WorldWideScience

Sample records for operational variable effects

  1. The effects of criterion variability on relative operating characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Brown, W.S. [Brookhaven Natl. Lab., Bldg. 130, Upton, NY 11973-5000 (United States); Emmerich, D.S. [State Univ. of New York at Stony Brook, Stony Brook, NY 11974 (United States)

    1995-05-01

    The form of the relative operating characteristic (ROC) describing auditory detection typically differs from that expected based on the assumption that the observer`s responses reflect underlying distributions that are normal and of equal variance [e.g., Green and Swets, {ital Signal} {ital Detection} {ital Theory} {ital and} {ital Psychophysics}]. Specifically, it is found that binormal ROCs often have slopes less than one, and are not strictly linear [Watson {ital et} {ital al}., 283--288 (1964)]. It has been suggested that nonlinear binormal ROCs may be the result of extreme criteria being more variable than those more centrally positioned [Emmerich and Binder, J. Acoust. Soc. Am. Suppl. 1 {bold 65}, S59 (1979)]. The forms of rating ROCs obtained in an experiment designed to reveal the effects of such variability were consistent with the proposition that criteria associated with ``no`` responses are more variable than those associated with ``yes`` responses. Criterion operating characteristics [Wickelgren, J. Math. Psychol. {bold 5}, 102--122], which reflect the relative locations and variances of the boundaries of confidence categories, favored the same interpretation. It is concluded that the variability of criteria defining categories of rated confidence is sizable and not necessarily constant across criteria, and that such variability significantly influences the forms of empirical ROCs determined using confidence ratings in auditory signal detection.

  2. effects of operational variables on the pulp yield and lignin ...

    African Journals Online (AJOL)

    DEPT OF AGRICULTURAL ENGINEERING

    delignification conditions for the production of pulp and paper from the plant. Cyperus articula- ... pulp yields were obtained using low values of the process variables while the reverse was the case for the residual ..... Chemical Engineering.

  3. Variability as an Operant?

    Science.gov (United States)

    Holth, Per

    2012-01-01

    A series of experiments on operant variability by Neuringer and colleagues (e.g., Neuringer, 1986, 2002; Page & Neuringer, 1985) have been repeatedly cited as showing that behavioral variability can be reinforced by making reinforcement contingent on it. They showed that the degree of variability in pigeons' eight-peck sequences, as measured by U…

  4. OIL SPILL DISPERSANT EFFECTIVENESS PROTOCOL. I: IMPACT OF OPERATIONAL VARIABLES

    Science.gov (United States)

    The current U.S. Environmental Protection Agency protocol for testing the effectiveness of dispersants, the swirling flask test, has been found to give widely varying results in the hands of different testing laboratories. The sources of the ambiguities in the test were determin...

  5. Analysis of Variable Speed Optimization Operation Effect of Different-type Pumps in Jiangdu Pumping Station

    Science.gov (United States)

    Jinxian, Qiu; Jilin, Cheng; Jinyao, Luo; Rentian, Zhang; Lihua, Zhang; Yi, Gong

    2010-06-01

    The following paper puts forward 45 combination schemes of different-type pumps in different daily-average heads and operation loads in Jiangdu Pumping Station. Based on every scheme, the minimum electricity consumption cost selected as the objective function, this paper gives the results of variable speed optimal operations with dynamic planning methods in both considering time-sharing electricity prices and not, simultaneously, it gives the results of fixed speed conventional operation considering time-sharing electricity prices. Then according to the unit energy consumption cost, the paper gives comparison analysis of the effect of different-type pumps in variable speed optimization operation, the conclusions can offer decision-making bases for optimization research of pumping stations considering time-sharing electricity prices and tide levels of Yangtze River, and offer references for transformation and economical operation of large and medium-size pumping stations.

  6. What is the Effect of Interannual Hydroclimatic Variability on Water Supply Reservoir Operations?

    Science.gov (United States)

    Galelli, S.; Turner, S. W. D.

    2015-12-01

    Rather than deriving from a single distribution and uniform persistence structure, hydroclimatic data exhibit significant trends and shifts in their mean, variance, and lagged correlation through time. Consequentially, observed and reconstructed streamflow records are often characterized by features of interannual variability, including long-term persistence and prolonged droughts. This study examines the effect of these features on the operating performance of water supply reservoirs. We develop a Stochastic Dynamic Programming (SDP) model that can incorporate a regime-shifting climate variable. We then compare the performance of operating policies—designed with and without climate variable—to quantify the contribution of interannual variability to standard policy sub-optimality. The approach uses a discrete-time Markov chain to partition the reservoir inflow time series into small number of 'hidden' climate states. Each state defines a distinct set of inflow transition probability matrices, which are used by the SDP model to condition the release decisions on the reservoir storage, current-period inflow and hidden climate state. The experimental analysis is carried out on 99 hypothetical water supply reservoirs fed from pristine catchments in Australia—all impacted by the Millennium drought. Results show that interannual hydroclimatic variability is a major cause of sub-optimal hedging decisions. The practical import is that conventional optimization methods may misguide operators, particularly in regions susceptible to multi-year droughts.

  7. The Effects of Operational and Environmental Variables on Efficiency of Danish Water and Wastewater Utilities

    Directory of Open Access Journals (Sweden)

    Andrea Guerrini

    2015-06-01

    Full Text Available Efficiency improvement is one of three patterns a public utility should follow in order to get funds for investments realization. The other two are recourse to bank loans or to private equity and tariff increase. Efficiency can be improved, for example, by growth and vertical integration and may be conditioned by environmental variables, such as customer and output density. Prior studies into the effects of these variables on the efficiency of water utilities do not agree on certain points (e.g., scale and economies of scope and rarely consider others (e.g., density economies. This article aims to contribute to the literature by analysing the efficiency of water utilities in Denmark, observing the effects of operational and environmental variables. The method is based on two-stage Data Envelopment Analysis (DEA applied to 101 water utilities. We found that the efficiency of the water sector was not affected by the observed variables, whereas that of wastewater was improved by smaller firm size, vertical integration strategy, and higher population density.

  8. Operant Variability: A Conceptual Analysis

    Science.gov (United States)

    Barba, Lourenco de Souza

    2012-01-01

    Some researchers claim that variability is an operant dimension of behavior. The present paper reviews the concept of operant behavior and emphasizes that differentiation is the behavioral process that demonstrates an operant relation. Differentiation is conceived as change in the overlap between two probability distributions: the distribution of…

  9. Operating Reserves and Variable Generation

    Energy Technology Data Exchange (ETDEWEB)

    Ela, E.; Milligan, M.; Kirby, B.

    2011-08-01

    This report tries to first generalize the requirements of the power system as it relates to the needs of operating reserves. It also includes a survey of operating reserves and how they are managed internationally in system operations today and then how new studies and research are proposing they may be managed in the future with higher penetrations of variable generation.

  10. Effects of design and operating variables on process characteristics in a methane discharge: a numerical study

    Science.gov (United States)

    Bera, K.; Farouk, B.; Lee, Y. H.

    2001-05-01

    A self-consistent two-dimensional radio frequency capacitively coupled glow discharge model has been developed in cylindrical coordinates for a methane discharge using a fluid model. The objective of the study is to identify the effects of design and operating variables of the reactor on the process characteristics such as the deposition rate, uniformity and the quality of the diamond-like-carbon film. The simulations provide insights to charged species dynamics and investigate their effects on the plasma process for a depositing methane discharge. The model includes continuity equations for electrons and positive and negative ions, and energy equation for electrons. Swarm data as a function of electron energy are provided as input to the model. The model predicts the electron density, ion density, and their fluxes and energies to the cathode. The roles of electrons, dominating ions and radicals in a capacitively coupled discharge are investigated. The radical and neutral densities in the discharge are calculated using a gas phase chemistry model. The diamond-like-carbon thin-film deposition rate is predicted using surface chemistry model. The gas phase chemistry model considers diffusion of radicals and neutrals along with creation and loss terms. The surface deposition/etching process involves adsorption-desorption, adsorption layer reaction, ion stitching, direct ion incorporation, etching and carbon sputtering. A systematic parametric study of plasma processing has been performed to identify process parameters to obtain better film deposition/etching on a wafer. The present work shows how plasma equipment simulation can be used for the practical investigation and optimization of a plasma-assisted chemical vapour deposition process. The simultaneous treatment of plasma dynamics and surface processes enables a very precise prediction of the process characteristics in terms of the film deposition rate, uniformity and the quality as functions of discharge control

  11. Effect of Operation Variables on Hydrodenitrogenation and Hydrodesulfurization over NiMo/Al2O3 Catalysts

    Institute of Scientific and Technical Information of China (English)

    段爱军; 徐春明; 林世雄

    2003-01-01

    Using the JQ-Ⅱ high pressure hydrogenation micro-reactor unit, the reactivity of Athabasca bitumen derived heavy gas oil was studied over commercial and homemade hydrotreating catalysts. The effects of catalyst preparation variables and the influences of operation conditions, such as pressure, temperature, hydrogen/oil ratio and space velocity were also examined. It was shown that the optimal concentrations of the active components were 5% of NiO, 20% of MoO3 and 3.5% of phosphorus (by mass), and the suitable operation conditions were determined experimentally.

  12. Operant variability when reinforcement is delayed.

    Science.gov (United States)

    Wagner, Katie; Neuringer, Allen

    2006-05-01

    Operant responses are often weakened when delays are imposed between the responses and reinforcers. We examined what happens when delayed reinforcers were contingent upon operant response variability. Three groups of rats were rewardedfor varying their response sequences, with onegroup rewarded for high variability, another for middle, and the third for low levels. Consistent with many reports in the literature, responding slowed significantly in all groups as delays were lengthened. Consistent with other reports, large differences in variability were maintained across the three groups despite the delays. Reinforced variability appears to be relatively immune to disruption by such things as delays, response slowing, prefeeding, and noncontingent reinforcement. Furthermore, the small effects on variability depended on baseline levels: As delays lengthened, variability increased in the low group, was statistically unchanged in the middle group, and decreased in the high group, an interaction similar to that reported previously when reinforcement frequencies were lowered. Thus, variable operant responding is controlled by reinforcement contingencies, but sometimes differently than more commonly studied repetitive responding.

  13. Effect of operational variables on nitrogen transformations in duckweed stabilization ponds

    NARCIS (Netherlands)

    Caicedo Bejarano, J.R.

    2005-01-01

    There is a diversity of conventional technologies available for removal of pollutants from wastewater. Most of these technologies are aerobic alternatives with high construction cost and high energy consumption and require skilled personal for operation and maintenance.

  14. Effect of operational variables on nitrogen transformations in duckweed stabilization ponds

    OpenAIRE

    Caicedo Bejarano, J.R.

    2005-01-01

    There is a diversity of conventional technologies available for removal of pollutants from wastewater. Most of these technologies are aerobic alternatives with high construction cost and high energy consumption and require skilled personal for operation and maintenance. As a consequence, only countries with a high gross national product (GNP) can afford these options. Where these technologies were introduced in developing countries, in most cases these could not be operated sustainably, leadi...

  15. Effect of operational variables on nitrogen transformations in duckweed stabilization ponds

    OpenAIRE

    Caicedo Bejarano, J.R.

    2005-01-01

    There is a diversity of conventional technologies available for removal of pollutants from wastewater. Most of these technologies are aerobic alternatives with high construction cost and high energy consumption and require skilled personal for operation and maintenance. As a consequence, only countries with a high gross national product (GNP) can afford these options. Where these technologies were introduced in developing countries, in most cases these could not be operated sustainably, leadi...

  16. Effect of operational variables on nitrogen transformations in duckweed stabilization ponds

    NARCIS (Netherlands)

    Caicedo Bejarano, J.R.

    2005-01-01

    There is a diversity of conventional technologies available for removal of pollutants from wastewater. Most of these technologies are aerobic alternatives with high construction cost and high energy consumption and require skilled personal for operation and maintenance.

  17. Effect of operational variables on nitrogen transformations in duckweed stabilization ponds

    NARCIS (Netherlands)

    Caicedo Bejarano, J.R.

    2005-01-01

    There is a diversity of conventional technologies available for removal of pollutants from wastewater. Most of these technologies are aerobic alternatives with high construction cost and high energy consumption and require skilled personal for operation and maintenance.

  18. Repressing the effects of variable speed harmonic orders in operational modal analysis

    Science.gov (United States)

    Randall, R. B.; Coats, M. D.; Smith, W. A.

    2016-10-01

    Discrete frequency components such as machine shaft orders can disrupt the operation of normal Operational Modal Analysis (OMA) algorithms. With constant speed machines, they have been removed using time synchronous averaging (TSA). This paper compares two approaches for varying speed machines. In one method, signals are transformed into the order domain, and after the removal of shaft speed related components by a cepstral notching method, are transformed back to the time domain to allow normal OMA. In the other simpler approach an exponential shortpass lifter is applied directly in the time domain cepstrum to enhance the modal information at the expense of other disturbances. For simulated gear signals with speed variations of both ±5% and ±15%, the simpler approach was found to give better results The TSA method is shown not to work in either case. The paper compares the results with those obtained using a stationary random excitation.

  19. Effect of Processing Variables and Enzymatic Activity on Wheat Flour Dough Extruded Under Different Operating Conditions

    Directory of Open Access Journals (Sweden)

    Roma Giuliani

    2009-01-01

    Full Text Available Low processing temperatures are required to improve the texture of products when enzymes are directly added to the extruder. Interaction among processing variables and enzymatic activity can occur during extrusion. In this research, the influence of some extrusion parameters (barrel temperature, dough moisture and screw speed on the activity of two commercial enzymes (Grindamyl Amylase 1000 and Grindamyl Protease 41 has been studied. Wheat flour was used as a model system, and macromolecular degradation was determined by water solubility index (WSI. Moreover, gelatinization degree and die pressure were evaluated. Results showed that barrel temperature affected enzyme activity. High values of WSI were obtained at high barrel temperature using Grindamyl Protease 41. When Grindamyl Amylase 1000 was used, low values of starch gelatinization were obtained. The activity of both enzymes was negatively affected by high values of dough moisture.

  20. Operant Variability and the Power of Reinforcement

    Science.gov (United States)

    Neuringer, Allen

    2009-01-01

    Reinforcers contingent on response variability exert powerful and precise control over levels of variability, from stereotypy to stochasticity. This paper reviews how variability-contingent reinforcers interact with non-contingent, eliciting events to influence the variability of operant responses. Relationships to stimulus control, choice,…

  1. Properties of two variables Toeplitz type operators

    Directory of Open Access Journals (Sweden)

    Elżbieta Król-Klimkowska

    2016-11-01

    Full Text Available The investigation of properties of generalized Toeplitz operators with respect to the pairs of doubly commuting contractions (the abstract analogue of classical two variable Toeplitz operators is proceeded. We especially concentrate on the condition of existence such a non-zero operator. There are also presented conditions of analyticity of such an operator.

  2. Operant Variability and Voluntary Action

    Science.gov (United States)

    Neuringer, Allen; Jensen, Greg

    2010-01-01

    A behavior-based theory identified 2 characteristics of voluntary acts. The first, extensively explored in operant-conditioning experiments, is that voluntary responses produce the reinforcers that control them. This bidirectional relationship--in which reinforcer depends on response and response on reinforcer--demonstrates the functional nature…

  3. Variable Order and Distributed Order Fractional Operators

    Science.gov (United States)

    Lorenzo, Carl F.; Hartley, Tom T.

    2002-01-01

    Many physical processes appear to exhibit fractional order behavior that may vary with time or space. The continuum of order in the fractional calculus allows the order of the fractional operator to be considered as a variable. This paper develops the concept of variable and distributed order fractional operators. Definitions based on the Riemann-Liouville definitions are introduced and behavior of the operators is studied. Several time domain definitions that assign different arguments to the order q in the Riemann-Liouville definition are introduced. For each of these definitions various characteristics are determined. These include: time invariance of the operator, operator initialization, physical realization, linearity, operational transforms. and memory characteristics of the defining kernels. A measure (m2) for memory retentiveness of the order history is introduced. A generalized linear argument for the order q allows the concept of "tailored" variable order fractional operators whose a, memory may be chosen for a particular application. Memory retentiveness (m2) and order dynamic behavior are investigated and applications are shown. The concept of distributed order operators where the order of the time based operator depends on an additional independent (spatial) variable is also forwarded. Several definitions and their Laplace transforms are developed, analysis methods with these operators are demonstrated, and examples shown. Finally operators of multivariable and distributed order are defined in their various applications are outlined.

  4. Application of response surface methodology to assess the combined effect of operating variables on high-pressure coal gasification for H2-rich gas production

    OpenAIRE

    Fermoso Domínguez, Javier; Gil Matellanes, María Victoria; Arias Rozada, Borja; González Plaza, Marta; Pevida García, Covadonga; Pis Martínez, José Juan; Rubiera González, Fernando

    2010-01-01

    Coal gasification was performed by means of a high-pressure fixed bed gasifier fitted with a solids feeding system in continuous mode, using oxygen and steam as gasifying agents. The main aim of the paper was to assess the combined effects of the operating variables (temperature, oxygen and steam concentrations) on high-pressure coal gasification. To this end a face centered central composite design (FCCCD) based on response surface methodology (RSM) was used. The response variables studied w...

  5. NACA research on combustors for aircraft gas turbines I : effects of operating variables on steady-state performance

    Science.gov (United States)

    Olson, Walter T; Childs, J Howard

    1950-01-01

    Some of the systematic research conducted by the NACA on aircraft gas-turbine combustors is reviewed. Trends depicting the effect of inlet-air pressure, temperature, and velocity and fuel-air ratio on performance characteristics, such as combustion efficiency, maximum temperature rise attainable, pressure loss, and combustor-outlet temperature distribution are described for a variety of turbojet combustors of the liquid-fuel type. These trends are further discussed as effects significant to the turbojet engine, such as altitude operational limits, specific fuel consumption, thrust, acceleration, and turbine life.

  6. approach to gearbox diagnosis under variable operating conditions

    Directory of Open Access Journals (Sweden)

    Lixiang Duan

    2016-08-01

    Full Text Available Gearbox diagnosis under stationary operating conditions has been extensively investigated; however, variable operating conditions such as load and speed changes play important roles in affecting the accuracy of gearbox diagnosis. This article presents an integrative approach of intrinsic time-scale decomposition and hierarchical temporal memory for gearbox diagnosis under variable operating conditions. A total of two modules are emphasized including a feature extraction method and an integrative feature fusion and classification model. Intrinsic time-scale decomposition method is investigated to extract the gearbox features which are insensitive to variable operating conditions, and its performance overcomes the commonly used empirical mode decomposition in terms of decomposition result and computational efficiency. Hierarchical temporal memory integrates feature fusion and pattern classification in one model to autonomously diagnose gearbox defect. Performance comparison among the presented method, back-propagation neural network, support vector machine, and fuzzy c-means clustering using experimental data demonstrate the effectiveness of the presented method.

  7. Virtual Airport Simulation Technology: Perceptions of Airport Operations Initial Training Program Variables and Effectiveness for Airside Professional Competence

    Science.gov (United States)

    DeCarlo, Jeffrey

    2010-01-01

    Air travel is expected to grow by a factor of 2 to 3 times by 2025 and people working in the aviation system, including airport personnel, pilots, and air traffic controllers, must be able to safely and efficiently operate in this arena ("NextGen"). In response to the personnel training and education requirements concomitant with "NextGen,"…

  8. Dynamics of Polymeric Fluids: Part Ⅱ The Molecular Theory of Die Swell: Correlation of Ultimate Die Swelling Effect to the Molecular Parameters and the Operational Variables

    Institute of Scientific and Technical Information of China (English)

    Mingshi SONG; Qiang XU; Guixian HU; Sizhu WU

    2006-01-01

    A general expression for the correlation of the simple shear(tanφ)to the molecular parameters and the shear rate(γ)was deduced. It shows that the simple shear(tanφ)may be resolved into free recoil(recoverable strain)and viscous heating(unrecoverable strain). The magnitudes of the simple shears for recoil(tanφE)and(tanφv)for viscous heating not only depended on the molecular parameters and the operational variables,but also on the exponential fractions of the recoverable(1-(W)γ)and unrecoverable((W)γ)conformations for recoil and viscous heating. Therefore the magnitudes of the simple shears(tanφE)for recoil and(tanφv)for viscous heating are, respectively, expressed as the partition function to the(1-(W)γ)th power and the partition function to the(-(W)γ)th power. Thus correlations of the total recoil and the ultimately recoverable strains to the molecular parameters [n', a, η0, G0NN and(1--(W)γ)] and the operational variables(·γ, (L/D)and tr)were deduced respectively, which show that at very different shear rates(0≤·γ≤∞)the polymeric liquids may exhibit a very different viscoelastic behaviors. After introducing the uniform two-dimensional extension, the definition of swelling ratio and the ratio of L to D [De=(L/D)], two expressions for the ultimate die swelling effect and the ultimate extrudate swelling ratio BEVT5 to the molecular parameters [n', a, η0, G0N and(1--(W)·γ)] and the operational variables(·γ,(L/D)and tr)were obtained. The two correlation expressions were verified by the experimental data of high-density polyethylene (HDPE) which shows that the two correlation expressions can be used to predict the correlations of the ultimate extrudate swelling behaviors of polymeric liquids to the molecular parameters and the operational variables.

  9. Ozone application in water sources: effects of operational parameters and water quality variables on ozone residual profiles and decay rates

    Directory of Open Access Journals (Sweden)

    F. A. Lage Filho

    2010-12-01

    Full Text Available Systematic ozonation tests were conducted by means of a mobile pilot plant. Water source 1 was a low turbidity stream with very low solids content and very low turbidity, apparent color and alkalinity. Water source 2 was reservoir water with higher turbidity, solids content and alkalinity than source 1. The ozone plant was a counter-current contactor composed of four columns in series. Variations in contact time, in the feed gas concentration (in terms of percent by weight of ozone and in splitting of the total applied ozone dosage between columns 1 and 2 were tested. Concentration - time (CT products were calculated and decay coefficients K were estimated from experimental data. The relative importance of water quality and certain operational parameters with regard to CT products and ozone decay was assessed. Total CT values seemed to increase with: (a total applied ozone dosage, (b percent by weight of ozone in the feed gas to the bubble contactor, (c increasing contact time and (d higher water quality, with regard to turbidity, apparent color, total organic carbon and particle counts. As the total applied ozone dosage was increased, the more important the contact time and ozone dosage configuration became for the total CT value. The apparent first order ozone decay rate constant (K decreased with increasing total applied ozone dosage. The contact time appeared to exert a much stronger influence on total CT values than on K values, particularly so as the total applied ozone dosage was increased.

  10. Continuous production of iron-based nanocrystals by laser pyrolysis. Effect of operating variables on size, composition and magnetic response

    Science.gov (United States)

    Malumbres, A.; Martínez, G.; Mallada, R.; Hueso, J. L.; Bomatí-Miguel, O.; Santamaría, J.

    2013-08-01

    Well dispersed iron-based magnetic nanoparticles have been prepared by gas phase laser-driven decomposition of iron pentacarbonyl. Agglomeration of the newly synthesized nanoparticles could be avoided by using a liquid collection system in which the exit stream from the laser reactor was bubbled through triethylene glycol (TREG). The effect of different experimental parameters (precursor concentration, laser power, working pressure, residence time) was studied and, by selecting the appropriate conditions, the size of the resulting magnetic nanocrystals could be tuned from ultrasmall (ca. 2.5 nm) to around 12 nm. For nanoparticle sizes around 10 nm and larger a metallic iron core could be preserved. These iron/iron oxide core-shell compositions exhibit very high values of magnetization, 127 emu g-1.

  11. Interval arithmetic operations for uncertainty analysis with correlated interval variables

    Institute of Scientific and Technical Information of China (English)

    Chao Jiang; Chun-Ming Fu; Bing-Yu Ni; Xu Han

    2016-01-01

    A new interval arithmetic method is proposed to solve interval functions with correlated intervals through which the overestimation problem existing in interval analy-sis could be significantly alleviated. The correlation between interval parameters is defined by the multidimensional par-allelepiped model which is convenient to describe the correlative and independent interval variables in a unified framework. The original interval variables with correlation are transformed into the standard space without correlation, and then the relationship between the original variables and the standard interval variables is obtained. The expressions of four basic interval arithmetic operations, namely addi-tion, subtraction, multiplication, and division, are given in the standard space. Finally, several numerical examples and a two-step bar are used to demonstrate the effectiveness of the proposed method.

  12. CFD-aided cell settler design optimization and scale-up: effect of geometric design and operational variables on separation performance.

    Science.gov (United States)

    Shen, Yuyi; Yanagimachi, Kurt

    2011-01-01

    The inclined multiplate (lamella) gravity settler has proven to be an effective cell retention device in industrial perfusion cell culture applications. Investigations on the effects of geometric design and operational variables of the cell settler are crucial to understanding how to best improve the settler performance. Maximizing the harvest/perfusion flow rate while minimizing viable cell loss out of the harvest is the primary challenge for optimization of the settler design. This study demonstrated that computational fluid dynamics (CFD) can be utilized to accurately model and evaluate the settler separation performance for near-monodisperse suspensions and therefore aid in the design optimization of the settler under these baseline conditions. With the preferred geometric features that were identified from CFD modeling results, we proposed design guidelines for the scale-up of these multiplate settler systems. With these guidelines and performance verification using the CFD model, a new large-scale settler was designed and fabricated for a perfusion cell culture process using a minimally aggregating production cell line. Perfusion cell culture runs with this particular cell line were performed with this settler, and the CFD model was able to predict the initial ramp-up performance, proving it to be a valuable scale-up design tool for this production process.

  13. Development of Flexible Software Process Lines with Variability Operations

    DEFF Research Database (Denmark)

    Dohrmann, Patrick; Schramm, Joachim; Kuhrmann, Marco

    2016-01-01

    the development of flexible software process lines. Method: We conducted a longitudinal study in which we studied 5 variants of the V-Modell XT process line for 2 years. Results: Our results show the variability operation instrument feasible in practice. We analyzed 616 operation exemplars addressing various......Context: A software process line helps to systematically develop and manage families of processes and, as part of this, variability operations provide means to modify and reuse pre-defined process assets. Objective: Our goal is to evaluate the feasibility of variability operations to support...... customization scenarios, and we found 87 different operation types. Conclusions: Although variability operations are only one instrument among others, our results suggest this instrument useful to implement variability in real-life software process lines....

  14. Development of Flexible Software Process Lines with Variability Operations

    DEFF Research Database (Denmark)

    Dohrmann, Patrick; Schramm, Joachim; Kuhrmann, Marco

    2016-01-01

    Context: A software process line helps to systematically develop and manage families of processes and, as part of this, variability operations provide means to modify and reuse pre-defined process assets. Objective: Our goal is to evaluate the feasibility of variability operations to support...... the development of flexible software process lines. Method: We conducted a longitudinal study in which we studied 5 variants of the V-Modell XT process line for 2 years. Results: Our results show the variability operation instrument feasible in practice. We analyzed 616 operation exemplars addressing various...... customization scenarios, and we found 87 different operation types. Conclusions: Although variability operations are only one instrument among others, our results suggest this instrument useful to implement variability in real-life software process lines....

  15. Survey of variable speed operation of wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Ola; Hylander, J.; Thorborg, K. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Electric Power Engineering

    1996-12-01

    During the last five years the production and operation of variable-speed wind turbines have advanced from a few experimental machines to a serial production of at least 10 MW of installed capacity of variable speed machines per week. The rated power of serial wind turbines is today around 600 kW and for the prototypes up to 3000 kW. Variable speed operation of wind turbines can be obtained with several different types of electrical generating systems, such as synchronous generators with diode rectifiers and thyristor inverters or induction generators with IGBT-converters, for the wide speed range. For the narrow speed range the wound motor induction generator with a rotor cascade or a controlled rotor resistance is preferable. The development of permanent magnetic material and the reduction of costs of the power electronic components have opened a possibility of designing cost-effective wind turbines with a directly driven generator. Pitch control together with variable speed will make it possible to limit the power variation within a few percent, 2 to 5 %, of the rated power. 7 refs, 4 figs, 2 tabs

  16. Development of Flexible Software Process Lines with Variability Operations

    DEFF Research Database (Denmark)

    Schramm, Joachim; Dohrmann, Patrick; Kuhrmann, Marco

    2015-01-01

    Context: Software processes evolve over time and several approaches were proposed to support the required flexibility. Yet, little is known whether these approaches sufficiently support the development of large software processes. A software process line helps to systematically develop and manage...... families of processes and, as part of this, variability operations provide means to modify and reuse pre-defined process assets. Objective: Our goal is to evaluate the feasibility of variability operations to support the development of flexible software process lines. Method: We conducted a longitudinal...... study in which we studied 5 variants of the V-Modell XT process line for 2 years. Results: Our results show the variability operation instrument feasible in practice. We analyzed 616 operation exemplars addressing various customization scenarios, and we found 87 different operation types contributed...

  17. The inter- and intra-operator variability in manual spot segmentation and its effect on spot quantitation in two-dimensional electrophoresis analysis.

    Science.gov (United States)

    Millioni, Renato; Sbrignadello, Stefano; Tura, Andrea; Iori, Elisabetta; Murphy, Ellen; Tessari, Paolo

    2010-05-01

    Separation of complex mixtures of proteins by 2-DE is a fundamental component of current proteomic technology. Quantitative analysis of the images generated by digitization of such gels is critical for identifying alterations in protein expression within a given biological system. Software packages are designed for this purpose. The accurate definition of protein spot boundaries, using a suitable method of image segmentation, is a key requirement for image analysis. It is often necessary for operators to intervene manually to correct mistakes in spot segmentation; therefore operator subjectivity and differences in ability can weaken the analysis. We estimated the error in spot quantification after manual spot segmentation, which was performed by different operators, using two different software packages. Our results clearly show that this operation was associated with significant inter- and intra-variability and an overestimation of subsequent spot intensity, especially when spots were weak. For comparative studies, we suggest separately analysing spots which have been manually segmented by imposing a requirement for at least a threefold difference in spot intensity in addition to use of statistical tests.

  18. Effects of a Dual-Loop Exhaust Gas Recirculation System and Variable Nozzle Turbine Control on the Operating Parameters of an Automotive Diesel Engine

    Directory of Open Access Journals (Sweden)

    Giorgio Zamboni

    2017-01-01

    Full Text Available Reduction of NOX emissions and fuel consumption are the main topics in engine development, forcing the adoption of complex techniques and components, whose interactions have to be clearly understood for proper and reliable operations and management of the whole system. The investigation presented in this paper aimed at the development of integrated control strategies of turbocharging, high pressure (HP and low pressure (LP exhaust gas recirculation (EGR systems for better NOX emissions and fuel consumption, while analyzing their reciprocal influence and the resulting variations of engine quantities. The study was based on an extended experimental program in three part load engine operating conditions. In the paper a comparison of the behavior of the main engine sub-systems (intake and exhaust circuits, turbocharger turbine and compressor, HP and LP EGR loops in a wide range of operating modes is presented and discussed, considering open and closed loop approaches for variable nozzle turbine (VNT control, and showing how these affect engine performance and emissions. The potential of significant decrease in NOX emissions through the integration of HP and LP EGR was confirmed, while a proper VNT management allowed for improved fuel consumption level, if an open loop control scheme is followed. At higher engine speed and load, further actions have to be applied to compensate for observed soot emissions increase.

  19. The effect of the variable frequency drive of the CNC roll grinding machine on the operation of other devices in low-voltage electrical installation

    Directory of Open Access Journals (Sweden)

    Simić Ninoslav

    2016-01-01

    Full Text Available This paper presents one of the observations that have been collected during the years of testing of electrical installations. A typical case from industrial plant in which are installed loads with variable frequency regulation is analyzed. We propose a simple way by measuring the frequency of the voltage in the objects, to establish the existence of possible irregularities in the operation of the individual units and analyze the influence of the current and voltage signal shape of one load to the work of other loads in the plant. The need for verification of electrical installations immediately upon receipt and installation of electrical equipment is emphasized and the use of the latest standards in the design and selection of equipment, in order to avoid unplanned expenses is recommended.

  20. QUANTIFICATION OF THE EFFECT OF SOME OPERATIONAL VARIABLES ON THE CELL GROWTH YIELD (Yx/s OF Penilcilium chrysogenum BY SURFACE RESPONSE ANALYSIS

    Directory of Open Access Journals (Sweden)

    M.E.A.G. OPRIME

    1997-12-01

    Full Text Available The yield coefficient Yx/s was correlated with variables such as temperature (22.8-29.2 oC, concentrations of corn steep liquor (6.4-57.4 g/L, ammonium sulfate (5.6-18.4 g/L, sucrose (4.0-36.0 g/L and soybean oil (3.0-7.0 g/L, all important variables in the growth stage of the Penicillium chrysogenum fungus. An empirical model was obtained by response surface statistical experimental design. The tests were performed with a complex culture medium in a rotatory shaker. The highest Yx/s values were obtained at low sucrose concentrations (~4.0 g/L and high corn steep liquor concentrations (~57.4 g/L. Temperature, ammonium sulfate and soybean oil concentrations showed no significant effect on Yx/s

  1. Electric Motors Maintenance Planning From Its Operating Variables

    Science.gov (United States)

    Rodrigues, Francisco; Fonseca, Inácio; Farinha, José Torres; Ferreira, Luís; Galar, Diego

    2017-09-01

    The maintenance planning corresponds to an approach that seeks to maximize the availability of equipment and, consequently, increase the levels of competitiveness of companies by increasing production times. This paper presents a maintenance planning based on operating variables (number of hours worked, duty cycles, number of revolutions) to maximizing the availability of operation of electrical motors. The reading of the operating variables and its sampling is done based on predetermined sampling cycles and subsequently is made the data analysis through time series algorithms aiming to launch work orders before reaching the variables limit values. This approach is supported by tools and technologies such as logical applications that enable a graphical user interface for access to relevant information about their Physical Asset HMI (Human Machine Interface), including the control and supervision by acquisition through SCADA (Supervisory Control And data acquisition) data, also including the communication protocols among different logical applications.

  2. Tridiagonal Operators and Zeros of Polynomials in Two Variables

    Directory of Open Access Journals (Sweden)

    Chrysi G. Kokologiannaki

    2016-01-01

    Full Text Available The aim of this paper is to connect the zeros of polynomials in two variables with the eigenvalues of a self-adjoint operator. This is done by use of a functional-analytic method. The polynomials in two variables are assumed to satisfy a five-term recurrence relation, similar to the three-term recurrence relation that the classical orthogonal polynomials satisfy.

  3. Measuring Cyber Operations Effectiveness

    Science.gov (United States)

    2014-11-01

    using network scanners and frameworks like the SANS Critical Security Controls. Finally, a network vulnerability penetration test can be performed to...effectiveness in network, defensive, and offensive operations is a difficult task. Measures may be static , automated, some combination of both or...by SANS identifies using port scanners as a way to verify the setup has been performed correctly and only needed ports and protocols are allowed

  4. Toeplitz Operators with BMO Symbols of Several Complex Variables

    Institute of Scientific and Technical Information of China (English)

    Zhong Hua HE; Guang Fu CAO

    2012-01-01

    In this note we prove that the boundedness and compactness of the Toeplitz operator on the Bergman space L2a (Bn) for several complex variables with a BMO1 symbol is completely determined by the boundary behavior of its Berezin transform.

  5. Variable operator technique and the min-max theorem

    Indian Academy of Sciences (India)

    Sambhu Nath Datta

    2000-09-01

    We investigate a variation method where the trial function is generated from the application of a variable operator on a reference function. Two conditions are identified, one for obtaining a maximum and another for a minimum. Although the conditions are easy to understand, the overall formulation is somewhat unusual as each condition gives rise to a two-step variation process. As an example, projection operators are used to form the variable operator, and by this tactics one obtains the new interpretation that the pseudopotential formalism is in fact equivalent to a minimax procedure. The two-step variational process is nevertheless more flexible than the pseudopotential formalism, for it can also be used when the variable operator isnot manifestly expressed in terms of projectors. This is illustrated by a comparison of the two-step method with the variational solution of Dirac’s relativistic electron equation. The same comparison leads to an alternative proof that the process of maximizing energy by varying the – coupling operator eliminates all negative-energy contributions from a trial spinor. The latter observation is crucial for the derivation of the min-max theorem in relativistic quantum mechanics.

  6. Work flow with manual re-registration of cardiac 18F-FDG PET and attenuation correction CT to compensate for respiratory motion: Effects and inter-operator variability

    DEFF Research Database (Denmark)

    Juhl, Christian; Christensen, Nana Louise; Møller, Lone W.;

    observed in 15 % (6/40) of the scans, and, as expected, mainly in lateral segments. It was estimated that 80% (5/6) of these artefacts could be reduced using manual re-registration procedure. This is in agreement with previous reports1-3. The inter-operator variability was generally low, except in a few......-registration is currently the most feasible. In this study, we examine both the effect on misalignment artefacts and the inter-operator variability of manual re-registration performed by the technologist in a step before the final image reconstruction and verified by a second technologist before image analysis. Method: 40...... 18F-FDG viability scans were examined. After the patient scan, a fast image reconstruction of low quality was made and used for manual re-registration of PET and AC CT, before starting the high quality reconstruction used for analysis. The left ventricle was reoriented and segmented in QPS (Cedar...

  7. Optimizing Wellfield Operation in a Variable Power Price Regime

    DEFF Research Database (Denmark)

    Bauer-Gottwein, Peter; Schneider, Raphael; Davidsen, Claus

    2016-01-01

    of operating the combined wellfield-storage-demand system over the course of a 2-year planning period based on a time series of observed price on the Danish power market and a deterministic, time-varying hourly water demand. In the SDP setup, hourly pumping rates are the decision variables. Constraints include......-rate pumping benchmark. Minor savings up to 10% were found in the baseline scenario, while the scenario with constant EFP and unlimited pumping rate resulted in savings up to 40%. Key factors determining potential cost savings obtained by flexible wellfield operation under a variable power price regime......Wellfield management is a multiobjective optimization problem. One important objective has been energy efficiency in terms of minimizing the energy footprint (EFP) of delivered water (MWh/m3). However, power systems in most countries are moving in the direction of deregulated markets and price...

  8. Optimizing wellfield operation in a variable power price regime

    DEFF Research Database (Denmark)

    Bauer-Gottwein, Peter; Schneider, Raphael; Davidsen, Claus

    markets and power price variability is increasing in many markets because of increased penetration of intermittent renewable power sources. In this context the relevant management objective becomes minimizing the cost of energy used for pumping and distribution of groundwater rather than minimizing energy...... the combined wellfield-storage-demand system over the course of a 2-year planning period based on a time series of observed price on the Danish power market and a deterministic, time-varying hourly water demand. In the SDP setup, hourly pumping rates are the decision variables. Constraints include storage...... policy. Minor savings up to 10% were found in the baseline scenario, while the scenario with constant EFP and unlimited pumping rate resulted in savings up to 40%. Key factors determining potential cost savings obtained by flexible wellfield operation under a variable power price regime are the shape...

  9. Reasons for reservoir effect variability

    DEFF Research Database (Denmark)

    Philippsen, Bente

    2013-01-01

    Freshwater reservoir effects can be large and highly variable. I will present my investigations into the short-term variability of the freshwater reservoir effect in two Northern German rivers. The samples analysed in this study were collected between 2007 and 2012. Reservoir ages of water samples......, aquatic plants and fish from the rivers Alster and Trave range between zero and about 3,000 radiocarbon years. The reservoir age of water DIC depends to a large extent on the origin of the water and is for example correlated with precipitation amounts. These short-term variations are smoothed out in water...... plants. Their carbon should represent an average value of the entire growth season. However, there are large reservoir age variations in aquatic plants and animals as well. These can best be explained by the multitude of carbon sources which can be utilized by aquatic organisms, and which have...

  10. Analytic Thermoelectric Couple Modeling: Variable Material Properties and Transient Operation

    Science.gov (United States)

    Mackey, Jonathan A.; Sehirlioglu, Alp; Dynys, Fred

    2015-01-01

    To gain a deeper understanding of the operation of a thermoelectric couple a set of analytic solutions have been derived for a variable material property couple and a transient couple. Using an analytic approach, as opposed to commonly used numerical techniques, results in a set of useful design guidelines. These guidelines can serve as useful starting conditions for further numerical studies, or can serve as design rules for lab built couples. The analytic modeling considers two cases and accounts for 1) material properties which vary with temperature and 2) transient operation of a couple. The variable material property case was handled by means of an asymptotic expansion, which allows for insight into the influence of temperature dependence on different material properties. The variable property work demonstrated the important fact that materials with identical average Figure of Merits can lead to different conversion efficiencies due to temperature dependence of the properties. The transient couple was investigated through a Greens function approach; several transient boundary conditions were investigated. The transient work introduces several new design considerations which are not captured by the classic steady state analysis. The work helps to assist in designing couples for optimal performance, and also helps assist in material selection.

  11. Commutators of Integral Operators with Variable Kernels on Hardy Spaces

    Indian Academy of Sciences (India)

    Pu Zhang; Kai Zhao

    2005-11-01

    Let $T_{,}(0≤ < n)$ be the singular and fractional integrals with variable kernel $(x,z)$, and $[b, T_{,}]$ be the commutator generated by $T_{,}$ and a Lipschitz function . In this paper, the authors study the boundedness of $[b, T_{,}]$ on the Hardy spaces, under some assumptions such as the $L^r$-Dini condition. Similar results and the weak type estimates at the end-point cases are also given for the homogeneous convolution operators $T_{\\overline{},}(0≤ < n)$. The smoothness conditions imposed on $\\overline{}$ are weaker than the corresponding known results.

  12. The Fractional Maximal Operator and Marcinkiewicz Integrals Associated with Schr ¨odinger Operators on Morrey Spaces with Variable Exponent

    Institute of Scientific and Technical Information of China (English)

    Yu Shu; Min Wang

    2015-01-01

    In this paper, we prove the boundedness of the fractional maximal opera-tor, Hardy-Littlewood maximal operator and marcinkiewicz integrals associated with Schr ¨odinger operator on Morrey spaces with variable exponent.

  13. Optimizing Wellfield Operation in a Variable Power Price Regime.

    Science.gov (United States)

    Bauer-Gottwein, Peter; Schneider, Raphael; Davidsen, Claus

    2016-01-01

    Wellfield management is a multiobjective optimization problem. One important objective has been energy efficiency in terms of minimizing the energy footprint (EFP) of delivered water (MWh/m(3) ). However, power systems in most countries are moving in the direction of deregulated markets and price variability is increasing in many markets because of increased penetration of intermittent renewable power sources. In this context the relevant management objective becomes minimizing the cost of electric energy used for pumping and distribution of groundwater from wells rather than minimizing energy use itself. We estimated EFP of pumped water as a function of wellfield pumping rate (EFP-Q relationship) for a wellfield in Denmark using a coupled well and pipe network model. This EFP-Q relationship was subsequently used in a Stochastic Dynamic Programming (SDP) framework to minimize total cost of operating the combined wellfield-storage-demand system over the course of a 2-year planning period based on a time series of observed price on the Danish power market and a deterministic, time-varying hourly water demand. In the SDP setup, hourly pumping rates are the decision variables. Constraints include storage capacity and hourly water demand fulfilment. The SDP was solved for a baseline situation and for five scenario runs representing different EFP-Q relationships and different maximum wellfield pumping rates. Savings were quantified as differences in total cost between the scenario and a constant-rate pumping benchmark. Minor savings up to 10% were found in the baseline scenario, while the scenario with constant EFP and unlimited pumping rate resulted in savings up to 40%. Key factors determining potential cost savings obtained by flexible wellfield operation under a variable power price regime are the shape of the EFP-Q relationship, the maximum feasible pumping rate and the capacity of available storage facilities.

  14. Zinc Oxide Nanoparticles Supported Lipase Immobilization for Biotransformation in Organic Solvents: A Facile Synthesis of Geranyl Acetate, Effect of Operative Variables and Kinetic Study.

    Science.gov (United States)

    Patel, Vrutika; Shah, Chandani; Deshpande, Milind; Madamwar, Datta

    2016-04-01

    The present study describes grafting of zinc oxide (ZnO) nanoparticles with polyethyleneimine (PEI) followed by modification with glutraldehyde used as the bridge for binding the enzyme to support. The prepared nanocomposites were then characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, and transmission electron microscopy, utilized for synthesis of geranyl acetate in n-hexane. Among all the three prepared nanocomposites (ZnO + PEI, ZnO + PEI + SAA, ZnO + PEI + GLU), Candida rugosa lipase immobilized on ZnO-PEI-GLU was found to be best for higher ester synthesis. The operating conditions that maximized geranyl acetate resulted in the highest yield of 94 % in 6 h, molar ratio of 0.1:0.4 M (geraniol/vinyl acetate) in the presence of n-hexane as reaction medium. Various kinetic parameters such as V max, K i(G), K m(G), and K m(VA) were determined using nonlinear regression analysis for order bi-bi mechanism. The kinetic study showed that reaction followed order bi-bi mechanism with inhibition by geraniol. Activation energy (E a ) was found to be lower for immobilized lipase (12.31 kJ mol(-1)) than crude lipase (19.04 kJ mol(-1)) indicating better catalytic efficiency of immobilized lipase. Immobilized biocatalyst demonstrated 2.23-fold increased catalytic activity than crude lipase and recycled 20 times. The studies revealed in this work showed a promising perspective of using low-cost nanobiocatalysts to overcome the well-known drawbacks of the chemical-catalyzed route.

  15. Flexible Design and Operation of Multi-Stage Flash (MSF Desalination Process Subject to Variable Fouling and Variable Freshwater Demand

    Directory of Open Access Journals (Sweden)

    Said Alforjani Said

    2013-10-01

    Full Text Available This work describes how the design and operation parameters of the Multi-Stage Flash (MSF desalination process are optimised when the process is subject to variation in seawater temperature, fouling and freshwater demand throughout the day. A simple polynomial based dynamic seawater temperature and variable freshwater demand correlations are developed based on actual data which are incorporated in the MSF mathematical model using gPROMS models builder 3.0.3. In addition, a fouling model based on stage temperature is considered. The fouling and the effect of noncondensable gases are incorporated into the calculation of overall heat transfer co-efficient for condensers. Finally, an optimisation problem is developed where the total daily operating cost of the MSF process is minimised by optimising the design (no of stages and the operating (seawater rejected flowrate and brine recycle flowrate parameters.

  16. Some questions of variable operational modes of an MHD generator

    Energy Technology Data Exchange (ETDEWEB)

    Belikov, V.V.; Breyev, V.V.; Gubarev, A.V.; Zotov, A.V.

    1979-01-01

    A Faraday MHD generator with solid electrodes is analyzed for the case of a variable load and three circuit configurations: series, parallel and independent excitation of the generator. The equivalent circuits are drawn along with the current-voltage and load characteristics (power and voltage at the load terminals as a function of generator current) for the series and parallel excitation cases. With independent excitation, the current-voltage characteristic is linear since the magnetic field induction in the generator channel at small magnetic Reynolds numbers does not depend on the generator current. The influence of the counterpressure at the channel outlet in a supersonic MHD generator is discussed in qualitative terms. Two modes are defined: when the pressure in the receiver following the channel is less than a certain value below the critical cross-section of the supersonic nozzle ahead of the channel (normal flow); and when the receiver pressure exceeds this specified value (anomalous flow), which leads to density jumps in the supersonic nozzle and subsonic flow in the interaction region. These concepts are employed in a discussion of the stability of steady-state flow and transient modes. Analytical expressions are derived for the excitation current and the load current in an MHD generator with a parallel configuration of the excitation winding, and these are plotted as a function of time. Transient operational modes of the generator with a series winding configuration of the magnet system are also shown, with the current plotted as a function of time. Expressions are derived for characteristic parameters which specify stable operational modes.

  17. Significance of design and operational variables in chemical phosphorus removal.

    Science.gov (United States)

    Szabó, A; Takács, I; Murthy, S; Daigger, G T; Licskó, I; Smith, S

    2008-05-01

    Batch and continuous experiments using model and real wastewaters were conducted to investigate the effect of metal salt (ferric and alum) addition in wastewater treatment and the corresponding phosphate removal from a design and operational perspective. Key factors expected to influence the phosphorus removal efficiency, such as pH, alkalinity, metal dose, metal type, initial and residual phosphate concentration, mixing, reaction time, age of flocs, and organic content of wastewater, were investigated. The lowest achievable concentration of orthophosphate under optimal conditions (0.01 to 0.05 mg/L) was similar for both aluminum and iron salts, with a broad optimum pH range of 5.0 to 7.0. Thus, in the typical operating range of wastewater treatment plants, pH is not a sensitive indicator of phosphorus removal efficiency. The most significant effect for engineering practice, apart from the metal dose, is that of mixing intensity and slow kinetic removal of phosphorus in contact with the chemical sludge formed. Experiments show that significant savings in chemical cost could be achieved by vigorously mixing the added chemical at the point of dosage and, if conditions allow, providing a longer contact time between the metal hydroxide flocs and the phosphate content of the wastewater. These conditions promoted the achievement of less than 0.1 mg/L residual orthophosphate content, even at lower metal-to-phosphorus molar ratios. These observations are consistent with the surface complexation model presented in a companion paper (Smith et al., 2008).

  18. Work flow with manual re-registration of cardiac 18F-FDG PET and attenuation correction CT to compensate for respiratory motion: Effects and inter-operator variability

    DEFF Research Database (Denmark)

    Juhl, Christian; Christensen, Nana Louise; Møller, Lone W.

    cases where the manual re-registration resulted in new artefacts. These were, however, easily identified and eliminated by second technologist in the verification-step resulting in an overall insignificant inter-operator variability. In conclusion, manual re-registration reduces artefacts due...

  19. USE OF GAS BURNERS TYPE "DAVA" OPERATING UNDER VARIABLE LOAD TO PRODUCE HEAT AND HOT WATER

    Directory of Open Access Journals (Sweden)

    Daud V.

    2014-12-01

    Full Text Available The article brings additional information referred to upgraded gas burners type "DAVA", which are characterized by high performance at variable load. Adaptation of burner operation is carried out automatically. There are presented design features that allow increase of the efficiency and the reliability of these burners at variable load, and reducing natural gas consumption. The range of variation of the coefficient of excess air affects the efficiency of the burner. The experimental results of the tests of gas burners of different power had confirmed the economic effect of the upgraded burners at heat production. It is proved that economic effect increases with increasing of burner output and of operation time during the season.

  20. Restoring Natural Streamflow Variability by Modifying Multi-purpose Reservoir Operation

    Science.gov (United States)

    Shiau, J.

    2010-12-01

    Multi-purpose reservoirs typically provide benefits of water supply, hydroelectric power, and flood mitigation. Hydroelectric power generations generally do not consume water. However, temporal distribution of downstream flows is highly changed due to hydro-peaking effects. Associated with offstream diversion of water supplies for municipal, industrial, and agricultural requirements, natural streamflow characteristics of magnitude, duration, frequency, timing, and rate of change is significantly altered by multi-purpose reservoir operation. Natural flow regime has long been recognized a master factor for ecosystem health and biodiversity. Restoration of altered flow regime caused by multi-purpose reservoir operation is the main objective of this study. This study presents an optimization framework that modifying reservoir operation to seeking balance between human and environmental needs. The methodology presented in this study is applied to the Feitsui Reservoir, located in northern Taiwan, with main purpose of providing stable water-supply and auxiliary purpose of electricity generation and flood-peak attenuation. Reservoir releases are dominated by two decision variables, i.e., duration of water releases for each day and percentage of daily required releases within the duration. The current releasing policy of the Feitsui Reservoir releases water for water-supply and hydropower purposes during 8:00 am to 16:00 pm each day and no environmental flows releases. Although greater power generation is obtained by 100% releases distributed within 8-hour period, severe temporal alteration of streamflow is observed downstream of the reservoir. Modifying reservoir operation by relaxing these two variables and reserve certain ratio of streamflow as environmental flow to maintain downstream natural variability. The optimal reservoir releasing policy is searched by the multi-criterion decision making technique for considering reservoir performance in terms of shortage ratio

  1. Operations Optimization of Hybrid Energy Systems under Variable Markets

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jun; Garcia, Humberto E.

    2016-07-01

    Hybrid energy systems (HES) have been proposed to be an important element to enable increasing penetration of clean energy. This paper investigates the operations flexibility of HES, and develops a methodology for operations optimization to maximize its economic value based on predicted renewable generation and market information. The proposed operations optimizer allows systematic control of energy conversion for maximal economic value, and is illustrated by numerical results.

  2. Human operant learning under concurrent reinforcement of response variability

    NARCIS (Netherlands)

    Maes, J.H.R.; Goot, M.H. van der

    2006-01-01

    This study asked whether the concurrent reinforcement of behavioral variability facilitates learning to emit a difficult target response. Sixty students repeatedly pressed sequences of keys, with an originally infrequently occurring target sequence consistently being followed by positive feedback. T

  3. WATER SUPPLY RESERVOIR OPERATION IN RELATION TO CLIMATE VARIABILITY: PIRAPAMA RIVER BASIN (PERNAMBUCO-BRAZIL

    Directory of Open Access Journals (Sweden)

    José Ráurium Bacalhau

    2016-01-01

    Full Text Available The vulnerability of water resources systems is highly influenced by the climate variability of the region. The effects are amplified when the region has high population density and important economic activities such as the Recife Metropolitan Region (RMR, whose population is 3.8 million inhabitants, corresponding to 51% of the urban population in Pernambuco State. The Pirapama reservoir was designed to produce 5.6 m³/s, which corresponds to 37% of the total water demand of the RMR. The objective of the paper is to define strategies for the Pirapama reservoir operation by using guide curves and taking into account the climate variability, particularly drought events, to minimize or even avoid the conditions of rationing and collapse of its storage. The rainfall-runoff model SMAP was used to simulate input streamflow in the period 1933−2014 and the water allocation model Acquanet was used to simulate the operation rules proposed. The guide curves were defined based on the Standard Runoff Index, which classify the input inflow in drought categories. For each drought category, a response goal was defined for withdrawal reduction. This strategy may be an efficient tool to deal with the climate variability present in Northeast Brazil, which can be amplified with the effects of the climate change. In this sense, the development of sustainable operation rules can be considered an adaptation measure for reducing the impacts of possible climate changes in the future.

