed the instability of some of the propofol-sufentanil samples. Two of the 5 studied mixtures displayed a continual increase in particle size. The same 2 preparations showed the greatest reductions in the absolute value of zeta potential, thereby confirming the correlation of both measurement methods. The increase in particle size was more distinct in the samples stored at higher temperatures and with higher sufentanil concentrations. To ensure the microbial stability of an emulsion infusion preparation, clinical regulations require that such preparations should be applied to patients within 12 hours of opening. In this respect, we can confirm that during this period, none of the studied propofol-sufentanil mixtures displayed any physical

  15. Separation of gas mixtures by supported complexes

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, D.A.; Lilga, M.A.; Hallen, R.T.; Lyke, S.E.

    1986-08-01

    The goal of this program is to determine the feasibility of solvent-dissolved coordination complexes for the separation of gas mixtures under bench-scale conditions. In particular, mixtures such as low-Btu gas are examined for CO and H/sub 2/ separation. Two complexes, Pd/sub 2/(dpm)/sub 2/Br/sub 2/ and Ru(CO)/sub 2/(PPh/sub 3/)/sub 3/, were examined in a bench-scale apparatus for the separation of binary (CO-N/sub 2/ or H/sub 2/-N/sub 2/) and quinary (H/sub 2/, CO, CO/sub 2/, CH/sub 4/, and N/sub 2/) mixtures. The separation of CO-N/sub 2/ was enhanced by the presence of the palladium complex in the 1,1,2-trichloroethane (TCE) solvent, especially at high gas and low liquid rates. The five-component gas mixture separation with the palladium complex in TCE provided quite unexpected results based on physical solubility and chemical coordination. The complex retained CO, while the solvent retained CO/sub 2/, CH/sub 4/, and N/sub 2/ to varying degrees. This allowed the hydrogen content to be enhanced due to its low solubility in TCE and inertness to the complex. Thus, a one-step, hydrogen separation can be achieved from gas mixtures with compositions similar to that of oxygen-blown coal gas. A preliminary economic evaluation of hydrogen separation was made for a system based on the palladium complex. The palladium system has a separation cost of 50 to 60 cents/MSCF with an assumed capital investment of $1.60/MSCF of annual capacity charged at 30% per year. This assumes a 3 to 4 year life for the complex. Starting with a 90% hydrogen feed, PSA separation costs are in the range of 30 to 50 cents/MSCF. The ruthenium complex was not as successful for hydrogen or carbon monoxide separation due to unfavorable kinetics. The palladium complex was found to strip hydrogen gas from H/sub 2/S. The complex could be regenerated with mild oxidants which removed the sulfur as SO/sub 2/. 24 refs., 26 figs., 10 tabs.

  16. Mixtures as a fungicide resistance management tactic.

    Science.gov (United States)

    van den Bosch, Frank; Paveley, Neil; van den Berg, Femke; Hobbelen, Peter; Oliver, Richard

    2014-12-01

    We have reviewed the experimental and modeling evidence on the use of mixtures of fungicides of differing modes of action as a resistance management tactic. The evidence supports the following conclusions. 1. Adding a mixing partner to a fungicide that is at-risk of resistance (without lowering the dose of the at-risk fungicide) reduces the rate of selection for fungicide resistance. This holds for the use of mixing partner fungicides that have either multi-site or single-site modes of action. The resulting predicted increase in the effective life of the at-risk fungicide can be large enough to be of practical relevance. The more effective the mixing partner (due to inherent activity and/or dose), the larger the reduction in selection and the larger the increase in effective life of the at-risk fungicide. 2. Adding a mixing partner while lowering the dose of the at-risk fungicide reduces the selection for fungicide resistance, without compromising effective disease control. The very few studies existing suggest that the reduction in selection is more sensitive to lowering the dose of the at-risk fungicide than to increasing the dose of the mixing partner. 3. Although there are very few studies, the existing evidence suggests that mixing two at-risk fungicides is also a useful resistance management tactic. The aspects that have received too little attention to draw generic conclusions about the effectiveness of fungicide mixtures as resistance management strategies are as follows: (i) the relative effect of the dose of the two mixing partners on selection for fungicide resistance, (ii) the effect of mixing on the effective life of a fungicide (the time from introduction of the fungicide mode of action to the time point where the fungicide can no longer maintain effective disease control), (iii) polygenically determined resistance, (iv) mixtures of two at-risk fungicides, (v) the emergence phase of resistance evolution and the effects of mixtures during this phase

  17. Investigation of rheological properties of mixtures of soft ice cream

    Directory of Open Access Journals (Sweden)

    L. V. Golubeva

    2012-01-01

    Full Text Available The paper presents the study of the rheological properties of multicomponent mixtures for soft ice cream enriched with various stabilizers to facilitate evaluation and selection of the optimal mixture.

  18. Methods for Assessing Curvature and Interaction in Mixture Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Piepel, Gregory F.(BATTELLE (PACIFIC NW LAB)); Hicks, Ruel D.(ASSOC WESTERN UNIVERSITY); Szychowski, Jeffrey M.(ASSOC WESTERN UNIVERSITY); Loeppky, Jason L.(ASSOC WESTERN UNIVERSITY)

    2002-05-01

    The terms curvature and interaction traditionally are not defined or used in the context of mixture experiments because curvature and interaction effects are partially confounded due to the mixture constrain that the component proportions sum to 1.

  19. Mixture Density Mercer Kernels: A Method to Learn Kernels

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper presents a method of generating Mercer Kernels from an ensemble of probabilistic mixture models, where each mixture model is generated from a Bayesian...

  20. Optimal (Solvent) Mixture Design through a Decomposition Based CAMD methodology

    DEFF Research Database (Denmark)

    Achenie, L.; Karunanithi, Arunprakash T.; Gani, Rafiqul

    2004-01-01

    Computer Aided Molecular/Mixture design (CAMD) is one of the most promising techniques for solvent design and selection. A decomposition based CAMD methodology has been formulated where the mixture design problem is solved as a series of molecular and mixture design sub-problems. This approach is...... is able to overcome most of the difficulties associated with the solution of mixture design problems. The new methodology has been illustrated with the help of a case study involving the design of solvent-anti solvent binary mixtures for crystallization of Ibuprofen.......Computer Aided Molecular/Mixture design (CAMD) is one of the most promising techniques for solvent design and selection. A decomposition based CAMD methodology has been formulated where the mixture design problem is solved as a series of molecular and mixture design sub-problems. This approach...

  1. Laser-induced capillary effect in thin layers of water-alcohol mixtures.

    Science.gov (United States)

    Ivanova, Natalia A; Tatosov, Aleksey V; Bezuglyi, Boris A

    2015-06-01

    The effect of droplet formation in thin layers of water-alcohol mixtures upon laser heating was studied. The droplet growth in the laser beam is governed by the surface tension gradient, which induces solutocapillary flows from the periphery to the center of the heated area. This gradient arises due to the local increase in surface tension caused by the evaporation of alcohol from the heated area of the layer. The experimental results have shown that the increase in the initial concentration of water in the mixture gives rise to the increase in droplet size. However, the increase in the power of laser irradiation leads to a decrease in the droplet growth rate. A simplified one-dimensional model of droplet growth is developed. The model involves the dependence of surface tension on both the temperature and concentration of components in the mixture, as well as the evaporation and condensation of alcohol. The experimental results are compared with those obtained using numerical simulations. A reasonable agreement between experimental and numerical results was shown.

  2. Investigation of a Gamma model for mixture STR samples

    DEFF Research Database (Denmark)

    Christensen, Susanne; Bøttcher, Susanne Gammelgaard; Lauritzen, Steffen L.

    The behaviour of PCR Amplification Kit, when used for mixture STR samples, is investigated. A model based on the Gamma distribution is fitted to the amplifier output for constructed mixtures, and the assumptions of the model is evaluated via residual analysis.......The behaviour of PCR Amplification Kit, when used for mixture STR samples, is investigated. A model based on the Gamma distribution is fitted to the amplifier output for constructed mixtures, and the assumptions of the model is evaluated via residual analysis....

  3. Quantum phases of Fermi-Fermi mixtures in optical lattices

    OpenAIRE

    Iskin, M.; de Melo, C. A. R. Sa

    2007-01-01

    The ground state phase diagram of Fermi-Fermi mixtures in optical lattices is analyzed as a function of interaction strength, population imbalance, filling fraction and tunneling parameters. It is shown that population imbalanced Fermi-Fermi mixtures reduce to strongly interacting Bose-Fermi mixtures in the molecular limit, in sharp contrast to homogeneous or harmonically trapped systems where the resulting Bose-Fermi mixture is weakly interacting. Furthermore, insulating phases are found in ...

  4. Penetration and survival of riparian tree roots in compacted coarse gravel mixtures

    Science.gov (United States)

    Muellner, Michael; Weissteiner, Clemens; Konzel, Christoph; Rauch, Hans Peter

    2016-04-01

    Root growth and penetration of riparian trees along paved cycling paths and service roads of rivers causes often traffic safety problems. Damages occur mostly on street surfaces with thin asphalt layers and especially in the upper part of the pavement structure. The maintainers of these roads are faced with frequent and high annual repair costs in order to guarantee traffic safety and pleasant cycling conditions. Analyses of the dominating process mechanisms demonstrated that mainly the naturally growing pioneer vegetation along rivers is responsible for the asphalt damages caused by their constant and rapid growth. The investigations of the root growth characteristics showed that tree roots mostly penetrate the road structure between the gravel sublayer and the asphalt because of the high compaction of the layer itself. In a second step of the research project the influence of different gravel size mixtures on the root penetration and survival are analysed. Coarse gravel size mixtures with the lowest possible fine granular fraction are suposed to inhibit root growth due to the mechanical impedance and air pruning of roots. Furthermore coarse gravel size mixtures could influence the presence of condensate formed at the underside of the asphalt layer. Therefore seven different compositions of matrix stone gravel size mixtures (0/32, 4/32, 8/32, 16/32, 0/64, 8/64 hydraulic bound mixture and 16/64) as sublayer material were tested in a small scale experimental set-up. Wooden boxes with a dimension of 1x1.5x0.5 m and 0.5x0.5x0.5 m were used as frames for the different matrix stone mixtures. On one side the boxes were delimited to the surrounding soil with a steel mesh followed by a wire mesh and a geotextile. Boxes were located in an 80 cm deep hole on a 30 cm thick drainage layer. Willow and poplar cuttings were planted laterally to the root penetrable side of the boxes. Large boxes were filled and compacted with 6 different gravel size mixtures (all but 4/32) and

  5. Mixture toxicity of the antiviral drug Tamiflu (oseltamivir ethylester) and its active metabolite oseltamivir acid

    Energy Technology Data Exchange (ETDEWEB)

    Escher, Beate I., E-mail: b.escher@uq.edu.au [University of Queensland, National Research Centre for Environmental Toxicology (Entox), 39 Kessels Rd, Brisbane, Qld 4108 (Australia); Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Duebendorf (Switzerland); Bramaz, Nadine; Lienert, Judit; Neuwoehner, Judith [Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Duebendorf (Switzerland); Straub, Juerg Oliver [F.Hoffmann-La Roche Ltd, Corporate Safety, Health and Environmental Protection, 4070 Basel (Switzerland)

    2010-02-18

    Tamiflu (oseltamivir ethylester) is an antiviral agent for the treatment of influenza A and B. The pro-drug Tamiflu is converted in the human body to the pharmacologically active metabolite, oseltamivir acid, with a yield of 75%. Oseltamivir acid is indirectly photodegradable and slowly biodegradable in sewage works and sediment/water systems. A previous environmental risk assessment has concluded that there is no bioaccumulation potential of either of the compounds. However, little was known about the ecotoxicity of the metabolite. Ester hydrolysis typically reduces the hydrophobicity and thus the toxicity of a compound. In this case, a zwitterionic, but overall neutral species is formed from the charged parent compound. If the speciation and predicted partitioning into biological membranes is considered, the metabolite may have a relevant contribution to the overall toxicity. These theoretical considerations triggered a study to investigate the toxicity of oseltamivir acid (OA), alone and in binary mixtures with its parent compound oseltamivir ethylester (OE). OE and OA were found to be baseline toxicants in the bioluminescence inhibition test with Vibrio fischeri. Their mixture effect lay between predictions for concentration addition and independent action for the mixture ratio excreted in urine and nine additional mixture ratios of OE and OA. In contrast, OE was an order of magnitude more toxic than OA towards algae, with a more pronounced effect when the direct inhibition of photosystem II was used as toxicity endpoint opposed to the 24 h growth rate endpoint. The binary mixtures in this assay yielded experimental mixture effects that agreed with predictions for independent action. This is consistent with the finding that OE exhibits slightly enhanced toxicity, while OA acts as baseline toxicant. Therefore, with respect to mixture classification, the two compounds can be considered as acting according to different modes of toxic action, although there are

  6. Continuous mixtures with bathtub-shaped failure rates

    OpenAIRE

    Block, Henry W.; LI, YULIN; Savits, Thomas H.; Wang, Jie

    2008-01-01

    The failure rate of a mixture of even the most standard distributions used in reliability can have a complicated shape. However, failure rates of mixtures of two carefully selected distributions will have the well-known bathtub shape. Here we show that mixtures of whole families of distribtions can have a bathtub-shaped failure rate.

  7. Lessons learned in managing alfalfa-grass mixtures

    Science.gov (United States)

    Grass-alfalfa mixtures have a number of benefits that make them attractive to producers. However, they can be problematic to establish and maintain. Research programs have made progress in understanding the benefits and challenges of alfalfa-grass mixtures. Mixtures may have greater winter survival ...

  8. 40 CFR 721.5769 - Mixture of nitrated alkylated phenols.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Mixture of nitrated alkylated phenols... Substances § 721.5769 Mixture of nitrated alkylated phenols. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a mixture of nitrated alkylated...

  9. 21 CFR 864.8625 - Hematology quality control mixture.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hematology quality control mixture. 864.8625 Section 864.8625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... quality control mixture. (a) Identification. A hematology quality control mixture is a device used...

  10. TEMPERATURE INFLUENCE ON PHASE STABILITY OF ETHANOL-GASOLINE MIXTURES

    Directory of Open Access Journals (Sweden)

    Valerian Cerempei

    2011-06-01

    Full Text Available The article investigates phase stability of ethanol-gasoline mixtures depending on their composition, water concentration in ethanol and ethanol-gasoline mixture and temperature. There have been determined the perfect functioning conditions of spark ignition engines fueled with ethanol-gasoline mixtures.

  11. 46 CFR 154.1735 - Methyl acetylene-propadiene mixture.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Methyl acetylene-propadiene mixture. 154.1735 Section... Operating Requirements § 154.1735 Methyl acetylene-propadiene mixture. (a) The composition of the methyl acetylene-propadiene mixture at loading must be within the following limits or specially approved by...

  12. Effect of mixture ratios and nitrogen carrier gas flow rates on the morphology of carbon nanotube structures grown by CVD

    CSIR Research Space (South Africa)

    Malgas, GF

    2008-02-01

    Full Text Available This paper reports on the growth of carbon nanotubes (CNTs) by thermal Chemical Vapour Deposition (CVD) and investigates the effects of nitrogen carrier gas flow rates and mixture ratios on the morphology of CNTs on a silicon substrate by vaporizing...

  13. Integrated phospholipidomics and transcriptomics analysis of Saccharomyces cerevisiae with enhanced tolerance to a mixture of acetic acid, furfural, and phenol

    Science.gov (United States)

    A mixture of acetic acid, furfural and phenol (AFP), three representative lignocellulose derived inhibitors, significantly inhibited the growth and bioethanol production of Saccharomyces cerevisiae. In order to uncover mechanisms behind the enhanced tolerance of an inhibitor-tolerant S.cerevisiae s...

  14. 两部制负荷率电价体系的设计及应用%Design and application of power selling price system with two parts load factor tariff

    Institute of Scientific and Technical Information of China (English)

    孙素苗

    2015-01-01

    Aiming at the problems of selling power price classification complexity, executing difficulty,cross subsidies severity,and not conducive to rational allocation of power resources, based on the deep analysis of selling power price classification frame,designs the merger scheme that adopting two parts load factor tariff to put together the selling power prices of large industry and general industry. The result shows that the merger more rationally reflects customer cost,decreases cross subsidies of selling power price,and has a role in promoting rational allocation of power resources.%针对我国目前销售电价分类复杂,执行中矛盾较多,交叉补贴严重,不利于电力资源合理配置的问题,在深入分析电价分类结构的基础上,设计了按两部制负荷率电价对大工业与一般工商业电价的归并方案。结果表明:归并后的电价方案较为合理地反映了用户的用电成本,减少了电价交叉补贴,对于电力资源的合理配置具有促进作用。

  15. [Comparison of two spectral mixture analysis models].

    Science.gov (United States)

    Wang, Qin-Jun; Lin, Qi-Zhong; Li, Ming-Xiao; Wang, Li-Ming

    2009-10-01

    A spectral mixture analysis experiment was designed to compare the spectral unmixing effects of linear spectral mixture analysis (LSMA) and constraint linear spectral mixture analysis (CLSMA). In the experiment, red, green, blue and yellow colors were printed on a coarse album as four end members. Thirty nine mixed samples were made according to each end member's different percent in one pixel. Then, field spectrometer was located on the top of the mixed samples' center to measure spectrum one by one. Inversion percent of each end member in the pixel was extracted using LSMA and CLSMA models. Finally, normalized mean squared error was calculated between inversion and real percent to compare the two models' effects on spectral unmixing. Results from experiment showed that the total error of LSMA was 0.30087 and that of CLSMA was 0.37552 when using all bands in the spectrum. Therefore, LSMA was 0.075 less than that of CLSMA when the whole bands of four end members' spectra were used. On the other hand, the total error of LSMA was 0.28095 and that of CLSMA was 0.29805 after band selection. So, LSMA was 0.017 less than that of CLSMA when bands selection was performed. Therefore, whether all or selected bands were used, the accuracy of LSMA was better than that of CLSMA because during the process of spectrum measurement, errors caused by instrument or human were introduced into the model, leading to that the measured data could not mean the strict requirement of CLSMA and therefore reduced its accuracy: Furthermore, the total error of LSMA using selected bands was 0.02 less than that using the whole bands. The total error of CLSMA using selected bands was 0.077 less than that using the whole bands. So, in the same model, spectral unmixing using selected bands to reduce the correlation of end members' spectra was superior to that using the whole bands.

  16. Flows and chemical reactions in heterogeneous mixtures

    CERN Document Server

    Prud'homme, Roger

    2014-01-01

    This book - a sequel of previous publications 'Flows and Chemical Reactions' and 'Chemical Reactions in Flows and Homogeneous Mixtures' - is devoted to flows with chemical reactions in heterogeneous environments.  Heterogeneous media in this volume include interfaces and lines. They may be the site of radiation. Each type of flow is the subject of a chapter in this volume. We consider first, in Chapter 1, the question of the generation of environments biphasic individuals: dusty gas, mist, bubble flow.  Chapter 2 is devoted to the study at the mesoscopic scale: particle-fluid exchange of mom

  17. Temperature relaxation in dense plasma mixtures

    Science.gov (United States)

    Faussurier, Gérald; Blancard, Christophe

    2016-09-01

    We present a model to calculate temperature-relaxation rates in dense plasma mixtures. The electron-ion relaxation rates are calculated using an average-atom model and the ion-ion relaxation rates by the Landau-Spitzer approach. This method allows the study of the temperature relaxation in many-temperature electron-ion and ion-ion systems such as those encountered in inertial confinement fusion simulations. It is of interest for general nonequilibrium thermodynamics dealing with energy flows between various systems and should find broad use in present high energy density experiments.

  18. Gaussian mixture model of heart rate variability.

    Directory of Open Access Journals (Sweden)

    Tommaso Costa

    Full Text Available Heart rate variability (HRV is an important measure of sympathetic and parasympathetic functions of the autonomic nervous system and a key indicator of cardiovascular condition. This paper proposes a novel method to investigate HRV, namely by modelling it as a linear combination of Gaussians. Results show that three Gaussians are enough to describe the stationary statistics of heart variability and to provide a straightforward interpretation of the HRV power spectrum. Comparisons have been made also with synthetic data generated from different physiologically based models showing the plausibility of the Gaussian mixture parameters.

