WorldWideScience

Sample records for maximum enstrophy growth

  1. An enstrophy-based linear and nonlinear receptivity theory

    Science.gov (United States)

    Sengupta, Aditi; Suman, V. K.; Sengupta, Tapan K.; Bhaumik, Swagata

    2018-05-01

    In the present research, a new theory of instability based on enstrophy is presented for incompressible flows. Explaining instability through enstrophy is counter-intuitive, as it has been usually associated with dissipation for the Navier-Stokes equation (NSE). This developed theory is valid for both linear and nonlinear stages of disturbance growth. A previously developed nonlinear theory of incompressible flow instability based on total mechanical energy described in the work of Sengupta et al. ["Vortex-induced instability of an incompressible wall-bounded shear layer," J. Fluid Mech. 493, 277-286 (2003)] is used to compare with the present enstrophy based theory. The developed equations for disturbance enstrophy and disturbance mechanical energy are derived from NSE without any simplifying assumptions, as compared to other classical linear/nonlinear theories. The theory is tested for bypass transition caused by free stream convecting vortex over a zero pressure gradient boundary layer. We explain the creation of smaller scales in the flow by a cascade of enstrophy, which creates rotationality, in general inhomogeneous flows. Linear and nonlinear versions of the theory help explain the vortex-induced instability problem under consideration.

  2. Enstrophy generation in a shock-dominated turbulence

    International Nuclear Information System (INIS)

    Miura, Hideaki.

    1995-09-01

    A mechanism of enstrophy generation is investigated numerically in a shock-dominated turbulence driven by a random external force which has only the compressible component. Enstrophy is generated, especially on collision of shock, as a pair of vortex tube of opposite sense of rotation behind curved shocks. The roles of various terms in enstrophy equation are clarified in enstrophy generation process. Generation of enstrophy is enhanced by strong alignment of each term of the enstrophy equation with the vorticity vector. (author)

  3. Similarity Decay of Enstrophy in an Electron Fluid

    International Nuclear Information System (INIS)

    Rodgers, D. J.; Matthaeus, W. H.; Mitchell, T. B.; Montgomery, D. C.

    2010-01-01

    A similarity decay law is proposed for enstrophy of a one-signed-vorticity fluid in a circular free-slip domain. It excludes the metastable equilibrium enstrophy which cannot drive turbulence, and approaches Batchelor's t -2 law for strong turbulence. Measurements of the decay of a turbulent electron fluid agree well with the predictions of the decay law for a variety of initial conditions.

  4. Enstrophy transport conditional on local flow topologies in different regimes of premixed turbulent combustion

    KAUST Repository

    Papapostolou, Vassilios

    2017-09-11

    Enstrophy is an intrinsic feature of turbulent flows, and its transport properties are essential for the understanding of premixed flame-turbulence interaction. The interrelation between the enstrophy transport and flow topologies, which can be assigned to eight categories based on the three invariants of the velocity-gradient tensor, has been analysed here. The enstrophy transport conditional on flow topologies in turbulent premixed flames has been analysed using a Direct Numerical Simulation database representing the corrugated flamelets (CF), thin reaction zones (TRZ) and broken reaction zones (BRZ) combustion regimes. The flame in the CF regime exhibits considerable flame-generated enstrophy, and the dilatation rate and baroclinic torque contributions to the enstrophy transport act as leading order sink and source terms, respectively. Consequently, flow topologies associated with positive dilatation rate values, contribute significantly to the enstrophy transport in the CF regime. By contrast, enstrophy decreases from the unburned to the burned gas side for the cases representing the TRZ and BRZ regimes, with diminishing influences of dilatation rate and baroclinic torque. The enstrophy transport in the TRZ and BRZ regimes is governed by the vortex-stretching and viscous dissipation contributions, similar to non-reacting flows, and topologies existing for all values of dilatation rate remain significant contributors.

  5. Enstrophy transport conditional on local flow topologies in different regimes of premixed turbulent combustion

    KAUST Repository

    Papapostolou, Vassilios; Wacks, Daniel H.; Chakraborty, Nilanjan; Klein, Markus; Im, Hong G.

    2017-01-01

    , enstrophy decreases from the unburned to the burned gas side for the cases representing the TRZ and BRZ regimes, with diminishing influences of dilatation rate and baroclinic torque. The enstrophy transport in the TRZ and BRZ regimes is governed

  6. Conservation laws of wave action and potential enstrophy for Rossby waves in a stratified atmosphere

    Science.gov (United States)

    Straus, D. M.

    1983-01-01

    The evolution of wave energy, enstrophy, and wave motion for atmospheric Rossby waves in a variable mean flow are discussed from a theoretical and pedagogic standpoint. In the absence of mean flow gradients, the wave energy density satisfies a local conservation law, with the appropriate flow velocity being the group velocity. In the presence of mean flow variations, wave energy is not conserved, but wave action is, provided the mean flow is independent of longitude. Wave enstrophy is conserved for arbitrary variations of the mean flow. Connections with Eliassen-Palm flux are also discussed.

  7. Geometry and scaling laws of excursion and iso-sets of enstrophy and dissipation in isotropic turbulence

    Science.gov (United States)

    Elsas, José Hugo; Szalay, Alexander S.; Meneveau, Charles

    2018-04-01

    Motivated by interest in the geometry of high intensity events of turbulent flows, we examine the spatial correlation functions of sets where turbulent events are particularly intense. These sets are defined using indicator functions on excursion and iso-value sets. Their geometric scaling properties are analysed by examining possible power-law decay of their radial correlation function. We apply the analysis to enstrophy, dissipation and velocity gradient invariants Q and R and their joint spatial distributions, using data from a direct numerical simulation of isotropic turbulence at Reλ ≈ 430. While no fractal scaling is found in the inertial range using box-counting in the finite Reynolds number flow considered here, power-law scaling in the inertial range is found in the radial correlation functions. Thus, a geometric characterisation in terms of these sets' correlation dimension is possible. Strong dependence on the enstrophy and dissipation threshold is found, consistent with multifractal behaviour. Nevertheless, the lack of scaling of the box-counting analysis precludes direct quantitative comparisons with earlier work based on multifractal formalism. Surprising trends, such as a lower correlation dimension for strong dissipation events compared to strong enstrophy events, are observed and interpreted in terms of spatial coherence of vortices in the flow.

  8. Total energy and potential enstrophy conserving schemes for the shallow water equations using Hamiltonian methods - Part 1: Derivation and properties

    Science.gov (United States)

    Eldred, Christopher; Randall, David

    2017-02-01

    The shallow water equations provide a useful analogue of the fully compressible Euler equations since they have similar characteristics: conservation laws, inertia-gravity and Rossby waves, and a (quasi-) balanced state. In order to obtain realistic simulation results, it is desirable that numerical models have discrete analogues of these properties. Two prototypical examples of such schemes are the 1981 Arakawa and Lamb (AL81) C-grid total energy and potential enstrophy conserving scheme, and the 2007 Salmon (S07) Z-grid total energy and potential enstrophy conserving scheme. Unfortunately, the AL81 scheme is restricted to logically square, orthogonal grids, and the S07 scheme is restricted to uniform square grids. The current work extends the AL81 scheme to arbitrary non-orthogonal polygonal grids and the S07 scheme to arbitrary orthogonal spherical polygonal grids in a manner that allows for both total energy and potential enstrophy conservation, by combining Hamiltonian methods (work done by Salmon, Gassmann, Dubos, and others) and discrete exterior calculus (Thuburn, Cotter, Dubos, Ringler, Skamarock, Klemp, and others). Detailed results of the schemes applied to standard test cases are deferred to part 2 of this series of papers.

  9. Tsallis Extended Thermodynamics Applied to 2-d Turbulence: Lévy Statistics and q-Fractional Generalized Kraichnanian Energy and Enstrophy Spectra

    Directory of Open Access Journals (Sweden)

    Peter W. Egolf

    2018-02-01

    Full Text Available The extended thermodynamics of Tsallis is reviewed in detail and applied to turbulence. It is based on a generalization of the exponential and logarithmic functions with a parameter q. By applying this nonequilibrium thermodynamics, the Boltzmann-Gibbs thermodynamic approach of Kraichnan to 2-d turbulence is generalized. This physical modeling implies fractional calculus methods, obeying anomalous diffusion, described by Lévy statistics with q < 5/3 (sub diffusion, q = 5/3 (normal or Brownian diffusion and q > 5/3 (super diffusion. The generalized energy spectrum of Kraichnan, occurring at small wave numbers k, now reveals the more general and precise result k−q. This corresponds well for q = 5/3 with the Kolmogorov-Oboukov energy spectrum and for q > 5/3 to turbulence with intermittency. The enstrophy spectrum, occurring at large wave numbers k, leads to a k−3q power law, suggesting that large wave-number eddies are in thermodynamic equilibrium, which is characterized by q = 1, finally resulting in Kraichnan’s correct k−3 enstrophy spectrum. The theory reveals in a natural manner a generalized temperature of turbulence, which in the non-equilibrium energy transfer domain decreases with wave number and shows an energy equipartition law with a constant generalized temperature in the equilibrium enstrophy transfer domain. The article contains numerous new results; some are stated in form of eight new (proven propositions.

  10. Allometries of Maximum Growth Rate versus Body Mass at Maximum Growth Indicate That Non-Avian Dinosaurs Had Growth Rates Typical of Fast Growing Ectothermic Sauropsids

    Science.gov (United States)

    Werner, Jan; Griebeler, Eva Maria

    2014-01-01

    We tested if growth rates of recent taxa are unequivocally separated between endotherms and ectotherms, and compared these to dinosaurian growth rates. We therefore performed linear regression analyses on the log-transformed maximum growth rate against log-transformed body mass at maximum growth for extant altricial birds, precocial birds, eutherians, marsupials, reptiles, fishes and dinosaurs. Regression models of precocial birds (and fishes) strongly differed from Case’s study (1978), which is often used to compare dinosaurian growth rates to those of extant vertebrates. For all taxonomic groups, the slope of 0.75 expected from the Metabolic Theory of Ecology was statistically supported. To compare growth rates between taxonomic groups we therefore used regressions with this fixed slope and group-specific intercepts. On average, maximum growth rates of ectotherms were about 10 (reptiles) to 20 (fishes) times (in comparison to mammals) or even 45 (reptiles) to 100 (fishes) times (in comparison to birds) lower than in endotherms. While on average all taxa were clearly separated from each other, individual growth rates overlapped between several taxa and even between endotherms and ectotherms. Dinosaurs had growth rates intermediate between similar sized/scaled-up reptiles and mammals, but a much lower rate than scaled-up birds. All dinosaurian growth rates were within the range of extant reptiles and mammals, and were lower than those of birds. Under the assumption that growth rate and metabolic rate are indeed linked, our results suggest two alternative interpretations. Compared to other sauropsids, the growth rates of studied dinosaurs clearly indicate that they had an ectothermic rather than an endothermic metabolic rate. Compared to other vertebrate growth rates, the overall high variability in growth rates of extant groups and the high overlap between individual growth rates of endothermic and ectothermic extant species make it impossible to rule out either

  11. Allometries of maximum growth rate versus body mass at maximum growth indicate that non-avian dinosaurs had growth rates typical of fast growing ectothermic sauropsids.

    Science.gov (United States)

    Werner, Jan; Griebeler, Eva Maria

    2014-01-01

    We tested if growth rates of recent taxa are unequivocally separated between endotherms and ectotherms, and compared these to dinosaurian growth rates. We therefore performed linear regression analyses on the log-transformed maximum growth rate against log-transformed body mass at maximum growth for extant altricial birds, precocial birds, eutherians, marsupials, reptiles, fishes and dinosaurs. Regression models of precocial birds (and fishes) strongly differed from Case's study (1978), which is often used to compare dinosaurian growth rates to those of extant vertebrates. For all taxonomic groups, the slope of 0.75 expected from the Metabolic Theory of Ecology was statistically supported. To compare growth rates between taxonomic groups we therefore used regressions with this fixed slope and group-specific intercepts. On average, maximum growth rates of ectotherms were about 10 (reptiles) to 20 (fishes) times (in comparison to mammals) or even 45 (reptiles) to 100 (fishes) times (in comparison to birds) lower than in endotherms. While on average all taxa were clearly separated from each other, individual growth rates overlapped between several taxa and even between endotherms and ectotherms. Dinosaurs had growth rates intermediate between similar sized/scaled-up reptiles and mammals, but a much lower rate than scaled-up birds. All dinosaurian growth rates were within the range of extant reptiles and mammals, and were lower than those of birds. Under the assumption that growth rate and metabolic rate are indeed linked, our results suggest two alternative interpretations. Compared to other sauropsids, the growth rates of studied dinosaurs clearly indicate that they had an ectothermic rather than an endothermic metabolic rate. Compared to other vertebrate growth rates, the overall high variability in growth rates of extant groups and the high overlap between individual growth rates of endothermic and ectothermic extant species make it impossible to rule out either of

  12. Allometries of maximum growth rate versus body mass at maximum growth indicate that non-avian dinosaurs had growth rates typical of fast growing ectothermic sauropsids.

    Directory of Open Access Journals (Sweden)

    Jan Werner

    Full Text Available We tested if growth rates of recent taxa are unequivocally separated between endotherms and ectotherms, and compared these to dinosaurian growth rates. We therefore performed linear regression analyses on the log-transformed maximum growth rate against log-transformed body mass at maximum growth for extant altricial birds, precocial birds, eutherians, marsupials, reptiles, fishes and dinosaurs. Regression models of precocial birds (and fishes strongly differed from Case's study (1978, which is often used to compare dinosaurian growth rates to those of extant vertebrates. For all taxonomic groups, the slope of 0.75 expected from the Metabolic Theory of Ecology was statistically supported. To compare growth rates between taxonomic groups we therefore used regressions with this fixed slope and group-specific intercepts. On average, maximum growth rates of ectotherms were about 10 (reptiles to 20 (fishes times (in comparison to mammals or even 45 (reptiles to 100 (fishes times (in comparison to birds lower than in endotherms. While on average all taxa were clearly separated from each other, individual growth rates overlapped between several taxa and even between endotherms and ectotherms. Dinosaurs had growth rates intermediate between similar sized/scaled-up reptiles and mammals, but a much lower rate than scaled-up birds. All dinosaurian growth rates were within the range of extant reptiles and mammals, and were lower than those of birds. Under the assumption that growth rate and metabolic rate are indeed linked, our results suggest two alternative interpretations. Compared to other sauropsids, the growth rates of studied dinosaurs clearly indicate that they had an ectothermic rather than an endothermic metabolic rate. Compared to other vertebrate growth rates, the overall high variability in growth rates of extant groups and the high overlap between individual growth rates of endothermic and ectothermic extant species make it impossible to rule

  13. Dinosaur Metabolism and the Allometry of Maximum Growth Rate

    OpenAIRE

    Myhrvold, Nathan P.

    2016-01-01

    The allometry of maximum somatic growth rate has been used in prior studies to classify the metabolic state of both extant vertebrates and dinosaurs. The most recent such studies are reviewed, and their data is reanalyzed. The results of allometric regressions on growth rate are shown to depend on the choice of independent variable; the typical choice used in prior studies introduces a geometric shear transformation that exaggerates the statistical power of the regressions. The maximum growth...

  14. Dinosaur Metabolism and the Allometry of Maximum Growth Rate.

    Science.gov (United States)

    Myhrvold, Nathan P

    2016-01-01

    The allometry of maximum somatic growth rate has been used in prior studies to classify the metabolic state of both extant vertebrates and dinosaurs. The most recent such studies are reviewed, and their data is reanalyzed. The results of allometric regressions on growth rate are shown to depend on the choice of independent variable; the typical choice used in prior studies introduces a geometric shear transformation that exaggerates the statistical power of the regressions. The maximum growth rates of extant groups are found to have a great deal of overlap, including between groups with endothermic and ectothermic metabolism. Dinosaur growth rates show similar overlap, matching the rates found for mammals, reptiles and fish. The allometric scaling of growth rate with mass is found to have curvature (on a log-log scale) for many groups, contradicting the prevailing view that growth rate allometry follows a simple power law. Reanalysis shows that no correlation between growth rate and basal metabolic rate (BMR) has been demonstrated. These findings drive a conclusion that growth rate allometry studies to date cannot be used to determine dinosaur metabolism as has been previously argued.

  15. Dinosaur Metabolism and the Allometry of Maximum Growth Rate

    Science.gov (United States)

    Myhrvold, Nathan P.

    2016-01-01

    The allometry of maximum somatic growth rate has been used in prior studies to classify the metabolic state of both extant vertebrates and dinosaurs. The most recent such studies are reviewed, and their data is reanalyzed. The results of allometric regressions on growth rate are shown to depend on the choice of independent variable; the typical choice used in prior studies introduces a geometric shear transformation that exaggerates the statistical power of the regressions. The maximum growth rates of extant groups are found to have a great deal of overlap, including between groups with endothermic and ectothermic metabolism. Dinosaur growth rates show similar overlap, matching the rates found for mammals, reptiles and fish. The allometric scaling of growth rate with mass is found to have curvature (on a log-log scale) for many groups, contradicting the prevailing view that growth rate allometry follows a simple power law. Reanalysis shows that no correlation between growth rate and basal metabolic rate (BMR) has been demonstrated. These findings drive a conclusion that growth rate allometry studies to date cannot be used to determine dinosaur metabolism as has been previously argued. PMID:27828977

  16. Occurrence and Impact of Insects in Maximum Growth Plantations

    Energy Technology Data Exchange (ETDEWEB)

    Nowak, J.T.; Berisford, C.W.

    2001-01-01

    Investigation of the relationships between intensive management practices and insect infestation using maximum growth potential studies of loblolly pine constructed over five years using a hierarchy of cultural treatments-monitoring differences in growth and insect infestation levels related to the increasing management intensities. This study shows that tree fertilization can increase coneworm infestation and demonstrated that tip moth management tree growth, at least initially.

  17. Growth and maximum size of tiger sharks (Galeocerdo cuvier) in Hawaii.

    Science.gov (United States)

    Meyer, Carl G; O'Malley, Joseph M; Papastamatiou, Yannis P; Dale, Jonathan J; Hutchinson, Melanie R; Anderson, James M; Royer, Mark A; Holland, Kim N

    2014-01-01

    Tiger sharks (Galecerdo cuvier) are apex predators characterized by their broad diet, large size and rapid growth. Tiger shark maximum size is typically between 380 & 450 cm Total Length (TL), with a few individuals reaching 550 cm TL, but the maximum size of tiger sharks in Hawaii waters remains uncertain. A previous study suggested tiger sharks grow rather slowly in Hawaii compared to other regions, but this may have been an artifact of the method used to estimate growth (unvalidated vertebral ring counts) compounded by small sample size and narrow size range. Since 1993, the University of Hawaii has conducted a research program aimed at elucidating tiger shark biology, and to date 420 tiger sharks have been tagged and 50 recaptured. All recaptures were from Hawaii except a single shark recaptured off Isla Jacques Cousteau (24°13'17″N 109°52'14″W), in the southern Gulf of California (minimum distance between tag and recapture sites  =  approximately 5,000 km), after 366 days at liberty (DAL). We used these empirical mark-recapture data to estimate growth rates and maximum size for tiger sharks in Hawaii. We found that tiger sharks in Hawaii grow twice as fast as previously thought, on average reaching 340 cm TL by age 5, and attaining a maximum size of 403 cm TL. Our model indicates the fastest growing individuals attain 400 cm TL by age 5, and the largest reach a maximum size of 444 cm TL. The largest shark captured during our study was 464 cm TL but individuals >450 cm TL were extremely rare (0.005% of sharks captured). We conclude that tiger shark growth rates and maximum sizes in Hawaii are generally consistent with those in other regions, and hypothesize that a broad diet may help them to achieve this rapid growth by maximizing prey consumption rates.

  18. Stocking and structure for maximum growth in sugar maple selection stands.

    Science.gov (United States)

    Thomas R. Crow; Carl H. Tubbs; Rodney D. Jacobs; Robert R. Oberg

    1981-01-01

    The impacts of stocking, structure, and cutting cycle on basal area, cubic foot volume, board foot volume, and diameter growth are considered. Recommendations are provided for maximum growth in uneven-aged sugar maple stands.

  19. Enstrophy-based proper orthogonal decomposition of flow past rotating cylinder at super-critical rotating rate

    Science.gov (United States)

    Sengupta, Tapan K.; Gullapalli, Atchyut

    2016-11-01

    Spinning cylinder rotating about its axis experiences a transverse force/lift, an account of this basic aerodynamic phenomenon is known as the Robins-Magnus effect in text books. Prandtl studied this flow by an inviscid irrotational model and postulated an upper limit of the lift experienced by the cylinder for a critical rotation rate. This non-dimensional rate is the ratio of oncoming free stream speed and the surface speed due to rotation. Prandtl predicted a maximum lift coefficient as CLmax = 4π for the critical rotation rate of two. In recent times, evidences show the violation of this upper limit, as in the experiments of Tokumaru and Dimotakis ["The lift of a cylinder executing rotary motions in a uniform flow," J. Fluid Mech. 255, 1-10 (1993)] and in the computed solution in Sengupta et al. ["Temporal flow instability for Magnus-robins effect at high rotation rates," J. Fluids Struct. 17, 941-953 (2003)]. In the latter reference, this was explained as the temporal instability affecting the flow at higher Reynolds number and rotation rates (>2). Here, we analyze the flow past a rotating cylinder at a super-critical rotation rate (=2.5) by the enstrophy-based proper orthogonal decomposition (POD) of direct simulation results. POD identifies the most energetic modes and helps flow field reconstruction by reduced number of modes. One of the motivations for the present study is to explain the shedding of puffs of vortices at low Reynolds number (Re = 60), for the high rotation rate, due to an instability originating in the vicinity of the cylinder, using the computed Navier-Stokes equation (NSE) from t = 0 to t = 300 following an impulsive start. This instability is also explained through the disturbance mechanical energy equation, which has been established earlier in Sengupta et al. ["Temporal flow instability for Magnus-robins effect at high rotation rates," J. Fluids Struct. 17, 941-953 (2003)].

  20. Conifers in cold environments synchronize maximum growth rate of tree-ring formation with day length.

    Science.gov (United States)

    Rossi, Sergio; Deslauriers, Annie; Anfodillo, Tommaso; Morin, Hubert; Saracino, Antonio; Motta, Renzo; Borghetti, Marco

    2006-01-01

    Intra-annual radial growth rates and durations in trees are reported to differ greatly in relation to species, site and environmental conditions. However, very similar dynamics of cambial activity and wood formation are observed in temperate and boreal zones. Here, we compared weekly xylem cell production and variation in stem circumference in the main northern hemisphere conifer species (genera Picea, Pinus, Abies and Larix) from 1996 to 2003. Dynamics of radial growth were modeled with a Gompertz function, defining the upper asymptote (A), x-axis placement (beta) and rate of change (kappa). A strong linear relationship was found between the constants beta and kappa for both types of analysis. The slope of the linear regression, which corresponds to the time at which maximum growth rate occurred, appeared to converge towards the summer solstice. The maximum growth rate occurred around the time of maximum day length, and not during the warmest period of the year as previously suggested. The achievements of photoperiod could act as a growth constraint or a limit after which the rate of tree-ring formation tends to decrease, thus allowing plants to safely complete secondary cell wall lignification before winter.

  1. High-Order Weno Simulations of Three-Dimensional Reshocked Richtmyer-Meshkov Instability to Late Times: Dynamics, Dependence on Initial Conditions, and Comparisons to Experimental Data

    Energy Technology Data Exchange (ETDEWEB)

    Schilling, O; Latini, M

    2010-01-12

    The dynamics of the reshocked multi-mode Richtmyer-Meshkov instability is investigated using 513 x 257{sup 2} three-dimensional ninth-order weighted essentially nonoscillatory shock-capturing simulations. A two-mode initial perturbation with superposed random noise is used to model the Mach 1.5 air/SF{sub 6} Vetter-Sturtevant shock tube experiment. The mass fraction and enstrophy isosurfaces, and density cross-sections are utilized to show the detailed flow structure before, during, and after reshock. It is shown that the mixing layer growth agrees well with the experimentally measured growth rate before and after reshock. The post-reshock growth rate is also in good agreement with the prediction of the Mikaelian model. A parametric study of the sensitivity of the layer growth to the choice of amplitudes of the short and long wavelength initial interfacial perturbation is also presented. Finally, the amplification effects of reshock are quantified using the evolution of the turbulent kinetic energy and turbulent enstrophy spectra, as well as the evolution of the baroclinic enstrophy production, buoyancy production, and shear production terms in the enstrophy and turbulent kinetic transport equations.

  2. Effects of lag and maximum growth in contaminant transport and biodegradation modeling

    International Nuclear Information System (INIS)

    Wood, B.D.; Dawson, C.N.

    1992-06-01

    The effects of time lag and maximum microbial growth on biodegradation in contaminant transport are discussed. A mathematical model is formulated that accounts for these effects, and a numerical case study is presented that demonstrates how lag influences biodegradation

  3. A parametrization of two-dimensional turbulence based on a maximum entropy production principle with a local conservation of energy

    International Nuclear Information System (INIS)

    Chavanis, Pierre-Henri

    2014-01-01

    In the context of two-dimensional (2D) turbulence, we apply the maximum entropy production principle (MEPP) by enforcing a local conservation of energy. This leads to an equation for the vorticity distribution that conserves all the Casimirs, the energy, and that increases monotonically the mixing entropy (H-theorem). Furthermore, the equation for the coarse-grained vorticity dissipates monotonically all the generalized enstrophies. These equations may provide a parametrization of 2D turbulence. They do not generally relax towards the maximum entropy state. The vorticity current vanishes for any steady state of the 2D Euler equation. Interestingly, the equation for the coarse-grained vorticity obtained from the MEPP turns out to coincide, after some algebraic manipulations, with the one obtained with the anticipated vorticity method. This shows a connection between these two approaches when the conservation of energy is treated locally. Furthermore, the newly derived equation, which incorporates a diffusion term and a drift term, has a nice physical interpretation in terms of a selective decay principle. This sheds new light on both the MEPP and the anticipated vorticity method. (paper)

  4. Direct numerical simulation of particle-laden turbulent channel flows with two- and four-way coupling effects: budgets of Reynolds stress and streamwise enstrophy

    International Nuclear Information System (INIS)

    Dritselis, Chris D

    2016-01-01

    The budgets of the Reynolds stress and streamwise enstrophy are evaluated through direct numerical simulations for the turbulent particle-laden flow in a vertical channel with momentum exchange between the two phases. The influence of the dispersed particles on the budgets is examined through a comparison of the particle-free and the particle-laden cases at the same Reynolds number of Re b = 5600 based on the bulk fluid velocity and the distance between the channel walls. Results are obtained for particle ensembles with four response times in simulations with and without streamwise gravity and inter-particle collisions at average mass (volume) fractions of 0.2 (2.7 × 10 −5 ) and 0.5 (6.8 × 10 −5 ). The particle feedback force on the flow of the carrier phase is modeled by a point-force approximation (PSIC-method). It is shown that all the terms in the budgets of the Reynolds stress components are decreased in the presence of particles. The level of reduction depends on the particle response time and it is higher under the effects of gravity and inter-particle collisions. A considerable reduction in all the terms of the streamwise enstrophy budget is also observed. In particular, all production mechanisms, and mainly vortex stretching, are inhibited in the particulate flows and thus the production of streamwise vorticity is significantly damped. A further insight into the direct particle effects on the fluid turbulence is provided by analyzing in detail the fluid–fluid, fluid–particle and particle–particle correlations, and the spectra of the fluid–particle energy exchange rate. The present results indicate that the turbulence production, dissipation and pressure–strain term are generally large quantities, but their summation is relatively small and comparable to the fluid–particle direct energy exchange rate. Consequently, the particle contribution can potentially increase or decrease the fluctuating fluid velocities and eventually control the

  5. Dual cascade and minimum enstrophy state in the tokamak scrape-off layer

    International Nuclear Information System (INIS)

    Mattor, N.; Cohen, R.H.; Xu, X.Q.

    1993-01-01

    In the Tokamak Scrape-off layer (SOL), there is experimental, theoretical, and computational evidence of an inverse energy cascade, wherein fluctuation energy transfers nonlinearly to large scale lengths. If the inverse cascade proceeds to the largest scales, it gives transport which is inherently nonlocal, precluding standard descriptions with local transport coefficients. This includes DIA based renormalization theories, γ/k 2 open-quotes mixing lengthclose quotes theories, and spectral or pseudo-spectral codes, all of which tend to involve a two-scale assumption, that turbulence acts on very short time and length scales relative to the equilibrium. The two-scale assumption is violated by turbulence undergoing a significant inverse cascade, and a different approach is called for. The authors postulate that the net effect of such turbulence is not local transport, but rather to supply the equilibrium with a steady source of energy at the minimum enstrophy. The form of the supplied energy is assessed through a variational calculation, which gives an equation for the equilibrium velocity profile, ∇ 2 V = λ 2 V, where λ 2 is an undetermined Lagrange multiplier. For a slab model, the solution in the SOL is V = V a exp[-λ(r-a)]y, where V a is the poloidal velocity at the SOL/edge interface. This velocity (from E x B in the simple model), leads to the potential profile, φ = -(V a B/λc)exp[-λ(r-a)]. For field lines connected to an endplate eφ = ΛT e , (where Λ ∼ 4 is nearly constant) giving also the T e profile. Thus, the profiles are given and the transport problem is solved, up to the two unknown constants λ and V a . One relation comes from heat balance. There are several candidates for the second constant, and the authors present numerical simulations which evaluate these

  6. Optimal control of algae growth by controlling CO 2 and nutrition flow using Pontryagin Maximum Principle

    Science.gov (United States)

    Mardlijah; Jamil, Ahmad; Hanafi, Lukman; Sanjaya, Suharmadi

    2017-09-01

    There are so many benefit of algae. One of them is using for renewable energy and sustainable in the future. The greater growth of algae will increasing biodiesel production and the increase of algae growth is influenced by glucose, nutrients and photosynthesis process. In this paper, the optimal control problem of the growth of algae is discussed. The objective function is to maximize the concentration of dry algae while the control is the flow of carbon dioxide and the nutrition. The solution is obtained by applying the Pontryagin Maximum Principle. and the result show that the concentration of algae increased more than 15 %.

  7. Exponential growth and Gaussian-like fluctuations of solutions of stochastic differential equations with maximum functionals

    International Nuclear Information System (INIS)

    Appleby, J A D; Wu, H

    2008-01-01

    In this paper we consider functional differential equations subjected to either instantaneous state-dependent noise, or to a white noise perturbation. The drift of the equations depend linearly on the current value and on the maximum of the solution. The functional term always provides positive feedback, while the instantaneous term can be mean-reverting or can exhibit positive feedback. We show in the white noise case that if the instantaneous term is mean reverting and dominates the history term, then solutions are recurrent, and upper bounds on the a.s. growth rate of the partial maxima of the solution can be found. When the instantaneous term is weaker, or is of positive feedback type, we determine necessary and sufficient conditions on the diffusion coefficient which ensure the exact exponential growth of solutions. An application of these results to an inefficient financial market populated by reference traders and speculators is given, in which the difference between the current instantaneous returns and maximum of the returns over the last few time units is used to determine trading strategies.

  8. Calculations of shape and stability of menisci in Czochralski growth with tables to determine meniscus heights, maximum heights and capillary constants

    International Nuclear Information System (INIS)

    Uelhoff, W.; Mika, K.

    1975-05-01

    The shape and stability of menisci occurring during Czochralski growth have been studied by means of numerical methods for the case of the free surface. The existence of minimal joining angles is shown, beyond which the growing crystal will separate from the melt. The dependence of the interface height on the joining angle for different crystal diameters was calculated. The maximum stable heights and the corresponding joining angles were determined as a function of crystal diameter. A method for measuring the capillary constant of the melt during Czochralski growth is proposed. The results are compared with known analytical approximations. Limitations of the applications caused by a finite crucible radius or low g values are pointed out. For practical use the following functions have been tabulated: 1) meniscus height in dependence on joining angle and crystal radius, 2) the radius-height-ratio in dependence on radius and angle for the calculation of the capillary constant, 3) the maximum stable height and the corresponding growth angle as a function of crystal radius. (orig.) [de

  9. Effects of light intensity on growth, anatomy and forage quality of two tropical grasses (Brachiaria brizantha and Panicum maximum var. trichoglume).

    NARCIS (Netherlands)

    Deinum, B.; Sulastri, R.D.; Zeinab, M.H.J.; Maassen, A.

    1996-01-01

    Effects of light intensity on growth, histology and anatomy, and nutritive value were studied in seedlings of two shade tolerant species: Brachiaria brizantha and Panicum maximum var. trichoglume. They were studied under greenhouse conditions in pots with sandy soil and sufficient N and cut after a

  10. Navier--Stokes relaxation to sinh--Poisson states at finite Reynolds numbers

    International Nuclear Information System (INIS)

    Montgomery, D.; Shan, X.; Matthaeus, W.H.

    1993-01-01

    A mathematical framework is proposed in which it seems possible to justify the computationally-observed relaxation of a two-dimensional Navier--Stokes fluid to a ''most probable,'' or maximum entropy, state. The relaxation occurs at large but finite Reynolds numbers, and involves substantial decay of higher-order ideal invariants such as enstrophy. A two-fluid formulation, involving interpenetrating positive and negative vorticity fluxes (continuous and square integrable) is developed, and is shown to be intimately related to the passive scalar decay problem. Increasing interpenetration of the two fluids corresponds to the decay of vorticity flux due to viscosity. It is demonstrated numerically that, in two dimensions, passive scalars decay rapidly, relative to mean-square vorticity (enstrophy). This observation provides a basis for assigning initial data to the two-fluid field variables

  11. Evidence of seasonal variation in longitudinal growth of height in a sample of boys from Stuttgart Carlsschule, 1771-1793, using combined principal component analysis and maximum likelihood principle.

    Science.gov (United States)

    Lehmann, A; Scheffler, Ch; Hermanussen, M

    2010-02-01

    Recent progress in modelling individual growth has been achieved by combining the principal component analysis and the maximum likelihood principle. This combination models growth even in incomplete sets of data and in data obtained at irregular intervals. We re-analysed late 18th century longitudinal growth of German boys from the boarding school Carlsschule in Stuttgart. The boys, aged 6-23 years, were measured at irregular 3-12 monthly intervals during the period 1771-1793. At the age of 18 years, mean height was 1652 mm, but height variation was large. The shortest boy reached 1474 mm, the tallest 1826 mm. Measured height closely paralleled modelled height, with mean difference of 4 mm, SD 7 mm. Seasonal height variation was found. Low growth rates occurred in spring and high growth rates in summer and autumn. The present study demonstrates that combining the principal component analysis and the maximum likelihood principle enables growth modelling in historic height data also. Copyright (c) 2009 Elsevier GmbH. All rights reserved.

  12. A local maximum in gibberellin levels regulates maize leaf growth by spatial control of cell division.

    Science.gov (United States)

    Nelissen, Hilde; Rymen, Bart; Jikumaru, Yusuke; Demuynck, Kirin; Van Lijsebettens, Mieke; Kamiya, Yuji; Inzé, Dirk; Beemster, Gerrit T S

    2012-07-10

    Plant growth rate is largely determined by the transition between the successive phases of cell division and expansion. A key role for hormone signaling in determining this transition was inferred from genetic approaches and transcriptome analysis in the Arabidopsis root tip. We used the developmental gradient at the maize leaf base as a model to study this transition, because it allows a direct comparison between endogenous hormone concentrations and the transitions between dividing, expanding, and mature tissue. Concentrations of auxin and cytokinins are highest in dividing tissues, whereas bioactive gibberellins (GAs) show a peak at the transition zone between the division and expansion zone. Combined metabolic and transcriptomic profiling revealed that this GA maximum is established by GA biosynthesis in the division zone (DZ) and active GA catabolism at the onset of the expansion zone. Mutants defective in GA synthesis and signaling, and transgenic plants overproducing GAs, demonstrate that altering GA levels specifically affects the size of the DZ, resulting in proportional changes in organ growth rates. This work thereby provides a novel molecular mechanism for the regulation of the transition from cell division to expansion that controls organ growth and size. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. The regulation of starch accumulation in Panicum maximum Jacq ...

    African Journals Online (AJOL)

    ... decrease the starch level. These observations are discussed in relation to the photosynthetic characteristics of P. maximum. Keywords: accumulation; botany; carbon assimilation; co2 fixation; growth conditions; mesophyll; metabolites; nitrogen; nitrogen levels; nitrogen supply; panicum maximum; plant physiology; starch; ...

  14. Variation of Maximum Tree Height and Annual Shoot Growth of Smith Fir at Various Elevations in the Sygera Mountains, Southeastern Tibetan Plateau

    Science.gov (United States)

    Wang, Yafeng; Čufar, Katarina; Eckstein, Dieter; Liang, Eryuan

    2012-01-01

    Little is known about tree height and height growth (as annual shoot elongation of the apical part of vertical stems) of coniferous trees growing at various altitudes on the Tibetan Plateau, which provides a high-elevation natural platform for assessing tree growth performance in relation to future climate change. We here investigated the variation of maximum tree height and annual height increment of Smith fir (Abies georgei var. smithii) in seven forest plots (30 m×40 m) along two altitudinal transects between 3,800 m and 4,200/4,390 m above sea level (a.s.l.) in the Sygera Mountains, southeastern Tibetan Plateau. Four plots were located on north-facing slopes and three plots on southeast-facing slopes. At each site, annual shoot growth was obtained by measuring the distance between successive terminal bud scars along the main stem of 25 trees that were between 2 and 4 m high. Maximum/mean tree height and mean annual height increment of Smith fir decreased with increasing altitude up to the tree line, indicative of a stress gradient (the dominant temperature gradient) along the altitudinal transect. Above-average mean minimum summer (particularly July) temperatures affected height increment positively, whereas precipitation had no significant effect on shoot growth. The time series of annual height increments of Smith fir can be used for the reconstruction of past climate on the southeastern Tibetan Plateau. In addition, it can be expected that the rising summer temperatures observed in the recent past and anticipated for the future will enhance Smith fir's growth throughout its altitudinal distribution range. PMID:22396738

  15. Formal comment on: Myhrvold (2016) Dinosaur metabolism and the allometry of maximum growth rate. PLoS ONE; 11(11): e0163205.

    Science.gov (United States)

    Griebeler, Eva Maria; Werner, Jan

    2018-01-01

    In his 2016 paper, Myhrvold criticized ours from 2014 on maximum growth rates (Gmax, maximum gain in body mass observed within a time unit throughout an individual's ontogeny) and thermoregulation strategies (ectothermy, endothermy) of 17 dinosaurs. In our paper, we showed that Gmax values of similar-sized extant ectothermic and endothermic vertebrates overlap. This strongly questions a correct assignment of a thermoregulation strategy to a dinosaur only based on its Gmax and (adult) body mass (M). Contrary, Gmax separated similar-sized extant reptiles and birds (Sauropsida) and Gmax values of our studied dinosaurs were similar to those seen in extant similar-sized (if necessary scaled-up) fast growing ectothermic reptiles. Myhrvold examined two hypotheses (H1 and H2) regarding our study. However, we did neither infer dinosaurian thermoregulation strategies from group-wide averages (H1) nor were our results based on that Gmax and metabolic rate (MR) are related (H2). In order to assess whether single dinosaurian Gmax values fit to those of extant endotherms (birds) or of ectotherms (reptiles), we already used a method suggested by Myhrvold to avoid H1, and we only discussed pros and cons of a relation between Gmax and MR and did not apply it (H2). We appreciate Myhrvold's efforts in eliminating the correlation between Gmax and M in order to statistically improve vertebrate scaling regressions on maximum gain in body mass. However, we show here that his mass-specific maximum growth rate (kC) replacing Gmax (= MkC) does not model the expected higher mass gain in larger than in smaller species for any set of species. We also comment on, why we considered extant reptiles and birds as reference models for extinct dinosaurs and why we used phylogenetically-informed regression analysis throughout our study. Finally, we question several arguments given in Myhrvold in order to support his results.

  16. Effects of friction on forced two-dimensional Navier-Stokes turbulence.

    Science.gov (United States)

    Blackbourn, Luke A K; Tran, Chuong V

    2011-10-01

    Large-scale dissipation mechanisms have been routinely employed in numerical simulations of two-dimensional turbulence to absorb energy at large scales, presumably mimicking the quasisteady picture of Kraichnan in an unbounded fluid. Here, "side effects" of such a mechanism--mechanical friction--on the small-scale dynamics of forced two-dimensional Navier-Stokes turbulence are elaborated by both theoretical and numerical analysis. Given a positive friction coefficient α, viscous dissipation of enstrophy has been known to vanish in the inviscid limit ν→0. This effectively renders the scale-neutral friction the only mechanism responsible for enstrophy dissipation in that limit. The resulting dynamical picture is that the classical enstrophy inertial range becomes a dissipation range in which the dissipation of enstrophy by friction mainly occurs. For each α>0, there exists a critical viscosity ν(c), which depends on physical parameters, separating the regimes of predominant viscous and frictional dissipation of enstrophy. It is found that ν(c)=[η'(1/3)/(Ck(f)(2))]exp[-η'(1/3)/(Cα)], where η' is half the enstrophy injection rate, k(f) is the forcing wave number, and C is a nondimensional constant (the Kraichnan-Batchelor constant). The present results have important theoretical and practical implications. Apparently, mechanical friction is a poor choice in numerical attempts to address fundamental issues concerning the direct enstrophy transfer in two-dimensional Navier-Stokes turbulence. Furthermore, as relatively strong friction naturally occurs on the surfaces and at lateral boundaries of experimental fluids as well as at the interfaces of shallow layers in geophysical fluid models, the frictional effects discussed in this study are crucial in understanding the dynamics of these systems.

  17. The last glacial maximum

    Science.gov (United States)

    Clark, P.U.; Dyke, A.S.; Shakun, J.D.; Carlson, A.E.; Clark, J.; Wohlfarth, B.; Mitrovica, J.X.; Hostetler, S.W.; McCabe, A.M.

    2009-01-01

    We used 5704 14C, 10Be, and 3He ages that span the interval from 10,000 to 50,000 years ago (10 to 50 ka) to constrain the timing of the Last Glacial Maximum (LGM) in terms of global ice-sheet and mountain-glacier extent. Growth of the ice sheets to their maximum positions occurred between 33.0 and 26.5 ka in response to climate forcing from decreases in northern summer insolation, tropical Pacific sea surface temperatures, and atmospheric CO2. Nearly all ice sheets were at their LGM positions from 26.5 ka to 19 to 20 ka, corresponding to minima in these forcings. The onset of Northern Hemisphere deglaciation 19 to 20 ka was induced by an increase in northern summer insolation, providing the source for an abrupt rise in sea level. The onset of deglaciation of the West Antarctic Ice Sheet occurred between 14 and 15 ka, consistent with evidence that this was the primary source for an abrupt rise in sea level ???14.5 ka.

  18. The troposphere-to-stratosphere transition in kinetic energy spectra and nonlinear spectral fluxes as seen in ECMWF analyses

    Science.gov (United States)

    Burgess, A. B. H.; Erler, A. R.; Shepherd, T. G.

    2012-04-01

    We present spectra, nonlinear interaction terms, and fluxes computed for horizontal wind fields from high-resolution meteorological analyses made available by ECMWF for the International Polar Year. Total kinetic energy spectra clearly show two spectral regimes: a steep spectrum at large scales and a shallow spectrum in the mesoscale. The spectral shallowing appears at ~200 hPa, and is due to decreasing rotational power with height, which results in the shallower divergent spectrum dominating in the mesoscale. The spectra we find are steeper than those observed in aircraft data and GCM simulations. Though the analyses resolve total spherical harmonic wavenumbers up to n = 721, effects of dissipation on the fluxes and spectra are visible starting at about n = 200. We find a weak forward energy cascade and a downscale enstrophy cascade in the mesoscale. Eddy-eddy nonlinear kinetic energy transfers reach maximum amplitudes at the tropopause, and decrease with height thereafter; zonal mean-eddy transfers dominate in the stratosphere. In addition, zonal anisotropy reaches a minimum at the tropopause. Combined with strong eddy-eddy interactions, this suggests flow in the tropopause region is very active and bears the greatest resemblance to isotropic turbulence. We find constant enstrophy flux over a broad range of wavenumbers around the tropopause and in the upper stratosphere. A relatively constant spectral enstrophy flux at the tropopause suggests a turbulent inertial range, and that the enstrophy flux is resolved. A main result of our work is its implications for explaining the shallow mesoscale spectrum observed in aircraft wind measurements, GCM studies, and now meteorological analyses. The strong divergent component in the shallow mesoscale spectrum indicates unbalanced flow, and nonlinear transfers decreasing quickly with height are characteristic of waves, not turbulence. Together with the downscale flux of energ y through the shallow spectral range, these

  19. Nonconservative and reverse spectral transfer in Hasegawa-Mima turbulence

    International Nuclear Information System (INIS)

    Terry, P.W.; Newman, D.E.

    1993-01-01

    The dual cascade is generally represented as a conservative cascade of enstrophy to short wavelengths through an enstrophy similarity range and an inverse cascade of energy to long wavelengths through an energy similarity range. This picture, based on a proof due to Kraichnan [Phys. Fluids 10, 1417 (1967)], is found to be significantly modified for a spectra of finite extent. Dimensional arguments and direct measurement of spectral flow in Hasegawa-Mima turbulence indicate that for both the energy and enstrophy cascades, transfer of the conserved quantity is accompanied by a nonconservative transfer of the other quantity. The decrease of a given invariant (energy or enstrophy) in the nonconservative transfer in one similarity range is balanced by the increase of that quantity in the other similarity range, thus maintaining net invariance. The increase or decrease of a given invariant quantity in one similarity range depends on the injection scale and is consistent with that quantity being carried in a self-similar transfer of the other invariant quantity. This leads, in an inertial range of finite size, to some energy being carried to small scales and some enstrophy being carried to large scales

  20. Estimation of the growth curve and heritability of the growth rate for giant panda (Ailuropoda melanoleuca) cubs.

    Science.gov (United States)

    Che, T D; Wang, C D; Jin, L; Wei, M; Wu, K; Zhang, Y H; Zhang, H M; Li, D S

    2015-03-27

    Giant panda cubs have a low survival rate during the newborn and early growth stages. However, the growth and developmental parameters of giant panda cubs during the early lactation stage (from birth to 6 months) are not well known. We examined the growth and development of giant panda cubs by the Chapman growth curve model and estimated the heritability of the maximum growth rate at the early lactation stage. We found that 83 giant panda cubs reached their maximum growth rate at approximately 75-120 days after birth. The body weight of cubs at 75 days was 4285.99 g. Furthermore, we estimated that the heritability of the maximum growth rate was moderate (h(2) = 0.38). Our study describes the growth and development of giant panda cubs at the early lactation stage and provides valuable growth benchmarks. We anticipate that our results will be a starting point for more detailed research on increasing the survival rate of giant panda cubs. Feeding programs for giant panda cubs need further improvement.

  1. Hopper Growth of Salt Crystals.

    Science.gov (United States)

    Desarnaud, Julie; Derluyn, Hannelore; Carmeliet, Jan; Bonn, Daniel; Shahidzadeh, Noushine

    2018-06-07

    The growth of hopper crystals is observed for many substances, but the mechanism of their formation remains ill understood. Here we investigate their growth by performing evaporation experiments on small volumes of salt solutions. We show that sodium chloride crystals that grow very fast from a highly supersaturated solution form a peculiar form of hopper crystal consisting of a series of connected miniature versions of the original cubic crystal. The transition between cubic and such hopper growth happens at a well-defined supersaturation where the growth rate of the cubic crystal reaches a maximum (∼6.5 ± 1.8 μm/s). Above this threshold, the growth rate varies as the third power of supersaturation, showing that a new mechanism, controlled by the maximum speed of surface integration of new molecules, induces the hopper growth of cubic crystals in cascade.

  2. Effect of Temperature and Relative Humidity on the Growth of ...

    African Journals Online (AJOL)

    were used to determine the temperature effect on the growth of H. fulvum. Maximum growth of H. ... The fungus showed maximum growth at 92.5 and 100% relative humidity. .... recommended that fruits and vegetables should be stored at low ...

  3. Estimation of the Maximum Theoretical Productivity of Fed-Batch Bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Bomble, Yannick J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); St. John, Peter C [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Crowley, Michael F [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-10-18

    A key step towards the development of an integrated biorefinery is the screening of economically viable processes, which depends sharply on the yields and productivities that can be achieved by an engineered microorganism. In this study, we extend an earlier method which used dynamic optimization to find the maximum theoretical productivity of batch cultures to explicitly include fed-batch bioreactors. In addition to optimizing the intracellular distribution of metabolites between cell growth and product formation, we calculate the optimal control trajectory of feed rate versus time. We further analyze how sensitive the productivity is to substrate uptake and growth parameters.

  4. Rectangular maximum-volume submatrices and their applications

    KAUST Repository

    Mikhalev, Aleksandr; Oseledets, I.V.

    2017-01-01

    We introduce a definition of the volume of a general rectangular matrix, which is equivalent to an absolute value of the determinant for square matrices. We generalize results of square maximum-volume submatrices to the rectangular case, show a connection of the rectangular volume with an optimal experimental design and provide estimates for a growth of coefficients and an approximation error in spectral and Chebyshev norms. Three promising applications of such submatrices are presented: recommender systems, finding maximal elements in low-rank matrices and preconditioning of overdetermined linear systems. The code is available online.

  5. Rectangular maximum-volume submatrices and their applications

    KAUST Repository

    Mikhalev, Aleksandr

    2017-10-18

    We introduce a definition of the volume of a general rectangular matrix, which is equivalent to an absolute value of the determinant for square matrices. We generalize results of square maximum-volume submatrices to the rectangular case, show a connection of the rectangular volume with an optimal experimental design and provide estimates for a growth of coefficients and an approximation error in spectral and Chebyshev norms. Three promising applications of such submatrices are presented: recommender systems, finding maximal elements in low-rank matrices and preconditioning of overdetermined linear systems. The code is available online.

  6. Gas-Jet Meniscus Control in Ribbon Growth

    Science.gov (United States)

    Zoutendyk, J. A.; Vonroos, O.

    1983-01-01

    Gas jet used to control shape of meniscus and thus to regulate ribbon thickness in vertical silicon-ribbon growth. Gas jet also cools ribbon, increasing maximum possible pull speed for silicon, contact angle of 11 degrees plus or minus 1 degree required for constant thickness ribbon growth. Cooling effect of gas jet increases maximum possible pull speed.

  7. Maximum of an Airy process plus Brownian motion and memory in Kardar-Parisi-Zhang growth

    Science.gov (United States)

    Le Doussal, Pierre

    2017-12-01

    We obtain several exact results for universal distributions involving the maximum of the Airy2 process minus a parabola and plus a Brownian motion, with applications to the one-dimensional Kardar-Parisi-Zhang (KPZ) stochastic growth universality class. This allows one to obtain (i) the universal limit, for large time separation, of the two-time height correlation for droplet initial conditions, e.g., C∞=limt2/t1→+∞h(t1) h (t2)¯c/h(t1)2¯c, with C∞≈0.623 , as well as conditional moments, which quantify ergodicity breaking in the time evolution; (ii) in the same limit, the distribution of the midpoint position x (t1) of a directed polymer of length t2; and (iii) the height distribution in stationary KPZ with a step. These results are derived from the replica Bethe ansatz for the KPZ continuum equation, with a "decoupling assumption" in the large time limit. They agree and confirm, whenever they can be compared, with (i) our recent tail results for two-time KPZ with the work by de Nardis and Le Doussal [J. Stat. Mech. (2017) 053212, 10.1088/1742-5468/aa6bce], checked in experiments with the work by Takeuchi and co-workers [De Nardis et al., Phys. Rev. Lett. 118, 125701 (2017), 10.1103/PhysRevLett.118.125701] and (ii) a recent result of Maes and Thiery [J. Stat. Phys. 168, 937 (2017), 10.1007/s10955-017-1839-2] on midpoint position.

  8. Overview of Maximum Power Point Tracking Techniques for Photovoltaic Energy Production Systems

    DEFF Research Database (Denmark)

    Koutroulis, Eftichios; Blaabjerg, Frede

    2015-01-01

    A substantial growth of the installed photovoltaic systems capacity has occurred around the world during the last decade, thus enhancing the availability of electric energy in an environmentally friendly way. The maximum power point tracking technique enables maximization of the energy production...... of photovoltaic sources during stochastically varying solar irradiation and ambient temperature conditions. Thus, the overall efficiency of the photovoltaic energy production system is increased. Numerous techniques have been presented during the last decade for implementing the maximum power point tracking...... process in a photovoltaic system. This article provides an overview of the operating principles of these techniques, which are suited for either uniform or non-uniform solar irradiation conditions. The operational characteristics and implementation requirements of these maximum power point tracking...

  9. Connection between the growth rate distribution and the size dependent crystal growth

    Science.gov (United States)

    Mitrović, M. M.; Žekić, A. A.; IIić, Z. Z.

    2002-07-01

    The results of investigations of the connection between the growth rate dispersions and the size dependent crystal growth of potassium dihydrogen phosphate (KDP), Rochelle salt (RS) and sodium chlorate (SC) are presented. A possible way out of the existing confusion in the size dependent crystal growth investigations is suggested. It is shown that the size independent growth exists if the crystals belonging to one growth rate distribution maximum are considered separately. The investigations suggest possible reason for the observed distribution maxima widths, and the high data scattering on the growth rate versus the crystal size dependence.

  10. Non-linear instability analysis of the two-dimensional Navier-Stokes equation: The Taylor-Green vortex problem

    Science.gov (United States)

    Sengupta, Tapan K.; Sharma, Nidhi; Sengupta, Aditi

    2018-05-01

    An enstrophy-based non-linear instability analysis of the Navier-Stokes equation for two-dimensional (2D) flows is presented here, using the Taylor-Green vortex (TGV) problem as an example. This problem admits a time-dependent analytical solution as the base flow, whose instability is traced here. The numerical study of the evolution of the Taylor-Green vortices shows that the flow becomes turbulent, but an explanation for this transition has not been advanced so far. The deviation of the numerical solution from the analytical solution is studied here using a high accuracy compact scheme on a non-uniform grid (NUC6), with the fourth-order Runge-Kutta method. The stream function-vorticity (ψ, ω) formulation of the governing equations is solved here in a periodic square domain with four vortices at t = 0. Simulations performed at different Reynolds numbers reveal that numerical errors in computations induce a breakdown of symmetry and simultaneous fragmentation of vortices. It is shown that the actual physical instability is triggered by the growth of disturbances and is explained by the evolution of disturbance mechanical energy and enstrophy. The disturbance evolution equations have been traced by looking at (a) disturbance mechanical energy of the Navier-Stokes equation, as described in the work of Sengupta et al., "Vortex-induced instability of an incompressible wall-bounded shear layer," J. Fluid Mech. 493, 277-286 (2003), and (b) the creation of rotationality via the enstrophy transport equation in the work of Sengupta et al., "Diffusion in inhomogeneous flows: Unique equilibrium state in an internal flow," Comput. Fluids 88, 440-451 (2013).

  11. Fatigue crack growth behavior under cyclic thermal transient stress

    International Nuclear Information System (INIS)

    Ueda, Masahiro; Kano, Takashi; Yoshitoshi, Atsushi.

    1986-01-01

    Thermal fatigue tests were performed using straight pipe specimens subjected to cyclic thermal shocks of liquid sodium, and crack growth behaviors were estimated using striation patterns observed clearly on any crack surface. Crack growth rate under cyclic thermal strain reaches the maximum at one depth, and after that it decreases gradually with crack depth. The peak location of crack growth rate becomes deeper by superposition of constant primary stress. Parallel cracks co-existing in the neighborhood move the peak to shallower location and decrease the maximum crack growth rate. The equivalent stress intensity factor range calculated by Walker's formula is successfully applied to the case of negative stress ratio. Fatigue crack growth rate under cyclic thermal strain agreed well with that under the constant temperature equal to the maximum value in the thermal cycle. Simplified methods for calculating the stress intensity factor and the crack interference factor have been developed. Crack growth behavior under thermal fatigue could be well predicted using numerical analysis results. (author)

  12. Fatigue crack growth behavior under cyclic transient thermal stress

    International Nuclear Information System (INIS)

    Ueda, Masahiro; Kano, Takashi; Yoshitoshi, Atsushi.

    1987-01-01

    Thermal fatigue tests were performed using straight pipe specimens subjected to cyclic thermal shocks of liquid sodium, and crack growth behaviors were estimated using striation patterns observed clearly on any crack surface. Crack growth rate under cyclic thermal strain reaches the maximum at one depth, and after that it decreases gradually with crack depth. The peak location of crack growth rate becomes deeper by superposition of constant primary stress. Parallel cracks co-existing in the neighborhood move the peak to shallower location and decrease the maximum crack growth rate. The equivalent stress intensity factor range calculated by Walker's formula is successfully applied to the case of negative stress ratio. Fatigue crack growth rate under cyclic thermal strain agreed well with that under the constant temperature equal to the maximum value in the thermal cycle. Simplified methods for calculating the stress intensity factor and the crack interference factor have been developed. Crack growth behavior under thermal fatigue could be well predicted using numerical analysis results. (author)

  13. Approximate maximum parsimony and ancestral maximum likelihood.

    Science.gov (United States)

    Alon, Noga; Chor, Benny; Pardi, Fabio; Rapoport, Anat

    2010-01-01

    We explore the maximum parsimony (MP) and ancestral maximum likelihood (AML) criteria in phylogenetic tree reconstruction. Both problems are NP-hard, so we seek approximate solutions. We formulate the two problems as Steiner tree problems under appropriate distances. The gist of our approach is the succinct characterization of Steiner trees for a small number of leaves for the two distances. This enables the use of known Steiner tree approximation algorithms. The approach leads to a 16/9 approximation ratio for AML and asymptotically to a 1.55 approximation ratio for MP.

  14. Infuences of Rice Husk Biochar (RHB on Rice Growth Performance and Fertilizer Nitrogen Recovery up to Maximum Tillering Stage

    Directory of Open Access Journals (Sweden)

    Deniel Anak Sang

    2018-03-01

    Full Text Available A pot study was carried out to investigate the effects of rice husk biochar addition on rice growth performance and fertilizer nitrogen recovery. The biochar effect was studied by using 15N labelled fertilizer urea (10 atom% 15N, as isotopic tracer, until maximum tillering stage (75 days after sowing. Rice husk biochar (RHB was applied at rates of 0, 5, 10 and 20 Mg ha-1 and laid in randomized complete block design with four replications. The result showed that biochar application significantly improved soil chemical properties (pH, total C, total N, and available P compared to control treatment. Biochar addition increased number of tiller and root dry matter weight up to 4% and 35%, respectively, compared to un-amended pot. Likewise, application of biochar significantly increased N, P and K uptake by 3%, 19% and 33%, respectively, as compared to the nutrient uptake from the control treatment. Biochar treatment had no significant impact on fertilizer nitrogen recovery in aboveground biomass, in the range of 41% and 42%, in comparison to the control. However, nitrogen fertilizer recovery in soil significantly increased by 47% over the control at application rate of 20 Mg ha-1 RHB.  Increased fertilizer N recovery in soil possibly reduced N losses to the environment from volatilization and denitrification processes. Total 15N fertilizer recovery also found increase at highest application of RHB biochar with an increment of 16%. In general, addition of biochar appeared to enhance crop growth performance but its effect on fertilizer N recovery in plant requires further study up to maturity of rice plant.

  15. Maximum heat flux in boiling in a large volume

    International Nuclear Information System (INIS)

    Bergmans, Dzh.

    1976-01-01

    Relationships are derived for the maximum heat flux qsub(max) without basing on the assumptions of both the critical vapor velocity corresponding to the zero growth rate, and planar interface. The Helmholz nonstability analysis of vapor column has been made to this end. The results of this examination have been used to find maximum heat flux for spherical, cylindric and flat plate heaters. The conventional hydrodynamic theory was found to be incapable of producing a satisfactory explanation of qsub(max) for small heaters. The occurrence of qsub(max) in the present case can be explained by inadequate removal of vapor output from the heater (the force of gravity for cylindrical heaters and surface tension for the spherical ones). In case of flat plate heater the qsub(max) value can be explained with the help of the hydrodynamic theory

  16. The maximum contraceptive prevalence 'demand curve': guiding discussions on programmatic investments.

    Science.gov (United States)

    Weinberger, Michelle; Sonneveldt, Emily; Stover, John

    2017-12-22

    Most frameworks for family planning include both access and demand interventions. Understanding how these two are linked and when each should be prioritized is difficult. The maximum contraceptive prevalence 'demand curve' was created based on a relationship between the modern contraceptive prevalence rate (mCPR) and mean ideal number of children to allow for a quantitative assessment of the balance between access and demand interventions. The curve represents the maximum mCPR that is likely to be seen given fertility intentions and related norms and constructs that influence contraceptive use. The gap between a country's mCPR and this maximum is referred to as the 'potential use gap.' This concept can be used by countries to prioritize access investments where the gap is large, and discuss implications for future contraceptive use where the gap is small. It is also used within the FP Goals model to ensure mCPR growth from access interventions does not exceed available demand.

  17. Crescimento e desenvolvimento do dossel de Panicum maximum cv. Mombaça Canopy growth and development of Panicum maximum "cv" Mombaça

    Directory of Open Access Journals (Sweden)

    Emerson Alexandrino

    2005-12-01

    , decrescendo posteriormente.It was assessed the evolution of tillering, forage biomass, leaf area index (LAI, interception of photosynthetically active radiation (IPAR, efficiency of radiation use (ERU in Panicum maximum "cv" Mombaça during the regrowth period of the grass, in the Summer and Autumn seasons. Similarly, grass growth indices were assessed: net assimilation rate (NAR, leaf area ratio (LAR and relative growth rate (RGR. All these variables were estimated from field observations taken on the 7th, 14th, 21st, 28th, 35th, 42nd and 49th days of the regrowth period (treatments, in the Summer and Autumn seasons. The experimental design was completely randomized with four replications. One area of 1,200m² was used in each season; 28 and 24 sampling points were chosen in the Summer and the Autunm seasons, respectively, for their similarity regarding canopy height and soil cover condition and randomly assigned to the treatments. The grass tillering was more intense in the first regrowth week and declined afterwards to reach negligible values from the fourth week on. Interception of the photosynthetically active radiation evolved in an asymptotic manner reaching highest value of 96%, without difference between Summer and Autumn. Leaf area index figures showed the same pattern in the Summer and Autumn, reaching the values of 8 and 4, respectively; on the other hand, forage biomass responded quadractically to the duration of the regrowth period. Radiation use efficiency reached the values of 1.76 and 0.54gDM/MJ in Summer and Autumn, respectively. RGR and NAR figures decreased in an asymptotic pattern in both seasons, with higher values in the Summer, while LAR figures increased initially in the first four weeks reaching values of 0.017 and 0.013m²/g towards the 28th day of the regrowth period, respectively in Autumn and Summer.

  18. First-Generation Jet Propulsion Laboratory "Hockey-Puck" Free-Flying Magnetometers for Distributed In-Situ Multiprobe Measurement of Current Density Filamentation in the Northern Auroral Zone: Enstrophy Mission

    Science.gov (United States)

    Javadi, H.; Blaes, B.; Boehm, M.; Boykins, K.; Gibbs, J.; Goodman, W.; Lieneweg, U.; Lux, J.; Lynch, K.; Narvaez, P.