  4. Safe Operation and Alignment of the Variable Pulse Width Laser at the US Army Research Laboratory

    Science.gov (United States)

    2016-02-01

    ARL-TN-0736 ● FEB 2016 US Army Research Laboratory Safe Operation and Alignment of the Variable Pulse Width Laser at the US Army...Laboratory Safe Operation and Alignment of the Variable Pulse Width Laser at the US Army Research Laboratory by Jennifer L Gottfried...TITLE AND SUBTITLE Safe Operation and Alignment of the Variable -Pulse Width Laser at the US Army Research Laboratory 5a. CONTRACT NUMBER 5b

  5. Hidden Variables and Placebo Effects

    Science.gov (United States)

    Goradia, Shantilal

    2006-03-01

    God's response to prayers and placebo leads to a question. How does He respond deterministically? He may be controlling at least one of the two variables of the uncertainty principle by extending His invisible soul to each body particle locally. Amazingly, many Vedic verses support this answer. One describes the size of the soul as arithmetically matching the size of the nucleons as if a particle is a soul. One gives a name meaning particle soul (anu-atma), consistent with particle's indeterministic behavior like that of (soulful) bird’s flying in any directions irrespective of the direction of throw. One describes souls as eternal consistent with the conservation of baryon number. One links the souls to the omnipresent (param- atma) like Einstein Rosen bridges link particles to normal spacetime. One claims eternal coexistence of matter and soul as is inflationary universe in physics/0210040 V2. The implicit scientific consistency of such verses makes the relationship of particle source of consciousness to the omnipresent Supreme analogous to the relationship of quantum source of gravitons in my gr-qc/0507130 to normal spacetime This frees us from the postulation of quantum wormholes and quantum foam. Dr. Hooft's view in ``Does God play dice,'' Physicsword, Dec 2005 seems consistent with my progressive conference presentations in Russia, Europe, India, and USA (Hindu University) in 2004/05. I see implications for nanoscience.

  6. Development of control strategy of variable speed limits for improving traffic operations at freeway bottlenecks

    Institute of Scientific and Technical Information of China (English)

    李志斌; 刘攀; 王炜; 徐铖铖

    2014-01-01

    A control strategy of variable speed limits (VSL) was developed to reduce the travel time at freeway recurrent bottleneck areas. The proposed control strategy particularly focused on preventing the capacity drop and increasing the discharge flow. A cell transmission model (CTM) was developed to evaluate the effects of the proposed VSL control strategy on the traffic operations. The results show that the total travel time is reduced by 25.5% and the delay is reduced by 56.1%. The average travel speed is increased by 34.3% and the queue length is reduced by 31.0%. The traffic operation is improved by the proposed VSL control strategy. The way to use the proposed VSL control strategy in different types of freeway bottlenecks was also discussed by considering different traffic flow characteristics. It is concluded that the VSL control strategy is effective for merge bottlenecks but is less effective for diverge bottlenecks.

  7. Discretized representations of harmonic variables by bilateral Jacobi operators

    Directory of Open Access Journals (Sweden)

    Andreas Ruffing

    2000-01-01

    Full Text Available Starting from a discrete Heisenberg algebra we solve several representation problems for a discretized quantum oscillator in a weighted sequence space. The Schrödinger operator for a discrete harmonic oscillator is derived. The representation problem for a q-oscillator algebra is studied in detail. The main result of the article is the fact that the energy representation for the discretized momentum operator can be interpreted as follows: It allows to calculate quantum properties of a large number of non-interacting harmonic oscillators at the same time. The results can be directly related to current research on squeezed laser states in quantum optics. They reveal and confirm the observation that discrete versions of continuum Schrodinger operators allow more structural freedom than their continuum analogs do.

  8. Variable Geometry Aircraft Pylon Structure and Related Operation Techniques

    Science.gov (United States)

    Shah, Parthiv N. (Inventor)

    2014-01-01

    An aircraft control structure can be utilized for purposes of drag management, noise control, or aircraft flight maneuvering. The control structure includes a high pressure engine nozzle, such as a bypass nozzle or a core nozzle of a turbofan engine. The nozzle exhausts a high pressure fluid stream, which can be swirled using a deployable swirl vane architecture. The control structure also includes a variable geometry pylon configured to be coupled between the nozzle and the aircraft. The variable geometry pylon has a moveable pylon section that can be deployed into a deflected state to maintain or alter a swirling fluid stream (when the swirl vane architecture is deployed) for drag management purposes, or to assist in the performance of aircraft flight maneuvers.

  9. Zone edge effects with variable rate irrigation

    Science.gov (United States)

    Variable rate irrigation (VRI) systems may offer solutions to enhance water use efficiency by addressing variability within a field. However, the design of VRI systems should be considered to maximize application uniformity within sprinkler zones, while minimizing edge effects between such zones alo...

  10. Effect of the operating variables of a fluid catalytic cracking unit (FCC) on the naphtha gum formation; Efeito das variaveis operacionais de uma unidade de craqueamento catalitico (FCC) na formacao da goma na nafta

    Energy Technology Data Exchange (ETDEWEB)

    Mattos, Leandro Generoso de [PETROBRAS, Betim, MG (Brazil). Unidade de Negocio Refinaria Gabriel Passos (REGAP). Gerencia de Hidrotratamento e Coque]. E-mail: leandrogm@petrobras.com.br; Almeida, Gustavo Matheus de [Universidade de Sao Paulo (USP), SP (Brazil). Escola Politecnica. Dept. de Engenharia Quimica]. E-mail: gustavo@lscp.pqi.ep.usp.br; Oliveira, Eder Domingos de; Cardoso, Marcelo [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Quimica]. E-mails: eder@deq.ufmg.br; mcardoso@deq.ufmg.br

    2006-12-15

    One of the main problems brought by gasoline combustion in vehicles is the deposition of gum in the fuel system. Gum, though soluble in gasoline, appears in the form of a viscous residue after gasoline has evaporated. The carbon deposits coating carburetors, nozzles, collector pipes, intake valves and combustion chambers affect the car's steering capacity, lower the engine's performance and increase the emission of exhaust gas. Given the sort of refining used in Brazil, the content of naphtha resulting from catalytic cracking in gasoline coming from refineries is quite significant. The chains resulting from catalytic or thermal cracking processes have a strong tendency to form gum. In Fluid Catalytic Cracking (FCC), a complex network of chemical reactions takes place, which can either be catalytic or thermal. Principal Component Analysis techniques (PCA), stepwise regression and genetic algorithms have been used to select the operating variables of FCC that will bear the most influence on gum formation. An ARN (Artificial Neural Networks) software tool was also used to anticipate gum forming from operating variables selected by means of the above mentioned techniques. The results achieved in forecasting gum forming in cracked naphtha lead us to believe that the data analysis methodology used was suitable. It is possible to forecast potential gum through seven variables with a 10% Mean Relative Error (MRE) and a 1.75 g/100 mL Mean Absolute Error (MAE) with a linear correlation coefficient of 0.844; or through eight variables with an 11% MRE and a 1.93 g/100 mL MAE with a linear correlation coefficient of 0.829. In the first case, the methodology employed to reduce variables was stepwise regression, and in the second, genetic algorithms. (author)

  11. On the Use of Variability Operations in the V-Modell XT Software Process Line

    DEFF Research Database (Denmark)

    Kuhrmann, Marco; Méndez Fernández, Daniel; Ternité, Thomas

    2016-01-01

    . In this article, we present a study on the feasibility of variability operations to support the development of software process lines in the context of the V-Modell XT. We analyze which variability operations are defined and practically used. We provide an initial catalog of variability operations......Software process lines provide a systematic approach to develop and manage software processes. It defines a reference process containing general process assets, whereas a well-defined customization approach allows process engineers to create new process variants, e.g., by extending or modifying...... as an improvement proposal for other process models. Our findings show that 69 variability operation types are defined across several metamodel versions of which, however, 25 remain unused. The found variability operations allow for systematically modifying the content of process model elements and the process...

  12. The commutants of analytic Toeplitz operators for several complex variables

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    It is proved that if  is a nonconstant bounded analytic function on the unit ball B n and continuous on S n in C n , and ψ is a bounded measurable function on S n such that T * and T ψ commute, then ψ is the boundary value of an analytic function on B n . In addition, the commutants of two Toeplitz operators are also discussed.

  13. Variability of extreme flap loads during turbine operation

    Energy Technology Data Exchange (ETDEWEB)

    Ronold, K.O. [Det Norske Veritas, Hoevik (Norway); Larsen, G.C. [Risoe National Lab., Wind Energy and Atmospheric Physics Dept., Roskilde (Denmark)

    1999-03-01

    The variability of extreme flap loads is of utmost importance for design of wind-turbine rotor blades. The flap loads of interest consist of the flap-wise bendin moment response at the blade root whose variability in the short-term, for a given wind climate, can be represented by a stationary process. A model for the short-term bending moment process is presented, and the distribution of its associated maxima is derived. A model for the wind climate is given in terms of the probability distributions for the 10-minute mean wind speed and the standard deviation of the arbitrary wind speed. This is used to establish the distribution of the largest flap-wise bending moment in a specific reference period, and it is outlined how a characteristic bending moment for use in design can be extracted from this distribution. The application of the presented distribution models is demonstrated by a numerical example for a site-specific wind turbine. (au)

  14. Variable-mass Thermodynamics Calculation Model for Gas-operated Automatic Weapon%Variable-mass Thermodynamics Calculation Model for Gas-operated Automatic Weapon

    Institute of Scientific and Technical Information of China (English)

    陈建彬; 吕小强

    2011-01-01

    Aiming at the fact that the energy and mass exchange phenomena exist between barrel and gas-operated device of the automatic weapon, for describing its interior ballistics and dynamic characteristics of the gas-operated device accurately, a new variable-mass thermodynamics model is built. It is used to calculate the automatic mechanism velocity of a certain automatic weapon, the calculation results coincide with the experimental results better, and thus the model is validated. The influences of structure parameters on gas-operated device' s dynamic characteristics are discussed. It shows that the model is valuable for design and accurate performance prediction of gas-operated automatic weapon.

  15. Freshwater reservoir effect variability in Northern Germany

    DEFF Research Database (Denmark)

    Philippsen, B.; Heinemeier, J.

    2013-01-01

    The freshwater reservoir effect is a potential problem when radiocarbon dating fish bones, shells, human bones, or food crusts on pottery from sites near rivers or lakes. The reservoir age in hardwater rivers can be up to several thousand years and may be highly variable. Accurate 14C dating...... of freshwater-based samples requires knowing the order of magnitude of the reservoir effect and its degree of variability. Measurements on modern riverine materials may not give a single reservoir age correction that can be applied to archaeological samples, but they show the order of magnitude and variability...

  16. Effects of submerged operation on the heart rate variability of oceanauts in "Jiaolong"submersibles%潜航作业对“蛟龙号”潜航员心率变异性的影响

    Institute of Scientific and Technical Information of China (English)

    石路; 李洋洋; 杨海飞; 石中瑗; 张延猛; 张宁

    2016-01-01

    Objective To observe the effects of submerged operation on the sympathetic nerve and vagus nerve of the autonomic nervous system (ANS)in "Jiaolong"oceanauts and also to explore the regulation of human cardiovascular function during submerged operation.Methods Six oceanauts underwent simulated submerged operation in "Jiaolong".Electrocardiogram (ECG)was detected before submerged operation,at hour 1.5 and 2.5 respectively.Quantitative analyses were made on various indicators of heart rate variability (HRV),including low-frequency (LF),high-frequency (HF),total power (TP),LF /HF ratio and HF /TP ratio by using frequency spectral method.Results LF control value before submerged operation was (2 950 ±248)ms2 .The LF value at hour 1.5 during submerged operation increased to(3 633 ±232)ms2 ,and statistical significance could be noted when comparisons were made between them(P <0.05).The LF value at hour 2.5 during submerged operation decreased to(2 800 ±184)ms2 .Statistical significance could be noticed when it was compared with that at hour 1.5(P <0.05),however,no statistical significance could be found when it was compared with the control value before submerged operation(P <0.05).The control value of HF before submerged operation was(1 700 ±107) ms2 ,the HFvalue decreased to (1 200 ±156 )ms2 at hour 1.5 after submerged operation,and statistical significance could be noted when comparisons were made between them(P <0.05).The HFvalue increased to (1 917 ±15)ms2 at hour 2.5 after submerged operation,and statistical significance could be seen when it was compared with that at hour 1.5 (P <0.05 ).However,no statistical significance could be found when it was compared with the value before submerged operation(P <0.05).And no statistical significance could be seen when it was compared with the control value(P <0.05).The LF /HF ratio detected before submerged operation was 1.73 ±0.81,but its value at hour 1.5 after submerged operation increased to a significant value of

  17. Random Effect and Latent Variable Model Selection

    CERN Document Server

    Dunson, David B

    2008-01-01

    Presents various methods for accommodating model uncertainty in random effects and latent variable models. This book focuses on frequentist likelihood ratio and score tests for zero variance components. It also focuses on Bayesian methods for random effects selection in linear mixed effects and generalized linear mixed models

  18. Job rotation: Effects on muscular activity variability.

    Science.gov (United States)

    Rodriguez, Andres C; Barrero, Lope H

    2017-04-01

    Job rotation strategies have been used for years as an administrative intervention to reduce the risk of musculoskeletal disorders. The benefits of job rotation have been hypothesized to occur via changes in muscular activity variability (MAV). However, the effect of job rotation on MAV has not been fully analyzed in a literature review. A wide search was conducted to identify studies testing the effect of different job rotation strategies on MAV. Twenty-six studies of acceptable quality were included. Several studies on different types of tasks supported the view that job rotation can increase muscular activity variability, particularly with strategies such as alternating tasks and pace changes. However, it remains uncertain whether such variability changes immediately translate into benefits for the worker because little evidence was found that showed simultaneous changes in different muscular groups. Additionally, variability was occasionally achieved at the expense of average activity in the assessed muscles. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Consideration of environmental and operational variability for damage diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, H. (Hoon); Worden, K.; Farrar, C. R. (Charles R.)

    2002-01-01

    Damage diagnosis is a problem that can be addressed at many levels. Stated in its most basic form, the objective is to ascertain simply if damage is present or not. In a statistical pattern recognition paradigm of this problem, the philosophy is to collect baseline signatures from a system to be monitored and to compare subsequent data to see if the new 'pattern' deviates significantly from the baseline data. Unfortunately, matters are seldom as simple as this. In reality, structures will be subjected to changing environmental and operational conditions that will affect measured signals. In this case, there may be a wide range of normal conditions, and it is clearly undesirable to signal damage simply because of a change in the environment. In this paper, a unique combination of time series analysis, neural networks, and statistical inference techniques is developed for damage classification explicitly taking into account these natural variations of the system in order to minimize false positive indication of true system changes.

  20. Measuring Information Technology Performance: Operational Efficiency and Operational Effectiveness

    Science.gov (United States)

    Moore, Annette G.

    2012-01-01

    This dissertation provides a practical approach for measuring operational efficiency and operational effectiveness for IT organizations introducing the ITIL process framework. The intent of the study was to assist Chief Information Officers (CIOs) in explaining the impact of introducing the Information Technology Infrastructure Library (ITIL)…

  1. Measuring Information Technology Performance: Operational Efficiency and Operational Effectiveness

    Science.gov (United States)

    Moore, Annette G.

    2012-01-01

    This dissertation provides a practical approach for measuring operational efficiency and operational effectiveness for IT organizations introducing the ITIL process framework. The intent of the study was to assist Chief Information Officers (CIOs) in explaining the impact of introducing the Information Technology Infrastructure Library (ITIL)…

  2. Statistical identification of effective input variables. [SCREEN

    Energy Technology Data Exchange (ETDEWEB)

    Vaurio, J.K.

    1982-09-01

    A statistical sensitivity analysis procedure has been developed for ranking the input data of large computer codes in the order of sensitivity-importance. The method is economical for large codes with many input variables, since it uses a relatively small number of computer runs. No prior judgemental elimination of input variables is needed. The sceening method is based on stagewise correlation and extensive regression analysis of output values calculated with selected input value combinations. The regression process deals with multivariate nonlinear functions, and statistical tests are also available for identifying input variables that contribute to threshold effects, i.e., discontinuities in the output variables. A computer code SCREEN has been developed for implementing the screening techniques. The efficiency has been demonstrated by several examples and applied to a fast reactor safety analysis code (Venus-II). However, the methods and the coding are general and not limited to such applications.

  3. Approximation of Functions of Two Variables by Certain Linear Positive Operators

    Indian Academy of Sciences (India)

    Fatma Taşdelen; Ali Olgun; Gülen Bascanbaz-Tunca

    2007-08-01

    We introduce certain linear positive operators and study some approximation properties of these operators in the space of functions, continuous on a compact set, of two variables. We also find the order of this approximation by using modulus of continuity. Moreover we define an th order generalization of these operators and observe its approximation properties. Furthermore, we study the convergence of the linear positive operators in a weighted space of functions of two variables and find the rate of this convergence using weighted modulus of continuity.

  4. Freshwater reservoir effect variability in Northern Germany

    DEFF Research Database (Denmark)

    Philippsen, Bente; Heinemeier, Jan

    2012-01-01

    The freshwater reservoir effect is a potential problem when radiocarbon dating fishbones, shells, human bones or food crusts on pottery from sites next to rivers or lakes. The reservoir age in rivers containing considerable amounts of dissolved 14C-free carbonates can be up to several thousand...... years and may be highly variable. For accurate radiocarbon dating of freshwater-based samples, the order of magnitude of the reservoir effect as well as the degree of variability has to be known. The initial problem in this case was the accurate dating of food crusts on pottery from the Mesolithic sites...

  5. Formal Pseudodifferential Operators in One and Several Variables, Central Extensions, and Integrable Systems

    Directory of Open Access Journals (Sweden)

    Jarnishs Beltran

    2015-01-01

    Full Text Available We review some aspects of the theory of Lie algebras of (twisted and untwisted formal pseudodifferential operators in one and several variables in a general algebraic context. We focus mainly on the construction and classification of nontrivial central extensions. As applications, we construct hierarchies of centrally extended Lie algebras of formal differential operators in one and several variables, Manin triples and hierarchies of nonlinear equations in Lax and zero curvature form.

  6. ISSUES IN DELIVERY OPERATIONS – CAN VARIABLE PAY SCHEMES REALLY WORK?

    Directory of Open Access Journals (Sweden)

    Katija Vojvodić

    2016-12-01

    Full Text Available Ongoing changes in business objectives increasingly result in implementation of different business strategies striving to improve the workers’ performance. In that context, variable pay schemes have been utilised to increase employees’ motivation and productivity. Unlike the sales and warehouse sector, a number of issues emerge with respect to the variable pay schemes in delivery operations. The paper aims to examine issues and challenges associated with the introduction of variable pay schemes in the field of delivery operations. In this paper, we illustrate and analyse a case study from delivery operations of the FMCG sector in the market of Bosnia and Herzegovina. In this sense, the paper addresses the following research questions: What is the intended purpose of variable pay schemes? Which variables affect delivery operations? Why delivery performance should be carefully monitored? Which external factors influence delivery driver productivity? Can variable pay schemes attract, motivate or retain employees? Can variable pay schemes really work in delivery operations? The discussion presented in the paper has important practical implications related to workforce management and may be useful to managers and other subjects involved in designing pay and reward structures.

  7. MOMENT GENERATING FUNCTIONS OF RANDOM VARIABLES AND ASYMPTOTIC BEHAVIOUR FOR GENERALIZED FELLER OPERATORS

    Institute of Scientific and Technical Information of China (English)

    Ji-hua Xu; Jing-hui Zhao

    2000-01-01

    After giving the representation of moment gqnerating function for the S-λ type random variable by solving a differential equation, we prove that this type random variable is of regular n-r order moment. Furthermore we establish the higher order asymptotic formula for generalized Feller operators by making use of the generalized Taylor formula.

  8. Product Variables as Criteria of Teacher Effectiveness.

    Science.gov (United States)

    Schofield, Hilary L.; Start, K. B.

    1979-01-01

    Explanations are offered for observed discrepant and null findings in the area of predictive information about teacher effectiveness. It is argued that if tautologies are to be avoided, only product variables are appropriate criteria of success. Some recommendations regarding future research are offered. (Author/GSK)

  9. Effect of pre- and post-operative phenylbutazone and morphine administration on the breathing response to skin incision, recovery quality, behavior and cardiorespiratory variables in horses undergoing fetlock arthroscopy. A pilot study.

    Directory of Open Access Journals (Sweden)

    Clara eConde-Ruiz

    2015-11-01

    Full Text Available This prospective blinded randomized study aimed to determine whether the timing of morphine and phenylbutazone administration affects the breathing response to skin incision, recovery quality, behavior and cardiorespiratory variables in horses undergoing fetlock arthroscopy.Ten Standardbred horses were premedicated with acepromazine (0.04 mg kg-1 IM and romifidine (0.04 mg kg-1 IV. Anesthesia was induced with diazepam (0.05 mg kg-1 and ketamine (2.2 mg kg-1 IV at T0. Horses in group PRE (n = 5 received morphine (0.1 mg kg-1 and phenylbutazone (2.2 mg kg-1 IV after induction and an equivalent amount of saline after surgery. Horses in group POST (n = 5 received the inversed treatment. Anesthesia was maintained with isoflurane 2% in 100% oxygen. Hypotension (mean arterial pressure < 60 mmHg was treated with dobutamine. All horses breathed spontaneously. Dobutamine requirements, respiratory rate (fR, heart rate (HR, mean arterial blood pressure, end tidal CO2, inspired (i and expired (e tidal and minute volume (VT and V̇E, inspiratory time (IT and the inspiratory gas flow (VTi/IT were measured every five minutes. Data were averaged during four 15 minutes periods before (P1, P2 and after the incision (P3, P4. Serial blood-gas analyses were also performed. Recoveries were unassisted, video-recorded and scored by three anesthetists blinded to the treatment. The post-operative behavior of the horses (25 demeanors, HR and fR were recorded at three time points before induction (T0-24h, T0-12h, and T0-2h and six time points after recovery (TR (TR+2, 4, 6, 12, 24, 48 h.Data were compared between groups using a Wilcoxon test and within groups using a Friedman test or a Kruskal-Wallis signed rank test when applicable.Tidal volumes (VTe and VTi were higher in PRE than in POST during all the considered periods but the difference between groups was only significant during P2 (VTe in ml kg-1 in PRE: 13 [9, 15], in POST: 9 [8,9], p = 0.01. None of the other

  10. Creation and Annihilation Operators for Orthogonal Polynomials of Continuous and Discrete Variables

    OpenAIRE

    Lorente, M

    2004-01-01

    We develop general expressions for the raising and lowering operators that belong to the orthogonal polynomials of hypergeometric type with discrete and continuous variable. We construct the creation and annihilation operators that correspond to the normalized polynomials and study their algebraic properties in the case of the Kravchuk/Hermite Meixner/Laguerre polynomials.

  11. 3D facial landmarks: Inter-operator variability of manual annotation

    DEFF Research Database (Denmark)

    Fagertun, Jens; Harder, Stine; Rosengren, Anders;

    2014-01-01

    was randomly chosen. Six operators twice manually annotated 73 anatomical and pseudo-landmarks, using a three-step scheme producing a dense point correspondence map. We analyzed both the intra- and inter-operator variability, using mixed-model ANOVA. We then compared four sparse sets of landmarks in order...

  12. Modeling and Operational Testing of an Isolated Variable Speed PMSG Wind Turbine with Battery Energy Storage

    Directory of Open Access Journals (Sweden)

    BAROTE, L.

    2012-05-01

    Full Text Available This paper presents the modeling and operational testing of an isolated permanent magnet synchronous generator (PMSG, driven by a small wind turbine with a battery energy storage system during wind speed and load variations. The whole system is initially modeled, including the PMSG, the boost converter and the storage system. The required power for the connected loads can be effectively delivered and supplied by the proposed wind turbine and energy storage systems, subject to an appropriate control method. Energy storage devices are required for power balance and power quality in stand alone wind energy systems. The main purpose is to supply 230 V / 50 Hz domestic appliances through a single-phase inverter. The experimental waveforms, compared to the simulation results, show a good prediction of the electrical variable parameters. Furthermore, it can be seen that the results validate the stability of the supply.

  13. Adaptive variable-structure finite-time mode control for spacecraft proximity operations with actuator saturation

    Science.gov (United States)

    Lee, Daero; Vukovich, George; Gui, Haichao

    2017-05-01

    This paper presents an adaptive variable-structure finite-time control for spacecraft proximity maneuvers under parameter uncertainties, external disturbances and actuator saturation. The coupled six degrees-of-freedom dynamics are modeled for spacecraft relative motion, where the exponential coordinates on the Lie group SE(3) are employed to describe relative configuration. No prior knowledge of inertia matrix and mass of the spacecraft is required for the proposed control law, which implies that the proposed control scheme can be applied in spacecraft systems with large parametric uncertainties in inertia matrix and mass. Finite-time convergence of the feedback system with the proposed control law is established. Numerical simulation results are presented to illustrate the effectiveness of the proposed control law for spacecraft proximity operations with actuator saturation.

  14. Stellar Variability Effects on Transit Spectroscopy

    Science.gov (United States)

    Zellem, Robert Thomas; Swain, Mark R.; Shkolnik, Evgenya; Line, Michael R.; Llama, Joe

    2016-10-01

    Stellar variability caused by surface magnetic activity poses a great challenge to accurately and precisely characterize the atmospheres of transiting exoplanets. We present a preliminary analysis of the effects of unocculted star spots at IR wavelengths on planetary transmission and emission spectra. We will explore how stellar variability changes the derived exoplanet atmospheric parameters inferred through retrievals for a group of exoplanetary hosts stars. Our study includes stars ranging in activity levels from an inactive sun to a very active late-type star, and a range of planetary masses from super-Earths to Jupiters. These effects will be especially important for the high precision measurements (TESS orbiting nearby M dwarfs, which are more active than solar-type stars.

  15. Estimating Interaction Effects With Incomplete Predictor Variables

    Science.gov (United States)

    Enders, Craig K.; Baraldi, Amanda N.; Cham, Heining

    2014-01-01

    The existing missing data literature does not provide a clear prescription for estimating interaction effects with missing data, particularly when the interaction involves a pair of continuous variables. In this article, we describe maximum likelihood and multiple imputation procedures for this common analysis problem. We outline 3 latent variable model specifications for interaction analyses with missing data. These models apply procedures from the latent variable interaction literature to analyses with a single indicator per construct (e.g., a regression analysis with scale scores). We also discuss multiple imputation for interaction effects, emphasizing an approach that applies standard imputation procedures to the product of 2 raw score predictors. We thoroughly describe the process of probing interaction effects with maximum likelihood and multiple imputation. For both missing data handling techniques, we outline centering and transformation strategies that researchers can implement in popular software packages, and we use a series of real data analyses to illustrate these methods. Finally, we use computer simulations to evaluate the performance of the proposed techniques. PMID:24707955

  16. Effective operator formalism for open quantum systems

    DEFF Research Database (Denmark)

    Reiter, Florentin; Sørensen, Anders Søndberg

    2012-01-01

    We present an effective operator formalism for open quantum systems. Employing perturbation theory and adiabatic elimination of excited states for a weakly driven system, we derive an effective master equation which reduces the evolution to the ground-state dynamics. The effective evolution...... involves a single effective Hamiltonian and one effective Lindblad operator for each naturally occurring decay process. Simple expressions are derived for the effective operators which can be directly applied to reach effective equations of motion for the ground states. We compare our method...

  17. The experimental studies of operating modes of a diesel-generator set at variable speed

    Science.gov (United States)

    Obukhov, S. G.; Plotnikov, I. A.; Surkov, M. A.; Sumarokova, L. P.

    2017-02-01

    A diesel generator set working at variable speed to save fuel is studied. The results of experimental studies of the operating modes of an autonomous diesel generator set are presented. Areas for regulating operating modes are determined. It is demonstrated that the transfer of the diesel generator set to variable speed of the diesel engine makes it possible to improve the energy efficiency of the autonomous generator source, as well as the environmental and ergonomic performance of the equipment as compared with general industrial analogues.

  18. Dimension reduction of decision variables for multireservoir operation: A spectral optimization model

    Science.gov (United States)

    Chen, Duan; Leon, Arturo S.; Gibson, Nathan L.; Hosseini, Parnian

    2016-01-01

    Optimizing the operation of a multireservoir system is challenging due to the high dimension of the decision variables that lead to a large and complex search space. A spectral optimization model (SOM), which transforms the decision variables from time domain to frequency domain, is proposed to reduce the dimensionality. The SOM couples a spectral dimensionality-reduction method called Karhunen-Loeve (KL) expansion within the routine of Nondominated Sorting Genetic Algorithm (NSGA-II). The KL expansion is used to represent the decision variables as a series of terms that are deterministic orthogonal functions with undetermined coefficients. The KL expansion can be truncated into fewer significant terms, and consequently, fewer coefficients by a predetermined number. During optimization, operators of the NSGA-II (e.g., crossover) are conducted only on the coefficients of the KL expansion rather than the large number of decision variables, significantly reducing the search space. The SOM is applied to the short-term operation of a 10-reservoir system in the Columbia River of the United States. Two scenarios are considered herein, the first with 140 decision variables and the second with 3360 decision variables. The hypervolume index is used to evaluate the optimization performance in terms of convergence and diversity. The evaluation of optimization performance is conducted for both conventional optimization model (i.e., NSGA-II without KL) and the SOM with different number of KL terms. The results show that the number of decision variables can be greatly reduced in the SOM to achieve a similar or better performance compared to the conventional optimization model. For the scenario with 140 decision variables, the optimal performance of the SOM model is found with six KL terms. For the scenario with 3360 decision variables, the optimal performance of the SOM model is obtained with 11 KL terms.

  19. Dynamic Quantum Allocation and Swap-Time Variability in Time-Sharing Operating Systems.

    Science.gov (United States)

    Bhat, U. Narayan; Nance, Richard E.

    The effects of dynamic quantum allocation and swap-time variability on central processing unit (CPU) behavior are investigated using a model that allows both quantum length and swap-time to be state-dependent random variables. Effective CPU utilization is defined to be the proportion of a CPU busy period that is devoted to program processing, i.e.…

  20. Synthesis of biochemical applications on digital microfluidic biochips with operation variability

    DEFF Research Database (Denmark)

    Alistar, Mirela; Maftei, Elena; Pop, Paul

    2010-01-01

    , but as discrete droplets. Researchers have presented approaches for the synthesis of digital microfluidic biochips, which, starting from a biochemical application and a given biochip architecture, determine the allocation, resource binding, scheduling and placement of the operations in the application. Existing......Microfluidic-based biochips are replacing the conventional biochemical analyzers, and are able to integrate on-chip all the necessary functions for biochemical analysis using microfluidics. The digital microfluidic biochips are based on the manipulation of liquids not as a continuous flow...... approaches consider that on-chip operations, such as splitting a droplet of liquid, are perfect. However, these operations have variability margins, which can impact the correctness of the biochemical application.We consider that a split operation, which goes beyond specified variability bounds, is faulty...

  1. Variable viscosity effects on mixed convection heat and mass ...

    African Journals Online (AJOL)

    Variable viscosity effects on mixed convection heat and mass transfer along a ... PROMOTING ACCESS TO AFRICAN RESEARCH ... Keywords: Variable viscosity, Chemical Reaction, Viscous Dissipation, Finite difference method, Suction.

  2. Operation ranges and dynamic capabilities of variable-speed pumped-storage hydropower

    Science.gov (United States)

    Mercier, Thomas; Olivier, Mathieu; Dejaeger, Emmanuel

    2017-04-01

    The development of renewable and intermittent power generation creates incentives for the development of both energy storage solutions and more flexible power generation assets. Pumped-storage hydropower (PSH) is the most established and mature energy storage technology, but recent developments in power electronics have created a renewed interest by providing PSH units with a variable-speed feature, thereby increasing their flexibility. This paper reviews technical considerations related to variable-speed PSH in link with the provision of primary frequency control, also referred to as frequency containment reserves (FCRs). Based on the detailed characteristics of a scale model pump-turbine, the variable-speed operation ranges in pump and turbine modes are precisely assessed and the implications for the provision of FCRs are highlighted. Modelling and control for power system studies are discussed, both for fixed- and variable-speed machines and simulation results are provided to illustrate the high dynamic capabilities of variable-speed PSH.

  3. Online Synthesis for Operation Execution Time Variability on Digital Microfluidic Biochips

    DEFF Research Database (Denmark)

    Alistar, Mirela; Pop, Paul

    2014-01-01

    Several approaches have been proposed for the synthesis of digital microfluidic biochips, which, starting from a biochemical application and a given biochip architecture, determine the allocation, resource binding, scheduling, placement and routing of the operations in the application. Researchers...... an online synthesis strategy that re-synthesizes the application at runtime when operations experience variability in their execution time, obtaining thus shorter application execution times. The proposed strategy has been evaluated using several benchmarks....

  4. Determining adjustment variables for rationalising a design for fleet operation in public passenger transport

    Directory of Open Access Journals (Sweden)

    Carlos Fabián Flórez Valero

    2010-04-01

    Full Text Available This investigation was aimed at establishing aspects leading to adjusting the operational design of public transport fleet operation to make it more profitable for private investors. Data obtained from more than a year’s operation by the Alianza Sat S.A. was used (this being a bus- company alliance grouping about 100 buses from some of Bogotá’s collective transport companies for carrying out the present investigation regarding fleet administration and operation. Simply implementing conventionally-designed routing plans is not enough for rationalising fleet operation, as most public collective transport is not directly operated by companies The Alianza Sat S.A. bus fleet was used for testing hypotheses demonstrating that current operational design for the company’s routes (in Bogotá’s current public transport market conditions leads to reducing the company’s income. The investigation revealed that public pas-senger transport bus fleet revenue can be increased if aspects different to those considered in standard route design methodology are controlled. The investigation has determined alternative rationalisation for operational collective public passenger transport company design regarding adjusting aspects such as the demand pattern, operating scheme, route variability, etc. This will provide an innovative and useful tool for rationalising the operational design of bus routes operating in cities having weak public transport control and excess bus supply.

  5. Variable effects of temperature on insect herbivory

    Directory of Open Access Journals (Sweden)

    Nathan P. Lemoine

    2014-05-01

    Full Text Available Rising temperatures can influence the top-down control of plant biomass by increasing herbivore metabolic demands. Unfortunately, we know relatively little about the effects of temperature on herbivory rates for most insect herbivores in a given community. Evolutionary history, adaptation to local environments, and dietary factors may lead to variable thermal response curves across different species. Here we characterized the effect of temperature on herbivory rates for 21 herbivore-plant pairs, encompassing 14 herbivore and 12 plant species. We show that overall consumption rates increase with temperature between 20 and 30 °C but do not increase further with increasing temperature. However, there is substantial variation in thermal responses among individual herbivore-plant pairs at the highest temperatures. Over one third of the herbivore-plant pairs showed declining consumption rates at high temperatures, while an approximately equal number showed increasing consumption rates. Such variation existed even within herbivore species, as some species exhibited idiosyncratic thermal response curves on different host plants. Thus, rising temperatures, particularly with respect to climate change, may have highly variable effects on plant-herbivore interactions and, ultimately, top-down control of plant biomass.

  6. Variability of exposure and estimation of cumulative exposure in a manually operated coal mine

    Energy Technology Data Exchange (ETDEWEB)

    Mamuya, S.H.D.; Bratveit, M.; Mwaiselage, J.; Moen, B.E. [University of Bergen, Bergen (Norway). Center for International Health

    2006-10-15

    This study aims at estimating variability in exposure to respirable dust and assessing whether the a priori grouping by job team is appropriate for an exposure-response study on respiratory effects among workers in a manually operated coal mine in Tanzania. Furthermore, estimated exposure levels were used to calculate cumulative exposure. Full-shift personal respirable dust samples (n = 204) were collected from 141 randomly chosen workers at underground and surface work sites. The geometric mean exposure for respirable dust varied from 0.07 mg m{sup -3} for office workers to 1.96 mg m{sup -3} for the development team. The analogous range of respirable quartz exposure was 0.006-0.073 mg m{sup -3}. Variance components were estimated using random effect models. For most job teams the within-worker variance component was considerably higher than the between-worker variance component. For respirable dust the estimated attenuation of the linear exposure-response relationship was low (5.9%) when grouping by job team. Grouping by job team was considered appropriate for studying the association between current dust exposure and respiratory effects. Based on the estimated worker-specific mean exposure in the job teams, the arithmetic mean cumulative exposure for the 299 workers who participated in the epidemiological part of the study was 38.1 mg. yr m{sup -3} for respirable dust and 2.0 mg. yr m{sup -3} for quartz.

  7. Strategy for the Operation of Cooling Towers with variable Speed Fans

    CERN Document Server

    Iñigo-Golfín, J

    2001-01-01

    Within the SPS Cooling Water Project at CERN aimed at the reduction of water consumption, this primary open cooling loop will be closed and all the primary cooling circuit components will be upgraded to the new required duty and brought to the necessary safety and operability standards. In particular the tower fans will be fitted with variable frequency drives to replace the existing two speed motors. This paper presents a study to optimize the operation of SPS cooling towers taking into account outdoor conditions (wet and dry bulb temperatures) and the entirety of the primary circuit in which they will operate.

  8. Commutators of Littlewood-Paley Operators on Herz Spaces with Variable Exponent

    Institute of Scientific and Technical Information of China (English)

    Hongbin Wang; Yihong Wu

    2016-01-01

    LetΩ∈L2(Sn−1) be homogeneous function of degree zero and b be BMO functions. In this paper, we obtain some boundedness of the Littlewood-Paley Opera-tors and their higher-order commutators on Herz spaces with variable exponent.

  9. Effects-Based Operations Has Limitations

    Science.gov (United States)

    2005-05-17

    2002. 3 Fayette, Daniel F . "Effects-Based Operations" Air Force Research Laboratory <http://www.afrl.af.mil/techconn/index.htm> [June 2001]. 4...Arlington, VA, 2001. Fayette, Daniel F . "Effects-Based Operations" Air Force Research Laboratory <http://www.afrl.af.mil/techconn/index.htm> [June

  10. Comparative Analysis of Upper Ocean Heat Content Variability from Ensemble Operational Ocean Analyses

    Science.gov (United States)

    Xue, Yan; Balmaseda, Magdalena A.; Boyer, Tim; Ferry, Nicolas; Good, Simon; Ishikawa, Ichiro; Rienecker, Michele; Rosati, Tony; Yin, Yonghong; Kumar, Arun

    2012-01-01

    Upper ocean heat content (HC) is one of the key indicators of climate variability on many time-scales extending from seasonal to interannual to long-term climate trends. For example, HC in the tropical Pacific provides information on thermocline anomalies that is critical for the longlead forecast skill of ENSO. Since HC variability is also associated with SST variability, a better understanding and monitoring of HC variability can help us understand and forecast SST variability associated with ENSO and other modes such as Indian Ocean Dipole (IOD), Pacific Decadal Oscillation (PDO), Tropical Atlantic Variability (TAV) and Atlantic Multidecadal Oscillation (AMO). An accurate ocean initialization of HC anomalies in coupled climate models could also contribute to skill in decadal climate prediction. Errors, and/or uncertainties, in the estimation of HC variability can be affected by many factors including uncertainties in surface forcings, ocean model biases, and deficiencies in data assimilation schemes. Changes in observing systems can also leave an imprint on the estimated variability. The availability of multiple operational ocean analyses (ORA) that are routinely produced by operational and research centers around the world provides an opportunity to assess uncertainties in HC analyses, to help identify gaps in observing systems as they impact the quality of ORAs and therefore climate model forecasts. A comparison of ORAs also gives an opportunity to identify deficiencies in data assimilation schemes, and can be used as a basis for development of real-time multi-model ensemble HC monitoring products. The OceanObs09 Conference called for an intercomparison of ORAs and use of ORAs for global ocean monitoring. As a follow up, we intercompared HC variations from ten ORAs -- two objective analyses based on in-situ data only and eight model analyses based on ocean data assimilation systems. The mean, annual cycle, interannual variability and longterm trend of HC have

  11. Effect of firm variables on patent price

    Directory of Open Access Journals (Sweden)

    Shyam Sreekumaran Nair

    2012-03-01

    Full Text Available In this study, using singleton patent auction price data from Ocean Tomo, LLC, we analyse the effect of firm variables on patent price. Patents owned by small firms attract higher price than patents owned by large firms, if they engage in multi-country filings. The patents owned by small firms get cited more than the patents owned by large firms. The patents owned by individual inventors attract a higher price than the patents owned by organisations when multi-country filings are not included. We believe that the lack of resources is preventing individual inventors from engaging in multi-country filings and maximising the revenue from their invention. A larger representative data should be used to replicate the results before generalising it.

  12. Stochastic Multi-Timescale Power System Operations With Variable Wind Generation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Hongyu; Krad, Ibrahim; Florita, Anthony; Hodge, Bri-Mathias; Ibanez, Eduardo; Zhang, Jie; Ela, Erik

    2017-09-01

    This paper describes a novel set of stochastic unit commitment and economic dispatch models that consider stochastic loads and variable generation at multiple operational timescales. The stochastic model includes four distinct stages: stochastic day-ahead security-constrained unit commitment (SCUC), stochastic real-time SCUC, stochastic real-time security-constrained economic dispatch (SCED), and deterministic automatic generation control (AGC). These sub-models are integrated together such that they are continually updated with decisions passed from one to another. The progressive hedging algorithm (PHA) is applied to solve the stochastic models to maintain the computational tractability of the proposed models. Comparative case studies with deterministic approaches are conducted in low wind and high wind penetration scenarios to highlight the advantages of the proposed methodology, one with perfect forecasts and the other with current state-of-the-art but imperfect deterministic forecasts. The effectiveness of the proposed method is evaluated with sensitivity tests using both economic and reliability metrics to provide a broader view of its impact.

  13. The effect of operating an electrical grid

    Energy Technology Data Exchange (ETDEWEB)

    Pruss, V.L.; Limonov, A.I.

    1982-01-01

    The operation of a grid is discussed as its control in order to maintain its readiness for electric power supply of the consumers connected to the grid. Methods are proposed for determining the effect of operation as the difference in the readiness of the grid in the presence and absence of its servicing. The dependences of the value of this effect on the technical characteristics of the grid are cited.

  14. Effective operator formalism for open quantum systems

    DEFF Research Database (Denmark)

    Reiter, Florentin; Sørensen, Anders Søndberg

    2012-01-01

    We present an effective operator formalism for open quantum systems. Employing perturbation theory and adiabatic elimination of excited states for a weakly driven system, we derive an effective master equation which reduces the evolution to the ground-state dynamics. The effective evolution...

  15. Induced Interval-Valued Intuitionistic Fuzzy Hybrid Aggregation Operators with TOPSIS Order-Inducing Variables

    Directory of Open Access Journals (Sweden)

    Jun-Ling Zhang

    2012-01-01

    Full Text Available Two induced aggregation operators with novelly designed TOPSIS order-inducing variables are proposed: Induced Interval-valued Intuitionistic Fuzzy Hybrid Averaging (I-IIFHA operator and Induced Interval-valued Intuitionistic Fuzzy Hybrid Geometric (I-IIFHG operator. The merit of two aggregation operators is that they can consider additional preference information of decision maker’s attitudinal characteristics besides argument-dependent information and argument-independent information. Some desirable properties of I-IIFHA and I-IIFHG are studied and theoretical analysis also shows that they can include a wide range of aggregation operators as special cases. Further, we extend these operators to form a novel group decision-making method for selecting the most desirable alternative in multiple attribute multi-interest group decision-making problems with attribute values and decision maker’s interest values taking the form of interval-valued intuitionistic fuzzy numbers, and application research to real estate purchase selection shows its practicality.

  16. Operating characteristics of heavy loaded cylindrical journal bearing with variable axial profile

    Directory of Open Access Journals (Sweden)

    Stanislaw Strzelecki

    2005-12-01

    Full Text Available During the operation of turbounit its bearings displace as a result of heat elongation of bearings supports. It changes the static deflection line of rotor determined during assembly of the turbounit, causing an increase in the stresses on the bearing edges and a decrease in the dynamic state of the machine. One of possibilities to avoid the edge stresses is to apply the bearings with variable axial profile, e.g. hyperboloidal, convex profile in the axial cross-section of bearing. Application of journal bearings with hyperboloidal profile allows to extend the bearing operation range without the stress concentration on the edges of bush. These bearings successfully carry the extreme load in conditions of misaligned axis of journal and the bush eliminating the necessity of using self-aligning bearings. Operating characteristics of bearing include the resulting force, attitude angle, oil film pressure and temperature distributions, minimum oil film thickness, maximum oil film temperature. In literature there is a lack of data on the operating characteristics of heavy loaded hyperboloidal journal bearings operating at the conditions of adiabatic oil film and static equilibrium position of the journal. For the hyperboloidal bearing the operating characteristics have been obtained. Different values of length to diameter ratio, assumed shape and inclination ratio coefficients have been assumed. Iterative solution of the Reynolds', energy and viscosity equations was applied. Adiabatic oil film, laminar flow in the bearing gap as well as aligned and misaligned orientation of journal in the bush were considered.

  17. Variable Frequency Operations of an Offshore Wind Power Plant with HVDC-VSC: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Gevorgian, V.; Singh, M.; Muljadi, E.

    2011-12-01

    In this paper, a constant Volt/Hz operation applied to the Type 1 wind turbine generator. Various control aspects of Type 1 generators at the plant level and at the turbine level will be investigated. Based on DOE study, wind power generation may reach 330 GW by 2030 at the level of penetration of 20% of the total energy production. From this amount of wind power, 54 GW of wind power will be generated at offshore wind power plants. The deployment of offshore wind power plants requires power transmission from the plant to the load center inland. Since this power transmission requires submarine cable, there is a need to use High-Voltage Direct Current (HVDC) transmission. Otherwise, if the power is transmitted via alternating current, the reactive power generated by the cable capacitance may cause an excessive over voltage in the middle of the transmission distance which requires unnecessary oversized cable voltage breakdown capability. The use of HVDC is usually required for transmission distance longer than 50 kilometers of submarine cables to be economical. The use of HVDC brings another advantage; it is capable of operating at variable frequency. The inland substation will be operated to 60 Hz synched with the grid, the offshore substation can be operated at variable frequency, thus allowing the wind power plant to be operated at constant Volt/Hz. In this paper, a constant Volt/Hz operation applied to the Type 1 wind turbine generator. Various control aspects of Type 1 generators at the plant level and at the turbine level will be investigated.

  18. The quest for process operations variability reduction in manufacturing firms in South Africa

    Directory of Open Access Journals (Sweden)

    Madi Katombe

    2016-09-01

    Full Text Available In an era characterised by a volatile economy, intense competition, and rising energy and material costs, improving operational efficiency has become a necessity for margin purposes and long-term business success. This research study attempts to develop a model for process operations variability reduction that integrates the fundamental drivers, the intermediate measures and the four traditional competitive capabilities: quality, cost, delivery reliability and speed of delivery. In addition, it highlights the precise mechanisms in plants that lead to multiple competitive capabilities development. The concept of a routine-based approach to capabilities development provides a nexus between the earlier actions by the organisation and competitive advantage. Using longitudinal data from the Manufacturing Circle of South Africa, a statistical analysis was conducted to support the model, and path analysis models were developed which confirmed that the performance frontier is really a surface that spans many different dimensions. It is observed that the model clearly outlines pathways to process operations variability reduction through better execution of the routines concerned with maintaining the performance by current processes, improving existing processes, and transforming or changing to new processes.

  19. Effect of citicoline on blood pressure variability

    Directory of Open Access Journals (Sweden)

    O. D. Ostroumova

    2014-01-01

    Full Text Available The authors give the results of their investigation dealing with citicoline therapy in patients with hypertension and cognitive impairments.Objective: to determine the efficiency of citicoline therapy on the level and variability of both systolic and diastolic blood pressures (BP (SBP and DBP.Patients and methods. The investigation covered 60 patients with Stage II hypertension and a goal BP of < 140/90 mm Hg within ≥3 months before their inclusion. The patients were randomized into 2 groups: 30 patients in the study group were assigned to receive a cycle of 10 injections of citicoline in a daily dose of 1000 mg dropwise intravenously, then 1000 mg/day orally for as long as 3 months. 30 patients comprised the control group.Results and discussion. 24-hour BP monitoring indicated that during 4-week citicoline therapy there were significant (p<0.05 reductions in average nocturnal SBP (by 4.1±2.24 mm Hg, average daytime (-1.5±0.39 mm Hg and average nighttime (-1.5±0.37 mm Hg BP variabilities; such changes were not found in the control group. In the study group, normal daytime SBP variability at baseline (≤15 mm Hg was seen in 15 (50% patients; that after citicoline treatment was in 21 (70%; in the control group, this was in 15 (50% and 14 (46.7% patients before and after 4-week therapy, respectively. In the study group, normal nocturnal SBP variability at baseline (≤ 15 mm Hg was seen in 15 (50% patients; that after citicoline treatment was in 23 (76.7%; in the control group, this was in 15 (50% and 16 (53.3% patients, respectively.Twenty-one (70% patients in each group had baseline normal daytime DBP variability (<14 mm Hg; following 4 weeks of treatment, the number of patients with normal daytime DBP variability remained unchanged in the control group and that increased by one patient (n = 22 (73.3% in the citicoline group. Normal nocturnal DBP variability at baseline (<12 mm Hg was observed in 19 (63.3% patients in each group

  20. Variable speed induction motor operation from a 20-kHz power bus

    Science.gov (United States)

    Hansen, Irving G.

    Induction motors are recognized for their simple rugged construction to date, however, their application to variable speed or servo drives has been hampered by limitations on their control. Induction motor drives tend to be complex and to display troublesome low speed characteristics due in part to nonsinusoidal driving voltages. A technique was developed which involves direct synthesis of sinusoidal driving voltages from a high frequency power bus and independent control of frequency and voltages. Separation offrequency and voltage allows independent control of rotor and stator flux, full four-quadrant operation, and instantaneous torque control. Recent test results, current status of the technology, and proposed aerospace applications will be discussed.

  1. Experimental diagnosis of the influence of operational variables on the performance of a solar absorption cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Venegas, M.; Rodriguez-Hidalgo, M.C.; Lecuona, A.; Rodriguez, P.; Gutierrez, G. [Dpto. Ingenieria Termica y de Fluidos, Universidad Carlos III de Madrid, Avda. Universidad 30, 28911 Leganes, Madrid (Spain); Salgado, R. [Dpto. Ingenieria Mecanica, Universidad Interamericana de Puerto Rico, Recinto de Bayamon, 500 Carretera Dr. John Will Harris Bayamon, PR 00957-6257 (United States)

    2011-04-15

    This paper presents the analysis of the performance of a solar cooling facility along one summer season using a commercial single-effect water-lithium bromide absorption chiller aiming at domestic applications. The facility works only with solar energy using flat plate collectors and it is located at Universidad Carlos III de Madrid, Spain. The statistical analysis performed with the gathered data shows the influence of five daily operational variables on the system performance. These variables are solar energy received along the day (H) and the average values, along the operating period of the solar cooling facility (from sunrise to the end of the cold-water production), of the ambient temperature (anti T), the wind velocity magnitude (V), the wind direction ({theta}) and the relative humidity (RH). First order correlation functions are given. The analysis of the data allows concluding that the most influential variables on the daily cooling energy produced and the daily averaged solar COP are H, V and {theta}. The period length of cold-water production is determined mainly by H and anti T. (author)

  2. Deterministic Quantum Secure Direct Communication with Dense Coding and Continuous Variable Operations

    Institute of Scientific and Technical Information of China (English)

    HAN Lian-Fang; CHEN Yue-Ming; YUAN Hao

    2009-01-01

    We propose a deterministic quantum secure direct communication protocol by using dense coding.The two check photon sequences are used to check the securities of the channels between the message sender and the receiver.The continuous variable operations instead of the usual discrete unitary operations are performed on the travel photons so that the security of the present protocol can be enhanced.Therefore some specific attacks such as denial-of-service attack, intercept-measure-resend attack and invisible photon attack can be prevented in ideal quantum channel.In addition, the scheme is still secure in noise channel.Furthurmore, this protocol has the advantage of high capacity and can be realized in the experiment.

  3. The effects of surgeons and anesthesiologists on operating room efficiency

    Directory of Open Access Journals (Sweden)

    Nessa Timoney

    2016-09-01

    Conclusion: In some procedures types a significant part of the variability in operative time is due to the interaction between the surgeon and anesthesiologist. Reviewing operative records should allow identification of efficient/inefficient combinations.

  4. Effects of Marker Variables on WAIS Communalities.

    Science.gov (United States)

    Puhan, Biranchi N.

    1981-01-01

    One hundred undergraduate arts students were tested on all the scales of Wechsler Adult Intelligence Scales (WAIS) and the Differential Aptitude Tests. Varimax solutions were extracted on WAIS scores under four analytic conditions. No progressive increment in the WAIS communalities was marked as the marker variables increased. (Author/RL)

  5. Analysis of Boiler Operational Variables Prior to Tube Leakage Fault by Artificial Intelligent System

    Directory of Open Access Journals (Sweden)

    Al-Kayiem Hussain H.

    2014-07-01

    Full Text Available Steam boilers are considered as a core of any steam power plant. Boilers are subjected to various types of trips leading to shut down of the entire plant. The tube leakage is the worse among the common boiler faults, where the shutdown period lasts for around four to five days. This paper describes the rules of the Artificial Intelligent Systems to diagnosis the boiler variables prior to tube leakage occurrence. An Intelligent system based on Artificial Neural Network was designed and coded in MATLAB environment. The ANN was trained and validated using real site data acquired from coal fired power plant in Malaysia. Ninety three boiler operational variables were identified for the present investigation based on the plant operator experience. Various neural networks topology combinations were investigated. The results showed that the NN with two hidden layers performed better than one hidden layer using Levenberg-Maquardt training algorithm. Moreover, it was noticed that hyperbolic tangent function for input and output nodes performed better than other activation function types.

  6. Ocean Variability Effects on Underwater Acoustic Communications

    Science.gov (United States)

    2007-09-30

    B is about 6 dB higher than that during enviromental case A. Due to the large aperture and deployment range of the MPL array, the channel impulse...coherence. IMPACT /APPLICATIONS The developed receiver is a robust structure for high data rate underwater digital communications at high frequencies...H.-C. Song, W. S. Hodgkiss, M. B. Porter, and the KauaiEx group, “ Impact of Ocean Variability on Coherent Underwater Acoustic Communications

  7. Populations in variable environments: the effect of variability in a species' primary resource

    National Research Council Canada - National Science Library

    Stephen A. Davis; Roger P. Pech; Edward A. Catchpole

    2002-01-01

    ...Mechanistic models for herbivore populations responding to rainfall–driven pasture are used to explore the effect of temporal variability in a primary resource on the abundance and distribution of a species...