  19. Spectrometric mixture analysis: An unexpected wrinkle

    Indian Academy of Sciences (India)

    Robert De Levie

    2009-09-01

    The spectrometric analysis of a mixture of two chemically and spectroscopically similar compounds is illustrated for the simultaneous spectrometric determination of caffeine and theobromine, the primary stimulants in coffee and tea, based on their ultraviolet absorbances. Their analysis indicates that such measurements may need an unexpectedly high precision to yield accurate answers, because of an artifact of inverse cancellation, in which a small noise or drift signal is misinterpreted in terms of a concentration difference. The computed sum of the concentrations is not affected.

  20. Bayesian mixture models for partially verified data

    DEFF Research Database (Denmark)

    Kostoulas, Polychronis; Browne, William J.; Nielsen, Søren Saxmose;

    2013-01-01

    for some individuals, in order to minimize this loss in the discriminatory power. The distribution of the continuous antibody response against MAP has been obtained for healthy, MAP-infected and MAP-infectious cows of different age groups. The overall power of the milk-ELISA to discriminate between healthy......Bayesian mixture models can be used to discriminate between the distributions of continuous test responses for different infection stages. These models are particularly useful in case of chronic infections with a long latent period, like Mycobacterium avium subsp. paratuberculosis (MAP) infection...

  1. Two-microphone Separation of Speech Mixtures

    DEFF Research Database (Denmark)

    2006-01-01

    of Speech Mixtures," 2006, submited for journal publication. See also, [2] Michael Syskind Pedersen, DeLiang Wang, Jan Larsen and Ulrik Kjems: "Overcomplete Blind Source Separation by Combining ICA and Binary Time-Frequency Masking," in proceedings of IEEE International workshop on Machine Learning......In this demonstration we show the separation of 3-7 mixed speech sources based on information from two microphones. Separation with background noise is demonstrated too. The algorithms are described in 1] Michael Syskind Pedersen, DeLiang Wang, Jan Larsen and Ulrik Kjems: "Two-microphone Separation...

  2. Video compressive sensing using Gaussian mixture models.

    Science.gov (United States)

    Yang, Jianbo; Yuan, Xin; Liao, Xuejun; Llull, Patrick; Brady, David J; Sapiro, Guillermo; Carin, Lawrence

    2014-11-01

    A Gaussian mixture model (GMM)-based algorithm is proposed for video reconstruction from temporally compressed video measurements. The GMM is used to model spatio-temporal video patches, and the reconstruction can be efficiently computed based on analytic expressions. The GMM-based inversion method benefits from online adaptive learning and parallel computation. We demonstrate the efficacy of the proposed inversion method with videos reconstructed from simulated compressive video measurements, and from a real compressive video camera. We also use the GMM as a tool to investigate adaptive video compressive sensing, i.e., adaptive rate of temporal compression.

  3. Molecular weight scaling in critical polymer mixtures

    DEFF Research Database (Denmark)

    Gehlsen, M.D.; Rosedale, J.R.; Bates, F.S.

    1992-01-01

    , DELTA-X(D), and molecular weight by small-angle neutron scattering. The critical point for demixing was determined to scale as chi(eff,c) is similar to N(-delta) with delta = 1.01 +/- 0.05, where N is the degree of polymerization. This result confirms the mean-field prediction of Flory and Huggins.......Symmetric binary mixtures of partially deuterated polymers were prepared at the critical composition. The segment-segment interaction energy parameter chi(eff) was varied by adjusting the difference in deuterium content DELTA-X(D) between species. Chi(eff) was measured as a function of temperature...

  4. Growth Econometrics

    OpenAIRE

    JOHNSON, Paul; Steven N. Durlauf; Temple, Johnathan R. W.

    2004-01-01

    This paper provides a survey and synthesis of econometric tools that have been employed to study economic growth. While these tools range across a variety of statistical methods, they are united in the common goals of first, identifying interesting contemporaneous patterns in growth data and second, drawing inferences on long-run economic outcomes from cross-section and temporal variation in growth. We describe the main stylized facts that have motivated the development of growth econometrics...

  5. An equiratio mixture model for non-additive components : a case study for aspartame/acesulfame-K mixtures

    NARCIS (Netherlands)

    Schifferstein, H.N.J.

    1996-01-01

    The Equiratio Mixture Model predicts the psychophysical function for an equiratio mixture type on the basis of the psychophysical functions for the unmixed components. The model reliably estimates the sweetness of mixtures of sugars and sugar-alchohols, but is unable to predict intensity for asparta

  6. Prediction of saturated liquid enthalpy of refrigerant mixtures

    Institute of Scientific and Technical Information of China (English)

    CHEN ZeShao; CHEN JianXin; HU Peng

    2007-01-01

    New corresponding temperature and corresponding enthalpy of refrigerant mixtures were defined. The relationship between saturated liquid corresponding enthalpy and corresponding temperature of refrigerant mixtures accorded with that of pure components. The characteristic parameters of saturated liquid enthalpy difference of refrigerant mixtures were calculated by three methods according to the different application conditions. The generalized equation of saturated liquid enthalpy of refrigerant mixtures was presented. The calculated values were compared with the values in literature for five ternary and binary refrigerant mixtures, namely R404A, R407A, R407B, R32/R134a, and R410A. The overall average absolute deviation was less than 1.0%.

  7. Numerical Simulation of Nanostructure Growth

    Science.gov (United States)

    Hwang, Helen H.; Bose, Deepak; Govindan, T. R.; Meyyappan, M.

    2004-01-01

    Nanoscale structures, such as nanowires and carbon nanotubes (CNTs), are often grown in gaseous or plasma environments. Successful growth of these structures is defined by achieving a specified crystallinity or chirality, size or diameter, alignment, etc., which in turn depend on gas mixture ratios. pressure, flow rate, substrate temperature, and other operating conditions. To date, there has not been a rigorous growth model that addresses the specific concerns of crystalline nanowire growth, while demonstrating the correct trends of the processing conditions on growth rates. Most crystal growth models are based on the Burton, Cabrera, and Frank (BCF) method, where adatoms are incorporated into a growing crystal at surface steps or spirals. When the supersaturation of the vapor is high, islands nucleate to form steps, and these steps subsequently spread (grow). The overall bulk growth rate is determined by solving for the evolving motion of the steps. Our approach is to use a phase field model to simulate the growth of finite sized nanowire crystals, linking the free energy equation with the diffusion equation of the adatoms. The phase field method solves for an order parameter that defines the evolving steps in a concentration field. This eliminates the need for explicit front tracking/location, or complicated shadowing routines, both of which can be computationally expensive, particularly in higher dimensions. We will present results demonstrating the effect of process conditions, such as substrate temperature, vapor supersaturation, etc. on the evolving morphologies and overall growth rates of the nanostructures.

  8. Resource Availability Alters Biodiversity Effects in Experimental Grass-Forb Mixtures.

    Directory of Open Access Journals (Sweden)

    Alrun Siebenkäs

    Full Text Available Numerous experiments, mostly performed in particular environments, have shown positive diversity-productivity relationships. Although the complementary use of resources is discussed as an important mechanism explaining diversity effects, less is known about how resource availability controls the strength of diversity effects and how this response depends on the functional composition of plant communities. We studied aboveground biomass production in experimental monocultures, two- and four-species mixtures assembled from two independent pools of four perennial grassland species, each representing two functional groups (grasses, forbs and two growth statures (small, tall, and exposed to different combinations of light and nutrient availability. On average, shade led to a decrease in aboveground biomass production of 24% while fertilization increased biomass production by 36%. Mixtures were on average more productive than expected from their monocultures (relative yield total, RYT>1 and showed positive net diversity effects (NE: +34% biomass increase; mixture minus mean monoculture biomass. Both trait-independent complementarity effects (TICE: +21% and dominance effects (DE: +12% positively contributed to net diversity effects, while trait-dependent complementarity effects were minor (TDCE: +1%. Shading did not alter diversity effects and overyielding. Fertilization decreased RYT and the proportion of biomass gain through TICE and TDCE, while DE increased. Diversity effects did not increase with species richness and were independent of functional group or growth stature composition. Trait-based analyses showed that the dominance of species with root and leaf traits related to resource conservation increased TICE. Traits indicating the tolerance of shade showed positive relationships with TDCE. Large DE were associated with the dominance of species with tall growth and low diversity in leaf nitrogen concentrations. Our field experiment shows that

  9. Removal of a mixture of pesticides by a Streptomyces consortium: Influence of different soil systems.

    Science.gov (United States)

    Fuentes, María S; Raimondo, Enzo E; Amoroso, María J; Benimeli, Claudia S

    2017-04-01

    Although the use of organochlorine pesticides (OPs) is restricted or banned in most countries, they continue posing environmental and health concerns, so it is imperative to develop methods for removing them from the environment. This work is aimed to investigate the simultaneous removal of three OPs (lindane, chlordane and methoxychlor) from diverse types of systems by employing a native Streptomyces consortium. In liquid systems, a satisfactory microbial growth was observed accompanied by removal of lindane (40.4%), methoxychlor (99.5%) and chlordane (99.8%). In sterile soil microcosms, the consortium was able to grow without significant differences in the different textured soils (clay silty loam, sandy and loam), both contaminated or not contaminated with the OPs-mixture. The Streptomyces consortium was able to remove all the OPs in sterile soil microcosm (removal order: clay silty loam > loam > sandy). So, clay silty loam soil (CSLS) was selected for next assays. In non-sterile CSLS microcosms, chlordane removal was only about 5%, nonetheless, higher rates was observed for lindane (11%) and methoxychlor (20%). In CSLS slurries, the consortium exhibited similar growth levels, in the presence of or in the absence of the OPs-mixture. Not all pesticides were removed in the same way; the order of pesticide dissipation was: methoxychlor (26%)>lindane (12.5%)>chlordane (10%). The outlines of microbial growth and pesticides removal provide information about using actinobacteria consortium as strategies for bioremediation of OPs-mixture in diverse soil systems. Texture of soils and assay conditions (sterility, slurry formulation) were determining factors influencing the removal of each pesticide of the mixture.

  10. Investigation of Adding Proportion of RAP in Recycled Asphalt Mixture

    Directory of Open Access Journals (Sweden)

    Cao He

    2016-01-01

    Full Text Available According to the relationship between gradation and proportion of Reclaimed Asphalt Pavement (RAP and design gradation of recycled mixture, the authors discussed the influence of proportion of RAP on gradation adjustment of recycled mixture. And then, recycled mixture with 0%, 30%, 50%, 70% of RAP were made, and Influence of proportion of RAP on high and low temperature performance, water stability and anti-aging performance of recycled mixture were discussed. The results and analysis indicate that gradation of recycled mixture would not be adjusted to aiming gradation if proportion of RAP was too big. With the increase of proportion of RAP, high temperature performance and anti-aging performance of recycled mixture enhanced, but low temperature performance and water stability decayed sharply. In practical application, reasonable proportion of RAP should be determined according to gradation, performance demand and economy of recycled mixture.

  11. Systems and methods for removing components of a gas mixture

    Science.gov (United States)

    None

    2016-09-06

    A system for removing components of a gaseous mixture is provided comprising: a reactor fluid containing vessel having conduits extending therefrom, aqueous fluid within the reactor, the fluid containing a ligand and a metal, and at least one reactive surface within the vessel coupled to a power source. A method for removing a component from a gaseous mixture is provided comprising exposing the gaseous mixture to a fluid containing a ligand and a reactive metal, the exposing chemically binding the component of the gaseous mixture to the ligand. A method of capturing a component of a gaseous mixture is provided comprising: exposing the gaseous mixture to a fluid containing a ligand and a reactive metal, the exposing chemically binding the component of the gaseous mixture to the ligand, altering the oxidation state of the metal, the altering unbinding the component from the ligand, and capturing the component.

  12. Health and environmental effects of complex chemical mixtures: proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-01

    The Office of Health and Environmental Research (OHER) of the Department of Energy supports a broad long-term research program on human health and environmental effects from potential exposure to energy-related complex chemical mixtures. The program seeks basic mechanistic data on the effects of complex mixtures at the cellular, molecular, and whole animal levels to aid in predicting human health effects and seeks ecological data on biological and physical transformations in the mixtures, concentrations of the mixtures in various compartments of the environment, and potential routes for human exposure to these mixtures (e.g., food chain). On June 17-18, 1985, OHER held its First Annual Technical Meeting on the Complex Chemical Mixtures Program in Chicago, IL. The primary purpose of the meeting was to enable principal investigators to report the research status and accomplishments of ongoing complex chemical mixture studies supported by OHER. To help focus future research directions round table discussions were conducted.

  13. A simple mixture to enhance muscle transmittance

    Science.gov (United States)

    Oliveira, Luís; Lage, Armindo; Clemente, Manuel Pais; Tuchin, Valery V.

    2008-06-01

    Skeletal muscle is a fibrous tissue composed by muscle fibers and interstitial fluid. Due to this constitution, the muscle presents a non uniform refractive index profile that origins strong light scattering. One way to improve tissue transmittance is to reduce this refractive index mismatch by immersing the muscle in an optical clearing agent. As a consequence of such immersion tissue also suffers dehydration. The study of the optical clearing effect created by a simple mixture composed by ethanol, glycerol and distilled water has proven its effectiveness according to the variations observed in the parameters under study. The effect was characterized in terms of its magnitude, time duration and histological variations. The applied treatment has created a small reduction of the global sample refractive index that is justified by the long time rehydration caused by water in the immersing solution. From the reduction in sample pH we could also identify the dehydration process created in the sample. The immersion treatment has originated fiber bundle contraction and a spread distribution of the muscle fiber bundles inside. New studies with the mixture used, or with other combinations of its constituents might be interesting to perform with the objective to develop new clinical procedures.

  14. Non-equilibrium properties of hadronic mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Prakasch, Madappa (State Univ. of New York, Stony Brook, NY (United States). Physics Dept.); Prakasch, Manju (State Univ. of New York, Stony Brook, NY (United States). Physics Dept.); Venugopalan, R. (State Univ. of New York, Stony Brook, NY (United States). Physics Dept.); Welke, G. (Michigan State Univ., East Lansing, MI (United States). National Superconducting Cyclotron Lab.)

    1993-05-01

    The equilibration of hot hadronic matter is studied in the framework of relativistic kinetic theory. Various non-equilibrium properties of a mixture comprised of pions, kaons and nucleons are calculated in the dilute limit for small deviations from local thermal equilibrium. Interactions between these constituents are specified through the empirical phase shifts. The properties calculated include the relaxation/collision times, momentum and energy persistence ratios in elastic collisions, and transport properties such as the viscosity, the thermal conductivity, and the diffusion and thermal diffusion coefficients. The Chapman-Enskog formalism is extended to extract relaxation times associated with shear and heat flows, and drag and diffusion flows in a mixture. The equilibrium number concentration of the constituents is chosen to mimic those expected in the mid-rapidity interval of CERN and RHIC experiments. In this case, kaons and nucleons are found to equilibrate significantly more slowly than pions. These results shed new light on the influence of collective flow effects on the transverse momentum distributions of kaons and nucleons versus those of pions in ultra-relativistic nuclear collisions. (orig.)

  15. A mixture approach to vagueness and ambiguity.

    Directory of Open Access Journals (Sweden)

    Steven Verheyen

    Full Text Available When asked to indicate which items from a set of candidates belong to a particular natural language category inter-individual differences occur: Individuals disagree which items should be considered category members. The premise of this paper is that these inter-individual differences in semantic categorization reflect both ambiguity and vagueness. Categorization differences are said to be due to ambiguity when individuals employ different criteria for categorization. For instance, individuals may disagree whether hiking or darts is the better example of sports because they emphasize respectively whether an activity is strenuous and whether rules apply. Categorization differences are said to be due to vagueness when individuals employ different cut-offs for separating members from non-members. For instance, the decision to include hiking in the sports category or not, may hinge on how strenuous different individuals require sports to be. This claim is supported by the application of a mixture model to categorization data for eight natural language categories. The mixture model can identify latent groups of categorizers who regard different items likely category members (i.e., ambiguity with categorizers within each of the groups differing in their propensity to provide membership responses (i.e., vagueness. The identified subgroups are shown to emphasize different sets of category attributes when making their categorization decisions.

  16. Predicting the toxicity of metal mixtures.

    Science.gov (United States)

    Balistrieri, Laurie S; Mebane, Christopher A

    2014-01-01

    The toxicity of single and multiple metal (Cd, Cu, Pb, and Zn) solutions to trout is predicted using an approach that combines calculations of: (1) solution speciation; (2) competition and accumulation of cations (H, Ca, Mg, Na, Cd, Cu, Pb, and Zn) on low abundance, high affinity and high abundance, low affinity biotic ligand sites; (3) a toxicity function that accounts for accumulation and potency of individual toxicants; and (4) biological response. The approach is evaluated by examining water composition from single metal toxicity tests of trout at 50% mortality, results of theoretical calculations of metal accumulation on fish gills and associated mortality for single, binary, ternary, and quaternary metal solutions, and predictions for a field site impacted by acid rock drainage. These evaluations indicate that toxicity of metal mixtures depends on the relative affinity and potency of toxicants for a given aquatic organism, suites of metals in the mixture, dissolved metal concentrations and ratios, and background solution composition (temperature, pH, and concentrations of major ions and dissolved organic carbon). A composite function that incorporates solution composition, affinity and competition of cations for two types of biotic ligand sites, and potencies of hydrogen and individual metals is proposed as a tool to evaluate potential toxicity of environmental solutions to trout.

  17. Transport and radiation in complex LTE mixtures

    Science.gov (United States)

    Janssen, Jesper; Peerenboom, Kim; Suijker, Jos; Gnybida, Mykhailo; van Dijk, Jan

    2014-10-01

    Complex LTE mixtures are for example encountered in re-entry, welding, spraying and lighting. These mixtures typically contain a rich chemistry in combination with large temperature gradients. LTE conditions are also interesting because they can aid in the validation of NLTE algorithms. An example is the calculation of transport properties. In this work a mercury free high intensity discharge lamp is considered. The investigation focusses on using salts like InI or SnI as a buffer species. By using these species a dominant background gas like mercury is no longer present. As a consequence the diffusion algorithms based on Fick's law are no longer applicable and the Stefan-Maxwell equations must be solved. This system of equations is modified with conservation rules to set a coldspot pressure for saturated species and enforce the mass dosage for unsaturated species. The radiative energy transport is taken into account by raytracing. Quantum mechanical simulations have been used to calculate the potential curves and the transition dipole moments for indium with iodine and tin with iodine. The results of these calculations have been used to predict the quasistatic broadening by iodine. The work was supported by the project SCHELP from the Belgium IWT (Project Number 110003) and the CATRENE SEEL Project (CA502).

  18. Foaming characteristics of refigerant/lubricant mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Goswami, D.Y.; Shah, D.O.; Jotshi, C.K.; Bhagwat, S.; Leung, M.; Gregory, A.

    1997-04-01

    The air-conditioning and refrigeration industry has moved to HFC refrigerants which have zero ozone depletion and low global warming potential due to regulations on CFC and HCFC refrigerants and concerns for the environment. The change in refrigerants has prompted the switch from mineral oil and alkylbenzene lubricants to polyolester-based lubricants. This change has also brought about a desire for lubricant, refrigerant and compressor manufacturers to understand the foaming properties of alternative refrigerant/ lubricant mixtures, as well as the mechanisms which affect these properties. The objectives of this investigation are to experimentally determine the foaming absorption and desorption rates of HFC and blended refrigerants in polyolester lubricant and to define the characteristics of the foam formed when the refrigerant leaves the refrigerant/ lubricant mixture after being exposed to a pressure drop. The refrigerants being examined include baseline refrigerants: CFC-12 (R-12) and HCFC-22 (R-22); alternative refrigerants: HFC-32 (R-32), R-125, R-134a, and R-143a; and blended refrigerants: R-404A, R-407C, and R-410A. The baseline refrigerants are tested with ISO 32 (Witco 3GS) and ISO 68 (4GS) mineral oils while the alternative and blended refrigerants are tested with two ISO 68 polyolesters (Witco SL68 and ICI RL68H).

  19. Optical properties of a heated cornstarch mixture

    Science.gov (United States)

    Vazquez-Landaverde, Pedro A.; Morales Sánchez, Eduardo; Huerta-Ruelas, Jorge A.