    2000-01-01

    The sub-orbital rocket mission was a collaborative project between the University of New Hampshire, Cornell University, and the Jet Propulsion Laboratory (JPL) to study filamentation phenomena in the northern Auroral zone. The Enstrophy mission test flies the JPL Free-Flying Magnetometer (FFM) concept. The FFM technology development task has been funded by NASA develop miniaturized, low-power, integrated "sensorcrafts". JPL's role was to design, integrate, test, and deliver four FFMs for deployment from the sounding rocket, allowing a unique determination of curl-B. This provides a direct measurement of magnetic-field-aligned current density along the rocket trajectory. A miniaturized three-axis fluxgate magnetometer was integrated with a 4-channel 22-bit sigma-delta Analog to Digital Converter (ADC), four temperature sensors, digital control electronics, seven (Li-SOCl2) batteries, two (4 deg x 170 deg field of view) sun-sensors, a fan-shaped-beam laser diode beacon, a (16 MHz) stable Temperature Compensated Crystal Oscillator (TCXO) clock, Radio Frequency (RF) communication subsystem, and an antenna for approximately 15 minutes of operation where data was collected continuously and transmitted in three (3) bursts (approximately 26 seconds each) to ground station antennas at Poker Flat, Alaska. FFMs were stowed within two trays onboard the rocket during the rocket launch and were released simultaneously using the spinning action of the rocket at approximately 300 km altitude (approximately 100 sec. into the flight). FFMs were deployed with spin rate of approximately 17 Hz and approximately 3 m/sec linear velocity with respect to the rocket. For testing purposes while the rocket was in the launch pad and during flight prior to release of FFMs from the rocket, commands (such as "power on", "test", "flight", "power off', and clock "Reset" signal) were transmitted via a infrared Light Emitting Diode to an infrared detector in the FFM. Special attention was paid to low

  19. Maximum permissible dose

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    This chapter presents a historic overview of the establishment of radiation guidelines by various national and international agencies. The use of maximum permissible dose and maximum permissible body burden limits to derive working standards is discussed

  20. Predicting areas of sustainable error growth in quasigeostrophic flows using perturbation alignment properties

    Science.gov (United States)

    Rivière, G.; Hua, B. L.

    2004-10-01

    A new perturbation initialization method is used to quantify error growth due to inaccuracies of the forecast model initial conditions in a quasigeostrophic box ocean model describing a wind-driven double gyre circulation. This method is based on recent analytical results on Lagrangian alignment dynamics of the perturbation velocity vector in quasigeostrophic flows. More specifically, it consists in initializing a unique perturbation from the sole knowledge of the control flow properties at the initial time of the forecast and whose velocity vector orientation satisfies a Lagrangian equilibrium criterion. This Alignment-based Initialization method is hereafter denoted as the AI method.In terms of spatial distribution of the errors, we have compared favorably the AI error forecast with the mean error obtained with a Monte-Carlo ensemble prediction. It is shown that the AI forecast is on average as efficient as the error forecast initialized with the leading singular vector for the palenstrophy norm, and significantly more efficient than that for total energy and enstrophy norms. Furthermore, a more precise examination shows that the AI forecast is systematically relevant for all control flows whereas the palenstrophy singular vector forecast leads sometimes to very good scores and sometimes to very bad ones.A principal component analysis at the final time of the forecast shows that the AI mode spatial structure is comparable to that of the first eigenvector of the error covariance matrix for a "bred mode" ensemble. Furthermore, the kinetic energy of the AI mode grows at the same constant rate as that of the "bred modes" from the initial time to the final time of the forecast and is therefore characterized by a sustained phase of error growth. In this sense, the AI mode based on Lagrangian dynamics of the perturbation velocity orientation provides a rationale of the "bred mode" behavior.

  1. Rethinking wave-kinetic theory applied to zonal flows

    Science.gov (United States)

    Parker, Jeffrey

    2017-10-01

    Over the past two decades, a number of studies have employed a wave-kinetic theory to describe fluctuations interacting with zonal flows. Recent work has uncovered a defect in this wave-kinetic formulation: the system is dominated by the growth of (arbitrarily) small-scale zonal structures. Theoretical calculations of linear growth rates suggest, and nonlinear simulations confirm, that this system leads to the concentration of zonal flow energy in the smallest resolved scales, irrespective of the numerical resolution. This behavior results from the assumption that zonal flows are extremely long wavelength, leading to the neglect of key terms responsible for conservation of enstrophy. A corrected theory, CE2-GO, is presented; it is free of these errors yet preserves the intuitive phase-space mathematical structure. CE2-GO properly conserves enstrophy as well as energy, and yields accurate growth rates of zonal flow. Numerical simulations are shown to be well-behaved and not dependent on box size. The steady-state limit simplifies into an exact wave-kinetic form which offers the promise of deeper insight into the behavior of wavepackets. The CE2-GO theory takes its place in a hierarchy of models as the geometrical-optics reduction of the more complete cumulant-expansion statistical theory CE2. The new theory represents the minimal statistical description, enabling an intuitive phase-space formulation and an accurate description of turbulence-zonal flow dynamics. This work was supported by an NSF Graduate Research Fellowship, a US DOE Fusion Energy Sciences Fellowship, and US DOE Contract Nos. DE-AC52-07NA27344 and DE-AC02-09CH11466.

  2. Treponema pallidum 3-Phosphoglycerate Mutase Is a Heat-Labile Enzyme That May Limit the Maximum Growth Temperature for the Spirochete

    Science.gov (United States)

    Benoit, Stéphane; Posey, James E.; Chenoweth, Matthew R.; Gherardini, Frank C.

    2001-01-01

    In the causative agent of syphilis, Treponema pallidum, the gene encoding 3-phosphoglycerate mutase, gpm, is part of a six-gene operon (tro operon) that is regulated by the Mn-dependent repressor TroR. Since substrate-level phosphorylation via the Embden-Meyerhof pathway is the principal way to generate ATP in T. pallidum and Gpm is a key enzyme in this pathway, Mn could exert a regulatory effect on central metabolism in this bacterium. To study this, T. pallidum gpm was cloned, Gpm was purified from Escherichia coli, and antiserum against the recombinant protein was raised. Immunoblots indicated that Gpm was expressed in freshly extracted infective T. pallidum. Enzyme assays indicated that Gpm did not require Mn2+ while 2,3-diphosphoglycerate (DPG) was required for maximum activity. Consistent with these observations, Mn did not copurify with Gpm. The purified Gpm was stable for more than 4 h at 25°C, retained only 50% activity after incubation for 20 min at 34°C or 10 min at 37°C, and was completely inactive after 10 min at 42°C. The temperature effect was attenuated when 1 mM DPG was added to the assay mixture. The recombinant Gpm from pSLB2 complemented E. coli strain PL225 (gpm) and restored growth on minimal glucose medium in a temperature-dependent manner. Increasing the temperature of cultures of E. coli PL225 harboring pSLB2 from 34 to 42°C resulted in a 7- to 11-h period in which no growth occurred (compared to wild-type E. coli). These data suggest that biochemical properties of Gpm could be one contributing factor to the heat sensitivity of T. pallidum. PMID:11466272

  3. Maximum standard metabolic rate corresponds with the salinity of maximum growth in hatchlings of the estuarine northern diamondback terrapin (Malaclemys terrapin terrapin): Implications for habitat conservation

    Science.gov (United States)

    Rowe, Christopher L.

    2018-01-01

    I evaluated standard metabolic rates (SMR) of hatchling northern diamondback terrapins (Malaclemys terrapin terrapin) across a range of salinities (salinity = 1.5, 4, 8, 12, and 16 psu) that they may encounter in brackish habitats such as those in the Maryland portion of the Chesapeake Bay, U.S.A. Consumption of O2 and production of CO2 by resting, unfed animals served as estimates of SMR. A peak in SMR occurred at 8 psu which corresponds closely with the salinity at which hatchling growth was previously shown to be maximized (salinity ∼ 9 psu). It appears that SMR is influenced by growth, perhaps reflecting investments in catabolic pathways that fuel anabolism. This ecophysiological information can inform environmental conservation and management activities by identifying portions of the estuary that are bioenergetically optimal for growth of hatchling terrapins. I suggest that conservation and restoration efforts to protect terrapin populations in oligo-to mesohaline habitats should prioritize protection or creation of habitats in regions where average salinity is near 8 psu and energetic investments in growth appear to be maximized.

  4. Effect of ethanol and methanol on growth of ruminal bacteria Selenomonas ruminantium and Butyrivibrio fibrisolvens.

    Science.gov (United States)

    Patterson, J A; Ricke, S C

    2015-01-01

    The effect of ethanol and methanol on growth of several ruminal bacterial strains was examined. Ethanol concentrations as low as 0.2% had a significant, but moderate, inhibitory effect on lag time or growth over time and 3.3% ethanol significantly inhibited maximum optical density obtained by both Selenomonas ruminantium and Butyrivibrio fibrisolvens. Little growth of either strain occurred at 10% ethanol concentrations. Methanol concentrations below 0.5% had little effect on either growth or maximum optical density of Selenomonas ruminantium whereas methanol concentrations below 3.3% had little effect on growth or maximum optical density of Butyrivibrio fibrisolvens. Higher methanol concentrations increasingly inhibited growth of both strains and no growth occurred at a 10% methanol concentration. Concentrations of ethanol or methanol used to add hydrophobic compounds to culture media should be kept below 1%.

  5. Growth of the green mussel, Perna viridis L., in a sea water circulating system

    Digital Repository Service at National Institute of Oceanography (India)

    Chatterji, A.; Ansari, Z.A.; Ingole, B.S.; Parulekar, A.H.

    Growth of the green mussel, P. viridis L., was studied in a sea water circulating system for 12 months. The maximum growth rate was recorded during March - May, coinciding with the maximum abundance of phytoplankton. The other hydrological...

  6. Egg production, growth and development of the cyclopoid copepod Oithona similis

    DEFF Research Database (Denmark)

    Sabatini, Marina; Kiørboe, Thomas

    1994-01-01

    Egg production, growth and development rates of Oithona similis were measured in the laboratory as a function of food concentration and composition. On an optimum diet, development is isochronal and growth is near exponential. The maximum juvenile growth rate at 15 degree C (0.2 day-1) is similar...... to juvenile growth in calanoid copepods. The maximum weight-specific egg production rate (0.1 day-1), on the other hand, is substantially less than in free-spawning calanoids, but similar to that in egg-carrying calanoids. In the Kattegat, Oithona spp. egg production is strongly limited by food during summer...

  7. Artificial neural network-based model for the prediction of optimal growth and culture conditions for maximum biomass accumulation in multiple shoot cultures of Centella asiatica.

    Science.gov (United States)

    Prasad, Archana; Prakash, Om; Mehrotra, Shakti; Khan, Feroz; Mathur, Ajay Kumar; Mathur, Archana

    2017-01-01

    An artificial neural network (ANN)-based modelling approach is used to determine the synergistic effect of five major components of growth medium (Mg, Cu, Zn, nitrate and sucrose) on improved in vitro biomass yield in multiple shoot cultures of Centella asiatica. The back propagation neural network (BPNN) was employed to predict optimal biomass accumulation in terms of growth index over a defined culture duration of 35 days. The four variable concentrations of five media components, i.e. MgSO 4 (0, 0.75, 1.5, 3.0 mM), ZnSO 4 (0, 15, 30, 60 μM), CuSO 4 (0, 0.05, 0.1, 0.2 μM), NO 3 (20, 30, 40, 60 mM) and sucrose (1, 3, 5, 7 %, w/v) were taken as inputs for the ANN model. The designed model was evaluated by performing three different sets of validation experiments that indicated a greater similarity between the target and predicted dataset. The results of the modelling experiment suggested that 1.5 mM Mg, 30 μM Zn, 0.1 μM Cu, 40 mM NO 3 and 6 % (w/v) sucrose were the respective optimal concentrations of the tested medium components for achieving maximum growth index of 1654.46 with high centelloside yield (62.37 mg DW/culture) in the cultured multiple shoots. This study can facilitate the generation of higher biomass of uniform, clean, good quality C. asiatica herb that can efficiently be utilized by pharmaceutical industries.

  8. Study of two-dimensional interchange turbulence

    International Nuclear Information System (INIS)

    Sugama, Hideo; Wakatani, Masahiro.

    1990-04-01

    An eddy viscosity model describing enstrophy transfer in two-dimensional turbulence is presented. This model is similar to that of Canuto et al. and provides an equation for the energy spectral function F(k) as a function of the energy input rate to the system per unit wavenumber, γ s (k). In the enstrophy-transfer inertial range, F(k)∝ k -3 is predicted by the model. The eddy viscosity model is applied to the interchange turbulence of a plasma in shearless magnetic field. Numerical simulation of the two-dimensional interchange turbulence demonstrates that the energy spectrum in the high wavenumber region is well described by this model. The turbulent transport driven by the interchange turbulence is expressed in terms of the Nusselt number Nu, the Rayleigh number Ra and Prantl number Pr in the same manner as that of thermal convection problem. When we use the linear growth rate for γ s (k), our theoretical model predicts that Nu ∝ (Ra·Pr) 1/2 for a constant background pressure gradient and Nu ∝ (Ra·Pr) 1/3 for a self-consistent background pressure profile with the stress-free slip boundary conditions. The latter agrees with our numerical result showing Nu ∝ Ra 1/3 . (author)

  9. Inviscid limit of stochastic damped 2D Navier–Stokes equations

    International Nuclear Information System (INIS)

    Bessaih, Hakima; Ferrario, Benedetta

    2014-01-01

    We consider the inviscid limit of the stochastic damped 2D Navier–Stokes equations. We prove that, when the viscosity vanishes, the stationary solution of the stochastic damped Navier–Stokes equations converges to a stationary solution of the stochastic damped Euler equation and that the rate of dissipation of enstrophy converges to zero. In particular, this limit obeys an enstrophy balance. The rates are computed with respect to a limit measure of the unique invariant measure of the stochastic damped Navier–Stokes equations. (paper)

  10. Orientations of dendritic growth during solidification

    Science.gov (United States)

    Lee, Dong Nyung

    2017-03-01

    Dendrites are crystalline forms which grow far from the limit of stability of the plane front and adopt an orientation which is as close as possible to the heat flux direction. Dendritic growth orientations for cubic metals, bct Sn, and hcp Zn, can be controlled by thermal conductivity, Young's modulus, and surface energy. The control factors have been elaborated. Since the dendrite is a single crystal, its properties such as thermal conductivity that influences the heat flux direction, the minimum Young's modulus direction that influences the strain energy minimization, and the minimum surface energy plane that influences the crystal/liquid interface energy minimization have been proved to control the dendritic growth direction. The dendritic growth directions of cubic metals are determined by the minimum Young's modulus direction and/or axis direction of symmetry of the minimum crystal surface energy plane. The dendritic growth direction of bct Sn is determined by its maximum thermal conductivity direction and the minimum surface energy plane normal direction. The primary dendritic growth direction of hcp Zn is determined by its maximum thermal conductivity direction and the minimum surface energy plane normal direction and the secondary dendrite arm direction of hcp Zn is normal to the primary dendritic growth direction.

  11. Maximum Langmuir Fields in Planetary Foreshocks Determined from the Electrostatic Decay Threshold

    Science.gov (United States)

    Robinson, P. A.; Cairns, Iver H.

    1995-01-01

    Maximum electric fields of Langmuir waves at planetary foreshocks are estimated from the threshold for electrostatic decay, assuming it saturates beam driven growth, and incorporating heliospheric variation of plasma density and temperature. Comparisons with spacecraft observations yields good quantitative agreement. Observations in type 3 radio sources are also in accord with this interpretation. A single mechanism can thus account for the highest fields of beam driven waves in both contexts.

  12. Hydraulic Limits on Maximum Plant Transpiration

    Science.gov (United States)

    Manzoni, S.; Vico, G.; Katul, G. G.; Palmroth, S.; Jackson, R. B.; Porporato, A. M.

    2011-12-01

    Photosynthesis occurs at the expense of water losses through transpiration. As a consequence of this basic carbon-water interaction at the leaf level, plant growth and ecosystem carbon exchanges are tightly coupled to transpiration. In this contribution, the hydraulic constraints that limit transpiration rates under well-watered conditions are examined across plant functional types and climates. The potential water flow through plants is proportional to both xylem hydraulic conductivity (which depends on plant carbon economy) and the difference in water potential between the soil and the atmosphere (the driving force that pulls water from the soil). Differently from previous works, we study how this potential flux changes with the amplitude of the driving force (i.e., we focus on xylem properties and not on stomatal regulation). Xylem hydraulic conductivity decreases as the driving force increases due to cavitation of the tissues. As a result of this negative feedback, more negative leaf (and xylem) water potentials would provide a stronger driving force for water transport, while at the same time limiting xylem hydraulic conductivity due to cavitation. Here, the leaf water potential value that allows an optimum balance between driving force and xylem conductivity is quantified, thus defining the maximum transpiration rate that can be sustained by the soil-to-leaf hydraulic system. To apply the proposed framework at the global scale, a novel database of xylem conductivity and cavitation vulnerability across plant types and biomes is developed. Conductivity and water potential at 50% cavitation are shown to be complementary (in particular between angiosperms and conifers), suggesting a tradeoff between transport efficiency and hydraulic safety. Plants from warmer and drier biomes tend to achieve larger maximum transpiration than plants growing in environments with lower atmospheric water demand. The predicted maximum transpiration and the corresponding leaf water

  13. Influence of Plant Population and Nitrogen-Fertilizer at Various Levels on Growth and Growth Efficiency of Maize

    Directory of Open Access Journals (Sweden)

    M. I. Tajul

    2013-01-01

    Full Text Available Field experiments were conducted to evaluate plant population and N-fertilizer effects on yield and yield components of maize (Zea mays L.. Three levels of plant populations (53000, 66000, and 800000 plants ha−1 corresponding to spacings of 75 × 25, 60 × 25, and 50 × 25 cm and 4 doses of N (100, 140, 180, and 220 kg ha−1 were the treatment variables. Results revealed that plant growth, light interception (LI, yield attributes, and grain yield varied significantly due to the variations in population density and N-rates. Crop growth rate (CGR was the highest with the population of 80,000 ha−1 receiving 220 kg N ha−1, while relative growth rate (RGR showed an opposite trend of CGR. Light absorption was maximum when most of densely populated plant received the highest amount of N (220 kg N ha−1. Response of soil-plant-analysis development (SPAD value as well as N-content to N-rates was found significant. Plant height was the maximum at the lowest plant density with the highest amount of N. Plants that received 180 kg N ha−1 with 80,000 plants ha−1 had larger foliage, greater SPAD value, and higher amount of grains cob−1 that contributed to the maximum yield (5.03 t ha−1 and the maximum harvest index (HI compared to the plants in other treatments.

  14. Cosmic shear measurement with maximum likelihood and maximum a posteriori inference

    Science.gov (United States)

    Hall, Alex; Taylor, Andy

    2017-06-01

    We investigate the problem of noise bias in maximum likelihood and maximum a posteriori estimators for cosmic shear. We derive the leading and next-to-leading order biases and compute them in the context of galaxy ellipticity measurements, extending previous work on maximum likelihood inference for weak lensing. We show that a large part of the bias on these point estimators can be removed using information already contained in the likelihood when a galaxy model is specified, without the need for external calibration. We test these bias-corrected estimators on simulated galaxy images similar to those expected from planned space-based weak lensing surveys, with promising results. We find that the introduction of an intrinsic shape prior can help with mitigation of noise bias, such that the maximum a posteriori estimate can be made less biased than the maximum likelihood estimate. Second-order terms offer a check on the convergence of the estimators, but are largely subdominant. We show how biases propagate to shear estimates, demonstrating in our simple set-up that shear biases can be reduced by orders of magnitude and potentially to within the requirements of planned space-based surveys at mild signal-to-noise ratio. We find that second-order terms can exhibit significant cancellations at low signal-to-noise ratio when Gaussian noise is assumed, which has implications for inferring the performance of shear-measurement algorithms from simplified simulations. We discuss the viability of our point estimators as tools for lensing inference, arguing that they allow for the robust measurement of ellipticity and shear.

  15. Simulations of a single vortex ring using an unbounded, regularized particle-mesh based vortex method

    DEFF Research Database (Denmark)

    Hejlesen, Mads Mølholm; Spietz, Henrik J.; Walther, Jens Honore

    2014-01-01

    , unbounded particle-mesh based vortex method is used to simulate the instability, transition to turbulence and eventual destruction of a single vortex ring. From the simulation data a novel method on analyzing the dynamics of the enstrophy is presented based on the alignment of the vorticity vector...... with the principal axis of the strain rate tensor. We find that the dynamics of the enstrophy density is dominated by the local flow deformation and axis of rotation, which is used to infer some concrete tendencies related to the topology of the vorticity field....

  16. Irradiation growth in zirconium alloys: a review

    International Nuclear Information System (INIS)

    Fidleris, V.

    1980-09-01

    The change in shape during irradiation without external stress, irradiation growth, was first discovered in uranium and later in graphite, zirconium and other core materials which exhibit anisotropic physical properties. The direction of maximum growth of metals invariably corresponds with the direction of minimum thermal expansion. In polycrystalline zirconium alloys growth is positive in the direction of maximum deformation during fabrication and in other directions it can be either positive or negative depending on the preferred orientation of grains (crystallographic texture). Growth increases gradually with temperature between 300 K and 620 K and rapidly with fluence up to about 1 x 10 25 n.m. -2 (Eμ1 MeV). At higher fluences the growth appears to saturate in annealed materials and reach a steady rate approximately proportional to dislocation density in cold-worked materials. Above 600 K both annealed and cold-worked materials have similar steady growth rates. Irradiation growth is caused by the segregation to different sinks of the vacancies and interstitials generated by irradiation, but the dominant types of sinks for each type of point defect and the mode of transport of the point defects to sinks cannot therefore be predicted theoretically. For the purpose of designing reactor core components empirical equations have been derived that can satisfactorily predict the steady state growth behaviour from texture and microstructure. (auth)

  17. Preliminarily study on the maximum handling size, prey size and species selectivity of growth hormone transgenic and non-transgenic common carp Cyprinus carpio when foraging on gastropods

    Science.gov (United States)

    Zhu, Tingbing; Zhang, Lihong; Zhang, Tanglin; Wang, Yaping; Hu, Wei; Olsen, Rolf Eric; Zhu, Zuoyan

    2017-10-01

    The present study preliminarily examined the differences in maximum handling size, prey size and species selectivity of growth hormone transgenic and non-transgenic common carp Cyprinus carpio when foraging on four gastropods species (Bellamya aeruginosa, Radix auricularia, Parafossarulus sinensis and Alocinma longicornis) under laboratory conditions. In the maximum handling size trial, five fish from each age group (1-year-old and 2-year-old) and each genotype (transgenic and non-transgenic) of common carp were individually allowed to feed on B. aeruginosa with wide shell height range. The results showed that maximum handling size increased linearly with fish length, and there was no significant difference in maximum handling size between the two genotypes. In the size selection trial, three pairs of 2-year-old transgenic and non-transgenic carp were individually allowed to feed on three size groups of B. aeruginosa. The results show that the two genotypes of C. carpio favored the small-sized group over the large-sized group. In the species selection trial, three pairs of 2-year-old transgenic and non-transgenic carp were individually allowed to feed on thin-shelled B. aeruginosa and thick-shelled R. auricularia, and five pairs of 2-year-old transgenic and non-transgenic carp were individually allowed to feed on two gastropods species (P. sinensis and A. longicornis) with similar size and shell strength. The results showed that both genotypes preferred thin-shelled Radix auricularia rather than thick-shelled B. aeruginosa, but there were no significant difference in selectivity between the two genotypes when fed on P. sinensis and A. longicornis. The present study indicates that transgenic and non-transgenic C. carpio show similar selectivity of predation on the size- and species-limited gastropods. While this information may be useful for assessing the environmental risk of transgenic carp, it does not necessarily demonstrate that transgenic common carp might

  18. Maximum Acceleration Recording Circuit

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1995-01-01

    Coarsely digitized maximum levels recorded in blown fuses. Circuit feeds power to accelerometer and makes nonvolatile record of maximum level to which output of accelerometer rises during measurement interval. In comparison with inertia-type single-preset-trip-point mechanical maximum-acceleration-recording devices, circuit weighs less, occupies less space, and records accelerations within narrower bands of uncertainty. In comparison with prior electronic data-acquisition systems designed for same purpose, circuit simpler, less bulky, consumes less power, costs and analysis of data recorded in magnetic or electronic memory devices. Circuit used, for example, to record accelerations to which commodities subjected during transportation on trucks.

  19. Value of volume measurements in evaluating abdominal aortic aneurysms growth rate and need for surgical treatment

    Energy Technology Data Exchange (ETDEWEB)

    Kontopodis, Nikolaos, E-mail: kontopodisn@yahoo.gr [Department of Vascular Surgery, University of Crete Medical School, Heraklion (Greece); Metaxa, Eleni, E-mail: emmetaxa@gmail.com [Institute of Applied and Computational Mathematics, Foundation for Research and Technology-Hellas, Heraklion, Crete (Greece); Papaharilaou, Yannis, E-mail: yannisp@iacm.forth.gr [Institute of Applied and Computational Mathematics, Foundation for Research and Technology-Hellas, Heraklion, Crete (Greece); Georgakarakos, Efstratios, E-mail: efstratiosgeorg@gmail.com [Vascular Surgery Department, “Demokritus” University of Thrace Medical School, Alexandroupolis (Greece); Tsetis, Dimitris, E-mail: tsetis@med.uoc.gr [Interventional Radiology Unit, Department of Radiology, University of Crete Medical School, Heraklion, Crete (Greece); Ioannou, Christos V., E-mail: ioannou@med.uoc.gr [Department of Vascular Surgery, University of Crete Medical School, Heraklion (Greece)

    2014-07-15

    Purpose: To examine whether indices other than the traditionally used abdominal aortic aneurysm (AAA) maximum diameter, such as AAA volume, intraluminal thrombus (ILT) thickness and ILT volume, may be superior to evaluate aneurismal enlargement. Materials and methods: Thirty-four small AAAs (initially presenting a maximum diameter <5.5 cm which is the threshold for surgical repair) with an initial and a follow-up CT were examined. Median increase and percentile annual change of these variables was calculated. Correlation between growth rates as determined by the new indices under evaluation and those of maximum diameter were assessed. AAAs were divided according to outcome (surveillance vs. elective repair after follow-up which is based on the maximum diameter criterion) and according to growth rate (high vs. low) based on four indices. Contingency between groups of high/low growth rate regarding each of the four indices on one hand and those regarding need for surgical repair on the other was assessed. Results: A strong correlation between growth rates of maximum diameter and those of AAA and ILT volumes could be established. Evaluation of contingency between groups of outcome and those of growth rate revealed significant associations only for AAA and ILT volumes. Subsequently AAAs with a rapid volumetric increase over time had a likelihood ratio of 10 to be operated compared to those with a slower enlargement. Regarding increase of maximum diameter, likelihood ratio between AAAs with rapid and those with slow expansion was only 3. Conclusion: Growth rate of aneurysms regarding 3Dimensional indices of AAA and ILT volumes is significantly associated with the need for surgical intervention while the same does not hold for growth rates determined by 2Dimensional indices of maximum diameter and ILT thickness.

  20. Value of volume measurements in evaluating abdominal aortic aneurysms growth rate and need for surgical treatment

    International Nuclear Information System (INIS)

    Kontopodis, Nikolaos; Metaxa, Eleni; Papaharilaou, Yannis; Georgakarakos, Efstratios; Tsetis, Dimitris; Ioannou, Christos V.

    2014-01-01

    Purpose: To examine whether indices other than the traditionally used abdominal aortic aneurysm (AAA) maximum diameter, such as AAA volume, intraluminal thrombus (ILT) thickness and ILT volume, may be superior to evaluate aneurismal enlargement. Materials and methods: Thirty-four small AAAs (initially presenting a maximum diameter <5.5 cm which is the threshold for surgical repair) with an initial and a follow-up CT were examined. Median increase and percentile annual change of these variables was calculated. Correlation between growth rates as determined by the new indices under evaluation and those of maximum diameter were assessed. AAAs were divided according to outcome (surveillance vs. elective repair after follow-up which is based on the maximum diameter criterion) and according to growth rate (high vs. low) based on four indices. Contingency between groups of high/low growth rate regarding each of the four indices on one hand and those regarding need for surgical repair on the other was assessed. Results: A strong correlation between growth rates of maximum diameter and those of AAA and ILT volumes could be established. Evaluation of contingency between groups of outcome and those of growth rate revealed significant associations only for AAA and ILT volumes. Subsequently AAAs with a rapid volumetric increase over time had a likelihood ratio of 10 to be operated compared to those with a slower enlargement. Regarding increase of maximum diameter, likelihood ratio between AAAs with rapid and those with slow expansion was only 3. Conclusion: Growth rate of aneurysms regarding 3Dimensional indices of AAA and ILT volumes is significantly associated with the need for surgical intervention while the same does not hold for growth rates determined by 2Dimensional indices of maximum diameter and ILT thickness

  1. Neutron spectra unfolding with maximum entropy and maximum likelihood

    International Nuclear Information System (INIS)

    Itoh, Shikoh; Tsunoda, Toshiharu

    1989-01-01

    A new unfolding theory has been established on the basis of the maximum entropy principle and the maximum likelihood method. This theory correctly embodies the Poisson statistics of neutron detection, and always brings a positive solution over the whole energy range. Moreover, the theory unifies both problems of overdetermined and of underdetermined. For the latter, the ambiguity in assigning a prior probability, i.e. the initial guess in the Bayesian sense, has become extinct by virtue of the principle. An approximate expression of the covariance matrix for the resultant spectra is also presented. An efficient algorithm to solve the nonlinear system, which appears in the present study, has been established. Results of computer simulation showed the effectiveness of the present theory. (author)

  2. Maximum Power from a Solar Panel

    Directory of Open Access Journals (Sweden)

    Michael Miller

    2010-01-01

    Full Text Available Solar energy has become a promising alternative to conventional fossil fuel sources. Solar panels are used to collect solar radiation and convert it into electricity. One of the techniques used to maximize the effectiveness of this energy alternative is to maximize the power output of the solar collector. In this project the maximum power is calculated by determining the voltage and the current of maximum power. These quantities are determined by finding the maximum value for the equation for power using differentiation. After the maximum values are found for each time of day, each individual quantity, voltage of maximum power, current of maximum power, and maximum power is plotted as a function of the time of day.

  3. Fast maximum likelihood estimation of mutation rates using a birth-death process.

    Science.gov (United States)

    Wu, Xiaowei; Zhu, Hongxiao

    2015-02-07

    Since fluctuation analysis was first introduced by Luria and Delbrück in 1943, it has been widely used to make inference about spontaneous mutation rates in cultured cells. Under certain model assumptions, the probability distribution of the number of mutants that appear in a fluctuation experiment can be derived explicitly, which provides the basis of mutation rate estimation. It has been shown that, among various existing estimators, the maximum likelihood estimator usually demonstrates some desirable properties such as consistency and lower mean squared error. However, its application in real experimental data is often hindered by slow computation of likelihood due to the recursive form of the mutant-count distribution. We propose a fast maximum likelihood estimator of mutation rates, MLE-BD, based on a birth-death process model with non-differential growth assumption. Simulation studies demonstrate that, compared with the conventional maximum likelihood estimator derived from the Luria-Delbrück distribution, MLE-BD achieves substantial improvement on computational speed and is applicable to arbitrarily large number of mutants. In addition, it still retains good accuracy on point estimation. Published by Elsevier Ltd.

  4. Monitoring urban growth around Rustenburg, South Africa, using ...

    African Journals Online (AJOL)

    Nale Mudau

    spatial growth of Rustenburg city in South Africa from 2007 to 2012 using ... Many studies point out that population growth in urban areas is a result of ... maximum likelihood, minimum distance, spectral unmixing and neutral networks. ..... Bands (Case Study: Arid Region of Iran)', American-Eurasian Journal of Agricultural.

  5. Effect of cultivation conditions on growth and antifungal activity of ...

    African Journals Online (AJOL)

    Administrator

    Growth and production of antifungal agent by Mycena leptocephala was investigated in different culture media composition at various initial pH and temperatures. Maximum growth and activity was observed at the initial pH of 5.5 and 25oC. No detectable growth and activity was observed at pH of 3.5 and 7.5. Growth of the ...

  6. Growth of microalgae in autotrophic stationary systems

    Directory of Open Access Journals (Sweden)

    Paulo Cunha

    2008-06-01

    Full Text Available In this paper we evaluate the growth of nine marine microalgae species (Nannochloropsis oculata, Thalassiosira pseudonana, Phaeodactylum tricornutum, Isochrysis galbana, Tetraselmis suecica, Tetraselmis chuii, Chaetoceros muelleri, Thalassiosira fluviatilis and Isochrysis sp. and one freshwater species (Chlorella vulgaris under stationary autotrophy conditions, using erlenmeyers fl asks with 800mL of culture medium exposed to constant light intensities providing a photon flux density of about 150μmol.m-2.s-1 and 25±2oC temperature and constant air flow. The experiment was carried out in a controlled environment considering a block delineating randomized over time with three replicates. The Nannochloropsis oculata showed the highest value of maximum cellular density, but with a longer period of time and a lower growth rate. This was probably due to its tiny cell size, demanding a large number of cells per volume to attain its optimum conditions for light, nutrients, water and atmospheric carbon dioxide. In addition, in spite of showing one of the lowest values of maximum cellular density, Thalassiosira fluviatilis was the species that reached its maximum in a short period of time at the highest growth rate. Chlorella vulgaris was the only freshwater species tested and it showed the poorest performance for all the variables analyzed in the current study.

  7. Maximum likelihood estimation for Cox's regression model under nested case-control sampling

    DEFF Research Database (Denmark)

    Scheike, Thomas Harder; Juul, Anders

    2004-01-01

    -like growth factor I was associated with ischemic heart disease. The study was based on a population of 3784 Danes and 231 cases of ischemic heart disease where controls were matched on age and gender. We illustrate the use of the MLE for these data and show how the maximum likelihood framework can be used......Nested case-control sampling is designed to reduce the costs of large cohort studies. It is important to estimate the parameters of interest as efficiently as possible. We present a new maximum likelihood estimator (MLE) for nested case-control sampling in the context of Cox's proportional hazards...... model. The MLE is computed by the EM-algorithm, which is easy to implement in the proportional hazards setting. Standard errors are estimated by a numerical profile likelihood approach based on EM aided differentiation. The work was motivated by a nested case-control study that hypothesized that insulin...

  8. Short Communication Synergistic effect of rhizobia and plant growth promoting rhizobacteria on the growth and nodulation of lentil seedlings under axenic conditions

    Directory of Open Access Journals (Sweden)

    Muhammad Zafar-ul-Hye

    2013-05-01

    Full Text Available Plant growth promoting rhizobacteria (PGPR containing ACC-deaminase in combination with rhizobia can improve the growth and nodulation in plants by suppressing the endogenous level of ethylene. In the present study, ten strains, each of PGPR and rhizobia from the previously screened cultures were tested for their effect as co-inoculants on growth and nodulation of lentil in growth pouches under axenic conditions. Results showed that most of the combinations improved the lentil growth as compared to the un-inoculated control. Maximum increase in shoot length (1.87 fold, root length (1.97 fold and total biomass (1.98 fold over the un-inoculated control was observed in the treatment where the lentil seedlings were inoculated with the combination Z24P10. Co-inoculation also improved the nodulation in lentil and the maximum number of nodules plant-1 (24 nodules were observed in the combination Z22P10. However, there was no nodulation in few combinations. It is concluded that the co-inoculation with rhizobia and PGPR containing ACC-deaminase has improved the growth and nodulation in lentil under axenic conditions and the selected combinations may be evaluated in pot and field trials

  9. Spatial variations of growth within domes having different patterns of principal growth directions

    Directory of Open Access Journals (Sweden)

    Jerzy Nakielski

    2014-01-01

    Full Text Available Growth rate variations for two paraboloidal domes: A and B, identical when seen from the outside but differing in the internal pattern of principal growth directions, were modeled by means of the growth tensor and a natural coordinate system. In dome A periclinal trajectories in the axial plane were given by confocal parabolas (as in a tunical dome, in dome B by parabolas converging to the vertex (as in a dome without a tunica. Accordingly, two natural coordinate systems, namely paraboloidal for A and convergent parabolic for B, were used. In both cases, the rate of growth in area on the surfaces of domes was assumed to be isotropic and identical in corresponding points. It appears that distributions of growth rates within domes A and B are similar in their peripheral and central parts and different only in their distal regions. In the latter, growth rates are relatively large; the maximum relative rate of growth in volume is around the geometric focus in dome A, and on the surface around the vertex in dome B.

  10. Maximum concentrations at work and maximum biologically tolerable concentration for working materials 1991

    International Nuclear Information System (INIS)

    1991-01-01

    The meaning of the term 'maximum concentration at work' in regard of various pollutants is discussed. Specifically, a number of dusts and smokes are dealt with. The valuation criteria for maximum biologically tolerable concentrations for working materials are indicated. The working materials in question are corcinogeneous substances or substances liable to cause allergies or mutate the genome. (VT) [de

  11. 40 CFR 1042.140 - Maximum engine power, displacement, power density, and maximum in-use engine speed.

    Science.gov (United States)

    2010-07-01

    ... cylinders having an internal diameter of 13.0 cm and a 15.5 cm stroke length, the rounded displacement would... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Maximum engine power, displacement... Maximum engine power, displacement, power density, and maximum in-use engine speed. This section describes...

  12. Credal Networks under Maximum Entropy

    OpenAIRE

    Lukasiewicz, Thomas

    2013-01-01

    We apply the principle of maximum entropy to select a unique joint probability distribution from the set of all joint probability distributions specified by a credal network. In detail, we start by showing that the unique joint distribution of a Bayesian tree coincides with the maximum entropy model of its conditional distributions. This result, however, does not hold anymore for general Bayesian networks. We thus present a new kind of maximum entropy models, which are computed sequentially. ...

  13. Power electronics and control techniques for maximum energy harvesting in photovoltaic systems

    CERN Document Server

    Femia, Nicola

    2012-01-01

    Incentives provided by European governments have resulted in the rapid growth of the photovoltaic (PV) market. Many PV modules are now commercially available, and there are a number of power electronic systems for processing the electrical power produced by PV systems, especially for grid-connected applications. Filling a gap in the literature, Power Electronics and Control Techniques for Maximum Energy Harvesting in Photovoltaic Systems brings together research on control circuits, systems, and techniques dedicated to the maximization of the electrical power produced by a photovoltaic (PV) so

  14. Maximum Entropy in Drug Discovery

    Directory of Open Access Journals (Sweden)

    Chih-Yuan Tseng

    2014-07-01

    Full Text Available Drug discovery applies multidisciplinary approaches either experimentally, computationally or both ways to identify lead compounds to treat various diseases. While conventional approaches have yielded many US Food and Drug Administration (FDA-approved drugs, researchers continue investigating and designing better approaches to increase the success rate in the discovery process. In this article, we provide an overview of the current strategies and point out where and how the method of maximum entropy has been introduced in this area. The maximum entropy principle has its root in thermodynamics, yet since Jaynes’ pioneering work in the 1950s, the maximum entropy principle has not only been used as a physics law, but also as a reasoning tool that allows us to process information in hand with the least bias. Its applicability in various disciplines has been abundantly demonstrated. We give several examples of applications of maximum entropy in different stages of drug discovery. Finally, we discuss a promising new direction in drug discovery that is likely to hinge on the ways of utilizing maximum entropy.

  15. Maximum Quantum Entropy Method

    OpenAIRE

    Sim, Jae-Hoon; Han, Myung Joon

    2018-01-01

    Maximum entropy method for analytic continuation is extended by introducing quantum relative entropy. This new method is formulated in terms of matrix-valued functions and therefore invariant under arbitrary unitary transformation of input matrix. As a result, the continuation of off-diagonal elements becomes straightforward. Without introducing any further ambiguity, the Bayesian probabilistic interpretation is maintained just as in the conventional maximum entropy method. The applications o...

  16. AEROSOL NUCLEATION AND GROWTH DURING LAMINAR TUBE FLOW: MAXIMUM SATURATIONS AND NUCLEATION RATES. (R827354C008)

    Science.gov (United States)

    An approximate method of estimating the maximum saturation, the nucleation rate, and the total number nucleated per second during the laminar flow of a hot vapour–gas mixture along a tube with cold walls is described. The basis of the approach is that the temperature an...

  17. Temperature and rainfall strongly drive temporal growth variation in Asian tropical forest trees.

    Science.gov (United States)

    Vlam, Mart; Baker, Patrick J; Bunyavejchewin, Sarayudh; Zuidema, Pieter A

    2014-04-01

    Climate change effects on growth rates of tropical trees may lead to alterations in carbon cycling of carbon-rich tropical forests. However, climate sensitivity of broad-leaved lowland tropical trees is poorly understood. Dendrochronology (tree-ring analysis) provides a powerful tool to study the relationship between tropical tree growth and annual climate variability. We aimed to establish climate-growth relationships for five annual-ring forming tree species, using ring-width data from 459 canopy and understory trees from a seasonal tropical forest in western Thailand. Based on 183/459 trees, chronologies with total lengths between 29 and 62 years were produced for four out of five species. Bootstrapped correlation analysis revealed that climate-growth responses were similar among these four species. Growth was significantly negatively correlated with current-year maximum and minimum temperatures, and positively correlated with dry-season precipitation levels. Negative correlations between growth and temperature may be attributed to a positive relationship between temperature and autotrophic respiration rates. The positive relationship between growth and dry-season precipitation levels likely reflects the strong water demand during leaf flush. Mixed-effect models yielded results that were consistent across species: a negative effect of current wet-season maximum temperatures on growth, but also additive positive effects of, for example, prior dry-season maximum temperatures. Our analyses showed that annual growth variability in tropical trees is determined by a combination of both temperature and precipitation variability. With rising temperature, the predominantly negative relationship between temperature and growth may imply decreasing growth rates of tropical trees as a result of global warming.

  18. Energy and protein requirements for growth of the local domestic ...

    African Journals Online (AJOL)

    The diet 3 in the grower phase improved growth with the highest EFU, 0.12, and was better utilized by the birds than in the chick starter phase where it was least utilized. High energy, high protein diet enhanced growth while low energy, high protein diet did not support maximum growth especially in the chick starter phase.

  19. Weighted Maximum-Clique Transversal Sets of Graphs

    OpenAIRE

    Chuan-Min Lee

    2011-01-01

    A maximum-clique transversal set of a graph G is a subset of vertices intersecting all maximum cliques of G. The maximum-clique transversal set problem is to find a maximum-clique transversal set of G of minimum cardinality. Motivated by the placement of transmitters for cellular telephones, Chang, Kloks, and Lee introduced the concept of maximum-clique transversal sets on graphs in 2001. In this paper, we study the weighted version of the maximum-clique transversal set problem for split grap...

  20. Climate-simulated raceway pond culturing: quantifying the maximum achievable annual biomass productivity of Chlorella sorokiniana in the contiguous USA

    Energy Technology Data Exchange (ETDEWEB)

    Huesemann, M.; Chavis, A.; Edmundson, S.; Rye, D.; Hobbs, S.; Sun, N.; Wigmosta, M.

    2017-09-13

    Chlorella sorokiniana (DOE 1412) emerged as one of the most promising microalgae strains from the NAABB consortium project, with a remarkable doubling time under optimal conditions of 2.57 hr-1. However, its maximum achievable annual biomass productivity in outdoor ponds in the contiguous United States remained unknown. In order to address this knowledge gap, this alga was cultured in indoor LED-lighted and temperature-controlled raceways in nutrient replete freshwater (BG-11) medium at pH 7 under conditions simulating the daily sunlight intensity and water temperature fluctuations during three seasons in Southern Florida, an optimal outdoor pond culture location for this organism identified by biomass growth modeling. Prior strain characterization indicated that the average maximum specific growth rate (µmax) at 36 ºC declined continuously with pH, with µmax corresponding to 5.92, 5.83, 4.89, and 4.21 day-1 at pH 6, 7, 8, and 9, respectively. In addition, the maximum specific growth rate declined nearly linearly with increasing salinity until no growth was observed above 35 g/L NaCl. In the climate-simulated culturing studies, the volumetric ash-free dry weight-based biomass productivities during the linear growth phase were 57, 69, and 97 mg/L-day for 30-year average light and temperature simulations for January (winter), March (spring), and July (summer), respectively, which corresponds to average areal productivities of 11.6, 14.1, and 19.9 g/m2-day at a constant pond depth of 20.5 cm. The photosynthetic efficiencies (PAR) in the three climate-simulated pond culturing experiments ranged from 4.1 to 5.1%. The annual biomass productivity was estimated as ca. 15 g/m2-day, nearly double the U.S. Department of Energy (DOE) 2015 State of Technology annual cultivation productivity of 8.5 g/m2-day, but this is still significantly below the projected 2022 target of ca. 25 g/m2-day (U.S. DOE, 2016) for economic microalgal biofuel production, indicating the need for

  1. Maximum power demand cost

    International Nuclear Information System (INIS)

    Biondi, L.

    1998-01-01

    The charging for a service is a supplier's remuneration for the expenses incurred in providing it. There are currently two charges for electricity: consumption and maximum demand. While no problem arises about the former, the issue is more complicated for the latter and the analysis in this article tends to show that the annual charge for maximum demand arbitrarily discriminates among consumer groups, to the disadvantage of some [it

  2. Distribution and growth of wood-borers in Bombay offshore waters

    Digital Repository Service at National Institute of Oceanography (India)

    Raveendran, T.V.; Wagh, A.B.

    . singaporeana and Teredo parksi at 62 m depths. T. indomalaiica and Teredora princesae were of very rare occurrence. B. campanellata was the fastest growing species with a maximum growth-rate of 65 mm. month/1. Growth rate was faster during the monsoon period...

  3. Effect of error in crack length measurement on maximum load fracture toughness of Zr-2.5Nb pressure tube material

    International Nuclear Information System (INIS)

    Bind, A.K.; Sunil, Saurav; Singh, R.N.; Chakravartty, J.K.

    2016-03-01

    Recently it was found that maximum load toughness (J max ) for Zr-2.5Nb pressure tube material was practically unaffected by error in Δ a . To check the sensitivity of the J max to error in Δ a measurement, the J max was calculated assuming no crack growth up to the maximum load (P max ) for as received and hydrogen charged Zr-2.5Nb pressure tube material. For load up to the P max , the J values calculated assuming no crack growth (J NC ) were slightly higher than that calculated based on Δ a measured using DCPD technique (JDCPD). In general, error in the J calculation found to be increased exponentially with Δ a . The error in J max calculation was increased with an increase in Δ a and a decrease in J max . Based on deformation theory of J, an analytic criterion was developed to check the insensitivity of the J max to error in Δ a . There was very good linear relation was found between the J max calculated based on Δ a measured using DCPD technique and the J max calculated assuming no crack growth. This relation will be very useful to calculate J max without measuring the crack growth during fracture test especially for irradiated material. (author)

  4. Mathematical modeling of microbial growth in milk

    Directory of Open Access Journals (Sweden)

    Jhony Tiago Teleken

    2011-12-01

    Full Text Available A mathematical model to predict microbial growth in milk was developed and analyzed. The model consists of a system of two differential equations of first order. The equations are based on physical hypotheses of population growth. The model was applied to five different sets of data of microbial growth in dairy products selected from Combase, which is the most important database in the area with thousands of datasets from around the world, and the results showed a good fit. In addition, the model provides equations for the evaluation of the maximum specific growth rate and the duration of the lag phase which may provide useful information about microbial growth.

  5. Age and growth of Cape stumpnose Rhabdosargus holubi (Pisces ...

    African Journals Online (AJOL)

    We examined and counted the opaque zones in the sectioned otoliths of 134 R. holubi to determine its age and growth parameters. The otoliths from two recaptured fish marked with oxytetracycline confirmed that one opaque zone was deposited annually. The species reached a maximum age of 18 years and growth was ...

  6. Ion permeability of the cytoplasmic membrane limits the maximum growth temperature of bacteria and archaea

    NARCIS (Netherlands)

    van de Vossenberg, J.L C M; Ubbink-Kok, T.; Elferink, M.G.L.; Driessen, A.J.M.; Konings, W.N

    1995-01-01

    Protons and sodium ions are the most commonly used coupling ions in energy transduction in bacteria and archaea. At their growth temperature, the permeability of the cytoplasmic membrane of thermophilic bacteria to protons is high compared with that of sodium ions. In some thermophiles, sodium is

  7. 49 CFR 230.24 - Maximum allowable stress.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Maximum allowable stress. 230.24 Section 230.24... Allowable Stress § 230.24 Maximum allowable stress. (a) Maximum allowable stress value. The maximum allowable stress value on any component of a steam locomotive boiler shall not exceed 1/4 of the ultimate...

  8. Development and Evaluation of Herbal Formulations for Hair Growth

    Directory of Open Access Journals (Sweden)

    Lipi Purwal

    2008-01-01

    Full Text Available Hair formulation of Emblica officinalis (Euphorbiaceae, Bacopa, monnieri (Scrophulariaceae, Trigonella foenumgraecum (Leguminosae, Murraya koenigii (Rutaceae in various concentrations in the form of herbal oil were studied for their hair growth activity. Each drug was tested for their hair growth activity in a concentration range for 1-10% separately. Based on these results mixture of crude drugs Murraya koeniigi, leaf (Rutaceae, Bacopa monnieri, leaf (Scrophulariaceae, Trigonella foenumgraecum (Leguminosae, Murraya koenigii (Rutaceae were prepared in varying concentration in the form of herbal hair oil by three different oils preparation techniques and were tested for hair growth activity. The result revealed that the hair growth activity of each drug was found proportional to the concentration range tested. Similarly higher concentrations of drug in the formulation were found to have higher hair growth activities. But looking towards the formulation viscosity the maximum concentration of combined drug was found to be 30% at their maximum level. The formulation containing 7.5% of each drug used for the study and showed excellent hair growth activity with standard (2% minoxidil ethanolic solution by an enlargement of follicular size and prolongation of the anagen phase. It holds the promise of potent herbal alternative for minoxidil. Excellent results of hair growth were seen in formulation prepared by cloth pouch decoction method of oils preparation technique.

  9. A maximum power point tracking for photovoltaic-SPE system using a maximum current controller

    Energy Technology Data Exchange (ETDEWEB)

    Muhida, Riza [Osaka Univ., Dept. of Physical Science, Toyonaka, Osaka (Japan); Osaka Univ., Dept. of Electrical Engineering, Suita, Osaka (Japan); Park, Minwon; Dakkak, Mohammed; Matsuura, Kenji [Osaka Univ., Dept. of Electrical Engineering, Suita, Osaka (Japan); Tsuyoshi, Akira; Michira, Masakazu [Kobe City College of Technology, Nishi-ku, Kobe (Japan)

    2003-02-01

    Processes to produce hydrogen from solar photovoltaic (PV)-powered water electrolysis using solid polymer electrolysis (SPE) are reported. An alternative control of maximum power point tracking (MPPT) in the PV-SPE system based on the maximum current searching methods has been designed and implemented. Based on the characteristics of voltage-current and theoretical analysis of SPE, it can be shown that the tracking of the maximum current output of DC-DC converter in SPE side will track the MPPT of photovoltaic panel simultaneously. This method uses a proportional integrator controller to control the duty factor of DC-DC converter with pulse-width modulator (PWM). The MPPT performance and hydrogen production performance of this method have been evaluated and discussed based on the results of the experiment. (Author)

  10. Effect of Temperature and Relative Humidity on the Growth of ...

    African Journals Online (AJOL)

    The effects of temperature and relative humidity on the growth of Helminthosporium fulvum were investigated. Various temperature regimes of 10oC, 15oC, 20oC, 25oC, 30oC, 35oC and 40¢ªC were used to determine the temperature effect on the growth of H. fulvum. Maximum growth of H. fulvum was obtained at 25¢ªC ...

  11. Growth properties and growth factor responsiveness in skin fibroblasts from centenarians.

    Science.gov (United States)

    Tesco, G; Vergelli, M; Grassilli, E; Salomoni, P; Bellesia, E; Sikora, E; Radziszewska, E; Barbieri, D; Latorraca, S; Fagiolo, U; Santacaterina, S; Amaducci, L; Tiozzo, R; Franceschi, C; Sorbi, S

    1998-03-27

    Human fibroblast cultures, which have a finite replicative lifespan in vitro, are the most widely used model for the study of senescence at the cellular level. An inverse relationship between replicative capability and donor age has been reported in human fibroblast strains. We studied the growth capacity of fibroblast primary cultures derived from people whose lifespan was as closer as possible to the expected maximum human lifespan, i.e. people over one hundred. Our data suggest that outgrowth of fibroblasts from biopsies, growth kinetics at different population doubling levels, capability to respond to a classical mitogenic stimulus (such as 20% serum) and a variety of growth factors, were remarkably similar in fibroblasts from centenarians and young controls. On the whole, our data challenge the tenet of a simple and strict relationship between in vivo aging and in vitro proliferative capability of human fibroblasts, at least at the individual level.

  12. Morphometric Analysis of Mandibular Growth in Skeletal Class III Malocclusion

    Directory of Open Access Journals (Sweden)

    Jenny Zwei-Chieng Chang

    2006-01-01

    Conclusion: We conclude that thin-plate spline analysis and the finite element morphometric method are efficient for the localization and quantification of size and shape changes that occur during mandibular growth. Plots of maximum and minimum principal directions can provide useful information about the trends of growth changes.

  13. Growth factors regulate glutamine synthetase activity in ...

    African Journals Online (AJOL)

    Khaled

    2012-07-10

    Jul 10, 2012 ... glutamate and ammonia, which in turn, cells are supplied with ammonia ... out to determine the maximum growth time at which cells will be .... Western blot technique for detection the glutamine synthetase enzyme. Lane 1;.

  14. Hydraulic limits on maximum plant transpiration and the emergence of the safety-efficiency trade-off.

    Science.gov (United States)

    Manzoni, Stefano; Vico, Giulia; Katul, Gabriel; Palmroth, Sari; Jackson, Robert B; Porporato, Amilcare

    2013-04-01

    Soil and plant hydraulics constrain ecosystem productivity by setting physical limits to water transport and hence carbon uptake by leaves. While more negative xylem water potentials provide a larger driving force for water transport, they also cause cavitation that limits hydraulic conductivity. An optimum balance between driving force and cavitation occurs at intermediate water potentials, thus defining the maximum transpiration rate the xylem can sustain (denoted as E(max)). The presence of this maximum raises the question as to whether plants regulate transpiration through stomata to function near E(max). To address this question, we calculated E(max) across plant functional types and climates using a hydraulic model and a global database of plant hydraulic traits. The predicted E(max) compared well with measured peak transpiration across plant sizes and growth conditions (R = 0.86, P efficiency trade-off in plant xylem. Stomatal conductance allows maximum transpiration rates despite partial cavitation in the xylem thereby suggesting coordination between stomatal regulation and xylem hydraulic characteristics. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  15. Lake Basin Fetch and Maximum Length/Width

    Data.gov (United States)

    Minnesota Department of Natural Resources — Linear features representing the Fetch, Maximum Length and Maximum Width of a lake basin. Fetch, maximum length and average width are calcuated from the lake polygon...

  16. Maximum permissible voltage of YBCO coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Wen, J.; Lin, B.; Sheng, J.; Xu, J.; Jin, Z. [Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai (China); Hong, Z., E-mail: zhiyong.hong@sjtu.edu.cn [Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai (China); Wang, D.; Zhou, H.; Shen, X.; Shen, C. [Qingpu Power Supply Company, State Grid Shanghai Municipal Electric Power Company, Shanghai (China)

    2014-06-15

    Highlights: • We examine three kinds of tapes’ maximum permissible voltage. • We examine the relationship between quenching duration and maximum permissible voltage. • Continuous I{sub c} degradations under repetitive quenching where tapes reaching maximum permissible voltage. • The relationship between maximum permissible voltage and resistance, temperature. - Abstract: Superconducting fault current limiter (SFCL) could reduce short circuit currents in electrical power system. One of the most important thing in developing SFCL is to find out the maximum permissible voltage of each limiting element. The maximum permissible voltage is defined as the maximum voltage per unit length at which the YBCO coated conductors (CC) do not suffer from critical current (I{sub c}) degradation or burnout. In this research, the time of quenching process is changed and voltage is raised until the I{sub c} degradation or burnout happens. YBCO coated conductors test in the experiment are from American superconductor (AMSC) and Shanghai Jiao Tong University (SJTU). Along with the quenching duration increasing, the maximum permissible voltage of CC decreases. When quenching duration is 100 ms, the maximum permissible of SJTU CC, 12 mm AMSC CC and 4 mm AMSC CC are 0.72 V/cm, 0.52 V/cm and 1.2 V/cm respectively. Based on the results of samples, the whole length of CCs used in the design of a SFCL can be determined.

  17. Application of Low cost Spirulina growth medium using Deep sea water

    Science.gov (United States)

    Lim, Dae-hack; Kim, Bong-ju; Lee, Sung-jae; Choi, Nag-chul; Park, Cheon-young

    2017-04-01

    Deep-sea water has a relatively constant temperature, abundant nutrients such as calcium, magnesium, nitrates, and phosphates, etc., and stable water quality, even though there might be some variations of their compositions according to collection places. Thus, deep-sea water would be a good substrate for algal growth and biomass production since it contains various nutrients, including a fluorescent red pigment, and β-carotene, etc. The aim of this study was to investigate the economics of a culture condition through comparative analysis to Spirulina platensis growth characteristic under various medium conditions for cost-effective production of Spirulina sp.. Growth experiments were performed with S. platensis under various culture medium conditions (deep sea water + SP medium). Growth tests for culture medium demonstrated that the deep sea water to SP medium ratio of 50:50(W/W) was effective in S. platensis with the maximum biomass (1.35g/L) and minimum medium making cost per production mass (133.28 KRW/g). Parameter estimation of bio-kinetics (maximum growth rate and yield) for low cost medium results showed that the maximum growth rate and yield of N, P, K were obtained under deep sea water to SP medium ratio of 50:50(W/W) of 0.057 1/day and 0.151, 0.076, 0.123, respectively. Acknowledgment : "This research was a part of the project titled 'Development of microalgae culture technique for cosmetic materials based on ocean deep sea water(20160297)', funded by the Ministry of Oceans and Fisheries, Korea."

  18. Receiver function estimated by maximum entropy deconvolution

    Institute of Scientific and Technical Information of China (English)

    吴庆举; 田小波; 张乃铃; 李卫平; 曾融生

    2003-01-01

    Maximum entropy deconvolution is presented to estimate receiver function, with the maximum entropy as the rule to determine auto-correlation and cross-correlation functions. The Toeplitz equation and Levinson algorithm are used to calculate the iterative formula of error-predicting filter, and receiver function is then estimated. During extrapolation, reflective coefficient is always less than 1, which keeps maximum entropy deconvolution stable. The maximum entropy of the data outside window increases the resolution of receiver function. Both synthetic and real seismograms show that maximum entropy deconvolution is an effective method to measure receiver function in time-domain.

  19. Growth Normal Faulting at the Western Edge of the Metropolitan Taipei Basin since the Last Glacial Maximum, Northern Taiwan

    Directory of Open Access Journals (Sweden)

    Chih-Tung Chen

    2010-01-01

    Full Text Available Growth strata analysis is an useful tool in understanding kinematics and the evolution of active faults as well as the close relationship between sedimentation and tectonics. Here we present the Shanchiao Fault as a case study which is an active normal fault responsible for the formation of the 700-m-thick late Quaternary deposits in Taipei Basin at the northern tip of the Taiwan mountain belt. We compiled a sedimentary record, particularly the depositional facies and their dated ages, at three boreholes (SCF-1, SCF-2 and WK-1, from west to east along the Wuku Profile that traverses the Shanchiao Fault at its central segment. By incorporating the global sea level change curve, we find that thickness changes of sediments and changes of depositional environments in the Wuku area are in a good agreement with a rapid sea level rise since the Last Glacial Maximum (LGM of about 23 ka. Combining depositional facies changes and their ages with their thickness, we are able to introduce a simple back-stripping method to reconstruct the evolution of growing strata across the Shanchiao Fault since the LGM. We then estimate the vertical tectonic slip rate since 23 ka, which exhibits 2.2 mm yr-1 between SCF-2 and WK-1 and 1.1 mm yr-1 between SCF-1 and SCF-2. We also obtain the Holocene tectonic subsidence rate of 2.3 mm yr-1 at WK-1 and 0.9 mm yr-1 at SCF-2 since 8.4 ka. We thus conclude that the fault zone consists of a high-angle main fault to the east between SCF-2 and WK-1 and a western lower-angle branch fault between SCF-1 and SCF-2, resembling a tulip structure developed under sinistral transtensional tectonism. We find that a short period of 600-yr time span in 9 - 8.4 ka shows important tectonic subsidence of 7.4 and 3.3 m for the main and branch fault, respectively, consistent with possible earthquake events proposed by previous studies during that time. A correlation between geomorphology and subsurface geology in the Shanchiao Fault zone shows

  20. Experimental workflow for developing a feed forward strategy to control biomass growth and exploit maximum specific methane productivity of Methanothermobacter marburgensis in a biological methane production process (BMPP

    Directory of Open Access Journals (Sweden)

    Alexander Krajete

    2016-08-01

    Full Text Available Recently, interests for new biofuel generations allowing conversion of gaseous substrate(s to gaseous product(s arose for power to gas and waste to value applications. An example is biological methane production process (BMPP with Methanothermobacter marburgensis. The latter, can convert carbon dioxide (CO2 and hydrogen (H2, having different origins and purities, to methane (CH4, water and biomass. However, these gas converting bioprocesses are tendentiously gas limited processes and the specific methane productivity per biomass amount (qCH4 tends to be low. Therefore, this contribution proposes a workflow for the development of a feed forward strategy to control biomass, growth (rx and qCH4 in a continuous gas limited BMPP. The proposed workflow starts with a design of experiment (DoE to optimize media composition and search for a liquid based limitation to control selectively growth. From the DoE it came out that controlling biomass growth was possible independently of the dilution and gassing rate applied while not affecting methane evolution rates (MERs. This was done by shifting the process from a natural gas limited state to a controlled liquid limited growth. The latter allowed exploiting the maximum biocatalytic activity for methane formation of Methanothermobacter marburgensis. An increase of qCH4 from 42 to 129 mmolCH4 g−1 h−1 was achieved by applying a liquid limitation compare with the reference state. Finally, a verification experiment was done to verify the feeding strategy transferability to a different process configuration. This evidenced the ratio of the fed KH2PO4 to rx (R(FKH2PO4/rx has an appropriate parameter for scaling feeds in a continuous gas limited BMPP. In the verification experiment CH4 was produced in a single bioreactor step at a methane evolution rate (MER of   132 mmolCH4*L−1*h−1 at a CH4 purity of 93 [Vol.%].

  1. Lagrangian statistics across the turbulent-nonturbulent interface in a turbulent plane jet.

    Science.gov (United States)

    Taveira, Rodrigo R; Diogo, José S; Lopes, Diogo C; da Silva, Carlos B

    2013-10-01

    Lagrangian statistics from millions of particles are used to study the turbulent entrainment mechanism in a direct numerical simulation of a turbulent plane jet at Re(λ) ≈ 110. The particles (tracers) are initially seeded at the irrotational region of the jet near the turbulent shear layer and are followed as they are drawn into the turbulent region across the turbulent-nonturbulent interface (TNTI), allowing the study of the enstrophy buildup and thereby characterizing the turbulent entrainment mechanism in the jet. The use of Lagrangian statistics following fluid particles gives a more correct description of the entrainment mechanism than in previous works since the statistics in relation to the TNTI position involve data from the trajectories of the entraining fluid particles. The Lagrangian statistics for the particles show the existence of a velocity jump and a characteristic vorticity jump (with a thickness which is one order of magnitude greater than the Kolmogorov microscale), in agreement with previous results using Eulerian statistics. The particles initially acquire enstrophy by viscous diffusion and later by enstrophy production, which becomes "active" only deep inside the turbulent region. Both enstrophy diffusion and production near the TNTI differ substantially from inside the turbulent region. Only about 1% of all particles find their way into pockets of irrotational flow engulfed into the turbulent shear layer region, indicating that "engulfment" is not significant for the present flow, indirectly suggesting that the entrainment is largely due to "nibbling" small-scale mechanisms acting along the entire TNTI surface. Probability density functions of particle positions suggests that the particles spend more time crossing the region near the TNTI than traveling inside the turbulent region, consistent with the particles moving tangent to the interface around the time they cross it.