  8. Boundary Operators in Effective String Theory

    CERN Document Server

    Hellerman, Simeon

    2016-01-01

    Various universal features of relativistic rotating strings depend on the organization of allowed local operators on the worldsheet. In this paper, we study the set of Neumann boundary operators in effective string theory, which are relevant for the controlled study of open relativistic strings with freely moving endpoints. Relativistic open strings are thought to encode the dynamics of confined quark-antiquark pairs in gauge theories in the planar approximation. Neumann boundary operators can be organized by their behavior under scaling of the target space coordinates X, and the set of allowed X-scaling exponents is bounded above by +1/2 and unbounded below. Negative contributions to X-scalings come from powers of a single invariant, or "dressing" operator, which is bilinear in the embedding coordinates. In particular, we show that all Neumann boundary operators are dressed by quarter-integer powers of this invariant, and we demonstrate how this rule arises from various ways of regulating the short-distance ...

  9. A mathematical model for removal of human pathogenic viruses and bacteria by slow sand filtration under variable operational conditions

    NARCIS (Netherlands)

    Schijven, J.F.; Berg, H.H.J.L. van den; Colin, M.; Dullemont, Y.; Hijnen, W.A.M.; Magic-Knezev, A.; Oorthuizen, W.A.; Wubbels, G.

    2013-01-01

    Slow sand filtration (SSF) in drinking water production removes pathogenic microorganisms, but detection limits and variable operational conditions complicate assessment of removal efficiency. Therefore, amodel was developed to predict removal ofhuman pathogenic viruses and bacteria as a function of

  10. Category Variability Effect in Category Learning with Auditory Stimuli

    Directory of Open Access Journals (Sweden)

    Lee-Xieng eYang

    2014-10-01

    Full Text Available The category variability effect refers to that people tend to classify the midpoint item between two categories as the category more variable. This effect is regarded as evidence against the exemplar model, such as GCM (Generalized Context Model and favoring the rule model, such as GRT (i.e., the decision bound model. Although this effect has been found in conceptual category learning, it is not often observed in perceptual category learning. To figure out why the category variability effect is seldom reported in the past studies, we propose two hypotheses. First, due to sequence effect, the midpoint item would be classified as different categories, when following different items. When we combine these inconsistent responses for the midpoint item, no category variability effect occurs. Second, instead of the combination of sequence effect in different categorization conditions, the combination of different categorization strategies conceals the category variability effect. One experiment is conducted with single tones of different frequencies as stimuli. The collected data reveal sequence effect. However, the modeling results with the MAC model and the decision bound model support that the existence of individual differences is the reason for why no category variability effect occurs. Three groups are identified by their categorization strategy. Group 1 is rule user, placing the category boundary close to the low-variability category, hence inducing category variability effect. Group 2 takes the MAC strategy and classifies the midpoint item as different categories, depending on its preceding item. Group 3 classifies the midpoint item as the low-variability category, which is consistent with the prediction of the decision bound model as well as GCM. Nonetheless, our conclusion is that category variability effect can be found in perceptual category learning, but might be concealed by the averaged data.

  11. The Operational Testing Effectiveness Evaluation Method

    Science.gov (United States)

    1988-04-01

    compared, testing methods improved, and critics silenced . Given that checking IOT&E assessments against operational data seemed to be common sense, was...history of OT&E, discussing the poasibility that the record of frequent convulsive organizational change is related to the lack of adequate feedback on... silence the critics, and ultimately ensure that the weapons reaching the ramp really are effective and suitable. 30 ~• x , .-.-. I- BIBLIOGRAPH d Books

  12. New Indicators of Psychological Operations Effects

    Science.gov (United States)

    1975-06-01

    Psychological Oo)erations Effectiveness, the Autacrican University, Washington, I). C., May 1967. -(Cinfac Response 796 . 59. Paul F. Lazarsfeld and Morris...1975Sby -•- GENERAL RESEARCH4 CORPORATION • McLean, Virginia 22101 i-_ ,- _ PREFACE, It has been 25 years since Paul M. A. ILinebarger wrote Frontiers...CPT Josepih Thach of the Psycho- logical Operations BDanch, ODCSOPS; and COL Raymond Deitch, formerly chief l* Paul M. A. Linebarger, Frontiers in

  13. An Evaluation of OpenSHMEM Interfaces for the Variable-length Alltoallv() Collective Operation

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Matthew Graham [ORNL; Shamis, Pavel [ORNL; Gorentla Venkata, Manjunath [ORNL

    2015-01-01

    Alltoallv() is a collective operation which allows all pro- cesses to exchange variable amounts of data with all other processes in the communication group. This means that Alltoallv() requires not only O(N2) communications, but typically also additional exchanges of the data lengths that will be transmitted in the eventual Alltoallv() call. This pre-exchange is used to calculate the proper offsets for the re- ceiving buffers on the target processes. However, we propose two new can- didate interfaces for Alltoallv() that would mitigate the need for the user to set up this extra exchange of information at the possible cost of memory efficiency. We explain the new interface variants and show how a single call can be used in place of the traditional Alltoall()/Alltoallv() pair. We then discuss the performance tradeoffs for overall communica- tion and memory costs, as well as both software and hardware-based optimizations and their applicability to the various proposed interfaces.

  14. THE EFFECTS OF CLIMATIC VARIABLES AND CROP AREA ON MAIZE YIELD AND VARIABILITY IN GHANA

    Directory of Open Access Journals (Sweden)

    Henry De-Graft Acquah

    2012-10-01

    Full Text Available Climate change tends to have negative effects on crop yield through its influence on crop production. Understanding the relationship between climatic variables and crop area on the mean and variance of crop yield will facilitate development of appropriate policies to cope with climate change. This paper examines the effects of climatic variables and crop area on the mean and variance of maize yield in Ghana. The Just and Pope stochastic production function using the Cobb-Douglas functional form was employed. The results show that average maize yield is positively related to crop area and negatively related to rainfall and temperature. Furthermore, increase in crop area and temperature will enlarge maize yield variability while rainfall increase will decrease the variability in maize yield.

  15. BUSINESS OPERATIONS BETWEEN EFFICIENCY AND EFFECTIVENESS

    Directory of Open Access Journals (Sweden)

    Vojko Potočan

    2006-12-01

    Full Text Available The existence and development of organizations depends on achievement of requisite holistic efficiency and effectiveness of their operations and bahaviour. But in theory (of organization and management and business practice do not exist common understanding of efficiency and effectiveness, their relations and sinergies. When we try to investigate their definitions and relations we must take into account problems of many conflicts, which reflect their “different non-optimalty (unsuitability, inapproapriateness”. This contribution discusses three theses: 1 how to more (requisitely holistically understand relations between efficiency and effectiveness in the frame of business (its working and functioning, 2 how to understand their relations from the viewpoint of conflicts, and 3 one can create solution to remove a problem of different conflicts between efficiency and effectiveness in business.

  16. Environmental effects of DFDF normal operation

    Energy Technology Data Exchange (ETDEWEB)

    Park, J. J.; Lee, H. H.; Shin, J. M.; Kim, J. H.; Yang, M. S. [KAERI, Taejon (Korea, Republic of)

    2003-07-01

    A DUPIC nuclear fuel is a newly developed fuel for CANDU reactors based on the concept of refabrication of spent PWR fuel by a dry process. Because a spent PWR fuel, a highly radioactive material, is used as a starting material, the experimental verification of DUPIC nuclear fuel fabrication requires an appropriate facility which should satisfy engineering requirements and guarantees safe operation. DUPIC nuclear fuel development team modified M6 hot-cell in IMEF to construct the dedicated facility(DFDF) for the experiment. The experiment with spent PWR fuel have been conducted since January of 2000. Environmental effects of DFDF normal operation have been investigated when DUPIC nuclear fuel is fabricated with the maximum capacity of 50 kg U/yr. The analysis results of the radiological safety of DFDF facility have shown that both national regulation limit and IMEF design criteria are satisfied.

  17. Modeling and Operational Testing of an Isolated Variable Speed PMSG Wind Turbine with Battery Energy Storage

    OpenAIRE

    BAROTE, L.; MARINESCU, C.

    2012-01-01

    This paper presents the modeling and operational testing of an isolated permanent magnet synchronous generator (PMSG), driven by a small wind turbine with a battery energy storage system during wind speed and load variations. The whole system is initially modeled, including the PMSG, the boost converter and the storage system. The required power for the connected loads can be effectively delivered and supplied by the proposed wind turbine and energy storage systems, subject to an appropri...

  18. Bayesian Variable Selection in Cost-Effectiveness Analysis

    Directory of Open Access Journals (Sweden)

    Miguel A. Negrín

    2010-04-01

    Full Text Available Linear regression models are often used to represent the cost and effectiveness of medical treatment. The covariates used may include sociodemographic variables, such as age, gender or race; clinical variables, such as initial health status, years of treatment or the existence of concomitant illnesses; and a binary variable indicating the treatment received. However, most studies estimate only one model, which usually includes all the covariates. This procedure ignores the question of uncertainty in model selection. In this paper, we examine four alternative Bayesian variable selection methods that have been proposed. In this analysis, we estimate the inclusion probability of each covariate in the real model conditional on the data. Variable selection can be useful for estimating incremental effectiveness and incremental cost, through Bayesian model averaging, as well as for subgroup analysis.

  19. Effects of Tai Chi exercise on heart rate variability.

    Science.gov (United States)

    Cole, Aimee R; Wijarnpreecha, Karn; Chattipakorn, Siriporn C; Chattipakorn, Nipon

    2016-05-01

    Tai Chi is a callisthenic exercise form that incorporates aerobic exercise with diaphragmatic breathing. These two aspects alone have been shown to enhance the heart rate variability, warranting research into the effects of Tai Chi on autonomic nervous system modulation and heart rate variability. A low heart rate variability has been shown to be indicative of compromised health. Any methods to enhance the heart rate variability, in particular, non-pharmacological methods, are therefore seen as beneficial to health and are sought after. The aim of this review was to comprehensively summarize the currently published studies regarding the effects of Tai Chi on heart rate variability. Both consistent and inconsistent findings are presented and discussed, and an overall conclusion attained which could benefit future clinical studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. To investigate the influence of machine operating variables on formulations derived from lactose types in capsule filling: part 2.

    Science.gov (United States)

    Moolchandani, Vikas; Augsburger, Larry L; Gupta, Abhay; Khan, Mansoor A; Langridge, John; Hoag, Stephen W

    2016-01-01

    This study is the second in a series that examines the characterizing and selection of suitable grades of lactose for capsule formulation development. Based upon the previous study, four grades were selected for further study. The effects of drug load and operational variables on formulations derived from these four lactose types were evaluated for physicochemical and mechanical attributes of plugs and their capsules on an instrumented dosing-disc capsule filling machine (H&H KFM/3) using acetaminophen as a model, highly soluble and poorly compressible drug. The results obtained were as follows: (1) flowability reduced upon increasing drug load; (2) powder bed height (PBH) and compression force (CF) had positive significant effect on plug weight (p < 0.05); (3) ejection force was positively and significantly correlated with increasing speed and CF (p < 0.05); (4) AL capsule plugs had the highest plug crushing force which was followed by DCL15; (5) the crushing strength of plugs made from DCL11 increased with increasing acetaminophen concentration; (6) higher CF had a significant negative impact on acetaminophen release at 15 min time point (p < 0.05); (7) at 10% and 40% drug load, formulations containing AL showed the quickest drug release; and (8) increased drug load had a significant negative impact on the release rate at 15 and 45 min time points (p < 0.05). Overall, the results from this study provides information on risk based assessment of filler selection based on drug load and the range of machine operating variables which will help in defining criteria for meeting key quality attributes for capsule formulation development.

  1. Operation results of Wertheim-Meig. Analysis of some variables (1989-2009.

    Directory of Open Access Journals (Sweden)

    Rafael E. Pérez Castro

    2011-06-01

    Full Text Available A retrospective cross-sectional study was made to 63 patients operated with the surgical technique Wertheim-Meig having cervical cancer in stage I (1A2 and 1b1 during the corresponding period to the decade (1989-2009 in the University General Hospital Camilo Cienfuegos, with the objective to determine some factors associated to this pathology , so as the morbidity of this technique. The studied group was conformed by 63 patients who had the inclusion requirements taking into consideration the stages (t1a2, T1b1 from the total of patients having a cervical cancer. The HC was checked in a retrospective way collecting variables in a form such as: age groups, clinical stage, complications and survival, arriving to the following conclusions: the highest incidence of cervical cancer was in third decade of life (31 to 40 years. As a risk factor was: having sex at 17 years old or less than this age. It was very significant. Postoperative complications were minimum. It was found a 92% of survival, 2 recurrence (3.1%, 4 deaths (6.3% and a free interval diseases of 93.6%.

  2. Squeezed State Effects on Continuous Variable Quantum Erasing

    Science.gov (United States)

    Bonanno, Peter; Kasisomayajula, Vijay; Russo, Onofrio

    2008-03-01

    Experimental verification of complementarity using quantum erasing for the continuous variable (CV) infinite dimensional Hilbert space has been considered. [1] The complemetary pair is that of the canonically conjugate amplitude and phase quadratures of light. The amplitude quadrature is labeled to a squeezed meter signal by quantum nondemolition (QND) [2] entanglement coupling. [3] Knowledge of which eigenstate (WE) can be obtained by measuring this amplitude in the meter state, and can thereafter be `lost' by measuring the quadrature phase of the meter, thus restoring the quadrature phase of the signal beam in a process known as quantum erasure. [4] The coupling, i.e. the labeling of the signal state to the meter state, is implemented with a beam splitter coupled to the squeezed light meter beam. [4] We investigate the effects of using the unitary squeeze operator S(z)=exp.5ex1 -.1em/ -.15em.25ex2 (z*a^2 - za^+2) where z = re^i(squeezing angle) on selected coherent states under certain conditions. [5,6] [1] U. L. Anderson et al., Phys. Rev. Lett. 93, 100403 (2004). [2] V. B. Braginsky et al., Science 209, 547 (1980). [3] R. Bruckmeimer et al., Phys. Rev. Lett. 79, 43 (1997). [4] P. Grangier et al., Nature 396, 537 (1998). [5] C. M. Caves, Phys. Rev. D 23, 1693 (1981). [6] D. Stoler, Phys. Rev. D. 1, 3217 (1970), D. Stoler, Phys. Rev. D. 4, 1925 (1971). .

  3. The impact of alternative dispatch intervals on operating reserve requirements for variable generation

    Energy Technology Data Exchange (ETDEWEB)

    Milligan, Michael [National Renewable Energy Lab. (NREL), Boulder, CO (United States); King, Jack [RePPAE LLC, Wexford, PA (United States); Beuning, Stephen [Xcel Energy, Denver, CO (United States); Kirby, Brendan

    2011-07-01

    In the Western Interconnection of the United States, an energy imbalance market (EIM) has been proposed. This would effectively pool the variability of load, wind, and solar generation, and other deviations in generation schedules. The proposed market would perform an economic dispatch every 5 minutes. If implemented, this would be a significant change from the hourly scheduling and dispatch that occurs throughout most of the West. We analyze the impact of alternative scheduling and dispatch intervals on three types of reserves: regulation, following/spin, and following/non-spin. We compare the existing practice of hourly scheduling and dispatch with a 40-minute advance notification with 30-minute and 10-minute scheduling and dispatch. We also analyze the impact of alternative notification periods such as 30-minute scheduling/dispatch with 10, 30, and 40-minute notifications. We find that moving from a 60-minute dispatch to a 10-minute dispatch results in a 70% saving on deployed regulation. (orig.)

  4. The Evaluation of Physical Variables Which Effects Classroom Management

    OpenAIRE

    Ayşe KARAÇALI

    2006-01-01

    Classroom managament has great importance on increasing productivity of education activities.So that,it is necessary to be careful while arranging classroom environment.The teacher has an important role on arranging classroom environment.The teachers should arrange the classroom by taking care classroom physical variables and effects of classroom management.It increases productivity of education.This research explains the importance of classroom management and classroom’s physical variables o...

  5. Regional Greenland accumulation variability from Operation IceBridge airborne accumulation radar

    Science.gov (United States)

    Lewis, Gabriel; Osterberg, Erich; Hawley, Robert; Whitmore, Brian; Marshall, Hans Peter; Box, Jason

    2017-03-01

    The mass balance of the Greenland Ice Sheet (GrIS) in a warming climate is of critical interest to scientists and the general public in the context of future sea-level rise. An improved understanding of temporal and spatial variability of snow accumulation will reduce uncertainties in GrIS mass balance models and improve projections of Greenland's contribution to sea-level rise, currently estimated at 0.089 ± 0.03 m by 2100. Here we analyze 25 NASA Operation IceBridge accumulation radar flights totaling > 17 700 km from 2013 to 2014 to determine snow accumulation in the GrIS dry snow and percolation zones over the past 100-300 years. IceBridge accumulation rates are calculated and used to validate accumulation rates from three regional climate models. Averaged over all 25 flights, the RMS difference between the models and IceBridge accumulation is between 0.023 ± 0.019 and 0.043 ± 0.029 m w.e. a-1, although each model shows significantly larger differences from IceBridge accumulation on a regional basis. In the southeast region, for example, the Modèle Atmosphérique Régional (MARv3.5.2) overestimates by an average of 20.89 ± 6.75 % across the drainage basin. Our results indicate that these regional differences between model and IceBridge accumulation are large enough to significantly alter GrIS surface mass balance estimates. Empirical orthogonal function analysis suggests that the first two principal components account for 33 and 19 % of the variance, and correlate with the Atlantic Multidecadal Oscillation (AMO) and wintertime North Atlantic Oscillation (NAO), respectively. Regions that disagree strongest with climate models are those in which we have the fewest IceBridge data points, requiring additional in situ measurements to verify model uncertainties.

  6. Operations variables in the transesterification process of vegetable oil: a review - chemical catalysis

    Directory of Open Access Journals (Sweden)

    Andrés Felipe Rojas González

    2010-05-01

    Full Text Available This article describes the results of a bibliographic review of the effects of operation conditions on process yield in the chemical transesterification of vegetable oil. The parameters studied were: temperature and time reaction, alcohol:oil molar ratio, catalyst and alcohol type, catalyst concentration, mixed intensity and free fatty acid and water concentration. It also reports that this pro- cess has been carried out with basic and acid catalysts using homogeneous and heterogeneous catalytic processes for a wide va- riety of oils. It was found that reaction yield increased when temperature and time reaction increased; however this parameter de- creased at low catalyst concentration ( 1% w/w and water (> 3% w/w concentration in oil.

  7. A framework for model-based optimization of bioprocesses under uncertainty: Identifying critical parameters and operating variables

    DEFF Research Database (Denmark)

    Morales Rodriguez, Ricardo; Meyer, Anne S.; Gernaey, Krist

    2011-01-01

    -Carlo technique) and sensitivity analysis (such as global techniques). The results of the case study point towards the enzyme loading as the most significant variable influencing the operational cost of additives in the conversion of lignocellulose to ethanol. Moreover, the results also show...

  8. A Banach algebra of functions of several variables of finite total variation and Lipschitzian superposition operators. I

    NARCIS (Netherlands)

    Chistyakov, VV

    2005-01-01

    It is shown that the space of functions of n real variables with finite total variation in the sense of Vitali, Hardy and Krause, defined on a rectangle I-a(b) C R-n, is a Banach algebra under the pointwise operations and Hildebrandt-Leonov's norm. This result generalizes the classical case of funct

  9. Relationships between personality variables and bizarreness effects in free recall.

    Science.gov (United States)

    Moss, Brett J; Worthen, James B; Haydel, Leslie A; Mahon, Blaithin D Mac; Savoy, Sarah C

    2008-01-01

    Relationships between 6 personality variables and each of 3 different measures of recall for bizarre and common sentences were examined. The personality variables investigated included measures of sensation seeking, novelty experiencing, desire for novelty, arousal-seeking tendency, social potency, and conservatism. Recall was measured in terms of sentences accessed, target words recovered per accessed sentence, and misplaced target words. The results indicated the typical pattern of bizarreness effects on recall and significant relationships between personality variables and these effects. Arousal seeking and conservatism were positively related to a bizarreness advantage in sentences accessed. Additionally, high social potency was related to the recovery of more details from common than bizarre sentences, and high desire for novelty was related to a greater bizarre misplacement effect. The results are discussed in terms of orienting and defensive responses to bizarreness.

  10. Estimates of Some Integral Operators with Bounded Variable Kernels on the Hardy and Weak Hardy Spaces over Rn

    Institute of Scientific and Technical Information of China (English)

    Hua WANG

    2016-01-01

    In this paper, we first introduce Lσ 1-(log L)σ 2 conditions satisfied by the variable kernelsΩ (x, z) for 0 ≤ σ 1 ≤ 1 and σ 2 ≥ 0. Under these new smoothness conditions, we will prove the boundedness properties of singular integral operators TΩ , fractional integrals TΩ ,α and parametric Marcinkiewicz integralsμρΩ with variable kernels on the Hardy spaces Hp(Rn) and weak Hardy spaces WHp(Rn). Moreover, by using the interpolation arguments, we can get some corresponding results for the above integral operators with variable kernels on Hardy–Lorentz spaces Hp,q(Rn) for all p

  11. Improving Organisational Effectiveness of Coalition Operations

    NARCIS (Netherlands)

    Bisig, E.; Ann-Renée; Hof, T.; Seiler, S.; Yanakiev, Y.

    2010-01-01

    Transformation of military operations demands new tools to support the performance of coalition forces in multinational operations. This paper contributes to one of the fundamental objectives of SAS-081/RSY, namely to the objective to share experience from the implementation of methods and tools and

  12. Improving Organisational Effectiveness of Coalition Operations

    NARCIS (Netherlands)

    Bisig, E.; Ann-Renée; Hof, T.; Seiler, S.; Yanakiev, Y.

    2010-01-01

    Transformation of military operations demands new tools to support the performance of coalition forces in multinational operations. This paper contributes to one of the fundamental objectives of SAS-081/RSY, namely to the objective to share experience from the implementation of methods and tools and

  13. The effect of pre-operative optimization on post-operative outcome in Crohn's disease resections

    DEFF Research Database (Denmark)

    El-Hussuna, Alaa; Iesalnieks, Igors; Horesh, Nir

    2017-01-01

    on the post-operative outcome in CD. METHOD: This is a multicentre retrospective cohort study. The primary outcome was 30-day post-operative complications. Secondary outcomes were intra-abdominal septic complications, surgical site infection (SSI), re-operation, length of post-operative stay in a hospital......BACKGROUND: The timing of surgical intervention in Crohn's disease (CD) may depend on pre-operative optimization (PO) which includes different interventions to decrease the risk for unfavourable post-operative outcome. The objective of this study was to investigate the effect of multi-model PO...

  14. A Simplified and Improved Free-Variable Framework for Hilbert's epsilon as an Operator of Indefinite Committed Choice

    CERN Document Server

    Wirth, Claus-Peter

    2011-01-01

    Free variables occur frequently in mathematics and computer science with ad hoc and altering semantics. We present the most recent version of our free-variable framework for two-valued logics with properly improved functionality, but only two kinds of free variables left (instead of three): implicitly universally and implicitly existentially quantified ones, now simply called "free atoms" and "free variables", respectively. The quantificational expressibility and the problem-solving facilities of our framework exceed standard first-order and even higher-order modal logics, and directly support Fermat's descente infinie. With the improved version of our framework, we can now also model Henkin quantification, neither using quantifiers (binders) nor raising (Skolemization). We propose a new semantics for Hilbert's epsilon as a choice operator with the following features: We avoid overspecification (such as right-uniqueness), but admit indefinite choice, committed choice, and classical logics. Moreover, our seman...

  15. Effective Operators Within the Ab Initio No-Core Shell Model

    Energy Technology Data Exchange (ETDEWEB)

    Stetcu, I; Barrett, B R; Navratil, P; Vary, J P

    2004-11-30

    We implement an effective operator formalism for general one- and two-body operators, obtaining results consistent with the no-core shell model (NCSM) wave functions. The Argonne V8' nucleon-nucleon potential was used in order to obtain realistic wave functions for {sup 4}He, {sup 6}Li and {sup 12}C. In the NCSM formalism, we compute electromagnetic properties using the two-body cluster approximation for the effective operators and obtain results which are sensitive to the range of the bare operator. To illuminate the dependence on the range, we employ a Gaussian two-body operator of variable range, finding weak renormalization of long range operators (e.g., quadrupole) in a fixed model space. This is understood in terms of the two-body cluster approximation which accounts mainly for short-range correlations. Consequently, short range operators, such as the relative kinetic energy, will be well renormalized in the two-body cluster approximation.

  16. Courses of action for effects based operations using evolutionary algorithms

    Science.gov (United States)

    Haider, Sajjad; Levis, Alexander H.

    2006-05-01

    This paper presents an Evolutionary Algorithms (EAs) based approach to identify effective courses of action (COAs) in Effects Based Operations. The approach uses Timed Influence Nets (TINs) as the underlying mathematical model to capture a dynamic uncertain situation. TINs provide a concise graph-theoretic probabilistic approach to specify the cause and effect relationships that exist among the variables of interest (actions, desired effects, and other uncertain events) in a problem domain. The purpose of building these TIN models is to identify and analyze several alternative courses of action. The current practice is to use trial and error based techniques which are not only labor intensive but also produce sub-optimal results and are not capable of modeling constraints among actionable events. The EA based approach presented in this paper is aimed to overcome these limitations. The approach generates multiple COAs that are close enough in terms of achieving the desired effect. The purpose of generating multiple COAs is to give several alternatives to a decision maker. Moreover, the alternate COAs could be generalized based on the relationships that exist among the actions and their execution timings. The approach also allows a system analyst to capture certain types of constraints among actionable events.

  17. Improving Organisational Effectiveness of Coalition Operations

    OpenAIRE

    Bisig, E.; Ann-Renée; Hof, van 't, G.; Seiler, S; Yanakiev, Y.

    2010-01-01

    Transformation of military operations demands new tools to support the performance of coalition forces in multinational operations. This paper contributes to one of the fundamental objectives of SAS-081/RSY, namely to the objective to share experience from the implementation of methods and tools and latest research results in support of transformation and management in the new security environment. In addition, it focuses on the cognitive and human aspects of defence transformation. The goal ...

  18. The Effects of International Operations on the Relationship Between Manufacturing Improvement Programs and Operational Performance

    DEFF Research Database (Denmark)

    Matyusz, Zsolt; Demeter, Krisztina; Boer, Harry

    The link between manufacturing programs and operational performance, and the effects of company internal and external factors on that relationship, are well studied in the literature, both theoretically and empirically. However, previous studies rarely took into account how the scope of operations...... of the business unit affects the relationship between manufacturing programs and performances. We investigate the scope of operations from the manufacturing perspective (i.e. companies that manufacture in only one country have narrow scope of operations, while companies that manufacture in more than one country...... have broad scope of operations). We apply structural equation modelling (SEM) using PLS path modelling to investigate the effect of scope of operations on the relationship between manufacturing improvement programs and operational performance. Manufacturing improvement programs are programs like...

  19. The Evaluation of Physical Variables Which Effects Classroom Management

    Directory of Open Access Journals (Sweden)

    Ayşe KARAÇALI

    2006-06-01

    Full Text Available Classroom managament has great importance on increasing productivity of education activities.So that,it is necessary to be careful while arranging classroom environment.The teacher has an important role on arranging classroom environment.The teachers should arrange the classroom by taking care classroom physical variables and effects of classroom management.It increases productivity of education.This research explains the importance of classroom management and classroom’s physical variables on positive learning environment and reaching the students’learning aims.

  20. Effectiveness evaluation of STOL transport operations

    Science.gov (United States)

    Hitt, E. F.; Bruckner, J. M. H.; Drago, V. J.; Brown, R. A.; Rea, F. G.; Porter, R. F.

    1973-01-01

    A short-takeoff and landing (STOL) systems simulation model has been developed and implemented in a computer code (known as STOL OPS) which permits evaluation of the operation of a STOL aircraft and its avionics in a commercial airline operating environment. STOL OPS concentrated on the avionics functions of navigation, guidance, control, communication, hazard aviodance, and systems management. External world factors influencing the operation of the STOL aircraft include each airport and its geometry, air traffic at each airport, air traffic control equipment and procedures, weather (including winds and visibility), and the flight path between each airport served by the route. The development of the STOL OPS program provides NASA a set of computer programs which can be used for detailed analysis of a STOL aircraft and its avionics and permit establishment of system requirements as a function of airline mission performance goals.

  1. Effect of Instructions on Selected Jump Squat Variables.

    Science.gov (United States)

    Talpey, Scott W; Young, Warren B; Beseler, Bradley

    2016-09-01

    Talpey, SW, Young, WB, and Beseler, B. Effect of instructions on selected jump squat variables. J Strength Cond Res 30(9): 2508-2513, 2016-The purpose of this study was to compare 2 instructions on the performance of selected variables in a jump squat (JS) exercise. The second purpose was to determine the relationships between JS variables and sprint performance. Eighteen male subjects with resistance training experience performed 2 sets of 4 JS with no extra load with the instructions to concentrate on (a) jumping for maximum height and (b) extending the legs as fast as possible to maximize explosive force. Sprint performance was assessed at 0- to 10-m and 10- to 20-m distances. From the JS jump height, peak power, relative peak power, peak force, peak velocity, and countermovement distance were measured from a force platform and position transducer system. The JS variables under the 2 instructions were compared with paired t-tests, and the relationships between these variables and sprint performance were determined with Pearson's correlations. The jump height instruction produced greater mean jump height and peak velocity (p 0.05). Jump height was the variable that correlated most strongly with 10-m time and 10- to 20-m time under both instructions. The height instruction produced a stronger correlation with 10-m time (r = -0.455), but the fast leg extension JS produced a greater correlation with 10-20 time (r = -0.545). The results indicate that instructions have a meaningful influence on JS variables and therefore need to be taken into consideration when assessing or training athletes.

  2. The development of an operational LCIA-methodology with impact categories based on the control variables in the Planetary Boundaries framework

    DEFF Research Database (Denmark)

    Ryberg, Morten; Owsianiak, Mikolaj; Hauschild, Michael Zwicky

    2016-01-01

    these limitations is to directly use the control variables in the PB-framework as impact categories in LCIA, which is also the objective of this study. This work defines a mathematical framework for a LCIA-methodology where Characterization Factors (CFs) are included for all Earth system processes in the PB...... understanding of the cause-effect chain is missing for the latter. The CFs were estimated by identifying the environmental models needed to model the control variables of the PB-framework and adapting these to fit the LCIA-framework. This work provides a full set of CFs for all the Earth system processes......This study presents a first attempt at an operational LCIA-methodology basing the definition of the impact categories on the control variables as defined in the Planetary Boundaries (PB) framework. The PB-framework introduced a set of biophysical Earth system processes and defined quantitative PBs...

  3. Effect of atrioventricular conduction on heart rate variability

    KAUST Repository

    Ahmad, Talha Jamal

    2011-08-01

    This paper discusses the effect of atrioventricular conduction time (AVCT) on the short-term Heart Rate Variability (HRV) by computing HRV parameters using intervals between the onsets of successive P waves (PP time series) for three groups: normal, arrhythmia and sudden cardiac death (SCD) patients. A very precise wavelet transform based ECG delineator was developed to detect PP, PR and RR time series. Mean PR variation in arrhythmia and SCD group was found to be significantly high as compared to the normal group. It was observed that when PR variations in arrhythmia and SCD cases crossed a certain threshold, RR variability no longer provided a very accurate estimate of HRV. In such cases, PP variability was able to provide a better assessment of HRV. © 2011 IEEE.

  4. Rolling element bearing defect diagnosis under variable speed operation through angle synchronous averaging of wavelet de-noised estimate

    Science.gov (United States)

    Mishra, C.; Samantaray, A. K.; Chakraborty, G.

    2016-05-01

    Rolling element bearings are widely used in rotating machines and their faults can lead to excessive vibration levels and/or complete seizure of the machine. Under special operating conditions such as non-uniform or low speed shaft rotation, the available fault diagnosis methods cannot be applied for bearing fault diagnosis with full confidence. Fault symptoms in such operating conditions cannot be easily extracted through usual measurement and signal processing techniques. A typical example is a bearing in heavy rolling mill with variable load and disturbance from other sources. In extremely slow speed operation, variation in speed due to speed controller transients or external disturbances (e.g., varying load) can be relatively high. To account for speed variation, instantaneous angular position instead of time is used as the base variable of signals for signal processing purposes. Even with time synchronous averaging (TSA) and well-established methods like envelope order analysis, rolling element faults in rolling element bearings cannot be easily identified during such operating conditions. In this article we propose to use order tracking on the envelope of the wavelet de-noised estimate of the short-duration angle synchronous averaged signal to diagnose faults in rolling element bearing operating under the stated special conditions. The proposed four-stage sequential signal processing method eliminates uncorrelated content, avoids signal smearing and exposes only the fault frequencies and its harmonics in the spectrum. We use experimental data1

  5. Reliability of a Large Series-parallel System in Variable Operating Conditions

    Institute of Scientific and Technical Information of China (English)

    Joanna Soszynska

    2006-01-01

    In this paper, a semi-Markov model of system operation processes is proposed and its selected parameters are determined. A series-parallel multi-state system is considered, and its reliability and risk characteristics found. Subsequently,a joint model of system operation process and system multi-state reliability and risk is constructed. Moreover, the asymptotic approach to reliability and risk evaluation of a multi-state series-parallel system in its operation process is applied to a port grain transportation system.

  6. Bayesian nonparametric centered random effects models with variable selection.

    Science.gov (United States)

    Yang, Mingan

    2013-03-01

    In a linear mixed effects model, it is common practice to assume that the random effects follow a parametric distribution such as a normal distribution with mean zero. However, in the case of variable selection, substantial violation of the normality assumption can potentially impact the subset selection and result in poor interpretation and even incorrect results. In nonparametric random effects models, the random effects generally have a nonzero mean, which causes an identifiability problem for the fixed effects that are paired with the random effects. In this article, we focus on a Bayesian method for variable selection. We characterize the subject-specific random effects nonparametrically with a Dirichlet process and resolve the bias simultaneously. In particular, we propose flexible modeling of the conditional distribution of the random effects with changes across the predictor space. The approach is implemented using a stochastic search Gibbs sampler to identify subsets of fixed effects and random effects to be included in the model. Simulations are provided to evaluate and compare the performance of our approach to the existing ones. We then apply the new approach to a real data example, cross-country and interlaboratory rodent uterotrophic bioassay.

  7. Improving Organisational Effectiveness of Coalition Operations

    Science.gov (United States)

    2010-04-01

    review of the relevant models and variables, as well as products other NATO Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting...group processes. New York: John Wiley. (pp. 131- 185). [21] Harpaz, I. (2002). Advantages and disadvantages of telecommuting for the individual... telecommuting arrangements: Worker perception and managerial prescriptions. SAM Advanced Management Journal, 57(3), 35-42. Improving Organisational

  8. Effect of promoter architecture on the cell-to-cell variability in gene expression.

    Directory of Open Access Journals (Sweden)

    Alvaro Sanchez

    2011-03-01

    Full Text Available According to recent experimental evidence, promoter architecture, defined by the number, strength and regulatory role of the operators that control transcription, plays a major role in determining the level of cell-to-cell variability in gene expression. These quantitative experiments call for a corresponding modeling effort that addresses the question of how changes in promoter architecture affect variability in gene expression in a systematic rather than case-by-case fashion. In this article we make such a systematic investigation, based on a microscopic model of gene regulation that incorporates stochastic effects. In particular, we show how operator strength and operator multiplicity affect this variability. We examine different modes of transcription factor binding to complex promoters (cooperative, independent, simultaneous and how each of these affects the level of variability in transcriptional output from cell-to-cell. We propose that direct comparison between in vivo single-cell experiments and theoretical predictions for the moments of the probability distribution of mRNA number per cell can be used to test kinetic models of gene regulation. The emphasis of the discussion is on prokaryotic gene regulation, but our analysis can be extended to eukaryotic cells as well.

  9. Webpage aesthetics, performance and usability: design variables and their effects.

    Science.gov (United States)

    Schmidt, Kristi E; Liu, Yili; Sridharan, Srivatsan

    2009-06-01

    The primary objectives of this research are to identify the underlying clusters of design variables affecting the perceived usability of a webpage and to examine the effects of webpage design variables on webpage performance. Fifty-seven design variables and 10 underlying clusters that conceptualise the structure of user webpage judgement are identified through content analysis on literature and structured interviews, balanced incomplete block user survey administration and cluster analysis. Five clusters are selected to conduct three experiments that quantify the change in user aesthetic preference, perceived ease of interaction and interaction speed as a function of loading speed, image colour, image size, font size, link style, and column width. Results show that user performance alone is not a good indicator of aesthetic judgement and overall effectiveness of a webpage. The value of integrating global construct analysis processes and local controlled experimentation processes in ergonomic interface research is illustrated. Fifty-seven webpage design variables are defined, ranked and clustered according to perceived importance and overall preference. Experimental results illustrate that both technical performance and aesthetic factors are important webpage design considerations.

  10. The effect of economic variables over a biodiesel production plant

    Energy Technology Data Exchange (ETDEWEB)

    Marchetti, J.M., E-mail: jmarchetti@plapiqui.edu.ar [Planta Piloto de Ingenieria Quimica (UNS-CONICET), Camino La Carrindanga km 7, 8000 Bahia Blanca (Argentina)

    2011-09-15

    Highlights: {yields} Influence of the mayor economic parameters for biodiesel production. {yields} Variations of profitability of a biodiesel plant due to changes in the market scenarios. {yields} Comparison of economic indicators of a biodiesel production facility when market variables are modified. - Abstract: Biodiesel appears as one of the possible alternative renewable fuels to substitute diesel fuel derived from petroleum. Several researches have been done on the technical aspects of biodiesel production in an attempt to develop a better and cleaner alternative to the conventional process. Economic studies have been carried out to have a better understanding of the high costs and benefits of different technologies in the biodiesel industry. In this work it is studied the effect of the most important economic variables of a biodiesel production process over the general economy of a conventional plant which employs sodium methoxide as catalyst. It has been analyzed the effect of the oil price, the amount of free fatty acid, the biodiesel price, the cost of the glycerin, the effect due to the modification on the methanol price, the washing water price, and several others. Small variations on some of the major market variables would produce significant effects over the global economy of the plant, making it non profitable in some cases.

  11. Operational Risk Management of Fatigue Effects II

    Science.gov (United States)

    2008-08-01

    Class A mishaps from FY1972-FY2000 ( Luna , 2003). Fatigue was cited as a major or causal factor in 26 USAF Class A mishaps over that same period...is not acquired, it induces involuntary, unplanned sleep (i.e., falling asleep on the job and at the wheel). As individuals work across the day and...commander, supervisor and operator has a moral responsibility to protect our personnel from the possibility of fatigue-induced mishaps. The work we do with

  12. Effect of operating conditions on gearbox noise

    Science.gov (United States)

    Oswald, Fred B.; Zakrajsek, James J.; Townsend, Dennis P.; Atherton, William; Lin, Hsiang Hsi

    1992-04-01

    Low contact ratio spur gears were tested in the NASA gear noise rig to study the noise radiated from the top of the gearbox. The measured sound power from the gearbox top was obtained from a near field acoustic intensity scan taken at 63 nodes just above the surface. The sound power was measured at a matrix of 45 operating speeds and torque levels. Results are presented in the form of a spectral speed map and as a plot of sound power versus torque (at constant speed) and as sound power versus speed (at constant torque). Because of the presence of vibration modes, operating speed was found to have more impact on noise generation than torque level. A NASA gear dynamics code was used to compute the gear tooth dynamic overload at the same 45 operating conditions used for the experiment. Similar trends were found between the analytical results for dynamic tooth overload and experimental results for sound power. Dynamic analysis may be used to design high quality gears with profile relief optimized for minimum dynamic load and noise.

  13. Qigong Effects on Heart Rate Variability and Peripheral Vasomotor Responses.

    Science.gov (United States)

    Chang, Mei-Ying

    2015-11-01

    Population aging is occurring worldwide, and preventing cardiovascular event in older people is a unique challenge. The aim of this study was to examine the effects of a 12-week qigong (eight-form moving meditation) training program on the heart rate variability and peripheral vasomotor response of middle-aged and elderly people in the community. This was a quasi-experimental study that included the pre-test, post-test, and nonequivalent control group designs. Seventy-seven participants (experimental group = 47; control group = 30) were recruited. The experimental group performed 30 min of eight-form moving meditation 3 times per week for 12 weeks, and the control group continued their normal daily activities. After 12 weeks, the interaction effects indicated that compared with the control group, the experimental group exhibited significantly improved heart rate variability and peripheral vasomotor responses.

  14. Pointwise estimates of the Green's function of a second order differential operator with the variable coefficient

    Science.gov (United States)

    Ashyralyev, Allaberen; Tetikoglu, Fatih Sabahattin

    2015-09-01

    In this study, the Green's function of the second order differential operator Ax defined by the formula Axu =-a (x )ux x(x )+δ u (x ), δ ≥0 , a (x )=a (x +2 π ), x ∈ℝ1 with domain D (Ax)={ u (x ):u (x ),u '(x ),u″(x )∈C (ℝ1),u (x )=u (x +2 π ), x ∈ℝ1,∫0 2 π u (x )d x =0 } is presented. The estimates for the Green's function and it's derivative are obtained. The positivity of the operator Ax is proved.

  15. A Formally Specified Type System and Operational Semantics for Higher-Order Procedural Variables

    CERN Document Server

    Crolard, Tristan

    2009-01-01

    We formally specified the type system and operational semantics of LOOPw with Ott and Isabelle/HOL proof assistant. Moreover, both the type system and the semantics of LOOPw have been tested using Isabelle/HOL program extraction facility for inductively defined relations. In particular, the program that computes the Ackermann function type checks and behaves as expected. The main difference (apart from the choice of an Ada-like concrete syntax) with LOOPw comes from the treatment of parameter passing. Indeed, since Ott does not currently fully support alpha-conversion, we rephrased the operational semantics with explicit aliasing in order to implement the out parameter passing mode.

  16. DRIVE (Distribution and Repair in Variable Environments): Design and Operation of the Ogden Prototype

    Science.gov (United States)

    1992-01-01

    of convexity. Let F(s) be the probability of meeting the availabilty goal when the number of LRUs in stock is s. The base is deemed to be in a poor...of operation. Given the assumption that expected demands are propor- tional to usage , DRINP has to estimate hours of operation for each item at each...To relate flying hours to LRU usage , we must take into account the number of copies of the LRU on the aircraft and the proportion of air- craft of a

  17. The effects of hypnosis on heart rate variability.

    Science.gov (United States)

    Yüksel, Ramazan; Ozcan, Osman; Dane, Senol

    2013-01-01

    Uslu et al. (2012 ) suggested that hypnotic status can modulate cerebral blood flow. The authors investigated the effects of hypnosis on heart rate variability (HRV). In women, HRV decreased during hypnosis. Posthypnotic values were higher compared to prehypnotic and hypnotic values. Women had highest HRV parameters in the posthypnotic condition. It appears that hypnosis can produce cardiac and cognitive activations. Hypnotherapy may be useful in some cardiac clinical conditions characterized by an autonomic imbalance or some cardiac arrhythmias.

  18. Radiating fluid spheres in the effective variables approximation

    CERN Document Server

    Barreto, W; Martínez, H

    2002-01-01

    We study the evolution of spherically symmetric radiating fluid distributions using the effective variables method, implemented {\\it ab initio} in Schwarzschild coordinates. To illustrate the procedure and to establish some comparison with the original method, we integrate numerically the set of equations at the surface for two different models. The first model is derived from the Schwarzschild interior solution. The second model is inspired in the Tolman VI solution.

  19. Evaluating disease management programme effectiveness: an introduction to instrumental variables.

    Science.gov (United States)

    Linden, Ariel; Adams, John L

    2006-04-01

    This paper introduces the concept of instrumental variables (IVs) as a means of providing an unbiased estimate of treatment effects in evaluating disease management (DM) programme effectiveness. Model development is described using zip codes as the IV. Three diabetes DM outcomes were evaluated: annual diabetes costs, emergency department (ED) visits and hospital days. Both ordinary least squares (OLS) and IV estimates showed a significant treatment effect for diabetes costs (P = 0.011) but neither model produced a significant treatment effect for ED visits. However, the IV estimate showed a significant treatment effect for hospital days (P = 0.006) whereas the OLS model did not. These results illustrate the utility of IV estimation when the OLS model is sensitive to the confounding effect of hidden bias.

  20. Efficient Construction of Discrete Adjoint Operators on Unstructured Grids Using Complex Variables

    Science.gov (United States)

    Nielsen, Eric J.; Kleb, William L.

    2005-01-01

    A methodology is developed and implemented to mitigate the lengthy software development cycle typically associated with constructing a discrete adjoint solver for aerodynamic simulations. The approach is based on a complex-variable formulation that enables straightforward differentiation of complicated real-valued functions. An automated scripting process is used to create the complex-variable form of the set of discrete equations. An efficient method for assembling the residual and cost function linearizations is developed. The accuracy of the implementation is verified through comparisons with a discrete direct method as well as a previously developed handcoded discrete adjoint approach. Comparisons are also shown for a large-scale configuration to establish the computational efficiency of the present scheme. To ultimately demonstrate the power of the approach, the implementation is extended to high temperature gas flows in chemical nonequilibrium. Finally, several fruitful research and development avenues enabled by the current work are suggested.

  1. Efficient Construction of Discrete Adjoint Operators on Unstructured Grids by Using Complex Variables

    Science.gov (United States)

    Nielsen, Eric J.; Kleb, William L.

    2005-01-01

    A methodology is developed and implemented to mitigate the lengthy software development cycle typically associated with constructing a discrete adjoint solver for aerodynamic simulations. The approach is based on a complex-variable formulation that enables straightforward differentiation of complicated real-valued functions. An automated scripting process is used to create the complex-variable form of the set of discrete equations. An efficient method for assembling the residual and cost function linearizations is developed. The accuracy of the implementation is verified through comparisons with a discrete direct method as well as a previously developed handcoded discrete adjoint approach. Comparisons are also shown for a large-scale configuration to establish the computational efficiency of the present scheme. To ultimately demonstrate the power of the approach, the implementation is extended to high temperature gas flows in chemical nonequilibrium. Finally, several fruitful research and development avenues enabled by the current work are suggested.

  2. An Expansion Formula with Higher-Order Derivatives for Fractional Operators of Variable Order

    Directory of Open Access Journals (Sweden)

    Ricardo Almeida

    2013-01-01

    Full Text Available We obtain approximation formulas for fractional integrals and derivatives of Riemann-Liouville and Marchaud types with a variable fractional order. The approximations involve integer-order derivatives only. An estimation for the error is given. The efficiency of the approximation method is illustrated with examples. As applications, we show how the obtained results are useful to solve differential equations, and problems of the calculus of variations that depend on fractional derivatives of Marchaud type.

  3. Inter-operator Variability in Defining Uterine Position Using Three-dimensional Ultrasound Imaging

    DEFF Research Database (Denmark)

    Baker, Mariwan; Jensen, Jørgen Arendt; Behrens, Claus F.

    2013-01-01

    for daily laser alignment. In each session the US-scans were acquired by the seven operators. The uterus was outlined in each of the US imagesets using Clarity autosegmentation in the workstation. Further, the shifts in the uterine centre of mass relative to the reference were measured for the three...... orthogonal directions; left (+)-right (LR), anterior (+)-posterior (AP), and inferior (+)-superior (IS), respectively. The same operator delineated the target volumes. The average inter-operator deviation ±1SD of the daily US scans was (in mm); LR: day 1 (-0.4±0.9), day 2 (-0.3±0.6), day 3 (- 1.0±1.2), day 4...... (1.3±0.5); AP: day 1 (0.0±1.7), day 2 (0.1±0.7), day 3 (-1.0±0.9), day 4 (0.2±1.2); IS: day 1 (-1.5±2.6), day 2 (0.1±1.8), day 3 (0.1±1.1), day 4 (0.5±3.1), respectively. The largest inter-operator discordance was observed to be 4.7 mm in the IS-direction in day 4. Published studies report...

  4. Certain operators in the space of entire functions represented by Dirichlet series of several complex variables

    Directory of Open Access Journals (Sweden)

    Suzanne Daoud

    1992-05-01

    Full Text Available In this paper, we consider the space X of all Entire functions represented by Dirichlet series equipped with various topologies. The main result is concerned with finding certain continuous linear operators which are used to determine the proper bases in X.

  5. Run-up Variability due to Source Effects

    Science.gov (United States)

    Del Giudice, Tania; Zolezzi, Francesca; Traverso, Chiara; Valfrè, Giulio; Poggi, Pamela; Parker, Eric J.

    2010-05-01

    This paper investigates the variability of tsunami run-up at a specific location due to uncertainty in earthquake source parameters. It is important to quantify this 'inter-event' variability for probabilistic assessments of tsunami hazard. In principal, this aspect of variability could be studied by comparing field observations at a single location from a number of tsunamigenic events caused by the same source. As such an extensive dataset does not exist, we decided to study the inter-event variability through numerical modelling. We attempt to answer the question 'What is the potential variability of tsunami wave run-up at a specific site, for a given magnitude earthquake occurring at a known location'. The uncertainty is expected to arise from the lack of knowledge regarding the specific details of the fault rupture 'source' parameters. The following steps were followed: the statistical distributions of the main earthquake source parameters affecting the tsunami height were established by studying fault plane solutions of known earthquakes; a case study based on a possible tsunami impact on Egypt coast has been set up and simulated, varying the geometrical parameters of the source; simulation results have been analyzed deriving relationships between run-up height and source parameters; using the derived relationships a Monte Carlo simulation has been performed in order to create the necessary dataset to investigate the inter-event variability of the run-up height along the coast; the inter-event variability of the run-up height along the coast has been investigated. Given the distribution of source parameters and their variability, we studied how this variability propagates to the run-up height, using the Cornell 'Multi-grid coupled Tsunami Model' (COMCOT). The case study was based on the large thrust faulting offshore the south-western Greek coast, thought to have been responsible for the infamous 1303 tsunami. Numerical modelling of the event was used to

  6. Variable Cosmological Constant as a Planck Scale Effect

    CERN Document Server

    Shapiro, I L; Espana-Bonet, C; Ruiz-Lapuente, P; Shapiro, Ilya L.; Sola, Joan; Espana-Bonet, Cristina; Ruiz-Lapuente, Pilar

    2003-01-01

    We construct a semiclassical FLRW cosmological model assuming a running cosmological constant (CC). It turns out that the CC becomes variable at arbitrarily low energies due to the remnant quantum effects of the heaviest particles, e.g. the Planck scale physics. These effects are universal in the sense that they lead to a low-energy structure common to a large class of high-energy theories. Remarkably, the uncertainty concerning the unknown high-energy dynamics is accumulated into a single parameter \

  7. Towards Sustainability: Effective Operations Strategies, Quality Management and Operational Excellence in Banking

    Directory of Open Access Journals (Sweden)

    Vesna Tornjanski

    2017-02-01

    Full Text Available This paper sets out to extend and deepen the understanding the ways toward economic sustainability through efficient and effective growth operations strategies, quality management and operational excellence in banking. In this study we define new quality management practices based on developed conceptual architecture of digital platform for operations function in banking. Additionally, we employ decision making framework consisted of two parts: introduction of new operations services using Total Unduplicated Reach and Frequency (TURF statistical analysis and segregation of core from actual and augmented operations services utilizing Analytic Network Process (ANP method based on BOCR model. Proposed quality management practices were used for the first time in this paper for particular purposes and have the high potential to impact the excellence in banking business. The study can contribute to operations management, quality management, innovation management, IT management, business process management and decision making in service organizations.

  8. Use of Frequency Response Metrics to Assess the Planning and Operating Requirements for Reliable Integration of Variable Renewable Generation

    Energy Technology Data Exchange (ETDEWEB)

    Eto, Joseph H.; Undrill, John; Mackin, Peter; Daschmans, Ron; Williams, Ben; Haney, Brian; Hunt, Randall; Ellis, Jeff; Illian, Howard; Martinez, Carlos; O' Malley, Mark; Coughlin, Katie; LaCommare, Kristina Hamachi

    2010-12-20

    An interconnected electric power system is a complex system that must be operated within a safe frequency range in order to reliably maintain the instantaneous balance between generation and load. This is accomplished by ensuring that adequate resources are available to respond to expected and unexpected imbalances and restoring frequency to its scheduled value in order to ensure uninterrupted electric service to customers. Electrical systems must be flexible enough to reliably operate under a variety of"change" scenarios. System planners and operators must understand how other parts of the system change in response to the initial change, and need tools to manage such changes to ensure reliable operation within the scheduled frequency range. This report presents a systematic approach to identifying metrics that are useful for operating and planning a reliable system with increased amounts of variable renewable generation which builds on existing industry practices for frequency control after unexpected loss of a large amount of generation. The report introduces a set of metrics or tools for measuring the adequacy of frequency response within an interconnection. Based on the concept of the frequency nadir, these metrics take advantage of new information gathering and processing capabilities that system operators are developing for wide-area situational awareness. Primary frequency response is the leading metric that will be used by this report to assess the adequacy of primary frequency control reserves necessary to ensure reliable operation. It measures what is needed to arrest frequency decline (i.e., to establish frequency nadir) at a frequency higher than the highest set point for under-frequency load shedding within an interconnection. These metrics can be used to guide the reliable operation of an interconnection under changing circumstances.

  9. The Effect of Antifibrinolytic Prophylaxis on Postoperative Outcomes in Patients Undergoing Cardiac Operations

    Science.gov (United States)

    Koul, Abhinav; Ferraris, Victor; Davenport, Daniel L; Ramaiah, Chandrashekhar

    2012-01-01

    Antifibrinolytic agents such as aprotinin and epsilon aminocaproic acid limit postoperative bleeding and blood transfusion in patients undergoing cardiac operations using cardiopulmonary bypass (CPB). Recent evidence suggests that these agents have adverse side effects that influence operative mortality and morbidity. We studied postoperative bleeding, transfusion rates, and operative outcomes in our patients in order to assess the efficacy of these agents during cardiac operations requiring CPB. We reviewed records of 520 patients undergoing a variety of cardiac operations between January 2005 and May 2009. We measured multiple variables including pre-operative risk factors, antifibrinolytic agent used, and outcomes of operation, such as measures of bleeding and blood transfusion, as well as serious operative morbidity and mortality. Postoperative bleeding rates varied significantly between patients receiving aprotinin and those receiving aminocaproic acid (P 0.05), though individuals in the aprotinin group did receive FFP more frequently than patients in the aminocaproic acid group (P 0.05). Our study shows that aprotinin is more effective at controlling operative site bleeding than aminocaproic acid. Reduced operative site bleeding did not portend better outcome or differences in transfusion requirements. Aminocaproic acid remains a safe and cost-effective option for antifibrinolytic prophylaxis because of unavailability of aprotinin. PMID:23101999

  10. The effects of seasonally variable dragonfly predation on butterfly assemblages.

    Science.gov (United States)

    Tiitsaar, Anu; Kaasik, Ants; Teder, Tiit

    2013-01-01

    Where predation is seasonally variable, the potential impact of a predator on individual prey species will critically depend on phenological synchrony of the predator with the prey. Here we explored the effects of seasonally variable predation in multispecies assemblages of short-lived prey. The study was conducted in a landscape in which we had previously demonstrated generally high, but spatially and seasonally variable dragonfly-induced mortality in adult butterflies. In this system, we show that patterns of patch occupancy in butterfly species flying during periods of peak dragonfly abundance are more strongly associated with spatial variation in dragonfly abundance than patch occupancy of species flying when dragonfly density was low. We provide evidence indicating that this differential sensitivity of different butterfly species to between-habitat differences in dragonfly abundance is causally tied to seasonal variation in the intensity of dragonfly predation. The effect of dragonfly predation could also be measured at the level of whole local butterfly assemblages. With dragonfly density increasing, butterfly species richness decreased, and butterfly species composition tended to show a shift toward a greater proportion of species flying during periods of off-peak dragonfly abundance.