    2007-03-01

    In this study, the objective was to evaluate optical properties of a corn starch-water mixture as descriptors of its behavior under processing conditions. A solution of corn starch in water was prepared and heated from 25 to 85°C in a temperature-controlled optical cell. For the measurement of optical properties, a polarized laser beam modulated through a photoelastic modulator and an analyzer, was used as optical probe. It was possible to measure transmitted light, along with optical rotation. Optical measurements showed changes related to temperature dependent phenomena such as starch granule swelling and gelatinization, in the ranges 25 to 60°C, 60 to 85°C. Above 80°C transmission values were higher, due to the solution clarification caused by corn starch gelatinization. Regarding optical rotation, it was difficult to obtain reliable measurements at low temperatures due to the high turbidity of the system. However, once gel was formed at higher temperatures, optical rotation and light transmission increased. This study demonstrated that optical techniques are suitable for the study of the behavior of water-starch mixtures under processing conditions such as heating, revealing a promising future for the monitoring of such phenomena in the production line to lower costs and improve product quality.

  20. Thermodynamics of organic mixtures containing amines

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Juan Antonio [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain)]. E-mail: jagl@termo.uva.es; Mozo, Ismael [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain); Fuente, Isaias Garcia de la [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain); Cobos, Jose Carlos [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain)

    2006-02-01

    Binary mixtures containing pyridine (PY), or 2-methylpyridine (2MPY) or 3-methylpyridine (3MPY) or 4-methylpyridine (4MPY) and an organic solvent as benzene, toluene, alkane, or 1-alkanol are investigated in the framework of DISQUAC. The corresponding interaction parameters are reported. The model describes accurately a whole set of thermodynamic properties: vapor-liquid equilibria (VLE), liquid-liquid equilibria (LLE), solid-liquid equilibria (SLE), molar excess Gibbs energies (G{sup E}), molar excess enthalpies (H{sup E}), molar excess heat capacities at constant pressure (C{sub P}{sup E}) and the concentration-concentration structure factor (S{sub CC}(0)). It is remarkable that DISQUAC correctly predicts the W-shaped curve of the C{sub P}{sup E} of the pyridine + n-hexadecane system. The model can be applied successfully to mixtures with strong positive or negative deviations from the Raoult's law. DISQUAC improves the theoretical results from UNIFAC (Dortmund version). The replacement of pyridine by a methylpyridine leads to a weakening of the amine-amine interactions, ascribed to the steric effect caused by the methyl group attached to the aromatic ring. This explains that for a given solvent (alkane, 1-alkanol) H{sup E}(pyridine)>H{sup E}(methylpyridine)

  1. Multisubstrate kinetics of PAH mixture biodegradation: analysis in the double-logarithmic plot.

    Science.gov (United States)

    Baboshin, Mikhail; Golovleva, Ludmila

    2011-02-01

    The proposed method of kinetic analysis of aqueous-phase biodegradation of polycyclic aromatic hydrocarbons (PAH) mixture presupposes representation of kinetic curves for each pair of mixture components, S(x) and S(y), in double-logarithmic coordinates (ln S(x); ln S(y)). If PAH mixture conversion corresponds to the multisubstrate model with a common active site, then the graphs in double-logarithmic coordinates are straight lines with the angular coefficients equal to the ratio of respective first-order rate constants k(y)(x)= V(y)K(x)/K(y)V(x), where K(x) and K(y) are half-saturation constants, V(x) and V( y ) are the maximum conversion rates for substrates S(x) and S(y); the graph slope does not depend on any concentrations and remains constant during the change of reaction rates as a result of inhibition, induction/inactivation of enzymes or biomass growth. The formulated method has been used to analyze PAH mixture conversion by the culture of Sphingomonas sp. VKM B-2434. It has been shown that this process does not satisfy the multisubstrate model with a single active site. The results suggest that the strain VKM B-2434 contains at least two dioxygenases of different substrate specificity: one enzyme converts phenanthrene and fluoranthene and the other converts acenaphthene and acenaphthylene. The ratios of first-order rate constants have been obtained for these pairs of substrates.

  2. A Finite Mixture of Nonlinear Random Coefficient Models for Continuous Repeated Measures Data.

    Science.gov (United States)

    Kohli, Nidhi; Harring, Jeffrey R; Zopluoglu, Cengiz

    2016-09-01

    Nonlinear random coefficient models (NRCMs) for continuous longitudinal data are often used for examining individual behaviors that display nonlinear patterns of development (or growth) over time in measured variables. As an extension of this model, this study considers the finite mixture of NRCMs that combine features of NRCMs with the idea of finite mixture (or latent class) models. The efficacy of this model is that it allows the integration of intrinsically nonlinear functions where the data come from a mixture of two or more unobserved subpopulations, thus allowing the simultaneous investigation of intra-individual (within-person) variability, inter-individual (between-person) variability, and subpopulation heterogeneity. Effectiveness of this model to work under real data analytic conditions was examined by executing a Monte Carlo simulation study. The simulation study was carried out using an R routine specifically developed for the purpose of this study. The R routine used maximum likelihood with the expectation-maximization algorithm. The design of the study mimicked the output obtained from running a two-class mixture model on task completion data.

  3. Preparation of azo polyelectrolyte self-assembled multilayers by using N,N-dimethylformamide/H2O mixtures as solvents

    Institute of Scientific and Technical Information of China (English)

    Tuo Xinlin; Chen Di; Wang Xiaogong

    2006-01-01

    N,N-Dimethylformamide (DMF)/H2O mixtures were used as solvents to fabricate azo polyelectrolyte (PEAPH)/poly(diallyldimethyl ammonium chloride)(PDAC)self-assembled multilayers with the layer-by-layer electrostatic adsorption technique.PEAPH is a copolymer of acrylic acid and azobenzene-containing acrylate.The effect of the ratio of DMF to water on the .multilayer growth,structure and surface morphology was studied in some details.Results show that DMF/H2O mixtures are proper media for PEAPH/PDAC multilayer fabrication.The ratio of DMF to water in the mixture has significant influence on the multilayer structure and surface morphology.With the increase of DMF content,the multilayer thickness has a better linear growth relationship with the bilayer number,and the multilayer surface becomes smoother.Moreover,azo chromophores show less H-aggregation when the multilayers are fabricated from DMF/H2O mixtures with higher DMF contents.These studies demonstrate that using organic solvent and water mixtures is an effective way to control the multilayer construction by adjusting the media properties.This method can be applied to multilayer fabrication of other water-insoluble polyelectrolytes.

  4. An OHD-RIKES and simulation study comparing a benzylmethylimidazolium ionic liquid with an equimolar mixture of dimethylimidazolium and benzene.

    Science.gov (United States)

    Xue, Lianjie; Tamas, George; Matthews, Richard P; Stone, Anthony J; Hunt, Patricia A; Quitevis, Edward L; Lynden-Bell, Ruth M

    2015-04-21

    The principal difference between 1-benzyl-3-methyl-imidazolium triflimide [BzC1im][NTf2] and an equimolar mixture of benzene and dimethylimidazolium triflimide [C1C1im][NTf2] is that in the former the benzene moieties are tied to the imidazolium ring, while in the latter they move independently. We use femtosecond optical heterodyne-detected Raman-induced Kerr effect spectroscopy (OHD-RIKES) and molecular simulations to explore some properties of these two systems. The Kerr spectra show small differences in the spectral densities; the simulations also show very similar environments for both the imidazolium rings and the phenyl or benzene parts of the molecules. The low frequency vibrational densities of states are also similar in the model systems. In order to perform the simulations we developed a model for the [BzC1im](+) cation and found that the barriers to rotation of the two parts of the molecule are low.

  5. 突发事件下两部收费契约协调闭环供应链研究%Research on Closed-loop Supply Chain Coordination with Two-part Tariff Contract under Disruptions

    Institute of Scientific and Technical Information of China (English)

    牟宗玉; 曹德弼; 刘晓冰; 李新然

    2013-01-01

    This paper studies the coordination of the closed-loop supply chain(CLSC)with one manufacturer and one retailer who recollects the used products .We design the model that can be coordinated by a two-part tariff contract in static environment .Based on the model , we get the optimal profits by K-T condition and the optimal response strategy of the centralized CLSC under demand disruptions caused by an emergent event .The conclu-sion shows that the two-part tariff contract which has been signed can ’ t coordinate the decentralized CLSC any more under disruptions .Then we give two strategies to coordinate the CLSC .One strategy is that the wholesale price and the transfer price of used products with the original contract are improved in the case that the manufac -turer bears the deviation costs , and the other is that we retain the wholesale price and the transfer price of used products with the original contract unchanged under the condition that the retailer bears the deviation costs .The manufacturer and the retailer need to bargain with each other to determine the fixed fee in both of the above strat-egies , and we can realize the coordination of the CLSC under disruptions .In addition , we have proved the feasi-bility of them .%本文针对由一个制造商和一个零售商组成的零售商负责回收闭环供应链的协调问题,首先设计了稳定环境下两部收费契约协调闭环供应链模型。在此基础上,针对突发事件影响下造成零售商面临的市场需求发生变化时,运用K-T条件对集中式决策下的闭环供应链的最优利润进行求解,给出了最优应对策略。通过研究表明:当突发事件发生时,原适用于稳定环境下的两部收费契约将不再对分散式决策下的闭环供应链起协调作用。为此,本研究给出了两种协调策略,一是在制造商自身承担突发事件引起的偏差成本的情况下,通过对原有的两部收费契约中的批

  6. Quantification of the joint effects of mixtures of hepatotoxic agents: evaluation of a theoretical model in mice

    Energy Technology Data Exchange (ETDEWEB)

    Shelton, D.W.; Weber, L.J.

    1981-10-01

    An approach previously developed for studying the effects of toxic mixtures on whole organism performances (i.e., growth, mortality) was evaluated to determine its applicability and limitations at the organ system level. The approach was tested by quantifying the hepatotoxic effects of carbon tetrachloride (CCl/sub 4/), monochlorobenzene (MCB), acetaminophen (ACET), and selected mixtures of these compounds in male albino CF-1 mice. Based upon parallel dose-response curves, concentration addition was predicted for the mixtures of both CCl/sub 4/ + MCB and CCl/sub 4/ + ACET. The actual dose-response relationship for each mixture was empirically determined and compared to the predicted curves. In the case of the CCl/sub 4/ + ACET mixture revealed a statistical difference between the observed and predicted curves. The joint effects for the mixture of CCl/sub 4/ + MCB is thus classified as concentration additive. The model proves to be adequate in predicting, classifying, and describing the joint effects of these hepatotoxicants.

  7. Analytical processing of binary mixture information by olfactory bulb glomeruli.

    Directory of Open Access Journals (Sweden)

    Max L Fletcher

    Full Text Available Odors are rarely composed of a single compound, but rather contain a large and complex variety of chemical components. Often, these mixtures are perceived as having unique qualities that can be quite different than the combination of their components. In many cases, a majority of the components of a mixture cannot be individually identified. This synthetic processing of odor information suggests that individual component representations of the mixture must interact somewhere along the olfactory pathway. The anatomical nature of sensory neuron input into segregated glomeruli with the bulb suggests that initial input of odor information into the bulb is analytic. However, a large network of interneurons within the olfactory bulb could allow for mixture interactions via mechanisms such as lateral inhibition. Currently in mammals, it is unclear if postsynaptic mitral/tufted cell glomerular mixture responses reflect the analytical mixture input, or provide the initial basis for synthetic processing with the olfactory system. To address this, olfactory bulb glomerular binary mixture representations were compared to representations of each component using transgenic mice expressing the calcium indicator G-CaMP2 in olfactory bulb mitral/tufted cells. Overall, dorsal surface mixture representations showed little mixture interaction and often appeared as a simple combination of the component representations. Based on this, it is concluded that dorsal surface glomerular mixture representations remain largely analytical with nearly all component information preserved.

  8. Mixture Model and MDSDCA for Textual Data

    Science.gov (United States)

    Allouti, Faryel; Nadif, Mohamed; Hoai An, Le Thi; Otjacques, Benoît

    E-mailing has become an essential component of cooperation in business. Consequently, the large number of messages manually produced or automatically generated can rapidly cause information overflow for users. Many research projects have examined this issue but surprisingly few have tackled the problem of the files attached to e-mails that, in many cases, contain a substantial part of the semantics of the message. This paper considers this specific topic and focuses on the problem of clustering and visualization of attached files. Relying on the multinomial mixture model, we used the Classification EM algorithm (CEM) to cluster the set of files, and MDSDCA to visualize the obtained classes of documents. Like the Multidimensional Scaling method, the aim of the MDSDCA algorithm based on the Difference of Convex functions is to optimize the stress criterion. As MDSDCA is iterative, we propose an initialization approach to avoid starting with random values. Experiments are investigated using simulations and textual data.

  9. Bayesian Estimation of a Mixture Model

    Directory of Open Access Journals (Sweden)

    Ilhem Merah

    2015-05-01

    Full Text Available We present the properties of a bathtub curve reliability model having both a sufficient adaptability and a minimal number of parameters introduced by Idée and Pierrat (2010. This one is a mixture of a Gamma distribution G(2, (1/θ and a new distribution L(θ. We are interesting by Bayesian estimation of the parameters and survival function of this model with a squared-error loss function and non-informative prior using the approximations of Lindley (1980 and Tierney and Kadane (1986. Using a statistical sample of 60 failure data relative to a technical device, we illustrate the results derived. Based on a simulation study, comparisons are made between these two methods and the maximum likelihood method of this two parameters model.

  10. CRITICALITY CURVES FOR PLUTONIUM HYDRAULIC FLUID MIXTURES

    Energy Technology Data Exchange (ETDEWEB)

    WITTEKIND WD

    2007-10-03

    This Calculation Note performs and documents MCNP criticality calculations for plutonium (100% {sup 239}Pu) hydraulic fluid mixtures. Spherical geometry was used for these generalized criticality safety calculations and three geometries of neutron reflection are: {sm_bullet}bare, {sm_bullet}1 inch of hydraulic fluid, or {sm_bullet}12 inches of hydraulic fluid. This document shows the critical volume and critical mass for various concentrations of plutonium in hydraulic fluid. Between 1 and 2 gallons of hydraulic fluid were discovered in the bottom of HA-23S. This HA-23S hydraulic fluid was reported by engineering to be Fyrquel 220. The hydraulic fluid in GLovebox HA-23S is Fyrquel 220 which contains phosphorus. Critical spherical geometry in air is calculated with 0 in., 1 in., or 12 inches hydraulic fluid reflection.

  11. POROSITY CALCULATION OF MIXTURES OF FIBROUS PARTICLES

    Institute of Scientific and Technical Information of China (English)

    Ruping Zou; Aibing Yu

    2003-01-01

    The initial forming of fiber blend to high green density, i.e. the packing of fibrous particles, is important to the reinforcement of composite materials. It is very useful to develop a general predictive method for the optimum selection of particle mixtures for the property control of ceramic or composite products. This paper presents such a mathematical model developed on the basis of the similarity analysis between the spherical and non-spherical particle packings and assesses its applicability to the packing of fibrous particles with discrete and/or continuous length distributions. The results indicate that the model can predict this packing system well and hence provide an effective way to solve various packing problems in the composite materials processing.

  12. Continuum thermodynamics of chemically reacting fluid mixtures

    CERN Document Server

    Bothe, Dieter

    2014-01-01

    We consider viscous and heat conducting mixtures of molecularly miscible chemical species forming a fluid in which the constituents can undergo chemical reactions. Assuming a common temperature for all components, a first main aim is the derivation of a closed system of partial mass and partial momentum balances plus a common balance of internal energy. This is achieved by careful exploitation of the entropy principle which, in particular, requires appropriate definitions of absolute temperature and chemical potentials based on an adequate definition of thermal energy that excludes diffusive contributions. The latter is crucial in order to obtain a closure framework for the interaction forces between the different species. The interaction forces split into a thermo-mechanical and a chemical part, where the former turns out to be symmetric if binary interactions are assumed. In the non-reactive case, this leads to a system of Navier-Stokes type sub-systems, coupled by interspecies friction forces. For chemical...

  13. Quantum-coherent mixtures of causal relations

    CERN Document Server

    MacLean, Jean-Philippe W; Spekkens, Robert W; Resch, Kevin J

    2016-01-01

    Understanding the causal influences that hold among the parts of a system is critical both to explaining that system's natural behaviour and to controlling it through targeted interventions. In a quantum world, understanding causal relations is equally important, but the set of possibilities is far richer. The two basic ways in which a pair of time-ordered quantum systems may be causally related are by a cause-effect mechanism or by a common cause acting on both. Here, we show that it is possible to have a coherent mixture of these two possibilities. We realize such a nonclassical causal relation in a quantum optics experiment and derive a set of criteria for witnessing the coherence based on a quantum version of Berkson's paradox. The interplay of causality and quantum theory lies at the heart of challenging foundational puzzles, such as Bell's theorem and the search for quantum gravity, but could also provide a resource for novel quantum technologies.

  14. Processes assessment in binary mixture plant

    Directory of Open Access Journals (Sweden)

    N. Shankar Ganesh, T. Srinivas

    2013-01-01

    Full Text Available Binary fluid system has an efficient system of heat recovery compared to a single fluid system due to a better temperature match between hot and cold fluids. There are many applications with binary fluid system i.e. Kalina power generation, vapor absorption refrigeration, combined power and cooling etc. Due to involvement of three properties (pressure, temperature and concentration in the processes evaluation, the solution is complicated compared to a pure substance. The current work simplifies this complex nature of solution and analyzes the basic processes to understand the processes behavior in power generation as well as cooling plants. Kalina power plant consists of regenerator, heat recovery vapor generator, condenser, mixture, separator, turbine, pump and throttling device. In addition to some of these components, the cooling plant consists of absorber which is similar in operation of condenser. The amount of vapor at the separator decreases with an increase in its pressure and temperature.

  15. Derived thermodynamic properties of alcohol + cyclohexylamine mixtures

    Directory of Open Access Journals (Sweden)

    IVONA R. RADOVIĆ

    2010-02-01

    Full Text Available Thermal expansion coefficients, α, excess thermal expansion coefficients, αE, isothermal coefficients of pressure excess molar enthalpy, (∂HE/∂pT,x, partial molar volumes, , partial molar volumes at infinite dilution, , partial excess molar volumes, , and partial excess molar volumes at infinite dilution, , were calculated using experimental densities and excess molar volumes, , data. All calculations are performed for the binary systems of cyclohexylamine with 1-propanol or 1-butanol or 2-butanol or 2-methyl-2-propanol. The Redlich–Kister polynomial and the reduced excess molar volume approach were used in the evaluation of these properties. In addition, the aim of this investigation was to provide a set of various volumetric data in order to asses the influence of temperature, chain length and position of hydroxyl group in the alcohol molecule on the molecular interactions in the examined binary mixtures.

  16. Thermodynamic modeling of CO2 mixtures

    DEFF Research Database (Denmark)

    Bjørner, Martin Gamel

    performed satisfactorily and predicted the general behavior of the systems, but qCPA used fewer adjustable parameters to achieve similar predictions. It has been demonstrated that qCPA is a promising model which, compared to CPA, systematically improves the predictions of the experimentally determined phase......, accurate predictions of the thermodynamic properties and phase equilibria of mixtures containing CO2 are challenging with classical models such as the Soave-Redlich-Kwong (SRK) equation of state (EoS). This is believed to be due to the fact, that CO2 has a large quadrupole moment which the classical models...... do not explicitly account for. In this thesis, in an attempt to obtain a physically more consistent model, the cubicplus association (CPA) EoS is extended to include quadrupolar interactions. The new quadrupolar CPA (qCPA) can be used with the experimental value of the quadrupolemoment...

  17. Urea and deuterium mixtures at high pressures

    Energy Technology Data Exchange (ETDEWEB)

    Donnelly, M., E-mail: m.donnelly-2@sms.ed.ac.uk; Husband, R. J.; Frantzana, A. D.; Loveday, J. S. [Centre for Science at Extreme Conditions and School of Physics and Astronomy, The University of Edinburgh, Erskine Williamson Building, Peter Guthrie Tait Road, The King’s Buildings, Edinburgh EH9 3FD (United Kingdom); Bull, C. L. [ISIS, Rutherford Appleton Laboratory, Oxford Harwell, Didcot OX11 0QX (United Kingdom); Klotz, S. [IMPMC, CNRS UMR 7590, Université P and M Curie, 4 Place Jussieu, 75252 Paris (France)

    2015-03-28

    Urea, like many network forming compounds, has long been known to form inclusion (guest-host) compounds. Unlike other network formers like water, urea is not known to form such inclusion compounds with simple molecules like hydrogen. Such compounds if they existed would be of interest both for the fundamental insight they provide into molecular bonding and as potential gas storage systems. Urea has been proposed as a potential hydrogen storage material [T. A. Strobel et al., Chem. Phys. Lett. 478, 97 (2009)]. Here, we report the results of high-pressure neutron diffraction studies of urea and D{sub 2} mixtures that indicate no inclusion compound forms up to 3.7 GPa.