  2. Development and validation of an extensive growth and growth boundary model for psychrotolerant Lactobacillus spp. in seafood and meat products

    DEFF Research Database (Denmark)

    Mejlholm, Ole; Dalgaard, Paw

    2013-01-01

    A new and extensive growth and growth boundary model for psychrotolerant Lactobacillus spp. was developed and validated for processed and unprocessed products of seafood and meat. The new model was developed by refitting and expanding an existing cardinal parameter model for growth and the growth...... of psychrotolerant Lactobacillus spp. was clearly demonstrated. The new model can be used to predict growth of psychrotolerant Lactobacillus spp. in seafood and meat products e.g. prediction of the time to a critical cell concentration of bacteria is considered useful for establishing the shelf life. In addition...... boundary of lactic acid bacteria (LAB) in processed seafood (O. Mejlholm and P. Dalgaard, J. Food Prot. 70. 2485–2497, 2007). Initially, to estimate values for the maximum specific growth rate at the reference temperature of 25°C (μref) and the theoretical minimum temperature that prevents growth...

  3. Maximum Gene-Support Tree

    Directory of Open Access Journals (Sweden)

    Yunfeng Shan

    2008-01-01

    Full Text Available Genomes and genes diversify during evolution; however, it is unclear to what extent genes still retain the relationship among species. Model species for molecular phylogenetic studies include yeasts and viruses whose genomes were sequenced as well as plants that have the fossil-supported true phylogenetic trees available. In this study, we generated single gene trees of seven yeast species as well as single gene trees of nine baculovirus species using all the orthologous genes among the species compared. Homologous genes among seven known plants were used for validation of the finding. Four algorithms—maximum parsimony (MP, minimum evolution (ME, maximum likelihood (ML, and neighbor-joining (NJ—were used. Trees were reconstructed before and after weighting the DNA and protein sequence lengths among genes. Rarely a gene can always generate the “true tree” by all the four algorithms. However, the most frequent gene tree, termed “maximum gene-support tree” (MGS tree, or WMGS tree for the weighted one, in yeasts, baculoviruses, or plants was consistently found to be the “true tree” among the species. The results provide insights into the overall degree of divergence of orthologous genes of the genomes analyzed and suggest the following: 1 The true tree relationship among the species studied is still maintained by the largest group of orthologous genes; 2 There are usually more orthologous genes with higher similarities between genetically closer species than between genetically more distant ones; and 3 The maximum gene-support tree reflects the phylogenetic relationship among species in comparison.

  4. Data compilation of respiration, feeding, and growth rates of marine pelagic organisms

    DEFF Research Database (Denmark)

    2013-01-01

    's adaptation to the environment, with consequently less universal mass scaling properties. Data on body mass, maximum ingestion and clearance rates, respiration rates and maximum growth rates of animals living in the ocean epipelagic were compiled from the literature, mainly from original papers but also from...

  5. Growth of Chlorella vulgaris and associated bacteria in photobioreactors

    Science.gov (United States)

    Lakaniemi, Aino‐Maija; Intihar, Veera M.; Tuovinen, Olli H.; Puhakka, Jaakko A.

    2012-01-01

    Summary The aim of this study was to test three flat plate photobioreactor configurations for growth of Chlorella vulgaris under non‐axenic conditions and to characterize and quantify associated bacterial communities. The photobioreactor cultivations were conducted using tap water‐based media to introduce background bacterial population. Growth of algae was monitored over time with three independent methods. Additionally, the quantity and quality of eukaryotes and bacteria were analysed using culture‐independent molecular tools based on denaturing gradient gel electrophoresis (PCR‐DGGE) and quantitative polymerase chain reaction (QPCR). Static mixers used in the flat plate photobioreactors did not generally enhance the growth at the low light intensities used. The maximum biomass concentration and maximum specific growth rate were 1.0 g l−1 and 2.0 day−1 respectively. Bacterial growth as determined by QPCR was associated with the growth of C. vulgaris. Based on PCR‐DGGE, bacteria in the cultures mainly originated from the tap water. Bacterial community profiles were diverse but reproducible in all flat plate cultures. Most prominent bacteria in the C. vulgaris cultures belonged to the class Alphaproteobacteria and especially to the genus Sphingomonas. Analysis of the diversity of non‐photosynthetic microorganisms in algal mass cultures can provide useful information on the public health aspects and unravel community interactions. PMID:21936882

  6. Maximum neutron flux in thermal reactors

    International Nuclear Information System (INIS)

    Strugar, P.V.

    1968-12-01

    Direct approach to the problem is to calculate spatial distribution of fuel concentration if the reactor core directly using the condition of maximum neutron flux and comply with thermal limitations. This paper proved that the problem can be solved by applying the variational calculus, i.e. by using the maximum principle of Pontryagin. Mathematical model of reactor core is based on the two-group neutron diffusion theory with some simplifications which make it appropriate from maximum principle point of view. Here applied theory of maximum principle are suitable for application. The solution of optimum distribution of fuel concentration in the reactor core is obtained in explicit analytical form. The reactor critical dimensions are roots of a system of nonlinear equations and verification of optimum conditions can be done only for specific examples

  7. 75 FR 43840 - Inflation Adjustment of the Ordinary Maximum and Aggravated Maximum Civil Monetary Penalties for...

    Science.gov (United States)

    2010-07-27

    ...-17530; Notice No. 2] RIN 2130-ZA03 Inflation Adjustment of the Ordinary Maximum and Aggravated Maximum... remains at $250. These adjustments are required by the Federal Civil Penalties Inflation Adjustment Act [email protected] . SUPPLEMENTARY INFORMATION: The Federal Civil Penalties Inflation Adjustment Act of 1990...

  8. Half-width at half-maximum, full-width at half-maximum analysis

    Indian Academy of Sciences (India)

    addition to the well-defined parameter full-width at half-maximum (FWHM). The distribution of ... optical side-lobes in the diffraction pattern resulting in steep central maxima [6], reduc- tion of effects of ... and broad central peak. The idea of.

  9. Two-dimensional maximum entropy image restoration

    International Nuclear Information System (INIS)

    Brolley, J.E.; Lazarus, R.B.; Suydam, B.R.; Trussell, H.J.

    1977-07-01

    An optical check problem was constructed to test P LOG P maximum entropy restoration of an extremely distorted image. Useful recovery of the original image was obtained. Comparison with maximum a posteriori restoration is made. 7 figures

  10. Maximum power point tracking

    International Nuclear Information System (INIS)

    Enslin, J.H.R.

    1990-01-01

    A well engineered renewable remote energy system, utilizing the principal of Maximum Power Point Tracking can be m ore cost effective, has a higher reliability and can improve the quality of life in remote areas. This paper reports that a high-efficient power electronic converter, for converting the output voltage of a solar panel, or wind generator, to the required DC battery bus voltage has been realized. The converter is controlled to track the maximum power point of the input source under varying input and output parameters. Maximum power point tracking for relative small systems is achieved by maximization of the output current in a battery charging regulator, using an optimized hill-climbing, inexpensive microprocessor based algorithm. Through practical field measurements it is shown that a minimum input source saving of 15% on 3-5 kWh/day systems can easily be achieved. A total cost saving of at least 10-15% on the capital cost of these systems are achievable for relative small rating Remote Area Power Supply systems. The advantages at larger temperature variations and larger power rated systems are much higher. Other advantages include optimal sizing and system monitor and control

  11. 7 CFR 3565.210 - Maximum interest rate.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Maximum interest rate. 3565.210 Section 3565.210... AGRICULTURE GUARANTEED RURAL RENTAL HOUSING PROGRAM Loan Requirements § 3565.210 Maximum interest rate. The interest rate for a guaranteed loan must not exceed the maximum allowable rate specified by the Agency in...

  12. Body growth and life history in wild mountain gorillas (Gorilla beringei beringei) from Volcanoes National Park, Rwanda.

    Science.gov (United States)

    Galbany, Jordi; Abavandimwe, Didier; Vakiener, Meagan; Eckardt, Winnie; Mudakikwa, Antoine; Ndagijimana, Felix; Stoinski, Tara S; McFarlin, Shannon C

    2017-07-01

    Great apes show considerable diversity in socioecology and life history, but knowledge of their physical growth in natural settings is scarce. We characterized linear body size growth in wild mountain gorillas from Volcanoes National Park, Rwanda, a population distinguished by its extreme folivory and accelerated life histories. In 131 individuals (0.09-35.26 years), we used non-invasive parallel laser photogrammetry to measure body length, back width, arm length and two head dimensions. Nonparametric LOESS regression was used to characterize cross-sectional distance and velocity growth curves for males and females, and consider links with key life history milestones. Sex differences became evident between 8.5 and 10.0 years of age. Thereafter, female growth velocities declined, while males showed increased growth velocities until 10.0-14.5 years across dimensions. Body dimensions varied in growth; females and males reached 98% of maximum body length at 11.7 and 13.1 years, respectively. Females attained 95.3% of maximum body length by mean age at first birth. Neonates were 31% of maternal size, and doubled in size by mean weaning age. Males reached maximum body and arm length and back width before emigration, but experienced continued growth in head dimensions. While comparable data are scarce, our findings provide preliminary support for the prediction that mountain gorillas reach maximum body size at earlier ages compared to more frugivorous western gorillas. Data from other wild populations are needed to better understand comparative great ape development, and investigate links between trajectories of physical, behavioral, and reproductive maturation. © 2017 Wiley Periodicals, Inc.

  13. Leaf Dynamics of Panicum maximum under Future Climatic Changes.

    Science.gov (United States)

    Britto de Assis Prado, Carlos Henrique; Haik Guedes de Camargo-Bortolin, Lívia; Castro, Érique; Martinez, Carlos Alberto

    2016-01-01

    Panicum maximum Jacq. 'Mombaça' (C4) was grown in field conditions with sufficient water and nutrients to examine the effects of warming and elevated CO2 concentrations during the winter. Plants were exposed to either the ambient temperature and regular atmospheric CO2 (Control); elevated CO2 (600 ppm, eC); canopy warming (+2°C above regular canopy temperature, eT); or elevated CO2 and canopy warming (eC+eT). The temperatures and CO2 in the field were controlled by temperature free-air controlled enhancement (T-FACE) and mini free-air CO2 enrichment (miniFACE) facilities. The most green, expanding, and expanded leaves and the highest leaf appearance rate (LAR, leaves day(-1)) and leaf elongation rate (LER, cm day(-1)) were observed under eT. Leaf area and leaf biomass were higher in the eT and eC+eT treatments. The higher LER and LAR without significant differences in the number of senescent leaves could explain why tillers had higher foliage area and leaf biomass in the eT treatment. The eC treatment had the lowest LER and the fewest expanded and green leaves, similar to Control. The inhibitory effect of eC on foliage development in winter was indicated by the fewer green, expanded, and expanding leaves under eC+eT than eT. The stimulatory and inhibitory effects of the eT and eC treatments, respectively, on foliage raised and lowered, respectively, the foliar nitrogen concentration. The inhibition of foliage by eC was confirmed by the eC treatment having the lowest leaf/stem biomass ratio and by the change in leaf biomass-area relationships from linear or exponential growth to rectangular hyperbolic growth under eC. Besides, eC+eT had a synergist effect, speeding up leaf maturation. Therefore, with sufficient water and nutrients in winter, the inhibitory effect of elevated CO2 on foliage could be partially offset by elevated temperatures and relatively high P. maximum foliage production could be achieved under future climatic change.

  14. Growth and α-amylase production by strains of Lactobacillus ...

    African Journals Online (AJOL)

    A cassava starch medium was used to analyse the dynamics of batch growth and α-amylase production of strains of Lactobacillus plantarum and Rhizopus oryzae isolated from cassava dried chips. The strains displayed a growth of 0.5h-1 and 0.55 h-1, a biomass yield on cassava starch of 0.49g/g and 0.5g/g, a maximum ...

  15. MXLKID: a maximum likelihood parameter identifier

    International Nuclear Information System (INIS)

    Gavel, D.T.

    1980-07-01

    MXLKID (MaXimum LiKelihood IDentifier) is a computer program designed to identify unknown parameters in a nonlinear dynamic system. Using noisy measurement data from the system, the maximum likelihood identifier computes a likelihood function (LF). Identification of system parameters is accomplished by maximizing the LF with respect to the parameters. The main body of this report briefly summarizes the maximum likelihood technique and gives instructions and examples for running the MXLKID program. MXLKID is implemented LRLTRAN on the CDC7600 computer at LLNL. A detailed mathematical description of the algorithm is given in the appendices. 24 figures, 6 tables

  16. Creep crack growth by grain boundary cavitation under monotonic and cyclic loading

    Science.gov (United States)

    Wen, Jian-Feng; Srivastava, Ankit; Benzerga, Amine; Tu, Shan-Tung; Needleman, Alan

    2017-11-01

    Plane strain finite deformation finite element calculations of mode I crack growth under small scale creep conditions are carried out. Attention is confined to isothermal conditions and two time histories of the applied stress intensity factor: (i) a monononic increase to a plateau value subsequently held fixed; and (ii) a cyclic time variation. The crack growth calculations are based on a micromechanics constitutive relation that couples creep deformation and damage due to grain boundary cavitation. Grain boundary cavitation, with cavity growth due to both creep and diffusion, is taken as the sole failure mechanism contributing to crack growth. The influence on the crack growth rate of loading history parameters, such as the magnitude of the applied stress intensity factor, the ratio of the applied minimum to maximum stress intensity factors, the loading rate, the hold time and the cyclic loading frequency, are explored. The crack growth rate under cyclic loading conditions is found to be greater than under monotonic creep loading with the plateau applied stress intensity factor equal to its maximum value under cyclic loading conditions. Several features of the crack growth behavior observed in creep-fatigue tests naturally emerge, for example, a Paris law type relation is obtained for cyclic loading.

  17. Effect of temperature on growth of psychrophilic and psychrotrophic members of Rhodotorula aurantiaca.

    Science.gov (United States)

    Sabri, A; Jacques, P; Weekers, F; Baré, G; Hiligsmann, S; Moussaïf, M; Thonart, P

    2000-01-01

    The thermo-dependence of growth kinetic parameters was investigated for the Antarctic psychrophilic strain Rhodotorula aurantiaca and a psychrotrophic strain of the same species isolated in Belgium (Ardennes area). Cell production, maximum growth rate (mu max), and half-saturation constant for glucose uptake (Ks) of both yeasts were temperature dependent. For the two yeasts, a maximum cell production was observed at about 0 degree C, and cell production decreased when temperature increased. The mu max values for both strains increased with temperature up to a maximum of 10 degrees C for the psychrophilic strain and 17 degrees C for the psychrotrophic strain. For both yeasts, Ks for glucose was relatively constant at low temperatures. It increased at temperatures above 10 degrees C for the psychrophilic strain and 17 degrees C for the psychrotrophic strain. Although its glucose affinity was lower, the psychrotrophic strain grew more rapidly than the psychrophilic one. The difference in growth rate and substrate affinity was related to the origin of the strain and the adaptation strategy of R. aurantiaca to environmental conditions.

  18. Climate Response of Tree Radial Growth at Different Timescales in the Qinling Mountains.

    Directory of Open Access Journals (Sweden)

    Changfeng Sun

    Full Text Available The analysis of the tree radial growth response to climate is crucial for dendroclimatological research. However, the response relationships between tree-ring indices and climatic factors at different timescales are not yet clear. In this study, the tree-ring width of Huashan pine (Pinus armandii from Huashan in the Qinling Mountains, north-central China, was used to explore the response differences of tree growth to climatic factors at daily, pentad (5 days, dekad (10 days and monthly timescales. Correlation function and linear regression analysis were applied in this paper. The tree-ring width showed a more sensitive response to daily and pentad climatic factors. With the timescale decreasing, the absolute value of the maximum correlation coefficient between the tree-ring data and precipitation increases as well as temperature (mean, minimum and maximum temperature. Compared to the other three timescales, pentad was more suitable for analysing the response of tree growth to climate. Relative to the monthly climate data, the association between the tree-ring data and the pentad climate data was more remarkable and accurate, and the reconstruction function based on the pentad climate was also more reliable and stable. We found that the major climatic factor limiting Huashan pine growth was the precipitation of pentads 20-35 (from April 6 to June 24 rather than the well-known April-June precipitation. The pentad was also proved to be a better timescale for analysing the climate and tree growth in the western and eastern Qinling Mountains. The formation of the earlywood density of Chinese pine (Pinus tabulaeformis from Shimenshan in western Qinling was mainly affected by the maximum temperature of pentads 28-32 (from May 16 to June 9. The maximum temperature of pentads 28-33 (from May 16 to June 14 was the major factor affecting the ring width of Chinese pine from Shirenshan in eastern Qinling.

  19. Change in Photosystem II Photochemistry During Algal Growth Phases of Chlorella vulgaris and Scenedesmus obliquus.

    Science.gov (United States)

    Oukarroum, Abdallah

    2016-06-01

    Sensitivity of photosynthetic processes towards environmental stress is used as a bioanalytical tool to evaluate the responses of aquatic plants to a changing environment. In this paper, change of biomass density, chlorophyll a fluorescence and photosynthetic parameters during growth phases of two microalgae Chlorella vulgaris and Scenedesmus obliquus were studied. The photosynthetic growth behaviour changed significantly with cell age and algae species. During the exponential phase of growth, the photosynthesis capacity reached its maximum and decreased in ageing algal culture during stationary phase. In conclusion, the chlorophyll a fluorescence OJIP method and the derived fluorescence parameters would be an accurate method for obtaining information on maximum photosynthetic capacities and monitoring algal cell growth. This will contribute to more understanding, for example, of toxic actions of pollutants in microalgae test.

  20. Maximum growth potential in loblolly pine: results from a 47-year-old spacing study in Hawaii

    Science.gov (United States)

    Lisa J. Samuelson; Thomas L. Eberhardt; John R. Butnor; Tom A. Stokes; Kurt H. Johnsen

    2010-01-01

    Growth, allocation to woody root biomass, wood properties, leaf physiology, and shoot morphology were examined in a 47-year-old loblolly pine (Pinus taeda L.) density trial located in Maui, Hawaii, to determine if stands continued to carry the high density, basal area, and volume reported at younger ages and to identify potential factors controlling...

  1. Influence of nitrogen and phosphorous on the growth and root morphology of Acer mono.

    Science.gov (United States)

    Razaq, Muhammad; Zhang, Peng; Shen, Hai-Long; Salahuddin

    2017-01-01

    Nitrogen and phosphorous are critical determinants of plant growth and productivity, and both plant growth and root morphology are important parameters for evaluating the effects of supplied nutrients. Previous work has shown that the growth of Acer mono seedlings is retarded under nursery conditions; we applied different levels of N (0, 5, 10, and 15 g plant-1) and P (0, 4, 6 and 8 g plant-1) fertilizer to investigate the effects of fertilization on the growth and root morphology of four-year-old seedlings in the field. Our results indicated that both N and P application significantly affected plant height, root collar diameter, chlorophyll content, and root morphology. Among the nutrient levels, 10 g N and 8 g P were found to yield maximum growth, and the maximum values of plant height, root collar diameter, chlorophyll content, and root morphology were obtained when 10 g N and 8 g P were used together. Therefore, the present study demonstrates that optimum levels of N and P can be used to improve seedling health and growth during the nursery period.

  2. 78 FR 9845 - Minimum and Ordinary Maximum and Aggravated Maximum Civil Monetary Penalties for a Violation of...

    Science.gov (United States)

    2013-02-12

    ... maximum penalty amount of $75,000 for each violation, except that if the violation results in death... the maximum civil penalty for a violation is $175,000 if the violation results in death, serious... Penalties for a Violation of the Hazardous Materials Transportation Laws or Regulations, Orders, Special...

  3. Effect of Temperature and pH on Formulating the Kinetic Growth Parameters and Lactic Acid Production of Lactobacillus bulgaricus

    Directory of Open Access Journals (Sweden)

    Marzieh Aghababaie

    2014-09-01

    Results: Second order model for Xmax, μmax, P and K was significant but product formation parameters were almost constant. The optimum values of temperature and pH for attaining maximum biomass, maximum specific growth rate, and maximum acid production were obtained at 44 °C and 5.7, respectively. Conclusions: The attained empirical mathematical correlations of RSM alongside the kinetic equations could be used to determine growth conditions under predefined temperature and pH in the fermentation process. Keywords: Lactobacillus bulgaricus, Richards model, Response surface methodology, Lactic acid production, Luedeking-Piret model

  4. Wavelength selection in injection-driven Hele-Shaw flows: A maximum amplitude criterion

    Science.gov (United States)

    Dias, Eduardo; Miranda, Jose

    2013-11-01

    As in most interfacial flow problems, the standard theoretical procedure to establish wavelength selection in the viscous fingering instability is to maximize the linear growth rate. However, there are important discrepancies between previous theoretical predictions and existing experimental data. In this work we perform a linear stability analysis of the radial Hele-Shaw flow system that takes into account the combined action of viscous normal stresses and wetting effects. Most importantly, we introduce an alternative selection criterion for which the selected wavelength is determined by the maximum of the interfacial perturbation amplitude. The effectiveness of such a criterion is substantiated by the significantly improved agreement between theory and experiments. We thank CNPq (Brazilian Sponsor) for financial support.

  5. Performance analysis and comparison of an Atkinson cycle coupled to variable temperature heat reservoirs under maximum power and maximum power density conditions

    International Nuclear Information System (INIS)

    Wang, P.-Y.; Hou, S.-S.

    2005-01-01

    In this paper, performance analysis and comparison based on the maximum power and maximum power density conditions have been conducted for an Atkinson cycle coupled to variable temperature heat reservoirs. The Atkinson cycle is internally reversible but externally irreversible, since there is external irreversibility of heat transfer during the processes of constant volume heat addition and constant pressure heat rejection. This study is based purely on classical thermodynamic analysis methodology. It should be especially emphasized that all the results and conclusions are based on classical thermodynamics. The power density, defined as the ratio of power output to maximum specific volume in the cycle, is taken as the optimization objective because it considers the effects of engine size as related to investment cost. The results show that an engine design based on maximum power density with constant effectiveness of the hot and cold side heat exchangers or constant inlet temperature ratio of the heat reservoirs will have smaller size but higher efficiency, compression ratio, expansion ratio and maximum temperature than one based on maximum power. From the view points of engine size and thermal efficiency, an engine design based on maximum power density is better than one based on maximum power conditions. However, due to the higher compression ratio and maximum temperature in the cycle, an engine design based on maximum power density conditions requires tougher materials for engine construction than one based on maximum power conditions

  6. Effect of Drought Stress on Growth and Morphological Characteristics of Two Garlic (Allium sativum L. Ecotypes in Different Planting Densities

    Directory of Open Access Journals (Sweden)

    shiva akbari

    2017-10-01

    underground organs and leaf area from measured samples of treatments were used. Results and Discussion The results showed that the highest value of maximum leaf area index (LAI, maximum total dry matter accumulation (TDM, maximum crop growth rate (CGR and maximum of net assimilation rate (NAR were observed at 100% ETc with the value of 5.537, 387.53 gr.m-2, 10.47 gr m-2day-1 and 4.92 gr.m-2leaf.day-1 respectively; and by applying the irrigation treatment of 80% ETc these values decreased to 3.745, 262.60 gr.m-2, 6.31 gr.m-2day-1 and 3.71 gr.m-2leaf.day-1 respectively. Drought stress can decrease cell development and division and plant photosynthesis, and thus, it can decrease leaf area index and consequently decrease light absorption, photosynthetic area, dry matter and crop growth rate. Difference between ecotypes in terms of number of leaves, maximum total dry matter accumulation and maximum crop growth rate was significant. Maximum crop growth rate (CGR in Toroud ecotype was higher than Tabas ecotype but number of leaves and maximum concentration of total dry matter (TDM in Tabas ecotype were higher than corresponding values in Toruod ecotype. The effect of planting density on maximum leaf area index (LAI, maximum total dry matter (TDM and maximum net assimilation rate (NAR was significant. The highest value of maximum leaf area index (5.017 and maximum total dry matter (358.57 g.m-2 concentration were obtained from 50 plant.m-2 density. The highest value of maximum net assimilation rate (4.61 was obtained from 30 plant.m-2 density. It could be because of having leaves exposed to more light and less shading. Conclusion Applying drought stress at the irrigation treatment of 80% ETc decreased studied growth characteristics of garlic. Therefore, it is recommended that garlic should be avoided from facing drought stress and its water requirement must be met as much as possible. In general, under drought stress, two studied ecotypes did not have any preference related to the

  7. Feedback Limits to Maximum Seed Masses of Black Holes

    International Nuclear Information System (INIS)

    Pacucci, Fabio; Natarajan, Priyamvada; Ferrara, Andrea

    2017-01-01

    The most massive black holes observed in the universe weigh up to ∼10 10 M ⊙ , nearly independent of redshift. Reaching these final masses likely required copious accretion and several major mergers. Employing a dynamical approach that rests on the role played by a new, relevant physical scale—the transition radius—we provide a theoretical calculation of the maximum mass achievable by a black hole seed that forms in an isolated halo, one that scarcely merged. Incorporating effects at the transition radius and their impact on the evolution of accretion in isolated halos, we are able to obtain new limits for permitted growth. We find that large black hole seeds ( M • ≳ 10 4 M ⊙ ) hosted in small isolated halos ( M h ≲ 10 9 M ⊙ ) accreting with relatively small radiative efficiencies ( ϵ ≲ 0.1) grow optimally in these circumstances. Moreover, we show that the standard M • – σ relation observed at z ∼ 0 cannot be established in isolated halos at high- z , but requires the occurrence of mergers. Since the average limiting mass of black holes formed at z ≳ 10 is in the range 10 4–6 M ⊙ , we expect to observe them in local galaxies as intermediate-mass black holes, when hosted in the rare halos that experienced only minor or no merging events. Such ancient black holes, formed in isolation with subsequent scant growth, could survive, almost unchanged, until present.

  8. Options for economic growth in Bangladesh : an application of the Von Neumann model

    NARCIS (Netherlands)

    Stolwijk, H.J.J.

    1987-01-01

    This study comprises an analysis and a quantification of the growth potential of the Bangladesh economy.

    Questions to be answered in this respect are a.o.:

    • what is the maximum (balanced) growth rate of the economy;
    • what does the economy look

    • Growth and xanthan production of Xanthomonas campestris depending on the N-source concentration

      Energy Technology Data Exchange (ETDEWEB)

      Prell, A [Academy of Sciences of the Czech Republic, Prague (Czech Republic). Inst. of Microbiology; Lasik, J [Academy of Sciences of the Czech Republic, Prague (Czech Republic). Inst. of Microbiology; Konicek, J [Academy of Sciences of the Czech Republic, Prague (Czech Republic). Inst. of Microbiology; Sobotka, M [Academy of Sciences of the Czech Republic, Prague (Czech Republic). Inst. of Microbiology; Sys, J [Academy of Sciences of the Czech Republic, Prague (Czech Republic). Inst. of Microbiology

      1995-11-01

      Growth of X. campestris and production of xanthan were studied in several batch fermentations with different starting concentrations of N-source. The dependencies of growth, productivity and yields on initial N-source concentration were observed. The maximum yields in the course of cultivations were identified. (orig.)

    • Crystal nucleation and dendrite growth of metastable phases in undercooled melts

      International Nuclear Information System (INIS)

      Herlach, Dieter

      2011-01-01

      Research highlights: → Homogenous nucleation. → Effects of convection on dendrite growth kinetics. → Description of disorder trapping validated by experiment. - Abstract: An undercooled melt possesses an enhanced free enthalpy that opens up the possibility to crystallize metastable crystalline solids in competition with their stable counterparts. Crystal nucleation selects the crystallographic phase whereas the growth dynamics controls microstructure evolution. We apply containerless processing techniques such as electromagnetic and electrostatic levitation to containerlesss undercool and solidify metallic melts. Owing to the complete avoidance of heterogeneous nucleation on container-walls a large undercooling range becomes accessible with the extra benefit that the freely suspended drop is direct accessible for in situ observation of crystallization far away from equilibrium. Results of investigations of maximum undercoolability on pure zirconium are presented showing the limit of maximum undercoolability set by the onset of homogeneous nucleation. Rapid dendrite growth is measured as a function of undercooling by a high-speed camera and analysed within extended theories of non-equilibrium solidification. In such both supersaturated solid solutions and disordered superlattice structure of intermetallics are formed at high growth velocities. A sharp interface theory of dendrite growth is capable to describe the non-equilibrium solidification phenomena during rapid crystallization of deeply undercooled melts. Eventually, anomalous growth behaviour of Al-rich Al-Ni alloys is presented, which may be caused by forced convection.

    • LCLS Maximum Credible Beam Power

      International Nuclear Information System (INIS)

      Clendenin, J.

      2005-01-01

      The maximum credible beam power is defined as the highest credible average beam power that the accelerator can deliver to the point in question, given the laws of physics, the beam line design, and assuming all protection devices have failed. For a new accelerator project, the official maximum credible beam power is determined by project staff in consultation with the Radiation Physics Department, after examining the arguments and evidence presented by the appropriate accelerator physicist(s) and beam line engineers. The definitive parameter becomes part of the project's safety envelope. This technical note will first review the studies that were done for the Gun Test Facility (GTF) at SSRL, where a photoinjector similar to the one proposed for the LCLS is being tested. In Section 3 the maximum charge out of the gun for a single rf pulse is calculated. In Section 4, PARMELA simulations are used to track the beam from the gun to the end of the photoinjector. Finally in Section 5 the beam through the matching section and injected into Linac-1 is discussed

    • Relation of Growth of Streptococcus lactis and Streptococcus cremoris to Amino Acid Transport

      NARCIS (Netherlands)

      Poolman, Bert; Konings, Wil N.

      The maximum specific growth rate of Streptococcus lactis and Streptococcus cremoris on synthetic medium containing glutamate but no glutamine decreases rapidly above pH 7. Growth of these organisms is extended to pH values in excess of 8 in the presence of glutamine. These results can be explained

    • Growth and development of male "little" mice assessed with Parks' theory of feeding and growth.

      Science.gov (United States)

      Puche, Rodolfo C; Alloatti, Rosa; Chapo, Gustavo

      2002-01-01

      This work was designed to characterize the appetite kinetics and growth of male C57BL/6J (lit) mice. Those variables were assessed with Parks' function of ad libitum feeding and growth. Heterozygous mice (lit/+) attained their mature weight at 12-15 weeks of age, peak growth rate (3.5 g/week) at 5 weeks and displayed the normal decay of food conversion efficiency as a function of age. The homozygous genotype has a chronic defect in the synthesis and secretion of growth hormone (GH). Homozygous mice could not be assessed with Park's function. From the 4th to the 15th week of age, body weight increased linearly and exhibited constant food conversion efficiency. Food intake of both genotypes was commensurate with their body weights. Lit/lit mice became progressively obese. At 40 weeks of age, body fat of lit/lit mice was fivefold that of lit/+ and their body weight was similar to their heterozygous controls. The chronic deficiency of growth hormone produced a lower bone mass (compared to heterozygous controls). Bone mass of both genotypes attained maturity at 12-15 weeks with a maximum growth rate at 5 weeks. Body weight and bone mass grow harmoniously in lit/+ but not in lit/lit mice.

    • Model for predicting non-linear crack growth considering load sequence effects (LOSEQ)

      International Nuclear Information System (INIS)

      Fuehring, H.

      1982-01-01

      A new analytical model for predicting non-linear crack growth is presented which takes into account the retardation as well as the acceleration effects due to irregular loading. It considers not only the maximum peak of a load sequence to effect crack growth but also all other loads of the history according to a generalised memory criterion. Comparisons between crack growth predicted by using the LOSEQ-programme and experimentally observed data are presented. (orig.) [de

    • A new system for sodium flux growth of bulk GaN. Part II: in situ investigation of growth processes

      KAUST Repository

      Von Dollen, Paul

      2016-09-09

      We report recent results of bulk GaN crystal growth using the sodium flux method in a new crucible-free growth system. We observed a (0001) Ga face (+c-plane) growth rate >50 µm/h for growth at a N2 overpressure of ~5 MPa and 860 °C, which is the highest crystal growth rate reported for this technique to date. Omega X-ray rocking curve (ω-XRC) measurements indicated the presence of multiple grains, though full width at half maximum (FWHM) values for individual peaks were <100 arcseconds. Oxygen impurity concentrations as measured by secondary ion mass spectroscopy (SIMS) were >1020 atoms/cm3. By monitoring the nitrogen pressure decay over the course of the crystal growth, we developed an in situ method that correlates gas phase changes with precipitation of GaN from the sodium-gallium melt. Based on this analysis, the growth rate may have actually been as high as 90 µm/h, as it would suggest GaN growth ceased prior to the end of the run. We also observed gas phase behavior identified as likely characteristic of GaN polynucleation.

    • A new system for sodium flux growth of bulk GaN. Part II: in situ investigation of growth processes

      KAUST Repository

      Von Dollen, Paul; Pimputkar, Siddha; Alreesh, Mohammed Abo; Nakamura, Shuji; Speck, James S.

      2016-01-01

      We report recent results of bulk GaN crystal growth using the sodium flux method in a new crucible-free growth system. We observed a (0001) Ga face (+c-plane) growth rate >50 µm/h for growth at a N2 overpressure of ~5 MPa and 860 °C, which is the highest crystal growth rate reported for this technique to date. Omega X-ray rocking curve (ω-XRC) measurements indicated the presence of multiple grains, though full width at half maximum (FWHM) values for individual peaks were <100 arcseconds. Oxygen impurity concentrations as measured by secondary ion mass spectroscopy (SIMS) were >1020 atoms/cm3. By monitoring the nitrogen pressure decay over the course of the crystal growth, we developed an in situ method that correlates gas phase changes with precipitation of GaN from the sodium-gallium melt. Based on this analysis, the growth rate may have actually been as high as 90 µm/h, as it would suggest GaN growth ceased prior to the end of the run. We also observed gas phase behavior identified as likely characteristic of GaN polynucleation.

    • Effect of Sugar Concentration in Jerusalem Artichoke Extract on Kluyveromyces marxianus Growth and Ethanol Production

      OpenAIRE

      Margaritis, Argyrios; Bajpai, Pratima

      1983-01-01

      The effect of inulin sugars concentration on the growth and ethanol production by Kluyveromyces marxianus UCD (FST) 55-82 was studied. A maximum ethanol concentration of 102 g/liter was obtained from 250 g of sugars per liter initial concentration. The maximum specific growth rate varied from 0.44 h−1 at 50 g of sugar per liter to 0.13 h−1 at 300 g of sugar per liter, whereas the ethanol yield remained almost constant at 0.45 g of ethanol per g of sugars utilized.

    • 13 CFR 107.840 - Maximum term of Financing.

      Science.gov (United States)

      2010-01-01

      ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Maximum term of Financing. 107.840... COMPANIES Financing of Small Businesses by Licensees Structuring Licensee's Financing of An Eligible Small Business: Terms and Conditions of Financing § 107.840 Maximum term of Financing. The maximum term of any...

    • Indirect effect of Moringa oleifera supplemented diet on growth rates ...

      African Journals Online (AJOL)

      weaning boer goat kids. ... of pregnant and lactating does could be advantageous for maximum milk production to support their kids' healthy early growth and development especially under unfavorable conditions such as during winter and drought.

    • Determination of the maximum inhibitory dilution of cetylpyridinium chloride-based mouthwashes against staphylococcus aureus: an in vitro study

      Directory of Open Access Journals (Sweden)

      Evandro Watanabe

      2008-08-01

      Full Text Available The aim of this in vitro study was to determine the maximum inhibitory dilution (MID of four cetylpyridinium chloride (CPC-based mouthwashes: CPC+Propolis, CPC+Malva, CPC+Eucaliptol+Juá+Romã+Propolis (Natural Honey® and CPC (Cepacol®, against 28 Staphylococcus aureus field strains, using the agar dilution method. Decimal dilutions ranging from 1/10 to 1/655,360 were prepared and added to Mueller Hinton Agar. Strains were inoculated using Steers multipoint inoculator. The inocula were seeded onto the surface of the culture medium in Petri dishes containing different dilutions of the mouthwashes. The dishes were incubated at 37ºC for 24 h. For readings, the MID was considered as the maximum dilution of mouthwash still capable of inhibiting microbial growth. The obtained data showed that CPC+Propolis had antimicrobial activity against 27 strains at 1/320 dilution and against all 28 strains at 1/160 dilution, CPC+Malva inhibited the growth of all 28 strains at 1/320 dilution, CPC+Eucaliptol+Juá+Romã+Propolis inhibited the growth of 2 strains at 1/640 dilution and all 28 strains at 1/320 dilution, and Cepacol® showed antimicrobial activity against 3 strains at 1/320 dilution and against all 28 strains at 1/160 dilution. Data were submitted to Kruskal-Wallis test, showing that the MID of Cepacol® was lower than that determined for the other products (p<0.05. In conclusion, CPC-mouthwashes showed antimicrobial activity against S. aureus and the addition of other substances to CPC improved its antimicrobial effect.

  1. 20 CFR 226.52 - Total annuity subject to maximum.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Total annuity subject to maximum. 226.52... COMPUTING EMPLOYEE, SPOUSE, AND DIVORCED SPOUSE ANNUITIES Railroad Retirement Family Maximum § 226.52 Total annuity subject to maximum. The total annuity amount which is compared to the maximum monthly amount to...

  2. Universal growth modes of high-elevation conifers

    Czech Academy of Sciences Publication Activity Database

    Datsenko, N. M.; Sonechkin, D. M.; Büntgen, Ulf; Yang, B.

    2016-01-01

    Roč. 38, JUN (2016), s. 38-50 ISSN 1125-7865 Institutional support: RVO:67179843 Keywords : tree-ring chronologies * summer temperature-variations * northeastern tibetan plateau * climate signal * fennoscandian summers * annual precipitation * density * variability * qinghai * Growth modes * Ring width and maximum latewood density * Eigenvector analysis Subject RIV: EF - Botanics Impact factor: 2.259, year: 2016

  3. Clostridium tyrobutyricum strains show wide variation in growth at different NaCl, pH, and temperature conditions.

    Science.gov (United States)

    Ruusunen, Marjo; Surakka, Anu; Korkeala, Hannu; Lindström, Miia

    2012-10-01

    Outgrowth from Clostridium tyrobutyricum spores in milk can lead to butyric acid fermentation in cheeses, causing spoilage and economical loss to the dairy industry. The aim of this study was to investigate the growth of 10 C. tyrobutyricum strains at different NaCl, pH, and temperature conditions. Up to 7.5-fold differences among the maximum growth rates of different strains in the presence of 2.0% NaCl were observed. Five of 10 strains were able to grow in the presence of 3.0% NaCl, while a NaCl concentration of 3.5% was completely inhibitory to all strains. Seven of 10 strains were able to grow at pH 5.0, and up to 4- and 12.5-fold differences were observed among the maximum growth rates of different strains at pH 5.5 and 7.5, respectively. The maximum growth temperatures varied from 40.2 to 43.3°C. The temperature of 10°C inhibited the growth of all strains, while 8 of 10 strains grew at 12 and 15°C. Despite showing no growth, all strains were able to survive at 10°C. In conclusion, wide variation was observed among different C. tyrobutyricum strains in their ability to grow at different stressful conditions. Understanding the physiological diversity among the strains is important when designing food control measures and predictive models for the growth of spoilage organisms in cheese.

  4. Effect of food microstructure on growth dynamics of Listeria monocytogenes in fish-based model systems.

    Science.gov (United States)

    Verheyen, Davy; Bolívar, Araceli; Pérez-Rodríguez, Fernando; Baka, Maria; Skåra, Torstein; Van Impe, Jan F

    2018-06-01

    Traditionally, predictive growth models for food pathogens are developed based on experiments in broth media, resulting in models which do not incorporate the influence of food microstructure. The use of model systems with various microstructures is a promising concept to get more insight into the influence of food microstructure on microbial dynamics. By means of minimal variation of compositional and physicochemical factors, these model systems can be used to study the isolated effect of certain microstructural aspects on microbial growth, survival and inactivation. In this study, the isolated effect on microbial growth dynamics of Listeria monocytogenes of two food microstructural aspects and one aspect influenced by food microstructure were investigated, i.e., the nature of the food matrix, the presence of fat droplets, and microorganism growth morphology, respectively. To this extent, fish-based model systems with various microstructures were used, i.e., a liquid, a second more viscous liquid system containing xanthan gum, an emulsion, an aqueous gel, and a gelled emulsion. Growth experiments were conducted at 4 and 10 °C, both using homogeneous and surface inoculation (only for the gelled systems). Results regarding the influence of the growth morphology indicated that the lag phase of planktonic cells in the liquid system was similar to the lag phase of submerged colonies in the xanthan system. The lag phase of submerged colonies in each gelled system was considerably longer than the lag phase of surface colonies on these respective systems. The maximum specific growth rate of planktonic cells in the liquid system was significantly lower than for submerged colonies in the xanthan system at 10 °C, while no significant differences were observed at 4 °C. The maximum cell density was higher for submerged colonies than for surface colonies. The nature of the food matrix only exerted an influence on the maximum specific growth rate, which was

  5. Analyses of multi-color plant-growth light sources in achieving maximum photosynthesis efficiencies with enhanced color qualities.

    Science.gov (United States)

    Wu, Tingzhu; Lin, Yue; Zheng, Lili; Guo, Ziquan; Xu, Jianxing; Liang, Shijie; Liu, Zhuguagn; Lu, Yijun; Shih, Tien-Mo; Chen, Zhong

    2018-02-19

    An optimal design of light-emitting diode (LED) lighting that benefits both the photosynthesis performance for plants and the visional health for human eyes has drawn considerable attention. In the present study, we have developed a multi-color driving algorithm that serves as a liaison between desired spectral power distributions and pulse-width-modulation duty cycles. With the aid of this algorithm, our multi-color plant-growth light sources can optimize correlated-color temperature (CCT) and color rendering index (CRI) such that photosynthetic luminous efficacy of radiation (PLER) is maximized regardless of the number of LEDs and the type of photosynthetic action spectrum (PAS). In order to illustrate the accuracies of the proposed algorithm and the practicalities of our plant-growth light sources, we choose six color LEDs and German PAS for experiments. Finally, our study can help provide a useful guide to improve light qualities in plant factories, in which long-term co-inhabitance of plants and human beings is required.

  6. Effect of Furfural on Saccharomyces carlsbergensis Growth, Physiology and Ethanol Production.

    Science.gov (United States)

    Lopes da Silva, Teresa; Santo, Rui; Reis, Alberto; Passarinho, Paula C

    2017-06-01

    This work described the effect of furfural, a product resulting from the lignocellulosic material pretreatment, on Saccharomyces carlsbergensis growth and ethanol production. Flow cytometry was used to evaluate the yeast membrane potential, membrane integrity, reactive oxygen species production and lipid content. Above 0.3 g/L of furfural, a progressive decrease in the maximal specific growth rate was observed, reaching 53% of the value obtained in the absence of toxic when the cells were grown in the presence of 4 g/L of furfural. In general, the yeast biomass concentration and yield were less affected by the furfural presence than the specific growth rate, and a maximum reduction of 25% was observed for the assay at 4 g/L. The ethanol production was even less affected by the furfural presence than the yeast growth. At 4 g/L of furfural, the maximum ethanol concentration was reduced by only 10% relatively to the maximum ethanol concentration observed in the absence of toxic. At 5 g/L of furfural, the yeast cells were barely able to keep metabolic functions and produced a final ethanol concentration of 0.87 g/L although growth was undetectable. S. carlsbergensis membrane potential was affected by the furfural presence, concomitantly with the ethanol production. However, at 4 g/L, most of the yeast cells (90%) displayed the cytoplasmic membrane depolarized. The proportion of cells with increasing reactive oxygen species (ROS) production levels increased for the experiments at 0-4 g/L. For the experiment at 4.5 g/L of furfural, ROS production was observed for only 11% of the yeast cells. The yeast lipid content was also severely affected by the furfural presence. Both polar and neutral lipids decreased in the presence of furfural, and this reduction was more notorious during the stationary phase.

  7. Evaluation of staphylococcus aureus growth in unirradiated and irradiated cured meats using the Gompertz equation

    International Nuclear Information System (INIS)

    Szczawinski, J.; Szczawinska, M.

    1993-01-01

    1. Sodium nitrite, in concentration of 156 mg/kg, exerted little (from practical point of view) inhibitory effect on S. aureus in cured meat. Its addition caused lag time extension, increase of exponential growth rate, decrease of generation time and maximum population density of staphylococci in samples of cured meat stored at 20 C. 2. Growth curves of Staphylococcus aureus in unirradiated and irradiated (50 kGy) meats cured without sodium nitrite were similar. 3. Irradiation of meat cured with 156 mg/kg sodium nitrite with increasing doses of ionizing radiation (0, 10, 30, 50 kGy) progressively decreased growth rates and lag time and increased generation time and maximum population densities of Staphylococcus aureus in samples inoculated after radiation treatment and incubated at 20 C. (orig.)

  8. Aging, Maturation and Growth of Sauropodomorph Dinosaurs as Deduced from Growth Curves Using Long Bone Histological Data: An Assessment of Methodological Constraints and Solutions.

    Science.gov (United States)

    Griebeler, Eva Maria; Klein, Nicole; Sander, P Martin

    2013-01-01

    Information on aging, maturation, and growth is important for understanding life histories of organisms. In extinct dinosaurs, such information can be derived from the histological growth record preserved in the mid-shaft cortex of long bones. Here, we construct growth models to estimate ages at death, ages at sexual maturity, ages at which individuals were fully-grown, and maximum growth rates from the growth record preserved in long bones of six sauropod dinosaur individuals (one indeterminate mamenchisaurid, two Apatosaurus sp., two indeterminate diplodocids, and one Camarasaurus sp.) and one basal sauropodomorph dinosaur individual (Plateosaurus engelhardti). Using these estimates, we establish allometries between body mass and each of these traits and compare these to extant taxa. Growth models considered for each dinosaur individual were the von Bertalanffy model, the Gompertz model, and the logistic model (LGM), all of which have inherently fixed inflection points, and the Chapman-Richards model in which the point is not fixed. We use the arithmetic mean of the age at the inflection point and of the age at which 90% of asymptotic mass is reached to assess respectively the age at sexual maturity or the age at onset of reproduction, because unambiguous indicators of maturity in Sauropodomorpha are lacking. According to an AIC-based model selection process, the LGM was the best model for our sauropodomorph sample. Allometries established are consistent with literature data on other Sauropodomorpha. All Sauropodomorpha reached full size within a time span similar to scaled-up modern mammalian megaherbivores and had similar maximum growth rates to scaled-up modern megaherbivores and ratites, but growth rates of Sauropodomorpha were lower than of an average mammal. Sauropodomorph ages at death probably were lower than that of average scaled-up ratites and megaherbivores. Sauropodomorpha were older at maturation than scaled-up ratites and average mammals, but

  9. Aging, Maturation and Growth of Sauropodomorph Dinosaurs as Deduced from Growth Curves Using Long Bone Histological Data: An Assessment of Methodological Constraints and Solutions.

    Directory of Open Access Journals (Sweden)

    Eva Maria Griebeler

    Full Text Available Information on aging, maturation, and growth is important for understanding life histories of organisms. In extinct dinosaurs, such information can be derived from the histological growth record preserved in the mid-shaft cortex of long bones. Here, we construct growth models to estimate ages at death, ages at sexual maturity, ages at which individuals were fully-grown, and maximum growth rates from the growth record preserved in long bones of six sauropod dinosaur individuals (one indeterminate mamenchisaurid, two Apatosaurus sp., two indeterminate diplodocids, and one Camarasaurus sp. and one basal sauropodomorph dinosaur individual (Plateosaurus engelhardti. Using these estimates, we establish allometries between body mass and each of these traits and compare these to extant taxa. Growth models considered for each dinosaur individual were the von Bertalanffy model, the Gompertz model, and the logistic model (LGM, all of which have inherently fixed inflection points, and the Chapman-Richards model in which the point is not fixed. We use the arithmetic mean of the age at the inflection point and of the age at which 90% of asymptotic mass is reached to assess respectively the age at sexual maturity or the age at onset of reproduction, because unambiguous indicators of maturity in Sauropodomorpha are lacking. According to an AIC-based model selection process, the LGM was the best model for our sauropodomorph sample. Allometries established are consistent with literature data on other Sauropodomorpha. All Sauropodomorpha reached full size within a time span similar to scaled-up modern mammalian megaherbivores and had similar maximum growth rates to scaled-up modern megaherbivores and ratites, but growth rates of Sauropodomorpha were lower than of an average mammal. Sauropodomorph ages at death probably were lower than that of average scaled-up ratites and megaherbivores. Sauropodomorpha were older at maturation than scaled-up ratites and average

  10. Maximum likely scale estimation

    DEFF Research Database (Denmark)

    Loog, Marco; Pedersen, Kim Steenstrup; Markussen, Bo

    2005-01-01

    A maximum likelihood local scale estimation principle is presented. An actual implementation of the estimation principle uses second order moments of multiple measurements at a fixed location in the image. These measurements consist of Gaussian derivatives possibly taken at several scales and/or ...

  11. Maximum gravitational redshift of white dwarfs

    International Nuclear Information System (INIS)

    Shapiro, S.L.; Teukolsky, S.A.

    1976-01-01

    The stability of uniformly rotating, cold white dwarfs is examined in the framework of the Parametrized Post-Newtonian (PPN) formalism of Will and Nordtvedt. The maximum central density and gravitational redshift of a white dwarf are determined as functions of five of the nine PPN parameters (γ, β, zeta 2 , zeta 3 , and zeta 4 ), the total angular momentum J, and the composition of the star. General relativity predicts that the maximum redshifts is 571 km s -1 for nonrotating carbon and helium dwarfs, but is lower for stars composed of heavier nuclei. Uniform rotation can increase the maximum redshift to 647 km s -1 for carbon stars (the neutronization limit) and to 893 km s -1 for helium stars (the uniform rotation limit). The redshift distribution of a larger sample of white dwarfs may help determine the composition of their cores

  12. Feedback Limits to Maximum Seed Masses of Black Holes

    Energy Technology Data Exchange (ETDEWEB)

    Pacucci, Fabio; Natarajan, Priyamvada [Department of Physics, Yale University, P.O. Box 208121, New Haven, CT 06520 (United States); Ferrara, Andrea [Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa (Italy)

    2017-02-01

    The most massive black holes observed in the universe weigh up to ∼10{sup 10} M {sub ⊙}, nearly independent of redshift. Reaching these final masses likely required copious accretion and several major mergers. Employing a dynamical approach that rests on the role played by a new, relevant physical scale—the transition radius—we provide a theoretical calculation of the maximum mass achievable by a black hole seed that forms in an isolated halo, one that scarcely merged. Incorporating effects at the transition radius and their impact on the evolution of accretion in isolated halos, we are able to obtain new limits for permitted growth. We find that large black hole seeds ( M {sub •} ≳ 10{sup 4} M {sub ⊙}) hosted in small isolated halos ( M {sub h} ≲ 10{sup 9} M {sub ⊙}) accreting with relatively small radiative efficiencies ( ϵ ≲ 0.1) grow optimally in these circumstances. Moreover, we show that the standard M {sub •}– σ relation observed at z ∼ 0 cannot be established in isolated halos at high- z , but requires the occurrence of mergers. Since the average limiting mass of black holes formed at z ≳ 10 is in the range 10{sup 4–6} M {sub ⊙}, we expect to observe them in local galaxies as intermediate-mass black holes, when hosted in the rare halos that experienced only minor or no merging events. Such ancient black holes, formed in isolation with subsequent scant growth, could survive, almost unchanged, until present.

  13. Economic analysis of crystal growth in space

    Science.gov (United States)

    Ulrich, D. R.; Chung, A. M.; Yan, C. S.; Mccreight, L. R.

    1972-01-01

    Many advanced electronic technologies and devices for the 1980's are based on sophisticated compound single crystals, i.e. ceramic oxides and compound semiconductors. Space processing of these electronic crystals with maximum perfection, purity, and size is suggested. No ecomonic or technical justification was found for the growth of silicon single crystals for solid state electronic devices in space.

  14. Revealing the Maximum Strength in Nanotwinned Copper

    DEFF Research Database (Denmark)

    Lu, L.; Chen, X.; Huang, Xiaoxu

    2009-01-01

    boundary–related processes. We investigated the maximum strength of nanotwinned copper samples with different twin thicknesses. We found that the strength increases with decreasing twin thickness, reaching a maximum at 15 nanometers, followed by a softening at smaller values that is accompanied by enhanced...

  15. 49 CFR 195.406 - Maximum operating pressure.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Maximum operating pressure. 195.406 Section 195.406 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS... HAZARDOUS LIQUIDS BY PIPELINE Operation and Maintenance § 195.406 Maximum operating pressure. (a) Except for...

  16. Effect of metal tolerant plant growth promoting bacteria on growth and metal accumulation in Zea mays plants grown in fly ash amended soil.

    Science.gov (United States)

    Kumar, Kalpna V; Patra, D D

    2013-01-01

    The present study was undertaken to examine the effect of the application of fly ash (FA) into Garden soil (GS), with and without inoculation of plant growth promoting bacteria (PGPB), on the growth and metal uptake by Zea mays plants. Three FA tolerant PGPB strains, Pseudomonas sp. PS5, PS14, and Bacillus sp. BC29 were isolated from FA contaminated soils and assessed for their plant growth promoting features on the Z. mays plants. All three strains were also examined for their ability to solubilize phosphate and to produce Indole Acetic Acid (IAA), siderophores, and hydrogencynide acid (HCN) production. Although inoculation of all strains significantly enhanced the growth of plants at both the concentration of FA but maximum growth was observed in plants inoculated with BC29 and PS14 at low level (25%) of FA concentration. The experimental results explored the plant growth promoting features of selected strains which not only enhanced growth and biomass of plants but also protected them from toxicity of FA.

  17. Large-area sheet task advanced dendritic web growth development

    Science.gov (United States)

    Duncan, C. S.; Seidensticker, R. G.; Mchugh, J. P.

    1984-01-01

    The thermal models used for analyzing dendritic web growth and calculating the thermal stress were reexamined to establish the validity limits imposed by the assumptions of the models. Also, the effects of thermal conduction through the gas phase were evaluated and found to be small. New growth designs, both static and dynamic, were generated using the modeling results. Residual stress effects in dendritic web were examined. In the laboratory, new techniques for the control of temperature distributions in three dimensions were developed. A new maximum undeformed web width of 5.8 cm was achieved. A 58% increase in growth velocity of 150 micrometers thickness was achieved with dynamic hardware. The area throughput goals for transient growth of 30 and 35 sq cm/min were exceeded.

  18. Maximum spectral demands in the near-fault region

    Science.gov (United States)

    Huang, Yin-Nan; Whittaker, Andrew S.; Luco, Nicolas

    2008-01-01

    The Next Generation Attenuation (NGA) relationships for shallow crustal earthquakes in the western United States predict a rotated geometric mean of horizontal spectral demand, termed GMRotI50, and not maximum spectral demand. Differences between strike-normal, strike-parallel, geometric-mean, and maximum spectral demands in the near-fault region are investigated using 147 pairs of records selected from the NGA strong motion database. The selected records are for earthquakes with moment magnitude greater than 6.5 and for closest site-to-fault distance less than 15 km. Ratios of maximum spectral demand to NGA-predicted GMRotI50 for each pair of ground motions are presented. The ratio shows a clear dependence on period and the Somerville directivity parameters. Maximum demands can substantially exceed NGA-predicted GMRotI50 demands in the near-fault region, which has significant implications for seismic design, seismic performance assessment, and the next-generation seismic design maps. Strike-normal spectral demands are a significantly unconservative surrogate for maximum spectral demands for closest distance greater than 3 to 5 km. Scale factors that transform NGA-predicted GMRotI50 to a maximum spectral demand in the near-fault region are proposed.

  19. Biodegradation and growth characteristics of a toluene-degrading ...

    African Journals Online (AJOL)

    A toluene-degrading strain was isolated from active sludge in this study. Both growth characteristic and the performance to degrade toluene by the strain in batch culture mode were evaluated. Results showed that the isolated strain presented a good ability to remove toluene with the maximum removal efficiency of 93.8%.

  20. The growth hormone/insulin-like growth factor-I axis hormones and bone markers in elite athletes in response to a maximum exercise test

    DEFF Research Database (Denmark)

    Ehrnborg, C.; Lange, K.H.; Dall, R.

    2003-01-01

    -53 yr) from Denmark, the United Kingdom, Italy, and Sweden participated in the study. The serum concentrations of total GH, GH22 kDa, IGF-I, IGF binding protein (IGFBP)-2, IGFBP-3, acid-labile subunit, procollagen type III (P-III-P), and the bone markers osteocalcin, carboxy-terminal cross......-linked telopeptide of type I collagen (ICTP), and carboxy-terminal propeptide of type I procollagen were measured. The maximum exercise test showed, in both genders, a peak concentration of total GH (P ... in both genders, with a peak value in the direct post-exercise phase and a subsequent decrease to baseline levels or below within 120 min. The osteocalcin and propeptide of type I procollagen values did not change during the exercise test. Specific reference ranges for each variable in the GH/IGF-I axis...

  1. Maximum allowable load on wheeled mobile manipulators

    International Nuclear Information System (INIS)

    Habibnejad Korayem, M.; Ghariblu, H.

    2003-01-01

    This paper develops a computational technique for finding the maximum allowable load of mobile manipulator during a given trajectory. The maximum allowable loads which can be achieved by a mobile manipulator during a given trajectory are limited by the number of factors; probably the dynamic properties of mobile base and mounted manipulator, their actuator limitations and additional constraints applied to resolving the redundancy are the most important factors. To resolve extra D.O.F introduced by the base mobility, additional constraint functions are proposed directly in the task space of mobile manipulator. Finally, in two numerical examples involving a two-link planar manipulator mounted on a differentially driven mobile base, application of the method to determining maximum allowable load is verified. The simulation results demonstrates the maximum allowable load on a desired trajectory has not a unique value and directly depends on the additional constraint functions which applies to resolve the motion redundancy

  2. Robust Maximum Association Estimators

    NARCIS (Netherlands)

    A. Alfons (Andreas); C. Croux (Christophe); P. Filzmoser (Peter)

    2017-01-01

    textabstractThe maximum association between two multivariate variables X and Y is defined as the maximal value that a bivariate association measure between one-dimensional projections αX and αY can attain. Taking the Pearson correlation as projection index results in the first canonical correlation

  3. Selection of the Maximum Spatial Cluster Size of the Spatial Scan Statistic by Using the Maximum Clustering Set-Proportion Statistic.

    Science.gov (United States)

    Ma, Yue; Yin, Fei; Zhang, Tao; Zhou, Xiaohua Andrew; Li, Xiaosong

    2016-01-01

    Spatial scan statistics are widely used in various fields. The performance of these statistics is influenced by parameters, such as maximum spatial cluster size, and can be improved by parameter selection using performance measures. Current performance measures are based on the presence of clusters and are thus inapplicable to data sets without known clusters. In this work, we propose a novel overall performance measure called maximum clustering set-proportion (MCS-P), which is based on the likelihood of the union of detected clusters and the applied dataset. MCS-P was compared with existing performance measures in a simulation study to select the maximum spatial cluster size. Results of other performance measures, such as sensitivity and misclassification, suggest that the spatial scan statistic achieves accurate results in most scenarios with the maximum spatial cluster sizes selected using MCS-P. Given that previously known clusters are not required in the proposed strategy, selection of the optimal maximum cluster size with MCS-P can improve the performance of the scan statistic in applications without identified clusters.

  4. Maximum-Likelihood Detection Of Noncoherent CPM

    Science.gov (United States)

    Divsalar, Dariush; Simon, Marvin K.

    1993-01-01

    Simplified detectors proposed for use in maximum-likelihood-sequence detection of symbols in alphabet of size M transmitted by uncoded, full-response continuous phase modulation over radio channel with additive white Gaussian noise. Structures of receivers derived from particular interpretation of maximum-likelihood metrics. Receivers include front ends, structures of which depends only on M, analogous to those in receivers of coherent CPM. Parts of receivers following front ends have structures, complexity of which would depend on N.

  5. Mechanical model for filament buckling and growth by phase ordering.

    Science.gov (United States)

    Rey, Alejandro D; Abukhdeir, Nasser M

    2008-02-05

    A mechanical model of open filament shape and growth driven by phase ordering is formulated. For a given phase-ordering driving force, the model output is the filament shape evolution and the filament end-point kinematics. The linearized model for the slope of the filament is the Cahn-Hilliard model of spinodal decomposition, where the buckling corresponds to concentration fluctuations. Two modes are predicted: (i) sequential growth and buckling and (ii) simultaneous buckling and growth. The relation among the maximum buckling rate, filament tension, and matrix viscosity is given. These results contribute to ongoing work in smectic A filament buckling.

  6. Effects of intensive forest management practices on insect infestation levels and loblolly pine growth

    Science.gov (United States)

    John T. Nowak; C. Wayne Berisford

    2000-01-01

    Intensive forest management practices have been shown to increase tree growth and shorten rotation time. However, they may also lead to an increased need for insect pest management because of higher infestation levels and lower action thresholds. To investigate the relationship between intensive management practices arid insect infestation, maximum growth potential...

  7. Maximum Entropy Fundamentals

    Directory of Open Access Journals (Sweden)

    F. Topsøe

    2001-09-01

    Full Text Available Abstract: In its modern formulation, the Maximum Entropy Principle was promoted by E.T. Jaynes, starting in the mid-fifties. The principle dictates that one should look for a distribution, consistent with available information, which maximizes the entropy. However, this principle focuses only on distributions and it appears advantageous to bring information theoretical thinking more prominently into play by also focusing on the "observer" and on coding. This view was brought forward by the second named author in the late seventies and is the view we will follow-up on here. It leads to the consideration of a certain game, the Code Length Game and, via standard game theoretical thinking, to a principle of Game Theoretical Equilibrium. This principle is more basic than the Maximum Entropy Principle in the sense that the search for one type of optimal strategies in the Code Length Game translates directly into the search for distributions with maximum entropy. In the present paper we offer a self-contained and comprehensive treatment of fundamentals of both principles mentioned, based on a study of the Code Length Game. Though new concepts and results are presented, the reading should be instructional and accessible to a rather wide audience, at least if certain mathematical details are left aside at a rst reading. The most frequently studied instance of entropy maximization pertains to the Mean Energy Model which involves a moment constraint related to a given function, here taken to represent "energy". This type of application is very well known from the literature with hundreds of applications pertaining to several different elds and will also here serve as important illustration of the theory. But our approach reaches further, especially regarding the study of continuity properties of the entropy function, and this leads to new results which allow a discussion of models with so-called entropy loss. These results have tempted us to speculate over

  8. Nucleation and crystal growth behavior of nepheline in simulated high-level waste glasses

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Amoroso, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Mcclane, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-09-26

    The Savannah River National Laboratory (SRNL) has been tasked with supporting glass formulation development and process control strategies in key technical areas, relevant to the Department of Energy’s Office of River Protection (DOE-ORP) and related to high-level waste (HLW) vitrification at the Waste Treatment and Immobilization Plant (WTP). Of specific interest is the development of predictive models for crystallization of nepheline (NaAlSiO4) in HLW glasses formulated at high alumina concentrations. This report summarizes recent progress by researchers at SRNL towards developing a predicative tool for quantifying nepheline crystallization in HLW glass canisters using laboratory experiments. In this work, differential scanning calorimetry (DSC) was used to obtain the temperature regions over which nucleation and growth of nepheline occur in three simulated HLW glasses - two glasses representative of WTP projections and one glass representative of the Defense Waste Processing Facility (DWPF) product. The DWPF glass, which has been studied previously, was chosen as a reference composition and for comparison purposes. Complementary quantitative X-ray diffraction (XRD) and optical microscopy confirmed the validity of the methodology to determine nucleation and growth behavior as a function of temperature. The nepheline crystallization growth region was determined to generally extend from ~ 500 to >850 °C, with the maximum growth rates occurring between 600 and 700 °C. For select WTP glass compositions (high Al2O3 and B2O3), the nucleation range extended from ~ 450 to 600 °C, with the maximum nucleation rates occurring at ~ 530 °C. For the DWPF glass composition, the nucleation range extended from ~ 450 to 750 °C with the maximum nucleation rate occurring at ~ 640 °C. The nepheline growth at the peak temperature, as determined by XRD, was between 35 - 75 wt.% /hour. A maximum nepheline growth rate of ~ 0.1 mm/hour at 700 °C was measured for the DWPF

  9. Nucleation and crystal growth behavior of nepheline in simulated high-level waste glasses

    International Nuclear Information System (INIS)

    Fox, K.; Amoroso, J.; Mcclane, D.

