Numerical simulation for heat transfer performance in unsteady flow of Williamson fluid driven by a wedge-geometry

NASA Astrophysics Data System (ADS)

Hamid, Aamir; Hashim; Khan, Masood

2018-06-01

The main concern of this communication is to investigate the two-layer flow of a non-Newtonian rheological fluid past a wedge-shaped geometry. One remarkable aspect of this article is the mathematical formulation for two-dimensional flow of Williamson fluid by incorporating the effect of infinite shear rate viscosity. The impacts of heat transfer mechanism on time-dependent flow field are further studied. At first, we employ the suitable non-dimensional variables to transmute the time-dependent governing flow equations into a system of non-linear ordinary differential equations. The converted conservation equations are numerically integrated subject to physically suitable boundary conditions with the aid of Runge-Kutta Fehlberg integration procedure. The effects of involved pertinent parameters, such as, moving wedge parameter, wedge angle parameter, local Weissenberg number, unsteadiness parameter and Prandtl number on the non-dimensional velocity and temperature distributions have been evaluated. In addition, the numerical values of the local skin friction coefficient and the local Nusselt number are compared and presented through tables. The outcomes of this study indicate that the rate of heat transfer increases with the growth of both wedge angle parameter and unsteadiness parameter. Moreover, a substantial rise in the fluid velocity is observed with enhancement in the viscosity ratio parameter while an opposite trend is true for the non-dimensional temperature field. A comparison is presented between the current study and already published works and results found to be in outstanding agreement. Finally, the main findings of this article are highlighted in the last section.

Novel third-order Lovelock wormhole solutions

NASA Astrophysics Data System (ADS)

Mehdizadeh, Mohammad Reza; Lobo, Francisco S. N.

2016-06-01

In this work, we consider wormhole geometries in third-order Lovelock gravity and investigate the possibility that these solutions satisfy the energy conditions. In this framework, by applying a specific equation of state, we obtain exact wormhole solutions, and by imposing suitable values for the parameters of the theory, we find that these geometries satisfy the weak energy condition in the vicinity of the throat, due to the presence of higher-order curvature terms. Finally, we trace out a numerical analysis, by assuming a specific redshift function, and find asymptotically flat solutions that satisfy the weak energy condition throughout the spacetime.

Oxidation Kinetics of Ferritic Alloys in High-Temperature Steam Environments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parker, Stephen S.; White, Josh; Hosemann, Peter

High-temperature isothermal steam oxidation kinetic parameters of several ferritic alloys were determined by thermogravimetric analysis. We measured the oxidation kinetic constant (k) as a function of temperature from 900°C to 1200°C. The results show a marked increase in oxidation resistance compared to reference Zircaloy-2, with kinetic constants 3–5 orders of magnitude lower across the experimental temperature range. Our results of this investigation supplement previous findings on the properties of ferritic alloys for use as candidate cladding materials and extend kinetic parameter measurements to high-temperature steam environments suitable for assessing accident tolerance for light water reactor applications.

Oxidation Kinetics of Ferritic Alloys in High-Temperature Steam Environments

DOE PAGES

Parker, Stephen S.; White, Josh; Hosemann, Peter; ...

2017-11-03

High-temperature isothermal steam oxidation kinetic parameters of several ferritic alloys were determined by thermogravimetric analysis. We measured the oxidation kinetic constant (k) as a function of temperature from 900°C to 1200°C. The results show a marked increase in oxidation resistance compared to reference Zircaloy-2, with kinetic constants 3–5 orders of magnitude lower across the experimental temperature range. Our results of this investigation supplement previous findings on the properties of ferritic alloys for use as candidate cladding materials and extend kinetic parameter measurements to high-temperature steam environments suitable for assessing accident tolerance for light water reactor applications.

Oxidation Kinetics of Ferritic Alloys in High-Temperature Steam Environments

NASA Astrophysics Data System (ADS)

Parker, Stephen S.; White, Josh; Hosemann, Peter; Nelson, Andrew

2018-02-01

High-temperature isothermal steam oxidation kinetic parameters of several ferritic alloys were determined by thermogravimetric analysis. The oxidation kinetic constant ( k) was measured as a function of temperature from 900°C to 1200°C. The results show a marked increase in oxidation resistance compared to reference Zircaloy-2, with kinetic constants 3-5 orders of magnitude lower across the experimental temperature range. The results of this investigation supplement previous findings on the properties of ferritic alloys for use as candidate cladding materials and extend kinetic parameter measurements to high-temperature steam environments suitable for assessing accident tolerance for light water reactor applications.

Suitable Site Selection of Small Dams Using Geo-Spatial Technique: a Case Study of Dadu Tehsil, Sindh

NASA Astrophysics Data System (ADS)

Khalil, Zahid

2016-07-01

Decision making about identifying suitable sites for any project by considering different parameters, is difficult. Using GIS and Multi-Criteria Analysis (MCA) can make it easy for those projects. This technology has proved to be an efficient and adequate in acquiring the desired information. In this study, GIS and MCA were employed to identify the suitable sites for small dams in Dadu Tehsil, Sindh. The GIS software is used to create all the spatial parameters for the analysis. The parameters that derived are slope, drainage density, rainfall, land use / land cover, soil groups, Curve Number (CN) and runoff index with a spatial resolution of 30m. The data used for deriving above layers include 30 meter resolution SRTM DEM, Landsat 8 imagery, and rainfall from National Centre of Environment Prediction (NCEP) and soil data from World Harmonized Soil Data (WHSD). Land use/Land cover map is derived from Landsat 8 using supervised classification. Slope, drainage network and watershed are delineated by terrain processing of DEM. The Soil Conservation Services (SCS) method is implemented to estimate the surface runoff from the rainfall. Prior to this, SCS-CN grid is developed by integrating the soil and land use/land cover raster. These layers with some technical and ecological constraints are assigned weights on the basis of suitability criteria. The pair wise comparison method, also known as Analytical Hierarchy Process (AHP) is took into account as MCA for assigning weights on each decision element. All the parameters and group of parameters are integrated using weighted overlay in GIS environment to produce suitable sites for the Dams. The resultant layer is then classified into four classes namely, best suitable, suitable, moderate and less suitable. This study reveals a contribution to decision making about suitable sites analysis for small dams using geo-spatial data with minimal amount of ground data. This suitability maps can be helpful for water resource management organizations in determination of feasible rainwater harvesting structures (RWH).

To Find a Better Dosimetric Parameter in the Predicting of Radiation-Induced Lung Toxicity Individually: Ventilation, Perfusion or CT based.

PubMed

Xiao, Lin-Lin; Yang, Guoren; Chen, Jinhu; Wang, Xiaohui; Wu, Qingwei; Huo, Zongwei; Yu, Qingxi; Yu, Jinming; Yuan, Shuanghu

2017-03-15

This study aimed to find a better dosimetric parameter in predicting of radiation-induced lung toxicity (RILT) in patients with non-small cell lung cancer (NSCLC) individually: ventilation(V), perfusion (Q) or computerized tomography (CT) based. V/Q single-photon emission computerized tomography (SPECT) was performed within 1 week prior to radiotherapy (RT). All V/Q imaging data was integrated into RT planning system, generating functional parameters based on V/Q SPECT. Fifty-seven NSCLC patients were enrolled in this prospective study. Fifteen (26.3%) patients underwent grade ≥2 RILT, the remaining forty-two (73.7%) patients didn't. Q-MLD, Q-V20, V-MLD, V-V20 of functional parameters correlated more significantly with the occurrence of RILT compared to V20, MLD of anatomical parameters (r = 0.630; r = 0.644; r = 0.617; r = 0.651 vs. r = 0.424; r = 0.520 p < 0.05, respectively). In patients with chronic obstructive pulmonary diseases (COPD), V functional parameters reflected significant advantage in predicting RILT; while in patients without COPD, Q functional parameters reflected significant advantage. Analogous results were existed in fractimal analysis of global pulmonary function test (PFT). In patients with central-type NSCLC, V parameters were better than Q parameters; while in patients with peripheral-type NSCLC, the results were inverse. Therefore, this study demonstrated that choosing a suitable dosimetric parameter individually can help us predict RILT accurately.

Hands-on parameter search for neural simulations by a MIDI-controller.

PubMed

Eichner, Hubert; Borst, Alexander

2011-01-01

Computational neuroscientists frequently encounter the challenge of parameter fitting--exploring a usually high dimensional variable space to find a parameter set that reproduces an experimental data set. One common approach is using automated search algorithms such as gradient descent or genetic algorithms. However, these approaches suffer several shortcomings related to their lack of understanding the underlying question, such as defining a suitable error function or getting stuck in local minima. Another widespread approach is manual parameter fitting using a keyboard or a mouse, evaluating different parameter sets following the users intuition. However, this process is often cumbersome and time-intensive. Here, we present a new method for manual parameter fitting. A MIDI controller provides input to the simulation software, where model parameters are then tuned according to the knob and slider positions on the device. The model is immediately updated on every parameter change, continuously plotting the latest results. Given reasonably short simulation times of less than one second, we find this method to be highly efficient in quickly determining good parameter sets. Our approach bears a close resemblance to tuning the sound of an analog synthesizer, giving the user a very good intuition of the problem at hand, such as immediate feedback if and how results are affected by specific parameter changes. In addition to be used in research, our approach should be an ideal teaching tool, allowing students to interactively explore complex models such as Hodgkin-Huxley or dynamical systems.

Hands-On Parameter Search for Neural Simulations by a MIDI-Controller

PubMed Central

Eichner, Hubert; Borst, Alexander

2011-01-01

Computational neuroscientists frequently encounter the challenge of parameter fitting – exploring a usually high dimensional variable space to find a parameter set that reproduces an experimental data set. One common approach is using automated search algorithms such as gradient descent or genetic algorithms. However, these approaches suffer several shortcomings related to their lack of understanding the underlying question, such as defining a suitable error function or getting stuck in local minima. Another widespread approach is manual parameter fitting using a keyboard or a mouse, evaluating different parameter sets following the users intuition. However, this process is often cumbersome and time-intensive. Here, we present a new method for manual parameter fitting. A MIDI controller provides input to the simulation software, where model parameters are then tuned according to the knob and slider positions on the device. The model is immediately updated on every parameter change, continuously plotting the latest results. Given reasonably short simulation times of less than one second, we find this method to be highly efficient in quickly determining good parameter sets. Our approach bears a close resemblance to tuning the sound of an analog synthesizer, giving the user a very good intuition of the problem at hand, such as immediate feedback if and how results are affected by specific parameter changes. In addition to be used in research, our approach should be an ideal teaching tool, allowing students to interactively explore complex models such as Hodgkin-Huxley or dynamical systems. PMID:22066027

Selection of suitable NDT methods for building inspection

NASA Astrophysics Data System (ADS)

Pauzi Ismail, Mohamad

2017-11-01

Construction of modern structures requires good quality concrete with adequate strength and durability. Several accidents occurred in the civil constructions and were reported in the media. Such accidents were due to poor workmanship and lack of systematic monitoring during the constructions. In addition, water leaking and cracking in residential houses was commonly reported too. Based on these facts, monitoring the quality of concrete in structures is becoming more and more important subject. This paper describes major Non-destructive Testing (NDT) methods for evaluating structural integrity of concrete building. Some interesting findings during actual NDT inspections on site are presented. The NDT methods used are explained, compared and discussed. The suitable methods are suggested as minimum NDT methods to cover parameters required in the inspection.

Equicontrollability and the model following problem

NASA Technical Reports Server (NTRS)

Curran, R. T.

1971-01-01

Equicontrollability and its application to the linear time-invariant model-following problem are discussed. The problem is presented in the form of two systems, the plant and the model. The requirement is to find a controller to apply to the plant so that the resultant compensated plant behaves, in an input-output sense, the same as the model. All systems are assumed to be linear and time-invariant. The basic approach is to find suitable equicontrollable realizations of the plant and model and to utilize feedback so as to produce a controller of minimal state dimension. The concept of equicontrollability is a generalization of control canonical (phase variable) form applied to multivariable systems. It allows one to visualize clearly the effects of feedback and to pinpoint the parameters of a multivariable system which are invariant under feedback. The basic contributions are the development of equicontrollable form; solution of the model-following problem in an entirely algorithmic way, suitable for computer programming; and resolution of questions on system decoupling.

SASS Applied to Optimum Work Roll Profile Selection in the Hot Rolling of Wide Steel

NASA Astrophysics Data System (ADS)

Nolle, Lars

The quality of steel strip produced in a wide strip rolling mill depends heavily on the careful selection of initial ground work roll profiles for each of the mill stands in the finishing train. In the past, these profiles were determined by human experts, based on their knowledge and experience. In previous work, the profiles were successfully optimised using a self-organising migration algorithm (SOMA). In this research, SASS, a novel heuristic optimisation algorithm that has only one control parameter, has been used to find the optimum profiles for a simulated rolling mill. The resulting strip quality produced using the profiles found by SASS is compared with results from previous work and the quality produced using the original profile specifications. The best set of profiles found by SASS clearly outperformed the original set and performed equally well as SOMA without the need of finding a suitable set of control parameters.

Factor analysis in optimization of formulation of high content uniformity tablets containing low dose active substance.

PubMed

Lukášová, Ivana; Muselík, Jan; Franc, Aleš; Goněc, Roman; Mika, Filip; Vetchý, David

2017-11-15

Warfarin is intensively discussed drug with narrow therapeutic range. There have been cases of bleeding attributed to varying content or altered quality of the active substance. Factor analysis is useful for finding suitable technological parameters leading to high content uniformity of tablets containing low amount of active substance. The composition of tabletting blend and technological procedure were set with respect to factor analysis of previously published results. The correctness of set parameters was checked by manufacturing and evaluation of tablets containing 1-10mg of warfarin sodium. The robustness of suggested technology was checked by using "worst case scenario" and statistical evaluation of European Pharmacopoeia (EP) content uniformity limits with respect to Bergum division and process capability index (Cpk). To evaluate the quality of active substance and tablets, dissolution method was developed (water; EP apparatus II; 25rpm), allowing for statistical comparison of dissolution profiles. Obtained results prove the suitability of factor analysis to optimize the composition with respect to batches manufactured previously and thus the use of metaanalysis under industrial conditions is feasible. Copyright © 2017 Elsevier B.V. All rights reserved.

TADtool: visual parameter identification for TAD-calling algorithms.

PubMed

Kruse, Kai; Hug, Clemens B; Hernández-Rodríguez, Benjamín; Vaquerizas, Juan M

2016-10-15

Eukaryotic genomes are hierarchically organized into topologically associating domains (TADs). The computational identification of these domains and their associated properties critically depends on the choice of suitable parameters of TAD-calling algorithms. To reduce the element of trial-and-error in parameter selection, we have developed TADtool: an interactive plot to find robust TAD-calling parameters with immediate visual feedback. TADtool allows the direct export of TADs called with a chosen set of parameters for two of the most common TAD calling algorithms: directionality and insulation index. It can be used as an intuitive, standalone application or as a Python package for maximum flexibility. TADtool is available as a Python package from GitHub (https://github.com/vaquerizaslab/tadtool) or can be installed directly via PyPI, the Python package index (tadtool). kai.kruse@mpi-muenster.mpg.de, jmv@mpi-muenster.mpg.deSupplementary information: Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press.

ConvAn: a convergence analyzing tool for optimization of biochemical networks.

PubMed

Kostromins, Andrejs; Mozga, Ivars; Stalidzans, Egils

2012-01-01

Dynamic models of biochemical networks usually are described as a system of nonlinear differential equations. In case of optimization of models for purpose of parameter estimation or design of new properties mainly numerical methods are used. That causes problems of optimization predictability as most of numerical optimization methods have stochastic properties and the convergence of the objective function to the global optimum is hardly predictable. Determination of suitable optimization method and necessary duration of optimization becomes critical in case of evaluation of high number of combinations of adjustable parameters or in case of large dynamic models. This task is complex due to variety of optimization methods, software tools and nonlinearity features of models in different parameter spaces. A software tool ConvAn is developed to analyze statistical properties of convergence dynamics for optimization runs with particular optimization method, model, software tool, set of optimization method parameters and number of adjustable parameters of the model. The convergence curves can be normalized automatically to enable comparison of different methods and models in the same scale. By the help of the biochemistry adapted graphical user interface of ConvAn it is possible to compare different optimization methods in terms of ability to find the global optima or values close to that as well as the necessary computational time to reach them. It is possible to estimate the optimization performance for different number of adjustable parameters. The functionality of ConvAn enables statistical assessment of necessary optimization time depending on the necessary optimization accuracy. Optimization methods, which are not suitable for a particular optimization task, can be rejected if they have poor repeatability or convergence properties. The software ConvAn is freely available on www.biosystems.lv/convan. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

SPOTting model parameters using a ready-made Python package

NASA Astrophysics Data System (ADS)

Houska, Tobias; Kraft, Philipp; Breuer, Lutz

2015-04-01

The selection and parameterization of reliable process descriptions in ecological modelling is driven by several uncertainties. The procedure is highly dependent on various criteria, like the used algorithm, the likelihood function selected and the definition of the prior parameter distributions. A wide variety of tools have been developed in the past decades to optimize parameters. Some of the tools are closed source. Due to this, the choice for a specific parameter estimation method is sometimes more dependent on its availability than the performance. A toolbox with a large set of methods can support users in deciding about the most suitable method. Further, it enables to test and compare different methods. We developed the SPOT (Statistical Parameter Optimization Tool), an open source python package containing a comprehensive set of modules, to analyze and optimize parameters of (environmental) models. SPOT comes along with a selected set of algorithms for parameter optimization and uncertainty analyses (Monte Carlo, MC; Latin Hypercube Sampling, LHS; Maximum Likelihood, MLE; Markov Chain Monte Carlo, MCMC; Scuffled Complex Evolution, SCE-UA; Differential Evolution Markov Chain, DE-MCZ), together with several likelihood functions (Bias, (log-) Nash-Sutcliff model efficiency, Correlation Coefficient, Coefficient of Determination, Covariance, (Decomposed-, Relative-, Root-) Mean Squared Error, Mean Absolute Error, Agreement Index) and prior distributions (Binomial, Chi-Square, Dirichlet, Exponential, Laplace, (log-, multivariate-) Normal, Pareto, Poisson, Cauchy, Uniform, Weibull) to sample from. The model-independent structure makes it suitable to analyze a wide range of applications. We apply all algorithms of the SPOT package in three different case studies. Firstly, we investigate the response of the Rosenbrock function, where the MLE algorithm shows its strengths. Secondly, we study the Griewank function, which has a challenging response surface for optimization methods. Here we see simple algorithms like the MCMC struggling to find the global optimum of the function, while algorithms like SCE-UA and DE-MCZ show their strengths. Thirdly, we apply an uncertainty analysis of a one-dimensional physically based hydrological model build with the Catchment Modelling Framework (CMF). The model is driven by meteorological and groundwater data from a Free Air Carbon Enrichment (FACE) experiment in Linden (Hesse, Germany). Simulation results are evaluated with measured soil moisture data. We search for optimal parameter sets of the van Genuchten-Mualem function and find different equally optimal solutions with some of the algorithms. The case studies reveal that the implemented SPOT methods work sufficiently well. They further show the benefit of having one tool at hand that includes a number of parameter search methods, likelihood functions and a priori parameter distributions within one platform independent package.

Calculation of optical parameters for covalent binary alloys used in optical memories/solar cells: a modified approach

NASA Astrophysics Data System (ADS)

Bhatnagar, Promod K.; Gupta, Poonam; Singh, Laxman

2001-06-01

Chalcogenide based alloys find applications in a number of devices like optical memories, IR detectors, optical switches, photovoltaics, compound semiconductor heterosrtuctures etc. We have modified the Gurman's statistical thermodynamic model (STM) of binary covalent alloys. In the Gurman's model, entropy calculations are based on the number of structural units present. The need to modify this model arose due to the fact that it gives equal probability for all the tetrahedra present in the alloy. We have modified the Gurman's model by introducing the concept that the entropy is based on the bond arrangement rather than that on the structural units present. In the present work calculation based on this modification have been presented for optical properties, which find application in optical switching/memories, solar cells and other optical devices. It has been shown that the calculated optical parameters (for a typical case of GaxSe1-x) based on modified model are closer to the available experimental results. These parameters include refractive index, extinction coefficient, dielectric functions, optical band gap etc. GaxSe1-x has been found to be suitable for reversible optical memories also, where phase change (a yields c and vice versa) takes place at specified physical conditions. DTA/DSC studies also suggest the suitability of this material for optical switching/memory applications. We have also suggested possible use of GaxSe1-x (x = 0.4) in place of oxide layer in a Metal - Oxide - Semiconductor type solar cells. The new structure is Metal - Ga2Se3 - GaAs. The I-V characteristics and other parameters calculated for this structure are found to be much better than that for Si based solar cells. Maximum output power is obtained at the intermediate layer thickness approximately 40 angstroms for this typical solar cell.

Seat pan and backrest pressure distribution while sitting in office chairs.

PubMed

Zemp, Roland; Taylor, William R; Lorenzetti, Silvio

2016-03-01

Nowadays, an increasing amount of time is spent seated, especially in office environments, where sitting comfort and support are increasingly important due to the prevalence of musculoskeletal disorders. The aim of this study was to develop a methodology for chair-specific sensor mat calibration, to evaluate the interconnections between specific pressure parameters and to establish those that are most meaningful and significant in order to differentiate pressure distribution measures between office chairs. The shape of the exponential calibration function was highly influenced by the material properties and geometry of the office chairs, and therefore a chair-specific calibration proved to be essential. High correlations were observed between the eight analysed pressure parameters, whereby the pressure parameters could be reduced to a set of four and three parameters for the seat pan and the backrest respectively. In order to find significant differences between office chairs, gradient parameters should be analysed for the seat pan, whereas for the backrest almost all parameters are suitable. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Projecting date palm distribution in Iran under climate change using topography, physicochemical soil properties, soil taxonomy, land use, and climate data

NASA Astrophysics Data System (ADS)

Shabani, Farzin; Kumar, Lalit; Taylor, Subhashni

2014-11-01

This study set out to model potential date palm distribution under current and future climate scenarios using an emission scenario, in conjunction with two different global climate models (GCMs): CSIRO-Mk3.0 (CS), and MIROC-H (MR), and to refine results based on suitability under four nonclimatic parameters. Areas containing suitable physicochemical soil properties and suitable soil taxonomy, together with land slopes of less than 10° and suitable land uses for date palm ( Phoenix dactylifera) were selected as appropriate refining tools to ensure the CLIMEX results were accurate and robust. Results showed that large regions of Iran are projected as likely to become climatically suitable for date palm cultivation based on the projected scenarios for the years 2030, 2050, 2070, and 2100. The study also showed CLIMEX outputs merit refinement by nonclimatic parameters and that the incremental introduction of each additional parameter decreased the disagreement between GCMs. Furthermore, the study indicated that the least amount of disagreement in terms of areas conducive to date palm cultivation resulted from CS and MR GCMs when the locations of suitable physicochemical soil properties and soil taxonomy were used as refinement tools.

Reverse design and characteristic study of multi-range HMCVT

NASA Astrophysics Data System (ADS)

Zhu, Zhen; Chen, Long; Zeng, Falin

2017-09-01

The reduction of fuel consumption and increase of transmission efficiency is one of the key problems of the agricultural machinery. Many promising technologies such as hydromechanical continuously variable transmissions (HMCVT) are the focus of research and investments, but there is little technical documentation that describes the design principle and presents the design parameters. This paper presents the design idea and characteristic study of HMCVT, in order to find out the suitable scheme for the big horsepower tractors. Analyzed the kinematics and dynamics of a large horsepower tractor, according to the characteristic parameters, a hydro-mechanical continuously variable transmission has been designed. Compared with the experimental curves and theoretical curves of the stepless speed regulation of transmission, the experimental result illustrates the rationality of the design scheme.

Development and validation of a habitat suitability model for the non-indigenous seagrass Zostera japonica in North America

EPA Science Inventory

We developed a spatially-explicit, flexible 3-parameter habitat suitability model that can be used to identify and predict areas at higher risk for non-native dwarf eelgrass (Zostera japonica) invasion. The model uses simple environmental parameters (depth, nearshore slope, and s...

Findings on the phytoextraction and phytostabilization of soils contaminated with heavy metals.

PubMed

Cheraghi, M; Lorestani, B; Khorasani, N; Yousefi, N; Karami, M

2011-12-01

As a result of human activities such as mining, metal pollution has become one of the most serious environmental problems today. Phytoremediation, an emerging cost-effective, non-intrusive, and aesthetically pleasing technology that uses the remarkable ability of plants to concentrate elements can be potentially used to remediate metal-contaminated sites. The aim of this work was to assess the extent of metal accumulation by plants found in a mining area in Hamedan province with the ultimate goal of finding suitable plants for phytoextraction and phytostabilization (two processes of phytoremediation). To this purpose, shoots and roots of the 12 plant species and the associated soil samples were collected and analyzed by measurement of total concentrations of some elements (Fe, Mn, Zn, and Cu) using atomic absorption spectrophotometer and then biological absorption coefficient, bioconcentration factor, and translocation factor parameters calculated for each element. Our results showed that none of the plants were suitable for phytoextraction and phytostabilization of Fe, Zn, and Cu, while Chenopodium botrys, Stipa barbata, Cousinia bijarensis, Scariola orientalis, Chondrila juncea, and Verbascum speciosum, with a high biological absorption coefficient for Mn, were suitable for phytoextraction of Mn, and C. bijarensis, C. juncea, V. speciosum, S. orientalis, C. botrys, and S. barbata, with a high bioconcentration factor and low translocation factor for Mn, had the potential for the phytostabilization of this element.

Experimental analysis of green roof substrate detention characteristics.

PubMed

Yio, Marcus H N; Stovin, Virginia; Werdin, Jörg; Vesuviano, Gianni

2013-01-01

Green roofs may make an important contribution to urban stormwater management. Rainfall-runoff models are required to evaluate green roof responses to specific rainfall inputs. The roof's hydrological response is a function of its configuration, with the substrate - or growing media - providing both retention and detention of rainfall. The objective of the research described here is to quantify the detention effects due to green roof substrates, and to propose a suitable hydrological modelling approach. Laboratory results from experimental detention tests on green roof substrates are presented. It is shown that detention increases with substrate depth and as a result of increasing substrate organic content. Model structures based on reservoir routing are evaluated, and it is found that a one-parameter reservoir routing model coupled with a parameter that describes the delay to start of runoff best fits the observed data. Preliminary findings support the hypothesis that the reservoir routing parameter values can be defined from the substrate's physical characteristics.

Entropy bounds in terms of the w parameter

NASA Astrophysics Data System (ADS)

Abreu, Gabriel; Barceló, Carlos; Visser, Matt

2011-12-01

In a pair of recent articles [PRL 105 (2010) 041302; JHEP 1103 (2011) 056] two of the current authors have developed an entropy bound for equilibrium uncollapsed matter using only classical general relativity, basic thermodynamics, and the Unruh effect. An odd feature of that bound, [InlineMediaObject not available: see fulltext.], was that the proportionality constant, 1/2 , was weaker than that expected from black hole thermodynamics, 1/4 . In the current article we strengthen the previous results by obtaining a bound involving the (suitably averaged) w parameter. Simple causality arguments restrict this averaged < w> parameter to be ≤ 1. When equality holds, the entropy bound saturates at the value expected based on black hole thermodynamics. We also add some clarifying comments regarding the (net) positivity of the chemical potential. Overall, we find that even in the absence of any black hole region, we can nevertheless get arbitrarily close to the Bekenstein entropy.

Plasma Parameters From Reentry Signal Attenuation

DOE PAGES

Statom, T. K.

2018-02-27

This study presents the application of a theoretically developed method that provides plasma parameter solution space information from measured RF attenuation that occurs during reentry. The purpose is to provide reentry plasma parameter information from the communication signal attenuation. The theoretical development centers around the attenuation and the complex index of refraction. The methodology uses an imaginary index of the refraction matching algorithm with a tolerance to find suitable solutions that satisfy the theory. The imaginary matching terms are then used to determine the real index of refraction resulting in the complex index of refraction. Then a filter is usedmore » to reject nonphysical solutions. Signal attenuation-based plasma parameter properties investigated include the complex index of refraction, plasma frequency, electron density, collision frequency, propagation constant, attenuation constant, phase constant, complex plasma conductivity, and electron mobility. RF plasma thickness attenuation is investigated and compared to the literature. Finally, similar plasma thickness for a specific signal attenuation can have different plasma properties.« less

Plasma Parameters From Reentry Signal Attenuation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Statom, T. K.

This study presents the application of a theoretically developed method that provides plasma parameter solution space information from measured RF attenuation that occurs during reentry. The purpose is to provide reentry plasma parameter information from the communication signal attenuation. The theoretical development centers around the attenuation and the complex index of refraction. The methodology uses an imaginary index of the refraction matching algorithm with a tolerance to find suitable solutions that satisfy the theory. The imaginary matching terms are then used to determine the real index of refraction resulting in the complex index of refraction. Then a filter is usedmore » to reject nonphysical solutions. Signal attenuation-based plasma parameter properties investigated include the complex index of refraction, plasma frequency, electron density, collision frequency, propagation constant, attenuation constant, phase constant, complex plasma conductivity, and electron mobility. RF plasma thickness attenuation is investigated and compared to the literature. Finally, similar plasma thickness for a specific signal attenuation can have different plasma properties.« less

Routine health monitoring in an aquatic species (Oryzias latipes) used in toxicological testing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Twerdok, L.E.; Beaman, J.R.; Curry, M.W.

1995-12-31

It is critical to establish baseline health endpoints in animal models used in toxicological studies. In mammalian models, procedures for monitoring the health status of test animals have been established and in use for many years; in many aquatic models, including medaka, much of this routine health screening has not been documented. Thus, the purpose of this study was to characterize routine health parameters in medaka and to identify parameters sensitive to changes in health status which could affect the suitability of animals for use in general toxicity and immunotoxicological studies. The endpoints assessed included histopathology (31 organs), identification ofmore » endogenous bacterial flora and, gross necropsy including body weight, length, hematocrit, leukocrit, and plasma immunoglobulin levels. Additional parameters included anterior kidney (the teleost bone marrow equivalent) weight and cell yields plus superoxide anion production. Histological findings included observation of age-related incidence of granulomatous lesions in a variety of organs. Multiple strains of Aeromonas and Pseudomonas were the predominant internal flora in healthy medaka. Hematocrit, leukocrit and plasma IgM levels were within the normal range for this species. Comparisons were made between healthy and handling-stressed fish. Evaluation of data collected to date suggest that leukocrit and superoxide anion production were the most sensitive indicators of the fish health status and suitability for use in general and/or immunotoxicological studies.« less

Evaluation of global onshore wind energy potential and generation costs.

PubMed

Zhou, Yuyu; Luckow, Patrick; Smith, Steven J; Clarke, Leon

2012-07-17

In this study, we develop an updated global estimate of onshore wind energy potential using reanalysis wind speed data, along with updated wind turbine technology performance, land suitability factors, cost assumptions, and explicit consideration of transmission distance in the calculation of transmission costs. We find that wind has the potential to supply a significant portion of the world energy needs, although this potential varies substantially by region and with assumptions such as on what types of land can be used to site wind farms. Total global economic wind potential under central assumptions, that is, intermediate between optimistic and pessimistic, is estimated to be approximately 119.5 petawatt hours per year (13.6 TW) at less than 9 cents/kWh. A sensitivity analysis of eight key parameters is presented. Wind potential is sensitive to a number of input parameters, particularly wind speed (varying by -70% to +450% at less than 9 cents/kWh), land suitability (by -55% to +25%), turbine density (by -60% to +80%), and cost and financing options (by -20% to +200%), many of which have important policy implications. As a result of sensitivities studied here we suggest that further research intended to inform wind supply curve development focus not purely on physical science, such as better resolved wind maps, but also on these less well-defined factors, such as land-suitability, that will also have an impact on the long-term role of wind power.

An architecture for efficient gravitational wave parameter estimation with multimodal linear surrogate models

NASA Astrophysics Data System (ADS)

O'Shaughnessy, Richard; Blackman, Jonathan; Field, Scott E.

2017-07-01

The recent direct observation of gravitational waves has further emphasized the desire for fast, low-cost, and accurate methods to infer the parameters of gravitational wave sources. Due to expense in waveform generation and data handling, the cost of evaluating the likelihood function limits the computational performance of these calculations. Building on recently developed surrogate models and a novel parameter estimation pipeline, we show how to quickly generate the likelihood function as an analytic, closed-form expression. Using a straightforward variant of a production-scale parameter estimation code, we demonstrate our method using surrogate models of effective-one-body and numerical relativity waveforms. Our study is the first time these models have been used for parameter estimation and one of the first ever parameter estimation calculations with multi-modal numerical relativity waveforms, which include all \\ell ≤slant 4 modes. Our grid-free method enables rapid parameter estimation for any waveform with a suitable reduced-order model. The methods described in this paper may also find use in other data analysis studies, such as vetting coincident events or the computation of the coalescing-compact-binary detection statistic.

Development and validation of a habitat suitability model for ...

EPA Pesticide Factsheets

We developed a spatially-explicit, flexible 3-parameter habitat suitability model that can be used to identify and predict areas at higher risk for non-native dwarf eelgrass (Zostera japonica) invasion. The model uses simple environmental parameters (depth, nearshore slope, and salinity) to quantitatively describe habitat suitable for Z. japonica invasion based on ecology and physiology from the primary literature. Habitat suitability is defined with values ranging from zero to one, where one denotes areas most conducive to Z. japonica and zero denotes areas not likely to support Z. japonica growth. The model was applied to Yaquina Bay, Oregon, USA, an area that has well documented Z. japonica expansion over the last two decades. The highest suitability values for Z. japonica occurred in the mid to upper portions of the intertidal zone, with larger expanses occurring in the lower estuary. While the upper estuary did contain suitable habitat, most areas were not as large as in the lower estuary, due to inappropriate depth, a steeply sloping intertidal zone, and lower salinity. The lowest suitability values occurred below the lower intertidal zone, within the Yaquina River channel. The model was validated by comparison to a multi-year time series of Z. japonica maps, revealing a strong predictive capacity. Sensitivity analysis performed to evaluate the contribution of each parameter to the model prediction revealed that depth was the most important factor. Sh

Ordered weighted averaging with fuzzy quantifiers: GIS-based multicriteria evaluation for land-use suitability analysis

NASA Astrophysics Data System (ADS)

Malczewski, Jacek

2006-12-01

The objective of this paper is to incorporate the concept of fuzzy (linguistic) quantifiers into the GIS-based land suitability analysis via ordered weighted averaging (OWA). OWA is a multicriteria evaluation procedure (or combination operator). The nature of the OWA procedure depends on some parameters, which can be specified by means of fuzzy (linguistic) quantifiers. By changing the parameters, OWA can generate a wide range of decision strategies or scenarios. The quantifier-guided OWA procedure is illustrated using land-use suitability analysis in a region of Mexico.

Comparison of sampling techniques for Bayesian parameter estimation

NASA Astrophysics Data System (ADS)

Allison, Rupert; Dunkley, Joanna

2014-02-01

The posterior probability distribution for a set of model parameters encodes all that the data have to tell us in the context of a given model; it is the fundamental quantity for Bayesian parameter estimation. In order to infer the posterior probability distribution we have to decide how to explore parameter space. Here we compare three prescriptions for how parameter space is navigated, discussing their relative merits. We consider Metropolis-Hasting sampling, nested sampling and affine-invariant ensemble Markov chain Monte Carlo (MCMC) sampling. We focus on their performance on toy-model Gaussian likelihoods and on a real-world cosmological data set. We outline the sampling algorithms themselves and elaborate on performance diagnostics such as convergence time, scope for parallelization, dimensional scaling, requisite tunings and suitability for non-Gaussian distributions. We find that nested sampling delivers high-fidelity estimates for posterior statistics at low computational cost, and should be adopted in favour of Metropolis-Hastings in many cases. Affine-invariant MCMC is competitive when computing clusters can be utilized for massive parallelization. Affine-invariant MCMC and existing extensions to nested sampling naturally probe multimodal and curving distributions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Betti, R.; Christopherson, A. R.; Spears, B. K.

Estimating the level of alpha heating and determining the onset of the burning plasma regime is essential to finding the path towards thermonuclear ignition. In a burning plasma, the alpha heating exceeds the external input energy to the plasma. Using a simple model of the implosion, it is shown that a general relation can be derived, connecting the burning plasma regime to the yield enhancement due to alpha heating and to experimentally measurable parameters such as the Lawson ignition parameter. A general alpha-heating curve is found, independent of the target and suitable to assess the performance of all laser fusionmore » experiments whether direct or indirect drive. The onset of the burning plasma regime inside the hot spot of current implosions on the National Ignition Facility requires a fusion yield of about 50 kJ.« less

Coevolution of Glauber-like Ising dynamics and topology

NASA Astrophysics Data System (ADS)

Mandrà, Salvatore; Fortunato, Santo; Castellano, Claudio

2009-11-01

We study the coevolution of a generalized Glauber dynamics for Ising spins with tunable threshold and of the graph topology where the dynamics takes place. This simple coevolution dynamics generates a rich phase diagram in the space of the two parameters of the model, the threshold and the rewiring probability. The diagram displays phase transitions of different types: spin ordering, percolation, and connectedness. At variance with traditional coevolution models, in which all spins of each connected component of the graph have equal value in the stationary state, we find that, for suitable choices of the parameters, the system may converge to a state in which spins of opposite sign coexist in the same component organized in compact clusters of like-signed spins. Mean field calculations enable one to estimate some features of the phase diagram.

A comparative study based on physical characteristics of suitable packing materials in biofiltration.

PubMed

Dorado, A D; Lafuente, F J; Gabriel, D; Gamisans, X

2010-02-01

In the present work, 10 packing materials commonly used as support media in biofiltration are analysed and compared to evaluate their suitability according to physical characteristics. The nature of the packing material in biofilters is an important factor for the success in their construction and operation. Different packing materials have been used in biofiltration without a global agreement about which ones are the most adequate for biofiltration success. The materials studied were chosen according to previous works in the field of biofiltration including both organic and inorganic (or synthetic) materials. A set of nine different parameters were selected to cope with well-established factors, such as a material-specific surface area, pressure drop, nutrient supply, water retentivity, sorption capacity, and purchase cost. One ranking of packing materials was established for each parameter studied in order to define a relative suitability degree. Since biofiltration success generally depends on a combination of the ranked parameters, a procedure was defined to compare packing materials suitability under common situations in biofiltration. The selected scenarios, such as biofiltration of intermittent loads of pollutants and biofiltration of waste gases with low relative humidity, were investigated. The results indicate that, out of the packing materials studied, activated carbons were ranked top of several parameter rankings and were shown to be a significantly better packing material when parameters were combined to assess such selected scenarios.

Structure-activity relationships of pyrethroid insecticides. Part 2. The use of molecular dynamics for conformation searching and average parameter calculation

NASA Astrophysics Data System (ADS)

Hudson, Brian D.; George, Ashley R.; Ford, Martyn G.; Livingstone, David J.

1992-04-01

Molecular dynamics simulations have been performed on a number of conformationally flexible pyrethroid insecticides. The results indicate that molecular dynamics is a suitable tool for conformational searching of small molecules given suitable simulation parameters. The structures derived from the simulations are compared with the static conformation used in a previous study. Various physicochemical parameters have been calculated for a set of conformations selected from the simulations using multivariate analysis. The averaged values of the parameters over the selected set (and the factors derived from them) are compared with the single conformation values used in the previous study.

Methods of Constructing a Blended Performance Function Suitable for Formation Flight

NASA Technical Reports Server (NTRS)

Ryan, Jack

2017-01-01

Two methods for constructing performance functions for formation fight-for-drag-reduction suitable for use with an extreme-seeking control system are presented. The first method approximates an a prior measured or estimated drag-reduction performance function by combining real-time measurements of readily available parameters. The parameters are combined with weightings determined from a minimum squares optimization to form a blended performance function.

Genome-Wide Comparative Gene Family Classification

PubMed Central

Frech, Christian; Chen, Nansheng

2010-01-01

Correct classification of genes into gene families is important for understanding gene function and evolution. Although gene families of many species have been resolved both computationally and experimentally with high accuracy, gene family classification in most newly sequenced genomes has not been done with the same high standard. This project has been designed to develop a strategy to effectively and accurately classify gene families across genomes. We first examine and compare the performance of computer programs developed for automated gene family classification. We demonstrate that some programs, including the hierarchical average-linkage clustering algorithm MC-UPGMA and the popular Markov clustering algorithm TRIBE-MCL, can reconstruct manual curation of gene families accurately. However, their performance is highly sensitive to parameter setting, i.e. different gene families require different program parameters for correct resolution. To circumvent the problem of parameterization, we have developed a comparative strategy for gene family classification. This strategy takes advantage of existing curated gene families of reference species to find suitable parameters for classifying genes in related genomes. To demonstrate the effectiveness of this novel strategy, we use TRIBE-MCL to classify chemosensory and ABC transporter gene families in C. elegans and its four sister species. We conclude that fully automated programs can establish biologically accurate gene families if parameterized accordingly. Comparative gene family classification finds optimal parameters automatically, thus allowing rapid insights into gene families of newly sequenced species. PMID:20976221

Toward Rigorous Parameterization of Underconstrained Neural Network Models Through Interactive Visualization and Steering of Connectivity Generation

PubMed Central

Nowke, Christian; Diaz-Pier, Sandra; Weyers, Benjamin; Hentschel, Bernd; Morrison, Abigail; Kuhlen, Torsten W.; Peyser, Alexander

2018-01-01

Simulation models in many scientific fields can have non-unique solutions or unique solutions which can be difficult to find. Moreover, in evolving systems, unique final state solutions can be reached by multiple different trajectories. Neuroscience is no exception. Often, neural network models are subject to parameter fitting to obtain desirable output comparable to experimental data. Parameter fitting without sufficient constraints and a systematic exploration of the possible solution space can lead to conclusions valid only around local minima or around non-minima. To address this issue, we have developed an interactive tool for visualizing and steering parameters in neural network simulation models. In this work, we focus particularly on connectivity generation, since finding suitable connectivity configurations for neural network models constitutes a complex parameter search scenario. The development of the tool has been guided by several use cases—the tool allows researchers to steer the parameters of the connectivity generation during the simulation, thus quickly growing networks composed of multiple populations with a targeted mean activity. The flexibility of the software allows scientists to explore other connectivity and neuron variables apart from the ones presented as use cases. With this tool, we enable an interactive exploration of parameter spaces and a better understanding of neural network models and grapple with the crucial problem of non-unique network solutions and trajectories. In addition, we observe a reduction in turn around times for the assessment of these models, due to interactive visualization while the simulation is computed. PMID:29937723

Hardrock Elastic Physical Properties: Birch's Seismic Parameter Revisited

NASA Astrophysics Data System (ADS)

Wu, M.; Milkereit, B.

2014-12-01

Identifying rock composition and properties is imperative in a variety of fields including geotechnical engineering, mining, and petroleum exploration, in order to accurately make any petrophysical calculations. Density is, in particular, an important parameter that allows us to differentiate between lithologies and estimate or calculate other petrophysical properties. It is well established that compressional and shear wave velocities of common crystalline rocks increase with increasing densities (i.e. the Birch and Nafe-Drake relationships). Conventional empirical relations do not take into account S-wave velocity. Physical properties of Fe-oxides and massive sulfides, however, differ significantly from the empirical velocity-density relationships. Currently, acquiring in-situ density data is challenging and problematic, and therefore, developing an approximation for density based on seismic wave velocity and elastic moduli would be beneficial. With the goal of finding other possible or better relationships between density and the elastic moduli, a database of density, P-wave velocity, S-wave velocity, bulk modulus, shear modulus, Young's modulus, and Poisson's ratio was compiled based on a multitude of lab samples. The database is comprised of isotropic, non-porous metamorphic rock. Multi-parameter cross plots of the various elastic parameters have been analyzed in order to find a suitable parameter combination that reduces high density outliers. As expected, the P-wave velocity to S-wave velocity ratios show no correlation with density. However, Birch's seismic parameter, along with the bulk modulus, shows promise in providing a link between observed compressional and shear wave velocities and rock densities, including massive sulfides and Fe-oxides.

Driving Performance Under Alcohol in Simulated Representative Driving Tasks

PubMed Central

Kenntner-Mabiala, Ramona; Kaussner, Yvonne; Jagiellowicz-Kaufmann, Monika; Hoffmann, Sonja; Krüger, Hans-Peter

2015-01-01

Abstract Comparing drug-induced driving impairments with the effects of benchmark blood alcohol concentrations (BACs) is an approved approach to determine the clinical relevance of findings for traffic safety. The present study aimed to collect alcohol calibration data to validate findings of clinical trials that were derived from a representative test course in a dynamic driving simulator. The driving performance of 24 healthy volunteers under placebo and with 0.05% and 0.08% BACs was measured in a double-blind, randomized, crossover design. Trained investigators assessed the subjects’ driving performance and registered their driving errors. Various driving parameters that were recorded during the simulation were also analyzed. Generally, the participants performed worse on the test course (P < 0.05 for the investigators’ assessment) under the influence of alcohol. Consistent with the relevant literature, lane-keeping performance parameters were sensitive to the investigated BACs. There were significant differences between the alcohol and placebo conditions in most of the parameters analyzed. However, the total number of errors was the only parameter discriminating significantly between all three BAC conditions. In conclusion, data show that the present experimental setup is suitable for future psychopharmacological research. Thereby, for each drug to be investigated, we recommend to assess a profile of various parameters that address different levels of driving. On the basis of this performance profile, the total number of driving errors is recommended as the primary endpoint. However, this overall endpoint should be completed by a specifically sensitive parameter that is chosen depending on the effect known to be induced by the tested drug. PMID:25689289

Isoflurane is a suitable alternative to ether for anesthetizing rats prior to euthanasia for gene expression analysis.

PubMed

Nakatsu, Noriyuki; Igarashi, Yoshinobu; Aoshi, Taiki; Hamaguchi, Isao; Saito, Masumichi; Mizukami, Takuo; Momose, Haruka; Ishii, Ken J; Yamada, Hiroshi

2017-01-01

Diethyl ether (ether) had been widely used in Japan for anesthesia, despite its explosive properties and toxicity to both humans and animals. We also had used ether as an anesthetic for euthanizing rats for research in the Toxicogenomics Project (TGP). Because the use of ether for these purposes will likely cease, it is required to select an alternative anesthetic which is validated for consistency with existing TGP data acquired under ether anesthesia. We therefore compared two alternative anesthetic candidates, isoflurane and pentobarbital, with ether in terms of hematological findings, serum biochemical parameters, and gene expressions. As a result, few differences among the three agents were observed. In hematological and serum biochemistry analysis, no significant changes were found. In gene expression analysis, four known genes were extracted as differentially expressed genes in the liver of rats anesthetized with ether, isoflurane, or pentobarbital. However, no significant relationships were detected using gene ontology, pathway, or gene enrichment analyses by DAVID and TargetMine. Surprisingly, although it was expected that the lung would be affected by administration via inhalation, only one differentially expressed gene was extracted in the lung. Taken together, our data indicate that there are no significant differences among ether, isoflurane, and pentobarbital with respect to effects on hematological parameters, serum biochemistry parameters, and gene expression. Based on its smallest affect to existing data and its safety profile for humans and animals, we suggest isoflurane as a suitable alternative anesthetic for use in rat euthanasia in toxicogenomics analysis.

Maximum likelihood estimation of protein kinetic parameters under weak assumptions from unfolding force spectroscopy experiments

NASA Astrophysics Data System (ADS)

Aioanei, Daniel; Samorì, Bruno; Brucale, Marco

2009-12-01

Single molecule force spectroscopy (SMFS) is extensively used to characterize the mechanical unfolding behavior of individual protein domains under applied force by pulling chimeric polyproteins consisting of identical tandem repeats. Constant velocity unfolding SMFS data can be employed to reconstruct the protein unfolding energy landscape and kinetics. The methods applied so far require the specification of a single stretching force increase function, either theoretically derived or experimentally inferred, which must then be assumed to accurately describe the entirety of the experimental data. The very existence of a suitable optimal force model, even in the context of a single experimental data set, is still questioned. Herein, we propose a maximum likelihood (ML) framework for the estimation of protein kinetic parameters which can accommodate all the established theoretical force increase models. Our framework does not presuppose the existence of a single force characteristic function. Rather, it can be used with a heterogeneous set of functions, each describing the protein behavior in the stretching time range leading to one rupture event. We propose a simple way of constructing such a set of functions via piecewise linear approximation of the SMFS force vs time data and we prove the suitability of the approach both with synthetic data and experimentally. Additionally, when the spontaneous unfolding rate is the only unknown parameter, we find a correction factor that eliminates the bias of the ML estimator while also reducing its variance. Finally, we investigate which of several time-constrained experiment designs leads to better estimators.

Competing Uses of Underground Systems Related to Energy Supply: Applying Single- and Multiphase Simulations for Site Characterization and Risk-Analysis

NASA Astrophysics Data System (ADS)

Kissinger, A.; Walter, L.; Darcis, M.; Flemisch, B.; Class, H.

2012-04-01

Global climate change, shortage of resources and the resulting turn towards renewable sources of energy lead to a growing demand for the utilization of subsurface systems. Among these competing uses are Carbon Capture and Storage (CCS), geothermal energy, nuclear waste disposal, "renewable" methane or hydrogen storage as well as the ongoing production of fossil resources like oil, gas, and coal. Besides competing among themselves, these technologies may also create conflicts with essential public interests like water supply. For example, the injection of CO2 into the underground causes an increase in pressure reaching far beyond the actual radius of influence of the CO2 plume, potentially leading to large amounts of displaced salt water. Finding suitable sites is a demanding task for several reasons. Natural systems as opposed to technical systems are always characterized by heterogeneity. Therefore, parameter uncertainty impedes reliable predictions towards capacity and safety of a site. State of the art numerical simulations combined with stochastic approaches need to be used to obtain a more reliable assessment of the involved risks and the radii of influence of the different processes. These simulations may include the modeling of single- and multiphase non-isothermal flow, geo-chemical and geo-mechanical processes in order to describe all relevant physical processes adequately. Stochastic approaches have the aim to estimate a bandwidth of the key output parameters based on uncertain input parameters. Risks for these different underground uses can then be made comparable with each other. Along with the importance and the urgency of the competing processes this may lead to a more profound basis for a decision. Communicating risks to stake holders and a concerned public is crucial for the success of finding a suitable site for CCS (or other subsurface utilization). We present and discuss first steps towards an approach for addressing the issue of competitive utilization of the subsurface and the required process of communication between scientists, engineers, policy makers, and societies.

An analysis of sensitivity of CLIMEX parameters in mapping species potential distribution and the broad-scale changes observed with minor variations in parameters values: an investigation using open-field Solanum lycopersicum and Neoleucinodes elegantalis as an example

NASA Astrophysics Data System (ADS)

da Silva, Ricardo Siqueira; Kumar, Lalit; Shabani, Farzin; Picanço, Marcelo Coutinho

2018-04-01

A sensitivity analysis can categorize levels of parameter influence on a model's output. Identifying parameters having the most influence facilitates establishing the best values for parameters of models, providing useful implications in species modelling of crops and associated insect pests. The aim of this study was to quantify the response of species models through a CLIMEX sensitivity analysis. Using open-field Solanum lycopersicum and Neoleucinodes elegantalis distribution records, and 17 fitting parameters, including growth and stress parameters, comparisons were made in model performance by altering one parameter value at a time, in comparison to the best-fit parameter values. Parameters that were found to have a greater effect on the model results are termed "sensitive". Through the use of two species, we show that even when the Ecoclimatic Index has a major change through upward or downward parameter value alterations, the effect on the species is dependent on the selection of suitability categories and regions of modelling. Two parameters were shown to have the greatest sensitivity, dependent on the suitability categories of each species in the study. Results enhance user understanding of which climatic factors had a greater impact on both species distributions in our model, in terms of suitability categories and areas, when parameter values were perturbed by higher or lower values, compared to the best-fit parameter values. Thus, the sensitivity analyses have the potential to provide additional information for end users, in terms of improving management, by identifying the climatic variables that are most sensitive.

A fully-stochasticized, age-structured population model for population viability analysis of fish: Lower Missouri River endangered pallid sturgeon example

USGS Publications Warehouse

Wildhaber, Mark L.; Albers, Janice; Green, Nicholas; Moran, Edward H.

2017-01-01

We develop a fully-stochasticized, age-structured population model suitable for population viability analysis (PVA) of fish and demonstrate its use with the endangered pallid sturgeon (Scaphirhynchus albus) of the Lower Missouri River as an example. The model incorporates three levels of variance: parameter variance (uncertainty about the value of a parameter itself) applied at the iteration level, temporal variance (uncertainty caused by random environmental fluctuations over time) applied at the time-step level, and implicit individual variance (uncertainty caused by differences between individuals) applied within the time-step level. We found that population dynamics were most sensitive to survival rates, particularly age-2+ survival, and to fecundity-at-length. The inclusion of variance (unpartitioned or partitioned), stocking, or both generally decreased the influence of individual parameters on population growth rate. The partitioning of variance into parameter and temporal components had a strong influence on the importance of individual parameters, uncertainty of model predictions, and quasiextinction risk (i.e., pallid sturgeon population size falling below 50 age-1+ individuals). Our findings show that appropriately applying variance in PVA is important when evaluating the relative importance of parameters, and reinforce the need for better and more precise estimates of crucial life-history parameters for pallid sturgeon.

Molecular dynamics study of combustion reactions in supercritical environment. Part 1: Carbon dioxide and water force field parameters refitting and critical isotherms of binary mixtures

DOE PAGES

Masunov, Artem E.; Atlanov, Arseniy Alekseyevich; Vasu, Subith S.

2016-10-04

Oxy-fuel combustion process is expected to drastically increase the energy efficiency and enable easy carbon sequestration. In this technology the combustion products (carbon dioxide and water) are used to control the temperature and nitrogen is excluded from the combustion chamber, so that nitrogen oxide pollutants do not form. Therefore, in oxycombustion the carbon dioxide and water are present in large concentrations in their transcritical state, and may play an important role in kinetics. The computational chemistry methods may assist in understanding these effects, and Molecular Dynamics with ReaxFF force field seem to be a suitable tool for such a study.more » Here we investigate applicability of the ReaxFF to describe the critical phenomena in carbon dioxide and water and find that several nonbonding parameters need adjustment. We report the new parameter set, capable to reproduce the critical temperatures and pressures. Furthermore, the critical isotherms of CO 2/H 2O binary mixtures are computationally studied here for the first time and their critical parameters are reported.« less

Molecular dynamics study of combustion reactions in supercritical environment. Part 1: Carbon dioxide and water force field parameters refitting and critical isotherms of binary mixtures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Masunov, Artem E.; Atlanov, Arseniy Alekseyevich; Vasu, Subith S.

Oxy-fuel combustion process is expected to drastically increase the energy efficiency and enable easy carbon sequestration. In this technology the combustion products (carbon dioxide and water) are used to control the temperature and nitrogen is excluded from the combustion chamber, so that nitrogen oxide pollutants do not form. Therefore, in oxycombustion the carbon dioxide and water are present in large concentrations in their transcritical state, and may play an important role in kinetics. The computational chemistry methods may assist in understanding these effects, and Molecular Dynamics with ReaxFF force field seem to be a suitable tool for such a study.more » Here we investigate applicability of the ReaxFF to describe the critical phenomena in carbon dioxide and water and find that several nonbonding parameters need adjustment. We report the new parameter set, capable to reproduce the critical temperatures and pressures. Furthermore, the critical isotherms of CO 2/H 2O binary mixtures are computationally studied here for the first time and their critical parameters are reported.« less

Nonlinear Multiscale Modeling of 3D Woven Fiber Composites under Ballistic Loading

DTIC Science & Technology

2013-07-11

contact parameters on the underlying damage processes is being studied and worked on. We further develop a material model suitable particularly for...of Material and Process Engineering. 2011/05/23 00:00:00, . : , TOTAL: 1 (d) Manuscripts Number of Peer-Reviewed Conference Proceeding publications...continuum damage mechanics suitable for polymer materials. The effect of contact parameters on the underlying damage processes is being studied and

White LED compared with other light sources: age-dependent photobiological effects and parameters for evaluation.

PubMed

Rebec, Katja Malovrh; Klanjšek-Gunde, Marta; Bizjak, Grega; Kobav, Matej B

2015-01-01

Ergonomic science at work and living places should appraise human factors concerning the photobiological effects of lighting. Thorough knowledge on this subject has been gained in the past; however, few attempts have been made to propose suitable evaluation parameters. The blue light hazard and its influence on melatonin secretion in age-dependent observers is considered in this paper and parameters for its evaluation are proposed. New parameters were applied to analyse the effects of white light-emitting diode (LED) light sources and to compare them with the currently applied light sources. The photobiological effects of light sources with the same illuminance but different spectral power distribution were determined for healthy 4-76-year-old observers. The suitability of new parameters is discussed. Correlated colour temperature, the only parameter currently used to assess photobiological effects, is evaluated and compared to new parameters.

Diffusive and Arrestedlike Dynamics in Currency Exchange Markets

NASA Astrophysics Data System (ADS)

Clara-Rahola, J.; Puertas, A. M.; Sánchez-Granero, M. A.; Trinidad-Segovia, J. E.; de las Nieves, F. J.

2017-02-01

This work studies the symmetry between colloidal dynamics and the dynamics of the Euro-U.S. dollar currency exchange market (EURUSD). We consider the EURUSD price in the time range between 2001 and 2015, where we find significant qualitative symmetry between fluctuation distributions from this market and the ones belonging to colloidal particles in supercooled or arrested states. In particular, we find that models used for arrested physical systems are suitable for describing the EURUSD fluctuation distributions. Whereas the corresponding mean-squared price displacement (MSPD) to the EURUSD is diffusive for all years, when focusing in selected time frames within a day, we find a two-step MSPD when the New York Stock Exchange market closes, comparable to the dynamics in supercooled systems. This is corroborated by looking at the price correlation functions and non-Gaussian parameters and can be described by the theoretical model. We discuss the origin and implications of this analogy.

Which model based on fluorescence quenching is suitable to study the interaction between trans-resveratrol and BSA?

NASA Astrophysics Data System (ADS)

Wei, Xin Lin; Xiao, Jian Bo; Wang, Yuanfeng; Bai, Yalong

2010-01-01

There are several models by means of quenching fluorescence of BSA to determine the binding parameters. The binding parameters obtained from different models are quite different from each other. Which model is suitable to study the interaction between trans-resveratrol and BSA? Herein, twelve models based fluorescence quenching of BSA were compared. The number of binding sites increasing with increased binding constant for similar compounds binding to BSA maybe one approach to resolve this question. For example, here eleven flavonoids were tested to illustrate that the double logarithm regression curve is suitable to study binding polyphenols to BSA.

Allocation of solid waste collection bins and route optimisation using geographical information system: A case study of Dhanbad City, India.

PubMed

Khan, D; Samadder, S R

2016-07-01

Collection of municipal solid waste is one of the most important elements of municipal waste management and requires maximum fund allocated for waste management. The cost of collection and transportation can be reduced in comparison with the present scenario if the solid waste collection bins are located at suitable places so that the collection routes become minimum. This study presents a suitable solid waste collection bin allocation method at appropriate places with uniform distance and easily accessible location so that the collection vehicle routes become minimum for the city Dhanbad, India. The network analyst tool set available in ArcGIS was used to find the optimised route for solid waste collection considering all the required parameters for solid waste collection efficiently. These parameters include the positions of solid waste collection bins, the road network, the population density, waste collection schedules, truck capacities and their characteristics. The present study also demonstrates the significant cost reductions that can be obtained compared with the current practices in the study area. The vehicle routing problem solver tool of ArcGIS was used to identify the cost-effective scenario for waste collection, to estimate its running costs and to simulate its application considering both travel time and travel distance simultaneously. © The Author(s) 2016.

Study of the suitability of a commercial hydroxyapatite powder to obtain sintered compacts for medical applications

NASA Astrophysics Data System (ADS)

Palacio, C.; Jaramillo, D.; Correa, S.; Arroyave, M.

2017-06-01

Hydroxyapatite (HA) is a material widely used by the medical community due to its Ca/P ratio is comparable to the Ca/P ratio of bones and teeth, which promotes osteoinduction and osteoconduction processes when in contact with bone tissue, either as volume piece or coating. This work focuses on studying the quality of the commercial HA powder MKnano-#MKN-HXAP-S12 µm, after processing, to obtain sintered compact discs with suitable physical and chemical characteristics for implants applications. The HA powder was processed through calcination, grinding, pressing and sintering to evaluate the effect of such as procedures in the compacts dics quality. The raw powder was characterized by laser diffraction, SEM, XRF, XRD, TGA and DSC while the characteristics of the obtained compact discs were determined by dilatometry and XRD to identify the sintering temperature range, constituent phases, the amorphous content and the crystallinity degree, parameters that allow determining their suitability for implants applications. Although, it was not possible to obtain sintered compacts with the suitable chemical composition and without fractures, this work allowed to identify the parameters that determine the suitability of a HA powder to obtain sintered compacts for medical applications, as well as the characterization protocol that allows the evaluation of such parameters.

Automatic Differentiation in Quantum Chemistry with Applications to Fully Variational Hartree-Fock.

PubMed

Tamayo-Mendoza, Teresa; Kreisbeck, Christoph; Lindh, Roland; Aspuru-Guzik, Alán

2018-05-23

Automatic differentiation (AD) is a powerful tool that allows calculating derivatives of implemented algorithms with respect to all of their parameters up to machine precision, without the need to explicitly add any additional functions. Thus, AD has great potential in quantum chemistry, where gradients are omnipresent but also difficult to obtain, and researchers typically spend a considerable amount of time finding suitable analytical forms when implementing derivatives. Here, we demonstrate that AD can be used to compute gradients with respect to any parameter throughout a complete quantum chemistry method. We present DiffiQult , a Hartree-Fock implementation, entirely differentiated with the use of AD tools. DiffiQult is a software package written in plain Python with minimal deviation from standard code which illustrates the capability of AD to save human effort and time in implementations of exact gradients in quantum chemistry. We leverage the obtained gradients to optimize the parameters of one-particle basis sets in the context of the floating Gaussian framework.

MHD effects and heat transfer for the UCM fluid along with Joule heating and thermal radiation using Cattaneo-Christov heat flux model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shah, S., E-mail: sajidshah313@yahoo.com; Hussain, S.; Sagheer, M.

2016-08-15

Present study examines the numerical analysis of MHD flow of Maxwell fluid with thermal radiation and Joule heating by considering the recently developed Cattaneo-Christov heat flux model which explains the time relaxation characteristics for the heat flux. The objective is to analyze the governing parameters such as viscoelastic fluid parameter, Magnetic parameter, Eckert and Prandtl number’s impact on the velocity and temperature profiles through graphs and tables. Suitable similarity transformations have been used to reduce the formulated PDEs into a system of coupled non-linear ODEs. Shooting technique has been invoked for finding the numerical solutions of the dimensionless velocity andmore » temperature profiles. Additionally, the MATLAB built-in routine bvp4c has also been used to verify and strengthen the results obtained by shooting method. From some special cases of the present work, a comparison with the previously published results has been presented.« less

Consistency of the tachyon warm inflationary universe models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Xiao-Min; Zhu, Jian-Yang, E-mail: zhangxm@mail.bnu.edu.cn, E-mail: zhujy@bnu.edu.cn

2014-02-01

This study concerns the consistency of the tachyon warm inflationary models. A linear stability analysis is performed to find the slow-roll conditions, characterized by the potential slow-roll (PSR) parameters, for the existence of a tachyon warm inflationary attractor in the system. The PSR parameters in the tachyon warm inflationary models are redefined. Two cases, an exponential potential and an inverse power-law potential, are studied, when the dissipative coefficient Γ = Γ{sub 0} and Γ = Γ(φ), respectively. A crucial condition is obtained for a tachyon warm inflationary model characterized by the Hubble slow-roll (HSR) parameter ε{sub H}, and the conditionmore » is extendable to some other inflationary models as well. A proper number of e-folds is obtained in both cases of the tachyon warm inflation, in contrast to existing works. It is also found that a constant dissipative coefficient (Γ = Γ{sub 0}) is usually not a suitable assumption for a warm inflationary model.« less

Iterative Importance Sampling Algorithms for Parameter Estimation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grout, Ray W; Morzfeld, Matthias; Day, Marcus S.

In parameter estimation problems one computes a posterior distribution over uncertain parameters defined jointly by a prior distribution, a model, and noisy data. Markov chain Monte Carlo (MCMC) is often used for the numerical solution of such problems. An alternative to MCMC is importance sampling, which can exhibit near perfect scaling with the number of cores on high performance computing systems because samples are drawn independently. However, finding a suitable proposal distribution is a challenging task. Several sampling algorithms have been proposed over the past years that take an iterative approach to constructing a proposal distribution. We investigate the applicabilitymore » of such algorithms by applying them to two realistic and challenging test problems, one in subsurface flow, and one in combustion modeling. More specifically, we implement importance sampling algorithms that iterate over the mean and covariance matrix of Gaussian or multivariate t-proposal distributions. Our implementation leverages massively parallel computers, and we present strategies to initialize the iterations using 'coarse' MCMC runs or Gaussian mixture models.« less

Automatic Differentiation in Quantum Chemistry with Applications to Fully Variational Hartree–Fock

PubMed Central

2018-01-01

Automatic differentiation (AD) is a powerful tool that allows calculating derivatives of implemented algorithms with respect to all of their parameters up to machine precision, without the need to explicitly add any additional functions. Thus, AD has great potential in quantum chemistry, where gradients are omnipresent but also difficult to obtain, and researchers typically spend a considerable amount of time finding suitable analytical forms when implementing derivatives. Here, we demonstrate that AD can be used to compute gradients with respect to any parameter throughout a complete quantum chemistry method. We present DiffiQult, a Hartree–Fock implementation, entirely differentiated with the use of AD tools. DiffiQult is a software package written in plain Python with minimal deviation from standard code which illustrates the capability of AD to save human effort and time in implementations of exact gradients in quantum chemistry. We leverage the obtained gradients to optimize the parameters of one-particle basis sets in the context of the floating Gaussian framework.