  18. Quantum-coherent mixtures of causal relations

    Science.gov (United States)

    MacLean, Jean-Philippe W.; Ried, Katja; Spekkens, Robert W.; Resch, Kevin J.

    2017-01-01

    Understanding the causal influences that hold among parts of a system is critical both to explaining that system's natural behaviour and to controlling it through targeted interventions. In a quantum world, understanding causal relations is equally important, but the set of possibilities is far richer. The two basic ways in which a pair of time-ordered quantum systems may be causally related are by a cause-effect mechanism or by a common-cause acting on both. Here we show a coherent mixture of these two possibilities. We realize this nonclassical causal relation in a quantum optics experiment and derive a set of criteria for witnessing the coherence based on a quantum version of Berkson's effect, whereby two independent causes can become correlated on observation of their common effect. The interplay of causality and quantum theory lies at the heart of challenging foundational puzzles, including Bell's theorem and the search for quantum gravity. PMID:28485394

  19. Bioavailability and variability of biphasic insulin mixtures

    DEFF Research Database (Denmark)

    Søeborg, Tue; Rasmussen, Christian Hove; Mosekilde, Erik

    2012-01-01

    Absorption of subcutaneously administered insulin is associated with considerable variability. Some of this variability was quantitatively explained for both soluble insulin and insulin suspensions in a recent contribution to this journal (Søeborg et al., 2009). In the present article......, the absorption kinetics for mixtures of insulins is described. This requires that the bioavailability of the different insulins is considered. A short review of insulin bioavailability and a description of the subcutaneous depot thus precede the presentation of possible mechanisms associated with subcutaneous...... insulin degradation. Soluble insulins are assumed to be degraded enzymatically in the subcutaneous tissue. Suspended insulin crystals form condensed heaps that are assumed to be degraded from their surface by invading macrophages. It is demonstrated how the shape of the heaps affects the absorption...

  20. Analyzing spinodal decomposition of an anisotropic fluid mixture

    Science.gov (United States)

    Gruhn, Thomas; Pogorelov, Evgeny; Seiferling, Felix; Emmerich, Heike

    2017-02-01

    Spinodal decomposition leads to spontaneous fluctuations of the local concentration. In the early stage, the resulting pattern provides explicit information about the material properties of the mixture. In the case of two isotropic fluids, the static structure factor shows the characteristic ring shape. If one component is a liquid crystal, the pattern is typically anisotropic and the structure factor is more complex. Using numerical methods, we investigate how structure factors can be used to extract information about material properties like the diffusion constant or the isotropic and the anisotropic contributions to the interfacial tension. The method is based on momenta taken from structure factors in the early stage of the spinodal demixing. We perform phase field calculations for an isotropic and an anisotropic spinodal decomposition. A comparison of the extracted results with analytic values is made. The calculations show that linear modes dominate in the beginning of the growth process, while non-linear modes grow monotonously in the region of the k-space for which damping is predicted by the linearized theory. As long as non-linear modes are small enough, linearized theory can be applied to extract material properties from the structure factor.

  1. Critical Phenomena in Liquid-Liquid Mixtures

    Science.gov (United States)

    Jacobs, D. T.

    2000-04-01

    Critical phenomena provide intriguing and essential insight into many issues in condensed matter physics because of the many length scales involved. Large density or concentration fluctuations near a system's critical point effectively mask the identity of the system and produce universal phenomena that have been well studied in simple liquid-vapor and liquid-liquid systems. Such systems have provided useful model systems to test theoretical predictions which can then be extended to more complicated systems. Along various thermodynamic paths, several quantities exhibit a simple power-law dependence close to the critical point. The critical exponents describing these relationships are universal and should depend only on a universality class determined by the order-parameter and spatial dimensionality of the system. Liquid gas, binary fluid mixtures, uniaxial ferromagnetism, polymer-solvent, and protein solutions all belong to the same (Ising model) universality class. The diversity of critical systems that can be described by universal relations indicates that experimental measurements on one system should yield the same information as on another. Our experimental investigations have tested existing theory and also extended universal behavior into new areas. By measuring the coexistence curve, heat capacity, thermal expansion and static light scattering (turbidity) in various liquid-liquid and polymer-solvent systems, we have determined critical exponents and amplitudes that have sometimes confirmed and other times challenged current theory. Recent experiments investigating the heat capacity and light scattering in a liquid-liquid mixture very close to the critical point will be discussed. This research is currently supported by The Petroleum Research Fund and by NASA grant NAG8-1433 with some student support from NSF-DMR 9619406.

  2. Long-term development of nursing mixtures of Sitka spruce and larch species in an experiment in northern Scotland

    Directory of Open Access Journals (Sweden)

    William L. Mason

    2014-12-01

    Full Text Available Aim of the study: An experiment was established in 1966 to compare the growth and development of 50: 50 mixtures of Sitka spruce (Picea sitchensis with either Japanese larch (Larix kaempferi or tamarack (L. laricina with that found in pure plots of Sitka spruce. The site was one of moderate nitrogen availability where the presence of heather (Calluna vulgaris could be expected to limit the growth ofSitka spruce.Area of the study: North-east Scotland.Material and methods: There were different patterns of spruce growth in the pure plots and in the mixtures, with faster spruce growth in mixture in the years approaching and immediately following canopy closure (i.e. ages 15-25. Foliage analysis suggested that this was linked with improved nitrogen status of spruce trees in the mixed compared to the pure plots.Main results: At years 20 and 25 there were significant differences in height, diameter, and basal area between treatments, with the largest basal area being found in the Japanese larch/Sitka spruce mixtures, indicative of overyielding in the mixed plots. However, when the experiment was clearfelled at 41 years of age, all treatments had self-thinned to produce spruce dominated stands of similar height with only an occasional larch tree surviving in plots that were originally 50:50 mixtures.Research highlights: There were no differences between treatments in basal area, harvested volume or sawlog outturn after 41 years. These results can be interpreted as showing facilitation between the larch and the spruce during the establishment phase followed by competition for light once canopy closure had occurred.Keywords: Mixed stand dynamics; facilitation; nitrogen status; product outturn.

  3. Measurement of electron attachment coefficient in oxygen and oxygen-argon mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, B.; Nakamura, Y. [Keio University, Tokyo (Japan)

    1998-07-01

    We analyzed the electron arrival time signal measured in pure oxygen and in dilute oxygen-argon mixtures by using a double shutter electron drift tube with variable drift distance and derived the density normalized attachment coefficient for respective gases. The present attachment coefficient determined for pure oxygen agreed well with previously reported values and we confirmed that the present apparatus was useful in determining electron attachment coefficient even if there were no ionization, when there will be no steady state current growth and, hence, the steady state Townsend (SST) method can not be applied in principle. The measured attachment coefficients in the mixtures agreed very well with the calculation using our latest cross section set for the oxygen molecule and that `II be a confirmation for the validity of the cross section set. 11 refs., 8 figs., 1 tab.

  4. Effective separation of propylene/propane binary mixtures by ZIF-8 membranes

    KAUST Repository

    Pan, Yichang

    2012-02-01

    The separation of propylene/propane mixtures is one of the most important but challenging processes in the petrochemical industry. A novel zeolitic imidazole framework (ZIF-8) membrane prepared by a facile hydrothermal seeded growth method showed excellent separation performances for a wide range of propylene/propane mixtures. The membrane showed a permeability of propylene up to 200. barrers and a propylene to propane separation factor up to 50 at optimal separation conditions, well surpassing the "upper-bound trade-off" lines of existing polymer and carbon membranes. The experimental data also showed that the membranes had excellent reproducibility, long-term stability and thermal stability. © 2011 Elsevier B.V.

  5. Use of Linear Spectral Mixture Model to Estimate Rice Planted Area Based on MODIS Data

    Directory of Open Access Journals (Sweden)

    Lei Wang

    2008-06-01

    Full Text Available MODIS (Moderate Resolution Imaging Spectroradiometer is a key instrument aboard the Terra (EOS AM and Aqua (EOS PM satellites. Linear spectral mixture models are applied to MOIDS data for the sub-pixel classification of land covers. Shaoxing county of Zhejiang Province in China was chosen to be the study site and early rice was selected as the study crop. The derived proportions of land covers from MODIS pixel using linear spectral mixture models were compared with unsupervised classification derived from TM data acquired on the same day, which implies that MODIS data could be used as satellite data source for rice cultivation area estimation, possibly rice growth monitoring and yield forecasting on the regional scale.

  6. ZIF-78 membrane derived from amorphous precursors with permselectivity for cyclohexanone/cyclohexanol mixture

    KAUST Repository

    Fan, Lili

    2014-07-01

    Cyclohexanone and cyclohexanol are products of selective oxidation of cyclohexane. They are important industrial intermediates and difficult to be separated due to their close boiling points. In this work, well-intergrown ZIF-78 membrane was successfully synthesized on the porous silica substrate by secondary growth method and applied for separation of cyclohexanone/cyclohexanol mixture for the first time. Meanwhile, a facile method for seeding procedure was developed by utilizing the amorphous ZIF-78 precursors to provide better-distributed nucleation sites. Both XRD and SEM results confirmed the good quality of the membrane. The pervaporation separation of cyclohexanone/ cyclohexanol mixture were carried out at room temperature with permselectivity of 1:2 and total flux around 8.7 × 10-2 kg m-2 h-1. © 2013 Elsevier Inc. All rights reserved.

  7. Use of Linear Spectral Mixture Model to Estimate Rice Planted Area Based on MODIS Data

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    MODIS (Moderate Resolution Imaging Spectroradiometer) is a key instrument aboard the Terra (EOS AM) and Aqua (EOS PM) satellites.Linear spectral mixture models are applied to MOIDS data for the sub-pixel classification of land covers.Shaoxing county of Zhcjiang Province in China was chosen to be the study site and early rice was selected as the study crop.The derived proportions of land covers from MODIS pixel using linear spectral mixture models were compared with unsupervised classification derived from TM data acquired on the same day,which implies that MODIS data could be used as satellite data source for rice cultivation area estimation,possibly rice growth monitoring and yield forecasting on the regional scale.

  8. Endocrine disrupting effects in rats perinatally exposed to a dietary relevant mixture of phytoestrogens.

    Science.gov (United States)

    Boberg, Julie; Mandrup, Karen Riiber; Jacobsen, Pernille Rosenskjold; Isling, Louise Krag; Hadrup, Niels; Berthelsen, Line; Elleby, Anders; Kiersgaard, Maria; Vinggaard, Anne Marie; Hass, Ulla; Nellemann, Christine

    2013-09-01

    Dietary phytoestrogens may prevent certain human diseases, but endocrine activity has been reported in animal studies. Sprague-Dawley rats were exposed perinatally to a 1-, 10- or 100-fold "high human dietary intake" mixture of 12 phytoestrogens consisting of mainly the lignan secoisolarici resinol and the isoflavones genistein and daidzein. This mixture induced persistent adverse effects, as adult male mammary glands showed hypertrophic growth. A reduced anogenital distance in newborn males indicated an anti-androgenic mode of action. Testosterone levels, testis and prostate weights, and expression of selected genes in testis and prostate were unaffected. Decreased serum estradiol was seen in genistein-exposed dams. This study indicated adverse effects at high intake levels in rats, but does not provide evidence for risk of phytoestrogen-mediated endocrine disruption at normal human dietary consumption levels. Further studies are warranted to increase the knowledge upon which risk assessment on dietary phytoestrogen exposure during pregnancy and infancy is based.

  9. Nuclear fuel alloys or mixtures and method of making thereof

    Science.gov (United States)

    Mariani, Robert Dominick; Porter, Douglas Lloyd

    2016-04-05

    Nuclear fuel alloys or mixtures and methods of making nuclear fuel mixtures are provided. Pseudo-binary actinide-M fuel mixtures form alloys and exhibit: body-centered cubic solid phases at low temperatures; high solidus temperatures; and/or minimal or no reaction or inter-diffusion with steel and other cladding materials. Methods described herein through metallurgical and thermodynamics advancements guide the selection of amounts of fuel mixture components by use of phase diagrams. Weight percentages for components of a metallic additive to an actinide fuel are selected in a solid phase region of an isothermal phase diagram taken at a temperature below an upper temperature limit for the resulting fuel mixture in reactor use. Fuel mixtures include uranium-molybdenum-tungsten, uranium-molybdenum-tantalum, molybdenum-titanium-zirconium, and uranium-molybdenum-titanium systems.

  10. Maximum likelihood estimation of finite mixture model for economic data

    Science.gov (United States)

    Phoong, Seuk-Yen; Ismail, Mohd Tahir

    2014-06-01

    Finite mixture model is a mixture model with finite-dimension. This models are provides a natural representation of heterogeneity in a finite number of latent classes. In addition, finite mixture models also known as latent class models or unsupervised learning models. Recently, maximum likelihood estimation fitted finite mixture models has greatly drawn statistician's attention. The main reason is because maximum likelihood estimation is a powerful statistical method which provides consistent findings as the sample sizes increases to infinity. Thus, the application of maximum likelihood estimation is used to fit finite mixture model in the present paper in order to explore the relationship between nonlinear economic data. In this paper, a two-component normal mixture model is fitted by maximum likelihood estimation in order to investigate the relationship among stock market price and rubber price for sampled countries. Results described that there is a negative effect among rubber price and stock market price for Malaysia, Thailand, Philippines and Indonesia.

  11. Effects of the Wetting Particles on Phase Separation of Binary Mixtures

    Institute of Scientific and Technical Information of China (English)

    LIU Ji-Wen; MA Yu-qiang

    2000-01-01

    We study phase separation of binary mixtures in the presence of mobile particles by the lattice Monte Carlo simulation. The presence of mobile particles changes tile morphology of the domain growth, in agreement with earlier experimental result. By varying the wetting interaction strength, we can control the speed of phase separation, and find a critical wetting strength beyond which the growth of the domains slows down. We propose a novel scaling function which describes the growth of the domain size L(t) as a function of time. It suggests an applicable way to tune the speed of phase separation by the coupling between the phase decomposition and the mobile particle-wetting process.

  12. Optimizing the value of the posterior condylar offset, proximal tibial resection and slope in order to achieve the right balance of the posterior cruciate ligament - clinical application of the molding function of the two parts of the PCL

    Science.gov (United States)

    Bogojevski, Ljubomir; Doksevska, Milena Bogojevska

    2017-01-01

    Introduction: In order to achieve the right balance of the posterior cruciate ligament using the skeletal method is very difficult, almost impossible (Mahoney). Our hypothesis for the right balance of the PCL by using the skeletal method is based on several defined facts: - PCL is a union based of two anatomically independent, but functionally synergic parts, posteromedial and anterolateral part. - The length of the posteromedial part of the PCL is determined by the belonging of the medial compartment and is shortest in varus and longest in valgus deformation. - The length of the anterolateral part of the PCL, placed centrally is unchangeable (cca 38 mm) in every knee and is independent from the anatomical appearance (deformation). - The cylindrical shape of the distal posterior part of the femur (Ficat) depends of the molding function of the PCL (Kapandji) and is a result of the proportion of the both parts of the PCL that is consisted of: shorter posteromedial part, less bone stock on the medial and more bone stock on the lateral condyle (varus knee) and vice versa, longer posteromedial part, more bone stock on the medial condyle and less on the lateral (valgus knee). According to that, the neutral bone stock is achieved by equalization of the lengths of the two parts (common radius of the cylinder) of the PCL, that is basis for the interligamentary balance of the posterior cruciate ligament. Methods: The basic characteristics of the interligamentary balance of the PCL that we started in 2008 are the following: 1. Posterior condylar offset is equal to the even length of the both part of the PCL. 2. Decrease of the values of proximal tibial resection from 10 in varus to 4-6 in valgus. 3. Femoral valgus cut from 6 in excessive varus deformity to 4 in valgus. Results: The clinical evaluation of the cases divided in groups excessive varus, mean varus, valgus type 1, 2 (Krakow) showed right distribution in the groups of the postoperative ROM and intraoperative

  13. DURABILITY OF ASPHALT CONCRETE MIXTURES USING DOLOMITE AGGREGATES

    Directory of Open Access Journals (Sweden)

    Imad Al-Shalout

    2015-12-01

    Full Text Available This study deals with the durability of asphalt concrete, including the effects of different gradations, compaction temperatures and immersion time on the durability potential of mixtures. The specific objectives of this study are: to investigate the effect of compaction temperature on the mechanical properties of asphalt concrete mixtures; investigate the effect of bitumen content and different aggregate gradations on the durability potential of bituminous mixtures.

  14. Antiandrogenic activity of phthalate mixtures: Validity of concentration addition

    Energy Technology Data Exchange (ETDEWEB)

    Christen, Verena [University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Crettaz, Pierre; Oberli-Schrämmli, Aurelia [Swiss Federal Office of Public Health, Division Chemical Products, 3003 Bern (Switzerland); Fent, Karl, E-mail: karl.fent@bluewin.ch [University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Swiss Federal Institute of Technology Zürich (ETH Zürich), Department of Environmental Sciences, 8092 Zürich (Switzerland)

    2012-03-01

    Phthalates and bisphenol A have very widespread use leading to significant exposure of humans. They are suspected to interfere with the endocrine system, including the androgen, estrogen and the thyroid hormone system. Here we analyzed the antiandrogenic activity of six binary, and one ternary mixture of phthalates exhibiting complete antiandrogenic dose–response curves, and binary mixtures of phthalates and bisphenol A at equi-effective concentrations of EC{sub 10}, EC{sub 25} and EC{sub 50} in MDA-kb2 cells. Mixture activity followed the concentration addition (CA) model with a tendency to synergism at high and antagonism at low concentrations. Isoboles and the toxic unit approach (TUA) confirmed the additive to synergistic activity of the binary mixtures BBP + DBP, DBP + DEP and DEP + BPA at high concentrations. Both methods indicate a tendency to antagonism for the EC{sub 10} mixtures BBP + DBP, BBP + DEP and DBP + DEP, and the EC{sub 25} mixture of DBP + BPA. A ternary mixture revealed synergism at the EC{sub 50}, and weak antagonistic activity at the EC{sub 25} level by the TUA. A mixture of five phthalates representing a human urine composition and reflecting exposure to corresponding parent compounds showed no antiandrogenic activity. Our study demonstrates that CA is an appropriate concept to account for mixture effects of antiandrogenic phthalates and bisphenol A. The interaction indicates a departure from additivity to antagonism at low concentrations, probably due to interaction with the androgen receptor and/or cofactors. This study emphasizes that a risk assessment of phthalates should account for mixture effects by applying the CA concept. -- Highlights: ► Antiandrogenic activity of mixtures of 2 and 3 phthalates are assessed in MDA-kb2 cells. ► Mixture activities followed the concentration addition model. ► A tendency to synergism at high and antagonism at low levels occurred.

  15. Determination of thermal conductivity in foundry mould mixtures

    Directory of Open Access Journals (Sweden)

    G. Solenički

    2010-01-01

    Full Text Available For a thorough understanding of the behaviour of foundry mould mixtures, a good knowledge of thermal properties of mould materials is needed. Laboratory determination of thermal conductivity of mould mixtures enables a better control over scabbing defects which are a major problem in green sand mould mixtures. A special instrument has been designed for that purpose and it is described in this work.

  16. Tails assumptions and posterior concentration rates for mixtures of Gaussians

    OpenAIRE

    Naulet, Zacharie; Rousseau, Judith

    2016-01-01

    Nowadays in density estimation, posterior rates of convergence for location and location-scale mixtures of Gaussians are only known under light-tail assumptions; with better rates achieved by location mixtures. It is conjectured, but not proved, that the situation should be reversed under heavy tails assumptions. The conjecture is based on the feeling that there is no need to achieve a good order of approximation in regions with few data (say, in the tails), favoring location-scale mixtures w...