    2017-01-01

    The Savannah River National Laboratory (SRNL) has been tasked with supporting glass formulation development and process control strategies in key technical areas, relevant to the Department of Energy's Office of River Protection (DOE-ORP) and related to high-level waste (HLW) vitrification at the Waste Treatment and Immobilization Plant (WTP). Of specific interest is the development of predictive models for crystallization of nepheline (NaAlSiO4) in HLW glasses formulated at high alumina concentrations. This report summarizes recent progress by researchers at SRNL towards developing a predicative tool for quantifying nepheline crystallization in HLW glass canisters using laboratory experiments. In this work, differential scanning calorimetry (DSC) was used to obtain the temperature regions over which nucleation and growth of nepheline occur in three simulated HLW glasses - two glasses representative of WTP projections and one glass representative of the Defense Waste Processing Facility (DWPF) product. The DWPF glass, which has been studied previously, was chosen as a reference composition and for comparison purposes. Complementary quantitative X-ray diffraction (XRD) and optical microscopy confirmed the validity of the methodology to determine nucleation and growth behavior as a function of temperature. The nepheline crystallization growth region was determined to generally extend from ~ 500 to >850 °C, with the maximum growth rates occurring between 600 and 700 °C. For select WTP glass compositions (high Al2O3 and B2O3), the nucleation range extended from ~ 450 to 600 °C, with the maximum nucleation rates occurring at ~ 530 °C. For the DWPF glass composition, the nucleation range extended from ~ 450 to 750 °C with the maximum nucleation rate occurring at ~ 640 °C. The nepheline growth at the peak temperature, as determined by XRD, was between 35 - 75 wt.% /hour. A maximum nepheline growth rate of ~ 0.1 mm/hour at 700 °C was measured for the DWPF

  10. 22 CFR 201.67 - Maximum freight charges.

    Science.gov (United States)

    2010-04-01

    ..., commodity rate classification, quantity, vessel flag category (U.S.-or foreign-flag), choice of ports, and... the United States. (2) Maximum charter rates. (i) USAID will not finance ocean freight under any... owner(s). (4) Maximum liner rates. USAID will not finance ocean freight for a cargo liner shipment at a...

  11. Determination of the maximum-depth to potential field sources by a maximum structural index method

    Science.gov (United States)

    Fedi, M.; Florio, G.

    2013-01-01

    A simple and fast determination of the limiting depth to the sources may represent a significant help to the data interpretation. To this end we explore the possibility of determining those source parameters shared by all the classes of models fitting the data. One approach is to determine the maximum depth-to-source compatible with the measured data, by using for example the well-known Bott-Smith rules. These rules involve only the knowledge of the field and its horizontal gradient maxima, and are independent from the density contrast. Thanks to the direct relationship between structural index and depth to sources we work out a simple and fast strategy to obtain the maximum depth by using the semi-automated methods, such as Euler deconvolution or depth-from-extreme-points method (DEXP). The proposed method consists in estimating the maximum depth as the one obtained for the highest allowable value of the structural index (Nmax). Nmax may be easily determined, since it depends only on the dimensionality of the problem (2D/3D) and on the nature of the analyzed field (e.g., gravity field or magnetic field). We tested our approach on synthetic models against the results obtained by the classical Bott-Smith formulas and the results are in fact very similar, confirming the validity of this method. However, while Bott-Smith formulas are restricted to the gravity field only, our method is applicable also to the magnetic field and to any derivative of the gravity and magnetic field. Our method yields a useful criterion to assess the source model based on the (∂f/∂x)max/fmax ratio. The usefulness of the method in real cases is demonstrated for a salt wall in the Mississippi basin, where the estimation of the maximum depth agrees with the seismic information.

  12. Potential of plant growth promoting rhizobacteria and chemical fertilizers on soil enzymes and plant growth

    International Nuclear Information System (INIS)

    Nosheen, A.; Bano, A.

    2014-01-01

    The present investigation deals with the role of Plant Growth Promoting Rhizobacteria and chemical fertilizers alone or in combination on urease, invertase and phosphatase activities of rhizospheric soil and also on general impact on growth of safflower cvv. Thori and Saif-32. The PGPR (Azospirillum brasilense and Azotobacter vinelandii) were applied at 10/sup 6/ cells/mL as seed inoculation prior to sowing. Chemical fertilizers were applied at full (Urea 60 Kg ha/sup -1/ and Diammonium phosphate (DAP) 30 Kg ha/sup -1/), half (Urea 30 Kg ha/sup -1/ and DAP 15 Kg ha/sup -1/) and quarter doses (Urea 15 Kg ha-1 and DAP 7.5 Kg ha/sup -1/) during sowing. The chemical fertilizers and PGPR enhanced urease and invertase activities of soil. Presence of PGPR in combination with quarter and half doses of chemical fertilizers further augmented their effect on soil enzymes activities. The soil phosphatase activity was greater in Azospirillum and Azotobacter in combination with half dose of chemical fertilizers. Maximum increase in leaf melondialdehyde content was recorded in full dose of chemical fertilizers whereas coinoculation treatment exhibited significant reduction in cv. Thori. Half and quarter dose of chemical fertilizers increased the shoot length of safflower whereas maximum increase in leaf protein was recorded in Azotobacter in combination with full dose of chemical fertilizers. Root length was improved by Azospirillum and Azotobacter in combination with quarter dose of chemical fertilizers. Leaf area and chlorophyll contents were significantly improved by Azotobacter in combination with half dose of chemical fertilizers. It is inferred that PGPR can supplement 50 % chemical fertilizers for better plant growth and soil health. (author)

  13. 40 CFR 141.13 - Maximum contaminant levels for turbidity.

    Science.gov (United States)

    2010-07-01

    ... turbidity. 141.13 Section 141.13 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER... Maximum contaminant levels for turbidity. The maximum contaminant levels for turbidity are applicable to... part. The maximum contaminant levels for turbidity in drinking water, measured at a representative...

  14. Overview of Maximum Power Point Tracking Techniques for Photovoltaic Energy Production Systems

    DEFF Research Database (Denmark)

    Koutroulis, Eftichios; Blaabjerg, Frede

    2017-01-01

    production of PV sources, despite the stochastically varying solar irradiation and ambient temperature conditions. Thereby, the overall efficiency of the PV energy production system is increased. Numerous techniques have been presented during the last decades for implementing the MPPT process in a PV system......A substantial growth of the installed photovoltaic (PV) systems capacity has occurred around the world during the last decade, thus enhancing the availability of electric energy in an environmentally friendly way. The maximum power point tracking (MPPT) technique enables to maximize the energy....... This chapter provides an overview of the operating principles of these techniques, which are suited for either uniform or nonuniform solar irradiation conditions. The operational characteristics and implementation requirements of these MPPT methods are also analyzed in order to demonstrate their performance...

  15. Soap film flows: Statistics of two-dimensional turbulence

    International Nuclear Information System (INIS)

    Vorobieff, P.; Rivera, M.; Ecke, R.E.

    1999-01-01

    Soap film flows provide a very convenient laboratory model for studies of two-dimensional (2-D) hydrodynamics including turbulence. For a gravity-driven soap film channel with a grid of equally spaced cylinders inserted in the flow, we have measured the simultaneous velocity and thickness fields in the irregular flow downstream from the cylinders. The velocity field is determined by a modified digital particle image velocimetry method and the thickness from the light scattered by the particles in the film. From these measurements, we compute the decay of mean energy, enstrophy, and thickness fluctuations with downstream distance, and the structure functions of velocity, vorticity, thickness fluctuation, and vorticity flux. From these quantities we determine the microscale Reynolds number of the flow R λ ∼100 and the integral and dissipation scales of 2D turbulence. We also obtain quantitative measures of the degree to which our flow can be considered incompressible and isotropic as a function of downstream distance. We find coarsening of characteristic spatial scales, qualitative correspondence of the decay of energy and enstrophy with the Batchelor model, scaling of energy in k space consistent with the k -3 spectrum of the Kraichnan endash Batchelor enstrophy-scaling picture, and power-law scalings of the structure functions of velocity, vorticity, vorticity flux, and thickness. These results are compared with models of 2-D turbulence and with numerical simulations. copyright 1999 American Institute of Physics

  16. Modelling maximum canopy conductance and transpiration in ...

    African Journals Online (AJOL)

    There is much current interest in predicting the maximum amount of water that can be transpired by Eucalyptus trees. It is possible that industrial waste water may be applied as irrigation water to eucalypts and it is important to predict the maximum transpiration rates of these plantations in an attempt to dispose of this ...

  17. 40 CFR 141.62 - Maximum contaminant levels for inorganic contaminants.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant levels for inorganic contaminants. 141.62 Section 141.62 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Water Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels § 141.62 Maximum...

  18. Nonlinear Growth Models as Measurement Models: A Second-Order Growth Curve Model for Measuring Potential.

    Science.gov (United States)

    McNeish, Daniel; Dumas, Denis

    2017-01-01

    Recent methodological work has highlighted the promise of nonlinear growth models for addressing substantive questions in the behavioral sciences. In this article, we outline a second-order nonlinear growth model in order to measure a critical notion in development and education: potential. Here, potential is conceptualized as having three components-ability, capacity, and availability-where ability is the amount of skill a student is estimated to have at a given timepoint, capacity is the maximum amount of ability a student is predicted to be able to develop asymptotically, and availability is the difference between capacity and ability at any particular timepoint. We argue that single timepoint measures are typically insufficient for discerning information about potential, and we therefore describe a general framework that incorporates a growth model into the measurement model to capture these three components. Then, we provide an illustrative example using the public-use Early Childhood Longitudinal Study-Kindergarten data set using a Michaelis-Menten growth function (reparameterized from its common application in biochemistry) to demonstrate our proposed model as applied to measuring potential within an educational context. The advantage of this approach compared to currently utilized methods is discussed as are future directions and limitations.

  19. The Role of Gamma Irradiation on Growth and Some Metabolic Activities of Spirulina platensis

    International Nuclear Information System (INIS)

    Moussa, H.R.; El-Shaer, E.A.; Ismaiel, M.M.S.; Shabana, E.F.; Gabr, M.A.

    2015-01-01

    Spirulina platensis cells were exposed to different doses of gamma irradiation 0.0; (control), 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 Kilo Gray (kGy) using Co 60 as a gamma source at the Cyclotron Unit, Nuclear Research Center, Egyptian Atomic Energy Authority. After which, the cells were cultivated on Zarrouk medium for 14 days (the exponential phase of growth). The optimum growth of Spirulina platensis was recorded at 2.0 kGy as compared to the control after the 14th day of incubation. All of the following analyses were done after 10 days of growth. The results of pigments analysis revealed that the chlorophyll a and carotenoid contents of Spirulina platensis were reached their maximum rate at a dose of 2.0 kGy, Which induces the same trend for phycobiliproteins fractions. The photosynthetic activity and total carbohydrate content of the irradiated Spirulina cells increased with elevating the doses of gamma irradiation and reached a maximum value at a dose of 2.0 kGy as compared to the control. The activity of ribulose-1,5-bisphosphate-carboxylase/oxygenase (RUBISCO) was increased up to irradiation dose of 2.0 kGy. whereas, the maximum activity of the phosphoenol pyruvate carboxylase (PEPCASE) was recorded at the irradiation dose of 1.0 kGy Spirulina platensis cells were exposed to different doses of gamma irradiation 0.0; (control), 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 Kilo Gray (kGy) using Co 60 as a gamma source at the Cyclotron Unit, Nuclear Research Center, Egyptian Atomic Energy Authority. After which, the cells were cultivated on Zarrouk medium for 14 days (the exponential phase of growth). The optimum growth of Spirulina platensis was recorded at 2.0 kGy as compared to the control after the 14th day of incubation. All of the following analyses were done after 10 days of growth. The results of pigments analysis revealed that the chlorophyll a and carotenoid contents of Spirulina platensis were reached their maximum rate at a dose of 2.0 kGy, Which induces the same

  20. Weak scale from the maximum entropy principle

    Science.gov (United States)

    Hamada, Yuta; Kawai, Hikaru; Kawana, Kiyoharu

    2015-03-01

    The theory of the multiverse and wormholes suggests that the parameters of the Standard Model (SM) are fixed in such a way that the radiation of the S3 universe at the final stage S_rad becomes maximum, which we call the maximum entropy principle. Although it is difficult to confirm this principle generally, for a few parameters of the SM, we can check whether S_rad actually becomes maximum at the observed values. In this paper, we regard S_rad at the final stage as a function of the weak scale (the Higgs expectation value) vh, and show that it becomes maximum around vh = {{O}} (300 GeV) when the dimensionless couplings in the SM, i.e., the Higgs self-coupling, the gauge couplings, and the Yukawa couplings are fixed. Roughly speaking, we find that the weak scale is given by vh ˜ T_{BBN}2 / (M_{pl}ye5), where ye is the Yukawa coupling of electron, T_BBN is the temperature at which the Big Bang nucleosynthesis starts, and M_pl is the Planck mass.

  1. Changes in pyridine metabolism profile during growth of trigonelline-forming Lotus japonicus cell cultures.

    Science.gov (United States)

    Yin, Yuling; Matsui, Ayu; Sakuta, Masaaki; Ashihara, Hiroshi

    2008-12-01

    Changes in the profile of pyridine metabolism during growth of cells were investigated using trigonelline-forming suspension-cultured cells of Lotus japonicus. Activity of the de novo and salvage pathways of NAD biosynthesis was estimated from the in situ metabolism of [(3)H] quinolinic acid and [(14)C] nicotinamide. Maximum activity of the de novo pathway for NAD synthesis was found in the exponential growth phase, whereas activity of the salvage pathway was increased in the lag phase of cell growth. Expression profiles of some genes related to pyridine metabolism were examined using the expression sequence tags obtained from the L. japonicus database. Transcript levels of NaPRT and NIC, encoding salvage enzymes, were enhanced in the lag phase of cell growth, whereas the maximum expression of NADS was found in the exponential growth phase. Correspondingly, the activities of the salvage enzymes, nicotinate phosphoribosyltransferase (EC 2.4.2.11) and nicotinamidase (EC 3.5.1.19), increased one day after transfer of the stationary phase cells to the fresh medium. The greatest in situ trigonelline synthesis, both from [(3)H] quinolinic acid and [(14)C] nicotinamide, was found in the stationary phase of cell growth. The role of trigonelline in leguminous plants is discussed.

  2. Effects of cutting frequency and fertilizer-N application on growth ...

    African Journals Online (AJOL)

    N rates on growth and production of guinea grass (Panicum maximum Jacq). The experiment was conducted in Nsukka, Nigeria. Treatments comprised four levels of fertilizer N (0, 150, 300 and 450 kg N ha- 1) and four cutting intervals (3, 6, ...

  3. Accurate modeling and maximum power point detection of ...

    African Journals Online (AJOL)

    Accurate modeling and maximum power point detection of photovoltaic ... Determination of MPP enables the PV system to deliver maximum available power. ..... adaptive artificial neural network: Proposition for a new sizing procedure.

  4. 40 CFR 141.61 - Maximum contaminant levels for organic contaminants.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant levels for organic contaminants. 141.61 Section 141.61 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER... Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels § 141.61 Maximum contaminant...

  5. The power and robustness of maximum LOD score statistics.

    Science.gov (United States)

    Yoo, Y J; Mendell, N R

    2008-07-01

    The maximum LOD score statistic is extremely powerful for gene mapping when calculated using the correct genetic parameter value. When the mode of genetic transmission is unknown, the maximum of the LOD scores obtained using several genetic parameter values is reported. This latter statistic requires higher critical value than the maximum LOD score statistic calculated from a single genetic parameter value. In this paper, we compare the power of maximum LOD scores based on three fixed sets of genetic parameter values with the power of the LOD score obtained after maximizing over the entire range of genetic parameter values. We simulate family data under nine generating models. For generating models with non-zero phenocopy rates, LOD scores maximized over the entire range of genetic parameters yielded greater power than maximum LOD scores for fixed sets of parameter values with zero phenocopy rates. No maximum LOD score was consistently more powerful than the others for generating models with a zero phenocopy rate. The power loss of the LOD score maximized over the entire range of genetic parameters, relative to the maximum LOD score calculated using the correct genetic parameter value, appeared to be robust to the generating models.

  6. Standardization of growth and fermentation criteria of Lasiodiplodia ...

    African Journals Online (AJOL)

    GREGO

    2007-03-19

    Mar 19, 2007 ... maximum growth on solid as well as liquid media. Optimum .... Extraction and measurement of JA: JA was extracted from fungal cultural filtrate of L. .... be related to consumption of JA due to carbon limitation or change in pH in the .... Activated by an Enzyme That Conjugates It to Isoleucine in. Arabidopsis.

  7. Log-Normal Turbulence Dissipation in Global Ocean Models

    Science.gov (United States)

    Pearson, Brodie; Fox-Kemper, Baylor

    2018-03-01

    Data from turbulent numerical simulations of the global ocean demonstrate that the dissipation of kinetic energy obeys a nearly log-normal distribution even at large horizontal scales O (10 km ) . As the horizontal scales of resolved turbulence are larger than the ocean is deep, the Kolmogorov-Yaglom theory for intermittency in 3D homogeneous, isotropic turbulence cannot apply; instead, the down-scale potential enstrophy cascade of quasigeostrophic turbulence should. Yet, energy dissipation obeys approximate log-normality—robustly across depths, seasons, regions, and subgrid schemes. The distribution parameters, skewness and kurtosis, show small systematic departures from log-normality with depth and subgrid friction schemes. Log-normality suggests that a few high-dissipation locations dominate the integrated energy and enstrophy budgets, which should be taken into account when making inferences from simplified models and inferring global energy budgets from sparse observations.

  8. Influence of Soil Type and Drainage on Growth of Swamp Chestnut Oak (Quercus Michauxii Nutt.) Seedlings

    Science.gov (United States)

    Donald D. Hook

    1969-01-01

    Swamp chestnut oak (Quercus michauxii Nutt.) seedlings were grown for 2 years in five soil types in drained and undrained pots. First-year height growth was related to soil type and pot drainage, but second-year height growth was related only to soil type. Results suggest that swamp chestnut oak is site-sensitive. But slow growth, a maximum of 2...

  9. Growth inhibition of Listeria monocytogenes by a nonbacteriocinogenic Carnobacterium piscicola

    DEFF Research Database (Denmark)

    Nilsson, Lilian; Bech Hansen, T.; Garrido, P.

    2005-01-01

    Aims: This study elucidates the mechanisms by which a nonbacteriocinogenic Carnobacterium piscicola inhibits growth of Listeria monocytogenes. Methods and Results: Listeria monocytogenes was exposed to live cultures of a bacteriocin-negative variant of C. piscicola A9b in co-culture, in a diffusion...... chamber system, and to a cell-free supernatant. Suppression of maximum cell density (0-3.5 log units) of L. monocytogenes was proportional to initial levels of C. pisciola (10(3)-10(7) CFU ml(-1)). Cell-to-cell contact was not required to cause inhibition. The cell-free C. piscicola supernatant caused...... a decrease in L. monocytogenes maximum cell density, which was abolished by glucose addition but not by amino acid, vitamin or mineral addition. The fermentate also gave rise to a longer lag phase and a reduction in growth rate. These effects were independent of glucose and may have been caused by acetate...

  10. Maximum Power Training and Plyometrics for Cross-Country Running.

    Science.gov (United States)

    Ebben, William P.

    2001-01-01

    Provides a rationale for maximum power training and plyometrics as conditioning strategies for cross-country runners, examining: an evaluation of training methods (strength training and maximum power training and plyometrics); biomechanic and velocity specificity (role in preventing injury); and practical application of maximum power training and…

  11. Crystal growth velocity in deeply undercooled Ni-Si alloys

    Science.gov (United States)

    Lü, Y. J.

    2012-02-01

    The crystal growth velocity of Ni95Si5 and Ni90Si10 alloys as a function of undercooling is investigated using molecular dynamics simulations. The modified imbedded atom method potential yields the equilibrium liquidus temperatures T L ≈ 1505 and 1387 K for Ni95Si5 and Ni90Si10 alloys, respectively. From the liquidus temperatures down to the deeply undercooled region, the crystal growth velocities of both the alloys rise to the maximum with increasing undercooling and then drop slowly, whereas the athermal growth process presented in elemental Ni is not observed in Ni-Si alloys. Instead, the undercooling dependence of the growth velocity can be well-described by the diffusion-limited model, furthermore, the activation energy associated with the diffusion from melt to interface increases as the concentration increases from 5 to 10 at.% Si, resulting in the remarkable decrease of growth velocity.

  12. A mesic maximum in biological water use demarcates biome sensitivity to aridity shifts.

    Science.gov (United States)

    Good, Stephen P; Moore, Georgianne W; Miralles, Diego G

    2017-12-01

    Biome function is largely governed by how efficiently available resources can be used and yet for water, the ratio of direct biological resource use (transpiration, E T ) to total supply (annual precipitation, P) at ecosystem scales remains poorly characterized. Here, we synthesize field, remote sensing and ecohydrological modelling estimates to show that the biological water use fraction (E T /P) reaches a maximum under mesic conditions; that is, when evaporative demand (potential evapotranspiration, E P ) slightly exceeds supplied precipitation. We estimate that this mesic maximum in E T /P occurs at an aridity index (defined as E P /P) between 1.3 and 1.9. The observed global average aridity of 1.8 falls within this range, suggesting that the biosphere is, on average, configured to transpire the largest possible fraction of global precipitation for the current climate. A unimodal E T /P distribution indicates that both dry regions subjected to increasing aridity and humid regions subjected to decreasing aridity will suffer declines in the fraction of precipitation that plants transpire for growth and metabolism. Given the uncertainties in the prediction of future biogeography, this framework provides a clear and concise determination of ecosystems' sensitivity to climatic shifts, as well as expected patterns in the amount of precipitation that ecosystems can effectively use.

  13. Regional maximum rainfall analysis using L-moments at the Titicaca Lake drainage, Peru

    Science.gov (United States)

    Fernández-Palomino, Carlos Antonio; Lavado-Casimiro, Waldo Sven

    2017-08-01

    The present study investigates the application of the index flood L-moments-based regional frequency analysis procedure (RFA-LM) to the annual maximum 24-h rainfall (AM) of 33 rainfall gauge stations (RGs) to estimate rainfall quantiles at the Titicaca Lake drainage (TL). The study region was chosen because it is characterised by common floods that affect agricultural production and infrastructure. First, detailed quality analyses and verification of the RFA-LM assumptions were conducted. For this purpose, different tests for outlier verification, homogeneity, stationarity, and serial independence were employed. Then, the application of RFA-LM procedure allowed us to consider the TL as a single, hydrologically homogeneous region, in terms of its maximum rainfall frequency. That is, this region can be modelled by a generalised normal (GNO) distribution, chosen according to the Z test for goodness-of-fit, L-moments (LM) ratio diagram, and an additional evaluation of the precision of the regional growth curve. Due to the low density of RG in the TL, it was important to produce maps of the AM design quantiles estimated using RFA-LM. Therefore, the ordinary Kriging interpolation (OK) technique was used. These maps will be a useful tool for determining the different AM quantiles at any point of interest for hydrologists in the region.

  14. Listeria monocytogenes Growth Kinetics in Milkshakes Made from Naturally and Artificially Contaminated Ice Cream

    OpenAIRE

    Salazar, Joelle K.; Bathija, Vriddi M.; Carstens, Christina K.; Narula, Sartaj S.; Shazer, Arlette; Stewart, Diana; Tortorello, Mary Lou

    2018-01-01

    This study assessed the growth of Listeria monocytogenes in milkshakes made using the process-contaminated ice cream associated with a listeriosis outbreak in comparison to milkshakes made with artificially contaminated ice cream. For all temperatures, growth kinetics including growth rates, lag phases, maximum populations, and population increases were determined for the naturally and artificially derived contaminants at 5, 10, 15, and 25°C storage for 144 h. The artificially inoculated L. m...

  15. Seed Germination and Early Growth Responses of Hyssop, Sweet Basil and Oregano to Temperature Levels

    Directory of Open Access Journals (Sweden)

    Sajad MIJANI

    2013-12-01

    Full Text Available The objectives of this survey were to determine the effect of temperature on germination and seedling growth of Hyssop (Hyssopus officinalis L., Sweet basil (Ocimum basilicum L. and Oregano (Origanum vulgare L. (Lamiaceae family as well as comparing species regarding germination behavior and growth characteristics. Seeds were germinated on a temperature-gradient bar varying between 5 and 40 °C (with 5 °C intervals. Results indicated that the highest germination percentage of hyssop (92-98%, sweet basil (86-90% and oregano (74-77% occurred at 20-30 °C, 25-30 °C and 20-30 °C, respectively; therefore, moderate and warm temperatures are proper for germination of all species. In all species the maximum germination rate obtained at 30 °C. Among all species, Day 10 % of Sweet basil Germination had the lowest value, which indicates faster germination. The cardinal temperatures (base, optimum and ceiling or maximum were estimated by the segmented model. Base temperature (Tb was calculated for hyssop, sweet basil and oregano as 3.42, 5.70 and 5.46 °C, respectively. Optimal temperature (To calculated for all species was approximately 30°C, So warmer temperatures are much more proper for them. The species showed different maximum temperatures (Tm from 42.91 (Oregano to 48.05 °C (Hyssop. In Hyssop and Sweet basil optimum growth of seedlings were observed at 30°C while Oregano reached its best growth at 25°C. The difference between maximum and minimum temperatures of germination knowing as temperature range (TR index could show adaptation capability to broad sites for planting and domestication. Regarding this index Hyssop stood in the first place.

  16. Maximum physical capacity testing in cancer patients undergoing chemotherapy

    DEFF Research Database (Denmark)

    Knutsen, L.; Quist, M; Midtgaard, J

    2006-01-01

    BACKGROUND: Over the past few years there has been a growing interest in the field of physical exercise in rehabilitation of cancer patients, leading to requirements for objective maximum physical capacity measurement (maximum oxygen uptake (VO(2max)) and one-repetition maximum (1RM)) to determin...... early in the treatment process. However, the patients were self-referred and thus highly motivated and as such are not necessarily representative of the whole population of cancer patients treated with chemotherapy....... in performing maximum physical capacity tests as these motivated them through self-perceived competitiveness and set a standard that served to encourage peak performance. CONCLUSION: The positive attitudes in this sample towards maximum physical capacity open the possibility of introducing physical testing...

  17. MAXIMUM PRINCIPLE FOR SUBSONIC FLOW WITH VARIABLE ENTROPY

    Directory of Open Access Journals (Sweden)

    B. Sizykh Grigory

    2017-01-01

    Full Text Available Maximum principle for subsonic flow is fair for stationary irrotational subsonic gas flows. According to this prin- ciple, if the value of the velocity is not constant everywhere, then its maximum is achieved on the boundary and only on the boundary of the considered domain. This property is used when designing form of an aircraft with a maximum critical val- ue of the Mach number: it is believed that if the local Mach number is less than unit in the incoming flow and on the body surface, then the Mach number is less then unit in all points of flow. The known proof of maximum principle for subsonic flow is based on the assumption that in the whole considered area of the flow the pressure is a function of density. For the ideal and perfect gas (the role of diffusion is negligible, and the Mendeleev-Clapeyron law is fulfilled, the pressure is a function of density if entropy is constant in the entire considered area of the flow. Shows an example of a stationary sub- sonic irrotational flow, in which the entropy has different values on different stream lines, and the pressure is not a function of density. The application of the maximum principle for subsonic flow with respect to such a flow would be unreasonable. This example shows the relevance of the question about the place of the points of maximum value of the velocity, if the entropy is not a constant. To clarify the regularities of the location of these points, was performed the analysis of the com- plete Euler equations (without any simplifying assumptions in 3-D case. The new proof of the maximum principle for sub- sonic flow was proposed. This proof does not rely on the assumption that the pressure is a function of density. Thus, it is shown that the maximum principle for subsonic flow is true for stationary subsonic irrotational flows of ideal perfect gas with variable entropy.

  18. Maximum power point tracker based on fuzzy logic

    International Nuclear Information System (INIS)

    Daoud, A.; Midoun, A.

    2006-01-01

    The solar energy is used as power source in photovoltaic power systems and the need for an intelligent power management system is important to obtain the maximum power from the limited solar panels. With the changing of the sun illumination due to variation of angle of incidence of sun radiation and of the temperature of the panels, Maximum Power Point Tracker (MPPT) enables optimization of solar power generation. The MPPT is a sub-system designed to extract the maximum power from a power source. In the case of solar panels power source. the maximum power point varies as a result of changes in its electrical characteristics which in turn are functions of radiation dose, temperature, ageing and other effects. The MPPT maximum the power output from panels for a given set of conditions by detecting the best working point of the power characteristic and then controls the current through the panels or the voltage across them. Many MPPT methods have been reported in literature. These techniques of MPPT can be classified into three main categories that include: lookup table methods, hill climbing methods and computational methods. The techniques vary according to the degree of sophistication, processing time and memory requirements. The perturbation and observation algorithm (hill climbing technique) is commonly used due to its ease of implementation, and relative tracking efficiency. However, it has been shown that when the insolation changes rapidly, the perturbation and observation method is slow to track the maximum power point. In recent years, the fuzzy controllers are used for maximum power point tracking. This method only requires the linguistic control rules for maximum power point, the mathematical model is not required and therefore the implementation of this control method is easy to real control system. In this paper, we we present a simple robust MPPT using fuzzy set theory where the hardware consists of the microchip's microcontroller unit control card and

  19. Hydrodynamics at the smallest scales: a solvability criterion for Navier-Stokes equations in high dimensions.

    Science.gov (United States)

    Viswanathan, T M; Viswanathan, G M

    2011-01-28

    Strong global solvability is difficult to prove for high-dimensional hydrodynamic systems because of the complex interplay between nonlinearity and scale invariance. We define the Ladyzhenskaya-Lions exponent α(L)(n)=(2+n)/4 for Navier-Stokes equations with dissipation -(-Δ)(α) in R(n), for all n≥2. We review the proof of strong global solvability when α≥α(L)(n), given smooth initial data. If the corresponding Euler equations for n>2 were to allow uncontrolled growth of the enstrophy (1/2)∥∇u∥(L²)(2), then no globally controlled coercive quantity is currently known to exist that can regularize solutions of the Navier-Stokes equations for α<α(L)(n). The energy is critical under scale transformations only for α=α(L)(n).

  20. Dynamic predictive model for growth of Salmonella spp. in scrambled egg mix.

    Science.gov (United States)

    Li, Lin; Cepeda, Jihan; Subbiah, Jeyamkondan; Froning, Glenn; Juneja, Vijay K; Thippareddi, Harshavardhan

    2017-06-01

    Liquid egg products can be contaminated with Salmonella spp. during processing. A dynamic model for the growth of Salmonella spp. in scrambled egg mix - high solids (SEM) was developed and validated. SEM was prepared and inoculated with ca. 2 log CFU/mL of a five serovar Salmonella spp. cocktail. Salmonella spp. growth data at isothermal temperatures (10, 15, 20, 25, 30, 35, 37, 39, 41, 43, 45, and 47 °C) in SEM were collected. Baranyi model was used (primary model) to fit growth data and the maximum growth rate and lag phase duration for each temperature were determined. A secondary model was developed with maximum growth rate as a function of temperature. The model performance measures, root mean squared error (RMSE, 0.09) and pseudo-R 2 (1.00) indicated good fit for both primary and secondary models. A dynamic model was developed by integrating the primary and secondary models and validated using two sinusoidal temperature profiles, 5-15 °C (low temperature) for 480 h and 10-40 °C (high temperature) for 48 h. The RMSE values for the sinusoidal low and high temperature profiles were 0.47 and 0.42 log CFU/mL, respectively. The model can be used to predict Salmonella spp. growth in case of temperature abuse during liquid egg processing. Copyright © 2016. Published by Elsevier Ltd.

  1. Maximum entropy methods

    International Nuclear Information System (INIS)

    Ponman, T.J.

    1984-01-01

    For some years now two different expressions have been in use for maximum entropy image restoration and there has been some controversy over which one is appropriate for a given problem. Here two further entropies are presented and it is argued that there is no single correct algorithm. The properties of the four different methods are compared using simple 1D simulations with a view to showing how they can be used together to gain as much information as possible about the original object. (orig.)

  2. Maximum entropy deconvolution of low count nuclear medicine images

    International Nuclear Information System (INIS)

    McGrath, D.M.

    1998-12-01

    Maximum entropy is applied to the problem of deconvolving nuclear medicine images, with special consideration for very low count data. The physics of the formation of scintigraphic images is described, illustrating the phenomena which degrade planar estimates of the tracer distribution. Various techniques which are used to restore these images are reviewed, outlining the relative merits of each. The development and theoretical justification of maximum entropy as an image processing technique is discussed. Maximum entropy is then applied to the problem of planar deconvolution, highlighting the question of the choice of error parameters for low count data. A novel iterative version of the algorithm is suggested which allows the errors to be estimated from the predicted Poisson mean values. This method is shown to produce the exact results predicted by combining Poisson statistics and a Bayesian interpretation of the maximum entropy approach. A facility for total count preservation has also been incorporated, leading to improved quantification. In order to evaluate this iterative maximum entropy technique, two comparable methods, Wiener filtering and a novel Bayesian maximum likelihood expectation maximisation technique, were implemented. The comparison of results obtained indicated that this maximum entropy approach may produce equivalent or better measures of image quality than the compared methods, depending upon the accuracy of the system model used. The novel Bayesian maximum likelihood expectation maximisation technique was shown to be preferable over many existing maximum a posteriori methods due to its simplicity of implementation. A single parameter is required to define the Bayesian prior, which suppresses noise in the solution and may reduce the processing time substantially. Finally, maximum entropy deconvolution was applied as a pre-processing step in single photon emission computed tomography reconstruction of low count data. Higher contrast results were

  3. Risk of Soil Recontamination Due to Using Eleusine coracana and Panicum maximum Straw After Phytoremediation of Picloram.

    Science.gov (United States)

    Nascimento, Alex Favaro; Pires, Fábio Ribeiro; Chagas, Kristhiano; de Oliveira Procópio, Sergio; Oliveira, Marcelo Antonio; Cargnelutti Filho, Alberto; Belo, Alessandra Ferreira; Egreja Filho, Fernando Barboza

    2015-01-01

    This study aimed to evaluate the herbicidal activity of picloram on the biomass of the remediation plants Eleusine coracana and Panicum maximum after cultivation in a soil contaminated with this herbicide. These species were grown in three soils, differentiated based on texture (clayish, middle, and sandy, with 460, 250, and 40 g kg(-1) of the clay, respectively), previously contaminated with picloram (0, 80, and 160 g ha(-1)). After 90 days, the plants were harvested and an extract was produced by maceration of leaves and stems of these plants. It was applied to pots containing washed sand, comprising a bioassay in a growth chamber using soybean as a bioindicator for picloram. Soil and plant samples were analyzed by HPLC. The results showed the presence of picloram or metabolites with herbicidal activity in the shoots of E. coracana and P. maximum at phytotoxic levels with regard to soybean plants, indicating that they work only as phytoextractors and that the presence of straw on the soil surface can promote recontamination within the area. It is not recommended to cultivate species susceptible to picloram in areas where it was reported remediation by E. indica and P. maximum and still present residues of these species.

  4. Implications of late-in-life density-dependent growth for fishery size-at-entry leading to maximum sustainable yield

    DEFF Research Database (Denmark)

    van Gemert, Rob; Andersen, Ken Haste

    2018-01-01

    -in-life density-dependent growth: North Sea plaice (Pleuronectes platessa), Northeast Atlantic (NEA) mackerel (Scomber scombrus), and Baltic sprat (Sprattus sprattus balticus). For all stocks, the model predicts exploitation at MSY with a large size-at-entry into the fishery, indicating that late-in-life density...

  5. Maximum Principles for Discrete and Semidiscrete Reaction-Diffusion Equation

    Directory of Open Access Journals (Sweden)

    Petr Stehlík

    2015-01-01

    Full Text Available We study reaction-diffusion equations with a general reaction function f on one-dimensional lattices with continuous or discrete time ux′  (or  Δtux=k(ux-1-2ux+ux+1+f(ux, x∈Z. We prove weak and strong maximum and minimum principles for corresponding initial-boundary value problems. Whereas the maximum principles in the semidiscrete case (continuous time exhibit similar features to those of fully continuous reaction-diffusion model, in the discrete case the weak maximum principle holds for a smaller class of functions and the strong maximum principle is valid in a weaker sense. We describe in detail how the validity of maximum principles depends on the nonlinearity and the time step. We illustrate our results on the Nagumo equation with the bistable nonlinearity.

  6. Minimal length, Friedmann equations and maximum density

    Energy Technology Data Exchange (ETDEWEB)

    Awad, Adel [Center for Theoretical Physics, British University of Egypt,Sherouk City 11837, P.O. Box 43 (Egypt); Department of Physics, Faculty of Science, Ain Shams University,Cairo, 11566 (Egypt); Ali, Ahmed Farag [Centre for Fundamental Physics, Zewail City of Science and Technology,Sheikh Zayed, 12588, Giza (Egypt); Department of Physics, Faculty of Science, Benha University,Benha, 13518 (Egypt)

    2014-06-16

    Inspired by Jacobson’s thermodynamic approach, Cai et al. have shown the emergence of Friedmann equations from the first law of thermodynamics. We extend Akbar-Cai derivation http://dx.doi.org/10.1103/PhysRevD.75.084003 of Friedmann equations to accommodate a general entropy-area law. Studying the resulted Friedmann equations using a specific entropy-area law, which is motivated by the generalized uncertainty principle (GUP), reveals the existence of a maximum energy density closed to Planck density. Allowing for a general continuous pressure p(ρ,a) leads to bounded curvature invariants and a general nonsingular evolution. In this case, the maximum energy density is reached in a finite time and there is no cosmological evolution beyond this point which leaves the big bang singularity inaccessible from a spacetime prospective. The existence of maximum energy density and a general nonsingular evolution is independent of the equation of state and the spacial curvature k. As an example we study the evolution of the equation of state p=ωρ through its phase-space diagram to show the existence of a maximum energy which is reachable in a finite time.

  7. Maximum-Entropy Inference with a Programmable Annealer

    Science.gov (United States)

    Chancellor, Nicholas; Szoke, Szilard; Vinci, Walter; Aeppli, Gabriel; Warburton, Paul A.

    2016-03-01

    Optimisation problems typically involve finding the ground state (i.e. the minimum energy configuration) of a cost function with respect to many variables. If the variables are corrupted by noise then this maximises the likelihood that the solution is correct. The maximum entropy solution on the other hand takes the form of a Boltzmann distribution over the ground and excited states of the cost function to correct for noise. Here we use a programmable annealer for the information decoding problem which we simulate as a random Ising model in a field. We show experimentally that finite temperature maximum entropy decoding can give slightly better bit-error-rates than the maximum likelihood approach, confirming that useful information can be extracted from the excited states of the annealer. Furthermore we introduce a bit-by-bit analytical method which is agnostic to the specific application and use it to show that the annealer samples from a highly Boltzmann-like distribution. Machines of this kind are therefore candidates for use in a variety of machine learning applications which exploit maximum entropy inference, including language processing and image recognition.

  8. Effect of vapor-phase oxygen on chemical vapor deposition growth of graphene

    Science.gov (United States)

    Terasawa, Tomo-o.; Saiki, Koichiro

    2015-03-01

    To obtain a large-area single-crystal graphene, chemical vapor deposition (CVD) growth on Cu is considered the most promising. Recently, the surface oxygen on Cu has been found to suppress the nucleation of graphene. However, the effect of oxygen in the vapor phase was not elucidated sufficiently. Here, we investigate the effect of O2 partial pressure (PO2) on the CVD growth of graphene using radiation-mode optical microscopy. The nucleation density of graphene decreases monotonically with PO2, while its growth rate reaches a maximum at a certain pressure. Our results indicate that PO2 is an important parameter to optimize in the CVD growth of graphene.

  9. Probabilistic maximum-value wind prediction for offshore environments

    DEFF Research Database (Denmark)

    Staid, Andrea; Pinson, Pierre; Guikema, Seth D.

    2015-01-01

    statistical models to predict the full distribution of the maximum-value wind speeds in a 3 h interval. We take a detailed look at the performance of linear models, generalized additive models and multivariate adaptive regression splines models using meteorological covariates such as gust speed, wind speed......, convective available potential energy, Charnock, mean sea-level pressure and temperature, as given by the European Center for Medium-Range Weather Forecasts forecasts. The models are trained to predict the mean value of maximum wind speed, and the residuals from training the models are used to develop...... the full probabilistic distribution of maximum wind speed. Knowledge of the maximum wind speed for an offshore location within a given period can inform decision-making regarding turbine operations, planned maintenance operations and power grid scheduling in order to improve safety and reliability...

  10. Characterizing graphs of maximum matching width at most 2

    DEFF Research Database (Denmark)

    Jeong, Jisu; Ok, Seongmin; Suh, Geewon

    2017-01-01

    The maximum matching width is a width-parameter that is de ned on a branch-decomposition over the vertex set of a graph. The size of a maximum matching in the bipartite graph is used as a cut-function. In this paper, we characterize the graphs of maximum matching width at most 2 using the minor o...

  11. Arsenic-resistant and plant growth-promoting Firmicutes and γ-Proteobacteria species from industrially polluted irrigation water and corresponding cropland.

    Science.gov (United States)

    Qamar, N; Rehman, Y; Hasnain, S

    2017-09-01

    The aim of the study was to explore irrigation water polluted with industrial waste and corresponding cropland to screen bacteria for As detoxification and plant growth promotion. Plant growth-promoting (PGP) As-resistant cropland bacteria were isolated from contaminated irrigation water and corresponding agricultural soil. Phylogenetic analysis revealed that the isolates belonged to two distinct bacterial lineages; Firmicutes and γ-Proteobacteria. Maximum As(V) resistance was exhibited by Klebsiella pneumoniae T22 and Klebsiella oxytoca N53 (550 mmol l -1 ), whereas maximum resistance against As(III) was exhibited by K. oxytoca N53 (200 mmol l -1 ). Maximum As(V) reduction was shown by K. pneumoniae T22 (6·7 mmol l -1 ), whereas maximum As(III) oxidation was exhibited by Bacillus subtilis T23 (4·8 mmol l -1 ). As resistance genes arsB and ACR3 were detected in many of the isolates through polymerase chain reaction. Many of these isolates exhibited PGP traits such as hydrogen cyanide and auxin production as well as phosphate solubilization. The bacterial strains were able to enhance Triticum aestivum growth both in the absence and presence of As, and statistically significant increase in shoot and root lengths was observed especially in case of Acinetobacter lwoffii T24 and Citrobacter freundii N52-treated plants. Cropland bacteria have the ability to support plant growth. Bacteria of croplands irrigated with industrially polluted water develop resistance against toxicants. These bacteria are helpful for the plant growth in such contaminated lands. The bacteria capable of both As detoxification and plant growth promotion, such as A. lwoffii T24 and C. freundii N52, are ideal for remediation and reclamation of polluted lands for agriculture purposes. © 2017 The Society for Applied Microbiology.

  12. Growth decline assessment in Pinus sylvestris L. and Pinus nigra Arnold. forest by using 3-PG model

    Energy Technology Data Exchange (ETDEWEB)

    Navarro-Cerrillo, R.M.; Beira, J.; Suarez, J.; Xenakis, G.; Sánchez-Salguero, R.; Hernández-Clemente, R.

    2016-07-01

    Aim of the study: We assessed the ability of the 3-PG process-based model to accurately predict growth of Pinus sylvestris and P. nigra plantations across a range of sites, showing declining growth trends, in southern Spain. Area of study: The study area is located in “Sierra de Los Filabres” (Almería). Material and methods: The model was modified in fifteen parameters to predict diameter (DBH, cm), basal area increment (BAI, cm2 yr-1) and leaf area index (LAI, m2 m-2) in healthy trees and trees showing declining growth. We assumed that a set of specific physiological parameters (stem partitioning ratio-pFS20, maximum litterfall rate-γFx, maximum canopy conductance-gCx, specific leaf area for mature aged stands-σ1, age at which specific leaf area = ½ (σ0 + σ1), age at full canopy cover-tc, and canopy boundary layer conductance-gB) included in 3-PG would be suitable for predicting growth decline related to climate conditions. The calibrated model was evaluated using dendrochronological and LAI data obtained from plots. Main results: Observed and simulated DBH showed a high correlation (R2 > 0.99) between modelled and measured values for both species. In contrast, modelled and observed BAI showed lower correlation (R2 < 0.68). Sensitivity analysis on 3-PG outputs showed that the foliage parameters - maximum litterfall rate, maximum canopy conductance, specific leaf area for mature aged stands, age at which specific leaf area, and age at full canopy cover - were important for DBH and BAI predictions under drought stress. Research highlights: Our overall results indicated that the 3-PG model could predict growth response of pine plantations to climatic stress with desirable accuracy in southern Spain by using readily available soil and climatic data with physiological parameters derived from experiments. (Author)

  13. The Maximum Resource Bin Packing Problem

    DEFF Research Database (Denmark)

    Boyar, J.; Epstein, L.; Favrholdt, L.M.

    2006-01-01

    Usually, for bin packing problems, we try to minimize the number of bins used or in the case of the dual bin packing problem, maximize the number or total size of accepted items. This paper presents results for the opposite problems, where we would like to maximize the number of bins used...... algorithms, First-Fit-Increasing and First-Fit-Decreasing for the maximum resource variant of classical bin packing. For the on-line variant, we define maximum resource variants of classical and dual bin packing. For dual bin packing, no on-line algorithm is competitive. For classical bin packing, we find...

  14. Maximum entropy analysis of EGRET data

    DEFF Research Database (Denmark)

    Pohl, M.; Strong, A.W.

    1997-01-01

    EGRET data are usually analysed on the basis of the Maximum-Likelihood method \\cite{ma96} in a search for point sources in excess to a model for the background radiation (e.g. \\cite{hu97}). This method depends strongly on the quality of the background model, and thus may have high systematic unce...... uncertainties in region of strong and uncertain background like the Galactic Center region. Here we show images of such regions obtained by the quantified Maximum-Entropy method. We also discuss a possible further use of MEM in the analysis of problematic regions of the sky....

  15. Density estimation by maximum quantum entropy

    International Nuclear Information System (INIS)

    Silver, R.N.; Wallstrom, T.; Martz, H.F.

    1993-01-01

    A new Bayesian method for non-parametric density estimation is proposed, based on a mathematical analogy to quantum statistical physics. The mathematical procedure is related to maximum entropy methods for inverse problems and image reconstruction. The information divergence enforces global smoothing toward default models, convexity, positivity, extensivity and normalization. The novel feature is the replacement of classical entropy by quantum entropy, so that local smoothing is enforced by constraints on differential operators. The linear response of the estimate is proportional to the covariance. The hyperparameters are estimated by type-II maximum likelihood (evidence). The method is demonstrated on textbook data sets

  16. Growth and development studies Hiroshima and Nagasaki: research plan

    Energy Technology Data Exchange (ETDEWEB)

    Finch, S C; Jablon, S; Hrubec, Zdenek

    1962-03-21

    This report summarizes the research plan for prospective evaluation of growth and development in those exposed to varying amounts of ionizing radiation during childhood or while in utero in Hiroshima or Nagasaki. Some experimental observations are briefly presented to provide background information, and the results of previous studies of growth and development at the Atomic Bomb Casualty Commission (ABCC) are reviewed. Procedures have been described for determining the top of the growth curve for the in utero exposed and the maximum growth and development of those exposed during childhood in comparison to their nonexposed counterparts. Differences in growth and development found between exposed and nonexposed individuals will be analysed in relation to radiation dose, age at time of exposure, sex, and socioeconomic factors. Attempts will be made to determine whether or not abnormalities in visual acuity are increased in those exposed while in utero or during childhood as compared to nonexposed or comparable ages. 23 references, 2 tables.

  17. Growth conditions of 0-group plaice Pleuronectes platessa in the western Wadden Sea as revealed by otolith microstructure analysis

    Science.gov (United States)

    Cardoso, Joana F. M. F.; Freitas, Vânia; de Paoli, Hélène; Witte, Johannes IJ.; van der Veer, Henk W.

    2016-05-01

    Growth studies based on population-based growth estimates are limited by the fact that they do not take into account differences in age/size structure within the population. To overcome these problems, otolith microstructure analysis is often used to estimate individual growth. Here, we analyse growth of 0-group plaice in the western Wadden Sea in two years: a year preceded by a mild winter (1995) and a year preceded by a severe winter (1996). Growth was analysed by combining information on individual growth based on otolith analysis with predictions of maximum growth (= under optimal food conditions) based on a Dynamic Energy Budget model. Otolith analysis revealed that settlement occurred earlier in 1995 than in 1996. In both years, one main cohort was found, followed by a group of late settlers. No differences in mean length-at-age were found between these groups. DEB modelling suggested that growth was not maximal during the whole growing season: realized growth (the fraction of maximum growth realized by 0-group plaice) declined in the summer, although this decline was relatively small. In addition, late settling individuals exhibited lower realized growth than individuals from the main cohort. This study confirms that growth conditions for 0-group plaice are not optimal and that a growth reduction occurs in summer, as suggested in previous studies.

  18. Breast meat quality of chickens with divergent growth rates and its relation to growth curve parameters

    Directory of Open Access Journals (Sweden)

    P. C. Muth

    2017-11-01

    Full Text Available The effects of the increase of body weight of contemporary broilers during growth on functional meat quality and color characteristics of the chicken breast muscle are controversially debated. Therefore, male chickens (n = 264 of a fast-growing commercial broiler (Ross 308 and two slow-growing experimental meat-type chicken lines were compared at equal age and at similar body weight in order to investigate the effect of growth rate on selected functional breast meat traits and meat color. Additionally, the breast meat characteristics of birds with different growth profiles were compared within lines. When the body weight of commercial broilers reached about 40 to 60 % of their growth potential, they exhibited particularly high ultimate pH values compared with slow-growing lines. The ability of the meat of fast-growing broilers to retain water during cooking was impaired (5 to 16 percentage points increased cooking loss compared to slow-growing lines, which, in contrast to pH, was only marginally affected by body weight and/or age at slaughter. No unfavorable correlations of breast meat quality traits with the growth profile, represented by growth curve parameters derived from the Gompertz–Laird equation, were detected within any of the investigated chicken lines. It is noteworthy that the associations of ultimate pH and cooking loss with maximum growth speed indicate a non-linear relationship. Thus, some of the functional characteristics of breast meat of the fast-growing broiler resembled the white-striping defect described for poultry meat, but the hypothesis that selection on increased growth rates is detrimental for meat quality per se could not be confirmed. In fact, an elevated growth potential in particular, i.e., body weight at maturity, could have some beneficial effects for the water-holding capacity of breast meat, regardless of the genotypic growth rate.

  19. Evaluation of creep-fatigue crack growth for large-scale FBR reactor vessel and NDE assessment

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Young Sang; Kim, Jong Bum; Kim, Seok Hun; Yoo, Bong

    2001-03-01

    Creep fatigue crack growth contributes to the failure of FRB reactor vessels in high temperature condition. In the design stage of reactor vessel, crack growth evaluation is very important to ensure the structural safety and setup the in-service inspection strategy. In this study, creep-fatigue crack growth evaluation has been performed for the semi-elliptical surface cracks subjected to thermal loading. The thermal stress analysis of a large-scale FBR reactor vessel has been carried out for the load conditions. The distributions of axial, radial, hoop, and Von Mises stresses were obtained for the loading conditions. At the maximum point of the axial and hoop stress, the longitudinal and circumferential surface cracks (i.e. PTS crack, NDE short crack and shallow long crack) were postulated. Using the maximum and minimum values of stresses, the creep-fatigue crack growth of the proposed cracks was simulated. The crack growth rate of circumferential cracks becomes greater than that of longitudinal cracks. The total crack growth of the largest PTS crack is very small after 427 cycles. The structural integrity of a large-scale reactor can be maintained for the plant life. The crack depth growth of the shallow long crack is faster than that of the NDE short crack. In the ISI of the large-scale FBR reactor vessel, the ultrasonic inspection is beneficial to detect the shallow circumferential cracks.

  20. Growth decline assessment in Pinus sylvestris L. and Pinus nigra Arnold. forest by using 3-PG model.

    Directory of Open Access Journals (Sweden)

    Rafael M. Navarro-Cerrillo

    2016-12-01

    Full Text Available Aim of the study: We assessed the ability of the 3-PG process-based model to accurately predict growth of Pinus sylvestris and P. nigra plantations across a range of sites, showing declining growth trends, in southern Spain. Area of study: The study area is located in “Sierra de Los Filabres” (Almería. Material and methods: The model was modified in fifteen parameters to predict diameter (DBH, cm, basal area increment (BAI, cm2 yr-1 and leaf area index (LAI, m2 m-2 in healthy trees and trees showing declining growth. We assumed that a set of specific physiological parameters (stem partitioning ratio-pFS20, maximum litterfall rate-γFx, maximum canopy conductance-gCx, specific leaf area for mature aged stands-σ1, age at which specific leaf area = ½ (σ0 + σ1, age at full canopy cover-tc, and canopy boundary layer conductance-gB included in 3-PG would be suitable for predicting growth decline related to climate conditions. The calibrated model was evaluated using dendrochronological and LAI data obtained from plots. Main results: Observed and simulated DBH showed a high correlation (R2 > 0.99 between modelled and measured values for both species. In contrast, modelled and observed BAI showed lower correlation (R2 < 0.68. Sensitivity analysis on 3-PG outputs showed that the foliage parameters - maximum litterfall rate, maximum canopy conductance, specific leaf area for mature aged stands, age at which specific leaf area, and age at full canopy cover - were important for DBH and BAI predictions under drought stress. Research highlights: Our overall results indicated that the 3-PG model could predict growth response of pine plantations to climatic stress with desirable accuracy in southern Spain by using readily available soil and climatic data with physiological parameters derived from experiments. Keywords: Hybrid process model; forest management models; growth prediction; Pinus spp, Parameterization; forest decline.

  1. Arabidopsis Growth Simulation Using Image Processing Technology

    Directory of Open Access Journals (Sweden)

    Junmei Zhang

    2014-01-01

    Full Text Available This paper aims to provide a method to represent the virtual Arabidopsis plant at each growth stage. It includes simulating the shape and providing growth parameters. The shape is described with elliptic Fourier descriptors. First, the plant is segmented from the background with the chromatic coordinates. With the segmentation result, the outer boundary series are obtained by using boundary tracking algorithm. The elliptic Fourier analysis is then carried out to extract the coefficients of the contour. The coefficients require less storage than the original contour points and can be used to simulate the shape of the plant. The growth parameters include total area and the number of leaves of the plant. The total area is obtained with the number of the plant pixels and the image calibration result. The number of leaves is derived by detecting the apex of each leaf. It is achieved by using wavelet transform to identify the local maximum of the distance signal between the contour points and the region centroid. Experiment result shows that this method can record the growth stage of Arabidopsis plant with fewer data and provide a visual platform for plant growth research.

  2. Growth physiology and fate of diatoms in the ocean: a review

    Science.gov (United States)

    Sarthou, Géraldine; Timmermans, Klaas R.; Blain, Stéphane; Tréguer, Paul

    2005-01-01

    Diatoms are a major component of phytoplankton community. They tend to dominate under natural high-nutrient concentrations, as well as during artificial Fe fertilisation experiments. They are main players in the biogeochemical cycle of carbon (C), as they can account for 40% of the total primary production in the Ocean and dominate export production, as well as in the biogeochemical cycles of the other macro-nutrients, nitrogen (N), phosphorus (P), and silicon (Si). Another important nutrient is Fe, which was shown to have a direct or indirect effect on nearly all the biogeochemical parameters of diatoms. In the present paper, an inventory is made of the growth, physiology and fate of many diatom species, including maximum growth rate, photosynthetic parameters (maximum specific rate of photosynthesis, photosynthetic efficiency and light adaptation parameter), nutrient limitation (half-saturation constant for growth/uptake), cellular elemental ratios, and loss terms (sinking rates, autolysis rates and grazing rates). This is a first step for improvement of the parameterisation of physiologically based phytoplankton growth and global 3D carbon models. This review is a synthesis of a large number of published laboratory experiments using monospecific cultures as well as field data. Our compilation confirms that size is an important factor explaining variations of biogeochemical parameters of diatoms (e.g. maximum growth rate, photosynthesis parameters, half-saturation constants, sinking rate, and grazing). Some variations of elemental ratios can be explained by adaptation of intracellular requirements or storage of Fe, and P, for instance. The important loss processes of diatoms pointed out by this synthesis are (i) sinking, as single cells as well as through aggregation which generally greatly increases sinking rate, (ii) cell autolysis, which can significantly reduce net growth rates, especially under nutrient limitation when gross growth rates are low, and (iii

  3. The free growth criterion for grain initiation in TiB 2 inoculated γ-titanium aluminide based alloys

    Science.gov (United States)

    Gosslar, D.; Günther, R.

    2014-02-01

    γ-titanium aluminide (γ-TiAl) based alloys enable for the design of light-weight and high-temperature resistant engine components. This work centers on a numerical study of the condition for grain initiation during solidification of TiB2 inoculated γ-TiAl based alloys. Grain initiation is treated according to the so-called free growth criterion. This means that the free growth barrier for grain initiation is determined by the maximum interfacial mean curvature between a nucleus and the melt. The strategy presented in this paper relies on iteratively increasing the volume of a nucleus, which partially wets a hexagonal TiB2 crystal, minimizing the interfacial energy and calculating the corresponding interfacial curvature. The hereby obtained maximum curvature yields a scaling relation between the size of TiB2 crystals and the free growth barrier. Comparison to a prototypical TiB2 crystal in an as cast γ-TiAl based alloy allowed then to predict the free growth barrier prevailing under experimental conditions. The validity of the free growth criterion is discussed by an interfacial energy criterion.

  4. A novel process-based model of microbial growth: self-inhibition in Saccharomyces cerevisiae aerobic fed-batch cultures.

    Science.gov (United States)

    Mazzoleni, Stefano; Landi, Carmine; Cartenì, Fabrizio; de Alteriis, Elisabetta; Giannino, Francesco; Paciello, Lucia; Parascandola, Palma

    2015-07-30

    Microbial population dynamics in bioreactors depend on both nutrients availability and changes in the growth environment. Research is still ongoing on the optimization of bioreactor yields focusing on the increase of the maximum achievable cell density. A new process-based model is proposed to describe the aerobic growth of Saccharomyces cerevisiae cultured on glucose as carbon and energy source. The model considers the main metabolic routes of glucose assimilation (fermentation to ethanol and respiration) and the occurrence of inhibition due to the accumulation of both ethanol and other self-produced toxic compounds in the medium. Model simulations reproduced data from classic and new experiments of yeast growth in batch and fed-batch cultures. Model and experimental results showed that the growth decline observed in prolonged fed-batch cultures had to be ascribed to self-produced inhibitory compounds other than ethanol. The presented results clarify the dynamics of microbial growth under different feeding conditions and highlight the relevance of the negative feedback by self-produced inhibitory compounds on the maximum cell densities achieved in a bioreactor.

  5. Analogue of Pontryagin's maximum principle for multiple integrals minimization problems

    OpenAIRE

    Mikhail, Zelikin

    2016-01-01

    The theorem like Pontryagin's maximum principle for multiple integrals is proved. Unlike the usual maximum principle, the maximum should be taken not over all matrices, but only on matrices of rank one. Examples are given.

  6. Microprocessor Controlled Maximum Power Point Tracker for Photovoltaic Application

    International Nuclear Information System (INIS)

    Jiya, J. D.; Tahirou, G.

    2002-01-01

    This paper presents a microprocessor controlled maximum power point tracker for photovoltaic module. Input current and voltage are measured and multiplied within the microprocessor, which contains an algorithm to seek the maximum power point. The duly cycle of the DC-DC converter, at which the maximum power occurs is obtained, noted and adjusted. The microprocessor constantly seeks for improvement of obtained power by varying the duty cycle

  7. A dynamic regression analysis tool for quantitative assessment of bacterial growth written in Python.

    Science.gov (United States)

    Hoeflinger, Jennifer L; Hoeflinger, Daniel E; Miller, Michael J

    2017-01-01

    Herein, an open-source method to generate quantitative bacterial growth data from high-throughput microplate assays is described. The bacterial lag time, maximum specific growth rate, doubling time and delta OD are reported. Our method was validated by carbohydrate utilization of lactobacilli, and visual inspection revealed 94% of regressions were deemed excellent. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Maximum entropy reconstructions for crystallographic imaging; Cristallographie et reconstruction d`images par maximum d`entropie

    Energy Technology Data Exchange (ETDEWEB)

    Papoular, R

    1997-07-01

    The Fourier Transform is of central importance to Crystallography since it allows the visualization in real space of tridimensional scattering densities pertaining to physical systems from diffraction data (powder or single-crystal diffraction, using x-rays, neutrons, electrons or else). In turn, this visualization makes it possible to model and parametrize these systems, the crystal structures of which are eventually refined by Least-Squares techniques (e.g., the Rietveld method in the case of Powder Diffraction). The Maximum Entropy Method (sometimes called MEM or MaxEnt) is a general imaging technique, related to solving ill-conditioned inverse problems. It is ideally suited for tackling undetermined systems of linear questions (for which the number of variables is much larger than the number of equations). It is already being applied successfully in Astronomy, Radioastronomy and Medical Imaging. The advantages of using MAXIMUM Entropy over conventional Fourier and `difference Fourier` syntheses stem from the following facts: MaxEnt takes the experimental error bars into account; MaxEnt incorporate Prior Knowledge (e.g., the positivity of the scattering density in some instances); MaxEnt allows density reconstructions from incompletely phased data, as well as from overlapping Bragg reflections; MaxEnt substantially reduces truncation errors to which conventional experimental Fourier reconstructions are usually prone. The principles of Maximum Entropy imaging as applied to Crystallography are first presented. The method is then illustrated by a detailed example specific to Neutron Diffraction: the search for proton in solids. (author). 17 refs.