Introducing conjoint analysis method into delayed lotteries studies: its validity and time stability are higher than in adjusting.

PubMed

Białek, Michał; Markiewicz, Łukasz; Sawicki, Przemysław

2015-01-01

The delayed lotteries are much more common in everyday life than are pure lotteries. Usually, we need to wait to find out the outcome of the risky decision (e.g., investing in a stock market, engaging in a relationship). However, most research has studied the time discounting and probability discounting in isolation using the methodologies designed specifically to track changes in one parameter. Most commonly used method is adjusting, but its reported validity and time stability in research on discounting are suboptimal. The goal of this study was to introduce the novel method for analyzing delayed lotteries-conjoint analysis-which hypothetically is more suitable for analyzing individual preferences in this area. A set of two studies compared the conjoint analysis with adjusting. The results suggest that individual parameters of discounting strength estimated with conjoint have higher predictive value (Study 1 and 2), and they are more stable over time (Study 2) compared to adjusting. We discuss these findings, despite the exploratory character of reported studies, by suggesting that future research on delayed lotteries should be cross-validated using both methods.

Renormalization group fixed points of foliated gravity-matter systems

NASA Astrophysics Data System (ADS)

Biemans, Jorn; Platania, Alessia; Saueressig, Frank

2017-05-01

We employ the Arnowitt-Deser-Misner formalism to study the renormalization group flow of gravity minimally coupled to an arbitrary number of scalar, vector, and Dirac fields. The decomposition of the gravitational degrees of freedom into a lapse function, shift vector, and spatial metric equips spacetime with a preferred (Euclidean) "time"- direction. In this work, we provide a detailed derivation of the renormalization group flow of Newton's constant and the cosmological constant on a flat Friedmann-Robertson-Walker background. Adding matter fields, it is shown that their contribution to the flow is the same as in the covariant formulation and can be captured by two parameters d g d λ . We classify the resulting fixed point structure as a function of these parameters finding that the existence of non-Gaussian renormalization group fixed points is rather generic. In particular the matter content of the standard model and its most common extensions gives rise to one non-Gaussian fixed point with real critical exponents suitable for Asymptotic Safety. Moreover, we find non-Gaussian fixed points for any number of scalar matter fields, making the scenario attractive for cosmological model building.

Large-scale high density 3D AMT for mineral exploration — A case history from volcanic massive sulfide Pb-Zn deposit with 2000 AMT sites

NASA Astrophysics Data System (ADS)

Chen, R.; Chen, S.; He, L.; Yao, H.; Li, H.; Xi, X.; Zhao, X.

2017-12-01

EM method plays a key role in volcanic massive sulfide (VMS) deposit which is with high grade and high economic value. However, the performance of high density 3D AMT in detecting deep concealed VMS targets is not clear. The size of a typical VMS target is less than 100 m x 100 m x 50 m, it's a challenge task to find it with large depth. We carried a test in a VMS Pb-Zn deposit using high density 3D AMT with site spacing as 20 m and profile spacing as 40 - 80 m. About 2000 AMT sites were acquired in an area as 2000 m x 1500 m. Then we used a sever with 8 CPUs (Intel Xeon E7-8880 v3, 2.3 GHz, 144 cores), 2048 GB RAM, and 40 TB disk array to invert above 3D AMT sites using integral equation forward modeling and re-weighted conjugated-gradient inversion. The depth of VMS ore body is about 600 m and the size of the ore body is about 100 x 100 x 20m with dip angle about 45 degree. We finds that it's very hard to recover the location and shape of the ore body by 3D AMT inversion even using the data of all AMT sites and frequencies. However, it's possible to recover the location and shape of the deep concealed ore body if we adjust the inversion parameters carefully. A new set of inversion parameter needs to be find for high density 3D AMT data set and the inversion parameters working good for Dublin Secret Model II (DSM 2) is not suitable for our real data. This problem may be caused by different data density and different number of frequency. We find a set of good inversion parameter by comparing the shape and location of ore body with inversion result and trying different inversion parameters. And the application of new inversion parameter in nearby area with high density AMT sites shows that the inversion result is improved greatly.

One-dimensional sections of exotic spacetimes with superconducting circuits

NASA Astrophysics Data System (ADS)

Sabín, Carlos

2018-05-01

We introduce analogue quantum simulations of 1 + 1 dimensional sections of exotic 3 + 1 dimensional spacetimes, such as Alcubierre warp-drive spacetime, Gödel rotating universe and Kerr highly-rotating black hole metric. Suitable magnetic flux profiles along a SQUID array embedded in a superconducting transmission line allow to generate an effective spatiotemporal dependence in the speed of light, which is able to mimic the corresponding light propagation in a dimensionally-reduced exotic spacetime. In each case, we discuss the technical constraints and the links with possible chronology protection mechanisms and we find the optimal region of parameters for the experimental implementation.

On isochronous derivatives of the first and second order in space dynamics tasks

NASA Technical Reports Server (NTRS)

Bakshiyan, B. T.; Sukhanov, A. A.

1979-01-01

The first and second isochronous derivatives are calculated from the vector of state of dynamic system using its initial value. Use is made of the method of finding a fundamental solution of conjugate variational equations. This solution and the corresponding universal relationship for isochronous derivatives are found for the two-body problem in a form which is simple and suitable for computer programming. The form of these relationships was obtained for motion which differs from parabolic motion. Formulas are given for isochronous derivatives using the gravitational parameter in the two-body problem.

Global astrometry with the space interferometry mission

NASA Technical Reports Server (NTRS)

Boden, A.; Unwin, S.; Shao, M.

1997-01-01

The prospects for global astrometric measurements with the space interferometry mission (SIM) are discussed. The SIM mission will perform four microarcsec astrometric measurements on objects as faint as 20 mag using the optical interferometry technique with a 10 m baseline. The SIM satellite will perform narrow angle astrometry and global astrometry by means of an astrometric grid. The sensitivities of the SIM global astrometric performance and the grid accuracy versus instrumental parameters and sky coverage schemes are reported on. The problems in finding suitable astrometric grid objects to support microarcsec astrometry, and related ground-based observation programs are discussed.

Model selection using cosmic chronometers with Gaussian Processes

NASA Astrophysics Data System (ADS)

Melia, Fulvio; Yennapureddy, Manoj K.

2018-02-01

The use of Gaussian Processes with a measurement of the cosmic expansion rate based solely on the observation of cosmic chronometers provides a completely cosmology-independent reconstruction of the Hubble constant H(z) suitable for testing different models. The corresponding dispersion σH is smaller than ~ 9% over the entire redshift range (lesssim zlesssim 20) of the observations, rivaling many kinds of cosmological measurements available today. We use the reconstructed H(z) function to test six different cosmologies, and show that it favours the Rh=ct universe, which has only one free parameter (i.e., H0) over other models, including Planck ΛCDM . The parameters of the standard model may be re-optimized to improve the fits to the reconstructed H(z) function, but the results have smaller p-values than one finds with Rh=ct.

Alpha Heating and Burning Plasmas in Inertial Confinement Fusion.

PubMed

Betti, R; Christopherson, A R; Spears, B K; Nora, R; Bose, A; Howard, J; Woo, K M; Edwards, M J; Sanz, J

2015-06-26

Estimating the level of alpha heating and determining the onset of the burning plasma regime is essential to finding the path towards thermonuclear ignition. In a burning plasma, the alpha heating exceeds the external input energy to the plasma. Using a simple model of the implosion, it is shown that a general relation can be derived, connecting the burning plasma regime to the yield enhancement due to alpha heating and to experimentally measurable parameters such as the Lawson ignition parameter. A general alpha-heating curve is found, independent of the target and suitable to assess the performance of all laser fusion experiments whether direct or indirect drive. The onset of the burning plasma regime inside the hot spot of current implosions on the National Ignition Facility requires a fusion yield of about 50 kJ.

A Comparative Study for Flow of Viscoelastic Fluids with Cattaneo-Christov Heat Flux.

PubMed

Hayat, Tasawar; Muhammad, Taseer; Alsaedi, Ahmed; Mustafa, Meraj

2016-01-01

This article examines the impact of Cattaneo-Christov heat flux in flows of viscoelastic fluids. Flow is generated by a linear stretching sheet. Influence of thermal relaxation time in the considered heat flux is seen. Mathematical formulation is presented for the boundary layer approach. Suitable transformations lead to a nonlinear differential system. Convergent series solutions of velocity and temperature are achieved. Impacts of various influential parameters on the velocity and temperature are sketched and discussed. Numerical computations are also performed for the skin friction coefficient and heat transfer rate. Our findings reveal that the temperature profile has an inverse relationship with the thermal relaxation parameter and the Prandtl number. Further the temperature profile and thermal boundary layer thickness are lower for Cattaneo-Christov heat flux model in comparison to the classical Fourier's law of heat conduction.

Predicting perturbation patterns from the topology of biological networks.

PubMed

Santolini, Marc; Barabási, Albert-László

2018-06-20

High-throughput technologies, offering an unprecedented wealth of quantitative data underlying the makeup of living systems, are changing biology. Notably, the systematic mapping of the relationships between biochemical entities has fueled the rapid development of network biology, offering a suitable framework to describe disease phenotypes and predict potential drug targets. However, our ability to develop accurate dynamical models remains limited, due in part to the limited knowledge of the kinetic parameters underlying these interactions. Here, we explore the degree to which we can make reasonably accurate predictions in the absence of the kinetic parameters. We find that simple dynamically agnostic models are sufficient to recover the strength and sign of the biochemical perturbation patterns observed in 87 biological models for which the underlying kinetics are known. Surprisingly, a simple distance-based model achieves 65% accuracy. We show that this predictive power is robust to topological and kinetic parameter perturbations, and we identify key network properties that can increase up to 80% the recovery rate of the true perturbation patterns. We validate our approach using experimental data on the chemotactic pathway in bacteria, finding that a network model of perturbation spreading predicts with ∼80% accuracy the directionality of gene expression and phenotype changes in knock-out and overproduction experiments. These findings show that the steady advances in mapping out the topology of biochemical interaction networks opens avenues for accurate perturbation spread modeling, with direct implications for medicine and drug development.

Assessment and modeling of groundwater quality using WQI and GIS in Upper Egypt area.

PubMed

Rabeiy, Ragab ElSayed

2017-04-04

The continuous growth and development of population need more fresh water for drinking, irrigation, and domestic in arid countries like Egypt. Evaluation the quality of groundwater is an essential study to ensure its suitability for different purposes. In this study, 812 groundwater samples were taken within the middle area of Upper Egypt (Sohag Governorate) to assess the quality of groundwater for drinking and irrigation purposes. Eleven water parameters were analyzed at each groundwater sample (Na + , K + , Ca 2+ , Mg 2+ , HCO 3 - SO 4 2- , Fe 2+ , Mn 2+ , Cl - , electrical conductivity, and pH) to exploit them in water quality evaluation. A classical statistics were applied for the raw data to examine the distribution of physicochemical parameters in the investigated area. The relationship between groundwater parameters was tested using the correlation coefficient where a strong relationship was found between several water parameters such as Ca 2+ and Cl - . Water quality index (WQI) is a mathematical model used to transform many water parameters into a single indicator value which represents the water quality level. Results of WQI showed that 20% of groundwater samples are excellent, 75% are good for drinking, and 7% are very poor water while only 1% of samples are unsuitable for drinking. To test the suitability of groundwater for irrigation, three indices are used; they are sodium adsorption ration (SAR), sodium percentage (Na%), and permeability index (PI). For irrigation suitability, the study proved that most sampling sites are suitable while less than 3% are unsuitable for irrigation. The spatial distribution of the estimated values of WQI, SAR, Na%, PI, and each groundwater parameter was spatially modeled using GIS.

On the orbital stability of pendulum-like vibrations of a rigid body carrying a rotor

NASA Astrophysics Data System (ADS)

Yehia, Hamad M.; El-Hadidy, E. G.

2013-09-01

One of the most notable effects in mechanics is the stabilization of the unstable upper equilibrium position of a symmetric body fixed from one point on its axis of symmetry, either by giving the body a suitable angular velocity or by adding a suitably spinned rotor along its axis. This effect is widely used in technology and in space dynamics. The aim of the present article is to explore the effect of the presence of a rotor on a simple periodic motion of the rigid body and its motion as a physical pendulum. The equation in the variation for pendulum vibrations takes the form in which α depends on the moments of inertia, ρ on the gyrostatic momentum of the rotor and ν (the modulus of the elliptic function) depends on the total energy of the motion. This equation, which reduces to Lame's equation when ρ = 0, has not been studied to any extent in the literature. The determination of the zones of stability and instability of plane motion reduces to finding conditions for the existence of primitive periodic solutions (with periods 4 K( ν), 8 K( ν)) with those parameters. Complete analysis of primitive periodic solutions of this equation is performed analogously to that of Ince for Lame's equation. Zones of stability and instability are determined analytically and illustrated in a graphical form by plotting surfaces separating them in the three-dimensional space of parameters. The problem is also solved numerically in certain regions of the parameter space, and results are compared to analytical ones.

Production of oils and fats by oleaginous microorganisms with an emphasis given to the potential of the nonconventional yeast Yarrowia lipolytica.

PubMed

Carsanba, E; Papanikolaou, S; Erten, H

2018-05-15

Recently, there has been a great upsurge of interest in studies related to several aspects of microbial lipid production, which is one of the top topics in relevant research fields due to the high demand of these fatty materials in food, medical, oleochemical and biofuel industries. Lipid accumulation by the so-called "oleaginous microorganisms" can generate more than 20% w/w of oil in dry biomass and is governed by a plethora of parameters, such as medium pH, incubation temperature, nutrient limitation and C/N (carbon/nitrogen) ratio, which drastically affect the lipid production bioprocess. Until now, considerable work has been undertaken to find the cheapest substrate to enable lipid fermentation by oleaginous microorganisms. This review principally details information regarding microbial lipids, suitable production conditions and focuses attention on using the yeast Yarrowia lipolytica to achieve these objectives. Lipid production by this yeast is discussed and the necessary conditions and suitable substrates are reviewed.

Development of porous ceramsite from construction and demolition waste.

PubMed

Wang, Chuan; Wu, Jian-Zhi; Zhang, Fu-Shen

2013-01-01

The disposal of construction and demolition (C&D) waste has become a serious problem in China due to the rapid increase of Chinese construction industry in recent years. In the present study, typical C&D waste was employed for ceramsite fabrication so as to find a new way for its effective recycling. A novel process was developed for manufacturing high-quality porous ceramsite according to the special chemical composition and properties of C&D waste. Most importantly, a unique bloating agent was developed for the porous structure formation since it was difficult to obtain a suitable porous structure using traditional bloating agents. The effects of processing parameters such as sintering temperature, heating rate and soaking time were investigated, and the bloating mechanism for ceramsite was discussed. The C&D waste ceramsite (CDWC), with high-intensity, low density and homogeneous mechanical properties, was much more suitable for application in the construction field. This study provides a practical process for efficient recycling of the rapidly increasing quantities of C&D waste.

Variations of cosmic large-scale structure covariance matrices across parameter space

NASA Astrophysics Data System (ADS)

Reischke, Robert; Kiessling, Alina; Schäfer, Björn Malte

2017-03-01

The likelihood function for cosmological parameters, given by e.g. weak lensing shear measurements, depends on contributions to the covariance induced by the non-linear evolution of the cosmic web. As highly non-linear clustering to date has only been described by numerical N-body simulations in a reliable and sufficiently precise way, the necessary computational costs for estimating those covariances at different points in parameter space are tremendous. In this work, we describe the change of the matter covariance and the weak lensing covariance matrix as a function of cosmological parameters by constructing a suitable basis, where we model the contribution to the covariance from non-linear structure formation using Eulerian perturbation theory at third order. We show that our formalism is capable of dealing with large matrices and reproduces expected degeneracies and scaling with cosmological parameters in a reliable way. Comparing our analytical results to numerical simulations, we find that the method describes the variation of the covariance matrix found in the SUNGLASS weak lensing simulation pipeline within the errors at one-loop and tree-level for the spectrum and the trispectrum, respectively, for multipoles up to ℓ ≤ 1300. We show that it is possible to optimize the sampling of parameter space where numerical simulations should be carried out by minimizing interpolation errors and propose a corresponding method to distribute points in parameter space in an economical way.

Design of a Single Motor Based Leg Structure with the Consideration of Inherent Mechanical Stability

NASA Astrophysics Data System (ADS)

Taha Manzoor, Muhammad; Sohail, Umer; Noor-e-Mustafa; Nizami, Muhammad Hamza Asif; Ayaz, Yasar

2017-07-01

The fundamental aspect of designing a legged robot is constructing a leg design that is robust and presents a simple control problem. In this paper, we have successfully designed a robotic leg based on a unique four bar mechanism with only one motor per leg. The leg design parameters used in our platform are extracted from design principles used in biological systems, multiple iterations and previous research findings. These principles guide a robotic leg to have minimal mechanical passive impedance, low leg mass and inertia, a suitable foot trajectory utilizing a practical balance between leg kinematics and robot usage, and the resultant inherent mechanical stability. The designed platform also exhibits the key feature of self-locking. Theoretical tools and software iterations were used to derive these practical features and yield an intuitive sense of the required leg design parameters.

Inverting the parameters of an earthquake-ruptured fault with a genetic algorithm

NASA Astrophysics Data System (ADS)

Yu, Ting-To; Fernàndez, Josè; Rundle, John B.

1998-03-01

Natural selection is the spirit of the genetic algorithm (GA): by keeping the good genes in the current generation, thereby producing better offspring during evolution. The crossover function ensures the heritage of good genes from parent to offspring. Meanwhile, the process of mutation creates a special gene, the character of which does not exist in the parent generation. A program based on genetic algorithms using C language is constructed to invert the parameters of an earthquake-ruptured fault. The verification and application of this code is shown to demonstrate its capabilities. It is determined that this code is able to find the global extreme and can be used to solve more practical problems with constraints gathered from other sources. It is shown that GA is superior to other inverting schema in many aspects. This easy handling and yet powerful algorithm should have many suitable applications in the field of geosciences.

Quasi-Static 3-Point Reinforced Carbon-Carbon Bend Test and Analysis for Shuttle Orbiter Wing Leading Edge Impact Damage Thresholds

NASA Technical Reports Server (NTRS)

Fasanella, Edwin L.; Sotiris, Kellas

2006-01-01

Static 3-point bend tests of Reinforced Carbon-Carbon (RCC) were conducted to failure to provide data for additional validation of an LS-DYNA RCC model suitable for predicting the threshold of impact damage to shuttle orbiter wing leading edges. LS-DYNA predictions correlated well with the average RCC failure load, and were good in matching the load vs. deflection. However, correlating the detectable damage using NDE methods with the cumulative damage parameter in LS-DYNA material model 58 was not readily achievable. The difficulty of finding internal RCC damage with NDE and the high sensitivity of the mat58 damage parameter to the load near failure made the task very challenging. In addition, damage mechanisms for RCC due to dynamic impact of debris such as foam and ice and damage mechanisms due to a static loading were, as expected, not equivalent.

Applicability and feasibility of systematic review for performing evidence-based risk assessment in food and feed safety.

PubMed

Aiassa, E; Higgins, J P T; Frampton, G K; Greiner, M; Afonso, A; Amzal, B; Deeks, J; Dorne, J-L; Glanville, J; Lövei, G L; Nienstedt, K; O'connor, A M; Pullin, A S; Rajić, A; Verloo, D

2015-01-01

Food and feed safety risk assessment uses multi-parameter models to evaluate the likelihood of adverse events associated with exposure to hazards in human health, plant health, animal health, animal welfare, and the environment. Systematic review and meta-analysis are established methods for answering questions in health care, and can be implemented to minimize biases in food and feed safety risk assessment. However, no methodological frameworks exist for refining risk assessment multi-parameter models into questions suitable for systematic review, and use of meta-analysis to estimate all parameters required by a risk model may not be always feasible. This paper describes novel approaches for determining question suitability and for prioritizing questions for systematic review in this area. Risk assessment questions that aim to estimate a parameter are likely to be suitable for systematic review. Such questions can be structured by their "key elements" [e.g., for intervention questions, the population(s), intervention(s), comparator(s), and outcome(s)]. Prioritization of questions to be addressed by systematic review relies on the likely impact and related uncertainty of individual parameters in the risk model. This approach to planning and prioritizing systematic review seems to have useful implications for producing evidence-based food and feed safety risk assessment.

Wing attachment position of fruit fly minimizes flight cost

NASA Astrophysics Data System (ADS)

Noest, Robert; Wang, Jane

Flight is energetically costly which means insects need to find ways to reduce their energy expenditure during sustained flight. Previous work has shown that insect muscles can recover some of the energy used for producing flapping motion. Moreover the form of flapping motions are efficient for generating the required force to balance the weight. In this talk, we show that one of the morphological parameters, the wing attachment point on a fly, is suitably located to further reduce the cost for flight, while allowing the fly to be close to stable. We investigate why this is the case and attempt to find a general rule for the optimal location of the wing hinge. Our analysis is based on computations of flapping free flight together with the Floquet stability analysis of periodic flight for descending, hovering and ascending cases.

An exploration of viscosity models in the realm of kinetic theory of liquids originated fluids

NASA Astrophysics Data System (ADS)

Hussain, Azad; Ghafoor, Saadia; Malik, M. Y.; Jamal, Sarmad

The preeminent perspective of this article is to study flow of an Eyring Powell fluid model past a penetrable plate. To find the effects of variable viscosity on fluid model, continuity, momentum and energy equations are elaborated. Here, viscosity is taken as function of temperature. To understand the phenomenon, Reynold and Vogel models of variable viscosity are incorporated. The highly non-linear partial differential equations are transfigured into ordinary differential equations with the help of suitable similarity transformations. The numerical solution of the problem is presented. Graphs are plotted to visualize the behavior of pertinent parameters on the velocity and temperature profiles.

Why Clothes Don't Fall Apart: Tension Transmission in Staple Yarns

NASA Astrophysics Data System (ADS)

Warren, Patrick B.; Ball, Robin C.; Goldstein, Raymond E.

2018-04-01

The problem of how staple yarns transmit tension is addressed within abstract models in which the Amontons-Coulomb friction laws yield a linear programing (LP) problem for the tensions in the fiber elements. We find there is a percolation transition such that above the percolation threshold the transmitted tension is in principle unbounded. We determine that the mean slack in the LP constraints is a suitable order parameter to characterize this supercritical state. We argue the mechanism is generic, and in practical terms, it corresponds to a switch from a ductile to a brittle failure mode accompanied by a significant increase in mechanical strength.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salmilehto, J.; Deppe, F.; Di Ventra, M.

Memristors are resistive elements retaining information of their past dynamics. They have garnered substantial interest due to their potential for representing a paradigm change in electronics, information processing and unconventional computing. Given the advent of quantum technologies, a design for a quantum memristor with superconducting circuits may be envisaged. Along these lines, we introduce such a quantum device whose memristive behavior arises from quasiparticle-induced tunneling when supercurrents are cancelled. Here in this paper, for realistic parameters, we find that the relevant hysteretic behavior may be observed using current state-of-the-art measurements of the phase-driven tunneling current. Finally, we develop suitable methodsmore » to quantify memory retention in the system.« less

Quantum Memristors with Superconducting Circuits

PubMed Central

Salmilehto, J.; Deppe, F.; Di Ventra, M.; Sanz, M.; Solano, E.

2017-01-01

Memristors are resistive elements retaining information of their past dynamics. They have garnered substantial interest due to their potential for representing a paradigm change in electronics, information processing and unconventional computing. Given the advent of quantum technologies, a design for a quantum memristor with superconducting circuits may be envisaged. Along these lines, we introduce such a quantum device whose memristive behavior arises from quasiparticle-induced tunneling when supercurrents are cancelled. For realistic parameters, we find that the relevant hysteretic behavior may be observed using current state-of-the-art measurements of the phase-driven tunneling current. Finally, we develop suitable methods to quantify memory retention in the system. PMID:28195193

50 CFR 23.65 - What factors are considered in making a finding that an applicant is suitably equipped to house...

Code of Federal Regulations, 2011 CFR

2011-10-01

... finding that an applicant is suitably equipped to house and care for a live specimen? 23.65 Section 23.65... an applicant is suitably equipped to house and care for a live specimen? (a) Purpose. Under Article... house and care for them. (b) General principles. We will follow these general principles in making a...

Laser Direct Metal Deposition of 2024 Al Alloy: Trace Geometry Prediction via Machine Learning.

PubMed

Caiazzo, Fabrizia; Caggiano, Alessandra

2018-03-19

Laser direct metal deposition is an advanced additive manufacturing technology suitably applicable in maintenance, repair, and overhaul of high-cost products, allowing for minimal distortion of the workpiece, reduced heat affected zones, and superior surface quality. Special interest is growing for the repair and coating of 2024 aluminum alloy parts, extensively utilized for a wide range of applications in the automotive, military, and aerospace sectors due to its excellent plasticity, corrosion resistance, electric conductivity, and strength-to-weight ratio. A critical issue in the laser direct metal deposition process is related to the geometrical parameters of the cross-section of the deposited metal trace that should be controlled to meet the part specifications. In this research, a machine learning approach based on artificial neural networks is developed to find the correlation between the laser metal deposition process parameters and the output geometrical parameters of the deposited metal trace produced by laser direct metal deposition on 5-mm-thick 2024 aluminum alloy plates. The results show that the neural network-based machine learning paradigm is able to accurately estimate the appropriate process parameters required to obtain a specified geometry for the deposited metal trace.

Laser Direct Metal Deposition of 2024 Al Alloy: Trace Geometry Prediction via Machine Learning

PubMed Central

2018-01-01

Laser direct metal deposition is an advanced additive manufacturing technology suitably applicable in maintenance, repair, and overhaul of high-cost products, allowing for minimal distortion of the workpiece, reduced heat affected zones, and superior surface quality. Special interest is growing for the repair and coating of 2024 aluminum alloy parts, extensively utilized for a wide range of applications in the automotive, military, and aerospace sectors due to its excellent plasticity, corrosion resistance, electric conductivity, and strength-to-weight ratio. A critical issue in the laser direct metal deposition process is related to the geometrical parameters of the cross-section of the deposited metal trace that should be controlled to meet the part specifications. In this research, a machine learning approach based on artificial neural networks is developed to find the correlation between the laser metal deposition process parameters and the output geometrical parameters of the deposited metal trace produced by laser direct metal deposition on 5-mm-thick 2024 aluminum alloy plates. The results show that the neural network-based machine learning paradigm is able to accurately estimate the appropriate process parameters required to obtain a specified geometry for the deposited metal trace. PMID:29562682

Analytical design of modified Smith predictor for unstable second-order processes with time delay

NASA Astrophysics Data System (ADS)

Ajmeri, Moina; Ali, Ahmad

2017-06-01

In this paper, a modified Smith predictor using three controllers, namely, stabilising (Gc), set-point tracking (Gc1), and load disturbance rejection (Gc2) controllers is proposed for second-order unstable processes with time delay. Controllers of the proposed structure are tuned using direct synthesis approach as this method enables the user to achieve a trade-off between the performance and robustness by adjusting a single design parameter. Furthermore, suitable values of the tuning parameters are recommended after studying their effect on the closed-loop performance and robustness. This is the main advantage of the proposed work over other recently published manuscripts, where authors provide only suitable ranges for the tuning parameters in spite of giving their suitable values. Simulation studies show that the proposed method results in satisfactory performance and improved robustness as compared to the recently reported control schemes. It is observed that the proposed scheme is able to work in the noisy environment also.

Comparision of the different probability distributions for earthquake hazard assessment in the North Anatolian Fault Zone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yilmaz, Şeyda, E-mail: seydayilmaz@ktu.edu.tr; Bayrak, Erdem, E-mail: erdmbyrk@gmail.com; Bayrak, Yusuf, E-mail: bayrak@ktu.edu.tr

In this study we examined and compared the three different probabilistic distribution methods for determining the best suitable model in probabilistic assessment of earthquake hazards. We analyzed a reliable homogeneous earthquake catalogue between a time period 1900-2015 for magnitude M ≥ 6.0 and estimated the probabilistic seismic hazard in the North Anatolian Fault zone (39°-41° N 30°-40° E) using three distribution methods namely Weibull distribution, Frechet distribution and three-parameter Weibull distribution. The distribution parameters suitability was evaluated Kolmogorov-Smirnov (K-S) goodness-of-fit test. We also compared the estimated cumulative probability and the conditional probabilities of occurrence of earthquakes for different elapsed timemore » using these three distribution methods. We used Easyfit and Matlab software to calculate these distribution parameters and plotted the conditional probability curves. We concluded that the Weibull distribution method was the most suitable than other distribution methods in this region.« less

Numerical modeling techniques for flood analysis

NASA Astrophysics Data System (ADS)

Anees, Mohd Talha; Abdullah, K.; Nawawi, M. N. M.; Ab Rahman, Nik Norulaini Nik; Piah, Abd. Rahni Mt.; Zakaria, Nor Azazi; Syakir, M. I.; Mohd. Omar, A. K.

2016-12-01

Topographic and climatic changes are the main causes of abrupt flooding in tropical areas. It is the need to find out exact causes and effects of these changes. Numerical modeling techniques plays a vital role for such studies due to their use of hydrological parameters which are strongly linked with topographic changes. In this review, some of the widely used models utilizing hydrological and river modeling parameters and their estimation in data sparse region are discussed. Shortcomings of 1D and 2D numerical models and the possible improvements over these models through 3D modeling are also discussed. It is found that the HEC-RAS and FLO 2D model are best in terms of economical and accurate flood analysis for river and floodplain modeling respectively. Limitations of FLO 2D in floodplain modeling mainly such as floodplain elevation differences and its vertical roughness in grids were found which can be improve through 3D model. Therefore, 3D model was found to be more suitable than 1D and 2D models in terms of vertical accuracy in grid cells. It was also found that 3D models for open channel flows already developed recently but not for floodplain. Hence, it was suggested that a 3D model for floodplain should be developed by considering all hydrological and high resolution topographic parameter's models, discussed in this review, to enhance the findings of causes and effects of flooding.

Electron paramagnetic resonance field-modulation eddy-current analysis of silver-plated graphite resonators

NASA Astrophysics Data System (ADS)

Mett, Richard R.; Anderson, James R.; Sidabras, Jason W.; Hyde, James S.

2005-09-01

Magnetic field modulation is often introduced into a cylindrical TE011 electron paramagnetic resonance (EPR) cavity through silver plating over a nonconductive substrate. The plating thickness must be many times the skin depth of the rf and smaller than the skin depth of the modulation. We derive a parameter that quantifies the modulation field penetration and find that it also depends on resonator dimensions. Design criteria based on this parameter are presented graphically. This parameter is then used to predict the behavior of eddy currents in substrates of moderate conductivity, such as graphite. The conductivity of the graphite permits improved plating uniformity and permits use of electric discharge machining (EDM) techniques to make the resonator. EDM offers precision tolerances of 0.005 mm and is suitable for small, complicated shapes that are difficult to machine by other methods. Analytic predictions of the modulation penetration are compared with the results of finite-element simulations. Simulated magnetic field modulation uniformity and penetration are shown for several elemental coils and structures including the plated graphite TE011 cavity. Fabrication and experimental testing of the structure are discussed. Spatial inhomogeneity of the modulation phase is also investigated by computer simulation. We find that the modulation phase is uniform to within 1% over the TE011 cavity. Structures of lower symmetry have increased phase nonuniformity.

Underground Mining Method Selection Using WPM and PROMETHEE

NASA Astrophysics Data System (ADS)

Balusa, Bhanu Chander; Singam, Jayanthu

2018-04-01

The aim of this paper is to represent the solution to the problem of selecting suitable underground mining method for the mining industry. It is achieved by using two multi-attribute decision making techniques. These two techniques are weighted product method (WPM) and preference ranking organization method for enrichment evaluation (PROMETHEE). In this paper, analytic hierarchy process is used for weight's calculation of the attributes (i.e. parameters which are used in this paper). Mining method selection depends on physical parameters, mechanical parameters, economical parameters and technical parameters. WPM and PROMETHEE techniques have the ability to consider the relationship between the parameters and mining methods. The proposed techniques give higher accuracy and faster computation capability when compared with other decision making techniques. The proposed techniques are presented to determine the effective mining method for bauxite mine. The results of these techniques are compared with methods used in the earlier research works. The results show, conventional cut and fill method is the most suitable mining method.

Demonstrating the suitability of genetic algorithms for driving microbial ecosystems in desirable directions.

PubMed

Vandecasteele, Frederik P J; Hess, Thomas F; Crawford, Ronald L

2007-07-01

The functioning of natural microbial ecosystems is determined by biotic interactions, which are in turn influenced by abiotic environmental conditions. Direct experimental manipulation of such conditions can be used to purposefully drive ecosystems toward exhibiting desirable functions. When a set of environmental conditions can be manipulated to be present at a discrete number of levels, finding the right combination of conditions to obtain the optimal desired effect becomes a typical combinatorial optimisation problem. Genetic algorithms are a class of robust and flexible search and optimisation techniques from the field of computer science that may be very suitable for such a task. To verify this idea, datasets containing growth levels of the total microbial community of four different natural microbial ecosystems in response to all possible combinations of a set of five chemical supplements were obtained. Subsequently, the ability of a genetic algorithm to search this parameter space for combinations of supplements driving the microbial communities to high levels of growth was compared to that of a random search, a local search, and a hill-climbing algorithm, three intuitive alternative optimisation approaches. The results indicate that a genetic algorithm is very suitable for driving microbial ecosystems in desirable directions, which opens opportunities for both fundamental ecological research and industrial applications.

Ambulatory instrumentation suitable for long-term monitoring of cattle health.

PubMed

Schoenig, S A; Hildreth, T S; Nagl, L; Erickson, H; Spire, M; Andresen, D; Warren, S

2004-01-01

The benefits of real-time health diagnoses of cattle are potentially tremendous. Early detection of transmissible disease, whether from natural or terrorist events, could help to avoid huge financial losses in the agriculture industry while also improving meat quality. This work discusses physiological and behavioral parameters relevant to cattle state-of-health assessment. These parameters, along with a potentially harsh monitoring environment, drive a set of design considerations that must be addressed when building systems to acquire long-term, real-time measurements in the field. A prototype system is presented that supports the measurement of suitable physiologic parameters and begins to address the design constraints for continuous state-of-health determination in free-roaming cattle.

Introducing conjoint analysis method into delayed lotteries studies: its validity and time stability are higher than in adjusting

PubMed Central

Białek, Michał; Markiewicz, Łukasz; Sawicki, Przemysław

2015-01-01

The delayed lotteries are much more common in everyday life than are pure lotteries. Usually, we need to wait to find out the outcome of the risky decision (e.g., investing in a stock market, engaging in a relationship). However, most research has studied the time discounting and probability discounting in isolation using the methodologies designed specifically to track changes in one parameter. Most commonly used method is adjusting, but its reported validity and time stability in research on discounting are suboptimal. The goal of this study was to introduce the novel method for analyzing delayed lotteries—conjoint analysis—which hypothetically is more suitable for analyzing individual preferences in this area. A set of two studies compared the conjoint analysis with adjusting. The results suggest that individual parameters of discounting strength estimated with conjoint have higher predictive value (Study 1 and 2), and they are more stable over time (Study 2) compared to adjusting. We discuss these findings, despite the exploratory character of reported studies, by suggesting that future research on delayed lotteries should be cross-validated using both methods. PMID:25674069

Traversable wormholes satisfying the weak energy condition in third-order Lovelock gravity

NASA Astrophysics Data System (ADS)

Zangeneh, Mahdi Kord; Lobo, Francisco S. N.; Dehghani, Mohammad Hossein

2015-12-01

In this paper, we consider third-order Lovelock gravity with a cosmological constant term in an n -dimensional spacetime M4×Kn -4, where Kn -4 is a constant curvature space. We decompose the equations of motion to four and higher dimensional ones and find wormhole solutions by considering a vacuum Kn -4 space. Applying the latter constraint, we determine the second- and third-order Lovelock coefficients and the cosmological constant in terms of specific parameters of the model, such as the size of the extra dimensions. Using the obtained Lovelock coefficients and Λ , we obtain the four-dimensional matter distribution threading the wormhole. Furthermore, by considering the zero tidal force case and a specific equation of state, given by ρ =(γ p -τ )/[ω (1 +γ )], we find the exact solution for the shape function which represents both asymptotically flat and nonflat wormhole solutions. We show explicitly that these wormhole solutions in addition to traversibility satisfy the energy conditions for suitable choices of parameters and that the existence of a limited spherically symmetric traversable wormhole with normal matter in a four-dimensional spacetime implies a negative effective cosmological constant.

The fractal geometry of Hartree-Fock

NASA Astrophysics Data System (ADS)

Theel, Friethjof; Karamatskou, Antonia; Santra, Robin

2017-12-01

The Hartree-Fock method is an important approximation for the ground-state electronic wave function of atoms and molecules so that its usage is widespread in computational chemistry and physics. The Hartree-Fock method is an iterative procedure in which the electronic wave functions of the occupied orbitals are determined. The set of functions found in one step builds the basis for the next iteration step. In this work, we interpret the Hartree-Fock method as a dynamical system since dynamical systems are iterations where iteration steps represent the time development of the system, as encountered in the theory of fractals. The focus is put on the convergence behavior of the dynamical system as a function of a suitable control parameter. In our case, a complex parameter λ controls the strength of the electron-electron interaction. An investigation of the convergence behavior depending on the parameter λ is performed for helium, neon, and argon. We observe fractal structures in the complex λ-plane, which resemble the well-known Mandelbrot set, determine their fractal dimension, and find that with increasing nuclear charge, the fragmentation increases as well.

Status of MAPA (Modular Accelerator Physics Analysis) and the Tech-X Object-Oriented Accelerator Library

NASA Astrophysics Data System (ADS)

Cary, J. R.; Shasharina, S.; Bruhwiler, D. L.

1998-04-01

The MAPA code is a fully interactive accelerator modeling and design tool consisting of a GUI and two object-oriented C++ libraries: a general library suitable for treatment of any dynamical system, and an accelerator library including many element types plus an accelerator class. The accelerator library inherits directly from the system library, which uses hash tables to store any relevant parameters or strings. The GUI can access these hash tables in a general way, allowing the user to invoke a window displaying all relevant parameters for a particular element type or for the accelerator class, with the option to change those parameters. The system library can advance an arbitrary number of dynamical variables through an arbitrary mapping. The accelerator class inherits this capability and overloads the relevant functions to advance the phase space variables of a charged particle through a string of elements. Among other things, the GUI makes phase space plots and finds fixed points of the map. We discuss the object hierarchy of the two libraries and use of the code.

Development of tiger habitat suitability model using geospatial tools-a case study in Achankmar Wildlife Sanctuary (AMWLS), Chhattisgarh India.

PubMed

Singh, R; Joshi, P K; Kumar, M; Dash, P P; Joshi, B D

2009-08-01

Geospatial tools supported by ancillary geo-database and extensive fieldwork regarding the distribution of tiger and its prey in Anchankmar Wildlife Sanctuary (AMWLS) were used to build a tiger habitat suitability model. This consists of a quantitative geographical information system (GIS) based approach using field parameters and spatial thematic information. The estimates of tiger sightings, its prey sighting and predicted distribution with the assistance of contextual environmental data including terrain, road network, settlement and drainage surfaces were used to develop the model. Eight variables in the dataset viz., forest cover type, forest cover density, slope, aspect, altitude, and distance from road, settlement and drainage were seen as suitable proxies and were used as independent variables in the analysis. Principal component analysis and binomial multiple logistic regression were used for statistical treatments of collected habitat parameters from field and independent variables respectively. The assessment showed a strong expert agreement between the predicted and observed suitable areas. A combination of the generated information and published literature was also used while building a habitat suitability map for the tiger. The modeling approach has taken the habitat preference parameters of the tiger and potential distribution of prey species into account. For assessing the potential distribution of prey species, independent suitability models were developed and validated with the ground truth. It is envisaged that inclusion of the prey distribution probability strengthens the model when a key species is under question. The results of the analysis indicate that tiger occur throughout the sanctuary. The results have been found to be an important input as baseline information for population modeling and natural resource management in the wildlife sanctuary. The development and application of similar models can help in better management of the protected areas of national interest.

SUITABILITY OF USING IN VITRO AND COMPUTATIONALLY ESTIMATED PARAMETERS IN SIMPLIFIED PHARMACOKINETIC MODELS

EPA Science Inventory

A challenge in PBPK model development is estimating the parameters for absorption, distribution, metabolism, and excretion of the parent compound and metabolites of interest. One approach to reduce the number of parameters has been to simplify pharmacokinetic models by lumping p...

Assessment of Groundwater quality in Krishnagiri and Vellore Districts in Tamil Nadu, India

NASA Astrophysics Data System (ADS)

Shanmugasundharam, A.; Kalpana, G.; Mahapatra, S. R.; Sudharson, E. R.; Jayaprakash, M.

2017-07-01

Groundwater quality is important as it is the main factor determining its suitability for drinking, domestic, agricultural and industrial purposes. The suitability of groundwater for drinking and irrigation has been assessed in north and eastern part of Krishnagiri district, South-western part of Vellore district and contiguous with Andhra Pradesh states, India. A total of 31 groundwater samples were collected in the study area. The groundwater quality assessment has been carried out by evaluating the physicochemical parameters such as pH, EC, TDS, {HCO}3^{ - }, Cl-, {SO}4^{2 - }, Ca2+, Mg2+, Na+ and K+. The dominant cations are in the order of Na+ > K+ > Ca2+ > Mg2+ while the dominant anions have the trends of Cl- > {HCO}3^{ - } > {SO}4^{2 - } > CO3. The quality of the water is evaluated using Wilcox diagram and the results reveals that most of the samples are found to be suitable for irrigation. Based on these parameters, groundwater has been assessed in favor of its suitability for drinking and irrigation purpose.

Multi-Agent Architecture with Support to Quality of Service and Quality of Control

NASA Astrophysics Data System (ADS)

Poza-Luján, Jose-Luis; Posadas-Yagüe, Juan-Luis; Simó-Ten, Jose-Enrique

Multi Agent Systems (MAS) are one of the most suitable frameworks for the implementation of intelligent distributed control system. Agents provide suitable flexibility to give support to implied heterogeneity in cyber-physical systems. Quality of Service (QoS) and Quality of Control (QoC) parameters are commonly utilized to evaluate the efficiency of the communications and the control loop. Agents can use the quality measures to take a wide range of decisions, like suitable placement on the control node or to change the workload to save energy. This article describes the architecture of a multi agent system that provides support to QoS and QoC parameters to optimize de system. The architecture uses a Publish-Subscriber model, based on Data Distribution Service (DDS) to send the control messages. Due to the nature of the Publish-Subscribe model, the architecture is suitable to implement event-based control (EBC) systems. The architecture has been called FSACtrl.

Buried Man-made Structure Imaging using 2-D Resistivity Inversion

NASA Astrophysics Data System (ADS)

Anderson Bery, Andy; Nordiana, M. M.; El Hidayah Ismail, Noer; Jinmin, M.; Nur Amalina, M. K. A.

2018-04-01

This study is carried out with the objective to determine the suitable resistivity inversion method for buried man-made structure (bunker). This study was carried out with two stages. The first stage is suitable array determination using 2-D computerized modeling method. One suitable array is used for the infield resistivity survey to determine the dimension and location of the target. The 2-D resistivity inversion results showed that robust inversion method is suitable to resolve the top and bottom part of the buried bunker as target. In addition, the dimension of the buried bunker is successfully determined with height of 7 m and length of 20 m. The location of this target is located at -10 m until 10 m of the infield resistivity survey line. The 2-D resistivity inversion results obtained in this study showed that the parameters selection is important in order to give the optimum results. These parameters are array type, survey geometry and inversion method used in data processing.

Accurate estimation of seismic source parameters of induced seismicity by a combined approach of generalized inversion and genetic algorithm: Application to The Geysers geothermal area, California

NASA Astrophysics Data System (ADS)

Picozzi, M.; Oth, A.; Parolai, S.; Bindi, D.; De Landro, G.; Amoroso, O.

2017-05-01

The accurate determination of stress drop, seismic efficiency, and how source parameters scale with earthquake size is an important issue for seismic hazard assessment of induced seismicity. We propose an improved nonparametric, data-driven strategy suitable for monitoring induced seismicity, which combines the generalized inversion technique together with genetic algorithms. In the first step of the analysis the generalized inversion technique allows for an effective correction of waveforms for attenuation and site contributions. Then, the retrieved source spectra are inverted by a nonlinear sensitivity-driven inversion scheme that allows accurate estimation of source parameters. We therefore investigate the earthquake source characteristics of 633 induced earthquakes (Mw 2-3.8) recorded at The Geysers geothermal field (California) by a dense seismic network (i.e., 32 stations, more than 17.000 velocity records). We find a nonself-similar behavior, empirical source spectra that require an ωγ source model with γ > 2 to be well fit and small radiation efficiency ηSW. All these findings suggest different dynamic rupture processes for smaller and larger earthquakes and that the proportion of high-frequency energy radiation and the amount of energy required to overcome the friction or for the creation of new fractures surface changes with earthquake size. Furthermore, we observe also two distinct families of events with peculiar source parameters that in one case suggests the reactivation of deep structures linked to the regional tectonics, while in the other supports the idea of an important role of steeply dipping faults in the fluid pressure diffusion.

Attractive Flicker--Guiding Attention in Dynamic Narrative Visualizations.

PubMed

Waldner, Manuela; Le Muzic, Mathieu; Bernhard, Matthias; Purgathofer, Werner; Viola, Ivan

2014-12-01

Focus+context techniques provide visual guidance in visualizations by giving strong visual prominence to elements of interest while the context is suppressed. However, finding a visual feature to enhance for the focus to pop out from its context in a large dynamic scene, while leading to minimal visual deformation and subjective disturbance, is challenging. This paper proposes Attractive Flicker, a novel technique for visual guidance in dynamic narrative visualizations. We first show that flicker is a strong visual attractor in the entire visual field, without distorting, suppressing, or adding any scene elements. The novel aspect of our Attractive Flicker technique is that it consists of two signal stages: The first "orientation stage" is a short but intensive flicker stimulus to attract the attention to elements of interest. Subsequently, the intensive flicker is reduced to a minimally disturbing luminance oscillation ("engagement stage") as visual support to keep track of the focus elements. To find a good trade-off between attraction effectiveness and subjective annoyance caused by flicker, we conducted two perceptual studies to find suitable signal parameters. We showcase Attractive Flicker with the parameters obtained from the perceptual statistics in a study of molecular interactions. With Attractive Flicker, users were able to easily follow the narrative of the visualization on a large display, while the flickering of focus elements was not disturbing when observing the context.

Is there enough evidence so that mandible can be used as a tool for sex dimorphism? A systematic review.

PubMed

Hazari, Puja; Hazari, Rakesh S; Mishra, Sunil Kumar; Agrawal, Surendra; Yadav, Mukesh

2016-01-01

One of the most challenging tasks for forensic science is to identify the unknown human skeletal remains of deceased individuals. Study of sex by distinguishing the various morphological characteristics of bones is utmost important in forensic anthropology and for medico-legal assessment. The purpose of this article is to review the literature, to find if there is sufficient evidence to establish the use of mandible in sex identification. An electronic search was performed to identify suitable literature, using database of MEDLINE, PubMed, and EBSCOhost. Published articles in between January 2000 and April 2015 were searched. The main focus of search was on the various parameters of mandible studied in last 15 years for sex dimorphism. The focus was on the articles published on radiographic studies as well as on morphometric studies of dry mandible in which skeletal parameters were studied. The screening of titles and abstracts were done, suitable literature that fulfilled the inclusion criteria was selected for a full-text reading. The initial literature search resulted in 89 articles, out of which only 36 articles fulfilled the inclusion criteria and were included in this systematic review. Out of 16 radiographic studies, 14 showed statistically significant results that the adult mandible could be used with increased sensitivity and objectivity to identify both sex and population affinity compared to other standard analytical techniques, whereas two studies showed insignificant results. Out of 20 morphometric studies of dry mandible 15 studies showed a positive correlation between sex dimorphism and mandibular parameters and five studies did not show any positive correlations between the two.

Characterization of Chlorella sorokiniana, UTEX 1230.

PubMed

Lizzul, Alessandro Marco; Lekuona-Amundarain, Aitor; Purton, Saul; Campos, Luiza Cintra

2018-04-13

This paper characterizes the strain Chlorella sorokiniana UTEX 1230 within a laboratory setting using a 1 L bubble column. The findings show that productivity can be trebled under mixotrophic conditions (from 0.2 g·L −1 ·d −1 to 0.66 g·L −1 ·d −1 ) with the addition of sodium acetate. The results also indicate that both the growth rate and final yield increase with the cultivation temperature, with most parameters showing an optimum in the range of 30–35 °C. The maximum specific growth rate was found to be in the region of 0.12 h −1 at a surface irradiance between 100–500 µE·m −2 ·s −1 . This high growth rate makes the strain particularly suited to the rapid production of biomass, suitable for either whole cell bioprocessing or bioremediation. However, the relatively low lipid productivity (9.2 mg·L −1 ·d −1 ) confirms previous findings which would indicate poor applicability for biodiesel production. The strain shows greater promise in wastewater treatment applications with removal rates of nitrogen and phosphorus in the region of 37 and 30 mg·L −1 ·d −1 respectively. Furthermore, the findings show that a fed-batch strategy to inorganic nutrient loading can increase the final yield by around 50% compared to a conventional batch run. This is particularly interesting as fed-batch production techniques are rarely used within microalgal cultivation, so provide an interesting avenue for further investigation. Overall, the findings show that C. sorokiniana UTEX 1230 is a robust and fast-growing microalgal strain suitable both for the laboratory and scale-up.

Light nuclei of even mass number in the Skyrme model

NASA Astrophysics Data System (ADS)

Battye, R. A.; Manton, N. S.; Sutcliffe, P. M.; Wood, S. W.

2009-09-01

We consider the semiclassical rigid-body quantization of Skyrmion solutions of mass numbers B=4,6,8,10, and 12. We determine the allowed quantum states for each Skyrmion and find that they often match the observed states of nuclei. The spin and isospin inertia tensors of these Skyrmions are accurately calculated for the first time and are used to determine the excitation energies of the quantum states. We calculate the energy level splittings, using a suitably chosen parameter set for each mass number. We find good qualitative and encouraging quantitative agreement with experiment. In particular, the rotational bands of beryllium-8 and carbon-12, along with isospin 1 triplets and isospin 2 quintets, are especially well reproduced. We also predict the existence of states that have not yet been observed and make predictions for the unknown quantum numbers of some observed states.

An Adaptive Kalman Filter using a Simple Residual Tuning Method

NASA Technical Reports Server (NTRS)

Harman, Richard R.

1999-01-01

One difficulty in using Kalman filters in real world situations is the selection of the correct process noise, measurement noise, and initial state estimate and covariance. These parameters are commonly referred to as tuning parameters. Multiple methods have been developed to estimate these parameters. Most of those methods such as maximum likelihood, subspace, and observer Kalman Identification require extensive offline processing and are not suitable for real time processing. One technique, which is suitable for real time processing, is the residual tuning method. Any mismodeling of the filter tuning parameters will result in a non-white sequence for the filter measurement residuals. The residual tuning technique uses this information to estimate corrections to those tuning parameters. The actual implementation results in a set of sequential equations that run in parallel with the Kalman filter. Equations for the estimation of the measurement noise have also been developed. These algorithms are used to estimate the process noise and measurement noise for the Wide Field Infrared Explorer star tracker and gyro.

Modelling decremental ramps using 2- and 3-parameter "critical power" models.

PubMed

Morton, R Hugh; Billat, Veronique

2013-01-01

The "Critical Power" (CP) model of human bioenergetics provides a valuable way to identify both limits of tolerance to exercise and mechanisms that underpin that tolerance. It applies principally to cycling-based exercise, but with suitable adjustments for analogous units it can be applied to other exercise modalities; in particular to incremental ramp exercise. It has not yet been applied to decremental ramps which put heavy early demand on the anaerobic energy supply system. This paper details cycling-based bioenergetics of decremental ramps using 2- and 3-parameter CP models. It derives equations that, for an individual of known CP model parameters, define those combinations of starting intensity and decremental gradient which will or will not lead to exhaustion before ramping to zero; and equations that predict time to exhaustion on those decremental ramps that will. These are further detailed with suitably chosen numerical and graphical illustrations. These equations can be used for parameter estimation from collected data, or to make predictions when parameters are known.

Absolute Ages and Distances of 22 GCs Using Monte Carlo Main-sequence Fitting

NASA Astrophysics Data System (ADS)

O'Malley, Erin M.; Gilligan, Christina; Chaboyer, Brian

2017-04-01

The recent Gaia Data Release 1 of stellar parallaxes provides ample opportunity to find metal-poor main-sequence stars with precise parallaxes. We select 21 such stars with parallax uncertainties better than σ π /π ≤ 0.10 and accurate abundance determinations suitable for testing metal-poor stellar evolution models and determining the distance to Galactic globular clusters (GCs). A Monte Carlo analysis was used, taking into account uncertainties in the model construction parameters, to generate stellar models and isochrones to fit to the calibration stars. The isochrones that fit the calibration stars best were then used to determine the distances and ages of 22 GCs with metallicities ranging from -2.4 dex to -0.7 dex. We find distances with an average uncertainty of 0.15 mag and absolute ages ranging from 10.8 to 13.6 Gyr with an average uncertainty of 1.6 Gyr. Using literature proper motion data, we calculate orbits for the clusters, finding six that reside within the Galactic disk/bulge, while the rest are considered halo clusters. We find no strong evidence for a relationship between age and Galactocentric distance, but we do find a decreasing age-[Fe/H] relation.

Mapping Environmental Suitability for Malaria Transmission, Greece

PubMed Central

Sudre, Bertrand; Rossi, Massimiliano; Van Bortel, Wim; Danis, Kostas; Baka, Agoritsa; Vakalis, Nikos

2013-01-01

During 2009–2012, Greece experienced a resurgence of domestic malaria transmission. To help guide malaria response efforts, we used spatial modeling to characterize environmental signatures of areas suitable for transmission. Nonlinear discriminant analysis indicated that sea-level altitude and land-surface temperature parameters are predictive in this regard. PMID:23697370

An Additional Approach to Model Current Followers and Amplifiers with Electronically Controllable Parameters from Commercially Available ICs

NASA Astrophysics Data System (ADS)

Sotner, R.; Kartci, A.; Jerabek, J.; Herencsar, N.; Dostal, T.; Vrba, K.

2012-12-01

Several behavioral models of current active elements for experimental purposes are introduced in this paper. These models are based on commercially available devices. They are suitable for experimental tests of current- and mixed-mode filters, oscillators, and other circuits (employing current-mode active elements) frequently used in analog signal processing without necessity of onchip fabrication of proper active element. Several methods of electronic control of intrinsic resistance in the proposed behavioral models are discussed. All predictions and theoretical assumptions are supported by simulations and experiments. This contribution helps to find a cheaper and more effective way to preliminary laboratory tests without expensive on-chip fabrication of special active elements.

Quantum Memristors with Superconducting Circuits

DOE PAGES

Salmilehto, J.; Deppe, F.; Di Ventra, M.; ...

2017-02-14

Memristors are resistive elements retaining information of their past dynamics. They have garnered substantial interest due to their potential for representing a paradigm change in electronics, information processing and unconventional computing. Given the advent of quantum technologies, a design for a quantum memristor with superconducting circuits may be envisaged. Along these lines, we introduce such a quantum device whose memristive behavior arises from quasiparticle-induced tunneling when supercurrents are cancelled. Here in this paper, for realistic parameters, we find that the relevant hysteretic behavior may be observed using current state-of-the-art measurements of the phase-driven tunneling current. Finally, we develop suitable methodsmore » to quantify memory retention in the system.« less

Error-correcting codes on scale-free networks

NASA Astrophysics Data System (ADS)

Kim, Jung-Hoon; Ko, Young-Jo

2004-06-01

We investigate the potential of scale-free networks as error-correcting codes. We find that irregular low-density parity-check codes with the highest performance known to date have degree distributions well fitted by a power-law function p (k) ˜ k-γ with γ close to 2, which suggests that codes built on scale-free networks with appropriate power exponents can be good error-correcting codes, with a performance possibly approaching the Shannon limit. We demonstrate for an erasure channel that codes with a power-law degree distribution of the form p (k) = C (k+α)-γ , with k⩾2 and suitable selection of the parameters α and γ , indeed have very good error-correction capabilities.

Deploying the ODISEES Ontology-guided Search in the NASA Earth Exchange (NEX)

NASA Astrophysics Data System (ADS)

Huffer, E.; Gleason, J. L.; Cotnoir, M.; Spaulding, R.; Deardorff, G.

2016-12-01

Robust, semantically rich metadata can support data discovery and access, and facilitate machine-to-machine transactions with services such as data subsetting, regridding, and reformatting. Despite this, for users not already familiar with the data in a given archive, most metadata is insufficient to help them find appropriate data for their projects. With this in mind, the Ontology-driven Interactive Search Environment (ODISEES) Data Discovery Portal was developed to enable users to find and download data variables that satisfy precise, parameter-level criteria, even when they know little or nothing about the naming conventions employed by data providers, or where suitable data might be archived. ODISEES relies on an Earth science ontology and metadata repository that provide an ontological framework for describing NASA data holdings with enough detail and fidelity to enable researchers to find, compare and evaluate individual data variables. Users can search for data by indicating the specific parameters desired, and comparing the results in a table that lets them quickly determine which data is most suitable. ODISEES and OLYMPUS, a tool for generating the semantically enhanced metadata used by ODISEES, are being developed in collaboration with the NASA Earth Exchange (NEX) project at the NASA Ames Research Center to prototype a robust data discovery and access service that could be made available to NEX users. NEX is a collaborative platform that provides researchers with access to TB to PB-scale datasets and analysis tools to operate on those data. By integrating ODISEES into the NEX Web Portal we hope to enable NEX users to locate datasets relevant to their research and download them directly into the NAS environment, where they can run applications using those datasets on the NAS supercomputers. This poster will describe the prototype integration of ODISEES into the NEX portal development environment, the mechanism implemented to use NASA APIs to retrieve data, and the approach to transfer data into the NAS supercomputing environment. Finally, we will describe the end-to-end demonstration of the capabilities implemented. This work was funded by the Advanced Information Systems Technology Program of NASA's Research Opportunities in Space and Earth Science.

Analytical functions for beta and gamma absorbed fractions of iodine-131 in spherical and ellipsoidal volumes.

PubMed

Mowlavi, Ali Asghar; Fornasier, Maria Rossa; Mirzaei, Mohammd; Bregant, Paola; de Denaro, Mario

2014-10-01

The beta and gamma absorbed fractions in organs and tissues are the important key factors of radionuclide internal dosimetry based on Medical Internal Radiation Dose (MIRD) approach. The aim of this study is to find suitable analytical functions for beta and gamma absorbed fractions in spherical and ellipsoidal volumes with a uniform distribution of iodine-131 radionuclide. MCNPX code has been used to calculate the energy absorption from beta and gamma rays of iodine-131 uniformly distributed inside different ellipsoids and spheres, and then the absorbed fractions have been evaluated. We have found the fit parameters of a suitable analytical function for the beta absorbed fraction, depending on a generalized radius for ellipsoid based on the radius of sphere, and a linear fit function for the gamma absorbed fraction. The analytical functions that we obtained from fitting process in Monte Carlo data can be used for obtaining the absorbed fractions of iodine-131 beta and gamma rays for any volume of the thyroid lobe. Moreover, our results for the spheres are in good agreement with the results of MIRD and other scientific literatures.

Mechanically activated fly ash as a high performance binder for civil engineering

NASA Astrophysics Data System (ADS)

Rieger, D.; Kullová, L.; Čekalová, M.; Novotný, P.; Pola, M.

2017-01-01

This study is aimed for investigation of fly ash binder with suitable properties for civil engineering needs. The fly ash from Czech brown coal power plant Prunerov II was used and mechanically activated to achieve suitable particle size for alkaline activation of hardening process. This process is driven by dissolution of aluminosilicate content of fly ash and by subsequent development of inorganic polymeric network called geopolymer. Hardening kinetics at 25 and 30 °C were measured by strain controlled small amplitude oscillatory rheometry with strain of 0.01 % and microstructure of hardened binder was evaluated by scanning electron microscopy. Strength development of hardened binder was investigated according to compressional and flexural strength for a period of 180 days. Our investigation finds out, that mechanically activated fly ash can be comparable to metakaolin geopolymers, according to setting time and mechanical parameters even at room temperature curing. Moreover, on the bases of long time strength development, achieved compressional strength of 134.5 after 180 days is comparable to performance of high grade Portland cement concretes.

The limitation of the proposed collection efficiency for fiber probes on the visible and near-infrared diffuse spectroscopy

NASA Astrophysics Data System (ADS)

Zhang, Linna; Ding, Hongyan; Lin, Ling; Wang, Yimin; Guo, Xin

2017-12-01

A fiber is usually used as a probe in visible and near-infrared diffuse spectra measurement. However, the use of different fiber probes in the same measurement may cause data mismatch problems. Our group has researched the influence of the parameters of fiber probe, including the aperture angle, on the diffuse spectrum by a modified Monte Carlo model. To eliminate the influence of the aperture angle, we proposed a fitted equation of correction coefficient to correct its difference in practical range. However, we did not discuss the limitation of this method. In this work, we explored the collection efficiency in different optical environment with Monte Carlo simulation method, and find the suitable conditions-weak absorbing and strong scattering media, for the proposed collection efficiency. Furthermore, we tried to explain the stability of the collection efficiency in this condition. This work gives suitable conditions for the collection efficiency. The use of collection efficiency can help reduce the influence of different measurement systems and is also helpful to the model translation.

Optimized Assistive Human-Robot Interaction Using Reinforcement Learning.

PubMed

Modares, Hamidreza; Ranatunga, Isura; Lewis, Frank L; Popa, Dan O

2016-03-01

An intelligent human-robot interaction (HRI) system with adjustable robot behavior is presented. The proposed HRI system assists the human operator to perform a given task with minimum workload demands and optimizes the overall human-robot system performance. Motivated by human factor studies, the presented control structure consists of two control loops. First, a robot-specific neuro-adaptive controller is designed in the inner loop to make the unknown nonlinear robot behave like a prescribed robot impedance model as perceived by a human operator. In contrast to existing neural network and adaptive impedance-based control methods, no information of the task performance or the prescribed robot impedance model parameters is required in the inner loop. Then, a task-specific outer-loop controller is designed to find the optimal parameters of the prescribed robot impedance model to adjust the robot's dynamics to the operator skills and minimize the tracking error. The outer loop includes the human operator, the robot, and the task performance details. The problem of finding the optimal parameters of the prescribed robot impedance model is transformed into a linear quadratic regulator (LQR) problem which minimizes the human effort and optimizes the closed-loop behavior of the HRI system for a given task. To obviate the requirement of the knowledge of the human model, integral reinforcement learning is used to solve the given LQR problem. Simulation results on an x - y table and a robot arm, and experimental implementation results on a PR2 robot confirm the suitability of the proposed method.

The quality estimation of exterior wall’s and window filling’s construction design

NASA Astrophysics Data System (ADS)

Saltykov, Ivan; Bovsunovskaya, Maria

2017-10-01

The article reveals the term of “artificial envelope” in dwelling building. Authors offer a complex multifactorial approach to the design quality estimation of external fencing structures, which is based on various parameters impact. These referred parameters are: functional, exploitation, cost, and also, the environmental index is among them. The quality design index Qк is inputting for the complex characteristic of observed above parameters. The mathematical relation of this index from these parameters is the target function for the quality design estimation. For instance, the article shows the search of optimal variant for wall and window designs in small, middle and large square dwelling premises of economic class buildings. The graphs of target function single parameters are expressed for the three types of residual chamber’s dimensions. As a result of the showing example, there is a choice of window opening’s dimensions, which make the wall’s and window’s constructions properly correspondent to the producible complex requirements. The authors reveal the comparison of recommended window filling’s square in accordance with the building standards, and the square, due to the finding of the optimal variant of the design quality index. The multifactorial approach for optimal design searching, which is mentioned in this article, can be used in consideration of various construction elements of dwelling buildings in accounting of suitable climate, social and economic construction area features.

Process Optimization of Dual-Laser Beam Welding of Advanced Al-Li Alloys Through Hot Cracking Susceptibility Modeling

NASA Astrophysics Data System (ADS)

Tian, Yingtao; Robson, Joseph D.; Riekehr, Stefan; Kashaev, Nikolai; Wang, Li; Lowe, Tristan; Karanika, Alexandra

2016-07-01

Laser welding of advanced Al-Li alloys has been developed to meet the increasing demand for light-weight and high-strength aerospace structures. However, welding of high-strength Al-Li alloys can be problematic due to the tendency for hot cracking. Finding suitable welding parameters and filler material for this combination currently requires extensive and costly trial and error experimentation. The present work describes a novel coupled model to predict hot crack susceptibility (HCS) in Al-Li welds. Such a model can be used to shortcut the weld development process. The coupled model combines finite element process simulation with a two-level HCS model. The finite element process model predicts thermal field data for the subsequent HCS hot cracking prediction. The model can be used to predict the influences of filler wire composition and welding parameters on HCS. The modeling results have been validated by comparing predictions with results from fully instrumented laser welds performed under a range of process parameters and analyzed using high-resolution X-ray tomography to identify weld defects. It is shown that the model is capable of accurately predicting the thermal field around the weld and the trend of HCS as a function of process parameters.