  11. Synthesis of Biochemical Applications on Digital Microfluidic Biochips with Operation Execution Time Variability

    DEFF Research Database (Denmark)

    Alistar, Mirela; Pop, Paul

    2015-01-01

    Microfluidic-based biochips are replacing the conventional biochemical analyzers, and are able to integrate all the necessary functions for biochemical analysis. The digital microfluidic biochips are based on the manipulation of liquids not as a continuous flow, but as discrete droplets. Several...... approaches have been proposed for the synthesis of digital microfluidic biochips, which, starting from a biochemical application and a given biochip architecture, determine the allocation, resource binding, scheduling, placement and routing of the operations in the application. Researchers have assumed...

  12. Operation of the matrix converter as energy sources link of variable voltage; Operacion del convertidor matricial como enlace de fuentes de energia de voltaje variable

    Energy Technology Data Exchange (ETDEWEB)

    Lozano-Garcia, J. M; Hernandez-Figueroa, M. A; Estrada Garcia, H. J; Martinez-Patino, J [Universidad de Guanajuato, Campus Irapuato-Salamanca, Salamanca, Guanajuato (Mexico)]. E-mails: jm.lozano@ugto.mx; mahf@ugto.mx; hestrada@ugto.mx; jesusmp23@ugto.mx

    2013-03-15

    Renewable energy technologies, as wind turbines, have had a remarkable penetration in power systems worldwide, causing that actual power grids became dependent and vulnerable to the variability of the energy generated by this type of resource. In that sense, power converters provide a crucial function in the performance of the overall electrical system when they are used as links between this type of generators and the power system. In this paper, a matrix converter is proposed as link device, to cope with distorted and variable voltages as the ones found in wind turbines operation where generated voltages are directly dependent on wind's speed. An analysis of its main functional characteristics when it operates subject to distorted input-voltage condition, in order to synthesize a set of output voltages with constant magnitude and frequency and without harmonic distortion, is presented. Numerical simulations and experimental results from a laboratory-scale prototype are presented to validate the converter performance. [Spanish] La gran penetracion que ha tenido la generacion de energia mediante recursos renovables, como los generadores eolicos, en el mercado energetico, han ocasionado que las redes electricas sean mas dependientes y vulnerables a la variabilidad de la energia que se genera con este tipo de recursos. En ese sentido, los convertidores de potencia utilizados como enlace entre este tipo de generadores y el sistema electrico son determinantes en el comportamiento final que se tendra en el sistema electrico. En el presente trabajo se propone la utilizacion del convertidor matricial como dispositivo de enlace y se analizan sus caracteristicas operativas en casos donde se requiere la generacion de senales de voltaje sinusoidales y con valores constantes tanto en magnitud como en frecuencia a partir de senales variables, situacion que se presenta comunmente en los aerogeneradores donde el voltaje generado depende directamente de la velocidad del

  13. Operator- and software-related post-experimental variability and source of error in 2-DE analysis.

    Science.gov (United States)

    Millioni, Renato; Puricelli, Lucia; Sbrignadello, Stefano; Iori, Elisabetta; Murphy, Ellen; Tessari, Paolo

    2012-05-01

    In the field of proteomics, several approaches have been developed for separating proteins and analyzing their differential relative abundance. One of the oldest, yet still widely used, is 2-DE. Despite the continuous advance of new methods, which are less demanding from a technical standpoint, 2-DE is still compelling and has a lot of potential for improvement. The overall variability which affects 2-DE includes biological, experimental, and post-experimental (software-related) variance. It is important to highlight how much of the total variability of this technique is due to post-experimental variability, which, so far, has been largely neglected. In this short review, we have focused on this topic and explained that post-experimental variability and source of error can be further divided into those which are software-dependent and those which are operator-dependent. We discuss these issues in detail, offering suggestions for reducing errors that may affect the quality of results, summarizing the advantages and drawbacks of each approach.

  14. Speed-variable Switched Differential Pump System for Direct Operation of Hydraulic Cylinders

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Roemer, Daniel Beck; Pedersen, Henrik Clemmensen;

    2015-01-01

    Efforts to overcome the inherent loss of energy due to throttling in valve driven hydraulic systems are many, and various approaches have been proposed by research communities as well as the industry. Recently, a so-called speed-variable differential pump was proposed for direct drive of hydraulic...... differential cylinders. The main idea was here to utilize an electric rotary drive, with the shaft interconnected to two antiparallel fixed displacement gear pumps, to actuate a differential cylinder. With the design carried out such that the area ratio of the cylinder matches the displacement ratio of the two...... gear pumps, the throttling losses are confined to cross port leakage in the cylinder and leakage of the pumps. However, it turns out that the volumetric pump losses and the pressure dynamics of the cylinder and connecting pipes may cause pressure increase- or decrease in the cylinder chambers, which...

  15. Efficient high-resolution 3-D interpolation of meteorological variables for operational use

    Directory of Open Access Journals (Sweden)

    C. Lussana

    2009-08-01

    Full Text Available In recent years, the use of mesoscale meteorological network data has been growing. An Optimal Interpolation (OI method is used to interpolate on a regular grid the hourly averaged values of temperature, relative humidity, wind vector, atmospheric pressure, and hourly cumulated precipitation. For all variables, except precipitation, the background (i.e. first guess information is obtained by detrending the observations using the geographical parameters. For precipitation, the M. Lema radar-derived best estimate of precipitation rate at the ground is used. The characteristics of the OI schemes are shown in several test cases using data from ARPA Lombardia's mesoscale meteorological network. Finally, a quantitative diagnostics for temperature and relative humidity is carried out by using Cross Validation (CV scores computed with large sets of data.

  16. The effects of variable speed and drive train component efficiencies on wind turbine energy capture

    Energy Technology Data Exchange (ETDEWEB)

    Fingersh, L.J.; Robinson, M.C.

    1998-05-01

    A wind turbine rotor achieves optimal aerodynamic efficiency at a single tip-speed ratio (TSR). To maintain that optimal TSR and maximize energy capture in the stochastic wind environment, it is necessary to employ variable-speed operation. Conventional constant-speed wind turbines have, in the past, been converted into variable-speed turbines by attaching power electronics to the conventional induction generator and gearbox drive train. Such turbines have shown marginal, if any, improvement in energy capture over their constant-speed counterparts. These discrepancies have been shown to be the result of drive train components that are not optimized for variable-speed operation. Traditional drive trains and power electronic converters are designed to achieve maximum efficiency at full load and speed. However, the main energy producing winds operate the turbine at light load for long periods of time. Because of this, significant losses to efficiency occur. This investigation employs a quasi-static model to demonstrate the dramatic effect that component efficiency curves can have on overall annual energy capture.

  17. Design of Stirrer Impeller with Variable Operational Speed for a Food Waste Homogenizer

    Directory of Open Access Journals (Sweden)

    Idris A. Kayode

    2016-05-01

    Full Text Available A conceptualized impeller called KIA is designed for impact agitation of food waste in a homogenizer. A comparative analysis of the performance of KIA is made with three conventional impeller types, Rushton, Anchor, and Pitched Blade. Solid–liquid mixing of a moisture-rich food waste is simulated under various operational speeds, in order to compare the dispersions and thermal distributions at homogenous slurry conditions. Using SolidWorks, the design of the impellers employs an Application Programming Interface (API which acts as the canvas for creating a graphical user interface (GUI for automation of its assembly. A parametric analysis of the homogenizer, at varying operational speeds, enables the estimation of the critical speed of the mixing shaft diameter and the deflection under numerous mixing conditions and impeller configurations. The numerical simulation of the moisture-rich food waste (approximated as a Newtonian carrot–orange soup is performed with ANSYS CFX v.15.0. The velocity and temperature field distribution of the homogenizer for various impeller rotational speeds are analyzed. It is anticipated that the developed model will help in the selection of a suitable impeller for efficient mixing of food waste in the homogenizer.

  18. Operational matrices with respect to Hermite polynomials and their applications in solving linear dierential equations with variable coecients

    Directory of Open Access Journals (Sweden)

    A. Aminataei

    2014-05-01

    Full Text Available In this paper, a new and ecient approach is applied for numerical approximation of the linear dierential equations with variable coecients based on operational matrices with respect to Hermite polynomials. Explicit formulae which express the Hermite expansioncoecients for the moments of derivatives of any dierentiable function in terms of the original expansion coecients of the function itself are given in the matrix form. The mainimportance of this scheme is that using this approach reduces solving the linear dierentialequations to solve a system of linear algebraic equations, thus greatly simplifying the problem. In addition, two experiments are given to demonstrate the validity and applicability of the method

  19. Simulating the effect of meteorological variability on a lake ecosystem

    Science.gov (United States)

    Frassl, M. A.; Schlabing, D.; Eder, M. M.; Rothhaupt, K.-O.; Rinke, K.

    2012-04-01

    Water temperature is a main driver of phytoplankton development. On the one hand, temperature directly affects cell metabolism. On the other hand, the hydrodynamic regime with annual cycles of stratification and mixis affects the light and nutrient supply of the algae and thus governs cardinal events of phytoplankton development. This could be the timing of the spring bloom or the maximum biomass attained. However, the response of lake ecosystems dynamics to a changing climate is not only linked to a rising temperature, but also to inter-annual and -seasonal meteorological variability. Ecological models have proven to provide a useful tool for quantifying effects of a changing climate on lake ecosystems. Especially lake models are convenient for climate change studies as the meteorological input data directly drive the hydrodynamics of the lake, which, in turn, govern ecosystem dynamics. To account for the effect of rising temperature and increased variability, different meteorological time series are needed. A Vector-Autoregressive Weathergenerator is able to provide reliable time-series that sustain dependencies between different meteorological variables. Furthermore, it offers the possibility to run Monte Carlo simulations with past climatic conditions in comparison to scenarios of possible future climatic conditions. It thus provides a tool for both, including statistical properties of meteorological data and assessing uncertainties inherent in deterministic models. In this study, we applied a one-dimensional hydrodynamic-ecological lake model (DYRESM-CAEDYM) to a large monomictic lake. We ran Monte Carlo simulations with four different "what-if" scenarios (unchanged climate, increased mean temperature, higher variability and the combination of higher temperature and variability) and analysed changes in water temperature and cardinal events in phytoplankton dynamics. A detailed study on the hydrodynamic response of Lake Constance to climate change is presented

  20. Effect of Submucosal Injection of Dexamethasone on Post-operative Sequelae of Third Molar Surgery

    Directory of Open Access Journals (Sweden)

    S P Deo

    2011-06-01

    Full Text Available Introduction: This study was carried out to evaluate the effects of a single pre-operative sub-mucosal injection of dexamethasone after third molar surgery to see the effects on post-operative discomfort. Methods: This study was a prospective, double-blind, randomized, clinical trial. The subjects were forty patients who underwent surgical removal of the mandibular impacted third molar under local anesthesia and after being randomly assigned to receive either an 8 mg dexamethasone as submucosal injection or a normal saline injection into the lower buccal vestibule adjacent to the third molar. The maximum interincisal distance and facial contours were measured at the baseline and post-surgically on Day 2 and 7. Post-operative pain was evaluated subjectively using a visual analog scale and objectively by counting the number of analgesic tablets used. All subjects were operated upon by the same investigator to minimize the difference from inter-operator variability. Results: There was a signicant difference in the measurements of the degree of swelling and trismus between the two groups on the 2nd post-operative day. In contrast, there was no statistically signicant difference between the groups on the 7th post-operative day. The test group also used fewer analgesics post-operatively. Conclusions: Submucosal injection of dexamethasone after third molar surgery is effective in reducing postoperative swelling and trismus. It also delays the onset of post-operative pain. Keywords: dexamethasone, submucosal injection, third molar, third molar surgery, third molar extraction

  1. Relativistic Parker winds with variable effective polytropic index

    CERN Document Server

    Meliani, Z; Tsinganos, K; Vlahakis, N

    2004-01-01

    Spherically symmetric hydrodynamical outflows accelerated thermally in the vicinity of a compact object are studied by generalizing an equation of state with a variable effective polytropic index, appropriate to describe relativistic temperatures close to the central object and nonrelativistic ones further away. Relativistic effects introduced by the Schwarzschild metric and the presence of relativistic temperatures in the corona are compared with previous results for a constant effective polytropic index and also with results of the classical wind theory. By a parametric study of the polytropic index and the location of the sonic transition it is found that space time curvature and relativistic temperatures tend to increase the efficiency of thermal driving in accelerating the outflow. Thus conversely to the classical Parker wind, the outflow is accelerated even for polytropic indices higher than 3/2. The results of this simple but fully relativistic extension of the polytropic equation of state may be usefu...

  2. Effects of HBV Genetic Variability on RNAi Strategies

    Directory of Open Access Journals (Sweden)

    Nattanan Panjaworayan

    2011-01-01

    Full Text Available RNAi strategies present promising antiviral strategies against HBV. RNAi strategies require base pairing between short RNAi effectors and targets in the HBV pregenome or other RNAs. Natural variation in HBV genotypes, quasispecies variation, or mutations selected by the RNAi strategy could potentially make these strategies less effective. However, current and proposed antiviral strategies against HBV are being, or could be, designed to avoid this. This would involve simultaneous targeting of multiple regions of the genome, or regions in which variation or mutation is not tolerated. RNAi strategies against single genotypes or against variable regions of the genome would need to have significant other advantages to be part of robust therapies.

  3. Prediction of operational variables involved in the Production Process of Crude Oil by Steam Assisted Gravity Drainage (SAGD

    Directory of Open Access Journals (Sweden)

    David Lowy

    2015-06-01

    Full Text Available (Received: 2015/04/16 - Accepted: 2015/05/29This paper presents the oil deposit and operational variables that influence the implementation of the Steam Assisted Gravity Drainage (SAGD process for the Production of Heavy and Extra-heavy Crude Oil. This process consists of drilling two parallel horizontal wells, one above the other, where the upper well is used for steam injection and the lower well is used for production. The efficiency of the process is greatly affected by the deposit and operating parameters (vertical spacing of wells, injection pressure, preheating period, among others. Furthermore, the prediction of the maximum rate of oil extraction was determined using an example with currently available real data of Block 20 of the Pungarayacu Field.

  4. Experimental Research of Variable Operating Performance on Water Source Multi-Connected Air-Conditioning System with Digital Scroll Compressor

    Directory of Open Access Journals (Sweden)

    Xingwang Zhu

    2013-05-01

    Full Text Available In this study, we study the water source heat pump and digital scroll compressor and experimentally in the multi-connected air-conditioning system. Variable performance is developed when the unit operates in refrigerating and heating mode. The maximum of refrigerating capacity is 36519.95W when inlet water temperature of the condenser is 30°C and dry-bulb temperature of indoor air is 32°C, at the same time the maximum of EER is 4.33 when inlet water temperature of the condenser is 20°C and dry-bulb temperature of indoor air is 27°C. The unit operates in heating mode, the maximum of heating capacity and EER is 33275.73W and 3.86 when inlet water temperature of the condenser is 30°C and dry-bulb temperature of indoor air is 20°C.

  5. Speed-variable Switched Differential Pump System for Direct Operation of Hydraulic Cylinders

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Roemer, Daniel Beck; Pedersen, Henrik Clemmensen

    2015-01-01

    proportional valves, this design allows to control the lower chamber pressure levels, throttling excess compression flow to tank. The resulting design introduces additional losses due to throttling of excess compression flow, but also improves the dynamic properties of the system significantly. The proposed...... differential cylinders. The main idea was here to utilize an electric rotary drive, with the shaft interconnected to two antiparallel fixed displacement gear pumps, to actuate a differential cylinder. With the design carried out such that the area ratio of the cylinder matches the displacement ratio of the two...... may seriously influence the dynamics and hence the performance during operation. This paper presents an analysis of these properties, and a redesign of the hydraulic system concept is proposed. Here the area- and displacement ratios are deliberately mismatched, causing inherent pressure build...

  6. Online Synthesis for Error Recovery in Digital Microfluidic Biochips with Operation Variability

    DEFF Research Database (Denmark)

    Alistar, Mirela; Pop, Paul; Madsen, Jan

    2012-01-01

    , but as discrete droplets. Researchers have presented approaches for the synthesis of digital microfluidic biochips, which, starting from a biochemical application and a given biochip architecture, determine the allocation, resource binding, scheduling, placement and routing of the operations in the application......Microfluidic-based biochips are replacing the conventional biochemical analyzers, and are able to integrate on-chip all the necessary functions for biochemical analysis using microfluidics. The digital microfluidic biochips are based on the manipulation of liquids not as a continuous flow....... The droplet volumes can vary erroneously due to parametric faults, thus impacting negatively the correctness of the application. Researchers have proposed approaches that synthesize offline predetermined recovery subroutines, which are activated online when errors occur. In this paper, we propose an online...

  7. Essential self-adjointness of n-dimensional Dirac operators with a variable mass term

    Science.gov (United States)

    Kalf, Hubert; Yamada, Osanobu

    2001-06-01

    We give some results about the essential self-adjointness of the Dirac operator H=∑j=1nαj pj+m(x) αn+1+V(x) IN (N=2 [(n+1)/2]), on [C0∞(Rn{0})]N, where the αj (j=1,2,…,n) are Dirac matrices and m(x) and V(x) are real-valued functions. We are mainly interested in a singularity of V(x) and m(x) near the origin which preserves the essential self-adjointness of H. As a result, if m=m(r) is spherically symmetric or m(x)≡V(x), then we can permit a singularity of m and V which is stronger than that of the Coulomb potential.

  8. Patient satisfaction with total knee replacement cannot be predicted from pre-operative variables alone: A cohort study from the National Joint Registry for England and Wales.

    Science.gov (United States)

    Baker, P N; Rushton, S; Jameson, S S; Reed, M; Gregg, P; Deehan, D J

    2013-10-01

    Pre-operative variables are increasingly being used to determine eligibility for total knee replacement (TKR). This study was undertaken to evaluate the relationships, interactions and predictive capacity of variables available pre- and post-operatively on patient satisfaction following TKR. Using nationally collected patient reported outcome measures and data from the National Joint Registry for England and Wales, we identified 22 798 patients who underwent TKR for osteoarthritis between August 2008 and September 2010. The ability of specific covariates to predict satisfaction was assessed using ordinal logistic regression and structural equational modelling. Only 4959 (22%) of 22 278 patients rated the results of their TKR as 'excellent', despite the majority (71%, n = 15 882) perceiving their knee symptoms to be much improved. The strongest predictors of satisfaction were post-operative variables. Satisfaction was significantly and positively related to the perception of symptom improvement (operative success) and the post-operative EuroQol-5D score. While also significant within the models pre-operative variables were less important and had a minimal influence upon post-operative satisfaction. The most robust predictions of satisfaction occurred only when both pre- and post-operative variables were considered together. These findings question the appropriateness of restricting access to care based on arbitrary pre-operative thresholds as these factors have little bearing on post-operative satisfaction.

  9. Torque control of synchronous and induction generators for variable speed operation of wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Ola; Ulen, E. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Electric Power Engineering

    1996-12-01

    The aim of this paper is to investigate variable speed electrical systems. Synchronous generators with diode rectifiers and line-commutated thyristor converters are compared with induction generators with force commutated transistor converters and scalar control. The system characteristics are examined regarding possible speed of response (bandwidth) of the torque control, including the sensitivity to disturbances for the drive train and also the possibility to get damping of the drive train resonance. Analyses, simulations and laboratory tests with a 40 kW machine set-up have been performed. The investigation shows that the system with synchronous generator is well suited for wind power applications. A rapid standard DC-current regulator is included in the torque control and can be used for damping of the resonance. The torque control has a bandwidth up to about 3 Hz and the DC-voltage controller up to about 1 Hz. The system with induction generator with scalar control (no transformations) is more difficult to control. A linear approach is only possible up to about 1.5 Hz. In this region it turns out that the behaviour can be visualized as an added inertia on the generator side that can be rather big. 4 refs, 9 figs

  10. Towards Automated Annotation of Benthic Survey Images: Variability of Human Experts and Operational Modes of Automation.

    Directory of Open Access Journals (Sweden)

    Oscar Beijbom

    Full Text Available Global climate change and other anthropogenic stressors have heightened the need to rapidly characterize ecological changes in marine benthic communities across large scales. Digital photography enables rapid collection of survey images to meet this need, but the subsequent image annotation is typically a time consuming, manual task. We investigated the feasibility of using automated point-annotation to expedite cover estimation of the 17 dominant benthic categories from survey-images captured at four Pacific coral reefs. Inter- and intra- annotator variability among six human experts was quantified and compared to semi- and fully- automated annotation methods, which are made available at coralnet.ucsd.edu. Our results indicate high expert agreement for identification of coral genera, but lower agreement for algal functional groups, in particular between turf algae and crustose coralline algae. This indicates the need for unequivocal definitions of algal groups, careful training of multiple annotators, and enhanced imaging technology. Semi-automated annotation, where 50% of the annotation decisions were performed automatically, yielded cover estimate errors comparable to those of the human experts. Furthermore, fully-automated annotation yielded rapid, unbiased cover estimates but with increased variance. These results show that automated annotation can increase spatial coverage and decrease time and financial outlay for image-based reef surveys.

  11. Continuous operation of four-state continuous-variable quantum key distribution system

    Science.gov (United States)

    Matsubara, Takuto; Ono, Motoharu; Oguri, Yusuke; Ichikawa, Tsubasa; Hirano, Takuya; Kasai, Kenta; Matsumoto, Ryutaroh; Tsurumaru, Toyohiro

    2016-10-01

    We report on the development of continuous-variable quantum key distribution (CV-QKD) system that are based on discrete quadrature amplitude modulation (QAM) and homodyne detection of coherent states of light. We use a pulsed light source whose wavelength is 1550 nm and repetition rate is 10 MHz. The CV-QKD system can continuously generate secret key which is secure against entangling cloner attack. Key generation rate is 50 kbps when the quantum channel is a 10 km optical fiber. The CV-QKD system we have developed utilizes the four-state and post-selection protocol [T. Hirano, et al., Phys. Rev. A 68, 042331 (2003).]; Alice randomly sends one of four states {|+/-α⟩,|+/-𝑖α⟩}, and Bob randomly performs x- or p- measurement by homodyne detection. A commercially available balanced receiver is used to realize shot-noise-limited pulsed homodyne detection. GPU cards are used to accelerate the software-based post-processing. We use a non-binary LDPC code for error correction (reverse reconciliation) and the Toeplitz matrix multiplication for privacy amplification.

  12. Towards Automated Annotation of Benthic Survey Images: Variability of Human Experts and Operational Modes of Automation.

    Science.gov (United States)

    Beijbom, Oscar; Edmunds, Peter J; Roelfsema, Chris; Smith, Jennifer; Kline, David I; Neal, Benjamin P; Dunlap, Matthew J; Moriarty, Vincent; Fan, Tung-Yung; Tan, Chih-Jui; Chan, Stephen; Treibitz, Tali; Gamst, Anthony; Mitchell, B Greg; Kriegman, David

    2015-01-01

    Global climate change and other anthropogenic stressors have heightened the need to rapidly characterize ecological changes in marine benthic communities across large scales. Digital photography enables rapid collection of survey images to meet this need, but the subsequent image annotation is typically a time consuming, manual task. We investigated the feasibility of using automated point-annotation to expedite cover estimation of the 17 dominant benthic categories from survey-images captured at four Pacific coral reefs. Inter- and intra- annotator variability among six human experts was quantified and compared to semi- and fully- automated annotation methods, which are made available at coralnet.ucsd.edu. Our results indicate high expert agreement for identification of coral genera, but lower agreement for algal functional groups, in particular between turf algae and crustose coralline algae. This indicates the need for unequivocal definitions of algal groups, careful training of multiple annotators, and enhanced imaging technology. Semi-automated annotation, where 50% of the annotation decisions were performed automatically, yielded cover estimate errors comparable to those of the human experts. Furthermore, fully-automated annotation yielded rapid, unbiased cover estimates but with increased variance. These results show that automated annotation can increase spatial coverage and decrease time and financial outlay for image-based reef surveys.

  13. Towards Automated Annotation of Benthic Survey Images: Variability of Human Experts and Operational Modes of Automation

    Science.gov (United States)

    Beijbom, Oscar; Edmunds, Peter J.; Roelfsema, Chris; Smith, Jennifer; Kline, David I.; Neal, Benjamin P.; Dunlap, Matthew J.; Moriarty, Vincent; Fan, Tung-Yung; Tan, Chih-Jui; Chan, Stephen; Treibitz, Tali; Gamst, Anthony; Mitchell, B. Greg; Kriegman, David

    2015-01-01

    Global climate change and other anthropogenic stressors have heightened the need to rapidly characterize ecological changes in marine benthic communities across large scales. Digital photography enables rapid collection of survey images to meet this need, but the subsequent image annotation is typically a time consuming, manual task. We investigated the feasibility of using automated point-annotation to expedite cover estimation of the 17 dominant benthic categories from survey-images captured at four Pacific coral reefs. Inter- and intra- annotator variability among six human experts was quantified and compared to semi- and fully- automated annotation methods, which are made available at coralnet.ucsd.edu. Our results indicate high expert agreement for identification of coral genera, but lower agreement for algal functional groups, in particular between turf algae and crustose coralline algae. This indicates the need for unequivocal definitions of algal groups, careful training of multiple annotators, and enhanced imaging technology. Semi-automated annotation, where 50% of the annotation decisions were performed automatically, yielded cover estimate errors comparable to those of the human experts. Furthermore, fully-automated annotation yielded rapid, unbiased cover estimates but with increased variance. These results show that automated annotation can increase spatial coverage and decrease time and financial outlay for image-based reef surveys. PMID:26154157

  14. Effective operator contributions to the oblique parameters

    CERN Document Server

    Sánchez-Colón, G

    1998-01-01

    We present a model and process independent study of the contributions from non-Standard Model physics to the oblique parameters S, T and U. We show that within an effective lagrangian parameterization the expressions for the oblique parameters in terms of observables are consistent, while those in terms of the vector-boson vacuum polarization tensors are ambiguous. We obtain the constraints on the scale of new physics derived from current data on S, T and U and note that deviations in U from its Standard Model value would favor a scenario where the underlying physics does not decouple.

  15. Giving top quark effective operators a boost

    CERN Document Server

    Englert, Christoph

    2016-01-01

    We investigate the prospects to systematically improve generic effective field theory-based searches for new physics in the top sector during LHC run 2 as well as the high luminosity phase. In particular, we assess the benefits of high momentum transfer final states on top EFT-fit as a function of systematic uncertainties in comparison with sensitivity expected from fully-resolved analyses focusing on $t\\bar t$ production. We find that constraints are typically driven by fully-resolved selections, while boosted top quarks can serve to break degeneracies in the global fit. This demystifies and clarifies the importance of high momentum transfer final states for global fits to new interactions in the top sector from direct measurements.

  16. Giving top quark effective operators a boost

    Directory of Open Access Journals (Sweden)

    Christoph Englert

    2016-12-01

    Full Text Available We investigate the prospects to systematically improve generic effective field theory-based searches for new physics in the top sector during LHC run 2 as well as the high luminosity phase. In particular, we assess the benefits of high momentum transfer final states on top EFT-fit as a function of systematic uncertainties in comparison with sensitivity expected from fully-resolved analyses focusing on tt¯ production. We find that constraints are typically driven by fully-resolved selections, while boosted top quarks can serve to break degeneracies in the global fit. This demystifies and clarifies the importance of high momentum transfer final states for global fits to new interactions in the top sector from direct measurements.

  17. Giving top quark effective operators a boost

    Science.gov (United States)

    Englert, Christoph; Moore, Liam; Nordström, Karl; Russell, Michael

    2016-12-01

    We investigate the prospects to systematically improve generic effective field theory-based searches for new physics in the top sector during LHC run 2 as well as the high luminosity phase. In particular, we assess the benefits of high momentum transfer final states on top EFT-fit as a function of systematic uncertainties in comparison with sensitivity expected from fully-resolved analyses focusing on t t bar production. We find that constraints are typically driven by fully-resolved selections, while boosted top quarks can serve to break degeneracies in the global fit. This demystifies and clarifies the importance of high momentum transfer final states for global fits to new interactions in the top sector from direct measurements.

  18. The effect of fabric and stabbing variables on severance appearance.

    Science.gov (United States)

    Cowper, E J; Carr, D J; Horsfall, I; Fergusson, S M

    2015-04-01

    During a stabbing, apparel fabrics are usually damaged and may be penetrated. Despite numerous studies considering forces required to penetrate skin and human stabbing performance, none have systematically evaluated which variables affect severance appearance from a textile science perspective using a human stabbing participant assessment. Although the human performance aspects of stabbing attacks have been previously studied, there has been a bias towards male assailants. The effects of fabric elasticity and tension applied have been identified as major factors influencing the severance profile in the fabric resulting from a stab attack. However, previous studies have considered limited fabric types with little emphasis on the physical and mechanical textile properties. The purpose of the current research was to use a human participant study (male n=5; female n=5) to determine the effect of fabric extension (0%, 10%) on the severance profile. Fabric type (single jersey; 100% cotton; 93% cotton/7% elastane), age (not laundered; laundered 60 times) and knife type (carving, bread) were also considered. Severance length was affected by participant sex, fabric type, laundering and knife type. The severances formed in this study were not significantly affected by the amount a fabric was extended when stabbed. Variability was observed in the severance appearance among participants where prior training influenced the angle of impact and knife withdrawal technique.

  19. Effects of Stretching Exercise on Heart Rate Variability During Pregnancy.

    Science.gov (United States)

    Logan, Jeongok G; Yeo, SeonAe

    Little evidence exists for effects of low-intensity exercises such as stretching on cardiovascular health in pregnant women. Our aim was to evaluate the effect of a 20-minute stretching exercise on heart rate variability (HRV), blood pressure (BP), and heart rate (HR) in healthy pregnant women. In 15 pregnant women with a mean (SD) age of 29.47 (4.07) years and mean (SD) gestational weeks of 26.53 (8.35), HRV, and BP were measured before and after the 20-minute stretching exercise. Compared with before the stretching exercise, standard deviation of the normal-to-normal intervals, total variability of heart rate, increased by 7.40 milliseconds (t = -2.31, P = .04) and root mean square of successive differences, a surrogate measure of parasympathetic outflow, also increased by 11.68 milliseconds (Z = -2.04, P = .04) after the stretching exercise. Diastolic BP and HR decreased by 2.13 mm Hg (t = 1.93, P = .07) and 3.31 bpm (t = 2.17, P = .05), respectively, but they did not reach statistical significance. These preliminary data suggest that 20 minutes of stretching exercise may promote cardiovascular health by attenuating the loss of parasympathetic tone associated with pregnancy.

  20. Almost monotonicity formulas for elliptic and parabolic operators with variable coefficients

    KAUST Repository

    Matevosyan, Norayr

    2010-10-21

    In this paper we extend the results of Caffarelli, Jerison, and Kenig [Ann. of Math. (2)155 (2002)] and Caffarelli and Kenig [Amer. J. Math.120 (1998)] by establishing an almost monotonicity estimate for pairs of continuous functions satisfying u± ≥ 0 Lu± ≥ -1, u+ · u_ = 0 ;in an infinite strip (global version) or a finite parabolic cylinder (localized version), where L is a uniformly parabolic operator Lu = LA,b,cu := div(A(x, s)∇u) + b(x,s) · ∇u + c(x,s)u - δsu with double Dini continuous A and uniformly bounded b and c. We also prove the elliptic counterpart of this estimate.This closes the gap between the known conditions in the literature (both in the elliptic and parabolic case) imposed on u± in order to obtain an almost monotonicity estimate.At the end of the paper, we demonstrate how to use this new almost monotonicity formula to prove the optimal C1,1-regularity in a fairly general class of quasi-linear obstacle-type free boundary problems. © 2010 Wiley Periodicals, Inc.

  1. Advantages of variable-speed operation of hydraulic turbo-engines; Vorteile durch den drehzahlvariablen Betrieb von hydraulischen Stroemungsmaschinen

    Energy Technology Data Exchange (ETDEWEB)

    Harbort, T. [Stuttgart Univ. (Germany). Inst. fuer Stroemungsmechanik und Hydraulische Stroemungsmaschinen

    1997-12-31

    The performance of current hydraulic turbo-engines in the variable speed sector is monitored and judged. The study covers radial and axial engines as well as Pelton turbines. Variable-speed operation of hydraulic turbo-engines can be realized by means of different combinations of electrical rotating machines and frequency converters. The operating range of the frequency converter plays an important role in the optimization of performance and is taken into account. The smoothness of run of reaction turbines and their cavitation performance can be enhanced by speed regulation. But above all, efficiency is more or less substantially enhanced during partial load or in the case of greatly varying heights of drop. The latter holds true also of Pelton turbines. (orig.) [Deutsch] Das Betriebsverhalten der gaengigen hydraulischen Stroemungsmaschinen wird in Hinblick auf den drehzahlvariablen Betrieb erfasst und beurteilt. Die Untersuchung erfolgt fuer Radialmaschinen, Axialmaschinen und Peltonturbinen. Der drehzahlvariable Betrieb hydraulischer Stroemungsmaschinen kann mit verschiedenen Kombinationen von elektrischen Maschinen und Frequenzumrichtern realisiert werden. Der Arbeitsbereich des Frequenzumrichters spielt eine wichtige Rolle fuer die Optimierung des Betriebsverhaltens und wird beruecksichtigt. Bei Ueberdruckturbinen kann man durch Drehzahlregelung eine groessere Laufruhe sowie ein guenstigeres Kavitationsverhalten erreichen. Vor allem aber sind im Teillastbereich oder bei stark schwankenden Fallhoehen mehr oder weniger grosse Wirkungsgradgewinne erzielbar. Das letztere gilt auch fuer Peltonturbinen. (orig.)

  2. Effective Operators from Exact Many-Body Renormalization

    Energy Technology Data Exchange (ETDEWEB)

    Lisetskiy, A F; Kruse, M G; Barrett, B R; Navratil, P; Stetcu, I; Vary, J P

    2009-06-11

    We construct effective two-body Hamiltonians and E2 operators for the p-shell by performing 16{h_bar}{Omega} ab initio no-core shell model (NCSM) calculations for A = 5 and A = 6 nuclei and explicitly projecting the many-body Hamiltonians and E2 operator onto the 0{h_bar}{Omega} space. We then separate the effective E2 operator into one-body and two-body contributions employing the two-body valence cluster approximation. We analyze the convergence of proton and neutron valence one-body contributions with increasing model space size and explore the role of valence two-body contributions. We show that the constructed effective E2 operator can be parametrized in terms of one-body effective charges giving a good estimate of the NCSM result for heavier p-shell nuclei.

  3. Organizational effectiveness of coalition operations' headquarters : A theoretical model

    NARCIS (Netherlands)

    Vogler-Bisig, E.; Blais, A.R.; Hof, T.; Tresch, T.S.; Seiler, S.; Yanakiev, Y.

    2012-01-01

    Purpose - This article describes a theoretical model that allows understanding, explaining, and measuring the perceived organizational effectiveness of multinational coalition operations' headquarters. Design/methodology/approach - The proposed model is based on subject matter experts' opinions and

  4. Elements for Effective Management of Operating Pump and Treat Systems

    Science.gov (United States)

    This fact sheet summarizes key aspects of effective management for operating pump and treat (P&T) systems based on lessons learned from conducting optimization evaluations at 20 Superfund-financed P&T systems.

  5. Effects of power on perceived and objective group variability: evidence that more powerful groups are more variable.

    Science.gov (United States)

    Guinote, Ana; Judd, Charles M; Brauer, Markus

    2002-05-01

    The perception of group variability is affected by social power and status. Three different mechanisms may be responsible for these effects: (a) the power of the perceiver affects perceived group variability; (b) the power of the perceived group affects its perceived variability; and (c) the power of the group affects its actual variability. Two studies are reported to tease apart these three mechanisms and provide support for the third. In the first study, high- and low-power groups interacted and subsequently judged each other. In the second study, participants observed and rated the Study 1 groups, either knowing their power relationship or not. Results suggest that members of high-power groups manifest greater interpersonal variability than members of low-power groups.

  6. Country-Specific Effects of Climate Variability on Human Migration.

    Science.gov (United States)

    Gray, Clark; Wise, Erika

    2016-04-01

    Involuntary human migration is among the social outcomes of greatest concern in the current era of global climate change. Responding to this concern, a growing number of studies have investigated the consequences of short to medium-term climate variability for human migration using demographic and econometric approaches. These studies have provided important insights, but at the same time have been significantly limited by lack of expertise in the use of climate data, access to cross-national data on migration, and attention to model specification. To address these limitations, we link data on internal and international migration over a 6-year period from 9,812 origin households in Kenya, Uganda, Nigeria, Burkina Faso and Senegal to high-resolution gridded climate data from both station and satellite sources. Analyses of these data using several plausible specifications reveal that climate variability has country-specific effects on migration: Migration tends to increase with temperature anomalies in Uganda, tends to decrease with temperature anomalies in Kenya and Burkina Faso, and shows no consistent relationship with temperature in Nigeria and Senegal. Consistent with previous studies, precipitation shows weak and inconsistent relationships with migration across countries. These results challenge generalizing narratives that foresee a consistent migratory response to climate change across the globe.

  7. Effect of Zn Adsorption on Charge of Variable Charge Soils

    Institute of Scientific and Technical Information of China (English)

    SUNHAN-YUAN

    1993-01-01

    The variation in appa rent carge of two typical variable charge soils resulting from Zn adsorption were studied by KCl saturation and NH4NO3 replacement methods.Results showed that zinc were adsorbed specifically to those sites with negative charge.As in different pH ranges,the percantages of specific and electrostatic adsorptions of zine and the mechanisms of specific adsorption were different,the effects of Zn adsorption on apparent charge were varied and could be characterized as:when 1 mmol Zn2+ was adsorbed,a change about 1 mmol in the apparent charge was observed in the low pH range(1),1.4 to 1.5mmol in the moderate pH range(II) and 0.55 to 0.6mmol in the high pH range (III).These experimental data,in terms of soil charge,proved once more author's conclusion in the preceding paper(Sun,1993) that in accordance with the behaviors of Zn adsorption by the variable charge soils in relation to pH,three pH ranges with different adsorption mechanisms were delineated;that is,in Range I,specific adsorption was the predominant mechanism,in Ranges II and III,specific and electrostatic adsorptions co-existed,but their specific adsorption mechanisms were not identical.

  8. Controlled English for Effective Communication during Coalition Operations

    Science.gov (United States)

    2013-06-01

    simplified and common form of expression in English , which is not only user- friendly in nature but is also restricted in vocabulary and grammar for clear...18th ICCRTS C2 in Underdeveloped, Degraded and Denied Operational Environments Title of Paper: Controlled English for Effective Communication...4. TITLE AND SUBTITLE Controlled English for Effective Communication during Coalition Operations 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c

  9. Effects of antecedent variables on disruptive behavior and accurate responding in young children in outpatient settings.

    Science.gov (United States)

    Boelter, Eric W; Wacker, David P; Call, Nathan A; Ringdahl, Joel E; Kopelman, Todd; Gardner, Andrew W

    2007-01-01

    The effects of manipulations of task variables on inaccurate responding and disruption were investigated with 3 children who engaged in noncompliance. With 2 children in an outpatient clinic, task directives were first manipulated to identify directives that guided accurate responding; then, additional dimensions of the task were manipulated to evaluate their influence on disruptive behavior. With a 3rd child, similar procedures were employed at school. Results showed one-step directives set the occasion for accurate responding and that other dimensions of the task (e.g., preference) functioned as motivating operations for negative reinforcement.

  10. Simulation model of a variable-speed pumped-storage power plant in unstable operating conditions in pumping mode

    Science.gov (United States)

    Martínez-Lucas, G.; Pérez-Díaz, J. I.; Sarasúa, J. I.; Cavazzini, G.; Pavesi, G.; Ardizzon, G.

    2017-04-01

    This paper presents a dynamic simulation model of a laboratory-scale pumped-storage power plant (PSPP) operating in pumping mode with variable speed. The model considers the dynamic behavior of the conduits by means of an elastic water column approach, and synthetically generates both pressure and torque pulsations that reproduce the operation of the hydraulic machine in its instability region. The pressure and torque pulsations are generated each from a different set of sinusoidal functions. These functions were calibrated from the results of a CFD model, which was in turn validated from experimental data. Simulation model results match the numerical results of the CFD model with reasonable accuracy. The pump-turbine model (the functions used to generate pressure and torque pulsations inclusive) was up-scaled by hydraulic similarity according to the design parameters of a real PSPP and included in a dynamic simulation model of the said PSPP. Preliminary conclusions on the impact of unstable operation conditions on the penstock fatigue were obtained by means of a Monte Carlo simulation-based fatigue analysis.

  11. Observer-based scheme for tuning the control of variable speed wind turbines operating in hostile environments

    DEFF Research Database (Denmark)

    Caruana, Cedric; Al-Durra, Ahmed; Blaabjerg, Frede

    2016-01-01

    the control law. The proposed observer identifies variations in the power coefficient surface over time due to the effect of the environment on the rotor blades. Simulations for both open- and closed-loop operations are shown. The proposed technique shows the potential to alleviate the performance degradation...

  12. On the effective operators for Dark Matter annihilations

    Energy Technology Data Exchange (ETDEWEB)

    Simone, Andrea De; Thamm, Andrea [CERN, Theory Division, CH-1211 Geneva 23 (Switzerland); Monin, Alexander [Institut de Théorie des Phénomènes Physiques, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne (Switzerland); Urbano, Alfredo, E-mail: andrea.desimone@sissa.it, E-mail: alexander.monin@epfl.ch, E-mail: andrea.thamm@cern.ch, E-mail: alfredo.urbano@sissa.it [SISSA, via Bonomea 265, I-34136 Trieste (Italy)

    2013-02-01

    We consider effective operators describing Dark Matter (DM) interactions with Standard Model fermions. In the non-relativistic limit of the DM field, the operators can be organized according to their mass dimension and their velocity behaviour, i.e. whether they describe s- or p-wave annihilations. The analysis is carried out for self-conjugate DM (real scalar or Majorana fermion). In this case, the helicity suppression at work in the annihilation into fermions is lifted by electroweak bremsstrahlung. We construct and study all dimension-8 operators encoding such an effect. These results are of interest in indirect DM searches.

  13. On the effective operators for Dark Matter annihilations

    CERN Document Server

    De Simone, Andrea; Thamm, Andrea; Urbano, Alfredo

    2013-01-01

    We consider effective operators describing Dark Matter (DM) interactions with Standard Model fermions. In the non-relativistic limit of the DM field, the operators can be organized according to their mass dimension and their velocity behaviour, i.e. whether they describe s- or p-wave annihilations. The analysis is carried out for self-conjugate DM (real scalar or Majorana fermion). In this case, the helicity suppression at work in the annihilation into fermions is lifted by electroweak bremsstrahlung. We construct and study all dimension-8 operators encoding such an effect. These results are of interest in indirect DM searches.

  14. Climate variability effects on spatial soil moisture dynamics

    OpenAIRE

    A. J. Teuling; Hupet, F.; R. Uijlenhoet; P. A. Troch

    2007-01-01

    We investigate the role of interannual climate variability on spatial soil moisture variability dynamics for a field site in Louvain-la-Neuve, Belgium. Observations were made during 3 years under intermediate (1999), wet (2000), and extremely dry conditions (2003). Soil moisture variability dynamics are simulated with a comprehensive model for the period 1989-2003. The results show that climate variability induces non-uniqueness and two distinct hysteresis modes in the yearly relation between...

  15. Effects of interannual climate variability on tropical tree cover

    NARCIS (Netherlands)

    Holmgren, M.; Hirota, M.; Nes, van E.H.; Scheffer, M.

    2013-01-01

    Climatic warming is substantially intensifying the global water cycle1 and is projected to increase rainfall variability2. Using satellite data, we show that higher climatic variability is associated with reduced tree cover in the wet tropics globally. In contrast, interannual variability in rainfal

  16. Climate variability effects on spatial soil moisture dynamics

    NARCIS (Netherlands)

    Teuling, A.J.; Hupet, F.; Uijlenhoet, R.; Troch, P.A.

    2007-01-01

    We investigate the role of interannual climate variability on spatial soil moisture variability dynamics for a field site in Louvain-la-Neuve, Belgium. Observations were made during 3 years under intermediate (1999), wet (2000), and extremely dry conditions (2003). Soil moisture variability dynamics

  17. Effect of desired speed variability on highway traffic flow.

    Science.gov (United States)

    Lipshtat, Azi

    2009-06-01

    Traffic flow is a function of many natural, environmental, and human factors. Not only that weather and road condition can vary, but drivers' decisions and policies also can affect the flow. Here we analyze the effect of distribution of desired speeds. We show that a broader distribution can reduce the flow efficiency and increase congestions. Since different drivers react differently to changes in weather or road conditions, such a change leads to a change in desired speed distribution as well. As a result, nonintuitive changes in traffic flow may occur. Besides providing insight and analyzing the underlying mechanism of a collective phenomenon, this example sheds light on a fundamental aspect of computational modeling. Although "mean-field" models that deal with average values only and ignore variability are simpler and easier to analyze, they can very easily turn into oversimplifications and miss relevant qualitative phenomena.

  18. Tillage Effects on Spatiotemporal Variability of Particulate Organic Matter

    Directory of Open Access Journals (Sweden)

    Juhwan Lee

    2009-01-01

    Full Text Available This study was performed to evaluate effects of no-till (NT and standard tillage (ST on POM in two 15-ha neighboring fields from 2003 to 2004. We also evaluated the effects of minimum tillage (MT on POM after both NT and ST fields were converted to MT in the summer of 2005. We quantified C and N stocks of three size fractions (53–250, 250–1000, and 1000–2000 μm of POM (0–0.15 m depth. The POM-C 53–250 μm and 250–1000 μm fractions decreased by 25% and 36% after six months under ST, whereas relatively little change occurred under NT, suggesting significant tillage effects over the period 2003-2004. Only small changes in POM content then occurred under MT on both fields. Changes in POM-N were similar to POM-C changes upon tillage conversions. This suggests that reduced tillage did not lead to soil C increase compared to ST but may help maintain the level of soil C for a typical California farming system. Short-term, field level variability of POM was primarily affected by tillage and was further influenced by clay content, bulk density, and scale of observation.

  19. The effect of work pace on workload, motor variability and fatigue during simulated light assembly work.

    Science.gov (United States)

    Bosch, T; Mathiassen, S E; Visser, B; de Looze, M P; van Dieën, J H

    2011-02-01

    This study investigated the effect of work pace on workload, motor variability and fatigue during light assembly work. Upper extremity kinematics and electromyography (EMG) were obtained on a cycle-to-cycle basis for eight participants during two conditions, corresponding to "normal" and "high" work pace according to a predetermined time system for engineering. Indicators of fatigue, pain sensitivity and performance were recorded before, during and after the task. The level and variability of muscle activity did not differ according to work pace, and manifestations of muscle fatigue or changed pain sensitivity were not observed. In the high work pace, however, participants moved more efficiently, they showed more variability in wrist speed and acceleration, but they also made more errors. These results suggest that an increased work pace, within the range addressed here, will not have any substantial adverse effects on acute motor performance and fatigue in light, cyclic assembly work. STATEMENT OF RELEVANCE: In the manufacturing industry, work pace is a key issue in production system design and hence of interest to ergonomists as well as engineers. In this laboratory study, increasing the work pace did not show adverse effects in terms of biomechanical exposures and muscle fatigue, but it did lead to more errors. For the industrial engineer, this observation suggests that an increase in work pace might diminish production quality, even without any noticeable fatigue being experienced by the operators.

  20. Noncompact Heisenberg spin magnets from high-energy QCD; 1 Baxter Q-operator and Separation of Variables

    CERN Document Server

    Derkachov, S E; Manashov, A N

    2001-01-01

    We analyze a completely integrable two-dimensional quantum-mechanical model that emerged in the recent studies of the compound gluonic states in multi-color QCD at high energy. The model represents a generalization of the well-known homogenous Heisenberg spin magnet to infinite-dimensional representations of the SL(2,C) group and can be reformulated within the Quantum Inverse Scattering Method. Solving the Yang-Baxter equation, we obtain the R-matrix for the SL(2,C) representations of the principal series and discuss its properties. We explicitly construct the Baxter Q-operator for this model and show how it can be used to determine the energy spectrum. We apply Sklyanin's method of the Separated Variables to obtain an integral representation for the eigenfunctions of the Hamiltonian. We demonstrate that the language of Feynman diagrams supplemented with the method of uniqueness provide a powerful technique for analyzing the properties of the model.

  1. Effect of planting distance in morphoagronomic variables moringa (Moringa oleifera.

    Directory of Open Access Journals (Sweden)

    Ariel Antonio Sosa-Rodríguez

    2016-12-01

    Full Text Available The aim of this study was to determine the effect of ve planting distances in morphoagronomic variables of Moringa oleifera Lam. The work was conducted in areas of the Agricultural Research Institute “Jorge Dimitrov”, the municipality Bayamo, Granma province, Cuba, on the period from November to February of 2014-2015, respectively. A design of randomized blocks with three replications was used. Five treatments were evaluated with consistent planting distances; the cut was made at 10 cm above the oor every fortnight. Signi cant effects (p<0.05 between treatments, plant height and number of shoots/plants where planting distances signi cantly increased the number of bolters/plants (p<0.05 were found with averages of ve and three in the major and minor planting distance respectively. Planting distances used in uenced the morphoagronomic indicators of Moringa oleifera vc. Super Genium. Biomass yield decreased signi cantly (p<0.05 with increasing distance from planting 7 t/ha with the 10 cm x 10 cm, up to 2 t/ha with 20 cm x 20 cm treatment.

  2. The effects of variable sample biomass on comparative metagenomics.

    Science.gov (United States)

    Chafee, Meghan; Maignien, Loïs; Simmons, Sheri L

    2015-07-01

    Longitudinal studies that integrate samples with variable biomass are essential to understand microbial community dynamics across space or time. Shotgun metagenomics is widely used to investigate these communities at the functional level, but little is known about the effects of combining low and high biomass samples on downstream analysis. We investigated the interacting effects of DNA input and library amplification by polymerase chain reaction on comparative metagenomic analysis using dilutions of a single complex template from an Arabidopsis thaliana-associated microbial community. We modified the Illumina Nextera kit to generate high-quality large-insert (680 bp) paired-end libraries using a range of 50 pg to 50 ng of input DNA. Using assembly-based metagenomic analysis, we demonstrate that DNA input level has a significant impact on community structure due to overrepresentation of low-GC genomic regions following library amplification. In our system, these differences were largely superseded by variations between biological replicates, but our results advocate verifying the influence of library amplification on a case-by-case basis. Overall, this study provides recommendations for quality filtering and de-replication prior to analysis, as well as a practical framework to address the issue of low biomass or biomass heterogeneity in longitudinal metagenomic surveys.

  3. Effect of Streamflow Forecast Uncertainty on Real-Time Reservoir Operation

    Science.gov (United States)

    Zhao, T.; Cai, X.; Yang, D.

    2010-12-01

    Various hydrological forecast products have been applied to real-time reservoir operation, including deterministic streamflow forecast (DSF), DSF-based probabilistic streamflow forecast (DPSF), and ensemble streamflow forecast (ESF), which represent forecast uncertainty in the form of deterministic forecast error, deterministic forecast error-based uncertainty distribution, and ensemble forecast errors, respectively. Compared to previous studies that treat these forecast products as ad hoc inputs for reservoir operation models, this paper attempts to model the uncertainties involved in the various forecast products and explores their effect on real-time reservoir operation decisions. In hydrology, there are various indices reflecting the magnitude of streamflow forecast uncertainty; meanwhile, few models illustrate the forecast uncertainty evolution process. This research introduces Martingale Model of Forecast Evolution (MMFE) from supply chain management and justifies its assumptions for quantifying the evolution of uncertainty in streamflow forecast as time progresses. Based on MMFE, this research simulates the evolution of forecast uncertainty in DSF, DPSF, and ESF, and applies the reservoir operation models (dynamic programming, DP; stochastic dynamic programming, SDP; and standard operation policy, SOP) to assess the effect of different forms of forecast uncertainty on real-time reservoir operation. Through a hypothetical single-objective real-time reservoir operation model, the results illustrate that forecast uncertainty exerts significant effects. Reservoir operation efficiency, as measured by a utility function, decreases as the forecast uncertainty increases. Meanwhile, these effects also depend on the type of forecast product being used. In general, the utility of reservoir operation with ESF is nearly as high as the utility obtained with a perfect forecast; the utilities of DSF and DPSF are similar to each other but not as efficient as ESF. Moreover

  4. [Effects of variable-interval punishment on lever pressing maintained by variable-ratio reinforcement in the rat].

    Science.gov (United States)

    Iida, Naritoshi; Kimura, Hiroshi

    2007-12-01

    The effects of reinforcement and punishment on response suppression under variable-ratio reinforcement and variable-interval punishment schedules were investigated. In the baseline period, lever pressing in rats was maintained by a variable-ratio food reinforcement schedule. In the punishment condition, responding was punished by a grid shock under a variable-interval schedule. Baseline and punishment conditions alternated, and were continued until the response stabilized. Three rats were given five or six punishment rates with a fixed reinforcement rate and another three rats were given four or five reinforcement rates with a fixed punishment rate. The results indicated that the responses were either completely suppressed or not suppressed at all. When the punishment rate increased or the reinforcement rate decreased, the response was suppressed completely. Whereas when the punishment rate decreased or the reinforcement rate increased, the responses were not suppressed. These results agree with the predictions of the molar theory.