  9. Mechanical coupling limits the density and quality of self-organized carbon nanotube growth

    Science.gov (United States)

    Bedewy, Mostafa; Hart, A. John

    2013-03-01

    Aligned carbon nanotube (CNT) structures are promising for many applications; however, as-grown CNT "forests" synthesized by chemical vapor deposition (CVD) are typically low-density and mostly comprise tortuous defective CNTs. Here, we present evidence that the density and alignment of self-organized CNT growth is limited by mechanical coupling among CNTs in contact, in combination with their diameter-dependent growth rates. This study is enabled by comprehensive X-ray characterization of the spatially and temporally-varying internal morphology of CNT forests. Based on this data, we model the time evolution and diameter-dependent scaling of the ensuing mechanical forces on catalyst nanoparticles during CNT growth, which arise from the mismatch between the collective lengthening rate of the forest and the diameter-dependent growth rates of individual CNTs. In addition to enabling self-organization of CNTs into forests, time-varying forces between CNTs in contact dictate the hierarchical tortuous morphology of CNT forests, and may be sufficient to influence the structural quality of CNTs. These forces reach a maximum that is coincident with the maximum density observed in our growth process, and are proportional to CNT diameter. Therefore, we propose that improved manufacturing strategies for self-organized CNTs should consider both chemical and mechanical effects. This may be especially necessary to achieve high density CNT forests with low defect density, such as for improved thermal interfaces and high-permeability membranes.Aligned carbon nanotube (CNT) structures are promising for many applications; however, as-grown CNT "forests" synthesized by chemical vapor deposition (CVD) are typically low-density and mostly comprise tortuous defective CNTs. Here, we present evidence that the density and alignment of self-organized CNT growth is limited by mechanical coupling among CNTs in contact, in combination with their diameter-dependent growth rates. This study is

  10. Energy expenditure, economic growth, and the minimum EROI of society

    International Nuclear Information System (INIS)

    Fizaine, Florian; Court, Victor

    2016-01-01

    We estimate energy expenditure for the US and world economies from 1850 to 2012. Periods of high energy expenditure relative to GDP (from 1850 to 1945), or spikes (1973–74 and 1978–79) are associated with low economic growth rates, and periods of low or falling energy expenditure are associated with high and rising economic growth rates (e.g. 1945–1973). Over the period 1960–2010 for which we have continuous year-to-year data for control variables (capital formation, population, and unemployment rate) we estimate that, statistically, in order to enjoy positive growth, the US economy cannot afford to spend more than 11% of its GDP on energy. Given the current energy intensity of the US economy, this translates in a minimum societal EROI of approximately 11:1 (or a maximum tolerable average price of energy of twice the current level). Granger tests consistently reveal a one way causality running from the level of energy expenditure (as a fraction of GDP) to economic growth in the US between 1960 and 2010. A coherent economic policy should be founded on improving net energy efficiency. This would yield a “double dividend”: increased societal EROI (through decreased energy intensity of capital investment), and decreased sensitivity to energy price volatility. - Highlights: •We estimate energy expenditures as a fraction of GDP for the US, the world (1850–2012), and the UK (1300–2008). •Statistically speaking, the US economy cannot afford to allocate more than 11% of its GDP to energy expenditures in order to have a positive growth rate. •This corresponds to a maximum tolerable average price of energy of twice the current level. •In the same way, US growth is only possible if its primary energy system has at least a minimum EROI of approximately 11:1.

  11. Optimal Growth in Hypersonic Boundary Layers

    Science.gov (United States)

    Paredes, Pedro; Choudhari, Meelan M.; Li, Fei; Chang, Chau-Lyan

    2016-01-01

    The linear form of the parabolized linear stability equations is used in a variational approach to extend the previous body of results for the optimal, nonmodal disturbance growth in boundary-layer flows. This paper investigates the optimal growth characteristics in the hypersonic Mach number regime without any high-enthalpy effects. The influence of wall cooling is studied, with particular emphasis on the role of the initial disturbance location and the value of the spanwise wave number that leads to the maximum energy growth up to a specified location. Unlike previous predictions that used a basic state obtained from a self-similar solution to the boundary-layer equations, mean flow solutions based on the full Navier-Stokes equations are used in select cases to help account for the viscous- inviscid interaction near the leading edge of the plate and for the weak shock wave emanating from that region. Using the full Navier-Stokes mean flow is shown to result in further reduction with Mach number in the magnitude of optimal growth relative to the predictions based on the self-similar approximation to the base flow.

  12. Comprehensive performance analyses and optimization of the irreversible thermodynamic cycle engines (TCE) under maximum power (MP) and maximum power density (MPD) conditions

    International Nuclear Information System (INIS)

    Gonca, Guven; Sahin, Bahri; Ust, Yasin; Parlak, Adnan

    2015-01-01

    This paper presents comprehensive performance analyses and comparisons for air-standard irreversible thermodynamic cycle engines (TCE) based on the power output, power density, thermal efficiency, maximum dimensionless power output (MP), maximum dimensionless power density (MPD) and maximum thermal efficiency (MEF) criteria. Internal irreversibility of the cycles occurred during the irreversible-adiabatic processes is considered by using isentropic efficiencies of compression and expansion processes. The performances of the cycles are obtained by using engine design parameters such as isentropic temperature ratio of the compression process, pressure ratio, stroke ratio, cut-off ratio, Miller cycle ratio, exhaust temperature ratio, cycle temperature ratio and cycle pressure ratio. The effects of engine design parameters on the maximum and optimal performances are investigated. - Highlights: • Performance analyses are conducted for irreversible thermodynamic cycle engines. • Comprehensive computations are performed. • Maximum and optimum performances of the engines are shown. • The effects of design parameters on performance and power density are examined. • The results obtained may be guidelines to the engine designers

  13. Growth stimulation of Porphyromonas endodontalis by hemoglobin and protoporphyrin IX.

    Science.gov (United States)

    Zerr, M A; Cox, C D; Johnson, W T; Drake, D R

    2000-12-01

    Porphyromonas endodontalis, like other Porphyromonas species, has a complex set of nutritional requirements. In addition to being an obligate anaerobe, the bacterium must be grown in a complex medium consisting of amino acids, reducing agents and heme compounds. P. endodontalis accumulates high concentrations of heme pigments to the extent that colonies appear black on blood agar. This accumulation of heme and the need for these compounds has been characterized as iron requirements by these species. However, in our studies, P. endodontalis demonstrated growth dependence on hemoglobin or protoporphyrin IX but not on free iron. Iron added to other heme compounds actually decreased growth stimulation by porphyrin-containing compounds. P. endodontalis actively transported free iron, but this process did not appear to be critical for growth. The maximum stimulation of growth by protoporphyrin IX, under conditions of iron deprivation, suggests that P. endodontalis requires the porphyrin moiety as a growth factor.

  14. Shower maximum detector for SDC calorimetry

    International Nuclear Information System (INIS)

    Ernwein, J.

    1994-01-01

    A prototype for the SDC end-cap (EM) calorimeter complete with a pre-shower and a shower maximum detector was tested in beams of electrons and Π's at CERN by an SDC subsystem group. The prototype was manufactured from scintillator tiles and strips read out with 1 mm diameter wave-length shifting fibers. The design and construction of the shower maximum detector is described, and results of laboratory tests on light yield and performance of the scintillator-fiber system are given. Preliminary results on energy and position measurements with the shower max detector in the test beam are shown. (authors). 4 refs., 5 figs

  15. Maximum Power Point Tracking in Variable Speed Wind Turbine Based on Permanent Magnet Synchronous Generator Using Maximum Torque Sliding Mode Control Strategy

    Institute of Scientific and Technical Information of China (English)

    Esmaeil Ghaderi; Hossein Tohidi; Behnam Khosrozadeh

    2017-01-01

    The present study was carried out in order to track the maximum power point in a variable speed turbine by minimizing electromechanical torque changes using a sliding mode control strategy.In this strategy,fhst,the rotor speed is set at an optimal point for different wind speeds.As a result of which,the tip speed ratio reaches an optimal point,mechanical power coefficient is maximized,and wind turbine produces its maximum power and mechanical torque.Then,the maximum mechanical torque is tracked using electromechanical torque.In this technique,tracking error integral of maximum mechanical torque,the error,and the derivative of error are used as state variables.During changes in wind speed,sliding mode control is designed to absorb the maximum energy from the wind and minimize the response time of maximum power point tracking (MPPT).In this method,the actual control input signal is formed from a second order integral operation of the original sliding mode control input signal.The result of the second order integral in this model includes control signal integrity,full chattering attenuation,and prevention from large fluctuations in the power generator output.The simulation results,calculated by using MATLAB/m-file software,have shown the effectiveness of the proposed control strategy for wind energy systems based on the permanent magnet synchronous generator (PMSG).

  16. 32 CFR 842.35 - Depreciation and maximum allowances.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Depreciation and maximum allowances. 842.35... LITIGATION ADMINISTRATIVE CLAIMS Personnel Claims (31 U.S.C. 3701, 3721) § 842.35 Depreciation and maximum allowances. The military services have jointly established the “Allowance List-Depreciation Guide” to...

  17. Influence of culture media and environmental factors on mycelial growth and sporulation of Lasiodiplodia theobromae (Pat.) Griffon and Maubl.

    Science.gov (United States)

    Saha, A; Mandal, P; Dasgupta, S; Saha, D

    2008-05-01

    Lasiodiplodia theobromae, a common tea (Camellia sinensis) pathogen, usually does not sporulate or sporulates poorly in common media, which makes spore production difficult. In this study the effects of culture media, carbon source, nitrogen source, temperature, pH and light on mycelial growth and sporulation were evaluated. Among several carbon sources tested, glucose and sucrose were found superior for growth. Potassium nitrate supplemented media showed maximum growth amongst the tested inorganic nitrogen sources while peptone produced maximum growth among the tested organic nitrogen sources. Tea root extract supplemented potato dextrose agar medium was found to be the most suitable for mycelial growth and sporulation of L. theobromae. The fungus grow at temperatures ranging from 40 to 36 degrees C, with optimum growth at 28 degrees C and no growth was noted at 40 degrees C. There was no significant effect of different light period on growth of L. theobromae, but light enhanced sporulation. The fungus grow at pH 3.0-8.0 and optimum growth was observed at pH 6.0. Tea root extract supplemented potato dextrose agar medium with pH 6.0 was the most suitable for production of conidia of L. theobromae at 28 degrees C. Hence this media may be recommended for inoculum production for further studies.

  18. 40 CFR 141.63 - Maximum contaminant levels (MCLs) for microbiological contaminants.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant levels (MCLs) for microbiological contaminants. 141.63 Section 141.63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Water Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels § 141.63 Maximum...

  19. Particle Swarm Optimization Based of the Maximum Photovoltaic ...

    African Journals Online (AJOL)

    Photovoltaic electricity is seen as an important source of renewable energy. The photovoltaic array is an unstable source of power since the peak power point depends on the temperature and the irradiation level. A maximum peak power point tracking is then necessary for maximum efficiency. In this work, a Particle Swarm ...

  20. 40 CFR 1045.140 - What is my engine's maximum engine power?

    Science.gov (United States)

    2010-07-01

    ...) Maximum engine power for an engine family is generally the weighted average value of maximum engine power... engine family's maximum engine power apply in the following circumstances: (1) For outboard or personal... value for maximum engine power from all the different configurations within the engine family to...

  1. 42 CFR 409.62 - Lifetime maximum on inpatient psychiatric care.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Lifetime maximum on inpatient psychiatric care. 409....62 Lifetime maximum on inpatient psychiatric care. There is a lifetime maximum of 190 days on inpatient psychiatric hospital services available to any beneficiary. Therefore, once an individual receives...

  2. Maximum-entropy description of animal movement.

    Science.gov (United States)

    Fleming, Chris H; Subaşı, Yiğit; Calabrese, Justin M

    2015-03-01

    We introduce a class of maximum-entropy states that naturally includes within it all of the major continuous-time stochastic processes that have been applied to animal movement, including Brownian motion, Ornstein-Uhlenbeck motion, integrated Ornstein-Uhlenbeck motion, a recently discovered hybrid of the previous models, and a new model that describes central-place foraging. We are also able to predict a further hierarchy of new models that will emerge as data quality improves to better resolve the underlying continuity of animal movement. Finally, we also show that Langevin equations must obey a fluctuation-dissipation theorem to generate processes that fall from this class of maximum-entropy distributions when the constraints are purely kinematic.

  3. Extreme Maximum Land Surface Temperatures.

    Science.gov (United States)

    Garratt, J. R.

    1992-09-01

    There are numerous reports in the literature of observations of land surface temperatures. Some of these, almost all made in situ, reveal maximum values in the 50°-70°C range, with a few, made in desert regions, near 80°C. Consideration of a simplified form of the surface energy balance equation, utilizing likely upper values of absorbed shortwave flux (1000 W m2) and screen air temperature (55°C), that surface temperatures in the vicinity of 90°-100°C may occur for dry, darkish soils of low thermal conductivity (0.1-0.2 W m1 K1). Numerical simulations confirm this and suggest that temperature gradients in the first few centimeters of soil may reach 0.5°-1°C mm1 under these extreme conditions. The study bears upon the intrinsic interest of identifying extreme maximum temperatures and yields interesting information regarding the comfort zone of animals (including man).

  4. On Maximum Entropy and Inference

    Directory of Open Access Journals (Sweden)

    Luigi Gresele

    2017-11-01

    Full Text Available Maximum entropy is a powerful concept that entails a sharp separation between relevant and irrelevant variables. It is typically invoked in inference, once an assumption is made on what the relevant variables are, in order to estimate a model from data, that affords predictions on all other (dependent variables. Conversely, maximum entropy can be invoked to retrieve the relevant variables (sufficient statistics directly from the data, once a model is identified by Bayesian model selection. We explore this approach in the case of spin models with interactions of arbitrary order, and we discuss how relevant interactions can be inferred. In this perspective, the dimensionality of the inference problem is not set by the number of parameters in the model, but by the frequency distribution of the data. We illustrate the method showing its ability to recover the correct model in a few prototype cases and discuss its application on a real dataset.

  5. The effects of varying sampling intervals on the growth and survival ...

    African Journals Online (AJOL)

    Four different sampling intervals were investigated during a six-week outdoor nursery management of Heterobranchus longifilis (Valenciennes, 1840) fry in outdoor concrete tanks in order to determine the most suitable sampling regime for maximum productivity in terms of optimum growth and survival of hatchlings and ...

  6. Larval migration and growth of marine prawns in the estuarine habitat

    Digital Repository Service at National Institute of Oceanography (India)

    Achuthankutty, C.T.; Nair, S.R.S.

    -monsoon season (56.3%). The lower reaches of the estuary sustained the maximum density (73.2%). All species except @iM. affinis@@ had an initial growth in the mangrove swamp and a later stay in the estuary before finally migrating back to the sea. @iM. affinis...

  7. Growth of Clostridium perfringens during cooling of refried beans.

    Science.gov (United States)

    Cevallos-Cevallos, Juan M; Akins, E Deann; Friedrich, Loretta M; Danyluk, Michelle D; Simonne, Amarat H

    2012-10-01

    Outbreaks of Clostridium perfringens have been associated with dishes containing refried beans from food service establishments. However, growth of C. perfringens in refried beans has not been investigated, and predictive models have not been validated in this food matrix. We investigated the growth of C. perfringens during the cooling of refried beans. Refried beans (pinto and black, with and without salt added) were inoculated with 3 log CFU/g C. perfringens spores and incubated isothermally at 12, 23, 30, 35, 40, 45, and 50°C. The levels of C. perfringens were monitored 3, 5, 8, and 10 h after inoculation, and then fitted to the Baranyi primary model and the Rosso secondary model prior to solving the Baranyi differential equation. The final model was validated by dynamic cooling experiments carried out in stockpots, thus mimicking the worst possible food service conditions. All refried beans samples supported the growth of C. perfringens, and all models fit the data with pseudo-R(2) values of 0.95 or greater and mean square errors of 0.3 or lower. The estimated maximum specific growth rates were generally higher in pinto beans, with or without salt added (2.64 and 1.95 h(-1), respectively), when compared with black beans, with or without salt added (1.78 and 1.61 h(-1), respectively). After 10 h of incubation, maximum populations of C. perfringens were significantly higher in samples with no salt added (7.9 log CFU/g for both pinto and black beans) than in samples with salt added (7.3 and 7.2 log CFU/g for pinto and black beans, respectively). The dynamic model predicted the growth of C. perfringens during cooling, with an average root mean squared error of 0.44. The use of large stockpots to cool refried beans led to an observed 1.2-log increase (1.5-log increase predicted by model) in levels of C. perfringens during cooling. The use of shallower pans for cooling is recommended, because they cool faster, therefore limiting the growth of C. perfringens.

  8. Fractal Dimension and Maximum Sunspot Number in Solar Cycle

    Directory of Open Access Journals (Sweden)

    R.-S. Kim

    2006-09-01

    Full Text Available The fractal dimension is a quantitative parameter describing the characteristics of irregular time series. In this study, we use this parameter to analyze the irregular aspects of solar activity and to predict the maximum sunspot number in the following solar cycle by examining time series of the sunspot number. For this, we considered the daily sunspot number since 1850 from SIDC (Solar Influences Data analysis Center and then estimated cycle variation of the fractal dimension by using Higuchi's method. We examined the relationship between this fractal dimension and the maximum monthly sunspot number in each solar cycle. As a result, we found that there is a strong inverse relationship between the fractal dimension and the maximum monthly sunspot number. By using this relation we predicted the maximum sunspot number in the solar cycle from the fractal dimension of the sunspot numbers during the solar activity increasing phase. The successful prediction is proven by a good correlation (r=0.89 between the observed and predicted maximum sunspot numbers in the solar cycles.

  9. Automatic maximum entropy spectral reconstruction in NMR

    International Nuclear Information System (INIS)

    Mobli, Mehdi; Maciejewski, Mark W.; Gryk, Michael R.; Hoch, Jeffrey C.

    2007-01-01

    Developments in superconducting magnets, cryogenic probes, isotope labeling strategies, and sophisticated pulse sequences together have enabled the application, in principle, of high-resolution NMR spectroscopy to biomolecular systems approaching 1 megadalton. In practice, however, conventional approaches to NMR that utilize the fast Fourier transform, which require data collected at uniform time intervals, result in prohibitively lengthy data collection times in order to achieve the full resolution afforded by high field magnets. A variety of approaches that involve nonuniform sampling have been proposed, each utilizing a non-Fourier method of spectrum analysis. A very general non-Fourier method that is capable of utilizing data collected using any of the proposed nonuniform sampling strategies is maximum entropy reconstruction. A limiting factor in the adoption of maximum entropy reconstruction in NMR has been the need to specify non-intuitive parameters. Here we describe a fully automated system for maximum entropy reconstruction that requires no user-specified parameters. A web-accessible script generator provides the user interface to the system

  10. Stationary neutrino radiation transport by maximum entropy closure

    International Nuclear Information System (INIS)

    Bludman, S.A.

    1994-11-01

    The authors obtain the angular distributions that maximize the entropy functional for Maxwell-Boltzmann (classical), Bose-Einstein, and Fermi-Dirac radiation. In the low and high occupancy limits, the maximum entropy closure is bounded by previously known variable Eddington factors that depend only on the flux. For intermediate occupancy, the maximum entropy closure depends on both the occupation density and the flux. The Fermi-Dirac maximum entropy variable Eddington factor shows a scale invariance, which leads to a simple, exact analytic closure for fermions. This two-dimensional variable Eddington factor gives results that agree well with exact (Monte Carlo) neutrino transport calculations out of a collapse residue during early phases of hydrostatic neutron star formation

  11. Growth and Maturation of Plectropomus spp. in the Saudi Arabian Red Sea

    KAUST Repository

    DesRosiers, Noah

    2011-05-01

    Two species of plectropomid grouper (Plectropomus areolatus and P. pessuliferus) are found in the Red Sea. In Saudi Arabia these are the most valuable fishes by weight, averaging wholesale prices around US $15 per kilogram (personal observation). Over the past two decades, the number of fishing vessels in the Saudi Arabian Red Sea has tripled. Despite this increase in fishing effort Saudi Arabia has not implemented any marine resource management for Red Sea fisheries. Little biological data are currently available to inform managers. The research presented here addresses knowledge gaps on the growth pattern, longevity and sexual ontogeny of Plectropomus spp. in the Red Sea. Collections of each species were established by purchasing landed individuals from fishermen and fish markets distributed evenly between three latitudinal regions around the country. The total length of each fish was measured to the nearest millimeter. Age was estimated by enumerating annual bands visualized in transverse sections of sagittal otoliths. Sexual stage was determined via histological examination of gonadal tissue. Plots of total length versus age were fitted with reparameterized von Bertalanffy growth functions constrained to a size-at-settlement estimate of 20 mm. P. pessuliferus achieved a larger size (maximum 960 mm) and an older age (maximum 19 years) than P. areolatus (maximum size 570 mm, maximum age 9 years). While no regional patterns were found for P. pesuliferus, likelihood ratio tests revealed regional differences in growth pattern for P. areolatus, finding an increasing mean age, increasing mean length, and decreasing growth rate with decreasing latitude. In addition, males of P. areolatus were more abundant in the Southern region. These findings contradict existing theories about the effects of latitudinal temperature gradients on life history. It is hypothesized that the broader continental shelf in the Southern region may be providing a haven for these species in the

  12. Maximum power per VA control of vector controlled interior ...

    Indian Academy of Sciences (India)

    Thakur Sumeet Singh

    2018-04-11

    Apr 11, 2018 ... Department of Electrical Engineering, Indian Institute of Technology Delhi, New ... The MPVA operation allows maximum-utilization of the drive-system. ... Permanent magnet motor; unity power factor; maximum VA utilization; ...

  13. Application of maximum entropy to neutron tunneling spectroscopy

    International Nuclear Information System (INIS)

    Mukhopadhyay, R.; Silver, R.N.

    1990-01-01

    We demonstrate the maximum entropy method for the deconvolution of high resolution tunneling data acquired with a quasielastic spectrometer. Given a precise characterization of the instrument resolution function, a maximum entropy analysis of lutidine data obtained with the IRIS spectrometer at ISIS results in an effective factor of three improvement in resolution. 7 refs., 4 figs

  14. Enhancement of bone formation in rabbits by recombinant human growth hormone

    International Nuclear Information System (INIS)

    Ehrnberg, A.; Brosjoe, O.; Laaftman, P.; Nilsson, O.; Stroemberg, L.

    1993-01-01

    We studied the effect of human recombinant growth hormone on diaphyseal bone in 40 adult rabbits. The diaphyseal periosteum of one femur in each animal was mechanically stimulated by a nylon cerclage band. The bands induced an increase in bone formation, bone mineral content, and maximum torque capacity of the diaphyseal bone at 1 and 2 months. Growth hormone enhanced the anabolic effect of the cerclage bands on bone metabolism, evidenced by a further increase in torsional strength of the femurs. (au) (32 refs.)

  15. The maximum economic depth of groundwater abstraction for irrigation

    Science.gov (United States)

    Bierkens, M. F.; Van Beek, L. P.; de Graaf, I. E. M.; Gleeson, T. P.

    2017-12-01

    Over recent decades, groundwater has become increasingly important for agriculture. Irrigation accounts for 40% of the global food production and its importance is expected to grow further in the near future. Already, about 70% of the globally abstracted water is used for irrigation, and nearly half of that is pumped groundwater. In many irrigated areas where groundwater is the primary source of irrigation water, groundwater abstraction is larger than recharge and we see massive groundwater head decline in these areas. An important question then is: to what maximum depth can groundwater be pumped for it to be still economically recoverable? The objective of this study is therefore to create a global map of the maximum depth of economically recoverable groundwater when used for irrigation. The maximum economic depth is the maximum depth at which revenues are still larger than pumping costs or the maximum depth at which initial investments become too large compared to yearly revenues. To this end we set up a simple economic model where costs of well drilling and the energy costs of pumping, which are a function of well depth and static head depth respectively, are compared with the revenues obtained for the irrigated crops. Parameters for the cost sub-model are obtained from several US-based studies and applied to other countries based on GDP/capita as an index of labour costs. The revenue sub-model is based on gross irrigation water demand calculated with a global hydrological and water resources model, areal coverage of crop types from MIRCA2000 and FAO-based statistics on crop yield and market price. We applied our method to irrigated areas in the world overlying productive aquifers. Estimated maximum economic depths range between 50 and 500 m. Most important factors explaining the maximum economic depth are the dominant crop type in the area and whether or not initial investments in well infrastructure are limiting. In subsequent research, our estimates of

  16. What controls the maximum magnitude of injection-induced earthquakes?

    Science.gov (United States)

    Eaton, D. W. S.

    2017-12-01

    Three different approaches for estimation of maximum magnitude are considered here, along with their implications for managing risk. The first approach is based on a deterministic limit for seismic moment proposed by McGarr (1976), which was originally designed for application to mining-induced seismicity. This approach has since been reformulated for earthquakes induced by fluid injection (McGarr, 2014). In essence, this method assumes that the upper limit for seismic moment release is constrained by the pressure-induced stress change. A deterministic limit is given by the product of shear modulus and the net injected fluid volume. This method is based on the assumptions that the medium is fully saturated and in a state of incipient failure. An alternative geometrical approach was proposed by Shapiro et al. (2011), who postulated that the rupture area for an induced earthquake falls entirely within the stimulated volume. This assumption reduces the maximum-magnitude problem to one of estimating the largest potential slip surface area within a given stimulated volume. Finally, van der Elst et al. (2016) proposed that the maximum observed magnitude, statistically speaking, is the expected maximum value for a finite sample drawn from an unbounded Gutenberg-Richter distribution. These three models imply different approaches for risk management. The deterministic method proposed by McGarr (2014) implies that a ceiling on the maximum magnitude can be imposed by limiting the net injected volume, whereas the approach developed by Shapiro et al. (2011) implies that the time-dependent maximum magnitude is governed by the spatial size of the microseismic event cloud. Finally, the sample-size hypothesis of Van der Elst et al. (2016) implies that the best available estimate of the maximum magnitude is based upon observed seismicity rate. The latter two approaches suggest that real-time monitoring is essential for effective management of risk. A reliable estimate of maximum

  17. Topics in Bayesian statistics and maximum entropy

    International Nuclear Information System (INIS)

    Mutihac, R.; Cicuttin, A.; Cerdeira, A.; Stanciulescu, C.

    1998-12-01

    Notions of Bayesian decision theory and maximum entropy methods are reviewed with particular emphasis on probabilistic inference and Bayesian modeling. The axiomatic approach is considered as the best justification of Bayesian analysis and maximum entropy principle applied in natural sciences. Particular emphasis is put on solving the inverse problem in digital image restoration and Bayesian modeling of neural networks. Further topics addressed briefly include language modeling, neutron scattering, multiuser detection and channel equalization in digital communications, genetic information, and Bayesian court decision-making. (author)

  18. Maximum vehicle cabin temperatures under different meteorological conditions

    Science.gov (United States)

    Grundstein, Andrew; Meentemeyer, Vernon; Dowd, John

    2009-05-01

    A variety of studies have documented the dangerously high temperatures that may occur within the passenger compartment (cabin) of cars under clear sky conditions, even at relatively low ambient air temperatures. Our study, however, is the first to examine cabin temperatures under variable weather conditions. It uses a unique maximum vehicle cabin temperature dataset in conjunction with directly comparable ambient air temperature, solar radiation, and cloud cover data collected from April through August 2007 in Athens, GA. Maximum cabin temperatures, ranging from 41-76°C, varied considerably depending on the weather conditions and the time of year. Clear days had the highest cabin temperatures, with average values of 68°C in the summer and 61°C in the spring. Cloudy days in both the spring and summer were on average approximately 10°C cooler. Our findings indicate that even on cloudy days with lower ambient air temperatures, vehicle cabin temperatures may reach deadly levels. Additionally, two predictive models of maximum daily vehicle cabin temperatures were developed using commonly available meteorological data. One model uses maximum ambient air temperature and average daily solar radiation while the other uses cloud cover percentage as a surrogate for solar radiation. From these models, two maximum vehicle cabin temperature indices were developed to assess the level of danger. The models and indices may be useful for forecasting hazardous conditions, promoting public awareness, and to estimate past cabin temperatures for use in forensic analyses.

  19. Combining Experiments and Simulations Using the Maximum Entropy Principle

    DEFF Research Database (Denmark)

    Boomsma, Wouter; Ferkinghoff-Borg, Jesper; Lindorff-Larsen, Kresten

    2014-01-01

    are not in quantitative agreement with experimental data. The principle of maximum entropy is a general procedure for constructing probability distributions in the light of new data, making it a natural tool in cases when an initial model provides results that are at odds with experiments. The number of maximum entropy...... in the context of a simple example, after which we proceed with a real-world application in the field of molecular simulations, where the maximum entropy procedure has recently provided new insight. Given the limited accuracy of force fields, macromolecular simulations sometimes produce results....... Three very recent papers have explored this problem using the maximum entropy approach, providing both new theoretical and practical insights to the problem. We highlight each of these contributions in turn and conclude with a discussion on remaining challenges....

  20. Growth Kinetics of Diazotrophic Bacillus sphaericus UPMB10 Cultured Using Different Types and Concentrations of Carbon and Nitrogen Sources

    Directory of Open Access Journals (Sweden)

    Ooi, T. C.

    2008-01-01

    Full Text Available Growth kinetics of newly isolated diazotrophic Bacillus sphaericus UPMB10 grown in various carbon (lactate, acetate, glycerol, malate, fructose, xylose and sucrose and nitrogen (glutamate, yeast extract, arginine, hystadine, glycine, polypeptone, tryptophan, lysine, NH4Cl and urea sources was investigated using 2 L stirred tank fermenter. The highest growth was obtained in a medium containing lactate as a carbon source, which gave the highest maximum cell concentration of 2.30 g/L, which is corresponding to maximum viable cell count of 4.60 x 10^9 cfu/mL. However, the highest cell yield (1.06 g cell/g carbon consumed was obtained in cultivation using glycerol though slightly lower maximum viable cell count was obtained (3.22 x 10^9 cfu/mL. In addition, cost for the production of live cell using glycerol was about 15 times lower than the cost using lactate. Growth performance of this bacterium when yeast extract was used as a nitrogen source was comparable to the use of pure amino acid. The medium containing 1.8 g/L glycerol and 2 g/L yeast extract was suggested as optimal for growth of this bacterium, which gave carbon to nitrogen ratio (C/N of 10:1. The maximum viable cell count obtained in cultivation using optimised medium in 2 L stirred tank fermenter was 3.34 x 10^9 cfu/mL and the cells maintained its capacity for N2 fixation at 18 nmol C2H2/h.mL.

  1. Maximum entropy beam diagnostic tomography

    International Nuclear Information System (INIS)

    Mottershead, C.T.

    1985-01-01

    This paper reviews the formalism of maximum entropy beam diagnostic tomography as applied to the Fusion Materials Irradiation Test (FMIT) prototype accelerator. The same formalism has also been used with streak camera data to produce an ultrahigh speed movie of the beam profile of the Experimental Test Accelerator (ETA) at Livermore

  2. Influência do oeríodo de cultivo de Panicum maximum (cultivar Tanzânia na fitorremediação de solo contaminado com picloram Influence of Panicum maximum cultivation period on phytoremediation of soil contaminated with picloram

    Directory of Open Access Journals (Sweden)

    M.L. Carmo

    2008-06-01

    Full Text Available O objetivo deste trabalho foi avaliar a influência do tempo de cultivo de Panicum maximum (cultivar Tanzânia sobre a fitorremediação de solo contaminado com picloram. O experimento foi conduzido em casa de vegetação no período de setembro de 2006 a fevereiro de 2007. Os fatores foram compostos pela combinação entre quatro períodos de cultivo da espécie vegetal Panicum maximum (cultivar Tanzânia (0, 60, 80 e 100 dias e três doses do picloram (0, 80 e 160 g ha-1, totalizando 12 tratamentos. O delineamento experimental utilizado foi o inteiramente casualizado em esquema fatorial 4 x 3, com quatro repetições. Como substrato utilizaram-se amostras de solo classificado como Latossolo Vermelho eutroférrico. Após o tempo estabelecido de atuação da espécie fitorremediadora, efetuou-se a semeadura das espécies bioindicadoras da presença do picloram: tomate e soja. As espécies bioindicadoras demonstraram alta sensibilidade à presença do picloram no solo, sendo inviável o cultivo dessas culturas em áreas contaminadas com esse herbicida sem a execução de algum procedimento remediador. O cultivo prévio de Tanzânia por 60 dias garantiu crescimento inicial satisfatório das plantas de soja e tomate quando a contaminação inicial não foi maior que 80 g ha-1 de picloram. Acima desse valor, a fitorremediação ocorrida proporcionou menor crescimento das plantas de soja e tomate, sendo necessário maior tempo de descontaminação.The objective of this study was to evaluate the influence of cultivation time of Panicum maximum (cv. Tanzania on phyto-remediation of soil contaminated with picloram. The experiment was carried out under greenhouse conditions from September 2006 to February 2007, using euthroferric Red Latosol samples as substrate for plant growth. The experiment was arranged in a completely randomized design, with four replicates, with treatments in a 4 x 3 factorial scheme. The treatments comprised twelve combinations of

  3. A Maximum Radius for Habitable Planets.

    Science.gov (United States)

    Alibert, Yann

    2015-09-01

    We compute the maximum radius a planet can have in order to fulfill two constraints that are likely necessary conditions for habitability: 1- surface temperature and pressure compatible with the existence of liquid water, and 2- no ice layer at the bottom of a putative global ocean, that would prevent the operation of the geologic carbon cycle to operate. We demonstrate that, above a given radius, these two constraints cannot be met: in the Super-Earth mass range (1-12 Mearth), the overall maximum that a planet can have varies between 1.8 and 2.3 Rearth. This radius is reduced when considering planets with higher Fe/Si ratios, and taking into account irradiation effects on the structure of the gas envelope.

  4. On semidefinite programming relaxations of maximum k-section

    NARCIS (Netherlands)

    de Klerk, E.; Pasechnik, D.V.; Sotirov, R.; Dobre, C.

    2012-01-01

    We derive a new semidefinite programming bound for the maximum k -section problem. For k=2 (i.e. for maximum bisection), the new bound is at least as strong as a well-known bound by Poljak and Rendl (SIAM J Optim 5(3):467–487, 1995). For k ≥ 3the new bound dominates a bound of Karisch and Rendl

  5. Biochar and flyash inoculated with plant growth promoting rhizobacteria act as potential biofertilizer for luxuriant growth and yield of tomato plant.

    Science.gov (United States)

    Tripti; Kumar, Adarsh; Usmani, Zeba; Kumar, Vipin; Anshumali

    2017-04-01

    Overuse of agrochemical fertilizers alarmingly causes deterioration in soil health and soil-flora. Persistence of these agrochemicals exerts detrimental effects on environment, potentially inducing toxic effects on human health, thus pronouncing an urgent need for a safer substitute. The present study investigates the potential use of agricultural and industrial wastes as carrier materials, viz. biochar and flyash, respectively, for preparation of bioformulations (or biofertilizers) using two plant growth promoting rhizobacteria, Bacillus sp. strain A30 and Burkholderia sp. strain L2, and its effect on growth of Lycopersicon esculentum Mill. (tomato). The viability of strains was determined based on colony forming units (cfu) count of each bioformulation at an interval of 60 days for a period of 240 days. Seeds were coated with different carrier based bioformulations and pot experiment(s) were carried out to access its effects on plant growth parameters. Biochar based bioformulations showed higher cfu count and maximum viability for strain L2 (10 7  cfu g -1 ) at 240 days of storage. Maximum percentage of seed germination was also observed in biochar inoculated with strain L2. Significant (p < 0.05) increase in plant growth parameters (dry and fresh biomass, length, number of flowers) were ascertained from the pot experiment and amongst all bioformulations, biochar inoculated with strain L2 performed consistently thriving results for tomato yield. Furthermore, post-harvest study of this bioformulation treated soil improved physico-chemical properties and dehydrogenase activity as compared to pre-plantation soil status. Overall, we show that prepared biochar based bioformulation using Burkholderia sp. L2 as inoculum can tremendously enhance the productivity of tomato, soil fertility, and can also act as a sustainable substitute for chemical fertilizers. In addition, mixture of biochar and flyash inoculated with strain L2 also showed noteworthy results for the

  6. Modeling multisite streamflow dependence with maximum entropy copula

    Science.gov (United States)

    Hao, Z.; Singh, V. P.

    2013-10-01

    Synthetic streamflows at different sites in a river basin are needed for planning, operation, and management of water resources projects. Modeling the temporal and spatial dependence structure of monthly streamflow at different sites is generally required. In this study, the maximum entropy copula method is proposed for multisite monthly streamflow simulation, in which the temporal and spatial dependence structure is imposed as constraints to derive the maximum entropy copula. The monthly streamflows at different sites are then generated by sampling from the conditional distribution. A case study for the generation of monthly streamflow at three sites in the Colorado River basin illustrates the application of the proposed method. Simulated streamflow from the maximum entropy copula is in satisfactory agreement with observed streamflow.

  7. CT findings of rectosigmoid carcinoma showing exophytic growth

    International Nuclear Information System (INIS)

    Ohgi, Kazuyuki; Kohno, Atsushi; Higuchi, Mutsumi

    1987-01-01

    CT findings of 7 rectosigmoid carcinomas showing exophytic growth were evaluated. All cases had bulky masses, ranging from 6.0 to 11.5 cm in maximum diameter. All masses were difficult to differentiate from the other pelvic masses on CT, presumably due to their exophytic growth and/or invasion to the surrounding organs. However, 3 out of 7 cases showed diffuse rectosigmoidal wall thickening adjacent to the primary tumor, and it is considered to be valuable in the determination of primary site. All female cases had gynecological symptom such as genital bleeding, due to uterine and/or vaginal invasion. When indeterminate pelvic mass is revealed by CT, rectosigmoid carcinoma should be considered into differential diagnosis. (author)

  8. Effect of salt-tolerant plant growth-promoting rhizobacteria on wheat plants and soil health in a saline environment.

    Science.gov (United States)

    Upadhyay, S K; Singh, D P

    2015-01-01

    Salt-tolerant plant growth-promoting rhizobacteria (ST-PGPR) significantly influence the growth and yield of wheat crops in saline soil. Wheat growth improved in pots with inoculation of all nine ST-PGPR (ECe = 4.3 dS·m(-1) ; greenhouse experiment), while maximum growth and dry biomass was observed in isolate SU18 Arthrobacter sp.; simultaneously, all ST-PGPR improved soil health in treated pot soil over controls. In the field experiment, maximum wheat root dry weight and shoot biomass was observed after inoculation with SU44 B. aquimaris, and SU8 B. aquimaris, respectively, after 60 and 90 days. Isolate SU8 B. aquimaris, induced significantly higher proline and total soluble sugar accumulation in wheat, while isolate SU44 B. aquimaris, resulted in higher accumulation of reducing sugars after 60 days. Percentage nitrogen (N), potassium (K) and phosphorus (P) in leaves of wheat increased significantly after inoculation with ST-PGPR, as compared to un-inoculated plants. Isolate SU47 B. subtilis showed maximum reduction of sodium (Na) content in wheat leaves of about 23% at both 60 and 90 days after sowing, and produced the best yield of around 17.8% more than the control. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  9. Maximum stellar iron core mass

    Indian Academy of Sciences (India)

    60, No. 3. — journal of. March 2003 physics pp. 415–422. Maximum stellar iron core mass. F W GIACOBBE. Chicago Research Center/American Air Liquide ... iron core compression due to the weight of non-ferrous matter overlying the iron cores within large .... thermal equilibrium velocities will tend to be non-relativistic.

  10. Generation and growth rates of nonlinear distortions in a traveling wave tube

    International Nuclear Information System (INIS)

    Woehlbier, John G.; Dobson, Ian; Booske, John H.

    2002-01-01

    The structure of a steady state multifrequency model of a traveling wave tube amplifier is exploited to describe the generation of intermodulation frequencies and calculate their growth rates. The model describes the evolution of Fourier coefficients of circuit and electron beam quantities and has the form of differential equations with quadratic nonlinearities. Intermodulation frequencies are sequentially generated by the quadratic nonlinearities in a series solution of the differential equations. A formula for maximum intermodulation growth rates is derived and compared to simulation results

  11. Effects of light and phytochrome in heterotrophic growth of Lemna minor L.

    NARCIS (Netherlands)

    Rombach, J.

    1976-01-01

    Axenic cultures of Lemna minor L. were grown on a medium containing sugars and amino acids. In continuous darkness the growth rate was one-tenth of the maximum in continuous light. In darkness early death revealed a thiamine deficiency; this

  12. Investigation on the Relationship owth of Agricultural Sector’s Growth with Growth of Industrial and Service Sectors (Commerce, Transportation, Telecommunication in Iran

    Directory of Open Access Journals (Sweden)

    yaghoob zeraatkish

    2014-03-01

    Full Text Available Agriculture has always been considerd as one of the important sectors in domestic and international economy .Based on the Central Bank Statistics; agriculture’s share in the Iranian GDP at the constant price of the year 1998 was 13 percent of the GDP in the year 2007. Therefore, studies on the role of agriculture in an economy and its interactions with other economic sectors should be considered with a special attention. This paper aimed at surveying the effects of growth of value-added in agriculture on the value-added of different sectors of industry, services as well as subordinate sectors of transportation, communication and commerce. In this regard, the status of the period between 1967 to 2009 is used. To determine the relationship among the study variables, some econometric techniques such as VAR were used. The results of VAR technique proves that there is a positive relation among the growth of value-added in the agricultural sector with the growth of industrial sector and the growth of sub-sectors of communication, transportation and commerce. Among the mentioned sectors and sub-sectors, the growth of commerce has maximum effect on the agricultural growth. Furthermore, in the short term, the growth variant of trading sector presented the largest share in explaining the variants of the agriculture sector . The growth variant of communication sector is trivial

  13. Exponential Growth of Nonlinear Ballooning Instability

    International Nuclear Information System (INIS)

    Zhu, P.; Hegna, C. C.; Sovinec, C. R.

    2009-01-01

    Recent ideal magnetohydrodynamic (MHD) theory predicts that a perturbation evolving from a linear ballooning instability will continue to grow exponentially in the intermediate nonlinear phase at the same linear growth rate. This prediction is confirmed in ideal MHD simulations. When the Lagrangian compression, a measure of the ballooning nonlinearity, becomes of the order of unity, the intermediate nonlinear phase is entered, during which the maximum plasma displacement amplitude as well as the total kinetic energy continues to grow exponentially at the rate of the corresponding linear phase.

  14. Flow topologies in different regimes of premixed turbulent combustion: A direct numerical simulation analysis

    KAUST Repository

    Wacks, Daniel H.

    2016-12-02

    The distributions of flow topologies within the flames representing the corrugated flamelets, thin reaction zones, and broken reaction zone regimes of premixed turbulent combustion are investigated using direct numerical simulation data of statistically planar turbulent H-2-air flames with an equivalence ratio phi = 0.7. It was found that the diminishing influence of dilatation rate with increasing Karlovitz number has significant influences on the statistical behaviors of the first, second, and third invariants (i.e., P, Q, and R) of the velocity gradient tensor. These differences are reflected in the distributions of the flow topologies within the flames considered in this analysis. This has important consequences for those topologies that make dominant contributions to the scalar-turbulence interaction and vortex-stretching terms in the scalar dissipation rate and enstrophy transport equations, respectively. Detailed physical explanations are provided for the observed regime dependences of the flow topologies and their implications on the scalar dissipation rate and enstrophy transport.

  15. Flow topologies in different regimes of premixed turbulent combustion: A direct numerical simulation analysis

    KAUST Repository

    Wacks, Daniel H.; Chakraborty, Nilanjan; Klein, Markus; Arias, Paul G.; Im, Hong G.

    2016-01-01

    The distributions of flow topologies within the flames representing the corrugated flamelets, thin reaction zones, and broken reaction zone regimes of premixed turbulent combustion are investigated using direct numerical simulation data of statistically planar turbulent H-2-air flames with an equivalence ratio phi = 0.7. It was found that the diminishing influence of dilatation rate with increasing Karlovitz number has significant influences on the statistical behaviors of the first, second, and third invariants (i.e., P, Q, and R) of the velocity gradient tensor. These differences are reflected in the distributions of the flow topologies within the flames considered in this analysis. This has important consequences for those topologies that make dominant contributions to the scalar-turbulence interaction and vortex-stretching terms in the scalar dissipation rate and enstrophy transport equations, respectively. Detailed physical explanations are provided for the observed regime dependences of the flow topologies and their implications on the scalar dissipation rate and enstrophy transport.

  16. Maximum entropy beam diagnostic tomography

    International Nuclear Information System (INIS)

    Mottershead, C.T.

    1985-01-01

    This paper reviews the formalism of maximum entropy beam diagnostic tomography as applied to the Fusion Materials Irradiation Test (FMIT) prototype accelerator. The same formalism has also been used with streak camera data to produce an ultrahigh speed movie of the beam profile of the Experimental Test Accelerator (ETA) at Livermore. 11 refs., 4 figs

  17. A portable storage maximum thermometer

    International Nuclear Information System (INIS)

    Fayart, Gerard.

    1976-01-01

    A clinical thermometer storing the voltage corresponding to the maximum temperature in an analog memory is described. End of the measurement is shown by a lamp switch out. The measurement time is shortened by means of a low thermal inertia platinum probe. This portable thermometer is fitted with cell test and calibration system [fr

  18. A Maximum Resonant Set of Polyomino Graphs

    Directory of Open Access Journals (Sweden)

    Zhang Heping

    2016-05-01

    Full Text Available A polyomino graph P is a connected finite subgraph of the infinite plane grid such that each finite face is surrounded by a regular square of side length one and each edge belongs to at least one square. A dimer covering of P corresponds to a perfect matching. Different dimer coverings can interact via an alternating cycle (or square with respect to them. A set of disjoint squares of P is a resonant set if P has a perfect matching M so that each one of those squares is M-alternating. In this paper, we show that if K is a maximum resonant set of P, then P − K has a unique perfect matching. We further prove that the maximum forcing number of a polyomino graph is equal to the cardinality of a maximum resonant set. This confirms a conjecture of Xu et al. [26]. We also show that if K is a maximal alternating set of P, then P − K has a unique perfect matching.

  19. Effect of combined function of temperature and water activity on the growth of Vibrio harveyi

    OpenAIRE

    Zhou,Kang; Gui,Meng; Li,Pinglan; Xing,Shaohua; Cui,Tingting; Peng,Zhaohui

    2012-01-01

    Vibrio harveyi is considered as a causative agent of the systemic disease, vibriosis, which occurs in many biological fields. The effects of temperatures (12.9-27.1 ºC) and water activity (NaCl% 0.6%-3.4%) on V. harveyi were investigated. The behavior and growth characteristics of V. harveyi was studied and modeled. Growth curves were fitted by using Gompertz and Baranyi models, and the Baranyi model showed a better fittness. Then, the maximum growth rates (µmax) and lag phase durations (LPD,...

  20. Effect of CO2 Concentration on Growth and Biochemical Composition of Newly Isolated Indigenous Microalga Scenedesmus bajacalifornicus BBKLP-07.

    Science.gov (United States)

    Patil, Lakkanagouda; Kaliwal, Basappa

    2017-05-01

    Photosynthetic mitigation of CO 2 through microalgae is gaining great importance due to its higher photosynthetic ability compared to plants, and the biomass can be commercially exploited for various applications. CO 2 fixation capability of the newly isolated freshwater microalgae Scenedesmus bajacalifornicus BBKLP-07 was investigated using a 1-l photobioreactor. The cultivation was carried at varying concentration of CO 2 ranging from 5 to 25%, and the temperature and light intensities were kept constant. A maximum CO 2 fixation rate was observed at 15% CO 2 concentration. Characteristic growth parameters such as biomass productivity, specific growth rate, and maximum biomass yield, and biochemical parameters such as carbohydrate, protein, lipid, chlorophyll, and carotenoid were determined and discussed. It was observed that the effect of CO 2 concentration on growth and biochemical composition was quite significant. The maximum biomass productivity was 0.061 ± 0.0007 g/l/day, and the rate of CO 2 fixation was 0.12 ± 0.002 g/l/day at 15% CO 2 concentration. The carbohydrate and lipid content were maximum at 25% CO 2 with 26.19 and 25.81% dry cell weight whereas protein, chlorophyll, and carotenoid contents were 32.89% dry cell weight, 25.07 μg/ml and 6.15 μg/ml respectively at 15% CO 2 concentration.

  1. Scaling of fecundity, growth and development in marine planktonic copepods

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Sabatini, M.

    1995-01-01

    We compiled information from the literature on female and egg sizes and maximum egg production, growth and developmental rates in marine planktonic copepods. While specific growth and developmental rates are invariant with body mass, weight- specific fecundity scales with female body mass(-0...... to 50% and have weight-specific fecundities that are 2.5 times and egg production rates that are 7.5 times those of the former, Nauplii develop faster (by a factor of 2) but grow slower (by 20 to 40%) than copepodites in both spawning types. The main demographic implications of these findings are (1...

  2. Spatio-temporal observations of the tertiary ozone maximum

    Directory of Open Access Journals (Sweden)

    V. F. Sofieva

    2009-07-01

    Full Text Available We present spatio-temporal distributions of the tertiary ozone maximum (TOM, based on GOMOS (Global Ozone Monitoring by Occultation of Stars ozone measurements in 2002–2006. The tertiary ozone maximum is typically observed in the high-latitude winter mesosphere at an altitude of ~72 km. Although the explanation for this phenomenon has been found recently – low concentrations of odd-hydrogen cause the subsequent decrease in odd-oxygen losses – models have had significant deviations from existing observations until recently. Good coverage of polar night regions by GOMOS data has allowed for the first time to obtain spatial and temporal observational distributions of night-time ozone mixing ratio in the mesosphere.

    The distributions obtained from GOMOS data have specific features, which are variable from year to year. In particular, due to a long lifetime of ozone in polar night conditions, the downward transport of polar air by the meridional circulation is clearly observed in the tertiary ozone maximum time series. Although the maximum tertiary ozone mixing ratio is achieved close to the polar night terminator (as predicted by the theory, TOM can be observed also at very high latitudes, not only in the beginning and at the end, but also in the middle of winter. We have compared the observational spatio-temporal distributions of the tertiary ozone maximum with that obtained using WACCM (Whole Atmosphere Community Climate Model and found that the specific features are reproduced satisfactorily by the model.

    Since ozone in the mesosphere is very sensitive to HOx concentrations, energetic particle precipitation can significantly modify the shape of the ozone profiles. In particular, GOMOS observations have shown that the tertiary ozone maximum was temporarily destroyed during the January 2005 and December 2006 solar proton events as a result of the HOx enhancement from the increased ionization.

  3. Effects of substrate concentrations on the growth of heterotrophic bacteria and algae in secondary facultative ponds.

    Science.gov (United States)

    Kayombo, S; Mbwette, T S A; Katima, J H Y; Jorgensen, S E

    2003-07-01

    This paper presents the effect of substrate concentration on the growth of a mixed culture of algae and heterotrophic bacteria in secondary facultative ponds (SFPs) utilizing settled domestic sewage as a sole source of organic carbon. The growth of the mixed culture was studied at the concentrations ranging between 200 and 800 mg COD/l in a series of batch chemostat reactors. From the laboratory data, the specific growth rate (micro) was determined using the modified Gompertz model. The maximum specific growth rate ( micro(max)) and half saturation coefficients (K(s)) were calculated using the Monod kinetic equation. The maximum observed growth rate ( micro(max)) for heterotrophic bacteria was 3.8 day(-1) with K(s) of 200 mg COD/l. The micro(max) for algal biomass based on suspended volatile solids was 2.7 day(-1) with K(s) of 110 mg COD/l. The micro(max) of algae based on the chlorophyll-a was 3.5 day(-1) at K(s) of 50mg COD/l. The observed specific substrate removal by heterotrophic bacteria varied between the concentrations of substrate used and the average value was 0.82 (mg COD/mg biomass). The specific substrate utilization rate in the bioreactors was direct proportional to the specific growth rate. Hence, the determined Monod kinetic parameters are useful for the definition of the operation of SFPs.

  4. Aromatase inhibitor (anastrozole) affects growth of endometrioma cells in culture.

    Science.gov (United States)

    Badawy, Shawky Z A; Brown, Shereene; Kaufman, Lydia; Wojtowycz, Martha A

    2015-05-01

    To study the effects of aromatase inhibitor (anastrozole) on the growth and estradiol secretion of endometrioma cells in culture. Endometrioma cells are grown in vitro until maximum growth before used in this study. This was done in the research laboratory for tissue culture, in an academic hospital. Testosterone at a concentration of 10 μg/mL was added as a substrate for the intracellular aromatase. In addition, aromatase inhibitor was added at a concentration of 200 and 300 μg/mL. The effect on cell growth and estradiol secretion is evaluated using Student's t-test. The use of testosterone increased estradiol secretion by endometrioma cells in culture. The use of aromatase inhibitor significantly inhibited the growth of endometrioma cells, and estradiol secretion. Aromatase inhibitor (anastrozole) may be an effective treatment for endometriosis due to inhibition of cellular aromatase. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  5. Ga-assisted catalyst-free growth mechanism of GaAs nanowires by molecular beam epitaxy

    International Nuclear Information System (INIS)

    Colombo, C.; Spirkoska, D.; Frimmer, M.; Abstreiter, G.; Fontcuberta i Morral, A.

    2008-01-01

    The mechanisms of Ga-assisted GaAs nanowires grown by molecular beam epitaxy are addressed. The axial and radial growth rates as a function of the Ga rate and As pressure indicate that on the opposite of what is observed in thin film epitaxy, the growth rate of the nanowires is arsenic limited. As a consequence, the axial growth rate of the wires can be controlled by the As 4 pressure. Additionally, due to the small As 4 pressure leading to nanowire growth, the deposition on the facets is very slow, leading to a much lower radial growth rate. Finally, we present a model that is able to accurately describe the presented observations and predicts a maximum length of nontapered nanowires of 40 μm

  6. Globally Increased Crop Growth and Cropping Intensity from the Long-Term Satellite-Based Observations

    Science.gov (United States)

    Chen, Bin

    2018-04-01

    Understanding the spatiotemporal change trend of global crop growth and multiple cropping system under climate change scenarios is a critical requirement for supporting the food security issue that maintains the function of human society. Many studies have predicted the effects of climate changes on crop production using a combination of filed studies and models, but there has been limited evidence relating decadal-scale climate change to global crop growth and the spatiotemporal distribution of multiple cropping system. Using long-term satellite-derived Normalized Difference Vegetation Index (NDVI) and observed climate data from 1982 to 2012, we investigated the crop growth trend, spatiotemporal pattern trend of agricultural cropping intensity, and their potential correlations with respect to the climate change drivers at a global scale. Results show that 82.97 % of global cropland maximum NDVI witnesses an increased trend while 17.03 % of that shows a decreased trend over the past three decades. The spatial distribution of multiple cropping system is observed to expand from lower latitude to higher latitude, and the increased cropping intensity is also witnessed globally. In terms of regional major crop zones, results show that all nine selected zones have an obvious upward trend of crop maximum NDVI (p impact on the crop growth trend.

  7. Investigation of mixotrophic, heterotrophic, and autotrophic growth of Chlorella vulgaris under agricultural waste medium.

    Science.gov (United States)

    Mohammad Mirzaie, M A; Kalbasi, M; Mousavi, S M; Ghobadian, B

    2016-01-01

    Growth of Chlorella vulgaris and its lipid production were investigated under autotrophic, heterotrophic, and mixotrophic conditions. Cheap agricultural waste molasses and corn steep liquor from industries were used as carbon and nitrogen sources, respectively. Chlorella vulgaris grew remarkably under this agricultural waste medium, which resulted in a reduction in the final cost of the biodiesel production. Maximum dry weight of 2.62 g L(-1) was obtained in mixotrophic growth with the highest lipid concentration of 0.86 g L(-1). These biomass and lipid concentrations were, respectively, 140% and 170% higher than autotrophic growth and 300% and 1200% higher than heterotrophic growth. In mixotrophic growth, independent or simultaneous occurrence of autotrophic and heterotrophic metabolisms was investigated. The growth of the microalgae was observed to take place first heterotrophically to a minimum substrate concentration with a little fraction in growth under autotrophic metabolism, and then the cells grew more autotrophically. It was found that mixotrophic growth was not a simple combination of heterotrophic and autotrophic growth.

  8. Direct maximum parsimony phylogeny reconstruction from genotype data

    OpenAIRE

    Sridhar, Srinath; Lam, Fumei; Blelloch, Guy E; Ravi, R; Schwartz, Russell

    2007-01-01

    Abstract Background Maximum parsimony phylogenetic tree reconstruction from genetic variation data is a fundamental problem in computational genetics with many practical applications in population genetics, whole genome analysis, and the search for genetic predictors of disease. Efficient methods are available for reconstruction of maximum parsimony trees from haplotype data, but such data are difficult to determine directly for autosomal DNA. Data more commonly is available in the form of ge...

  9. Fungic microflora of Panicum maximum and Styosanthes spp. commercial seed / Microflora fúngica de sementes comerciais de Panicum maximum e Stylosanthes spp.

    Directory of Open Access Journals (Sweden)

    Larissa Rodrigues Fabris

    2010-09-01

    Full Text Available The sanitary quality of 26 lots commercial seeds of tropical forages, produced in different regions (2004-05 and 2005-06 was analyzed. The lots were composed of seeds of Panicum maximum ('Massai', 'Mombaça' e 'Tanzânia' and stylo ('Estilosantes Campo Grande' - ECG. Additionally, seeds of two lots of P. maximum for exportation were analyzed. The blotter test was used, at 20ºC under alternating light and darkness in a 12 h photoperiod, for seven days. The Aspergillus, Cladosporium and Rhizopus genus consisted the secondary or saprophytes fungi (FSS with greatest frequency in P. maximum lots. In general, there was low incidence of these fungus in the seeds. In relation to pathogenic fungi (FP, it was detected high frequency of contaminated lots by Bipolaris, Curvularia, Fusarium and Phoma genus. Generally, there was high incidence of FP in P. maximum seeds. The occurrence of Phoma sp. was hight, because in 81% of the lots showed incidence superior to 50%. In 'ECG' seeds it was detected FSS (Aspergillus, Cladosporium, and Penicillium genus and FP (Bipolaris, Curvularia, Fusarium and Phoma genus, usually, in low incidence. FSS and FP were associated to P. maximum seeds for exportation, with significant incidence in some cases. The results indicated that there was a limiting factor in all producer regions regarding sanitary quality of the seeds.Sementes comerciais de forrageiras tropicais, pertencente a 26 lotes produzidos em diferentes regiões (safras 2004-05 e 2005-06, foram avaliadas quanto à sanidade. Foram analisadas sementes de cultivares de Panicum maximum (Massai, Mombaça e Tanzânia e de estilosantes (Estilosantes Campo Grande – ECG. Adicionalmente, avaliou-se a qualidade sanitária de dois lotes de sementes de P. maximum destinados à exportação. Para isso, as sementes foram submetidas ao teste de papel de filtro em gerbox, os quais foram incubados a 20ºC, com fotoperíodo de 12 h, durante sete dias. Os fungos saprófitos ou

  10. Effect of Different Nitrogen Levels on Phenology, Growth Indices and Yield of two Lentil Cultivars under Rainfed Conditions in Mashhad

    Directory of Open Access Journals (Sweden)

    M Bannayan Aval

    2018-02-01

    significant on vegetative, reproductive and overall plant growth based on days and growth degree-days. Also, 40 kg urea fertilizer per hectare showed that maximum of these traits. The effect of cultivar was significant on days and growth degree-days of planting to emergence, vegetative growth, reproductive growth and overall plant growth. Maximum of these traits were obtained in the Birjand cultivar. The difference in two lentil cultivars is related to genetic differences and their different adaptations to region. Urea fertilizer and cultivar interaction effects was not significant on phenological stages. Urea fertilizer had a significant effect on leaf area index, dry matter accumulation and yield. The highest leaf area index was obtained in treatment of 40 kg urea fertilizer per hectare. More production of leaf area affected on other growth indices and led to increasing of crop production. The highest grain and biological yield were achieved in this treatment. Cultivar effect was significant on maximum leaf area index, dry matter accumulation and yield. Birjand cultivar had maximum leaf area index, dry matter accumulation, crop growth rate, grain and biological yield. Since the most of growth indices are dependent on leaf area index, changes in this indicator through change in the nitrogen fertilizer levels, is one of the most important practices to improve yield. Correlation analysis showed that, grain yield had positive and significant correlations with vegetative growth, reproductive growth, overall plant growth, maximum leaf area index and dry matter accumulation. Conclusions In this study, using of 40 kg urea fertilizer per hectare had a greater effect on leaf area index in comparison to other nitrogen fertilizer levels. That leads to an increase in the dry mater accumulation, crop growth rate and eventually increased the seed yield. So, application of 40 kg urea fertilizer per hectare is advised to achieve maximum crop production. Birjand cultivar had a good situation

  11. 78 FR 49370 - Inflation Adjustment of Maximum Forfeiture Penalties

    Science.gov (United States)

    2013-08-14

    ... ``civil monetary penalties provided by law'' at least once every four years. DATES: Effective September 13... increases the maximum civil monetary forfeiture penalties available to the Commission under its rules... maximum civil penalties established in that section to account for inflation since the last adjustment to...

  12. 5 CFR 838.711 - Maximum former spouse survivor annuity.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Maximum former spouse survivor annuity... Orders Awarding Former Spouse Survivor Annuities Limitations on Survivor Annuities § 838.711 Maximum former spouse survivor annuity. (a) Under CSRS, payments under a court order may not exceed the amount...

  13. Growth of Listeria spp. in shredded cabbage is enhanced by a mild heat treatment.

    Science.gov (United States)

    Ells, Timothy C; Truelstrup Hansen, Lisbeth

    2010-03-01

    Mild thermal processing can enhance the shelf life of cut fruits and vegetables by delaying the onset of spoilage and preserving the organoleptic properties of shredded cabbage. However, food safety issues related to this process have not been fully investigated. Therefore, the survival and growth of Listeria spp. on cabbage treated in this manner was examined. Experimentally, 24 strains of Listeria spp. (including L. monocytogenes) were inoculated onto cut and intact cabbage tissues and stored at 5 degrees C. All strains on intact tissues exhibited a moderate decline in numbers (up to 1.0 log CFU/cm(2)) over the 28-day storage period. Conversely, cut tissue supported growth of most strains during the first 7 to 14 days of incubation with maximum increases of 1.2 log CFU/cm(2). Subsequently, the survival or growth on heat-treated (50 degrees C for 3 min) and untreated shredded cabbage of four L. monocytogenes and four nonpathogenic Listeria spp. strains were compared during storage for 21 days at 5 degrees C. Growth on untreated shred for all strains was similar to the results observed on cut tissue with a maximum increase of approximately 1.0 log CFU/g. However, in the heat-treated cabbage shred all strains displayed a rapid increase in growth (up to 2.5 log CFU/g) during the first 7 days of incubation, which may be indicative of the destruction of an endogenous growth-inhibiting compound within the cabbage. In conclusion, this study shows that mild thermal treatments of cut cabbage may promote pathogen growth if other inimical barriers are not implemented downstream of the thermal treatment.

  14. A tropospheric ozone maximum over the equatorial Southern Indian Ocean

    Directory of Open Access Journals (Sweden)

    L. Zhang

    2012-05-01

    Full Text Available We examine the distribution of tropical tropospheric ozone (O3 from the Microwave Limb Sounder (MLS and the Tropospheric Emission Spectrometer (TES by using a global three-dimensional model of tropospheric chemistry (GEOS-Chem. MLS and TES observations of tropospheric O3 during 2005 to 2009 reveal a distinct, persistent O3 maximum, both in mixing ratio and tropospheric column, in May over the Equatorial Southern Indian Ocean (ESIO. The maximum is most pronounced in 2006 and 2008 and less evident in the other three years. This feature is also consistent with the total column O3 observations from the Ozone Mapping Instrument (OMI and the Atmospheric Infrared Sounder (AIRS. Model results reproduce the observed May O3 maximum and the associated interannual variability. The origin of the maximum reflects a complex interplay of chemical and dynamic factors. The O3 maximum is dominated by the O3 production driven by lightning nitrogen oxides (NOx emissions, which accounts for 62% of the tropospheric column O3 in May 2006. We find the contribution from biomass burning, soil, anthropogenic and biogenic sources to the O3 maximum are rather small. The O3 productions in the lightning outflow from Central Africa and South America both peak in May and are directly responsible for the O3 maximum over the western ESIO. The lightning outflow from Equatorial Asia dominates over the eastern ESIO. The interannual variability of the O3 maximum is driven largely by the anomalous anti-cyclones over the southern Indian Ocean in May 2006 and 2008. The lightning outflow from Central Africa and South America is effectively entrained by the anti-cyclones followed by northward transport to the ESIO.