Achieving Fair Throughput among TCP Flows in Multi-Hop Wireless Mesh Networks

NASA Astrophysics Data System (ADS)

Hou, Ting-Chao; Hsu, Chih-Wei

Previous research shows that the IEEE 802.11 DCF channel contention mechanism is not capable of providing throughput fairness among nodes in different locations of the wireless mesh network. The node nearest the gateway will always strive for the chance to transmit data, causing fewer transmission opportunities for the nodes farther from the gateway, resulting in starvation. Prior studies modify the DCF mechanism to address the fairness problem. This paper focuses on the fairness study when TCP flows are carried over wireless mesh networks. By not modifying lower layer protocols, the current work identifies TCP parameters that impact throughput fairness and proposes adjusting those parameters to reduce frame collisions and improve throughput fairness. With the aid of mathematical formulation and ns2 simulations, this study finds that frame transmission from each node can be effectively controlled by properly controlling the delayed ACK timer and using a suitable advertised window. The proposed method reduces frame collisions and greatly improves TCP throughput fairness.

Evaluation of two outlier-detection-based methods for detecting tissue-selective genes from microarray data.

PubMed

Kadota, Koji; Konishi, Tomokazu; Shimizu, Kentaro

2007-05-01

Large-scale expression profiling using DNA microarrays enables identification of tissue-selective genes for which expression is considerably higher and/or lower in some tissues than in others. Among numerous possible methods, only two outlier-detection-based methods (an AIC-based method and Sprent's non-parametric method) can treat equally various types of selective patterns, but they produce substantially different results. We investigated the performance of these two methods for different parameter settings and for a reduced number of samples. We focused on their ability to detect selective expression patterns robustly. We applied them to public microarray data collected from 36 normal human tissue samples and analyzed the effects of both changing the parameter settings and reducing the number of samples. The AIC-based method was more robust in both cases. The findings confirm that the use of the AIC-based method in the recently proposed ROKU method for detecting tissue-selective expression patterns is correct and that Sprent's method is not suitable for ROKU.

1 MeV, 10 kW DC electron accelerator for industrial applications

NASA Astrophysics Data System (ADS)

Nayak, B.; Acharya, S.; Bhattacharjee, D.; Bakhtsingh, R. I.; Rajan, R.; Sharma, D. K.; Dewangan, S.; Sharma, V.; Patel, R.; Tiwari, R.; Benarjee, S.; Srivastava, S. K.

2016-03-01

Several modern applications of radiation processing like medical sterilization, rubber vulcanization, polymerization, cross-linking and pollution control from thermal power stations etc. require D.C. electron accelerators of energy ranging from a few hundred keVs to few MeVs and power from a few kilowatts to hundreds of kilowatts. To match these requirements, a 3 MeV, 30 kW DC electron linac has been developed at BARC, Mumbai and current operational experience of 1 MeV, 10 kW beam power will be described in this paper. The LINAC composed mainly of Electron Gun, Accelerating Tubes, Magnets, High Voltage source and provides 10 kW beam power at the Ti beam window stably after the scanning section. The control of the LINAC is fully automated. Here Beam Optics study is carried out to reach the preferential parameters of Accelerating as well as optical elements. Beam trials have been conducted to find out the suitable operation parameters of the system.

Fabrication of Titania Nanotubes for Gas Sensing Applications

NASA Astrophysics Data System (ADS)

Dzilal, A. A.; Muti, M. N.; John, O. D.

2010-03-01

Detection of hydrogen is needed for industrial process control and medical applications where presence of hydrogen indicates different type of health problems. Titanium dioxide nanotube structure is chosen as an active component in the gas sensor because of its highly sensitive electrical resistance to hydrogen over a wide range of concentrations. The objective of the work is to fabricate good quality titania nanotubes suitable for hydrogen sensing applications. The fabrication method used is anodizing method. The anodizing parameters namely the voltage, time duration, concentration of hydrofluoric acid in water, separation between the electrodes and the ambient temperature are varied accordingly to find the optimum anodizing conditions for production of good quality titania nanotubes. The highly ordered porous titania nanotubes produced by this method are in tabular shape and have good uniformity and alignment over large areas. From the investigation done, certain set of anodizing parameters have been found to produce good quality titania nanotubes with diameter ranges from 47 nm to 94 nm.

Design of Clinical Support Systems Using Integrated Genetic Algorithm and Support Vector Machine

NASA Astrophysics Data System (ADS)

Chen, Yung-Fu; Huang, Yung-Fa; Jiang, Xiaoyi; Hsu, Yuan-Nian; Lin, Hsuan-Hung

Clinical decision support system (CDSS) provides knowledge and specific information for clinicians to enhance diagnostic efficiency and improving healthcare quality. An appropriate CDSS can highly elevate patient safety, improve healthcare quality, and increase cost-effectiveness. Support vector machine (SVM) is believed to be superior to traditional statistical and neural network classifiers. However, it is critical to determine suitable combination of SVM parameters regarding classification performance. Genetic algorithm (GA) can find optimal solution within an acceptable time, and is faster than greedy algorithm with exhaustive searching strategy. By taking the advantage of GA in quickly selecting the salient features and adjusting SVM parameters, a method using integrated GA and SVM (IGS), which is different from the traditional method with GA used for feature selection and SVM for classification, was used to design CDSSs for prediction of successful ventilation weaning, diagnosis of patients with severe obstructive sleep apnea, and discrimination of different cell types form Pap smear. The results show that IGS is better than methods using SVM alone or linear discriminator.

Statistical methods for clinical verification of dose response parameters related to esophageal stricture and AVM obliteration from radiotherapy

NASA Astrophysics Data System (ADS)

Mavroidis, Panayiotis; Lind, Bengt K.; Theodorou, Kyriaki; Laurell, Göran; Fernberg, Jan-Olof; Lefkopoulos, Dimitrios; Kappas, Constantin; Brahme, Anders

2004-08-01

The purpose of this work is to provide some statistical methods for evaluating the predictive strength of radiobiological models and the validity of dose-response parameters for tumour control and normal tissue complications. This is accomplished by associating the expected complication rates, which are calculated using different models, with the clinical follow-up records. These methods are applied to 77 patients who received radiation treatment for head and neck cancer and 85 patients who were treated for arteriovenous malformation (AVM). The three-dimensional dose distribution delivered to esophagus and AVM nidus and the clinical follow-up results were available for each patient. Dose-response parameters derived by a maximum likelihood fitting were used as a reference to evaluate their compatibility with the examined treatment methodologies. The impact of the parameter uncertainties on the dose-response curves is demonstrated. The clinical utilization of the radiobiological parameters is illustrated. The radiobiological models (relative seriality and linear Poisson) and the reference parameters are validated to prove their suitability in reproducing the treatment outcome pattern of the patient material studied (through the probability of finding a worse fit, area under the ROC curve and khgr2 test). The analysis was carried out for the upper 5 cm of the esophagus (proximal esophagus) where all the strictures are formed, and the total volume of AVM. The estimated confidence intervals of the dose-response curves appear to have a significant supporting role on their clinical implementation and use.

Using FEP's List and a PA Methodology for Evaluating Suitable Areas for the LLW Repository in Italy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Risoluti, P.; Ciabatti, P.; Mingrone, G.

2002-02-26

In Italy following a referendum held in 1987, nuclear energy has been phased out. Since 1998, a general site selection process covering the whole Italian territory has been under way. A GIS (Geographic Information System) methodology was implemented in three steps using the ESRI Arc/Info and Arc/View platforms. The screening identified approximately 0.8% of the Italian territory as suitable for locating the LLW Repository. 200 areas have been identified as suitable for the location of the LLW Repository, using a multiple exclusion criteria procedure (1:500,000), regional scale (1:100.000) and local scale (1:25,000-1:10,000). A methodology for evaluating these areas has beenmore » developed allowing, along with the evaluation of the long term efficiency of the engineered barrier system (EBS), the characterization of the selected areas in terms of physical and safety factors and planning factors. The first step was to identify, on a referenced FEPs list, a group of geomorphological, geological, hydrogeological, climatic and human behavior caused process and/or events, which were considered of importance for the site evaluation, taking into account the Italian situation. A site evaluation system was established ascribing weighted scores to each of these processes and events, which were identified as parameters of the new evaluation system. The score of each parameter is ranging from 1 (low suitability) to 3 (high suitability). The corresponding weight is calculated considering the effect of the parameter in terms of total dose to the critical group, using an upgraded AMBER model for PA calculation. At the end of the process an index obtained by a score weighted sum gives the degree of suitability of the selected areas for the LLW Repository location. The application of the methodology to two selected sites is given in the paper.« less

A GIS model predicting potential distributions of a lineage: a test case on hermit spiders (Nephilidae: Nephilengys).

PubMed

Năpăruş, Magdalena; Kuntner, Matjaž

2012-01-01

Although numerous studies model species distributions, these models are almost exclusively on single species, while studies of evolutionary lineages are preferred as they by definition study closely related species with shared history and ecology. Hermit spiders, genus Nephilengys, represent an ecologically important but relatively species-poor lineage with a globally allopatric distribution. Here, we model Nephilengys global habitat suitability based on known localities and four ecological parameters. We geo-referenced 751 localities for the four most studied Nephilengys species: N. cruentata (Africa, New World), N. livida (Madagascar), N. malabarensis (S-SE Asia), and N. papuana (Australasia). For each locality we overlaid four ecological parameters: elevation, annual mean temperature, annual mean precipitation, and land cover. We used linear backward regression within ArcGIS to select two best fit parameters per species model, and ModelBuilder to map areas of high, moderate and low habitat suitability for each species within its directional distribution. For Nephilengys cruentata suitable habitats are mid elevation tropics within Africa (natural range), a large part of Brazil and the Guianas (area of synanthropic spread), and even North Africa, Mediterranean, and Arabia. Nephilengys livida is confined to its known range with suitable habitats being mid-elevation natural and cultivated lands. Nephilengys malabarensis, however, ranges across the Equator throughout Asia where the model predicts many areas of high ecological suitability in the wet tropics. Its directional distribution suggests the species may potentially spread eastwards to New Guinea where the suitable areas of N. malabarensis largely surpass those of the native N. papuana, a species that prefers dry forests of Australian (sub)tropics. Our model is a customizable GIS tool intended to predict current and future potential distributions of globally distributed terrestrial lineages. Its predictive potential may be tested in foreseeing species distribution shifts due to habitat destruction and global climate change.

Seismic source parameters of the induced seismicity at The Geysers geothermal area, California, by a generalized inversion approach

NASA Astrophysics Data System (ADS)

Picozzi, Matteo; Oth, Adrien; Parolai, Stefano; Bindi, Dino; De Landro, Grazia; Amoroso, Ortensia

2017-04-01

The accurate determination of stress drop, seismic efficiency and how source parameters scale with earthquake size is an important for seismic hazard assessment of induced seismicity. We propose an improved non-parametric, data-driven strategy suitable for monitoring induced seismicity, which combines the generalized inversion technique together with genetic algorithms. In the first step of the analysis the generalized inversion technique allows for an effective correction of waveforms for the attenuation and site contributions. Then, the retrieved source spectra are inverted by a non-linear sensitivity-driven inversion scheme that allows accurate estimation of source parameters. We therefore investigate the earthquake source characteristics of 633 induced earthquakes (ML 2-4.5) recorded at The Geysers geothermal field (California) by a dense seismic network (i.e., 32 stations of the Lawrence Berkeley National Laboratory Geysers/Calpine surface seismic network, more than 17.000 velocity records). We find for most of the events a non-selfsimilar behavior, empirical source spectra that requires ωγ source model with γ > 2 to be well fitted and small radiation efficiency ηSW. All these findings suggest different dynamic rupture processes for smaller and larger earthquakes, and that the proportion of high frequency energy radiation and the amount of energy required to overcome the friction or for the creation of new fractures surface changes with the earthquake size. Furthermore, we observe also two distinct families of events with peculiar source parameters that, in one case suggests the reactivation of deep structures linked to the regional tectonics, while in the other supports the idea of an important role of steeply dipping fault in the fluid pressure diffusion.

Environmental variables and definitive host distribution: a habitat suitability modelling for endohelminth parasites in the marine realm

PubMed Central

Kuhn, Thomas; Cunze, Sarah; Kochmann, Judith; Klimpel, Sven

2016-01-01

Marine nematodes of the genus Anisakis are common parasites of a wide range of aquatic organisms. Public interest is primarily based on their importance as zoonotic agents of the human Anisakiasis, a severe infection of the gastro-intestinal tract as result of consuming live larvae in insufficiently cooked fish dishes. The diverse nature of external impacts unequally influencing larval and adult stages of marine endohelminth parasites requires the consideration of both abiotic and biotic factors. Whereas abiotic factors are generally more relevant for early life stages and might also be linked to intermediate hosts, definitive hosts are indispensable for a parasite’s reproduction. In order to better understand the uneven occurrence of parasites in fish species, we here use the maximum entropy approach (Maxent) to model the habitat suitability for nine Anisakis species accounting for abiotic parameters as well as biotic data (definitive hosts). The modelled habitat suitability reflects the observed distribution quite well for all Anisakis species, however, in some cases, habitat suitability exceeded the known geographical distribution, suggesting a wider distribution than presently recorded. We suggest that integrative modelling combining abiotic and biotic parameters is a valid approach for habitat suitability assessments of Anisakis, and potentially other marine parasite species. PMID:27507328

Environmental variables and definitive host distribution: a habitat suitability modelling for endohelminth parasites in the marine realm

NASA Astrophysics Data System (ADS)

Kuhn, Thomas; Cunze, Sarah; Kochmann, Judith; Klimpel, Sven

2016-08-01

Marine nematodes of the genus Anisakis are common parasites of a wide range of aquatic organisms. Public interest is primarily based on their importance as zoonotic agents of the human Anisakiasis, a severe infection of the gastro-intestinal tract as result of consuming live larvae in insufficiently cooked fish dishes. The diverse nature of external impacts unequally influencing larval and adult stages of marine endohelminth parasites requires the consideration of both abiotic and biotic factors. Whereas abiotic factors are generally more relevant for early life stages and might also be linked to intermediate hosts, definitive hosts are indispensable for a parasite’s reproduction. In order to better understand the uneven occurrence of parasites in fish species, we here use the maximum entropy approach (Maxent) to model the habitat suitability for nine Anisakis species accounting for abiotic parameters as well as biotic data (definitive hosts). The modelled habitat suitability reflects the observed distribution quite well for all Anisakis species, however, in some cases, habitat suitability exceeded the known geographical distribution, suggesting a wider distribution than presently recorded. We suggest that integrative modelling combining abiotic and biotic parameters is a valid approach for habitat suitability assessments of Anisakis, and potentially other marine parasite species.

Simultaneous gates in frequency-crowded multilevel systems using fast, robust, analytic control shapes

NASA Astrophysics Data System (ADS)

Theis, L. S.; Motzoi, F.; Wilhelm, F. K.

2016-01-01

We present a few-parameter ansatz for pulses to implement a broad set of simultaneous single-qubit rotations in frequency-crowded multilevel systems. Specifically, we consider a system of two qutrits whose working and leakage transitions suffer from spectral crowding (detuned by δ ). In order to achieve precise controllability, we make use of two driving fields (each having two quadratures) at two different tones to simultaneously apply arbitrary combinations of rotations about axes in the X -Y plane to both qubits. Expanding the waveforms in terms of Hanning windows, we show how analytic pulses containing smooth and composite-pulse features can easily achieve gate errors less than 10-4 and considerably outperform known adiabatic techniques. Moreover, we find a generalization of the WAHWAH (Weak AnHarmonicity With Average Hamiltonian) method by Schutjens et al. [R. Schutjens, F. A. Dagga, D. J. Egger, and F. K. Wilhelm, Phys. Rev. A 88, 052330 (2013)], 10.1103/PhysRevA.88.052330 that allows precise separate single-qubit rotations for all gate times beyond a quantum speed limit. We find in all cases a quantum speed limit slightly below 2 π /δ for the gate time and show that our pulses are robust against variations in system parameters and filtering due to transfer functions, making them suitable for experimental implementations.

Development of robust behaviour recognition for an at-home biomonitoring robot with assistance of subject localization and enhanced visual tracking.

PubMed

Imamoglu, Nevrez; Dorronzoro, Enrique; Wei, Zhixuan; Shi, Huangjun; Sekine, Masashi; González, José; Gu, Dongyun; Chen, Weidong; Yu, Wenwei

2014-01-01

Our research is focused on the development of an at-home health care biomonitoring mobile robot for the people in demand. Main task of the robot is to detect and track a designated subject while recognizing his/her activity for analysis and to provide warning in an emergency. In order to push forward the system towards its real application, in this study, we tested the robustness of the robot system with several major environment changes, control parameter changes, and subject variation. First, an improved color tracker was analyzed to find out the limitations and constraints of the robot visual tracking considering the suitable illumination values and tracking distance intervals. Then, regarding subject safety and continuous robot based subject tracking, various control parameters were tested on different layouts in a room. Finally, the main objective of the system is to find out walking activities for different patterns for further analysis. Therefore, we proposed a fast, simple, and person specific new activity recognition model by making full use of localization information, which is robust to partial occlusion. The proposed activity recognition algorithm was tested on different walking patterns with different subjects, and the results showed high recognition accuracy.

Development of Robust Behaviour Recognition for an at-Home Biomonitoring Robot with Assistance of Subject Localization and Enhanced Visual Tracking

PubMed Central

Imamoglu, Nevrez; Dorronzoro, Enrique; Wei, Zhixuan; Shi, Huangjun; González, José; Gu, Dongyun; Yu, Wenwei

2014-01-01

Our research is focused on the development of an at-home health care biomonitoring mobile robot for the people in demand. Main task of the robot is to detect and track a designated subject while recognizing his/her activity for analysis and to provide warning in an emergency. In order to push forward the system towards its real application, in this study, we tested the robustness of the robot system with several major environment changes, control parameter changes, and subject variation. First, an improved color tracker was analyzed to find out the limitations and constraints of the robot visual tracking considering the suitable illumination values and tracking distance intervals. Then, regarding subject safety and continuous robot based subject tracking, various control parameters were tested on different layouts in a room. Finally, the main objective of the system is to find out walking activities for different patterns for further analysis. Therefore, we proposed a fast, simple, and person specific new activity recognition model by making full use of localization information, which is robust to partial occlusion. The proposed activity recognition algorithm was tested on different walking patterns with different subjects, and the results showed high recognition accuracy. PMID:25587560

Phytochemical, spectroscopic and density functional theory study of Diospyrin, and non-bonding interactions of Diospyrin with atmospheric gases

NASA Astrophysics Data System (ADS)

Fazl-i-Sattar; Ullah, Zakir; Ata-ur-Rahman; Rauf, Abdur; Tariq, Muhammad; Tahir, Asif Ali; Ayub, Khurshid; Ullah, Habib

2015-04-01

Density functional theory (DFT) and phytochemical study of a natural product, Diospyrin (DO) have been carried out. A suitable level of theory was developed, based on correlating the experimental and theoretical data. Hybrid DFT method at B3LYP/6-31G (d,p) level of theory is employed for obtaining the electronic, spectroscopic, inter-molecular interaction and thermodynamic properties of DO. The exact structure of DO is confirmed from the nice validation of the theory and experiment. Non-covalent interactions of DO with different atmospheric gases such as NH3, CO2, CO, and H2O were studied to find out its electroactive nature. The experimental and predicted geometrical parameters, IR and UV-vis spectra (B3LYP/6-31+G (d,p) level of theory) show excellent correlation. Inter-molecular non-bonding interaction of DO with atmospheric gases is investigated through geometrical parameters, electronic properties, charge analysis, and thermodynamic parameters. Electronic properties include, ionization potential (I.P.), electron affinities (E.A.), electrostatic potential (ESP), density of states (DOS), HOMO, LUMO, and band gap. All these characterizations have corroborated each other and confirmed the presence of non-covalent nature in DO with the mentioned gases.

Simulations of galaxy cluster collisions with a dark plasma component

NASA Astrophysics Data System (ADS)

Spethmann, Christian; Veermäe, Hardi; Sepp, Tiit; Heikinheimo, Matti; Deshev, Boris; Hektor, Andi; Raidal, Martti

2017-12-01

Context. Dark plasma is an intriguing form of self-interacting dark matter with an effective fluid-like behavior, which is well motivated by various theoretical particle physics models. Aims: We aim to find an explanation for an isolated mass clump in the Abell 520 system, which cannot be explained by traditional models of dark matter, but has been detected in weak lensing observations. Methods: We performed N-body smoothed particle hydrodynamics simulations of galaxy cluster collisions with a two component model of dark matter, which is assumed to consist of a predominant non-interacting dark matter component and a 10-40% mass fraction of dark plasma. Results: The mass of a possible dark clump was calculated for each simulation in a parameter scan over the underlying model parameters. In two higher resolution simulations shock-waves and Mach cones were observed to form in the dark plasma halos. Conclusions: By choosing suitable simulation parameters, the observed distributions of dark matter in both the Bullet cluster (1E 0657-558) and Abell 520 (MS 0451.5+0250) can be qualitatively reproduced. Movies associated to Figs. A.1 and A.2 are available at http://www.aanda.org

Spatial analysis of cities using Renyi entropy and fractal parameters

NASA Astrophysics Data System (ADS)

Chen, Yanguang; Feng, Jian

2017-12-01

The spatial distributions of cities fall into two groups: one is the simple distribution with characteristic scale (e.g. exponential distribution), and the other is the complex distribution without characteristic scale (e.g. power-law distribution). The latter belongs to scale-free distributions, which can be modeled with fractal geometry. However, fractal dimension is not suitable for the former distribution. In contrast, spatial entropy can be used to measure any types of urban distributions. This paper is devoted to generalizing multifractal parameters by means of dual relation between Euclidean and fractal geometries. The main method is mathematical derivation and empirical analysis, and the theoretical foundation is the discovery that the normalized fractal dimension is equal to the normalized entropy. Based on this finding, a set of useful spatial indexes termed dummy multifractal parameters are defined for geographical analysis. These indexes can be employed to describe both the simple distributions and complex distributions. The dummy multifractal indexes are applied to the population density distribution of Hangzhou city, China. The calculation results reveal the feature of spatio-temporal evolution of Hangzhou's urban morphology. This study indicates that fractal dimension and spatial entropy can be combined to produce a new methodology for spatial analysis of city development.

Stochastic resonance in a time-delayed feedback tristable system and its application in fault diagnosis

NASA Astrophysics Data System (ADS)

Shi, Peiming; Yuan, Danzhen; Han, Dongying; Zhang, Ying; Fu, Rongrong

2018-06-01

Stochastic resonance (SR) phenomena in a time-delayed feedback tristable system driven by Gaussian white noise are investigated by simulating the potential function, mean first-passage time (MFPT), and signal-to-noise ratio (SNR) of the system. Through the use of a short delay time, the generalized potential function and stationary probability density function (PDF) are obtained. The delay feedback term has a significant effect on both equations, and that the parameters b, c, and d have different effects on the three wells of the potential function. The MFPT is calculated, which plays an extremely important role in research on particles escape rates. We find that the delay feedback term can affect the noise enhanced stability (NES). In addition, the SR characteristics are studied by the index of SNR. The simulation demonstrates that SNR is a non-monotonic distributed and that the peak SNR value can be attained by adjusting the appropriate parameters. Finally, the proposed theory is combined with a variable step method and applied to the detection of high frequencies in experiments. The result indicates that the fault frequency can be identified, and that the energy of the fault signal can be enhanced under suitable delay feedback parameters.

An Adaptive Kalman Filter Using a Simple Residual Tuning Method

NASA Technical Reports Server (NTRS)

Harman, Richard R.

1999-01-01

One difficulty in using Kalman filters in real world situations is the selection of the correct process noise, measurement noise, and initial state estimate and covariance. These parameters are commonly referred to as tuning parameters. Multiple methods have been developed to estimate these parameters. Most of those methods such as maximum likelihood, subspace, and observer Kalman Identification require extensive offline processing and are not suitable for real time processing. One technique, which is suitable for real time processing, is the residual tuning method. Any mismodeling of the filter tuning parameters will result in a non-white sequence for the filter measurement residuals. The residual tuning technique uses this information to estimate corrections to those tuning parameters. The actual implementation results in a set of sequential equations that run in parallel with the Kalman filter. A. H. Jazwinski developed a specialized version of this technique for estimation of process noise. Equations for the estimation of the measurement noise have also been developed. These algorithms are used to estimate the process noise and measurement noise for the Wide Field Infrared Explorer star tracker and gyro.

Statistical Analyses of Femur Parameters for Designing Anatomical Plates.

PubMed

Wang, Lin; He, Kunjin; Chen, Zhengming

2016-01-01

Femur parameters are key prerequisites for scientifically designing anatomical plates. Meanwhile, individual differences in femurs present a challenge to design well-fitting anatomical plates. Therefore, to design anatomical plates more scientifically, analyses of femur parameters with statistical methods were performed in this study. The specific steps were as follows. First, taking eight anatomical femur parameters as variables, 100 femur samples were classified into three classes with factor analysis and Q-type cluster analysis. Second, based on the mean parameter values of the three classes of femurs, three sizes of average anatomical plates corresponding to the three classes of femurs were designed. Finally, based on Bayes discriminant analysis, a new femur could be assigned to the proper class. Thereafter, the average anatomical plate suitable for that new femur was selected from the three available sizes of plates. Experimental results showed that the classification of femurs was quite reasonable based on the anatomical aspects of the femurs. For instance, three sizes of condylar buttress plates were designed. Meanwhile, 20 new femurs are judged to which classes the femurs belong. Thereafter, suitable condylar buttress plates were determined and selected.

Model parameter estimation approach based on incremental analysis for lithium-ion batteries without using open circuit voltage

NASA Astrophysics Data System (ADS)

Wu, Hongjie; Yuan, Shifei; Zhang, Xi; Yin, Chengliang; Ma, Xuerui

2015-08-01

To improve the suitability of lithium-ion battery model under varying scenarios, such as fluctuating temperature and SoC variation, dynamic model with parameters updated realtime should be developed. In this paper, an incremental analysis-based auto regressive exogenous (I-ARX) modeling method is proposed to eliminate the modeling error caused by the OCV effect and improve the accuracy of parameter estimation. Then, its numerical stability, modeling error, and parametric sensitivity are analyzed at different sampling rates (0.02, 0.1, 0.5 and 1 s). To identify the model parameters recursively, a bias-correction recursive least squares (CRLS) algorithm is applied. Finally, the pseudo random binary sequence (PRBS) and urban dynamic driving sequences (UDDSs) profiles are performed to verify the realtime performance and robustness of the newly proposed model and algorithm. Different sampling rates (1 Hz and 10 Hz) and multiple temperature points (5, 25, and 45 °C) are covered in our experiments. The experimental and simulation results indicate that the proposed I-ARX model can present high accuracy and suitability for parameter identification without using open circuit voltage.

Multi-objective control of nonlinear boiler-turbine dynamics with actuator magnitude and rate constraints.

PubMed

Chen, Pang-Chia

2013-01-01

This paper investigates multi-objective controller design approaches for nonlinear boiler-turbine dynamics subject to actuator magnitude and rate constraints. System nonlinearity is handled by a suitable linear parameter varying system representation with drum pressure as the system varying parameter. Variation of the drum pressure is represented by suitable norm-bounded uncertainty and affine dependence on system matrices. Based on linear matrix inequality algorithms, the magnitude and rate constraints on the actuator and the deviations of fluid density and water level are formulated while the tracking abilities on the drum pressure and power output are optimized. Variation ranges of drum pressure and magnitude tracking commands are used as controller design parameters, determined according to the boiler-turbine's operation range. Copyright © 2012 ISA. Published by Elsevier Ltd. All rights reserved.

Self-adaptive multi-objective harmony search for optimal design of water distribution networks

NASA Astrophysics Data System (ADS)

Choi, Young Hwan; Lee, Ho Min; Yoo, Do Guen; Kim, Joong Hoon

2017-11-01

In multi-objective optimization computing, it is important to assign suitable parameters to each optimization problem to obtain better solutions. In this study, a self-adaptive multi-objective harmony search (SaMOHS) algorithm is developed to apply the parameter-setting-free technique, which is an example of a self-adaptive methodology. The SaMOHS algorithm attempts to remove some of the inconvenience from parameter setting and selects the most adaptive parameters during the iterative solution search process. To verify the proposed algorithm, an optimal least cost water distribution network design problem is applied to three different target networks. The results are compared with other well-known algorithms such as multi-objective harmony search and the non-dominated sorting genetic algorithm-II. The efficiency of the proposed algorithm is quantified by suitable performance indices. The results indicate that SaMOHS can be efficiently applied to the search for Pareto-optimal solutions in a multi-objective solution space.

20 CFR 408.611 - What happens to your monthly benefits while we are finding a suitable representative payee for you?

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false What happens to your monthly benefits while we are finding a suitable representative payee for you? 408.611 Section 408.611 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS Representative Payment...

20 CFR 408.611 - What happens to your monthly benefits while we are finding a suitable representative payee for you?

Code of Federal Regulations, 2011 CFR

2011-04-01

... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false What happens to your monthly benefits while we are finding a suitable representative payee for you? 408.611 Section 408.611 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS Representative Payment...

20 CFR 408.611 - What happens to your monthly benefits while we are finding a suitable representative payee for you?

Code of Federal Regulations, 2013 CFR

2013-04-01

... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false What happens to your monthly benefits while we are finding a suitable representative payee for you? 408.611 Section 408.611 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS Representative Payment...

20 CFR 408.611 - What happens to your monthly benefits while we are finding a suitable representative payee for you?

Code of Federal Regulations, 2012 CFR

2012-04-01

... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false What happens to your monthly benefits while we are finding a suitable representative payee for you? 408.611 Section 408.611 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS Representative Payment...

20 CFR 408.611 - What happens to your monthly benefits while we are finding a suitable representative payee for you?

Code of Federal Regulations, 2014 CFR

2014-04-01

... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false What happens to your monthly benefits while we are finding a suitable representative payee for you? 408.611 Section 408.611 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS Representative Payment...

Multisource Data Classification Using A Hybrid Semi-supervised Learning Scheme

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vatsavai, Raju; Bhaduri, Budhendra L; Shekhar, Shashi

2009-01-01

In many practical situations thematic classes can not be discriminated by spectral measurements alone. Often one needs additional features such as population density, road density, wetlands, elevation, soil types, etc. which are discrete attributes. On the other hand remote sensing image features are continuous attributes. Finding a suitable statistical model and estimation of parameters is a challenging task in multisource (e.g., discrete and continuous attributes) data classification. In this paper we present a semi-supervised learning method by assuming that the samples were generated by a mixture model, where each component could be either a continuous or discrete distribution. Overall classificationmore » accuracy of the proposed method is improved by 12% in our initial experiments.« less

Identification of artificial groundwater recharging zone using a GIS-based fuzzy logic approach: a case study in a coal mine area of the Damodar Valley, India

NASA Astrophysics Data System (ADS)

Tiwari, Ashwani Kumar; Lavy, Muriel; Amanzio, Gianpiero; De Maio, Marina; Singh, Prasoon Kumar; Mahato, Mukesh Kumar

2017-12-01

The West Bokaro coalfield is a richest coal-mining belt in the Damodar Valley, India. The extensive mining of the area has resulted in disruption of the groundwater availability in terms of both quantity and quality. This has led to a drinking water crisis, especially during the pre-monsoon period in the West Bokaro coalfield area. The characterization of the hydrogeological system and the artificial recharging of the aquifers might help to better manage the problem of the groundwater-level depletion. For this purpose, seven important hydrogeological factors (water depth, slope, drainage, soil, infiltration, lithology, and landuse) have been considered to define the most suitable locations for artificial groundwater recharging in the mining area. Different thematic maps were prepared from existing maps and data sets, remote-sensing images, and field investigations for identification of the most suitable locations for artificial recharge. Thematic layers for these parameters were prepared, classified, weighted, and integrated into a geographic information system (GIS) environment by means of fuzzy logic. The results of the study indicate that about 29 and 31% of the area are very suitable and suitable for recharging purposes in the West Bokaro coalfield. However, the rest of the area is moderate to unsuitable for recharging due to the ongoing mining and related activities in the study area. The groundwater recharging map of the study area was validated with measured electrical conductivity (EC) values in the groundwater, and it indicated that validation can be accepted for the identification of groundwater recharging sites. These findings are providing useful information for the proper planning and sustainable management of the groundwater resources in the study area.

The effect of cryopreservation on goat semen characteristics related to sperm freezability.

PubMed

Dorado, J; Muñoz-Serrano, A; Hidalgo, M

2010-08-01

Seminal quality parameters were used to evaluate the effect of freeze-thawing procedure on goat sperm characteristics, and to relate possible changes in sperm parameters to cryopreservation success. Semen samples (n=110) were frozen with TRIS and milk-based extenders and thawed. Sperm quality parameters (motility, morphology and acrosome) were compared between fresh and frozen-thawed samples. Sperm freezability was judged by classifying the semen samples as "suitable" or "not suitable" according to the sperm quality parameters assessed before and after thawing. Fertility data was obtained after cervical insemination with frozen semen doses. The ejaculates were grouped into two categories according to their fertility results. In experiment 1, significant differences were found between semen extenders (P<0.001), bucks (P<0.05) and ejaculates within the same male (P<0.05) in terms of sperm quality. There was no seasonal effect (P>0.05) on the majority of the sperm parameters assessed after thawing. Moreover, significant differences (P<0.001) in semen parameters assessed in fresh semen and frozen-thawed samples were found between groups. The effect of the freeze-thawing procedure on sperm quality parameters was also different (P<0.05) between extenders within the same group. The number of sperm quality parameters that had changed after cryopreservation was lower in "suitable" semen samples before and after thawing. In experiment 2, no differences (P>0.05) in semen parameters assessed in fresh semen and frozen-thawed samples were found between groups. The effect of freezing and thawing on sperm quality parameters were different (P<0.05) between extenders within the same group. Only mean beat cross frequency (BCF) values were significantly higher (P<0.05) in TRIS diluted samples that led to successful pregnancies after artificial insemination. In conclusion, CASA-derived motility parameters, together with traditional semen assessment methods, give valuable information on sperm quality before and after freezing. Therefore, the identification of ejaculates as "good" or "bad" based on fresh and post-thaw semen parameters studied in the present experiment were good indicators of goat semen freezability, although the fertilizing capacity of frozen-thawed goat spermatozoa are not revealed by this quality study. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Development of habitat suitability indices for the Candy Darter, with cross-scale validation across representative populations

USGS Publications Warehouse

Dunn, Corey G.; Angermeier, Paul

2016-01-01

Understanding relationships between habitat associations for individuals and habitat factors that limit populations is a primary challenge for managers of stream fishes. Although habitat use by individuals can provide insight into the adaptive significance of selected microhabitats, not all habitat parameters will be significant at the population level, particularly when distributional patterns partially result from habitat degradation. We used underwater observation to quantify microhabitat selection by an imperiled stream fish, the Candy Darter Etheostoma osburni, in two streams with robust populations. We developed multiple-variable and multiple-life-stage habitat suitability indices (HSIs) from microhabitat selection patterns and used them to assess the suitability of available habitat in streams where Candy Darter populations were extirpated, localized, or robust. Next, we used a comparative framework to examine relationships among (1) habitat availability across streams, (2) projected habitat suitability of each stream, and (3) a rank for the likely long-term viability (robustness) of the population inhabiting each stream. Habitat selection was characterized by ontogenetic shifts from the low-velocity, slightly embedded areas used by age-0 Candy Darters to the swift, shallow areas with little fine sediment and complex substrate, which were used by adults. Overall, HSIs were strongly correlated with population rank. However, we observed weak or inverse relationships between predicted individual habitat suitability and population robustness for multiple life stages and variables. The results demonstrated that microhabitat selection by individuals does not always reflect population robustness, particularly when based on a single life stage or season, which highlights the risk of generalizing habitat selection that is observed during nonstressful periods or for noncritical resources. These findings suggest that stream fish managers may need to be cautious when implementing conservation measures based solely on observations of habitat selection by individuals and that detailed study at the individual and population levels may be necessary to identify habitat that limits populations.

Predicting habitat suitability for wildlife in southeastern Arizona using Geographic Information Systems: scaled quail, a case study

Treesearch

Kirby D. Bristow; Susan R. Boe; Richard A. Ockenfels

2005-01-01

Studies have used Geographic Information Systems (GIS) to evaluate habitat suitability for wildlife on a landscape scale, yet few have established the accuracy of these models. Based on documented habitat selection patterns of scaled quail (Callipepla squamata pallida), we produced GIS covers for several habitat parameters to create a map of...

Arc Habitat Suitability Index computer software

Treesearch

Thomas M. Juntti; Mark A. Rumble

2006-01-01

This user manual describes the Arc Habitat Suitability Index (ArcHSI), which is a geographical information system (GIS) model that estimates the ability of an area to meet the food and cover requirements of an animal species. The components and parameters of the model occur in tables and can be easily edited or otherwise modified. ArcHSI runs on personal computers with...

Mathematical Model to estimate the wind power using four-parameter Burr distribution

NASA Astrophysics Data System (ADS)

Liu, Sanming; Wang, Zhijie; Pan, Zhaoxu

2018-03-01

When the real probability of wind speed in the same position needs to be described, the four-parameter Burr distribution is more suitable than other distributions. This paper introduces its important properties and characteristics. Also, the application of the four-parameter Burr distribution in wind speed prediction is discussed, and the expression of probability distribution of output power of wind turbine is deduced.

Application of the soil-ecological multiplicative index to assess suitability of Cis-Ural chernozems for cultivation with due account for economic parameters

NASA Astrophysics Data System (ADS)

Levykin, S. V.; Chibilev, A. A.; Kazachkov, G. V.; Petrishchev, V. P.

2017-02-01

The evolution of Russian concepts concerning the assessment of soil suitability for cultivation in relation to several campaigns on large-scale plowing of virgin steppe soils is examined. The major problems of agricultural land use in steppe areas—preservation of rainfed farming in the regions with increasing climatic risks, underestimation of the potential of arable lands in land cadaster assessments, and much lower factual yields in comparison with potential yields—are considered. It is suggested that the assessments of arable lands should be performed on the basis of the soil-ecological index (SEI) developed by I. Karmanov with further conversion of SEI values into nominal monetary values. Under conditions of land reforms and economic reforms, it is important to determine suitability of steppe chernozems for plowing and economic feasibility of their use for crop growing in dependence on macroeconomic parameters. This should support decisions on optimization of land use in the steppe zone on the basis of the principles suggested by V. Dokuchaev. The developed approach for assessing soil suitability for cultivation was tested in the subzone of herbaceous-fescue-feather grass steppes in the Cis-Ural part of Orenburg oblast and used for the assessment of soil suitability for cultivation in the southern and southeastern regions of Orenburg oblast.

Monte Carlo simulations of relativistic radiation-mediated shocks - I. Photon-rich regime

NASA Astrophysics Data System (ADS)

Ito, Hirotaka; Levinson, Amir; Stern, Boris E.; Nagataki, Shigehiro

2018-02-01

We explore the physics of relativistic radiation-mediated shocks (RRMSs) in the regime where photon advection dominates over photon generation. For this purpose, a novel iterative method for deriving a self-consistent steady-state structure of RRMS is developed, based on a Monte Carlo code that solves the transfer of photons subject to Compton scattering and pair production/annihilation. Systematic study is performed by imposing various upstream conditions which are characterized by the following three parameters: the photon-to-baryon inertia ratio ξu*, the photon-to-baryon number ratio \\tilde{n}, and the shock Lorentz factor γu. We find that the properties of RRMSs vary considerably with these parameters. In particular, while a smooth decline in the velocity, accompanied by a gradual temperature increase is seen for ξu* ≫ 1, an efficient bulk Comptonization, that leads to a heating precursor, is found for ξu* ≲ 1. As a consequence, although particle acceleration is highly inefficient in these shocks, a broad non-thermal spectrum is produced in the latter case. The generation of high-energy photons through bulk Comptonization leads, in certain cases, to a copious production of pairs that provide the dominant opacity for Compton scattering. We also find that for certain upstream conditions a weak subshock appears within the flow. For a choice of parameters suitable to gamma-ray bursts, the radiation spectrum within the shock is found to be compatible with that of the prompt emission, suggesting that subphotospheric shocks may give rise to the observed non-thermal features despite the absence of accelerated particles.

Quasispecies dynamics on a network of interacting genotypes and idiotypes: applications to autoimmunity and immunodeficiency

NASA Astrophysics Data System (ADS)

Barbosa, Valmir C.; Donangelo, Raul; Souza, Sergio R.

2016-06-01

In spite of their many facets, the phenomena of autoimmunity and immunodeficiency seem to be related to each other through the subtle links connecting the mutation and action of retroviruses (viruses whose genetic material can find its way into that of the host’s cells and destroy them) to immune response and adaptation. In a previous work, we introduced a network model of how a set of interrelated genotypes (called a quasispecies, in the stationary state, representing for example a population of viruses) and a set of interrelated idiotypes (an idiotypic network, representing the immune system through its population of B and T cells) interact. That model, which does not cover the case of a retroviral quasispecies, is here extended by the addition of a further parameter (ν) to account for the action of retroviruses (i.e. the destruction of idiotypes by genotypes). We give simulation results within a suitable parameter niche, highlighting the issues of quasispecies survival and of the onset of autoimmunity through the appearance of the so-called pathogenic idiotypes (those that mimic some external pathogen). Our main findings refer to how ν and λ, a parameter describing the rate at which idiotypes get stimulated, relate to each other. While for ν >λ the quasispecies survives at the expense of weakening the immune system significantly or even destroying it, for ν <λ the fittest genotypes of the quasispecies become mimicked inside the immune system as pathogenic idiotypes. The latter is in agreement with the current understanding of the HIV quasispecies.

Incorporation of Solar-Induced Chlorophyll Fluorescence into the Breathing Earth System Simulator (BESS)

NASA Astrophysics Data System (ADS)

Dechant, B.; Ryu, Y.; Jiang, C.; Yang, K.

2017-12-01

Solar-induced chlorophyll fluorescence (SIF) is rapidly becoming an important tool to remotely estimate terrestrial gross primary productivity (GPP) at large spatial scales. Many findings, however, are based on empirical relationships between SIF and GPP that have been found to be dependent on plant functional types. Therefore, combining model-based analysis with observations is crucial to improve our understanding of SIF-GPP relationships. So far, most model-based results were based on SCOPE, a complex ecophysiological model with explicit description of canopy layers and a large number of parameters that may not be easily obtained reliably on large scales. Here, we report on our efforts to incorporate SIF into a two-big leaf (sun and shade) process-based model that is suitable for obtaining its inputs entirely from satellite products. We examine if the SIF-GPP relationships are consistent with the findings from SCOPE simulations and investigate if incorporation of the SIF signal into BESS can help improve GPP estimation. A case study in a rice paddy is presented.

Weakly dynamic dark energy via metric-scalar couplings with torsion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sur, Sourav; Bhatia, Arshdeep Singh, E-mail: sourav.sur@gmail.com, E-mail: arshdeepsb@gmail.com

We study the dynamical aspects of dark energy in the context of a non-minimally coupled scalar field with curvature and torsion. Whereas the scalar field acts as the source of the trace mode of torsion, a suitable constraint on the torsion pseudo-trace provides a mass term for the scalar field in the effective action. In the equivalent scalar-tensor framework, we find explicit cosmological solutions representing dark energy in both Einstein and Jordan frames. We demand the dynamical evolution of the dark energy to be weak enough, so that the present-day values of the cosmological parameters could be estimated keeping themmore » within the confidence limits set for the standard LCDM model from recent observations. For such estimates, we examine the variations of the effective matter density and the dark energy equation of state parameters over different redshift ranges. In spite of being weakly dynamic, the dark energy component differs significantly from the cosmological constant, both in characteristics and features, for e.g. it interacts with the cosmological (dust) fluid in the Einstein frame, and crosses the phantom barrier in the Jordan frame. We also obtain the upper bounds on the torsion mode parameters and the lower bound on the effective Brans-Dicke parameter. The latter turns out to be fairly large, and in agreement with the local gravity constraints, which therefore come in support of our analysis.« less

Weakly dynamic dark energy via metric-scalar couplings with torsion

NASA Astrophysics Data System (ADS)

Sur, Sourav; Singh Bhatia, Arshdeep

2017-07-01

We study the dynamical aspects of dark energy in the context of a non-minimally coupled scalar field with curvature and torsion. Whereas the scalar field acts as the source of the trace mode of torsion, a suitable constraint on the torsion pseudo-trace provides a mass term for the scalar field in the effective action. In the equivalent scalar-tensor framework, we find explicit cosmological solutions representing dark energy in both Einstein and Jordan frames. We demand the dynamical evolution of the dark energy to be weak enough, so that the present-day values of the cosmological parameters could be estimated keeping them within the confidence limits set for the standard LCDM model from recent observations. For such estimates, we examine the variations of the effective matter density and the dark energy equation of state parameters over different redshift ranges. In spite of being weakly dynamic, the dark energy component differs significantly from the cosmological constant, both in characteristics and features, for e.g. it interacts with the cosmological (dust) fluid in the Einstein frame, and crosses the phantom barrier in the Jordan frame. We also obtain the upper bounds on the torsion mode parameters and the lower bound on the effective Brans-Dicke parameter. The latter turns out to be fairly large, and in agreement with the local gravity constraints, which therefore come in support of our analysis.

Assessment of the viscoelastic mechanical properties of polycarbonate urethane for medical devices.

PubMed

Beckmann, Agnes; Heider, Yousef; Stoffel, Marcus; Markert, Bernd

2018-06-01

The underlying research work introduces a study of the mechanical properties of polycarbonate urethane (PCU), used in the construction of various medical devices. This comprises the discussion of a suitable material model, the application of elemental experiments to identify the related parameters and the numerical simulation of the applied experiments in order to calibrate and validate the mathematical model. In particular, the model of choice for the simulation of PCU response is the non-linear viscoelastic Bergström-Boyce material model, applied in the finite-element (FE) package Abaqus®. For the parameter identification, uniaxial tension and unconfined compression tests under in-laboratory physiological conditions were carried out. The geometry of the samples together with the applied loadings were simulated in Abaqus®, to insure the suitability of the modelling approach. The obtained parameters show a very good agreement between the numerical and the experimental results. Copyright © 2018 Elsevier Ltd. All rights reserved.

Kamlet-Taft solvent parameters, NMR spectroscopic analysis and thermoelectrochemistry of lithium-glyme solvate ionic liquids and their dilute solutions.

PubMed

Black, Jeffrey J; Dolan, Andrew; Harper, Jason B; Aldous, Leigh

2018-06-06

Solvate ionic liquids are a relatively new class of liquids produced by combining a coordinating solvent with a salt. They have a variety of uses and their suitability for such depends upon the ratio of salt to coordinating solvent. This work investigates the Kamlet-Taft solvent parameters of, NMR chemical shifts of nuclei in, and thermoelectrochemistry of a selected set of solvate ionic liquids produced from glymes (methyl terminated oligomers of ethylene glycol) and lithium bis(trifluoromethylsulfonyl)imide at two different compositions. The aim is to improve the understanding of the interactions occurring in these ionic liquids to help select suitable solvate ionic liquids for future applications.

Nonequilibrium evolution of scalar fields in FRW cosmologies

NASA Astrophysics Data System (ADS)

Boyanovsky, D.; de Vega, H. J.; Holman, R.

1994-03-01

We derive the effective equations for the out of equilibrium time evolution of the order parameter and the fluctuations of a scalar field theory in spatially flat FRW cosmologies. The calculation is performed both to one loop and in a nonperturbative, self-consistent Hartree approximation. The method consists of evolving an initial functional thermal density matrix in time and is suitable for studying phase transitions out of equilibrium. The renormalization aspects are studied in detail and we find that the counterterms depend on the initial state. We investigate the high temperature expansion and show that it breaks down at long times. We also obtain the time evolution of the initial Boltzmann distribution functions, and argue that to one-loop order or in the Hartree approximation the time evolved state is a ``squeezed'' state. We illustrate the departure from thermal equilibrium by numerically studying the case of a free massive scalar field in de Sitter and radiation-dominated cosmologies. It is found that a suitably defined nonequilibrium entropy per mode increases linearly with comoving time in a de Sitter cosmology, whereas it is not a monotonically increasing function in the radiation-dominated case.

Can constructed wetlands treat wastewater for reuse in agriculture? Review of guidelines and examples in South Europe.

PubMed

Lavrnić, Stevo; Mancini, Maurizio L

2016-01-01

South Europe is one of the areas negatively affected by climate change. Issues with water shortage are already visible, and are likely to increase. Since agriculture is the biggest freshwater consumer, it is important to find new water sources that could mitigate the climate change impact. In order to overcome problems and protect the environment, a better approach towards wastewater management is needed. That includes an increase in the volume of wastewater that is treated and a paradigm shift towards a more sustainable system where wastewater is actually considered as a resource. This study evaluates the potential of constructed wetlands (CWs) to treat domestic wastewater and produce effluent that will be suitable for reuse in agriculture. In South Europe, four countries (Greece, Italy, Portugal and Spain) have national standards that regulate wastewater reuse in agriculture. Wastewater treatment plants (WWTPs) that are based on CWs in these four countries were analysed and their effluents compared with the quality needed for reuse. In general, it was found that CWs have trouble reaching the strictest standards, especially regarding microbiological parameters. However, their effluents are found to be suitable for reuse in areas that do not require water of the highest quality.

Solution Path for Pin-SVM Classifiers With Positive and Negative $\\tau $ Values.

PubMed

Huang, Xiaolin; Shi, Lei; Suykens, Johan A K

2017-07-01

Applying the pinball loss in a support vector machine (SVM) classifier results in pin-SVM. The pinball loss is characterized by a parameter τ . Its value is related to the quantile level and different τ values are suitable for different problems. In this paper, we establish an algorithm to find the entire solution path for pin-SVM with different τ values. This algorithm is based on the fact that the optimal solution to pin-SVM is continuous and piecewise linear with respect to τ . We also show that the nonnegativity constraint on τ is not necessary, i.e., τ can be extended to negative values. First, in some applications, a negative τ leads to better accuracy. Second, τ = -1 corresponds to a simple solution that links SVM and the classical kernel rule. The solution for τ = -1 can be obtained directly and then be used as a starting point of the solution path. The proposed method efficiently traverses τ values through the solution path, and then achieves good performance by a suitable τ . In particular, τ = 0 corresponds to C-SVM, meaning that the traversal algorithm can output a result at least as good as C-SVM with respect to validation error.

Comparison of Clustering Techniques for Residential Energy Behavior using Smart Meter Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jin, Ling; Lee, Doris; Sim, Alex

Current practice in whole time series clustering of residential meter data focuses on aggregated or subsampled load data at the customer level, which ignores day-to-day differences within customers. This information is critical to determine each customer’s suitability to various demand side management strategies that support intelligent power grids and smart energy management. Clustering daily load shapes provides fine-grained information on customer attributes and sources of variation for subsequent models and customer segmentation. In this paper, we apply 11 clustering methods to daily residential meter data. We evaluate their parameter settings and suitability based on 6 generic performance metrics and post-checkingmore » of resulting clusters. Finally, we recommend suitable techniques and parameters based on the goal of discovering diverse daily load patterns among residential customers. To the authors’ knowledge, this paper is the first robust comparative review of clustering techniques applied to daily residential load shape time series in the power systems’ literature.« less

20 CFR 416.611 - What happens to your monthly benefits while we are finding a suitable representative payee for you?

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false What happens to your monthly benefits while we are finding a suitable representative payee for you? 416.611 Section 416.611 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Representative Payment § 416.611 What happens to your...

20 CFR 404.2011 - What happens to your monthly benefits while we are finding a suitable representative payee for you?

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false What happens to your monthly benefits while we are finding a suitable representative payee for you? 404.2011 Section 404.2011 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Representative Payment § 404.2011 What happens to your...

Classifying zones of suitability for manual drilling using textural and hydraulic parameters of shallow aquifers: a case study in northwestern Senegal

NASA Astrophysics Data System (ADS)

Fussi, F. Fabio; Fumagalli, Letizia; Fava, Francesco; Di Mauro, Biagio; Kane, Cheik Hamidou; Niang, Magatte; Wade, Souleye; Hamidou, Barry; Colombo, Roberto; Bonomi, Tullia

2017-12-01

A method is proposed that uses analysis of borehole stratigraphic logs for the characterization of shallow aquifers and for the assessment of areas suitable for manual drilling. The model is based on available borehole-log parameters: depth to hard rock, depth to water, thickness of laterite and hydraulic transmissivity of the shallow aquifer. The model is applied to a study area in northwestern Senegal. A dataset of boreholes logs has been processed using a software package (TANGAFRIC) developed during the research. After a manual procedure to assign a standard category describing the lithological characteristics, the next step is the automated extraction of different textural parameters and the estimation of hydraulic conductivity using reference values available in the literature. The hydraulic conductivity values estimated from stratigraphic data have been partially validated, by comparing them with measured values from a series of pumping tests carried out in large-diameter wells. The results show that this method is able to produce a reliable interpretation of the shallow hydrogeological context using information generally available in the region. The research contributes to improving the identification of areas where conditions are suitable for manual drilling. This is achieved by applying the described method, based on a structured and semi-quantitative approach, to classify the zones of suitability for given manual drilling techniques using data available in most African countries. Ultimately, this work will support proposed international programs aimed at promoting low-cost water supply in Africa and enhancing access to safe drinking water for the population.

SP_Ace: Stellar Parameters And Chemical abundances Estimator

NASA Astrophysics Data System (ADS)

Boeche, C.; Grebel, E. K.

2018-05-01

SP_Ace (Stellar Parameters And Chemical abundances Estimator) estimates the stellar parameters Teff, log g, [M/H], and elemental abundances. It employs 1D stellar atmosphere models in Local Thermodynamic Equilibrium (LTE). The code is highly automated and suitable for analyzing the spectra of large spectroscopic surveys with low or medium spectral resolution (R = 2000-20 000). A web service for calculating these values with the software is also available.

Efficient design based on perturbed parameter ensembles to identify plausible and diverse variants of a model for climate change projections

NASA Astrophysics Data System (ADS)

Karmalkar, A.; Sexton, D.; Murphy, J.

2017-12-01

We present exploratory work towards developing an efficient strategy to select variants of a state-of-the-art but expensive climate model suitable for climate projection studies. The strategy combines information from a set of idealized perturbed parameter ensemble (PPE) and CMIP5 multi-model ensemble (MME) experiments, and uses two criteria as basis to select model variants for a PPE suitable for future projections: a) acceptable model performance at two different timescales, and b) maintaining diversity in model response to climate change. We demonstrate that there is a strong relationship between model errors at weather and climate timescales for a variety of key variables. This relationship is used to filter out parts of parameter space that do not give credible simulations of historical climate, while minimizing the impact on ranges in forcings and feedbacks that drive model responses to climate change. We use statistical emulation to explore the parameter space thoroughly, and demonstrate that about 90% can be filtered out without affecting diversity in global-scale climate change responses. This leads to identification of plausible parts of parameter space from which model variants can be selected for projection studies.

Selection of operating parameters on the basis of hydrodynamics in centrifugal partition chromatography for the purification of nybomycin derivatives.

PubMed

Adelmann, S; Baldhoff, T; Koepcke, B; Schembecker, G

2013-01-25

The selection of solvent systems in centrifugal partition chromatography (CPC) is the most critical point in setting up a separation. Therefore, lots of research was done on the topic in the last decades. But the selection of suitable operating parameters (mobile phase flow rate, rotational speed and mode of operation) with respect to hydrodynamics and pressure drop limit in CPC is still mainly driven by experience of the chromatographer. In this work we used hydrodynamic analysis for the prediction of most suitable operating parameters. After selection of different solvent systems with respect to partition coefficients for the target compound the hydrodynamics were visualized. Based on flow pattern and retention the operating parameters were selected for the purification runs of nybomycin derivatives that were carried out with a 200 ml FCPC(®) rotor. The results have proven that the selection of optimized operating parameters by analysis of hydrodynamics only is possible. As the hydrodynamics are predictable by the physical properties of the solvent system the optimized operating parameters can be estimated, too. Additionally, we found that dispersion and especially retention are improved if the less viscous phase is mobile. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

Customized rating assessment of climate suitability (CRACS): climate satisfaction evaluation based on subjective perception.

PubMed

Lin, Tzu-Ping; Yang, Shing-Ru; Matzarakis, Andreas

2015-12-01

Climate not only influences the behavior of people in urban environments but also affects people's schedules and travel plans. Therefore, providing people with appropriate long-term climate evaluation information is crucial. Therefore, we developed an innovative climate assessment system based on field investigations conducted in three cities located in Northern, Central, and Southern Taiwan. The field investigations included the questionnaire surveys and climate data collection. We first analyzed the relationship between the participants and climate parameters comprising physiologically equivalent temperature, air temperature, humidity, wind speed, solar radiation, cloud cover, and precipitation. Second, we established the neutral value, comfort range, and dissatisfied range of each parameter. Third, after verifying that the subjects' perception toward the climate parameters vary based on individual preferences, we developed the customized rating assessment of climate suitability (CRACS) approach, which featured functions such as personalized and default climate suitability information to be used by users exhibiting varying demands. Finally, we performed calculations using the climate conditions of two cities during the past 10 years to demonstrate the performance of the CRACS approach. The results can be used as a reference when planning activities in the city or when organizing future travel plans. The flexibility of the assessment system enables it to be adjusted for varying regions and usage characteristics.

Customized rating assessment of climate suitability (CRACS): climate satisfaction evaluation based on subjective perception

NASA Astrophysics Data System (ADS)

Lin, Tzu-Ping; Yang, Shing-Ru; Matzarakis, Andreas

2015-12-01

Climate not only influences the behavior of people in urban environments but also affects people's schedules and travel plans. Therefore, providing people with appropriate long-term climate evaluation information is crucial. Therefore, we developed an innovative climate assessment system based on field investigations conducted in three cities located in Northern, Central, and Southern Taiwan. The field investigations included the questionnaire surveys and climate data collection. We first analyzed the relationship between the participants and climate parameters comprising physiologically equivalent temperature, air temperature, humidity, wind speed, solar radiation, cloud cover, and precipitation. Second, we established the neutral value, comfort range, and dissatisfied range of each parameter. Third, after verifying that the subjects' perception toward the climate parameters vary based on individual preferences, we developed the customized rating assessment of climate suitability (CRACS) approach, which featured functions such as personalized and default climate suitability information to be used by users exhibiting varying demands. Finally, we performed calculations using the climate conditions of two cities during the past 10 years to demonstrate the performance of the CRACS approach. The results can be used as a reference when planning activities in the city or when organizing future travel plans. The flexibility of the assessment system enables it to be adjusted for varying regions and usage characteristics.

Evaluation of antibacterial properties of novel phthalocyanines against Escherichia coli--comparison of analytical methods.

PubMed

Mikula, Premysl; Kalhotka, Libor; Jancula, Daniel; Zezulka, Stepan; Korinkova, Radka; Cerny, Jiri; Marsalek, Blahoslav; Toman, Petr

2014-09-05

We analyzed antibacterial effects of several novel phthalocyanines against Escherichia coli and evaluated the suitability of flow cytometry for the detection of antibacterial effects of phthalocyanines in comparison with routinely used cultivation. After 3h of exposure under cool white light eight cationic phthalocyanines showed very high antibacterial activity in the concentration of 2.00 mg L(-1) and four of them were even efficient in the concentration of 0.20 mg L(-1). Antibacterial activity of neutral and anionic compounds was considerably lower or even negligible. No antibacterial effect was detected when bacteria were exposed without illumination. Binding affinity to bacterial cells was found to represent an important parameter influencing phthalocyanine antibacterial activity that can be modified by total charge of peripheral substituents and by the presence of suitable functional groups inside them. Agglomeration of cells observed in suspensions treated with a higher concentration of certain cationic phthalocyanines (the strongest binders to bacterial membrane) affected cytometric measurements of total cell counts, thus without appropriate pretreatment of the sample before analysis this parameter seems not to be fully valid in the evaluation of phthalocyanine antibacterial activity. Cytometric measurement of cell membrane integrity appears to be a suitable and even more sensitive parameter than cultivation. Copyright © 2014 Elsevier B.V. All rights reserved.

Measurement of spectral characteristics and CCT mixture of PDMS and the luminophore depending on the geometric parameters and the concentration of the samples of the special optical fibers

NASA Astrophysics Data System (ADS)

Jargus, Jan; Nedoma, Jan; Fajkus, Marcel; Novak, Martin; Bednarek, Lukas; Vasinek, Vladimir

2017-05-01

White light is produced by a suitable combination of spectral components RGB (colors) or through exposure excitation of blue light (the blue component of light). This blue part of the light is partly and suitably transformed by luminophore so that the resulting emitted spectrum corresponded to the spectral characteristics of white light with a given correlated color temperature (CCT). This paper deals with the measurement of optical properties of a mixture polydimethylsiloxane (PDMS) and luminophore, which is irradiated by the blue LED (Light-Emitting Diode) to obtain the white color of light. The subject of the investigation is the dependence of CCT on the concentration of the luminophore in a mixture of PDMS and different geometrical parameters of the samples. There are many kinds of PDMS and luminophore. We used PDMS Sylgard 184 and luminophore-labeled U2. More accurately Yttrium Aluminium Oxide: Cerium Y3Al5O12: Ce. From the analyzed data, we determined, which mutual combinations of concentration of the mixture of luminophore and PDMS together with the geometric parameters of the samples of the special optical fibers are suitable for illumination, while we get the desired CCT.

Comparison of gating methods for the real-time analysis of left ventricular function in nonimaging blood pool studies.

PubMed

Beard, B B; Stewart, J R; Shiavi, R G; Lorenz, C H

1995-01-01

Gating methods developed for electrocardiographic-triggered radionuclide ventriculography are being used with nonimaging detectors. These methods have not been compared on the basis of their real-time performance or suitability for determination of load-independent indexes of left ventricular function. This work evaluated the relative merits of different gating methods for nonimaging radionuclude ventriculographic studies, with particular emphasis on their suitability for real-time measurements and the determination of pressure-volume loops. A computer model was used to investigate the relative accuracy of forward gating, backward gating, and phase-mode gating. The durations of simulated left ventricular time-activity curves were randomly varied. Three acquisition parameters were considered: frame rate, acceptance window, and sample size. Twenty-five studies were performed for each combination of acquisition parameters. Hemodynamic and shape parameters from each study were compared with reference parameters derived directly from the random time-activity curves. Backward gating produced the largest errors under all conditions. For both forward gating and phase-mode gating, ejection fraction was underestimated and time to end systole and normalized peak ejection rate were overestimated. For the hemodynamic parameters, forward gating was marginally superior to phase-mode gating. The mean difference in errors between forward and phase-mode gating was 1.47% (SD 2.78%). However, for root mean square shape error, forward gating was several times worse in every case and seven times worse than phase-mode gating on average. Both forward and phase-mode gating are suitable for real-time hemodynamic measurements by nonimaging techniques. The small statistical difference between the methods is not clinically significant. The true shape of the time-activity curve is maintained most accurately by phase-mode gating.

Comparison of gating methods for the real-time analysis of left ventricular function in nonimaging blood pool studies

PubMed Central

Beard, Brian B.; Stewart, James R.; Shiavi, Richard G.; Lorenz, Christine H.

2018-01-01

Background Gating methods developed for electrocardiographic-triggered radionuclide ventriculography are being used with nonimaging detectors. These methods have not been compared on the basis of their real-time performance or suitability for determination of load-independent indexes of left ventricular function. This work evaluated the relative merits of different gating methods for nonimaging radionuclude ventriculographic studies, with particular emphasis on their suitability for real-time measurements and the determination of pressure-volume loops. Methods and Results A computer model was used to investigate the relative accuracy of forward gating, backward gating, and phase-mode gating. The durations of simulated left ventricular time-activity curves were randomly varied. Three acquisition parameters were considered: frame rate, acceptance window, and sample size. Twenty-five studies were performed for each combination of acquisition parameters. Hemodynamic and shape parameters from each study were compared with reference parameters derived directly from the random time-activity curves. Backward gating produced the largest errors under all conditions. For both forward gating and phase-mode gating, ejection fraction was underestimated and time to end systole and normalized peak ejection rate were overestimated. For the hemodynamic parameters, forward gating was marginally superior to phase-mode gating. The mean difference in errors between forward and phase-mode gating was 1.47% (SD 2.78%). However, for root mean square shape error, forward gating was several times worse in every case and seven times worse than phase-mode gating on average. Conclusions Both forward and phase-mode gating are suitable for real-time hemodynamic measurements by nonimaging techniques. The small statistical difference between the methods is not clinically significant. The true shape of the time-activity curve is maintained most accurately by phase-mode gating. PMID:9420820

An empirical approach to the stopping power of solids and gases for ions from 3Li to 18Ar

NASA Astrophysics Data System (ADS)

Paul, Helmut; Schinner, Andreas

2001-08-01

A large collection of stopping power data for projectiles from 3Li to 18Ar is investigated as a possible basis for producing a table of stopping powers. We divide the experimental stopping powers for a particular projectile (nuclear charge Z1) by those for alpha particles in the same element, as given in ICRU Report 49. With proper normalization, we then obtain experimental stopping power ratios Srel that lie approximately on a single curve, provided we treat solid and gaseous targets separately, and provided we exclude H 2 and He targets. For every projectile, this curve is then fitted by a 3-parameter sigmoid function Srel= Srel( a, b, c). We find that the three parameters a, b and c depend smoothly on Z1 and can themselves be fitted by suitable functions af, bf and cf of Z1, separately for solid and gaseous targets. The low energy limit (coefficient a) for solids agrees approximately with the prediction by Lindhard and Scharff. We find that agas< asol in almost all cases. Introducing the coefficients af , bf and cf in Srel, we can calculate the stopping power for any ion (3⩽ Z1⩽18), and for any element (except H 2 and He) and any mixture or compound contained in the ICRU table.