  5. Effect of Flux Adjustments on Temperature Variability in Climate Models

    Energy Technology Data Exchange (ETDEWEB)

    Duffy, P.; Bell, J.; Covey, C.; Sloan, L.

    1999-12-27

    It has been suggested that ''flux adjustments'' in climate models suppress simulated temperature variability. If true, this might invalidate the conclusion that at least some of observed temperature increases since 1860 are anthropogenic, since this conclusion is based in part on estimates of natural temperature variability derived from flux-adjusted models. We assess variability of surface air temperatures in 17 simulations of internal temperature variability submitted to the Coupled Model Intercomparison Project. By comparing variability in flux-adjusted vs. non-flux adjusted simulations, we find no evidence that flux adjustments suppress temperature variability in climate models; other, largely unknown, factors are much more important in determining simulated temperature variability. Therefore the conclusion that at least some of observed temperature increases are anthropogenic cannot be questioned on the grounds that it is based in part on results of flux-adjusted models. Also, reducing or eliminating flux adjustments would probably do little to improve simulations of temperature variability.

  6. Effective onion leaf fleck management and variability of storage pathogens

    Directory of Open Access Journals (Sweden)

    Rasiukevičiūtė Neringa

    2016-01-01

    Full Text Available Botrytis spp. cause several diseases in Allium crops and depending on meteorological conditions economic losses can exceed 50%. Forecasting models improve plant protection and sometimes reduce consumption of fungicides, because applications are made precisely during the favourable periods for disease development. Our aim was to evaluate the iMETOS®sm B. cinerea forecasting model as an effective onion leaf fleck management system and estimate the variability of onion bulb pathogens during storage. Assessment of forecasting model data showed that favourable conditions for leaf fleck development arise in July, but greatly depend on that year’s meteorological conditions. During an experimental year the first sprayings with fungicides were applied as forecasted from the model, which resulted in application 19, 6 and 23 days earlier than conventional treatment application times. In 2012-2014 iMETOS®sm treatment yield increased by 3.51 t ha-1, 3.87 t ha-1 and3.40 t ha-1 relative to the control. During storage most frequent injuries were fungal (44% and bacterial (41%, followed by insects (7% and physiological (9%. The highest prevalence of injuries was detected after 2 months of storage.

  7. Effect of methamphetamine dependence on heart rate variability.

    Science.gov (United States)

    Henry, Brook L; Minassian, Arpi; Perry, William

    2012-05-01

    Methamphetamine (METH) is an increasing popular and highly addictive stimulant associated with autonomic nervous system (ANS) dysfunction, cardiovascular pathology and neurotoxicity. Heart rate variability (HRV) has been used to assess autonomic function and predict mortality in cardiac disorders and drug intoxication, but has not been characterized in METH use. We recorded HRV in a sample of currently abstinent individuals with a history of METH dependence compared to age- and gender-matched drug-free comparison subjects. HRV was assessed using time domain, frequency domain, and non-linear entropic analyses in 17 previously METH-dependent and 21 drug-free comparison individuals during a 5 minute rest period. The METH-dependent group demonstrated significant reduction in HRV, reduced parasympathetic activity, and diminished heartbeat complexity relative to comparison participants. More recent METH use was associated with increased sympathetic tone. Chronic METH exposure may be associated with decreased HRV, impaired vagal function, and reduction in heart rate complexity as assessed by multiple methods of analysis. We discuss and review evidence that impaired HRV may be related to the cardiotoxic or neurotoxic effects of prolonged METH use.

  8. C-X Operational Effectiveness in the Intratheater Environment

    Science.gov (United States)

    1983-06-01

    8217.3urviva3; i li ty include the air:lrop, ti’.1 :-: coff I lcJnding- ct:ld L:\\P .!:S :?h:tses of tactical airlift o~)erutions. J\\.11 of t~ 1esc t"’hases l...airlift aircraft against heat seeking SAM’s, although their effectiveness have not been sutstantiated. During the Southeast Asian conflict, C-130’s...Operational effectiveness in other theaters of operation such as South l!est Asian or Pacific • . 168 f . Notes - Chapter VI 1. Discussed in

  9. On instanton effects in the operator product expansion

    CERN Document Server

    Alday, Luis F

    2016-01-01

    We revisit the computation of instanton effects to various correlation functions in ${\\cal N}=4$ SYM and clarify a controversy existing in the literature regarding their consistency with the OPE and conformal symmetry. To check these properties, we examine the conformal partial wave decomposition of four-point correlators involving combinations of half-BPS and Konishi operators and isolate the contribution from the conformal primary scalar operators of twist four. We demonstrate that the leading instanton correction to this contribution is indeed consistent with conformal symmetry and compute the corresponding corrections to the OPE coefficients and the scaling dimensions of such twist-four operators. Our analysis justifies the regularization procedure used to compute ultraviolet divergent instanton contribution to correlation functions involving unprotected operators.

  10. [Effects of situational and individual variables on critical thinking expression].

    Science.gov (United States)

    Tanaka, Yuko; Kusumi, Takashi

    2016-04-01

    The present study examined when people decide to choose an expression that is based on critical thinking, and how situational and individual variables affect such a decision process. Given a conversation scenario including overgeneralization with two friends, participants decided whether to follow the conversation by a critical-thinking expression or not. The authors controlled purpose and topic as situational variables, and measured critical-thinking ability, critical-thinking disposition, and self-monitoring as individual variables. We conducted an experiment in which the situational variables were counterbalanced in a within-subject design with 60 university students. The results of logistic regression analysis showed differences within individuals in the decision process whether to choose a critical-thinking expression, and that some situational factors and some subscales of the individual measurements were related to the differences.

  11. Effect of Dissolved Oxygen on Operation of EGSB

    Institute of Scientific and Technical Information of China (English)

    LI Hui-li; L(U) Bing-nan; LI Qing-wei

    2007-01-01

    An expanded granular sludge bed (EGSB) reactor was adopted to study the dissolved oxygen (DO) effect on the operation. With the chemical oxygen demand (COD) 800-1800mg/L, pH6.0-7.3, volume loading rate (VLR) 5.4-11.5kg COD/(m3·d), the operational behaviors of EGSB reactor was researched. And the max DO concentration which influenced steady operation of EGSB reactor was determined by contrasting the changes due to different concentrations of the influent DO. With the COD 1200-2000mg/L, VLR 7.2-12.0kg COD/(m3·d), the operational characteristic of EGSB reactor was researched by aerating the recycle effluent. The results was: when the DO concentration of influent was under 3.0mg/L, the removal efficiency of COD was 82%-90% and the operation of the EGSB reactor was steady; when the DO concentration of influent was over 3.0mg/L, the oxidationreduction potential (ORP) fluctuated greatly and the operation of the EGSB reactor was instable; the acidified wastewater of saccharide whose pH value was 5.1-6.5 could be treated by aerating the recycle effluent and the efficiency of COD was up to 85%-92%.

  12. Effects of temporal variability on HBV model calibration

    Directory of Open Access Journals (Sweden)

    Steven Reinaldo Rusli

    2015-10-01

    Full Text Available This study aimed to investigate the effect of temporal variability on the optimization of the Hydrologiska Byråns Vattenbalansavedlning (HBV model, as well as the calibration performance using manual optimization and average parameter values. By applying the HBV model to the Jiangwan Catchment, whose geological features include lots of cracks and gaps, simulations under various schemes were developed: short, medium-length, and long temporal calibrations. The results show that, with long temporal calibration, the objective function values of the Nash-Sutcliffe efficiency coefficient (NSE, relative error (RE, root mean square error (RMSE, and high flow ratio generally deliver a preferable simulation. Although NSE and RMSE are relatively stable with different temporal scales, significant improvements to RE and the high flow ratio are seen with longer temporal calibration. It is also noted that use of average parameter values does not lead to better simulation results compared with manual optimization. With medium-length temporal calibration, manual optimization delivers the best simulation results, with NSE, RE, RMSE, and the high flow ratio being 0.563 6, 0.122 3, 0.978 8, and 0.854 7, respectively; and calibration using average parameter values delivers NSE, RE, RMSE, and the high flow ratio of 0.481 1, 0.467 6, 1.021 0, and 2.784 0, respectively. Similar behavior is found with long temporal calibration, when NSE, RE, RMSE, and the high flow ratio using manual optimization are 0.525 3, −0.069 2, 1.058 0, and 0.980 0, respectively, as compared with 0.490 3, 0.224 8, 1.096 2, and 0.547 9, respectively, using average parameter values. This study shows that selection of longer periods of temporal calibration in hydrological analysis delivers better simulation in general for water balance analysis.

  13. Intertwining operator method and supersymmetry for effective mass Schroedinger equations

    Energy Technology Data Exchange (ETDEWEB)

    Suzko, A.A. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); JIPENP, National Academy of Sciences of Belarus, Minsk (Belarus)], E-mail: suzko@cv.jinr.ru; Schulze-Halberg, A. [Mathematics Department, University of Colima, Bernal Diaz del Castillo 340, Colima 28045 (Mexico)], E-mail: xbat@ucol.mx

    2008-09-08

    By application of the intertwining operator method to Schroedinger equations with position-dependent (effective) mass, we construct Darboux transformations, establish the supersymmetry factorization technique and show equivalence of both formalisms. Our findings prove equivalence of the intertwining technique and the method of point transformations.

  14. Investigation of 3d Effects on Fel Operation

    NARCIS (Netherlands)

    van Werkhoven, G. H. C.; Faatz, B.; Schep, T. J.

    1993-01-01

    An investigation is made of 3D effects on FEL operation by comparing the 3D simulation code TDA with a 1 1/2D model. In the latter model, the full spatial dependence of the radiation field is taken into account, whereas the electrons are treated as moving in a 1D, density-averaged ponderomotive pote

  15. Complexity, Networking, & Effects-Based Approaches to Operations

    Science.gov (United States)

    2006-06-01

    40 Figure 10. Miller’s Living Systems Model ....................................47 Figure 11. State versus Non- State Living Systems...human organizations and to apply it in an effects-based context. State and non- state living systems The model described above extrapolates quite... STATE LIVING SYSTEMS MODEL 52 Complexity, Networking, and Effects-Based Approaches to Operations The living systems model organizations such as the

  16. Validation of Generic Models for Variable Speed Operation Wind Turbines Following the Recent Guidelines Issued by IEC 61400-27

    Directory of Open Access Journals (Sweden)

    Andrés Honrubia-Escribano

    2016-12-01

    Full Text Available Considerable efforts are currently being made by several international working groups focused on the development of generic, also known as simplified or standard, wind turbine models for power system stability studies. In this sense, the first edition of International Electrotechnical Commission (IEC 61400-27-1, which defines generic dynamic simulation models for wind turbines, was published in February 2015. Nevertheless, the correlations of the IEC generic models with respect to specific wind turbine manufacturer models are required by the wind power industry to validate the accuracy and corresponding usability of these standard models. The present work conducts the validation of the two topologies of variable speed wind turbines that present not only the largest market share, but also the most technological advances. Specifically, the doubly-fed induction machine and the full-scale converter (FSC topology are modeled based on the IEC 61400-27-1 guidelines. The models are simulated for a wide range of voltage dips with different characteristics and wind turbine operating conditions. The simulated response of the IEC generic model is compared to the corresponding simplified model of a wind turbine manufacturer, showing a good correlation in most cases. Validation error sources are analyzed in detail, as well. In addition, this paper reviews in detail the previous work done in this field. Results suggest that wind turbine manufacturers are able to adjust the IEC generic models to represent the behavior of their specific wind turbines for power system stability analysis.

  17. Climate variability effects on urban recharge beneath low impact development

    Science.gov (United States)

    Newcomer, M. E.; Gurdak, J. J.

    2012-12-01

    Groundwater resources in urban and coastal environments are highly vulnerable to human pressures and climate variability and change, and many communities face water shortages and need to find alternative water supplies. Therefore, understanding how low impact development (LID) site planning and integrated/best management practices (BMPs) affect recharge rates and volumes is important because of the increasing use of LID and BMP to reduce stormwater runoff and improve surface-water quality. Often considered a secondary management benefit, many BMPs may also enhance recharge to local aquifers; however these hypothesized benefits have not been thoroughly tested or quantified. In this study, we quantify stormwater capture and recharge enhancement beneath a BMP infiltration trench of the LID research network at San Francisco State University, San Francisco, California. Stormwater capture and retention was analyzed using the SCS TR-55 curve number method and in-situ infiltration rates to assess LID storage. Recharge was quantified using vadose zone monitoring equipment, a detailed water budget analysis, and a Hydrus-2D model. Additionally, the effects of historical and predicted future precipitation on recharge rates were examined using precipitation from the Geophysical Fluid Dynamic Laboratory (GFDL) A1F1 climate scenario. Observed recharge rates beneath the infiltration trench range from 1,600 to 3,700 mm/year and are an order of magnitude greater than recharge beneath an irrigated grass lawn and a natural setting. The Hydrus-2D model results indicate increased recharge under the GFDL A1F1 scenario compared with historical and GFDL modeled 20th century rates because of the higher frequency of large precipitation events that induce runoff into the infiltration trench. However, under a simulated A1F1 El Niño year, recharge calculated by a water budget does not increase compared with current El Niño recharge rates. In comparison, simulated recharge rates were

  18. Effect of oligonucleotide primers in determining viral variability within hosts

    Directory of Open Access Journals (Sweden)

    Moya Andrés

    2004-12-01

    Full Text Available Abstract Background Genetic variability in viral populations is usually estimated by means of polymerase chain reaction (PCR based methods in which the relative abundance of each amplicon is assumed to be proportional to the frequency of the corresponding template in the initial sample. Although bias in template-to-product ratios has been described before, its relevance in describing viral genetic variability at the intrapatient level has not been fully assessed yet. Results To investigate the role of oligonucleotide design in estimating viral variability within hosts, genetic diversity in hepatitis C virus (HCV populations from eight infected patients was characterised by two parallel PCR amplifications performed with two slightly different sets of primers, followed by cloning and sequencing (mean = 89 cloned sequences per patient. Population genetics analyses of viral populations recovered by pairs of amplifications revealed that in seven patients statistically significant differences were detected between populations sampled with different set of primers. Conclusions Genetic variability analyses demonstrates that PCR selection due to the choice of primers, differing in their degeneracy degree at some nucleotide positions, can eclipse totally or partially viral variants, hence yielding significant different estimates of viral variability within a single patient and therefore eventually producing quite different qualitative and quantitative descriptions of viral populations within each host.

  19. Assessment of Blasting Operations Effects During Highway Tunnel Construction

    Directory of Open Access Journals (Sweden)

    Valašková Veronika

    2015-12-01

    Full Text Available Blasting operations are one of the fundamental parts of daily civil engineering. Drilling and blasting still remain the only possible ways of tunnelling in very adverse geological conditions. However, this method is a source of various disadvantages, the main one being tremors propagating through the geological environment which not only affect buildings, but also disturb the comfort of living in the vicinity of the source. Designing this procedure is mostly done using standardized empirical relations. This article shows the possibility of using a FEM technique in predicting blast effects. This approach is demonstrated in a simple case study on the impact of blasting operations on steel pipes.

  20. Assault on the Most Nasty Effective Operator at the LHC

    CERN Document Server

    Krauss, Frank; Plehn, Tilman

    2016-01-01

    Higher-dimensional multi-gluon interactions affect essentially all effective Lagrangian analyses at the LHC. We show that, contrary to common lore, such operators are best constrained in multi-jet production. Our limit on the corresponding new physics scale in the multi-TeV range exceeds the typical reach of global dimension-6 Higgs and top analyses. This implies that the pure Yang-Mills operator can safely be neglected in almost all specific higher-dimensional analyses at Run II.

  1. Overcoming the effects of stress on reactor operator performance

    Energy Technology Data Exchange (ETDEWEB)

    He Xuhong; Wei Li; Zhao Bingquan [Tsinghua Univ., Nuclear Power Plant Simulation Training Center, Beijing (China)

    2003-03-01

    Reactor operators may be exposed to significant levels of stress during plant emergencies and their performance may be affected by the stress. This paper first identified the potential sources of stress in the nuclear power plant, then discussed the ways in which stress is likely to affect the reactor operators, and finally identified several training approaches for reducing or eliminating stress effects. The challenges for effective stress reducing training may seem daunting, yet the challenges are real and must be addressed. This paper reviewed researches in training design, knowledge and skill acquisition, and training transfer point to a number of strategies that can be used to address these challenges and lead to more effective training and development. (author)

  2. Composed planar Hall effect sensors with dual-mode operation

    Science.gov (United States)

    Mor, Vladislav; Roy, Debangsu; Schultz, Moty; Klein, Lior

    2016-02-01

    We present a composed planar Hall effect sensor with two modes of operation: (a) an ON mode where the composed sensor responds to magnetic field excitations similarly to the response of a regular planar Hall effect sensor, and (b) an OFF mode where the response is negligible. The composed planar Hall effect sensor switches from the OFF mode to the ON mode when it is exposed to a magnetic field which exceeds a certain threshold determined by the sensor design. The features of this sensor make it useful as a switch triggered by magnetic field and as a sensing device with memory, as its mode of operation indicates exposure to a magnetic field larger than a certain threshold without the need to be activated during the exposure itself.

  3. Composed planar Hall effect sensors with dual-mode operation

    Directory of Open Access Journals (Sweden)

    Vladislav Mor

    2016-02-01

    Full Text Available We present a composed planar Hall effect sensor with two modes of operation: (a an ON mode where the composed sensor responds to magnetic field excitations similarly to the response of a regular planar Hall effect sensor, and (b an OFF mode where the response is negligible. The composed planar Hall effect sensor switches from the OFF mode to the ON mode when it is exposed to a magnetic field which exceeds a certain threshold determined by the sensor design. The features of this sensor make it useful as a switch triggered by magnetic field and as a sensing device with memory, as its mode of operation indicates exposure to a magnetic field larger than a certain threshold without the need to be activated during the exposure itself.

  4. Simulating the Effect of Peacekeeping Operations 2010-2035

    Science.gov (United States)

    Hegre, Håvard; Hultman, Lisa; Nygård, Håvard Mokleiv

    We simulate how a set of different UN policies for peace-keeping operations is likely to affect the global incidence of internal armed conflict. The simulation is based on a statistical model that estimates the efficacy of UN peacekeeping operations (PKOs) in preventing the onset, escalation, continuation, and recurrence of internal armed conflict. The model takes into account a set of important conflict predictors for which we have projections up to 2035 from the UN and the IIASA. The estimates are based on a 1970-2008 cross-sectional dataset of changes between conflict levels and new data on PKO budgets and mandates. The simulations show a strong effect of PKOs on the global incidence of major conflicts, although restricted to operations with robust mandates. Extensive use of 'transformational' PKOs can reduce the global incidence of the most lethal conflicts with 65%.

  5. The effects of variable-time delivery of food items and praise on problem behavior reinforced by escape.

    Science.gov (United States)

    Lomas, Joanna E; Fisher, Wayne W; Kelley, Michael E

    2010-01-01

    Prior research indicates that reinforcement of an appropriate response (e.g., compliance) can produce concomitant reductions in problem behavior reinforced by escape when problem behavior continues to produce negative reinforcement (e.g., Lalli et al., 1999). These effects may be due to a preference for positive over negative reinforcement or to positive reinforcement acting as an abolishing operation, rendering demands less aversive and escape from demands less effective as negative reinforcement. In the current investigation, we delivered a preferred food item and praise on a variable-time 15-s schedule while providing escape for problem behavior on a fixed-ratio 1 schedule in a demand condition for 3 participants with problem behavior maintained by negative reinforcement. Results for all 3 participants showed that variable-time delivery of preferred edible items reduced problem behavior even though escape continued to be available for these responses. These findings are discussed in the context of motivating operations.

  6. Nurse Scheduling by Cooperative GA with Effective Mutation Operator

    Science.gov (United States)

    Ohki, Makoto

    In this paper, we propose an effective mutation operators for Cooperative Genetic Algorithm (CGA) to be applied to a practical Nurse Scheduling Problem (NSP). The nurse scheduling is a very difficult task, because NSP is a complex combinatorial optimizing problem for which many requirements must be considered. In real hospitals, the schedule changes frequently. The changes of the shift schedule yields various problems, for example, a fall in the nursing level. We describe a technique of the reoptimization of the nurse schedule in response to a change. The conventional CGA is superior in ability for local search by means of its crossover operator, but often stagnates at the unfavorable situation because it is inferior to ability for global search. When the optimization stagnates for long generation cycle, a searching point, population in this case, would be caught in a wide local minimum area. To escape such local minimum area, small change in a population should be required. Based on such consideration, we propose a mutation operator activated depending on the optimization speed. When the optimization stagnates, in other words, when the optimization speed decreases, the mutation yields small changes in the population. Then the population is able to escape from a local minimum area by means of the mutation. However, this mutation operator requires two well-defined parameters. This means that user have to consider the value of these parameters carefully. To solve this problem, we propose a periodic mutation operator which has only one parameter to define itself. This simplified mutation operator is effective over a wide range of the parameter value.

  7. Composed planar Hall effect sensors with dual-mode operation

    OpenAIRE

    Vladislav Mor; Debangsu Roy; Moty Schultz; Lior Klein

    2016-01-01

    We present a composed planar Hall effect sensor with two modes of operation: (a) an ON mode where the composed sensor responds to magnetic field excitations similarly to the response of a regular planar Hall effect sensor, and (b) an OFF mode where the response is negligible. The composed planar Hall effect sensor switches from the OFF mode to the ON mode when it is exposed to a magnetic field which exceeds a certain threshold determined by the sensor design. The features of this sensor make ...

  8. EFFECTS OF FLOTATION VARIABLES ON FELDSPATHIC SAND CONCENTRATION

    Directory of Open Access Journals (Sweden)

    ALEJANDRO ARGÜELLES - DÍAZ

    2014-01-01

    Full Text Available El objetivo de este trabajo es determinar la influencia que determinadas variables (como son, concentraciones del colector, dilución de la pulpa, tiempos de acondicionamiento, pH y velocidad de agitación de la pulpa ejercen en el rendimiento del proceso de flotación de arena feldespática, utilizado para separar el cuarzo del feldespato, así como estimar los valores que proporcionan un rendimiento óptimo. Las arenas feldespáticas provinieron de un depósito sedimentario ubicado en Sarreaus, provincia de Orense al noroeste de España. El rendimiento de flotación se basa en dos parámetros: ley y recuperación. Cada uno de estos parámetros fue determinado en una serie de experimentos en los cuales se varió cada vez una de las variables manteniéndose fijos los valores del resto. Los resultados indican que es posible obtener un rendimiento elevado en la flotación habiéndose determinado las variables óptimas de proceso. Con dichas variables óptimas la ley media del concentrado fue del 95.1% y la recuperación media del 25.6%.

  9. Heart Rate Variability: Effect of Exercise Intensity on Postexercise Response

    Science.gov (United States)

    James, David V. B.; Munson, Steven C.; Maldonado-Martin, Sara; De Ste Croix, Mark B. A.

    2012-01-01

    The purpose of the present study was to investigate the influence of two exercise intensities (moderate and severe) on heart rate variability (HRV) response in 16 runners 1 hr prior to (-1 hr) and at +1 hr, +24 hr, +48 hr, and +72 hr following each exercise session. Time domain indexes and a high frequency component showed a significant decrease…

  10. Heart Rate Variability: Effect of Exercise Intensity on Postexercise Response

    Science.gov (United States)

    James, David V. B.; Munson, Steven C.; Maldonado-Martin, Sara; De Ste Croix, Mark B. A.

    2012-01-01

    The purpose of the present study was to investigate the influence of two exercise intensities (moderate and severe) on heart rate variability (HRV) response in 16 runners 1 hr prior to (-1 hr) and at +1 hr, +24 hr, +48 hr, and +72 hr following each exercise session. Time domain indexes and a high frequency component showed a significant decrease…

  11. Variable thermal resistor based on self-powered Peltier effect

    Energy Technology Data Exchange (ETDEWEB)

    Min Gao; Yatim, N Md [School of Engineering, Cardiff University, Cardiff, CF24 3AA (United Kingdom)

    2008-11-21

    Heat flow through a thermoelectric material or device can be varied by an electrical resistor connected in parallel to it. This phenomenon is exploited to design a novel thermal component-variable thermal resistor. The theoretical background to this novel application is provided and an experimental result to demonstrate its feasibility is reported. (fast track communication)

  12. The effects of attachment components on formal-operational thinking

    Directory of Open Access Journals (Sweden)

    Vukčević Branimir

    2010-01-01

    Full Text Available In this work our aim is to examine how the components of attachment influence the thinking development of adolescents in familial context. We investigated the components of attachment: unresolved family traumatisation, the use of external security base, fear of loss of external security base, negative self concept, negative other concept, capacity for mentalisation, low control of anger. We used a revised Questionnaire for Assessment of Adult and Adolescent Attachment (in original: UPIPAV-R. Formal operations were tested by Bond's Logical Operations Test. We examined the cultural-pedagogical status of the family, the parental mediation characteristic for the development of formal operations, and family property as the aspects of familial context. The sample consisted of 200 pupils aged 14 to 19. According to the attachment theory, secure attachment provides the feel of security in environment exploration, which is the ground of personality development. We assumed that components of attachment contribute formal-operational thinking development and change the influence of familial cultural-supportive tools. The findings show us that the culturalpedagogical status of the family improves formal operations development and unresolved family traumatisation has negative influence. Capacity for mentalisation has a positive indirect effect on thinking development through the influence of the cultural-pedagogical status of the family. The low control of anger has a negative indirect effect on thinking development; it increases the influence of unresolved family traumatisation. Negative self concept has indirect effects on thinking development through increasing this negative influence of unresolved family traumatisation and decreasing the role of familial cultural-supportive tools.

  13. A nonlinear rheological model for the ultrasonically induced squeeze film effect in variable friction haptic displays

    Science.gov (United States)

    Son, Kwon Joong

    2017-08-01

    A squeeze film induced by ultrasonic vibration between two solid surfaces in contact can dramatically reduce the friction between them. This phenomenon, so-called the squeeze film effect, has been utilized in variable friction tactile displays for texture rendering purposes. Such tactile displays can provoke a haptic sensation to a finger pad in a controllable way. A real-time adjustment of the coefficient of lateral friction between the human finger pad and the tactile display can be accomplished by modulating the vibration amplitude of the tactile panel. Therefore, driving a reliable friction model is a key step towards designing and controlling tactile displays utilizing the squeeze film effect. This paper derives a modified Herschel- Bulkley rheological model to express the lateral friction exerted on a human fingertip via an air squeeze film as a function of the operating parameters such as the driving voltage amplitude, the finger sliding speed, and the contact pressure. In contrast to the conventional Coulomb friction model, such a rheology model can account for the sliding velocity dependence. This modeling work may contribute to the optimal control of the ultrasonic variable friction tactile displays.

  14. Variable turbulent convection as the cause of the Blazhko effect - testing the Stothers model

    CERN Document Server

    Smolec, R; Kolenberg, K; Bryson, S; Cote, M T; Morris, R L

    2011-01-01

    The amplitude and phase modulation observed in a significant fraction of the RR Lyrae variables - the Blazhko effect - represents a long-standing enigma in stellar pulsation theory. No satisfactory explanation for the Blazhko effect has been proposed so far. In this paper we focus on the Stothers (2006) idea, in which modulation is caused by changes in the structure of the outer convective zone, caused by a quasi-periodically changing magnetic field. However, up to this date no quantitative estimates were made to investigate whether such a mechanism can be operational and whether it is capable of reproducing the light variation we observe in Blazhko variables. We address the latter problem. We use a simplified model, in which the variation of turbulent convection is introduced into the non-linear hydrodynamic models in an ad hoc way, neglecting interaction with the magnetic field. We study the light curve variation through the modulation cycle and properties of the resulting frequency spectra. Our results are...

  15. Current understanding of the effects of enviromental and irradiation variables on RPV embrittlement

    Energy Technology Data Exchange (ETDEWEB)

    Odette, G.R.; Lucas, G.E.; Wirth, B.; Liu, C.L. [Univ. of California, Santa Barbara, CA (United States)

    1997-02-01

    Radiation enhanced diffusion at RPV operating temperatures around 290{degrees}C leads to the formation of various ultrafine scale hardening phases, including copper-rich and copper-catalyzed manganese-nickel rich precipitates. In addition, defect cluster or cluster-solute complexes, manifesting a range of thermal stability, develop under irradiation. These features contribute directly to hardening which in turn is related to embrittlement, manifested as shifts in Charpy V-notch transition temperature. Models based on the thermodynamics, kinetics and micromechanics of the embrittlement processes have been developed; these are broadly consistent with experiment and rationalize the highly synergistic effects of most important irradiation (temperature, flux, fluence) and metallurgical (copper, nickel, manganese, phosphorous and heat treatment) variables on both irradiation hardening and recovery during post-irradiation annealing. A number of open questions remain which can be addressed with a hierarchy of new theoretical and experimental tools.

  16. The effects of variable-time versus contingent reinforcement delivery on problem behavior maintained by escape.

    Science.gov (United States)

    Lomas Mevers, Joanna E; Fisher, Wayne W; Kelley, Michael E; Fredrick, Laura D

    2014-01-01

    Results of previous research indicate that the delivery of positive reinforcement (e.g., food) for an appropriate, alternative target response (e.g., compliance) or delivery of food on a time-based schedule can decrease problem behavior reinforced by escape, even when problem behavior continues to produce negative reinforcement (e.g., Lalli et al., ; Lomas, Fisher, & Kelley, ). In this study, we compared the levels of both compliance and problem behavior when food and praise were delivered either contingent on compliance or on a time-based schedule. Results for 3 of the 4 participants showed that contingent delivery of preferred edible items and praise was more effective in both reducing problem behavior and increasing compliance compared to variable-time delivery of these same items. These findings are discussed in the context of motivating operations and competition between positive and negative reinforcement.

  17. Application of principal component analysis enables to effectively find important physical variables for optimization of fluid bed granulator conditions.

    Science.gov (United States)

    Otsuka, Tomoko; Iwao, Yasunori; Miyagishima, Atsuo; Itai, Shigeru

    2011-05-16

    Principal component analysis was applied to effectively optimize the operational conditions of a fluidized bed granulator for preparing granules with excellent compaction and tablet physical properties. The crucial variables that affect the properties of the granules, their compactability and the resulting tablet properties were determined through analysis of a series of granulation and tabletting experiments. Granulation was performed while the flow rate and concentration of the binder were changed as independent operational variables, according to a two-factor central composite design. Thirteen physicochemical properties of granules and tablets were examined: powder properties (particle size, size distribution width, Carr's index, Hausner ratio and aspect ratio), compactability properties (pressure transmission ratio, die wall force and ejection force) and tablet properties (tensile strength, friability, disintegration time, weight variation and drug content uniformity). Principal component analysis showed that the pressure transmission ratio, die wall force and Carr's index were the most important variables in granule preparation. Multiple regression analysis also confirmed these results. Furthermore, optimized operational conditions obtained from the multiple regression analysis enabled the production of granules with desirable properties for tabletting. This study presents the first use of principle component analysis for identifying and successfully predicting the most important variables in the process of granulation and tabletting. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Effective management strategy for establishing an operating room satellite pharmacy.

    Science.gov (United States)

    Brakebill, J I; Schoeneman, P F; Buchanan, B

    1988-11-01

    The steps involved in justifying and implementing an operating room (OR) pharmacy satellite are described. A hospital administrator's viewpoint on the project is included. Objectives of the satellite were to reduce inventory costs, improve control of distribution, reduce loss of revenue and improve patient charging, improve IV compounding and labeling, and significantly improve narcotic control and accountability. The satellite provides comprehensive services 12 hours a day, five days a week. Effective after-hours procedures have been developed to provide efficient drug distribution when the pharmacy is closed. Achieved benefits of the satellite include decreased drug inventory, improved patient charging, accurate labeling, improved IV compounding, and improved pharmacy/surgery relations. The OR pharmacy satellite is a successful cost-effective operation.

  19. Operating characteristics of isocaloric fountain-effect pumps

    Science.gov (United States)

    Kittel, Peter

    1988-01-01

    The governing equations of thermomechanical (fountain-effect) pumps are usually given for pumps operating at a constant temperature difference. These are the thermomechanical and mechanocaloric effects in which the pressure head and mass flow are independent of each other. Here, these equations are recast for a pump operating at a constant heat input (isocaloric). This form more closely represents how such pumps are likely to be used. Under these conditions, the pressure head and mass flow are shown to be related. For ideal pumps, the head and flow are related by a universal curve. For real pumps (those that have normal fluid leakage), a family of curves is developed. These curves approach the curve for an ideal pump at high flow rates. The isocaloric equations are also extended to multistage pumps.

  20. Random operators disorder effects on quantum spectra and dynamics

    CERN Document Server

    Aizenman, Michael

    2015-01-01

    This book provides an introduction to the mathematical theory of disorder effects on quantum spectra and dynamics. Topics covered range from the basic theory of spectra and dynamics of self-adjoint operators through Anderson localization-presented here via the fractional moment method, up to recent results on resonant delocalization. The subject's multifaceted presentation is organized into seventeen chapters, each focused on either a specific mathematical topic or on a demonstration of the theory's relevance to physics, e.g., its implications for the quantum Hall effect. The mathematical chapters include general relations of quantum spectra and dynamics, ergodicity and its implications, methods for establishing spectral and dynamical localization regimes, applications and properties of the Green function, its relation to the eigenfunction correlator, fractional moments of Herglotz-Pick functions, the phase diagram for tree graph operators, resonant delocalization, the spectral statistics conjecture, and rela...

  1. Effect of process variables on the quality attributes of briquettes from wheat, oat, canola and barley

    Energy Technology Data Exchange (ETDEWEB)

    Jaya Shankar Tumuluru

    2011-08-01

    Effect of process variables on the quality attributes of briquettes from wheat, oat, canola and barley straw Jaya Shankar Tumuluru*, L. G. Tabil, Y. Song, K. L. Iroba and V. Meda Biomass is a renewable energy source and environmentally friendly substitute for fossil fuels such as coal and petroleum products. Major limitation of biomass for successful energy application is its low bulk density, which makes it very difficult and costly to transport and handle. To overcome this limitation, biomass has to be densified. The commonly used technologies for densification of biomass are pelletization and briquetting. Briquetting offers many advantages at it can densify larger particles sizes of biomass at higher moisture contents. Briquetting is influenced by a number of feedstock and process variables such as moisture content, particle size distribution, and some operating variables such as temperature and densification pressure. In the present study, experiments were designed and conducted based on Box-Behnken design to produce briquettes using barley, wheat, canola and barley straws. A laboratory scale hydraulic briquette press was used for the present study. The experimental process variables and their levels used in the present study were pressure levels (7.5, 10, 12.5 MPa), three levels of temperature (90, 110, 130 C), at three moisture content levels (9, 12, 15% w.b.), and three levels of particle size (19.1, 25.04, 31.75 mm). The quality variables studied includes moisture content, initial density and final briquette density after two weeks of storage, size distribution index and durability. The raw biomass was initially chopped and size reduced using a hammer mill. The ground biomass was conditioned at different moisture contents and was further densified using laboratory hydraulic press. For each treatment combination, ten briquettes were manufactured at a residence time of about 30 s after compression pressure setpoint was achieved. After compression, the initial

  2. Investigation of the effects of operator technique on handheld sensor data for landmine detection

    Science.gov (United States)

    Tantum, Stacy L.; Morton, Kenneth D., Jr.; Collins, Leslie M.; Torrione, Peter A.

    2012-06-01

    Ground penetrating radar (GPR) is a commonly employed sensing modality for landmine detection. It has been successfully deployed in vehicular systems, and is also being integrated into handheld systems. Handheld mine detection systems are typically deployed in situations where either the terrain or mission renders a vehicular-based system less effective. Handheld systems are often more compact and maneuverable, but quality of the sensor data may also be more dependent on the operators experience with and technique in using the system. In particular, the sensor height with respect to the air-ground interface may be more variable than with a vehicular-based system. This variation in sensor height above the air-ground interface may have the potential to adversely affect mine detection performance with the GPR sensing modality. In this work, the effects of operator technique on handheld sensor data quality is investigated, and ground alignment is explored as a potential approach to reducing variability in the sensor data quality due to operator technique. Results for data measured with a standard GPR/EMI handheld sensor at a standardized test site are presented.

  3. Operating Conditions Effects Onenzyme Activity: Case Enzyme Protease

    Directory of Open Access Journals (Sweden)

    Adel Oueslati

    2014-09-01

    Full Text Available The Proteases an enzyme added to detergents to degrade the protein spots origin.Their action is manifested through its activity the middle of washing clothes. This activity depends on the operating conditions. In this article, the effects of temperature and pH of the reaction and the substrate concentration and time of washing medium on the enzyme activity were studied. There action mechanism has been shown. The activity measurements were made by absorption spectrometry

  4. The effects of variable fluid properties on thin film stability

    Science.gov (United States)

    D'Alessio, S. J. D.; Seth, C. J. M. P.; Pascal, J. P.

    2014-12-01

    A theoretical investigation has been conducted to study the impact of variable fluid properties on the stability of gravity-driven flow of a thin film down a heated incline. The incline is maintained at a uniform temperature which exceeds the temperature of the ambient gas above the fluid and is thus responsible for heating the thin fluid layer. The variable fluid properties are allowed to vary linearly with temperature. It is assumed that long-wave perturbations are most unstable. Based on this, a stability analysis was carried out whereby the governing linearized perturbation equations were expanded in powers of the wavenumber which is a small parameter. New interesting results illustrating how the critical Reynolds number and perturbation phase speed depend on the various dimensionless parameters have been obtained.

  5. Analysis of 3-D Propagation Effects Due to Environmental Variability

    Science.gov (United States)

    2014-09-30

    presence of 3-D environmental variations, especially shelf break canyons . Work was also performed in support of 2-D propagation in shallow water to...propagation in the Monterey Bay Canyon . This was motivated by observations of highly variable directional features in measured acoustic vector data...Rev. 8-98) Prescribed by ANSI Std Z39-18 2 the Monterey Bay Canyon were used as inputs to the model, and broadband calculations were performed

  6. Bounds on supersymmetric effective operators from heavy diphoton searches

    CERN Document Server

    Ghilencea, D.M.

    2017-01-01

    We identify the bounds on supersymmetric effective operators beyond MSSM, from heavy diphoton resonance ($X$) negative searches at the LHC, where $X$ is identified with the neutral CP-even (odd) $H$ ($A$) or both (mass degenerate). While minimal supersymmetric models (MSSM, etc) comply with the data, a leading effective operator of $d=6$ can contribute significantly to diphoton production $\\sigma\\sim 1$ fb, well above its MSSM value and in conflict with recent data. Both the $b\\bar b$ and $gg$ production mechanisms of $H$ and $A$ can contribute comparably to this. We examine the dependence of the diphoton cross section $\\sigma$ on the values of $m_X$, $\\Lambda$ and $\\tan\\beta$, under the experimental constraints from the SM-like higgs couplings $hgg$ and $h\\gamma\\gamma$ (due to mixing) and from the $b\\bar b$ and $t\\bar t$ searches. These give $\\Lambda$ larger than $\\sim 5$ TeV for $m_X$ in the range $0.5-1$ TeV. We show how to generate the $d=6$ effective operator from microscopic (renormalizable) models. Thi...

  7. Modeling heart rate variability including the effect of sleep stages

    Science.gov (United States)

    Soliński, Mateusz; Gierałtowski, Jan; Żebrowski, Jan

    2016-02-01

    We propose a model for heart rate variability (HRV) of a healthy individual during sleep with the assumption that the heart rate variability is predominantly a random process. Autonomic nervous system activity has different properties during different sleep stages, and this affects many physiological systems including the cardiovascular system. Different properties of HRV can be observed during each particular sleep stage. We believe that taking into account the sleep architecture is crucial for modeling the human nighttime HRV. The stochastic model of HRV introduced by Kantelhardt et al. was used as the initial starting point. We studied the statistical properties of sleep in healthy adults, analyzing 30 polysomnographic recordings, which provided realistic information about sleep architecture. Next, we generated synthetic hypnograms and included them in the modeling of nighttime RR interval series. The results of standard HRV linear analysis and of nonlinear analysis (Shannon entropy, Poincaré plots, and multiscale multifractal analysis) show that—in comparison with real data—the HRV signals obtained from our model have very similar properties, in particular including the multifractal characteristics at different time scales. The model described in this paper is discussed in the context of normal sleep. However, its construction is such that it should allow to model heart rate variability in sleep disorders. This possibility is briefly discussed.

  8. Variable Depth Bragg Peak Method for Single Event Effects Testing

    Science.gov (United States)

    Buchner, S.; Kanyogoro, N.; Foster, C.; O'Neill, P.

    2011-01-01

    Traditionally, accelerator SEE testing is accomplished by removing the tops of packages so that the IC chips are accessible to heavy ions. However, ICs in some advanced packages cannot be de-lidded so a different approach is used that involves grinding and/or chemically etching away part of the package and the chip from the back side. The parts are then tested from the back side with ions having sufficient range to reach the sensitive volume. More recently, the entire silicon substrate in an SOI/SRAM was removed, making it possible to use low-energy ions with shorter ranges. Where removal of part of the package is not possible, facilities at Michigan State, NASA Space Radiation Laboratory, GANIL (France) and GSI (Germany) offer high-energy heavy ions with long ranges so that the ions can reach the devices' sensitive volumes without much change in the LET. Unfortunately, a run will typically involve only one ion species having a single energy and LET due to the long time it takes to tune a new energy. The Variable Depth Bragg Peak (VDBP) method is similar to the above method in that it involves the use of high-energy heavy ions that are able to pass through the packaging material and reach the device, obviating the need to remove the package. However, the method provides a broad range of LETs from a single ion by inserting degraders in the beam that modify the ion energy and, therefore, the LET. The crux of the method involves establishing a fiduciary point for degrader thickness, i.e., where the Bragg peak is located precisely at the sensitive volume in the device, for which the measured SEU cross-section and the ion LET are both also maxima and can be calculated using a Monte-Carlo program, TRIM. Once the fiduciary point has been established, calibrated high density polyethylene (HDPE) degraders are inserted into or removed from the beam to vary the ion LET at the device in a known manner. After each change of degrader thickness, the SEU cross-section is measured

  9. Investigation of 3D effects on FEL operation

    Science.gov (United States)

    van Werkhoven, G. H. C.; Faatz, B.; Schep, T. J.

    1993-07-01

    An investigation is made of 3D effects on FEL operation by comparing the 3D simulation code TDA with a 1 {1}/{2}D model. In the latter model, the full spatial dependence of the radiation field is taken into account, whereas the electrons are treated as moving in a 1D, density-averaged ponderomotive potential. Three dimensional effects like a radial beam profile, emittance and betatron oscillations are investigated. For FELIX parameters, the 1 {1}/{2}D model is in good agreement with TDA.

  10. Correlates of team effectiveness: An exploratory study of firefighter's operations during emergency situations.

    Science.gov (United States)

    Jouanne, Elise; Charron, Camilo; Chauvin, Christine; Morel, Gaël

    2017-05-01

    This paper examines elements contributing to the effectiveness of firefighting teams carrying out typical tasks. Fourteen firefighter crews were filmed during nineteen real operations and answered questionnaires relating to psychosocial dimensions. Results have shown that "enriched closed-loops" of communication, positive emotional interactions and a "gamma" type of adaptation are positively related to team effectiveness. Conversely, open and incomplete loops of communication, negative emotional interactions, "beta" and "alpha" types of adaptation are negatively related to team effectiveness. Furthermore, there is a mediated link between organisational trust and motivation on the one hand and team effectiveness on the other. These findings highlight the necessity to consider both cognitive and psychosocial variables to account for team effectiveness in the firefighting profession. They also emphasize the need to expand firefighter training to the "non-technical" aspects of the competence.

  11. 50 CFR 260.103 - Operations and operating procedures shall be in accordance with an effective sanitation program.

    Science.gov (United States)

    2010-10-01

    ... be in accordance with an effective sanitation program. 260.103 Section 260.103 Wildlife and Fisheries... Operations and operating procedures shall be in accordance with an effective sanitation program. (a) All..., choppers, and containers which fail to meet appropriate and adequate sanitation requirements will...

  12. Health effects of airborne exposures from concentrated animal feeding operations

    DEFF Research Database (Denmark)

    Heederik, Dick; Sigsgaard, Torben; Thorne, Peter S

    2006-01-01

    effects related to low-level gas and particulate emissions. Most information comes from studies among workers in CAFO installations. Research over the last decades has shown that microbial exposures, especially endotoxin exposure, are related to deleterious respiratory health effects, of which cross......-shift lung function decline and accelerated decline over time are the most pronounced effects. Studies in naïve subjects and workers have shown respiratory inflammatory responses related to the microbial load. This working group, which was part of the Conference on Environmental Health Impacts...... of Concentrated Animal Feeding Operations: Anticipating Hazards-Searching for Solutions, concluded that there is a great need to evaluate health effects from exposures to the toxic gases, vapors, and particles emitted into the general environment by CAFOs. Research should focus not only on nuisance and odors...

  13. Effects of Adjusting for Instrumental Variables on Bias and Precision of Effect Estimates

    Science.gov (United States)

    Myers, Jessica A.; Rassen, Jeremy A.; Gagne, Joshua J.; Huybrechts, Krista F.; Schneeweiss, Sebastian; Rothman, Kenneth J.; Joffe, Marshall M.; Glynn, Robert J.

    2011-01-01

    Recent theoretical studies have shown that conditioning on an instrumental variable (IV), a variable that is associated with exposure but not associated with outcome except through exposure, can increase both bias and variance of exposure effect estimates. Although these findings have obvious implications in cases of known IVs, their meaning remains unclear in the more common scenario where investigators are uncertain whether a measured covariate meets the criteria for an IV or rather a confounder. The authors present results from two simulation studies designed to provide insight into the problem of conditioning on potential IVs in routine epidemiologic practice. The simulations explored the effects of conditioning on IVs, near-IVs (predictors of exposure that are weakly associated with outcome), and confounders on the bias and variance of a binary exposure effect estimate. The results indicate that effect estimates which are conditional on a perfect IV or near-IV may have larger bias and variance than the unconditional estimate. However, in most scenarios considered, the increases in error due to conditioning were small compared with the total estimation error. In these cases, minimizing unmeasured confounding should be the priority when selecting variables for adjustment, even at the risk of conditioning on IVs. PMID:22025356

  14. The effects of dogmatism and social class variables on consumer ethnocentrism in Malta

    OpenAIRE

    Caruana, Albert; Magri, Emanuel

    1996-01-01

    Explores the effects of dogmatism and social class variables on consumer ethnocentrism and formulates hypotheses linking these variables. Also considers the effects of a number of classificatory variables on consumer ethnocentrism. Reports the findings from a survey of consumers in Malta which show not only that dogmatism and age are positively related to consumer ethnocentrism but also that consumer ethnocentrism is lower among consumers with higher levels of education. Discusses the implica...

  15. The effects of dogmatism and social class variables on consumer ethnocentrism in Malta

    OpenAIRE

    Caruana, Albert; Magri, Emanuel

    1996-01-01

    Explores the effects of dogmatism and social class variables on consumer ethnocentrism and formulates hypotheses linking these variables. Also considers the effects of a number of classificatory variables on consumer ethnocentrism. Reports the findings from a survey of consumers in Malta which show not only that dogmatism and age are positively related to consumer ethnocentrism but also that consumer ethnocentrism is lower among consumers with higher levels of education. Discusses the implica...

  16. Effects of Operational Losses in Active Magnetic Bearing Designs.

    Directory of Open Access Journals (Sweden)

    Prince Owusu-Ansah

    2016-04-01

    Full Text Available This paper studies the effects of different forms of operational losses that are associated with active magnetic bearing designs.Active magnetic bearings are generally considered as having much lower frictional losses as compared to fluid and roller bearings, however AMBs are considered as more complex mechatronic systems, associated with various potential power loss mechanisms during it cycle of operation. Minimizing of losses consist of various measures and depends largely on the requirements of the application,among all these losses, aerodynamic losses are classified as been the more dominant in modern high speed applications and turbomachinery especially in expanders and compressors where its working gases are considered to be under very high pressures and temperaturesVarious forms of losses such as hysteresis, eddy current, iron, aerodynamic have been discussed. The methods of reducing these losses in order reduce energy losses with the ultimate goal of improving bearing efficiency haveall been discussed in this paper

  17. Majority, Minority, and Parity: Effects of Gender and Group Size on Perceived Group Variability

    Science.gov (United States)

    Voci, Alberto; Hewstone, Miles; Crisp, Richard J.; Rubin, Mark

    2008-01-01

    We investigated the effects of gender and group size on perceptions of group variability, using groups of students taking different majors that varied in the proportion of men and women (female-majority, parity, and male-majority). We found that both group size and gender had consistent effects on perceived out-group variability, even when…

  18. Effect of induced ruminal acidosis on blood variables in heifers

    Science.gov (United States)

    2013-01-01

    Background Ruminal acidosis is responsible for the onset of different pathologies in dairy and feedlot cattle, but there are major difficulties in the diagnosis. This study modelled the data obtained from various blood variables to identify those that could indicate the severity of ruminal acidosis. Six heifers were fed three experimental rations throughout three periods. The diets were characterised by different starch levels: high starch (HS), medium starch (MS) and low starch, as the control diet (CT). Ruminal pH values were continuously measured using wireless sensors and compared with pH measurements obtained by rumenocentesis. Blood samples were analysed for complete blood count, biochemical profile, venous blood gas, blood lipopolysaccharide (LPS) and LPS-binding proteins (LBP). Results The regression coefficient comparing the ruminal pH values, obtained using the two methods, was 0.56 (P = 0.040). Feeding the CT, MS and HS led to differences in the time spent below the 5.8, 5.5 and 5.0 pH thresholds and in several variables, including dry matter intake (7.7 vs. 6.9 vs. 5.1 kg/d; P = 0.002), ruminal nadir pH (5.69 vs. 5.47 vs. 5.44; P = 0.042), mean ruminal pH (6.50 vs. 6.34 vs. 6.31; P = 0.012), haemoglobin level (11.1 vs. 10.9 vs. 11.4 g/dL; P = 0.010), platelet count (506 vs. 481 vs. 601; P = 0.008), HCO3- (31.8 vs. 31.3 vs. 30.6 mmol/L; P = 0.071) and LBP (5.9 vs. 9.5 vs. 10.5 μg/mL; P acidosis, subacute ruminal acidosis and acute ruminal acidosis) using haemoglobin, mean platelet volume, β-hydroxybutyrate, glucose and reduced haemoglobin. Conclusions Although additional studies are necessary to confirm the reliability of these discriminant functions, the use of plasma variables in a multifactorial model appeared to be useful for the evaluation of ruminal acidosis severity. PMID:23647881

  19. New Calculations in Dirac Gaugino Models: Operators, Expansions, and Effects

    CERN Document Server

    Carpenter, Linda M

    2015-01-01

    In this work we calculate important one loop SUSY-breaking parameters in models with Dirac gauginos, which are implied by the existence of heavy messenger fields. We find that these SUSY-breaking effects are all related by a small number of parameters, thus the general theory is tightly predictive. In order to make the most accurate analyses of one loop effects, we introduce calculations using an expansion in SUSY breaking messenger mass, rather than relying on postulating the forms of effective operators. We use this expansion to calculate one loop contributions to gaugino masses, non-holomorphic SM adjoint masses, new A-like and B-like terms, and linear terms. We also test the Higgs potential in such models, and calculate one loop contributions to the Higgs mass in certain limits of R-symmetric models, finding a very large contribution in many regions of the $\\mu$-less MSSM, where Higgs fields couple to standard model adjoint fields.

  20. Clustering of haemostatic variables and the effect of high cashew and walnut diets on these variables in metabolic syndrome patients.

    Science.gov (United States)

    Pieters, Marlien; Oosthuizen, Welma; Jerling, Johann C; Loots, Du Toit; Mukuddem-Petersen, Janine; Hanekom, Susanna M

    2005-09-01

    We investigated the effect of a high walnut and cashew diet on haemostatic variables in people with the metabolic syndrome. Factor analysis was used to determine how the haemostatic variables cluster with other components of the metabolic syndrome and multiple regression to determine possible predictors. This randomized, control, parallel, controlled-feeding trial included 68 subjects who complied with the Third National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol criteria. After a 3-week run-in following the control diet, subjects were divided into three groups receiving either walnuts or cashews (20 energy%) or a control diet for 8 weeks. The nut intervention had no significant effect on von Willebrand factor antigen, fibrinogen, factor VII coagulant activity, plasminogen activator inhibitor 1 activity, tissue plasminogen activator activity or thrombin activatable fibrinolysis inhibitor. Statistically, fibrinogen clustered with the body-mass-correlates and acute phase response factors, and factor VII coagulant activity clustered with high-density lipoprotein cholesterol (HDL-C). Tissue plasminogen activator activity, plasminogen activator inhibitor 1 activity and von Willebrand factor antigen clustered into a separate endothelial function factor. HDL-C and markers of obesity were the strongest predictors of the haemostatic variables. We conclude that high walnut and cashew diets did not influence haemostatic factors in this group of metabolic syndrome subjects. The HDL-C increase and weight loss may be the main focus of dietary intervention for the metabolic syndrome. Furthermore, diet composition may have only limited effects if weight loss is not achieved.

  1. Attenuation of treatment effect due to measurement variability in assessment of progression-free survival.

    Science.gov (United States)

    Hong, S; Schmitt, N; Stone, A; Denne, J

    2012-01-01

    For normally distributed data analyzed with linear models, it is well known that measurement error on an independent variable leads to attenuation of the effect of the independent variable on the dependent variable. However, for time-to-event variables such as progression-free survival (PFS), the effect of the measurement variability in the underlying measurements defining the event is less well understood. We conducted a simulation study to evaluate the impact of measurement variability in tumor assessment on the treatment effect hazard ratio for PFS and on the median PFS time, for different tumor assessment frequencies. Our results show that scan measurement variability can cause attenuation of the treatment effect (i.e. the hazard ratio is closer to one) and that the extent of attenuation may be increased with more frequent scan assessments. This attenuation leads to inflation of the type II error. Therefore, scan measurement variability should be minimized as far as possible in order to reveal a treatment effect that is closest to the truth. In disease settings where the measurement variability is shown to be large, consideration may be given to inflating the sample size of the study to maintain statistical power.