  15. Solar maximum observatory

    International Nuclear Information System (INIS)

    Rust, D.M.

    1984-01-01

    The successful retrieval and repair of the Solar Maximum Mission (SMM) satellite by Shuttle astronauts in April 1984 permitted continuance of solar flare observations that began in 1980. The SMM carries a soft X ray polychromator, gamma ray, UV and hard X ray imaging spectrometers, a coronagraph/polarimeter and particle counters. The data gathered thus far indicated that electrical potentials of 25 MeV develop in flares within 2 sec of onset. X ray data show that flares are composed of compressed magnetic loops that have come too close together. Other data have been taken on mass ejection, impacts of electron beams and conduction fronts with the chromosphere and changes in the solar radiant flux due to sunspots. 13 references

  16. Post optimization paradigm in maximum 3-satisfiability logic programming

    Science.gov (United States)

    Mansor, Mohd. Asyraf; Sathasivam, Saratha; Kasihmuddin, Mohd Shareduwan Mohd

    2017-08-01

    Maximum 3-Satisfiability (MAX-3SAT) is a counterpart of the Boolean satisfiability problem that can be treated as a constraint optimization problem. It deals with a conundrum of searching the maximum number of satisfied clauses in a particular 3-SAT formula. This paper presents the implementation of enhanced Hopfield network in hastening the Maximum 3-Satisfiability (MAX-3SAT) logic programming. Four post optimization techniques are investigated, including the Elliot symmetric activation function, Gaussian activation function, Wavelet activation function and Hyperbolic tangent activation function. The performances of these post optimization techniques in accelerating MAX-3SAT logic programming will be discussed in terms of the ratio of maximum satisfied clauses, Hamming distance and the computation time. Dev-C++ was used as the platform for training, testing and validating our proposed techniques. The results depict the Hyperbolic tangent activation function and Elliot symmetric activation function can be used in doing MAX-3SAT logic programming.

  17. Mass mortality of the vermetid gastropod Ceraesignum maximum

    Science.gov (United States)

    Brown, A. L.; Frazer, T. K.; Shima, J. S.; Osenberg, C. W.

    2016-09-01

    Ceraesignum maximum (G.B. Sowerby I, 1825), formerly Dendropoma maximum, was subject to a sudden, massive die-off in the Society Islands, French Polynesia, in 2015. On Mo'orea, where we have detailed documentation of the die-off, these gastropods were previously found in densities up to 165 m-2. In July 2015, we surveyed shallow back reefs of Mo'orea before, during and after the die-off, documenting their swift decline. All censused populations incurred 100% mortality. Additional surveys and observations from Mo'orea, Tahiti, Bora Bora, and Huahine (but not Taha'a) suggested a similar, and approximately simultaneous, die-off. The cause(s) of this cataclysmic mass mortality are currently unknown. Given the previously documented negative effects of C. maximum on corals, we expect the die-off will have cascading effects on the reef community.

  18. Feeding, growth, and food conversion of the marine planktonic copepod Calanus helgolandicus

    Energy Technology Data Exchange (ETDEWEB)

    Paffenhoefer, G.A.

    1976-01-01

    Food intake, growth rate, and food conversion of nauplii, copepodids, and adult females of Calanus helgolandicus were investigated experimentally at 15/sup 0/C. The diatom Lauderia borealis and the dinoflagellates Gonyaulax polyedra, Gymnodinium splendens, and Prorocentrum micans were offered separately as food at concentrations ranging from 41 to 101 ..mu..g C liter/sup -1/. Amounts of food ingested differed with concentration and species. Daily exponential growth rates were highest for nauplii and young copepodids (k = 0.29 to 0.41) and decreased gradually with increasing age of the copepods to k = 0.02. Gross growth efficiency changed during the different juvenile life periods of the copepod with maximum values for the period CdI to CIII. Feeding on L. borealis at lower food concentrations resulted in an increase in gross growth efficiency. (auth)

  19. Lipase Production in Solid-State Fermentation Monitoring Biomass Growth of Aspergillus niger Using Digital Image Processing

    Science.gov (United States)

    Dutra, Julio C. V.; da Terzi, Selma C.; Bevilaqua, Juliana Vaz; Damaso, Mônica C. T.; Couri, Sônia; Langone, Marta A. P.; Senna, Lilian F.

    The aim of this study was to monitor the biomass growth of Aspergillus niger in solid-state fermentation (SSF) for lipase production using digital image processing technique. The strain A. niger 11T53A14 was cultivated in SSF using wheat bran as support, which was enriched with 0.91% (m/v) of ammonium sulfate. The addition of several vegetable oils (castor, soybean, olive, corn, and palm oils) was investigated to enhance lipase production. The maximum lipase activity was obtained using 2% (m/m) castor oil. In these conditions, the growth was evaluated each 24 h for 5 days by the glycosamine content analysis and digital image processing. Lipase activity was also determined. The results indicated that the digital image process technique can be used to monitor biomass growth in a SSF process and to correlate biomass growth and enzyme activity. In addition, the immobilized esterification lipase activity was determined for the butyl oleate synthesis, with and without 50% v/v hexane, resulting in 650 and 120 U/g, respectively. The enzyme was also used for transesterification of soybean oil and ethanol with maximum yield of 2.4%, after 30 min of reaction.

  20. Lipase production in solid-state fermentation monitoring biomass growth of aspergillus niger using digital image processing.

    Science.gov (United States)

    Dutra, Júlio C V; da C Terzi, Selma; Bevilaqua, Juliana Vaz; Damaso, Mônica C T; Couri, Sônia; Langone, Marta A P; Senna, Lilian F

    2008-03-01

    The aim of this study was to monitor the biomass growth of Aspergillus niger in solid-state fermentation (SSF) for lipase production using digital image processing technique. The strain A. niger 11T53A14 was cultivated in SSF using wheat bran as support, which was enriched with 0.91% (m/v) of ammonium sulfate. The addition of several vegetable oils (castor, soybean, olive, corn, and palm oils) was investigated to enhance lipase production. The maximum lipase activity was obtained using 2% (m/m) castor oil. In these conditions, the growth was evaluated each 24 h for 5 days by the glycosamine content analysis and digital image processing. Lipase activity was also determined. The results indicated that the digital image process technique can be used to monitor biomass growth in a SSF process and to correlate biomass growth and enzyme activity. In addition, the immobilized esterification lipase activity was determined for the butyl oleate synthesis, with and without 50% v/v hexane, resulting in 650 and 120 U/g, respectively. The enzyme was also used for transesterification of soybean oil and ethanol with maximum yield of 2.4%, after 30 min of reaction.

  1. Phenomenology of two-dimensional stably stratified turbulence under large-scale forcing

    KAUST Repository

    Kumar, Abhishek; Verma, Mahendra K.; Sukhatme, Jai

    2017-01-01

    In this paper, we characterise the scaling of energy spectra, and the interscale transfer of energy and enstrophy, for strongly, moderately and weakly stably stratified two-dimensional (2D) turbulence, restricted in a vertical plane, under large-scale random forcing. In the strongly stratified case, a large-scale vertically sheared horizontal flow (VSHF) coexists with small scale turbulence. The VSHF consists of internal gravity waves and the turbulent flow has a kinetic energy (KE) spectrum that follows an approximate k−3 scaling with zero KE flux and a robust positive enstrophy flux. The spectrum of the turbulent potential energy (PE) also approximately follows a k−3 power-law and its flux is directed to small scales. For moderate stratification, there is no VSHF and the KE of the turbulent flow exhibits Bolgiano–Obukhov scaling that transitions from a shallow k−11/5 form at large scales, to a steeper approximate k−3 scaling at small scales. The entire range of scales shows a strong forward enstrophy flux, and interestingly, large (small) scales show an inverse (forward) KE flux. The PE flux in this regime is directed to small scales, and the PE spectrum is characterised by an approximate k−1.64 scaling. Finally, for weak stratification, KE is transferred upscale and its spectrum closely follows a k−2.5 scaling, while PE exhibits a forward transfer and its spectrum shows an approximate k−1.6 power-law. For all stratification strengths, the total energy always flows from large to small scales and almost all the spectral indicies are well explained by accounting for the scale-dependent nature of the corresponding flux.

  2. Phenomenology of two-dimensional stably stratified turbulence under large-scale forcing

    KAUST Repository

    Kumar, Abhishek

    2017-01-11

    In this paper, we characterise the scaling of energy spectra, and the interscale transfer of energy and enstrophy, for strongly, moderately and weakly stably stratified two-dimensional (2D) turbulence, restricted in a vertical plane, under large-scale random forcing. In the strongly stratified case, a large-scale vertically sheared horizontal flow (VSHF) coexists with small scale turbulence. The VSHF consists of internal gravity waves and the turbulent flow has a kinetic energy (KE) spectrum that follows an approximate k−3 scaling with zero KE flux and a robust positive enstrophy flux. The spectrum of the turbulent potential energy (PE) also approximately follows a k−3 power-law and its flux is directed to small scales. For moderate stratification, there is no VSHF and the KE of the turbulent flow exhibits Bolgiano–Obukhov scaling that transitions from a shallow k−11/5 form at large scales, to a steeper approximate k−3 scaling at small scales. The entire range of scales shows a strong forward enstrophy flux, and interestingly, large (small) scales show an inverse (forward) KE flux. The PE flux in this regime is directed to small scales, and the PE spectrum is characterised by an approximate k−1.64 scaling. Finally, for weak stratification, KE is transferred upscale and its spectrum closely follows a k−2.5 scaling, while PE exhibits a forward transfer and its spectrum shows an approximate k−1.6 power-law. For all stratification strengths, the total energy always flows from large to small scales and almost all the spectral indicies are well explained by accounting for the scale-dependent nature of the corresponding flux.

  3. Maximum phytoplankton concentrations in the sea

    DEFF Research Database (Denmark)

    Jackson, G.A.; Kiørboe, Thomas

    2008-01-01

    A simplification of plankton dynamics using coagulation theory provides predictions of the maximum algal concentration sustainable in aquatic systems. These predictions have previously been tested successfully against results from iron fertilization experiments. We extend the test to data collect...

  4. Differential growth response of Ulva lactuca to ammonium and nitrate assimilation

    DEFF Research Database (Denmark)

    Ale, Marcel Tutor; Mikkelsen, Jørn Dalgaard; Meyer, Anne S

    2011-01-01

    and fluctuating levels of nitrogen sources. Our understanding of the influences of this varying condition on the uptake and growth responses of U. lactuca is limited. In this present work, we examined the growth response of U. lactuca exposed to different sources of nitrogen (NH4+; NO3−; and the combination NH4NO...... as the nitrogen source. The NH4Cl and NaNO3 rich media (50 μM of N) accelerated U. lactuca growth to a maximum specific growth rate of 16.4 ± 0.18% day−1 and 9.4 ± 0.72% day−1, respectively. The highest biomass production rate obtained was 22.5 ± 0.24 mg DW m−2·day−1. The presence of ammonium apparently...... discriminated the nitrate uptake by U. lactuca when exposed to NH4NO3. Apart from showing the significant differential growth response of U. lactuca to different nitrogen sources, the work exhibits the applicability of a photo-scanning approach for acquiring precise quantitative growth data for U. lactuca...

  5. Epitaxial growth of nobel metals on alumina substrates

    International Nuclear Information System (INIS)

    Al-Mohammad, A.

    2007-06-01

    The influence of the reconstructed (0001) α-Al 2 O 3 surface on the heteroepitaxial growth and adhesion properties of small metal particles (gold, silver and copper) of noncontinuous thin films has been investigated. The crystallographic structure and morphology of substrate surfaces were examined by Reflection High Energy Electron Diffraction and Atomic Force Microscopy techniques. The reconstructed surfaces are terminated by one or more Aluminum atomic layers. By means of the Transmission Electronic Microscopy, the various granulometric and lattice parameters variations are investigated during different stages of the heteroepitaxial growth of metallic thin films. We estimated the adhesion energy values for each case of metal//(0001)α-Al 2 O 3 interfaces by two methods: the maximum cluster density and the Lifshits theory of Van der Waals energy of interfaces. The results of both methods are in good agreement. Using these methods, we found interfaces Hamaker's constants values and we investigated all the heteroepitaxial growth steps.(author)

  6. Growth of AlN films and their characterization

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Rakesh B.; Gao, Ying; Zhang, Jianping; Qhaleed Fareed, R.S.; Gaska, Remis [Sensor Electronic Technology, Inc., 1195 Atlas Rd., Columbia, SC 29209 (United States); Li, Jiawei; Arjunan, Arulchakkravarthi; Yang, Jinwei; Asif Khan, M. [Department of Electrical Engineering, University of South Carolina, Columbia, SC 29208 (United States); Kuokstis, Edmundas [MTMI, Vilnius University, Vilnius (Lithuania)

    2006-06-15

    Single crystal AlN layers have been produced by migration enhanced metal organic chemical vapor deposition (MEMOCVD), hydride vapor phase epitaxy (HVPE) and their combination. The growth was carried out on 2'' basal plane sapphire substrates. In MEMOCVD, the duration and waveforms of precursors were varied to achieve better surface mobility and thus better atomic incorporation. It resulted in superior layer quality templates with the narrowest (002) X-ray rocking curve full width half maximum (FWHM). Such high quality AlN templates were used as seeds for subsequent HVPE growth. Thick films with thickness ranging from 1-25 {mu}m have been grown by HVPE with growth rates as high as 200 {mu}m/min, highest ever reported. Films grown by the two methods have been extensively characterized by Nomarski microscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), high-resolution X-ray diffractometry (HRXRD), and photoluminescence (PL). (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. On the Pontryagin maximum principle for systems with delays. Economic applications

    Science.gov (United States)

    Kim, A. V.; Kormyshev, V. M.; Kwon, O. B.; Mukhametshin, E. R.

    2017-11-01

    The Pontryagin maximum principle [6] is the key stone of finite-dimensional optimal control theory [1, 2, 5]. So beginning with opening the maximum principle it was important to extend the maximum principle on various classes of dynamical systems. In t he paper we consider some aspects of application of i-smooth analysis [3, 4] in the theory of the Pontryagin maximum principle [6] for systems with delays, obtained results can be applied by elaborating optimal program controls in economic models with delays.

  8. Effects of environmental conditions on growth and survival of Salmonella in pasteurized whole egg

    DEFF Research Database (Denmark)

    Jakociune, Dziuginta; Bisgaard, Magne; Hervé, Gaëlle

    2014-01-01

    This study investigated the influence of three parameters (time, temperature and NaCl concentration) on survival and four parameters (temperature, NaCl and lysozyme concentrations and pH) on growth of Salmonella enterica serovar Enteritidis (S. Enteritidis) in pasteurized whole egg (PWE). Doehlert......Cl at a fixed heating time of 120s, while maximum growth rate was estimated at 25°C and 0% of NaCl. pH and lysozyme concentration were shown not to influence growth performance significantly in the range of values studied. Results inform industry of the optimal pasteurization and storage parameters for liquid...

  9. Ethanol production and maximum cell growth are highly correlated with membrane lipid composition during fermentation as determined by lipidomic analysis of 22 Saccharomyces cerevisiae strains.

    Science.gov (United States)

    Henderson, Clark M; Lozada-Contreras, Michelle; Jiranek, Vladimir; Longo, Marjorie L; Block, David E

    2013-01-01

    Optimizing ethanol yield during fermentation is important for efficient production of fuel alcohol, as well as wine and other alcoholic beverages. However, increasing ethanol concentrations during fermentation can create problems that result in arrested or sluggish sugar-to-ethanol conversion. The fundamental cellular basis for these problem fermentations, however, is not well understood. Small-scale fermentations were performed in a synthetic grape must using 22 industrial Saccharomyces cerevisiae strains (primarily wine strains) with various degrees of ethanol tolerance to assess the correlation between lipid composition and fermentation kinetic parameters. Lipids were extracted at several fermentation time points representing different growth phases of the yeast to quantitatively analyze phospholipids and ergosterol utilizing atmospheric pressure ionization-mass spectrometry methods. Lipid profiling of individual fermentations indicated that yeast lipid class profiles do not shift dramatically in composition over the course of fermentation. Multivariate statistical analysis of the data was performed using partial least-squares linear regression modeling to correlate lipid composition data with fermentation kinetic data. The results indicate a strong correlation (R(2) = 0.91) between the overall lipid composition and the final ethanol concentration (wt/wt), an indicator of strain ethanol tolerance. One potential component of ethanol tolerance, the maximum yeast cell concentration, was also found to be a strong function of lipid composition (R(2) = 0.97). Specifically, strains unable to complete fermentation were associated with high phosphatidylinositol levels early in fermentation. Yeast strains that achieved the highest cell densities and ethanol concentrations were positively correlated with phosphatidylcholine species similar to those known to decrease the perturbing effects of ethanol in model membrane systems.

  10. Effect of temperature, salinity, and food availability on the growth and food-conversion efficiency of postlarval pinfish

    International Nuclear Information System (INIS)

    Peters, D.S.; Boyd, M.T.; DeVane, J.C. Jr.

    1976-01-01

    Growth rate, feeding rate, and food-conversion efficiency of postlarval pinfish, Lagodon rhomboides, were measured under various combinations of temperature, salinity, and food availability. Data were analyzed by multiple regression and presented as response surfaces. Temperature accounted for most of the variation in maximum feeding rate. Temperature and feeding rate accounted for over 90 percent of the observed variation in growth rate. Salinity effects were more important in predicting growth efficiency than in predicting growth rate. Because a feeding--temperature interaction affects growth and because the effect of thermal effluents on food availability is unknown, it is impossible at this time to predict whether thermal alteration of the environment would increase or decrease growth of pinfish

  11. Combined inoculation of Pseudomonas fluorescens and Trichoderma harzianum for enhancing plant growth of vanilla (Vanilla planifolia).

    Science.gov (United States)

    Sandheep, A R; Asok, A K; Jisha, M S

    2013-06-15

    This study was conducted to evaluate the plant growth promoting efficiency of combined inoculation of rhizobacteria on Vanilla plants. Based on the in vitro performance of indigenous Trichoderma spp. and Pseudomonas spp., four effective antagonists were selected and screened under greenhouse experiment for their growth enhancement potential. The maximum percentage of growth enhancement were observed in the combination of Trichoderma harzianum with Pseudomonas fluorescens treatment followed by Pseudomonas fluorescens, Trichoderma harzianum, Pseudomonas putida and Trichoderma virens, respectively in decreasing order. Combined inoculation of Trichoderma harzianum and Pseudomonas fluorescens registered the maximum length of vine (82.88 cm), highest number of leaves (26.67/plant), recorded the highest fresh weight of shoots (61.54 g plant(-1)), fresh weight of roots (4.46 g plant(-1)) and dry weight of shoot (4.56 g plant(-1)) where as the highest dry weight of roots (2.0806 g plant(-1)) were achieved with treatments of Pseudomonas fluorescens. Among the inoculated strains, combined inoculation of Trichoderma harzianum and Pseudomonas fluorescens recorded the maximum nitrogen uptake (61.28 mg plant(-1)) followed by the combined inoculation of Trichoderma harzianum (std) and Pseudomonas fluorescens (std) (55.03 mg plant(-1)) and the highest phosphorus uptake (38.80 mg plant(-1)) was recorded in dual inoculation of Trichoderma harzianum and Pseudomonas fluorescens.

  12. Índices morfogênicos e de crescimento durante o estabelecimento e a rebrotação do capim-Mombaça (Panicum maximum Jacq. Morphogenic traits and growth indices during the establishment and regrowth of Mombaçagrass (Panicum maximum Jacq.

    Directory of Open Access Journals (Sweden)

    Carlos Augusto de Miranda Gomide

    2003-08-01

    Full Text Available Com o objetivo de estimar as características morfogênicas e os índices de crescimento do capim-Mombaça, um ensaio foi conduzido em casa de vegetação. Estudou-se o desenvolvimento das plantas em três crescimentos: o crescimento seminal de estabelecimento (C1, o da brotação após corte ao 16º dia (C2 e 37º dia (C3 do crescimento de estabelecimento. As variáveis estimadas foram: índices de crescimento [taxa de crescimento relativo (TCR, taxa assimilatória líquida (TAL e razão de área foliar (RAF], e os índices morfogênicos [taxa de aparecimento foliar (TApF, taxa de alongamento foliar (TAlF, taxa de expansão da área foliar e taxa de senescência foliar]. Colheitas foram feitas ao longo do desenvolvimento das plantas em cada crescimento considerado: 13, 20, 27, 42, 55, 69 e 83 dias após emergência (C1; 0, 3, 6, 10, 17, 24, 38, 52 e 66 dias após o corte aos 16 dias (C2 e 0, 1, 3, 7, 21, 35, 49, 63 e 77 dias após o corte aos 37 dias (C3. Foram observadas três repetições (vasos, segundo delineamento inteiramente casualizado. Altos valores de TAL, RAF e TCR foram observados no início do crescimento seminal (C1 das plantas, caindo assintoticamente com o avanço da idade. O corte aos 37 dias de idade comprometeu o crescimento das plantas expresso em seus valores de TApF, a TAlF e a taxa de expansão da área foliar, RAF, TAL e TCR, sendo observados valores negativos para estes dois últimos índices, nos primeiros dias de brotação. A baixa demanda respiratória e a alocação de fotoassimilados para o crescimento foliar garantiram às plantas cortadas aos 16 dias, balanço positivo de carbono, possibilitando sua rápida recuperação.A trial was carried out in green-house to estimate morphogenic traits and growth indices of Mombaçagrass development. Three growths were considered: the seminal, establishment growth (G1 and the regrowths following a clipping taken on the 16th (G2 and 37th (G3 days of the seminal growth. The

  13. Parametric optimization of thermoelectric elements footprint for maximum power generation

    DEFF Research Database (Denmark)

    Rezania, A.; Rosendahl, Lasse; Yin, Hao

    2014-01-01

    The development studies in thermoelectric generator (TEG) systems are mostly disconnected to parametric optimization of the module components. In this study, optimum footprint ratio of n- and p-type thermoelectric (TE) elements is explored to achieve maximum power generation, maximum cost......-performance, and variation of efficiency in the uni-couple over a wide range of the heat transfer coefficient on the cold junction. The three-dimensional (3D) governing equations of the thermoelectricity and the heat transfer are solved using the finite element method (FEM) for temperature dependent properties of TE...... materials. The results, which are in good agreement with the previous computational studies, show that the maximum power generation and the maximum cost-performance in the module occur at An/Ap

  14. Cell growth characterization using multi-electrode bioimpedance spectroscopy

    International Nuclear Information System (INIS)

    Lu, Yi-Yu; Huang, Yu-Jie; Cheng, Kuo-Sheng; Huang, Ji-Jer

    2013-01-01

    Cell growth characterization during culturing is an important issue in a variety of biomedical applications. In this study an electrical bioimpedance spectroscopy-based multi-electrode culture monitoring system was developed to characterize cell growth. A PC12 cell line was cultured for the cell growth study. The bioimpedance variations for PC12 cell growth within the initial 12 h were measured over a range between 1 kHz and 4 MHz at three different medium concentrations. Within this frequency range, the largest bioimpedance value was 1.9 times the smallest bioimpedance value. The phase angle decreased over the range from 1 to 10 kHz when cells were growing. Then, the phase angle approached a constant over the frequency range between 10 kHz and 2 MHz. Thereafter, the phase angle increased rapidly from 20 to 52 degrees during cell culturing between 8 and 12 h at 4 MHz. The maximum cell number after culturing for 12 h increased by 25.8% for the control sites with poly-D-lysine (PDL) pastes. For the normal growth factor, the cell number increased up to 4.78 times from 8 to 12 h, but only 0.96 and 1.60 times for the other two medium growth factors. The correlation coefficients between impedance and cell number were 0.868 (coating with PDL), and 0.836 (without PDL) for the normal concentration medium. Thus, impedance may be used as an index for cell growth characterization. (paper)

  15. Coronary ligation reduces maximum sustained swimming speed in Chinook salmon, Oncorhynchus tshawytscha

    DEFF Research Database (Denmark)

    Farrell, A P; Steffensen, J F

    1987-01-01

    The maximum aerobic swimming speed of Chinook salmon (Oncorhynchus tshawytscha) was measured before and after ligation of the coronary artery. Coronary artery ligation prevented blood flow to the compact layer of the ventricular myocardium, which represents 30% of the ventricular mass, and produced...... a statistically significant 35.5% reduction in maximum swimming speed. We conclude that the coronary circulation is important for maximum aerobic swimming and implicit in this conclusion is that maximum cardiac performance is probably necessary for maximum aerobic swimming performance....

  16. Effects of bruxism on the maximum bite force

    Directory of Open Access Journals (Sweden)

    Todić Jelena T.

    2017-01-01

    Full Text Available Background/Aim. Bruxism is a parafunctional activity of the masticatory system, which is characterized by clenching or grinding of teeth. The purpose of this study was to determine whether the presence of bruxism has impact on maximum bite force, with particular reference to the potential impact of gender on bite force values. Methods. This study included two groups of subjects: without and with bruxism. The presence of bruxism in the subjects was registered using a specific clinical questionnaire on bruxism and physical examination. The subjects from both groups were submitted to the procedure of measuring the maximum bite pressure and occlusal contact area using a single-sheet pressure-sensitive films (Fuji Prescale MS and HS Film. Maximal bite force was obtained by multiplying maximal bite pressure and occlusal contact area values. Results. The average values of maximal bite force were significantly higher in the subjects with bruxism compared to those without bruxism (p 0.01. Maximal bite force was significantly higher in the males compared to the females in all segments of the research. Conclusion. The presence of bruxism influences the increase in the maximum bite force as shown in this study. Gender is a significant determinant of bite force. Registration of maximum bite force can be used in diagnosing and analysing pathophysiological events during bruxism.

  17. Influence of temperature on growth rate and lag phase of fungi isolated from Argentine corn.

    Science.gov (United States)

    González, H H; Resnik, S L; Vaamonde, G

    1988-03-01

    The influence of temperature on the growth of nine strains of fungi belonging to the genera Eurotium, Aspergillus, Penicillium and Fusarium has been investigated for the temperature range 15-35 degrees C. The lag phase and the growth rate were evaluated by using a laboratory medium. The maximum growth rate for E. repens, A. wentii and P. chrysogenum was observed at about 25 degrees C, for P. citrinum near 30 degrees C and for F. semitectum and F. moniliforme between 20 and 25 degrees C. The growth rate of A. niger, A. flavus and A. parasiticus increased with increasing temperatures in the range studied. For all strains studied it appeared that the higher the growth rate the lower the lag phase was.

  18. Maximum Likelihood based comparison of the specific growth rates for P. aeruginosa and four mutator strains

    DEFF Research Database (Denmark)

    Philipsen, Kirsten Riber; Christiansen, Lasse Engbo; Mandsberg, Lotte Frigaard

    2008-01-01

    with an exponentially decaying function of the time between observations is suggested. A model with a full covariance structure containing OD-dependent variance and an autocorrelation structure is compared to a model with variance only and with no variance or correlation implemented. It is shown that the model...... are used for parameter estimation. The data is log-transformed such that a linear model can be applied. The transformation changes the variance structure, and hence an OD-dependent variance is implemented in the model. The autocorrelation in the data is demonstrated, and a correlation model...... that best describes data is a model taking into account the full covariance structure. An inference study is made in order to determine whether the growth rate of the five bacteria strains is the same. After applying a likelihood-ratio test to models with a full covariance structure, it is concluded...

  19. Nitrogen stimulates phenological traits, growth and growing degree days of maize

    International Nuclear Information System (INIS)

    Hammad, H.M.; Ahmad, A.; Farhad, W.; Abbas, F.

    2013-01-01

    Field experiments were conducted during 2009 and 2010 to evaluate the effects of nitrogen (N) application timings and rates on phenology of autumn sown maize under semi-arid climatic conditions of Faisalabad, Pakistan. Plant development, growth and yield components were optimized by the N application in three splits; 1/3rd N at V2, 1/3rd N at V16 and 1/3rd N at R1 stages at the rate of 250 kg ha-1. At this rate, the crop achieved more calendar days and thermal time in each growth stage. The treatments T2 (1/3rd N at V2 stage, 1/3rd N at V16 stage and 1/3rd N at R1 stage) and N4 (250 kg N ha-1) accumulated the maximum days to silking and maturity (51 and 102 days, respectively), which resulted in the maximum crop growth rate and grain yield (8.38 t ha/sup -1/). The highest net benefit and marginal rate of return ($1857 and 22%, respectively) were achieved by N/sub 4/ treatment. Therefore, 250 kg N ha-1 with three above mentioned splits of N application may produce optimum grain yield of maize under semi-arid environmental and agricultural conditions similar to those of the reported experiments. (author)

  20. Acumulación de hojarasca en un pastizal de Panicum maximum y en un sistema silvopastoril de Panicum maximum y Leucaena leucocephala Litter accumulation in a Panicum maximum grassland and in a silvopastoral system of Panicum maximum and Leucaena leucocephala

    Directory of Open Access Journals (Sweden)

    Saray Sánchez

    2007-09-01

    Full Text Available Se realizó un estudio en la Estación Experimental de Pastos y Forrajes "Indio Hatuey", Matanzas, Cuba, con el objetivo de determinar la acumulación de la hojarasca en un pastizal de Panicum maximum Jacq cv. Likoni y en un sistema silvopastoril de Panicum maximum y Leucaena leucocephala (Lam de Wit cv. Cunningham. En los pastizales de P. maximum de ambos sistemas se determinó la acumulación de la hojarasca según la técnica propuesta por Bruce y Ebershon (1982, mientras que la hojarasca de L. leucocephala acumulada en el sistema silvopastoril se determinó según Santa Regina et al. (1997. De forma general, los resultados demostraron que en ambos pastizales la guinea acumuló una menor cantidad de hojarasca durante el período junio-diciembre, etapa en la que se produce su mayor desarrollo vegetativo. En la leucaena la mayor producción de hojarasca ocurrió en el período de diciembre a enero, asociada con la caída natural de sus hojas que se produce por efecto de las temperaturas más bajas y la escasa humedad en el suelo. En el sistema silvopastoril la hojarasca de leucaena representó el mayor porcentaje de peso dentro de la producción total, con un contenido más alto de nitrógeno y de calcio que el de la hojarasca del estrato herbáceo. En la guinea la lluvia fue el factor climático que mayor correlación negativa presentó con la producción de hojarasca en ambos sistemas, y en la leucaena la mayor correlación negativa se encontró con la temperatura mínima.A study was carried out at the Experimental Station of Pastures and Forages "Indio Hatuey", Matanzas, Cuba, with the objective of determining the litter accumulation in a pastureland of Panicum maximum Jacq cv. Likoni and in a silvopastoral system of Panicum maximum and Leucaena leucocephala (Lam de Wit cv. Cunningham. In the P. maximum pasturelands of both systems the litter accumulation was determined by means of the technique proposed by Bruce and Ebershon (1982, while

  1. Parameters determining maximum wind velocity in a tropical cyclone

    International Nuclear Information System (INIS)

    Choudhury, A.M.

    1984-09-01

    The spiral structure of a tropical cyclone was earlier explained by a tangential velocity distribution which varies inversely as the distance from the cyclone centre outside the circle of maximum wind speed. The case has been extended in the present paper by adding a radial velocity. It has been found that a suitable combination of radial and tangential velocities can account for the spiral structure of a cyclone. This enables parametrization of the cyclone. Finally a formula has been derived relating maximum velocity in a tropical cyclone with angular momentum, radius of maximum wind speed and the spiral angle. The shapes of the spirals have been computed for various spiral angles. (author)

  2. Exercise-induced maximum metabolic rate scaled to body mass by ...

    African Journals Online (AJOL)

    Exercise-induced maximum metabolic rate scaled to body mass by the fractal ... rate scaling is that exercise-induced maximum aerobic metabolic rate (MMR) is ... muscle stress limitation, and maximized oxygen delivery and metabolic rates.

  3. Electron density distribution in Si and Ge using multipole, maximum ...

    Indian Academy of Sciences (India)

    Si and Ge has been studied using multipole, maximum entropy method (MEM) and ... and electron density distribution using the currently available versatile ..... data should be subjected to maximum possible utility for the characterization of.

  4. The maximum-entropy method in superspace

    Czech Academy of Sciences Publication Activity Database

    van Smaalen, S.; Palatinus, Lukáš; Schneider, M.

    2003-01-01

    Roč. 59, - (2003), s. 459-469 ISSN 0108-7673 Grant - others:DFG(DE) XX Institutional research plan: CEZ:AV0Z1010914 Keywords : maximum-entropy method, * aperiodic crystals * electron density Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.558, year: 2003

  5. Maximum-entropy clustering algorithm and its global convergence analysis

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Constructing a batch of differentiable entropy functions touniformly approximate an objective function by means of the maximum-entropy principle, a new clustering algorithm, called maximum-entropy clustering algorithm, is proposed based on optimization theory. This algorithm is a soft generalization of the hard C-means algorithm and possesses global convergence. Its relations with other clustering algorithms are discussed.

  6. Flute instability growth on a magnetized plasma column

    International Nuclear Information System (INIS)

    Rose, D. V.; Genoni, T. C.; Welch, D. R.; Mehlhorn, T. A.; Porter, J. L.; Ditmire, T.

    2006-01-01

    The growth of the flute-type instability for a field-aligned plasma column immersed in a uniform magnetic field is studied. Particle-in-cell simulations are compared with a semi-analytic dispersion analysis of the drift cyclotron instability in cylindrical geometry with a Gaussian density profile in the radial direction. For the parameters considered here, the dispersion analysis gives a local maximum for the peak growth rates as a function of R/r i , where R is the Gaussian characteristic radius and r i is the ion gyroradius. The electrostatic and electromagnetic particle-in-cell simulation results give azimuthal and radial mode numbers that are in reasonable agreement with the dispersion analysis. The electrostatic simulations give linear growth rates that are in good agreement with the dispersion analysis results, while the electromagnetic simulations yield growth rate trends that are similar to the dispersion analysis but that are not in quantitative agreement. These differences are ascribed to higher initial field fluctuation levels in the electromagnetic field solver. Overall, the simulations allow the examination of both the linear and nonlinear evolution of the instability in this physical system up to and beyond the point of wave energy saturation

  7. Growth hormone-insuline-like growth factor-I system in pejerrey Odontesthes bonariensis (Atheriniformes

    Directory of Open Access Journals (Sweden)

    S.E. Arranz

    2008-07-01

    Full Text Available Using biotechnology to increase the growth rates of fish is likely to reduce production costs per unit of food. Among vertebrates, fish appear to occupy a unique position, when growth patterns are considered. With few exceptions, fish species tend to grow indeterminately, implying that size is never fixed. Both hyperplasia and hypertrophy contribute to post-larval muscle growth in fish. Growth hormone (GH - Insulin-like Growth Factor I (IGF-I is the most important growth axis in fish. Our experimental model, the pejerrey, Odontesthes bonariensis (Ateriniformes is a South American inland water fish considered to be a promising species for intensive aquaculture. However, one major drawback to achieve this goal is its slow growth in captivity. In order to understand how growth is regulated in this species, our first objective was to characterized pejerrey GH- IGF-I axis. We first cloned and characterized pejerrey (pj GH, IGF-I and the growth hormone receptors (GHRs I and II. In addition to providing valuable data for evolutionary comparison of GH, investigation of GH action in teleosts is particularly important because of its potential application in aquaculture. GH can not only promote the somatic growth in fish but also lower dietary protein requirements. A prerequisite for providing sufficient amounts of GH for basic research and aquaculture application is a large-scale production of GH. For that purpose, recombinant pjGH was expressed in a bacterial system. Protocols for solubilization and proper folding were achieved. Activity of recombinant pjGH was assessed in fish by measuring the liver IGF-I response to different doses of GH. IGF-I transcript was measured in the liver after pjGHr in vivo stimulation by means of quantitative real-time PCR assays. A dose-dependent response of IGF-I mRNA was observed after pjGHr administration, and reached a 6 fold IGF-I maximum increase over control group when 2.5 µg pjGH /g-body weight were injected

  8. Assessing the Effect of Planting Date on Safflower Cultivars Growth and Seed Yield in Rafsanjan Condition

    Directory of Open Access Journals (Sweden)

    F Khatib

    2015-09-01

    Full Text Available The use of appropriate cultivar and planting date is the most important principles of agronomy; therefore, the aim of the present study was to consider the growth indices of different safflower cultivars and their relationships with seed yield. For this purpose, an experiment was conducted as factorial in randomized block design with four replicates included three planting dates (4 April, 25 April and 16 May and four safflower cultivars (411, Sina, Local Esfahan and Sofeh. The maximum leaf area index (2.33 obtained in the first planting date that it was not significantly different with the second planting date but it decreased up to 70% in the third planting date. In the first planting date, the maximum LAI obtained for Local Esfahan and 411 cultivars. Maximum total dry matter was 124.2 g m-2 for the first planting date that it decreased up to 31 and 78% in the second and third planting dates, respectively. In this planting date Sina and Local Esfahan cultivars had the higher dry matter. Maximum crop growth rate for the first planting date was 38.84 g m-2d-1 that it decreased up to 41 and 66% in the second and third planting dates, respectively. In this planting date, the highest total dry matter obtained for the Local Esfahan cultivar. The results showed that the maximum value of seed yield dedicated to 411 and Local Esfahan cultivars that it had the high correlation with maximum total dry matter. In respect to the present study, it is suggested to use 411 or Local Esfahan cultivars in the first planting date.

  9. Growth behaviors of bacteria in biofouling cake layer in a dead-end microfiltration system.

    Science.gov (United States)

    Chao, Yuanqing; Zhang, Tong

    2011-01-01

    The growth behaviors of three bacterial species, i.e. Escherichia coli, Pseudomonas putida and Aquabaculum hongkongensis, in biofouling cake layer (attached form) were investigated using an unstirred dead-end continuous microfiltration system, and were compared with those in suspended form. Results showed that all the three bacteria had larger average growth rates in suspended form than in attached form under high substrates levels. Under oligotrophic conditions, the average growth rates in the attached form were faster than those in the suspended form, especially for A. hongkongensis. The growth behaviors analysis presented the same results due to all the tested bacteria had higher maximum growth rate and saturation constant in suspended form than attached form, indicating the dominant growth mode would be shifted from attached form to suspended form with substrate concentration increase. Finally, total filtration resistance determined in the experiments increased significantly with the bacterial growth in filtration system. Copyright © 2010 Elsevier Ltd. All rights reserved.

  10. Maximum Potential Score (MPS: An operating model for a successful customer-focused strategy.

    Directory of Open Access Journals (Sweden)

    Cabello González, José Manuel

    2015-12-01

    Full Text Available One of marketers’ chief objectives is to achieve customer loyalty, which is a key factor for profitable growth. Therefore, they need to develop a strategy that attracts and maintains customers, giving them adequate motives, both tangible (prices and promotions and intangible (personalized service and treatment, to satisfy a customer and make him loyal to the company. Finding a way to accurately measure satisfaction and customer loyalty is very important. With regard to typical Relationship Marketing measures, we can consider listening to customers, which can help to achieve a competitive sustainable advantage. Customer satisfaction surveys are essential tools for listening to customers. Short questionnaires have gained considerable acceptance among marketers as a means to achieve a customer satisfaction measure. Our research provides an indication of the benefits of a short questionnaire (one/three questions. We find that the number of questions survey is significantly related to the participation in the survey (Net Promoter Score or NPS. We also prove that a the three question survey is more likely to have more participants than a traditional survey (Maximum Potential Score or MPS . Our main goal is to analyse one method as a potential predictor of customer loyalty. Using surveys, we attempt to empirically establish the causal factors in determining the satisfaction of customers. This paper describes a maximum potential operating model that captures with a three questions survey, important elements for a successful customer-focused strategy. MPS may give us lower participation rates than NPS but important information that helps to convert unhappy customers or just satisfied customers, into loyal customers.

  11. maximum neutron flux at thermal nuclear reactors

    International Nuclear Information System (INIS)

    Strugar, P.

    1968-10-01

    Since actual research reactors are technically complicated and expensive facilities it is important to achieve savings by appropriate reactor lattice configurations. There is a number of papers, and practical examples of reactors with central reflector, dealing with spatial distribution of fuel elements which would result in higher neutron flux. Common disadvantage of all the solutions is that the choice of best solution is done starting from the anticipated spatial distributions of fuel elements. The weakness of these approaches is lack of defined optimization criteria. Direct approach is defined as follows: determine the spatial distribution of fuel concentration starting from the condition of maximum neutron flux by fulfilling the thermal constraints. Thus the problem of determining the maximum neutron flux is solving a variational problem which is beyond the possibilities of classical variational calculation. This variational problem has been successfully solved by applying the maximum principle of Pontrjagin. Optimum distribution of fuel concentration was obtained in explicit analytical form. Thus, spatial distribution of the neutron flux and critical dimensions of quite complex reactor system are calculated in a relatively simple way. In addition to the fact that the results are innovative this approach is interesting because of the optimization procedure itself [sr

  12. Inhibitory effects of soluble algae products (SAP) released by Scenedesmus sp. LX1 on its growth and lipid production.

    Science.gov (United States)

    Zhang, Tian-Yuan; Yu, Yin; Wu, Yin-Hu; Hu, Hong-Ying

    2013-10-01

    Soluble algal products (SAP) accumulated in culture medium via water reuse may affect the growth of microalga during the cultivation. Scenedesmus sp. LX1, a freshwater microalga, was used in this study to investigate the effect of SAP on growth and lipid production of microalga. Under the SAP concentrations of 6.4-25.8 mg L(-1), maximum algal density (K) and maximum growth rate (Rmax) of Scenedesmus sp. LX1 were decreased by 50-80% and 35-70% compared with the control group, respectively. The effect of SAP on lipid accumulation of Scenedesmus sp. LX1 was non-significant. According to hydrophilic-hydrophobic and acid-base properties, SAP was fractionized into six fractions. All of the fractions could inhibit the growth of Scenedesmus sp. LX1. Organic bases (HIB, HOB) and hydrophilic acids (HIA) showed the strongest inhibition. HIA could also decrease the lipid content of Scenedesmus sp. LX1 by 59.2%. As the inhibitory effect, SAP should be seriously treated before water reuse. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Effect of road side dust pollution on the growth and total chlorophyll ...

    African Journals Online (AJOL)

    The effect of dust in Vitis vinifera L. on its pigmentation and growth was studied in 2012. Measurements were taken for plants in the Campus University of Balochistan, Quetta. A significant reduction in plant length, cover, number of leaves and total chlorophyll contents for V. vinifera L. was observed. The maximum reduction ...

  14. GLOBALLY INCREASED CROP GROWTH AND CROPPING INTENSITY FROM THE LONG-TERM SATELLITE-BASED OBSERVATIONS

    Directory of Open Access Journals (Sweden)

    B. Chen

    2018-04-01

    Full Text Available Understanding the spatiotemporal change trend of global crop growth and multiple cropping system under climate change scenarios is a critical requirement for supporting the food security issue that maintains the function of human society. Many studies have predicted the effects of climate changes on crop production using a combination of filed studies and models, but there has been limited evidence relating decadal-scale climate change to global crop growth and the spatiotemporal distribution of multiple cropping system. Using long-term satellite-derived Normalized Difference Vegetation Index (NDVI and observed climate data from 1982 to 2012, we investigated the crop growth trend, spatiotemporal pattern trend of agricultural cropping intensity, and their potential correlations with respect to the climate change drivers at a global scale. Results show that 82.97 % of global cropland maximum NDVI witnesses an increased trend while 17.03 % of that shows a decreased trend over the past three decades. The spatial distribution of multiple cropping system is observed to expand from lower latitude to higher latitude, and the increased cropping intensity is also witnessed globally. In terms of regional major crop zones, results show that all nine selected zones have an obvious upward trend of crop maximum NDVI (p < 0.001, and as for climatic drivers, the gradual temperature and precipitation changes have had a measurable impact on the crop growth trend.

  15. Kinetic characteristics and modeling of microalgae Chlorella vulgaris growth and CO2 biofixation considering the coupled effects of light intensity and dissolved inorganic carbon.

    Science.gov (United States)

    Chang, Hai-Xing; Huang, Yun; Fu, Qian; Liao, Qiang; Zhu, Xun

    2016-04-01

    Understanding and optimizing the microalgae growth process is an essential prerequisite for effective CO2 capture using microalgae in photobioreactors. In this study, the kinetic characteristics of microalgae Chlorella vulgaris growth in response to light intensity and dissolved inorganic carbon (DIC) concentration were investigated. The greatest values of maximum biomass concentration (Xmax) and maximum specific growth rate (μmax) were obtained as 2.303 g L(-1) and 0.078 h(-1), respectively, at a light intensity of 120 μmol m(-2) s(-1) and DIC concentration of 17 mM. Based on the results, mathematical models describing the coupled effects of light intensity and DIC concentration on microalgae growth and CO2 biofixation are proposed. The models are able to predict the temporal evolution of C. vulgaris growth and CO2 biofixation rates from lag to stationary phases. Verification experiments confirmed that the model predictions agreed well with the experimental results. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. 5 CFR 534.203 - Maximum stipends.

    Science.gov (United States)

    2010-01-01

    ... maximum stipend established under this section. (e) A trainee at a non-Federal hospital, clinic, or medical or dental laboratory who is assigned to a Federal hospital, clinic, or medical or dental... Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY UNDER OTHER SYSTEMS Student...

  17. Influence of maximum bite force on jaw movement during gummy jelly mastication.

    Science.gov (United States)

    Kuninori, T; Tomonari, H; Uehara, S; Kitashima, F; Yagi, T; Miyawaki, S

    2014-05-01

    It is known that maximum bite force has various influences on chewing function; however, there have not been studies in which the relationships between maximum bite force and masticatory jaw movement have been clarified. The aim of this study was to investigate the effect of maximum bite force on masticatory jaw movement in subjects with normal occlusion. Thirty young adults (22 men and 8 women; mean age, 22.6 years) with good occlusion were divided into two groups based on whether they had a relatively high or low maximum bite force according to the median. The maximum bite force was determined according to the Dental Prescale System using pressure-sensitive sheets. Jaw movement during mastication of hard gummy jelly (each 5.5 g) on the preferred chewing side was recorded using a six degrees of freedom jaw movement recording system. The motion of the lower incisal point of the mandible was computed, and the mean values of 10 cycles (cycles 2-11) were calculated. A masticatory performance test was conducted using gummy jelly. Subjects with a lower maximum bite force showed increased maximum lateral amplitude, closing distance, width and closing angle; wider masticatory jaw movement; and significantly lower masticatory performance. However, no differences in the maximum vertical or maximum anteroposterior amplitudes were observed between the groups. Although other factors, such as individual morphology, may influence masticatory jaw movement, our results suggest that subjects with a lower maximum bite force show increased lateral jaw motion during mastication. © 2014 John Wiley & Sons Ltd.

  18. Maximum parsimony on subsets of taxa.

    Science.gov (United States)

    Fischer, Mareike; Thatte, Bhalchandra D

    2009-09-21

    In this paper we investigate mathematical questions concerning the reliability (reconstruction accuracy) of Fitch's maximum parsimony algorithm for reconstructing the ancestral state given a phylogenetic tree and a character. In particular, we consider the question whether the maximum parsimony method applied to a subset of taxa can reconstruct the ancestral state of the root more accurately than when applied to all taxa, and we give an example showing that this indeed is possible. A surprising feature of our example is that ignoring a taxon closer to the root improves the reliability of the method. On the other hand, in the case of the two-state symmetric substitution model, we answer affirmatively a conjecture of Li, Steel and Zhang which states that under a molecular clock the probability that the state at a single taxon is a correct guess of the ancestral state is a lower bound on the reconstruction accuracy of Fitch's method applied to all taxa.

  19. Effects of Plant Growth Hormones on Mucor indicus Growth and Chitosan and Ethanol Production.

    Science.gov (United States)

    Safaei, Zahra; Karimi, Keikhosro; Golkar, Poorandokht; Zamani, Akram

    2015-07-22

    The objective of this study was to investigate the effects of indole-3-acetic acid (IAA) and kinetin (KIN) on Mucor indicus growth, cell wall composition, and ethanol production. A semi-synthetic medium, supplemented with 0-5 mg/L hormones, was used for the cultivations (at 32 °C for 48 h). By addition of 1 mg/L of each hormone, the biomass and ethanol yields were increased and decreased, respectively. At higher levels, however, an inverse trend was observed. The glucosamine fraction of the cell wall, as a representative for chitosan, followed similar but sharper changes, compared to the biomass. The highest level was 221% higher than that obtained without hormones. The sum of glucosamine and N-acetyl glucosamine (chitin and chitosan) was noticeably enhanced in the presence of the hormones. Increase of chitosan was accompanied by a decrease in the phosphate content, with the lowest phosphate (0.01 g/g cell wall) being obtained when the chitosan was at the maximum (0.45 g/g cell wall). In conclusion, IAA and KIN significantly enhanced the M. indicus growth and chitosan production, while at the same time decreasing the ethanol yield to some extent. This study shows that plant growth hormones have a high potential for the improvement of fungal chitosan production by M. indicus.

  20. Prey size and availability limits maximum size of rainbow trout in a large tailwater: insights from a drift-foraging bioenergetics model

    Science.gov (United States)

    Dodrill, Michael J.; Yackulic, Charles B.; Kennedy, Theodore A.; Haye, John W

    2016-01-01

    The cold and clear water conditions present below many large dams create ideal conditions for the development of economically important salmonid fisheries. Many of these tailwater fisheries have experienced declines in the abundance and condition of large trout species, yet the causes of these declines remain uncertain. Here, we develop, assess, and apply a drift-foraging bioenergetics model to identify the factors limiting rainbow trout (Oncorhynchus mykiss) growth in a large tailwater. We explored the relative importance of temperature, prey quantity, and prey size by constructing scenarios where these variables, both singly and in combination, were altered. Predicted growth matched empirical mass-at-age estimates, particularly for younger ages, demonstrating that the model accurately describes how current temperature and prey conditions interact to determine rainbow trout growth. Modeling scenarios that artificially inflated prey size and abundance demonstrate that rainbow trout growth is limited by the scarcity of large prey items and overall prey availability. For example, shifting 10% of the prey biomass to the 13 mm (large) length class, without increasing overall prey biomass, increased lifetime maximum mass of rainbow trout by 88%. Additionally, warmer temperatures resulted in lower predicted growth at current and lower levels of prey availability; however, growth was similar across all temperatures at higher levels of prey availability. Climate change will likely alter flow and temperature regimes in large rivers with corresponding changes to invertebrate prey resources used by fish. Broader application of drift-foraging bioenergetics models to build a mechanistic understanding of how changes to habitat conditions and prey resources affect growth of salmonids will benefit management of tailwater fisheries.

  1. Hydrogen induced crack growth in Grade-12 titanium

    International Nuclear Information System (INIS)

    Ahn, T.M.; Lee, K.S.

    1984-01-01

    Internal hydrogen induced crack growth rates were measured in Grade-12 titanium which is a candidate material for high-level nuclear waste containers. As-received and hydrogen charged samples (5 ppM to 330 ppM hydrogen) were used for slow crack growth measurements at constant loads using a Krak Gauge. The testing temperature ranged from room temperature to 148 0 C. The crack growth kinetics under low to moderate loads are linear, but this linear rate is interrupted by discrete fast crack jump segments with parabolic or cubic type kinetics. These fast jump segments are thought to be associated with the passage of the crack front through the alpha-beta interface phase or with the initial loading sequence. By measuring striation spacings on the fracture surface, most crack growth rates observed are found to be in stage II. The striations are considered to be associated with hydride fracture. The crack path is either transgranular in the alpha phase or interfacial in the alpha phase adjacent to the beta phase. For transgranular growth, crack growth rates are constant and slower than those for interfacial growth which is associated with fast crack growth through a high hydrogen concentration region. Most stage II crack growth rates depend slightly on the stress intensity suggesting the contribution of plastic tearing process to stage II kinetics. The activation energies for crack growth are much lower than the activation energy of hydrogen diffusion through the alpha phase, implying that hydrogen is transported along dislocations, grain boundaries or interfaces. When the temperature is increased, the crack velocity first reaches a maximum and then decreases at higher temperatures. These temperature effects come from lower hydrogen concentration trapped at dislocations or from slower hydride nucleation kinetics, both at higher temperatures

  2. Effects of pH on the growth and NH4-N uptake of Skeletonema costatum and Nitzschia closterium.

    Science.gov (United States)

    Gu, Xingyan; Li, Keqiang; Pang, Kai; Ma, Yunpeng; Wang, Xiulin

    2017-11-30

    Ocean acidification (OA) and eutrophication intensifies in coastal sea under anthropogenic impact. OA coupled with the NH 4 -N source effect in coastal water is likely to affect the planktonic ecosystem. In this work, Skeletonema costatum and Nitzschia closterium were chosen as typical species of diatom in Chinese coastal ecosystems to test the potential effect of OA and NH 4 -N. Results showed that the growth and NH 4 -N uptake of S. costatum and N. closterium were significantly inhibited by pH decline. The maximum uptake rate is higher than the maximum growth rate, implying that NH 4 -N was assimilated faster for S. costatum and N. closterium with decreasing pH. Therefore, the inhibition rate of the growth of the two diatoms by the coupling effect of OA and eutrophication (pH7.45) is higher that than in the coastal sea by the end of the 21st century (pH7.71). Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Role of plant growth regulators on oil yield and biodiesel production of linseed (linum usitatissimum l)

    International Nuclear Information System (INIS)

    Faizanullah, A.; Bano, A.; Nosheen, A.

    2010-01-01

    A field experiment was conducted to compare the effect of plant growth regulators (PGRs) viz. kinetin (K), chlorocholine chloride (CCC) and salicylic acid (SA) on seed yield, oil content and oil quality of Linseed (Linum usitatissimum L) cv. Chandni with a new perspective to biodiesel production. The growth regulators (10-6M) were applied as seed soaking for 10 h prior to cultivation. Kinetin significantly increased the number of capsules/plant, seed number/capsule, 1000 seed weight and total seed yield (kg/h). The growth regulators increased the seed oil content maximum being in kinetin and CCC treatments. Kinetin and CCC significantly decreased the oil acid value, free fatty acid content (% oleic acid) and increased the pH of oil. Nevertheless, SA significantly decreased the oil specific gravity and did not alter the pH. Only kinetin significantly increased the oil iodine value. The oil extracted from seeds of kinetin and CCC treated plants showed maximum conversion (% w/w) to methyl esters/biodiesel after transesterification. It can be inferred that PGRs can be utilized successfully for improving the biodiesel yield of linseed. (author)

  4. Quantification of growth, yield and radiation use efficiency of promising cotton cultivars at varying nitrogen levels

    International Nuclear Information System (INIS)

    Wajid, A.; Ahmad, A.; Khaliq, T.; Alam, S.; Hussaun, A.; Hussain, K.; Naseem, W.; Usman, M.; Ahmad, S.

    2010-01-01

    Cotton cultivars response to different doses of nitrogen for radiation interception, canopy development, growth and seed yield were studied in 2006. The experiment was laid out in randomized complete block design with split arrangement under the climatic conditions of Bahawalpur. Data on seed yield, total dry matter (TDM), leaf area index (LAI), fraction of intercepted radiation (Fi), accumulated radiation interception during the growth season (Sa) and radiation use efficiency (RUE) were taken into account. TDM pattern showed sigmoid growth curve for both cultivars and nitrogen levels and showed strong relationship (R2 = 0.98) with the accumulated intercepted radiation (Sa) for the season. Mean maximum value of fraction of incident PAR (Fi) remained 90% at 120 days after sowing (DAS) harvest due to maximum crop canopy development. Cultivar NIAB-111 produced 0.81 g m/sup -2/ of TDM for each MJ of accumulated PAR and nitrogen at the rate of 185 kg ha/sup -1/ statistically proved to be better in converting radiation into dry matter production. (author)

  5. [Impacts of climate warming on growth period and yield of rice in Northeast China during recent two decades].

    Science.gov (United States)

    Hou, Wen-jia; Geng, Ting; Chen, Qun; Chen, Chang-qing

    2015-01-01

    By using rice growth period, yield and climate observation data during the recent two decades, the impact of climate warming on rice in Northeast China was investigated by mathematical statistics methods. The results indicated that in the three provinces of Northeast China, the average, maximum and minimum temperatures in rice growing season were on the. rise, and the rainfall presented a downward trend during 1989-2009. Compared to 1990s, the rice whole growth periods of Heilongjiang, Jilin and Liaoning provinces in 2000s were prolonged 14 d, 4.5 d and 5.1 d, respectively. The increase of temperature in May, June and September could extend the rice growth period, while that in July would shorten the growth duration. The rice growth duration of registered varieties and experiment sites had a similar increasing trend in Northeast China except for the Heilongjiang Province, and the extension of registered varieties growth period was the main factor causing the prolonged growth period of rice at experiment sites. The change in daily average, minimum and maximum temperatures all could affect the rice yield in Northeast China. The increasing temperature significantly increased the rice yield in Heilongjiang Province, especially in the west region of Sanjiang Plain. Except for the south of Liaoning Province, rice yields in other regions of Northeast China were promoted by increasing temperature. Proper measures for breeding, cultivation and farming, could be adopted to fully improve the adaptation of rice to climate warming in Northeast China.

  6. Maximum length scale in density based topology optimization

    DEFF Research Database (Denmark)

    Lazarov, Boyan Stefanov; Wang, Fengwen

    2017-01-01

    The focus of this work is on two new techniques for imposing maximum length scale in topology optimization. Restrictions on the maximum length scale provide designers with full control over the optimized structure and open possibilities to tailor the optimized design for broader range...... of manufacturing processes by fulfilling the associated technological constraints. One of the proposed methods is based on combination of several filters and builds on top of the classical density filtering which can be viewed as a low pass filter applied to the design parametrization. The main idea...

  7. The growth rates of KDP crystals in solutions with potassium permanganate additives

    Science.gov (United States)

    Egorova, A. E.; Vorontsov, D. A.; Nezhdanov, A. V.; Noskova, A. N.; Portnov, V. N.

    2017-01-01

    We have found that growth of the {101} faces of a KDP (KH2PO4) crystal is suppressed, and the growth rate of the {100} faces passes through the maximum with increasing addition of KMnO4 to a solution with pH=4.7. We have concluded that the [MnH2PO4]2+ complex and MnO2 particles affect the growth kinetics. The X-ray and electronic paramagnetic resonance data show that manganese is incorporated into the crystal in the form of Mn3+ and Mn4+. The local excess of a positive charge in the area with incorporated [MnH2PO4]2+ complex can be compensated by the shift of the hydrogen atoms in the KDP structure.

  8. Growth enhancement of effective microorganisms for bioremediation of crude oil contaminated waters.

    Science.gov (United States)

    Mukred, Abdualdaim Mohammed; Abd-Hamid, Aidil; Hamzah, Ainon; Yusoff, Wan Mohtar Wan

    2008-07-01

    The bioremediation of polluted groundwater, wastewater aeration pond and biopond sites was investigated using bacteria isolated from these sites located at the oil refinery Terengganu Malaysia. Out of 62 isolates, only 16 isolates from groundwater (8) and wastewater aeration pond (3) and biopond (5) were chosen based on growth medium containing 1% (v/v) Tapis crude oil. Only four isolates; Acinetobacter faecalis, Staphylococcus sp., Pseudomonas putida and Neisseria elongata showed percentage biodegradation of crude oil more than 50% after 5 days using Mineral Salts Medium (MSM). The effect of physical parameters (temperature, pH and agitation) on growth by all four strains showed a maximum growth in MSM medium with 1% Tapis crude oil at 37 degrees C with pH 7 and agitation of 130 rpm.

  9. Maximum Water Hammer Sensitivity Analysis

    OpenAIRE

    Jalil Emadi; Abbas Solemani

    2011-01-01

    Pressure waves and Water Hammer occur in a pumping system when valves are closed or opened suddenly or in the case of sudden failure of pumps. Determination of maximum water hammer is considered one of the most important technical and economical items of which engineers and designers of pumping stations and conveyance pipelines should take care. Hammer Software is a recent application used to simulate water hammer. The present study focuses on determining significance of ...

  10. Growth and Development of Colletotrichum gloeosporioides f. alatae During Culture in Liquid Medium

    Directory of Open Access Journals (Sweden)

    Laura E. Cerón Rincón

    2006-01-01

    Full Text Available Some characteristics known as virulence factors for Colletotrichum sp. genus, like: weight of the produced mycelium, sporulation, poligalacturonase activity and pH medium were evaluated during the growth of C. gloeosporioides f. alatae in three liquid medium commonly used for fungi culture (Czapeck, Martin broth and potato broth and additionally (Czapeck with yam extract as the only source of carbon. After of 17 days of growth, maximum values were obtained for the above parameters in the last medium, compared with others growth media evaluated. The implemented medium with yam extract, supply nutritional requirements of the pathogen for the development of characteristic factors related with mechanism of infections that may play a role in the pathogenesis.

  11. Adsorption-controlled growth of BiMnO3 films by molecular-beam epitaxy

    International Nuclear Information System (INIS)

    Lee, J. H.; Ke, X.; Misra, R.; Schiffer, P.; Ihlefeld, J. F.; Mei, Z. G.; Liu, Z. K.; Xu, X. S.; Musfeldt, J. L.; Heeg, T.; Schlom, D. G.; Roeckerath, M.; Schubert, J.

    2010-01-01

    We have developed the means to grow BiMnO 3 thin films with unparalleled structural perfection by reactive molecular-beam epitaxy and determined its band gap. Film growth occurs in an adsorption-controlled growth regime. Within this growth window bounded by oxygen pressure and substrate temperature at a fixed bismuth overpressure, single-phase films of the metastable perovskite BiMnO 3 may be grown by epitaxial stabilization. X-ray diffraction reveals phase-pure and epitaxial films with ω rocking curve full width at half maximum values as narrow as 11 arc sec (0.003 deg. ). Optical absorption measurements reveal that BiMnO 3 has a direct band gap of 1.1±0.1 eV.

  12. Growth and nutrient efficiency of Betula alnoides clones in response to phosphorus supply

    Directory of Open Access Journals (Sweden)

    Lin Chen

    2016-12-01

    Full Text Available As phosphorus deficiency limits the productivity of many plantation forests in Asia, there is considerable interest in developing phosphorus-efficient clones for the region through targeted breeding programs. Therefore, we determined growth, nutrient concentrations and nutrient absorption and utility efficiencies of four Betula alnoides clones (C5, C6, 1-202 and BY1 in response to six phosphorus levels of 0, 17, 52, 70, 140 and 209 mg P plant-1 coded as P1 to P6, respectively. Maximum growth occurred in the P4, P5 and P6 plants since they had the largest height, biomass, leaf area and branch number. Phosphorus application increased the phosphorus concentrations of all clones. Nutrient loading was achieved with the P6 treatment because growth and biomass were not significantly higher, but root, stem and leaf phosphorus concentrations were approximately twice those of P4 plants. Clone BY1 had the highest phosphorus-efficiency, and is recommended for field application due to its maximum root collar diameter, biomass, root/shoot ratio, leaf area, nutrient absorption and utility efficiency among the four clones. The findings will help to improve the nutrient efficiency of this species in plantation forestry in Asia.

  13. Simulation of the ultrasound-induced growth and collapse of a near-wall bubble

    Science.gov (United States)

    Boyd, Bradley; Becker, Sid

    2017-11-01

    In this study, we consider the acoustically driven growth and collapse of a cavitation bubble in a fluid medium exposed to an ultrasound field. The bubble dynamics are modelled using a compressible, inviscid, multiphase model. The numerical scheme consists of a conservative interface capturing scheme which uses the fifth-order WENO reconstruction with a maximum-principle-satisfying and positivity-preserving limiter, and the HLLC approximate Riemann flux. To model the ultrasound input, a moving boundary oscillates through a fixed grid of finite-volume cells. The growth phase of the simulation shows the rapid non-spherical growth of the near-wall bubble. Once the bubble reaches its maximum size and the collapse phase begins, the simulation shows the formation of a jet which penetrates the bubble towards the wall at the later stages of the collapse. For a bubble with an initial radius of 50 μ m and an ultrasound pressure amplitude of 200 kPa, the pressure experienced by the wall increased rapidly nearing the end of the collapse, reaching a peak pressure of 13 MPa. This model is an important development in the field as it represents the physics of acoustic cavitation in more detail than before. This work was supported by the Royal Society of New Zealand's Marsden Fund.