Polarization-based compensation of astigmatism.

PubMed

Chowdhury, Dola Roy; Bhattacharya, Kallol; Chakraborty, Ajay K; Ghosh, Raja

2004-02-01

One approach to aberration compensation of an imaging system is to introduce a suitable phase mask at the aperture plane of an imaging system. We utilize this principle for the compensation of astigmatism. A suitable polarization mask used on the aperture plane together with a polarizer-retarder combination at the input of the imaging system provides the compensating polarization-induced phase steps at different quadrants of the apertures masked by different polarizers. The aberrant phase can be considerably compensated by the proper choice of a polarization mask and suitable selection of the polarization parameters involved. The results presented here bear out our theoretical expectation.

Characteristics of laser-induced plasma as a spectroscopic light emission source

NASA Astrophysics Data System (ADS)

Ma, Q. L.; Motto-Ros, V.; Lei, W. Q.; Wang, X. C.; Boueri, M.; Laye, F.; Zeng, C. Q.; Sausy, M.; Wartelle, A.; Bai, X. S.; Zheng, L. J.; Zeng, H. P.; Baudelet, M.; Yu, J.

2012-05-01

Laser-induced plasma is today a widespread spectroscopic emission source. It can be easily generated using compact and reliable nanosecond pulsed lasers and finds applications in various domains with laser-induced breakdown spectroscopy (LIBS). It is however such a particular medium which is intrinsically a transient and non-point light emitting source. Its timeand space-resolved diagnostics is therefore crucial for its optimized use. In this paper, we review our work on the investigation of the morphology and the evolution of the plasma. Different time scales relevant for the description of the plasma's kinetics and dynamics are covered by suitable techniques. Our results show detailed evolution and transformation of the plasma with high temporal and spatial resolutions. The effects of the laser parameters as well as the background gas are particularly studied.

Tri-axial tactile sensing element

NASA Astrophysics Data System (ADS)

Castellanos-Ramos, Julián.; Navas-González, Rafael; Vidal-Verdú, F.

2013-05-01

A 13 x 13 square millimetre tri-axial taxel is presented which is suitable for some medical applications, for instance in assistive robotics that involves contact with humans or in prosthetics. Finite Element Analysis is carried out to determine what structure is the best to obtain a uniform distribution of pressure on the sensing areas underneath the structure. This structure has been fabricated in plastic with a 3D printer and a commercial tactile sensor has been used to implement the sensing areas. A three axis linear motorized translation stage with a tri-axial precision force sensor is used to find the parameters of the linear regression model and characterize the proposed taxel. The results are analysed to see to what extent the goal has been reached in this specific implementation.

Resistance of Magnesium Alloys to Corrosion Fatigue for Biodegradable Implant Applications: Current Status and Challenges

PubMed Central

Raman, R. K. Singh; Harandi, Shervin Eslami

2017-01-01

Magnesium (Mg) alloys are attracting increasing interest as the most suitable metallic materials for construction of biodegradable and bio-absorbable temporary implants. However, Mg-alloys can suffer premature and catastrophic fracture under the synergy of cyclic loading and corrosion (i.e., corrosion fatigue (CF)). Though Mg alloys are reported to be susceptible to CF also in the corrosive human body fluid, there are very limited studies on this topic. Furthermore, the in vitro test parameters employed in these investigations have not properly simulated the actual conditions in the human body. This article presents an overview of the findings of available studies on the CF of Mg alloys in pseudo-physiological solutions and the employed testing procedures, as well as identifying the knowledge gap. PMID:29144428

Resistance of Magnesium Alloys to Corrosion Fatigue for Biodegradable Implant Applications: Current Status and Challenges.

PubMed

Raman, R K Singh; Harandi, Shervin Eslami

2017-11-16

Magnesium (Mg) alloys are attracting increasing interest as the most suitable metallic materials for construction of biodegradable and bio-absorbable temporary implants. However, Mg-alloys can suffer premature and catastrophic fracture under the synergy of cyclic loading and corrosion (i.e., corrosion fatigue (CF)). Though Mg alloys are reported to be susceptible to CF also in the corrosive human body fluid, there are very limited studies on this topic. Furthermore, the in vitro test parameters employed in these investigations have not properly simulated the actual conditions in the human body. This article presents an overview of the findings of available studies on the CF of Mg alloys in pseudo-physiological solutions and the employed testing procedures, as well as identifying the knowledge gap.

A note on variance estimation in random effects meta-regression.

PubMed

Sidik, Kurex; Jonkman, Jeffrey N

2005-01-01

For random effects meta-regression inference, variance estimation for the parameter estimates is discussed. Because estimated weights are used for meta-regression analysis in practice, the assumed or estimated covariance matrix used in meta-regression is not strictly correct, due to possible errors in estimating the weights. Therefore, this note investigates the use of a robust variance estimation approach for obtaining variances of the parameter estimates in random effects meta-regression inference. This method treats the assumed covariance matrix of the effect measure variables as a working covariance matrix. Using an example of meta-analysis data from clinical trials of a vaccine, the robust variance estimation approach is illustrated in comparison with two other methods of variance estimation. A simulation study is presented, comparing the three methods of variance estimation in terms of bias and coverage probability. We find that, despite the seeming suitability of the robust estimator for random effects meta-regression, the improved variance estimator of Knapp and Hartung (2003) yields the best performance among the three estimators, and thus may provide the best protection against errors in the estimated weights.

Testing modified gravity at large distances with the HI Nearby Galaxy Survey's rotation curves

NASA Astrophysics Data System (ADS)

Mastache, Jorge; Cervantes-Cota, Jorge L.; de la Macorra, Axel

2013-03-01

Recently a new—quantum motivated—theory of gravity has been proposed that modifies the standard Newtonian potential at large distances when spherical symmetry is considered. Accordingly, Newtonian gravity is altered by adding an extra Rindler acceleration term that has to be phenomenologically determined. Here we consider a standard and a power-law generalization of the Rindler modified Newtonian potential. The new terms in the gravitational potential are hypothesized to play the role of dark matter in galaxies. Our galactic model includes the mass of the integrated gas, and stars for which we consider three stellar mass functions (Kroupa, diet-Salpeter, and free mass model). We test this idea by fitting rotation curves of seventeen low surface brightness galaxies from the HI Nearby Galaxy Survey (THINGS). We find that the Rindler parameters do not perform a suitable fit to the rotation curves in comparison to standard dark matter profiles (Navarro-Frenk-White and Burkert) and, in addition, the computed parameters of the Rindler gravity show a high spread, posing the model as a nonacceptable alternative to dark matter.

Single-Step Seeded-Growth of Graphene Nanoribbons (GNRs) via Plasma-Enhanced Chemical Vapor Deposition (PECVD)

NASA Astrophysics Data System (ADS)

Hsu, C.-C.; Yang, K.; Tseng, W.-S.; Li, Yiliang; Li, Yilun; Tour, J. M.; Yeh, N.-C.

One of the main challenges in the fabrication of GNRs is achieving large-scale low-cost production with high quality. Current techniques, including lithography and unzipped carbon nanotubes, are not suitable for mass production. We have recently developed a single-step PECVD growth process of high-quality graphene sheets without any active heating. By adding some substituted aromatic as seeding molecules, we are able to rapidly grow GNRs vertically on various transition-metal substrates. The morphology and electrical properties of the GNRs are dependent on the growth parameters such as the growth time, gas flow and species of the seeding molecules. On the other hand, all GNRs exhibit strong infrared and optical absorption. From studies of the Raman spectra, scanning electron microscopic images, and x-ray/ultraviolet photoelectron spectra of these GNRs as functions of the growth parameters, we propose a model for the growth mechanism. Our findings suggest that our approach opens up a pathway to large-scale, inexpensive production of GNRs for applications to supercapacitors and solar cells. This work was supported by the Grubstake Award and NSF through IQIM at Caltech.

Statistical Optimization of Sustained Release Venlafaxine HCI Wax Matrix Tablet.

PubMed

Bhalekar, M R; Madgulkar, A R; Sheladiya, D D; Kshirsagar, S J; Wable, N D; Desale, S S

2008-01-01

The purpose of this research was to prepare a sustained release drug delivery system of venlafaxine hydrochloride by using a wax matrix system. The effects of bees wax and carnauba wax on drug release profile was investigated. A 3(2) full factorial design was applied to systemically optimize the drug release profile. Amounts of carnauba wax (X(1)) and bees wax (X(2)) were selected as independent variables and release after 12 h and time required for 50% (t(50)) drug release were selected as dependent variables. A mathematical model was generated for each response parameter. Both waxes retarded release after 12 h and increases the t(50) but bees wax showed significant influence. The drug release pattern for all the formulation combinations was found to be approaching Peppas kinetic model. Suitable combination of two waxes provided fairly good regulated release profile. The response surfaces and contour plots for each response parameter are presented for further interpretation of the results. The optimum formulations were chosen and their predicted results found to be in close agreement with experimental findings.

Statistical Optimization of Sustained Release Venlafaxine HCI Wax Matrix Tablet

PubMed Central

Bhalekar, M. R.; Madgulkar, A. R.; Sheladiya, D. D.; Kshirsagar, S. J.; Wable, N. D.; Desale, S. S.

2008-01-01

The purpose of this research was to prepare a sustained release drug delivery system of venlafaxine hydrochloride by using a wax matrix system. The effects of bees wax and carnauba wax on drug release profile was investigated. A 32 full factorial design was applied to systemically optimize the drug release profile. Amounts of carnauba wax (X1) and bees wax (X2) were selected as independent variables and release after 12 h and time required for 50% (t50) drug release were selected as dependent variables. A mathematical model was generated for each response parameter. Both waxes retarded release after 12 h and increases the t50 but bees wax showed significant influence. The drug release pattern for all the formulation combinations was found to be approaching Peppas kinetic model. Suitable combination of two waxes provided fairly good regulated release profile. The response surfaces and contour plots for each response parameter are presented for further interpretation of the results. The optimum formulations were chosen and their predicted results found to be in close agreement with experimental findings. PMID:20046773

Comparison of subpixel image registration algorithms

NASA Astrophysics Data System (ADS)

Boye, R. R.; Nelson, C. L.

2009-02-01

Research into the use of multiframe superresolution has led to the development of algorithms for providing images with enhanced resolution using several lower resolution copies. An integral component of these algorithms is the determination of the registration of each of the low resolution images to a reference image. Without this information, no resolution enhancement can be attained. We have endeavored to find a suitable method for registering severely undersampled images by comparing several approaches. To test the algorithms, an ideal image is input to a simulated image formation program, creating several undersampled images with known geometric transformations. The registration algorithms are then applied to the set of low resolution images and the estimated registration parameters compared to the actual values. This investigation is limited to monochromatic images (extension to color images is not difficult) and only considers global geometric transformations. Each registration approach will be reviewed and evaluated with respect to the accuracy of the estimated registration parameters as well as the computational complexity required. In addition, the effects of image content, specifically spatial frequency content, as well as the immunity of the registration algorithms to noise will be discussed.

Recovery of oil from oil-in-water emulsion using biopolymers by adsorptive method.

PubMed

Elanchezhiyan, S Sd; Sivasurian, N; Meenakshi, Sankaran

2014-09-01

In the present study, it is aimed to identify, a low cost sorbent for the recovery of oil from oil-in-water emulsion using biopolymers such as chitin and chitosan. Chitin has the greater adsorption capacity than chitosan due to its hydrophobic nature. The characterizations of chitin and chitosan were done using FTIR, SEM, EDAX, XRD, TGA and DSC techniques. Under batch equilibrium mode, a systematic study was performed to optimize the various equilibrium parameters viz., contact time, pH, dosage, initial concentration of oil, and temperature. The adsorption process reached equilibrium at 40 min of contact time and the percentage removal of oil was found to be higher (90%) in the acidic medium. The Freundlich and Langmuir models were applied to describe the equilibrium isotherms and the isotherm constants were calculated. Thermodynamic parameters such as ΔG°, ΔH° and ΔS° were calculated to find out the nature of the sorption mechanism. The kinetic studies were investigated with reaction-based and diffusion-based models. The suitable mechanism for the removal of oil has been established. Copyright © 2014 Elsevier B.V. All rights reserved.

Process Improvement of Reactive Dye Synthesis Using Six Sigma Concept

NASA Astrophysics Data System (ADS)

Suwanich, Thanapat; Chutima, Parames

2017-06-01

This research focuses on the problem occurred in the reactive dye synthesis process of a global manufacturer in Thailand which producing various chemicals for reactive dye products to supply global industries such as chemicals, textiles and garments. The product named “Reactive Blue Base” is selected in this study because it has highest demand and the current chemical yield shows a high variation, i.e. yield variation of 90.4% - 99.1% (S.D. = 2.405 and Cpk = -0.08) and average yield is 94.5% (lower than the 95% standard set by the company). The Six Sigma concept is applied aiming at increasing yield and reducing variation of this process. This approach is suitable since it provides a systematic guideline with five improvement phases (DMAIC) to effectively tackle the problem and find the appropriate parameter settings of the process. Under the new parameter settings, the process yield variation is reduced to range between 96.5% - 98.5% (S.D. = 0.525 and Cpk = 1.83) and the average yield is increased to 97.5% (higher than the 95% standard set by the company).

Evaluation of Two Outlier-Detection-Based Methods for Detecting Tissue-Selective Genes from Microarray Data

PubMed Central

Kadota, Koji; Konishi, Tomokazu; Shimizu, Kentaro

2007-01-01

Large-scale expression profiling using DNA microarrays enables identification of tissue-selective genes for which expression is considerably higher and/or lower in some tissues than in others. Among numerous possible methods, only two outlier-detection-based methods (an AIC-based method and Sprent’s non-parametric method) can treat equally various types of selective patterns, but they produce substantially different results. We investigated the performance of these two methods for different parameter settings and for a reduced number of samples. We focused on their ability to detect selective expression patterns robustly. We applied them to public microarray data collected from 36 normal human tissue samples and analyzed the effects of both changing the parameter settings and reducing the number of samples. The AIC-based method was more robust in both cases. The findings confirm that the use of the AIC-based method in the recently proposed ROKU method for detecting tissue-selective expression patterns is correct and that Sprent’s method is not suitable for ROKU. PMID:19936074

BluePyOpt: Leveraging Open Source Software and Cloud Infrastructure to Optimise Model Parameters in Neuroscience.

PubMed

Van Geit, Werner; Gevaert, Michael; Chindemi, Giuseppe; Rössert, Christian; Courcol, Jean-Denis; Muller, Eilif B; Schürmann, Felix; Segev, Idan; Markram, Henry

2016-01-01

At many scales in neuroscience, appropriate mathematical models take the form of complex dynamical systems. Parameterizing such models to conform to the multitude of available experimental constraints is a global non-linear optimisation problem with a complex fitness landscape, requiring numerical techniques to find suitable approximate solutions. Stochastic optimisation approaches, such as evolutionary algorithms, have been shown to be effective, but often the setting up of such optimisations and the choice of a specific search algorithm and its parameters is non-trivial, requiring domain-specific expertise. Here we describe BluePyOpt, a Python package targeted at the broad neuroscience community to simplify this task. BluePyOpt is an extensible framework for data-driven model parameter optimisation that wraps and standardizes several existing open-source tools. It simplifies the task of creating and sharing these optimisations, and the associated techniques and knowledge. This is achieved by abstracting the optimisation and evaluation tasks into various reusable and flexible discrete elements according to established best-practices. Further, BluePyOpt provides methods for setting up both small- and large-scale optimisations on a variety of platforms, ranging from laptops to Linux clusters and cloud-based compute infrastructures. The versatility of the BluePyOpt framework is demonstrated by working through three representative neuroscience specific use cases.

The super-GUT CMSSM revisited

DOE PAGES

Ellis, John; Evans, Jason L.; Mustafayev, Azar; ...

2016-10-28

Here, we revisit minimal supersymmetric SU(5) grand unification (GUT) models in which the soft supersymmetry-breaking parameters of the minimal supersymmetric Standard Model (MSSM) are universal at some input scale, M in, above the supersymmetric gauge-coupling unification scale, M GUT. As in the constrained MSSM (CMSSM), we assume that the scalar masses and gaugino masses have common values, m 0 and m 1/2, respectively, at M in, as do the trilinear soft supersymmetry-breaking parameters A 0. Going beyond previous studies of such a super-GUT CMSSM scenario, we explore the constraints imposed by the lower limit on the proton lifetime and themore » LHC measurement of the Higgs mass, m h. We find regions of m 0, m 1/2 A 0 and the parameters of the SU(5) superpotential that are compatible with these and other phenomenological constraints such as the density of cold dark matter, which we assume to be provided by the lightest neutralino. Typically, these allowed regions appear for m 0 and m 1/2 in the multi-TeV region, for suitable values of the unknown SU(5) GUT-scale phases and superpotential couplings, and with the ratio of supersymmetric Higgs vacuum expectation values tan β≲6.« less

Phytochemical, spectroscopic and density functional theory study of Diospyrin, and non-bonding interactions of Diospyrin with atmospheric gases.

PubMed

Fazl-i-Sattar; Ullah, Zakir; Ata-ur-Rahman; Rauf, Abdur; Tariq, Muhammad; Tahir, Asif Ali; Ayub, Khurshid; Ullah, Habib

2015-04-15

Density functional theory (DFT) and phytochemical study of a natural product, Diospyrin (DO) have been carried out. A suitable level of theory was developed, based on correlating the experimental and theoretical data. Hybrid DFT method at B3LYP/6-31G (d,p) level of theory is employed for obtaining the electronic, spectroscopic, inter-molecular interaction and thermodynamic properties of DO. The exact structure of DO is confirmed from the nice validation of the theory and experiment. Non-covalent interactions of DO with different atmospheric gases such as NH3, CO2, CO, and H2O were studied to find out its electroactive nature. The experimental and predicted geometrical parameters, IR and UV-vis spectra (B3LYP/6-31+G (d,p) level of theory) show excellent correlation. Inter-molecular non-bonding interaction of DO with atmospheric gases is investigated through geometrical parameters, electronic properties, charge analysis, and thermodynamic parameters. Electronic properties include, ionization potential (I.P.), electron affinities (E.A.), electrostatic potential (ESP), density of states (DOS), HOMO, LUMO, and band gap. All these characterizations have corroborated each other and confirmed the presence of non-covalent nature in DO with the mentioned gases. Copyright © 2015 Elsevier B.V. All rights reserved.

Nuclear binding energy using semi empirical mass formula

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ankita,, E-mail: ankitagoyal@gmail.com; Suthar, B.

2016-05-06

In the present communication, semi empirical mass formula using the liquid drop model has been presented. Nuclear binding energies are calculated using semi empirical mass formula with various constants given by different researchers. We also compare these calculated values with experimental data and comparative study for finding suitable constants is added using the error plot. The study is extended to find the more suitable constant to reduce the error.

Landfill site selection using combination of GIS and fuzzy AHP, a case study: Iranshahr, Iran.

PubMed

Torabi-Kaveh, M; Babazadeh, R; Mohammadi, S D; Zaresefat, M

2016-03-09

One of the most important recent challenges in solid waste management throughout the world is site selection of sanitary landfill. Commonly, because of simultaneous effects of social, environmental, and technical parameters on suitability of a landfill site, landfill site selection is a complex process and depends on several criteria and regulations. This study develops a multi-criteria decision analysis (MCDA) process, which combines geographic information system (GIS) analysis with a fuzzy analytical hierarchy process (FAHP), to determine suitable sites for landfill construction in Iranshahr County, Iran. The GIS was used to calculate and classify selected criteria and FAHP was used to assess the criteria weights based on their effectiveness on selection of potential landfill sites. Finally, a suitability map was prepared by overlay analyses and suitable areas were identified. Four suitability classes within the study area were separated, including high, medium, low, and very low suitability areas, which represented 18%, 15%, 55%, and 12% of the study area, respectively. © The Author(s) 2016.

New Possibilities in the Fabrication of Hybrid Components with Big Dimensions by Means of Selective Laser Melting (SLM)

NASA Astrophysics Data System (ADS)

Ascari, A.; Fortunato, A.; Liverani, E.; Gamberoni, A.; Tomesani, L.

The application of laser technology to welding of dissimilar AISI316 stainless steel components manufactured with selective laser melting (SLM) and traditional methods has been investigated. The role of laser parameters on weld bead formation has been studied experimentally, with particular attention placed on effects occurring at the interface between the two parts. In order to assess weld bead characteristics, standardised tensile tests were carried out on suitable specimens and the fracture zone was analysed. The results highlighted the possibility of exploiting suitable process parameters to appropriately shape the heat affected and fusion zones in order to maximise the mechanical performance of the component and minimise interactions between the two parent metals in the weld bead.

The Kjeldahl method as a primary reference procedure for total protein in certified reference materials used in clinical chemistry. II. Selection of direct Kjeldahl analysis and its preliminary performance parameters.

PubMed

Vinklárková, Bára; Chromý, Vratislav; Šprongl, Luděk; Bittová, Miroslava; Rikanová, Milena; Ohnútková, Ivana; Žaludová, Lenka

2015-01-01

To select a Kjeldahl procedure suitable for the determination of total protein in reference materials used in laboratory medicine, we reviewed in our previous article Kjeldahl methods adopted by clinical chemistry and found an indirect two-step analysis by total Kjeldahl nitrogen corrected for its nonprotein nitrogen and a direct analysis made on isolated protein precipitates. In this article, we compare both procedures on various reference materials. An indirect Kjeldahl method gave falsely lower results than a direct analysis. Preliminary performance parameters qualify the direct Kjeldahl analysis as a suitable primary reference procedure for the certification of total protein in reference laboratories.

Thermodynamical stability of FRW models with quintessence

NASA Astrophysics Data System (ADS)

Sharif, M.; Ashraf, Sara

2018-03-01

In this paper, we study the thermodynamic stability of quintessence in the background of homogeneous and isotropic universe model. For the evolutionary picture, we consider two different forms of potentials and investigate the behavior of different physical parameters. We conclude that the quintessence model expands adiabatically and this expansion is thermodynamically stable for both potentials with suitable model parameters.

Bayesian Regression of Thermodynamic Models of Redox Active Materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnston, Katherine

Finding a suitable functional redox material is a critical challenge to achieving scalable, economically viable technologies for storing concentrated solar energy in the form of a defected oxide. Demonstrating e ectiveness for thermal storage or solar fuel is largely accomplished by using a thermodynamic model derived from experimental data. The purpose of this project is to test the accuracy of our regression model on representative data sets. Determining the accuracy of the model includes parameter tting the model to the data, comparing the model using di erent numbers of param- eters, and analyzing the entropy and enthalpy calculated from themore » model. Three data sets were considered in this project: two demonstrating materials for solar fuels by wa- ter splitting and the other of a material for thermal storage. Using Bayesian Inference and Markov Chain Monte Carlo (MCMC), parameter estimation was preformed on the three data sets. Good results were achieved, except some there was some deviations on the edges of the data input ranges. The evidence values were then calculated in a variety of ways and used to compare models with di erent number of parameters. It was believed that at least one of the parameters was unnecessary and comparing evidence values demonstrated that the parameter was need on one data set and not signi cantly helpful on another. The entropy was calculated by taking the derivative in one variable and integrating over another. and its uncertainty was also calculated by evaluating the entropy over multiple MCMC samples. Afterwards, all the parts were written up as a tutorial for the Uncertainty Quanti cation Toolkit (UQTk).« less

Potential accuracy of translation estimation between radar and optical images

NASA Astrophysics Data System (ADS)

Uss, M.; Vozel, B.; Lukin, V.; Chehdi, K.

2015-10-01

This paper investigates the potential accuracy achievable for optical to radar image registration by area-based approach. The analysis is carried out mainly based on the Cramér-Rao Lower Bound (CRLB) on translation estimation accuracy previously proposed by the authors and called CRLBfBm. This bound is now modified to take into account radar image speckle noise properties: spatial correlation and signal-dependency. The newly derived theoretical bound is fed with noise and texture parameters estimated for the co-registered pair of optical Landsat 8 and radar SIR-C images. It is found that difficulty of optical to radar image registration stems more from speckle noise influence than from dissimilarity of the considered kinds of images. At finer scales (and higher speckle noise level), probability of finding control fragments (CF) suitable for registration is low (1% or less) but overall number of such fragments is high thanks to image size. Conversely, at the coarse scale, where speckle noise level is reduced, probability of finding CFs suitable for registration can be as high as 40%, but overall number of such CFs is lower. Thus, the study confirms and supports area-based multiresolution approach for optical to radar registration where coarse scales are used for fast registration "lock" and finer scales for reaching higher registration accuracy. The CRLBfBm is found inaccurate for the main scale due to intensive speckle noise influence. For other scales, the validity of the CRLBfBm bound is confirmed by calculating statistical efficiency of area-based registration method based on normalized correlation coefficient (NCC) measure that takes high values of about 25%.

Videothoracoscopic identification of chondromatous hamartoma of the lung

PubMed Central

Bohanes, Tomàš; Szkorupa, Marek; Klein, Jiří; Zapletalová, Jana; Chudáček, Josef; Vomáčková, Katherine; Vrba, Radek

2013-01-01

Introduction The main disadvantage of a videothoracoscopic procedure is the lack of touch sensation. The probability of easily finding the lesion is usually estimated according to computed tomography (CT). Aim To find useful parameters of location of chondromatous hamartoma of the lung parenchyma in relation to its size to assess the probability of successful search via a videothoracoscopic approach only. Material and methods A group of 55 patients operated on for chondromatous hamartoma of the lung at the First Department of Surgery in Olomouc from January 2006 to June 2011 was analyzed. Initially, the tumor's longest diameter and its nearest distance to the pleural surface were measured on CT scans. Subsequently, the surgery began using the videothoracoscopic approach. A short thoracotomy with direct palpation followed when videothoracoscopy failed. Results No significant differences in age, sex and side of localization between the group with and without successful videothoracoscopic detection were found. A significant difference was found in the median size (p = 0.026) and the depth of the tumor (p < 0.0001) and in the calculated index “tumor size/depth” (p < 0.0001). Deeper analysis revealed that the parameters “depth” and “index size/depth” are considered to be good predictors but the parameter “size” is not a suitable predictor. Conclusions The main predictors of successful videothoracoscopic detection of lung chondromatous hamartoma are considered to be the depth of the tumor in the lung parenchyma with a cut-off value ≤ 7.5 mm and the index “size/depth” with a cut-off value ≥ 1.54; the tumor size is not considered to be a good predictor. PMID:23837099

Optimal experimental design for assessment of enzyme kinetics in a drug discovery screening environment.

PubMed

Sjögren, Erik; Nyberg, Joakim; Magnusson, Mats O; Lennernäs, Hans; Hooker, Andrew; Bredberg, Ulf

2011-05-01

A penalized expectation of determinant (ED)-optimal design with a discrete parameter distribution was used to find an optimal experimental design for assessment of enzyme kinetics in a screening environment. A data set for enzyme kinetic data (V(max) and K(m)) was collected from previously reported studies, and every V(max)/K(m) pair (n = 76) was taken to represent a unique drug compound. The design was restricted to 15 samples, an incubation time of up to 40 min, and starting concentrations (C(0)) for the incubation between 0.01 and 100 μM. The optimization was performed by finding the sample times and C(0) returning the lowest uncertainty (S.E.) of the model parameter estimates. Individual optimal designs, one general optimal design and one, for laboratory practice suitable, pragmatic optimal design (OD) were obtained. In addition, a standard design (STD-D), representing a commonly applied approach for metabolic stability investigations, was constructed. Simulations were performed for OD and STD-D by using the Michaelis-Menten (MM) equation, and enzyme kinetic parameters were estimated with both MM and a monoexponential decay. OD generated a better result (relative standard error) for 99% of the compounds and an equal or better result [(root mean square error (RMSE)] for 78% of the compounds in estimation of metabolic intrinsic clearance. Furthermore, high-quality estimates (RMSE < 30%) of both V(max) and K(m) could be obtained for a considerable number (26%) of the investigated compounds by using the suggested OD. The results presented in this study demonstrate that the output could generally be improved compared with that obtained from the standard approaches used today.

Overspinning a Kerr black hole: The effect of the self-force

NASA Astrophysics Data System (ADS)

Colleoni, Marta; Barack, Leor

2015-05-01

We study the scenario in which a massive particle is thrown into a rapidly rotating Kerr black hole in an attempt to spin it up beyond its extremal limit, challenging weak cosmic censorship. We work in black-hole perturbation theory, and focus on nonspinning, uncharged particles sent in on equatorial orbits. We first identify the complete parameter-space region in which overspinning occurs when backreaction effects from the particle's self-gravity are ignored. We find, in particular, that overspinning can be achieved only with particles sent in from infinity. Gravitational self-force effects may prevent overspinning by radiating away a sufficient amount of the particle's angular momentum ("dissipative effect"), and/or by increasing the effective centrifugal repulsion, so that particles with suitable parameters never get captured ("conservative effect"). We analyze the full effect of the self-force, thereby completing previous studies by Jacobson and Sotiriou (who neglected the self-force) and by Barausse, Cardoso and Khanna (who considered the dissipative effect on a subset of orbits). Our main result is an inequality, involving certain self-force quantities, which describes a necessary and sufficient condition for the overspinning scenario to be overruled. This "censorship" condition is formulated on a certain one-parameter family of geodesics in the limit of an extremal Kerr geometry. We find that the censorship condition is insensitive to the dissipative effect (within the first-order self-force approximation used here), except for a subset of perfectly fine-tuned orbits, for which a separate censorship condition is derived. We do not obtain here the self-force input needed to evaluate either of our two conditions, but discuss the prospects for producing the necessary data using state-of-the-art numerical codes.

Inverse modeling of rainfall infiltration with a dual permeability approach using different matrix-fracture coupling variants.

NASA Astrophysics Data System (ADS)

Blöcher, Johanna; Kuraz, Michal

2017-04-01

In this contribution we propose implementations of the dual permeability model with different inter-domain exchange descriptions and metaheuristic optimization algorithms for parameter identification and mesh optimization. We compare variants of the coupling term with different numbers of parameters to test if a reduction of parameters is feasible. This can reduce parameter uncertainty in inverse modeling, but also allow for different conceptual models of the domain and matrix coupling. The different variants of the dual permeability model are implemented in the open-source objective library DRUtES written in FORTRAN 2003/2008 in 1D and 2D. For parameter identification we use adaptations of the particle swarm optimization (PSO) and Teaching-learning-based optimization (TLBO), which are population-based metaheuristics with different learning strategies. These are high-level stochastic-based search algorithms that don't require gradient information or a convex search space. Despite increasing computing power and parallel processing, an overly fine mesh is not feasible for parameter identification. This creates the need to find a mesh that optimizes both accuracy and simulation time. We use a bi-objective PSO algorithm to generate a Pareto front of optimal meshes to account for both objectives. The dual permeability model and the optimization algorithms were tested on virtual data and field TDR sensor readings. The TDR sensor readings showed a very steep increase during rapid rainfall events and a subsequent steep decrease. This was theorized to be an effect of artificial macroporous envelopes surrounding TDR sensors creating an anomalous region with distinct local soil hydraulic properties. One of our objectives is to test how well the dual permeability model can describe this infiltration behavior and what coupling term would be most suitable.

Comparison of haematology, coagulation and clinical chemistry parameters in blood samples from the sublingual vein and vena cava in Sprague-Dawley rats.

PubMed

Seibel, J; Bodié, K; Weber, S; Bury, D; Kron, M; Blaich, G

2010-10-01

The investigation of clinical pathology parameters (haematology, clinical chemistry and coagulation) is an important part of the preclinical evaluation of drug safety. However, the blood sampling method employed should avoid or minimize stress and injury in laboratory animals. In the present study, we compared the clinical pathology results from blood samples collected terminally from the vena cava (VC) immediately before necropsy with samples taken from the sublingual vein (VS) also prior to necropsy in order to determine whether the sampling method has an influence on clinical pathology parameters. Forty-six 12-week-old male Sprague-Dawley rats were assigned to two groups (VC or VS; n = 23 each). All rats were anaesthetized with isoflurane prior to sampling. In the VC group, blood was withdrawn from the inferior VC. For VS sampling, the tongue was gently pulled out and the VS was punctured. The haematology, coagulation and clinical chemistry parameters were compared. Equivalence was established for 13 parameters, such as mean corpuscular volume, white blood cells and calcium. No equivalence was found for the remaining 26 parameters, although they were considered to be similar when compared with the historical data and normal ranges. The most conspicuous finding was that activated prothrombin time was 30.3% less in blood taken from the VC (16.6 ± 0.89 s) than that in the VS samples (23.8 ± 1.58 s). Summing up, blood sampling from the inferior VC prior to necropsy appears to be a suitable and reliable method for terminal blood sampling that reduces stress and injury to laboratory rats in preclinical drug safety studies.

Noise induced phenomena in combustion

NASA Astrophysics Data System (ADS)

Liu, Hongliang

Quantitative models of combustion usually consist of systems of deterministic differential equations. However, there are reasons to suspect that noise may have a significant influence. In this thesis, our primary objective is to study the effect of noise on measurable quantities in the combustion process. Our first study involves combustion in a homogeneous gas. With a one step reaction model, we analytically estimate the requirements under which noise is important to create significant differences. Our simulation shows that a bi-modality phenomenon appears when appropriate parameters are applied, which agrees with our analytical result. Our second study involves steady planar flames. We use a relatively complete chemical model of the H2/air reaction system, which contains all eight reactive species (H2, O2, H, O, OH, H2O, HO2, H2O2) and N2. Our mathematical model for this system is a reacting flow model. We derive noise terms related to transport processes by a method advocated by Landau & Lifshitz, and we also derive noise terms related to chemical reactions. We develop a code to simulate this system. The numerical implementation relies on a good Riemann solver, suitable initial and boundary conditions, and so on. We also implement a code on a continuation method, which not only can be used to study approximate properties of laminar flames under deterministic governing equations, but also eliminates the difficulty of providing a suitable initial condition for governing equations with noise. With numerical experiments, we find the difference of flame speed exist when the noise is turned on or off although it is small when compared with the influence of other parameters, for example, the equivalence ratio. It will be a starting point for further studies to include noise in combustion.

Analysis of materials used for Greenhouse roof covering - structure using CFD

NASA Astrophysics Data System (ADS)

Subin, M. C.; Savio Lourence, Jason; Karthikeyan, Ram; Periasamy, C.

2018-04-01

Greenhouse is widely used to create a suitable environment for the growth of plant. During summer, high temperatures cause harm to the plant. This work calculates characteristics required to optimize the above-mentioned parameters using different roof structure covering materials for the greenhouse. Moreover, this work also presents a simulation of the cooling and heating system. In addition, a computer model based on Ansys Fluent has been using to predict the temperature profiles inside the greenhouse. Greenhouse roof structure shading may have a time-dependent effect the production, water and nutrient uptake in plants. An experiment was conducted in the emirate of Dubai in United Arab Emirates to discover the impact of different materials in order to have an optimal plant growth zone and yield production. These structures were poly ethylene and poly carbonate sheets of 2 different configurations. Results showed that poly carbonate sheets configuration of optimal thickness has given a high result in terms of yield production. Therefore, there is a need for appropriate material selection of greenhouse roof structure in this area of UAE. Major parameters and properties need to be considered while selecting a greenhouse roof structure are the resistance to solar radiation, weathering, thermal as well as mechanical properties and good abrasion resistance. In the present study, an experiment has been conducted to find out the material suitability of the greenhouse roof structure in terms of developing proper ambient conditions especially to minimize the energy lose by reducing the HVAC and lighting expenses. The configuration verified using the CFD, so it has been concluded that polycarbonate can be safely used in the greenhouse than other roof structure material having white or green colour.

Research on the optical and EPR spectral data and the local structure for the trigonal Mn4+ centers in MgTiO3 crystal

NASA Astrophysics Data System (ADS)

Liao, Bi-Tao; Mei, Yang; Chen, Bo-Wei; Zheng, Wen-Chen

2017-07-01

The optical bands and EPR (or spin-Hamiltonian) parameters (g factors g//, g⊥ and zero-field splitting D) for Mn4+ ions at the trigonal octahedral Ti4+ site of MgTiO3 crystal are uniformly computed by virtue of the complete diagonalization (of energy matrix) method based on the two-spin-orbit-parameter model, where besides the effects of spin-orbit parameter of central dn ion on the spectral data (in the classical crystal field theory), those of ligands are also contained. The computed eight optical and EPR spectral data with four suitable adjustable parameters (note: differing from those in the previous work within cubic symmetry approximation where the used Racah parameters violate the nephelauxetic effect, the present Racah parameters obey the effect and hence are suitable) are rationally coincident with the experimental values. In particular, the calculated ground state splitting 2D, the first excited splitting ΔE(2E) and g-anisotropy Δg (=g//-g⊥) (they depend strongly on the angular distortion of d3 centers) are in excellent agreement with the observed values, suggesting that the angular distortions caused by the impurity-induced local lattice relaxation obtained from the above calculation for the trigonal Mn4+ impurity center in MgTiO3: Mn4+ crystal seem to be acceptable.

Developing lignin-based bio-nanofibers by centrifugal spinning technique.

PubMed

Stojanovska, Elena; Kurtulus, Mustafa; Abdelgawad, Abdelrahman; Candan, Zeki; Kilic, Ali

2018-07-01

Lignin-based nanofibers were produced via centrifugal spinning from lignin-thermoplastic polyurethane polymer blends. The most suitable process parameters were chosen by optimization of the rotational speed, nozzle diameter and spinneret-to-collector distance using different blend ratios of the two polymers at different total polymer concentrations. The basic characteristics of polymer solutions were enlightened by their viscosity and surface tension. The morphology of the fibers produced was characterized by SEM, while their thermal properties by DSC and TG analysis. Multiply regression was used to determine the parameters that have higher impact on the fiber diameter. It was possible to obtain thermally stable lignin/polyurethane nanofibers with diameters below 500nm. From the aspect of spinnability, 1:1 lignin/TPU contents were shown to be more feasible. On the other side, the most suitable processing parameters were found to be angular velocity of 8500rpm for nozzles of 0.5mm diameter and working distance of 30cm. Copyright © 2018 Elsevier B.V. All rights reserved.

Beer fermentation: monitoring of process parameters by FT-NIR and multivariate data analysis.

PubMed

Grassi, Silvia; Amigo, José Manuel; Lyndgaard, Christian Bøge; Foschino, Roberto; Casiraghi, Ernestina

2014-07-15

This work investigates the capability of Fourier-Transform near infrared (FT-NIR) spectroscopy to monitor and assess process parameters in beer fermentation at different operative conditions. For this purpose, the fermentation of wort with two different yeast strains and at different temperatures was monitored for nine days by FT-NIR. To correlate the collected spectra with °Brix, pH and biomass, different multivariate data methodologies were applied. Principal component analysis (PCA), partial least squares (PLS) and locally weighted regression (LWR) were used to assess the relationship between FT-NIR spectra and the abovementioned process parameters that define the beer fermentation. The accuracy and robustness of the obtained results clearly show the suitability of FT-NIR spectroscopy, combined with multivariate data analysis, to be used as a quality control tool in the beer fermentation process. FT-NIR spectroscopy, when combined with LWR, demonstrates to be a perfectly suitable quantitative method to be implemented in the production of beer. Copyright © 2014 Elsevier Ltd. All rights reserved.

Cycling transport safety quantification

NASA Astrophysics Data System (ADS)

Drbohlav, Jiri; Kocourek, Josef

2018-05-01

Dynamic interest in cycling transport brings the necessity to design safety cycling infrastructure. In las few years, couple of norms with safety elements have been designed and suggested for the cycling infrastructure. But these were not fully examined. The main parameter of suitable and fully functional transport infrastructure is the evaluation of its safety. Common evaluation of transport infrastructure safety is based on accident statistics. These statistics are suitable for motor vehicle transport but unsuitable for the cycling transport. Cycling infrastructure evaluation of safety is suitable for the traffic conflicts monitoring. The results of this method are fast, based on real traffic situations and can be applied on any traffic situations.

Mixtures of GAMs for habitat suitability analysis with overdispersed presence / absence data

PubMed Central

Pleydell, David R.J.; Chrétien, Stéphane

2009-01-01

A new approach to species distribution modelling based on unsupervised classification via a finite mixture of GAMs incorporating habitat suitability curves is proposed. A tailored EM algorithm is outlined for computing maximum likelihood estimates. Several submodels incorporating various parameter constraints are explored. Simulation studies confirm, that under certain constraints, the habitat suitability curves are recovered with good precision. The method is also applied to a set of real data concerning presence/absence of observable small mammal indices collected on the Tibetan plateau. The resulting classification was found to correspond to species-level differences in habitat preference described in previous ecological work. PMID:20401331

A comparison of reproductive parameters of female Amur tigers (Panthera tigris altaica) in the wild and captivity.

PubMed

Gu, Jiayin; Guo, Yurong; Stott, Philip; Jiang, Guangshun; Ma, Jianzhang

2016-01-01

A healthy population of captive Amur tigers might assist recovery of the wild population in Northeast China if individuals were properly prepared and considered suitable for release in the wild. We analyzed the breeding records of 68 female Amur tigers from 1995 to 2010 in the Hengdaohezi Felid Breeding Center of China and compared the reproductive parameters of this population to wild female Amur tigers. We found that the reproductive parameters of the captive population (the age of first parturition, length of gestation and litter survival rate) were not significantly different from those of wild Amur tigers. Differences in birth date and litter size between wild and captive populations may be caused by management protocols for the captive population or insufficient field data from the wild population. Reproductive parameters of females giving birth after losing a litter were similar to parameters of females that did not lose a litter, except for birth date. These results provide no indication of major problems in using captive females for a breeding program for release of cubs into the wild, but additional information is still needed to assess their suitability. © 2015 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

On the relationship between ecosystem-scale hyperspectral reflectance and CO2 exchange in European mountain grasslands

NASA Astrophysics Data System (ADS)

Balzarolo, M.; Vescovo, L.; Hammerle, A.; Gianelle, D.; Papale, D.; Tomelleri, E.; Wohlfahrt, G.

2015-05-01

In this paper we explore the skill of hyperspectral reflectance measurements and vegetation indices (VIs) derived from these in estimating carbon dioxide (CO2) fluxes of grasslands. Hyperspectral reflectance data, CO2 fluxes and biophysical parameters were measured at three grassland sites located in European mountain regions using standardized protocols. The relationships between CO2 fluxes, ecophysiological variables, traditional VIs and VIs derived using all two-band combinations of wavelengths available from the whole hyperspectral data space were analysed. We found that VIs derived from hyperspectral data generally explained a large fraction of the variability in the investigated dependent variables but differed in their ability to estimate midday and daily average CO2 fluxes and various derived ecophysiological parameters. Relationships between VIs and CO2 fluxes and ecophysiological parameters were site-specific, likely due to differences in soils, vegetation parameters and environmental conditions. Chlorophyll and water-content-related VIs explained the largest fraction of variability in most of the dependent variables. Band selection based on a combination of a genetic algorithm with random forests (GA-rF) confirmed that it is difficult to select a universal band region suitable across the investigated ecosystems. Our findings have major implications for upscaling terrestrial CO2 fluxes to larger regions and for remote- and proximal-sensing sampling and analysis strategies and call for more cross-site synthesis studies linking ground-based spectral reflectance with ecosystem-scale CO2 fluxes.

Cumulative sum control charts for monitoring geometrically inflated Poisson processes: An application to infectious disease counts data.

PubMed

Rakitzis, Athanasios C; Castagliola, Philippe; Maravelakis, Petros E

2018-02-01

In this work, we study upper-sided cumulative sum control charts that are suitable for monitoring geometrically inflated Poisson processes. We assume that a process is properly described by a two-parameter extension of the zero-inflated Poisson distribution, which can be used for modeling count data with an excessive number of zero and non-zero values. Two different upper-sided cumulative sum-type schemes are considered, both suitable for the detection of increasing shifts in the average of the process. Aspects of their statistical design are discussed and their performance is compared under various out-of-control situations. Changes in both parameters of the process are considered. Finally, the monitoring of the monthly cases of poliomyelitis in the USA is given as an illustrative example.

Groundwater quality assessment for domestic and agriculture purposes in Puducherry region

NASA Astrophysics Data System (ADS)

Sridharan, M.; Senthil Nathan, D.

2017-11-01

Totally about 174 groundwater samples have been collected during pre-monsoon and post-monsoon season to study the suitability for domestic and agriculture purposes along the coastal aquifers of Puducherry region. Parameters such as pH, total dissolved solids (TDS), electrical conductivity (EC), sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), bicarbonate (HCO3), chloride (Cl) and sulfate (SO4) were analyzed to assess the suitability of groundwater for domestic purposes. Sodium adsorption ratio (SAR), magnesium adsorption ratio (MAR), residual sodium bicarbonate (RSC), soluble sodium percentage (Na%), permeability index (PI) and chlorinity index were assessed for irrigation purposes. The higher concentration of ions such as Na, Ca, Cl and So4 indicates seawater intrusion, mineral dissolution, intense agricultural practices and improper sewage disposal. The level of EC, TDS and hardness in the water samples indicates that maximum of them are suitable for drinking and domestic purposes. The parameters such as SAR, Na%, PI, MAR and Chlorinity index indicates that majority of water sample are very good to moderately suitable for agriculture. In pre-monsoon, RSC of about 5.7% of samples was higher which when used for a longer time alter the soil properties and reduce crop production. Wilcox diagram suggests that water samples are of medium saline to low sodium type indicating that groundwater is suitable for irrigation. Temporal variation of groundwater quality shows significant increasing trend in EC, TDS and ions like Mg, K and Cl in the last decade, mainly due to anthropogenic activities with little geogenic impact in the quality of groundwater.

Optimal correction and design parameter search by modern methods of rigorous global optimization

NASA Astrophysics Data System (ADS)

Makino, K.; Berz, M.

2011-07-01

Frequently the design of schemes for correction of aberrations or the determination of possible operating ranges for beamlines and cells in synchrotrons exhibit multitudes of possibilities for their correction, usually appearing in disconnected regions of parameter space which cannot be directly qualified by analytical means. In such cases, frequently an abundance of optimization runs are carried out, each of which determines a local minimum depending on the specific chosen initial conditions. Practical solutions are then obtained through an often extended interplay of experienced manual adjustment of certain suitable parameters and local searches by varying other parameters. However, in a formal sense this problem can be viewed as a global optimization problem, i.e. the determination of all solutions within a certain range of parameters that lead to a specific optimum. For example, it may be of interest to find all possible settings of multiple quadrupoles that can achieve imaging; or to find ahead of time all possible settings that achieve a particular tune; or to find all possible manners to adjust nonlinear parameters to achieve correction of high order aberrations. These tasks can easily be phrased in terms of such an optimization problem; but while mathematically this formulation is often straightforward, it has been common belief that it is of limited practical value since the resulting optimization problem cannot usually be solved. However, recent significant advances in modern methods of rigorous global optimization make these methods feasible for optics design for the first time. The key ideas of the method lie in an interplay of rigorous local underestimators of the objective functions, and by using the underestimators to rigorously iteratively eliminate regions that lie above already known upper bounds of the minima, in what is commonly known as a branch-and-bound approach. Recent enhancements of the Differential Algebraic methods used in particle optics for the computation of aberrations allow the determination of particularly sharp underestimators for large regions. As a consequence, the subsequent progressive pruning of the allowed search space as part of the optimization progresses is carried out particularly effectively. The end result is the rigorous determination of the single or multiple optimal solutions of the parameter optimization, regardless of their location, their number, and the starting values of optimization. The methods are particularly powerful if executed in interplay with genetic optimizers generating their new populations within the currently active unpruned space. Their current best guess provides rigorous upper bounds of the minima, which can then beneficially be used for better pruning. Examples of the method and its performance will be presented, including the determination of all operating points of desired tunes or chromaticities, etc. in storage ring lattices.

Modeling Multiplicative Error Variance: An Example Predicting Tree Diameter from Stump Dimensions in Baldcypress

Treesearch

Bernard R. Parresol

1993-01-01

In the context of forest modeling, it is often reasonable to assume a multiplicative heteroscedastic error structure to the data. Under such circumstances ordinary least squares no longer provides minimum variance estimates of the model parameters. Through study of the error structure, a suitable error variance model can be specified and its parameters estimated. This...

Systematic development of technical textiles

NASA Astrophysics Data System (ADS)

Beer, M.; Schrank, V.; Gloy, Y.-S.; Gries, T.

2016-07-01

Technical textiles are used in various fields of applications, ranging from small scale (e.g. medical applications) to large scale products (e.g. aerospace applications). The development of new products is often complex and time consuming, due to multiple interacting parameters. These interacting parameters are production process related and also a result of the textile structure and used material. A huge number of iteration steps are necessary to adjust the process parameter to finalize the new fabric structure. A design method is developed to support the systematic development of technical textiles and to reduce iteration steps. The design method is subdivided into six steps, starting from the identification of the requirements. The fabric characteristics vary depending on the field of application. If possible, benchmarks are tested. A suitable fabric production technology needs to be selected. The aim of the method is to support a development team within the technology selection without restricting the textile developer. After a suitable technology is selected, the transformation and correlation between input and output parameters follows. This generates the information for the production of the structure. Afterwards, the first prototype can be produced and tested. The resulting characteristics are compared with the initial product requirements.

Solubility parameters of hypromellose acetate succinate and plasticization in dry coating procedures.

PubMed

Klar, Fabian; Urbanetz, Nora Anne

2016-10-01

Solubility parameters of HPMCAS have not yet been investigated intensively. On this account, total and three-dimensional solubility parameters of HPMCAS were determined by using different experimental as well as computational methods. In addition, solubility properties of HPMCAS in a huge number of solvents were tested and a Teas plot for HPMCAS was created. The total solubility parameter of about 24 MPa(0.5) was confirmed by various procedures and compared with values of plasticizers. Twenty common pharmaceutical plasticizers were evaluated in terms of their suitability for supporting film formation of HPMCAS under dry coating conditions. Therefore, glass transition temperatures of mixtures of polymer and plasticizers were inspected and film formation of potential ones was further investigated in dry coating of pellets. Contact angles of plasticizers on HPMCAS were determined in order to give a hint of achievable coating efficiencies in dry coating, but none was found to spread on HPMCAS. A few common substances, e.g. dimethyl phthalate, glycerol monocaprylate, and polyethylene glycol 400, enabled plasticization of HPMCAS; however, only triethyl citrate and triacetin were found to be suitable for use in dry coating. Addition of acetylated monoglycerides to triacetin increased coating efficiency, which was likewise previously demonstrated for triethyl citrate.

The determination of water quality and metal concentrations of Ampang Hilir Lake, Selangor, Peninsular Malaysia.

PubMed

Said, Khaled S A; Shuhaimi-Othman, M; Ahmad, A K

2012-05-01

A study of water quality parameters (temperature, conductivity, total dissolved solid, dissolved oxygen, pH and water hardness) in Ampang Hilir Lake was conducted in January, April, July and October 2010. The water quality parameters were tested and recorded at different sampling stations chosen randomly using Hydrolab Data Sonde 4 and Surveyor 4 a water quality multi probe (USA). Six metals which were cadmium, chromium, lead, nickel, zinc and copper were determined in five different compartments of the lake namely water, total suspended solids, plankton, sediment and fish. The metals concentration were determined by Inductively Coupled Plasma Mass Spectrometer (ICP-MS), Perkin Elmer Elan, model 9000.The water quality parameters were compared with National Water Quality Standard (NWQS Malaysia) while metal concentrations were compared with Malaysian and international standards. The study shows that water quality parameters are of class 2. This condition is suitable for recreational activities where body contact is allowed and suitable for sensitive fishing activities. Furthermore, metal concentrations were found to be lower than the international standards, therefore toxic effects for these metals would be rarely observed and the adverse effects to aquatic organisms would not frequently occur.

Nuclear electric propulsion

NASA Technical Reports Server (NTRS)

Keaton, Paul W.; Tubb, David J.

1986-01-01

The feasibility is investigated of using nuclear electric propulsion (NEP) for slow freighter ships traveling from a 500 km low Earth orbit (LEO) to the Moon's orbit about the Earth, and on to Mars. NEP is also shown to be feasible for transporting people to Mars on long conjunction-class missions lasting about nine months one way, and on short sprint missions lasting four months one way. Generally, it was not attempted to optimize ion exhaust velocities, but rather suitable parameters to demonstrate NEP feasibility were chosen. Various combinations of missions are compared with chemical and nuclear thermal propulsion (NTR) systems. Typically, NEP and NTR can accomplish the same lifting task with similar mass in LEO. When compared to chemical propulsion, NEP was found to accomplish the same missions with 40% less mass in LEO. These findings are sufficiently encouraging as to merit further studies with optimum systems.

Biomechanical and morphological multi-parameter photoacoustic endoscope for identification of early esophageal disease

NASA Astrophysics Data System (ADS)

Jin, Dayang; Yang, Fen; Chen, Zhongjiang; Yang, Sihua; Xing, Da

2017-09-01

The combination of phase-sensitive photoacoustic (PA) imaging of tissue viscoelasticity with the esophagus-adaptive PA endoscope (PAE) technique allows the characterization of the biomechanical and morphological changes in the early stage of esophageal disease with high accuracy. In this system, the tissue biomechanics and morphology are obtained by detecting the PA phase and PA amplitude information, respectively. The PAE has a transverse resolution of approximately 37 μm and an outer diameter of 1.2 mm, which is suitable for detecting rabbit esophagus. Here, an in-situ biomechanical and morphological study of normal and diseased rabbit esophagus (tumors of esophagus and reflux esophagitis) was performed. The in-situ findings were highly consistent with those observed by histology. In summary, we demonstrated the potential application of PAE for early clinical detection of esophageal diseases.

In-Fiber Optic Salinity Sensing: A Potential Application for Offshore Concrete Structure Protection.

PubMed

Luo, Dong; Li, Peng; Yue, Yanchao; Ma, Jianxun; Yang, Hangzhou

2017-05-04

The protection of concrete structures against corrosion in marine environments has always been a challenge due to the presence of a saline solution-A natural corrosive agent to the concrete paste and steel reinforcements. The concentration of salt is a key parameter influencing the rate of corrosion. In this paper, we propose an optical fiber-based salinity sensor based on bundled multimode plastic optical fiber (POF) as a sensor probe and a concave mirror as a reflector in conjunction with an intensity modulation technique. A refractive index (RI) sensing approach is analytically investigated and the findings are in agreement with the experimental results. A maximum sensitivity of 14,847.486/RIU can be achieved at RI = 1.3525. The proposed technique is suitable for in situ measurement and monitoring of salinity in liquid.

A new method for predicting response in complex linear systems. II. [under random or deterministic steady state excitation

NASA Technical Reports Server (NTRS)

Bogdanoff, J. L.; Kayser, K.; Krieger, W.

1977-01-01

The paper describes convergence and response studies in the low frequency range of complex systems, particularly with low values of damping of different distributions, and reports on the modification of the relaxation procedure required under these conditions. A new method is presented for response estimation in complex lumped parameter linear systems under random or deterministic steady state excitation. The essence of the method is the use of relaxation procedures with a suitable error function to find the estimated response; natural frequencies and normal modes are not computed. For a 45 degree of freedom system, and two relaxation procedures, convergence studies and frequency response estimates were performed. The low frequency studies are considered in the framework of earlier studies (Kayser and Bogdanoff, 1975) involving the mid to high frequency range.

Refraction law and Fermat principle: a project using the ant colony optimization algorithm for undergraduate students in physics

NASA Astrophysics Data System (ADS)

Vuong, Q. L.; Rigaut, C.; Gossuin, Y.

2018-07-01

A programming project for undergraduate students in physics is proposed in this work. Its goal is to check the Snell–Descartes law of refraction using the Fermat principle and the ant colony optimization algorithm. The project involves basic mathematics and physics and is adapted to students with basic programming skills. More advanced tools can be used (but are not mandatory) as parallelization or object-oriented programming, which makes the project also suitable for more experienced students. We propose two tests to validate the program. Our algorithm is able to find solutions which are close to the theoretical predictions. Two quantities are defined to study its convergence and the quality of the solutions. It is also shown that the choice of the values of the simulation parameters is important to efficiently obtain precise results.

A Comparison of Parameter Study Creation and Job Submission Tools

NASA Technical Reports Server (NTRS)

DeVivo, Adrian; Yarrow, Maurice; McCann, Karen M.; Biegel, Bryan (Technical Monitor)

2001-01-01

We consider the differences between the available general purpose parameter study and job submission tools. These tools necessarily share many features, but frequently with differences in the way they are designed and implemented For this class of features, we will only briefly outline the essential differences. However we will focus on the unique features which distinguish the ILab parameter study and job submission tool from other packages, and which make the ILab tool easier and more suitable for use in our research and engineering environment.

A Scale-up Approach for Film Coating Process Based on Surface Roughness as the Critical Quality Attribute.

PubMed

Yoshino, Hiroyuki; Hara, Yuko; Dohi, Masafumi; Yamashita, Kazunari; Hakomori, Tadashi; Kimura, Shin-Ichiro; Iwao, Yasunori; Itai, Shigeru

2018-04-01

Scale-up approaches for film coating process have been established for each type of film coating equipment from thermodynamic and mechanical analyses for several decades. The objective of the present study was to establish a versatile scale-up approach for film coating process applicable to commercial production that is based on critical quality attribute (CQA) using the Quality by Design (QbD) approach and is independent of the equipment used. Experiments on a pilot scale using the Design of Experiment (DoE) approach were performed to find a suitable CQA from surface roughness, contact angle, color difference, and coating film properties by terahertz spectroscopy. Surface roughness was determined to be a suitable CQA from a quantitative appearance evaluation. When surface roughness was fixed as the CQA, the water content of the film-coated tablets was determined to be the critical material attribute (CMA), a parameter that does not depend on scale or equipment. Finally, to verify the scale-up approach determined from the pilot scale, experiments on a commercial scale were performed. The good correlation between the surface roughness (CQA) and the water content (CMA) identified at the pilot scale was also retained at the commercial scale, indicating that our proposed method should be useful as a scale-up approach for film coating process.

Selective laser melting of Inconel super alloy-a review

NASA Astrophysics Data System (ADS)

Karia, M. C.; Popat, M. A.; Sangani, K. B.

2017-07-01

Additive manufacturing is a relatively young technology that uses the principle of layer by layer addition of material in solid, liquid or powder form to develop a component or product. The quality of additive manufactured part is one of the challenges to be addressed. Researchers are continuously working at various levels of additive manufacturing technologies. One of the significant powder bed processes for met als is Selective Laser Melting (SLM). Laser based processes are finding more attention of researchers and industrial world. The potential of this technique is yet to be fully explored. Due to very high strength and creep resistance Inconel is extensively used nickel based super alloy for manufacturing components for aerospace, automobile and nuclear industries. Due to law content of Aluminum and Titanium, it exhibits good fabricability too. Therefore the alloy is ideally suitable for selective laser melting to manufacture intricate components with high strength requirements. The selection of suitable process for manufacturing for a specific component depends on geometrical complexity, production quantity, and cost and required strength. There are numerous researchers working on various aspects like metallurgical and micro structural investigations and mechanical properties, geometrical accuracy, effects of process parameters and its optimization and mathematical modeling etc. The present paper represents a comprehensive overview of selective laser melting process for Inconel group of alloys.

DoE optimization of a mercury isotope ratio determination method for environmental studies.

PubMed

Berni, Alex; Baschieri, Carlo; Covelli, Stefano; Emili, Andrea; Marchetti, Andrea; Manzini, Daniela; Berto, Daniela; Rampazzo, Federico

2016-05-15

By using the experimental design (DoE) technique, we optimized an analytical method for the determination of mercury isotope ratios by means of cold-vapor multicollector ICP-MS (CV-MC-ICP-MS) to provide absolute Hg isotopic ratio measurements with a suitable internal precision. By running 32 experiments, the influence of mercury and thallium internal standard concentrations, total measuring time and sample flow rate was evaluated. Method was optimized varying Hg concentration between 2 and 20 ng g(-1). The model finds out some correlations within the parameters affect the measurements precision and predicts suitable sample measurement precisions for Hg concentrations from 5 ng g(-1) Hg upwards. The method was successfully applied to samples of Manila clams (Ruditapes philippinarum) coming from the Marano and Grado lagoon (NE Italy), a coastal environment affected by long term mercury contamination mainly due to mining activity. Results show different extents of both mass dependent fractionation (MDF) and mass independent fractionation (MIF) phenomena in clams according to their size and sampling sites in the lagoon. The method is fit for determinations on real samples, allowing for the use of Hg isotopic ratios to study mercury biogeochemical cycles in complex ecosystems. Copyright © 2016 Elsevier B.V. All rights reserved.

Computational design of a Diels-Alderase from a thermophilic esterase: the importance of dynamics

NASA Astrophysics Data System (ADS)

Linder, Mats; Johansson, Adam Johannes; Olsson, Tjelvar S. G.; Liebeschuetz, John; Brinck, Tore

2012-09-01

A novel computational Diels-Alderase design, based on a relatively rare form of carboxylesterase from Geobacillus stearothermophilus, is presented and theoretically evaluated. The structure was found by mining the PDB for a suitable oxyanion hole-containing structure, followed by a combinatorial approach to find suitable substrates and rational mutations. Four lead designs were selected and thoroughly modeled to obtain realistic estimates of substrate binding and prearrangement. Molecular dynamics simulations and DFT calculations were used to optimize and estimate binding affinity and activation energies. A large quantum chemical model was used to capture the salient interactions in the crucial transition state (TS). Our quantitative estimation of kinetic parameters was validated against four experimentally characterized Diels-Alderases with good results. The final designs in this work are predicted to have rate enhancements of ≈103-106 and high predicted proficiencies. This work emphasizes the importance of considering protein dynamics in the design approach, and provides a quantitative estimate of the how the TS stabilization observed in most de novo and redesigned enzymes is decreased compared to a minimal, `ideal' model. The presented design is highly interesting for further optimization and applications since it is based on a thermophilic enzyme ( T opt = 70 °C).

EIGER detector: application in macromolecular crystallography.

PubMed

Casanas, Arnau; Warshamanage, Rangana; Finke, Aaron D; Panepucci, Ezequiel; Olieric, Vincent; Nöll, Anne; Tampé, Robert; Brandstetter, Stefan; Förster, Andreas; Mueller, Marcus; Schulze-Briese, Clemens; Bunk, Oliver; Wang, Meitian

2016-09-01

The development of single-photon-counting detectors, such as the PILATUS, has been a major recent breakthrough in macromolecular crystallography, enabling noise-free detection and novel data-acquisition modes. The new EIGER detector features a pixel size of 75 × 75 µm, frame rates of up to 3000 Hz and a dead time as low as 3.8 µs. An EIGER 1M and EIGER 16M were tested on Swiss Light Source beamlines X10SA and X06SA for their application in macromolecular crystallography. The combination of fast frame rates and a very short dead time allows high-quality data acquisition in a shorter time. The ultrafine ϕ-slicing data-collection method is introduced and validated and its application in finding the optimal rotation angle, a suitable rotation speed and a sufficient X-ray dose are presented. An improvement of the data quality up to slicing at one tenth of the mosaicity has been observed, which is much finer than expected based on previous findings. The influence of key data-collection parameters on data quality is discussed.

A preliminary study to metaheuristic approach in multilayer radiation shielding optimization

NASA Astrophysics Data System (ADS)

Arif Sazali, Muhammad; Rashid, Nahrul Khair Alang Md; Hamzah, Khaidzir

2018-01-01

Metaheuristics are high-level algorithmic concepts that can be used to develop heuristic optimization algorithms. One of their applications is to find optimal or near optimal solutions to combinatorial optimization problems (COPs) such as scheduling, vehicle routing, and timetabling. Combinatorial optimization deals with finding optimal combinations or permutations in a given set of problem components when exhaustive search is not feasible. A radiation shield made of several layers of different materials can be regarded as a COP. The time taken to optimize the shield may be too high when several parameters are involved such as the number of materials, the thickness of layers, and the arrangement of materials. Metaheuristics can be applied to reduce the optimization time, trading guaranteed optimal solutions for near-optimal solutions in comparably short amount of time. The application of metaheuristics for radiation shield optimization is lacking. In this paper, we present a review on the suitability of using metaheuristics in multilayer shielding design, specifically the genetic algorithm and ant colony optimization algorithm (ACO). We would also like to propose an optimization model based on the ACO method.

GIS-based multicriteria overlay analysis in soil-suitability evaluation for cotton (Gossypium spp.): A case study in the black soil region of Central India

NASA Astrophysics Data System (ADS)

Walke, N.; Obi Reddy, G. P.; Maji, A. K.; Thayalan, S.

2012-04-01

In this study an attempt was made to characterize the soils of the Ringanbodi watershed, Nagpur district, Maharashtra, Central India, for soil-suitability evaluation for cotton using geographic information system (GIS)-based multicriteria overlay analysis techniques. The study shows that 8 soil series and 16 soil series associations in the study area and soils were classified into three orders, i.e., Entisol, Inceptisol, and Vertisol. The analysis reveals that the soil associations E-F, F-G, G-H, and H-G are "moderately suitable" (S2), D-E are "marginally to moderately suitable," and C-D are marginally (S3) suitable. However, soils B-C are "not suitable" to "marginally suitable" (N2-S3) and A-B are "unsuitable" (N2) for cultivation of cotton. The area analysis shows that for a cotton crop an area about 966.7 ha (49.1%) of TGA is moderately suitable and classified as S2. An area about 469.9 ha (23.8%) of TGA is marginal to moderately suitable (S3-S2). The marginally suitable soils for cotton are classified as S3 and cover an area about 35.2 ha (1.8%) of TGA. However, a 172.3 ha (8.7%) area is not suitable (N2) to marginally suitable (S3) and a 326.9 (16.6%) area is not suitable (N2) for cotton because of uncorrectable factors like soil depth, slope, etc. The study demonstrated that GIS-based multicriteria overlay analysis of soil thematic parameters will be of immense help in soil-suitability evaluation for cotton.