  17. Constrained Fisher Scoring for a Mixture of Factor Analyzers

    Science.gov (United States)

    2016-09-01

    global appearance model across the entire sensor network. constrained maximum likelihood estimation, mixture of factor analyzers, Newton’s method...ARL-TR-7836• SEP 2016 US Army Research Laboratory Constrained Fisher Scoring for a Mixture of Factor Analyzers by Gene T Whipps, Emre Ertin, and...TR-7836• SEP 2016 US Army Research Laboratory Constrained Fisher Scoring for a Mixture of Factor Analyzers by Gene T Whipps Sensors and Electron

  18. Epitaxial Growth of GeGaAs.

    Science.gov (United States)

    1981-06-01

    liquid solvent for epitaxial growth of Ge. Because of the finite solubility of GaAs in Pb (7 x 10-4 atomic fraction at 500°C) relatively fast initial...mixture of Pb and Sn was used as a melt. The solubility of Ge in a PbSn eutetic mixture is significantly higher than the solubility of Ge in pure Pb...shallow donor acceptor levels. Addition of a deep level to the crystal lat- tice at this point would further pin the fermi level near mid-gap

  19. The transport phenomena during the growth of ZnTe crystal by the temperature gradient solution growth technique

    Science.gov (United States)

    Yin, Liying; Jie, Wanqi; Wang, Tao; Zhou, Boru; Yang, Fan

    2017-03-01

    A numerical model is developed to simulate the temperature field, the thermosolutal convection, the solute segregation and the growth interface morphology during the growth of ZnTe crystal from Te rich solution by the temperature gradient solution growth (TGSG) technique. Effects of the temperature gradient on the transport phenomena, the growth interface morphology and the growth rate are examined. The influences of the latent heat and the thermal conductivity of ZnTe crystal on the transport phenomena and the growth interface are also discussed. We find that the mass transfer of ZnTe in the solution is very slow because of the low diffusion coefficient and the lack of mixing in the lower part of the solution. During the growth, dilute solution with high density and low growth temperature accumulates in the central region of the growth interface, making the growth interface change into two distinct parts. The inner part is very concave, while the outer part is relatively flat. Growth conditions in front of the two parts of the growth interface are different. The crystalline quality of the inner part of the ingot is predicted to be worse than that of the outer part. High temperature gradient can significantly increase the growth rate, and avoid the diffusion controlled growth to some extent.

  20. Mixtures of conditional Gaussian scale mixtures applied to multiscale image representations.

    Directory of Open Access Journals (Sweden)

    Lucas Theis

    Full Text Available We present a probabilistic model for natural images that is based on mixtures of Gaussian scale mixtures and a simple multiscale representation. We show that it is able to generate images with interesting higher-order correlations when trained on natural images or samples from an occlusion-based model. More importantly, our multiscale model allows for a principled evaluation. While it is easy to generate visually appealing images, we demonstrate that our model also yields the best performance reported to date when evaluated with respect to the cross-entropy rate, a measure tightly linked to the average log-likelihood. The ability to quantitatively evaluate our model differentiates it from other multiscale models, for which evaluation of these kinds of measures is usually intractable.

  1. Use of multiline cultivars and cultivar mixtures for disease management.

    Science.gov (United States)

    Mundt, C C

    2002-01-01

    The usefulness of mixtures (multiline cultivars and cultivar mixtures) for disease management has been well demonstrated for rusts and powdery mildews of small grain crops. Such mixtures are more useful under some epidemiological conditions than under others, and experimental methodology, especially problems of scale, may be crucial in evaluating the potential efficacy of mixtures on disease. There are now examples of mixtures providing both low and high degrees of disease control for a wide range of pathosystems, including crops with large plants, and pathogens that demonstrate low host specificity, or are splash dispersed, soilborne, or insect vectored. Though most analyses of pathogen evolution in mixtures consider static costs of virulence to be the main mechanism countering selection for pathogen complexity, many other potential mechanisms need to be investigated. Agronomic and marketing considerations must be carefully evaluated when implementing mixture approaches to crop management. Practical difficulties associated with mixtures have often been overestimated, however, and mixtures will likely play an increasingly important role as we develop more sustainable agricultural systems.

  2. UTILIZATION OF WASTE PLASTIC BOTTLES IN ASPHALT MIXTURE

    Directory of Open Access Journals (Sweden)

    TAHER BAGHAEE MOGHADDAM

    2013-06-01

    Full Text Available Nowadays, large amounts of waste materials are being produced in the world. One of the waste materials is plastic bottle. Generating disposable plastic bottles is becoming a major problem in many countries. Using waste plastic as a secondary material in construction projects would be a solution to overcome the crisis of producing large amount of waste plastics in one hand and improving the structure’s characteristics such as resistance against cracking on the other hand. This study aimed to investigate the effects of adding plastic bottles in road pavement. Marshall properties as well as specific gravity of asphalt mixture containing different percentages of plastic bottles were evaluated. Besides, Optimum Asphalt Content (OAC was calculated for each percentages of plastic bottles used in the mix. The stiffness and fatigue characteristics of mixture were assessed at OAC value. Results showed that the stability and flow values of asphalt mixture increased by adding waste crushed plastic bottle into the asphalt mixture. Further, it was shown that the bulk specific gravity and stiffness of mixtures increased by adding lower amount of plastic bottles; however, adding higher amounts of plastic resulted in lower specific gravity and mix stiffness. In addition, it was concluded that the mixtures containing waste plastic bottles have lower OAC values compared to the conventional mixture, and this may reduce the amount of asphalt binder can be used in road construction projects. Besides, the mixtures containing waste plastic showed significantly greater fatigue resistance than the conventional mixture.

  3. [Construction of Three-Dimensional Isobologram for Ternary Pollutant Mixtures].

    Science.gov (United States)

    2015-12-01

    Tongji University, Shanghai 200092, China) Isobolographic analysis was widely used in the interaction assessment of binary mixtures. However, how to construct a three-dimensional (3D) isobologram for the assessment of toxicity interaction within ternary mixtures is still not reported up to date. The main purpose of this paper is to develop a 3D isobologram where the relative concentrations of three components are acted as three coordinate axes in 3D space to examine the toxicity interaction within ternary mixtures. Taking six commonly used pesticides in China, including three herbicides (2, 4-D, desmetryne and simetryn) and three insecticides ( dimethoate, imidacloprid and propoxur) as the mixture components, the uniform design ray procedure (UD-Ray) was used to rationally design the concentration composition of various components in the ternary mixtures so that effectively and comprehensively reflected the variety of actual environmental concentrations. The luminescent inhibition toxicities of single pesticides and their ternary mixtures to Vibrio fischeri at various concentration levels were determined by the microplate toxicity analysis. Selecting concentration addition (CA) as the addition reference, 3D isobolograms were constructed to study the toxicity interactions of various ternary mixtures. The results showed that the 3D isobologram could clearly and directly exhibit the toxicity interactions of ternary mixtures, and extend the use of isobolographic analysis into the ternary mixtures.

  4. Calculation and Analysis of Mean Opacity of Gold Mixtures

    Institute of Scientific and Technical Information of China (English)

    YAN An-ying; JIANG Ming; CHENG Xin-lu; YANG Xiang-dong

    2007-01-01

    A screened hydrogenic model for l splitting (SHML) is used to calculate the Rosseland mean opacities of high-Z Au, Ta, Yb, Ho, Gd, Sm, Nd, Sn, Ag plasmas and mixtures of gold and these elements at high temperature (T=200-400eV) and dense (ρ=1g/cm3).From the calculated Rosseland mean opacities of the mixtures, Au-Nd seems to be a better choice than other mixtures.Simultaneously, the reason that the mean opacities of mixture of Au-Sn decrease slightly when T=400eV is analyzed.

  5. Swelling characteristics of immersed sand-bentonite mixtures

    Institute of Scientific and Technical Information of China (English)

    丰土根; 崔红斌; 孙德安; 杜冰

    2008-01-01

    A laboratory one-dimensional consolidation apparatus was employed to research the swelling stress and volume of the sand-bentonite mixture under immersed conditions. The stress-strain characteristics of mixtures under varied mixing ratios and loading statuses were analyzed. Based on the results of tests, the mechanism of mixture swelling and collapsing was further discussed. The results show that mixtures with low sand ratios are suitable as hydraulic barrier or containment barriers of general landfills, geological repository and other hydraulic infrastructure works.

  6. Physical Stability of Freeze-Dried Isomalt Diastereomer Mixtures

    DEFF Research Database (Denmark)

    Koskinen, Anna-Kaisa; Fraser-Miller, Sara J.; Bøtker, Johan P.

    2016-01-01

    of the diastereomer compositions showed signs of physical instability when stored in the highest relative humidity condition. The four different crystalline diastereomer mixtures showed specific identifiable solid state properties. Conclusions Isomalt was shown to be a suitable excipient for freeze-drying. Preferably...... a mixture of the diastereomers should be used, as the mixture containing only one of the isomers showed physical instability. A mixture containing a 1:1 ratio of the two diastereomers showed the best physical stability in the amorphous form....

  7. Opacity Calculations for Non-Local Thermodynamic Equilibrium Mixtures

    Institute of Scientific and Technical Information of China (English)

    吴泽清; 韩国兴; 逄锦桥

    2002-01-01

    Based on the average atom model, a non-local thermodynamic equilibrium (non-LTE) model is developed to calculate opacity for mixtures. This model could be applied to high-Z problems. The mean ionization degrees of SiO2 of the present calculation are slightly higher compared with another model for mixtures. As an example, the opacity of Au and Nd mixture is calculated. The results show concrete non-LTE effects and the increase in opacity of the mixture is shown clearly.

  8. Growth references

    NARCIS (Netherlands)

    Buuren, S. van

    2007-01-01

    A growth reference describes the variation of an anthropometric measurement within a group of individuals. A reference is a tool for grouping and analyzing data and provides a common basis for comparing populations.1 A well known type of reference is the age-conditional growth diagram. The

  9. Moisture sensitivity examination of asphalt mixtures using thermodynamic, direct adhesion peel and compacted mixture mechanical tests

    OpenAIRE

    Zhang, Jizhe; AIREY, Gordon D; Grenfell, James; Apeagyei, Alex K.

    2016-01-01

    Moisture damage in asphalt mixtures is a complicated mode of pavement distress that results in the loss of stiffness and structural strength of the asphalt pavement layers. This paper evaluated the moisture sensitivity of different aggregate–bitumen combinations through three different approaches: surface energy, peel adhesion and the Saturation Ageing Tensile Stiffness (SATS) tests. In addition, the results obtained from these three tests were compared so as to characterise the relationship ...

  10. Extrapituitary growth hormone and growth?

    Science.gov (United States)

    Harvey, Steve; Baudet, Marie-Laure

    2014-09-01

    While growth hormone (GH) is obligatory for postnatal growth, it is not required for a number of growth-without-GH syndromes, such as early embryonic or fetal growth. Instead, these syndromes are thought to be dependent upon local growth factors, rather than pituitary GH. The GH gene is, however, also expressed in many extrapituitary tissues, particularly during early development and extrapituitary GH may be one of the local growth factors responsible for embryonic or fetal growth. Moreover, as the expression of the GH receptor (GHR) gene mirrors that of GH in extrapituitary tissues the actions of GH in early development are likely to be mediated by local autocrine or paracrine mechanisms, especially as extrapituitary GH expression occurs prior to the ontogeny of pituitary somatotrophs or the appearance of GH in the circulation. The extrapituitary expression of pituitary somatotrophs or the appearance of GH in the circulation. The extrapituitary expression of GH in embryos has also been shown to be of functional relevance in a number of species, since the immunoneutralization of endogenous GH or the blockade of GH production is accompanied by growth impairment or cellular apoptosis. The extrapituitary expression of the GH gene also persists in some central and peripheral tissues postnatally, which may reflect its continued functional importance and physiological or pathophysiological significance. The expression and functional relevance of extrapituitary GH, particularly during embryonic growth, is the focus of this brief review.

  11. The Effect of Blood Contamination on the Compressive Strength of Calcium-Enriched Mixture

    Directory of Open Access Journals (Sweden)

    Alireza Adl

    2015-03-01

    Full Text Available Statement of the Problem: In clinical situations, Calcium-Enriched Mixture (CEM comes into direct contact or even mixes with blood during or after placement. Purpose: The aim of this study was to evaluate the effect of blood contamination on the compressive strength of CEM. Materials and Method: Three experimental groups were included in this study. In the first group, CEM was mixed with distilled water and was exposed to normal saline (control group. In the second group, CEM cement was mixed with distilled water and then was exposed to blood. In the third group, CEM was mixed with and exposed to blood. Nine custom-made two-part split Plexiglas molds with five holes were used to form CEM samples for compressive strength testing (15 samples in each group. After 7 days of incubation, compressive bond strength testing was performed using a universal testing machine. Data were statistically analyzed using the Mann–Whitney U test with a significance level of p 0.05. Conclusion: It can be concluded that exposure to blood does not adversely affect the compressive strength of CEM, but incorporation of blood makes the cement very brittle.

  12. Pesticide mixtures, endocrine disruption, and amphibian declines: are we underestimating the impact?

    Science.gov (United States)

    Hayes, Tyrone B; Case, Paola; Chui, Sarah; Chung, Duc; Haeffele, Cathryn; Haston, Kelly; Lee, Melissa; Mai, Vien Phoung; Marjuoa, Youssra; Parker, John; Tsui, Mable

    2006-04-01

    Amphibian populations are declining globally at an alarming rate. Pesticides are among a number of proposed causes for these declines. Although a sizable database examining effects of pesticides on amphibians exists, the vast majority of these studies focus on toxicological effects (lethality, external malformations, etc.) at relatively high doses (parts per million). Very few studies focus on effects such as endocrine disruption at low concentrations. Further, most studies examine exposures to single chemicals only. The present study examined nine pesticides (four herbicides, two fungicides, and three insecticides) used on cornfields in the midwestern United States. Effects of each pesticide alone (0.1 ppb) or in combination were examined. In addition, we also examined atrazine and S-metolachlor combined (0.1 or 10 ppb each) and the commercial formulation Bicep II Magnum, which contains both of these herbicides. These two pesticides were examined in combination because they are persistent throughout the year in the wild. We examined larval growth and development, sex differentiation, and immune function in leopard frogs (Rana pipiens). In a follow-up study, we also examined the effects of the nine-compound mixture on plasma corticosterone levels in male African clawed frogs (Xenopus laevis). Although some of the pesticides individually inhibited larval growth and development, the pesticide mixtures had much greater effects. Larval growth and development were retarded, but most significantly, pesticide mixtures negated or reversed the typically positive correlation between time to metamorphosis and size at metamorphosis observed in controls: exposed larvae that took longer to metamorphose were smaller than their counterparts that metamorphosed earlier. The nine-pesticide mixture also induced damage to the thymus, resulting in immunosuppression and contraction of flavobacterial meningitis. The study in X. laevis revealed that these adverse effects may be due to an

  13. Porous concrete mixtures for pervious urban pavements

    Directory of Open Access Journals (Sweden)

    Castro, J.

    2007-08-01

    Full Text Available The present study aimed to analyze the hydraulic and mechanical behaviour of a series of roller-compacted, laboratory porous concrete mixtures. The mix design variables examined were the actual void ratio in the hardened concrete and the water/cement ratio. From these results the better dosages from the mechanical and hydraulical behaviour point of view were determined. One of the designs developed was found to exhibit excellent hydraulic capacity and 20% greater strength than the mixtures recommended in the literature. Moreover, concrete with an actual void ratio of only 14% was observed to meet permeability requirements. Maximum flexural strength of concretes with different w/c ratios was achieved with a cement paste content of 250 l/m3. Relationships were found between the void ratio and both 28-day concrete permeability and flexural strength. Finally, the doses exhibiting the best mechanical and hydraulic performance were identified.El trabajo realizado en este estudio consistió en analizar el comportamiento de diferentes dosificaciones de mezclas de hormigón poroso, fabricadas en laboratorio y compactadas con rodillo pesado para simular las condiciones de terreno. Las variables consideradas para el diseño de las mezclas fueron el porcentaje real de huecos en el hormigón endurecido y la razón agua/cemento. A partir de estos resultados se determinaron las dosificaciones que presentan mejor comportamiento desde el punto de vista mecánico e hidráulico. Los resultados muestran que existe una dosificación de hormigón poroso, distinta a las encontradas actualmente en la literatura internacional, que permite obtener resistencias hasta 20% más altas, manteniendo todavía una excelente capacidad hidráulica. Se determinó que una permeabilidad suficiente se puede obtener con un porcentaje real de huecos de 14%, y que agregar pasta de cemento en una proporción de 250 l/m3 permite maximizar la resistencia a flexotracción de hormigones que

  14. Experimental wax mixtures for dental use.

    Science.gov (United States)

    Kotsiomiti, E; McCabe, J F

    1997-07-01

    Improvements in the properties of dental waxes were sought by alterations in their composition. Twenty-six blends of paraffin wax, beeswax and inorganic filler were subjected to the following tests: plastic deformation (flow), linear thermal expansion, elastic modulus and flexural strength. Flow tests were conducted in accordance with the corresponding ISO specification. Thermal expansion coefficients were estimated using thermomechanical analysis. Mechanical properties were tested using a universal testing machine. Pure paraffin and beeswax were used as controls. The results were subjected to analysis using correlation and regression. Regression coefficients in the range of 0.90-0.99 were obtained in most cases, flow tests exhibiting the highest coefficients and flexural strength the lowest. The incorporated filler particles reduced the flow of the natural waxes, especially of the ester-containing beeswax, and improved the elastic modulus and strength. Good correlation was found between the ingredient proportions and measured properties, suggesting a relationship between them, although this is quite complicated in the case of tertiary wax mixtures. The experimental blends exhibited properties that are potentially useful for a range of clinical applications.

  15. Mixture latent autoregressive models for longitudinal data

    CERN Document Server

    Bartolucci, Francesco; Pennoni, Fulvia

    2011-01-01

    Many relevant statistical and econometric models for the analysis of longitudinal data include a latent process to account for the unobserved heterogeneity between subjects in a dynamic fashion. Such a process may be continuous (typically an AR(1)) or discrete (typically a Markov chain). In this paper, we propose a model for longitudinal data which is based on a mixture of AR(1) processes with different means and correlation coefficients, but with equal variances. This model belongs to the class of models based on a continuous latent process, and then it has a natural interpretation in many contexts of application, but it is more flexible than other models in this class, reaching a goodness-of-fit similar to that of a discrete latent process model, with a reduced number of parameters. We show how to perform maximum likelihood estimation of the proposed model by the joint use of an Expectation-Maximisation algorithm and a Newton-Raphson algorithm, implemented by means of recursions developed in the hidden Mark...

  16. Structure of colloidal sphere-plate mixtures

    Science.gov (United States)

    Doshi, N.; Cinacchi, G.; van Duijneveldt, J. S.; Cosgrove, T.; Prescott, S. W.; Grillo, I.; Phipps, J.; Gittins, D. I.

    2011-05-01

    In addition to containing spherical pigment particles, coatings usually contain plate-like clay particles. It is thought that these improve the opacity of the paint film by providing an efficient spacing of the pigment particles. This observation is counterintuitive, as suspensions of particles of different shapes and sizes tend to phase separate on increase of concentration. In order to clarify this matter a model colloidal system is studied here, with a sphere-plate diameter ratio similar to that found in paints. For dilute suspensions, small angle neutron scattering revealed that the addition of plates leads to enhanced density fluctuations of the spheres, in agreement with new theoretical predictions. On increasing the total colloid concentration the plates and spheres phase separate due to the disparity in their shape. This is in agreement with previous theoretical and experimental work on colloidal sphere-plate mixtures, where one particle acts as a depleting agent. The fact that no large scale phase separation is observed in coatings is ascribed to dynamic arrest in intimately mixed, or possibly micro-phase separated structures, at elevated concentration.

  17. Mixture modeling approach to flow cytometry data.

    Science.gov (United States)

    Boedigheimer, Michael J; Ferbas, John

    2008-05-01

    Flow Cytometry has become a mainstay technique for measuring fluorescent and physical attributes of single cells in a suspended mixture. These data are reduced during analysis using a manual or semiautomated process of gating. Despite the need to gate data for traditional analyses, it is well recognized that analyst-to-analyst variability can impact the dataset. Moreover, cells of interest can be inadvertently excluded from the gate, and relationships between collected variables may go unappreciated because they were not included in the original analysis plan. A multivariate non-gating technique was developed and implemented that accomplished the same goal as traditional gating while eliminating many weaknesses. The procedure was validated against traditional gating for analysis of circulating B cells in normal donors (n = 20) and persons with Systemic Lupus Erythematosus (n = 42). The method recapitulated relationships in the dataset while providing for an automated and objective assessment of the data. Flow cytometry analyses are amenable to automated analytical techniques that are not predicated on discrete operator-generated gates. Such alternative approaches can remove subjectivity in data analysis, improve efficiency and may ultimately enable construction of large bioinformatics data systems for more sophisticated approaches to hypothesis testing.