  14. Influence of Poly-(L-Lactic Acid Nanofiber Functionalization on Maximum Load, Young's Modulus, and Strain of Nanofiber Scaffolds Before and After Cultivation of Osteoblasts: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    Jürgen Paletta

    2009-01-01

    Full Text Available The aim of this study was to characterize the influence of functionalization of synthetic poly-(L-lactic acid (PLLA nanofibers on mechanical properties such as maximum load, elongation, and Young's modulus. Furthermore, the impact of osteoblast growth on the various nanofiber scaffolds stability was determined. Nanofiber matrices composed of PLLA, PLLA-collagen, or BMP-2–incorporated PLLA were produced from different solvents by electrospinning. Standardized test samples of each nanofiber scaffold were subjected to failure protocol before or after incubation in the presence of osteoblasts over a period of 22 days under osteoinductive conditions. PLLA nanofibers electrospun from hexafluoroisopropanol (HFIP showed a higher strain and tended to have increased maximum loads and Young's modulus compared to PLLA fibers spun from dichloromethane. In addition, they had a higher resistance during incubation in the presence of cells. Functionalization by incorporation of growth factors increased Young's modulus, independent of the solvent used. However, the incorporation of growth factors using the HFIP system resulted in a loss of strain. Similar results were observed when PLLA was blended with different ratios of collagen. Summarizing the results, this study indicates that different functionalization strategies influence the mechanical stability of PLLA nanofibers. Therefore, an optimization of nanofibers should not only account for the optimization of biological effects on cells, but also has to consider the stability of the scaffold.

  15. PTree: pattern-based, stochastic search for maximum parsimony phylogenies

    OpenAIRE

    Gregor, Ivan; Steinbr?ck, Lars; McHardy, Alice C.

    2013-01-01

    Phylogenetic reconstruction is vital to analyzing the evolutionary relationship of genes within and across populations of different species. Nowadays, with next generation sequencing technologies producing sets comprising thousands of sequences, robust identification of the tree topology, which is optimal according to standard criteria such as maximum parsimony, maximum likelihood or posterior probability, with phylogenetic inference methods is a computationally very demanding task. Here, we ...

  16. Transient Growth Analysis of Compressible Boundary Layers with Parabolized Stability Equations

    Science.gov (United States)

    Paredes, Pedro; Choudhari, Meelan M.; Li, Fei; Chang, Chau-Lyan

    2016-01-01

    The linear form of parabolized linear stability equations (PSE) is used in a variational approach to extend the previous body of results for the optimal, non-modal disturbance growth in boundary layer flows. This methodology includes the non-parallel effects associated with the spatial development of boundary layer flows. As noted in literature, the optimal initial disturbances correspond to steady counter-rotating stream-wise vortices, which subsequently lead to the formation of stream-wise-elongated structures, i.e., streaks, via a lift-up effect. The parameter space for optimal growth is extended to the hypersonic Mach number regime without any high enthalpy effects, and the effect of wall cooling is studied with particular emphasis on the role of the initial disturbance location and the value of the span-wise wavenumber that leads to the maximum energy growth up to a specified location. Unlike previous predictions that used a basic state obtained from a self-similar solution to the boundary layer equations, mean flow solutions based on the full Navier-Stokes (NS) equations are used in select cases to help account for the viscous-inviscid interaction near the leading edge of the plate and also for the weak shock wave emanating from that region. These differences in the base flow lead to an increasing reduction with Mach number in the magnitude of optimal growth relative to the predictions based on self-similar mean-flow approximation. Finally, the maximum optimal energy gain for the favorable pressure gradient boundary layer near a planar stagnation point is found to be substantially weaker than that in a zero pressure gradient Blasius boundary layer.

  17. The maximum significant wave height in the Southern North Sea

    NARCIS (Netherlands)

    Bouws, E.; Tolman, H.L.; Holthuijsen, L.H.; Eldeberky, Y.; Booij, N.; Ferier, P.

    1995-01-01

    The maximum possible wave conditions along the Dutch coast, which seem to be dominated by the limited water depth, have been estimated in the present study with numerical simulations. Discussions with meteorologists suggest that the maximum possible sustained wind speed in North Sea conditions is

  18. Maximum mass ratio of AM CVn-type binary systems and maximum white dwarf mass in ultra-compact X-ray binaries

    Directory of Open Access Journals (Sweden)

    Arbutina Bojan

    2011-01-01

    Full Text Available AM CVn-type stars and ultra-compact X-ray binaries are extremely interesting semi-detached close binary systems in which the Roche lobe filling component is a white dwarf transferring mass to another white dwarf, neutron star or a black hole. Earlier theoretical considerations show that there is a maximum mass ratio of AM CVn-type binary systems (qmax ≈ 2/3 below which the mass transfer is stable. In this paper we derive slightly different value for qmax and more interestingly, by applying the same procedure, we find the maximum expected white dwarf mass in ultra-compact X-ray binaries.

  19. Size dependence of efficiency at maximum power of heat engine

    KAUST Repository

    Izumida, Y.; Ito, N.

    2013-01-01

    We perform a molecular dynamics computer simulation of a heat engine model to study how the engine size difference affects its performance. Upon tactically increasing the size of the model anisotropically, we determine that there exists an optimum size at which the model attains the maximum power for the shortest working period. This optimum size locates between the ballistic heat transport region and the diffusive heat transport one. We also study the size dependence of the efficiency at the maximum power. Interestingly, we find that the efficiency at the maximum power around the optimum size attains a value that has been proposed as a universal upper bound, and it even begins to exceed the bound as the size further increases. We explain this behavior of the efficiency at maximum power by using a linear response theory for the heat engine operating under a finite working period, which naturally extends the low-dissipation Carnot cycle model [M. Esposito, R. Kawai, K. Lindenberg, C. Van den Broeck, Phys. Rev. Lett. 105, 150603 (2010)]. The theory also shows that the efficiency at the maximum power under an extreme condition may reach the Carnot efficiency in principle.© EDP Sciences Società Italiana di Fisica Springer-Verlag 2013.

  20. Size dependence of efficiency at maximum power of heat engine

    KAUST Repository

    Izumida, Y.

    2013-10-01

    We perform a molecular dynamics computer simulation of a heat engine model to study how the engine size difference affects its performance. Upon tactically increasing the size of the model anisotropically, we determine that there exists an optimum size at which the model attains the maximum power for the shortest working period. This optimum size locates between the ballistic heat transport region and the diffusive heat transport one. We also study the size dependence of the efficiency at the maximum power. Interestingly, we find that the efficiency at the maximum power around the optimum size attains a value that has been proposed as a universal upper bound, and it even begins to exceed the bound as the size further increases. We explain this behavior of the efficiency at maximum power by using a linear response theory for the heat engine operating under a finite working period, which naturally extends the low-dissipation Carnot cycle model [M. Esposito, R. Kawai, K. Lindenberg, C. Van den Broeck, Phys. Rev. Lett. 105, 150603 (2010)]. The theory also shows that the efficiency at the maximum power under an extreme condition may reach the Carnot efficiency in principle.© EDP Sciences Società Italiana di Fisica Springer-Verlag 2013.

  1. Influence of water activity and temperature on growth and mycotoxin production by Alternaria alternata on irradiated soya beans.

    Science.gov (United States)

    Oviedo, Maria Silvina; Ramirez, Maria Laura; Barros, Germán Gustavo; Chulze, Sofia Noemi

    2011-09-15

    The aim of this study was to determine the effects of water activity (a(w)) (0.99-0.90), temperature (15, 25 and 30°C) and their interactions on growth and alternariol (AOH) and alternariol monomethyl ether (AME) production by Alternaria alternata on irradiated soya beans. Maximum growth rates were obtained at 0.980 a(w) and 25°C. Minimum a(w) level for growth was dependent on temperature. Both strains were able to grow at the lowest a(w) assayed (0.90). Maximum amount of AOH was produced at 0.98 a(w) but at different temperatures, 15 and 25°C, for the strains RC 21 and RC 39 respectively. Maximum AME production was obtained at 0.98 a(w) and 30°C for both strains. The concentration range of both toxins varied considerably depending on a(w) and temperature interactions. The two metabolites were produced over the temperature range 15 to 30°C and a(w) range 0.99 to 0.96. The limiting a(w) for detectable mycotoxin production is slightly greater than that for growth. Two-dimensional profiles of a(w)× temperature were developed from these data to identify areas where conditions indicate a significant risk from AOH and AME accumulation on soya bean. Knowledge of AOH and AME production under marginal or sub-optimal temperature and a(w) conditions for growth can be important since improper storage conditions accompanied by elevated temperature and moisture content in the grain can favour further mycotoxin production and lead to reduction in grain quality. This could present a hazard if the grain is used for human consumption or animal feedstuff. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Maximum Principle for General Controlled Systems Driven by Fractional Brownian Motions

    International Nuclear Information System (INIS)

    Han Yuecai; Hu Yaozhong; Song Jian

    2013-01-01

    We obtain a maximum principle for stochastic control problem of general controlled stochastic differential systems driven by fractional Brownian motions (of Hurst parameter H>1/2). This maximum principle specifies a system of equations that the optimal control must satisfy (necessary condition for the optimal control). This system of equations consists of a backward stochastic differential equation driven by both fractional Brownian motions and the corresponding underlying standard Brownian motions. In addition to this backward equation, the maximum principle also involves the Malliavin derivatives. Our approach is to use conditioning and Malliavin calculus. To arrive at our maximum principle we need to develop some new results of stochastic analysis of the controlled systems driven by fractional Brownian motions via fractional calculus. Our approach of conditioning and Malliavin calculus is also applied to classical system driven by standard Brownian motions while the controller has only partial information. As a straightforward consequence, the classical maximum principle is also deduced in this more natural and simpler way.

  3. Water Deficit and Abscisic Acid Cause Differential Inhibition of Shoot versus Root Growth in Soybean Seedlings : Analysis of Growth, Sugar Accumulation, and Gene Expression.

    Science.gov (United States)

    Creelman, R A; Mason, H S; Bensen, R J; Boyer, J S; Mullet, J E

    1990-01-01

    Roots often continue to elongate while shoot growth is inhibited in plants subjected to low-water potentials. The cause of this differential response to water deficit was investigated. We examined hypocotyl and root growth, polysome status and mRNA populations, and abscisic acid (ABA) content in etiolated soybean (Glycine max [L.] Merr. cv Williams) seedlings whose growth was inhibited by transfer to low-water potential vermiculite or exogenous ABA. Both treatments affected growth and dry weight in a similar fashion. Maximum inhibition of hypocotyl growth occurred when internal ABA levels (modulated by ABA application) reached the endogenous level found in the elongating zone of seedlings grown in water-deficient vermiculite. Conversely, root growth was affected to only a slight extent in low-water potential seedlings and by most ABA treatments (in some, growth was promoted). In every seedling section examined, transfer of seedlings into low-water potential vermiculite caused ABA levels to increase approximately 5- to 10-fold over that found in well-watered seedlings. Changes in soluble sugar content, polysome status, and polysome mRNA translation products seen in low-water potential seedlings did not occur with ABA treatments sufficient to cause significant inhibition of hypocotyl elongation. These data suggest that both variation in endogenous ABA levels, and differing sensitivity to ABA in hypocotyls and roots can modulate root/shoot growth ratios. However, exogenous ABA did not induce changes in sugar accumulation, polysome status, and mRNA populations seen after transfer into low-water potential vermiculite.

  4. Direct maximum parsimony phylogeny reconstruction from genotype data.

    Science.gov (United States)

    Sridhar, Srinath; Lam, Fumei; Blelloch, Guy E; Ravi, R; Schwartz, Russell

    2007-12-05

    Maximum parsimony phylogenetic tree reconstruction from genetic variation data is a fundamental problem in computational genetics with many practical applications in population genetics, whole genome analysis, and the search for genetic predictors of disease. Efficient methods are available for reconstruction of maximum parsimony trees from haplotype data, but such data are difficult to determine directly for autosomal DNA. Data more commonly is available in the form of genotypes, which consist of conflated combinations of pairs of haplotypes from homologous chromosomes. Currently, there are no general algorithms for the direct reconstruction of maximum parsimony phylogenies from genotype data. Hence phylogenetic applications for autosomal data must therefore rely on other methods for first computationally inferring haplotypes from genotypes. In this work, we develop the first practical method for computing maximum parsimony phylogenies directly from genotype data. We show that the standard practice of first inferring haplotypes from genotypes and then reconstructing a phylogeny on the haplotypes often substantially overestimates phylogeny size. As an immediate application, our method can be used to determine the minimum number of mutations required to explain a given set of observed genotypes. Phylogeny reconstruction directly from unphased data is computationally feasible for moderate-sized problem instances and can lead to substantially more accurate tree size inferences than the standard practice of treating phasing and phylogeny construction as two separate analysis stages. The difference between the approaches is particularly important for downstream applications that require a lower-bound on the number of mutations that the genetic region has undergone.

  5. Direct maximum parsimony phylogeny reconstruction from genotype data

    Directory of Open Access Journals (Sweden)

    Ravi R

    2007-12-01

    Full Text Available Abstract Background Maximum parsimony phylogenetic tree reconstruction from genetic variation data is a fundamental problem in computational genetics with many practical applications in population genetics, whole genome analysis, and the search for genetic predictors of disease. Efficient methods are available for reconstruction of maximum parsimony trees from haplotype data, but such data are difficult to determine directly for autosomal DNA. Data more commonly is available in the form of genotypes, which consist of conflated combinations of pairs of haplotypes from homologous chromosomes. Currently, there are no general algorithms for the direct reconstruction of maximum parsimony phylogenies from genotype data. Hence phylogenetic applications for autosomal data must therefore rely on other methods for first computationally inferring haplotypes from genotypes. Results In this work, we develop the first practical method for computing maximum parsimony phylogenies directly from genotype data. We show that the standard practice of first inferring haplotypes from genotypes and then reconstructing a phylogeny on the haplotypes often substantially overestimates phylogeny size. As an immediate application, our method can be used to determine the minimum number of mutations required to explain a given set of observed genotypes. Conclusion Phylogeny reconstruction directly from unphased data is computationally feasible for moderate-sized problem instances and can lead to substantially more accurate tree size inferences than the standard practice of treating phasing and phylogeny construction as two separate analysis stages. The difference between the approaches is particularly important for downstream applications that require a lower-bound on the number of mutations that the genetic region has undergone.

  6. 20 CFR 10.806 - How are the maximum fees defined?

    Science.gov (United States)

    2010-04-01

    ... AMENDED Information for Medical Providers Medical Fee Schedule § 10.806 How are the maximum fees defined? For professional medical services, the Director shall maintain a schedule of maximum allowable fees.../Current Procedural Terminology (HCPCS/CPT) code which represents the relative skill, effort, risk and time...

  7. Maximum-likelihood estimation of the hyperbolic parameters from grouped observations

    DEFF Research Database (Denmark)

    Jensen, Jens Ledet

    1988-01-01

    a least-squares problem. The second procedure Hypesti first approaches the maximum-likelihood estimate by iterating in the profile-log likelihood function for the scale parameter. Close to the maximum of the likelihood function, the estimation is brought to an end by iteration, using all four parameters...

  8. Scientific substantination of maximum allowable concentration of fluopicolide in water

    Directory of Open Access Journals (Sweden)

    Pelo I.М.

    2014-03-01

    Full Text Available In order to substantiate fluopicolide maximum allowable concentration in the water of water reservoirs the research was carried out. Methods of study: laboratory hygienic experiment using organoleptic and sanitary-chemical, sanitary-toxicological, sanitary-microbiological and mathematical methods. The results of fluopicolide influence on organoleptic properties of water, sanitary regimen of reservoirs for household purposes were given and its subthreshold concentration in water by sanitary and toxicological hazard index was calculated. The threshold concentration of the substance by the main hazard criteria was established, the maximum allowable concentration in water was substantiated. The studies led to the following conclusions: fluopicolide threshold concentration in water by organoleptic hazard index (limiting criterion – the smell – 0.15 mg/dm3, general sanitary hazard index (limiting criteria – impact on the number of saprophytic microflora, biochemical oxygen demand and nitrification – 0.015 mg/dm3, the maximum noneffective concentration – 0.14 mg/dm3, the maximum allowable concentration - 0.015 mg/dm3.

  9. 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.

  10. Dispersion relation and growth rate in a Cherenkov free electron laser: Finite axial magnetic field

    International Nuclear Information System (INIS)

    Kheiri, Golshad; Esmaeilzadeh, Mahdi

    2013-01-01

    A theoretical analysis is presented for dispersion relation and growth rate in a Cherenkov free electron laser with finite axial magnetic field. It is shown that the growth rate and the resonance frequency of Cherenkov free electron laser increase with increasing axial magnetic field for low axial magnetic fields, while for high axial magnetic fields, they go to a saturation value. The growth rate and resonance frequency saturation values are exactly the same as those for infinite axial magnetic field approximation. The effects of electron beam self-fields on growth rate are investigated, and it is shown that the growth rate decreases in the presence of self-fields. It is found that there is an optimum value for electron beam density and Lorentz relativistic factor at which the maximum growth rate can take place. Also, the effects of velocity spread of electron beam are studied and it is found that the growth rate decreases due to the electron velocity spread

  11. Efficiency of autonomous soft nanomachines at maximum power.

    Science.gov (United States)

    Seifert, Udo

    2011-01-14

    We consider nanosized artificial or biological machines working in steady state enforced by imposing nonequilibrium concentrations of solutes or by applying external forces, torques, or electric fields. For unicyclic and strongly coupled multicyclic machines, efficiency at maximum power is not bounded by the linear response value 1/2. For strong driving, it can even approach the thermodynamic limit 1. Quite generally, such machines fall into three different classes characterized, respectively, as "strong and efficient," "strong and inefficient," and "balanced." For weakly coupled multicyclic machines, efficiency at maximum power has lost any universality even in the linear response regime.

  12. Zipf's law, power laws and maximum entropy

    International Nuclear Information System (INIS)

    Visser, Matt

    2013-01-01

    Zipf's law, and power laws in general, have attracted and continue to attract considerable attention in a wide variety of disciplines—from astronomy to demographics to software structure to economics to linguistics to zoology, and even warfare. A recent model of random group formation (RGF) attempts a general explanation of such phenomena based on Jaynes' notion of maximum entropy applied to a particular choice of cost function. In the present paper I argue that the specific cost function used in the RGF model is in fact unnecessarily complicated, and that power laws can be obtained in a much simpler way by applying maximum entropy ideas directly to the Shannon entropy subject only to a single constraint: that the average of the logarithm of the observable quantity is specified. (paper)

  13. Einstein-Dirac theory in spin maximum I

    International Nuclear Information System (INIS)

    Crumeyrolle, A.

    1975-01-01

    An unitary Einstein-Dirac theory, first in spin maximum 1, is constructed. An original feature of this article is that it is written without any tetrapod technics; basic notions and existence conditions for spinor structures on pseudo-Riemannian fibre bundles are only used. A coupling gravitation-electromagnetic field is pointed out, in the geometric setting of the tangent bundle over space-time. Generalized Maxwell equations for inductive media in presence of gravitational field are obtained. Enlarged Einstein-Schroedinger theory, gives a particular case of this E.D. theory. E. S. theory is a truncated E.D. theory in spin maximum 1. A close relation between torsion-vector and Schroedinger's potential exists and nullity of torsion-vector has a spinor meaning. Finally the Petiau-Duffin-Kemmer theory is incorporated in this geometric setting [fr

  14. Fuzzy Controller Design Using FPGA for Photovoltaic Maximum Power Point Tracking

    OpenAIRE

    Basil M Hamed; Mohammed S. El-Moghany

    2012-01-01

    The cell has optimum operating point to be able to get maximum power. To obtain Maximum Power from photovoltaic array, photovoltaic power system usually requires Maximum Power Point Tracking (MPPT) controller. This paper provides a small power photovoltaic control system based on fuzzy control with FPGA technology design and implementation for MPPT. The system composed of photovoltaic module, buck converter and the fuzzy logic controller implemented on FPGA for controlling on/off time of MOSF...

  15. Maximum penetration level of distributed generation without violating voltage limits

    NARCIS (Netherlands)

    Morren, J.; Haan, de S.W.H.

    2009-01-01

    Connection of Distributed Generation (DG) units to a distribution network will result in a local voltage increase. As there will be a maximum on the allowable voltage increase, this will limit the maximum allowable penetration level of DG. By reactive power compensation (by the DG unit itself) a

  16. A wavenumber-partitioning scheme for two-dimensional statistical closures

    International Nuclear Information System (INIS)

    Bowman, J.C.

    1994-11-01

    One of the principal advantages of statistical closure approximations for fluid turbulence is that they involve smoothly varying functions of wavenumber. This suggests the possibility of modeling a flow by following the evolution of only a few representative wavenumbers. This work presents two new techniques for the implementation of two-dimensional isotropic statistical closures that for the first time allows the inertial-range scalings of these approximation to be numerically demonstrated. A technique of wavenumber partitioning that conserves both energy and enstrophy is developed for two-dimensional statistical closures. Coupled with a new time-stepping scheme based on a variable integrating factor, this advance facilitates the computation of energy spectra over seven wavenumber decades, a task that will clearly remain outside the realm of conventional numerical simulations for the foreseeable future. Within the context of the test-field model, the method is used to demonstrate Kraichnan's logarithmically-corrected scaling for the enstrophy inertial range and to make a quantitative assessment of the effect of replacing the physical Laplacian viscosity with an enhanced hyperviscosity

  17. Thin-plate spline analysis of mandibular growth.

    Science.gov (United States)

    Franchi, L; Baccetti, T; McNamara, J A

    2001-04-01

    The analysis of mandibular growth changes around the pubertal spurt in humans has several important implications for the diagnosis and orthopedic correction of skeletal disharmonies. The purpose of this study was to evaluate mandibular shape and size growth changes around the pubertal spurt in a longitudinal sample of subjects with normal occlusion by means of an appropriate morphometric technique (thin-plate spline analysis). Ten mandibular landmarks were identified on lateral cephalograms of 29 subjects at 6 different developmental phases. The 6 phases corresponded to 6 different maturational stages in cervical vertebrae during accelerative and decelerative phases of the pubertal growth curve of the mandible. Differences in shape between average mandibular configurations at the 6 developmental stages were visualized by means of thin-plate spline analysis and subjected to permutation test. Centroid size was used as the measure of the geometric size of each mandibular specimen. Differences in size at the 6 developmental phases were tested statistically. The results of graphical analysis indicated a statistically significant change in mandibular shape only for the growth interval from stage 3 to stage 4 in cervical vertebral maturation. Significant increases in centroid size were found at all developmental phases, with evidence of a prepubertal minimum and of a pubertal maximum. The existence of a pubertal peak in human mandibular growth, therefore, is confirmed by thin-plate spline analysis. Significant morphological changes in the mandible during the growth interval from stage 3 to stage 4 in cervical vertebral maturation may be described as an upward-forward direction of condylar growth determining an overall "shrinkage" of the mandibular configuration along the measurement of total mandibular length. This biological mechanism is particularly efficient in compensating for major increments in mandibular size at the adolescent spurt.

  18. Logistic growth models of China pinks, cultivated on seven substrates, as a function of degree days

    Directory of Open Access Journals (Sweden)

    Marília Milani

    Full Text Available ABSTRACT: The objective of this study was to characterize the height (H and leaf number (LN of China pinks, grown in seven substrates, as a function of degree days, using the logistic growth model. H and LN were measured from 56 plants per substrate, for 392 plants in total. Plants that were grown on substrates formed of 50% soil with 50% rice husk ash (50% S + 50% RH and 80% rice husk ash with 20% worm castings (80% RH + 20% W had the longest vegetative growth period (74d, corresponding to 1317.9ºCd. The logistic growth model, adjusted for H, showed differences in the estimation of maximum expected height (α between the substrates, with values between 10.47cm for 50% S + 50% RH and 35.75cm for Mecplant(r. When α was estimated as LN, variation was also observed between the different substrates, from approximately 30 leaves on plants growing on 50% S + 50% RH to 34 leaves on the plants growing on the substrate formed of 80% RH + 20% W. Growth of China pinks can be characterized using H or LN in the logistic growth model as a function of degree days, being the provided plants adequately fertilized. The best substrates in terms of maximum height and leaf number were 80% soil + 20% worm castings and Mecplant(r. However, users must recalibrate the model with the estimated parameters before applying it to different growing conditions.

  19. 25 CFR 141.36 - Maximum finance charges on pawn transactions.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Maximum finance charges on pawn transactions. 141.36... PRACTICES ON THE NAVAJO, HOPI AND ZUNI RESERVATIONS Pawnbroker Practices § 141.36 Maximum finance charges on pawn transactions. No pawnbroker may impose an annual finance charge greater than twenty-four percent...

  20. Patient-specific Distraction Regimen to Avoid Growth-rod Failure.

    Science.gov (United States)

    Agarwal, Aakash; Jayaswal, Arvind; Goel, Vijay K; Agarwal, Anand K

    2018-02-15

    A finite element study to establish the relationship between patient's curve flexibility (determined using curve correction under gravity) in juvenile idiopathic scoliosis and the required distraction frequency to avoid growth rod fracture, as a function of time. To perform a parametric analysis using a juvenile scoliotic spine model (single mid-thoracic curve with the apex at the eighth thoracic vertebra) and establish the relationship between curve flexibility (determined using curve correction under gravity) and the distraction interval that allows a higher factor of safety for the growth rods. Previous studies have shown that frequent distraction with smaller magnitude of distractions are less likely to result in rod failure. However there has not been any methodology or a chart provided to apply this knowledge on to the individual patients that undergo the treatment. This study aims to fill in that gap. The parametric study was performed by varying the material properties of the disc, hence altering the axial stiffness of the scoliotic spine model. The stresses on the rod were found to increase with increased axial stiffness of the spine, and this resulted in the increase of required optimal frequency to achieve a factor of safety of two for growth rods. A relationship between the percentage correction in Cobb's angle due to gravity alone, and the required distraction interval for limiting the maximum von Mises stress to 255 MPa on the growth rods was established. The distraction interval required to limit the stresses to the selected nominal value reduces with increase in stiffness of the spine. Furthermore, the appropriate distraction interval reduces for each model as the spine becomes stiffer with time (autofusion). This points to the fact the optimal distraction frequency is a time-dependent variable that must be achieved to keep the maximum von Mises stress under the specified factor of safety. The current study demonstrates the possibility of

  1. Microprocessor-controlled step-down maximum-power-point tracker for photovoltaic systems

    Science.gov (United States)

    Mazmuder, R. K.; Haidar, S.

    1992-12-01

    An efficient maximum power point tracker (MPPT) has been developed and can be used with a photovoltaic (PV) array and a load which requires lower voltage than the PV array voltage to be operated. The MPPT makes the PV array to operate at maximum power point (MPP) under all insolation and temperature, which ensures the maximum amount of available PV power to be delivered to the load. The performance of the MPPT has been studied under different insolation levels.

  2. Intra-Annual Xylem Growth of Larix principis-rupprechtii at Its Upper and Lower Distribution Limits on the Luyashan Mountain in North-Central China

    Directory of Open Access Journals (Sweden)

    Yuan Jiang

    2015-10-01

    Full Text Available Altitude-related climatic factors, especially temperature, are important factors that affect tree growth in mountain forest ecosystems. The aims of this study were to estimate the intra-annual radial growth differences of Larix principis-rupprechtii (L. principis-rupprechtii between its upper and lower distribution limits, at 2740 and 2040 m a.s.l, respectively. Dynamics of xylem growth were observed by collecting microcore samples weekly during the 2011 growth season. The result indicated that different strategies were adopted at the two selected sites. Trees at the upper distribution limit adopted an “intensive strategy” with higher maximum growth rates (0.69 cell·day−1 within a shorter duration of 95 days, producing 21 new tracheids. By contrast, trees at the lower distribution limit exhibited an “extensive strategy” with lower maximum growth rates (0.53 cell·day−1 over a longer duration of 135 days, producing 50 tracheids. The soil temperature was probably the main factor limiting the onset of cambial activity for L. principis-rupprechtii, its daily mean thresholds for onset were 0 °C and 1.4 °C at the upper and lower distribution limits, respectively. These results indicate that L. principis-rupprechtii is able to adjust its xylem growth according to environmental conditions.

  3. Comparative effectiveness of different Rhizobium sp. for improving growth and yield of maize (Zea mays L.

    Directory of Open Access Journals (Sweden)

    Ijaz Mehboob, Zahir Ahmad Zahir, Muhammad Arshad, Muhammad Khalid

    2012-05-01

    Full Text Available During the last couple of decades, it has been demonstrated that rhizobia can associate with roots of non-legumes also without forming true nodules, and can promote their growth by using one or more of the direct or indirect mechanisms of actions. This work examines the growth and yield responses of maize to inoculation with different species of rhizobia, isolated from the root nodules of chickpea (Cicer arietinum L., lentil (Lens culinaris M. and mung bean (Vigna radiata L. in pots and fields. Twenty isolates of rhizobia were isolated from root nodules each of mung bean, lentil and chickpea and were screened under axenic conditions. On the basis of their promising performance under axenic conditions, nine most efficient isolates (three from each legume host were selected, characterized and further evaluated for their growth promoting activities by conducting pot and field experiments. Results of pot experiment revealed that maximum increase in grain yield, 1000 grain weight, N, P and K uptake (up to 47.89, 54.52, 73.46, 84.66 and 59.19% by CRI28, respectively, over un-inoculated control was produced by the isolate of Mesorhizobium ciceri. Whereas, maximum improvement in rest of the parameters was caused by the isolates of Rhizobium phaseoli (i.e. fresh biomass, straw yield and root length up to 36.30% by A18, 25.46% by S6 and 81.89% by A18, respectively over un-inoculated control. Rhizobium leguminosarum isolates came out to be the least effective among the species tested. Similarly, all the selected isolates improved the growth and yield attributing parameters in fields as well but with varying capacity compared with un-inoculated control. The selected isolates of Mesorhizobium ciceri and Rhizobium phaseoli again remained superior compared to the isolates of Rhizobium leguminosarum under field conditions. The results of this study imply that rhizobium species had potential to promote growth and yield of maize but this technology should be

  4. Introduction to maximum entropy

    International Nuclear Information System (INIS)

    Sivia, D.S.

    1989-01-01

    The maximum entropy (MaxEnt) principle has been successfully used in image reconstruction in a wide variety of fields. The author reviews the need for such methods in data analysis and shows, by use of a very simple example, why MaxEnt is to be preferred over other regularizing functions. This leads to a more general interpretation of the MaxEnt method, and its use is illustrated with several different examples. Practical difficulties with non-linear problems still remain, this being highlighted by the notorious phase problem in crystallography. He concludes with an example from neutron scattering, using data from a filter difference spectrometer to contrast MaxEnt with a conventional deconvolution. 12 refs., 8 figs., 1 tab

  5. Probable maximum flood control

    International Nuclear Information System (INIS)

    DeGabriele, C.E.; Wu, C.L.

    1991-11-01

    This study proposes preliminary design concepts to protect the waste-handling facilities and all shaft and ramp entries to the underground from the probable maximum flood (PMF) in the current design configuration for the proposed Nevada Nuclear Waste Storage Investigation (NNWSI) repository protection provisions were furnished by the United States Bureau of Reclamation (USSR) or developed from USSR data. Proposed flood protection provisions include site grading, drainage channels, and diversion dikes. Figures are provided to show these proposed flood protection provisions at each area investigated. These areas are the central surface facilities (including the waste-handling building and waste treatment building), tuff ramp portal, waste ramp portal, men-and-materials shaft, emplacement exhaust shaft, and exploratory shafts facility

  6. Introduction to maximum entropy

    International Nuclear Information System (INIS)

    Sivia, D.S.

    1988-01-01

    The maximum entropy (MaxEnt) principle has been successfully used in image reconstruction in a wide variety of fields. We review the need for such methods in data analysis and show, by use of a very simple example, why MaxEnt is to be preferred over other regularizing functions. This leads to a more general interpretation of the MaxEnt method, and its use is illustrated with several different examples. Practical difficulties with non-linear problems still remain, this being highlighted by the notorious phase problem in crystallography. We conclude with an example from neutron scattering, using data from a filter difference spectrometer to contrast MaxEnt with a conventional deconvolution. 12 refs., 8 figs., 1 tab

  7. Application of Maximum Entropy Distribution to the Statistical Properties of Wave Groups

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The new distributions of the statistics of wave groups based on the maximum entropy principle are presented. The maximum entropy distributions appear to be superior to conventional distributions when applied to a limited amount of information. Its applications to the wave group properties show the effectiveness of the maximum entropy distribution. FFT filtering method is employed to obtain the wave envelope fast and efficiently. Comparisons of both the maximum entropy distribution and the distribution of Longuet-Higgins (1984) with the laboratory wind-wave data show that the former gives a better fit.

  8. Growth dependence of conjugation explains limited plasmid invasion in biofilms: an individual‐based modelling study

    DEFF Research Database (Denmark)

    Merkey, Brian; Lardon, Laurent; Seoane, Jose Miguel

    2011-01-01

    Plasmid invasion in biofilms is often surprisingly limited in spite of the close contact of cells in a biofilm. We hypothesized that this poor plasmid spread into deeper biofilm layers is caused by a dependence of conjugation on the growth rate (relative to the maximum growth rate) of the donor......, we find that invasion of a resident biofilm is indeed limited when plasmid transfer depends on growth, but not so in the absence of growth dependence. Using sensitivity analysis we also find that parameters related to timing (i.e. a lag before the transconjugant can transfer, transfer proficiency...... and scan speed) and spatial reach (EPS yield, conjugal pilus length) are more important for successful plasmid invasion than the recipients' growth rate or the probability of segregational loss. While this study identifies one factor that can limit plasmid invasion in biofilms, the new individual...

  9. Maximum-confidence discrimination among symmetric qudit states

    International Nuclear Information System (INIS)

    Jimenez, O.; Solis-Prosser, M. A.; Delgado, A.; Neves, L.

    2011-01-01

    We study the maximum-confidence (MC) measurement strategy for discriminating among nonorthogonal symmetric qudit states. Restricting to linearly dependent and equally likely pure states, we find the optimal positive operator valued measure (POVM) that maximizes our confidence in identifying each state in the set and minimizes the probability of obtaining inconclusive results. The physical realization of this POVM is completely determined and it is shown that after an inconclusive outcome, the input states may be mapped into a new set of equiprobable symmetric states, restricted, however, to a subspace of the original qudit Hilbert space. By applying the MC measurement again onto this new set, we can still gain some information about the input states, although with less confidence than before. This leads us to introduce the concept of sequential maximum-confidence (SMC) measurements, where the optimized MC strategy is iterated in as many stages as allowed by the input set, until no further information can be extracted from an inconclusive result. Within each stage of this measurement our confidence in identifying the input states is the highest possible, although it decreases from one stage to the next. In addition, the more stages we accomplish within the maximum allowed, the higher will be the probability of correct identification. We will discuss an explicit example of the optimal SMC measurement applied in the discrimination among four symmetric qutrit states and propose an optical network to implement it.

  10. On the morphological instability of a bubble during inertia-controlled growth

    Science.gov (United States)

    Martyushev, L. M.; Birzina, A. I.; Soboleva, A. S.

    2018-06-01

    The morphological stability of a spherical bubble growing under inertia control is analyzed. Based on the comparison of entropy productions for a distorted and undistorted surface and using the maximum entropy production principle, the morphological instability of the bubble under arbitrary amplitude distortions is shown. This result allows explaining a number of experiments where the surface roughness of bubbles was observed during their explosive-type growth.

  11. Effect of antibiotics on growth and laccase production from Cyathus bulleri and Pycnoporus cinnabarinus.

    Science.gov (United States)

    Dhawan, Shikha; Lal, Rup; Hanspal, Manjit; Kuhad, Ramesh Chander

    2005-08-01

    The effect of nine different antibiotics (chloramphenicol, ampicillin trihydrate, kanamycin A monosulfate, neomycin sulfate, erythromycin, thiostrepton, tetracycline, apramycin sulfate and streptomycin sulfate) on growth and laccase production from Cyathus bulleri and Pycnoporus cinnabarinus has been investigated. All the antibiotics tested at a concentration of 200 mg/l affected the fungal growth, release of protein and laccase production to different extent. Inhibition in fungal growth was found to be positively correlated with increase in laccase production. Interestingly, apramycin sulfate inhibited biomass production (14.9-26.2%), nevertheless, it stimulated maximum laccase production (18.2 U/ml) in both the fungi. Increasing concentrations of apramycin sulfate enhanced laccase production from P. cinnabarinus but not from C. bulleri.

  12. The spectrum of R Cygni during its exceptionally low maximum of 1983

    International Nuclear Information System (INIS)

    Wallerstein, G.; Dominy, J.F.; Mattei, J.A.; Smith, V.V.

    1985-01-01

    In 1983 R Cygni experienced its faintest maximum ever recorded. A study of the light curve shows correlations between brightness at maximum and interval from the previous cycle, in the sense that fainter maxima occur later than normal and are followed by maxima that occur earlier than normal. Emission and absorption lines in the optical and near infrared (2.2 μm region) reveal two significant correlations. The amplitude of line doubling is independent of the magnitude at maximum for msub(v)(max)=7.1 to 9.8. The velocities of the emission lines, however, correlate with the magnitude at maximum, in that during bright maxima they are negatively displaced by 15 km s -1 with respect to the red component of absorption lines, while during the faintest maximum there is no displacement. (author)

  13. Maximum likelihood estimation for integrated diffusion processes

    DEFF Research Database (Denmark)

    Baltazar-Larios, Fernando; Sørensen, Michael

    We propose a method for obtaining maximum likelihood estimates of parameters in diffusion models when the data is a discrete time sample of the integral of the process, while no direct observations of the process itself are available. The data are, moreover, assumed to be contaminated...... EM-algorithm to obtain maximum likelihood estimates of the parameters in the diffusion model. As part of the algorithm, we use a recent simple method for approximate simulation of diffusion bridges. In simulation studies for the Ornstein-Uhlenbeck process and the CIR process the proposed method works...... by measurement errors. Integrated volatility is an example of this type of observations. Another example is ice-core data on oxygen isotopes used to investigate paleo-temperatures. The data can be viewed as incomplete observations of a model with a tractable likelihood function. Therefore we propose a simulated...

  14. Pareto versus lognormal: a maximum entropy test.

    Science.gov (United States)

    Bee, Marco; Riccaboni, Massimo; Schiavo, Stefano

    2011-08-01

    It is commonly found that distributions that seem to be lognormal over a broad range change to a power-law (Pareto) distribution for the last few percentiles. The distributions of many physical, natural, and social events (earthquake size, species abundance, income and wealth, as well as file, city, and firm sizes) display this structure. We present a test for the occurrence of power-law tails in statistical distributions based on maximum entropy. This methodology allows one to identify the true data-generating processes even in the case when it is neither lognormal nor Pareto. The maximum entropy approach is then compared with other widely used methods and applied to different levels of aggregation of complex systems. Our results provide support for the theory that distributions with lognormal body and Pareto tail can be generated as mixtures of lognormally distributed units.

  15. Diffusive intergranular cavity growth in creep in tension and torsion

    International Nuclear Information System (INIS)

    Stanzl, S.E.; Argon, A.S.; Tschegg, E.K.

    1983-01-01

    Creep experiments were performed at 500 C in tension and torsion on high conductivity copper tubes with a uniform initial coverage of implanted water vapor bubbles on all grain boundaries. No significant differences were found in the times to fracture over a wide stress range when the results were correlated according to the maximum principal tensile stress in the two fields. The results indicate that the cavities grow in a crack-like mode but at one tenth the rate predicted from the theoretical model of Pharr and Nix. This difference is attributed partly to load shedding from boundaries normal to the maximum principal tensile stress to slanted boundaries, and partly to a lack of knowledge about th surface diffusion constant. The results indicate further that the contribution to intergranular cavity growth by power-law creep in negligible in comparison to the contribution by diffusional flow. Complementary tension and torsion experiments performed in initially uncavitated samples results in shorter creep lives in torsion than in tension due to more effective cavity nucleation in the former. The times to fracture in both of these cases obey Monkman and Grant's law, indicating the presence of constraints on growth by the lagging deformations by power-law creep in the surroundings of the cavitating isolated grain facets

  16. Metallothionein induction, antioxidative responses, glycogen and growth changes in Tubifex tubifex (Oligochaete) exposed to the fungicide, fenhexamid

    International Nuclear Information System (INIS)

    Mosleh, Yahia Y.; Paris-Palacios, Severine; Couderchet, Michel; Biagianti-Risbourg, Sylvie; Vernet, Guy

    2005-01-01

    Laboratory studies were conducted to determine the effects of different concentrations of fenhexamid (0.1, 1, and 10 mg L -1 ) on growth, oxidative stress, protein, glycogen, and metallothionein (MT) contents in Tubifex tubifex after an exposure of 2, 4, and 7 days. In addition, residues of the fungicide were followed in water and in the worms. In water, fenhexamid concentration decreased slowly (maximum - 2±0.03% after 2 days for 1 mg L -1 ). In the worms, it increased after 4 days and decreased thereafter, confirming that the worms were exposed to the fungicide and not to a degradation product. LC 50 values were between 95.22±5.36 and 32.11±1.8 mg L -1 depending on exposure time. Exposure to fenhexamid had a negative effect on T. tubifex growth (maximum effect -12.2±0.8% after 7 days with 10 mg L -1 ) demonstrating the toxic effect of the pesticide. This growth rate decrease was accompanied by a reduction in protein and glycogen contents. The activity of catalase (CAT), and glutathione reductase (GR) increased in response to the fungicide demonstrating an oxidative stress in the worms. In contrast glutathion-S-transferase activity (GST) decreased. Exposure to fenhexamid also induced synthesis of MT (maximum +78±8% after 2 days for 10 mg L -1 ). The specificity of MT concentration increase in response to metals is discussed. - Exposure to the fungicide fenhexamid increased metallothionein levels in Tubifex tubifex

  17. Numerical solutions of the complete Navier-Strokes equations. no. 27

    Science.gov (United States)

    Hassan, H. A.

    1996-01-01

    This report describes the development of an enstrophy model capable of predicting turbulence separation and its application to two airfoils at various angles of attack and Mach numbers. In addition, a two equation kappa-xi model with a tensor eddy viscosity was developed. Plans call for this model to be used in calculating three dimensional turbulent flows.

  18. 7 CFR 762.129 - Percent of guarantee and maximum loss.

    Science.gov (United States)

    2010-01-01

    ... loss. (a) General. The percent of guarantee will not exceed 90 percent based on the credit risk to the lender and the Agency both before and after the transaction. The Agency will determine the percentage of... PLP lenders will not be less than 80 percent. (d) Maximum loss. The maximum amount the Agency will pay...

  19. On the maximum entropy distributions of inherently positive nuclear data

    Energy Technology Data Exchange (ETDEWEB)

    Taavitsainen, A., E-mail: aapo.taavitsainen@gmail.com; Vanhanen, R.

    2017-05-11

    The multivariate log-normal distribution is used by many authors and statistical uncertainty propagation programs for inherently positive quantities. Sometimes it is claimed that the log-normal distribution results from the maximum entropy principle, if only means, covariances and inherent positiveness of quantities are known or assumed to be known. In this article we show that this is not true. Assuming a constant prior distribution, the maximum entropy distribution is in fact a truncated multivariate normal distribution – whenever it exists. However, its practical application to multidimensional cases is hindered by lack of a method to compute its location and scale parameters from means and covariances. Therefore, regardless of its theoretical disadvantage, use of other distributions seems to be a practical necessity. - Highlights: • Statistical uncertainty propagation requires a sampling distribution. • The objective distribution of inherently positive quantities is determined. • The objectivity is based on the maximum entropy principle. • The maximum entropy distribution is the truncated normal distribution. • Applicability of log-normal or normal distribution approximation is limited.

  20. Effects of fasting on maximum thermogenesis in temperature-acclimated rats

    Science.gov (United States)

    Wang, L. C. H.

    1981-09-01

    To further investigate the limiting effect of substrates on maximum thermogenesis in acute cold exposure, the present study examined the prevalence of this effect at different thermogenic capabilities consequent to cold- or warm-acclimation. Male Sprague-Dawley rats (n=11) were acclimated to 6, 16 and 26‡C, in succession, their thermogenic capabilities after each acclimation temperature were measured under helium-oxygen (21% oxygen, balance helium) at -10‡C after overnight fasting or feeding. Regardless of feeding conditions, both maximum and total heat production were significantly greater in 6>16>26‡C-acclimated conditions. In the fed state, the total heat production was significantly greater than that in the fasted state at all acclimating temperatures but the maximum thermogenesis was significant greater only in the 6 and 16‡C-acclimated states. The results indicate that the limiting effect of substrates on maximum and total thermogenesis is independent of the magnitude of thermogenic capability, suggesting a substrate-dependent component in restricting the effective expression of existing aerobic metabolic capability even under severe stress.

  1. The effect of Nitrogen on Radiation Use Efficiency and Growth indices of Maize Hybrids (Zea mays L. under Kermanshah Condition

    Directory of Open Access Journals (Sweden)

    M Ahmadi

    2018-02-01

    daily solar radiation in percent of absorbed radiation. The amount of cumulative absorbed radiation calculated through the multiplication simulated daily radiation in integral of absorbed photosynthetically active radiation fraction. Finally, radiation use efficiency calculated through the slope of linear regression between dry matter accumulation and cumulative absorbed photosynthetically active radiation. Also, grain yield measured for each treatment separately in the physiological maturity time. Results and Discussion The results showed that maximum and minimum of leaf area index, leaf area duration, crop growth rate and total dry matter yield were observed in KSC-704 and BC-678 hybrids, respectively. Also in all 3 hybrids, maximum leaf area index, leaf area duration, radiation absorption, crop growth rate, relative growth ratio and total dry matter yield improved by increasing of nitrogen fertilizer application from 138 to 483 kg.ha-1 of urea. The highest total dry matter yield (20450 kg ha-1 was related to 704 hybrid and consumption of 483 kg ha-1 of urea. Simon hybrid had higher grain yield than other hybrids at 483 kgha-1 of urea condition (10467 kg ha-1. Radiation use efficiency was not significantly different among maize hybrids. Regardless maize hybrids, by increasing of nitrogen fertilizer application from 138 to 238, 350 and 483 kg ha-1 of urea, radiation use efficiency improved from 2.33 to 2.63, 2.81 and 2.84 g MJ-1 (about 13%, 21% and 22%, respectively. Our results also indicated that there was a positive and significant correlation between radiation use efficiency and maximum leaf area index, maximum radiation absorption, maximum crop growth rate, maximum relative growth ratio, and maximum total dry matter. The positive correlation between radiation absorption with crop growth rate (0.98 and total dry matter (0.97 demonstrated more radiation absorbed lead to more crop growth rate subsequently higher total dry matter production by maize hybrids. Nitrogen

  2. Prediction of pathogen growth on iceberg lettuce under real temperature history during distribution from farm to table.

    Science.gov (United States)

    Koseki, Shigenobu; Isobe, Seiichiro

    2005-10-25

    The growth of pathogenic bacteria Escherichia coli O157:H7, Salmonella spp., and Listeria monocytogenes on iceberg lettuce under constant and fluctuating temperatures was modelled in order to estimate the microbial safety of this vegetable during distribution from the farm to the table. Firstly, we examined pathogen growth on lettuce at constant temperatures, ranging from 5 to 25 degrees C, and then we obtained the growth kinetic parameters (lag time, maximum growth rate (micro(max)), and maximum population density (MPD)) using the Baranyi primary growth model. The parameters were similar to those predicted by the pathogen modelling program (PMP), with the exception of MPD. The MPD of each pathogen on lettuce was 2-4 log(10) CFU/g lower than that predicted by PMP. Furthermore, the MPD of pathogens decreased with decreasing temperature. The relationship between mu(max) and temperature was linear in accordance with Ratkowsky secondary model as was the relationship between the MPD and temperature. Predictions of pathogen growth under fluctuating temperature used the Baranyi primary microbial growth model along with the Ratkowsky secondary model and MPD equation. The fluctuating temperature profile used in this study was the real temperature history measured during distribution from the field at harvesting to the retail store. Overall predictions for each pathogen agreed well with observed viable counts in most cases. The bias and root mean square error (RMSE) of the prediction were small. The prediction in which mu(max) was based on PMP showed a trend of overestimation relative to prediction based on lettuce. However, the prediction concerning E. coli O157:H7 and Salmonella spp. on lettuce greatly overestimated growth in the case of a temperature history starting relatively high, such as 25 degrees C for 5 h. In contrast, the overall prediction of L. monocytogenes under the same circumstances agreed with the observed data.

  3. Efficacy of the Frame and Hu mathematical model for the quantitative analysis of agents influencing growth of chick embryo fibroblasts

    International Nuclear Information System (INIS)

    Korohoda, K.; Czyz, J.

    1994-01-01

    The experiments on the effect of various sera and substratum surface area upon growth of chick embryo fibroblasts-like in secondary cultures are described and discussed on the grounds of a mathematical model for growth of anchorage-dependent cells proposed by Frame and Hu. The model and presented results demonstrate the mutual independence of the effects of agent influencing of rate of cell proliferation (i.e. accelerating or retarding growth) and the agents that modify the limitation of cell proliferation (i.e. maximum cell density at confluence). The model proposed by Frame and Hu due to its relative simplicity offers and easy mode of description and quantitative evaluation of experiments concerning cell growth regulation. It is shown that various sera added at constant concentration significantly modify the rate of cell proliferation with little effect upon the maximum cell density attainable. The cells grew much more slowly in the presence of calf serum than in the presence of chick serum and the addition of iron and zinc complexes to calf serum significantly accelerated cell growth. An increase in the substratum surface area by the addition of glass wool to culture vessels significantly increased cell density per constant volume of medium even when retardation of growth was observed. The results presented point to the need of direct cell counting for estimation of cell growth curves and discussion of effects of agents influencing parameters characterizing cell proliferation. (author). 34 refs, 5 figs, 2 tabs

  4. Maximum gain of Yagi-Uda arrays

    DEFF Research Database (Denmark)

    Bojsen, J.H.; Schjær-Jacobsen, Hans; Nilsson, E.

    1971-01-01

    Numerical optimisation techniques have been used to find the maximum gain of some specific parasitic arrays. The gain of an array of infinitely thin, equispaced dipoles loaded with arbitrary reactances has been optimised. The results show that standard travelling-wave design methods are not optimum....... Yagi–Uda arrays with equal and unequal spacing have also been optimised with experimental verification....

  5. Solar Maximum Mission Experiment - Ultraviolet Spectroscopy and Polarimetry on the Solar Maximum Mission

    Science.gov (United States)

    Tandberg-Hanssen, E.; Cheng, C. C.; Woodgate, B. E.; Brandt, J. C.; Chapman, R. D.; Athay, R. G.; Beckers, J. M.; Bruner, E. C.; Gurman, J. B.; Hyder, C. L.

    1981-01-01

    The Ultraviolet Spectrometer and Polarimeter on the Solar Maximum Mission spacecraft is described. It is pointed out that the instrument, which operates in the wavelength range 1150-3600 A, has a spatial resolution of 2-3 arcsec and a spectral resolution of 0.02 A FWHM in second order. A Gregorian telescope, with a focal length of 1.8 m, feeds a 1 m Ebert-Fastie spectrometer. A polarimeter comprising rotating Mg F2 waveplates can be inserted behind the spectrometer entrance slit; it permits all four Stokes parameters to be determined. Among the observing modes are rasters, spectral scans, velocity measurements, and polarimetry. Examples of initial observations made since launch are presented.

  6. Mediterranean climate effects. II. Conifer growth phenology across a Sierra Nevada ecotone.

    Science.gov (United States)

    Royce, E B; Barbour, M G

    2001-05-01

    Growth and xylem water potential of the lower elevation conifers Pinus jeffreyi and Abies concolor and the higher elevation Pinus monticola and Abies magnifica were monitored in their montane Mediterranean habitat of the southernmost Sierra Nevada mountains of California. Measurements were made across the ecotone between the midmontane and upper montane forests and through light and heavy snowfall years.Radial stem growth, averaging ∼1.5 mm/yr, started 2 wk after snow melt, providing that maximum air temperatures had reached 21°C, and ended when predawn water potentials fell rapidly at the onset of the summer drought. Leader growth started on or after a fixed date, providing that minimum air temperatures were above -4°C for Pinus species or +2.5°C for Abies species. The cue for leader growth was inferred to be photoperiodic. Leader growth ended when either a determinate internode length of ∼1 mm was reached or predawn water potentials fell rapidly. Abies magnifica grew more rapidly than the low-elevation species, but had a shorter growth period; its annual leader growth, as a consequence, was only 35 mm/yr vs. 50 mm/yr for the low-elevation species. Needle growth was similarly determinate in the absence of early drought. This growth phenology contributes to determining species distribution across the ecotone.

  7. Examining carbon emissions economic growth nexus for India: A multivariate cointegration approach

    International Nuclear Information System (INIS)

    Ghosh, Sajal

    2010-01-01

    The study probes cointegration and causality between carbon emissions and economic growth for India using ARDL bounds testing approach complemented by Johansen-Juselius maximum likelihood procedure in a multivariate framework by incorporating energy supply, investment and employment for time span 1971-2006. The study fails to establish long-run equilibrium relationship and long term causality between carbon emissions and economic growth; however, there exists a bi-directional short-run causality between the two. Hence, in the short-run, any effort to reduce carbon emissions could lead to a fall in the national income. This study also establishes unidirectional short-run causality running from economic growth to energy supply and energy supply to carbon emissions. The absence of causality running from energy supply to economic growth implies that in India, energy conservation and energy efficiency measures can be implemented to minimize the wastage of energy across value chain. Such measures would narrow energy demand-supply gap. Absence of long-run causality between carbon emissions and economic growth implies that in the long-run, focus should be given on harnessing energy from clean sources to curb carbon emissions, which would not affect the country's economic growth.

  8. Maximum β limited by ideal MHD ballooning instabilites in JT-60

    International Nuclear Information System (INIS)

    Seki, Shogo; Azumi, Masashi

    1986-03-01

    Maximum β limited by ideal MHD ballooning instabilities is investigated on divertor configurations in JT-60. Maximum β against ballooning modes in JT-60 has strong dependecy on the distribution of the safety factor over the magnetic surfaces. Maximum β is ∼ 2 % for q 0 = 1.0, while more than 3 % for q 0 = 1.5. These results suggest that the profile control of the safety factor, especially on the magnetic axis, is attractive to the higher β operation in JT-60. (author)

  9. A maximum principle for time dependent transport in systems with voids

    International Nuclear Information System (INIS)

    Schofield, S.L.; Ackroyd, R.T.

    1996-01-01

    A maximum principle is developed for the first-order time dependent Boltzmann equation. The maximum principle is a generalization of Schofield's κ(θ) principle for the first-order steady state Boltzmann equation, and provides a treatment of time dependent transport in systems with void regions. The formulation comprises a direct least-squares minimization allied with a suitable choice of bilinear functional, and gives rise to a maximum principle whose functional is free of terms that have previously led to difficulties in treating void regions. (Author)

  10. The maximum sizes of large scale structures in alternative theories of gravity

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, Sourav [IUCAA, Pune University Campus, Post Bag 4, Ganeshkhind, Pune, 411 007 India (India); Dialektopoulos, Konstantinos F. [Dipartimento di Fisica, Università di Napoli ' Federico II' , Complesso Universitario di Monte S. Angelo, Edificio G, Via Cinthia, Napoli, I-80126 Italy (Italy); Romano, Antonio Enea [Instituto de Física, Universidad de Antioquia, Calle 70 No. 52–21, Medellín (Colombia); Skordis, Constantinos [Department of Physics, University of Cyprus, 1 Panepistimiou Street, Nicosia, 2109 Cyprus (Cyprus); Tomaras, Theodore N., E-mail: sbhatta@iitrpr.ac.in, E-mail: kdialekt@gmail.com, E-mail: aer@phys.ntu.edu.tw, E-mail: skordis@ucy.ac.cy, E-mail: tomaras@physics.uoc.gr [Institute of Theoretical and Computational Physics and Department of Physics, University of Crete, 70013 Heraklion (Greece)

    2017-07-01

    The maximum size of a cosmic structure is given by the maximum turnaround radius—the scale where the attraction due to its mass is balanced by the repulsion due to dark energy. We derive generic formulae for the estimation of the maximum turnaround radius in any theory of gravity obeying the Einstein equivalence principle, in two situations: on a spherically symmetric spacetime and on a perturbed Friedman-Robertson-Walker spacetime. We show that the two formulae agree. As an application of our formula, we calculate the maximum turnaround radius in the case of the Brans-Dicke theory of gravity. We find that for this theory, such maximum sizes always lie above the ΛCDM value, by a factor 1 + 1/3ω, where ω>> 1 is the Brans-Dicke parameter, implying consistency of the theory with current data.

  11. Short Communication: Effects of temperature on growth, pigment composition and protein content of an Antarctic Cyanobacterium Nostoc commune

    Directory of Open Access Journals (Sweden)

    RANJANA TRIPATHI

    2012-11-01

    Full Text Available Tripathi R, Dhuldhaj UP, Singh S. 2012. Short Communication: Effects of temperature on growth, pigment composition and protein content of an Antarctic Cyanobacterium Nostoc commune. Nusantara Bioscience 4: 134-137. Effect of temperature variation on biomass accumulation, pigment composition and protein content were studied for the cyanobacterium Nostoc commune, isolated from Antarctica. Results confirmed the psychrotrophic behavior (optimum growth temperature 25◦C of the cyanobacterium. Low temperature increased the duration of lag phase and exponential growth phase. Maximum increase in biomass was recorded on 24th day at 25◦C and on 12th day at 50C. The downshift from 25 to 5◦C had almost negligible effect on chl a content. Maximal protein content was recorded for cultures growing at 50C on 12th day. The carotenoids/chl a ratio was maximum (2.48 at 50C on 9th day. It remained almost constant for cultures growing at 5 and 350C. There was an induction in protein synthesis following downshift in temperature from 25 to 5◦C.

  12. Alternative fuel cycle options: performance characteristics and impact on nuclear power growth potential

    International Nuclear Information System (INIS)

    Chang, Y.I.; Till, C.E.; Rudolph, R.R.; Deen, J.R.; King, M.J.

    1977-09-01

    The fuel utilization characteristics for LWR, SSCR, CANDU and LMFBR reactor concepts are quantified for various fuel cycle options, including once-through cycles, thorium cycles, and denatured cycles. The implications of various alternative reactor deployment strategies on the long-term nuclear power growth potential are then quantified in terms of the maximum nuclear capacity that can be achieved and the growth pattern over time, subject to the constraint of a fixed uranium-resource base. The overall objective of this study is to shed light on any large differences in the long-term potential that exist between various alternative reactor/fuel cycle deployment strategies

  13. Engineering of the redox imbalance of Fusarium oxysporum enables anaerobic growth on xylose.

    Science.gov (United States)

    Panagiotou, Gianni; Christakopoulos, Paul; Grotkjaer, Thomas; Olsson, Lisbeth

    2006-09-01

    Dissimilatory nitrate reduction metabolism, of the natural xylose-fermenting fungus Fusarium oxysporum, was used as a strategy to achieve anaerobic growth and ethanol production from xylose. Beneficial alterations of the redox fluxes and thereby of the xylose metabolism were obtained by taking advantage of the regeneration of the cofactor NAD(+) during the denitrification process. In batch cultivations, nitrate sustained growth under anaerobic conditions (1.21 g L(-1) biomass) and simultaneously a maximum yield of 0.55 moles of ethanol per mole of xylose was achieved, whereas substitution of nitrate with ammonium limited the growth significantly (0.15 g L(-1) biomass). Using nitrate, the maximum acetate yield was 0.21 moles per mole of xylose and no xylitol excretion was observed. Furthermore, the network structure in the central carbon metabolism of F. oxysporum was characterized in steady state. F. oxysporum grew anaerobically on [1-(13)C] labelled glucose and unlabelled xylose in chemostat cultivation with nitrate as nitrogen source. The use of labelled substrate allowed the precise determination of the glucose and xylose contribution to the carbon fluxes in the central metabolism of this poorly described microorganism. It was demonstrated that dissimilatory nitrate reduction allows F. oxysporum to exhibit typical respiratory metabolic behaviour with a highly active TCA cycle and a large demand for NADPH.

  14. Maximum nondiffracting propagation distance of aperture-truncated Airy beams

    Science.gov (United States)

    Chu, Xingchun; Zhao, Shanghong; Fang, Yingwu

    2018-05-01

    Airy beams have called attention of many researchers due to their non-diffracting, self-healing and transverse accelerating properties. A key issue in research of Airy beams and its applications is how to evaluate their nondiffracting propagation distance. In this paper, the critical transverse extent of physically realizable Airy beams is analyzed under the local spatial frequency methodology. The maximum nondiffracting propagation distance of aperture-truncated Airy beams is formulated and analyzed based on their local spatial frequency. The validity of the formula is verified by comparing the maximum nondiffracting propagation distance of an aperture-truncated ideal Airy beam, aperture-truncated exponentially decaying Airy beam and exponentially decaying Airy beam. Results show that the formula can be used to evaluate accurately the maximum nondiffracting propagation distance of an aperture-truncated ideal Airy beam. Therefore, it can guide us to select appropriate parameters to generate Airy beams with long nondiffracting propagation distance that have potential application in the fields of laser weapons or optical communications.

  15. Maximum Entropy and Theory Construction: A Reply to Favretti

    Directory of Open Access Journals (Sweden)

    John Harte

    2018-04-01

    Full Text Available In the maximum entropy theory of ecology (METE, the form of a function describing the distribution of abundances over species and metabolic rates over individuals in an ecosystem is inferred using the maximum entropy inference procedure. Favretti shows that an alternative maximum entropy model exists that assumes the same prior knowledge and makes predictions that differ from METE’s. He shows that both cannot be correct and asserts that his is the correct one because it can be derived from a classic microstate-counting calculation. I clarify here exactly what the core entities and definitions are for METE, and discuss the relevance of two critical issues raised by Favretti: the existence of a counting procedure for microstates and the choices of definition of the core elements of a theory. I emphasize that a theorist controls how the core entities of his or her theory are defined, and that nature is the final arbiter of the validity of a theory.

  16. A novel algorithm for single-axis maximum power generation sun trackers

    International Nuclear Information System (INIS)

    Lee, Kung-Yen; Chung, Chi-Yao; Huang, Bin-Juine; Kuo, Ting-Jung; Yang, Huang-Wei; Cheng, Hung-Yen; Hsu, Po-Chien; Li, Kang

    2017-01-01

    Highlights: • A novel algorithm for a single-axis sun tracker is developed to increase the efficiency. • Photovoltaic module is rotated to find the optimal angle for generating the maximum power. • Electric energy increases up to 8.3%, compared with that of the tracker with three fixed angles. • The rotation range is optimized to reduce energy consumption from the rotation operations. - Abstract: The purpose of this study is to develop a novel algorithm for a single-axis maximum power generation sun tracker in order to identify the optimal stopping angle for generating the maximum amount of daily electric energy. First, the photovoltaic modules of the single-axis maximum power generation sun tracker are automatically rotated from 50° east to 50° west. During the rotation, the instantaneous power generated at different angles is recorded and compared, meaning that the optimal angle for generating the maximum power can be determined. Once the rotation (detection) is completed, the photovoltaic modules are then rotated to the resulting angle for generating the maximum power. The photovoltaic module is rotated once per hour in an attempt to detect the maximum irradiation and overcome the impact of environmental effects such as shading from cloud cover, other photovoltaic modules and surrounding buildings. Furthermore, the detection range is halved so as to reduce the energy consumption from the rotation operations and to improve the reliability of the sun tracker. The results indicate that electric energy production is increased by 3.4% in spring and autumn, 5.4% in summer, and 8.3% in winter, compared with that of the same sun tracker with three fixed angles of 50° east in the morning, 0° at noon and 50° west in the afternoon.