Identifying mechanical property parameters of planetary soil using in-situ data obtained from exploration rovers

NASA Astrophysics Data System (ADS)

Ding, Liang; Gao, Haibo; Liu, Zhen; Deng, Zongquan; Liu, Guangjun

2015-12-01

Identifying the mechanical property parameters of planetary soil based on terramechanics models using in-situ data obtained from autonomous planetary exploration rovers is both an important scientific goal and essential for control strategy optimization and high-fidelity simulations of rovers. However, identifying all the terrain parameters is a challenging task because of the nonlinear and coupling nature of the involved functions. Three parameter identification methods are presented in this paper to serve different purposes based on an improved terramechanics model that takes into account the effects of slip, wheel lugs, etc. Parameter sensitivity and coupling of the equations are analyzed, and the parameters are grouped according to their sensitivity to the normal force, resistance moment and drawbar pull. An iterative identification method using the original integral model is developed first. In order to realize real-time identification, the model is then simplified by linearizing the normal and shearing stresses to derive decoupled closed-form analytical equations. Each equation contains one or two groups of soil parameters, making step-by-step identification of all the unknowns feasible. Experiments were performed using six different types of single-wheels as well as a four-wheeled rover moving on planetary soil simulant. All the unknown model parameters were identified using the measured data and compared with the values obtained by conventional experiments. It is verified that the proposed iterative identification method provides improved accuracy, making it suitable for scientific studies of soil properties, whereas the step-by-step identification methods based on simplified models require less calculation time, making them more suitable for real-time applications. The models have less than 10% margin of error comparing with the measured results when predicting the interaction forces and moments using the corresponding identified parameters.

Spatial Heterogeneity of Habitat Suitability for Rift Valley Fever Occurrence in Tanzania: An Ecological Niche Modelling Approach

PubMed Central

Sindato, Calvin; Stevens, Kim B.; Karimuribo, Esron D.; Mboera, Leonard E. G.; Paweska, Janusz T.; Pfeiffer, Dirk U.

2016-01-01

Background Despite the long history of Rift Valley fever (RVF) in Tanzania, extent of its suitable habitat in the country remains unclear. In this study we investigated potential effects of temperature, precipitation, elevation, soil type, livestock density, rainfall pattern, proximity to wild animals, protected areas and forest on the habitat suitability for RVF occurrence in Tanzania. Materials and Methods Presence-only records of 193 RVF outbreak locations from 1930 to 2007 together with potential predictor variables were used to model and map the suitable habitats for RVF occurrence using ecological niche modelling. Ground-truthing of the model outputs was conducted by comparing the levels of RVF virus specific antibodies in cattle, sheep and goats sampled from locations in Tanzania that presented different predicted habitat suitability values. Principal Findings Habitat suitability values for RVF occurrence were higher in the northern and central-eastern regions of Tanzania than the rest of the regions in the country. Soil type and precipitation of the wettest quarter contributed equally to habitat suitability (32.4% each), followed by livestock density (25.9%) and rainfall pattern (9.3%). Ground-truthing of model outputs revealed that the odds of an animal being seropositive for RVFV when sampled from areas predicted to be most suitable for RVF occurrence were twice the odds of an animal sampled from areas least suitable for RVF occurrence (95% CI: 1.43, 2.76, p < 0.001). Conclusion/Significance The regions in the northern and central-eastern Tanzania were more suitable for RVF occurrence than the rest of the regions in the country. The modelled suitable habitat is characterised by impermeable soils, moderate precipitation in the wettest quarter, high livestock density and a bimodal rainfall pattern. The findings of this study should provide guidance for the design of appropriate RVF surveillance, prevention and control strategies which target areas with these characteristics. PMID:27654268

Shear-induced chaos

NASA Astrophysics Data System (ADS)

Lin, Kevin K.; Young, Lai-Sang

2008-05-01

Guided by a geometric understanding developed in earlier works of Wang and Young, we carry out numerical studies of shear-induced chaos in several parallel but different situations. The settings considered include periodic kicking of limit cycles, random kicks at Poisson times and continuous-time driving by white noise. The forcing of a quasi-periodic model describing two coupled oscillators is also investigated. In all cases, positive Lyapunov exponents are found in suitable parameter ranges when the forcing is suitably directed.

Nonlinear analysis of AS4/PEEK thermoplastic composite laminate using a one parameter plasticity model

NASA Technical Reports Server (NTRS)

Sun, C. T.; Yoon, K. J.

1990-01-01

A one-parameter plasticity model was shown to adequately describe the orthotropic plastic deformation of AS4/PEEK (APC-2) unidirectional thermoplastic composite. This model was verified further for unidirectional and laminated composite panels with and without a hole. The nonlinear stress-strain relations were measured and compared with those predicted by the finite element analysis using the one-parameter elastic-plastic constitutive model. The results show that the one-parameter orthotropic plasticity model is suitable for the analysis of elastic-plastic deformation of AS4/PEEK composite laminates.

Elastic-plastic analysis of AS4/PEEK composite laminate using a one-parameter plasticity model

NASA Technical Reports Server (NTRS)

Sun, C. T.; Yoon, K. J.

1992-01-01

A one-parameter plasticity model was shown to adequately describe the plastic deformation of AS4/PEEK (APC-2) unidirectional thermoplastic composite. This model was verified further for unidirectional and laminated composite panels with and without a hole. The elastic-plastic stress-strain relations of coupon specimens were measured and compared with those predicted by the finite element analysis using the one-parameter plasticity model. The results show that the one-parameter plasticity model is suitable for the analysis of elastic-plastic deformation of AS4/PEEK composite laminates.

Exoplanet Biosignatures: A Framework for Their Assessment.

PubMed

Catling, David C; Krissansen-Totton, Joshua; Kiang, Nancy Y; Crisp, David; Robinson, Tyler D; DasSarma, Shiladitya; Rushby, Andrew J; Del Genio, Anthony; Bains, William; Domagal-Goldman, Shawn

2018-04-20

Finding life on exoplanets from telescopic observations is an ultimate goal of exoplanet science. Life produces gases and other substances, such as pigments, which can have distinct spectral or photometric signatures. Whether or not life is found with future data must be expressed with probabilities, requiring a framework of biosignature assessment. We present a framework in which we advocate using biogeochemical "Exo-Earth System" models to simulate potential biosignatures in spectra or photometry. Given actual observations, simulations are used to find the Bayesian likelihoods of those data occurring for scenarios with and without life. The latter includes "false positives" wherein abiotic sources mimic biosignatures. Prior knowledge of factors influencing planetary inhabitation, including previous observations, is combined with the likelihoods to give the Bayesian posterior probability of life existing on a given exoplanet. Four components of observation and analysis are necessary. (1) Characterization of stellar (e.g., age and spectrum) and exoplanetary system properties, including "external" exoplanet parameters (e.g., mass and radius), to determine an exoplanet's suitability for life. (2) Characterization of "internal" exoplanet parameters (e.g., climate) to evaluate habitability. (3) Assessment of potential biosignatures within the environmental context (components 1-2), including corroborating evidence. (4) Exclusion of false positives. We propose that resulting posterior Bayesian probabilities of life's existence map to five confidence levels, ranging from "very likely" (90-100%) to "very unlikely" (<10%) inhabited. Key Words: Bayesian statistics-Biosignatures-Drake equation-Exoplanets-Habitability-Planetary science. Astrobiology 18, xxx-xxx.

Designing a space-based galaxy redshift survey to probe dark energy

NASA Astrophysics Data System (ADS)

Wang, Yun; Percival, Will; Cimatti, Andrea; Mukherjee, Pia; Guzzo, Luigi; Baugh, Carlton M.; Carbone, Carmelita; Franzetti, Paolo; Garilli, Bianca; Geach, James E.; Lacey, Cedric G.; Majerotto, Elisabetta; Orsi, Alvaro; Rosati, Piero; Samushia, Lado; Zamorani, Giovanni

2010-12-01

A space-based galaxy redshift survey would have enormous power in constraining dark energy and testing general relativity, provided that its parameters are suitably optimized. We study viable space-based galaxy redshift surveys, exploring the dependence of the Dark Energy Task Force (DETF) figure-of-merit (FoM) on redshift accuracy, redshift range, survey area, target selection and forecast method. Fitting formulae are provided for convenience. We also consider the dependence on the information used: the full galaxy power spectrum P(k), P(k) marginalized over its shape, or just the Baryon Acoustic Oscillations (BAO). We find that the inclusion of growth rate information (extracted using redshift space distortion and galaxy clustering amplitude measurements) leads to a factor of ~3 improvement in the FoM, assuming general relativity is not modified. This inclusion partially compensates for the loss of information when only the BAO are used to give geometrical constraints, rather than using the full P(k) as a standard ruler. We find that a space-based galaxy redshift survey covering ~20000deg2 over with σz/(1 + z) <= 0.001 exploits a redshift range that is only easily accessible from space, extends to sufficiently low redshifts to allow both a vast 3D map of the universe using a single tracer population, and overlaps with ground-based surveys to enable robust modelling of systematic effects. We argue that these parameters are close to their optimal values given current instrumental and practical constraints.

Assessment of Climate Suitability of Maize in South Korea

NASA Astrophysics Data System (ADS)

Hyun, S.; Choi, D.; Seo, B.

2017-12-01

Assessing suitable areas for crops would be useful to design alternate cropping systems as an adaptation option to climate change adaptation. Although suitable areas could be identified by using a crop growth model, it would require a number of input parameters including cultivar and soil. Instead, a simple climate suitability model, e.g., EcoCrop model, could be used for an assessment of climate suitability for a major grain crop. The objective of this study was to assess of climate suitability for maize using the EcoCrop model under climate change conditions in Korea. A long term climate data from 2000 - 2100 were compiled from weather data source. The EcoCrop model implemented in R was used to determine climate suitability index at each grid cell. Overall, the EcoCrop model tended to identify suitable areas for maize production near the coastal areas whereas the actual major production areas located in inland areas. It is likely that the discrepancy between assessed and actual crop production areas would result from the socioeconomic aspects of maize production. Because the price of maize is considerably low, maize has been grown in an area where moisture and temperature conditions would be less than optimum. In part, a simple algorithm to predict climate suitability for maize would caused a relatively large error in climate suitability assessment under the present climate conditions. In 2050s, the climate suitability for maize increased in a large areas in southern and western part of Korea. In particular, the plain areas near the coastal region had considerably greater suitability index in the future compared with mountainous areas. The expansion of suitable areas for maize would help crop production policy making such as the allocation of rice production area for other crops due to considerably less demand for the rice in Korea.

Can a pairwise contact potential stabilize native protein folds against decoys obtained by threading?

PubMed

Vendruscolo, M; Najmanovich, R; Domany, E

2000-02-01

We present a method to derive contact energy parameters from large sets of proteins. The basic requirement on which our method is based is that for each protein in the database the native contact map has lower energy than all its decoy conformations that are obtained by threading. Only when this condition is satisfied one can use the proposed energy function for fold identification. Such a set of parameters can be found (by perceptron learning) if Mp, the number of proteins in the database, is not too large. Other aspects that influence the existence of such a solution are the exact definition of contact and the value of the critical distance Rc, below which two residues are considered to be in contact. Another important novel feature of our approach is its ability to determine whether an energy function of some suitable proposed form can or cannot be parameterized in a way that satisfies our basic requirement. As a demonstration of this, we determine the region in the (Rc, Mp) plane in which the problem is solvable, i.e., we can find a set of contact parameters that stabilize simultaneously all the native conformations. We show that for large enough databases the contact approximation to the energy cannot stabilize all the native folds even against the decoys obtained by gapless threading.

BluePyOpt: Leveraging Open Source Software and Cloud Infrastructure to Optimise Model Parameters in Neuroscience

PubMed Central

Van Geit, Werner; Gevaert, Michael; Chindemi, Giuseppe; Rössert, Christian; Courcol, Jean-Denis; Muller, Eilif B.; Schürmann, Felix; Segev, Idan; Markram, Henry

2016-01-01

At many scales in neuroscience, appropriate mathematical models take the form of complex dynamical systems. Parameterizing such models to conform to the multitude of available experimental constraints is a global non-linear optimisation problem with a complex fitness landscape, requiring numerical techniques to find suitable approximate solutions. Stochastic optimisation approaches, such as evolutionary algorithms, have been shown to be effective, but often the setting up of such optimisations and the choice of a specific search algorithm and its parameters is non-trivial, requiring domain-specific expertise. Here we describe BluePyOpt, a Python package targeted at the broad neuroscience community to simplify this task. BluePyOpt is an extensible framework for data-driven model parameter optimisation that wraps and standardizes several existing open-source tools. It simplifies the task of creating and sharing these optimisations, and the associated techniques and knowledge. This is achieved by abstracting the optimisation and evaluation tasks into various reusable and flexible discrete elements according to established best-practices. Further, BluePyOpt provides methods for setting up both small- and large-scale optimisations on a variety of platforms, ranging from laptops to Linux clusters and cloud-based compute infrastructures. The versatility of the BluePyOpt framework is demonstrated by working through three representative neuroscience specific use cases. PMID:27375471

Laser-Assisted Bending of Sharp Angles With Small Fillet Radius on Stainless Steel Sheets: Analysis of Experimental Set-Up and Processing Parameters

NASA Astrophysics Data System (ADS)

Gisario, Annamaria; Barletta, Massimiliano; Venettacci, Simone; Veniali, Francesco

2015-06-01

Achievement of sharp bending angles with small fillet radius on stainless steel sheets by mechanical bending requires sophisticated bending device and troublesome operational procedures, which can involve expensive molds, huge presses and large loads. In addition, springback is always difficult to control, thus often leading to final parts with limited precision and accuracy. In contrast, laser-assisted bending of metals is an emerging technology, as it often allows to perform difficult and multifaceted manufacturing tasks with relatively small efforts. In the present work, laser-assisted bending of stainless steel sheets to achieve sharp angles is thus investigated. First, bending trials were performed by combining laser irradiation with an auxiliary bending device triggered by a pneumatic actuator and based on kinematic of deformable quadrilaterals. Second, laser operational parameters, that is, scanning speed, power and number of passes, were varied to identify the most suitable processing settings. Bending angles and fillet radii were measured by coordinate measurement machine. Experimental data were elaborated by combined ANalysis Of Mean (ANOM) and ANalysis Of VAriance (ANOVA). Based on experimental findings, the best strategy to achieve an aircraft prototype from a stainless steel sheet was designed and implemented.

Product development using process monitoring and NDE data fusion

NASA Astrophysics Data System (ADS)

Peterson, Todd; Bossi, Richard H.

1998-03-01

Composite process/product development relies on both process monitoring information and nondestructive evaluation measurements for determining application suitability. In the past these activities have been performed and analyzed independently. Our present approach is to present the process monitoring and NDE data together in a data fusion workstation. This methodology leads to final product acceptance based on a combined process monitoring and NDE criteria. The data fusion work station combines process parameter and NDE data in a single workspace enabling all the data to be used in the acceptance/rejection decision process. An example application is the induction welding process, a unique joining method for assembling primary composite structure, that offers significant cost and weight advantages over traditional fasted structure. The determination of the required time, temperature and pressure conditions used in the process to achieve a complete weld is being aided by the use of ultrasonic inspection techniques. Full waveform ultrasonic inspection data is employed to evaluate the quality of spar cap to skin fit, an essential element of the welding process, and is processed to find a parameter that can be used for weld acceptance. Certification of the completed weld incorporates the data fusion methodology.

Static design of steel-concrete lining for traffic tunnels

NASA Astrophysics Data System (ADS)

Vojtasik, Karel; Mohyla, Marek; Hrubesova, Eva

2017-09-01

Article summarizes the results of research focused on the structural design of traffic tunnel linings that have been achieved in the framework of a research project TE01020168 that supports The Technology Agency of Czech Republic. This research aim is to find and develop a process for design structure parameters of tunnel linings. These are now mostly build up by a shotcrete technology. The shotcrete is commonly endorsed either with steel girders or steel fibres. Since the installation a lining structure is loaded while strength and deformational parameters of shotcrete start to rise till the setting time elapses. That’s reason why conventional approaches of reinforced concrete are not suitable. As well as there are other circumstances to step in shown in this article. Problem is solved by 3D analysis using numerical model that takes into account all the significant features of a tunnel lining construction process inclusive the interaction between lining structure with rock massive. Analysis output is a view into development of stress-strain state in respective construction parts of tunnel lining the whole structure around, including impact on stability of rock massive. The proposed method comprises all features involved in tunnel fabrication including geotechnics and construction technologies.

Inactivation kinetics of various chemical disinfectants on Aeromonas hydrophila planktonic cells and biofilms.

PubMed

Jahid, Iqbal Kabir; Ha, Sang-Do

2014-05-01

The present article focuses on the inactivation kinetics of various disinfectants including ethanol, sodium hypochlorite, hydrogen peroxide, peracetic acid, and benzalkonium chloride against Aeromonas hydrophila biofilms and planktonic cells. Efficacy was determined by viable plate count and compared using a modified Weibull model. The removal of the biofilms matrix was determined by the crystal violet assay and was confirmed by field-emission scanning electron microscope. The results revealed that all the experimental data and calculated Weibull α (scale) and β (shape) parameters had a good fit, as the R(2) values were between 0.88 and 0.99. Biofilms are more resistant to disinfectants than planktonic cells. Ethanol (70%) was the most effective in killing cells in the biofilms and significantly reduced (p<0.05) the biofilms matrix. The Weibull parameter b-value correlated (R(2)=0.6835) with the biofilms matrix removal. The present findings deduce that the Weibull model is suitable to determine biofilms matrix reduction as well as the effectiveness of chemical disinfectants on biofilms. The study showed that the Weibull model could successfully be used on food and food contact surfaces to determine the exact contact time for killing biofilms-forming foodborne pathogens.

Assessing a Suitable Contribution of the French Armor Branch to the Doctrinal Development of Violence: Mastering Operations in the Urban Environment

DTIC Science & Technology

2003-06-06

France : New Defense for a New Millennium,” Parameters, winter 1996-87, 99-108. 17George A. Bloch, “ French Military Reform: Lessons for America’s Army...ASSESSING A SUITABLE CONTRIBUTION OF THE FRENCH ARMOR BRANCH TO THE DOCTRINAL DEVELOPMENT OF VIOLENCE: MASTERING OPERATIONS IN THE URBAN ENVIRONMENT...MILITARY ART AND SCIENCE General Studies by Jean-Michel Millet, MAJ, FRENCH ARMY BTEMG, Paris, 2002 Fort Leavenworth, Kansas 2003 Approved for

Hierarchical Bayesian Modeling of Fluid-Induced Seismicity

NASA Astrophysics Data System (ADS)

Broccardo, M.; Mignan, A.; Wiemer, S.; Stojadinovic, B.; Giardini, D.

2017-11-01

In this study, we present a Bayesian hierarchical framework to model fluid-induced seismicity. The framework is based on a nonhomogeneous Poisson process with a fluid-induced seismicity rate proportional to the rate of injected fluid. The fluid-induced seismicity rate model depends upon a set of physically meaningful parameters and has been validated for six fluid-induced case studies. In line with the vision of hierarchical Bayesian modeling, the rate parameters are considered as random variables. We develop both the Bayesian inference and updating rules, which are used to develop a probabilistic forecasting model. We tested the Basel 2006 fluid-induced seismic case study to prove that the hierarchical Bayesian model offers a suitable framework to coherently encode both epistemic uncertainty and aleatory variability. Moreover, it provides a robust and consistent short-term seismic forecasting model suitable for online risk quantification and mitigation.

Centrifugal distortion coefficients of asymmetric-top molecules: Reduction of the octic terms of the rotational Hamiltonian

NASA Astrophysics Data System (ADS)

Ramachandra Rao, Ch. V. S.

1983-11-01

The rotational Hamiltonian of an asymmetric-top molecule in its standard form, containing terms up to eighth degree in the components of the total angular momentum, is transformed by a unitary transformation with parameters Spqr to a reduced Hamiltonian so as to avoid the indeterminacies inherent in fitting the complete Hamiltonian to observed energy levels. Expressions are given for the nine determinable combinations of octic constants Θ' i ( i = 1 to 9) which are invariant under the unitary transformation. A method of reduction suitable for energy calculations by matrix diagonalization is considered. The relations between the coefficients of the transformed Hamiltonian, for suitable choice of the parameters Spqr, and those of the reduced Hamiltonian are given. This enables the determination of the nine octic constants Θ' i in terms of the experimental constants.

[Evaluation of metabolic rate for a correct risk assessment of thermal environments].

PubMed

Del Ferraro, Simona; Molinaro, V

2010-01-01

The new law n.81/2008 recognises microclimate as one of physical agents for which risk assessment becomes obligatory. To achieve this it is necessary to evaluate suitable indices, based on heat balance equation, which depend on six parameters: the first four are related to thermal environment and the last two are related to the worker (metabolic rate and thermal insulation). The first four parameters are directly measurable in situ by using a multiple data acquisition unit provided with suitable sensors. Parameters related to the worker are not directly measurable. This aspect represents one of the problems which can lead to an inaccurate risk assessment. Aim of the paper was to identify a method which leads to a correct evaluation of the metabolic rate related to the worker under study. It was decided to follow the procedures described by the standard UNI EN ISO 8996:2005 which presents four different levels to evaluate metabolic rate, each one with an increasing degree of accuracy. Seven workers were selected: three performed light tasks and the other four did heavy work. The study showed that the results appear to be in acceptable agreement in the case of light work while there were detectable differences in value for heavy tasks. The Authors believe it is necessary to stress the importance of a suitable estimation of the metabolic rate in order to carry out a correct risk assessment which quantifies the risk exactly.

Evaluation of urethane snow plow blades as an alternative to rubber blades.

DOT National Transportation Integrated Search

1995-01-01

The purpose of this study was to determine if urethane blades are a suitable alternative to rubber blades for use on snow plows. The importance of finding a suitable alternative is due to the anticipated increased need to protect the new, longer last...

Evolutionary algorithms for the optimization of advective control of contaminated aquifer zones

NASA Astrophysics Data System (ADS)

Bayer, Peter; Finkel, Michael

2004-06-01

Simple genetic algorithms (SGAs) and derandomized evolution strategies (DESs) are employed to adapt well capture zones for the hydraulic optimization of pump-and-treat systems. A hypothetical contaminant site in a heterogeneous aquifer serves as an application template. On the basis of the results from numerical flow modeling, particle tracking is applied to delineate the pathways of the contaminants. The objective is to find the minimum pumping rate of up to eight recharge wells within a downgradient well placement area. Both the well coordinates and the pumping rates are subject to optimization, leading to a mixed discrete-continuous problem. This article discusses the ideal formulation of the objective function for which the number of particles and the total pumping rate are used as decision criteria. Boundary updating is introduced, which enables the reorganization of the decision space limits by the incorporation of experience from previous optimization runs. Throughout the study the algorithms' capabilities are evaluated in terms of the number of model runs which are needed to identify optimal and suboptimal solutions. Despite the complexity of the problem both evolutionary algorithm variants prove to be suitable for finding suboptimal solutions. The DES with weighted recombination reveals to be the ideal algorithm to find optimal solutions. Though it works with real-coded decision parameters, it proves to be suitable for adjusting discrete well positions. Principally, the representation of well positions as binary strings in the SGA is ideal. However, even if the SGA takes advantage of bookkeeping, the vital high discretization of pumping rates results in long binary strings, which escalates the model runs that are needed to find an optimal solution. Since the SGA string lengths increase with the number of wells, the DES gains superiority, particularly for an increasing number of wells. As the DES is a self-adaptive algorithm, it proves to be the more robust optimization method for the selected advective control problem than the SGA variants of this study, exhibiting a less stochastic search which is reflected in the minor variability of the found solutions.

The development of a tele-monitoring system for physiological parameters based on the B/S model.

PubMed

Shuicai, Wu; Peijie, Jiang; Chunlan, Yang; Haomin, Li; Yanping, Bai

2010-01-01

The development of a new physiological multi-parameter remote monitoring system is based on the B/S model. The system consists of a server monitoring center, Internet network and PC-based multi-parameter monitors. Using the B/S model, the clients can browse web pages via the server monitoring center and download and install ActiveX controls. The physiological multi-parameters are collected, displayed and remotely transmitted. The experimental results show that the system is stable, reliable and operates in real time. The system is suitable for use in physiological multi-parameter remote monitoring for family and community healthcare. Copyright © 2010 Elsevier Ltd. All rights reserved.

Identification and evaluation of air-pollution-tolerant plants around lignite-based thermal power station for greenbelt development.

PubMed

Govindaraju, M; Ganeshkumar, R S; Muthukumaran, V R; Visvanathan, P

2012-05-01

Thermal power plants emit various gaseous and particulate pollutants into the atmosphere. It is well known that trees help to reduce air pollution. Development of a greenbelt with suitable plant species around the source of emission will mitigate the air pollution. Selection of suitable plant species for a greenbelt is very important. Present study evaluates different plant species around Neyveli thermal power plant by calculating the Air Pollution Tolerance Index (APTI) which is based on their significant biochemical parameters. Also Anticipated Performance Index (API) was calculated for these plant species by combining APTI values with other socio-economic and biological parameters. Based on these indices, the most appropriate plant species were identified for the development of a greenbelt around the thermal power plant to mitigate air pollution. Among the 30 different plant species evaluated, Mangifere indica L. was identified as keystone species which is coming under the excellent category. Ambient air quality parameters were correlated with the biochemical characteristics of plant leaves and significant changes were observed in the plants biochemical characteristics due to the air pollution stress.

WHOLE-BODY VIBRATION EXERCISE IMPROVES FUNCTIONAL PARAMETERS IN PATIENTS WITH OSTEOGENESIS IMPERFECTA: A SYSTEMATIC REVIEW WITH A SUITABLE APPROACH.

PubMed

Sá-Caputo, Danubia C; Dionello, Carla da F; Frederico, Éric Heleno F F; Paineiras-Domingos, Laisa L; Sousa-Gonçalves, Cintia Renata; Morel, Danielle S; Moreira-Marconi, Eloá; Unger, Marianne; Bernardo-Filho, Mario

2017-01-01

Patients with osteogenesis imperfecta (OI) have abnormal bone modelling and resorption. The bone tissue adaptation and responsivity to dynamic and mechanical loading may be of therapeutic use under controlled circumstances. Improvements due to the wholebody vibration (WBV) exercises have been reported in strength, motion, gait, balance, posture and bone density in several osteopenic individuals, as in post-menopausal women or children with disabling conditions, as patients with OI. The aim of this investigation was to systematically analyse the current available literature to determine the effect of WBV exercises on functional parameters of OI patients. Three reviewers independently accessed bibliographical databases. Searches were performed in the PubMed, Scopus, Science Direct and PEDro databases using keywords related to possible interventions (including WBV) used in the management of patients with osteogenesis imperfecta . Three eligible studies were identified by searches in the analysed databases. It was concluded that WBV exercises could be an important option in the management of OI patients improving the mobility and functional parameters. However, further studies are necessary for establishing suitable protocols for these patients.

Results of including geometric nonlinearities in an aeroelastic model of an F/A-18

NASA Technical Reports Server (NTRS)

Buttrill, Carey S.

1989-01-01

An integrated, nonlinear simulation model suitable for aeroelastic modeling of fixed-wing aircraft has been developed. While the author realizes that the subject of modeling rotating, elastic structures is not closed, it is believed that the equations of motion developed and applied herein are correct to second order and are suitable for use with typical aircraft structures. The equations are not suitable for large elastic deformation. In addition, the modeling framework generalizes both the methods and terminology of non-linear rigid-body airplane simulation and traditional linear aeroelastic modeling. Concerning the importance of angular/elastic inertial coupling in the dynamic analysis of fixed-wing aircraft, the following may be said. The rigorous inclusion of said coupling is not without peril and must be approached with care. In keeping with the same engineering judgment that guided the development of the traditional aeroelastic equations, the effect of non-linear inertial effects for most airplane applications is expected to be small. A parameter does not tell the whole story, however, and modes flagged by the parameter as significant also need to be checked to see if the coupling is not a one-way path, i.e., the inertially affected modes can influence other modes.

Suitability of spring wheat varieties for the production of best quality pizza.

PubMed

Tehseen, Saima; Anjum, Faqir Muhammad; Pasha, Imran; Khan, Muhammad Issa; Saeed, Farhan

2014-08-01

The selection of appropriate wheat cultivars is an imperative issue in product development and realization. The nutritional profiling of plants and their cultivars along with their suitability for development of specific products is of considerable interests for multi-national food chains. In this project, Pizza-Hut Pakistan provided funds for the selection of suitable newly developed Pakistani spring variety for pizza production. In this regard, the recent varieties were selected and evaluated for nutritional and functional properties for pizza production. Additionally, emphasis has been paid to assess all varieties for their physico-chemical attributes, rheological parameters and mineral content. Furthermore, pizza prepared from respective flour samples were further evaluated for sensory attributes Results showed that Anmool, Abadgar, Imdad, SKD-1, Shafaq and Moomal have higher values for protein, gluten content, pelshenke value and SDS sedimentation and these were relatively better in studied parameters as compared to other varieties although which were considered best for good quality pizza production. TD-1 got significantly highest score for flavor of pizza and lowest score was observed from wheat variety Kiran. Moreover, it is concluded from current study that all wheat varieties except TJ-83 and Kiran exhibited better results for flavor.

A novel method for simultaneous measurement of doped optical fiber parameters

NASA Astrophysics Data System (ADS)

Karimi, M.; Seraji, F. E.

2010-05-01

Simultaneous measurement technique of evaluating the doped optical fibers (DOF) parameters is a suitable scheme for DOF production industries. In this paper, we introduce a novel technique to characterize simultaneously the main parameters of DOF such as absorption and emission cross-sections (ACS, ECS), background loss coefficient (BLC), and low dopant concentration using the gain equation of DOFs. We used this new method to determine the ACS, ECS, BLC in a standard sample of Al-P-Erbium doped optical fiber. The results have been analyzed and compared with other reports.

Influence of vehicles used for oral dosing of test molecules on the progression of Mycobacterium tuberculosis infection in mice.

PubMed

Singh, Shubhra; Dwivedi, Richa; Chaturvedi, Vinita

2012-11-01

Preclinical evaluation of drug-like molecules requires their oral administration to experimental animals using suitable vehicles. We studied the effect of oral dosing with corn oil, carboxymethyl cellulose, dimethyl sulfoxide, and polysorbate-80 on the progression of Mycobacterium tuberculosis infection in mice. Infection was monitored by physical (survival time and body weight) and bacteriological (viable counts in lungs) parameters. Compared with water, corn oil significantly improved both sets of parameters, whereas the other vehicles affected only physical parameters.

Influence of Vehicles Used for Oral Dosing of Test Molecules on the Progression of Mycobacterium tuberculosis Infection in Mice

PubMed Central

Singh, Shubhra; Dwivedi, Richa

2012-01-01

Preclinical evaluation of drug-like molecules requires their oral administration to experimental animals using suitable vehicles. We studied the effect of oral dosing with corn oil, carboxymethyl cellulose, dimethyl sulfoxide, and polysorbate-80 on the progression of Mycobacterium tuberculosis infection in mice. Infection was monitored by physical (survival time and body weight) and bacteriological (viable counts in lungs) parameters. Compared with water, corn oil significantly improved both sets of parameters, whereas the other vehicles affected only physical parameters. PMID:22926571

Digital adaptive flight controller development

NASA Technical Reports Server (NTRS)

Kaufman, H.; Alag, G.; Berry, P.; Kotob, S.

1974-01-01

A design study of adaptive control logic suitable for implementation in modern airborne digital flight computers was conducted. Two designs are described for an example aircraft. Each of these designs uses a weighted least squares procedure to identify parameters defining the dynamics of the aircraft. The two designs differ in the way in which control law parameters are determined. One uses the solution of an optimal linear regulator problem to determine these parameters while the other uses a procedure called single stage optimization. Extensive simulation results and analysis leading to the designs are presented.

Objective measures of motor dysfunction after compression spinal cord injury in adult rats: correlations with locomotor rating scores.

PubMed

Semler, Joerg; Wellmann, Katharina; Wirth, Felicitas; Stein, Gregor; Angelova, Srebrina; Ashrafi, Mahak; Schempf, Greta; Ankerne, Janina; Ozsoy, Ozlem; Ozsoy, Umut; Schönau, Eckhard; Angelov, Doychin N; Irintchev, Andrey

2011-07-01

Precise assessment of motor deficits after traumatic spinal cord injury (SCI) in rodents is crucial for understanding the mechanisms of functional recovery and testing therapeutic approaches. Here we analyzed the applicability to a rat SCI model of an objective approach, the single-frame motion analysis, created and used for functional analysis in mice. Adult female Wistar rats were subjected to graded compression of the spinal cord. Recovery of locomotion was analyzed using video recordings of beam walking and inclined ladder climbing. Three out of four parameters used in mice appeared suitable: the foot-stepping angle (FSA) and the rump-height index (RHI), measured during beam walking, and for estimating paw placement and body weight support, respectively, and the number of correct ladder steps (CLS), assessing skilled limb movements. These parameters, similar to the Basso, Beattie, and Bresnahan (BBB) locomotor rating scores, correlated with lesion volume and showed significant differences between moderately and severely injured rats at 1-9 weeks after SCI. The beam parameters, but not CLS, correlated well with the BBB scores within ranges of poor and good locomotor abilities. FSA co-varied with RHI only in the severely impaired rats, while RHI and CLS were barely correlated. Our findings suggest that the numerical parameters estimate, as intended by design, predominantly different aspects of locomotion. The use of these objective measures combined with BBB rating provides a time- and cost-efficient opportunity for versatile and reliable functional evaluations in both severely and moderately impaired rats, combining clinical assessment with precise numerical measures.

Factors influencing preclinical in vivo evaluation of mumps vaccine strain immunogenicity

PubMed Central

Halassy, B; Kurtović, T; Brgles, M; Lang Balija, M; Forčić, D

2015-01-01

Immunogenicity testing in animals is a necessary preclinical assay for demonstration of vaccine efficacy the results of which are often the basis for the decision whether to proceed or withdraw the further development of the novel vaccine candidate. However, in vivo assays are rarely, if at all, optimized and validated. Here we clearly demonstrate the importance of in vivo assay (mumps virus immunogenicity testing in guinea pigs) optimization for gaining reliable results and the suitability of Fractional factorial design of experiments (DoE) for such a purpose. By the use of DoE with resolution IV (2IV(4-1)) we clearly revealed that the parameters significantly increasing assay sensitivity were interval between animal immunizations followed by the body weight of experimental animals. The quantity (0 versus 2%) of the stabilizer (fetal bovine serum, FBS) in the sample was shown as non-influencing parameter in DoE setup. However, the separate experiment investigating only the FBS influence, and performed under other parameters optimally set, showed that FBS also influences the results of immunogenicity assay. Such finding indicated that (a) factors with strong influence on the measured outcome can hide the effects of parameters with modest/low influence and (b) the matrix of mumps virus samples to be compared for immunogenicity must be identical for reliable virus immunogenicity comparison. Finally the 3 mumps vaccine strains widely used for decades in the licensed vaccines were for the first time compared in an animal model, and results obtained were in line with their reported immunogenicity in human population supporting the predictive power of the optimized in vivo assay. PMID:26376015

Factors influencing preclinical in vivo evaluation of mumps vaccine strain immunogenicity.

PubMed

Halassy, B; Kurtović, T; Brgles, M; Lang Balija, M; Forčić, D

2015-01-01

Immunogenicity testing in animals is a necessary preclinical assay for demonstration of vaccine efficacy the results of which are often the basis for the decision whether to proceed or withdraw the further development of the novel vaccine candidate. However, in vivo assays are rarely, if at all, optimized and validated. Here we clearly demonstrate the importance of in vivo assay (mumps virus immunogenicity testing in guinea pigs) optimization for gaining reliable results and the suitability of Fractional factorial design of experiments (DoE) for such a purpose. By the use of DoE with resolution IV (2IV((4-1))) we clearly revealed that the parameters significantly increasing assay sensitivity were interval between animal immunizations followed by the body weight of experimental animals. The quantity (0 versus 2%) of the stabilizer (fetal bovine serum, FBS) in the sample was shown as non-influencing parameter in DoE setup. However, the separate experiment investigating only the FBS influence, and performed under other parameters optimally set, showed that FBS also influences the results of immunogenicity assay. Such finding indicated that (a) factors with strong influence on the measured outcome can hide the effects of parameters with modest/low influence and (b) the matrix of mumps virus samples to be compared for immunogenicity must be identical for reliable virus immunogenicity comparison. Finally the 3 mumps vaccine strains widely used for decades in the licensed vaccines were for the first time compared in an animal model, and results obtained were in line with their reported immunogenicity in human population supporting the predictive power of the optimized in vivo assay.

Immersion freezing by natural dust based on a soccer ball model with the Community Atmospheric Model version 5: climate effects

NASA Astrophysics Data System (ADS)

Wang, Yong; Liu, Xiaohong

2014-12-01

We introduce a simplified version of the soccer ball model (SBM) developed by Niedermeier et al (2014 Geophys. Res. Lett. 41 736-741) into the Community Atmospheric Model version 5 (CAM5). It is the first time that SBM is used in an atmospheric model to parameterize the heterogeneous ice nucleation. The SBM, which was simplified for its suitable application in atmospheric models, uses the classical nucleation theory to describe the immersion/condensation freezing by dust in the mixed-phase cloud regime. Uncertain parameters (mean contact angle, standard deviation of contact angle probability distribution, and number of surface sites) in the SBM are constrained by fitting them to recent natural dust (Saharan dust) datasets. With the SBM in CAM5, we investigate the sensitivity of modeled cloud properties to the SBM parameters, and find significant seasonal and regional differences in the sensitivity among the three SBM parameters. Changes of mean contact angle and the number of surface sites lead to changes of cloud properties in Arctic in spring, which could be attributed to the transport of dust ice nuclei to this region. In winter, significant changes of cloud properties induced by these two parameters mainly occur in northern hemispheric mid-latitudes (e.g., East Asia). In comparison, no obvious changes of cloud properties caused by changes of standard deviation can be found in all the seasons. These results are valuable for understanding the heterogeneous ice nucleation behavior, and useful for guiding the future model developments.

Accounting for human neurocognitive function in the design and evaluation of 360 degree situational awareness display systems

NASA Astrophysics Data System (ADS)

Metcalfe, Jason S.; Mikulski, Thomas; Dittman, Scott

2011-06-01

The current state and trajectory of development for display technologies supporting information acquisition, analysis and dissemination lends a broad informational infrastructure to operators of complex systems. The amount of information available threatens to outstrip the perceptual-cognitive capacities of operators, thus limiting their ability to effectively interact with targeted technologies. Therefore, a critical step in designing complex display systems is to find an appropriate match between capabilities, operational needs, and human ability to utilize complex information. The present work examines a set of evaluation parameters that were developed to facilitate the design of systems to support a specific military need; that is, the capacity to support the achievement and maintenance of real-time 360° situational awareness (SA) across a range of complex military environments. The focal point of this evaluation is on the reciprocity native to advanced engineering and human factors practices, with a specific emphasis on aligning the operator-systemenvironment fit. That is, the objective is to assess parameters for evaluation of 360° SA display systems that are suitable for military operations in tactical platforms across a broad range of current and potential operational environments. The approach is centered on five "families" of parameters, including vehicle sensors, data transmission, in-vehicle displays, intelligent automation, and neuroergonomic considerations. Parameters are examined under the assumption that displays designed to conform to natural neurocognitive processing will enhance and stabilize Soldier-system performance and, ultimately, unleash the human's potential to actively achieve and maintain the awareness necessary to enhance lethality and survivability within modern and future operational contexts.

Probabilistic treatment of the uncertainty from the finite size of weighted Monte Carlo data

NASA Astrophysics Data System (ADS)

Glüsenkamp, Thorsten

2018-06-01

Parameter estimation in HEP experiments often involves Monte Carlo simulation to model the experimental response function. A typical application are forward-folding likelihood analyses with re-weighting, or time-consuming minimization schemes with a new simulation set for each parameter value. Problematically, the finite size of such Monte Carlo samples carries intrinsic uncertainty that can lead to a substantial bias in parameter estimation if it is neglected and the sample size is small. We introduce a probabilistic treatment of this problem by replacing the usual likelihood functions with novel generalized probability distributions that incorporate the finite statistics via suitable marginalization. These new PDFs are analytic, and can be used to replace the Poisson, multinomial, and sample-based unbinned likelihoods, which covers many use cases in high-energy physics. In the limit of infinite statistics, they reduce to the respective standard probability distributions. In the general case of arbitrary Monte Carlo weights, the expressions involve the fourth Lauricella function FD, for which we find a new finite-sum representation in a certain parameter setting. The result also represents an exact form for Carlson's Dirichlet average Rn with n > 0, and thereby an efficient way to calculate the probability generating function of the Dirichlet-multinomial distribution, the extended divided difference of a monomial, or arbitrary moments of univariate B-splines. We demonstrate the bias reduction of our approach with a typical toy Monte Carlo problem, estimating the normalization of a peak in a falling energy spectrum, and compare the results with previously published methods from the literature.

A recurrent self-organizing neural fuzzy inference network.

PubMed

Juang, C F; Lin, C T

1999-01-01

A recurrent self-organizing neural fuzzy inference network (RSONFIN) is proposed in this paper. The RSONFIN is inherently a recurrent multilayered connectionist network for realizing the basic elements and functions of dynamic fuzzy inference, and may be considered to be constructed from a series of dynamic fuzzy rules. The temporal relations embedded in the network are built by adding some feedback connections representing the memory elements to a feedforward neural fuzzy network. Each weight as well as node in the RSONFIN has its own meaning and represents a special element in a fuzzy rule. There are no hidden nodes (i.e., no membership functions and fuzzy rules) initially in the RSONFIN. They are created on-line via concurrent structure identification (the construction of dynamic fuzzy if-then rules) and parameter identification (the tuning of the free parameters of membership functions). The structure learning together with the parameter learning forms a fast learning algorithm for building a small, yet powerful, dynamic neural fuzzy network. Two major characteristics of the RSONFIN can thus be seen: 1) the recurrent property of the RSONFIN makes it suitable for dealing with temporal problems and 2) no predetermination, like the number of hidden nodes, must be given, since the RSONFIN can find its optimal structure and parameters automatically and quickly. Moreover, to reduce the number of fuzzy rules generated, a flexible input partition method, the aligned clustering-based algorithm, is proposed. Various simulations on temporal problems are done and performance comparisons with some existing recurrent networks are also made. Efficiency of the RSONFIN is verified from these results.

Variation of parameters using Battin's universal functions

NASA Astrophysics Data System (ADS)

Burton, James R., III; Melton, Robert G.

This paper presents a variation of parameters analysis, suitable for use in situations involving small perturbations to the two-body problem, using Battin's universal functions. Unlike the universal variable formulation, this approach avoids the need to switch among different functional representations if the orbit transitions from elliptical, through parabolic, to hyperbolic state, making it attractive for use in simulating low-thrust trajectories ascending to escape or capturing into orbit.

On-board landmark navigation and attitude reference parallel processor system

NASA Technical Reports Server (NTRS)

Gilbert, L. E.; Mahajan, D. T.

1978-01-01

An approach to autonomous navigation and attitude reference for earth observing spacecraft is described along with the landmark identification technique based on a sequential similarity detection algorithm (SSDA). Laboratory experiments undertaken to determine if better than one pixel accuracy in registration can be achieved consistent with onboard processor timing and capacity constraints are included. The SSDA is implemented using a multi-microprocessor system including synchronization logic and chip library. The data is processed in parallel stages, effectively reducing the time to match the small known image within a larger image as seen by the onboard image system. Shared memory is incorporated in the system to help communicate intermediate results among microprocessors. The functions include finding mean values and summation of absolute differences over the image search area. The hardware is a low power, compact unit suitable to onboard application with the flexibility to provide for different parameters depending upon the environment.

Study of velocity and temperature distributions in boundary layer flow of fourth grade fluid over an exponential stretching sheet

NASA Astrophysics Data System (ADS)

Khan, Najeeb Alam; Saeed, Umair Bin; Sultan, Faqiha; Ullah, Saif; Rehman, Abdul

2018-02-01

This study deals with the investigation of boundary layer flow of a fourth grade fluid and heat transfer over an exponential stretching sheet. For analyzing two heating processes, namely, (i) prescribed surface temperature (PST), and (ii) prescribed heat flux (PHF), the temperature distribution in a fluid has been considered. The suitable transformations associated with the velocity components and temperature, have been employed for reducing the nonlinear model equation to a system of ordinary differential equations. The flow and temperature fields are revealed by solving these reduced nonlinear equations through an effective analytical method. The important findings in this analysis are to observe the effects of viscoelastic, cross-viscous, third grade fluid, and fourth grade fluid parameters on the constructed analytical expression for velocity profile. Likewise, the heat transfer properties are studied for Prandtl and Eckert numbers.

Three-dimensional metal-intercalated covalent organic frameworks for near-ambient energy storage

PubMed Central

Gao, Fei; Ding, Zijing; Meng, Sheng

2013-01-01

A new form of nanoporous material, metal intercalated covalent organic framework (MCOF) is proposed and its energy storage property revealed. Employing density functional and thermodynamical analysis, we find that stable, chemically active, porous materials could form by stacking covalent organic framework (COF) layers with metals as a gluing agent. Metal acts as active sites, while its aggregation is suppressed by a binding energy significantly larger than the corresponding cohesive energy of bulk metals. Two important parameters, metal binding and metal-metal separation, are tuned by selecting suitable building blocks and linkers when constructing COF layers. Systematic searches among a variety of elements and organic molecules identify Ca-intercalated COF with diphenylethyne units as optimal material for H2 storage, reaching a striking gravimetric density ~ 5 wt% at near-ambient conditions (300 K, 20 bar), in comparison to < 0.1 wt% for bare COF-1 under the same condition. PMID:23698018

Molecular nanomagnets with switchable coupling for quantum simulation

DOE PAGES

Chiesa, Alessandro; Whitehead, George F. S.; Carretta, Stefano; ...

2014-12-11

Molecular nanomagnets are attractive candidate qubits because of their wide inter- and intra-molecular tunability. Uniform magnetic pulses could be exploited to implement one- and two-qubit gates in presence of a properly engineered pattern of interactions, but the synthesis of suitable and potentially scalable supramolecular complexes has proven a very hard task. Indeed, no quantum algorithms have ever been implemented, not even a proof-of-principle two-qubit gate. In this paper we show that the magnetic couplings in two supramolecular {Cr7Ni}-Ni-{Cr7Ni} assemblies can be chemically engineered to fit the above requisites for conditional gates with no need of local control. Microscopic parameters aremore » determined by a recently developed many-body ab-initio approach and used to simulate quantum gates. We find that these systems are optimal for proof-of-principle two-qubit experiments and can be exploited as building blocks of scalable architectures for quantum simulation.« less

Transport model of controlled molecular rectifier showing unusual negative differential resistance effect.

PubMed

Granhen, Ewerton Ramos; Reis, Marcos Allan Leite; Souza, Fabrício M; Del Nero, Jordan

2010-12-01

We investigate theoretically the charge accumulated Q in a three-terminal molecular device in the presence of an external electric field. Our approach is based on ab initio Hartree-Fock and density functional theory methodology contained in Gaussian package. Our main finding is a negative differential resistance (NDR) in the charge Q as a function of an external electric field. To explain this NDR effect we apply a phenomenological capacitive model based on a quite general system composed of many localized levels (that can be LUMOs of a molecule) coupled to source and drain. The capacitance accounts for charging effects that can result in Coulomb blockade (CB) in the transport. We show that this CB effect gives rise to a NDR for a suitable set of phenomenological parameters, like tunneling rates and charging energies. The NDR profile obtained in both ab initio and phenomenological methodologies are in close agreement.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ellis, John; Evans, Jason L.; Nagata, Natsumi

We reconsider the minimal SU( 5) grand unified theory (GUT) in the context of no-scale supergravity inspired by string compactification scenarios, assuming that the soft supersymmetry-breaking parameters satisfy universality conditions at some input scale M in above the GUT scale M GUT. When setting up such a no-scale super-GUT model, special attention must be paid to avoiding the Scylla of rapid proton decay and the Charybdis of an excessive density of cold dark matter, while also having an acceptable mass for the Higgs boson. Furthermore, we do not find consistent solutions if none of the matter and Higgs fields aremore » assigned to twisted chiral supermultiplets, even in the presence of Giudice–Masiero terms. But, consistent solutions may be found if at least one fiveplet of GUT Higgs fields is assigned to a twisted chiral supermultiplet, with a suitable choice of modular weights. Spin-independent dark matter scattering may be detectable in some of these consistent solutions.« less

ComprehensiveBench: a Benchmark for the Extensive Evaluation of Global Scheduling Algorithms

NASA Astrophysics Data System (ADS)

Pilla, Laércio L.; Bozzetti, Tiago C.; Castro, Márcio; Navaux, Philippe O. A.; Méhaut, Jean-François

2015-10-01

Parallel applications that present tasks with imbalanced loads or complex communication behavior usually do not exploit the underlying resources of parallel platforms to their full potential. In order to mitigate this issue, global scheduling algorithms are employed. As finding the optimal task distribution is an NP-Hard problem, identifying the most suitable algorithm for a specific scenario and comparing algorithms are not trivial tasks. In this context, this paper presents ComprehensiveBench, a benchmark for global scheduling algorithms that enables the variation of a vast range of parameters that affect performance. ComprehensiveBench can be used to assist in the development and evaluation of new scheduling algorithms, to help choose a specific algorithm for an arbitrary application, to emulate other applications, and to enable statistical tests. We illustrate its use in this paper with an evaluation of Charm++ periodic load balancers that stresses their characteristics.

Effects of task complexity on rhythmic reproduction performance in adults.

PubMed

Iannarilli, Flora; Vannozzi, Giuseppe; Iosa, Marco; Pesce, Caterina; Capranica, Laura

2013-02-01

The aim of the present study was to investigate the effect of task complexity on the capability to reproduce rhythmic patterns. Sedentary musically illiterate individuals (age: 34.8±4.2 yrs; M±SD) were administered a rhythmic test including three rhythmic patterns to be reproduced by means of finger-tapping, foot-tapping and walking. For the quantification of subjects' ability in the reproduction of rhythmic patterns, qualitative and quantitative parameters were submitted to analysis. A stereophotogrammetric system was used to reconstruct and evaluate individual performances. The findings indicated a good internal stability of the rhythmic reproduction, suggesting that the present experimental design is suitable to discriminate the participants' rhythmic ability. Qualitative aspects of rhythmic reproduction (i.e., speed of execution and temporal ratios between events) varied as a function of the perceptual-motor requirements of the rhythmic reproduction task, with larger reproduction deviations in the walking task. Copyright © 2013 Elsevier B.V. All rights reserved.

Measures for a transdimensional multiverse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwartz-Perlov, Delia; Vilenkin, Alexander, E-mail: dperlov@cosmos.phy.tufts.edu, E-mail: vilenkin@cosmos.phy.tufts.edu

2010-06-01

The multiverse/landscape paradigm that has emerged from eternal inflation and string theory, describes a large-scale multiverse populated by ''pocket universes'' which come in a huge variety of different types, including different dimensionalities. In order to make predictions in the multiverse, we need a probability measure. In (3+1)d landscapes, the scale factor cutoff measure has been previously shown to have a number of attractive properties. Here we consider possible generalizations of this measure to a transdimensional multiverse. We find that a straightforward extension of scale factor cutoff to the transdimensional case gives a measure that strongly disfavors large amounts of slow-rollmore » inflation and predicts low values for the density parameter Ω, in conflict with observations. A suitable generalization, which retains all the good properties of the original measure, is the ''volume factor'' cutoff, which regularizes the infinite spacetime volume using cutoff surfaces of constant volume expansion factor.« less

Designing magnetic droplet soliton nucleation employing spin polarizer

NASA Astrophysics Data System (ADS)

Mohseni, Morteza; Mohseni, Majid

2018-04-01

We show by means of micromagnetic simulations that spin polarizer in nano-contact (NC) spin torque oscillators as the representative of the fixed layer in an orthogonal pseudo-spin valve can be employed to design and to control magnetic droplet soliton nucleation and dynamics. We found that using a tilted spin polarizer layer decreases the droplet nucleation time which is more suitable for high speed applications. However, a tilted spin polarizer increases the nucleation current and decreases the frequency stability of the droplet. Additionally, by driving the magnetization inhomogenously at the NC region, it is found that a tilted spin polarizer reduces the precession angle of the droplet and through an interplay with the Oersted field of the DC current, it breaks the spatial symmetry of the droplet profile. Our findings explore fundamental insight into nano-scale magnetic droplet soliton dynamics with potential tunability parameters for future microwave electronics.

Kinematic fingerprint of core-collapsed globular clusters

NASA Astrophysics Data System (ADS)

Bianchini, P.; Webb, J. J.; Sills, A.; Vesperini, E.

2018-03-01

Dynamical evolution drives globular clusters towards core collapse, which strongly shapes their internal properties. Diagnostics of core collapse have so far been based on photometry only, namely on the study of the concentration of the density profiles. Here, we present a new method to robustly identify core-collapsed clusters based on the study of their stellar kinematics. We introduce the kinematic concentration parameter, ck, the ratio between the global and local degree of energy equipartition reached by a cluster, and show through extensive direct N-body simulations that clusters approaching core collapse and in the post-core collapse phase are strictly characterized by ck > 1. The kinematic concentration provides a suitable diagnostic to identify core-collapsed clusters, independent from any other previous methods based on photometry. We also explore the effects of incomplete radial and stellar mass coverage on the calculation of ck and find that our method can be applied to state-of-art kinematic data sets.

Passive runaway electron suppression in tokamak disruptions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, H. M.; Helander, P.; Boozer, A. H.

2013-07-15

Runaway electrons created in disruptions pose a serious problem for tokamaks with large current. It would be desirable to have a runaway electron suppression method which is passive, i.e., a method that does not rely on an uncertain disruption prediction system. One option is to let the large electric field inherent in the disruption drive helical currents in the wall. This would create ergodic regions in the plasma and increase the runaway losses. Whether these regions appear at a suitable time and place to affect the formation of the runaway beam depends on disruption parameters, such as electron temperature andmore » density. We find that it is difficult to ergodize the central plasma before a beam of runaway current has formed. However, the ergodic outer region will make the Ohmic current profile contract, which can lead to instabilities that yield large runaway electron losses.« less

Analysis and observation of moving domain fronts in a ring of coupled electronic self-oscillators

NASA Astrophysics Data System (ADS)

English, L. Q.; Zampetaki, A.; Kevrekidis, P. G.; Skowronski, K.; Fritz, C. B.; Abdoulkary, Saidou

2017-10-01

In this work, we consider a ring of coupled electronic (Wien-bridge) oscillators from a perspective combining modeling, simulation, and experimental observation. Following up on earlier work characterizing the pairwise interaction of Wien-bridge oscillators by Kuramoto-Sakaguchi phase dynamics, we develop a lattice model for a chain thereof, featuring an exponentially decaying spatial kernel. We find that for certain values of the Sakaguchi parameter α, states of traveling phase-domain fronts involving the coexistence of two clearly separated regions of distinct dynamical behavior, can establish themselves in the ring lattice. Experiments and simulations show that stationary coexistence domains of synchronization only manifest themselves with the introduction of a local impurity; here an incoherent cluster of oscillators can arise reminiscent of the chimera states in a range of systems with homogeneous oscillators and suitable nonlocal interactions between them.

Detection of text strings from mixed text/graphics images

NASA Astrophysics Data System (ADS)

Tsai, Chien-Hua; Papachristou, Christos A.

2000-12-01

A robust system for text strings separation from mixed text/graphics images is presented. Based on a union-find (region growing) strategy the algorithm is thus able to classify the text from graphics and adapts to changes in document type, language category (e.g., English, Chinese and Japanese), text font style and size, and text string orientation within digital images. In addition, it allows for a document skew that usually occurs in documents, without skew correction prior to discrimination while these proposed methods such a projection profile or run length coding are not always suitable for the condition. The method has been tested with a variety of printed documents from different origins with one common set of parameters, and the experimental results of the performance of the algorithm in terms of computational efficiency are demonstrated by using several tested images from the evaluation.

Improved maximum average correlation height filter with adaptive log base selection for object recognition

NASA Astrophysics Data System (ADS)

Tehsin, Sara; Rehman, Saad; Awan, Ahmad B.; Chaudry, Qaiser; Abbas, Muhammad; Young, Rupert; Asif, Afia

2016-04-01

Sensitivity to the variations in the reference image is a major concern when recognizing target objects. A combinational framework of correlation filters and logarithmic transformation has been previously reported to resolve this issue alongside catering for scale and rotation changes of the object in the presence of distortion and noise. In this paper, we have extended the work to include the influence of different logarithmic bases on the resultant correlation plane. The meaningful changes in correlation parameters along with contraction/expansion in the correlation plane peak have been identified under different scenarios. Based on our research, we propose some specific log bases to be used in logarithmically transformed correlation filters for achieving suitable tolerance to different variations. The study is based upon testing a range of logarithmic bases for different situations and finding an optimal logarithmic base for each particular set of distortions. Our results show improved correlation and target detection accuracies.

Opinion evolution and rare events in an open community

NASA Astrophysics Data System (ADS)

Ye, Yusong; Yang, Zhuoqin; Zhang, Zili

2016-11-01

There are many multi-stable phenomena in society. To explain these multi-stable phenomena, we have studied opinion evolution in an open community. We focus on probability of transition (or the mean transition time) that the system transfer from one state to another. We suggest a bistable model to provide an interpretation of these phenomena. The quasi-potential method that we used is the most important method to calculate the transition time and it can be used to determine the whole probability density. We study the condition of bistability and then discuss rare events in a multi-stable system. In our model, we find that two parameters, ;temperature; and ;persuading intensity,; influence the behavior of the system; a suitable ;persuading intensity; and low ;temperature; make the system more stable. This means that the transition rarely happens. The asymmetric phenomenon caused by ;public-opinion; is also discussed.

Continuous-variable quantum probes for structured environments

NASA Astrophysics Data System (ADS)

Bina, Matteo; Grasselli, Federico; Paris, Matteo G. A.

2018-01-01

We address parameter estimation for structured environments and suggest an effective estimation scheme based on continuous-variables quantum probes. In particular, we investigate the use of a single bosonic mode as a probe for Ohmic reservoirs, and obtain the ultimate quantum limits to the precise estimation of their cutoff frequency. We assume the probe prepared in a Gaussian state and determine the optimal working regime, i.e., the conditions for the maximization of the quantum Fisher information in terms of the initial preparation, the reservoir temperature, and the interaction time. Upon investigating the Fisher information of feasible measurements, we arrive at a remarkable simple result: homodyne detection of canonical variables allows one to achieve the ultimate quantum limit to precision under suitable, mild, conditions. Finally, upon exploiting a perturbative approach, we find the invariant sweet spots of the (tunable) characteristic frequency of the probe, able to drive the probe towards the optimal working regime.

Laser-induced plasmonic colours on metals

NASA Astrophysics Data System (ADS)

Guay, Jean-Michel; Calà Lesina, Antonino; Côté, Guillaume; Charron, Martin; Poitras, Daniel; Ramunno, Lora; Berini, Pierre; Weck, Arnaud

2017-07-01

Plasmonic resonances in metallic nanoparticles have been used since antiquity to colour glasses. The use of metal nanostructures for surface colourization has attracted considerable interest following recent developments in plasmonics. However, current top-down colourization methods are not ideally suited to large-scale industrial applications. Here we use a bottom-up approach where picosecond laser pulses can produce a full palette of non-iridescent colours on silver, gold, copper and aluminium. We demonstrate the process on silver coins weighing up to 5 kg and bearing large topographic variations (~1.5 cm). We find that colours are related to a single parameter, the total accumulated fluence, making the process suitable for high-throughput industrial applications. Statistical image analyses of laser-irradiated surfaces reveal various nanoparticle size distributions. Large-scale finite-difference time-domain computations based on these nanoparticle distributions reproduce trends seen in reflectance measurements, and demonstrate the key role of plasmonic resonances in colour formation.

Physiological and behavioral parameters of infants' categorization: changes in heart rate and duration of examining across trials.

PubMed

Elsner, Birgit; Pauen, Sabina; Jeschonek, Susanna

2006-11-01

This report investigates the relations between duration of examining and heart rate (HR) across several trials of an object-examination task. A total of N= 20 11-month-olds were familiarized with a sequence of 10 different exemplars from the same global category (animals or furniture) before they received an exemplar from the contrasting category at test. Consistent with previous findings, HR was lower during states of focused attention (i.e. examining) than during states of casual attention (i.e. looking) or non-looking. Over the familiarization trials, examining stayed about the same, while mean HR increased. At test, examining increased and mean HR decreased, indicating that infants focused their attention on the out-of-category object. Psychophysiological and behavioral measures of attention were systematically related over trials, suggesting that heart rate provides a suitable objective measure to study infants' categorization performance in object-examination tasks.

Laser-induced plasmonic colours on metals

PubMed Central

Guay, Jean-Michel; Calà Lesina, Antonino; Côté, Guillaume; Charron, Martin; Poitras, Daniel; Ramunno, Lora; Berini, Pierre; Weck, Arnaud

2017-01-01

Plasmonic resonances in metallic nanoparticles have been used since antiquity to colour glasses. The use of metal nanostructures for surface colourization has attracted considerable interest following recent developments in plasmonics. However, current top-down colourization methods are not ideally suited to large-scale industrial applications. Here we use a bottom-up approach where picosecond laser pulses can produce a full palette of non-iridescent colours on silver, gold, copper and aluminium. We demonstrate the process on silver coins weighing up to 5 kg and bearing large topographic variations (∼1.5 cm). We find that colours are related to a single parameter, the total accumulated fluence, making the process suitable for high-throughput industrial applications. Statistical image analyses of laser-irradiated surfaces reveal various nanoparticle size distributions. Large-scale finite-difference time-domain computations based on these nanoparticle distributions reproduce trends seen in reflectance measurements, and demonstrate the key role of plasmonic resonances in colour formation. PMID:28719576

Producing Acetic Acid of Acetobacter pasteurianus by Fermentation Characteristics and Metabolic Flux Analysis.

PubMed

Wu, Xuefeng; Yao, Hongli; Liu, Qing; Zheng, Zhi; Cao, Lili; Mu, Dongdong; Wang, Hualin; Jiang, Shaotong; Li, Xingjiang

2018-03-19

The acetic acid bacterium Acetobacter pasteurianus plays an important role in acetic acid fermentation, which involves oxidation of ethanol to acetic acid through the ethanol respiratory chain under specific conditions. In order to obtain more suitable bacteria for the acetic acid industry, A. pasteurianus JST-S screened in this laboratory was compared with A. pasteurianus CICC 20001, a current industrial strain in China, to determine optimal fermentation parameters under different environmental stresses. The maximum total acid content of A. pasteurianus JST-S was 57.14 ± 1.09 g/L, whereas that of A. pasteurianus CICC 20001 reached 48.24 ± 1.15 g/L in a 15-L stir stank. Metabolic flux analysis was also performed to compare the reaction byproducts. Our findings revealed the potential value of the strain in improvement of industrial vinegar fermentation.

An ergonomic approach to design hand tool for agricultural production.

PubMed

Khidiya, Mahendra Singh; Bhardwaj, Awadhesh

2012-01-01

Hand tool mechanisms designed to reduce the risk factors have rarely been studied. In this paper it is analyze trowel firstly designing in CATIA and then its Finite Element Analysis has been carried out by ABAQUS. The main emphasis is on finding stresses by using this software, then removing them by suitable mechanical working on tool & ergonomic change in the design of handle to make it more comfortable. Body part discomfort score and overall discomfort rating experienced by the subjects had also been estimated. During the muscular activity workers physiological responses i.e. energy expenditure rate, oxygen consumption rate and heart rate increases. This increase in physiological responses is related to the type, intensity and duration of work and thus sets limits to the performance of heavy work. In this paper oxygen consumption rate and heart rate was used for physiological cost estimation. These parameters were measured by Computerized Ambulatory Metabolic Measurement System K4b2.

A power management system for energy harvesting and wireless sensor networks application based on a novel charge pump circuit

NASA Astrophysics Data System (ADS)

Aloulou, R.; De Peslouan, P.-O. Lucas; Mnif, H.; Alicalapa, F.; Luk, J. D. Lan Sun; Loulou, M.

2016-05-01

Energy Harvesting circuits are developed as an alternative solution to supply energy to autonomous sensor nodes in Wireless Sensor Networks. In this context, this paper presents a micro-power management system for multi energy sources based on a novel design of charge pump circuit to allow the total autonomy of self-powered sensors. This work proposes a low-voltage and high performance charge pump (CP) suitable for implementation in standard complementary metal oxide semiconductor (CMOS) technologies. The CP design was implemented using Cadence Virtuoso with AMS 0.35μm CMOS technology parameters. Its active area is 0.112 mm2. Consistent results were obtained between the measured findings of the chip testing and the simulation results. The circuit can operate with an 800 mV supply and generate a boosted output voltage of 2.835 V with 1 MHz as frequency.

Suitability of analytical methods to measure solubility for the purpose of nanoregulation.