  2. SYNERGIC EFFECT OF THE ACTION OF OPERATIONAL AND FINANCIAL RISK

    Directory of Open Access Journals (Sweden)

    MELANIA ELENA MICULEAC

    2014-10-01

    Full Text Available This paper allows us to understand the complex action of total risk at microeconomic level, taking into account several factors: the area in which it acts: the operating activity, generating an economic risk, and the financing activity, generating a financial risk; the nature of the observed indicators: the nature of the profit and the nature of the cash; the synergic effect of the action of operational and financial risk, resulting the total risk. We consider that the innovative value of the article resides in the suggested model of correlation between the activity volume and the capital structure, because different approaches give different results, that is why we suggest a unitary approach, a more pragmatic one of the phenomenon. Also, we established the phases observed in order to establish the global profitability threshold of an international corporation which develops activities in several sectors, through several branches. In this article we have used the method of real leverage which measures the total risk of a company by mixing the operating leverage with the financial leverage.

  3. Effects of operative treatment for muscular asthenopia caused by esophoria

    Directory of Open Access Journals (Sweden)

    Tao Zeng

    2016-05-01

    Full Text Available AIM:To observe the effects of operative treatment for muscular asthenopia caused by esophoria. METHODS:Twenty-one cases(42 eyeswith muscular asthenopia caused by esophoria were included. After examination of refraction, phoria and fusion function, all cases were given operative treatment to correct esophoria. RESULTS:At 1wk after surgery, clinical symptoms were improved evidently in all cases, such as headache, diplopia and eye swelling. After followed up for 1a, no recrudescence was found. Before surgery, at 1wk and 1a after surgery, esophoria in the distance were 20.3△±6.3△,-3.1△±1.4△,0.7△±1.6△ respectively and esophoria in the near distance were 10.5△±3.1△,-1.3△±0.6△,1.5△±0.8△ respectively. By comparison of esophoria before and after surgery in different stages separately, the differences were statistically(PP>0.05. CONCLUSION:Esophoria operation may relieve obviously muscular asthenopia caused by esophoria without changing fusion function.

  4. Operating Dedicated Data Centers - Is It Cost-Effective?

    Science.gov (United States)

    Ernst, M.; Hogue, R.; Hollowell, C.; Strecker-Kellog, W.; Wong, A.; Zaytsev, A.

    2014-06-01

    The advent of cloud computing centres such as Amazon's EC2 and Google's Computing Engine has elicited comparisons with dedicated computing clusters. Discussions on appropriate usage of cloud resources (both academic and commercial) and costs have ensued. This presentation discusses a detailed analysis of the costs of operating and maintaining the RACF (RHIC and ATLAS Computing Facility) compute cluster at Brookhaven National Lab and compares them with the cost of cloud computing resources under various usage scenarios. An extrapolation of likely future cost effectiveness of dedicated computing resources is also presented.

  5. Optimization of operating variables for production of ultra-fine talc in a stirred mill. Specific surface area investigations

    Directory of Open Access Journals (Sweden)

    Toraman Oner Yusuf

    2016-01-01

    Full Text Available Due to its properties such as chemical inertness, softness, whiteness, high thermal conductivity, low electrical conductivity and adsorption properties talc has wide industrial applications in paper, cosmetics, paints, polymer, ceramics, refractory materials and pharmaceutical. The demand for ultra-fine talc is emerging which drives the mineral industry to produce value added products. In this study, it was investigated how certain grinding parameters such as mill speed, ball filling ratio, powder filling ratio and grinding time of dry stirred mill affect grindability of talc ore (d97=127 μm. A series of laboratory experiments using a 24 full factorial design was conducted to determine the optimal operational parameters of a stirred mill in order to minimize the specific surface area. The main and interaction effects on the volume specific surface area (SV, m2.cm−3 of the ground product were evaluated using the Yates analysis. Under the optimal conditions at the stirrer speed of 600 rpm, grinding time of 20 min, sample mass of 5% and ball ratio of 70%, the resulting talc powder had larger volume specific surface area (i.e., 3.48 m2.cm−3 than the starting material (i.e., 1.84 m2.cm−3.

  6. Hysterectomy for benign conditions: Complications relative to surgical approach and other variables that lead to post-operative readmission within 90 days of surgery.

    Science.gov (United States)

    Lonky, Neal M; Mohan, Yasmina; Chiu, Vicki Y; Park, Jeanna; Kivnick, Seth; Hong, Christina; Hudson, Sharon M

    2017-08-01

    To examine variables associated with hysterectomy-related complications, relative to surgical approach and other variables, that lead to readmission within 90 days of surgery. We conducted an observational cohort study for which data were extracted from electronic health records. Data were extracted of all patients (n = 3106) who underwent hysterectomies at 10 Kaiser Permanente Southern California medical centers between June 2010 and September 2011. Patients who were pregnant or had a cancer diagnosis were excluded from the study. To identify univariate associations between examined variables and procedure type, chi-square tests for categorical variables and t-tests or analysis of variance for continuous variables were used. Generalized estimating equations methods were used to test associations between independent variables and primary outcomes of interest. Statistical significance was determined using a p-value variables associated with an increased risk for readmission included high estimated blood loss (201-300 mL and 301+ mL, relative to 0-50 mL; odds ratio = 2.28, confidence interval = 1.24-4.18 and odds ratio = 2.63, confidence interval = 1.67-4.14) and long length of stay of 3 days or more (relative to 0 days; odds ratio = 2.93, confidence interval = 1.28-6.69). Pelvic specimen weight in the 151-300 g and 501+ g ranges appeared protective (odds ratio = 0.40, confidence interval = 0.25-0.64 and odds ratio = 0.54, confidence interval = 0.33-0.90). In a sub-analysis of 1294 patients, 74 hospital operative complications directly related to hysterectomy were identified among 59 patients. The most common hospital operative complications were excessive bleeding associated with surgery or injury to nearby structures. Among the sub-sample of 1294 patients, those with hospital operative complications were more likely to experience post-operative complications that lead to readmission (odds ratio = 3

  7. Estimating the Impact of Time-Invariant Variables on FDI with Fixed Effects

    DEFF Research Database (Denmark)

    Davies, Ronald B.; Ionascu, Delia Simona; Kristjánsdóttir, Helga

    This paper applies the panel fixed effects with vector decomposition estimator to three FDI datasets to estimate the impact of time-invariant variables on FDI while including fixed effects. We find that the omission of fixed effects significantly biases several of these variables, especially those...... proxying for trade costs and culture. After including fixed effects, we find that many time-invariant variables indicate the importance of vertical FDI. We also find that by eliminating these biases, the differences across datasets largely disappear. Thus, controversies in the literature that are driven...

  8. High frequency chest compression effects heart rate variability.

    Science.gov (United States)

    Lee, Jongwon; Lee, Yong W; Warwick, Warren J

    2007-01-01

    High frequency chest compression (HFCC) supplies a sequence of air pulses through a jacket worn by a patient to remove excessive mucus for the treatment or prevention of lung disease patients. The air pulses produced from the pulse generator propagates over the thorax delivering the vibration and compression energy. A number of studies have demonstrated that the HFCC system increases the ability to clear mucus and improves lung function. Few studies have examined the change in instantaneous heart rate (iHR) and heart rate variability (HRV) during the HFCC therapy. The purpose of this study is to measure the change of HRV with four experimental protocols: (a) without HFCC, (b) during Inflated, (c)HFCC at 6Hz, and (d) HFCC at 21Hz. The nonlinearity and regularity of HRV was assessed by approximate entropy (ApEn), a method used to quantify the complexities and randomness. To compute the ApEn, we sectioned with a total of eight epochs and displayed the ApEn over the each epoch. Our results show significant differences in the both the iHR and HRV between the experimental protocols. The iHR was elevated at both the (c) 6Hz and (d) 21Hz condition from without HFCC (10%, 16%, respectively). We also found that the HFCC system tends to increase the HRV. Our study suggests that monitoring iHR and HRV are very important physiological indexes during HFCC therapy.

  9. Modeling Variable Phanerozoic Oxygen Effects on Physiology and Evolution.

    Science.gov (United States)

    Graham, Jeffrey B; Jew, Corey J; Wegner, Nicholas C

    2016-01-01

    Geochemical approximation of Earth's atmospheric O2 level over geologic time prompts hypotheses linking hyper- and hypoxic atmospheres to transformative events in the evolutionary history of the biosphere. Such correlations, however, remain problematic due to the relative imprecision of the timing and scope of oxygen change and the looseness of its overlay on the chronology of key biotic events such as radiations, evolutionary innovation, and extinctions. There are nevertheless general attributions of atmospheric oxygen concentration to key evolutionary changes among groups having a primary dependence upon oxygen diffusion for respiration. These include the occurrence of Devonian hypoxia and the accentuation of air-breathing dependence leading to the origin of vertebrate terrestriality, the occurrence of Carboniferous-Permian hyperoxia and the major radiation of early tetrapods and the origins of insect flight and gigantism, and the Mid-Late Permian oxygen decline accompanying the Permian extinction. However, because of variability between and error within different atmospheric models, there is little basis for postulating correlations outside the Late Paleozoic. Other problems arising in the correlation of paleo-oxygen with significant biological events include tendencies to ignore the role of blood pigment affinity modulation in maintaining homeostasis, the slow rates of O2 change that would have allowed for adaptation, and significant respiratory and circulatory modifications that can and do occur without changes in atmospheric oxygen. The purpose of this paper is thus to refocus thinking about basic questions central to the biological and physiological implications of O2 change over geological time.

  10. On a Class of Bias-Amplifying Variables that Endanger Effect Estimates

    CERN Document Server

    Pearl, Judea

    2012-01-01

    This note deals with a class of variables that, if conditioned on, tends to amplify confound- ing bias in the analysis of causal effects. This class, independently discovered by Bhat- tacharya and Vogt (2007) and Wooldridge (2009), includes instrumental variables and variables that have greater influence on treat- ment selection than on the outcome. We offer a simple derivation and an intuitive explana- tion of this phenomenon and then extend the analysis to non linear models. We show that: 1. the bias-amplifying potential of instru- mental variables extends over to non- linear models, though not as sweepingly as in linear models; 2. in non-linear models, conditioning on in- strumental variables may introduce new bias where none existed before; 3. in both linear and non-linear models, in- strumental variables have no effect on selection-induced bias.

  11. Thermal Effect in KTP Crystals During High Power Laser Operation

    Institute of Scientific and Technical Information of China (English)

    YAO Jian-Quan; YU Yi-Zhong; CHEN Jin; ZHANG Fan; WANG Peng; WANG Tao; ZHANG Bai-Gang

    2001-01-01

    We report on the theoretical and experimental studies of the thermal effect of the KTP crystal during high power operation. From the dependence of the refractive index temperature coefficients on wavelength, the dependence of the optimum phase-matching angles on temperature is derived. In the experiment, the angle of the frequency-doubled KTP crystal is tilted to compensate for the thermal effect and to obtain △φ = 0.7° when the green laser output power is 30 W and the KTP crystal temperature is about 80°C. We obtained the highest stable output power greater than 40 W with an L-shaped flat-flat intracavity frequency-doubled Nd:YAG laser. The experimental results are very consistent with the theoretical analysis.

  12. Scale effects on the variability of the raindrop size distribution

    Science.gov (United States)

    Raupach, Timothy; Berne, Alexis

    2016-04-01

    The raindrop size distribution (DSD) is of utmost important to the study of rainfall processes and microphysics. All important rainfall variables can be calculated as weighted moments of the DSD. Qualitative precipitation estimation (QPE) algorithms and numerical weather prediction (NWP) models both use the DSD in order to calculate quantities such as the rain rate. Often these quantities are calculated at a pixel scale: radar reflectivities, for example, are integrated over a volume, so a DSD for the volume must be calculated or assumed. We present results of a study in which we have investigated the change of support problem with respect to the DSD. We have attempted to answer the following two questions. First, if a DSD measured at point scale is used to represent an area, how much error does this introduce? Second, how representative are areal DSDs calculated by QPE and NWP algorithms of the microphysical process happening inside the pixel of interest? We simulated fields of DSDs at two representative spatial resolutions: at the 2.1x2.1 km2 resolution of a typical NWP pixel, and at the 5x5 km2 resolution of a Global Precipitation Mission (GPM) satellite-based weather radar pixel. The simulation technique uses disdrometer network data and geostatistics to simulate the non-parametric DSD at 100x100 m2 resolution, conditioned by the measured DSD values. From these simulations, areal DSD measurements were derived and compared to point measurements of the DSD. The results show that the assumption that a point represents an area introduces error that increases with areal size and drop size and decreases with integration time. Further, the results show that current areal DSD estimation algorithms are not always representative of sub-grid DSDs. Idealised simulations of areal DSDs produced representative values for rain rate and radar reflectivity, but estimations of drop concentration and characteristic drop size that were often outside the sub-grid value ranges.

  13. Variable environmental effects on a multicomponent sexually selected trait.

    Science.gov (United States)

    Cole, Gemma L; Endler, John A

    2015-04-01

    Multicomponent signals are made up of interacting elements that generate a functional signaling unit. The interactions between signal components and their effects on individual fitness are not well understood, and the effect of environment is even less so. It is usually assumed that color patterns appear the same in all light environments and that the effects of each color are additive. Using guppies, Poecilia reticulata, we investigated the effect of water color on the interactions between components of sexually selected male coloration. Through behavioral mate choice trials in four different water colors, we estimated the attractiveness of male color patterns, using multivariate fitness estimates and overall signal contrast. Our results show that females exhibit preferences that favor groups of colors rather than individual colors independently and that each environment favors different color combinations. We found that these effects are consistent with female guppies selecting entire color patterns on the basis of overall visual contrast. This suggests that both individuals and populations inhabiting different light environments will be subject to divergent, multivariate selection. Although the appearance of color patterns changes with light environment, achromatic components change little, suggesting that these could function in species recognition or other aspects of communication that must work across environments. Consequently, we predict different phylogenetic patterns between chromatic and achromatic signals within the same clades.

  14. Interdependence and Conventional and Special Operations Forces: A Decade of Tactical, Operational, and Strategic Effects

    Science.gov (United States)

    2014-05-14

    Mission, the Men, and Me: Lessons from a Former Delta Force Commander (New York: Penguin Group, 2008), 243. 28Naylor, 141. 11...operation went from planning to execution, this limited communication endangered the TF Rakkasans air assault; as the operation progressed during execution...Iraq, 2006-2008 (New York: Penguin Press HC, The, 2009), 193. 36 our top end units will

  15. Reducing the effect of damage on operational effectiveness with DINCS technology

    NARCIS (Netherlands)

    Smit, C.S.; Janssen, J.A.A.J.; Bodegraven, K.S. van; Logtmeijer, R.A.; Stanley, J.; Wildt, F.W.J. de; Annakin, B.; Doherty, G.

    2012-01-01

    The combat systems of a naval ship are essential to the operational effectiveness of the maritime unit; less obviously, this is also true for several marine systems. The operation of the combat systems, the control of (battle) damage, and the ship's mobility all depend on functions provided by a sub

  16. Reducing the effect of damage on operational effectiveness with DINCS technology

    NARCIS (Netherlands)

    Smit, C.S.; Janssen, J.A.A.J.; Bodegraven, K.S. van; Logtmeijer, R.A.; Stanley, J.; Wildt, F.W.J. de; Annakin, B.; Doherty, G.

    2012-01-01

    The combat systems of a naval ship are essential to the operational effectiveness of the maritime unit; less obviously, this is also true for several marine systems. The operation of the combat systems, the control of (battle) damage, and the ship's mobility all depend on functions provided by a

  17. Effects of Cueing and Modeling Variables in Teacher Training Systems.

    Science.gov (United States)

    Orme, Michael E. J.

    Theoretical considerations suggest that the differential effectiveness of teaching models and associated feedback procedures stems from their distinctive cueing properties. This led to the development of three treatment conditions which may be labeled "rating" (rehearsal of key discriminations), "observation" vicarious reinforcement), and "direct…

  18. Effects of Historical and Social Variables on Instruction Following

    Science.gov (United States)

    Kroger-Costa, Andreia; Abreu-Rodrigues, Josele

    2012-01-01

    The present study investigated the effect of the presence of the experimenter on behavioral sensitivity to contingency change. In history training, college students were exposed to differential reinforcement of low rate (DRL) and fixed-ratio (FR) schedules, and in testing, to a fixed-interval (FI) schedule. For the control group, instructions were…

  19. Strategies and Decision Support Systems for Integrating Variable Energy Resources in Control Centers for Reliable Grid Operations

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Lawrence E. [Alstom Grid Inc., Washington, DC (United States)

    2011-11-01

    This report provides findings from the field regarding the best ways in which to guide operational strategies, business processes and control room tools to support the integration of renewable energy into electrical grids.

  20. Strategies and Decision Support Systems for Integrating Variable Energy Resources in Control Centers for Reliable Grid Operations. Executive Summary

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Lawrence E. [Alstom Grid, Inc., Washington, DC (United States)

    2011-11-01

    This is the executive summary for a report that provides findings from the field regarding the best ways in which to guide operational strategies, business processes and control room tools to support the integration of renewable energy into electrical grids.

  1. The contribution of personal and seniority variables to the presence of stress symptoms among Israeli UAV operators.

    Science.gov (United States)

    Gal, Shiri; Shelef, Leah; Oz, Idit; Yavnai, Nirit; Carmon, Erez; Gordon, Shirley

    2016-01-01

    The exposure to war scenes via screens, despite offering a degree of detachment, can be stressful for the operator. The aim of the current study is to examine the existence of anxiety, depression, and post traumatic stress disorder (PTSD) symptoms among unmanned aerial vehicle (UAV) Israeli operators. Participants comprised 41 UAV operators (87.2% male), aged 22-38 (Mage = 26.05, SD = 3.54). Most (78.0%) reported having viewed battlefield scenes. All participants completed a total of five questionnaires: Beck Depression Inventory, State-Trait Anxiety Inventory, and three questionnaires of PTSD: Post Trauma Questionnaire (CAPS), the Post-Traumatic Cognition Inventory (CTPI), and the Post-Traumatic Symptom Scale (PSS). Mean scores of depression and anxiety were found significantly lower than diagnosis cut-off points (p UAV operators are highly beneficial for preventing psychopathology.

  2. Effect of operative conditions on a PEFC stack performance

    Energy Technology Data Exchange (ETDEWEB)

    Urbani, Francesco; Barbera, Orazio; Giacoppo, Giosue; Squadrito, Gaetano; Passalacqua, Enza [CNR-ITAE (Istituto di Tecnologie Avanzate per l' Energia ' Nicola Giordano' ), Salita S. Lucia sopra Contesse, 5-98126 Messina (Italy)

    2008-06-15

    The operative conditions influence the performance of a polymer electrolyte fuel cell (PEFC). In particular, when a multi-cell (stack) instead of a single cell is investigated, a proper water management and flow stoichiometric ratio are essential for obtaining high electrical conversion efficiency. In this paper, a five cell air cooled PEM fuel cell stack was designed and realized, and systematic studies on the influence of the reactants humidification have been carried out to optimize the operative conditions. Polarization curves and time test at a fixed current have been conducted for various cathode (RHC) and anode (RHA) inlet humidity conditions. In particular, a small decay and low performance were obtained for RHA and <70% and a considerable decay and low performance for RHA and >70%. A good compromise for water management, in terms of decay and performance, is obtained when a symmetrical RH of 70% was used, because in this case an optimal water balance was probably reached considering that high flow of gases was used. In fact, insufficient water content implies a lower ion conductivity of the membrane whereas excess of water yields to flooding of the electrodes and parasitic losses due to the presence of water in the gas channels. Consequently, these effects lead to a lowering of voltages during lifetime tests. In any case, the cathode RH has a stronger influence on the stack decay compared to the anode one. In the optimal selected conditions of RH a constant and stable power of about 55 W (at 20 A) was obtained during the 15 h of operation. (author)

  3. Effects of Operational Conditions on the Performance of Triethylamine Biofiltration

    Directory of Open Access Journals (Sweden)

    A Torkian, H Keshavarzi Shirazi, A Azimi

    2005-04-01

    Full Text Available Nitrogen compounds such as triethylamine are odorants generally found in chemical plants and foundries in which cold-box cores are made. In this study, the efficiency of biofiltration of triethylamine (TEA vapor was evaluated. Experiments were conducted in two 6-L biofilters arranged in three stages and packed with inoculated compost - wood chips (40:60v/v as the filter medium. The seed inoculum was obtained from municipal activated sludge. Tests were made to compare effects of initial temperature (30±1°C, biofilter A and (23±2 °C, biofilter B on the performance of the biofilter. TEA elimination rate pattern was evaluated by changing loading rates (6-138 gm-3h-1 and hydraulic retention times (40-60 s while operating at constant temperature and humidity at 50-55%. Results showed that organic loading rates (OLR of up to 114.4 gm-3h-1 (biofilter A and 90.56 gm-3h-1 (biofilter B could be handled without any apparent indication of maximum elimination capacity and substrate inhibition. The elimination capacity of biofilters could reach up to 72 gm-3h-1 (biofilter A and 61.5 gm-3h-1(biofilter B. When the loading of TEA exceeded the critical values, substrate inhibition occurred and the elimination capacity decreased. However, the requirement of keeping the pressure drop below 4 cm water gauge per meter of bed height to avoid operational problems warranted lower than maximum capacity operation. The optimal OLR values of 90±14 gm-3h-1 are suggested for hydraulic retention time value of 48 s and temperature of 30±1°C. Under these conditions, elimination capacity of 71±3 gm-3h-1and removal efficiency of 81±14% was achieved.

  4. Reliability and risk analysis and evaluation of a port oil pipeline transportation system in variable operation conditions

    Energy Technology Data Exchange (ETDEWEB)

    Soszynska, Joanna [Gdynia Maritime University, Gdynia (Poland)

    2009-07-01

    In the paper the semi-Markov model is applied to describe the port oil pipeline transportation system operation processes and its selected parameters are determined. Multi-state systems are considered and their reliability and risk are found. Next, the joint model of the systems' operation process and the systems' multi-state reliability is applied to the reliability and risk evaluation of the port oil pipeline transportation system. (author)

  5. The Generalized Regression Discontinuity Design: Using Multiple Assignment Variables and Cutoffs to Estimate Treatment Effects

    Science.gov (United States)

    Wong, Vivian C.; Steiner, Peter M.; Cook, Thomas D.

    2009-01-01

    This paper introduces a generalization of the regression-discontinuity design (RDD). Traditionally, RDD is considered in a two-dimensional framework, with a single assignment variable and cutoff. Treatment effects are measured at a single location along the assignment variable. However, this represents a specialized (and straight-forward)…

  6. Effectiveness of Variable Message Signs on Driving Behavior Based on a Driving Simulation Experiment

    Directory of Open Access Journals (Sweden)

    Xuedong Yan

    2014-01-01

    Full Text Available Variable message signs (VMSs, as one of the important ITS devices, provide real-time traffic information of road network to drivers in order to improve route choice and relieve the traffic congestion. In this study, the effectiveness of VMS on driving behavior was tested based on a driving simulation experiment. A road network with three levels of VMS location to route-diverging intersection and three types of VMS information format was designed in a high fidelity driving simulator platform. Fifty-two subjects who were classified by driver age, gender, and vocation successfully completed this experiment. The experimental results showed that driver characteristics, VMS location, and information format profoundly influence driving behaviors. Based on the research findings, it is suggested that VMS would be positioned between 150 m and 200 m upstream of the diverging point to balance the VMS effects on traffic safety and operation and the graphic information VMS format is better than the format with text massage only.

  7. Effect of Critical Processing Variables on Sesame Milk Quality

    Directory of Open Access Journals (Sweden)

    Ibrahim Afaneh

    2011-01-01

    Full Text Available Problem statement: In previous study sesame milk was developed. The developed milk had slightly acceptable dispersion stability and taste and there were a need to improve it. Approach: Dispersion stability and taste were improved by investigating the interaction effects of sesame seed to water ratios (10 or 12 or 14 % sesame seeds and different pasteurization treatments (65°C-30 min or 75°C-5 min or 85°C-5 min. Results: The best sesame seed concentration was 12% and the best heat treatment was 85°C -5 min. Conclusion/Recommendation: Sesame seed concentration and heat treatment of sesame milk had significant effect on sesame milk dispersion stability and sensory properties.

  8. Effects of Intervention and Team Culture on Operating Room Traffic.

    Science.gov (United States)

    Pulido, Ricardo W; Kester, Benjamin; Schwarzkopf, Ran

    How changes in the surgical team's culture can potentially reduce operating room (OR) traffic. Excessive OR traffic during surgical procedures can present a risk to the patient's safety and recovery. Data suggest that limiting the number of OR personnel during the intraoperative period can reduce excessive OR traffic. However, it is unclear whether the surgeon's verbal intervention can also successfully reduce intraoperative OR traffic. This study compares traffic rates in hip and knee arthroplasty cases against traffic rates during nonarthroplasty cases to examine the effects of verbal interventions implemented by the surgeon to reduce intraoperative traffic. The study consisted of 16 orthopedic surgeons in a noninterventional group and 1 orthopedic surgeon in the interventional group. The surgeon in the interventional group implemented verbal protocols to OR staff to limit excessive intraoperative traffic. Operating room traffic was monitored for 3 consecutive months (January-March 2015) with the use of infrared automated door counters that tracked door openings when someone entered or left the OR. A total of 50 hip and knee arthroplasties cases and 157 nonarthroplasty cases were tracked during the study period. A total of 134 hours and 4482 movements were collected for the hip and knee arthroplasty cases. A total of 498 hours and 22 902 movements were collected for the nonarthroplasty cases. Comparing the 2 groups, the interventional group averaged 33 movements per hour while the noninterventional group averaged 46 movements per hour (P traffic can be reduced through simple verbal protocols established by the surgical team.

  9. Operational stability of organic field-effect transistors.

    Science.gov (United States)

    Bobbert, Peter A; Sharma, Abhinav; Mathijssen, Simon G J; Kemerink, Martijn; de Leeuw, Dago M

    2012-03-02

    Organic field-effect transistors (OFETs) are considered in technological applications for which low cost or mechanical flexibility are crucial factors. The environmental stability of the organic semiconductors used in OFETs has improved to a level that is now sufficient for commercialization. However, serious problems remain with the stability of OFETs under operation. The causes for this have remained elusive for many years. Surface potentiometry together with theoretical modeling provide new insights into the mechanisms limiting the operational stability. These indicate that redox reactions involving water are involved in an exchange of mobile charges in the semiconductor with protons in the gate dielectric. This mechanism elucidates the established key role of water and leads in a natural way to a universal "stress function", describing the stretched exponential-like time dependence ubiquitously observed. Further study is needed to determine the generality of the mechanism and the role of other mechanisms. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Intelligent grid management with variable grid fees as indirect control system for Distribution System Operators; Intelligentes Netzlastmanagement mit variablen Netzentgelten als indirektes Steuerungsinstrument fuer Verteilnetzbetreiber

    Energy Technology Data Exchange (ETDEWEB)

    Engel, Stephan; Nestle, David; Selzam, Patrick; Strauss, Philipp [Fraunhofer Institut fuer Windenergie und Energiesystemtechnik, Kassel (Germany)

    2011-07-01

    Variable grid fees are an incentive system to motivate the grid customers to adjust their energy consumption to the requirements of the distribution grid. Therefore, the Distribution System Operator can reduce grid peak load, improve the integration of fluctuating renewable power producers and optimize the grid load prediction. Compared to variable grid fees which are just in the research stage, peak power demand prices are an existing incentive system. The comparison between these two incentive systems demonstrates which system can support more efficiently the requirements of a sustainable energy system. In E-Energy-Project ''Modellstadt Mannheim'', a proposal for a transparent calculation of variable grid fees will be developed and a technical solution deployed. (orig.)

  11. Regional variability of environmental effects of energy crop rotations

    Science.gov (United States)

    Prescher, Anne-Katrin; Peter, Christiane; Specka, Xenia; Willms, Matthias; Glemnitz, Michael

    2014-05-01

    The use of energy crops for bioenergy production is increasingly promoted by different frameworks and policies (ECCP, UNFCCC). Energy cropping decreases greenhouse gas emissions by replacing the use of fossil fuel. However, despite this, growing in monocultures energy crop rotations has low environmental benefit. It is broadly accepted consensus that sustainable energy cropping is only realizable by crop rotations which include several energy crop species. Four crop rotations consisting of species mixtures of C3, C4 and leguminous plants and their crop positions were tested to identify the environmental effect of energy cropping systems. The experimental design included four replicates per crop rotation each covering four cultivation years. The study took place at five sites across Germany covering a considerable range of soil types (loamy sand to silt loam), temperatures (7.5 ° C - 10.0 ° C) and precipitation (559 mm - 807 mm) which allow a regional comparison of crop rotation performance. Four indicators were used to characterize the environmental conditions: (1) greenhouse gas (GHG) emissions from the management actions; (2) change in humus carbon (Chum); (3) groundwater recharge (RGW) and (4) nitrogen dynamics. The indicators were derived by balance, by an empirical model and by a dynamic model, respectively, all based and calibrated on measured values. The results show that the crop rotation impact on environmental indicators varied between plant species mixtures and the crop positions, between sites and climate. Crop rotations with 100 % energy crops (including C4 plants) had negative influence on Chum, GHG emissions per area and RGW in comparison to the rotation of 50 % energy crops and 50 % cash crops, which were mainly due to the remaining straw on the field. However, the biogas yield of the latter rotation was smaller, thus GHG emissions per product were higher, pointing out the importance to distinguish between GHG emissions per product and per area

  12. The effect of pacing strategies on the variability of speech movement sequences in dysarthria.

    Science.gov (United States)

    McHenry, Monica A

    2003-06-01

    There are many potential sources of variability in speech production, particularly in individuals with dysarthria. The degree and time course of stabilization of the speech production system during recovery from a neurological insult is not constant across individuals. Another source of variability in speech production is speaking rate. Although individuals with no neurological impairments typically show increased variability at reduced speaking rates, this phenomenon has not been explored extensively in individuals with dysarthria. Because rate control strategies are commonly used in dysarthria treatment, it is of clinical importance to know if individuals with dysarthria produce less variable speech with rate reduction. Six individuals with mild dysarthria, 6 with moderate-to-severe dysarthria, and 6 matched normal controls repeated an utterance in four speaking rate conditions: habitual, fast, breaks between words, and stretched. Data were analyzed using the spatiotemporal index (STI), a composite measure of spatial and temporal variability across token repetitions. The normal controls consistently demonstrated the least variability, regardless of rate condition. Both groups with dysarthria were the least variable in the stretched condition and the most variable in the fast condition. The STI values of the group with moderate-to-severe dysarthria were significantly different from both the individuals with mild dysarthria and the normal controls. There were no significant differences between the group with mild dysarthria and the normal controls. In general, slowing the speaking rate in individuals with dysarthria reduces spatiotemporal variability; however, the effect of reduced spatiotemporal variability on intelligibility requires further investigation.

  13. Analysis of the Effects of a Flexible Ramping Ancillary Service Product on Power System Operations: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Krad, Ibrahim; Ibanez, Eduardo; Ela, Erik

    2015-10-19

    The recent increased interest in utilizing variable generation (VG) resources such as wind and solar in power systems has motivated investigations into new operating procedures. Although these resources provide desirable value to a system (e.g., no fuel costs or emissions), interconnecting them provides unique challenges. Their variable, non-controllable nature in particular requires significant attention, because it directly results in increased power system variability and uncertainty. One way to handle this is via new operating reserve schemes. Operating reserves provide upward and downward generation and ramping capacity to counteract uncertainty and variability prior to their realization. For instance, uncertainty and variability in real-time dispatch can be accounted for in the hour-ahead unit commitment. New operating reserve methodologies that specifically account for the increased variability and uncertainty caused by VG are currently being investigated and developed by academia and industry. This paper examines one method inspired by the new operating reserve product being proposed by the California Independent System Operator. The method is based on examining the potential ramping requirements at any given time and enforcing those requirements via a reserve demand curve in the market-clearing optimization as an additional ancillary service product.

  14. Ozone precursors have regionally variable effect on radiative forcing

    Science.gov (United States)

    Schultz, Colin

    2013-02-01

    When released near the surface, carbon monoxide, assorted nitrogen oxides (NOx ), and nonmethane hydrocarbons (NMHC) contribute to the production of ozone, a key component of photochemical smog, which is known to have serious deleterious effects on human health. However, when ozone gets lifted into the troposphere, it is a greenhouse gas. That these ozone precursors have such a dual-pronged effect—affecting both human health and the global radiation budget—suggests that mitigating their emissions could be a potential method to both improve air quality and dampen the rate of anthropogenic climate change.

  15. Effect of Operating Conditions on CSTR performance: an Experimental Study

    Directory of Open Access Journals (Sweden)

    Mohd Danish

    2015-02-01

    Full Text Available In this work, Saponification reaction of ethyl acetate by sodium hydroxide is studied experimentally in a continuous stirred tank reactor at 1 atmospheric pressure. The aim of this study is to investigate the influence of operating conditions on the conversion and specific rate constant. The parameters considered for analysis are temperature, feed flow rate, residence time, volume of reactor and stirrer rate. The steady state conversion of 0.45 achieved after a period of 30 minutes. Conversion decreases with increase of reactant flow rate due to decrease of residence time. The stirrer rate has a positive effect on the conversion and rate constant. Specific rate constant and conversion increase with temperature within the studied temperature range. Within the range of reactor volume selected for analysis, conversion increases with increase in reactor volume. The results obtained in this study may be helpful in maximizing the conversion of ethyl acetate saponification reaction at industrial scale in a CSTR.

  16. The Operational and Tactical Nexus: Small Steps Toward Seamless Effects-Based Operations

    Science.gov (United States)

    2006-02-01

    of early military aviation pioneers who availed themselves of time, here at Maxwell, to reflect solid research, innova- tive thought, and lucid ... dream a nearer reality. The Tactical Training/Operational Campaigning Dichotomy Another impediment to the realization of true EBO is the dichotomy...chance at lay- ing the foundations for the USAF’s EBO dream . Embracing a continuum, particularly at the tactical and operational nexus, is the key to EBO

  17. Effects of ocean thermocline variability on noncoherent underwater acoustic communications.

    Science.gov (United States)

    Siderius, Martin; Porter, Michael B; Hursky, Paul; McDonald, Vincent

    2007-04-01

    The performance of acoustic modems in the ocean is strongly affected by the ocean environment. A storm can drive up the ambient noise levels, eliminate a thermocline by wind mixing, and whip up violent waves and thereby break up the acoustic mirror formed by the ocean surface. The combined effects of these and other processes on modem performance are not well understood. The authors have been conducting experiments to study these environmental effects on various modulation schemes. Here the focus is on the role of the thermocline on a widely used modulation scheme (frequency-shift keying). Using data from a recent experiment conducted in 100-m-deep water off the coast of Kauai, HI, frequency-shift-key modulation performance is shown to be strongly affected by diurnal cycles in the thermocline. There is dramatic variation in performance (measured by bit error rates) between receivers in the surface duct and receivers in the thermocline. To interpret the performance variations in a quantitative way, a precise metric is introduced based on a signal-to-interference-noise ratio that encompasses both the ambient noise and intersymbol interference. Further, it will be shown that differences in the fading statistics for receivers in and out of the thermocline explain the differences in modem performance.

  18. New calculations in Dirac gaugino models: operators, expansions, and effects

    Science.gov (United States)

    Carpenter, Linda M.; Goodman, Jessica

    2015-07-01

    In this work we calculate important one loop SUSY-breaking parameters in models with Dirac gauginos, which are implied by the existence of heavy messenger fields. We find that these SUSY-breaking effects are all related by a small number of parameters, thus the general theory is tightly predictive. In order to make the most accurate analyses of one loop effects, we introduce calculations using an expansion in SUSY breaking messenger mass, rather than relying on postulating the forms of effective operators. We use this expansion to calculate one loop contributions to gaugino masses, non-holomorphic SM adjoint masses, new A-like and B-like terms, and linear terms. We also test the Higgs potential in such models, and calculate one loop contributions to the Higgs mass in certain limits of R-symmetric models, finding a very large contribution in many regions of the [InlineMediaObject not available: see fulltext.], where Higgs fields couple to standard model adjoint fields.

  19. The effects of clumping on wind line variability

    CERN Document Server

    Massa, D; Fullerton, A W

    2007-01-01

    We review the effects of clumping on the profiles of resonance doublets. By allowing the ratio of the doublet oscillator strenghts to be a free parameter, we demonstrate that doublet profiles contain more information than is normally utilized. In clumped (or porous) winds, this ratio can lies between unity and the ratio of the f-values, and can change as a function of velocity and time, depending on the fraction of the stellar disk that is covered by material moving at a particular velocity at a given moment. Using these insights, we present the results of SEI modeling of a sample of B supergiants, zeta Pup and a time series for a star whose terminal velocity is low enough to make the components of its Si IV 1400 doublet independent. These results are interpreted within the framework of the Oskinova et al. (2007) model, and demonstrate how the doublet profiles can be used to extract information about wind structure.

  20. Biofeedback on heart rate variability in cardiac rehabilitation: practical feasibility and psycho-physiological effects

    National Research Council Canada - National Science Library

    Climov, Daniela; Lysy, Camille; Berteau, Sylvain; Dutrannois, Jacques; Dereppe, Hubert; Brohet, Christian; Melin, Jacques

    2014-01-01

    .... It has been applied to patients with various cardiovascular disorders. The purpose of this study was to investigate the practical feasibility and the psychophysiological effects of biofeedback applied to heart rate variability (HRV biofeedback...

  1. Sputtering by the Solar Wind: Effects of Variable Composition

    Science.gov (United States)

    Killen, R. M.; Arrell, W. M.; Sarantos, M.; Delory, G. T.

    2011-01-01

    It has long been recognized that solar wind bombardment onto exposed surfaces in the solar system will produce an energetic component to the exospheres about those bodies. Laboratory experiments have shown that there is no increase in the sputtering yield caused by highly charged heavy ions for metallic and for semiconducting surfaces, but the sputter yield can be noticeably increased in the case of a good insulating surface. Recently measurements of the solar wind composition have become available. It is now known that the solar wind composition is highly dependent on the origin of the particular plasma. Using the measured composition of the slow wind, fast wind, solar energetic particle (SEP) population, and coronal mass ejection (CME), broken down into its various components, we have estimated the total sputter yield for each type of solar wind. Whereas many previous calculations of sputtering were limited to the effects of proton bombardment. we show that the heavy ion component. especially the He++ component. can greatly enhance the total sputter yield during times when the heavy ion population is enhanced. We will discuss sputtering of both neutrals and ions.

  2. Health Effects of Operators in the Production of Wood Pellets

    Energy Technology Data Exchange (ETDEWEB)

    Hagstroem, K.; Arvidsson, H.; Bryngelsson, I.L.; Fedeli, C. [Oerebro Univ. (Sweden). Dept. of Occupational and Environmental Medicine; Eriksson, K. [Univ. Hospital of Umeaa (Sweden). Dept. of Occupational and Environmental Medicine; Andersson, E. [Sahlgrenska Univ. Hospital, Goeteborg (Sweden). Dept. of Occupational and Environmental Medicine

    2006-07-15

    The environmental and energy policy in Sweden is aiming to replace fossil energy with renewable sources such as biofuels, e.g., wood Pellets produced from shavings and sawdust of pine and spruce. Reported health effects in the wood processing industries are airway, eye and skin irritation, reduced lung function as well as eczema. The aim of our study was to investigate the prevalence of airway and skin symptoms and measure lung function in a population of pellet operators in the Swedish wood industry. Additional reported acute effects from the airways, eyes, nose and skin were recorded. From May 2004 until April 2005 50 blue-collar workers from four Swedish pellet-producing industries were investigated. The study included a questionnaire about skin and airway symptoms (n=50), acute effect questionnaire (n=67; 44 individuals) as well as a test of the lung function (spirometry) before and after work shift (n=118; 39 individuals). Acute effects questionnaire and spirometry were done one to three times per participants and for the acute effects the worker had to assess their symptoms in the airways, eyes, nose and skin between 6 and 8 times during a day. The results from the symptom questionnaires were compared with reference data from other Swedish studies and the lung function data with a European reference material. Statistical tests used were chi-2-test for the questionnaire, t-test for lung function before shift compared expected values, and for difference in lung function between before and after work shift mixed models with subjects as a random factor. No statistical significant difference was seen for the skin and airway symptoms in the questionnaire. Reported acute effects were seen especially for eye and nose symptoms (table 1). Spirometry showed significantly higher forced vital capacity (FVC; p=0.0003) and no difference in forced expiratory volume in 1 second (FEV1; p=0.08) before work shift compared to expected values. FVC was 108,1 % and FEV1 was 104

  3. The effects of auditory stimulation with music on heart rate variability in healthy women

    OpenAIRE

    Roque, Adriano L. [UNESP; Valenti, Vitor E.; Guida, Heraldo L; Campos, Mônica F.; André Knap; Vanderlei, Luiz Carlos M. [UNESP; Ferreira, Lucas L.; Celso Ferreira; Luiz Carlos de Abreu

    2013-01-01

    OBJECTIVES: There are no data in the literature with regard to the acute effects of different styles of music on the geometric indices of heart rate variability. In this study, we evaluated the acute effects of relaxant baroque and excitatory heavy metal music on the geometric indices of heart rate variability in women. METHODS: We conducted this study in 21 healthy women ranging in age from 18 to 35 years. We excluded persons with previous experience with musical ins...

  4. Influence of curve magnitude and other variables on operative time, blood loss and transfusion requirements in adolescent idiopathic scoliosis.

    LENUS (Irish Health Repository)

    Nugent, M

    2015-05-03

    Posterior spinal instrumentation and fusion for correction of adolescent idiopathic scoliosis (AIS) typically requires lengthy operating time and may be associated with significant blood loss and subsequent transfusion. This study aimed to identify factors predictive of duration of surgery, intraoperative blood loss and transfusion requirements in an Irish AIS cohort.

  5. Development and validation of the control variable transformation operators using the cubed-sphere grid system to represent a background error covariance

    Science.gov (United States)

    Kwun, Jihye; Song, Hyo-Jong; Ha, Ji-Hyun

    2014-05-01

    A background error covariance matrix is essential in a data assimilation system in terms of its spreading out dynamically balanced increments to the horizontal model grid points and the vertical levels. The full representation of the matrix is impossible because of its huge size, the matrix is therefore constructed implicitly by means of a control variable transformation. It is assumed that the forecast errors in the control variables are statistically independent. We utilized two approaches to dividing the unbalanced and the balanced parts; a method is using balance operators derived based on numerical discretization of partial differential equations, and the other is a regression-based approach. We used the spectral element method accompanying the cubed-sphere grid system, which guarantees a scalable performance in the configuration of using multiple CPUs. To model the background error covariance matrix, horizontal wind was decomposed into a rotational component and a divergent component by introducing stream function and velocity potential as control variables. The dynamical constraint of a balance between mass and wind was imposed by applying the linear balance operator and the nonlinear balance operator including cyclonic wind terms. The unbalanced velocity potential and the unbalanced mass variable is defined by using regression coefficients. The experimental background error statistics has been calculated by exploiting the ensemble samples of the Community Atmosphere Model (CAM) - Local Ensemble Transform Kalman Filter (LETKF). In order to understand the structure of the background error covariance, we performed single observation experiments using a three-dimensional variational data assimilation system on the cubed-sphere grid with the spectral transformation that was developed by Korea Institute of Atmospheric Prediction Systems(KIAPS) of which results will be presented.

  6. Effect Analysis of Design Variables on the Disc in a Double-Eccentric Butterfly Valve

    Directory of Open Access Journals (Sweden)

    Sangmo Kang

    2014-01-01

    Full Text Available We have performed a shape optimization of the disc in an industrial double-eccentric butterfly valve using the effect analysis of design variables to enhance the valve performance. For the optimization, we select three performance quantities such as pressure drop, maximum stress, and mass (weight as the responses and three dimensions regarding the disc shape as the design variables. Subsequently, we compose a layout of orthogonal array (L16 by performing numerical simulations on the flow and structure using a commercial package, ANSYS v13.0, and then make an effect analysis of the design variables on the responses using the design of experiments. Finally, we formulate a multiobjective function consisting of the three responses and then propose an optimal combination of the design variables to maximize the valve performance. Simulation results show that the disc thickness makes the most significant effect on the performance and the optimal design provides better performance than the initial design.

  7. Effect analysis of design variables on the disc in a double-eccentric butterfly valve.

    Science.gov (United States)

    Kang, Sangmo; Kim, Da-Eun; Kim, Kuk-Kyeom; Kim, Jun-Oh

    2014-01-01

    We have performed a shape optimization of the disc in an industrial double-eccentric butterfly valve using the effect analysis of design variables to enhance the valve performance. For the optimization, we select three performance quantities such as pressure drop, maximum stress, and mass (weight) as the responses and three dimensions regarding the disc shape as the design variables. Subsequently, we compose a layout of orthogonal array (L16) by performing numerical simulations on the flow and structure using a commercial package, ANSYS v13.0, and then make an effect analysis of the design variables on the responses using the design of experiments. Finally, we formulate a multiobjective function consisting of the three responses and then propose an optimal combination of the design variables to maximize the valve performance. Simulation results show that the disc thickness makes the most significant effect on the performance and the optimal design provides better performance than the initial design.

  8. The effect of variability in body segment parameters on joint moment using Monte Carlo simulations.

    Science.gov (United States)

    Nguyen, Tam C; Reynolds, Karen J

    2014-01-01

    This study used Monte Carlo methods to simulate the effects of variability and uncertainty in inertial body segment parameters (BSPs) on joint torques calculated using inverse dynamics. The average and standard deviation values of BSPs from previously published studies were used as inputs into the Monte Carlo simulation. Data from five groups were evaluated: cadaveric subjects; living subjects (Caucasian only); female living subjects (Caucasian only); male living subjects (Caucasian only); and living subjects (non-Caucasian). The differences in BSPs observed between the different groups were statistically significant; however, using BSP variability data from these groups made little difference to the calculated joint torques. This suggests that for slow and repeatable movement such as walking, BSPs have little effect on joint moments, except for the swing phase. Even then, the magnitude of difference in the swing phase due to variability in BSPs is not much greater than the inter-trial variability. As expected, distal BSPs have little effect on proximal joint moment.

  9. Revealing local variability properties of human heartbeat intervals with the local effective Hölder exponent

    NARCIS (Netherlands)

    Struzik, Z.R.

    2000-01-01

    The local effective H'older exponent has been applied to evaluate the variability of heart rate locally at an arbitrary position (time) and resolution (scale). The local effective H'older exponent [8, 9] used is effectively insensitive to local polynomial trends in heartbeat rate due to the use of t

  10. Revealing Local Variablity Properties of Human Heartbeat Intervals with the Local Effective Hölder Exponent

    NARCIS (Netherlands)

    Struzik, Z.R.

    2001-01-01

    The local effective Holder exponent has been applied to evaluate the variability of heart rate locally at an arbitrary position (time) and resolution (scale). The local effective Holder exponent [1,2] used is effectively insensitive to local polynomial trends in heartbeat rate due to the use of the

  11. ESTIMACIÓN DE VARIABLES DE OPERACIÓN DE UN BIORREACTOR CON CÉLULAS DE Azadirachta indica A. Juss ESTIMATION OF OPERATION VARIABLES OF A BIOREACTOR WITH Azadirachta indica A. Juss. CELLS

    Directory of Open Access Journals (Sweden)

    Walter Muñoz Cruz

    2006-12-01

    Full Text Available Se estudiaron las variables de operación de un biorreactor de tanque agitado para el cultivo de células en suspensión de Azadirachta indica A. Juss. Se utilizó carboximetilcelulosa, CMC 0,7 % p/v, para estimar el coeficiente de transferencia de oxígeno, kLa, entre 120 - 400 rpm y entre 0,05 - 0,6 vvm, obteniéndose valores de 0,5 - 8,0 h-1. El kLa para suspensiones de A. indica en erlenmeyers fue de 0,6 - 1,2 h-1. Con los resultados anteriores se definieron las condiciones de operación del biorreactor y se evaluó el crecimiento de células de A. indica a 200 rpm y 0,2 vvm de aire, alcanzando 9,2 g cel secas/l. El crecimiento celular no fue limitado por el suministro de oxígeno. Los tamaños de aglomerados celulares cultivados en erlenmeyers con bafles agitados magnéticamente y en biorreactor fueron similares, pero menores que los obtenidos en erlemeyers con agitación orbital. El presente estudio establece parámetros para la operación de biorreactores con A. indica y confirma que los medios con CMC pueden utilizarse para estimar variables operacionales en biorreactores.Operation variables of a stirred tank bioreactor were studied in order to culture cell suspension of Azadirachta indica A. Juss Carboximethylcelulose, CMC 0,7 % w/v, was used to estimate the coefficient of oxygen transfer, kLa, between 120 - 400 rpm and 0,05 - 0,6 vvm, obtaining values of 0,5 - 8,0 h-1. The kLa for suspension cultures of A. indica in erlenmeyers was 0,6 - 1,2 h-1. Based upon the previous results, the operation conditions of the bioreactor were defined and cell growth of A. indica was evaluated at 200 rpm and 0,2 vvm of air, reaching 9,2 g dry cell/l. Celular growth was not limited by dissolved oxygen. The sizes of cell agglomerates magnetically stirred in erlemeyers with bafles and in the bioreactor were similar, but smaller that those obtained in erlenmeyers with orbital agitation. The present study establishes parameters for operation of bioreactors

  12. Significance of Radiological Variables Studied on Orthopantamogram to Pridict Post-Operative Inferior Alveoler Nerve Paresthesia After Third Molar Extraction

    OpenAIRE

    Pathak, Sachin; Mishra, Nitin; Rastogi, Madhur Kant; Sharma, Shalini

    2014-01-01

    Context: Removal of impacted third molar is a procedure that is often associated with post-operative complications. The rate of complications is somewhat high because of its proximity to the vital structures. Inferior alveolar nerve paresthesia is one of the common complications of impacted their molar surgery. This is due to intimate relationship between roots of mandibular third molar and inferior alveolar canal. To access the proximity of inferior alveolar canal to third molar many diagnos...

  13. Standardization of Operator-Dependent Variables Affecting Precision and Accuracy of the Disk Diffusion Method for Antibiotic Susceptibility Testing.

    Science.gov (United States)

    Hombach, Michael; Maurer, Florian P; Pfiffner, Tamara; Böttger, Erik C; Furrer, Reinhard

    2015-12-01

    Parameters like zone reading, inoculum density, and plate streaking influence the precision and accuracy of disk diffusion antibiotic susceptibility testing (AST). While improved reading precision has been demonstrated using automated imaging systems, standardization of the inoculum and of plate streaking have not been systematically investigated yet. This study analyzed whether photometrically controlled inoculum preparation and/or automated inoculation could further improve the standardization of disk diffusion. Suspensions of Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 29213 of 0.5 McFarland standard were prepared by 10 operators using both visual comparison to turbidity standards and a Densichek photometer (bioMérieux), and the resulting CFU counts were determined. Furthermore, eight experienced operators each inoculated 10 Mueller-Hinton agar plates using a single 0.5 McFarland standard bacterial suspension of E. coli ATCC 25922 using regular cotton swabs, dry flocked swabs (Copan, Brescia, Italy), or an automated streaking device (BD-Kiestra, Drachten, Netherlands). The mean CFU counts obtained from 0.5 McFarland standard E. coli ATCC 25922 suspensions were significantly different for suspensions prepared by eye and by Densichek (P counts that were closer to the CLSI/EUCAST target of 10(8) CFU/ml than those resulting from Densichek preparation. No significant differences in the standard deviations of the CFU counts were observed. The interoperator differences in standard deviations when dry flocked swabs were used decreased significantly compared to the differences when regular cotton swabs were used, whereas the mean of the standard deviations of all operators together was not significantly altered. In contrast, automated streaking significantly reduced both interoperator differences, i.e., the individual standard deviations, compared to the standard deviations for the manual method, and the mean of the standard deviations of all operators

  14. Determining effective forecast horizons for multi-purpose reservoirs with short- and long-term operating objectives

    Science.gov (United States)

    Luchner, Jakob; Anghileri, Daniela; Castelletti, Andrea

    2017-04-01

    Real-time control of multi-purpose reservoirs can benefit significantly from hydro-meteorological forecast products. Because of their reliability, the most used forecasts range on time scales from hours to few days and are suitable for short-term operation targets such as flood control. In recent years, hydro-meteorological forecasts have become more accurate and reliable on longer time scales, which are more relevant to long-term reservoir operation targets such as water supply. While the forecast quality of such products has been studied extensively, the forecast value, i.e. the operational effectiveness of using forecasts to support water management, has been only relatively explored. It is comparatively easy to identify the most effective forecasting information needed to design reservoir operation rules for flood control but it is not straightforward to identify which forecast variable and lead time is needed to define effective hedging rules for operational targets with slow dynamics such as water supply. The task is even more complex when multiple targets, with diverse slow and fast dynamics, are considered at the same time. In these cases, the relative importance of different pieces of information, e.g. magnitude and timing of peak flow rate and accumulated inflow on different time lags, may vary depending on the season or the hydrological conditions. In this work, we analyze the relationship between operational forecast value and streamflow forecast horizon for different multi-purpose reservoir trade-offs. We use the Information Selection and Assessment (ISA) framework to identify the most effective forecast variables and horizons for informing multi-objective reservoir operation over short- and long-term temporal scales. The ISA framework is an automatic iterative procedure to discriminate the information with the highest potential to improve multi-objective reservoir operating performance. Forecast variables and horizons are selected using a feature

  15. Identification of the minimum effective dose for normally distributed data using a Bayesian variable selection approach.

    Science.gov (United States)

    Otava, Martin; Shkedy, Ziv; Hothorn, Ludwig A; Talloen, Willem; Gerhard, Daniel; Kasim, Adetayo

    2017-02-16

    The identification of the minimum effective dose is of high importance in the drug development process. In early stage screening experiments, establishing the minimum effective dose can be translated into a model selection based on information criteria. The presented alternative, Bayesian variable selection approach, allows for selection of the minimum effective dose, while taking into account model uncertainty. The performance of Bayesian variable selection is compared with the generalized order restricted information criterion on two dose-response experiments and through the simulations study. Which method has performed better depends on the complexity of the underlying model and the effect size relative to noise.