  17. Effects of variability in probable maximum precipitation patterns on flood losses

    Science.gov (United States)

    Zischg, Andreas Paul; Felder, Guido; Weingartner, Rolf; Quinn, Niall; Coxon, Gemma; Neal, Jeffrey; Freer, Jim; Bates, Paul

    2018-05-01

    The assessment of the impacts of extreme floods is important for dealing with residual risk, particularly for critical infrastructure management and for insurance purposes. Thus, modelling of the probable maximum flood (PMF) from probable maximum precipitation (PMP) by coupling hydrological and hydraulic models has gained interest in recent years. Herein, we examine whether variability in precipitation patterns exceeds or is below selected uncertainty factors in flood loss estimation and if the flood losses within a river basin are related to the probable maximum discharge at the basin outlet. We developed a model experiment with an ensemble of probable maximum precipitation scenarios created by Monte Carlo simulations. For each rainfall pattern, we computed the flood losses with a model chain and benchmarked the effects of variability in rainfall distribution with other model uncertainties. The results show that flood losses vary considerably within the river basin and depend on the timing and superimposition of the flood peaks from the basin's sub-catchments. In addition to the flood hazard component, the other components of flood risk, exposure, and vulnerability contribute remarkably to the overall variability. This leads to the conclusion that the estimation of the probable maximum expectable flood losses in a river basin should not be based exclusively on the PMF. Consequently, the basin-specific sensitivities to different precipitation patterns and the spatial organization of the settlements within the river basin need to be considered in the analyses of probable maximum flood losses.

  18. Maximum potential preventive effect of hip protectors

    NARCIS (Netherlands)

    van Schoor, N.M.; Smit, J.H.; Bouter, L.M.; Veenings, B.; Asma, G.B.; Lips, P.T.A.M.

    2007-01-01

    OBJECTIVES: To estimate the maximum potential preventive effect of hip protectors in older persons living in the community or homes for the elderly. DESIGN: Observational cohort study. SETTING: Emergency departments in the Netherlands. PARTICIPANTS: Hip fracture patients aged 70 and older who

  19. 24 CFR 232.565 - Maximum loan amount.

    Science.gov (United States)

    2010-04-01

    ... URBAN DEVELOPMENT MORTGAGE AND LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER AUTHORITIES MORTGAGE INSURANCE FOR NURSING HOMES, INTERMEDIATE CARE FACILITIES, BOARD AND CARE HOMES, AND ASSISTED... Fire Safety Equipment Eligible Security Instruments § 232.565 Maximum loan amount. The principal amount...

  20. Achieving maximum sustainable yield in mixed fisheries

    NARCIS (Netherlands)

    Ulrich, Clara; Vermard, Youen; Dolder, Paul J.; Brunel, Thomas; Jardim, Ernesto; Holmes, Steven J.; Kempf, Alexander; Mortensen, Lars O.; Poos, Jan Jaap; Rindorf, Anna

    2017-01-01

    Achieving single species maximum sustainable yield (MSY) in complex and dynamic fisheries targeting multiple species (mixed fisheries) is challenging because achieving the objective for one species may mean missing the objective for another. The North Sea mixed fisheries are a representative example

  1. Maximum Power Point Tracking of Photovoltaic System for Traffic Light Application

    Directory of Open Access Journals (Sweden)

    Riza Muhida

    2013-07-01

    Full Text Available Photovoltaic traffic light system is a significant application of renewable energy source. The development of the system is an alternative effort of local authority to reduce expenditure for paying fees to power supplier which the power comes from conventional energy source. Since photovoltaic (PV modules still have relatively low conversion efficiency, an alternative control of maximum power point tracking (MPPT method is applied to the traffic light system. MPPT is intended to catch up the maximum power at daytime in order to charge the battery at the maximum rate in which the power from the battery is intended to be used at night time or cloudy day. MPPT is actually a DC-DC converter that can step up or down voltage in order to achieve the maximum power using Pulse Width Modulation (PWM control. From experiment, we obtained the voltage of operation using MPPT is at 16.454 V, this value has error of 2.6%, if we compared with maximum power point voltage of PV module that is 16.9 V. Based on this result it can be said that this MPPT control works successfully to deliver the power from PV module to battery maximally.

  2. Stochastic behavior of a cold standby system with maximum repair time

    Directory of Open Access Journals (Sweden)

    Ashish Kumar

    2015-09-01

    Full Text Available The main aim of the present paper is to analyze the stochastic behavior of a cold standby system with concept of preventive maintenance, priority and maximum repair time. For this purpose, a stochastic model is developed in which initially one unit is operative and other is kept as cold standby. There is a single server who visits the system immediately as and when required. The server takes the unit under preventive maintenance after a maximum operation time at normal mode if one standby unit is available for operation. If the repair of the failed unit is not possible up to a maximum repair time, failed unit is replaced by new one. The failure time, maximum operation time and maximum repair time distributions of the unit are considered as exponentially distributed while repair and maintenance time distributions are considered as arbitrary. All random variables are statistically independent and repairs are perfect. Various measures of system effectiveness are obtained by using the technique of semi-Markov process and RPT. To highlight the importance of the study numerical results are also obtained for MTSF, availability and profit function.

  3. Batch growth kinetic studies of locally isolated cyanide-degrading Serratia marcescens strain AQ07.

    Science.gov (United States)

    Karamba, Kabiru Ibrahim; Ahmad, Siti Aqlima; Zulkharnain, Azham; Yasid, Nur Adeela; Ibrahim, Salihu; Shukor, Mohd Yunus

    2018-01-01

    The evaluation of degradation and growth kinetics of Serratia marcescens strain AQ07 was carried out using three half-order models at all the initial concentrations of cyanide with the values of regression exceeding 0.97. The presence of varying cyanide concentrations reveals that the growth and degradation of bacteria were affected by the increase in cyanide concentration with a total halt at 700 ppm KCN after 72 h incubation. In this study, specific growth and degradation rates were found to trail the substrate inhibition kinetics. These two rates fitted well to the kinetic models of Teissier, Luong, Aiba and Heldane, while the performance of Monod model was found to be unsatisfactory. These models were used to clarify the substrate inhibition on the bacteria growth. The analyses of these models have shown that Luong model has fitted the experimental data with the highest coefficient of determination ( R 2 ) value of 0.9794 and 0.9582 with the lowest root mean square error (RMSE) value of 0.000204 and 0.001, respectively, for the specific rate of degradation and growth. It is the only model that illustrates the maximum substrate concentration ( S m ) of 713.4 and empirical constant ( n ) of 1.516. Tessier and Aiba fitted the experimental data with a R 2 value of 0.8002 and 0.7661 with low RMSE of 0.0006, respectively, for specific biodegradation rate, while having a R 2 value of 0.9 and RMSE of 0.001, respectively, for specific growth rate. Haldane has the lowest R 2 value of 0.67 and 0.78 for specific biodegradation and growth rate with RMSE of 0.0006 and 0.002, respectively. This indicates the level of the bacteria stability in varying concentrations of cyanide and the maximum cyanide concentration it can tolerate within a specific time period. The biokinetic constant predicted from this model demonstrates a good ability of the locally isolated bacteria in cyanide remediation in industrial effluents.

  4. Overexpression of a novel endogenous NADH kinase in Aspergillus nidulans enhances growth

    DEFF Research Database (Denmark)

    Panagiotou, Gianni; Grotkjær, Thomas; Hofmann, Gerald

    2009-01-01

    .7.1.86) has been identified. The enzyme has a predicted molecular weight of 49 kDa. We characterised the role of this NADH kinase by genomic integration of the putative gene AN8837.2 under a strong constitutive promoter. The physiological effects of overexpressed NADH kinase in combination with different...... yield on glucose and the maximum specific growth rate increased from 0.47 g/g and 0.22 h(-1) (wild type) to 0.54 g/g and 0.26 h(-1) (NADH kinase overexpressed), respectively. The results suggest that overexpression of NADH kinase improves the growth efficiency of the cell by increasing the access...

  5. Generic maximum likely scale selection

    DEFF Research Database (Denmark)

    Pedersen, Kim Steenstrup; Loog, Marco; Markussen, Bo

    2007-01-01

    in this work is on applying this selection principle under a Brownian image model. This image model provides a simple scale invariant prior for natural images and we provide illustrative examples of the behavior of our scale estimation on such images. In these illustrative examples, estimation is based......The fundamental problem of local scale selection is addressed by means of a novel principle, which is based on maximum likelihood estimation. The principle is generally applicable to a broad variety of image models and descriptors, and provides a generic scale estimation methodology. The focus...

  6. Growth of polymer nanoparticles in microemulsion polymerization initiated with γ ray

    International Nuclear Information System (INIS)

    Xu Xiangling; Ge Xuewu; Ye Qiang; Zhang Zhicheng; Zuo Ju; Niu Aizhen; Zhang Manwei

    1999-01-01

    In microemulsion polymerization of styrene, butyl acrylate and methyl methacrylate initiated with gamma ray, growth of polymer nanoparticles was observed with photon correlation spectroscopy, and the conversion curve was recorded with a dilatometer. There is some similarity in the growth of polymer particles. The size of polymer particles rapidly increases up to their maximum at the early stage. With the increase of conversion, the large particles supply their monomer to newly formed particles and become smaller. In all these three microemulsion polymerizations, the evidence of continuous nucleation was observed. When monomer is styrene or butyl acrylate, a plateau of polymerization rate emerges. When monomer is methyl methacrylate, no plateau of polymerization is observed

  7. Maximum principle and convergence of central schemes based on slope limiters

    KAUST Repository

    Mehmetoglu, Orhan; Popov, Bojan

    2012-01-01

    A maximum principle and convergence of second order central schemes is proven for scalar conservation laws in dimension one. It is well known that to establish a maximum principle a nonlinear piecewise linear reconstruction is needed and a typical choice is the minmod limiter. Unfortunately, this implies that the scheme uses a first order reconstruction at local extrema. The novelty here is that we allow local nonlinear reconstructions which do not reduce to first order at local extrema and still prove maximum principle and convergence. © 2011 American Mathematical Society.

  8. Information Entropy Production of Maximum Entropy Markov Chains from Spike Trains

    Science.gov (United States)

    Cofré, Rodrigo; Maldonado, Cesar

    2018-01-01

    We consider the maximum entropy Markov chain inference approach to characterize the collective statistics of neuronal spike trains, focusing on the statistical properties of the inferred model. We review large deviations techniques useful in this context to describe properties of accuracy and convergence in terms of sampling size. We use these results to study the statistical fluctuation of correlations, distinguishability and irreversibility of maximum entropy Markov chains. We illustrate these applications using simple examples where the large deviation rate function is explicitly obtained for maximum entropy models of relevance in this field.

  9. Effet de Panicum maximum sur la productivité des femelles primipares durant le cycle de reproduction chez le cobaye (Cavia porcellus L.

    Directory of Open Access Journals (Sweden)

    Danho, M.

    2012-01-01

    Full Text Available Effect of Panicum maximum on Productivity of Primiparous Females during Reproduction Cycle in Guinea Pigs (Cavia porcellus L.. In Ivory Coast, Guinea pigs reared for meat (Cavia porcellus L. are mainly fed with Panicum maximum. To assess the effect of the latter during pregnancy and lactation (RC of these animals, primiparous dams were fed ad libitum, Panicum maximum alone during the RC (MOD1 or associated with pellets for rabbits during lactation (MOD2, or associated with pellets for rabbits during the last part of the pregnancy period and the lactation (MOD3, or associated with pellets for rabbits during the entire RC (MOD4. The number of corpora lutea per female was 1.3 ± 0.5 and 2.0 ± 0.0 respectively for MOD1 and MOD4. No pre-embryonic mortality was recorded. The mean weight of the young guinea pigs of MOD1 (54.7 ± 10. g was only 55% of that of MOD4 (98.6 ± 13.6 g. At weaning, the average weight gain of young guinea pigs of MOD1 (40.5 ± 22.2 g represented a third of those obtained with other diets that did not significantly differ. At the end of RC, the weight gain of dams was 17 ± 13.3% for MOD1 compared to 50% for MOD2, MOD3 and MOD4. Feeding Panicum maximum alone induces chronic malnutrition which in turn is responsible of the low ovulation rate and reduced growth in guinea pig breeding.

  10. Effect of gamma-radiation of pollen tube growth and seed set in barley-rye crosses

    International Nuclear Information System (INIS)

    Rohilla, J.S.; Khanna, V.K.

    1993-01-01

    One variety of barley and one variety of rye were taken to study the effect of gamma-radiation on pollen germination, pollen tube growth and seed set in barley-rye crosses. There was an increase in pollen germination and pollen tube growth over control at 1 kR dose but it was reduced at higher doses. Seed set was maximum at 1 kR and it was more than control from 1-5 kR. Only seeds of the cross Karan - 4 (1 kR)*MRSP-992 were able to germinate. In these germinated seeds the root growth was arrested after the fourth day of germination and they turned brown. The shoot growth was also very poor and it stopped after a week. (author) 11 refs.; 2 tabs

  11. Genotype-temperature interaction in the regulation of development, growth, and morphometrics in wild-type, and growth-hormone transgenic coho salmon.

    Directory of Open Access Journals (Sweden)

    Mare Lõhmus

    2010-04-01

    Full Text Available The neuroendocrine system is an important modulator of phenotype, directing cellular genetic responses to external cues such as temperature. Behavioural and physiological processes in poikilothermic organisms (e.g. most fishes, are particularly influenced by surrounding temperatures.By comparing the development and growth of two genotypes of coho salmon (wild-type and transgenic with greatly enhanced growth hormone production at six different temperatures, ranging between 8 degrees and 18 degrees C, we observed a genotype-temperature interaction and possible trend in directed neuroendocrine selection. Differences in growth patterns of the two genotypes were compared by using mathematical models, and morphometric analyses of juvenile salmon were performed to detect differences in body shape. The maximum hatching and alevin survival rates of both genotypes occurred at 12 degrees C. At lower temperatures, eggs containing embryos with enhanced GH production hatched after a shorter incubation period than wild-type eggs, but this difference was not apparent at and above 16 degrees C. GH transgenesis led to lower body weights at the time when the yolk sack was completely absorbed compared to the wild genotype. The growth of juvenile GH-enhanced salmon was to a greater extent stimulated by higher temperatures than the growth of the wild-type. Increased GH production significantly influenced the shape of the salmon growth curves.Growth hormone overexpression by transgenesis is able to stimulate the growth of coho salmon over a wide range of temperatures. Temperature was found to affect growth rate, survival, and body morphology between GH transgenic and wild genotype coho salmon, and differential responses to temperature observed between the genotypes suggests they would experience different selective forces should they ever enter natural ecosystems. Thus, GH transgenic fish would be expected to differentially respond and adapt to shifts in environmental

  12. Maximum power point tracker for photovoltaic power plants

    Science.gov (United States)

    Arcidiacono, V.; Corsi, S.; Lambri, L.

    The paper describes two different closed-loop control criteria for the maximum power point tracking of the voltage-current characteristic of a photovoltaic generator. The two criteria are discussed and compared, inter alia, with regard to the setting-up problems that they pose. Although a detailed analysis is not embarked upon, the paper also provides some quantitative information on the energy advantages obtained by using electronic maximum power point tracking systems, as compared with the situation in which the point of operation of the photovoltaic generator is not controlled at all. Lastly, the paper presents two high-efficiency MPPT converters for experimental photovoltaic plants of the stand-alone and the grid-interconnected type.

  13. Maximum mass-particle velocities in Kantor's information mechanics

    International Nuclear Information System (INIS)

    Sverdlik, D.I.

    1989-01-01

    Kantor's information mechanics links phenomena previously regarded as not treatable by a single theory. It is used here to calculate the maximum velocities υ m of single particles. For the electron, υ m /c ∼ 1 - 1.253814 x 10 -77 . The maximum υ m corresponds to υ m /c ∼ 1 -1.097864 x 10 -122 for a single mass particle with a rest mass of 3.078496 x 10 -5 g. This is the fastest that matter can move. Either information mechanics or classical mechanics can be used to show that υ m is less for heavier particles. That υ m is less for lighter particles can be deduced from an information mechanics argument alone

  14. A comparison of methods of predicting maximum oxygen uptake.

    OpenAIRE

    Grant, S; Corbett, K; Amjad, A M; Wilson, J; Aitchison, T

    1995-01-01

    The aim of this study was to compare the results from a Cooper walk run test, a multistage shuttle run test, and a submaximal cycle test with the direct measurement of maximum oxygen uptake on a treadmill. Three predictive tests of maximum oxygen uptake--linear extrapolation of heart rate of VO2 collected from a submaximal cycle ergometer test (predicted L/E), the Cooper 12 min walk, run test, and a multi-stage progressive shuttle run test (MST)--were performed by 22 young healthy males (mean...

  15. A Maximum Entropy Method for a Robust Portfolio Problem

    Directory of Open Access Journals (Sweden)

    Yingying Xu

    2014-06-01

    Full Text Available We propose a continuous maximum entropy method to investigate the robustoptimal portfolio selection problem for the market with transaction costs and dividends.This robust model aims to maximize the worst-case portfolio return in the case that allof asset returns lie within some prescribed intervals. A numerical optimal solution tothe problem is obtained by using a continuous maximum entropy method. Furthermore,some numerical experiments indicate that the robust model in this paper can result in betterportfolio performance than a classical mean-variance model.

  16. The kinetics of ice-lens growth in porous media

    KAUST Repository

    Style, Robert W.

    2012-01-09

    Abstract We analyse the growth rate of segregated ice (ice lenses) in freezing porous media. For typical colloidal materials such as soils we show that the commonly employed Clapeyron equation is not valid macroscopically at the interface between the ice lens and the surrounding porous medium owing to the viscous dynamics of flow in premelted films. The flow in these films gives rise to an \\'interfacial resistance\\' to flow towards the growing ice which causes a significant drop in predicted ice-growth (heave) rates. This explains why many previous models predict ice-growth rates that are much larger than those seen in experiments. We derive an explicit formula for the ice-growth rate in a given porous medium, and show that this only depends on temperature and on the external pressures imposed on the freezing system. This growth-rate formula contains a material-specific function which can be calculated (with knowledge of the geometry and material of the porous medium), but which is also readily experimentally measurable. We apply the formula to plate-like particles, and show that the results can be matched with previous experimental data. Finally we show how the interfacial resistance explains the observation that the maximum heave rate in soils occurs in medium-grained particles such as silts, while heave rates are smaller for fine-and coarse-grained particles. © 2012 Cambridge University Press.

  17. Entanglement Growth in Quench Dynamics with Variable Range Interactions

    Directory of Open Access Journals (Sweden)

    J. Schachenmayer

    2013-09-01

    Full Text Available Studying entanglement growth in quantum dynamics provides both insight into the underlying microscopic processes and information about the complexity of the quantum states, which is related to the efficiency of simulations on classical computers. Recently, experiments with trapped ions, polar molecules, and Rydberg excitations have provided new opportunities to observe dynamics with long-range interactions. We explore nonequilibrium coherent dynamics after a quantum quench in such systems, identifying qualitatively different behavior as the exponent of algebraically decaying spin-spin interactions in a transverse Ising chain is varied. Computing the buildup of bipartite entanglement as well as mutual information between distant spins, we identify linear growth of entanglement entropy corresponding to propagation of quasiparticles for shorter-range interactions, with the maximum rate of growth occurring when the Hamiltonian parameters match those for the quantum phase transition. Counterintuitively, the growth of bipartite entanglement for long-range interactions is only logarithmic for most regimes, i.e., substantially slower than for shorter-range interactions. Experiments with trapped ions allow for the realization of this system with a tunable interaction range, and we show that the different phenomena are robust for finite system sizes and in the presence of noise. These results can act as a direct guide for the generation of large-scale entanglement in such experiments, towards a regime where the entanglement growth can render existing classical simulations inefficient.

  18. Strategies for the coupling of global and local crystal growth models

    Science.gov (United States)

    Derby, Jeffrey J.; Lun, Lisa; Yeckel, Andrew

    2007-05-01

    The modular coupling of existing numerical codes to model crystal growth processes will provide for maximum effectiveness, capability, and flexibility. However, significant challenges are posed to make these coupled models mathematically self-consistent and algorithmically robust. This paper presents sample results from a coupling of the CrysVUn code, used here to compute furnace-scale heat transfer, and Cats2D, used to calculate melt fluid dynamics and phase-change phenomena, to form a global model for a Bridgman crystal growth system. However, the strategy used to implement the CrysVUn-Cats2D coupling is unreliable and inefficient. The implementation of under-relaxation within a block Gauss-Seidel iteration is shown to be ineffective for improving the coupling performance in a model one-dimensional problem representative of a melt crystal growth model. Ideas to overcome current convergence limitations using approximations to a full Newton iteration method are discussed.

  19. correlation between maximum dry density and cohesion

    African Journals Online (AJOL)

    HOD

    represents maximum dry density, signifies plastic limit and is liquid limit. Researchers [6, 7] estimate compaction parameters. Aside from the correlation existing between compaction parameters and other physical quantities there are some other correlations that have been investigated by other researchers. The well-known.

  20. Life-history and spatial determinants of somatic growth dynamics in Komodo dragon populations.

    Science.gov (United States)

    Laver, Rebecca J; Purwandana, Deni; Ariefiandy, Achmad; Imansyah, Jeri; Forsyth, David; Ciofi, Claudio; Jessop, Tim S

    2012-01-01

    Somatic growth patterns represent a major component of organismal fitness and may vary among sexes and populations due to genetic and environmental processes leading to profound differences in life-history and demography. This study considered the ontogenic, sex-specific and spatial dynamics of somatic growth patterns in ten populations of the world's largest lizard the Komodo dragon (Varanus komodoensis). The growth of 400 individual Komodo dragons was measured in a capture-mark-recapture study at ten sites on four islands in eastern Indonesia, from 2002 to 2010. Generalized Additive Mixed Models (GAMMs) and information-theoretic methods were used to examine how growth rates varied with size, age and sex, and across and within islands in relation to site-specific prey availability, lizard population density and inbreeding coefficients. Growth trajectories differed significantly with size and between sexes, indicating different energy allocation tactics and overall costs associated with reproduction. This leads to disparities in maximum body sizes and longevity. Spatial variation in growth was strongly supported by a curvilinear density-dependent growth model with highest growth rates occurring at intermediate population densities. Sex-specific trade-offs in growth underpin key differences in Komodo dragon life-history including evidence for high costs of reproduction in females. Further, inverse density-dependent growth may have profound effects on individual and population level processes that influence the demography of this species.

  1. Life-history and spatial determinants of somatic growth dynamics in Komodo dragon populations.

    Directory of Open Access Journals (Sweden)

    Rebecca J Laver

    Full Text Available Somatic growth patterns represent a major component of organismal fitness and may vary among sexes and populations due to genetic and environmental processes leading to profound differences in life-history and demography. This study considered the ontogenic, sex-specific and spatial dynamics of somatic growth patterns in ten populations of the world's largest lizard the Komodo dragon (Varanus komodoensis. The growth of 400 individual Komodo dragons was measured in a capture-mark-recapture study at ten sites on four islands in eastern Indonesia, from 2002 to 2010. Generalized Additive Mixed Models (GAMMs and information-theoretic methods were used to examine how growth rates varied with size, age and sex, and across and within islands in relation to site-specific prey availability, lizard population density and inbreeding coefficients. Growth trajectories differed significantly with size and between sexes, indicating different energy allocation tactics and overall costs associated with reproduction. This leads to disparities in maximum body sizes and longevity. Spatial variation in growth was strongly supported by a curvilinear density-dependent growth model with highest growth rates occurring at intermediate population densities. Sex-specific trade-offs in growth underpin key differences in Komodo dragon life-history including evidence for high costs of reproduction in females. Further, inverse density-dependent growth may have profound effects on individual and population level processes that influence the demography of this species.

  2. Life-History and Spatial Determinants of Somatic Growth Dynamics in Komodo Dragon Populations

    Science.gov (United States)

    Laver, Rebecca J.; Purwandana, Deni; Ariefiandy, Achmad; Imansyah, Jeri; Forsyth, David; Ciofi, Claudio; Jessop, Tim S.

    2012-01-01

    Somatic growth patterns represent a major component of organismal fitness and may vary among sexes and populations due to genetic and environmental processes leading to profound differences in life-history and demography. This study considered the ontogenic, sex-specific and spatial dynamics of somatic growth patterns in ten populations of the world’s largest lizard the Komodo dragon (Varanus komodoensis). The growth of 400 individual Komodo dragons was measured in a capture-mark-recapture study at ten sites on four islands in eastern Indonesia, from 2002 to 2010. Generalized Additive Mixed Models (GAMMs) and information-theoretic methods were used to examine how growth rates varied with size, age and sex, and across and within islands in relation to site-specific prey availability, lizard population density and inbreeding coefficients. Growth trajectories differed significantly with size and between sexes, indicating different energy allocation tactics and overall costs associated with reproduction. This leads to disparities in maximum body sizes and longevity. Spatial variation in growth was strongly supported by a curvilinear density-dependent growth model with highest growth rates occurring at intermediate population densities. Sex-specific trade-offs in growth underpin key differences in Komodo dragon life-history including evidence for high costs of reproduction in females. Further, inverse density-dependent growth may have profound effects on individual and population level processes that influence the demography of this species. PMID:23028983

  3. Maximum Work of Free-Piston Stirling Engine Generators

    Science.gov (United States)

    Kojima, Shinji

    2017-04-01

    Using the method of adjoint equations described in Ref. [1], we have calculated the maximum thermal efficiencies that are theoretically attainable by free-piston Stirling and Carnot engine generators by considering the work loss due to friction and Joule heat. The net work done by the Carnot cycle is negative even when the duration of heat addition is optimized to give the maximum amount of heat addition, which is the same situation for the Brayton cycle described in our previous paper. For the Stirling cycle, the net work done is positive, and the thermal efficiency is greater than that of the Otto cycle described in our previous paper by a factor of about 2.7-1.4 for compression ratios of 5-30. The Stirling cycle is much better than the Otto, Brayton, and Carnot cycles. We have found that the optimized piston trajectories of the isothermal, isobaric, and adiabatic processes are the same when the compression ratio and the maximum volume of the same working fluid of the three processes are the same, which has facilitated the present analysis because the optimized piston trajectories of the Carnot and Stirling cycles are the same as those of the Brayton and Otto cycles, respectively.

  4. Maximum growth rates and possible life strategies of different bacterioplankton groups in relation to phosphorus availability in a freshwater reservoir

    Czech Academy of Sciences Publication Activity Database

    Šimek, Karel; Horňák, Karel; Jezbera, Jan; Nedoma, Jiří; Vrba, Jaroslav; Straškrábová, Viera; Macek, Miroslav; Dolan, J. R.; Hahn, M.W.

    2006-01-01

    Roč. 8, č. 9 (2006), s. 1613-1624 ISSN 1462-2912 R&D Projects: GA ČR(CZ) GA206/05/0007; GA AV ČR(CZ) 1QS600170504 Grant - others:MŠM(CZ) 60076658/01 Institutional research plan: CEZ:AV0Z60170517 Keywords : bacterioplankton community composition * growth of bacteria and flagellates * phosphorus availability * reservoir * top-down and bottom-up control Subject RIV: EE - Microbiology, Virology Impact factor: 4.630, year: 2006

  5. 40 CFR 141.51 - Maximum contaminant level goals for inorganic contaminants.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant level goals for inorganic contaminants. 141.51 Section 141.51 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Level...

  6. 40 CFR 141.50 - Maximum contaminant level goals for organic contaminants.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant level goals for organic contaminants. 141.50 Section 141.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Level...

  7. 40 CFR 141.52 - Maximum contaminant level goals for microbiological contaminants.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant level goals for microbiological contaminants. 141.52 Section 141.52 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Level...

  8. Solar maximum mission

    International Nuclear Information System (INIS)

    Ryan, J.

    1981-01-01

    By understanding the sun, astrophysicists hope to expand this knowledge to understanding other stars. To study the sun, NASA launched a satellite on February 14, 1980. The project is named the Solar Maximum Mission (SMM). The satellite conducted detailed observations of the sun in collaboration with other satellites and ground-based optical and radio observations until its failure 10 months into the mission. The main objective of the SMM was to investigate one aspect of solar activity: solar flares. A brief description of the flare mechanism is given. The SMM satellite was valuable in providing information on where and how a solar flare occurs. A sequence of photographs of a solar flare taken from SMM satellite shows how a solar flare develops in a particular layer of the solar atmosphere. Two flares especially suitable for detailed observations by a joint effort occurred on April 30 and May 21 of 1980. These flares and observations of the flares are discussed. Also discussed are significant discoveries made by individual experiments

  9. Kinetics of phosphate uptake, growth, and accumulation of cyclic diphosphoglycerate in a phosphate-limited continuous culture of Methanobacterium thermoautotrophicum.

    OpenAIRE

    Krueger, R D; Harper, S H; Campbell, J W; Fahrney, D E

    1986-01-01

    The archaebacterium Methanobacterium thermoautotrophicum was grown in continuous culture at 65 degrees C in a phosphate-limited medium at specific growth rates from 0.06 to 0.28 h-1 (maximum growth rate [mu max] = 0.36 h-1). Cyclic-2,3-diphosphoglycerate (cyclic DPG) levels ranged from 2 to 20 mM in Pi-limited cells, compared with about 30 mM in batch-grown cells. The Monod constant for Pi-limited growth was 5 nM. Pi uptake rates were determined by following the disappearance of 32Pi from the...

  10. IMPACT OF TAX EVASION ON THE ECONOMIC GROWTH IN THE EUROPEAN UNION

    Directory of Open Access Journals (Sweden)

    FLORIN BOȘTINĂ

    2017-12-01

    Full Text Available The relevance of the research topic emerges from the fact that an important part of the fiscal revenues is lost annually through activities of fiscal planning, fiscal circumvention and tax evasion, undertaken by the private sector. In this respect, the aim of the paper is to estimate, by using the econometric analysis, the impact of tax evasion on the economic growth in the European Union for the period 1997-2010 for which the data was available. For the tax evasion it have been used index as a proxy that optimizes by maximum. Thus the main hypothesis (that the index tax evasion positively influences the economic growth was not rejected, even after including some specific control variables in the regressive models. In other words, as tax evasion is increased the economic growth is likely to decrease.

  11. Study of growth kinetics in melt-textured YBa2Cu3O7-x

    International Nuclear Information System (INIS)

    Athur, S.P.; Selvamanickam, V.; Balachandran, U.; Salama, K.

    1996-01-01

    Directional solidification has been shown to be a successful way of achieving high current densities in bulk YBCO. The lack of understanding of the growth kinetics, however, makes it difficult to fabricate longer samples and reduce the processing times. To study the growth kinetics, quenching experiments of undoped YBa 2 Cu 3 O 7-x (Y-123) and Y-123 doped with Pt and Nd from above the peritectic temperature with different holding times, t, were conducted. The results of these experiments indicate that the average 211 particle size varies as t 1/3 . Growth rate experiments were also conducted on these samples to determine the maximum growth rate for plane front solidification, R max . This quantity was measured for undoped and doped Y-123 and its was found that the addition of Pt did not increase R max while the addition of Nd doubled the growth rate. Using the coarsening results together with the growth rate experiments, the diffusivity of Y in liquid and the 211-liquid interfacial energy for undoped and doped Y-123 were calculated. copyright 1996 Materials Research Society

  12. How long do centenarians survive? Life expectancy and maximum lifespan.

    Science.gov (United States)

    Modig, K; Andersson, T; Vaupel, J; Rau, R; Ahlbom, A

    2017-08-01

    The purpose of this study was to explore the pattern of mortality above the age of 100 years. In particular, we aimed to examine whether Scandinavian data support the theory that mortality reaches a plateau at particularly old ages. Whether the maximum length of life increases with time was also investigated. The analyses were based on individual level data on all Swedish and Danish centenarians born from 1870 to 1901; in total 3006 men and 10 963 women were included. Birth cohort-specific probabilities of dying were calculated. Exact ages were used for calculations of maximum length of life. Whether maximum age changed over time was analysed taking into account increases in cohort size. The results confirm that there has not been any improvement in mortality amongst centenarians in the past 30 years and that the current rise in life expectancy is driven by reductions in mortality below the age of 100 years. The death risks seem to reach a plateau of around 50% at the age 103 years for men and 107 years for women. Despite the rising life expectancy, the maximum age does not appear to increase, in particular after accounting for the increasing number of individuals of advanced age. Mortality amongst centenarians is not changing despite improvements at younger ages. An extension of the maximum lifespan and a sizeable extension of life expectancy both require reductions in mortality above the age of 100 years. © 2017 The Association for the Publication of the Journal of Internal Medicine.

  13. Modelling information flow along the human connectome using maximum flow.

    Science.gov (United States)

    Lyoo, Youngwook; Kim, Jieun E; Yoon, Sujung

    2018-01-01

    The human connectome is a complex network that transmits information between interlinked brain regions. Using graph theory, previously well-known network measures of integration between brain regions have been constructed under the key assumption that information flows strictly along the shortest paths possible between two nodes. However, it is now apparent that information does flow through non-shortest paths in many real-world networks such as cellular networks, social networks, and the internet. In the current hypothesis, we present a novel framework using the maximum flow to quantify information flow along all possible paths within the brain, so as to implement an analogy to network traffic. We hypothesize that the connection strengths of brain networks represent a limit on the amount of information that can flow through the connections per unit of time. This allows us to compute the maximum amount of information flow between two brain regions along all possible paths. Using this novel framework of maximum flow, previous network topological measures are expanded to account for information flow through non-shortest paths. The most important advantage of the current approach using maximum flow is that it can integrate the weighted connectivity data in a way that better reflects the real information flow of the brain network. The current framework and its concept regarding maximum flow provides insight on how network structure shapes information flow in contrast to graph theory, and suggests future applications such as investigating structural and functional connectomes at a neuronal level. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Exploring high-density baryonic matter: Maximum freeze-out density

    Energy Technology Data Exchange (ETDEWEB)

    Randrup, Joergen [Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Cleymans, Jean [University of Cape Town, UCT-CERN Research Centre and Department of Physics, Rondebosch (South Africa)

    2016-08-15

    The hadronic freeze-out line is calculated in terms of the net baryon density and the energy density instead of the usual T and μ{sub B}. This analysis makes it apparent that the freeze-out density exhibits a maximum as the collision energy is varied. This maximum freeze-out density has μ{sub B} = 400 - 500 MeV, which is above the critical value, and it is reached for a fixed-target bombarding energy of 20-30 GeV/N well within the parameters of the proposed NICA collider facility. (orig.)

  15. Growth of cadmium oxide whiskers on cadmium sulphide single crystals with copper as growth activator

    Energy Technology Data Exchange (ETDEWEB)

    Koparanova, N.; Simov, S. (Bylgarska Akademiya na Naukite, Sofia. Inst. po Fizika na Tvyrdoto Tyalo); Genchev, D. (Bylgarska Akademiya na Naukite, Sofia. Inst. za Yadrena Izsledvaniya i Yadrena Energetika); Metchenov, G. (Research Inst. of Criminalistics and Criminology, Sofia (Bulgaria))

    1985-02-01

    Some results on the growth and morphology of cadmium oxide whiskers, obtained on cadmium sulphide single crystals with copper as a growth activator, are presented in this work. Cadmium oxide whiskers have been obtained on brace 112-bar0 brace faces of cadmium sulphide plates with a copper layer deposited in advance. The whiskers grew during the annealing of the plates in a weak stream of technically pure argon at temperatures 670 to 730 deg C for 15 min to 3.5 h. Details about the procedure have been given elsewhere. The composition and morphology of the whiskers have been studied by an X-ray microanalyser JEOL 35 DDS and a scanning electron microscope JEOL, JSM 35. The optical microscopic observations have shown that after annealing, a gray-black granular layer is formed on the cadmium sulphide single crystals and this layer can easily be separated from the crystal substrate. Under the granular layer the crystal is heavily damaged. The whiskers grow on the granular layer and they are coloured yellow-brown or red-brown. The maximum whisker length attains several hundreds of micrometres and in some cases up to 1 mm or more.

  16. Growth of cadmium oxide whiskers on cadmium sulphide single crystals with copper as growth activator

    International Nuclear Information System (INIS)

    Koparanova, N.; Simov, S.

    1985-01-01

    Some results on the growth and morphology of cadmium oxide whiskers, obtained on cadmium sulphide single crystals with copper as a growth activator, are presented in this work. Cadmium oxide whiskers have been obtained on brace 112-bar0 brace faces of cadmium sulphide plates with a copper layer deposited in advance. The whiskers grew during the annealing of the plates in a weak stream of technically pure argon at temperatures 670 to 730 deg C for 15 min to 3.5 h. Details about the procedure have been given elsewhere. The composition and morphology of the whiskers have been studied by an X-ray microanalyser JEOL 35 DDS and a scanning electron microscope JEOL, JSM 35. The optical microscopic observations have shown that after annealing, a gray-black granular layer is formed on the cadmium sulphide single crystals and this layer can easily be separated from the crystal substrate. Under the granular layer the crystal is heavily damaged. The whiskers grow on the granular layer and they are coloured yellow-brown or red-brown. The maximum whisker length attains several hundreds of micrometres and in some cases up to 1 mm or more. (author)

  17. Maximum organic carbon limits at different melter feed rates (U)

    International Nuclear Information System (INIS)

    Choi, A.S.

    1995-01-01

    This report documents the results of a study to assess the impact of varying melter feed rates on the maximum total organic carbon (TOC) limits allowable in the DWPF melter feed. Topics discussed include: carbon content; feed rate; feed composition; melter vapor space temperature; combustion and dilution air; off-gas surges; earlier work on maximum TOC; overview of models; and the results of the work completed

  18. Maximum speed of dewetting on a fiber

    NARCIS (Netherlands)

    Chan, Tak Shing; Gueudre, Thomas; Snoeijer, Jacobus Hendrikus

    2011-01-01

    A solid object can be coated by a nonwetting liquid since a receding contact line cannot exceed a critical speed. We theoretically investigate this forced wetting transition for axisymmetric menisci on fibers of varying radii. First, we use a matched asymptotic expansion and derive the maximum speed

  19. Maximum entropy estimation via Gauss-LP quadratures

    NARCIS (Netherlands)

    Thély, Maxime; Sutter, Tobias; Mohajerin Esfahani, P.; Lygeros, John; Dochain, Denis; Henrion, Didier; Peaucelle, Dimitri

    2017-01-01

    We present an approximation method to a class of parametric integration problems that naturally appear when solving the dual of the maximum entropy estimation problem. Our method builds up on a recent generalization of Gauss quadratures via an infinite-dimensional linear program, and utilizes a

  20. Maximum Power Tracking by VSAS approach for Wind Turbine, Renewable Energy Sources

    Directory of Open Access Journals (Sweden)

    Nacer Kouider Msirdi

    2015-08-01

    Full Text Available This paper gives a review of the most efficient algorithms designed to track the maximum power point (MPP for catching the maximum wind power by a variable speed wind turbine (VSWT. We then design a new maximum power point tracking (MPPT algorithm using the Variable Structure Automatic Systems approach (VSAS. The proposed approachleads efficient algorithms as shown in this paper by the analysis and simulations.

  1. Growth Indicators of a 48-Clone Sugar Cane Population (Saccharum spp. with Forage Potential

    Directory of Open Access Journals (Sweden)

    Yoslen Fernández Gálvez

    2016-09-01

    Full Text Available The aim of this paper was to determine growth indicators in a 48-clone sugar cane population, with promising phenotypical features for forage production. The following indicators were assessed: leaf area (A, leaf area index (LA1; leaf area ratio (LAR; specific leaf area (SLA; leaf weight ratio (LWR; crop growth rate (CGR; net assimilation rate (NAR; relative growth rate in weight (RGR; biomass production speed (G; leaf area duration (LAD; and biomass duration (Z, monthly (187 - 370 days. The minimum, the mean, the maximum values, and the population variance were determined for all cutting ages and the variables assessed. The results achieved have provided quantitative values that can be used as reference for selection and assessment of forage genotypes for ruminant nutrition.

  2. Estimating the maximum potential revenue for grid connected electricity storage :

    Energy Technology Data Exchange (ETDEWEB)

    Byrne, Raymond Harry; Silva Monroy, Cesar Augusto.

    2012-12-01

    The valuation of an electricity storage device is based on the expected future cash flow generated by the device. Two potential sources of income for an electricity storage system are energy arbitrage and participation in the frequency regulation market. Energy arbitrage refers to purchasing (stor- ing) energy when electricity prices are low, and selling (discharging) energy when electricity prices are high. Frequency regulation is an ancillary service geared towards maintaining system frequency, and is typically procured by the independent system operator in some type of market. This paper outlines the calculations required to estimate the maximum potential revenue from participating in these two activities. First, a mathematical model is presented for the state of charge as a function of the storage device parameters and the quantities of electricity purchased/sold as well as the quantities o ered into the regulation market. Using this mathematical model, we present a linear programming optimization approach to calculating the maximum potential revenue from an elec- tricity storage device. The calculation of the maximum potential revenue is critical in developing an upper bound on the value of storage, as a benchmark for evaluating potential trading strate- gies, and a tool for capital nance risk assessment. Then, we use historical California Independent System Operator (CAISO) data from 2010-2011 to evaluate the maximum potential revenue from the Tehachapi wind energy storage project, an American Recovery and Reinvestment Act of 2009 (ARRA) energy storage demonstration project. We investigate the maximum potential revenue from two di erent scenarios: arbitrage only and arbitrage combined with the regulation market. Our analysis shows that participation in the regulation market produces four times the revenue compared to arbitrage in the CAISO market using 2010 and 2011 data. Then we evaluate several trading strategies to illustrate how they compare to the

  3. A Key Marine Diazotroph in a Changing Ocean: The Interacting Effects of Temperature, CO2 and Light on the Growth of Trichodesmium erythraeum IMS101.

    Directory of Open Access Journals (Sweden)

    Tobias G Boatman

    Full Text Available Trichodesmium is a globally important marine diazotroph that accounts for approximately 60 - 80% of marine biological N2 fixation and as such plays a key role in marine N and C cycles. We undertook a comprehensive assessment of how the growth rate of Trichodesmium erythraeum IMS101 was directly affected by the combined interactions of temperature, pCO2 and light intensity. Our key findings were: low pCO2 affected the lower temperature tolerance limit (Tmin but had no effect on the optimum temperature (Topt at which growth was maximal or the maximum temperature tolerance limit (Tmax; low pCO2 had a greater effect on the thermal niche width than low-light; the effect of pCO2 on growth rate was more pronounced at suboptimal temperatures than at supraoptimal temperatures; temperature and light had a stronger effect on the photosynthetic efficiency (Fv/Fm than did CO2; and at Topt, the maximum growth rate increased with increasing CO2, but the initial slope of the growth-irradiance curve was not affected by CO2. In the context of environmental change, our results suggest that the (i nutrient replete growth rate of Trichodesmium IMS101 would have been severely limited by low pCO2 at the last glacial maximum (LGM, (ii future increases in pCO2 will increase growth rates in areas where temperature ranges between Tmin to Topt, but will have negligible effect at temperatures between Topt and Tmax, (iii areal increase of warm surface waters (> 18°C has allowed the geographic range to increase significantly from the LGM to present and that the range will continue to expand to higher latitudes with continued warming, but (iv continued global warming may exclude Trichodesmium spp. from some tropical regions by 2100 where temperature exceeds Topt.

  4. 12 CFR 221.7 - Supplement: Maximum loan value of margin stock and other collateral.

    Science.gov (United States)

    2010-01-01

    ... value of margin stock and other collateral. (a) Maximum loan value of margin stock. The maximum loan... nonmargin stock and all other collateral. The maximum loan value of nonmargin stock and all other collateral... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Supplement: Maximum loan value of margin stock...

  5. MODEL PREDICTIVE CONTROL FOR PHOTOVOLTAIC STATION MAXIMUM POWER POINT TRACKING SYSTEM

    Directory of Open Access Journals (Sweden)

    I. Elzein

    2015-01-01

    Full Text Available The purpose of this paper is to present an alternative maximum power point tracking, MPPT, algorithm for a photovoltaic module, PVM, to produce the maximum power, Pmax, using the optimal duty ratio, D, for different types of converters and load matching.We present a state-based approach to the design of the maximum power point tracker for a stand-alone photovoltaic power generation system. The system under consideration consists of a solar array with nonlinear time-varying characteristics, a step-up converter with appropriate filter.The proposed algorithm has the advantages of maximizing the efficiency of the power utilization, can be integrated to other MPPT algorithms without affecting the PVM performance, is excellent for Real-Time applications and is a robust analytical method, different from the traditional MPPT algorithms which are more based on trial and error, or comparisons between present and past states. The procedure to calculate the optimal duty ratio for a buck, boost and buck-boost converters, to transfer the maximum power from a PVM to a load, is presented in the paper. Additionally, the existence and uniqueness of optimal internal impedance, to transfer the maximum power from a photovoltaic module using load matching, is proved.

  6. On the quirks of maximum parsimony and likelihood on phylogenetic networks.

    Science.gov (United States)

    Bryant, Christopher; Fischer, Mareike; Linz, Simone; Semple, Charles

    2017-03-21

    Maximum parsimony is one of the most frequently-discussed tree reconstruction methods in phylogenetic estimation. However, in recent years it has become more and more apparent that phylogenetic trees are often not sufficient to describe evolution accurately. For instance, processes like hybridization or lateral gene transfer that are commonplace in many groups of organisms and result in mosaic patterns of relationships cannot be represented by a single phylogenetic tree. This is why phylogenetic networks, which can display such events, are becoming of more and more interest in phylogenetic research. It is therefore necessary to extend concepts like maximum parsimony from phylogenetic trees to networks. Several suggestions for possible extensions can be found in recent literature, for instance the softwired and the hardwired parsimony concepts. In this paper, we analyze the so-called big parsimony problem under these two concepts, i.e. we investigate maximum parsimonious networks and analyze their properties. In particular, we show that finding a softwired maximum parsimony network is possible in polynomial time. We also show that the set of maximum parsimony networks for the hardwired definition always contains at least one phylogenetic tree. Lastly, we investigate some parallels of parsimony to different likelihood concepts on phylogenetic networks. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. GROWTH AND DEVELOPMENT OF Fimbrist ylis miliacea (L.V AHL

    Directory of Open Access Journals (Sweden)

    SYED OMAR BIN SYED RASTAN

    2008-01-01

    Full Text Available This experiment was conducted in the glasshouse of Universiti Putra Malaysia, to deter-mine the growth and development of Fimbristylis miliacea (L. Vahl. Twenty F. miliacea seeds were surface sown in ten plastic buckets of 18 cm diameter filled with 3 kg soil. After germina-tion only one plant/bucket was retained. Time of first seedling emergence, time and number of leaves appearing until first tiller formation, time of tiller formation, first inflorescence, the first 10 inflorescences appearance and their maturity were recorded for each plant. Plant height and the number of inflorescence per plant was recorded weekly for up to 4 months after sowing. The first ten inflorescences for each plant were tagged after emergence, subsequently mature inflo-rescences were collected and the numbers of spikelets/inflorescence, seeds/inflorescence, seeds/ plant and 1000 seed weight were determined. Statistical analysis was performed as complete randomized design on weekly observed plant height and inflorescence number using the SAS statistical software and means were tested using Tukey’s studentized range test at the 5% level of probability. Fimbristylis miliacea seedlings emerged at 3 days after planting of seeds. Approximate times required for the sequential production of 10 leaves, tillers, first 10 inflorescence and their maturity were 28 days after emergence (DAE, 35 DAE, 49 DAE, 63 DAE, respectively. Plant height increased rapidly from 3-8 WAE and maximum plant height (64.05 cm was attained at 10 WAE. This species had three important growth stages: a slow growth stage during the first 4 weeks after emergence (WAE; a rapid growth stage from 4-9 WAE; and finally, a maximum growth stage from 9-17 WAE. Within this first 4 weeks after emergence would be the most appropriate time for controlling this species with early post-emergence herbicides. Each F . miliacea plant produced on average of 2.3 tillers/plant and a total of 134 inflorescences, with 84

  8. Stimulation of chondrocytes in vitro by gene transfer with plasmids coding for epidermal growth factor (hEGF) and basic fibroblast growth factor (bFGF)

    DEFF Research Database (Denmark)

    Schmal, H; Mehlhorn, A T; Zwingmann, J

    2005-01-01

    Human epidermal growth factor (hEGF) and basic fibroblast growth factor (bFGF) influence critical characteristics of chondrocytes. The effects on metabolism and differentiation were evaluated following transfection using specific plasmids coding for both cytokines. Chondrocytes were isolated from...... of recombinant hEGF and bFGF resulted in a significant increase in cell proliferation and glucosaminoglycan production. Chondrocytes were transfected with vectors coding for either hEGF or bFGF and the production of these proteins was measured in supernatants by ELISA. Expression kinetics showed different...... patterns: hEGF was detectable 2.5 days following transfection and peaked at day 5.5, whereas bFGF-production reached its maximum 1.5 days after transfection, declining thereafter. Chondrocytes endogenously produced significant amounts of bFGF within 5 days following isolation. Proliferation of h...

  9. In-field High Throughput Phenotyping and Cotton Plant Growth Analysis Using LiDAR.

    Science.gov (United States)

    Sun, Shangpeng; Li, Changying; Paterson, Andrew H; Jiang, Yu; Xu, Rui; Robertson, Jon S; Snider, John L; Chee, Peng W

    2018-01-01

    Plant breeding programs and a wide range of plant science applications would greatly benefit from the development of in-field high throughput phenotyping technologies. In this study, a terrestrial LiDAR-based high throughput phenotyping system was developed. A 2D LiDAR was applied to scan plants from overhead in the field, and an RTK-GPS was used to provide spatial coordinates. Precise 3D models of scanned plants were reconstructed based on the LiDAR and RTK-GPS data. The ground plane of the 3D model was separated by RANSAC algorithm and a Euclidean clustering algorithm was applied to remove noise generated by weeds. After that, clean 3D surface models of cotton plants were obtained, from which three plot-level morphologic traits including canopy height, projected canopy area, and plant volume were derived. Canopy height ranging from 85th percentile to the maximum height were computed based on the histogram of the z coordinate for all measured points; projected canopy area was derived by projecting all points on a ground plane; and a Trapezoidal rule based algorithm was proposed to estimate plant volume. Results of validation experiments showed good agreement between LiDAR measurements and manual measurements for maximum canopy height, projected canopy area, and plant volume, with R 2 -values of 0.97, 0.97, and 0.98, respectively. The developed system was used to scan the whole field repeatedly over the period from 43 to 109 days after planting. Growth trends and growth rate curves for all three derived morphologic traits were established over the monitoring period for each cultivar. Overall, four different cultivars showed similar growth trends and growth rate patterns. Each cultivar continued to grow until ~88 days after planting, and from then on varied little. However, the actual values were cultivar specific. Correlation analysis between morphologic traits and final yield was conducted over the monitoring period. When considering each cultivar individually

  10. The liver taxis of receptor mediated lactosaminated human growth hormone

    International Nuclear Information System (INIS)

    Chen Zelian; Shi Lin; Li Tongling; Pang Qijie; He Juying; Guan Changtian

    2002-01-01

    Radiography imaging is used to assess liver taxis mechanism of anti-dwarfism drug lactosaminated human growth hormone (L-rhGH). Both L-rhGH and rhGH labelled with 131 I are used to study their biodistribution in animals (including rabbits, cocks and rats). The results show that L-rhGH is of specific hepatic targeting property, and the maximum hepatic concentration rate is 76.8%, which is two times of rhGH. Its hepatic binding is receptor mediated

  11. Maximum Likelihood and Restricted Likelihood Solutions in Multiple-Method Studies.

    Science.gov (United States)

    Rukhin, Andrew L

    2011-01-01

    A formulation of the problem of combining data from several sources is discussed in terms of random effects models. The unknown measurement precision is assumed not to be the same for all methods. We investigate maximum likelihood solutions in this model. By representing the likelihood equations as simultaneous polynomial equations, the exact form of the Groebner basis for their stationary points is derived when there are two methods. A parametrization of these solutions which allows their comparison is suggested. A numerical method for solving likelihood equations is outlined, and an alternative to the maximum likelihood method, the restricted maximum likelihood, is studied. In the situation when methods variances are considered to be known an upper bound on the between-method variance is obtained. The relationship between likelihood equations and moment-type equations is also discussed.

  12. A Bayes-Maximum Entropy method for multi-sensor data fusion

    Energy Technology Data Exchange (ETDEWEB)

    Beckerman, M.

    1991-01-01

    In this paper we introduce a Bayes-Maximum Entropy formalism for multi-sensor data fusion, and present an application of this methodology to the fusion of ultrasound and visual sensor data as acquired by a mobile robot. In our approach the principle of maximum entropy is applied to the construction of priors and likelihoods from the data. Distances between ultrasound and visual points of interest in a dual representation are used to define Gibbs likelihood distributions. Both one- and two-dimensional likelihoods are presented, and cast into a form which makes explicit their dependence upon the mean. The Bayesian posterior distributions are used to test a null hypothesis, and Maximum Entropy Maps used for navigation are updated using the resulting information from the dual representation. 14 refs., 9 figs.

  13. Functional Maximum Autocorrelation Factors

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Nielsen, Allan Aasbjerg

    2005-01-01

    MAF outperforms the functional PCA in concentrating the interesting' spectra/shape variation in one end of the eigenvalue spectrum and allows for easier interpretation of effects. Conclusions. Functional MAF analysis is a useful methods for extracting low dimensional models of temporally or spatially......Purpose. We aim at data where samples of an underlying function are observed in a spatial or temporal layout. Examples of underlying functions are reflectance spectra and biological shapes. We apply functional models based on smoothing splines and generalize the functional PCA in......\\verb+~+\\$\\backslash\\$cite{ramsay97} to functional maximum autocorrelation factors (MAF)\\verb+~+\\$\\backslash\\$cite{switzer85,larsen2001d}. We apply the method to biological shapes as well as reflectance spectra. {\\$\\backslash\\$bf Methods}. MAF seeks linear combination of the original variables that maximize autocorrelation between...

  14. Contrasting growth properties of Nocardioides JS614 on threedifferent vinyl halides.

    Science.gov (United States)

    Taylor, Anne E; Bottomley, Peter J; Semprini, Lewis

    2018-02-01

    Ethene (ETH)-grown inocula of Nocardioides JS614 grow on vinyl chloride (VC), vinyl fluoride (VF), or vinyl bromide (VB) as the sole carbon and energy source, with faster growth rates and higher cell yields on VC and VF than on VB. However, whereas acetate-grown inocula of JS614 grow on VC and VF after a lag period, growth on VB did not occur unless supplemental ethene oxide (EtO) was present in the medium. Despite inferior growth on VB, the maximum rate of VB consumption by ETH-grown cells was ~ 50% greater than the rates of VC and VF consumption, but Br - release during VB consumption was non-stoichiometric with VB consumption (~ 66%) compared to 100% release of Cl - and F - during VC and VF consumption. Evidence was obtained for VB turnover-dependent toxicity of cell metabolism in JS614 with both acetate-dependent respiration and growth being significantly reduced by VB turnover, but no VC or VF turnover-dependent toxicity of growth was detected. Reduced growth rate and cell yield of JS614 on VB probably resulted from a combination of inefficient metabolic processing of the highly unstable VB epoxide (t 0.5  = 45 s), accompanied by growth inhibitory effects of VB metabolites on acetate-dependent metabolism. The exact role(s) of EtO in promoting growth of alkene repressed JS614 on VB remains unresolved, with evidence of EtO inducing epoxide consuming activity prior to an increase in alkene oxidizing activity and supplementing reductant supply when VB is the growth substrate.

  15. Microbiological Quality of Panicum maximum Grass Silage with Addition of Lactobacillus sp. as Starter

    Science.gov (United States)

    Sumarsih, S.; Sulistiyanto, B.; Utama, C. S.

    2018-02-01

    The aim of the research was to evaluate microbiological quality of Panicum maximum grass silage with addition Lactobacillus sp as starter. The completely randomized design was been used on this research with 4 treaments and 3 replications. The treatments were P0 ( Panicum maximum grass silage without addition Lactobacillus sp ), P1 ( Panicum maximum grass silage with 2% addition Lactobacillus sp), P2 (Panicum maximum grass silage with 4% addition Lactobacillus sp) and P3 (Panicum maximum grass silage with 6% addition Lactobacillus sp).The parameters were microbial populations of Panicum maximum grass silage (total lactic acid bacteria, total bacteria, total fungi, and Coliform bacteria. The data obtained were analyzed variance (ANOVA) and further tests performed Duncan’s Multiple Areas. The population of lactic acid bacteria was higher (PMicrobiological quality of Panicum maximum grass silage with addition Lactobacillus sp was better than no addition Lactobacillus sp.

  16. Body temperatures in dinosaurs: what can growth curves tell us?

    Science.gov (United States)

    Griebeler, Eva Maria

    2013-01-01

    To estimate the body temperature (BT) of seven dinosaurs Gillooly, Alleen, and Charnov (2006) used an equation that predicts BT from the body mass and maximum growth rate (MGR) with the latter preserved in ontogenetic growth trajectories (BT-equation). The results of these authors evidence inertial homeothermy in Dinosauria and suggest that, due to overheating, the maximum body size in Dinosauria was ultimately limited by BT. In this paper, I revisit this hypothesis of Gillooly, Alleen, and Charnov (2006). I first studied whether BTs derived from the BT-equation of today's crocodiles, birds and mammals are consistent with core temperatures of animals. Second, I applied the BT-equation to a larger number of dinosaurs than Gillooly, Alleen, and Charnov (2006) did. In particular, I estimated BT of Archaeopteryx (from two MGRs), ornithischians (two), theropods (three), prosauropods (three), and sauropods (nine). For extant species, the BT value estimated from the BT-equation was a poor estimate of an animal's core temperature. For birds, BT was always strongly overestimated and for crocodiles underestimated; for mammals the accuracy of BT was moderate. I argue that taxon-specific differences in the scaling of MGR (intercept and exponent of the regression line, log-log-transformed) and in the parameterization of the Arrhenius model both used in the BT-equation as well as ecological and evolutionary adaptations of species cause these inaccuracies. Irrespective of the found inaccuracy of BTs estimated from the BT-equation and contrary to the results of Gillooly, Alleen, and Charnov (2006) I found no increase in BT with increasing body mass across all dinosaurs (Sauropodomorpha, Sauropoda) studied. This observation questions that, due to overheating, the maximum size in Dinosauria was ultimately limited by BT. However, the general high inaccuracy of dinosaurian BTs derived from the BT-equation makes a reliable test of whether body size in dinosaurs was ultimately limited

  17. Sodium Flux Growth of Bulk Gallium Nitride

    Science.gov (United States)

    Von Dollen, Paul Martin

    This dissertation focused on development of a novel apparatus and techniques for crystal growth of bulk gallium nitride (GaN) using the sodium flux method. Though several methods exist to produce bulk GaN, none have been commercialized on an industrial scale. The sodium flux method offers potentially lower cost production due to relatively mild process conditions while maintaining high crystal quality. But the current equipment and methods for sodium flux growth of bulk GaN are generally not amenable to large-scale crystal growth or in situ investigation of growth processes, which has hampered progress. A key task was to prevent sodium loss or migration from the sodium-gallium growth melt while permitting N2 gas to access the growing crystal, which was accomplished by implementing a reflux condensing stem along with a reusable sealed capsule. The reflux condensing stem also enabled direct monitoring and control of the melt temperature, which has not been previously reported for the sodium flux method. Molybdenum-based materials were identified from a corrosion study as candidates for direct containment of the corrosive sodium-gallium melt. Successful introduction of these materials allowed implementation of a crucible-free containment system, which improved process control and can potentially reduce crystal impurity levels. Using the new growth system, the (0001) Ga face (+c plane) growth rate was >50 mum/hr, which is the highest bulk GaN growth rate reported for the sodium flux method. Omega X-ray rocking curve (?-XRC) measurements indicated the presence of multiple grains, though full width at half maximum (FWHM) values for individual peaks were 1020 atoms/cm3, possibly due to reactor cleaning and handling procedures. This dissertation also introduced an in situ technique to correlate changes in N2 pressure with dissolution of nitrogen and precipitation of GaN from the sodium-gallium melt. Different stages of N2 pressure decay were identified and linked to

  18. Estimating Rhododendron maximum L. (Ericaceae) Canopy Cover Using GPS/GIS Technology

    Science.gov (United States)

    Tyler J. Tran; Katherine J. Elliott

    2012-01-01

    In the southern Appalachians, Rhododendron maximum L. (Ericaceae) is a key evergreen understory species, often forming a subcanopy in forest stands. Little is known about the significance of R. maximum cover in relation to other forest structural variables. Only recently have studies used Global Positioning System (GPS) technology...

  19. The optimal atmospheric CO2 concentration for the growth of winter wheat (Triticum aestivum).

    Science.gov (United States)

    Xu, Ming

    2015-07-20

    This study examined the optimal atmospheric CO2 concentration of the CO2 fertilization effect on the growth of winter wheat with growth chambers where the CO2 concentration was controlled at 400, 600, 800, 1000, and 1200 ppm respectively. I found that initial increase in atmospheric CO2 concentration dramatically enhanced winter wheat growth through the CO2 fertilization effect. However, this CO2 fertilization effect was substantially compromised with further increase in CO2 concentration, demonstrating an optimal CO2 concentration of 889.6, 909.4, and 894.2 ppm for aboveground, belowground, and total biomass, respectively, and 967.8 ppm for leaf photosynthesis. Also, high CO2 concentrations exceeding the optima not only reduced leaf stomatal density, length and conductance, but also changed the spatial distribution pattern of stomata on leaves. In addition, high CO2 concentration also decreased the maximum carboxylation rate (Vc(max)) and the maximum electron transport rate (J(max)) of leaf photosynthesis. However, the high CO2 concentration had little effect on leaf length and plant height. The optimal CO2 fertilization effect found in this study can be used as an indicator in selecting and breeding new wheat strains in adapting to future high atmospheric CO2 concentrations and climate change. Copyright © 2015. Published by Elsevier GmbH.

  20. Correlation of arbuscular mycorrhizal colonization with plant growth, nodulation, and shoot npk in legumes

    International Nuclear Information System (INIS)

    Javaid, A.; Anjum, T.; Shah, M.H.M.

    2007-01-01

    Correlation of arbuscular mycorrhizal colonization with different root and shoot growth, nodulation and shoot NPK parameters was studied in three legumes viz. Trifolium alexandrianum, Medicago polymorpha and Melilotus parviflora. The three test legume species showed different patterns of root and shoot growth, nodulation, mycorrhizal colonization and shoot N, P and K content. Different mycorrhizal structures viz. mycelium, arbuscules and vesicles showed different patters of correlation with different studied parameters. Mycelial infection showed an insignificantly positive correlation with root and shoot dry biomass and total root length. Maximum root length was however, negatively associated with mycelial infection. Both arbuscular and vesicular infections were negatively correlated with shoot dry biomass and different parameters of root growth. The association between arbuscular infection and maximum root length was significant. All the three mycorrhizal structures showed a positive correlation with number and biomass of nodules. The association between arbuscular infection and nodule number was significant. Mycelial infection was positively correlated with percentage and total shoot N and P. Similarly percentage N was also positively correlated with arbuscular and vesicular infections. By contrast, total shoot N showed a negative association with arbuscular as well as vesicular infections. Similarly both percentage and total shoot P were negatively correlated with arbuscular and vesicular infections. All the associations between mycorrhizal parameters and shoot K were negative except between vesicular infection and shoot %K. (author)