PubMed

Tantra, Ratna; Bouwmeester, Hans; Bolea, Eduardo; Rey-Castro, Carlos; David, Calin A; Dogné, Jean-Michel; Jarman, John; Laborda, Francisco; Laloy, Julie; Robinson, Kenneth N; Undas, Anna K; van der Zande, Meike

2016-01-01

Solubility is an important physicochemical parameter in nanoregulation. If nanomaterial is completely soluble, then from a risk assessment point of view, its disposal can be treated much in the same way as "ordinary" chemicals, which will simplify testing and characterisation regimes. This review assesses potential techniques for the measurement of nanomaterial solubility and evaluates the performance against a set of analytical criteria (based on satisfying the requirements as governed by the cosmetic regulation as well as the need to quantify the concentration of free (hydrated) ions). Our findings show that no universal method exists. A complementary approach is thus recommended, to comprise an atomic spectrometry-based method in conjunction with an electrochemical (or colorimetric) method. This article shows that although some techniques are more commonly used than others, a huge research gap remains, related with the need to ensure data reliability.

Ultralow-Noise SiN Trampoline Resonators for Sensing and Optomechanics

NASA Astrophysics Data System (ADS)

Reinhardt, Christoph; Müller, Tina; Bourassa, Alexandre; Sankey, Jack C.

2016-04-01

In force sensing, optomechanics, and quantum motion experiments, it is typically advantageous to create lightweight, compliant mechanical elements with the lowest possible force noise. Here, we report the fabrication and characterization of high-aspect-ratio, nanogram-scale Si3 N4 "trampolines" having quality factors above 4 ×107 and ringdown times exceeding 5 min (mHz linewidth). These devices exhibit thermally limited force noise sensitivities below 20 aN /Hz1 /2 at room temperature, which is the lowest among solid-state mechanical sensors. We also characterize the suitability of these devices for high-finesse cavity readout and optomechanics applications, finding no evidence of surface or bulk optical losses from the processed nitride in a cavity achieving finesse 40,000. These parameters provide access to a single-photon cooperativity C0˜8 in the resolved-sideband limit, wherein a variety of outstanding optomechanics goals become feasible.

Chemical Analysis of Soils: An Environmental Chemistry Laboratory for Undergraduate Science Majors.

ERIC Educational Resources Information Center

Willey, Joan D.; Avery, G. Brooks, Jr.; Manock, John J.; Skrabal, Stephen A.; Stehman, Charles F.

1999-01-01

Describes a laboratory exercise for undergraduate science students in which they evaluate soil samples for various parameters related to suitability for crop production and capability for retention of contaminants. (Contains 18 references.) (WRM)

Seasonal extreme value statistics for precipitation in Germany

NASA Astrophysics Data System (ADS)

Fischer, Madlen; Rust, Henning W.; Ulbrich, Uwe

2013-04-01

Extreme precipitation has a strong influence on environment, society and economy. It leads to large damage due to floods, mudslides, increased erosion or hail. While standard annual return levels are important for hydrological structures, seasonaly resolved return levels provide additional information for risk managment, e.g., for the agricultural sector. For 1208 stations in Germany, we calculate monthly resolved return levels. Instead of estimating parameters separately for every month in the year, we use a non-stationary approach and benefit from smoothly varying return levels throughout the year. This natural approach is more suitable to characterise seasonal variability of extreme precipitation and leads to more accurate return level estimates. Harmonic functions of different orders are used to describe the seasonal variation of GEV parameters and crossvalidation is used to determine a suitable model forall stations. Finally particularly vulnerable regions and associated month are investigated in more detail.

Towards the engineering of in vitro systems.

PubMed

Hold, Christoph; Panke, Sven

2009-08-06

Synthetic biology aims at rationally implementing biological systems from scratch. Given the complexity of living systems and our current lack of understanding of many aspects of living cells, this is a major undertaking. The design of in vitro systems can be considerably easier, because they can consist of fewer constituents, are quasi time invariant, their parameter space can be better accessed and they can be much more easily perturbed and then analysed chemically and mathematically. However, even for simplified in vitro systems, following a comprehensively rational design procedure is still difficult. When looking at a comparatively simple system, such as a medium-sized enzymatic reaction network as it is represented by glycolysis, major issues such as a lack of comprehensive enzyme kinetics and of suitable knowledge on crucial design parameters remain. Nevertheless, in vitro systems are very suitable to overcome these obstacles and therefore well placed to act as a stepping stone to engineering living systems.

Seasonal Variation of Groundwater Quality in Erode District, Tamil Nadu, India.

PubMed

Kavidha, R; Elangovan, K

2014-07-01

In recent years, the recurring environmental issues regarding hazardous waste, global climate change, stratospheric ozone depletion, groundwater contamination, disaster mitigation and removal of pollutant have become the focus of environmental attention. In the management of water resources, quality of water is just as important as its quantity. In order to assess the quality and/or suitability of groundwater for drinking and irrigation in Erode District, 144 water samples each in post-monsoon and pre-monsoon during the year 2007 were collected and analyzed for various parameters. These parameters were compared with IS: 10500-1991 drinking water standards. Out of 144 samples, 29 samples exceeded the permissible limit for both the monsoons, 71 samples were within the permissible limit for both the monsoons and the remaining samples exceeded the permissible limit for any one of the monsoon. During both monsoons, except some samples, most of the samples were suitable for drinking and irrigation.

A method to measure internal contact angle in opaque systems by magnetic resonance imaging.

PubMed

Zhu, Weiqin; Tian, Ye; Gao, Xuefeng; Jiang, Lei

2013-07-23

Internal contact angle is an important parameter for internal wettability characterization. However, due to the limitation of optical imaging, methods available for contact angle measurement are only suitable for transparent or open systems. For most of the practical situations that require contact angle measurement in opaque or enclosed systems, the traditional methods are not effective. Based upon the requirement, a method suitable for contact angle measurement in nontransparent systems is developed by employing MRI technology. In the Article, the method is demonstrated by measuring internal contact angles in opaque cylindrical tubes. It proves that the method also shows great feasibility in transparent situations and opaque capillary systems. By using the method, contact angle in opaque systems could be measured successfully, which is significant in understanding the wetting behaviors in nontransparent systems and calculating interfacial parameters in enclosed systems.

Investigation of two-stage air-cooled turbine suitable for flight at Mach number of 2.5 II : blade design

NASA Technical Reports Server (NTRS)

Miser, James W; Stewart, Warner L

1957-01-01

A blade design study is presented for a two-stage air-cooled turbine suitable for flight at a Mach number of 2.5 for which velocity diagrams have been previously obtained. The detailed procedure used in the design of the blades is given. In addition, the design blade shapes, surface velocity distributions, inner and outer wall contours, and other design data are presented. Of all the blade rows, the first-stage rotor has the highest solidity, with a value of 2.289 at the mean section. The second-stage stator also had a high mean-section solidity of 1.927, mainly because of its high inlet whirl. The second-stage rotor has the highest value of the suction-surface diffusion parameter, with a value of 0.151. All other blade rows have values for this parameter under 0.100.

Indicator Development for Potential Presence of Schistosomiasis Japonicum's Vector in Lake and Marshland Regions- A Case Study of Poyang Lake, Jiangxi Province, P.R. China

NASA Astrophysics Data System (ADS)

Marie, Tiphanie; Yesou, Herve; Huber, Claire; De Fraipont, Paul; Uribe, Carlos; Lacaux, Jean-Pierre; Lafaye, Murielle; Lai, Xijun; Desnos, Yves-Louis

2013-01-01

Earth observation data and bibliography on environmental parameters were used for mapping Oncomelania hupensis distribution, the Schistosomiasis japonicum’s intermediate host snail, within Poyang Lake (Jiangxi Province, P.R. China). Areas suitable for the development of O. hupensis, the vector of schistosomiasis, were derived from submersion time parameters and vegetation community indicators. ENVISAT time series data acquired from 2000 to 2009 were used for submersion times mapping, and 5 Beijing-1 data acquired during the dry season between 2006 and 2008 were used to map suitable vegetation for vector development. Yearly maps obtained indicate four principally potential endemic areas: the Gan Delta, the bank of the Fu He River, the Dalianzi Hu sector and the Poyang Lake Nature Reserve. Monthly maps from December 2005 to December 2008 show the dynamic of potential O. hupensis presence areas.

Application of GIS Technology for Town Planning Tasks Solving

NASA Astrophysics Data System (ADS)

Kiyashko, G. A.

2017-11-01

For developing territories, one of the most actual town-planning tasks is to find out the suitable sites for building projects. The geographic information system (GIS) allows one to model complex spatial processes and can provide necessary effective tools to solve these tasks. We propose several GIS analysis models which can define suitable settlement allocations and select appropriate parcels for construction objects. We implement our models in the ArcGIS Desktop package and verify by application to the existing objects in Primorsky Region (Primorye Territory). These suitability models use several variations of the analysis method combinations and include various ways to resolve the suitability task using vector data and a raster data set. The suitability models created in this study can be combined, and one model can be integrated into another as its part. Our models can be updated by other suitability models for further detailed planning.

The Primary Computer Dictionary.

ERIC Educational Resources Information Center

Girard, Suzanne; Willing, Kathlene

Suitable for children from kindergarten to grade three, this dictionary is designed to introduce young children to computer terminology at a level that they will understand and find useful. It is also suitable for parents as a home resource, for library use, and as a handbook for teachers. The first sentence of each definition contains the kernel…

Switching LPV Control for High Performance Tactical Aircraft

NASA Technical Reports Server (NTRS)

Lu, Bei; Wu, Fen; Kim, SungWan

2004-01-01

This paper examines a switching Linear Parameter-Varying (LPV) control approach to determine if it is practical to use for flight control designs within a wide angle of attack region. The approach is based on multiple parameter-dependent Lyapunov functions. The full parameter space is partitioned into overlapping subspaces and a family of LPV controllers are designed, each suitable for a specific parameter subspace. The hysteresis switching logic is used to accomplish the transition among different parameter subspaces. The proposed switching LPV control scheme is applied to an F-16 aircraft model with different actuator dynamics in low and high angle of attack regions. The nonlinear simulation results show that the aircraft performs well when switching among different angle of attack regions.

Extensions of different type parameterized inequalities for generalized [Formula: see text]-preinvex mappings via k-fractional integrals.

PubMed

Zhang, Yao; Du, Ting-Song; Wang, Hao; Shen, Yan-Jun; Kashuri, Artion

2018-01-01

The authors discover a general k -fractional integral identity with multi-parameters for twice differentiable functions. By using this integral equation, the authors derive some new bounds on Hermite-Hadamard's and Simpson's inequalities for generalized [Formula: see text]-preinvex functions through k -fractional integrals. By taking the special parameter values for various suitable choices of function h , some interesting results are also obtained.

Choice of fineness of pulverized coal

DOE Office of Scientific and Technical Information (OSTI.GOV)

E.N. Tolchinskii; A.Yu. Lavrent'ev

2002-11-15

Various methods for choosing the fineness of power plant coal dust are reviewed and analytical expressions for determining the fineness are presented. It is shown that the use of the yield of combustibles as a parameter is not always suitable for evaluating the fineness of pulverized coal. The suggested expression for computing the fineness bears composite parameters that allow for the heat value of the volatiles and for the internal surface of the fuel particles.

Deblocking of mobile stereo video

NASA Astrophysics Data System (ADS)

Azzari, Lucio; Gotchev, Atanas; Egiazarian, Karen

2012-02-01

Most of candidate methods for compression of mobile stereo video apply block-transform based compression based on the H-264 standard with quantization of transform coefficients driven by quantization parameter (QP). The compression ratio and the resulting bit rate are directly determined by the QP level and high compression is achieved for the price of visually noticeable blocking artifacts. Previous studies on perceived quality of mobile stereo video have revealed that blocking artifacts are the most annoying and most influential in the acceptance/rejection of mobile stereo video and can even completely cancel the 3D effect and the corresponding quality added value. In this work, we address the problem of deblocking of mobile stereo video. We modify a powerful non-local transform-domain collaborative filtering method originally developed for denoising of images and video. The method employs grouping of similar block patches residing in spatial and temporal vicinity of a reference block in filtering them collaboratively in a suitable transform domain. We study the most suitable way of finding similar patches in both channels of stereo video and suggest a hybrid four-dimensional transform to process the collected synchronized (stereo) volumes of grouped blocks. The results benefit from the additional correlation available between the left and right channel of the stereo video. Furthermore, addition sharpening is applied through an embedded alpha-rooting in transform domain, which improve the visual appearance of the deblocked frames.

A planning algorithm for quantifying decentralised water management opportunities in urban environments.

PubMed

Bach, Peter M; McCarthy, David T; Urich, Christian; Sitzenfrei, Robert; Kleidorfer, Manfred; Rauch, Wolfgang; Deletic, Ana

2013-01-01

With global change bringing about greater challenges for the resilient planning and management of urban water infrastructure, research has been invested in the development of a strategic planning tool, DAnCE4Water. The tool models how urban and societal changes impact the development of centralised and decentralised (distributed) water infrastructure. An algorithm for rigorous assessment of suitable decentralised stormwater management options in the model is presented and tested on a local Melbourne catchment. Following detailed spatial representation algorithms (defined by planning rules), the model assesses numerous stormwater options to meet water quality targets at a variety of spatial scales. A multi-criteria assessment algorithm is used to find top-ranking solutions (which meet a specific treatment performance for a user-defined percentage of catchment imperviousness). A toolbox of five stormwater technologies (infiltration systems, surface wetlands, bioretention systems, ponds and swales) is featured. Parameters that set the algorithm's flexibility to develop possible management options are assessed and evaluated. Results are expressed in terms of 'utilisation', which characterises the frequency of use of different technologies across the top-ranking options (bioretention being the most versatile). Initial results highlight the importance of selecting a suitable spatial resolution and providing the model with enough flexibility for coming up with different technology combinations. The generic nature of the model enables its application to other urban areas (e.g. different catchments, local municipal regions or entire cities).

Preparation and evaluation of carriers for detection of cholinesterase inhibitors.

PubMed

Vetchý, David; Pitschmann, Vladimír; Vetchá, Martina; Kašparovský, Tomáš; Matějovský, Lukáš

2015-01-01

The aim of the study was to use methods of pharmaceutical technology, and prepare carriers in the form of pellets suitable as a filling of detection tubes for enzymatic detection of cholinesterase inhibitors. The enzymatic detection was based on enzymatic hydrolysis of acetylthiocholine iodide and the subsequent colour reaction of its hydrolysis product with Ellman's reagent. The suitable carriers should be in the form of white, regular and sufficiently mechanically resistant particles of about 1 mm allowing it to capture the enzyme during the impregnation process and ensuring its high activity for enzymatic detection. Carriers consisting of microcrystalline cellulose, lactose, povidone, and sodium carboxymethyl cellulose were prepared using extrusion-spheronization method under three different drying conditions in either a hot air oven or a microwave oven. Subsequently, the carriers were impregnated with acetylcholinesterase and their size, shape, mechanical resistance, bulk, tapped and pycnometric density, Hausner ratio, intraparticular and total tapped porosity, and activity were measured and recorded. In this procedure, carriers with different physical parameters and different acetylcholinesterase activity were evaluated. It was found that higher acetylcholinesterase activity was associated not only with a higher intraparticular porosity but also with more regular particles characterized by high sphericity and low total tapped porosity. This unique finding is important for the preparation of detection tubes based on enzymatic detection which is still irreplaceable especially in the field of detection and analysis of super-toxic cholinesterase inhibitors.

Functionalization of Probe Tips and Supports for Single-Molecule Recognition Force Microscopy

NASA Astrophysics Data System (ADS)

Ebner, Andreas; Wildling, Linda; Zhu, Rong; Rankl, Christian; Haselgrübler, Thomas; Hinterdorfer, Peter; Gruber, Hermann J.

The measuring tip of a force microscope can be converted into a monomolecular sensor if one or few "ligand" molecules are attached to the apex of the tip while maintaining ligand function. Functionalized tips are used to study fine details of receptor-ligand interaction by force spectroscopy or to map cognate "receptor" molecules on the sample surface. The receptor (or target) molecules can be present on the surface of a biological specimen; alternatively, soluble target molecules must be immobilized on ultraflat supports. This review describes the methods of tip functionalization, as well as target molecule immobilization. Silicon nitride tips, silicon chips, and mica have usually been functionalized in three steps: (1) aminofunctionalization, (2) crosslinker attachment, and (3) ligand/receptor coupling, whereby numerous crosslinkers are available to couple widely different ligand molecules. Gold-covered tips and/or supports have usually been coated with a self-assembled monolayer, on top of which the ligand/receptor molecule has been coupled either directly or via a crosslinker molecule. Apart from these general strategies, many simplified methods have been used for tip and/or support functionalization, even single-step methods such as adsorption or chemisorption being very efficient under suitable circumstances. All methods are described with the same explicitness and critical parameters are discussed. In conclusion, this review should help to find suitable methods for specific problems of tip and support functionalization.

Nonlocal homogenization theory in metamaterials: Effective electromagnetic spatial dispersion and artificial chirality

NASA Astrophysics Data System (ADS)

Ciattoni, Alessandro; Rizza, Carlo

2015-05-01

We develop, from first principles, a general and compact formalism for predicting the electromagnetic response of a metamaterial with nonmagnetic inclusions in the long-wavelength limit, including spatial dispersion up to the second order. Specifically, by resorting to a suitable multiscale technique, we show that the effective medium permittivity tensor and the first- and second-order tensors describing spatial dispersion can be evaluated by averaging suitable spatially rapidly varying fields, each satisfying electrostatic-like equations within the metamaterial unit cell. For metamaterials with negligible second-order spatial dispersion, we exploit the equivalence of first-order spatial dispersion and reciprocal bianisotropic electromagnetic response to deduce a simple expression for the metamaterial chirality tensor. Such an expression allows us to systematically analyze the effect of the composite spatial symmetry properties on electromagnetic chirality. We find that even if a metamaterial is geometrically achiral, i.e., it is indistinguishable from its mirror image, it shows pseudo-chiral-omega electromagnetic chirality if the rotation needed to restore the dielectric profile after the reflection is either a 0∘ or 90∘ rotation around an axis orthogonal to the reflection plane. These two symmetric situations encompass two-dimensional and one-dimensional metamaterials with chiral response. As an example admitting full analytical description, we discuss one-dimensional metamaterials whose single chirality parameter is shown to be directly related to the metamaterial dielectric profile by quadratures.

Is the Spatial Distribution of Mankind's Most Basic Economic Traits Determined by Climate and Soil Alone?

PubMed Central

Beck, Jan; Sieber, Andrea

2010-01-01

Background Several authors, most prominently Jared Diamond (1997, Guns, Germs and Steel), have investigated biogeographic determinants of human history and civilization. The timing of the transition to an agricultural lifestyle, associated with steep population growth and consequent societal change, has been suggested to be affected by the availability of suitable organisms for domestication. These factors were shown to quantitatively explain some of the current global inequalities of economy and political power. Here, we advance this approach one step further by looking at climate and soil as sole determining factors. Methodology/Principal Findings As a simplistic ‘null model’, we assume that only climate and soil conditions affect the suitability of four basic landuse types – agriculture, sedentary animal husbandry, nomadic pastoralism and hunting-and-gathering. Using ecological niche modelling (ENM), we derive spatial predictions of the suitability for these four landuse traits and apply these to the Old World and Australia. We explore two aspects of the properties of these predictions, conflict potential and population density. In a calculation of overlap of landuse suitability, we map regions of potential conflict between landuse types. Results are congruent with a number of real, present or historical, regions of conflict between ethnic groups associated with different landuse traditions. Furthermore, we found that our model of agricultural suitability explains a considerable portion of population density variability. We mapped residuals from this correlation, finding geographically highly structured deviations that invite further investigation. We also found that ENM of agricultural suitability correlates with a metric of local wealth generation (Gross Domestic Product, Purchasing Power Parity). Conclusions/Significance From simplified assumptions on the links between climate, soil and landuse we are able to provide good predictions on complex features of human geography. The spatial distribution of deviations from ENM predictions identifies those regions requiring further investigation of potential explanations. Our findings and methodological approaches may be of applied interest, e.g., in the context of climate change. PMID:20463959

Evaluation of epididymal function through specific protein on spermatozoa.

PubMed

Del Río, A G; De Sánchez, L Z; Sirena, A

1984-01-01

Investigations were focused on the characterization of specific epididymal proteins on the human spermatozoa as a representative parameter for epididymal function. An easy and attainable method, suitable for investigators and clinical use, is proposed in this article.

Transfer of control system interface solutions from other domains to the thermal power industry.

PubMed

Bligård, L-O; Andersson, J; Osvalder, A-L

2012-01-01

In a thermal power plant the operators' roles are to control and monitor the process to achieve efficient and safe production. To achieve this, the human-machine interfaces have a central part. The interfaces need to be updated and upgraded together with the technical functionality to maintain optimal operation. One way of achieving relevant updates is to study other domains and see how they have solved similar issues in their design solutions. The purpose of this paper is to present how interface design solution ideas can be transferred from domains with operator control to thermal power plants. In the study 15 domains were compared using a model for categorisation of human-machine systems. The result from the domain comparison showed that nuclear power, refinery and ship engine control were most similar to thermal power control. From the findings a basic interface structure and three specific display solutions were proposed for thermal power control: process parameter overview, plant overview, and feed water view. The systematic comparison of the properties of a human-machine system allowed interface designers to find suitable objects, structures and navigation logics in a range of domains that could be transferred to the thermal power domain.

Non-spherical micro- and nanoparticles: fabrication, characterization and drug delivery applications.

PubMed

Mathaes, Roman; Winter, Gerhard; Besheer, Ahmed; Engert, Julia

2015-03-01

Micro- and nanoparticles in drug and vaccine delivery have opened up new possibilities in pharmaceutics. In the past, researchers focused mainly on particle size, surface chemistry and the use of various materials to control particle characteristics and functions. Lately, shape has been acknowledged as an important design parameter having an impact on the interaction with biological systems. In this review, we report on the latest developments in fabrication methods to tailor particle geometry, summarize analytical techniques for non-spherical particles and highlight the most important findings regarding their interaction with biological systems and their potential applications in drug delivery. The impact of shape on particle internalization into different cell types and particle biodistribution has been extensively studied in the past. Current research focuses on shape-dependent uptake mechanisms and applications for tumour therapy and vaccination. Different fabrication methods can be used to produce a variety of different particle types and shapes. Key challenges will be the transfer of new non-spherical particle fabrication methods from lab-scale to industrial large-scale production. Not all techniques may be scalable for the production of high quantities of particles. It will also be challenging to transfer the promising in vitro findings to suitable in vivo models.

Searching for the origins of musicality across species.

PubMed

Hoeschele, Marisa; Merchant, Hugo; Kikuchi, Yukiko; Hattori, Yuko; ten Cate, Carel

2015-03-19

In the introduction to this theme issue, Honing et al. suggest that the origins of musicality--the capacity that makes it possible for us to perceive, appreciate and produce music--can be pursued productively by searching for components of musicality in other species. Recent studies have highlighted that the behavioural relevance of stimuli to animals and the relation of experimental procedures to their natural behaviour can have a large impact on the type of results that can be obtained for a given species. Through reviewing laboratory findings on animal auditory perception and behaviour, as well as relevant findings on natural behaviour, we provide evidence that both traditional laboratory studies and studies relating to natural behaviour are needed to answer the problem of musicality. Traditional laboratory studies use synthetic stimuli that provide more control than more naturalistic studies, and are in many ways suitable to test the perceptual abilities of animals. However, naturalistic studies are essential to inform us as to what might constitute relevant stimuli and parameters to test with laboratory studies, or why we may or may not expect certain stimulus manipulations to be relevant. These two approaches are both vital in the comparative study of musicality.

Searching for the origins of musicality across species

PubMed Central

Hoeschele, Marisa; Merchant, Hugo; Kikuchi, Yukiko; Hattori, Yuko; ten Cate, Carel

2015-01-01

In the introduction to this theme issue, Honing et al. suggest that the origins of musicality—the capacity that makes it possible for us to perceive, appreciate and produce music—can be pursued productively by searching for components of musicality in other species. Recent studies have highlighted that the behavioural relevance of stimuli to animals and the relation of experimental procedures to their natural behaviour can have a large impact on the type of results that can be obtained for a given species. Through reviewing laboratory findings on animal auditory perception and behaviour, as well as relevant findings on natural behaviour, we provide evidence that both traditional laboratory studies and studies relating to natural behaviour are needed to answer the problem of musicality. Traditional laboratory studies use synthetic stimuli that provide more control than more naturalistic studies, and are in many ways suitable to test the perceptual abilities of animals. However, naturalistic studies are essential to inform us as to what might constitute relevant stimuli and parameters to test with laboratory studies, or why we may or may not expect certain stimulus manipulations to be relevant. These two approaches are both vital in the comparative study of musicality. PMID:25646517

Experimental test of the mechanism of reaction for (e,e'p) coincidence experiment. [/sup 12/C(e,e'p): DWIA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bernheim, M.; Bussiere, A.; Frullani, S.

1977-06-27

In order to test the validity of the distorted wave impulse approximation to describe (e,e'p) reactions and/or the suitability of the available optical potential parameters to calculate the distortion, the spectral function was measured for /sub 12/C(e,e'p)/sub 11/B in different kinematical configurations. Experimental results are shown together with the distributions computed with several values of the optical potential parameters. Data seem to indicate the necessity of using different parameters for p hole states and s hole states.

FIBER AND INTEGRATED OPTICS: New method for determination of the parameters of a channel waveguide

NASA Astrophysics Data System (ADS)

Galechyan, M. G.; Dianov, Evgenii M.; Lyndin, N. M.; Sychugov, V. A.; Tishchenko, A. V.; Usievich, B. A.

1992-02-01

A new method for the determination of the parameters of channel integrated optical waveguides is proposed. This method is based on measuring the spectral transmission of a system comprising the investigated waveguide and single-mode fiber waveguides, which are brought into contact with the channel waveguide. The results are reported of an investigation of two channel waveguides formed in glass by a variety of methods and characterized by different refractive index profiles. The proposed method is found to be suitable for determination of the parameters of the refractive index profile of the investigated channel waveguides.

Transfer-function-parameter estimation from frequency response data: A FORTRAN program

NASA Technical Reports Server (NTRS)

Seidel, R. C.

1975-01-01

A FORTRAN computer program designed to fit a linear transfer function model to given frequency response magnitude and phase data is presented. A conjugate gradient search is used that minimizes the integral of the absolute value of the error squared between the model and the data. The search is constrained to insure model stability. A scaling of the model parameters by their own magnitude aids search convergence. Efficient computer algorithms result in a small and fast program suitable for a minicomputer. A sample problem with different model structures and parameter estimates is reported.

An improved V-Lambda solution of the matrix Riccati equation

NASA Technical Reports Server (NTRS)

Bar-Itzhack, Itzhack Y.; Markley, F. Landis

1988-01-01

The authors present an improved algorithm for computing the V-Lambda solution of the matrix Riccati equation. The improvement is in the reduction of the computational load, results from the orthogonality of the eigenvector matrix that has to be solved for. The orthogonality constraint reduces the number of independent parameters which define the matrix from n-squared to n (n - 1)/2. The authors show how to specify the parameters, how to solve for them and how to form from them the needed eigenvector matrix. In the search for suitable parameters, the analogy between the present problem and the problem of attitude determination is exploited, resulting in the choice of Rodrigues parameters.

A Framework for Statewide Analysis of Site Suitability, Energy Estimation, Life Cycle Costs, Financial Feasibility and Environmental Assessment of Wind Farms: A Case Study of Indiana

NASA Astrophysics Data System (ADS)

Kumar, Indraneel

In the last decade, Midwestern states including Indiana have experienced an unprecedented growth in utility scale wind energy farms. For example, by end of 2013, Indiana had 1.5 GW of wind turbines installed, which could provide electrical energy for as many as half-a-million homes. However, there is no statewide systematic framework available for the evaluation of wind farm impacts on endangered species, required necessary setbacks and proximity standards to infrastructure, and life cycle costs. This research is guided to fill that gap and it addresses the following questions. How much land is suitable for wind farm siting in Indiana given the constraints of environmental, ecological, cultural, settlement, physical infrastructure and wind resource parameters? How much wind energy can be obtained? What are the life cycle costs and economic and financial feasibility? Is wind energy production and development in a state an emission free undertaking? The framework developed in the study is applied to a case study of Indiana. A fuzzy logic based AHP (Analytic Hierarchy Process) spatial site suitability analysis for wind energy is formulated. The magnitude of wind energy that could be sited and installed comprises input for economic and financial feasibility analysis for 20-25 years life cycle of wind turbines in Indiana. Monte Carlo simulation is used to account for uncertainty and nonlinearity in various costs and price parameters. Impacts of incentives and cost variables such as production tax credits, costs of capital, and economies of scale are assessed. Further, an economic input-output (IO) based environmental assessment model is developed for wind energy, where costs from financial feasibility analysis constitute the final demand vectors. This customized model for Indiana is used to assess emissions for criteria air pollutants, hazardous air pollutants and greenhouse gases (GHG) across life cycle events of wind turbines. The findings of the case study include that, Indiana has adequate suitable land area available to locate wind farms with installed capacity between 11 and 51 GW if 100 meters high turbines are used. For a 1.5 MW standard wind turbine, financial feasibility analysis shows that production tax credits and property tax abatements are helpful for financial success in Indiana. Also, the wind energy is not entirely emission free if life cycle events of wind turbine manufacturing, production, installation, construction and decommissioning are considered. The research developed a replicable and integrated framework for statewide life cycle analysis of wind energy production accounting for uncertainty into the analyses. Considering the complexity of life cycle analysis and lack of state specific data on performance of wind turbines and wind farms, this study should be considered an intermediate step.

The worth of data to reduce predictive uncertainty of an integrated catchment model by multi-constraint calibration

NASA Astrophysics Data System (ADS)

Koch, J.; Jensen, K. H.; Stisen, S.

2017-12-01

Hydrological models that integrate numerical process descriptions across compartments of the water cycle are typically required to undergo thorough model calibration in order to estimate suitable effective model parameters. In this study, we apply a spatially distributed hydrological model code which couples the saturated zone with the unsaturated zone and the energy portioning at the land surface. We conduct a comprehensive multi-constraint model calibration against nine independent observational datasets which reflect both the temporal and the spatial behavior of hydrological response of a 1000km2 large catchment in Denmark. The datasets are obtained from satellite remote sensing and in-situ measurements and cover five keystone hydrological variables: discharge, evapotranspiration, groundwater head, soil moisture and land surface temperature. Results indicate that a balanced optimization can be achieved where errors on objective functions for all nine observational datasets can be reduced simultaneously. The applied calibration framework was tailored with focus on improving the spatial pattern performance; however results suggest that the optimization is still more prone to improve the temporal dimension of model performance. This study features a post-calibration linear uncertainty analysis. This allows quantifying parameter identifiability which is the worth of a specific observational dataset to infer values to model parameters through calibration. Furthermore the ability of an observation to reduce predictive uncertainty is assessed as well. Such findings determine concrete implications on the design of model calibration frameworks and, in more general terms, the acquisition of data in hydrological observatories.

An Empirical Calibration of the Mixing-Length Parameter α

NASA Astrophysics Data System (ADS)

Ferraro, Francesco R.; Valenti, Elena; Straniero, Oscar; Origlia, Livia

2006-05-01

We present an empirical calibration of the mixing-length free parameter α based on a homogeneous infrared database of 28 Galactic globular clusters spanning a wide metallicity range (-2.15<[Fe/H]<-0.2). Empirical estimates of the red giant effective temperatures have been obtained from infrared colors. Suitable relations linking these temperatures to the cluster metallicity have been obtained and compared to theoretical predictions. An appropriate set of models for the Sun and Population II giants has been computed by using both the standard solar metallicity (Z/X)solar=0.0275 and the most recently proposed value (Z/X)solar=0.0177. We find that when the standard solar metallicity is adopted, a unique value of α=2.17 can be used to reproduce both the solar radius and the Population II red giant temperature. Conversely, when the new solar metallicity is adopted, two different values of α are required: α=1.86 to fit the solar radius and α~2.0 to fit the red giant temperatures. However, it must be noted that regardless the adopted solar reference, the α-parameter does not show any significant dependence on metallicity. Based on observations collected at the European Southern Observatory (ESO), La Silla, Chile. Also based on observations made with the Italian Telescopio Nazionale Galileo (TNG) operated on the island of La Palma by the Fundacion Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias.

[Application of classical isothermal adsorption models in heavy metal ions/ diatomite system and related problems].

PubMed

Zhu, Jian; Wu, Qing-Ding; Wang, Ping; Li, Ke-Lin; Lei, Ming-Jing; Zhang, Wei-Li

2013-11-01

In order to fully understand adsorption nature of Cu2+, Zn2+, Pb2+, Cd2+, Mn2+, Fe3+ onto natural diatomite, and to find problems of classical isothermal adsorption models' application in liquid/solid system, a series of isothermal adsorption tests were conducted. As results indicate, the most suitable isotherm models for describing adsorption of Pb2+, Cd2+, Cu2+, Zn2+, Mn2+, Fe3+ onto natural diatomite are Tenkin, Tenkin, Langmuir, Tenkin, Freundlich and Freundlich, respectively, the adsorption of each ion onto natural diatomite is mainly a physical process, and the adsorption reaction is favorable. It also can be found that, when using classical isothermal adsorption models to fit the experimental data in liquid/solid system, the equilibrium adsorption amount q(e) is not a single function of ion equilibrium concentration c(e), while is a function of two variables, namely c(e) and the adsorbent concentration W0, q(e) only depends on c(e)/W(0). Results also show that the classical isothermal adsorption models have a significant adsorbent effect, and their parameter values are unstable, the simulation values of parameter differ greatly from the measured values, which is unhelpful for practical use. The tests prove that four-adsorption-components model can be used for describing adsorption behavior of single ion in nature diatomite-liquid system, its parameters k and q(m) have constant values, which is favorable for practical quantitative calculation in a given system.

Energy Bounds for a Compressed Elastic Film on a Substrate

NASA Astrophysics Data System (ADS)

Bourne, David P.; Conti, Sergio; Müller, Stefan

2017-04-01

We study pattern formation in a compressed elastic film which delaminates from a substrate. Our key tool is the determination of rigorous upper and lower bounds on the minimum value of a suitable energy functional. The energy consists of two parts, describing the two main physical effects. The first part represents the elastic energy of the film, which is approximated using the von Kármán plate theory. The second part represents the fracture or delamination energy, which is approximated using the Griffith model of fracture. A simpler model containing the first term alone was previously studied with similar methods by several authors, assuming that the delaminated region is fixed. We include the fracture term, transforming the elastic minimisation into a free boundary problem, and opening the way for patterns which result from the interplay of elasticity and delamination. After rescaling, the energy depends on only two parameters: the rescaled film thickness, {σ }, and a measure of the bonding strength between the film and substrate, {γ }. We prove upper bounds on the minimum energy of the form {σ }^a {γ }^b and find that there are four different parameter regimes corresponding to different values of a and b and to different folding patterns of the film. In some cases, the upper bounds are attained by self-similar folding patterns as observed in experiments. Moreover, for two of the four parameter regimes we prove matching, optimal lower bounds.

The impact of chewing gum on halitosis parameters: a systematic review.

PubMed

Muniz, Francisco Wilker Mustafa Gomes; Friedrich, Stephanie Anagnostopoulos; Silveira, Carina Folgearini; Rösing, Cassiano Kuchenbecker

2017-02-17

This study aimed to analyze the impact of chewing gum on halitosis parameters. Three databases were searched with the following focused question: 'Can chewing gum additionally reduce halitosis parameters, such as organoleptic scores and volatile sulfur compounds (VSC), when compared to a control treatment'? Controlled clinical trials presenting at least two halitosis measurements (organoleptic scores and/or VSC) were included. Ten studies were included, and different active ingredients were used. One study was performed using a chewing gum without any active ingredient. Chewing gum containing probiotic bacterium was shown to significantly reduce the organoleptic scores. Chewing gums containing zinc acetate and magnolia bark extract as well as allylisothiocyanate (AITC) with zinc lactate significantly reduced the levels of VSC in comparison to a placebo chewing gum. Furthermore, a sodium bicarbonate-containing chewing gum significantly reduced the VSC levels in comparison to rinsing with water. Furthermore, eucalyptus-extract chewing gum showed significant reductions in both organoleptic scores and VSC when compared with a control chewing gum. Chewing gum containing sucrose was able to reduce the VSC levels, in comparison to xylitol and zinc citrate chewing gum, but only for 5 min. It was concluded that chewing gums containing probiotics Lactobaccilus, zinc acetate and magnolia bark extract, eucalyptus-extract, and AITC with zinc lactate may be suitable for halitosis management. However, the low number of included studies and the high heterogeneity among the selected studies may limit the clinical applications of these findings.

VizieR Online Data Catalog: OGLE UBVI phot. in Baade's Window (Paczynski+, 1999)

NASA Astrophysics Data System (ADS)

Paczynski, B.; Udalski, A.; Szymanski, M.; Kubiak, M.; Pietrzynski, G.; Soszynski, I.; Wozniak, P.; Zebrun, K.

2000-01-01

We present UBVI photometry for 8530 stars in Baade's Window obtained during the OGLE-II microlensing survey. Among these are over one thousand red clump giants. 1391 of them have photometry with errors smaller than 0.04, 0.06, 0.12, and 0.20 mag in the I, V, B, and U-band, respectively. We constructed a map of interstellar reddening. The corrected colors of the red clump giants: (U-B)0, (B-V)0, and (V-I)0 are very well correlated, indicating that a single parameter determines the observed spread of their values, reaching almost 2mag in the (U-B)0. It seems most likely that heavy element content is the dominant parameter, but it is possible that another parameter: the age (or mass) of a star moves it along the same trajectory in the color-color diagram as the metallicity. The current ambiguity can be resolved with spectral analysis, and our catalog may be useful as a finding list of red clump giants. We point out that these K giants are more suitable for a fair determination of the distribution of metallicity than brighter M giants. We also present a compilation of UBVI data for 308 red clump giants near the Sun, for which Hipparcos parallaxes are more accurate than 10%. Spectral analysis of their metallicity may provide information about the local metallicity distribution as well as the extent to which mass (age) of these stars affects their colors. (3 data files).

Influence of macromolecular precipitants on phase behavior of monoclonal antibodies.

PubMed

Rakel, Natalie; Galm, Lara; Bauer, Katharina Christin; Hubbuch, Juergen

2015-01-01

For the successful application of protein crystallization as a downstream step, a profound knowledge of protein phase behavior in solutions is needed. Therefore, a systematic screening was conducted to analyze the influence of macromolecular precipitants in the form of polyethylene glycol (PEG). First, the influence of molecular weight and concentration of PEG at different pH-values were investigated and analyzed in three-dimensional (3-D) phase diagrams to find appropriate conditions in terms of a fast kinetic and crystal size for downstream processing. In comparison to the use of salts as precipitant, PEG was more suitable to obtain compact 3-D crystals over a broad range of conditions, whereby the molecular weight of PEG is, besides the pH-value, the most important parameter. Second, osmotic second virial coefficients as parameters for protein interactions are experimentally determined with static light scattering to gain a deep insight view in the phase behavior on a molecular basis. The PEG-protein solutions were analyzed as a pseudo-one-compartment system. As the precipitant is also a macromolecule, the new approach of analyzing cross-interactions between the protein and the macromolecule PEG in form of the osmotic second cross-virial coefficient (B23 ) was applied. Both parameters help to understand the protein phase behavior. However, a predictive description of protein phase behavior for systems consisting of monoclonal antibodies and PEG as precipitant is not possible, as kinetic phenomena and concentration dependencies were not taken into account. © 2014 American Institute of Chemical Engineers.

Design of asymptotic estimators: an approach based on neural networks and nonlinear programming.

PubMed

Alessandri, Angelo; Cervellera, Cristiano; Sanguineti, Marcello

2007-01-01

A methodology to design state estimators for a class of nonlinear continuous-time dynamic systems that is based on neural networks and nonlinear programming is proposed. The estimator has the structure of a Luenberger observer with a linear gain and a parameterized (in general, nonlinear) function, whose argument is an innovation term representing the difference between the current measurement and its prediction. The problem of the estimator design consists in finding the values of the gain and of the parameters that guarantee the asymptotic stability of the estimation error. Toward this end, if a neural network is used to take on this function, the parameters (i.e., the neural weights) are chosen, together with the gain, by constraining the derivative of a quadratic Lyapunov function for the estimation error to be negative definite on a given compact set. It is proved that it is sufficient to impose the negative definiteness of such a derivative only on a suitably dense grid of sampling points. The gain is determined by solving a Lyapunov equation. The neural weights are searched for via nonlinear programming by minimizing a cost penalizing grid-point constraints that are not satisfied. Techniques based on low-discrepancy sequences are applied to deal with a small number of sampling points, and, hence, to reduce the computational burden required to optimize the parameters. Numerical results are reported and comparisons with those obtained by the extended Kalman filter are made.

Interpretations of the Patient-Therapist Relationship in Brief Dynamic Psychotherapy

PubMed Central

AMLO, SVEIN; ENGELSTAD, VIBEKE; FOSSUM, ARNE; SØRLIE, TORE; HØGLEND, PER; HEYERDAHL, OSCAR; SØRBYE, ØYSTEIN

1993-01-01

The authors examined whether persistent analysis of the patient-therapist relationship in brief dynamic psychotherapy favorably affects long-term dynamic change in patients initially deemed suitable for such treatment. As in common practice, 22 highly suitable patients were given a high number of transference interpretations per session. A comparison group of 21 patients with lower suitability received the same treatment, but transference interpretations were withheld. Statistical adjustment for the deliberate nonequivalence in pretreatment suitability indicated a significant negative effect of high numbers of transference interpretations on long-term dynamic changes. Demographic variables, DSM-III diagnoses, additional treatment, life events in the follow-up years, or therapist effects did not explain or obscure the findings. PMID:22700155

Advances in global sensitivity analyses of demographic-based species distribution models to address uncertainties in dynamic landscapes.

PubMed

Naujokaitis-Lewis, Ilona; Curtis, Janelle M R

2016-01-01

Developing a rigorous understanding of multiple global threats to species persistence requires the use of integrated modeling methods that capture processes which influence species distributions. Species distribution models (SDMs) coupled with population dynamics models can incorporate relationships between changing environments and demographics and are increasingly used to quantify relative extinction risks associated with climate and land-use changes. Despite their appeal, uncertainties associated with complex models can undermine their usefulness for advancing predictive ecology and informing conservation management decisions. We developed a computationally-efficient and freely available tool (GRIP 2.0) that implements and automates a global sensitivity analysis of coupled SDM-population dynamics models for comparing the relative influence of demographic parameters and habitat attributes on predicted extinction risk. Advances over previous global sensitivity analyses include the ability to vary habitat suitability across gradients, as well as habitat amount and configuration of spatially-explicit suitability maps of real and simulated landscapes. Using GRIP 2.0, we carried out a multi-model global sensitivity analysis of a coupled SDM-population dynamics model of whitebark pine (Pinus albicaulis) in Mount Rainier National Park as a case study and quantified the relative influence of input parameters and their interactions on model predictions. Our results differed from the one-at-time analyses used in the original study, and we found that the most influential parameters included the total amount of suitable habitat within the landscape, survival rates, and effects of a prevalent disease, white pine blister rust. Strong interactions between habitat amount and survival rates of older trees suggests the importance of habitat in mediating the negative influences of white pine blister rust. Our results underscore the importance of considering habitat attributes along with demographic parameters in sensitivity routines. GRIP 2.0 is an important decision-support tool that can be used to prioritize research, identify habitat-based thresholds and management intervention points to improve probability of species persistence, and evaluate trade-offs of alternative management options.

Advances in global sensitivity analyses of demographic-based species distribution models to address uncertainties in dynamic landscapes

PubMed Central

Curtis, Janelle M.R.

2016-01-01

Developing a rigorous understanding of multiple global threats to species persistence requires the use of integrated modeling methods that capture processes which influence species distributions. Species distribution models (SDMs) coupled with population dynamics models can incorporate relationships between changing environments and demographics and are increasingly used to quantify relative extinction risks associated with climate and land-use changes. Despite their appeal, uncertainties associated with complex models can undermine their usefulness for advancing predictive ecology and informing conservation management decisions. We developed a computationally-efficient and freely available tool (GRIP 2.0) that implements and automates a global sensitivity analysis of coupled SDM-population dynamics models for comparing the relative influence of demographic parameters and habitat attributes on predicted extinction risk. Advances over previous global sensitivity analyses include the ability to vary habitat suitability across gradients, as well as habitat amount and configuration of spatially-explicit suitability maps of real and simulated landscapes. Using GRIP 2.0, we carried out a multi-model global sensitivity analysis of a coupled SDM-population dynamics model of whitebark pine (Pinus albicaulis) in Mount Rainier National Park as a case study and quantified the relative influence of input parameters and their interactions on model predictions. Our results differed from the one-at-time analyses used in the original study, and we found that the most influential parameters included the total amount of suitable habitat within the landscape, survival rates, and effects of a prevalent disease, white pine blister rust. Strong interactions between habitat amount and survival rates of older trees suggests the importance of habitat in mediating the negative influences of white pine blister rust. Our results underscore the importance of considering habitat attributes along with demographic parameters in sensitivity routines. GRIP 2.0 is an important decision-support tool that can be used to prioritize research, identify habitat-based thresholds and management intervention points to improve probability of species persistence, and evaluate trade-offs of alternative management options. PMID:27547529

Probabilistic accounting of uncertainty in forecasts of species distributions under climate change

USGS Publications Warehouse

Wenger, Seth J.; Som, Nicholas A.; Dauwalter, Daniel C.; Isaak, Daniel J.; Neville, Helen M.; Luce, Charles H.; Dunham, Jason B.; Young, Michael K.; Fausch, Kurt D.; Rieman, Bruce E.

2013-01-01

Forecasts of species distributions under future climates are inherently uncertain, but there have been few attempts to describe this uncertainty comprehensively in a probabilistic manner. We developed a Monte Carlo approach that accounts for uncertainty within generalized linear regression models (parameter uncertainty and residual error), uncertainty among competing models (model uncertainty), and uncertainty in future climate conditions (climate uncertainty) to produce site-specific frequency distributions of occurrence probabilities across a species’ range. We illustrated the method by forecasting suitable habitat for bull trout (Salvelinus confluentus) in the Interior Columbia River Basin, USA, under recent and projected 2040s and 2080s climate conditions. The 95% interval of total suitable habitat under recent conditions was estimated at 30.1–42.5 thousand km; this was predicted to decline to 0.5–7.9 thousand km by the 2080s. Projections for the 2080s showed that the great majority of stream segments would be unsuitable with high certainty, regardless of the climate data set or bull trout model employed. The largest contributor to uncertainty in total suitable habitat was climate uncertainty, followed by parameter uncertainty and model uncertainty. Our approach makes it possible to calculate a full distribution of possible outcomes for a species, and permits ready graphical display of uncertainty for individual locations and of total habitat.

A Study on Land Suitability for Rice Cultivation in Khordha District of Odisha (India) Using Remote Sensing and GIS

NASA Astrophysics Data System (ADS)

Rath, Sudhansu S.; Panda, Jagabandhu; Annadurai, R.; Nanda, Sachikanta

2018-05-01

With the global population on the rise, it is important to address the increasing demand for food. According to FAO (Food and Agriculture Organization, United Nations), by 2050, the developing countries must double their food production to meet the growing demand. Proper land utilization can be one of the solutions for this problem. In view of this, the current study focussed on land suitability analysis for Khordha district of Odisha (India) for rice crop. This study estimated that the amount of land suitable for rice cropping was 195,731 ha against the currently cultivated land of 122,183.38 ha. Therefore, there was a possibility of more amount of land that could be available for rice cultivation in Khordha district than the currently cultivated area. In order to perform this exercise, the land use and land cover data from IRS (Indian remote sensing satellite), soil nutrient parameters like pH values and nitrogen, potassium, phosphorous and organic carbon contents were considered. In addition, the climatic parameters such as near surface temperature, rainfall and number of rainy days were taken into account. The unused land identified in Khordha district in this study might be utilized for cultivating rice crop in this region.

A Study on Land Suitability for Rice Cultivation in Khordha District of Odisha (India) Using Remote Sensing and GIS

NASA Astrophysics Data System (ADS)

Rath, Sudhansu S.; Panda, Jagabandhu; Annadurai, R.; Nanda, Sachikanta

2018-02-01

With the global population on the rise, it is important to address the increasing demand for food. According to FAO (Food and Agriculture Organization, United Nations), by 2050, the developing countries must double their food production to meet the growing demand. Proper land utilization can be one of the solutions for this problem. In view of this, the current study focussed on land suitability analysis for Khordha district of Odisha (India) for rice crop. This study estimated that the amount of land suitable for rice cropping was 195,731 ha against the currently cultivated land of 122,183.38 ha. Therefore, there was a possibility of more amount of land that could be available for rice cultivation in Khordha district than the currently cultivated area. In order to perform this exercise, the land use and land cover data from IRS (Indian remote sensing satellite), soil nutrient parameters like pH values and nitrogen, potassium, phosphorous and organic carbon contents were considered. In addition, the climatic parameters such as near surface temperature, rainfall and number of rainy days were taken into account. The unused land identified in Khordha district in this study might be utilized for cultivating rice crop in this region.

Stochastic mixed-mode oscillations in a three-species predator-prey model

NASA Astrophysics Data System (ADS)

Sadhu, Susmita; Kuehn, Christian

2018-03-01

The effect of demographic stochasticity, in the form of Gaussian white noise, in a predator-prey model with one fast and two slow variables is studied. We derive the stochastic differential equations (SDEs) from a discrete model. For suitable parameter values, the deterministic drift part of the model admits a folded node singularity and exhibits a singular Hopf bifurcation. We focus on the parameter regime near the Hopf bifurcation, where small amplitude oscillations exist as stable dynamics in the absence of noise. In this regime, the stochastic model admits noise-driven mixed-mode oscillations (MMOs), which capture the intermediate dynamics between two cycles of population outbreaks. We perform numerical simulations to calculate the distribution of the random number of small oscillations between successive spikes for varying noise intensities and distance to the Hopf bifurcation. We also study the effect of noise on a suitable Poincaré map. Finally, we prove that the stochastic model can be transformed into a normal form near the folded node, which can be linked to recent results on the interplay between deterministic and stochastic small amplitude oscillations. The normal form can also be used to study the parameter influence on the noise level near folded singularities.

WHOLE-BODY VIBRATION EXERCISE IMPROVES FUNCTIONAL PARAMETERS IN PATIENTS WITH OSTEOGENESIS IMPERFECTA: A SYSTEMATIC REVIEW WITH A SUITABLE APPROACH

PubMed Central

Sá-Caputo, Danubia C; Dionello, Carla da F; Frederico, Éric Heleno F. F; Paineiras-Domingos, Laisa L; Sousa-Gonçalves, Cintia Renata; Morel, Danielle S; Moreira-Marconi, Eloá; Unger, Marianne; Bernardo-Filho, Mario

2017-01-01

Background: Patients with osteogenesis imperfecta (OI) have abnormal bone modelling and resorption. The bone tissue adaptation and responsivity to dynamic and mechanical loading may be of therapeutic use under controlled circumstances. Improvements due to the wholebody vibration (WBV) exercises have been reported in strength, motion, gait, balance, posture and bone density in several osteopenic individuals, as in post-menopausal women or children with disabling conditions, as patients with OI. The aim of this investigation was to systematically analyse the current available literature to determine the effect of WBV exercises on functional parameters of OI patients. Materials and methods: Three reviewers independently accessed bibliographical databases. Searches were performed in the PubMed, Scopus, Science Direct and PEDro databases using keywords related to possible interventions (including WBV) used in the management of patients with osteogenesis imperfecta. Results: Three eligible studies were identified by searches in the analysed databases. Conclusion: It was concluded that WBV exercises could be an important option in the management of OI patients improving the mobility and functional parameters. However, further studies are necessary for establishing suitable protocols for these patients. PMID:28480432

On three dimensional object recognition and pose-determination: An abstraction based approach. Ph.D. Thesis - Michigan Univ. Final Report

NASA Technical Reports Server (NTRS)

Quek, Kok How Francis

1990-01-01

A method of computing reliable Gaussian and mean curvature sign-map descriptors from the polynomial approximation of surfaces was demonstrated. Such descriptors which are invariant under perspective variation are suitable for hypothesis generation. A means for determining the pose of constructed geometric forms whose algebraic surface descriptors are nonlinear in terms of their orienting parameters was developed. This was done by means of linear functions which are capable of approximating nonlinear forms and determining their parameters. It was shown that biquadratic surfaces are suitable companion linear forms for cylindrical approximation and parameter estimation. The estimates provided the initial parametric approximations necessary for a nonlinear regression stage to fine tune the estimates by fitting the actual nonlinear form to the data. A hypothesis-based split-merge algorithm for extraction and pose determination of cylinders and planes which merge smoothly into other surfaces was developed. It was shown that all split-merge algorithms are hypothesis-based. A finite-state algorithm for the extraction of the boundaries of run-length regions was developed. The computation takes advantage of the run list topology and boundary direction constraints implicit in the run-length encoding.

Prediction of ground water quality index to assess suitability for drinking purposes using fuzzy rule-based approach

NASA Astrophysics Data System (ADS)

Gorai, A. K.; Hasni, S. A.; Iqbal, Jawed

2016-11-01

Groundwater is the most important natural resource for drinking water to many people around the world, especially in rural areas where the supply of treated water is not available. Drinking water resources cannot be optimally used and sustained unless the quality of water is properly assessed. To this end, an attempt has been made to develop a suitable methodology for the assessment of drinking water quality on the basis of 11 physico-chemical parameters. The present study aims to select the fuzzy aggregation approach for estimation of the water quality index of a sample to check the suitability for drinking purposes. Based on expert's opinion and author's judgement, 11 water quality (pollutant) variables (Alkalinity, Dissolved Solids (DS), Hardness, pH, Ca, Mg, Fe, Fluoride, As, Sulphate, Nitrates) are selected for the quality assessment. The output results of proposed methodology are compared with the output obtained from widely used deterministic method (weighted arithmetic mean aggregation) for the suitability of the developed methodology.

ESTIMATING THE DISTRIBUTION OF HARVESTED ...

EPA Pesticide Factsheets

Habitat suitability models are used to forecast how environmental change may affect the abundance or distribution of species of interest. The development of habitat suitability models may be used to estimate the vulnerability of this valued ecosystem good to natural or anthropogenic stressors. Using natural history information, rule-based habitat suitability models were constructed in a GIS for two recreationally harvested bivalve species (cockles Clinocardium nuttallii; softshells Mya arenaria) common to NE Pacific estuaries (N. California to British Columbia). Tolerance limits of each species were evaluated with respect to four parameters that are easy to sample: salinity, depth, sediment grain size, and the presence of bioturbating burrowing shrimp and were determined through literature review. Spatially-explicit habitat maps were produced for Yaquina and Tillamook estuaries (Oregon) using environmental data from multiple studies ranging from 1960 to 2012. Suitability of a given location was ranked on a scale of 1-4 (lowest to highest) depending on the number of variables that fell within a bivalve’s tolerance limits. The models were tested by comparison of the distribution of each suitability class to the observed distribution of bivalves reported in benthic community studies (1996-2012). Results showed that the areas of highest habitat suitability (value=4) within our model contained the greatest proportion of bivalve observations and highest popula

Predicting potential global distributions of two Miscanthus grasses: implications for horticulture, biofuel production, and biological invasions.

PubMed

Hager, Heather A; Sinasac, Sarah E; Gedalof, Ze'ev; Newman, Jonathan A

2014-01-01

In many regions, large proportions of the naturalized and invasive non-native floras were originally introduced deliberately by humans. Pest risk assessments are now used in many jurisdictions to regulate the importation of species and usually include an estimation of the potential distribution in the import area. Two species of Asian grass (Miscanthus sacchariflorus and M. sinensis) that were originally introduced to North America as ornamental plants have since escaped cultivation. These species and their hybrid offspring are now receiving attention for large-scale production as biofuel crops in North America and elsewhere. We evaluated their potential global climate suitability for cultivation and potential invasion using the niche model CLIMEX and evaluated the models' sensitivity to the parameter values. We then compared the sensitivity of projections of future climatically suitable area under two climate models and two emissions scenarios. The models indicate that the species have been introduced to most of the potential global climatically suitable areas in the northern but not the southern hemisphere. The more narrowly distributed species (M. sacchariflorus) is more sensitive to changes in model parameters, which could have implications for modelling species of conservation concern. Climate projections indicate likely contractions in potential range in the south, but expansions in the north, particularly in introduced areas where biomass production trials are under way. Climate sensitivity analysis shows that projections differ more between the selected climate change models than between the selected emissions scenarios. Local-scale assessments are required to overlay suitable habitat with climate projections to estimate areas of cultivation potential and invasion risk.

Evaluation of stratospheric age of air from CF4, C2F6, C3F8, CHF3, HFC-125, HFC-227ea and SF6; implications for the calculations of halocarbon lifetimes, fractional release factors and ozone depletion potentials

NASA Astrophysics Data System (ADS)

Leedham Elvidge, Emma; Bönisch, Harald; Brenninkmeijer, Carl A. M.; Engel, Andreas; Fraser, Paul J.; Gallacher, Eileen; Langenfelds, Ray; Mühle, Jens; Oram, David E.; Ray, Eric A.; Ridley, Anna R.; Röckmann, Thomas; Sturges, William T.; Weiss, Ray F.; Laube, Johannes C.

2018-03-01

In a changing climate, potential stratospheric circulation changes require long-term monitoring. Stratospheric trace gas measurements are often used as a proxy for stratospheric circulation changes via the mean age of air values derived from them. In this study, we investigated five potential age of air tracers - the perfluorocarbons CF4, C2F6 and C3F8 and the hydrofluorocarbons CHF3 (HFC-23) and HFC-125 - and compare them to the traditional tracer SF6 and a (relatively) shorter-lived species, HFC-227ea. A detailed uncertainty analysis was performed on mean ages derived from these new tracers to allow us to confidently compare their efficacy as age tracers to the existing tracer, SF6. Our results showed that uncertainties associated with the mean age derived from these new age tracers are similar to those derived from SF6, suggesting that these alternative compounds are suitable in this respect for use as age tracers. Independent verification of the suitability of these age tracers is provided by a comparison between samples analysed at the University of East Anglia and the Scripps Institution of Oceanography. All five tracers give younger mean ages than SF6, a discrepancy that increases with increasing mean age. Our findings qualitatively support recent work that suggests that the stratospheric lifetime of SF6 is significantly less than the previous estimate of 3200 years. The impact of these younger mean ages on three policy-relevant parameters - stratospheric lifetimes, fractional release factors (FRFs) and ozone depletion potentials - is investigated in combination with a recently improved methodology to calculate FRFs. Updates to previous estimations for these parameters are provided.

Extreme weather events in southern Germany - Climatological risk and development of a large-scale identification procedure

NASA Astrophysics Data System (ADS)

Matthies, A.; Leckebusch, G. C.; Rohlfing, G.; Ulbrich, U.

2009-04-01

Extreme weather events such as thunderstorms, hail and heavy rain or snowfall can pose a threat to human life and to considerable tangible assets. Yet there is a lack of knowledge about present day climatological risk and its economic effects, and its changes due to rising greenhouse gas concentrations. Therefore, parts of economy particularly sensitve to extreme weather events such as insurance companies and airports require regional risk-analyses, early warning and prediction systems to cope with such events. Such an attempt is made for southern Germany, in close cooperation with stakeholders. Comparing ERA40 and station data with impact records of Munich Re and Munich Airport, the 90th percentile was found to be a suitable threshold for extreme impact relevant precipitation events. Different methods for the classification of causing synoptic situations have been tested on ERA40 reanalyses. An objective scheme for the classification of Lamb's circulation weather types (CWT's) has proved to be most suitable for correct classification of the large-scale flow conditions. Certain CWT's have been turned out to be prone to heavy precipitation or on the other side to have a very low risk of such events. Other large-scale parameters are tested in connection with CWT's to find out a combination that has the highest skill to identify extreme precipitation events in climate model data (ECHAM5 and CLM). For example vorticity advection in 700 hPa shows good results, but assumes knowledge of regional orographic particularities. Therefore ongoing work is focused on additional testing of parameters that indicate deviations of a basic state of the atmosphere like the Eady Growth Rate or the newly developed Dynamic State Index. Evaluation results will be used to estimate the skill of the regional climate model CLM concerning the simulation of frequency and intensity of the extreme weather events. Data of the A1B scenario (2000-2050) will be examined for a possible climate change signal.

Computational methods for the control of distributed parameter systems

NASA Technical Reports Server (NTRS)

Burns, J. A.; Cliff, E. M.; Powers, R. K.

1985-01-01

It is shown that care must be taken to ensure that finite dimensional approximations of distributed parameter systems preserve important system properties (i.e., controllability, observability, stabilizability, detectability, etc.). It is noted that, if the particular scheme used to construct the finite dimensional model does not take into account these system properties, the model may not be suitable for control design and analysis. These ideas are illustrated by a simple example, i.e., a cable-spring-mass system.

[Identification of Systemic Contaminations with Legionella Spec. in Drinking Water Plumbing Systems: Sampling Strategies and Corresponding Parameters].

PubMed

Völker, S; Schreiber, C; Müller, H; Zacharias, N; Kistemann, T

2017-05-01

After the amendment of the Drinking Water Ordinance in 2011, the requirements for the hygienic-microbiological monitoring of drinking water installations have increased significantly. In the BMBF-funded project "Biofilm Management" (2010-2014), we examined the extent to which established sampling strategies in practice can uncover drinking water plumbing systems systemically colonized with Legionella. Moreover, we investigated additional parameters that might be suitable for detecting systemic contaminations. We subjected the drinking water plumbing systems of 8 buildings with known microbial contamination (Legionella) to an intensive hygienic-microbiological sampling with high spatial and temporal resolution. A total of 626 drinking hot water samples were analyzed with classical culture-based methods. In addition, comprehensive hygienic observations were conducted in each building and qualitative interviews with operators and users were applied. Collected tap-specific parameters were quantitatively analyzed by means of sensitivity and accuracy calculations. The systemic presence of Legionella in drinking water plumbing systems has a high spatial and temporal variability. Established sampling strategies were only partially suitable to detect long-term Legionella contaminations in practice. In particular, the sampling of hot water at the calorifier and circulation re-entrance showed little significance in terms of contamination events. To detect the systemic presence of Legionella,the parameters stagnation (qualitatively assessed) and temperature (compliance with the 5K-rule) showed better results. © Georg Thieme Verlag KG Stuttgart · New York.

Differential evolution algorithm-based kernel parameter selection for Fukunaga-Koontz Transform subspaces construction

NASA Astrophysics Data System (ADS)

Binol, Hamidullah; Bal, Abdullah; Cukur, Huseyin

2015-10-01

The performance of the kernel based techniques depends on the selection of kernel parameters. That's why; suitable parameter selection is an important problem for many kernel based techniques. This article presents a novel technique to learn the kernel parameters in kernel Fukunaga-Koontz Transform based (KFKT) classifier. The proposed approach determines the appropriate values of kernel parameters through optimizing an objective function constructed based on discrimination ability of KFKT. For this purpose we have utilized differential evolution algorithm (DEA). The new technique overcomes some disadvantages such as high time consumption existing in the traditional cross-validation method, and it can be utilized in any type of data. The experiments for target detection applications on the hyperspectral images verify the effectiveness of the proposed method.

Chaos minimization in DC-DC boost converter using circuit parameter optimization

NASA Astrophysics Data System (ADS)

Sudhakar, N.; Natarajan, Rajasekar; Gourav, Kumar; Padmavathi, P.

2017-11-01

DC-DC converters are prone to several types of nonlinear phenomena including bifurcation, quasi periodicity, intermittency and chaos. These undesirable effects must be controlled for periodic operation of the converter to ensure the stability. In this paper an effective solution to control of chaos in solar fed DC-DC boost converter is proposed. Controlling of chaos is significantly achieved using optimal circuit parameters obtained through Bacterial Foraging Optimization Algorithm. The optimization renders the suitable parameters in minimum computational time. The obtained results are compared with the operation of traditional boost converter. Further the obtained results with BFA optimized parameter ensures the operations of the converter are within the controllable region. To elaborate the study of bifurcation analysis with optimized and unoptimized parameters are also presented.

Evaluation of moving-coil loudspeaker and passive radiator parameters using normal-incidence sound transmission measurements: theoretical developments.

PubMed

Leishman, Timothy W; Anderson, Brian E

2013-07-01

The parameters of moving-coil loudspeaker drivers are typically determined using direct electrical excitation and measurement. However, as electro-mechano-acoustical devices, their parameters should also follow from suitable mechanical or acoustical evaluations. This paper presents the theory of an acoustical method of excitation and measurement using normal-incidence sound transmission through a baffled driver as a plane-wave tube partition. Analogous circuits enable key parameters to be extracted from measurement results in terms of open and closed-circuit driver conditions. Associated tools are presented that facilitate adjacent field decompositions and derivations of sound transmission coefficients (in terms of driver parameters) directly from the circuits. The paper also clarifies the impact of nonanechoic receiving tube terminations and the specific benefits of downstream field decompositions.

Nudged-elastic band method with two climbing images: Finding transition states in complex energy landscapes

DOE PAGES

Zarkevich, Nikolai A.; Johnson, Duane D.