  18. Solubility of C60 in solvent mixtures.

    Science.gov (United States)

    Kulkarni, Pradnya P; Jafvert, Chad T

    2008-02-01

    The potential large-scale production of fullerene C60 and its widespread use in consumer products may translate into occupational and public exposure and in long-term environmental exposure. To assess the risk and fate of C60 in the environment, it is important to understand its solvate formation in common industrial solvents as the solvates may affect various properties of C60 including reactivity and toxicity, particularly when solvates occur in C60 clusters. In this study, the solubility measurements in mixed solvent system can provide useful information about solvate formation. The solubility of C60 was measured in pure toluene, tetrahydrofuran, ethanol, and acetonitrile to be 3000, 11, 1.4, and 0.04 mg/L, respectively. Additionally, the solubility of C60 was measured in mixtures of toluene-acetonitrile, toluene-ethanol, toluene-tetrahydrofuran, and acetonitrile-tetrahydrofuran. The solubility data were modeled with some accuracy using Wohl's equation. The estimated crystal energy term for C60 in tetrahydrofuran was different than that in the other solvents, indicating that the C60 solid phase in equilibrium with tetrahydrofuran solution may be a solvated crystal.

  19. Multicomponent mixtures for cryoprotection and ligand solubilization

    Directory of Open Access Journals (Sweden)

    Lidia Ciccone

    2015-09-01

    Full Text Available Mixed cryoprotectants have been developed for the solubilization of ligands for crystallization of protein–ligand complexes and for crystal soaking. Low affinity lead compounds with poor solubility are problematic for structural studies. Complete ligand solubilization is required for co-crystallization and crystal soaking experiments to obtain interpretable electron density maps for the ligand. Mixed cryo-preserving compounds are needed prior to X-ray data collection to reduce radiation damage at synchrotron sources. Here we present dual-use mixes that act as cryoprotectants and also promote the aqueous solubility of hydrophobic ligands. Unlike glycerol that increases protein solubility and can cause crystal melting the mixed solutions of cryo-preserving compounds that include precipitants and solubilizers, allow for worry-free crystal preservation while simultaneously solubilizing relatively hydrophobic ligands, typical of ligands obtained in high-throughput screening. The effectiveness of these mixture has been confirmed on a human transthyretin crystals both during crystallization and in flash freezing of crystals.

  20. Structure of colloidal sphere-plate mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Doshi, N; Cinacchi, G; Van Duijneveldt, J S; Cosgrove, T; Prescott, S W [School of Chemistry, University of Bristol, Bristol BS8 1TS (United Kingdom); Grillo, I [Institut Laue-Langevin, 6 rue Jules Horowitz BP 156, 38042 Grenoble Cedex 9 (France); Phipps, J [Imerys Minerals Ltd, Par Moor Centre, Par Moor Road, Par, Cornwall PL24 2SQ (United Kingdom); Gittins, D I, E-mail: Giorgio.Cinacchi@bristol.ac.uk, E-mail: J.S.van-Duijneveldt@bristol.ac.uk [Imerys Performance and Filtration Minerals Ltd, 130 Castilian Drive, Goleta, CA 93117 (United States)

    2011-05-18

    In addition to containing spherical pigment particles, coatings usually contain plate-like clay particles. It is thought that these improve the opacity of the paint film by providing an efficient spacing of the pigment particles. This observation is counterintuitive, as suspensions of particles of different shapes and sizes tend to phase separate on increase of concentration. In order to clarify this matter a model colloidal system is studied here, with a sphere-plate diameter ratio similar to that found in paints. For dilute suspensions, small angle neutron scattering revealed that the addition of plates leads to enhanced density fluctuations of the spheres, in agreement with new theoretical predictions. On increasing the total colloid concentration the plates and spheres phase separate due to the disparity in their shape. This is in agreement with previous theoretical and experimental work on colloidal sphere-plate mixtures, where one particle acts as a depleting agent. The fact that no large scale phase separation is observed in coatings is ascribed to dynamic arrest in intimately mixed, or possibly micro-phase separated structures, at elevated concentration.

  1. Exploring Literacy and Growth: An Analysis of Three Communities of Readers in Urban Senegal

    Science.gov (United States)

    Shiohata, Mariko

    2009-01-01

    This paper consists of two parts. The first part reviews how the arguments supporting literacy education have changed over the last five decades. Although there has been a shift in emphasis from economic to socio-cultural and personal dimensions, literacy is still considered mainly as an instrument for economic growth and poverty alleviation. The…

  2. Growth Stimulants

    OpenAIRE

    Matthews, Nyle J.

    1989-01-01

    A tiny pellet inserted under the skin of a calf's ear may increase weight gains as much as 15 to 20 percent. This same result would take years to accomplish through breeding and selection. These tiny pellets are growth stimulants. They are made of hormones that are constructed to slowly release minute amounts into the blood stream that stimulate the animal to produce natural body hormones. One of these hormones is a growth hormone. It regulates the rate of growth of the animal. Increasing the...

  3. Characterization of a strain capable of degrading a herbicide mixture of quinclorac and bensulfuronmethyl

    Institute of Scientific and Technical Information of China (English)

    LU Zhen-Mei; LI Zi-Mu; SANG Li-Ya; MIN Hang

    2008-01-01

    A bacterial strain,designated as LS,was isolated from a contaminated soil and was found to be capable of utilizing quinelorac,bensulfuromnethyl,and a mixture of the two as carbon and energy sources for growth.Strain LS was identified as Ochrobactrum sp.based on its physiological-biochemical properties,16S rDNA sequences,and phylogenetic analysis.The extent of degradation of quinclorac and bensulfuronmethyl at initial concentrations of 1.5 and 0.1 g L-1 was 90% and 67%,respectively,as measured by high performance liquid chromatography (HPLC).When a herbicide mixture of 0.34 g L-1 quinelorac and 0.02 g L-1 bensulfuronmethyl was applied as carbon sources,quinclorac and bensulfuronmethyl were degraded at 95.7% and 67.5%,respectively.It appears that quinclorac is utilized more easily in a mixture than in a single state.The optimal temperature for growth of strain LS was 37℃.Strain LS grew well at pH 6 to 9 and had the highest degradation level for quinclorac and bensulfuronmethyl at an initial pH of 7 and 8,respectively.Addition of 0.25 g L-1 yeast extract could promote the growth and extent of degradation of quinclorac and bensulfuronmethyl by strain LS.Strain LS also showed the capability to degrade other aromatic compounds such as catechol,propisochlor,4-chloro-2-methylphenoxyacetic acid sodium (MCPA-Na) and imazethapy.The isolate LS shows a huge potential to be used in bioremediation for treating complex herbicide residues.

  4. DESIGNS FOR MIXTURE AND PROCESS VARIABLES APPLIED IN TABLET FORMULATIONS

    NARCIS (Netherlands)

    DUINEVELD, CAA; SMILDE, AK; DOORNBOS, DA

    1993-01-01

    Although there are several methods for the construction of a design for process variables and mixture variables, there are not very many methods which are suitable to combine mixture and process variables in one design. Some of the methods which are feasible will be shown. These methods will be

  5. Toxicological evaluation and risk assessment of chemical mixtures

    NARCIS (Netherlands)

    Cassee, F.R.; Groten, J.P.; Bladeren, P.J. van; Feron, V.J.

    1998-01-01

    A major objective of combination toxicology is to establish whether a mixture of chemicals will result in an effect similar to that expected on the basis of additivity. This requires understanding of the basic concepts of the combined toxicological action of the compounds of the mixture: simple

  6. Learning Mixtures of Polynomials of Conditional Densities from Data

    DEFF Research Database (Denmark)

    L. López-Cruz, Pedro; Nielsen, Thomas Dyhre; Bielza, Concha;

    2013-01-01

    Mixtures of polynomials (MoPs) are a non-parametric density estimation technique for hybrid Bayesian networks with continuous and discrete variables. We propose two methods for learning MoP ap- proximations of conditional densities from data. Both approaches are based on learning MoP approximations......- ods with the approach for learning mixtures of truncated basis functions from data....

  7. Rheological properties of asphalt mixtures containing various fibers

    Institute of Scientific and Technical Information of China (English)

    叶群山; 吴少鹏; 陈筝; 刘至飞

    2008-01-01

    Rheological characteristics of fiber-modified asphalt mixture were investigated.Cellulous fiber,polyester fiber and mineral fiber were used as additives for asphalt mixture,and the dosages were 0.3%,0.3%,0.4%,respectively.Dynamic modulus test using superpave simple performance tester(SPT) was adopted to study the dynamic modulus and phase angle for the control mixture and fiber-modified ones at various temperatures and frequencies.Test results show that the rheological properties can be improved significantly by the addition of various fibers.The dynamic modulus increases with the increase of frequency,and the phase angle decreases with the increase of frequency.When various fibers are used,the dynamic modulus increases and phase angle decreases at each frequency.This indicates that the stiffness and the elastic portion of fiber-modified asphalt mixtures can be enhanced when various fibers are used,which results in the change of viscoelastic properties of mixtures.The creep test results show that the total strain and the permanent strain of asphalt mixtures during load-unload cycle can be significantly reduced,which results in the improvement of resistance to permanent deformation for asphalt mixtures containing various fiber additives.The Burgers model can be employed effectively to illustrate the rheological properties of fiber modified asphalt mixtures.

  8. Predicting Development of an Epidemics on Cultivar Mixtures

    DEFF Research Database (Denmark)

    Østergård, Hanne

    1983-01-01

    A mathematical model for the development of an epidemic on a plant cultivar mixture illustrates the influence of the infection efficiency, spore production rate, proportion of deposited spores, frequency of autodeposition, and composition of the mixture on the genetic composition of the pathogen...

  9. Mixture including hydrogen and hydrocarbon having pressure-temperature stability

    Science.gov (United States)

    Mao, Wendy L. (Inventor); Mao, Ho-Kwang (Inventor)

    2009-01-01

    The invention relates to a method of storing hydrogen that employs a mixture of hydrogen and a hydrocarbon that can both be used as fuel. In one embodiment, the method involves maintaining a mixture including hydrogen and a hydrocarbon in the solid state at ambient pressure and a temperature in excess of about 10 K.

  10. Kelvin Equation for a Non-Ideal Multicomponent Mixture

    DEFF Research Database (Denmark)

    Shapiro, Alexander; Stenby, Erling Halfdan

    1997-01-01

    The Kelvin equation is generalized by application to a case of a multicomponent non-ideal mixture. Such a generalization is necessary in order to describe the two-phase equilibrium in a capillary medium with respect to both normal and retrograde condensation. The equation obtained is applied...... to the equilibrium state of a hydrocarbon mixture ina gas-condensate reservoir....

  11. Directed Assembly of colloidal rods, spheres and their mixtures

    NARCIS (Netherlands)

    Bakker, H.E.

    2017-01-01

    The directed assembly of colloidal rods, spheres and their mixtures in external fields such as gravity, electric fields and shear flow was investigated. Using confocal microscopy we determined the experimental phase diagram of a binary mixture of colloidal silica rods and spheres that form a binary

  12. Evaluating Mixture Modeling for Clustering: Recommendations and Cautions

    Science.gov (United States)

    Steinley, Douglas; Brusco, Michael J.

    2011-01-01

    This article provides a large-scale investigation into several of the properties of mixture-model clustering techniques (also referred to as latent class cluster analysis, latent profile analysis, model-based clustering, probabilistic clustering, Bayesian classification, unsupervised learning, and finite mixture models; see Vermunt & Magdison,…

  13. Thermodynamic study of (anthracene + phenanthrene) solid state mixtures

    Science.gov (United States)

    Rice, James W.; Fu, Jinxia; Sandström, Emma; Ditto, Jenna C.; Suuberg, Eric M.

    2015-01-01

    Polycyclic aromatic hydrocarbons (PAH) are common components of many materials, such as petroleum and various types of tars. They are generally present in mixtures, occurring both naturally and as byproducts of fuel processing operations. It is important to understand the thermodynamic properties of such mixtures in order to understand better and predict their behavior (i.e., fate and transport) in the environment and in industrial operations. To characterize better the thermodynamic behavior of PAH mixtures, the phase behavior of a binary (anthracene + phenanthrene) system was studied by differential scanning calorimetry, X-ray diffraction, and the Knudsen effusion technique. Mixtures of (anthracene + phenanthrene) exhibit non-ideal mixture behavior. They form a lower-melting, phenanthrene-rich phase with an initial melting temperature of 372 K (identical to the melting temperature of pure phenanthrene) and a vapor pressure of roughly lnP/Pa = −2.38. The phenanthrene-rich phase coexists with an anthracene-rich phase when the mole fraction of phenanthrene (xP) in the mixture is less than or equal to 0.80. Mixtures initially at xP = 0.90 consist entirely of the phenanthrene-rich phase and sublime at nearly constant vapor pressure and composition, consistent with azeotrope-like behavior. Quasi-azeotropy was also observed for very high-content anthracene mixtures (2.5 < xP < 5) indicating that anthracene may accommodate very low levels of phenanthrene in its crystal structure. PMID:26973354

  14. Malabsorption of fructose-sorbitol mixtures. Interactions causing abdominal distress

    DEFF Research Database (Denmark)

    Rumessen, J J; Gudmand-Høyer, E

    1987-01-01

    Hydrogen breath tests were performed on 10 healthy adults after they had ingested a mixture of sorbitol and fructose, in which these substances were present in amounts corresponding to the individual absorption capacities. A significant malabsorption of this mixture was evident in 7 of 10 subjects...

  15. Thermodynamic study of (anthracene + phenanthrene) solid state mixtures.

    Science.gov (United States)

    Rice, James W; Fu, Jinxia; Sandström, Emma; Ditto, Jenna C; Suuberg, Eric M

    2015-11-01

    Polycyclic aromatic hydrocarbons (PAH) are common components of many materials, such as petroleum and various types of tars. They are generally present in mixtures, occurring both naturally and as byproducts of fuel processing operations. It is important to understand the thermodynamic properties of such mixtures in order to understand better and predict their behavior (i.e., fate and transport) in the environment and in industrial operations. To characterize better the thermodynamic behavior of PAH mixtures, the phase behavior of a binary (anthracene + phenanthrene) system was studied by differential scanning calorimetry, X-ray diffraction, and the Knudsen effusion technique. Mixtures of (anthracene + phenanthrene) exhibit non-ideal mixture behavior. They form a lower-melting, phenanthrene-rich phase with an initial melting temperature of 372 K (identical to the melting temperature of pure phenanthrene) and a vapor pressure of roughly lnP/Pa = -2.38. The phenanthrene-rich phase coexists with an anthracene-rich phase when the mole fraction of phenanthrene (xP) in the mixture is less than or equal to 0.80. Mixtures initially at xP = 0.90 consist entirely of the phenanthrene-rich phase and sublime at nearly constant vapor pressure and composition, consistent with azeotrope-like behavior. Quasi-azeotropy was also observed for very high-content anthracene mixtures (2.5 anthracene may accommodate very low levels of phenanthrene in its crystal structure.

  16. Explaining slow convergence of EM in low noise linear mixtures

    OpenAIRE

    Petersen, Kaare Brandt; Winther, Ole

    2005-01-01

    This report conducts an investigation of the convergence properties of the EM algorithm used for linear mixture models. Since the linear mixture model is a rather general approach, the analysis is relevant for a wide range of models which to some degree are subsets of each other: Independent Component Analysis (ICA), probabilistic PCA, Factor Analysis (FA), Independent Factor Analysis (IFA) and Mean Field ICA.

  17. Mixture Experiment Alternatives to the Slack Variable Approach

    Energy Technology Data Exchange (ETDEWEB)

    Piepel, Gregory F.; Landmesser, Samantha M.

    2009-07-01

    A mixture experiment involves mixing two or more components in various proportions and measuring one or more response variables on each mixture. This article presents mixture-experiment approaches for designing experiments and/or modeling the resulting data in situations where the slack-variable (SV) approach has been used. With the SV approach, one mixture component is designated the SV and the experiment is designed and/or the data are analyzed in terms of the remaining components. In a SV design, the proportion of the SV is obtained by subtracting from one the sum of the proportions of the remaining components, thus "taking up the slack". With the mixture-experiment approach, the experiment is designed and the data are analyzed using all of the mixture components. The article considers four situations in which the SV approach has been used, and explains for each situation that it is generally preferable to use an appropriate mixture-experiment approach. For each situation, the recommended mixture-experiment approach is discussed and compared to the SV approach using an example.

  18. Microscopic Hydrodynamic Modes in a Binary Hard Sphere Mixture

    Science.gov (United States)

    Reichl, L. E.; Gust, Erich D.

    2017-07-01

    We derive analytic microscopic expressions for the shear viscosity, the speed of sound, and the decay rates of the hydrodynamic modes in a hard sphere binary gas mixture directly from the spectral properties of coupled Boltzmann equations. We show that the analytic expressions give good agreement with experimental viscosity data and to the results of light scattering experiments on noble gas binary mixtures.

  19. DESIGNS FOR MIXTURE AND PROCESS VARIABLES APPLIED IN TABLET FORMULATIONS

    NARCIS (Netherlands)

    DUINEVELD, CAA; SMILDE, AK; DOORNBOS, DA

    1993-01-01

    Although there are several methods for the construction of a design for process variables and mixture variables, there are not very many methods which are suitable to combine mixture and process variables in one design. Some of the methods which are feasible will be shown. These methods will be comp

  20. Herbal mixtures in the traditional medicine of Eastern Cuba

    NARCIS (Netherlands)

    Hernández, J.; Volpato, G.

    2004-01-01

    Herbal mixtures in the traditional medicine of Eastern Cuba. Traditional herbal mixtures in Eastern Cuba are investigated through interviews with 130 knowledgeable people and traditional healers of the provinces of Santiago de Cuba and Guantanamo. One hundred seventy plant species and other products

  1. Coarsening Rates of Bicontinuous Structures in Polymer Mixtures

    NARCIS (Netherlands)

    Scholten, E.; Sagis, L.M.C.; Linden, van der E.

    2005-01-01

    We discuss the coarsening of domains in bicontinuous structure of aqueous polymer mixtures, driven by hydrodynamic flow. Taking into account the bending energy as a contribution to the interfacial energy, we derive a general expression for the coarsening rate in these mixtures. Examining the

  2. A Novel Approach for Evaluating Carbamate Mixtures for Dose Additivity

    Science.gov (United States)

    Two mathematical approaches were used to test the hypothesis ofdose-addition for a binary and a seven-chemical mixture ofN-methyl carbamates, toxicologically similar chemicals that inhibit cholinesterase (ChE). In the more novel approach, mixture data were not included in the ana...

  3. Mechanistic and Economical Characteristics of Asphalt Rubber Mixtures

    Directory of Open Access Journals (Sweden)

    Mena I. Souliman

    2016-01-01

    Full Text Available Load associated fatigue cracking is one of the major distress types occurring in flexible pavement systems. Flexural bending beam fatigue laboratory test has been used for several decades and is considered to be an integral part of the new superpave advanced characterization procedure. One of the most significant solutions to prolong the fatigue life for an asphaltic mixture is to utilize flexible materials as rubber. A laboratory testing program was performed on a conventional and Asphalt Rubber- (AR- gap-graded mixtures to investigate the impact of added rubber on the mechanical, mechanistic, and economical attributes of asphaltic mixtures. Strain controlled fatigue tests were conducted according to American Association of State Highway and Transportation Officials (AASHTO procedures. The results from the beam fatigue tests indicated that the AR-gap-graded mixtures would have much longer fatigue life compared with the reference (conventional mixtures. In addition, a mechanistic analysis using 3D-Move software coupled with a cost analysis study based on the fatigue performance on the two mixtures was performed. Overall, analysis showed that AR modified asphalt mixtures exhibited significantly lower cost of pavement per 1000 cycles of fatigue life per mile compared to conventional HMA mixture.

  4. Learning High-Dimensional Mixtures of Graphical Models

    CERN Document Server

    Anandkumar, A; Kakade, S M

    2012-01-01

    We consider the problem of learning mixtures of discrete graphical models in high dimensions and propose a novel method for estimating the mixture components with provable guarantees. The method proceeds mainly in three stages. In the first stage, it estimates the union of the Markov graphs of the mixture components (referred to as the union graph) via a series of rank tests. It then uses this estimated union graph to compute the mixture components via a spectral decomposition method. The spectral decomposition method was originally proposed for latent class models, and we adapt this method for learning the more general class of graphical model mixtures. In the end, the method produces tree approximations of the mixture components via the Chow-Liu algorithm. Our output is thus a tree-mixture model which serves as a good approximation to the underlying graphical model mixture. When the union graph has sparse node separators, we prove that our method has sample and computational complexities scaling as poly(p, ...