  16. Launch and Landing Effects Ground Operations (LLEGO) Model

    Science.gov (United States)

    2008-01-01

    LLEGO is a model for understanding recurring launch and landing operations costs at Kennedy Space Center for human space flight. Launch and landing operations are often referred to as ground processing, or ground operations. Currently, this function is specific to the ground operations for the Space Shuttle Space Transportation System within the Space Shuttle Program. The Constellation system to follow the Space Shuttle consists of the crewed Orion spacecraft atop an Ares I launch vehicle and the uncrewed Ares V cargo launch vehicle. The Constellation flight and ground systems build upon many elements of the existing Shuttle flight and ground hardware, as well as upon existing organizations and processes. In turn, the LLEGO model builds upon past ground operations research, modeling, data, and experience in estimating for future programs. Rather than to simply provide estimates, the LLEGO model s main purpose is to improve expenses by relating complex relationships among functions (ground operations contractor, subcontractors, civil service technical, center management, operations, etc.) to tangible drivers. Drivers include flight system complexity and reliability, as well as operations and supply chain management processes and technology. Together these factors define the operability and potential improvements for any future system, from the most direct to the least direct expenses.

  17. Effective representations of the space of linear bounded operators

    Directory of Open Access Journals (Sweden)

    Vasco Brattka

    2003-04-01

    Full Text Available Representations of topological spaces by infinite sequences of symbols are used in computable analysis to describe computations in topological spaces with the help of Turing machines. From the computer science point of view such representations can be considered as data structures of topological spaces. Formally, a representation of a topological space is a surjective mapping from Cantor space onto the corresponding space. Typically, one is interested in admissible, i.e. topologically well-behaved representations which are continuous and characterized by a certain maximality condition. We discuss a number of representations of the space of linear bounded operators on a Banach space. Since the operator norm topology of the operator space is nonseparable in typical cases, the operator space cannot be represented admissibly with respect to this topology. However, other topologies, like the compact open topology and the Fell topology (on the operator graph give rise to a number of promising representations of operator spaces which can partially replace the operator norm topology. These representations reflect the information which is included in certain data structures for operators, such as programs or enumerations of graphs. We investigate the sublattice of these representations with respect to continuous and computable reducibility. Certain additional conditions, such as finite dimensionality, let some classes of representations collapse, and thus, change the corresponding graph. Altogether, a precise picture of possible data structures for operator spaces and their mutual relation can be drawn.

  18. Cell separator operation within temperature ranges to minimize effects on Chinese hamster ovary cell perfusion culture.

    Science.gov (United States)

    Drouin, Hans; Ritter, Joachim B; Gorenflo, Volker M; Bowen, Bruce D; Piret, James M

    2007-01-01

    A cell retention device that provides reliable high-separation efficiency with minimal negative effects on the cell culture is essential for robust perfusion culture processes. External separation devices generally expose cells to periodic variations in temperature, most commonly temperatures below 37 degrees C, while the cells are outside the bioreactor. To examine this phenomenon, aliquots of approximately 5% of a CHO cell culture were exposed to 60 s cyclic variations of temperature simulating an acoustic separator environment. It was found that, for average exposure temperatures between 31.5 and 38.5 degrees C, there were no significant impacts on the rates of growth, glucose consumption, or t-PA production, defining an acceptable range of operating temperatures. These results were subsequently confirmed in perfusion culture experiments for average exposure temperatures between 31.6 and 38.1 degrees C. A 2(5-1) central composite factorial design experiment was then performed to systematically evaluate the effects of different operating variables on the inlet and outlet temperatures of a 10L acoustic separator. The power input, ambient temperature, as well as the perfusion and recycle flow rates significantly influenced the temperature, while the cell concentration did not. An empirical model was developed that predicted the temperature changes between the inlet and the outlet of the acoustic separator within +/-0.5 degrees C. A series of perfusion experiments determined the ranges of the significant operational settings that maintained the acoustic separator inlet and outlet temperatures within the acceptable range. For example, these objectives were always met by using the manufacturer-recommended operational settings as long as the recirculation flow rate was maintained above 15 L day(-1) and the ambient temperature was near 22 degrees C.

  19. Pre-operative variables affecting final vision outcome with a critical review of ocular trauma classification for posterior open globe (zone III) injury

    Science.gov (United States)

    Agrawal, Rupesh; Ho, Sue Wei; Teoh, Stephen

    2013-01-01

    Purpose: To identify pre-operative variables affecting the outcome of posterior open globe (zone III) injuries. Secondary objective was to re-look at the definition or landmarks for zone III injury and its clinical significance for predicting visual prognosis following open globe injury. Materials and Methods: Retrospective review of medical records of all hospitalized patients with surgical repair of open globe injury over last 10 years at a tertiary referral eye care center in Singapore. Out of 172 eyes with open globe injury, 28 eyes (16.3%) with zone III injury was identified and reviewed further. Pre-operative visual acuity (VA) and other variables, extent of scleral wound in reference to rectus insertion, relative afferent pupillary defect (RAPD) and final vision outcome were recorded. Results: Median age was 37 years with male predilection (92.9%). Mean follow-up was 12.9 months. Pre-operative VA was no light perception (NLP) in 16 (57.1%) eyes. Final VA remained NLP in 14 eyes (50.0%). The factors contributing to poor post-operative vision based on univariate regression analysis were the presence of RAPD, poor pre-operative VA, blunt trauma, extent of trauma, associated traumatic cataract, hyphema, vitreous loss and associated vitreo-retinal trauma. Further on, zone III injuries with scleral wound limited anterior to rectus insertion (6 eyes) had better vision outcome than those with injuries extending beyond rectus insertion (22 eyes). Conclusion: Initial VA, blunt ocular trauma, visual axis involvement, loss of light perception, presence of RAPD, traumatic cataract, hyphema, vitreous loss were the important determinants for final visual outcome in patients with zone III injury. Wound extending posterior to rectus insertion has poorer outcome as those limited anterior to rectus insertion. We suggest that there may be a need to relook at zone III injuries with reference to rectus insertion for prognostic significance, and further studies are warranted. PMID

  20. Application of response surface methodology and central composite rotatable design for modeling the influence of some operating variables of a Multi-Gravity Separator for coal cleaning

    Energy Technology Data Exchange (ETDEWEB)

    N. Aslan [Cumhuriyet University, Sivas (Turkey). Mining Engineering Department

    2007-03-15

    In this study, the application of response surface methodology (RSM) and central composite rotatable design (CCRD) for modeling the influence of some operating variables on the performance of a Multi-Gravity Separator (MGS) for coal cleaning was discussed. Four operating variables of MGS, namely drum speed, tilt angle, wash water and feed solids were changed during the tests based on the CCRD. In order to produce clean coal with MGS, mathematical model equations were derived by computer simulation programming applying least squares method using MATLAB 7.1. These equations that are second-order response functions representing ash content and combustible recovery of clean coal were expressed as functions of four operating parameters of MGS. Predicted values were found to be in good agreement with experimental values (R{sup 2} values of 0.84 and 0.93 for ash content and combustible recovery of clean coal, respectively). This study has shown that the CCRD and RSM could efficiently be applied for the modeling of MGS for coal and it is economical way of obtaining the maximum amount of information in a short period of time and with the fewest number of experiments. 12 refs., 5 figs., 4 tabs.

  1. Effects of Geopotential and Atmospheric Drag Effects on Frozen Orbits Using Nonsingular Variables

    Directory of Open Access Journals (Sweden)

    Paula Cristiane Pinto Mesquita Pardal

    2014-01-01

    Full Text Available The concept of frozen orbit has been applied in space missions mainly for orbital tracking and control purposes. This type of orbit is important for orbit design because it is characterized by keeping the argument of perigee and eccentricity constant on average, so that, for a given latitude, the satellite always passes at the same altitude, benefiting the users through this regularity. Here, the system of nonlinear differential equations describing the motion is studied, and the effects of geopotential and atmospheric drag perturbations on frozen orbits are taken into account. Explicit analytical expressions for secular and long period perturbations terms are obtained for the eccentricity and the argument of perigee. The classical equations of Brouwer and Brouwer and Hori theories are used. Nonsingular variables approach is used, which allows obtaining more precise previsions for CBERS (China Brazil Earth Resources Satellite satellites family and similar satellites (SPOT, Landsat, ERS, and IRS orbital evolution.

  2. One-loop potential with scale invariance and effective operators

    CERN Document Server

    Ghilencea, D M

    2016-01-01

    We study quantum corrections to the scalar potential in classically scale invariant theories, using a manifestly scale invariant regularization. To this purpose, the subtraction scale $\\mu$ of the dimensional regularization is generated after spontaneous scale symmetry breaking, from a subtraction function of the fields, $\\mu(\\phi,\\sigma)$. This function is then uniquely determined from general principles showing that it depends on the dilaton only, with $\\mu(\\sigma)\\sim \\sigma$. The result is a scale invariant one-loop potential $U$ for a higgs field $\\phi$ and dilaton $\\sigma$ that contains an additional {\\it finite} quantum correction $\\Delta U(\\phi,\\sigma)$, beyond the Coleman Weinberg term. $\\Delta U$ contains new, non-polynomial effective operators like $\\phi^6/\\sigma^2$ whose quantum origin is explained. A flat direction is maintained at the quantum level, the model has vanishing vacuum energy and the one-loop correction to the mass of $\\phi$ remains small without tuning (of its self-coupling, etc) bey...

  3. Effect of sampling variation on error of rainfall variables measured by optical disdrometer

    Science.gov (United States)

    Liu, X. C.; Gao, T. C.; Liu, L.

    2012-12-01

    During the sampling process of precipitation particles by optical disdrometers, the randomness of particles and sampling variability has great impact on the accuracy of precipitation variables. Based on a marked point model of raindrop size distribution, the effect of sampling variation on drop size distribution and velocity distribution measurement using optical disdrometers are analyzed by Monte Carlo simulation. The results show that the samples number, rain rate, drop size distribution, and sampling size have different influences on the accuracy of rainfall variables. The relative errors of rainfall variables caused by sampling variation in a descending order as: water concentration, mean diameter, mass weighed mean diameter, mean volume diameter, radar reflectivity factor, and number density, which are independent with samples number basically; the relative error of rain variables are positively correlated with the margin probability, which is also positively correlated with the rain rate and the mean diameter of raindrops; the sampling size is one of the main factors that influence the margin probability, with the decreasing of sampling area, especially the decreasing of short side of sample size, the probability of margin raindrops is getting greater, hence the error of rain variables are getting greater, and the variables of median size raindrops have the maximum error. To ensure the relative error of rainfall variables measured by optical disdrometer less than 1%, the width of light beam should be at least 40 mm.

  4. Effect of integral yoga on psychological and health variables and their correlations.

    Science.gov (United States)

    Khemka, Sushil S; Ramarao, Nagendra Hongasandra; Hankey, Alex

    2011-07-01

    Certain psychological and health variables are commonly measured in India. This study evaluates the effects of integral yoga practices on these variables and also the consistency of correlations observed between them. The study was a pre-post intervention study. The variables were measured at the beginning and the end of a one-month yoga course. There was no control group.The study was carried out at Swami Vivekananda Yoga Anusandhana Samsthana (S-VYASA) University, in its rural campus south of Bangalore. Based on health criteria, 108 subjects were selected out of 198 volunteers to form the experimental yoga group. Ages ranged from 17 to 63 years. The yogasanas (postures), pranayama (breathing exercises), relaxation techniques, meditation, chanting and lectures were the components of yoga intervention. The variables measured were sustained attention, emotional intelligence - EQ, general health - GHQ, guna personality - sattva, rajas and tamas. Significant pre-post changes were found in all variables. Significant correlations were found between the following pairs: The two sustained attention variables; emotional intelligence and general health; GHQ and tamas; sattva and tamas; and rajas and tamas. The study shows that there were significant changes in all variables (PEQ and general health variables correlate significantly with each other and negatively with tamas. EQ and tamas form positive and negative predictors of health respectively. Sattva correlates positively with EQ suggesting that a sattvic personality indicates better self-control. This suggests that, by improving guna personality, long-term yoga practice may stabilize EQ.

  5. The effect of continuous positive airway pressure on metabolic variables in patients with obstructive sleep apnoea.

    Science.gov (United States)

    Schlatzer, Christian; Schwarz, Esther I; Kohler, Malcolm

    2014-02-01

    Obstructive sleep apnoea (OSA) is increasingly considered as a risk factor for metabolic disturbances, such as diabetes mellitus or dyslipidaemia. Continuous positive airway pressure (CPAP) therapy, the standard treatment for patients with OSA, may improve various metabolic variables, such as insulin sensitivity, glucose metabolism, lipids, fat distribution and adipokines. Several observational and uncontrolled clinical studies claim an improvement of these metabolic variables through the use of CPAP. However, there is only a limited number of clinical randomised controlled trials (RCTs) evaluating the effect of CPAP on metabolic variables. In this review, we summarise and discuss non-randomised studies and RCTs evaluating the effect of CPAP on metabolic variables in patients with OSA. In summary, the currently available body of evidence does not support a clinically important effect of CPAP treatment on any of the investigated metabolic variables. However, some investigators found small, but statistically significant changes in some metabolic variables, thus beneficial effects of CPAP treatment in selected patient cohorts cannot be excluded. To answer this question, more data from RCTs with well-defined study populations are warranted.

  6. Contribution to the electrothermal simulation in power electronics. Development of a simulation methodology applied to switching circuits under variable operating conditions; Contribution a la simulation electrothermique en electronique de puissance. Developpement d`une methode de simulation pour circuits de commutation soumis a des commandes variables

    Energy Technology Data Exchange (ETDEWEB)

    Vales, P.

    1997-03-19

    In modern hybrid or monolithic integrated power circuits, electrothermal effects can no longer be ignored. A methodology is proposed in order to simulate electrothermal effects in power circuits, with a significant reduction of the computation time while taking into account electrical and thermal time constants which are usually widely different. A supervising program, written in Fortran, uses system call sequences and manages an interactive dialog between a fast thermal simulator and a general electrical simulator. This explicit coupling process between two specific simulators requires a multi-task operating system. The developed software allows for the prediction of the electrothermal power dissipation drift in the active areas of components, and the prediction of thermally-induced coupling effects between adjacent components. An application to the study of hard switching circuits working under variable operating conditions is presented

  7. Working group summary report on effects of pulsed operation

    Energy Technology Data Exchange (ETDEWEB)

    Gabriel, T.A. [Oak Ridge Natinonal Lab., TN (United States); Ni, L. [Paul Scherrer Institute, Villingen (Switzerland)

    1996-06-01

    In a short pulsed spallation neutron source, extremely high energy ({approx_gt}1 GeV) proton beam pulses are injected into a liquid metal target in a very short period of time ({approximately}1 {mu}sec) at a high repetition rate ({approximately}50 Hertz). The beam energy will be deposited in the target materials (such as mercury or lead) and converted into heat. It causes a sudden temperature rise and resulting pressure wave. This pressure wave travels through the liquid, reaches the steel container wall and may possibly lead to material damage due to induced stress. Almost all participants agreed that the shock problem due to the short pulse operation in the liquid metal target could be serious and could present a challenging problem. It was determined that the following points need to be addressed: (1) equation of state for mercury (2) code validation and benchmark experiments (3) shock effects on the entire target system (4) two phase flow by gas injection. All these investigations should be carried out in the framework of international cooperation. Two small scaled Hg pressure pulse tests are planned at ORNL to provide insight into the pressure wave propagation and thermal shock effects. One experiment will use exploding wires to generate the pulse pressure, the other the electron beam at ORELA. Also PSI, LANL, CERN (ISOLDE facility), INR and IPPE could contribute to the experimental methods for producing shock. The necessary R&D for bubble injection might be performed at PSI, RIGA, ORNL or Ben-Gurion University. All of the above experiments can possibly yield benchmarking data which is absolutely necessary for code validation.

  8. On some expectation and derivative operators related to integral representations of random variables with respect to a PII process

    CERN Document Server

    Goutte, Stéphane; Russo, Francesco

    2012-01-01

    Given a process with independent increments $X$ (not necessarily a martingale) and a large class of square integrable r.v. $H=f(X_T)$, $f$ being the Fourier transform of a finite measure $\\mu$, we provide explicit Kunita-Watanabe and F\\"ollmer-Schweizer decompositions. The representation is expressed by means of two significant maps: the expectation and derivative operators related to the characteristics of $X$. We also provide an explicit expression for the variance optimal error when hedging the claim $H$ with underlying process $X$. Those questions are motivated by finding the solution of the celebrated problem of global and local quadratic risk minimization in mathematical finance.

  9. Effect Of Long-Period Earthquake Ground Motions On Nonlinear Vibration Of Shells With Variable Thickness

    Science.gov (United States)

    Abdikarimov, R.; Bykovtsev, A.; Khodzhaev, D.; Research Team Of Geotechnical; Structural Engineers

    2010-12-01

    Long-period earthquake ground motions (LPEGM) with multiple oscillations have become a crucial consideration in seismic hazard assessment because of the rapid increase of tall buildings and special structures (SP).Usually, SP refers to innovative long-span structural systems. More specifically, they include many types of structures, such as: geodesic showground; folded plates; and thin shells. As continuation of previous research (Bykovtsev, Abdikarimov, Khodzhaev 2003, 2010) analysis of nonlinear vibrations (NV) and dynamic stability of SP simulated as shells with variable rigidity in geometrically nonlinear statement will be presented for two cases. The first case will represent NV example of a viscoelastic orthotropic cylindrical shell with radius R, length L and variable thickness h=h(x,y). The second case will be NV example of a viscoelastic shell with double curvature, variable thickness, and bearing the concentrated masses. In both cases we count, that the SP will be operates under seismic load generated by LPEGM with multiple oscillations. For different seismic loads simulations, Bykovtsev’s Model and methodology was used for generating LPEGM time history. The methodology for synthesizing LPEGM from fault with multiple segmentations was developed by Bykovtev (1978-2010) and based on 3D-analytical solutions by Bykovtsev-Kramarovskii (1987&1989) constructed for faults with multiple segmentations. This model is based on a kinematics description of displacement function on the fault and included in consideration of all possible combinations of 3 components of vector displacement (two slip vectors and one tension component). The opportunities to take into consideration fault segmentations with both shear and tension vector components of displacement on the fault plane provide more accurate LPEGM evaluations. Radiation patterns and directivity effects were included in the model and more physically realistic results for simulated LPEGM were considered. The

  10. Total electron count variability and stratospheric ozone effects on solar backscatter and LWIR emissions

    Science.gov (United States)

    Ross, John S.; Fiorino, Steven T.

    2017-05-01

    The development of an accurate ionospheric Total Electron Count (TEC) model is of critical importance to high frequency (HF) radio propagation and satellite communications. However, the TEC is highly variable and is continually influenced by geomagnetic storms, extreme UV radiation, and planetary waves. Being able to capture this variability is essential to improve current TEC models. The growing body of data involving ionospheric fluctuations and stratospheric variations has revealed a correlation. In particular, there is a marked and persistent association between increases in stratospheric ozone and variability of the TEC. The spectral properties of ozone show that it is a greenhouse gas that alters long wave emissions from Earth and interacts with the UV spectrum coming from the sun. This study uses the Laser Environment Effects Definition and Reference (LEEDR) radiative transfer and atmospheric characterization code to model the effects of changes in stratospheric ozone on solar backscatter and longwave (LWIR) terrestrial emissions and infer TEC and TEC variability.

  11. Effect of climatic variables on production and reproduction traits of colored broiler breeder poultry.

    Science.gov (United States)

    Nayak, G D; Behura, N C; Sardar, K K; Mishra, P K

    2015-04-01

    The present study was conducted to investigate the important climatic variables affecting production and reproduction in a broiler breeder flock. The experiment was conducted for a period of 1 year on colored synthetic female line male and female poultry birds. 630 female progeny and 194 male progenies from 69 sires and 552 dams produced in four consecutive hatches at an interval of 10 days were used for the present study. Each of the seven, body weight and reproduction traits were regressed with nine environmental variables. Initially, the data were subjected to hatch effect and sire effect corrections through best linear unbiased estimator (BLUE) method and, then, multiple linear regressions of environmental variables on each trait were applied. The overall regression was significant (pvariables except maximum temperature and minimum temperature were significant (pvariables play a significant role in production and reproduction of breeder broiler poultry. Controlling these variables in adverse weathers may increase production.

  12. Experimental validation of the simulation module of the water-cooled variable refrigerant flow system under cooling operation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yue Ming; Wu, Jing Yi [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai (China); Shiochi, Sumio [Daikin Industries, Ltd., 1304 Kanaoka-cho, Kita-ku, Sakai, Osaka 591-8511 (Japan)

    2010-05-15

    On the basis of EnergyPlus's codes, the catalogue and performance parameters from some related companies, a special simulation module for variable refrigerant flow system with a water-cooled condenser (water-cooled VRF) was developed and embedded in the software of EnergyPlus, the building energy simulation program. To evaluate the energy performance of the system and the accuracy of the simulation module, the measurement of the water-cooled VRF is built in Dalian, China. After simulation and comparison, some conclusions can be drawn. The mean of the absolute value of the daily error in the 9 days is 11.3% for cooling capacity while the one for compressor power is 15.7%. At the same time, the accuracy of the power simulation strongly depends on the accuracy of the cooling capacity simulation. (author)

  13. Achieving a 100% Renewable Grid: Operating Electric Power Systems with Extremely High Levels of Variable Renewable Energy

    Energy Technology Data Exchange (ETDEWEB)

    Kroposki, Benjamin; Johnson, Brian; Zhang, Yingchen; Gevorgian, Vahan; Denholm, Paul; Hodge, Bri-Mathias; Hannegan, Bryan

    2017-03-01

    What does it mean to achieve a 100% renewable grid? Several countries already meet or come close to achieving this goal. Iceland, for example, supplies 100% of its electricity needs with either geothermal or hydropower. Other countries that have electric grids with high fractions of renewables based on hydropower include Norway (97%), Costa Rica (93%), Brazil (76%), and Canada (62%). Hydropower plants have been used for decades to create a relatively inexpensive, renewable form of energy, but these systems are limited by natural rainfall and geographic topology. Around the world, most good sites for large hydropower resources have already been developed. So how do other areas achieve 100% renewable grids? Variable renewable energy (VRE), such as wind and solar photovoltaic (PV) systems, will be a major contributor, and with the reduction in costs for these technologies during the last five years, large-scale deployments are happening around the world.

  14. The Effects of Job Autonomy on Work Outcomes: Self Efficacy as an Intervening Variable

    OpenAIRE

    Susanti Saragih

    2011-01-01

    The purpose of this research was to examine the relationship between job autonomy and work outcomes (job performance, job satisfaction and job stress), self efficacy as a mediating variable. This research also investigated the impact of job satisfaction on job performance and job stress on job performance. Va-riables in this research were measured via a survey of 190 banking salespersons in D.I. Yogyakarta and Solo. Structural Equation Modeling (SEM) were used to examine the effects of job au...

  15. Modeling And Forecasting War Effects On Macro Economical Variables Of Iran

    OpenAIRE

    Seyed Mohammad Hosein Sadr; Atefeh Shahabadi Farahani

    2011-01-01

    In this study, we aim to evaluate effects of the 8-year war between Iran and Iraq (1980-1988) on economical indices of Iran. The underlying objective of the paper is to provide support for a model that predicts these macro economical variables with the GMDH-neural network method. The macro economical variables that we analyzed include: gross domestic production (GDP)-investment – consumption- inflation- interest rate– net export- government budget.The results indicate that investment decrease...

  16. Effect Analysis of Design Variables on the Disc in a Double-Eccentric Butterfly Valve

    OpenAIRE

    Sangmo Kang; Da-Eun Kim; Kuk-Kyeom Kim; Jun-Oh Kim

    2014-01-01

    We have performed a shape optimization of the disc in an industrial double-eccentric butterfly valve using the effect analysis of design variables to enhance the valve performance. For the optimization, we select three performance quantities such as pressure drop, maximum stress, and mass (weight) as the responses and three dimensions regarding the disc shape as the design variables. Subsequently, we compose a layout of orthogonal array (L16) by performing numerical simulations on the flow an...

  17. An Efficient Variable Screening Method for Effective Surrogate Models for Reliability-Based Design Optimization

    Science.gov (United States)

    2014-04-01

    reliability-based design optimization ( RBDO ) process, surrogate models are frequently used to reduce the number of simulations because analysis of a...the RBDO problem and thus mitigate the curse of dimensionality. Therefore, it is desirable to develop an efficient and effective variable...screening method for reduction of the dimension of the RBDO problem. In this paper, requirements of the variable screening method for deterministic design

  18. The Effects of Job Autonomy on Work Outcomes: Self Efficacy as an Intervening Variable

    OpenAIRE

    Susanti Saragih

    2011-01-01

    The purpose of this research was to examine the relationship between job autonomy and work outcomes (job performance, job satisfaction and job stress), self efficacy as a mediating variable. This research also investigated the impact of job satisfaction on job performance and job stress on job performance. Va-riables in this research were measured via a survey of 190 banking salespersons in D.I. Yogyakarta and Solo. Structural Equation Modeling (SEM) were used to examine the effects of job au...

  19. The effect of perceived advantage and disadvantage on the variability and stability of efficacy beliefs

    OpenAIRE

    Yoav Ganzach

    2016-01-01

    We examined the effect of perceptions of advantage and disadvantage on the variability and stability of efficacy beliefs in a competition. Perceptions of advantageous or disadvantageous opening position were experimentally manipulated (keeping the actual positions equal) and pre- and post-competition efficacy beliefs were observed. Perceiving an advantage resulted in more variability and less stability in efficacy beliefs. These results are explained by the higher sensiti...

  20. Radar-based alert system to operate a sewerage network: relevance and operational effectiveness after several years of use.

    Science.gov (United States)

    Faure, D; Payrastre, O; Auchet, P

    2005-01-01

    Since January 2000, the sewerage network of a very urbanised catchment area in the Greater Nancy Urban Community has been operated according to the alarms generated in real time by a storm alert system using weather radar data. This alert system is based on an automatic identification of intense rain cells in the radar images. This paper presents the characteristics of this alert system and synthesises the main results of two complementary studies realised in 2002 in order to estimate the relevance and the operational effectiveness of the alert system. The first study consisted in an off-line analysis of almost 50,000 intense rain cells detected in four years of historical radar data. The second study was an analysis of the experience feedback after two years of operational use of this alert system. The results of these studies are discussed in function of the initial operational objectives.

  1. Vacuum tube operation analysis under multi-harmonic driving and heavy beam loading effect in J-PARC RCS

    Science.gov (United States)

    Yamamoto, M.; Nomura, M.; Shimada, T.; Tamura, F.; Hara, K.; Hasegawa, K.; Ohmori, C.; Toda, M.; Yoshii, M.; Schnase, A.

    2016-11-01

    An rf cavity in the J-PARC RCS not only covers the frequency range of a fundamental acceleration pattern but also generates multi-harmonic rf voltage because it has a broadband impedance. However, analyzing the vacuum tube operation in the case of multi-harmonics is very complicated because many variables must be solved in a self-consistent manner. We developed a method to analyze the vacuum tube operation using a well-known formula and which includes the dependence on anode current for some variables. The calculation method is verified with beam tests, and the results indicate that it is efficient under condition of multi-harmonics with a heavy beam loading effect.

  2. Effects of Impaired Glucose Metabolism on Heart Rate Variability and Blood Pessure Variability in Essential Hpertensive Patients

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    To investigate the effects of impaired glucose metabolism (IGM) on cardiovascular autonomic nervous systems in essential hypertensive (EH) patients by comparing heart rate variability (HRV) and blood pressure variability (BPV) in EH patients with or without type 2 diabetes mellitus (T2DM). Simultaneous 24-h recordings of ambulatory ECG and blood pressure monitoring were performed in 36 male old patients with simple EH and 33 male old patients with EH combined with T2DM. HRV analysis included time domain parameters such as SDNN, SDANN, SDNNi, rMSSD and pNN50, and total spectral power (TP) of HRV, which mainly consists of VLF, LF and HF component along with LF/HF ratio, was also obtained. The value of ambulatory blood pressure was represented as the mean blood pressure (mean systolic/mSBP, diastolic/mDBP and pulse pressure/mPP)during different periods (24 h/24 h, day time/d and night time/n). Standard deviation (SD) as well as coefficient of variance (CV) of blood pressure during each above-mentioned period were obtained to reflect the long-term BPV. Our result showed that SDNN, SDNNi, SDANN, rMSSD, PNN50, TP and HF of HRV in cases of EH with T2DM were all significantly lower than those in simple EH subjects (P<0.05). No significant differences in VLF or LF was found between the two groups (P>0.05), while LF/HF ratio was significantly higher in EH with T2DM patients than in simple EH subjects (P<0.01).Moreover, dmSBP, 24 h-mPP and dmPP were all significantly higher in EH with T2DM patients than in simple EH subjects (P<0.05), while nmSBP, 24 h-mSBP, 24 h-mDBP, dmDBP, nmDBP or nmPP showed no significant difference between this two groups of patients (P>0.05). And dSBPSD,dSBPCV and 24 h-SBPSD were all significantly higher in EH with T2DM patients than in simple EH subjects (P<0.05), while the other BPV indexes showed no significant difference between this two groups (P>0.05). It is concluded that the cardiovascular autonomic nervous systems in EH patients

  3. Effect of climate variables on cocoa black pod incidence in Sabah using ARIMAX model

    Science.gov (United States)

    Ling Sheng Chang, Albert; Ramba, Haya; Mohd. Jaaffar, Ahmad Kamil; Kim Phin, Chong; Chong Mun, Ho

    2016-06-01

    Cocoa black pod disease is one of the major diseases affecting the cocoa production in Malaysia and also around the world. Studies have shown that the climate variables have influenced the cocoa black pod disease incidence and it is important to quantify the black pod disease variation due to the effect of climate variables. Application of time series analysis especially auto-regressive moving average (ARIMA) model has been widely used in economics study and can be used to quantify the effect of climate variables on black pod incidence to forecast the right time to control the incidence. However, ARIMA model does not capture some turning points in cocoa black pod incidence. In order to improve forecasting performance, other explanatory variables such as climate variables should be included into ARIMA model as ARIMAX model. Therefore, this paper is to study the effect of climate variables on the cocoa black pod disease incidence using ARIMAX model. The findings of the study showed ARIMAX model using MA(1) and relative humidity at lag 7 days, RHt - 7 gave better R square value compared to ARIMA model using MA(1) which could be used to forecast the black pod incidence to assist the farmers determine timely application of fungicide spraying and culture practices to control the black pod incidence.

  4. [Effectiveness of pre-operative education in reducing anxiety in surgical patients].

    Science.gov (United States)

    Díez-Álvarez, Esther; Arrospide, Arantzazu; Mar, Javier; Alvarez, Uzuri; Belaustegi, Alazne; Lizaur, Belen; Larrañaga, Aintzane; Arana, Jose M

    2012-01-01

    To evaluate the effectiveness of a structured pre-operative interview conducted by operating room nurses in order to reduce the pre-operative anxiety of patients, and to determine the profile of patients who can benefit from it. A randomised double-blind and prospective trial was conducted on a sample of 335 patients scheduled for surgery in two regional hospitals in the Basque Region of Spain, Alto Deba Hospital and Mendaro Hospital. We compared the alternative of using a structured briefing (test group) with the current situation without any formal intervention (control group). The effectiveness of the procedure was determined using the STAI state anxiety self-assessment questionnaire. The Chi-squared statistic was used to assess the differences in factors and the Student t-test for comparison of means in the continuous variables. The impact of the intervention on measures of state anxiety and trait anxiety was found to be not statistically significant, although the mean state anxiety state was slightly lower in the intervention group (18.96) than in the controls (20.03). Women undergoing surgery in the specialty of gynaecology showed the higher state anxiety compared with other specialties. As regards trait anxiety a higher ASA level is associated with higher anxiety. Furthermore, the consumption of psychotropic drugs is also related to a higher level of trait anxiety. The preoperative visit can be helpful when patients are selected according to specific characteristics: by type of anaesthesia, gender, or type of surgery. There may also be beneficial effects when preoperative education is tailored according to patient's anxiety risk. The time immediately before surgery may not be the best time for conducting the visit, as this may make the patients more anxious. Copyright © 2011 Elsevier España, S.L. All rights reserved.

  5. Intertest variability of mfVEP amplitude: reducing its effect on the interpretation of sequential tests.

    Science.gov (United States)

    Klistorner, A; Graham, S L

    2005-11-01

    The multi-focal visual evoked potential (mfVEP) has been recently introduced as an alternative to subjective perimetry in detecting visual field defects. This study examines the source of variability in the mfVEP amplitude, and determines the relationship of this variability to the strength of the signal itself across the visual field. It also investigates possible means to reduce the effects of this variability on between-test interpretation to allow for easier detection of progression. 85 normal subjects participated in the study. The mfVEP was recorded using Accumap (ObjectiVision Pty Ltd, Sydney, Australia). Each subject was tested twice with an interval between visits of 3-4 weeks. Comparison between tests was performed using coefficient of variability (CV). Variability was also analysed using scaling and clustering procedures. In the majority of the retinal areas CV fell within 15-20%. Variability increased with eccentricity, but there was no age dependency. There was a significant reduction of variability (by 15.8 +/- 6%, Student's t-test p<0.0001) when a scaling procedure was applied and this was consistent at all eccentricities. A clustering procedure reduced variability on average by a further 18.5 +/- 4.5% (Student's t-test p<0.0001). This result was also consistent at all eccentricities. Between test comparisons of raw mfVEP traces is limited by a variability of at least 15%. While this variability required the amplitude of the individual VEP signal to change by 30-40% in order to detect progression, scaling and clustering procedures were able to reduce the required change to 20-25%, thus making an interpretation of consecutive test results more clinically viable.

  6. Impact of data assimilation of physical variables on the spring bloom from TOPAZ operational runs in the North Atlantic

    Directory of Open Access Journals (Sweden)

    A. Samuelsen

    2009-12-01

    Full Text Available A reanalysis of the North Atlantic spring bloom in 2007 was produced using the real-time analysis from the TOPAZ North Atlantic and Arctic forecasting system. The TOPAZ system uses a hybrid coordinate general circulation ocean model and assimilates physical observations: sea surface anomalies, sea surface temperatures, and sea-ice concentrations using the Ensemble Kalman Filter. This ocean model was coupled to an ecosystem model, NORWECOM (Norwegian Ecological Model System, and the TOPAZ-NORWECOM coupled model was run throughout the spring and summer of 2007. The ecosystem model was run online, restarting from analyzed physical fields (result after data assimilation every 7 days. Biological variables were not assimilated in the model. The main purpose of the study was to investigate the impact of physical data assimilation on the ecosystem model. This was determined by comparing the results to those from a model without assimilation of physical data. The regions of focus are the North Atlantic and the Arctic Ocean. Assimilation of physical variables does not affect the results from the ecosystem model significantly. The differences between the weekly mean values of chlorophyll are normally within 5–10% during the summer months, and the maximum difference of ~20% occurs in the Arctic, also during summer. Special attention was paid to the nutrient input from the North Atlantic to the Nordic Seas and the impact of ice-assimilation on the ecosystem. The ice-assimilation increased the phytoplankton concentration: because there was less ice in the assimilation run, this increased both the mixing of nutrients during winter and the area where production could occur during summer. The forecast was also compared to remotely sensed chlorophyll, climatological nutrients, and in-situ data. The results show that the model reproduces a realistic annual cycle, but the chlorophyll concentrations tend to be between 0.1 and 1.0 mg chla/m3 too

  7. Extra U(1), effective operators, anomalies and dark matter

    CERN Document Server

    Dudas, Emilian; Mambrini, Yann; Zaldivar, Bryan

    2013-01-01

    A general analysis is performed on the dimension-six operators mixing an almost hidden Z' to the Standard Model (SM), when the Z' communicates with the SM via heavy mediators. These are fermions charged under both Z' and the SM, while all SM fermions are neutral under Z'. We classify the operators as a function of the gauge anomalies behaviour of mediators and explicitly compute the dimension-six operators coupling Z' to gluons, generated at one-loop by chiral but anomaly-free, sets of fermion mediators. We prove that only one operator contribute to the couplings between Z' charged matter and on-shell gluons. We then make a complete phenomenological analysis of the scenario where the lightest fermion charged under Z' is the dark matter candidate. Combining results from WMAP/PLANCK data, mono-jet searches at LHC, and direct/indirect dark matter detections restrict considerably the allowed parameter space.

  8. Effect of operational variables on nitrogen transformations in duckweed stabilization ponds

    NARCIS (Netherlands)

    Caicedo Berjarano, J.R.

    2005-01-01

    There is an urgent need to develop and improve low cost technologies for wastewater treatment that are within the economic and technological capabilities of developing countries. Simultaneously treating wastewater and producing duckweed in a pond system is therefore an attractive option to

  9. The Effects of Day-to-Day Variability of Physiological Data on Operator Functional State Classification

    Science.gov (United States)

    2013-03-01

    Unsupervised classification of high-frequency oscillations in human neocortical epilepsy and control patients. Journal of Neurophysiology, 104(5), 2900...and clinical Neurophysiology, 86, 210-223. Bishop, C. M. (2006). Pattern Recognition and Machine Learning. New York: Springer . Cauwenberghs, G

  10. Cost-effective design and operation of variable speed wind turbines

    NARCIS (Netherlands)

    Molenaar, D.P.

    2003-01-01

    In the past decades, the wind industry has grown from a niche business serving the environmental aware into one that has established itself as the most competitive form of renewable energy. Wind has the potential to play a more important role in the future world electricity supply provided that the

  11. Effect of operational variables on nitrogen transformations in duckweed stabilization ponds

    NARCIS (Netherlands)

    Caicedo Berjarano, J.R.

    2005-01-01

    There is an urgent need to develop and improve low cost technologies for wastewater treatment that are within the economic and technological capabilities of developing countries. Simultaneously treating wastewater and producing duckweed in a pond system is therefore an attractive option to contribut

  12. Cost-effective design and operation of variable speed wind turbines

    NARCIS (Netherlands)

    Molenaar, D.P.

    2003-01-01

    In the past decades, the wind industry has grown from a niche business serving the environmental aware into one that has established itself as the most competitive form of renewable energy. Wind has the potential to play a more important role in the future world electricity supply provided that the

  13. Standardizing effect size from linear regression models with log-transformed variables for meta-analysis.

    Science.gov (United States)

    Rodríguez-Barranco, Miguel; Tobías, Aurelio; Redondo, Daniel; Molina-Portillo, Elena; Sánchez, María José

    2017-03-17

    Meta-analysis is very useful to summarize the effect of a treatment or a risk factor for a given disease. Often studies report results based on log-transformed variables in order to achieve the principal assumptions of a linear regression model. If this is the case for some, but not all studies, the effects need to be homogenized. We derived a set of formulae to transform absolute changes into relative ones, and vice versa, to allow including all results in a meta-analysis. We applied our procedure to all possible combinations of log-transformed independent or dependent variables. We also evaluated it in a simulation based on two variables either normally or asymmetrically distributed. In all the scenarios, and based on different change criteria, the effect size estimated by the derived set of formulae was equivalent to the real effect size. To avoid biased estimates of the effect, this procedure should be used with caution in the case of independent variables with asymmetric distributions that significantly differ from the normal distribution. We illustrate an application of this procedure by an application to a meta-analysis on the potential effects on neurodevelopment in children exposed to arsenic and manganese. The procedure proposed has been shown to be valid and capable of expressing the effect size of a linear regression model based on different change criteria in the variables. Homogenizing the results from different studies beforehand allows them to be combined in a meta-analysis, independently of whether the transformations had been performed on the dependent and/or independent variables.

  14. Spatial variable selection methods for investigating acute health effects of fine particulate matter components.

    Science.gov (United States)

    Boehm Vock, Laura F; Reich, Brian J; Fuentes, Montserrat; Dominici, Francesca

    2015-03-01

    Multi-site time series studies have reported evidence of an association between short term exposure to particulate matter (PM) and adverse health effects, but the effect size varies across the United States. Variability in the effect may partially be due to differing community level exposure and health characteristics, but also due to the chemical composition of PM which is known to vary greatly by location and time. The objective of this article is to identify particularly harmful components of this chemical mixture. Because of the large number of highly-correlated components, we must incorporate some regularization into a statistical model. We assume that, at each spatial location, the regression coefficients come from a mixture model with the flavor of stochastic search variable selection, but utilize a copula to share information about variable inclusion and effect magnitude across locations. The model differs from current spatial variable selection techniques by accommodating both local and global variable selection. The model is used to study the association between fine PM (PM <2.5μm) components, measured at 115 counties nationally over the period 2000-2008, and cardiovascular emergency room admissions among Medicare patients.

  15. Effects of Microstructural Variability on Thermo-Mechanical Properties of a Woven Ceramic Matrix Composite

    Science.gov (United States)

    Goldsmith, Marlana B.; Sankar, Bhavani V.; Haftka, Raphael T.; Goldberg, Robert K.

    2013-01-01

    The objectives of this paper include identifying important architectural parameters that describe the SiC/SiC five-harness satin weave composite and characterizing the statistical distributions and correlations of those parameters from photomicrographs of various cross sections. In addition, realistic artificial cross sections of a 2D representative volume element (RVE) are generated reflecting the variability found in the photomicrographs, which are used to determine the effects of architectural variability on the thermo-mechanical properties. Lastly, preliminary information is obtained on the sensitivity of thermo-mechanical properties to architectural variations. Finite element analysis is used in combination with a response surface and it is shown that the present method is effective in determining the effects of architectural variability on thermo-mechanical properties.

  16. Assessing the relative effects of emissions, climate means, and variability on large water supply systems

    Science.gov (United States)

    Whateley, Sarah; Brown, Casey

    2016-11-01

    Some of the greatest societal risks of climate change rise from the potential impacts to water supply. Yet prescribing adaptation policies in the near term is made difficult by the uncertainty in climate projections at relevant spatial scales and the conflating effects of uncertainties in emissions, model error, and internal variability. In this work, a new framework is implemented to explore the vulnerability of reservoir systems in the northeastern U.S. to climate change and attribute vulnerabilities to changes in mean climate, natural variability, or emission scenarios. Analysis of variance is used to explore the contributions of uncertainties to system performance. Diagnosing the relative risks to water supply will help water resource engineers better adapt to uncertain future conditions. The results indicate that uncertainty in water supply system performance can be attributed mostly to uncertainty in internal variability over policy-relevant planning horizons, and thus, adaptation efforts should focus on managing variability.

  17. Enhancement of Transistor-to-Transistor Variability Due to Total Dose Effects in 65-nm MOSFETs

    CERN Document Server

    Gerardin, S; Cornale, D; Ding, L; Mattiazzo, S; Paccagnella, A; Faccio, F; Michelis, S

    2015-01-01

    We studied device-to-device variations as a function of total dose in MOSFETs, using specially designed test structures and procedures aimed at maximizing matching between transistors. Degradation in nMOSFETs is less severe than in pMOSFETs and does not show any clear increase in sample-to-sample variability due to the exposure. At doses smaller than 1 Mrad( SiO2) variability in pMOSFETs is also practically unaffected, whereas at very high doses-in excess of tens of Mrad( SiO2)-variability in the on-current is enhanced in a way not correlated to pre-rad variability. The phenomenon is likely due to the impact of random dopant fluctuations on total ionizing dose effects.

  18. Effect of running speed and leg prostheses on mediolateral foot placement and its variability.

    Directory of Open Access Journals (Sweden)

    Christopher J Arellano

    Full Text Available This study examined the effects of speed and leg prostheses on mediolateral (ML foot placement and its variability in sprinters with and without transtibial amputations. We hypothesized that ML foot placement variability would: 1. increase with running speed up to maximum speed and 2. be symmetrical between the legs of non-amputee sprinters but asymmetrically greater for the affected leg of sprinters with a unilateral transtibial amputation. We measured the midline of the body (kinematic data and center of pressure (kinetic data in the ML direction while 12 non-amputee sprinters and 7 Paralympic sprinters with transtibial amputations (6 unilateral, 1 bilateral ran across a range of speeds up to maximum speed on a high-speed force measuring treadmill. We quantified ML foot placement relative to the body's midline and its variability. We interpret our results with respect to a hypothesized relation between ML foot placement variability and lateral balance. We infer that greater ML foot placement variability indicates greater challenges with maintaining lateral balance. In non-amputee sprinters, ML foot placement variability for each leg increased substantially and symmetrically across speed. In sprinters with a unilateral amputation, ML foot placement variability for the affected and unaffected leg also increased substantially, but was asymmetric across speeds. In general, ML foot placement variability for sprinters with a unilateral amputation was within the range observed in non-amputee sprinters. For the sprinter with bilateral amputations, both affected legs exhibited the greatest increase in ML foot placement variability with speed. Overall, we find that maintaining lateral balance becomes increasingly challenging at faster speeds up to maximum speed but was equally challenging for sprinters with and without a unilateral transtibial amputation. Finally, when compared to all other sprinters in our subject pool, maintaining lateral balance

  19. Effect of running speed and leg prostheses on mediolateral foot placement and its variability.

    Science.gov (United States)

    Arellano, Christopher J; McDermott, William J; Kram, Rodger; Grabowski, Alena M

    2015-01-01

    This study examined the effects of speed and leg prostheses on mediolateral (ML) foot placement and its variability in sprinters with and without transtibial amputations. We hypothesized that ML foot placement variability would: 1. increase with running speed up to maximum speed and 2. be symmetrical between the legs of non-amputee sprinters but asymmetrically greater for the affected leg of sprinters with a unilateral transtibial amputation. We measured the midline of the body (kinematic data) and center of pressure (kinetic data) in the ML direction while 12 non-amputee sprinters and 7 Paralympic sprinters with transtibial amputations (6 unilateral, 1 bilateral) ran across a range of speeds up to maximum speed on a high-speed force measuring treadmill. We quantified ML foot placement relative to the body's midline and its variability. We interpret our results with respect to a hypothesized relation between ML foot placement variability and lateral balance. We infer that greater ML foot placement variability indicates greater challenges with maintaining lateral balance. In non-amputee sprinters, ML foot placement variability for each leg increased substantially and symmetrically across speed. In sprinters with a unilateral amputation, ML foot placement variability for the affected and unaffected leg also increased substantially, but was asymmetric across speeds. In general, ML foot placement variability for sprinters with a unilateral amputation was within the range observed in non-amputee sprinters. For the sprinter with bilateral amputations, both affected legs exhibited the greatest increase in ML foot placement variability with speed. Overall, we find that maintaining lateral balance becomes increasingly challenging at faster speeds up to maximum speed but was equally challenging for sprinters with and without a unilateral transtibial amputation. Finally, when compared to all other sprinters in our subject pool, maintaining lateral balance appears to be the

  20. Modelling the effects of (short-term solar variability on stratospheric chemistry

    Directory of Open Access Journals (Sweden)

    R. Muncaster

    2011-12-01

    Full Text Available The photochemical response of the stratosphere to short-term solar variability is investigated using a photochemistry column model with interactive photolysis calculation. The solar variability is here simply represented using the Lean (1997 solar minimum and maximum spectra. In order to isolate the photochemistry effect, simulations are devoid of diffusion or any other external forcing and the temperature is held constant. The solar mininum/maximum response is estimated for all chemical families and partitioning ratios, and the underlying photochemical mechanisms are described in detail. The ozone response peaks at 0.18 ppmv (approximatively 3% at 37 km altitude. In an attempt to find the simplest statistical model able to represent the effect of solar variability in the stratosphere, the diurnal-average response of ozone from an ensemble of 200 simulations is regressed linearly following two auto-regressive models. In the simplest case, an adjusted coefficient of determination R2 larger than 0.97 is found throughout the stratosphere using two predictors, namely the previous day's ozone perturbation and the current day's solar irradiance perturbation. A better accuracy (R2 larger than 0.9992 is achieved with an additional predictor, the previous day's solar irradiance perturbation. The skills of the two auto-regressive models at representing the effect of solar variability are then evaluated independently when coupled either on-line or off-line with the comprehensive photochemistry column model driven by the solar average spectrum. In all cases, the magnitude of the bias and the RMS error are found smaller than 5% and 20% of the ozone response, respectively. When used on-line, the 3-predictor model captures the ozone response to solar variability throughout the stratosphere with bias and RMS error

  1. Rainfall–runoff temporal variability in Kermanshah province, Iran and distinguishing anthropogenic effects from climatic effects

    Indian Academy of Sciences (India)

    P Ghafarian; S Gholami; E Owlad; H Gerivani

    2016-08-01

    Investigation of changes in rainfall and runoff patterns in various regions and determining their relationship in the sense of hydrology and climatology are of great importance, considering those patterns efficiently reveal the human and natural factors in this variability. One of the mathematical methods to recognise and model these fluctuations is Wavelet Analysis. This is a spectral method used in multivariateanalysis and also tracing fluctuations in temporal series. In this study, continuous wavelet transformation is used to identify temporal changes in rainfall–runoff patterns. The hydrological and rain gauge data were collected from in situ measurements of Kermanshah province located in the western border of Iran.Precipitation anomalies were reconsidered in a number of stations, including Kermanshah, for a period of 55 years (1955–2010) and discharge of Gamasiab River in Polchehr station, discharge of Khoram Rood River in Aran-Gharb station and discharge of Gharasoo River in Polekohne station. In addition, anomaliesof the climatic teleconnections were studied to emphasise the climatological effects on the runoff pattern in the region. The role of natural and anthropogenic effects (land use changes) has been distinguished and identified, using the comparison of the teleconnections and hydrological data. The results achieved from three stations show that there was an approximate correlation between rainfall, runoff and teleconnections until the year 1995; however, after 1995, a great difference appeared among them, specifically for the Aran-Gharb station (Khoram Rood River). The post-1995 slope of cumulative standardised anomaly is much steeper in the case of runoff compared to rainfall. As there were no significant climate changes in the region, it could be concluded that the runoff decrease is not caused by climatechanges, but by anthropogenic effects, human interventions and extra water usage from the surface and underground water resources for

  2. Rainfall-runoff temporal variability in Kermanshah province, Iran and distinguishing anthropogenic effects from climatic effects

    Science.gov (United States)

    Ghafarian, P.; Gholami, S.; Owlad, E.; Gerivani, H.

    2016-08-01

    Investigation of changes in rainfall and runoff patterns in various regions and determining their relationship in the sense of hydrology and climatology are of great importance, considering those patterns efficiently reveal the human and natural factors in this variability. One of the mathematical methods to recognise and model these fluctuations is Wavelet Analysis. This is a spectral method used in multivariate analysis and also tracing fluctuations in temporal series. In this study, continuous wavelet transformation is used to identify temporal changes in rainfall-runoff patterns. The hydrological and rain gauge data were collected from in situ measurements of Kermanshah province located in the western border of Iran. Precipitation anomalies were reconsidered in a number of stations, including Kermanshah, for a period of 55 years (1955-2010) and discharge of Gamasiab River in Polchehr station, discharge of Khoram Rood River in Aran-Gharb station and discharge of Gharasoo River in Polekohne station. In addition, anomalies of the climatic teleconnections were studied to emphasise the climatological effects on the runoff pattern in the region. The role of natural and anthropogenic effects (land use changes) has been distinguished and identified, using the comparison of the teleconnections and hydrological data. The results achieved from three stations show that there was an approximate correlation between rainfall, runoff and teleconnections until the year 1995; however, after 1995, a great difference appeared among them, specifically for the Aran-Gharb station (Khoram Rood River). The post-1995 slope of cumulative standardised anomaly is much steeper in the case of runoff compared to rainfall. As there were no significant climate changes in the region, it could be concluded that the runoff decrease is not caused by climate changes, but by anthropogenic effects, human interventions and extra water usage from the surface and underground water resources for

  3. The Effect of Experimental Variables on Industrial X-Ray Micro-Computed Sensitivity

    Science.gov (United States)

    Roth, Don J.; Rauser, Richard W.

    2014-01-01

    A study was performed on the effect of experimental variables on radiographic sensitivity (image quality) in x-ray micro-computed tomography images for a high density thin wall metallic cylinder containing micro-EDM holes. Image quality was evaluated in terms of signal-to-noise ratio, flaw detectability, and feature sharpness. The variables included: day-to-day reproducibility, current, integration time, voltage, filtering, number of frame averages, number of projection views, beam width, effective object radius, binning, orientation of sample, acquisition angle range (180deg to 360deg), and directional versus transmission tube.

  4. Effects of the Current Economic Crisis on the Fiscal Variables in EU Countries

    Directory of Open Access Journals (Sweden)

    Iulian Viorel BRAŞOVEANU

    2011-02-01

    Full Text Available Our paper aims to capture the effects of the current economic and financial crisis on fiscal variables, the 27 EU Member States, based on macroeconomic developments until 2010 and projected for 2011. Starting from the economic recession, from the increase of unemployment and the relative stability of prices in the EU overall (macroeconomic developments that characterize the current crisis, we analyze the effects of those developments on the public revenues and expenditures, on the conventional deficit and public debt, which are macroeconomic variables that comprise the pentagon of economic macro stabilization.

  5. An Exploration into the Effects of Fiscal Variables on Regional Growth

    OpenAIRE

    2003-01-01

    This paper explores the effects of several fiscal variables on regional economic growth in Spain over period 1965-1997. Panel estimates are provided for this sample. The results show that public consumption affects negatively growth, public investment exerts a positive (but non significant) effect on growth rate and public deficit reduces private investment and hence economic growth. The effects of taxes and social benefits seem not to be beneficial for regional growth. Alternative estimates ...

  6. Joint effects of climate variability and socioecological factors on dengue transmission: epidemiological evidence.

    Science.gov (United States)

    Akter, Rokeya; Hu, Wenbiao; Naish, Suchithra; Banu, Shahera; Tong, Shilu

    2017-06-01

    To assess the epidemiological evidence on the joint effects of climate variability and socioecological factors on dengue transmission. Following PRISMA guidelines, a detailed literature search was conducted in PubMed, Web of Science and Scopus. Peer-reviewed, freely available and full-text articles, considering both climate and socioecological factors in relation to dengue, published in English from January 1993 to October 2015 were included in this review. Twenty studies have met the inclusion criteria and assessed the impact of both climatic and socioecological factors on dengue dynamics. Among those, four studies have further investigated the relative importance of climate variability and socioecological factors on dengue transmission. A few studies also developed predictive models including both climatic and socioecological factors. Due to insufficient data, methodological issues and contextual variability of the studies, it is hard to draw conclusion on the joint effects of climate variability and socioecological factors on dengue transmission. Future research should take into account socioecological factors in combination with climate variables for a better understanding of the complex nature of dengue transmission as well as for improving the predictive capability of dengue forecasting models, to develop effective and reliable early warning systems. © 2017 John Wiley & Sons Ltd.

  7. The effects of variability in bank material properties on riverbank stability: Goodwin Creek, Mississippi

    Science.gov (United States)

    Parker, Chris; Simon, Andrew; Thorne, Colin R.