2015-01-09

The nudged-elastic band (NEB) method is modified with concomitant two climbing images (C2-NEB) to find a transition state (TS) in complex energy landscapes, such as those with a serpentine minimal energy path (MEP). If a single climbing image (C1-NEB) successfully finds the TS, then C2-NEB finds it too. Improved stability of C2-NEB makes it suitable for more complex cases, where C1-NEB misses the TS because the MEP and NEB directions near the saddle point are different. Generally, C2-NEB not only finds the TS, but guarantees, by construction, that the climbing images approach it from the opposite sides along the MEP.more » In addition, C2-NEB provides an accuracy estimate from the three images: the highest-energy one and its climbing neighbors. C2-NEB is suitable for fixed-cell NEB and the generalized solid-state NEB.« less

Effects of process parameters on properties of porous foams formed by laser-assisted melting of steel powder (AISI P21)/foaming agent (ZrH2) mixture

NASA Astrophysics Data System (ADS)

Seo, Ja-Ye; Lee, Ki-Yong; Shim, Do-Sik

2018-01-01

This paper describes the fabrication of lightweight metal foams using the directed energy deposition (DED) method. DED is a highly flexible additive manufacturing process wherein a metal powder mixed with a foaming agent is sprayed while a high-power laser is used to simultaneously melt the powder mixture into layered metal foams. In this study, a mixture of a carbon steel material (P21 powder) and a widely used foaming agent, ZrH2, is used to fabricate metal foams. The effects of various process parameters, such as the laser power, powder feed rate, powder gas flow rate, and scanning speed, on the deposition characteristics (porosity, pore size, and pore distribution) are investigated. The synthesized metal foams exhibit porosities of 10% or lower, and a mean pore area of 7 × 105 μm2. It is observed that the degree of foaming increases in proportion to the laser power to a certain extent. The results also show that the powder feed rate has the most pronounced effect on the porosity of the metal foams, while the powder gas flow rate is the most suitable parameter for adjusting the size of the pores formed within the foams. Further, the scanning speed, which determines the amounts of energy and powder delivered, has a significant effect on the height of the deposits as well as on the properties of the foams. Thus, during the DED process for fabricating metal foams, the pore size and distribution and hence the foam porosity can be tailored by varying the individual process parameters. These findings should be useful as reference data for the design of processes for fabricating porous metallic materials that meet the specific requirements for specialized parts.

Frame covariant nonminimal multifield inflation

NASA Astrophysics Data System (ADS)

Karamitsos, Sotirios; Pilaftsis, Apostolos

2018-02-01

We introduce a frame-covariant formalism for inflation of scalar-curvature theories by adopting a differential geometric approach which treats the scalar fields as coordinates living on a field-space manifold. This ensures that our description of inflation is both conformally and reparameterization covariant. Our formulation gives rise to extensions of the usual Hubble and potential slow-roll parameters to generalized fully frame-covariant forms, which allow us to provide manifestly frame-invariant predictions for cosmological observables, such as the tensor-to-scalar ratio r, the spectral indices nR and nT, their runnings αR and αT, the non-Gaussianity parameter fNL, and the isocurvature fraction βiso. We examine the role of the field space curvature in the generation and transfer of isocurvature modes, and we investigate the effect of boundary conditions for the scalar fields at the end of inflation on the observable inflationary quantities. We explore the stability of the trajectories with respect to the boundary conditions by using a suitable sensitivity parameter. To illustrate our approach, we first analyze a simple minimal two-field scenario before studying a more realistic nonminimal model inspired by Higgs inflation. We find that isocurvature effects are greatly enhanced in the latter scenario and must be taken into account for certain values in the parameter space such that the model is properly normalized to the observed scalar power spectrum PR. Finally, we outline how our frame-covariant approach may be extended beyond the tree-level approximation through the Vilkovisky-De Witt formalism, which we generalize to take into account conformal transformations, thereby leading to a fully frame-invariant effective action at the one-loop level.

Complex free-energy landscapes in biaxial nematic liquid crystals and the role of repulsive interactions: A Wang-Landau study

NASA Astrophysics Data System (ADS)

Kamala Latha, B.; Murthy, K. P. N.; Sastry, V. S. S.

2017-09-01

General quadratic Hamiltonian models, describing the interaction between liquid-crystal molecules (typically with D2 h symmetry), take into account couplings between their uniaxial and biaxial tensors. While the attractive contributions arising from interactions between similar tensors of the participating molecules provide for eventual condensation of the respective orders at suitably low temperatures, the role of cross coupling between unlike tensors is not fully appreciated. Our recent study with an advanced Monte Carlo technique (entropic sampling) showed clearly the increasing relevance of this cross term in determining the phase diagram (contravening in some regions of model parameter space), the predictions of mean-field theory, and standard Monte Carlo simulation results. In this context, we investigated the phase diagrams and the nature of the phases therein on two trajectories in the parameter space: one is a line in the interior region of biaxial stability believed to be representative of the real systems, and the second is the extensively investigated parabolic path resulting from the London dispersion approximation. In both cases, we find the destabilizing effect of increased cross-coupling interactions, which invariably result in the formation of local biaxial organizations inhomogeneously distributed. This manifests as a small, but unmistakable, contribution of biaxial order in the uniaxial phase. The free-energy profiles computed in the present study as a function of the two dominant order parameters indicate complex landscapes. On the one hand, these profiles account for the unusual thermal behavior of the biaxial order parameter under significant destabilizing influence from the cross terms. On the other, they also allude to the possibility that in real systems, these complexities might indeed be inhibiting the formation of a low-temperature biaxial order itself—perhaps reflecting the difficulties in their ready realization in the laboratory.

Parameters influencing the course of passive drug loading into lipid nanoemulsions.

PubMed

Göke, Katrin; Bunjes, Heike

2018-05-01

Passive drug loading can be used to effectively identify suitable colloidal lipid carrier systems for poorly water-soluble drugs. This method comprises incubation of preformed carrier systems with drug powder and subsequent determination of the resulting drug load of the carrier particles. Until now, the passive loading mechanism is unknown, which complicates reliable routine use. In this work, the influence of drug characteristics on the course of passive loading was investigated systematically varying drug surface area and drug solubility. Fenofibrate and flufenamic acid were used as model drugs; the carrier system was a trimyristin nanodispersion. Loading progress was analyzed by UV spectroscopy or by a novel method based on differential scanning calorimetry. While increasing drug solubility by micelle incorporation did not speed up passive loading, a large drug surface area and high water solubility were key parameters for fast loading. Since both factors are crucial in drug dissolution as described by the Noyes-Whitney equation, these findings point to a dissolution-diffusion-based passive loading mechanism. Accordingly, passive loading also occurred when drug and carrier particles were separated by a dialysis membrane. Knowledge of the loading mechanism allows optimizing the conditions for future passive loading studies and assessing the limitations of the method. Copyright © 2017 Elsevier B.V. All rights reserved.

The Healing Effect of Nettle Extract on Second Degree Burn Wounds

PubMed Central

Akbari, Hosein; Fatemi, Mohammad Javad; Iranpour, Maryam; Khodarahmi, Ali; Baghaee, Mehrdad; Pedram, Mir Sepehr; Saleh, Sahar; Araghi, Shirin

2015-01-01

BACKGROUND Numerous studies were carried out to develop more sophisticated dressings to expedite healing processes and diminish the bacterial burden in burn wounds. This study assessed the healing effect of nettle extract on second degree burns wound in rats in comparison with silver sulfadiazine and vaseline. METHODS Forty rats were randomly assigned to four equal groups. A deep second-degree burn was created on the back of each rat using a standard burning procedure. The burns were dressed daily with nettle extract in group 1, silver sulfadiazine in group 2, vaseline in group 3 and without any medication in group 4 as control group. The response to treatment was assessed by digital photography during the treatment until day 42. Histological scoring was undertaken for scar tissue samples on days 10 and 42. RESULTS A statistically significant difference was observed in group 1 compared with other groups regarding 4 scoring parameters after 10 days. A statistically significant difference was seen for fibrosis parameter after 42 days. In terms of difference of wound surface area, maximal healing was noticed at the same time in nettle group and minimal repair in the control group. CONCLUSION Our findings showed maximal rate of healing in the nettle group. So it may be a suitable substitute for silver sulfadiazine and vaseline when available. PMID:25606473

Analysis of Cryogenic Cycle with Process Modeling Tool: Aspen HYSYS

NASA Astrophysics Data System (ADS)

Joshi, D. M.; Patel, H. K.

2015-10-01

Cryogenic engineering deals with the development and improvement of low temperature techniques, processes and equipment. A process simulator such as Aspen HYSYS, for the design, analysis, and optimization of process plants, has features that accommodate the special requirements and therefore can be used to simulate most cryogenic liquefaction and refrigeration processes. Liquefaction is the process of cooling or refrigerating a gas to a temperature below its critical temperature so that liquid can be formed at some suitable pressure which is below the critical pressure. Cryogenic processes require special attention in terms of the integration of various components like heat exchangers, Joule-Thompson Valve, Turbo expander and Compressor. Here, Aspen HYSYS, a process modeling tool, is used to understand the behavior of the complete plant. This paper presents the analysis of an air liquefaction plant based on the Linde cryogenic cycle, performed using the Aspen HYSYS process modeling tool. It covers the technique used to find the optimum values for getting the maximum liquefaction of the plant considering different constraints of other parameters. The analysis result so obtained gives clear idea in deciding various parameter values before implementation of the actual plant in the field. It also gives an idea about the productivity and profitability of the given configuration plant which leads to the design of an efficient productive plant.

Static flexural properties of hedgehog spines conditioned in coupled temperature and relative humidity environments.

PubMed

Kennedy, Emily B; Hsiung, Bor-Kai; Swift, Nathan B; Tan, Kwek-Tze

2017-11-01

Hedgehogs are agile climbers, scaling trees and plants to heights exceeding 10m while foraging insects. Hedgehog spines (a.k.a. quills) provide fall protection by absorbing shock and could offer insights for the design of lightweight, material-efficient, impact-resistant structures. There has been some study of flexural properties of hedgehog spines, but an understanding of how this keratinous biological material is affected by various temperature and relative humidity treatments, or how spine color (multicolored vs. white) affects mechanics, is lacking. To bridge this gap in the literature, we use three-point bending to analyze the effect of temperature, humidity, spine color, and their interactions on flexural strength and modulus of hedgehog spines. We also compare specific strength and stiffness of hedgehog spines to conventional engineered materials. We find hedgehog spine flexural properties can be finely tuned by modifying environmental conditioning parameters. White spines tend to be stronger and stiffer than multicolored spines. Finally, for most temperature and humidity conditioning parameters, hedgehog spines are ounce for ounce stronger than 201 stainless steel rods of the same diameter but as pliable as styrene rods with a slightly larger diameter. This unique combination of strength and elasticity makes hedgehog spines exemplary shock absorbers, and a suitable reference model for biomimicry. Copyright © 2017 Elsevier Ltd. All rights reserved.

Aerodynamic roughness: A simple and alternative metric to detect the seasonality of canopy structure using flux-tower data

NASA Astrophysics Data System (ADS)

Chu, H.; Baldocchi, D. D.

2017-12-01

FLUXNET - the global network of eddy covariance tower sites provides valuable datasets of the direct and in situ measurements of fluxes and ancillary variables that are used across different disciplines and applications. Aerodynamic roughness (i.e., roughness length, zero plane displacement height) are one of the potential parameters that can be derived from flux-tower data and are crucial for the applications of land surface models and flux footprint models. As aerodynamic roughness are tightly associated with canopy structures (e.g., canopy height, leaf area), such parameters could potentially serve as an alternative metric for detecting the change of canopy structure (e.g., change of leaf areas in deciduous ecosystems). This study proposes a simple approach for deriving aerodynamic roughness from flux-tower data, and tests their suitability and robustness in detecting the seasonality of canopy structure. We run tests across a broad range of deciduous forests, and compare the seasonality derived from aerodynamic roughness (i.e., starting and ending dates of leaf-on period and peak-foliage period) against those obtained from remote sensing or in situ leaf area measurements. Our findings show aerodynamic roughness generally captures the timing of changes of leaf areas in deciduous forests. Yet, caution needs to be exercised while interpreting the absolute values of the roughness estimates.

Solvent systems with n-hexane and/or cyclohexane in countercurrent chromatography--Physico-chemical parameters and their impact on the separation of alkyl hydroxybenzoates.

PubMed

Englert, Michael; Vetter, Walter

2014-05-16

Countercurrent chromatography (CCC) is an efficient preparative separation technique based on the liquid-liquid distribution of compounds between two phases of a biphasic liquid system. The crucial parameter for the successful application is the selection of the solvent system. Especially for nonpolar analytes the selection options are limited. On the search for a suitable solvent system for the separation of an alkyl hydroxybenzoate homologous series, we noted that the substitution of cyclohexane with n-hexane was accompanied with unexpected differences in partitioning coefficients of the individual analytes. In this study, we investigated the influence of the subsequent substitution of n-hexane with cyclohexane in the n-hexane/cyclohexane/tert-butylmethylether/methanol/water solvent system family. Exact phase compositions and polarity, viscosity and density differences were determined to characterize the different mixtures containing n-hexane and/or cyclohexane. Findings were confirmed by performing CCC separations with different mixtures, which led to baseline resolution for positional isomers when increasing the amount of cyclohexane while the resolution between two pairs of structural isomers decreased. With the new methodology described, structurally similar compounds could be resolved by choosing a certain ratio of n-hexane to cyclohexane. Copyright © 2014 Elsevier B.V. All rights reserved.

Application of Remote Sensing and GIS in Landfill (waste Disposal) Site Selection and Environmental Impacts Assessment around Mysore City, Karnataka, India

NASA Astrophysics Data System (ADS)

Basavarajappa, T. H.

2012-07-01

Landfill site selection is a complex process involving geological, hydrological, environmental and technical parameters as well as government regulations. As such, it requires the processing of a good amount of geospatial data. Landfill site selection techniques have been analyzed for identifying their suitability. Application of Geographic Information System (GIS) is suitable to find best locations for such installations which use multiple criteria analysis. The use of Artificial intelligence methods, such as expert systems, can also be very helpful in solid waste planning and management. The waste disposal and its pollution around major cities in Karnataka are important problems affecting the environment. The Mysore is one of the major cities in Karnataka. The landfill site selection is the best way to control of pollution from any region. The main aim is to develop geographic information system to study the Landuse/ Landcover, natural drainage system, water bodies, and extents of villages around Mysore city, transportation, topography, geomorphology, lithology, structures, vegetation and forest information for landfill site selection. GIS combines spatial data (maps, aerial photographs, and satellite images) with quantitative, qualitative, and descriptive information database, which can support a wide range of spatial queries. For the Site Selection of an industrial waste and normal daily urban waste of a city town or a village, combining GIS with Analytical Hierarchy Process (AHP) will be more appropriate. This method is innovative because it establishes general indices to quantify overall environmental impact as well as individual indices for specific environmental components (i.e. surface water, groundwater, atmosphere, soil and human health). Since this method requires processing large quantities of spatial data. To automate the processes of establishing composite evaluation criteria, performing multiple criteria analysis and carrying out spatial clustering a suitable methodology was developed. The feasibility of site selection in the study area based on different criteria was used to obtain the layered data by integrating Remote Sensing and GIS. This methodology is suitable for all practical applications in other cities, also.

Modeling habitat distribution from organism occurrences and environmental data: Case study using anemonefishes and their sea anemone hosts

USGS Publications Warehouse

Guinotte, J.M.; Bartley, J.D.; Iqbal, A.; Fautin, D.G.; Buddemeier, R.W.

2006-01-01

We demonstrate the KGSMapper (Kansas Geological Survey Mapper), a straightforward, web-based biogeographic tool that uses environmental conditions of places where members of a taxon are known to occur to find other places containing suitable habitat for them. Using occurrence data for anemonefishes or their host sea anemones, and data for environmental parameters, we generated maps of suitable habitat for the organisms. The fact that the fishes are obligate symbionts of the anemones allowed us to validate the KGSMapper output: we were able to compare the inferred occurrence of the organism to that of the actual occurrence of its symbiont. Characterizing suitable habitat for these organisms in the Indo-West Pacific, the region where they naturally occur, can be used to guide conservation efforts, field work, etc.; defining suitable habitat for them in the Atlantic and eastern Pacific is relevant to identifying areas vulnerable to biological invasions. We advocate distinguishing between these 2 sorts of model output, terming the former maps of realized habitat and the latter maps of potential habitat. Creation of a niche model requires adding biotic data to the environmental data used for habitat maps: we included data on fish occurrences to infer anemone distribution and vice versa. Altering the selection of environmental variables allowed us to investigate which variables may exert the most influence on organism distribution. Adding variables does not necessarily improve precision of the model output. KGSMapper output distinguishes areas that fall within 1 standard deviation (SD) of the mean environmental variable values for places where members of the taxon occur, within 2 SD, and within the entire range of values; eliminating outliers or data known to be imprecise or inaccurate improved output precision mainly in the 2 SD range and beyond. Thus, KGSMapper is robust in the face of questionable data, offering the user a way to recognize and clean such data. It also functions well with sparse datasets. These features make it useful for biogeographic meta-analyses with the diverse, distributed datasets that are typical for marine organisms lacking direct commercial value. ?? Inter-Research 2006.

Selection of a Prototype Engine Monitor for Coast Guard Main Diesel Propulsion

DOT National Transportation Integrated Search

1979-04-01

A diesel engine monitor system has been synthesized from several parameter measurement subsystems which employ measurement techniques suitable for use on the main propulsion engines in U.S. Coast Cutters. The primary functions of the system are to mo...

Existence of Optimal Controls for Compressible Viscous Flow

NASA Astrophysics Data System (ADS)

Doboszczak, Stefan; Mohan, Manil T.; Sritharan, Sivaguru S.

2018-03-01

We formulate a control problem for a distributed parameter system where the state is governed by the compressible Navier-Stokes equations. Introducing a suitable cost functional, the existence of an optimal control is established within the framework of strong solutions in three dimensions.

Suitability Analysis For Scuba Diving To Develop Marine Tourism At Saebus Island, East Java, Indonesia

NASA Astrophysics Data System (ADS)

Wijaya, Putranto; Putra, Tri; Hidayat, Fatra; Levraeni, Chandra; Rizmaadi, Mada; Ambariyanto, Ambariyanto

2018-02-01

Indonesian government currently has policies to improve the performance of the tourism sector, including marine tourism. One of the attractions of marine tourism is the coral ecosystem especially through scuba diving activities. The purpose of this study was to determine the suitability of the coral ecosystem on Saebus Island, East Java, to find appropriate locations for scuba diving activities. Purposive samplings were done around the island to determine four stations which will be assessed through suitability analysis. Tourism Suitability Index was used to assess all stations for scuba diving activities. The result showed that all four stations were categorized as very suitable with the score: 85%, 85%, 85% and 83%, respectively. Several aspects that need to be improved and anticipated for diving at all stations are coral coverage and water current. These results suggest that there are several spots around Saebus Island that are suitable for diving site, and can be promoted as marine tourism destination.

Printed health information materials: evaluation of readability and suitability.

PubMed

Shieh, Carol; Hosei, Barbara

2008-01-01

This study examined readability and suitability of printed health information materials colleted from multiple sources. In phase I, nursing students used Simple Measure of Gobbledygook (SMOG; McLaughlin, 1969) to assess the readability of 21 materials collected from the community. In phases II and III, nursing students and registered nurses used SMOG and the Suitability Assessment of Materials (SAM; Doak, Doak, & Root, 1996) to evaluate 15 prenatal materials from a Healthy Start program. SMOG assigns a reading grade level based on the number of words with 3 or more syllables. SAM has 22 items in 6 evaluation areas: content, literacy demand, graphics, layout and typography, learning stimulation and motivation, and cultural appropriateness. Major findings included that 53% to 86% of the printed materials had a reading level at or higher than 9th grade; materials lacked summary, interaction, and modeled behaviors, and registered nurses rated more materials as not suitable and fewer as superior for suitability qualities than students. Improving printed materials to have lower reading levels and better suitability qualities are indicated.

Fabrics for aeronautic construction

NASA Technical Reports Server (NTRS)

Walen, E D

1918-01-01

The Bureau of Standards undertook the investigation of airplane fabrics with the view of finding suitable substitutes for the linen fabrics, and it was decided that the fibers to be considered were cotton, ramie, silk, and hemp. Of these, the cotton fiber was the logical one to be given primary consideration. Report presents the suitability, tensibility and stretching properties of cotton fabric obtained by laboratory tests.

75 FR 24892 - Certain Coated Paper Suitable for High-Quality Print Graphics Using Sheet-Fed Presses From the...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-06

... Industry Support Calculation Coated Paper Suitable For High-Quality Print Graphics Using Sheet-Fed Presses... employs an industry-wide test to determine whether, under section 773(c)(1)(B), available information in... sections 771(33)(E) and (F) of the Act. In addition, we find that Shandong Sun Paper Industry Joint Stock...

Evaluating the Suitability of Mathematical Thinking Problems for Senior High-School Students by Including Mathematical Sense Making and Global Planning

ERIC Educational Resources Information Center

van Velzen, Joke H.

2016-01-01

The mathematics curriculum often provides for relatively few mathematical thinking problems or non-routine problems that focus on a deepening of understanding mathematical concepts and the problem-solving process. To develop such problems, methods are required to evaluate their suitability. The purpose of this preliminary study was to find such an…

Integrating Spatial Multi Criteria Decision Making (SMCDM) with Geographic Information Systems (GIS) for delineation of the most suitable areas for aquifer storage and recovery (ASR)

NASA Astrophysics Data System (ADS)

Ahani Amineh, Zainab Banoo; Hashemian, Seyyed Jamal Al-Din; Magholi, Alireza

2017-08-01

Hamoon-Jazmoorian plain is located in southeast of Iran. Overexploitation of groundwater in this plain has led to water level decline and caused serious problems such as land subsidence, aquifer destruction and water quality degradation. The increasing population and agricultural development along with drought and climate change, have further increased the pressure on water resources in this region over the last years. In order to overcome such crisis, introduction of surface water into an aquifer at particular locations can be a suitable solution. A wide variety of methods have been developed to recharge groundwater, one of which is aquifer storage and recovery (ASR). One of the fundamental principles of making such systems is delineation of suitable areas based on scientific and natural facts in order to achieve relevant objectives. To that end, the Multi Criteria Decision Making (MCDM) in conjunction with the Geographic Information Systems (GIS) was applied in this study. More specifically, nine main parameters including depth of runoff as the considered source of water, morphology of the earth surface features such as geology, geomorphology, land use and land cover, drainage and aquifer characteristics along with quality of water in the aquifer were considered as the main layers in GIS. The runoff water available for artificial recharge in the basin was estimated through Soil Conservation Service (SCS) curve number method. The weighted curve number for each watershed was derived through spatial intersection of land use and hydrological soil group layers. Other thematic layers were extracted from satellite images, topographical map, and other collateral data sources, then weighed according to their influence in locating process. The Analytical Hierarchy Process (AHP) method was then used to calculate weights of individual parameters. The normalized weighted layers were then overlaid to build up the recharge potential map. The results revealed that 34% of the total area is suitable and very suitable for groundwater recharge.

Remote sensing and GIS-based site suitability analysis for tourism development in Gili Indah, East Lombok

NASA Astrophysics Data System (ADS)

Agnes, Debrina; Nandatama, Akbar; Isdyantoko, Bagus Andi; Aditya Nugraha, Fajri; Ghivarry, Giusti; Putra Aghni, Perwira; ChandraWijaya, Renaldi; Widayani, Prima

2016-11-01

Gili Indah area, located in Jerowaru, East Lombok Regency is a region that classified as farm area in spatial layout planning map of West Nusa Tenggara province. Gili Indah area has a potential as a new tourism attraction within its gilis (local term for ‘small island’). Assessment should be done to prevent ecological disturbance and infringement towards spatial layout planning map caused by incorrect landuse. Land suitability assessment will be done using remote sensing approach whilst satellite imagery being used to get information about ocean ecology and land physical spatial distribution that will be the parameter of tourism land suitability, such as water clarity, ocean current, type of beaches’ substrate, and beach typology. Field observation then will evaluate the accuracy of data extraction also as a material to do reinterpretation. The actual physical condition will be pictured after the spatial model built with GIS by tiered qualitative analysis approach. The result of assessment and mapping of tourism land suitability is that parts of Gili Indah Area (GiliMaringkik, Greater GiliBembeq, and Small GiliBembeq) are suitable for archipelago tourism while the others is not.

Integration of Genetic Algorithms and Fuzzy Logic for Urban Growth Modeling

NASA Astrophysics Data System (ADS)

Foroutan, E.; Delavar, M. R.; Araabi, B. N.

2012-07-01

Urban growth phenomenon as a spatio-temporal continuous process is subject to spatial uncertainty. This inherent uncertainty cannot be fully addressed by the conventional methods based on the Boolean algebra. Fuzzy logic can be employed to overcome this limitation. Fuzzy logic preserves the continuity of dynamic urban growth spatially by choosing fuzzy membership functions, fuzzy rules and the fuzzification-defuzzification process. Fuzzy membership functions and fuzzy rule sets as the heart of fuzzy logic are rather subjective and dependent on the expert. However, due to lack of a definite method for determining the membership function parameters, certain optimization is needed to tune the parameters and improve the performance of the model. This paper integrates genetic algorithms and fuzzy logic as a genetic fuzzy system (GFS) for modeling dynamic urban growth. The proposed approach is applied for modeling urban growth in Tehran Metropolitan Area in Iran. Historical land use/cover data of Tehran Metropolitan Area extracted from the 1988 and 1999 Landsat ETM+ images are employed in order to simulate the urban growth. The extracted land use classes of the year 1988 include urban areas, street, vegetation areas, slope and elevation used as urban growth physical driving forces. Relative Operating Characteristic (ROC) curve as an fitness function has been used to evaluate the performance of the GFS algorithm. The optimum membership function parameter is applied for generating a suitability map for the urban growth. Comparing the suitability map and real land use map of 1999 gives the threshold value for the best suitability map which can simulate the land use map of 1999. The simulation outcomes in terms of kappa of 89.13% and overall map accuracy of 95.58% demonstrated the efficiency and reliability of the proposed model.

Physicochemical characterization of allergens: quantity, identity, purity, aggregation and conformation.

PubMed

Koppelman, Stef J; Luykx, Dion M A M; de Jongh, Harmen H J; Veldhuizen, Willem Jan

2009-01-01

Allergens and allergoids can be characterized by means of physicochemical methods, resulting in a description of the protein on different structural levels. Several techniques are available and their suitability depends on the composition of the particular sample. Current European legislation on allergen products demands characterization of final products in particular focusing on identity, degree of modification (for allergoids) and stability of the composition. Structural parameters of allergens may be used to investigate the stability of an allergen product. The challenge is to identify and optimize techniques that allow determination of protein structure in the context of a formulated pharmaceutical product. As the majority of the products currently marketed are formulated with aluminium hydroxide or aluminium phosphate as a depot, most of the methods and techniques used for protein characterization in solution are not applicable. An additional hurdle is that allergen products are based on natural extracts, comprising a mixture of proteins, both allergens and non-allergens, sometimes in the presence of other uncharacterized components from the raw material. This paper describes which methods are suitable for the different stages of allergen product manufacturing, and how these relate to the current regulatory requirements. Some of the techniques are demonstrated using a model allergen, cod parvalbumin, and a chemically modified form thereof. We conclude that a variety of methods is available for characterization of proteins in solution, and that a limited number of techniques appear to be suitable for modified allergens (allergoids). Adaptation of existing methods, e.g. mass spectroscopy and infrared spectroscopy may be helpful to obtain protein parameters of allergens in a formulated allergen product. By choosing a combination of techniques, including those additional to physicochemical approaches, relevant parameters of allergens in formulated allergen products can be assessed in order to achieve a well-characterized pharmaceutical product.

Harmonising Reference Intervals for Three Calculated Parameters used in Clinical Chemistry.

PubMed

Hughes, David; Koerbin, Gus; Potter, Julia M; Glasgow, Nicholas; West, Nic; Abhayaratna, Walter P; Cavanaugh, Juleen; Armbruster, David; Hickman, Peter E

2016-08-01

For more than a decade there has been a global effort to harmonise all phases of the testing process, with particular emphasis on the most frequently utilised measurands. In addition, it is recognised that calculated parameters derived from these measurands should also be a target for harmonisation. Using data from the Aussie Normals study we report reference intervals for three calculated parameters: serum osmolality, serum anion gap and albumin-adjusted serum calcium. The Aussie Normals study was an a priori study that analysed samples from 1856 healthy volunteers. The nine analytes used for the calculations in this study were measured on Abbott Architect analysers. The data demonstrated normal (Gaussian) distributions for the albumin-adjusted serum calcium, the anion gap (using potassium in the calculation) and the calculated serum osmolality (using both the Bhagat et al. and Smithline and Gardner formulae). To assess the suitability of these reference intervals for use as harmonised reference intervals, we reviewed data from the Royal College of Pathologists of Australasia/Australasian Association of Clinical Biochemists (RCPA/AACB) bias survey. We conclude that the reference intervals for the calculated serum osmolality (using the Smithline and Gardner formulae) may be suitable for use as a common reference interval. Although a common reference interval for albumin-adjusted serum calcium may be possible, further investigations (including a greater range of albumin concentrations) are needed. This is due to the bias between the Bromocresol Green (BCG) and Bromocresol Purple (BCP) methods at lower serum albumin concentrations. Problems with the measurement of Total CO 2 in the bias survey meant that we could not use the data for assessing the suitability of a common reference interval for the anion gap. Further study is required.

Deep-sea benthic megafaunal habitat suitability modelling: A global-scale maximum entropy model for xenophyophores

NASA Astrophysics Data System (ADS)

Ashford, Oliver S.; Davies, Andrew J.; Jones, Daniel O. B.

2014-12-01

Xenophyophores are a group of exclusively deep-sea agglutinating rhizarian protozoans, at least some of which are foraminifera. They are an important constituent of the deep-sea megafauna that are sometimes found in sufficient abundance to act as a significant source of habitat structure for meiofaunal and macrofaunal organisms. This study utilised maximum entropy modelling (Maxent) and a high-resolution environmental database to explore the environmental factors controlling the presence of Xenophyophorea and two frequently sampled xenophyophore species that are taxonomically stable: Syringammina fragilissima and Stannophyllum zonarium. These factors were also used to predict the global distribution of each taxon. Areas of high habitat suitability for xenophyophores were highlighted throughout the world's oceans, including in a large number of areas yet to be suitably sampled, but the Northeast and Southeast Atlantic Ocean, Gulf of Mexico and Caribbean Sea, the Red Sea and deep-water regions of the Malay Archipelago represented particular hotspots. The two species investigated showed more specific habitat requirements when compared to the model encompassing all xenophyophore records, perhaps in part due to the smaller number and relatively more clustered nature of the presence records available for modelling at present. The environmental variables depth, oxygen parameters, nitrate concentration, carbon-chemistry parameters and temperature were of greatest importance in determining xenophyophore distributions, but, somewhat surprisingly, hydrodynamic parameters were consistently shown to have low importance, possibly due to the paucity of well-resolved global hydrodynamic datasets. The results of this study (and others of a similar type) have the potential to guide further sample collection, environmental policy, and spatial planning of marine protected areas and industrial activities that impact the seafloor, particularly those that overlap with aggregations of these conspicuously large single-celled eukaryotes.

Interpretations of the patient-therapist relationship in brief dynamic psychotherapy : effects on long-term mode-specific changes.

PubMed

Amlo, S; Engelstad, V; Fossum, A; Sørlie, T; Høglend, P; Heyerdahl, O; Sørbye, O

1993-01-01

The authors examined whether persistent analysis of the patient-therapist relationship in brief dynamic psychotherapy favorably affects long-term dynamic change in patients initially deemed suitable for such treatment. As in common practice, 22 highly suitable patients were given a high number of transference interpretations per session. A comparison group of 21 patients with lower suitability received the same treatment, but transference interpretations were withheld. Statistical adjustment for the deliberate nonequivalence in pretreatment suitability indicated a significant negative effect of high numbers of transference interpretations on long-term dynamic changes. Demographic variables, DSM-III diagnoses, additional treatment, life events in the follow-up years, or therapist effects did not explain or obscure the findings.

Summary Findings from the AVT-191 Project to Assess Sensitivity Analysis and Uncertainty Quantification Methods for Military Vehicle Design

NASA Technical Reports Server (NTRS)

Benek, John A.; Luckring, James M.

2017-01-01

A NATO symposium held in Greece in 2008 identified many promising sensitivity analysis and uncertainty quantification technologies, but the maturity and suitability of these methods for realistic applications was not clear. The NATO Science and Technology Organization, Task Group AVT-191 was established to evaluate the maturity and suitability of various sensitivity analysis and uncertainty quantification methods for application to realistic vehicle development problems. The program ran from 2011 to 2015, and the work was organized into four discipline-centric teams: external aerodynamics, internal aerodynamics, aeroelasticity, and hydrodynamics. This paper summarizes findings and lessons learned from the task group.

A Comparison of Two Path Planners for Planetary Rovers

NASA Technical Reports Server (NTRS)

Tarokh, M.; Shiller, Z.; Hayati, S.

1999-01-01

The paper presents two path planners suitable for planetary rovers. The first is based on fuzzy description of the terrain, and genetic algorithm to find a traversable path in a rugged terrain. The second planner uses a global optimization method with a cost function that is the path distance divided by the velocity limit obtained from the consideration of the rover static and dynamic stability. A description of both methods is provided, and the results of paths produced are given which show the effectiveness of the path planners in finding near optimal paths. The features of the methods and their suitability and application for rover path planning are compared

Analysis of several methods and inertial sensors locations to assess gait parameters in able-bodied subjects.

PubMed

Ben Mansour, Khaireddine; Rezzoug, Nasser; Gorce, Philippe

2015-10-01

The purpose of this paper was to determine which types of inertial sensors and which advocated locations should be used for reliable and accurate gait event detection and temporal parameter assessment in normal adults. In addition, we aimed to remove the ambiguity found in the literature of the definition of the initial contact (IC) from the lumbar accelerometer. Acceleration and angular velocity data was gathered from the lumbar region and the distal edge of each shank. This data was evaluated in comparison to an instrumented treadmill and an optoelectronic system during five treadmill speed sessions. The lumbar accelerometer showed that the peak of the anteroposterior component was the most accurate for IC detection. Similarly, the valley that followed the peak of the vertical component was the most precise for terminal contact (TC) detection. Results based on ANOVA and Tukey tests showed that the set of inertial methods was suitable for temporal gait assessment and gait event detection in able-bodied subjects. For gait event detection, an exception was found with the shank accelerometer. The tool was suitable for temporal parameters assessment, despite the high root mean square error on the detection of IC (RMSEIC) and TC (RMSETC). The shank gyroscope was found to be as accurate as the kinematic method since the statistical tests revealed no significant difference between the two techniques for the RMSE off all gait events and temporal parameters. The lumbar and shank accelerometers were the most accurate alternative to the shank gyroscope for gait event detection and temporal parameters assessment, respectively. Copyright © 2015. Published by Elsevier B.V.

A real-time multi-channel monitoring system for stem cell culture process.

PubMed

Xicai Yue; Drakakis, E M; Lim, M; Radomska, A; Hua Ye; Mantalaris, A; Panoskaltsis, N; Cass, A

2008-06-01

A novel, up to 128 channels, multi-parametric physiological measurement system suitable for monitoring hematopoietic stem cell culture processes and cell cultures in general is presented in this paper. The system aims to measure in real-time the most important physical and chemical culture parameters of hematopoietic stem cells, including physicochemical parameters, nutrients, and metabolites, in a long-term culture process. The overarching scope of this research effort is to control and optimize the whole bioprocess by means of the acquisition of real-time quantitative physiological information from the culture. The system is designed in a modular manner. Each hardware module can operate as an independent gain programmable, level shift adjustable, 16 channel data acquisition system specific to a sensor type. Up to eight such data acquisition modules can be combined and connected to the host PC to realize the whole system hardware. The control of data acquisition and the subsequent management of data is performed by the system's software which is coded in LabVIEW. Preliminary experimental results presented here show that the system not only has the ability to interface to various types of sensors allowing the monitoring of different types of culture parameters. Moreover, it can capture dynamic variations of culture parameters by means of real-time multi-channel measurements thus providing additional information on both temporal and spatial profiles of these parameters within a bioreactor. The system is by no means constrained in the hematopoietic stem cell culture field only. It is suitable for cell growth monitoring applications in general.

PURY: a database of geometric restraints of hetero compounds for refinement in complexes with macromolecular structures.

PubMed

Andrejasic, Miha; Praaenikar, Jure; Turk, Dusan

2008-11-01

The number and variety of macromolecular structures in complex with ;hetero' ligands is growing. The need for rapid delivery of correct geometric parameters for their refinement, which is often crucial for understanding the biological relevance of the structure, is growing correspondingly. The current standard for describing protein structures is the Engh-Huber parameter set. It is an expert data set resulting from selection and analysis of the crystal structures gathered in the Cambridge Structural Database (CSD). Clearly, such a manual approach cannot be applied to the vast and ever-growing number of chemical compounds. Therefore, a database, named PURY, of geometric parameters of chemical compounds has been developed, together with a server that accesses it. PURY is a compilation of the whole CSD. It contains lists of atom classes and bonds connecting them, as well as angle, chirality, planarity and conformation parameters. The current compilation is based on CSD 5.28 and contains 1978 atom classes and 32,702 bonding, 237,068 angle, 201,860 dihedral and 64,193 improper geometric restraints. Analysis has confirmed that the restraints from the PURY database are suitable for use in macromolecular crystal structure refinement and should be of value to the crystallographic community. The database can be accessed through the web server http://pury.ijs.si/, which creates topology and parameter files from deposited coordinates in suitable forms for the refinement programs MAIN, CNS and REFMAC. In the near future, the server will move to the CSD website http://pury.ccdc.cam.ac.uk/.

Determination of Stable-Unstable Regions of the Slosh Motion in Spinning Space Vehicle by Perturbation Technique

NASA Astrophysics Data System (ADS)

Kang, Jai Young

2005-12-01

The objectives of this study are to perform extensive analysis on internal mass motion for a wider parameter space and to provide suitable design criteria for a broader applicability for the class of spinning space vehicles. In order to examine the stability criterion determined by a perturbation method, some numerical simulations will be performed and compared at various parameter points. In this paper, Ince-Strutt diagram for determination of stable-unstable regions of the internal mass motion of the spinning thrusting space vehicle in terms of design parameters will be obtained by an analytical method. Also, phase trajectories of the motion will be obtained for various parameter values and their characteristics are compared.

Matrix elements of N-particle explicitly correlated Gaussian basis functions with complex exponential parameters

NASA Astrophysics Data System (ADS)

Bubin, Sergiy; Adamowicz, Ludwik

2006-06-01

In this work we present analytical expressions for Hamiltonian matrix elements with spherically symmetric, explicitly correlated Gaussian basis functions with complex exponential parameters for an arbitrary number of particles. The expressions are derived using the formalism of matrix differential calculus. In addition, we present expressions for the energy gradient that includes derivatives of the Hamiltonian integrals with respect to the exponential parameters. The gradient is used in the variational optimization of the parameters. All the expressions are presented in the matrix form suitable for both numerical implementation and theoretical analysis. The energy and gradient formulas have been programed and used to calculate ground and excited states of the He atom using an approach that does not involve the Born-Oppenheimer approximation.

Matrix elements of N-particle explicitly correlated Gaussian basis functions with complex exponential parameters.

PubMed

Bubin, Sergiy; Adamowicz, Ludwik

2006-06-14

In this work we present analytical expressions for Hamiltonian matrix elements with spherically symmetric, explicitly correlated Gaussian basis functions with complex exponential parameters for an arbitrary number of particles. The expressions are derived using the formalism of matrix differential calculus. In addition, we present expressions for the energy gradient that includes derivatives of the Hamiltonian integrals with respect to the exponential parameters. The gradient is used in the variational optimization of the parameters. All the expressions are presented in the matrix form suitable for both numerical implementation and theoretical analysis. The energy and gradient formulas have been programmed and used to calculate ground and excited states of the He atom using an approach that does not involve the Born-Oppenheimer approximation.

An analytical-numerical approach for parameter determination of a five-parameter single-diode model of photovoltaic cells and modules

NASA Astrophysics Data System (ADS)

Hejri, Mohammad; Mokhtari, Hossein; Azizian, Mohammad Reza; Söder, Lennart

2016-04-01

Parameter extraction of the five-parameter single-diode model of solar cells and modules from experimental data is a challenging problem. These parameters are evaluated from a set of nonlinear equations that cannot be solved analytically. On the other hand, a numerical solution of such equations needs a suitable initial guess to converge to a solution. This paper presents a new set of approximate analytical solutions for the parameters of a five-parameter single-diode model of photovoltaic (PV) cells and modules. The proposed solutions provide a good initial point which guarantees numerical analysis convergence. The proposed technique needs only a few data from the PV current-voltage characteristics, i.e. open circuit voltage Voc, short circuit current Isc and maximum power point current and voltage Im; Vm making it a fast and low cost parameter determination technique. The accuracy of the presented theoretical I-V curves is verified by experimental data.

Heat and mass transfer of Williamson nanofluid flow yield by an inclined Lorentz force over a nonlinear stretching sheet

NASA Astrophysics Data System (ADS)

Khan, Mair; Malik, M. Y.; Salahuddin, T.; Hussian, Arif.

2018-03-01

The present analysis is devoted to explore the computational solution of the problem addressing the variable viscosity and inclined Lorentz force effects on Williamson nanofluid over a stretching sheet. Variable viscosity is assumed to vary as a linear function of temperature. The basic mathematical modelled problem i.e. system of PDE's is converted nonlinear into ODE's via applying suitable transformations. Computational solutions of the problem is also achieved via efficient numerical technique shooting. Characteristics of controlling parameters i.e. stretching index, inclined angle, Hartmann number, Weissenberg number, variable viscosity parameter, mixed convention parameter, Brownian motion parameter, Prandtl number, Lewis number, thermophoresis parameter and chemical reactive species on concentration, temperature and velocity gradient. Additionally, friction factor coefficient, Nusselt number and Sherwood number are describe with the help of graphics as well as tables verses flow controlling parameters.

A Survey of Xenon Ion Sputter Yield Data and Fits Relevant to Electric Propulsion Spacecraft Integration

NASA Technical Reports Server (NTRS)

Yim, John T.

2017-01-01

A survey of low energy xenon ion impact sputter yields was conducted to provide a more coherent baseline set of sputter yield data and accompanying fits for electric propulsion integration. Data uncertainties are discussed and different available curve fit formulas are assessed for their general suitability. A Bayesian parameter fitting approach is used with a Markov chain Monte Carlo method to provide estimates for the fitting parameters while characterizing the uncertainties for the resulting yield curves.

Plasma-enhanced chemical vapor deposition of multiwalled carbon nanofibers.

PubMed

Matthews, Kristopher; Cruden, Brett A; Chen, Bin; Meyyappan, M; Delzeit, Lance

2002-10-01

Plasma-enhanced chemical vapor deposition is used to grow vertically aligned multiwalled carbon nanofibers (MWNFs). The graphite basal planes in these nanofibers are not parallel as in nanotubes; instead they exhibit a small angle resembling a stacked cone arrangement. A parametric study with varying process parameters such as growth temperature, feedstock composition, and substrate power has been conducted, and these parameters are found to influence the growth rate, diameter, and morphology. The well-aligned MWNFs are suitable for fabricating electrode systems in sensor and device development.

Plasma-enhanced chemical vapor deposition of multiwalled carbon nanofibers

NASA Technical Reports Server (NTRS)

Matthews, Kristopher; Cruden, Brett A.; Chen, Bin; Meyyappan, M.; Delzeit, Lance

2002-01-01

Plasma-enhanced chemical vapor deposition is used to grow vertically aligned multiwalled carbon nanofibers (MWNFs). The graphite basal planes in these nanofibers are not parallel as in nanotubes; instead they exhibit a small angle resembling a stacked cone arrangement. A parametric study with varying process parameters such as growth temperature, feedstock composition, and substrate power has been conducted, and these parameters are found to influence the growth rate, diameter, and morphology. The well-aligned MWNFs are suitable for fabricating electrode systems in sensor and device development.

Monolithic microwave integrated circuits: Interconnections and packaging considerations

NASA Astrophysics Data System (ADS)

Bhasin, K. B.; Downey, A. N.; Ponchak, G. E.; Romanofsky, R. R.; Anzic, G.; Connolly, D. J.

Monolithic microwave integrated circuits (MMIC's) above 18 GHz were developed because of important potential system benefits in cost reliability, reproducibility, and control of circuit parameters. The importance of interconnection and packaging techniques that do not compromise these MMIC virtues is emphasized. Currently available microwave transmission media are evaluated to determine their suitability for MMIC interconnections. An antipodal finline type of microstrip waveguide transition's performance is presented. Packaging requirements for MMIC's are discussed for thermal, mechanical, and electrical parameters for optimum desired performance.

Evaluation of Material Nonlinearities Using Rectangular Pulse Trains for Excitation

NASA Astrophysics Data System (ADS)

Chaziachmetovas, Andrius; Svilainis, Linas; Kybartas, Darius; Aleksandrovas, Arturas; Liaukonis, Dobilas

Aim of the presented investigation was to evaluate the suitability of the rectangular pulse trains for nonlinear material parameters study. It was assumed that if duty cycle of the excitation is 50% then second harmonic is significantly reduced. Excitation signal frequency was fixed to the A/D sampling frequency and signal carefully gated to reduce the signal leak into neighbouring frequency bins. Sine wave correlation was used to extract the harmonics content. Results of nonlinear parameters measurement for several materials are given as performance comparison.

Monolithic microwave integrated circuits: Interconnections and packaging considerations

NASA Technical Reports Server (NTRS)

Bhasin, K. B.; Downey, A. N.; Ponchak, G. E.; Romanofsky, R. R.; Anzic, G.; Connolly, D. J.

1984-01-01

Monolithic microwave integrated circuits (MMIC's) above 18 GHz were developed because of important potential system benefits in cost reliability, reproducibility, and control of circuit parameters. The importance of interconnection and packaging techniques that do not compromise these MMIC virtues is emphasized. Currently available microwave transmission media are evaluated to determine their suitability for MMIC interconnections. An antipodal finline type of microstrip waveguide transition's performance is presented. Packaging requirements for MMIC's are discussed for thermal, mechanical, and electrical parameters for optimum desired performance.

Thermal insulation materials for inside applications: Hygric and thermal properties

NASA Astrophysics Data System (ADS)

Jerman, Miloš; Černý, Robert

2017-11-01

Two thermal insulation materials suitable for the application on the interior side of historical building envelopes, namely calcium silicate and polyurethane-based foam are studied. Moisture diffusivity and thermal conductivity of both materials, as fundamental moisture and heat transport parameters, are measured in a dependence on moisture content. The measured data will be used as input parameters in computer simulation studies which will provide moisture and temperature fields necessary for an appropriate design of interior thermal insulation systems.

Data Compression With Application to Geo-Location

DTIC Science & Technology

2010-08-01

wireless sensor network requires the estimation of time-difference-of-arrival (TDOA) parameters using data collected by a set of spatially separated sensors. Compressing the data that is shared among the sensors can provide tremendous savings in terms of the energy and transmission latency. Traditional MSE and perceptual based data compression schemes fail to accurately capture the effects of compression on the TDOA estimation task; therefore, it is necessary to investigate compression algorithms suitable for TDOA parameter estimation. This thesis explores the

A Case Study on the Application of a Structured Experimental Method for Optimal Parameter Design of a Complex Control System

NASA Technical Reports Server (NTRS)

Torres-Pomales, Wilfredo

2015-01-01

This report documents a case study on the application of Reliability Engineering techniques to achieve an optimal balance between performance and robustness by tuning the functional parameters of a complex non-linear control system. For complex systems with intricate and non-linear patterns of interaction between system components, analytical derivation of a mathematical model of system performance and robustness in terms of functional parameters may not be feasible or cost-effective. The demonstrated approach is simple, structured, effective, repeatable, and cost and time efficient. This general approach is suitable for a wide range of systems.

Development of a laboratory prototype water quality monitoring system suitable for use in zero gravity

NASA Technical Reports Server (NTRS)

Misselhorn, J. E.; Witz, S.; Hartung, W. H.

1973-01-01

The development of a laboratory prototype water quality monitoring system for use in the evaluation of candidate water recovery systems and for study of techniques for measuring potability parameters is reported. Sensing techniques for monitoring of the most desirable parameters are reviewed in terms of their sensitivities and complexities, and their recommendations for sensing techniques are presented. Rationale for selection of those parameters to be monitored (pH, specific conductivity, Cr(+6), I2, total carbon, and bacteria) in a next generation water monitor is presented along with an estimate of flight system specifications. A master water monitor development schedule is included.

Traumatic Coagulopathy: Where are the Good Experimental Models?

DTIC Science & Technology

2008-10-01

XM, Tevaearai HT, Jegger D, Tucker O, von Segesser LK. Are standard human coagulation tests suitable in pigs and calves during extracorporeal ... circulation ? Artif Organs. 2001;25:579–584. 44. Karges HE, Funk KA, Ronneberger H. Activity of coagulation and fibrinolysis parameters in animals

EFFECTS OF SEASONAL AND WATER QUALITY PARAMETERS ON OYSTERS (CRASSOSTREA VIRGINICA) AND ASSOCIATED FISH POPULATIONS.

EPA Science Inventory

Influence of water quality and seasonal changes on disease prevalence and intensity of Perkinsus marinus, gonadal condition, recruitment potential, growth of caged juvenile oysters, and habitat suitability of reefs for fishes and macrobenthic invertebrates were measured in Callos...

Comparison of retention models for polymers 1. Poly(ethylene glycol)s.

PubMed

Bashir, Mubasher A; Radke, Wolfgang

2006-10-27

The suitability of three different retention models to predict the retention times of poly(ethylene glycol)s (PEGs) in gradient and isocratic chromatography was investigated. The models investigated were the linear (LSSM) and the quadratic solvent strength model (QSSM). In addition, a model describing the retention behaviour of polymers was extended to account for gradient elution (PM). It was found that all models are suited to properly predict gradient retention volumes provided the extraction of the analyte specific parameters is performed from gradient experiments as well. The LSSM and QSSM on principle cannot describe retention behaviour under critical or SEC conditions. Since the PM is designed to cover all three modes of polymer chromatography, it is therefore superior to the other models. However, the determination of the analyte specific parameters, which are needed to calibrate the retention behaviour, strongly depend on the suitable selection of initial experiments. A useful strategy for a purposeful selection of these calibration experiments is proposed.

The fractal-multifractal method and temporal resolution: Application to precipitation and streamflow

NASA Astrophysics Data System (ADS)

Maskey, M.; Puente, C. E.; Sivakumar, B.

2017-12-01

In the past, we have established that the deterministic fractal-multifractal (FM) method is a promising geometric tool to analyze hydro-climatic variables, such as precipitation, river flow, and temperature. In this study, we address the issue of temporal resolution to advance the suitability and usefulness of the FM approach in hydro-climate. Specifically, we elucidate the evolution of FM geometric parameters as computed at different time scales ranging from a day to a month (30-day) in increments of a day. For this purpose, both rainfall and river discharge records at Sacramento, California gathered over a year are encoded at different time scales. The analysis reveals that: (a) the FM approach yields faithful encodings of both kinds of data sets at the resolutions considered with reasonably small errors; and (b) the "best" FM parameters ultimately converge when the resolution is increased, thus allowing visualizing both hydrologic attributes. By addressing the scalability of the geometric patterns, these results further advance the suitability of the FM approach.

Validation study and routine control monitoring of moist heat sterilization procedures.

PubMed

Shintani, Hideharu

2012-06-01

The proposed approach to validation of steam sterilization in autoclaves follows the basic life cycle concepts applicable to all validation programs. Understand the function of sterilization process, develop and understand the cycles to carry out the process, and define a suitable test or series of tests to confirm that the function of the process is suitably ensured by the structure provided. Sterilization of product and components and parts that come in direct contact with sterilized product is the most critical of pharmaceutical processes. Consequently, this process requires a most rigorous and detailed approach to validation. An understanding of the process requires a basic understanding of microbial death, the parameters that facilitate that death, the accepted definition of sterility, and the relationship between the definition and sterilization parameters. Autoclaves and support systems need to be designed, installed, and qualified in a manner that ensures their continued reliability. Lastly, the test program must be complete and definitive. In this paper, in addition to validation study, documentation of IQ, OQ and PQ concretely were described.

Water absorption characteristics and structural properties of rice for sake brewing.

PubMed

Mizuma, Tomochika; Kiyokawa, Yoshifumi; Wakai, Yoshinori

2008-09-01

This study investigated the water absorption curve characteristics and structural properties of rice used for sake brewing. The parameter values in the water absorption rate equation were calculated using experimental data. Differences between sample parameters for rice used for sake brewing and typical rice were confirmed. The water absorption curve for rice suitable for sake brewing showed a quantitatively sharper turn in the S-shaped water absorption curve than that of typical rice. Structural characteristics, including specific volume, grain density, and powdered density of polished rice, were measured by a liquid substitution method using a Gay-Lussac pycnometer. In addition, we calculated internal porosity from whole grain and powdered grain densities. These results showed that a decrease in internal porosity resulted from invasion of water into the rice grain, and that a decrease in the grain density affected expansion during the water absorption process. A characteristic S-shape water absorption curve for rice suitable for sake brewing was related to the existence of an invisible Shinpaku-like structure.

Study of parameters in precision optical glass molding

NASA Astrophysics Data System (ADS)

Ni, Ying; Wang, Qin-hua; Yu, Jing-chi

2010-10-01

Precision glass compression molding is an attractive approach to manufacture small precision optics in large volume over traditional manufacturing techniques because of its advantages such as lower cost, faster time to market and being environment friendly. In order to study the relationship between the surface figures of molded lenses and molding process parameters such as temperature, pressure, heating rate, cooling rate and so on, we present some glass compression molding experiments using same low Tg (transition temperature) glass material to produce two different kinds of aspheric lenses by different molding process parameters. Based on results from the experiments, we know the major factors influencing surface figure of molded lenses and the changing range of these parameters. From the knowledge we could easily catch proper molding parameters which are suitable for aspheric lenses with diameter from 10mm to 30mm.

ZASPE: A Code to Measure Stellar Atmospheric Parameters and their Covariance from Spectra

NASA Astrophysics Data System (ADS)

Brahm, Rafael; Jordán, Andrés; Hartman, Joel; Bakos, Gáspár

2017-05-01

We describe the Zonal Atmospheric Stellar Parameters Estimator (zaspe), a new algorithm, and its associated code, for determining precise stellar atmospheric parameters and their uncertainties from high-resolution echelle spectra of FGK-type stars. zaspe estimates stellar atmospheric parameters by comparing the observed spectrum against a grid of synthetic spectra only in the most sensitive spectral zones to changes in the atmospheric parameters. Realistic uncertainties in the parameters are computed from the data itself, by taking into account the systematic mismatches between the observed spectrum and the best-fitting synthetic one. The covariances between the parameters are also estimated in the process. zaspe can in principle use any pre-calculated grid of synthetic spectra, but unbiased grids are required to obtain accurate parameters. We tested the performance of two existing libraries, and we concluded that neither is suitable for computing precise atmospheric parameters. We describe a process to synthesize a new library of synthetic spectra that was found to generate consistent results when compared with parameters obtained with different methods (interferometry, asteroseismology, equivalent widths).

Multi-model Analysis of Diffusion-weighted Imaging of Normal Testes at 3.0 T: Preliminary Findings.

PubMed

Min, Xiangde; Feng, Zhaoyan; Wang, Liang; Cai, Jie; Li, Basen; Ke, Zan; Zhang, Peipei; You, Huijuan; Yan, Xu

2018-04-01

This study aimed to establish diffusion quantitative parameters (apparent diffusion coefficient [ADC], DDC, α, D app , and K app ) in normal testes at 3.0 T. Sixty-four healthy volunteers in two age groups (A: 10-39 years; B: ≥ 40 years) underwent diffusion-weighted imaging scanning at 3.0 T. ADC 1000 , ADC 2000 , ADC 3000 , DDC, α, D app , and K app were calculated using the mono-exponential, stretched-exponential, and kurtosis models. The correlations between parameters and the age were analyzed. The parameters were compared between the age groups and between the right and the left testes. The average ADC 1000 , ADC 2000 , ADC 3000 , DDC, α, D app , and K app values did not significantly differ between the right and the left testes (P > .05 for all). The following significant correlations were found: positive correlations between age and testicular ADC 1000 , ADC 2000 , ADC 3000 , DDC, and D app (r = 0.516, 0.518, 0.518, 0.521, and 0.516, respectively; P < .01 for all) and negative correlations between age and testicular α and K app (r = -0.363, -0.427, respectively; P < .01 for both). Compared to group B, in group A, ADC 1000 , ADC 2000 , ADC 3000 , DDC, and D app were significantly lower (P < .05 for all), but α and K app were significantly higher (P < .05 for both). Our study demonstrated the applicability of the testicular mono-exponential, stretched-exponential, and kurtosis models. Our results can help establish a baseline for the normal testicular parameters in these diffusion models. The contralateral normal testis can serve as a suitable reference for evaluating the abnormalities of the other side. The effect of age on these parameters requires further attention. Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

The Junior Computer Dictionary. 101 Useful Words and Definitions to Introduce Students to Computer Terminology.

ERIC Educational Resources Information Center

Willing, Kathlene R.; Girard, Suzanne

Suitable for children from grades four to seven, this dictionary is designed to introduce children to computer terminology at a level that they will understand and find useful. It is also suitable as a home resource for parents, for library use, and as a handbook for teachers. For each word, the first sentence of the definition contains the kernel…

Groundwater quality assessment of the quaternary unconsolidated sedimentary basin near the Pi river using fuzzy evaluation technique

NASA Astrophysics Data System (ADS)

Mohamed, Adam Khalifa; Liu, Dan; Mohamed, Mohamed A. A.; Song, Kai

2018-05-01

The present study was carried out to assess the groundwater quality for drinking purposes in the Quaternary Unconsolidated Sedimentary Basin of the North Chengdu Plain, China. Six groups of water samples (S1, S2, S3, S4, S5, and S6) are selected in the study area. These samples were analyzed for 19 different physicochemical water quality parameters to assess groundwater quality. The physicochemical parameters of groundwater were compared with China's Quality Standards for Groundwater (GB/T14848-93). Interpretation of physicochemical data revealed that groundwater in the basin was slightly alkaline. Total hardness and total dissolved solid values show that the investigated water is classified as very hard and fresh water, respectively. The sustainability of groundwater for drinking purposes was assessed based on the fuzzy mathematics evaluation (FME) method. The results of the assessment were classified into five groups based on their relative suitability for portable use (grade I = most suitable to grade V = least suitable), according to (GB/T 14848-93). The assessment results reveal that the quality of groundwater in most of the wells was class I, II and III and suitable for drinking purposes, but well (S2) has been found to be in class V, which is classified as very poor and cannot be used for drinking. Also, the FME method was compared with the comprehensive evaluation method. The FME method was found to be more comprehensive and reasonable to assess groundwater quality. This study can provide an important frame of reference for decision making on improving groundwater quality in the study area and nearby surrounding.

Experimental and statistical determination of indicator parameters for the evaluation of fly ash and boiler ash PCDD/PCDF concentration from municipal solid waste incinerators.

PubMed

Streibel, T; Nordsieck, H; Neuer-Etscheidt, K; Schnelle-Kreis, J; Zimmermann, R

2007-04-01

On-line detectable indicator parameters in the flue gas of municipal solid waste incinerators (MSWI) such as chlorinated benzenes (PCBz) are well known surrogate compounds for gas-phase PCDD/PCDF concentration. In the here presented work derivation of indicators is broadened to the detection of fly and boiler ash fractions with increased PCDD/PCDF content. Subsequently these fractions could be subject to further treatment such as recirculation in the combustion chamber to destroy their PCDD/PCDF and other organic pollutants' content. Aim of this work was to detect suitable on-line detectable indicator parameters in the gas phase, which are well correlated to PCDD/PCDF concentration in the solid residues. For this, solid residues and gas-phase samples were taken at three MSWI plants in Bavaria. Analysis of the ash content from different plants yielded a broad variation range of PCDD/PCDF concentrations especially after disturbed combustion conditions. Even during normal operation conditions significantly increased PCDD/PCDF concentrations may occur after unanticipated disturbances. Statistical evaluation of gas phase and ash measurements was carried out by means of principal component analysis, uni- and multivariate correlation analysis. Surprisingly, well known indicators for gas-phase PCDD/PCDF concentration such as polychlorinated benzenes and phenols proved to be insufficiently correlated to PCDD/PCDF content of the solid residues. Moreover, no single parameter alone was found appropriate to describe the PCDD/PCDF content of fly and boiler ashes. On the other hand, multivariate fitting of three or four parameters yielded convenient correlation coefficients of at least r=0.8 for every investigated case. Thereby, comprehension of plant operation parameters such as temperatures and air flow alongside concentrations of inorganic compounds in the gas phase (HCl, CO, SO2, NOx) gave the best results. However, the suitable set of parameters suited best for estimation of PCDD/PCDF concentration in solid residues has to be derived anew for each individual plant and type of ash.

Safety data on 19 vehicles for use in 1 month oral rodent pre-clinical studies: administration of hydroxypropyl-ß-cyclodextrin causes renal toxicity.

PubMed

Healing, Guy; Sulemann, Tabassum; Cotton, Peter; Harris, Jayne; Hargreaves, Adam; Finney, Rowena; Kirk, Sarah; Schramm, Carolin; Garner, Clare; Pivette, Perrine; Burdett, Lisa

2016-01-01

Potential new drugs are assessed in pre-clinical in vivo studies to determine their safety profiles. The drugs are formulated in vehicles suitable for the route of administration and the physicochemical properties of the drug, aiming to achieve optimal exposure in the test species. The availability of safety data on vehicles is often limited (incomplete data, access restricted/private databases). Nineteen potentially useful vehicles that contained new and/or increased concentrations of excipients and for which little safety data have been published were tested. Vehicles were dosed orally once daily to HanWistar rats for a minimum of 28 days and a wide range of toxicological parameters were assessed. Only 30% (w/v) hydroxypropyl-ß-cyclodextrin was found unsuitable owing to effects on liver enzymes (AST, ALT and GLDH), urinary volume and the kidneys (tubular vacuolation and tubular pigment). 20% (v/v) oleic acid caused increased salivation and hence this vehicle should be used with caution. As 40% (v/v) tetraethylene glycol affected urinary parameters, its use should be carefully considered, particularly for compounds suspected to impact the renal system and studies longer than 1 month. There were no toxicologically significant findings with 10% (v/v) dimethyl sulphoxide, 20% (v/v) propylene glycol, 33% (v/v) Miglyol®812, 20% (w/v) Kolliphor®RH40, 10% (w/v) Poloxamer 407, 5% (w/v) polyvinylpyrrolidone K30 or 10% (v/v) Labrafil®M1944. All other vehicles tested caused isolated or low magnitude effects which would not prevent their use. The aim of sharing these data, including adverse findings, is to provide meaningful information for vehicle selection, thereby avoiding repetition of animal experimentation. Copyright © 2015 John Wiley & Sons, Ltd.

Multi-Dimensional Shallow Landslide Stability Analysis Suitable for Application at the Watershed Scale

NASA Astrophysics Data System (ADS)

Milledge, David; Bellugi, Dino; McKean, Jim; Dietrich, William E.

2013-04-01

Current practice in regional-scale shallow landslide hazard assessment is to adopt a one-dimensional slope stability representation. Such a representation cannot produce discrete landslides and thus cannot make predictions on landslide size. Furthermore, one-dimensional approaches cannot include lateral effects, which are known to be important in defining instability. Here we derive an alternative model that accounts for lateral resistance by representing the forces acting on each margin of an unstable block of soil. We model boundary frictional resistances using 'at rest' earth pressure on the lateral sides, and 'active' and 'passive' pressure, using the log-spiral method, on the upslope and downslope margins. We represent root reinforcement on each margin assuming that root cohesion declines exponentially with soil depth. We test our model's ability to predict failure of an observed landslide where the relevant parameters are relatively well constrained and find that our model predicts failure at the observed location and predicts that larger or smaller failures conformal to the observed shape are indeed more stable. We use a sensitivity analysis of the model to show that lateral reinforcement sets a minimum landslide size, and that the additional strength at the downslope boundary results in optimal shapes that are longer in the downslope direction. However, reinforcement effects alone cannot fully explain the size or shape distributions of observed landslides, highlighting the importance of the spatial pattern of key parameters (e.g. pore water pressure and soil depth) at the watershed scale. The application of the model at this scale requires an efficient method to find unstable shapes among an exponential number of candidates. In this context, the model allows a more extensive examination of the controls on landslide size, shape and location.

Gold Nanoparticle Mediated Laser Transfection for Efficient siRNA Mediated Gene Knock Down

PubMed Central

Heinemann, Dag; Schomaker, Markus; Kalies, Stefan; Schieck, Maximilian; Carlson, Regina; Escobar, Hugo Murua; Ripken, Tammo; Meyer, Heiko; Heisterkamp, Alexander

2013-01-01

Laser based transfection methods have proven to be an efficient and gentle alternative to established molecule delivery methods like lipofection or electroporation. Among the laser based methods, gold nanoparticle mediated laser transfection bears the major advantage of high throughput and easy usability. This approach uses plasmon resonances on gold nanoparticles unspecifically attached to the cell membrane to evoke transient and spatially defined cell membrane permeabilization. In this study, we explore the parameter regime for gold nanoparticle mediated laser transfection for the delivery of molecules into cell lines and prove its suitability for siRNA mediated gene knock down. The developed setup allows easy usage and safe laser operation in a normal lab environment. We applied a 532 nm Nd:YAG microchip laser emitting 850 ps pulses at a repetition rate of 20.25 kHz. Scanning velocities of the laser spot over the sample of up to 200 mm/s were tested without a decline in perforation efficiency. This velocity leads to a process speed of ∼8 s per well of a 96 well plate. The optimal particle density was determined to be ∼6 particles per cell using environmental scanning electron microscopy. Applying the optimized parameters transfection efficiencies of 88% were achieved in canine pleomorphic adenoma ZMTH3 cells using a fluorescent labeled siRNA while maintaining a high cell viability of >90%. Gene knock down of d2-EGFP was demonstrated and validated by fluorescence repression and western blot analysis. On basis of our findings and established mathematical models we suppose a mixed transfection mechanism consisting of thermal and multiphoton near field effects. Our findings emphasize that gold nanoparticle mediated laser transfection provides an excellent tool for molecular delivery for both, high throughput purposes and the transfection of sensitive cells types. PMID:23536802

Technical and investigative support for high density digital satellite recording systems

NASA Technical Reports Server (NTRS)

1982-01-01

Availability of tape in suitable widths continue to obstruct standardized methods on tests where width is an important parameter. These tests include flexibility, coefficients of friction, and abrasivity. The Fuji Beridox tape samples evaluated were obtained from a 1/2 inch video cassette.