  5. Mouth Growths

    Science.gov (United States)

    ... This Article Medical Dictionary Also of Interest (Quiz) Biology of the Mouth (Video) Root Canal Additional Content Medical News Mouth Growths By David F. Murchison, DDS, MMS, Clinical Professor, Department of Biological Sciences;Clinical Professor, The University ...

  6. Growth Problems

    Science.gov (United States)

    ... that can lead to significantly short stature is dwarfism . Dwarfism results from abnormal growth of the bones and cartilage in the body. In many forms of dwarfism the person has abnormal body proportions, such as ...

  7. Maintaining Growth

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    China's GDP grew 9.2 percent in 2011,a remarkable achievement outshining many other countries.However,the current condition of the national economy is less than appealing.The sequential quarterly GDP growth rates for 2011 stood at 9.7 percent,9.5 percent,9.1 percent and 8.9 percent,showing a trend of deceleration.A consensus has been made that stabilizing growth should be the primary goal for China's economic development.

  8. Viscoelastic Analysis of Asphalt Mixture Based on Creep Test

    Directory of Open Access Journals (Sweden)

    Lihua Zhao

    2013-01-01

    Full Text Available Two kinds of mineral fibers were added to AC-16C asphalt mixture. Trabecular bending creep experiments of asphalt mixtures were carried out at -10 and 20°C. The influence of mineral fibers on the low temperature viscoelasticity of asphalt mixtures were analyzed systemically. Furthermore, by using Origin, Burgers viscoelastic model was used to investigate the parameter regression for the creep test results at the different temperatures. The results show that the addition of mineral fibers can effectively improve the bending creep rate of asphalt mixtures, indicates the increase of crack resistance of asphalt mixtures. Good agreement between experimental data and Burgers model was found. The parameters of Burgers model at different temperatures can also provide data support for the viscoelastic design of asphalt pavements.

  9. Malabsorption of fructose-sorbitol mixtures. Interactions causing abdominal distress

    DEFF Research Database (Denmark)

    Rumessen, J J; Gudmand-Høyer, E

    1987-01-01

    Hydrogen breath tests were performed on 10 healthy adults after they had ingested a mixture of sorbitol and fructose, in which these substances were present in amounts corresponding to the individual absorption capacities. A significant malabsorption of this mixture was evident in 7 of 10 subjects....... The mixture caused mild to severe gastrointestinal distress in five subjects. When the carbohydrates were given separately, symptoms were absent. There was a significant correlation between the individual absorption capacities of fructose and of sorbitol. A mixture containing a similar amount of fructose......, but given as sucrose, and a similar amount of sorbitol was further given to four of the seven subjects showing malabsorption of the fructose-sorbitol mixture. Malabsorption now failed to appear, and symptoms were absent. These findings are of potential importance for the understanding of the physiologic...

  10. Overlapping Mixtures of Gaussian Processes for the Data Association Problem

    CERN Document Server

    Lázaro-Gredilla, Miguel; Lawrence, Neil

    2011-01-01

    In this work we introduce a mixture of GPs to address the data association problem, i.e. to label a group of observations according to the sources that generated them. Unlike several previously proposed GP mixtures, the novel mixture has the distinct characteristic of using no gating function to determine the association of samples and mixture components. Instead, all the GPs in the mixture are global and samples are clustered following "trajectories" across input space. We use a non-standard variational Bayesian algorithm to efficiently recover sample labels and learn the hyperparameters. We show how multi-object tracking problems can be disambiguated and also explore the characteristics of the model in traditional regression settings.

  11. Thermodiffusion in multicomponent hydrocarbon mixtures: Experimental investigations and computational analysis

    Science.gov (United States)

    VanVaerenbergh, Stefan; Srinivasan, Seshasai; Saghir, M. Ziad

    2009-09-01

    In an unprecedented experimental investigation, a ternary and a four component hydrocarbon mixture at high pressure have been studied in a nearly convection free environment to understand the thermodiffusion process. A binary mixture has also been investigated in this environment. Experimental investigations of the three mixtures have been conducted in space onboard the spacecraft FOTON-M3 thereby isolating the gravity-induced convection that otherwise interferes with thermodiffusion experiments on Earth. The experimental results have also been used to test a thermodiffusion model that has been calibrated based on the results of previous experimental investigations. It was found that with an increase in the number of components in the mixtures, the performance of the thermodiffusion model deteriorated. Computational analysis was also made to estimate the possible sources of errors. Simulations showed that the vibrations of the spacecraft could influence the estimates of thermodiffusion factors. It was also found that they are sensitive to slight variations in the temperature of the mixture.

  12. Fitting of Finite Mixture Distributions to Motor Insurance Claims

    Directory of Open Access Journals (Sweden)

    P. Sattayatham

    2012-01-01

    Full Text Available Problem statement: The modeling of claims is an important task of actuaries. Our problem is in modelling the actual motor insurance claim data set. In this study, we show that the actual motor insurance claim can be fitted by a finite mixture model. Approach: Firstly, we analyse the actual data set and then we choose the finite mixture Lognormal distributions as our model. The estimated parameters of the model are obtained from the EM algorithm. Then, we use the K-S and A-D test for showing how well the finite mixture Lognormal distributions fit the actual data set. We also mention the bootstrap technique in estimating the parameters. Results: From the tests, we found that the finite mixture lognormal distributions fit the actual data set with significant level 0.10. Conclusion: The finite mixture Lognormal distributions can be fitted to motor insurance claims and this fitting is better when the number of components (k are increase.

  13. The scent of mixtures: rules of odour processing in ants.

    Science.gov (United States)

    Perez, Margot; Giurfa, Martin; d'Ettorre, Patrizia

    2015-03-02

    Natural odours are complex blends of numerous components. Understanding how animals perceive odour mixtures is central to multiple disciplines. Here we focused on carpenter ants, which rely on odours in various behavioural contexts. We studied overshadowing, a phenomenon that occurs when animals having learnt a binary mixture respond less to one component than to the other, and less than when this component was learnt alone. Ants were trained individually with alcohols and aldehydes varying in carbon-chain length, either as single odours or binary mixtures. They were then tested with the mixture and the components. Overshadowing resulted from the interaction between chain length and functional group: alcohols overshadowed aldehydes, and longer chain lengths overshadowed shorter ones; yet, combinations of these factors could cancel each other and suppress overshadowing. Our results show how ants treat binary olfactory mixtures and set the basis for predictive analyses of odour perception in insects.

  14. Phase and viscosity behaviour of refrigerant-lubricant mixtures

    DEFF Research Database (Denmark)

    Cisneros, Sergio; Garcia, J.; Fernandez, J.

    2005-01-01

    The understanding of thermophysical properties and phase behaviour of refrigerant-lubricant oil mixtures is highly important for the optimal design of refrigeration and air-conditioning systems. Refrigerant lubricant mixtures, which are likely to have strong asymmetry, can show complex phase...... behaviour such as closed miscibility gaps, open miscibility gaps, liquid-liquid-vapour equilibrium, and even barotropic phenomena (density inversions). In fact, the type of phase behaviour that refrigerant-lubricant mixtures may show is linked to the transition between different types of phase diagrams......, mainly as a function of the molecular asymmetry. This also has a profound effect in the mixture transport properties. Thus, in this work the general aspects of phase and viscosity behaviour linked to the type of asymmetry found in refrigerant-lubricant mixtures are discussed in the context of phase...

  15. Superfluid and Insulating Phases of Fermion Mixtures in Optical Lattices

    Science.gov (United States)

    Iskin, M.; de Melo, C. A. R. Sá

    2007-08-01

    The ground state phase diagram of fermion mixtures in optical lattices is analyzed as a function of interaction strength, fermion filling factor, and tunneling parameters. In addition to standard superfluid, phase-separated or coexisting superfluid excess-fermion phases found in homogeneous or harmonically trapped systems, fermions in optical lattices have several insulating phases, including a molecular Bose-Mott insulator (BMI), a Fermi-Pauli (band) insulator (FPI), a phase-separated BMI-FPI mixture or a Bose-Fermi checkerboard (BFC). The molecular BMI phase is the fermion mixture counterpart of the atomic BMI found in atomic Bose systems, the BFC or BMI-FPI phases exist in Bose-Fermi mixtures, and lastly the FPI phase is particular to the Fermi nature of the constituent atoms of the mixture.

  16. Combustion of soybean oil and diesel mixtures for heating purposes

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, Adriana Correa; Sanz, Jose Francisco [European University Miguel de Cervantes, Valladolid (Spain)], E-mail: acorrea@uemc.es; Hernandez, Salvador; Navas, Luis Manuel; Rodriguez, Elena; Ruiz, Gonzalo [University of Valladolid (Spain). Dept. of Agricultural and Forest Engineering; San Jose, Julio [University of Valladolid (Spain). Dept. of Energetic Engineering; Gomez, Jaime [University of Valladolid (Spain). Dept. of Communications and Signal Theory and Telematics Engineering

    2008-07-01

    Using blends of vegetable oils with petroleum derivates for heating purposes has several advantages over other energy application for vegetable oils. This paper presents the results of an investigation by use of soybean oil and diesel mixture as fuel for producing heat in conventional diesel installation. The paper is set out as follows: properties characterization of soybean oil as fuel and of diesel oil, as well as the mixture of both; selection of the mixture according to their physical chemical properties and how they adapt to conventional combustion installation; experimentation with the selected mixture, allowing the main combustion parameters to be measured; processing the collected data, values of combustion, efficiency and reduction of emissions. Conclusions show that the use of soybean oil and diesel mixture for producing heat energy in conventional equipment is feasible and beneficial for reduction emissions. (author)

  17. Evaluation of vapor compression cycles using nonazeotropic refrigerant mixtures

    Science.gov (United States)

    Merriam, Richard L.

    A comprehensive investigation is carried out, on a systematic and consistent basis, to explore a range of advanced heat pump cycle concepts using nonazeotropic refrigerants for COP enhancement and capacity modulation along with the trade-offs associated with refrigerant mixture selection. The objectives of the study were to: identify candidate nonazeotropic mixtures and advanced heat pump cycle concepts with emphasis on their potential for single-speed capacity modulation with mixture composition control; assess the effect of conjunction with nonazeotropic mixture cycles; evaluate the cycles analytically and recommend the most promising cycles and mixtures for further development; and provide recommendations relating to the needs for additional refrigerant property data, experimental studies of basic heat transfer phenomena with mixed refrigerants, development of system components, and/or more detailed modeling of specific components.

  18. Effects of Mixing on Hopper Sedimentation in Clearing Mixtures

    DEFF Research Database (Denmark)

    Hjelmager Jensen, Jacob; Saremi, Sina

    2015-01-01

    and settling in high-concentration mixtures were examined theoretically. Analytical solutions for clearance of excess concentrations were derived for the limiting cases of (1) still-water clearance and (2) clearance when the amount of turbulence is abundant. When examining these analytical solutions......Hopper sedimentation is the result of precipitation of typically fine sediment from a homogenous, high-concentration mixture, which is not completely deficient of turbulence. If hopper sedimentation or loading is accomplished through a single-inflow system, or if the irregularity of the inflow...... concentrations is pronounced or simply terminated, then the hopper mixture will clear. Whereas turbulent mixing is redundant, when the mixture is homogeneous, it may take an active role when the mixture is clearing. The role of turbulence on hopper sedimentation has been the focus of several studies...

  19. Quantitative measurement of mixtures by terahertz time-domain spectroscopy

    Indian Academy of Sciences (India)

    Guifeng Liu; Zengyan Zhang; Shihua Ma; Hongwei Zhao; Xiaojing Ma; Wenfeng Wang

    2009-07-01

    Terahertz time-domain spectroscopy (THz-TDS) was applied for quantitatively analysing a series of binary mixtures and a ternary mixture. Binary mixtures having different weight ratios of two components, -aminophenol and m-nitroaniline, were investigated by THz-TDS in the range of 0.3 to 1.5 THz, and it was found that the absorption coefficients of the components in each mixture were linearly proportional to their concentrations in the mixture. The results from analysis were in agreement with actual values with a relative error of less than 7%. The quantitative method will help in the detection of illegal drugs, poisons and dangerous materials that are wrapped or mixed with other materials.

  20. Amorphous-crystalline Ni-Fe powder mixture: Hydrogenation and annealing effects on microstructure and electrical and magnetic properties

    Directory of Open Access Journals (Sweden)

    Milinčić Radovan

    2016-01-01

    Full Text Available The hydrogenation of a crystalline Ni-Fe (80 wt.% Ni, 20 wt.% Fe powder mixture leads to the formation of a mixture of Face Centered Cubic (FCC-Ni and FCC-Fe phase nanocrystals embedded in an amorphous matrix. The magnetic susceptibility of the nanostructured powder is 2.1 times higher than that of the as-produced crystalline mixture. Heating in the temperature range 420-590 K causes structural relaxation in the hydrogenated powder, resulting in an increase of the magnetic susceptibility and a decrease of the electrical resistivity. During the heating procedure, the reorientation of magnetic domains in nickel and iron takes place in the temperature range 580-650 K and 790-850 K, respectively. In the pressed sample from the powder mixture, the crystallization of the amorphous phase of nickel and its FCC lattice crystalline grain growth occurs in the temperature range 620-873 K causing a decrease in the magnetic susceptibility of the nickel FCC phase and a sudden drop in the electrical resistivity. Prolonged heating of the mixed powders at 873K results in the formation of a Ni-Fe solid solution with higher magnetic susceptibility than the starting mixture. [Projekat Ministarstva nauke Republike Srbije, br. 172057

  1. Optimization of Eisenia fetida stocking density for the bioconversion of rock phosphate enriched cow dung-waste paper mixtures.

    Science.gov (United States)

    Unuofin, F O; Mnkeni, P N S

    2014-11-01

    Vermitechnology is gaining recognition as an environmental friendly waste management strategy. Its successful implementation requires that the key operational parameters like earthworm stocking density be established for each target waste/waste mixture. One target waste mixture in South Africa is waste paper mixed with cow dung and rock phosphate (RP) for P enrichment. This study sought to establish optimal Eisenia fetida stocking density for maximum P release and rapid bioconversion of RP enriched cow dung-paper waste mixtures. E. fetida stocking densities of 0, 7.5, 12.5, 17.5 and 22.5 g-worms kg(-1) dry weight of cow dung-waste paper mixtures were evaluated. The stocking density of 12.5 g-worms kg(-1) resulted in the highest earthworm growth rate and humification of the RP enriched waste mixture as reflected by a C:N ratio of 1.9 in final vermicomposts. A germination test revealed that the resultant vermicompost had no inhibitory effect on the germination of tomato, carrot, and radish. Extractable P increased with stocking density up to 22.5 g-worm kg(-1) feedstock suggesting that for maximum P release from RP enriched wastes a high stocking density should be considered. Copyright © 2014. Published by Elsevier Ltd.

  2. Utilization of phosphate rock from Lisina for direct application: release of plant nutrients in the exchange-fertilizer mixtures.

    Science.gov (United States)

    Mihajlović, Marija; Perišić, Nebojša; Pezo, Lato; Stojanović, Mirjana; Milojković, Jelena; Lopičić, Zorica; Petrović, Marija

    2014-10-15

    This study examined the possibility of direct application of phosphate rock (PR) from Lisina deposit, in a mixture with natural clinoptilolite (Cp) and clinoptilolite partially saturated with ammonium ions (NH4-Cp). Solution P concentrations of the NH4-Cp/PR mixtures were sufficient for plant growth and ranged from 0.36 to 0.82 mg L(-1). The median NH4-Cp/PR ratio and the longest proposed mixing time had the most positive impact on the P concentration. Solution Ca concentrations of the NH4-Cp/PR mixtures were between 112.5 and 700.5 mg L(-1), indicating that use of the proposed NH4-Cp/PR mixtures solves the potential lack of Ca(2+) in the solution, which is typical for substrates of similar composition. Selected artificial neural networks (ANNs) were able to predict experimental variables for a broad range of the process parameters all through assay. Manifold effects of small changes in composition of the mixtures and time on the observed concentrations of nutrients were shown using the sensitivity analysis.

  3. Stability of porridge pre-mixture made with Brazil nut flour and green banana flour with and without milk powder

    Directory of Open Access Journals (Sweden)

    Clarissa Reschke Da Cunha

    2014-09-01

    Full Text Available The mixture of Brazil nut flour and green banana flour can improve the nutritional value of school meals, allowing for the use of regional ingredients derived from family agriculture. This study aimed to assess the stability of porridge pre-mixtures made with Brazil nut flour and green banana flour during six months of storage. Two types of pre-mixture were evaluated: with and without milk powder. These mixtures were packed in polyethylene/metallized polyester film, vacuum-sealed, and stored at room temperature. The products were evaluated for physicochemical composition, and every 30 days for moisture content, water activity, titratable acidity, pH, peroxide value and acidity of the lipid phase, total and thermotolerant coliforms, yeasts and molds, and sensory acceptance. There was no difference between the mixtures for the parameters evaluated. Moisture content, water activity, acidity of the lipid phase, and the yeast and mold count increased with storage time. The growth of yeasts and molds was more pronounced after 90 days of storage, when water activity reached the limit of 0.60. Although both products had good sensory acceptance throughout the period of study, it is recommended that the shelf life does not exceed 90 days.

  4. Population growth and economic growth.

    Science.gov (United States)

    Narayana, D L

    1984-01-01

    This discussion of the issues relating to the problem posed by population explosion in the developing countries and economic growth in the contemporary world covers the following: predictions of economic and social trends; the Malthusian theory of population; the classical or stationary theory of population; the medical triage model; ecological disaster; the Global 2000 study; the limits to growth; critiques of the Limits to Growth model; nonrenewable resources; food and agriculture; population explosion and stabilization; space and ocean colonization; and the limits perspective. The Limits to Growth model, a general equilibrium anti-growth model, is the gloomiest economic model ever constructed. None of the doomsday models, the Malthusian theory, the classical stationary state, the neo-Malthusian medical triage model, the Global 2000 study, are so far reaching in their consequences. The course of events that followed the publication of the "Limits to Growth" in 1972 in the form of 2 oil shocks, food shock, pollution shock, and price shock seemed to bear out formally the gloomy predictions of the thesis with a remarkable speed. The 12 years of economic experience and the knowledge of resource trends postulate that even if the economic pressures visualized by the model are at work they are neither far reaching nor so drastic. Appropriate action can solve them. There are several limitations to the Limits to Growth model. The central theme of the model, which is overshoot and collapse, is unlikely to be the course of events. The model is too aggregative to be realistic. It exaggerates the ecological disaster arising out of the exponential growth of population and industry. The gross underestimation of renewable resources is a basic flaw of the model. The most critical weakness of the model is its gross underestimation of the historical trend of technological progress and the technological possiblities within industry and agriculture. The model does correctly emphasize

  5. IGNITION IMPROVEMENT OF LEAN NATURAL GAS MIXTURES

    Energy Technology Data Exchange (ETDEWEB)

    Jason M. Keith

    2005-02-01

    This report describes work performed during a thirty month project which involves the production of dimethyl ether (DME) on-site for use as an ignition-improving additive in a compression-ignition natural gas engine. A single cylinder spark ignition engine was converted to compression ignition operation. The engine was then fully instrumented with a cylinder pressure transducer, crank shaft position sensor, airflow meter, natural gas mass flow sensor, and an exhaust temperature sensor. Finally, the engine was interfaced with a control system for pilot injection of DME. The engine testing is currently in progress. In addition, a one-pass process to form DME from natural gas was simulated with chemical processing software. Natural gas is reformed to synthesis gas (a mixture of hydrogen and carbon monoxide), converted into methanol, and finally to DME in three steps. Of additional benefit to the internal combustion engine, the offgas from the pilot process can be mixed with the main natural gas charge and is expected to improve engine performance. Furthermore, a one-pass pilot facility was constructed to produce 3.7 liters/hour (0.98 gallons/hour) DME from methanol in order to characterize the effluent DME solution and determine suitability for engine use. Successful production of DME led to an economic estimate of completing a full natural gas-to-DME pilot process. Additional experimental work in constructing a synthesis gas to methanol reactor is in progress. The overall recommendation from this work is that natural gas to DME is not a suitable pathway to improved natural gas engine performance. The major reasons are difficulties in handling DME for pilot injection and the large capital costs associated with DME production from natural gas.