The Spin Evolution of Fast-rotating, Magnetized Super-Chandrasekhar White Dwarfs in the Aftermath of White Dwarf Mergers

NASA Astrophysics Data System (ADS)

Becerra, L.; Rueda, J. A.; Lorén-Aguilar, P.; García-Berro, E.

2018-04-01

The evolution of the remnant of the merger of two white dwarfs is still an open problem. Furthermore, few studies have addressed the case in which the remnant is a magnetic white dwarf with a mass larger than the Chandrasekhar limiting mass. Angular momentum losses might bring the remnant of the merger to the physical conditions suitable for developing a thermonuclear explosion. Alternatively, the remnant may be prone to gravitational or rotational instabilities, depending on the initial conditions reached after the coalescence. Dipole magnetic braking is one of the mechanisms that can drive such losses of angular momentum. However, the timescale on which these losses occur depends on several parameters, like the strength of the magnetic field. In addition, the coalescence leaves a surrounding Keplerian disk that can be accreted by the newly formed white dwarf. Here we compute the post-merger evolution of a super-Chandrasekhar magnetized white dwarf taking into account all the relevant physical processes. These include magnetic torques acting on the star, accretion from the Keplerian disk, the threading of the magnetic field lines through the disk, and the thermal evolution of the white dwarf core. We find that the central remnant can reach the conditions suitable to develop a thermonuclear explosion before other instabilities (such as the inverse beta-decay instability or the secular axisymmetric instability) are reached, which would instead lead to gravitational collapse of the magnetized remnant.

The importance of conceptual models in the reactive transport simulation of oxygen ingress in sparsely fractured crystalline rock.

PubMed

Macquarrie, K T B; Mayer, K U; Jin, B; Spiessl, S M

2010-03-01

Redox evolution in sparsely fractured crystalline rocks is a key, and largely unresolved, issue when assessing the geochemical suitability of deep geological repositories for nuclear waste. Redox zonation created by the influx of oxygenated waters has previously been simulated using reactive transport models that have incorporated a variety of processes, resulting in predictions for the depth of oxygen penetration that may vary greatly. An assessment and direct comparison of the various underlying conceptual models are therefore needed. In this work a reactive transport model that considers multiple processes in an integrated manner is used to investigate the ingress of oxygen for both single fracture and fracture zone scenarios. It is shown that the depth of dissolved oxygen migration is greatly influenced by the a priori assumptions that are made in the conceptual models. For example, the ability of oxygen to access and react with minerals in the rock matrix may be of paramount importance for single fracture conceptual models. For fracture zone systems, the abundance and reactivity of minerals within the fractures and thin matrix slabs between the fractures appear to provide key controls on O(2) attenuation. The findings point to the need for improved understanding of the coupling between the key transport-reaction feedbacks to determine which conceptual models are most suitable and to provide guidance for which parameters should be targeted in field and laboratory investigations. Copyright 2009 Elsevier B.V. All rights reserved.

Foam injection molding of thermoplastic elastomers: Blowing agents, foaming process and characterization of structural foams

NASA Astrophysics Data System (ADS)

Ries, S.; Spoerrer, A.; Altstaedt, V.

2014-05-01

Polymer foams play an important role caused by the steadily increasing demand to light weight design. In case of soft polymers, like thermoplastic elastomers (TPE), the haptic feeling of the surface is affected by the inner foam structure. Foam injection molding of TPEs leads to so called structural foam, consisting of two compact skin layers and a cellular core. The properties of soft structural foams like soft-touch, elastic and plastic behavior are affected by the resulting foam structure, e.g. thickness of the compact skins and the foam core or density. This inner structure can considerably be influenced by different processing parameters and the chosen blowing agent. This paper is focused on the selection and characterization of suitable blowing agents for foam injection molding of a TPE-blend. The aim was a high density reduction and a decent inner structure. Therefore DSC and TGA measurements were performed on different blowing agents to find out which one is appropriate for the used TPE. Moreover a new analyzing method for the description of processing characteristics by temperature dependent expansion measurements was developed. After choosing suitable blowing agents structural foams were molded with different types of blowing agents and combinations and with the breathing mold technology in order to get lower densities. The foam structure was analyzed to show the influence of the different blowing agents and combinations. Finally compression tests were performed to estimate the influence of the used blowing agent and the density reduction on the compression modulus.

Laser scanning cytometry as a tool for biomarker validation

NASA Astrophysics Data System (ADS)

Mittag, Anja; Füldner, Christiane; Lehmann, Jörg; Tarnok, Attila

2013-03-01

Biomarkers are essential for diagnosis, prognosis, and therapy. As diverse is the range of diseases the broad is the range of biomarkers and the material used for analysis. Whereas body fluids can be relatively easily obtained and analyzed, the investigation of tissue is in most cases more complicated. The same applies for the screening and the evaluation of new biomarkers and the estimation of the binding of biomarkers found in animal models which need to be transferred into applications in humans. The latter in particular is difficult if it recognizes proteins or cells in tissue. A better way to find suitable cellular biomarkers for immunoscintigraphy or PET analyses may be therefore the in situ analysis of the cells in the respective tissue. In this study we present a method for biomarker validation using Laser Scanning Cytometry which allows the emulation of future in vivo analysis. The biomarker validation is exemplarily shown for rheumatoid arthritis (RA) on synovial membrane. Cryosections were scanned and analyzed by phantom contouring. Adequate statistical methods allowed the identification of suitable markers and combinations. The fluorescence analysis of the phantoms allowed the discrimination between synovial membrane of RA patients and non-RA control sections by using median fluorescence intensity and the "affected area". As intensity and area are relevant parameters of in vivo imaging (e.g. PET scan) too, the presented method allows emulation of a probable outcome of in vivo imaging, i.e. the binding of the target protein and hence, the validation of the potential of the respective biomarker.

Effect of two solanaceous plants on developmental and population parameters of the tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae).

PubMed

Pereyra, Patricia C; Sánchez, Norma E

2006-01-01

Tuta absoluta (Meyrick) is an important tomato pest that also feeds on other host-plants from the Solanceae family. We studied the effect of two cultivated plants, tomato (Lycopersicum esculentum Mill.) and potato Solanum tuberosum L. on the development and populational parameters of T. absoluta related with host-plant suitability. Larval developmental time, pupal weight, mean fecundity and an index of host-plant quality (IPQ = pupal weight / frass weight) were estimated. Age-specific survivorship and fecundity life tables were constructed in the laboratory to evaluate the following populational parameters: net reproductive rate (Ro), intrinsic rate of increase (r) and generation time (T). Larval developmental time was shorter and pupal weight was higher (P < 0.0001) for larvae reared on tomato (P < 0.0001). Mean fecundity was not significantly different on both plants (P = 0.07) and food quality of host-plant was higher for tomato (P = 0.02). Mean population parameters on tomato were: Ro = 48.92; T = 27.98, r = 0.14; and on potato: Ro = 14.43; T = 32.35, r = 0.08. Although results showed that tomato was a more suitable host-plant and had a better nutritional quality than potato, when T. absoluta fed on potato the potential population increase requires attention. Under appropriate climatic conditions, spatial and temporal coincidence between crop and pest, T. absoluta could become a pest for the potato crop.

Parameter regionalization of a monthly water balance model for the conterminous United States

USGS Publications Warehouse

Bock, Andrew R.; Hay, Lauren E.; McCabe, Gregory J.; Markstrom, Steven L.; Atkinson, R. Dwight

2016-01-01

A parameter regionalization scheme to transfer parameter values from gaged to ungaged areas for a monthly water balance model (MWBM) was developed and tested for the conterminous United States (CONUS). The Fourier Amplitude Sensitivity Test, a global-sensitivity algorithm, was implemented on a MWBM to generate parameter sensitivities on a set of 109 951 hydrologic response units (HRUs) across the CONUS. The HRUs were grouped into 110 calibration regions based on similar parameter sensitivities. Subsequently, measured runoff from 1575 streamgages within the calibration regions were used to calibrate the MWBM parameters to produce parameter sets for each calibration region. Measured and simulated runoff at the 1575 streamgages showed good correspondence for the majority of the CONUS, with a median computed Nash–Sutcliffe efficiency coefficient of 0.76 over all streamgages. These methods maximize the use of available runoff information, resulting in a calibrated CONUS-wide application of the MWBM suitable for providing estimates of water availability at the HRU resolution for both gaged and ungaged areas of the CONUS.

Parameter regionalization of a monthly water balance model for the conterminous United States

NASA Astrophysics Data System (ADS)

Bock, Andrew R.; Hay, Lauren E.; McCabe, Gregory J.; Markstrom, Steven L.; Atkinson, R. Dwight

2016-07-01

A parameter regionalization scheme to transfer parameter values from gaged to ungaged areas for a monthly water balance model (MWBM) was developed and tested for the conterminous United States (CONUS). The Fourier Amplitude Sensitivity Test, a global-sensitivity algorithm, was implemented on a MWBM to generate parameter sensitivities on a set of 109 951 hydrologic response units (HRUs) across the CONUS. The HRUs were grouped into 110 calibration regions based on similar parameter sensitivities. Subsequently, measured runoff from 1575 streamgages within the calibration regions were used to calibrate the MWBM parameters to produce parameter sets for each calibration region. Measured and simulated runoff at the 1575 streamgages showed good correspondence for the majority of the CONUS, with a median computed Nash-Sutcliffe efficiency coefficient of 0.76 over all streamgages. These methods maximize the use of available runoff information, resulting in a calibrated CONUS-wide application of the MWBM suitable for providing estimates of water availability at the HRU resolution for both gaged and ungaged areas of the CONUS.

Magnetically induced rotor vibration in dual-stator permanent magnet motors

NASA Astrophysics Data System (ADS)

Xie, Bang; Wang, Shiyu; Wang, Yaoyao; Zhao, Zhifu; Xiu, Jie

2015-07-01

Magnetically induced vibration is a major concern in permanent magnet (PM) motors, which is especially true for dual-stator motors. This work develops a two-dimensional model of the rotor by using energy method, and employs this model to examine the rigid- and elastic-body vibrations induced by the inner stator tooth passage force and that by the outer. The analytical results imply that there exist three typical vibration modes. Their presence or absence depends on the combination of magnet/slot, force's frequency and amplitude, the relative position between two stators, and other structural parameters. The combination and relative position affect these modes via altering the force phase. The predicted results are verified by magnetic force wave analysis by finite element method (FEM) and comparison with the existing results. Potential directions are also given with the anticipation of bringing forth more interesting and useful findings. As an engineering application, the magnetically induced vibration can be first reduced via the combination and then a suitable relative position.

Selected Schizosaccharomyces pombe Strains Have Characteristics That Are Beneficial for Winemaking

PubMed Central

Benito, Ángel; Jeffares, Daniel; Palomero, Felipe; Calderón, Fernando; Bai, Feng-Yan; Bähler, Jürg; Benito, Santiago

2016-01-01

At present, wine is generally produced using Saccharomyces yeast followed by Oenococus bacteria to complete malolactic fermentation. This method has some unsolved problems, such as the management of highly acidic musts and the production of potentially toxic products including biogenic amines and ethyl carbamate. Here we explore the potential of the fission yeast Schizosaccharomyces pombe to solve these problems. We characterise an extensive worldwide collection of S. pombe strains according to classic biochemical parameters of oenological interest. We identify three genetically different S. pombe strains that appear suitable for winemaking. These strains compare favourably to standard Saccharomyces cerevisiae winemaking strains, in that they perform effective malic acid deacidification and significantly reduce levels of biogenic amines and ethyl carbamate precursors without the need for any secondary bacterial malolactic fermentation. These findings indicate that the use of certain S. pombe strains could be advantageous for winemaking in regions where malic acid is problematic, and these strains also show superior performance with respect to food safety. PMID:27007548

No-scale SU( 5) super-GUTs

DOE PAGES

Ellis, John; Evans, Jason L.; Nagata, Natsumi; ...

2017-04-12

We reconsider the minimal SU( 5) grand unified theory (GUT) in the context of no-scale supergravity inspired by string compactification scenarios, assuming that the soft supersymmetry-breaking parameters satisfy universality conditions at some input scale M in above the GUT scale M GUT. When setting up such a no-scale super-GUT model, special attention must be paid to avoiding the Scylla of rapid proton decay and the Charybdis of an excessive density of cold dark matter, while also having an acceptable mass for the Higgs boson. Furthermore, we do not find consistent solutions if none of the matter and Higgs fields aremore » assigned to twisted chiral supermultiplets, even in the presence of Giudice–Masiero terms. But, consistent solutions may be found if at least one fiveplet of GUT Higgs fields is assigned to a twisted chiral supermultiplet, with a suitable choice of modular weights. Spin-independent dark matter scattering may be detectable in some of these consistent solutions.« less

Dynamic calibration of pan-tilt-zoom cameras for traffic monitoring.

PubMed

Song, Kai-Tai; Tai, Jen-Chao

2006-10-01

Pan-tilt-zoom (PTZ) cameras have been widely used in recent years for monitoring and surveillance applications. These cameras provide flexible view selection as well as a wider observation range. This makes them suitable for vision-based traffic monitoring and enforcement systems. To employ PTZ cameras for image measurement applications, one first needs to calibrate the camera to obtain meaningful results. For instance, the accuracy of estimating vehicle speed depends on the accuracy of camera calibration and that of vehicle tracking results. This paper presents a novel calibration method for a PTZ camera overlooking a traffic scene. The proposed approach requires no manual operation to select the positions of special features. It automatically uses a set of parallel lane markings and the lane width to compute the camera parameters, namely, focal length, tilt angle, and pan angle. Image processing procedures have been developed for automatically finding parallel lane markings. Interesting experimental results are presented to validate the robustness and accuracy of the proposed method.

Two-step fabrication technique of gold tips for use in point-contact spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Narasiwodeyar, S.; Dwyer, M.; Liu, M.

For a successful point-contact spectroscopy (PCS) measurement, metallic tips of proper shape and smoothness are essential to ensure the ballistic nature of a point-contact junction. Until recently, the fabrication of Au tips suitable for use in point-contact spectroscopy has remained more of an art involving a trial and error method rather than an automated scientific process. To address these issues, we have developed a technique with which one can prepare high quality Au tips reproducibly and systematically. It involves an electronic control of the driving voltages used for an electrochemical etching of a gold wire in a HCl-glycerol mixture ormore » a HCl solution. We find that a stopping current, below which the circuit is set to shut off, is a single very important parameter to produce an Au tip of desired shape. We present detailed descriptions for a two-step etching process for Au tips and also test results from PCS measurements using them.« less

Optimal quantum control of Bose-Einstein condensates in magnetic microtraps: Comparison of gradient-ascent-pulse-engineering and Krotov optimization schemes

NASA Astrophysics Data System (ADS)

Jäger, Georg; Reich, Daniel M.; Goerz, Michael H.; Koch, Christiane P.; Hohenester, Ulrich

2014-09-01

We study optimal quantum control of the dynamics of trapped Bose-Einstein condensates: The targets are to split a condensate, residing initially in a single well, into a double well, without inducing excitation, and to excite a condensate from the ground state to the first-excited state of a single well. The condensate is described in the mean-field approximation of the Gross-Pitaevskii equation. We compare two optimization approaches in terms of their performance and ease of use; namely, gradient-ascent pulse engineering (GRAPE) and Krotov's method. Both approaches are derived from the variational principle but differ in the way the control is updated, additional costs are accounted for, and second-order-derivative information can be included. We find that GRAPE produces smoother control fields and works in a black-box manner, whereas Krotov with a suitably chosen step-size parameter converges faster but can produce sharp features in the control fields.

Clustering change patterns using Fourier transformation with time-course gene expression data.

PubMed

Kim, Jaehee

2011-01-01

To understand the behavior of genes, it is important to explore how the patterns of gene expression change over a period of time because biologically related gene groups can share the same change patterns. In this study, the problem of finding similar change patterns is induced to clustering with the derivative Fourier coefficients. This work is aimed at discovering gene groups with similar change patterns which share similar biological properties. We developed a statistical model using derivative Fourier coefficients to identify similar change patterns of gene expression. We used a model-based method to cluster the Fourier series estimation of derivatives. We applied our model to cluster change patterns of yeast cell cycle microarray expression data with alpha-factor synchronization. It showed that, as the method clusters with the probability-neighboring data, the model-based clustering with our proposed model yielded biologically interpretable results. We expect that our proposed Fourier analysis with suitably chosen smoothing parameters could serve as a useful tool in classifying genes and interpreting possible biological change patterns.

Ultrafast optomechanical pulse picking

NASA Astrophysics Data System (ADS)

Lilienfein, Nikolai; Holzberger, Simon; Pupeza, Ioachim

2017-01-01

State-of-the-art optical switches for coupling pulses into and/or out of resonators are based on either the electro-optic or the acousto-optic effect in transmissive elements. In high-power applications, the damage threshold and other nonlinear and thermal effects in these elements impede further improvements in pulse energy, duration, and average power. We propose a new optomechanical switching concept which is based solely on reflective elements and is suitable for switching times down to the ten-nanosecond range. To this end, an isolated section of a beam path is moved in a system comprising mirrors rotating at a high angular velocity and stationary imaging mirrors, without affecting the propagation of the beam thereafter. We discuss three variants of the concept and exemplify practical parameters for its application in regenerative amplifiers and stack-and-dump enhancement cavities. We find that optomechanical pulse picking has the potential to achieve switching rates of up to a few tens of kilohertz while supporting pulse energies of up to several joules.

Mössbauer study of the effect of pH on Fe valence in iron-polygalacturonate as a medicine for human anaemia

NASA Astrophysics Data System (ADS)

Kuzmann, E.; Garg, V. K.; de Oliveira, A. C.; Klencsár, Z.; Szentmihályi, K.; Fodor, J.; May, Z.; Homonnay, Z.

2015-02-01

Iron-polygalacturonate complexes have been synthesized from polygalacturonic acid by applying a novel preparation method in order to develop medicine suitable for the effective iron supplementation of the human body in the case of anemia. Since the iron uptake depends on the oxidation state of iron, 57Fe Mössbauer spectroscopy was used to study the occurrence of different valence states in the iron-polygalacturonate complexes prepared under different circumstances. The Mössbauer-spectra indicated the presence of iron both in FeII and FeIII states in the investigated iron-polygalacturonate compounds, the occurrence of which varied with the preparation parameters. A correlation of the relative occurrence of iron valence states with the pH has been found. The relative occurrence of FeIII was found to increase with increasing pH. The knowledge of this correlation can help find optimum preparation conditions of iron-polygalacturonates to cure human anemia.

Quantitative Evaluation of the Total Magnetic Moments of Colloidal Magnetic Nanoparticles: A Kinetics-based Method.

PubMed

Liu, Haiyi; Sun, Jianfei; Wang, Haoyao; Wang, Peng; Song, Lina; Li, Yang; Chen, Bo; Zhang, Yu; Gu, Ning

2015-06-08

A kinetics-based method is proposed to quantitatively characterize the collective magnetization of colloidal magnetic nanoparticles. The method is based on the relationship between the magnetic force on a colloidal droplet and the movement of the droplet under a gradient magnetic field. Through computational analysis of the kinetic parameters, such as displacement, velocity, and acceleration, the magnetization of colloidal magnetic nanoparticles can be calculated. In our experiments, the values measured by using our method exhibited a better linear correlation with magnetothermal heating, than those obtained by using a vibrating sample magnetometer and magnetic balance. This finding indicates that this method may be more suitable to evaluate the collective magnetism of colloidal magnetic nanoparticles under low magnetic fields than the commonly used methods. Accurate evaluation of the magnetic properties of colloidal nanoparticles is of great importance for the standardization of magnetic nanomaterials and for their practical application in biomedicine. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Regularization Paths for Conditional Logistic Regression: The clogitL1 Package.

PubMed

Reid, Stephen; Tibshirani, Rob

2014-07-01

We apply the cyclic coordinate descent algorithm of Friedman, Hastie, and Tibshirani (2010) to the fitting of a conditional logistic regression model with lasso [Formula: see text] and elastic net penalties. The sequential strong rules of Tibshirani, Bien, Hastie, Friedman, Taylor, Simon, and Tibshirani (2012) are also used in the algorithm and it is shown that these offer a considerable speed up over the standard coordinate descent algorithm with warm starts. Once implemented, the algorithm is used in simulation studies to compare the variable selection and prediction performance of the conditional logistic regression model against that of its unconditional (standard) counterpart. We find that the conditional model performs admirably on datasets drawn from a suitable conditional distribution, outperforming its unconditional counterpart at variable selection. The conditional model is also fit to a small real world dataset, demonstrating how we obtain regularization paths for the parameters of the model and how we apply cross validation for this method where natural unconditional prediction rules are hard to come by.

Regularization Paths for Conditional Logistic Regression: The clogitL1 Package

PubMed Central

Reid, Stephen; Tibshirani, Rob

2014-01-01

We apply the cyclic coordinate descent algorithm of Friedman, Hastie, and Tibshirani (2010) to the fitting of a conditional logistic regression model with lasso (ℓ1) and elastic net penalties. The sequential strong rules of Tibshirani, Bien, Hastie, Friedman, Taylor, Simon, and Tibshirani (2012) are also used in the algorithm and it is shown that these offer a considerable speed up over the standard coordinate descent algorithm with warm starts. Once implemented, the algorithm is used in simulation studies to compare the variable selection and prediction performance of the conditional logistic regression model against that of its unconditional (standard) counterpart. We find that the conditional model performs admirably on datasets drawn from a suitable conditional distribution, outperforming its unconditional counterpart at variable selection. The conditional model is also fit to a small real world dataset, demonstrating how we obtain regularization paths for the parameters of the model and how we apply cross validation for this method where natural unconditional prediction rules are hard to come by. PMID:26257587

Bioinspired sensory systems for local flow characterization

NASA Astrophysics Data System (ADS)

Colvert, Brendan; Chen, Kevin; Kanso, Eva

2016-11-01

Empirical evidence suggests that many aquatic organisms sense differential hydrodynamic signals.This sensory information is decoded to extract relevant flow properties. This task is challenging because it relies on local and partial measurements, whereas classical flow characterization methods depend on an external observer to reconstruct global flow fields. Here, we introduce a mathematical model in which a bioinspired sensory array measuring differences in local flow velocities characterizes the flow type and intensity. We linearize the flow field around the sensory array and express the velocity gradient tensor in terms of frame-independent parameters. We develop decoding algorithms that allow the sensory system to characterize the local flow and discuss the conditions under which this is possible. We apply this framework to the canonical problem of a circular cylinder in uniform flow, finding excellent agreement between sensed and actual properties. Our results imply that combining suitable velocity sensors with physics-based methods for decoding sensory measurements leads to a powerful approach for understanding and developing underwater sensory systems.

Environmental statistics and optimal regulation

NASA Astrophysics Data System (ADS)

Sivak, David; Thomson, Matt

2015-03-01

The precision with which an organism can detect its environment, and the timescale for and statistics of environmental change, will affect the suitability of different strategies for regulating protein levels in response to environmental inputs. We propose a general framework--here applied to the enzymatic regulation of metabolism in response to changing nutrient concentrations--to predict the optimal regulatory strategy given the statistics of fluctuations in the environment and measurement apparatus, and the costs associated with enzyme production. We find: (i) relative convexity of enzyme expression cost and benefit influences the fitness of thresholding or graded responses; (ii) intermediate levels of measurement uncertainty call for a sophisticated Bayesian decision rule; and (iii) in dynamic contexts, intermediate levels of uncertainty call for retaining memory of the past. Statistical properties of the environment, such as variability and correlation times, set optimal biochemical parameters, such as thresholds and decay rates in signaling pathways. Our framework provides a theoretical basis for interpreting molecular signal processing algorithms and a classification scheme that organizes known regulatory strategies and may help conceptualize heretofore unknown ones.

Investigation of Joint Visibility Between SAR and Optical Images of Urban Environments

NASA Astrophysics Data System (ADS)

Hughes, L. H.; Auer, S.; Schmitt, M.

2018-05-01

In this paper, we present a work-flow to investigate the joint visibility between very-high-resolution SAR and optical images of urban scenes. For this task, we extend the simulation framework SimGeoI to enable a simulation of individual pixels rather than complete images. Using the extended SimGeoI simulator, we carry out a case study using a TerraSAR-X staring spotlight image and a Worldview-2 panchromatic image acquired over the city of Munich, Germany. The results of this study indicate that about 55 % of the scene are visible in both images and are thus suitable for matching and data fusion endeavours, while about 25 % of the scene are affected by either radar shadow or optical occlusion. Taking the image acquisition parameters into account, our findings can provide support regarding the definition of upper bounds for image fusion tasks, as well as help to improve acquisition planning with respect to different application goals.

Kinetic efficiency of polar monolithic capillary columns in high-pressure gas chromatography.

PubMed

Kurganov, A A; Korolev, A A; Shiryaeva, V E; Popova, T P; Kanateva, A Yu

2013-11-08

Poppe plots were used for analysis of kinetic efficiency of monolithic sorbents synthesized in quartz capillaries for utilization in high-pressure gas chromatography. Values of theoretical plate time and maximum number of theoretical plates occurred to depend significantly on synthetic parameters such as relative amount of monomer in the initial polymerization mixture, temperature and polymerization time. Poppe plots let one to find synthesis conditions suitable either for high-speed separations or for maximal efficiency. It is shown that construction of kinetic Poppe curves using potential Van Deemter data demands compressibility of mobile phase to be taken into consideration in the case of gas chromatography. Model mixture of light hydrocarbons C1 to C4 was then used for investigation of influence of carrier gas nature on kinetic efficiency of polymeric monolithic columns. Minimal values of theoretical plate times were found for CO2 and N2O carrier gases. Copyright © 2013 Elsevier B.V. All rights reserved.

Spectroscopic monitoring of bright A-F type candidate hybrid stars discovered by the Kepler mission

NASA Astrophysics Data System (ADS)

Lampens, Patricia; Frémat, Y.; Vermeylen, Lore; De Cat, Peter; Dumortier, Louis; Sódor, Ádám; Sharka, Marek; Bognár, Zsófia

2018-04-01

We report on a study of 250 optical spectra for 50 bright A/F-type candidate hybrid pulsating stars from the Kepler field. Most of the spectra have been collected with the high-resolution spectrograph HERMES attached to the Mercator telescope, La Palma. We determined the radial velocities (RVs), projected rotational velocities, fundamental atmospheric parameters and provide a classification based on the appearance of the cross-correlation profiles and the behaviour of the RVs with time in order to find true hybrid pulsators. Additionally, we also detected new spectroscopic binary and multiple systems in our sample and determined the fraction of spectroscopic systems. In order to be able to extend this investigation to the fainter A-F type candidate hybrid stars, various high-quality spectra collected with 3-4 m sized telescopes suitably equipped with a high-resolution spectrograph and furthermore located in the Northern hemisphere would be ideal. This programme could be done using the new instruments installed at the Devasthal Observatory.

Green synthesis of isopropyl myristate in novel single phase medium Part I: Batch optimization studies.

PubMed

Vadgama, Rajeshkumar N; Odaneth, Annamma A; Lali, Arvind M

2015-12-01

Isopropyl myristate finds many applications in food, cosmetic and pharmaceutical industries as an emollient, thickening agent, or lubricant. Using a homogeneous reaction phase, non-specific lipase derived from Candida antartica, marketed as Novozym 435, was determined to be most suitable for the enzymatic synthesis of isopropyl myristate. The high molar ratio of alcohol to acid creates novel single phase medium which overcomes mass transfer effects and facilitates downstream processing. The effect of various reaction parameters was optimized to obtain a high yield of isopropyl myristate. Effect of temperature, agitation speed, organic solvent, biocatalyst loading and batch operational stability of the enzyme was systematically studied. The conversion of 87.65% was obtained when the molar ratio of isopropyl alcohol to myristic acid (15:1) was used with 4% (w/w) catalyst loading and agitation speed of 150 rpm at 60 °C. The enzyme has also shown good batch operational stability under optimized conditions.

Polarization and photometric observations of the gamma-ray blazar PG 1553+113

NASA Astrophysics Data System (ADS)

Andruchow, I.; Combi, J. A.; Muñoz-Arjonilla, A. J.; Romero, G. E.; Cellone, S. A.; Martí, J.

2011-07-01

We present the results of an observational photo-polarimetry campaign of the blazar PG 1553+113 at optical wavelengths. The blazar was recently detected at very high energies (>100 GeV) by the HESS and MAGIC γ-ray Cherenkov telescopes. Our high-temporal resolution data show significant variations in the linear polarization percentage and position angle at inter-night time-scales, while at shorter (intra-night) time-scales both parameters varied less significantly, if at all. Changes in the polarization angle seem to be common in γ-ray emitting blazars. Simultaneous differential photometry (through the B and R bands) shows no significant variability in the total optical flux. We provide B and R magnitudes, along with a finding chart, for a set of field stars suitable for differential photometry. Based on observations collected at the Centro Astronómico Hispano Alemán (CAHA) at Calar Alto, operated jointly by the Max-Planck Institut für Astronomie and the Instituto de Astrofísica de Andalucía (CSIC).

Lunar Habitat Optimization Using Genetic Algorithms

NASA Technical Reports Server (NTRS)

SanScoucie, M. P.; Hull, P. V.; Tinker, M. L.; Dozier, G. V.

2007-01-01

Long-duration surface missions to the Moon and Mars will require bases to accommodate habitats for the astronauts. Transporting the materials and equipment required to build the necessary habitats is costly and difficult. The materials chosen for the habitat walls play a direct role in protection against each of the mentioned hazards. Choosing the best materials, their configuration, and the amount required is extremely difficult due to the immense size of the design region. Clearly, an optimization method is warranted for habitat wall design. Standard optimization techniques are not suitable for problems with such large search spaces; therefore, a habitat wall design tool utilizing genetic algorithms (GAs) has been developed. GAs use a "survival of the fittest" philosophy where the most fit individuals are more likely to survive and reproduce. This habitat design optimization tool is a multiobjective formulation of up-mass, heat loss, structural analysis, meteoroid impact protection, and radiation protection. This Technical Publication presents the research and development of this tool as well as a technique for finding the optimal GA search parameters.

Information Cost, Memory Length and Market Instability.

PubMed

Diks, Cees; Li, Xindan; Wu, Chengyao

2018-07-01

In this article, we study the instability of a stock market with a modified version of Diks and Dindo's (2008) model where the market is characterized by nonlinear interactions between informed traders and uninformed traders. In the interaction of heterogeneous agents, we replace the replicator dynamics for the fractions by logistic strategy switching. This modification makes the model more suitable for describing realistic price dynamics, as well as more robust with respect to parameter changes. One goal of our paper is to use this model to explore if the arrival of new information (news) and investor behavior have an effect on market instability. A second, related, goal is to study the way markets absorb new information, especially when the market is unstable and the price is far from being fully informative. We find that the dynamics become locally unstable and prices may deviate far from the fundamental price, routing to chaos through bifurcation, with increasing information costs or decreasing memory length of the uninformed traders.

Calculation of Inertial Parameters to Find Dynamic Human Response

NASA Astrophysics Data System (ADS)

Shaibani, Saami J.

2004-03-01

A number of authenticated models of the human body have been produced during decades of research, and yet deficient substitutes continue to be concocted. Recent examples of the latter sadly include: (a) if human = water and potato = water, then human = potato; (b) pancreas = hot dog; and, (c) spine = plastic pipe. Omission of any suitable use of biology in these cases makes the inadequacies involved all the more unacceptable. The unduly simplistic nature seen there is contrasted with the correct procedures documented in this paper. Particular attention is paid here to the fields of anatomy and anthropometry, and the unique challenges[1] associated with pediatric cases are also discussed. The results of this study show that the naivety in the flawed examples above and elsewhere is completely unjustified, even for first-order speculations. The importance of first-hand clinical experience is explained as an essential component in the determination of accurate biomechanical data for human kinematics. 1. Bull. Am. Phys. Soc., 44, 273 (1999).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yalcin, M.; Arol, A.I.

Coconut shells are the most widely used raw material for the production of activated carbon used in the gold production by cyanide leaching. There have been efforts to find alternatives to coconut shells. Shells and stones of certain fruits, have been tested. Although promising results to some extent were obtained, coconut shells remain the main source of activated carbon. Turkey has become a country of interest in terms of gold deposits of epithermal origin. Four deposits have already been discovered and, mining and milling operations are expected to start in the near future. Explorations are underway in many other areasmore » of high expectations. Turkey is also rich in fruits which can be a valuable source of raw material for activated carbon production. In this study, hazelnut shells, peach and apricot stones, abundantly available locally, have been tested to determine whether they are suitable for the gold metallurgy. Parameters of carbonization and activation have been optimized. Gold loading capacity and adsorption kinetics have been studied.« less

When mental fatigue maybe characterized by Event Related Potential (P300) during virtual wheelchair navigation.

PubMed

Lamti, Hachem A; Gorce, Philippe; Ben Khelifa, Mohamed Moncef; Alimi, Adel M

2016-12-01

The goal of this study is to investigate the influence of mental fatigue on the event related potential P300 features (maximum pick, minimum amplitude, latency and period) during virtual wheelchair navigation. For this purpose, an experimental environment was set up based on customizable environmental parameters (luminosity, number of obstacles and obstacles velocities). A correlation study between P300 and fatigue ratings was conducted. Finally, the best correlated features supplied three classification algorithms which are MLP (Multi Layer Perceptron), Linear Discriminate Analysis and Support Vector Machine. The results showed that the maximum feature over visual and temporal regions as well as period feature over frontal, fronto-central and visual regions were correlated with mental fatigue levels. In the other hand, minimum amplitude and latency features didn't show any correlation. Among classification techniques, MLP showed the best performance although the differences between classification techniques are minimal. Those findings can help us in order to design suitable mental fatigue based wheelchair control.

Double Barriers and Magnetic Field in Bilayer Graphene

NASA Astrophysics Data System (ADS)

Redouani, Ilham; Jellal, Ahmed; Bahlouli, Hocine

2015-12-01

We study the transmission probability in an AB-stacked bilayer graphene of Dirac fermions scattered by a double-barrier structure in the presence of a magnetic field. We take into account the full four bands structure of the energy spectrum and use the suitable boundary conditions to determine the transmission probability. Our numerical results show that for energies higher than the interlayer coupling, four ways for transmission are possible while for energies less than the height of the barrier, Dirac fermions exhibit transmission resonances and only one transmission channel is available. We show that, for AB-stacked bilayer graphene, there is no Klein tunneling at normal incidence. We find that the transmission displays sharp peaks inside the transmission gap around the Dirac point within the barrier regions while they are absent around the Dirac point in the well region. The effect of the magnetic field, interlayer electrostatic potential, and various barrier geometry parameters on the transmission probabilities is also discussed.

Sorption of poly(hexamethylenebiguanide) on cellulose: mechanism of binding and molecular recognition.

PubMed

Blackburn, Richard S; Harvey, Anna; Kettle, Lorna L; Payne, John D; Russell, Stephen J

2006-06-20

Antimicrobial agents such as poly(hexamethylene biguanide) (PHMB) find application in medical, apparel, and household textile sectors; although it is understood that certain concentrations need to be applied to achieve suitable performance, there has been very little work published concerning the interactions of the polymer and its adsorption mechanism on cellulose. In this paper, such physical chemistry parameters are examined and related to computational chemistry studies. Adsorption isotherms were constructed: at low concentrations, these were typical Langmuir isotherms; at higher concentrations, they were more indicative of Freundlich isotherms, attributed to a combination of electrostatic and hydrogen-bonding forces, which endorsed computational chemistry proposals. At lower concentrations, electrostatic interactions between PHMB and carboxylic acid groups in the cellulose dominate with a contribution to binding through hydrogen bonding; as the concentration of PHMB increases, hydrogen bonding with cellulose becomes increasingly dominant. At high PHMB concentrations, observations of increasing PHMB adsorption are attributed to monolayer aggregation and multilayer stacking of PHMB through electrostatic interactions with counterions and hydrogen bonding of biguanide groups.

Permeation studies through porcine small intestine of furosemide solutions for personalised paediatric administration.

PubMed

Provenza, N; Calpena, A C; Mallandrich, M; Sánchez, A; Egea, M A; Clares, B

2014-11-20

Personalized medicine is a challenging research area in paediatric drug design since no suitable pharmaceutical forms are currently available. Furosemide is an anthranilic acid derivative used in paediatric practice to treat cardiac and pulmonary disorders in premature infants and neonates. However, it is not commercialized in suitable dosage forms for paediatrics. Elaborating new paediatric formulations when no commercial forms are available is a common practice in pharmacy laboratories; amongst these, oral liquid formulations are the most common. We developed two extemporaneous paediatric oral solutions of furosemide (pure powder). The characterization and stability study were also performed. Parameters such as organoleptic characteristics, rheology, pH, content of active substance, and microbial stability were evaluated at three temperatures for two months. Evaluation of all these parameters showed that both solutions were stable for 60 days at 4 and 25 °C. Moreover, ex vivo studies were performed to evaluate the permeation behaviour of developed solutions through porcine small intestine to evaluate the potential paediatric biological parameters influencing the bioavailability and efficacy. A validated spectrofluorometric method was also used for this purpose. Our results guarantee a correct dosification, administration and potential efficacy of furosemide when is formulated in liquid oral forms for the treatment of cardiac and pulmonary disorders in children. Copyright © 2014 Elsevier B.V. All rights reserved.

Using implicit association tests in age-heterogeneous samples: The importance of cognitive abilities and quad model processes.

PubMed

Wrzus, Cornelia; Egloff, Boris; Riediger, Michaela

2017-08-01

Implicit association tests (IATs) are increasingly used to indirectly assess people's traits, attitudes, or other characteristics. In addition to measuring traits or attitudes, IAT scores also reflect differences in cognitive abilities because scores are based on reaction times (RTs) and errors. As cognitive abilities change with age, questions arise concerning the usage and interpretation of IATs for people of different age. To address these questions, the current study examined how cognitive abilities and cognitive processes (i.e., quad model parameters) contribute to IAT results in a large age-heterogeneous sample. Participants (N = 549; 51% female) in an age-stratified sample (range = 12-88 years) completed different IATs and 2 tasks to assess cognitive processing speed and verbal ability. From the IAT data, D2-scores were computed based on RTs, and quad process parameters (activation of associations, overcoming bias, detection, guessing) were estimated from individual error rates. Substantial IAT scores and quad processes except guessing varied with age. Quad processes AC and D predicted D2-scores of the content-specific IAT. Importantly, the effects of cognitive abilities and quad processes on IAT scores were not significantly moderated by participants' age. These findings suggest that IATs seem suitable for age-heterogeneous studies from adolescence to old age when IATs are constructed and analyzed appropriately, for example with D-scores and process parameters. We offer further insight into how D-scoring controls for method effects in IATs and what IAT scores capture in addition to implicit representations of characteristics. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

[Measurement of atomic number of alkali vapor and pressure of buffer gas based on atomic absorption].

PubMed

Zheng, Hui-jie; Quan, Wei; Liu, Xiang; Chen, Yao; Lu, Ji-xi

2015-02-01

High sensitivitymagnetic measurementscanbe achieved by utilizing atomic spinmanipulation in the spin-exchange-relaxation-free (SERF) regime, which uses an alkali cell as a sensing element. The atomic number density of the alkali vapor and the pressure of the buffer gasare among the most important parameters of the cell andrequire accurate measurement. A method has been proposed and developedto measure the atomic number density and the pressure based on absorption spectroscopy, by sweeping the absorption line and fittingthe experiment data with a Lorentzian profile to obtainboth parameters. Due to Doppler broadening and pressure broadening, which is mainly dominated by the temperature of the cell and the pressure of buffer gas respectively, this work demonstrates a simulation of the errorbetween the peaks of the Lorentzian profile and the Voigt profile caused by bothfactors. The results indicates that the Doppler broadening contribution is insignificant with an error less than 0.015% at 313-513 K for a 4He density of 2 amg, and an error of 0.1% in the presence of 0.6-5 amg at 393 K. We conclude that the Doppler broadening could be ignored under above conditions, and that the Lorentzianprofile is suitably applied to fit the absorption spectrumobtainingboth parameters simultaneously. In addition we discuss the resolution and the instability due to thelight source, wavelength and the temperature of the cell. We find that the cell temperature, whose uncertainty is two orders of magnitude larger than the instability of the light source and the wavelength, is one of the main factors which contributes to the error.

Reduction of eddy current losses in inductive transmission systems with ferrite sheets.

PubMed

Maaß, Matthias; Griessner, Andreas; Steixner, Viktor; Zierhofer, Clemens

2017-01-05

Improvements in eddy current suppression are necessary to meet the demand for increasing miniaturization of inductively driven transmission systems in industrial and biomedical applications. The high magnetic permeability and the simultaneously low electrical conductivity of ferrite materials make them ideal candidates for shielding metallic surfaces. For systems like cochlear implants the transmission of data as well as energy over an inductive link is conducted within a well-defined parameter set. For these systems, the shielding can be of particular importance if the properties of the link can be preserved. In this work, we investigate the effect of single and double-layered substrates consisting of ferrite and/or copper on the inductance and coupling of planar spiral coils. The examined link systems represent realistic configurations for active implantable systems such as cochlear implants. Experimental measurements are complemented with analytical calculations and finite element simulations, which are in good agreement for all measured parameters. The results are then used to study the transfer efficiency of an inductive link in a series-parallel resonant topology as a function of substrate size, the number of coil turns and coil separation. We find that ferrite sheets can be used to shield the system from unwanted metallic surfaces and to retain the inductive link parameters of the unperturbed system, particularly its transfer efficiency. The required size of the ferrite plates is comparable to the size of the coils, which makes the setup suitable for practical implementations. Since the sizes and geometries chosen for the studied inductive links are comparable to those of cochlear implants, our conclusions apply in particular to these systems.

Water Residence Time estimation by 1D deconvolution in the form of a l2 -regularized inverse problem with smoothness, positivity and causality constraints

NASA Astrophysics Data System (ADS)

Meresescu, Alina G.; Kowalski, Matthieu; Schmidt, Frédéric; Landais, François

2018-06-01

The Water Residence Time distribution is the equivalent of the impulse response of a linear system allowing the propagation of water through a medium, e.g. the propagation of rain water from the top of the mountain towards the aquifers. We consider the output aquifer levels as the convolution between the input rain levels and the Water Residence Time, starting with an initial aquifer base level. The estimation of Water Residence Time is important for a better understanding of hydro-bio-geochemical processes and mixing properties of wetlands used as filters in ecological applications, as well as protecting fresh water sources for wells from pollutants. Common methods of estimating the Water Residence Time focus on cross-correlation, parameter fitting and non-parametric deconvolution methods. Here we propose a 1D full-deconvolution, regularized, non-parametric inverse problem algorithm that enforces smoothness and uses constraints of causality and positivity to estimate the Water Residence Time curve. Compared to Bayesian non-parametric deconvolution approaches, it has a fast runtime per test case; compared to the popular and fast cross-correlation method, it produces a more precise Water Residence Time curve even in the case of noisy measurements. The algorithm needs only one regularization parameter to balance between smoothness of the Water Residence Time and accuracy of the reconstruction. We propose an approach on how to automatically find a suitable value of the regularization parameter from the input data only. Tests on real data illustrate the potential of this method to analyze hydrological datasets.

Ground Data System Analysis Tools to Track Flight System State Parameters for the Mars Science Laboratory (MSL) and Beyond

NASA Technical Reports Server (NTRS)

Allard, Dan; Deforrest, Lloyd

2014-01-01

Flight software parameters enable space mission operators fine-tuned control over flight system configurations, enabling rapid and dynamic changes to ongoing science activities in a much more flexible manner than can be accomplished with (otherwise broadly used) configuration file based approaches. The Mars Science Laboratory (MSL), Curiosity, makes extensive use of parameters to support complex, daily activities via commanded changes to said parameters in memory. However, as the loss of Mars Global Surveyor (MGS) in 2006 demonstrated, flight system management by parameters brings with it risks, including the possibility of losing track of the flight system configuration and the threat of invalid command executions. To mitigate this risk a growing number of missions have funded efforts to implement parameter tracking parameter state software tools and services including MSL and the Soil Moisture Active Passive (SMAP) mission. This paper will discuss the engineering challenges and resulting software architecture of MSL's onboard parameter state tracking software and discuss the road forward to make parameter management tools suitable for use on multiple missions.

Evaluation of selected recurrence measures in discriminating pre-ictal and inter-ictal periods from epileptic EEG data

NASA Astrophysics Data System (ADS)

Ngamga, Eulalie Joelle; Bialonski, Stephan; Marwan, Norbert; Kurths, Jürgen; Geier, Christian; Lehnertz, Klaus

2016-04-01

We investigate the suitability of selected measures of complexity based on recurrence quantification analysis and recurrence networks for an identification of pre-seizure states in multi-day, multi-channel, invasive electroencephalographic recordings from five epilepsy patients. We employ several statistical techniques to avoid spurious findings due to various influencing factors and due to multiple comparisons and observe precursory structures in three patients. Our findings indicate a high congruence among measures in identifying seizure precursors and emphasize the current notion of seizure generation in large-scale epileptic networks. A final judgment of the suitability for field studies, however, requires evaluation on a larger database.

A multimethod Global Sensitivity Analysis to aid the calibration of geomechanical models via time-lapse seismic data

NASA Astrophysics Data System (ADS)

Price, D. C.; Angus, D. A.; Garcia, A.; Fisher, Q. J.; Parsons, S.; Kato, J.

2018-03-01

Time-lapse seismic attributes are used extensively in the history matching of production simulator models. However, although proven to contain information regarding production induced stress change, it is typically only loosely (i.e. qualitatively) used to calibrate geomechanical models. In this study we conduct a multimethod Global Sensitivity Analysis (GSA) to assess the feasibility and aid the quantitative calibration of geomechanical models via near-offset time-lapse seismic data. Specifically, the calibration of mechanical properties of the overburden. Via the GSA, we analyse the near-offset overburden seismic traveltimes from over 4000 perturbations of a Finite Element (FE) geomechanical model of a typical High Pressure High Temperature (HPHT) reservoir in the North Sea. We find that, out of an initially large set of material properties, the near-offset overburden traveltimes are primarily affected by Young's modulus and the effective stress (i.e. Biot) coefficient. The unexpected significance of the Biot coefficient highlights the importance of modelling fluid flow and pore pressure outside of the reservoir. The FE model is complex and highly nonlinear. Multiple combinations of model parameters can yield equally possible model realizations. Consequently, numerical calibration via a large number of random model perturbations is unfeasible. However, the significant differences in traveltime results suggest that more sophisticated calibration methods could potentially be feasible for finding numerous suitable solutions. The results of the time-varying GSA demonstrate how acquiring multiple vintages of time-lapse seismic data can be advantageous. However, they also suggest that significant overburden near-offset seismic time-shifts, useful for model calibration, may take up to 3 yrs after the start of production to manifest. Due to the nonlinearity of the model behaviour, similar uncertainty in the reservoir mechanical properties appears to influence overburden traveltime to a much greater extent. Therefore, reservoir properties must be known to a suitable degree of accuracy before the calibration of the overburden can be considered.

Synthesis and characterization of cycloaliphatic hydrophilic polyurethanes, modified with l-ascorbic acid, as materials for soft tissue regeneration.

PubMed

Kucinska-Lipka, J; Gubanska, I; Strankowski, M; Cieśliński, H; Filipowicz, N; Janik, H

2017-06-01

In this paper we described synthesis and characteristic of obtained hydrophilic polyurethanes (PURs) modified with ascorbic acid (commonly known as vitamin C). Such materials may find an application in the biomedical field, for example in the regenerative medicine of soft tissues, according to ascorbic acid wide influence on tissue regeneration Flora (2009), Szymańska-Pasternak et al. (2011), Taikarimi and Ibrahim (2011), Myrvik and Volk (1954), Li et al. (2001), Cursino et al. (2005) . Hydrophilic PURs were obtained with the use of amorphous α,ω-dihydroxy(ethylene-butylene adipate) (dHEBA) polyol, 1,4-butanediol (BDO) chain extender and aliphatic 4,4'-methylenebis(cyclohexyl isocyanate) (HMDI). HMDI was chosen as a nontoxic diisocyanate, suitable for biomedical PUR synthesis. Modification with l-ascorbic acid (AA) was performed to improve obtained PUR materials biocompatibility. Chemical structure of obtained PURs was provided and confirmed by Fourier transform infrared spectroscopy (FTIR) and Proton nuclear magnetic resonance spectroscopy ( 1 HNMR). Differential scanning calorimetry (DSC) was used to indicate the influence of ascorbic acid modification on such parameters as glass transition temperature, melting temperature and melting enthalpies of obtained materials. To determine how these materials may potentially behave, after implementation in tissue, degradation behavior of obtained PURs in various chemical environments, which were represented by canola oil, saline solution, distilled water and phosphate buffered saline (PBS) was estimated. The influence of AA on hydrophilic-hydrophobic character of obtained PURs was established by contact angle study. This experiment revealed that ascorbic acid significantly improves hydrophilicity of obtained PUR materials and the same cause that they are more suitable candidates for biomedical applications. Good hemocompatibility characteristic of studied PUR materials was confirmed by the hemocompatibility test with human blood. Microbiological tests were carried out to indicate the microbiological sensitivity of obtained PURs. Results of performed studies showed that obtained AA-modified PUR materials may find an application in soft tissue regeneration. Copyright © 2017 Elsevier B.V. All rights reserved.

Automated Acquisition of Proximal Femur Morphological Characteristics

NASA Astrophysics Data System (ADS)

Tabakovic, Slobodan; Zeljkovic, Milan; Milojevic, Zoran

2014-10-01

The success of the hip arthroplasty surgery largely depends on the endoprosthesis adjustment to the patient's femur. This implies that the position of the femoral bone in relation to the pelvis is preserved and that the endoprosthesis position ensures its longevity. Dimensions and body shape of the hip joint endoprosthesis and its position after the surgery depend on a number of geometrical parameters of the patient's femur. One of the most suitable methods for determination of these parameters involves 3D reconstruction of femur, based on diagnostic images, and subsequent determination of the required geometric parameters. In this paper, software for automated determination of geometric parameters of the femur is presented. Detailed software development procedure for the purpose of faster and more efficient design of the hip endoprosthesis that ensures patients' specific requirements is also offered

Deterministic diffusion in flower-shaped billiards.

PubMed

Harayama, Takahisa; Klages, Rainer; Gaspard, Pierre

2002-08-01

We propose a flower-shaped billiard in order to study the irregular parameter dependence of chaotic normal diffusion. Our model is an open system consisting of periodically distributed obstacles in the shape of a flower, and it is strongly chaotic for almost all parameter values. We compute the parameter dependent diffusion coefficient of this model from computer simulations and analyze its functional form using different schemes, all generalizing the simple random walk approximation of Machta and Zwanzig. The improved methods we use are based either on heuristic higher-order corrections to the simple random walk model, on lattice gas simulation methods, or they start from a suitable Green-Kubo formula for diffusion. We show that dynamical correlations, or memory effects, are of crucial importance in reproducing the precise parameter dependence of the diffusion coefficent.

Proline puckering parameters for collagen structure simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Di, E-mail: diwu@fudan.edu.cn

Collagen is made of triple helices rich in proline residues, and hence is influenced by the conformational motions of prolines. Because the backbone motions of prolines are restricted by the helical structures, the only side chain motion—proline puckering—becomes an influential factor that may affect the stability of collagen structures. In molecular simulations, a proper proline puckering population is desired so to yield valid results of the collagen properties. Here we design the proline puckering parameters in order to yield suitable proline puckering populations as demonstrated in the experimental results. We test these parameters in collagen and the proline dipeptide simulations.more » Compared with the results of the PDB and the quantum calculations, we propose the proline puckering parameters for the selected collagen model simulations.« less

Dual-optical-response photonic crystal fibre interferometer for multi-parameter sensing

NASA Astrophysics Data System (ADS)

Villatoro, Joel; Minkovich, Vladimir P.; Zubia, Joseba

2014-05-01

An all-fiber mode interferometer consisting of a short segment of photonic crystal fiber (PCF) fusion spliced to standard single mode optical fiber and pressed on localized regions is proposed for multi-parameter sensing. In our configuration, the physical parameter being sensed changes the fringe contrast (or visibility) of the interference pattern and also causes a shift to the same. To achieve this dual effect the device is pressed on localized regions over a few millimeters. In this manner we introduce losses and effective refractive index changes to the interference modes, hence visibility and shift to the interference pattern. Our interferometer is suitable for monitoring diverse physical parameters such as weight, force, pressure, load, etc. The advantage is that no temperature or power fluctuations compensation is required.

Cell edge detection in JPEG2000 wavelet domain - analysis on sigmoid function edge model.

PubMed

Punys, Vytenis; Maknickas, Ramunas

2011-01-01

Big virtual microscopy images (80K x 60K pixels and larger) are usually stored using the JPEG2000 image compression scheme. Diagnostic quantification, based on image analysis, might be faster if performed on compressed data (approx. 20 times less the original amount), representing the coefficients of the wavelet transform. The analysis of possible edge detection without reverse wavelet transform is presented in the paper. Two edge detection methods, suitable for JPEG2000 bi-orthogonal wavelets, are proposed. The methods are adjusted according calculated parameters of sigmoid edge model. The results of model analysis indicate more suitable method for given bi-orthogonal wavelet.

Copper speciation in highway stormwater runoff as related to bioavailability and toxicity to ESA-listed salmon.

DOT National Transportation Integrated Search

2011-04-01

The objectives of this study were to 1) identify the effects of site location, storm hydrology, and water quality parameters on the concentration of dissolved copper (Cu2+diss) in Oregon highway runoff; 2) establish an analytical technique suitable f...

DOSE-DEPENDENCY OF 2-ACETYLAMINOFLUORENE BINDING TO LIVER DNA AND HEMOGLOBIN IN MICE AND RATS

EPA Science Inventory

The carcinogenic activity of 2-acetylaminofluorene (2-AAF) in mice and rats has been accurately described so that it is a suitable archetypical chemical for investigations of parameters of cross-species variation. The results of the study supported a pharmacokinetic model that re...

Radiochromic film dosimetry for UV-C treatments of apple fruit

USDA-ARS?s Scientific Manuscript database

Radiochromic films were evaluated for their suitability to estimate UV-C doses and dose uniformity on apple fruit surface. Parameters investigated included film type, color changes of the films in response to different UV-C doses, color stability of films, UV-C light intensity, and temperature. In...

Suitability of a liquid larval diet for rearing the Philippines fruit fly Bactrocera philippinensis (Diptera:Tephritidae)

USDA-ARS?s Scientific Manuscript database

A liquid larval diet as an artificial rearing medium was successfully tested for the Philippines fruit fly Bactrocera philippinensis Drew & Hancock. The biological parameters studied were pupal weight, adult emergence and fliers, sex ratio, fecundity and fertility. The insects performed most satisfa...

A prototype national cattle evaluation for feed intake and efficiency of Angus cattle

USDA-ARS?s Scientific Manuscript database

Recent development of technologies for measuring individual feed intake has made possible the collection of data suitable for breed-wide genetic evaluation. Goals of this research were to estimate genetic parameters for components of feed efficiency and develop a prototype system for conducting a ge...

Influence of water use and environmental parameters on proso millet yield

USDA-ARS?s Scientific Manuscript database

Proso millet (Panicum miliaceum L.) is a short-season, drought-tolerant C4 species capable of making use of limited available water supplies and is suitable for dryland crop rotations in the central Great Plains. Previously published water use/yield production functions for proso millet have slopes ...

Electrochemical Study and Determination of Electroactive Species with Screen-Printed Electrodes

ERIC Educational Resources Information Center

Martín-Yerga, Daniel; Costa Rama, Estefanía; Costa García, Agustín

2016-01-01

A lab appropriate to introduce voltammetric techniques and basic electrochemical parameters is described in this work. It is suitable to study theoretical concepts of electrochemistry in an applied way for analytical undergraduate courses. Two electroactive species, hexaammineruthenium and dopamine, are used as simple redox systems. Screen-printed…

50 CFR 23.65 - What factors are considered in making a finding that an applicant is suitably equipped to house...

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false What factors are considered in making a...) TAKING, POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND...) Factors Considered in Making Certain Findings § 23.65 What factors are considered in making a finding that...

Humic Fertilizer and Vermicompost Applied to the Soil Can Positively Affect Population Growth Parameters of Trichogramma brassicae (Hymenoptera: Trichogrammatidae) on Eggs of Tuta absoluta (Lepidoptera: Gelechiidae).

PubMed

Mohamadi, P; Razmjou, J; Naseri, B; Hassanpour, M

2017-12-01

The tomato leaf miner, Tuta absoluta (Meyrick), is a devastating pest of tomato worldwide. One of the control measures of T. absoluta is the use of biological control agents, such as Trichogramma wasps. Interactions between natural enemies and insect pests may be affected by application of fertilizers, because changes in plant quality through the fertilizer application may therefore affect herbivore characteristics and suitability of them to parasitism. Laboratory tests were carried out to evaluate the life table parameters of Trichogramma brassicae Bezdenko on T. absoluta eggs reared on tomato plants treated either with vermicompost (40%), humic fertilizer (2 g/kg soil), or control (suitable mixture of field soil and sand). Population growth parameters of T. brassicae were affected by fertilizer treatments. Significant differences were found for immature life period and total fecundity of T. brassicae on the treatments. Differences of intrinsic rate of natural increase (r m ), finite rate of increase (λ), net reproductive rate (R 0 ), mean generation time (T), and doubling time (DT) of T. brassicae among treatments were also significant. The lowest values of r m , λ, and R 0 were recorded for T. brassicae developed on T. absoluta eggs on control treatment, whereas the highest values of these parameters were observed on 2 g/kg humic fertilizer. Furthermore, T. brassicae had the shortest T and DT values on 2 g/kg humic fertilizer and 40% vermicompost treatments. Our results showed that application of humic fertilizer and vermicompost could positively affect population growth parameters of T. brassicae on eggs of T. absoluta fed on tomato plants.

Norfloxacin and metronidazole topical formulations for effective treatment of bacterial infections and burn wounds

PubMed Central

Dua, Kamal; Malipeddi, Venkata Ramana; Madan, Jyotsna; Gupta, Gaurav; Chakravarthi, Srikumar; Awasthi, Rajendra; Kikuchi, Irene Satiko; De Jesus Andreoli Pinto, Terezinha

2016-01-01

Introduction Our various previous findings have shown the suitability of norfloxacin in the treatment of bacterial infections and burn wounds in alone as well as in combination with Curcuma longa in various topical (ointments, gels, and creams) and transdermal drug delivery systems. Aims and methods Keeping these facts in consideration, we have made an another attempt to prepare semisolid formulations containing 1% w/w of norfloxacin and metronidazole with different bases like Carbopol, polyethylene glycol, and hydroxypropylmethyl cellulose for effective treatment of bacterial infections and burn wounds. The prepared formulations were evaluated for physicochemical parameters, in vitro drug release, antimicrobial activity, and burn wound healing properties. Results The prepared formulations were compared with Silver Sulfadiazine cream 1%, USP. Antimicrobial activity of norfloxacin semisolid formulations was found to be equally effective against both aerobic and anaerobic bacteria in comparison to a marketed formulation of Silver Sulfadiazine 1% cream, USP. Based on the burn wound healing property, the prepared norfloxacin semisolid formulation was found to be in good agreement with marketed Silver Sulfadiazine 1% cream, USP. Conclusions These findings suggest formulations containing norfloxacin and metronidazole may also prove as an effective alternative for existing remedies in the treatment of bacterial infections and burn wounds. PMID:28386462

A multiplex primer design algorithm for target amplification of continuous genomic regions.

PubMed

Ozturk, Ahmet Rasit; Can, Tolga

2017-06-19

Targeted Next Generation Sequencing (NGS) assays are cost-efficient and reliable alternatives to Sanger sequencing. For sequencing of very large set of genes, the target enrichment approach is suitable. However, for smaller genomic regions, the target amplification method is more efficient than both the target enrichment method and Sanger sequencing. The major difficulty of the target amplification method is the preparation of amplicons, regarding required time, equipment, and labor. Multiplex PCR (MPCR) is a good solution for the mentioned problems. We propose a novel method to design MPCR primers for a continuous genomic region, following the best practices of clinically reliable PCR design processes. On an experimental setup with 48 different combinations of factors, we have shown that multiple parameters might effect finding the first feasible solution. Increasing the length of the initial primer candidate selection sequence gives better results whereas waiting for a longer time to find the first feasible solution does not have a significant impact. We generated MPCR primer designs for the HBB whole gene, MEFV coding regions, and human exons between 2000 bp to 2100 bp-long. Our benchmarking experiments show that the proposed MPCR approach is able produce reliable NGS assay primers for a given sequence in a reasonable amount of time.

Dunye Guanxinning Improves Acute Myocardial Ischemia-Reperfusion Injury by Inhibiting Neutrophil Infiltration and Caspase-1 Activity

PubMed Central

Zhang, Q. G.; Wang, S. R.; Chen, X. M.; Guo, H. N.

2018-01-01

Acute myocardial infarction is the most serious manifestation of cardiovascular disease, and it is a life-threatening condition. Dunye Guanxinning (DG) is a protective traditional Chinese patent herbal medicine with high clinical efficacy and suitable for the treatment of myocardial infarction. However, the mechanism through which it is beneficial is unclear. In this study, we hypothesized that DG improves acute myocardial ischemia-reperfusion injury by inhibiting neutrophil infiltration and caspase-1 activity. We found that DG administration decreased infarct size and cardiomyocyte apoptosis and improved left ventricular ejection fraction, fractional shortening, end-systolic volume index, end-systolic diameter, and carotid arterial blood flow output in rats. DG administration also improved hemorheological parameters, myocardial damage biomarkers, and oxidative stress indexes. The findings showed that DG administration inhibited neutrophil infiltration and reduced the serum interleukin-1 beta (IL-1β) level and myocardial IL-1β maturation. Moreover, DG administration inhibited caspase-1 activity and activated adenosine monophosphate-activated protein kinase (AMPK) phosphorylation in rat hearts. These results suggested that DG administration inhibits inflammasome activity and IL-1β release through the AMPK pathway. Our findings support the clinical efficacy of DG and partially reveal its mechanism, which is beneficial for understanding the therapeutic effects of this protective traditional Chinese patent drug. PMID:29674944

Designing optimal stimuli to control neuronal spike timing

PubMed Central

Packer, Adam M.; Yuste, Rafael; Paninski, Liam

2011-01-01

Recent advances in experimental stimulation methods have raised the following important computational question: how can we choose a stimulus that will drive a neuron to output a target spike train with optimal precision, given physiological constraints? Here we adopt an approach based on models that describe how a stimulating agent (such as an injected electrical current or a laser light interacting with caged neurotransmitters or photosensitive ion channels) affects the spiking activity of neurons. Based on these models, we solve the reverse problem of finding the best time-dependent modulation of the input, subject to hardware limitations as well as physiologically inspired safety measures, that causes the neuron to emit a spike train that with highest probability will be close to a target spike train. We adopt fast convex constrained optimization methods to solve this problem. Our methods can potentially be implemented in real time and may also be generalized to the case of many cells, suitable for neural prosthesis applications. With the use of biologically sensible parameters and constraints, our method finds stimulation patterns that generate very precise spike trains in simulated experiments. We also tested the intracellular current injection method on pyramidal cells in mouse cortical slices, quantifying the dependence of spiking reliability and timing precision on constraints imposed on the applied currents. PMID:21511704

The fluorescence intensities ratio is not a reliable parameter for evaluation of protein unfolding transitions.

PubMed

Žoldák, Gabriel; Jancura, Daniel; Sedlák, Erik

2017-06-01

Monitoring the fluorescence of proteins, particularly the fluorescence of intrinsic tryptophan residues, is a popular method often used in the analysis of unfolding transitions (induced by temperature, chemical denaturant, and pH) in proteins. The tryptophan fluorescence provides several suitable parameters, such as steady-state fluorescence intensity, apparent quantum yield, mean fluorescence lifetime, position of emission maximum that are often utilized for the observation of the conformational/unfolding transitions of proteins. In addition, the fluorescence intensities ratio at different wavelengths (usually at 330 nm and 350 nm) is becoming an increasingly popular parameter for the evaluation of thermal transitions. We show that, under certain conditions, the use of this parameter for the analysis of unfolding transitions leads to the incorrect determination of thermodynamic parameters characterizing unfolding transitions in proteins (e.g., melting temperature) and, hence, can compromise the hit identification during high-throughput drug screening campaigns. © 2017 The Protein Society.

Spectroscopic properties of Cr3+ ions at the defect sites in cubic fluoroperovskite crystals

NASA Astrophysics Data System (ADS)

Wan-Lun, Yu; Xin-Min, Zhang; La-Xun, Yang; Bao-Qing, Zen

1994-09-01

The spin-Hamiltonian (SH) parameters for the 4A2(F) state of 3d3/3d7 ions for tetragonal and trigonal symmetries are studied as a function of the crystal-field (CF) parameters based on simultaneous diagonalization of the electrostatic, CF, and the spin-orbit-coupling Hamiltonians. The results obtained are compared to those in earlier works. The CF and SH parameters of Cr3+ ions at the A and M vacancies and at codoped Li+ sites in the cubic fluoroperovskites AMF3 are investigated by taking into account the contributions of the defects and the defect-induced lattice distortion. Suitable models are proposed for the lattice distortion, and the distortion parameters are obtained by adjusting them to fit to the observed data for the SH parameters and the energy of the first excited state.