  6. Mixtures of multiplicative cascade models in geochemistry

    Directory of Open Access Journals (Sweden)

    F. P. Agterberg

    2007-05-01

    Full Text Available Multifractal modeling of geochemical map data can help to explain the nature of frequency distributions of element concentration values for small rock samples and their spatial covariance structure. Useful frequency distribution models are the lognormal and Pareto distributions which plot as straight lines on logarithmic probability and log-log paper, respectively. The model of de Wijs is a simple multiplicative cascade resulting in discrete logbinomial distribution that closely approximates the lognormal. In this model, smaller blocks resulting from dividing larger blocks into parts have concentration values with constant ratios that are scale-independent. The approach can be modified by adopting random variables for these ratios. Other modifications include a single cascade model with ratio parameters that depend on magnitude of concentration value. The Turcotte model, which is another variant of the model of de Wijs, results in a Pareto distribution. Often a single straight line on logarithmic probability or log-log paper does not provide a good fit to observed data and two or more distributions should be fitted. For example, geochemical background and anomalies (extremely high values have separate frequency distributions for concentration values and for local singularity coefficients. Mixtures of distributions can be simulated by adding the results of separate cascade models. Regardless of properties of background, an unbiased estimate can be obtained of the parameter of the Pareto distribution characterizing anomalies in the upper tail of the element concentration frequency distribution or lower tail of the local singularity distribution. Computer simulation experiments and practical examples are used to illustrate the approach.

  7. Separating Dust Mixtures and Other External Aerosol Mixtures Using Airborne High Spectral Resolution Lidar Data

    Science.gov (United States)

    Burton, S. P.; Ferrare, R. A.; Vaughan, M.; Hostetler, C. A.; Rogers, R. R.; Hair, J. W.; Cook, A. L.; Harper, D. B.

    2013-12-01

    Knowledge of aerosol type is important for source attribution and for determining the magnitude and assessing the consequences of aerosol radiative forcing. The NASA Langley Research Center airborne High Spectral Resolution Lidar (HSRL-1) has acquired considerable datasets of both aerosol extensive parameters (e.g. aerosol optical depth) and intensive parameters (e.g. aerosol depolarization ratio, lidar ratio) that can be used to infer aerosol type. An aerosol classification methodology has been used extensively to classify HSRL-1 aerosol measurements of different aerosol types including dust, smoke, urban pollution, and marine aerosol. However, atmospheric aerosol is frequently not a single pure type, but instead occurs as a mixture of types, and this mixing affects the optical and radiative properties of the aerosol. Here we present a comprehensive and unified set of rules for characterizing external mixtures using several key aerosol intensive parameters: extinction-to-backscatter ratio (i.e. lidar ratio), backscatter color ratio, and depolarization ratio. Our mixing rules apply not just to the scalar values of aerosol intensive parameters, but to multi-dimensional normal distributions with variance in each measurement dimension. We illustrate the applicability of the mixing rules using examples of HSRL-1 data where mixing occurred between different aerosol types, including advected Saharan dust mixed with the marine boundary layer in the Caribbean Sea and locally generated dust mixed with urban pollution in the Mexico City surroundings. For each of these cases we infer a time-height cross section of mixing ratio along the flight track and we partition aerosol extinction into portions attributed to the two pure types. Since multiple aerosol intensive parameters are measured and included in these calculations, the techniques can also be used for cases without significant depolarization (unlike similar work by earlier researchers), and so a third example of a

  8. Integral Parameters for Characterizing Water, Energy, and Aeration Properties of Soilless Plant Growth Media

    DEFF Research Database (Denmark)

    Deepagoda Thuduwe Kankanamge Kelum, Chamindu; Lopez, Jose Choc Chen; Møldrup, Per

    2013-01-01

    systems are regaining increased worldwide attention. The optimal control of water availability and aeration is an essential prerequisite to successfully operate plant growth systems with soilless substrates such as aggregated foamed glass, perlite, rockwool, coconut coir, or mixtures thereof. While...

  9. Effects of dietary mixture of garlic (Allium sativum), coriander (Coriandrum sativum) and probiotics on immune responses and caecal counts in young laying hens.

    Science.gov (United States)

    Lee, J S; Kim, M J; Park, S H; Lee, S B; Wang, T; Jung, U S; Im, J; Kim, E J; Lee, K W; Lee, H G

    2016-09-28

    This study was conducted to evaluate the effects of a combined mixture of phytogenic extracts (garlic and coriander) and probiotics on growth performance and immune responses in laying hens based on the results of in vitro studies to screen for immunomodulatory potency of each ingredient. Several parameters of immunomodulatory potency were estimated using lamina propria leucocytes (LPLs) isolated from rat intestinal mucosa tissue. Results show that the combined mixture enhanced LPLs proliferation, increased LPL-mediated cytotoxicity against YAC-1 tumour cells, and decreased lipopolysaccharide (LPS)-induced cytokine production including tumour necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) in LPLs. For in vivo study, laying hens (n = 50/each diet group) were fed with control diet, a diet containing antibiotics (0.01% per kg feed) or the combined mixture (0.02% per kg feed) for 21 days. The dietary combined mixture improved egg production (p < 0.05) but not growth performance and carcass traits. Interestingly, the patterns of suppressing plasma IFN-γ productions during inflammation by LPS injection and decreasing caecal E. coli counts in the combined mixture group were comparable to those in the antibiotics group. Taken together, our results suggested that the 0.02% of combined mixture of phytogenic extracts and probiotics as ingredients has potential immunomodulatory effects in laying hens.

  10. Dynamic self-organization of microwell-aggregated cellular mixtures.

    Science.gov (United States)

    Song, Wei; Tung, Chih-Kuan; Lu, Yen-Chun; Pardo, Yehudah; Wu, Mingming; Das, Moumita; Kao, Der-I; Chen, Shuibing; Ma, Minglin

    2016-06-29

    Cells with different cohesive properties self-assemble in a spatiotemporal and context-dependent manner. Previous studies on cell self-organization mainly focused on the spontaneous structural development within a short period of time during which the cell numbers remained constant. However the effect of cell proliferation over time on the self-organization of cells is largely unexplored. Here, we studied the spatiotemporal dynamics of self-organization of a co-culture of MDA-MB-231 and MCF10A cells seeded in a well defined space (i.e. non-adherent microfabricated wells). When cell-growth was chemically inhibited, high cohesive MCF10A cells formed a core surrounded by low cohesive MDA-MB-231 cells on the periphery, consistent with the differential adhesion hypothesis (DAH). Interestingly, this aggregate morphology was completely inverted when the cells were free to grow. At an initial seeding ratio of 1 : 1 (MDA-MB-231 : MCF10A), the fast growing MCF10A cells segregated in the periphery while the slow growing MDA-MB-231 cells stayed in the core. Another morphology developed at an inequal seeding ratio (4 : 1), that is, the cell mixtures developed a side-by-side aggregate morphology. We conclude that the cell self-organization depends not only on the cell cohesive properties but also on the cell seeding ratio and proliferation. Furthermore, by taking advantage of the cell self-organization, we purified human embryonic stem cells-derived pancreatic progenitors (hESCs-PPs) from co-cultured feeder cells without using any additional tools or labels.

  11. Thermal conductivity measurements in Porous mixtures of methane hydrate and quartz sand

    Science.gov (United States)

    Waite, W.F.; deMartin, B.J.; Kirby, S.H.; Pinkston, J.; Ruppel, C.D.

    2002-01-01

    Using von Herzen and Maxwell's needle probe method, we measured thermal conductivity in four porous mixtures of quartz sand and methane gas hydrate, with hydrate composing 0, 33, 67 and 100% of the solid volume. Thermal conductivities were measured at a constant methane pore pressure of 24.8 MPa between -20 and +15??C, and at a constant temperature of -10??C between 3.5 and 27.6 MPa methane pore pressure. Thermal conductivity decreased with increasing temperature and increased with increasing methane pore pressure. Both dependencies weakened with increasing hydrate content. Despite the high thermal conductivity of quartz relative to methane hydrate, the largest thermal conductivity was measured in the mixture containing 33% hydrate rather than in hydrate-free sand. This suggests gas hydrate enhanced grain-to-grain heat transfer, perhaps due to intergranular contact growth during hydrate synthesis. These results for gas-filled porous mixtures can help constrain thermal conductivity estimates in porous, gas hydrate-bearing systems.

  12. Study on the recovery of hydrogen from refinery (hydrogen+methane) gas mixtures using hydrate technology

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A novel technique for separating hydrogen from (H2 + CH4) gas mixtures through hydrate formation/dissociation was proposed. In this work, a systematic experimental study was performed on the separation of hydrogen from (H2 + CH4) feed mixtures with various hydrogen contents (mole fraction x = 40%-90%). The experimental results showed that the hydrogen content could be enriched to as high as ~94% for various feed mixtures using the proposed hydrate technology under a temperature slightly above 0℃ and a pressure below 5.0 MPa. With the addition of a small amount of suitable additives, the rate of hydrate formation could be increased significantly. Anti-agglomeration was used to disperse hydrate particles into the condensate phase. Instead of preventing hydrate growth (as in the kinetic inhibitor tests), hydrates were allowed to form, but only as small dispersed particles. Anti-agglomeration could keep hydrate particles suspended in a range of condensate types at 1℃ and 5 MPa in the water-in-oil emulsion.

  13. Study on the recovery of hydrogen from refinery (hydrogen + methane) gas mixtures using hydrate technology

    Institute of Scientific and Technical Information of China (English)

    WANG XiuLin; CHEN GuangJin; YANG LanYing; ZHANG LinWei

    2008-01-01

    A novel technique for separating hydrogen from (H2 + CH4) gas mixtures through hydrate forma-tion/dissociation was proposed.In this work, a systematic experimental study was performed on the separation of hydrogen from (H2+CH4) feed mixtures with various hydrogen contents (mole fraction x =40%-90%).The experimental results showed that the hydrogen content could be enriched to as high as~94% for various feed mixtures using the proposed hydrate technology under a temperature slightly above 0℃ and a pressure below 5.0 MPa.With the addition of a small amount of suitable additives, the rate of hydrate formation could be increased significantly.Anti-agglomeration was used to disperse hydrate particles into the condensate phase.Instead of preventing hydrate growth (as in the kinetic inhibitor tests), hydrates were allowed to form, but only as small dispersed particles.Anti-agglomera-tion could keep hydrate particles suspended in a range of condensate types at 1℃ and 5 MPa in the water-in-oil emulsion.

  14. Effects of a Lactobacillus salivarius mixture on performance, intestinal health and serum lipids of broiler chickens.

    Science.gov (United States)

    Shokryazdan, Parisa; Faseleh Jahromi, Mohammad; Liang, Juan Boo; Ramasamy, Kalavathy; Sieo, Chin Chin; Ho, Yin Wan

    2017-01-01

    The ban or severe restriction on the use of antibiotics in poultry feeds to promote growth has led to considerable interest to find alternative approaches. Probiotics have been considered as such alternatives. In the present study, the effects of a Lactobacillus mixture composed from three previously isolated Lactobacillus salivarius strains (CI1, CI2 and CI3) from chicken intestines on performance, intestinal health status and serum lipids of broiler chickens has been evaluated. Supplementation of the mixture at a concentration of 0.5 or 1 g kg-1 of diet to broilers for 42 days improved body weight, body weight gain and FCR, reduced total cholesterol, LDL-cholesterol and triglycerides, increased populations of beneficial bacteria such as lactobacilli and bifidobacteria, decreased harmful bacteria such as E. coli and total aerobes, reduced harmful cecal bacterial enzymes such as β-glucosidase and β-glucuronidase, and improved intestinal histomorphology of broilers. Because of its remarkable efficacy on broiler chickens, the L. salivarius mixture could be considered as a good potential probiotic for chickens, and its benefits should be further evaluated on a commercial scale.

  15. Diamond growth in mantle fluids

    Science.gov (United States)

    Bureau, Hélène; Frost, Daniel J.; Bolfan-Casanova, Nathalie; Leroy, Clémence; Esteve, Imène; Cordier, Patrick

    2016-11-01

    In the upper mantle, diamonds can potentially grow from various forms of media (solid, gas, fluid) with a range of compositions (e.g. graphite, C-O-H fluids, silicate or carbonate melts). Inclusions trapped in diamonds are one of the few diagnostic tools that can constrain diamond growth conditions in the Earth's mantle. In this study, inclusion-bearing diamonds have been synthesized to understand the growth conditions of natural diamonds in the upper mantle. Diamonds containing syngenetic inclusions were synthesized in multi-anvil presses employing starting mixtures of carbonates, and silicate compositions in the presence of pure water and saline fluids (H2O-NaCl). Experiments were performed at conditions compatible with the Earth's geotherm (7 GPa, 1300-1400 °C). Results show that within the timescale of the experiments (6 to 30 h) diamond growth occurs if water and carbonates are present in the fluid phase. Water promotes faster diamond growth (up to 14 mm/year at 1400 °C, 7 GPa, 10 g/l NaCl), which is favorable to the inclusion trapping process. At 7 GPa, temperature and fluid composition are the main factors controlling diamond growth. In these experiments, diamonds grew in the presence of two fluids: an aqueous fluid and a hydrous silicate melt. The carbon source for diamond growth must be carbonate (CO32) dissolved in the melt or carbon dioxide species in the aqueous fluid (CO2aq). The presence of NaCl affects the growth kinetics but is not a prerequisite for inclusion-bearing diamond formation. The presence of small discrete or isolated volumes of water-rich fluids is necessary to grow inclusion-bearing peridotitic, eclogitic, fibrous, cloudy and coated diamonds, and may also be involved in the growth of ultradeep, ultrahigh-pressure metamorphic diamonds.

  16. The impact of social policy on changes in professional practice within learning disability services: different standards for children and adults? A two-part examination: part 2. Professional services under the coalition: the trends continue apace.

    Science.gov (United States)

    Race, David G; Malin, Nigel A

    2011-12-01

    This is the second of two articles examining links between policy developments and changes in professional practice within learning disability services in England. The first article focused on policy foundations over the last 30 years, and concluded that there was a developing gap in professional inputs between children's and adult services. This article, written one year into the Coalition government, argues that its policies--especially the large-scale reduction in public expenditure, but also the decline in support for inclusion of children in mainstream education, the rapid growth of academies, and proposals for the reorganization of the NHS--have exacerbated the trends identified earlier. In addition, local authorities, though outwardly compliant, have variously interpreted their responsibilities under the personalization agenda, in particular in relation to individual budgets, and this has resulted in assessments of need being based on 'service hours' rather than service quality and staff qualifications.

  17. An analysis of lethal and sublethal interactions among type I and type II pyrethroid pesticide mixtures using standard Hyalella azteca water column toxicity tests.

    Science.gov (United States)

    Hoffmann, Krista Callinan; Deanovic, Linda; Werner, Inge; Stillway, Marie; Fong, Stephanie; Teh, Swee

    2016-10-01

    A novel 2-tiered analytical approach was used to characterize and quantify interactions between type I and type II pyrethroids in Hyalella azteca using standardized water column toxicity tests. Bifenthrin, permethrin, cyfluthrin, and lambda-cyhalothrin were tested in all possible binary combinations across 6 experiments. All mixtures were analyzed for 4-d lethality, and 2 of the 6 mixtures (permethrin-bifenthrin and permethrin-cyfluthrin) were tested for subchronic 10-d lethality and sublethal effects on swimming motility and growth. Mixtures were initially analyzed for interactions using regression analyses, and subsequently compared with the additive models of concentration addition and independent action to further characterize mixture responses. Negative interactions (antagonistic) were significant in 2 of the 6 mixtures tested, including cyfluthrin-bifenthrin and cyfluthrin-permethrin, but only on the acute 4-d lethality endpoint. In both cases mixture responses fell between the additive models of concentration addition and independent action. All other mixtures were additive across 4-d lethality, and bifenthrin-permethrin and cyfluthrin-permethrin were also additive in terms of subchronic 10-d lethality and sublethal responses. Environ Toxicol Chem 2016;35:2542-2549. © 2016 SETAC.

  18. Effect of a sport drink mixture with and without addition of fluoride and magnesium on plaque formation, dental caries and general health of rats.

    Science.gov (United States)

    Sorvari, R; Koskinen-Kainulainen, M; Sorvari, T; Luoma, H

    1986-12-01

    A sport drink mixture (pH 3.2) containing 6% sucrose was given to Osborne-Mendel rats for 42 days. In some experimental groups the drink was supplemented with 15 ppm F, 38.5 ppm Mg or both F and Mg. The rats were fed a slightly cariogenic powdered diet containing 15% sucrose. Sport drink mixture increased significantly the accumulation of plaque but, compared with a group that drank distilled water, did not affect caries. Addition of fluoride to the sport drink mixture, alone or with magnesium, significantly reduced caries and tended to decrease plaque; addition of magnesium had no clear effect on plaque or caries. In spite of the fact that the rats had a sport drink mixture as the only drink for 6 wk, there were no untoward effects on growth, in histological studies of the inner organs, or in Ca, Mg, Na and K contents of kidney, heart and aorta.

  19. Contrasting effects of intraspecific trait variation on trait-based niches and performance of legumes in plant mixtures.

    Directory of Open Access Journals (Sweden)

    Christiane Roscher

    Full Text Available Niche differentiation, assumed to be a key mechanism of species coexistence, requires that species differ in their functional traits. So far it remains unclear to which extent trait plasticity leads to niche shifts of species at higher plant diversity, thereby increasing or decreasing niche overlap between species. To analyse this question it is convenient to measure niches indirectly via the variation in resource-uptake traits rather than directly via the resources used. We provisionally call these indirectly measured niches trait-based niches. We studied shoot- and leaf-morphological characteristics in seven legume species in monoculture and multi-species mixture in experimental grassland. Legume species varied in the extent of trait variation in response to plant diversity. Trait plasticity led to significant shifts in species niches in multiple dimensions. Single-species niches in several traits associated with height growth and filling of canopy space were expanded, while other niche dimensions were compressed or did not change with plant diversity. Niche separation among legumes decreased in dimensions related to height growth and space filling, but increased in dimensions related to leaf size and morphology. The total extent of occupied niche space was larger in mixture than in the combined monocultures for dimensions related to leaf morphology and smaller for dimensions related to whole-plant architecture. Taller growth, greater space filling and greater plasticity in shoot height were positively, while larger values and greater plasticity in specific leaf area were negatively related with increased performance of species in mixture. Our study shows that trait variation in response to plant diversity shifts species niches along trait axes. Plastically increased niche differentiation is restricted to niche dimensions that are apparently not related to size-dependent differences between species, but functional equivalence (convergence in

  20. Contrasting effects of intraspecific trait variation on trait-based niches and performance of legumes in plant mixtures.

    Science.gov (United States)

    Roscher, Christiane; Schumacher, Jens; Schmid, Bernhard; Schulze, Ernst-Detlef

    2015-01-01

    Niche differentiation, assumed to be a key mechanism of species coexistence, requires that species differ in their functional traits. So far it remains unclear to which extent trait plasticity leads to niche shifts of species at higher plant diversity, thereby increasing or decreasing niche overlap between species. To analyse this question it is convenient to measure niches indirectly via the variation in resource-uptake traits rather than directly via the resources used. We provisionally call these indirectly measured niches trait-based niches. We studied shoot- and leaf-morphological characteristics in seven legume species in monoculture and multi-species mixture in experimental grassland. Legume species varied in the extent of trait variation in response to plant diversity. Trait plasticity led to significant shifts in species niches in multiple dimensions. Single-species niches in several traits associated with height growth and filling of canopy space were expanded, while other niche dimensions were compressed or did not change with plant diversity. Niche separation among legumes decreased in dimensions related to height growth and space filling, but increased in dimensions related to leaf size and morphology. The total extent of occupied niche space was larger in mixture than in the combined monocultures for dimensions related to leaf morphology and smaller for dimensions related to whole-plant architecture. Taller growth, greater space filling and greater plasticity in shoot height were positively, while larger values and greater plasticity in specific leaf area were negatively related with increased performance of species in mixture. Our study shows that trait variation in response to plant diversity shifts species niches along trait axes. Plastically increased niche differentiation is restricted to niche dimensions that are apparently not related to size-dependent differences between species, but functional equivalence (convergence in height growth) rather