    2008-11-01

    Bank retreat is an important area of research within fluvial geomorphology and is a land management problem of global significance. The Yazoo River Basin in Mississippi is one example of a system which is experiencing excessive erosion and bank instability. The properties of bank materials are important in controlling the stability of stream banks and past studies have found that these properties are often variable spatially. Through an investigation of bank material properties on a stretch of Goodwin Creek in the Yazoo Basin, Mississippi, this study focuses on: i) how and why effective bank material properties vary through different scales; ii) how this variation impacts on the outputs from a bank stability model; and iii) how best to appropriately represent this variability within a bank stability model. The study demonstrates the importance that the variability of effective bank material properties has on bank stability: at both the micro-scale within a site, and at the meso-scale between sites in a reach. This variability was shown to have important implications for the usage of the Bank Stability and Toe Erosion Model (BSTEM), a deterministic bank stability model that currently uses a single value to describe each bank material property. As a result, a probabilistic representation of effective bank material strength parameters is recommended as a potential solution for any bank stability model that wishes to account for the important influence of the inherent variability of soil properties.

  8. Relative effects of precipitation variability and warming on grassland ecosystem function

    Directory of Open Access Journals (Sweden)

    P. A. Fay

    2011-07-01

    Full Text Available Precipitation and temperature drive many aspects of terrestrial ecosystem function. Climate change scenarios predict increasing precipitation variability and temperature, and long term experiments are required to evaluate the ecosystem consequences of interannual climate variation, increased growing season (intra-annual rainfall variability, and warming. We present results from an experiment applying increased growing season rainfall variability and year round warming in native perennial grassland. During ten years of study, total growing season rainfall varied 2-fold, and we found ~50–200 % interannual variability in plant growth and aboveground net primary productivity, leaf carbon assimilation (ACO2, and soil CO2 efflux (JCO2 despite only ∼40 % variation in mean volumetric soil water content (0–15 cm, Θ15. Interannual variation in soil moisture was thus amplified in most measures of ecosystem response. Differences between years in Θ15 explained the greatest portion (14–52 % of the variation in these processes. Experimentally increased intra-annual rainfall variability doubled the amplitude of intra-annual soil moisture variation and reduced Θ15 by 15 %, causing most ecosystem processes to decrease 8–40 % in some or all years with increased rainfall variability compared to ambient rainfall timing, suggesting reduced ecosystem rainfall use efficiency. Warming treatments increased 5 cm soil temperature, particularly during spring, fall, and winter. Warming advanced canopy green up in spring, increased winter JCO2, and reduced summer JCO2 and forb ANPP, suggesting that the effects of warming differed in cooler versus warmer parts of the year. We conclude that (1 major ecosystem processes in this grassland may be substantially altered by predicted changes in interannual climate variability, intra

  9. Relative effects of precipitation variability and warming on tallgrass prairie ecosystem function

    Directory of Open Access Journals (Sweden)

    P. A. Fay

    2011-10-01

    Full Text Available Precipitation and temperature drive many aspects of terrestrial ecosystem function. Climate change scenarios predict increasing precipitation variability and temperature, and long term experiments are required to evaluate the ecosystem consequences of interannual climate variation, increased growing season (intra-annual rainfall variability, and warming. We present results from an experiment applying increased growing season rainfall variability and year round warming in native tallgrass prairie. During ten years of study, total growing season rainfall varied 2-fold, and we found ~50–200% interannual variability in plant growth and aboveground net primary productivity (ANPP, leaf carbon assimilation (ACO2, and soil CO2 efflux (JCO2 despite only ~40% variation in mean volumetric soil water content (0–15 cm, Θ15. Interannual variation in soil moisture was thus amplified in most measures of ecosystem response. Differences between years in Θ15 explained the greatest portion (14–52% of the variation in these processes. Experimentally increased intra-annual season rainfall variability doubled the amplitude of intra-annual soil moisture variation and reduced Θ15 by 15%, causing most ecosystem processes to decrease 8–40% in some or all years with increased rainfall variability compared to ambient rainfall timing, suggesting reduced ecosystem rainfall use efficiency. Warming treatments increased soil temperature at 5 cm depth, particularly during spring, fall, and winter. Warming advanced canopy green up in spring, increased winter JCO2, and reduced summer JCO2 and forb ANPP, suggesting that the effects of warming differed in cooler versus warmer parts of the year. We conclude that (1 major ecosystem processes in this grassland may be substantially altered by predicted changes in

  10. The effect of muscle fatigue and low back pain on lumbar movement variability and complexity.

    Science.gov (United States)

    Bauer, C M; Rast, F M; Ernst, M J; Meichtry, A; Kool, J; Rissanen, S M; Suni, J H; Kankaanpää, M

    2017-04-01

    Changes in movement variability and complexity may reflect an adaptation strategy to fatigue. One unresolved question is whether this adaptation is hampered by the presence of low back pain (LBP). This study investigated if changes in movement variability and complexity after fatigue are influenced by the presence of LBP. It is hypothesised that pain free people and people suffering from LBP differ in their response to fatigue. The effect of an isometric endurance test on lumbar movement was tested in 27 pain free participants and 59 participants suffering from LBP. Movement variability and complexity were quantified with %determinism and sample entropy of lumbar angular displacement and velocity. Generalized linear models were fitted for each outcome. Bayesian estimation of the group-fatigue effect with 95% highest posterior density intervals (95%HPDI) was performed. After fatiguing %determinism decreased and sample entropy increased in the pain free group, compared to the LBP group. The corresponding group-fatigue effects were 3.7 (95%HPDI: 2.3-7.1) and -1.4 (95%HPDI: -2.7 to -0.1). These effects manifested in angular velocity, but not in angular displacement. The effects indicate that pain free participants showed more complex and less predictable lumbar movement with a lower degree of structure in its variability following fatigue while participants suffering from LBP did not. This may be physiological responses to avoid overload of fatigued tissue, increase endurance, or a consequence of reduced movement control caused by fatigue. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Military leadership with an operational effect in asymmetric operations - A new military leadership training concept in a new world

    DEFF Research Database (Denmark)

    Barfod, Jakob Rømer

    2015-01-01

    . Suddenly, it was extremely important that the Danish Defence transformed to a more expeditionary force capable of conducting asymmetric operations in different environments far away from Denmark. This is not done overnight but demands a new situational awareness in proportion to the need for leadership....... As tactics, doctrines, technologies and procedures had to be developed and changed, there was also a need for developing the approach to leadership. Suddenly the challenges in the operations were not only IEDs, ambushes, shootings and deprivation of families, but also leadership challenges in military staffs...... and units, which in many cases acted and commanded based on a mindset of linear and symmetric warfare with great emphasis on analysis of primarily cause and effect. On that basis, the Danish Defence around mid-2000 developed a new operational leadership concept with a changed and different leadership focus...

  12. A study on effects of demographic variables on success of social media

    Directory of Open Access Journals (Sweden)

    Marjan Mohammadreza

    2012-10-01

    Full Text Available In the recent years, social media have developed significantly and their usages have become main activities of internet users. The proposed study of this paper considers the effects of personal characteristics such as age, gender and marital status on social media. The study designs a questionnaire and distributes 385 questionnaires among students who are enrolled in different educational levels in governmental university named Allameh Tabatabayi university located in Tehran, Iran during the year of 2011. Because of abnormality of data, non-parametric test were used. In this research, we studied the effects of demographic variables on success of social media. The results showed that success of social media is more important among female students. Marriage situation shows that social media success variable is more important among married than single ones and, finally, this variable is more important among older people.

  13. Formal Operational Reasoning and the Primacy Effect in Impression Formation.

    Science.gov (United States)

    Palmquist, Wendy Jean

    1979-01-01

    Results showed that when information about a target individual was presented in two internally consistent blocks which were mutually contradictory, impressions produced by concrete operational adolescents contained a significantly greater proportion of evaluative statements in the same evaluative direction as the first block of information…

  14. the effect of transportation in logistics operation on an ...

    African Journals Online (AJOL)

    USER

    2016-04-07

    Apr 7, 2016 ... The need for transportation in logistic operation cannot be undermined if a business is to stay competitive in ... its delivery to the customer and after-sales service (Pollitt ... transport costs and faster transport time. Hence, lower ...

  15. Separating the effect of respiration from the heart rate variability for cases of constant harmonic breathing

    Directory of Open Access Journals (Sweden)

    Kircher Michael

    2015-09-01

    Full Text Available Heart Rate Variability studies are a known measure for the autonomous control of the heart rate. In special situations, its interpretation can be ambiguous, since the respiration has a major influence on the heart rate variability. For this reason it has often been proposed to measure Heart Rate Variability, while the subjects are breathing at a constant respiration rate. That way the spectral influence of the respiration is known. In this work we propose to remove this constant respiratory influence from the heart rate and the Heart Rate Variability parameters to gain respiration free autonomous controlled heart rate signal. The spectral respiratory component in the heart rate signal is detected and characterized. Subsequently the respiratory effect on Heart Rate Variability is removed using spectral filtering approaches, such as the Notch filter or the Raised Cosine filter. As a result new decoupled Heart Variability parameters are gained, which could lead to new additional interpretations of the autonomous control of the heart rate.

  16. Spontaneous temporal changes and variability of peripheral nerve conduction analyzed using a random effects model.

    Science.gov (United States)

    Krøigård, Thomas; Gaist, David; Otto, Marit; Højlund, Dorthe; Selmar, Peter E; Sindrup, Søren H

    2014-08-01

    The reproducibility of variables commonly included in studies of peripheral nerve conduction in healthy individuals has not previously been analyzed using a random effects regression model. We examined the temporal changes and variability of standard nerve conduction measures in the leg. Peroneal nerve distal motor latency, motor conduction velocity, and compound motor action potential amplitude; sural nerve sensory action potential amplitude and sensory conduction velocity; and tibial nerve minimal F-wave latency were examined in 51 healthy subjects, aged 40 to 67 years. They were reexamined after 2 and 26 weeks. There was no change in the variables except for a minor decrease in sural nerve sensory action potential amplitude and a minor increase in tibial nerve minimal F-wave latency. Reproducibility was best for peroneal nerve distal motor latency and motor conduction velocity, sural nerve sensory conduction velocity, and tibial nerve minimal F-wave latency. Between-subject variability was greater than within-subject variability. Sample sizes ranging from 21 to 128 would be required to show changes twice the magnitude of the spontaneous changes observed in this study. Nerve conduction studies have a high reproducibility, and variables are mainly unaltered during 6 months. This study provides a solid basis for the planning of future clinical trials assessing changes in nerve conduction.

  17. On Cyclic Variability in a Residual Effected HCCI Engine with Direct Gasoline Injection during Negative Valve Overlap

    Directory of Open Access Journals (Sweden)

    Jacek Hunicz

    2014-01-01

    Full Text Available This study contributes towards describing the nature of cycle-by-cycle variability in homogeneous charge compression ignition (HCCI engines. Experimental measurements were performed using a single cylinder research engine operated in the negative valve overlap (NVO mode and fuelled with direct gasoline injection. Both stoichiometric and lean mixtures were applied in order to distinguish between different exhaust-fuel reactions during the NVO period and their propagation into the main event combustion. The experimental results show that the mode of cycle-by-cycle variability depends on the NVO phenomena. Under stoichiometric mixture conditions, neither variability in the main event indicated mean effective pressure (IMEP nor the combustion timing was affected by the NVO phenomena; however, long period oscillations in IMEP were observed. In contrast, for lean mixture, where fuel oxidation during the NVO period took place, distinctive correlations between NVO phenomena and the main event combustion parameters were observed. A wavelet analysis revealed the presence of both long-term and short-term oscillations in IMEP, in accordance with the extent of NVO phenomena. Characteristic patterns in IMEP were recognized using an in-house algorithm.

  18. EFFECT OF INTRATHECAL ROPIVACAINE WITH DEXMEDETOMIDINE FOR OPERATIVE AND POST OPERATIVE ANALGESIA: A PROSPECTIVE RANDOMIZED STUDY

    Directory of Open Access Journals (Sweden)

    Nitish Kumar

    2014-03-01

    Full Text Available BACKGROUND: This prospective randomized double blind study was conducted to evaluate the effect and safety of intrathecal dexmedetomidine added to isobaric ropivacaine. MATERIALS AND METHODS: 120 adult female patients, who underwent vaginal hysterectomies, were randomly allocated to receive intrathecally either 3 ml of 0.75% isobaric ropivacaine + 0.5 ml normal saline (Group R or 3 ml of 0.75% isobaric ropivacaine +5 μg dexmedetomidine in 0.5 ml of normal saline (Group D. Following intrathecal administration, duration of onset of sensory and motor blockade, maximum dermatomal level achieved, duration of analgesia, hemodynamic parameters and incidence of side effects were observed. RESULTS: Duration of onset of sensory block upto T10, T8 and the highest level of block achieved i. e. T6 were similar in both the groups. The mean time of sensory regression to S2 was 297.71±34.11 min in group D and 221.35±22.70 min in group R. Time to achieve Bromage score 0 was significantly slower with the addition of dexmedetomidine (229.37±28.74 min in group R vs. 258.55±30.46 min in group D. Duration of postoperative analgesia was significantly greater in group D (270.00±38.75 min as compared to group R (174.77±22.31 min. The maximum VAS score for pain was less in group D (4.42±0.69 as compared to group R (7.03±0.78. There were no significant difference in hemodynamic parameters and incidence of side effects in both the groups. CONCLUSION: The addition of dexmedetomidine to ropivacaine intrathecally produces significantly longer sensory and motor blockade along with better postoperative analgesia, and excellent hemodynamic stability without any significant side effects.

  19. Effect Of Variable Practice On The Motor Learning Process In Manual Wheelchair Propulsion

    NARCIS (Netherlands)

    Leving, Marika T; Vegter, Riemer J K; de Groot, Sonja; van der Woude, Lucas H V

    Handrim wheelchair propulsion is a cyclic skill that needs to be learned during rehabilitation. It has been suggested that a higher intra-individual variability benefits the motor learning process of wheelchair propulsion. PURPOSE: The goal of the current study was to determine the effect of

  20. Effects of Speaker Variability on Learning Foreign-Accented English for EFL Learners

    Science.gov (United States)

    Gao, Yuan; Low, Renae; Jin, Putai; Sweller, John

    2013-01-01

    Using a cognitive load theory approach, we investigated the effects of speaker variability when individuals are learning to understand English as a foreign language (EFL) spoken by foreign-accented speakers. The use of multiple, Indian-accented speakers was compared to that of a single speaker for Chinese EFL learners with a higher or lower…

  1. Effects of social stress on heart rate and heart rate variability in growing pigs

    NARCIS (Netherlands)

    de Jong, IC; Sgoifo, A; Lambooij, E; Korte, SM; Blokhuis, HJ; Koolhaas, JM

    2000-01-01

    The effects of social stress on heart rate, heart rate variability and the occurrence of cardiac arrhythmias were studied in 12 growing pigs. Social stress was induced during a good competition test with a pen mate, and subsequently during a resident-intruder test with an unacquainted pig in which t

  2. Variability in Muscle Damage after Eccentric Exercise and the Repeated Bout Effect

    Science.gov (United States)

    Chen, Trevor C.

    2006-01-01

    The first purpose of this study was to determine a possible explanation for the variability in the response to eccentric exercise by having participants repeat the same exercise 1 year apart. The second purpose was to examine whether initial injury in response to eccentric exercise was associated with the extent of the repeated bout effect (RBE).…

  3. Advanced Nonlinear Latent Variable Modeling: Distribution Analytic LMS and QML Estimators of Interaction and Quadratic Effects

    Science.gov (United States)

    Kelava, Augustin; Werner, Christina S.; Schermelleh-Engel, Karin; Moosbrugger, Helfried; Zapf, Dieter; Ma, Yue; Cham, Heining; Aiken, Leona S.; West, Stephen G.

    2011-01-01

    Interaction and quadratic effects in latent variable models have to date only rarely been tested in practice. Traditional product indicator approaches need to create product indicators (e.g., x[superscript 2] [subscript 1], x[subscript 1]x[subscript 4]) to serve as indicators of each nonlinear latent construct. These approaches require the use of…

  4. Illustrations of the Basic Concepts Involved in Testing for Moderator/Mediator Variable Effects.

    Science.gov (United States)

    Chevalier, Shirley A.

    An important but too infrequently considered methodology that can be used in research, especially research focusing on Pearson's "r" (B. Walsh, 1996) or the multiple "R" (see B. Thompson, 1992) involves testing for moderator or mediator variable effects. As explained by M. Gall, W. Borg, and J. Gall (1996), moderator analysis "involves identifying…

  5. Effects of social stress on heart rate and heart rate variability in growing pigs

    NARCIS (Netherlands)

    de Jong, IC; Sgoifo, A; Lambooij, E; Korte, SM; Blokhuis, HJ; Koolhaas, JM

    2000-01-01

    The effects of social stress on heart rate, heart rate variability and the occurrence of cardiac arrhythmias were studied in 12 growing pigs. Social stress was induced during a good competition test with a pen mate, and subsequently during a resident-intruder test with an unacquainted pig in which t

  6. Variability in Muscle Damage after Eccentric Exercise and the Repeated Bout Effect

    Science.gov (United States)

    Chen, Trevor C.

    2006-01-01

    The first purpose of this study was to determine a possible explanation for the variability in the response to eccentric exercise by having participants repeat the same exercise 1 year apart. The second purpose was to examine whether initial injury in response to eccentric exercise was associated with the extent of the repeated bout effect (RBE).…

  7. Perceiving blocks of emotional pictures and sounds : effects on physiological variables

    NARCIS (Netherlands)

    Brouwer, A.M.; Wouwe, N.C. van; Mühl, C.; Erp, J.B.F. van; Toet, A.

    2013-01-01

    Most studies on physiological effects of emotion-inducing images and sounds examine stimulus locked variables reflecting a state of at most a few seconds. We here aimed to induce longer lasting emotional states using blocks of repetitive visual, auditory, and bimodal stimuli corresponding to specifi

  8. Effects of social stress on heart rate and heart rate variability in growing pigs

    NARCIS (Netherlands)

    de Jong, IC; Sgoifo, A; Lambooij, E; Korte, SM; Blokhuis, HJ; Koolhaas, JM

    The effects of social stress on heart rate, heart rate variability and the occurrence of cardiac arrhythmias were studied in 12 growing pigs. Social stress was induced during a good competition test with a pen mate, and subsequently during a resident-intruder test with an unacquainted pig in which

  9. Effects of Antecedent Variables on Disruptive Behavior and Accurate Responding in Young Children in Outpatient Settings

    Science.gov (United States)

    Boelter, Eric W.; Wacker, David P.; Call, Nathan A.; Ringdahl, Joel E.; Kopelman, Todd; Gardner, Andrew W.

    2007-01-01

    The effects of manipulations of task variables on inaccurate responding and disruption were investigated with 3 children who engaged in noncompliance. With 2 children in an outpatient clinic, task directives were first manipulated to identify directives that guided accurate responding; then, additional dimensions of the task were manipulated to…

  10. Effects of uncertainty in major input variables on simulated functional soil behaviour

    NARCIS (Netherlands)

    Finke, P.A.; Wösten, J.H.M.; Jansen, M.J.W.

    1997-01-01

    Uncertainties in major input variables in water and solute models were quantified and their effects on simulated functional aspects of soil behaviour were studied using basic soil properties from an important soil map unit in the Netherlands. Two sources of uncertainty were studied: spatial

  11. Effects of uncertainty in major input variables on simulated functional soil behaviour

    NARCIS (Netherlands)

    Finke, P.A.; Wösten, J.H.M.; Jansen, M.J.W.

    1996-01-01

    Uncertainties in major input variables in water and solute models were quantified and their effects on simulated functional aspects of soil behaviour were studied using basic soil properties from an important soil map unit in the Netherlands. Two sources of uncertainty were studied: spatial

  12. A Second-Order Conditionally Linear Mixed Effects Model with Observed and Latent Variable Covariates

    Science.gov (United States)

    Harring, Jeffrey R.; Kohli, Nidhi; Silverman, Rebecca D.; Speece, Deborah L.

    2012-01-01

    A conditionally linear mixed effects model is an appropriate framework for investigating nonlinear change in a continuous latent variable that is repeatedly measured over time. The efficacy of the model is that it allows parameters that enter the specified nonlinear time-response function to be stochastic, whereas those parameters that enter in a…

  13. The Detection and Interpretation of Interaction Effects between Continuous Variables in Multiple Regression.

    Science.gov (United States)

    Jaccard, James; And Others

    1990-01-01

    Issues in the detection and interpretation of interaction effects between quantitative variables in multiple regression analysis are discussed. Recent discussions associated with problems of multicollinearity are reviewed in the context of the conditional nature of multiple regression with product terms. (TJH)

  14. Effect of low-dose aspirin during pregnancy on fibrinolytic variables before and after parturition

    NARCIS (Netherlands)

    H.A. Bremer (Henk); N. Rotmans (Nel); E.J.Ph. Brommer; H.C.S. Wallenburg (Henk)

    1995-01-01

    textabstractOBJECTIVE: We assessed the effects of a daily oral dose of 60 to 80 mg of aspirin from 12 weeks gestation until delivery on fibrinolytic variables before and after parturition. STUDY DESIGN: In a prospective controlled study labor was electively induced in 24 patients, eight receiving

  15. Analysis of stress effects on the cognitive operating work

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Cheol Jung; Park, Jae Hee; Lee, Nahm Sik; Yu, Young Kwan [Korea Research Institute of Standards and Science, Taejon (Korea, Republic of)

    1994-07-01

    This study is carried out to develop the performance evaluation model which explains the relationship between PSFs(performance shaping factors) and performance. The model can improve the safety efficiency of the nuclear power plants by removing the wrong PSFs. The work scope and contents of the project have the following items, such as, survey of the performance evaluation/prediction models, selecting the PSFs and performance measures, task analysis on the EOP(emergency operating procedures) for LOCA(loss of coolant accident) and modeling the relationships between PSFs and performance measures, and knowledge representation using the IF...THEN... rules. The results, knowledge base, can be used to develop the performance evaluation model for nuclear power plant operators. 46 refs.

  16. Catalytic hydropyrolysis of microalgae: influence of operating variables on the formation and composition of bio-oil.

    Science.gov (United States)

    Chang, Zhoufan; Duan, Peigao; Xu, Yuping

    2015-05-01

    Catalytic hydropyrolysis of microalgae has been studied by using a batch reactor. Nine different heterogenous catalysts of Pd/C, Pt/C, Ru/C, Rh/C, CoMo/γ-Al2O3, Mo2C, MoS2, and activated carbon were screened. Mo2C was identified as the most suitable catalyst. With Mo2C catalyst, influence of reaction conditions on the yield and properties of the hydropyrolysis oil (HPO) was examined. Temperature was the most influential factor affecting the yield and quality of the HPO. Higher temperature will produce HPO with higher C and H content and lower N and O content but at the cost of lowering the yield of HPO. Mo2C promoted the in situ deoxygenation and desulfurization of the HPO which has a HHVs varying between 35.3 and 39.3 MJ/kg. The highest energy recovery of 87.5% was achieved. Thus, this work shows that the catalytic hydropyrolysis is an effective way to produce high quality bio-oil from microalgae.

  17. Modeling the Effects of Cyber Operations on Kinetic Battles

    Science.gov (United States)

    2014-06-01

    representation. This approach restricts us to a very specific range, but may help to gain insight. We represent blue color when Blue force wins, and...red color when Red force wins. The parameters are fixed as Table 3 except two analyzed ones, which are specified in the figure. The parameters are... candle light at night. But, as was stated before, anything electronic or related to electronics can be affected by a cyber operation. Cyber Forces A

  18. Operational Assessment of Space: Toward Efficiency and Effectiveness

    Science.gov (United States)

    2005-06-01

    operations. In the 1930s, Karl Popper argued that scientists should be looking for black swans. He believed scientist should test theories with the intent...framework to explain his own “art of war.” Clausewitz believed that 12 Alioto, 164. 13 Karl Popper , The Logic of Scientific Discovery (London...Raising Concerns: Arms Experts Worried at Pentagon Push for Superiority,” Washington Post, 29 March, 2005. Popper , Karl . The Logic of Scientific

  19. Design of Adaptive Organizations for Effects Based Operations

    Science.gov (United States)

    2009-04-04

    are labeled with the stereotype "<Service>." Figure 5.21 shows the sequence of data messages that are exchanged to carry out the operational concept...practitioner’s guide to coloured Petri nets, Int J Software Tools Technology Transfer 2 (1998), 98-132. S.W. Liles, On the characterization and analysis of...Conference. 1995. Manchester. Hansen, K.M.(2001), Towards a Coloured Petri Net Profile for the Unified Modeling Language - Issues, Definition, and

  20. Effects of short term bioturbation by common voles on biogeochemical soil variables.

    Directory of Open Access Journals (Sweden)

    Burkhard Wilske

    Full Text Available Bioturbation contributes to soil formation and ecosystem functioning. With respect to the active transport of matter by voles, bioturbation may be considered as a very dynamic process among those shaping soil formation and biogeochemistry. The present study aimed at characterizing and quantifying the effects of bioturbation by voles on soil water relations and carbon and nitrogen stocks. Bioturbation effects were examined based on a field set up in a luvic arenosol comprising of eight 50 × 50 m enclosures with greatly different numbers of common vole (Microtus arvalis L., ca. 35-150 individuals ha-1 mth-1. Eleven key soil variables were analyzed: bulk density, infiltration rate, saturated hydraulic conductivity, water holding capacity, contents of soil organic carbon (SOC and total nitrogen (N, CO2 emission potential, C/N ratio, the stable isotopic signatures of 13C and 15N, and pH. The highest vole densities were hypothesized to cause significant changes in some variables within 21 months. Results showed that land history had still a major influence, as eight key variables displayed an additional or sole influence of topography. However, the δ15N at depths of 10-20 and 20-30 cm decreased and increased with increasing vole numbers, respectively. Also the CO2 emission potential from soil collected at a depth of 15-30 cm decreased and the C/N ratio at 5-10 cm depth narrowed with increasing vole numbers. These variables indicated the first influence of voles on the respective mineralization processes in some soil layers. Tendencies of vole activity homogenizing SOC and N contents across layers were not significant. The results of the other seven key variables did not confirm significant effects of voles. Thus overall, we found mainly a first response of variables that are indicative for changes in biogeochemical dynamics but not yet of those representing changes in pools.

  1. Variable-density effects on the worth of pressure data for characterizing aquifer permeability

    Science.gov (United States)

    Yoon, Seonkyoo; Kang, Peter; Williams, John

    2017-04-01

    We investigate variable-density effects on the worth of pressure data for estimating aquifer permeability. In variable-density flow and transport in porous media, the pressure distribution is transient even without changes in boundary conditions because the variable-density gradient itself can induce gravity currents. This means that the transient pressure distribution is implicitly coupled with additional information from the variable-density gradient, and consequently the data can be more informative than in density invariant cases for aquifer characterization. To systematically investigate the informativeness of the transient pressure data, we analyze the performance of permeability characterization employing the pressure data under various levels of variable-density effects. The variable-density effects can be controlled by a mixed convection ratio, which is a ratio between two characteristic convections: free convection due to a density gradient and forced convection due to a hydraulic gradient. A 2D density-dependent flow and transport model is established to simulate a coastal aquifer system where density flow occurs due to density difference between saline seawater and fresh water. An ensemble Kalman filter (EnKF) with convariance localization and inflation is used to sequentially estimate heterogeneous aquifer permeability fields by conditioning on real-time pressure head data. The performance of the permeability estimation is analyzed in terms of accuracy of estimated permeability fields, and predictability of arrival times of breakthrough curves in a push-pull setting. The analysis shows that the accuracy and predictability of the inverse estimation can be most improved when the free convection is balanced with the forced convection, which corresponds to the mixed convection ratio being one. This demonstrates that the pressure data is most informative for characterizing aquifer permeability fields when the two characteristic convections are balanced.

  2. Strong-flavor-changing effective operator contributions to single top quark production

    CERN Document Server

    Ferreira, P M; 10.1103/PhysRevD.73.054025

    2006-01-01

    We study the effects of dimension six effective operators on the production of single top quarks at the CERN LHC. The operator set considered includes terms with effective gluon interactions and four- fermion terms. Analytic expressions for the several partonic cross sections of single top production will be presented, as well as the results of their integration on the parton density functions.

  3. The Effectiveness of Structured Co-Operative Teaching and Learning in Greek Primary School Classrooms

    Science.gov (United States)

    Kaldi, Stavroula; Filippatou, Diamanto; Anthopoulou, Barbara

    2014-01-01

    This study focuses upon the effectiveness of structured co-operative group work on primary school students, aged between 8.5 and 9.5 years old, regarding their content knowledge, attitudes towards co-operative group work, experiential learning and open-ended curriculum as well as students' social and learning behaviour during co-operative group…

  4. The Effectiveness of Structured Co-Operative Teaching and Learning in Greek Primary School Classrooms

    Science.gov (United States)

    Kaldi, Stavroula; Filippatou, Diamanto; Anthopoulou, Barbara

    2014-01-01

    This study focuses upon the effectiveness of structured co-operative group work on primary school students, aged between 8.5 and 9.5 years old, regarding their content knowledge, attitudes towards co-operative group work, experiential learning and open-ended curriculum as well as students' social and learning behaviour during co-operative group…

  5. Effect of pre-analytical handling on haematological variables in minipigs

    DEFF Research Database (Denmark)

    Olsen, A K; Bladbjerg, E-M; Jensen, A L

    2001-01-01

    Pre-analytical handling may be an important determinant of haematological variables, if analysis is delayed. We investigated the effect of anticoagulants, i.e. tripotassium ethylenediamine-tetraacetic acid (EDTA) and citric acid, theophylline, adenosine, dipyridamole (CTAD), storage time (0.5, 1......, the samples must be stored in a refrigerator until analysis. Our studies underline that time delay before analysis of haematological variables can cause increased variation, and should therefore be limited as far as possible in order to reduce the number of animals needed to make reliable conclusions...

  6. Effects of perceptual variables on numerosity comparisonin 5-6-year-olds and adults

    Directory of Open Access Journals (Sweden)

    Midori eTokita

    2013-07-01

    Full Text Available Although a critical issue in the debate over the existence of abstract numerical representation, it remains unclear whether and how perceptual variables affect numerosity judgment and how they change across development stages. In this research, we examine the effects of perceptual variables on approximate numerosity comparison in 5-6-year-olds and adults using the identical experimental procedure. In the assessment of the effect of the perceptual variables, we measured precision (i.e., Weber fraction and accuracy (i.e., point of subjective equality; PSE of the numerosity comparison. In Study 1, we tested how the manipulation of the cumulative element area would affect approximate numerosity comparison. The results showed that Weber fractions increased and the size of bias enlarged in the large element condition in both adults and 5-6-year-olds. In study 2, we tested how the manipulation of the array area would affect the precision and accuracy of approximate numerosity comparison. The results demonstrated that Weber fractions increased and the size of bias enlarged in the large array condition in both adults and 5-6-year-olds. Overall, our results suggest that the effect of perceptual variables on 5-6-year-olds is qualitatively similar to that on adults. In addition, we also tested whether the performance of approximate comparison correlated with the initial numerical skill in 5-6-year-olds to reveal least relationship between them.

  7. Regional Variability of the Effects of Land Use Systems on Soil Properties

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In order to explore the regional variability of the effects of land use systems on soil properties, Shouyang County in Shanxi Province and Danling County in Sichuan Province of China were selected as the study areas. Field soil samples of the four land use systems (natural forest, forest plantation, shrubland, and cropland) were collected, respectively, from the two areas. The general statistical tools were used to analyze soil data. The results showed that the influence of land use systems on soil properties was significant. In general, soils in slightly human-disturbed land use systems presented a higher fertility level than those in strongly human-disturbed land use systems in both areas. Furthermore, the impacts of the same land use systems on soil properties showed a distinct regional variability, and even in the same land use system,different farming systems and site management measures (such as irrigation, fertilization, and pesticides) could also lead to the regional heterogeneity in soil properties. The regional variability of land use effects on soil properties reveals the regional variability of the effects of human activities on environmental changes, and could explain the complex relationship between humans and the natural environment in certain ways.

  8. A Study of the Effective Variables on Earning Management: Iranian Evidence

    Directory of Open Access Journals (Sweden)

    Mahdi Moradi

    2012-08-01

    Full Text Available The current study aims to examine the effective variables an earning management in Tehran Stock exchange during 2004 -2010. In this research the discretionary accruals from modified Jones model to determine earning management in the firms have been used and auditor change and type of auditor (for examining accounting quality, type of ownership, number of main shareholders, percentage of ownership for largest shareholder, percentage of ownership main shareholders (for examining corporate governance, incentives of earning management (number of employee, equity-debt ratio, leverage and tax and also financial ratios (performance coefficient, changes in net income, gross income to sale ratio and current ratio, used firm size and type of industry variables have been considered as control variable. To analyze data the multiple regression and backward regression as well as interaction regression have been used cross-sectionally and collectively.

  9. Effects of climate oscillations on wind resource variability in the United States

    Science.gov (United States)

    Hamlington, B. D.; Hamlington, P. E.; Collins, S. G.; Alexander, S. R.; Kim, K.-Y.

    2015-01-01

    Natural climate variations in the United States wind resource are assessed by using cyclostationary empirical orthogonal functions (CSEOFs) to decompose wind reanalysis data. Compared to approaches that average climate signals or assume stationarity of the wind resource on interannual time scales, the CSEOF analysis isolates variability associated with specific climate oscillations, as well as their modulation from year to year. Contributions to wind speed variability from the modulated annual cycle (MAC) and the El Niño-Southern Oscillation (ENSO) are quantified, and information provided by the CSEOF analysis further allows the spatial variability of these effects to be determined. The impacts of the MAC and ENSO on the wind resource are calculated at existing wind turbine locations in the United States, revealing variations in the wind speed of up to 30% at individual sites. The results presented here have important implications for predictions of wind plant power output and siting.

  10. The effect of patient satisfaction with pharmacist consultation on medication adherence: an instrumental variable approach

    Directory of Open Access Journals (Sweden)

    Gu NY

    2008-12-01

    Full Text Available There are limited studies on quantifying the impact of patient satisfaction with pharmacist consultation on patient medication adherence. Objectives: The objective of this study is to evaluate the effect of patient satisfaction with pharmacist consultation services on medication adherence in a large managed care organization. Methods: We analyzed data from a patient satisfaction survey of 6,916 patients who had used pharmacist consultation services in Kaiser Permanente Southern California from 1993 to 1996. We compared treating patient satisfaction as exogenous, in a single-equation probit model, with a bivariate probit model where patient satisfaction was treated as endogenous. Different sets of instrumental variables were employed, including measures of patients' emotional well-being and patients' propensity to fill their prescriptions at a non-Kaiser Permanente (KP pharmacy. The Smith-Blundell test was used to test whether patient satisfaction was endogenous. Over-identification tests were used to test the validity of the instrumental variables. The Staiger-Stock weak instrument test was used to evaluate the explanatory power of the instrumental variables. Results: All tests indicated that the instrumental variables method was valid and the instrumental variables used have significant explanatory power. The single equation probit model indicated that the effect of patient satisfaction with pharmacist consultation was significant (p<0.010. However, the bivariate probit models revealed that the marginal effect of pharmacist consultation on medication adherence was significantly greater than the single equation probit. The effect increased from 7% to 30% (p<0.010 after controlling for endogeneity bias. Conclusion: After appropriate adjustment for endogeneity bias, patients satisfied with their pharmacy services are substantially more likely to adhere to their medication. The results have important policy implications given the increasing focus

  11. EFFECT OF DIFFERENT OPERATION METHODS ON METHANE HYDRATE FORMATION

    Institute of Scientific and Technical Information of China (English)

    HAO Wenfeng; FAN Shuanshi; WANG Jinqu

    2003-01-01

    Three experiments of static state storage method, low-temperature and constant-pressure storage method and low-temperature and constant-pressure storage method were carried out to investigate which method was best in gas hydrate. The relationships of hydrate rate, capacity and liquid temperature versus time were derived and three results were contrasted. The experimental results show lowtemperature and constant-pressure method is better than the other two methods because it's operation period is shorter and storage capacity is larger than the other two. Low-temperature and constant-pressure method is the best method. So new method will be new research objective.

  12. Determination of the effectiveness of concentrating mine-tunneling operations

    Energy Technology Data Exchange (ETDEWEB)

    Domanov, P.I.

    1979-02-01

    Experimental operations were conducted in 163 tunneling faces equipped with loading machines and mounted drilling machines and in 110 faces equipped with the pneumatic drilling machines 1PNB-2E in order to determine the optimal specific population of tunnellers in a working face. Following computerized processing of the obtained data, mathematical formulas were derived to compute the optimal rate of tunneling drifts with respect to productivity. Relationships were given for the productivity of drift miners and the rate of tunneling drifts, and between the complete cost of tunneling a drift and the velocity of tunneling. 3 figures.

  13. Radiation and annealing effects on integrated bipolar Operational Amplifier

    Science.gov (United States)

    Assaf, J.

    2017-02-01

    Integrated bipolar Operational Amplifier (op-amp) type μA 741 was irradiated with neutrons and gamma rays. The radiation on gain factors, slew rate, and power supply current have been evaluated. The experimental results show a decrease of these parameter values after exposing to the radiation. The advantage of the increase of the voltage power supplies and the thermal annealing treatment on the damaged parameters was also explored. The relationship among different frequency response parameters is also studied leading to an analytical formula for the above degraded parameters.

  14. The effects of climate variables on the outbreak of dengue in Queensland 2008-2009.

    Science.gov (United States)

    Hasan, Tasnim; Bambrick, Hilary

    2013-07-04

    Outbreaks of dengue occur in Queensland, Australia nearly every summer. In 2008-2009, there was an unusually large, protracted outbreak of dengue, comprised of 1,200 cases. We investigated the weather variables and their contribution to the 2008-2009 dengue outbreak in Queensland. Case data were obtained from the Communicable Disease Branch of Queensland Health for 2000-2010 for the towns of Cairns and Townsville. Monthly weather data (rainfall, maximum temperature, minimum temperature) and Southern Oscillation Index (SOI) was obtained from the Bureau of Meteorology (BOM). We used a negative binomial model to test associations between these variables and dengue. Lagged models were also created for one, two and three months. Our models suggest all weather variables but not the SOI were associated with dengue in both Cairns and Townsville, without a lag (pRainfall and temperature preceding the 2008-2009 outbreak were also not significantly different (p<0.01) from other years. Short-term (non-lagged) weather variables were associated with the number of dengue cases in Cairns and Townsville. No lag was seen and no association was seen between the SOI and the number of dengue cases, which suggests there may be limited potential to predict large dengue outbreaks using climate variability. The large outbreak in 2008-2009 may have been driven by other, non-weather factors in addition to the immediate weather effect.

  15. Effect of Heart Rate Variability Biofeedback on Sport Performance, a Systematic Review.

    Science.gov (United States)

    Jiménez Morgan, Sergio; Molina Mora, José Arturo

    2017-06-01

    Aim is to determine if the training with heart rate variability biofeedback allows to improve performance in athletes of different disciplines. Methods such as database search on Web of Science, SpringerLink, EBSCO Academic Search Complete, SPORTDiscus, Pubmed/Medline, and PROQUEST Academic Research Library, as well as manual reference registration. The eligibility criteria were: (a) published scientific articles; (b) experimental studies, quasi-experimental, or case reports; (c) use of HRV BFB as main treatment; (d) sport performance as dependent variable; (e) studies published until October 2016; (f) studies published in English, Spanish, French or Portuguese. The guidelines of the PRISMA statement were followed. Out of the 451 records found, seven items were included. All studies had a small sample size (range from 1 to 30 participants). In 85.71% of the studies (n = 6) the athletes enhanced psychophysiological variables that allowed them to improve their sport performance thanks to training with heart rate variability biofeedback. Despite the limited amount of experimental studies in the field to date, the findings suggest that heart rate variability biofeedback is an effective, safe, and easy-to-learn and apply method for both athletes and coaches in order to improve sport performance.

  16. Is Terzaghi’s effective stress a stress variable under seepage conditions?

    Institute of Scientific and Technical Information of China (English)

    雷国辉; 赵仲辉; 吴宏伟

    2015-01-01

    From the continuum mechanics perspective, an attempt was made to clarify the role of Terzaghi’s effective stress in the theoretical analysis of saturated soil subjected to seepage. The necessity of performing a coupled hydromechanical analysis to solve the seepage−deformation interaction problem was illustrated by examining the equations of static equilibrium among the effective stress, seepage force, pore-water pressure and total stress. The conceptual definition of stress variable that satisfies the principles of continuum mechanics is applied in the coupled hydromechanical analysis. It is shown that Terzaghi’s effective stress is in fact not a stress variable under seepage conditions, and the seepage force acting on the soil skeleton cannot be viewed as a body force. This offers a clue to the underlying cause of a paradox between the real Pascal’s hydrostatic state and the hydrostatic state predicted by a class of continuum hydromechanical theories.

  17. CP violation and matter effect for a variable earth density in very long baseline experiments

    CERN Document Server

    Brahmachari, B; Roy, P; Brahmachari, Biswajoy; Choubey, Sandhya; Roy, Probir

    2003-01-01

    The perturbative treatment of subdominant oscillation and the matter effect in neutrino beams/superbeams, propagating over long baselines and being used to look for CP violation, is studied here for a general matter density function varying with distance. New lowest order analytic expressions are given for different flavour transition and survival probabilities in a general neutrino mixing basis and a variable earth matter density profile. It is demonstrated that the matter effect in the muon neutrino (antineutrino) flavour survival probability vanishes to this order, provided the depletion, observed for atmospheric muon neutrinos and antineutrinos at super-Kamiokande, is strictly maximal. This result is independent of the earth density profile and the distance L between the source and the detector. In the general variable density case we show that one cannot separate the matter induced asymmetry from a genuine CP effect by keeping two detectors at distances $L_1$ and $L_2$ from the source while maintaining a...

  18. Investigation on the effects of geometric variables on the residual stresses and PWSCC growth in the RPV BMI penetration nozzles

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Sung; Ra, Myoung Soo [Sunchon National University, Suncheon (Korea, Republic of); Lee, Kyoung Soo [Korea Hydro Nuclear Company, Daejeon (Korea, Republic of)

    2015-03-15

    This study investigated the effects of various geometric variables on the residual stresses and PWSCC growth of RPV BMI penetration nozzles. An FE residual stress analysis procedure was developed and validated from the viewpoint of FFS assessment. The validated FE residual stress analysis procedure and the PWSCC growth assessment procedure in the ASME B and PV Code, Sec.XI were applied to the BMI penetration nozzles with specified ranges of the geometric variables. The total stresses at steady state during normal operation including welding residual stresses increase with increasing inclination angle of the BMI nozzles, and with tilt angle, depth, and root width of the J-groove weld. The lifetime from the assumed initial crack to the acceptance criteria according to the ASME B and PV Code, Sec.XI also decreases under these conditions. The total stresses decrease and the lifetime increases with increasing nozzle thickness, but outer radius of the BMI nozzles has an insignificant effect on both of these factors.

  19. Effective Management Tools in Implementing Operational Programme Administrative Capacity Development

    Directory of Open Access Journals (Sweden)

    Carmen – Elena DOBROTĂ

    2015-12-01

    Full Text Available Public administration in Romania and the administrative capacity of the central and local government has undergone a significant progress since 2007. The development of the administrative capacity deals with a set of structural and process changes that allow governments to improve the formulation and implementation of policies in order to achieve enhanced results. Identifying, developing and using management tools for a proper implementation of an operational programme dedicated to consolidate a performing public administration it was a challenging task, taking into account the types of interventions within Operational Programme Administrative Capacity Development 2007 – 2013 and the continuous changes in the economic and social environment in Romania and Europe. The aim of this article is to provide a short description of the approach used by the Managing Authority for OPACD within the performance management of the structural funds in Romania between 2008 and 2014. The paper offers a broad image of the way in which evaluations (ad-hoc, intermediate and performance were used in different stages of OP implementation as a tool of management.

  20. Are positive and negative reinforcement "different"? Insights from a free-operant differential outcomes effect.

    Science.gov (United States)

    Magoon, Michael A; Critchfield, Thomas S; Merrill, Dustin; Newland, M Christopher; Schneider, W Joel

    2017-01-01

    Although theoretical discussions typically assume that positive and negative reinforcement differ, the literature contains little unambiguous evidence that they produce differential behavioral effects. To test whether the two types of consequences control behavior differently, we pitted money-gain positive reinforcement and money-loss-avoidance negative reinforcement, scheduled through identically programmed variable-cycle schedules, against each other in concurrent schedules. Contingencies of response-produced feedback, normally different in positive and negative reinforcement, were made symmetrical. Steeper matching slopes were produced compared to a baseline consisting of all positive reinforcement. This free-operant differential outcomes effect supports the notion that that stimulus-presentation positive reinforcement and stimulus-elimination negative reinforcement are functionally "different." However, a control experiment showed that the feedback asymmetry of more traditional positive and negative reinforcement schedules also is sufficient to create a "difference" when the type of consequence is held constant. We offer these findings as a small step in meeting the very large challenge of moving negative reinforcement theory beyond decades of relative quiescence.

  1. Perioperative psychological and music interventions in elderly patients undergoing spinal anesthesia: effect on anxiety, heart rate variability, and postoperative pain.

    Science.gov (United States)

    Wang, Yisha; Dong, Youjing; Li, Yang

    2014-07-01

    The aim of this study was to evaluate the effects of perioperative psychological and music interventions in elderly patients undergoing elective surgery on anxiety, post-operative pain, and changes in heart rate variability (HRV) to ascertain if perioperative psychological and music interventions can affect overall anxiety levels. Fourty elderly patients undergoing elective surgery were randomized to two groups; one group received psychological and music intervention, and the other was the control. The intervention group underwent psychological intervention and listening to music for 30 min before surgery. The mean change in HRV as determined by low frequency (LF) power measurements. After the intervention, the ratio of mean LF to high frequency (HF) power decreased significantly in the intervention group compared to before the intervention (pmusic interventions can reduce anxiety and postoperative pain in elderly patients.

  2. Biofeedback on heart rate variability in cardiac rehabilitation: practical feasibility and psycho-physiological effects.

    Science.gov (United States)

    Climov, Daniela; Lysy, Camille; Berteau, Sylvain; Dutrannois, Jacques; Dereppe, Hubert; Brohet, Christian; Melin, Jacques

    2014-06-01

    Biofeedback is a self-regulation therapy by which the patient learns how to optimize the functioning of his autonomic nervous system. It has been applied to patients with various cardiovascular disorders. The purpose of this study was to investigate the practical feasibility and the psychophysiological effects of biofeedback applied to heart rate variability (HRV biofeedback) in order to increase cardiac coherence in coronary artery disease (CAD) patients participating in a cardiac rehabilitation programme. In this randomised and controlled study, 31 CAD patients were randomly assigned to an experimental or to a control group. The experimental group participated in a programme of 10 sessions of cardiac coherence biofeedback training, in addition to the rehabilitation programme. The control group participated in the usual cardiac rehabilitation programme only. Physiological variables (systolic and diastolic blood pressure, SDNN) and psychosocial variables (anxiety, depression, type D personality) were measured at the start and at the end of the programme in both groups. Statistical comparisons assessed the inter and intra group differences. The small sample size precludes any firm conclusions concerning the effect of cardiac coherence biofeedback on physiological or psychological variables. However, we observed a significant increase of the percentage of cardiac coherence, in relation with an increased SDNN index. Our study demonstrated the practical feasibility of cardiac coherence biofeedback training in CAD patients. Further research is desirable to investigate the potential benefit of cardiac coherence biofeedback as an adjunct to stress management in cardiac rehabilitation.

  3. Effects of atmospheric water vapor on detection performance of a linear variable filter based instrument

    Science.gov (United States)

    Shen, Sylvia S.; Miller, David P.; Lewis, Paul E.

    2010-08-01

    Linear variable filter design and fabrication for LWIR is now commercially available for use in the development of airborne reconnaissance or surveillance systems. The linear variable filter is attached directly to the cold shield of the focal plane array. The resulting compact spectrometer assemblies are completely contained in the Dewar system. This approach eliminates many of the wavelength calibration problems associated with current prism and grating systems and also facilitates the cost effective design and fabrication of aerial sensing systems for specific applications. An optimal 32 band linear-variablefilter- based system for detecting and discriminating a set of 11 chemicals representing a high probability of occurrence during a typical emergency response chemical incident was determined in a companion paper entitled "Linear Variable Filter Optimization for Emergency Response Chemical Detection and Discrimination". This paper addresses the effects of atmospheric water vapor on the performance of this optimal 32 band linear-variable-filter-based system. This paper also determines at what increased concentration levels above the optimal system design goal of 30 ppm-m can detection and discrimination of these 11 chemicals be achieved in realistic but imperfect atmospheric water vapor removal scenarios.

  4. Functional diversity of catch mitigates negative effects of temperature variability on fisheries yields.

    Science.gov (United States)

    Dee, Laura E; Miller, Steve J; Peavey, Lindsey E; Bradley, Darcy; Gentry, Rebecca R; Startz, Richard; Gaines, Steven D; Lester, Sarah E

    2016-08-17

    Temperature variation within a year can impact biological processes driving population abundances. The implications for the ecosystem services these populations provide, including food production from marine fisheries, are poorly understood. Whether and how temperature variability impacts fishery yields may depend on the number of harvested species and differences in their responses to varying temperatures. Drawing from previous theoretical and empirical studies, we predict that greater temperature variability within years will reduce yields, but harvesting a larger number of species, especially a more functionally diverse set, will decrease this impact. Using a global marine fisheries dataset, we find that within-year temperature variability reduces yields, but current levels of functional diversity (FD) of targeted species, measured using traits related to species' responses to temperature, largely offset this effect. Globally, high FD of catch could avoid annual losses in yield of 6.8% relative to projections if FD were degraded to the lowest level observed in the data. By contrast, species richness in the catch and in the ecosystem did not provide a similar mitigating effect. This work provides novel empirical evidence that short-term temperature variability can negatively impact the provisioning of ecosystem services, but that FD can buffer these negative impacts.

  5. Heart rate variability in elite triathletes, is variation in variability the key to effective training? A case comparison.

    Science.gov (United States)

    Plews, Daniel J; Laursen, Paul B; Kilding, Andrew E; Buchheit, Martin

    2012-11-01

    Measures of an athlete's heart rate variability (HRV) have shown potential to be of use in the prescription of training. However, little data exists on elite athletes who are regularly exposed to high training loads. This case study monitored daily HRV in two elite triathletes (one male: 22 year, VO2max 72.5 ml kg min(-1); one female: 20 year, VO2max 68.2 ml kg min(-1)) training 23 ± 2 h per week, over a 77-day period. During this period, one athlete performed poorly in a key triathlon event, was diagnosed as non-functionally over-reached (NFOR) and subsequently reactivated the dormant virus herpes zoster (shingles). The 7-day rolling average of the log-transformed square root of the mean sum of the squared differences between R-R intervals (Ln rMSSD), declined towards the day of triathlon event (slope = -0.17 ms/week; r2 = -0.88) in the NFOR athlete, remaining stable in the control (slope = 0.01 ms/week; r2 = 0.12). Furthermore, in the NFOR athlete, coefficient of variation of HRV (CV of Ln rMSSD 7-day rolling average) revealed large linear reductions towards NFOR (i.e., linear regression of HRV variables versus day number towards NFOR: -0.65%/week and r2 = -0.48), while these variables remained stable for the control athlete (slope = 0.04%/week). These data suggest that trends in both absolute HRV values and day-to-day variations may be useful measurements indicative of the progression towards mal-adaptation or non-functional over-reaching.

  6. The effects of auditory stimulation with music on heart rate variability in healthy women

    Directory of Open Access Journals (Sweden)

    Adriano L. Roque

    2013-07-01

    Full Text Available OBJECTIVES: There are no data in the literature with regard to the acute effects of different styles of music on the geometric indices of heart rate variability. In this study, we evaluated the acute effects of relaxant baroque and excitatory heavy metal music on the geometric indices of heart rate variability in women. METHODS: We conducted this study in 21 healthy women ranging in age from 18 to 35 years. We excluded persons with previous experience with musical instruments and persons who had an affinity for the song styles. We evaluated two groups: Group 1 (n = 21, who were exposed to relaxant classical baroque musical and excitatory heavy metal auditory stimulation; and Group 2 (n = 19, who were exposed to both styles of music and white noise auditory stimulation. Using earphones, the volunteers were exposed to baroque or heavy metal music for five minutes. After the first music exposure to baroque or heavy metal music, they remained at rest for five minutes; subsequently, they were re-exposed to the opposite music (70-80 dB. A different group of women were exposed to the same music styles plus white noise auditory stimulation (90 dB. The sequence of the songs was randomized for each individual. We analyzed the following indices: triangular index, triangular interpolation of RR intervals and Poincaré plot (standard deviation of instantaneous beat-by-beat variability, standard deviation of the long-term RR interval, standard deviation of instantaneous beat-by-beat variability and standard deviation of the long-term RR interval ratio, low frequency, high frequency, low frequency/high frequency ratio, standard deviation of all the normal RR intervals, root-mean square of differences between the adjacent normal RR intervals and the percentage of adjacent RR intervals with a difference of duration greater than 50 ms. Heart rate variability was recorded at rest for 10 minutes. RESULTS: The triangular index and the standard deviation of

  7. Effects of an Elementary Strategy on Operations of Exclusion.

    Science.gov (United States)

    Lawton, Joseph T.

    Effects of an advance organizer lesson (containing high-order science concepts relating to the law of capillary attraction, and an elementary problem-solving strategy for determining causal relations) were evaluated for a sample of 80 urban 6- and 10-year-old children. Significant sequential transfer effects were established from the lesson.…

  8. Effective Operational Assessment: A Return to the Basics

    Science.gov (United States)

    2010-10-27

    representatives examples, see James Clancy and Chuck Crossett , ―Measuring Effectiveness in Irregular Warfare,‖ Parameters (Summer 2007): 88–100...and Chuck Crossett . ―Measuring Effectiveness in Irregular Warfare.‖ Parameters (Summer 2007): 88–100. http://www.carlisle.army.mil/usawc/Parameters

  9. Delayed protective effect of telmisartan on lung ischemia/reperfusion injury in valve replacement operations.

    Science.gov (United States)

    Fan, Yongfeng; Zhang, Daguo; Xiang, Daokang

    2016-10-01

    The present study aimed to investigate the delayed protective effect of telmisartan on lung ischemic/reperfusion injury in patients undergoing heart valve replacement operations. In total, 180 patients diagnosed with rheumatic valve diseases were randomly divided into the telmisartan (T), captopril (C) and placebo (P) groups. In the telmisartan group, the patients were pretreated with telmisartan (1 mg/kg/day), at the time period 96-48 h before the operation, whereas in the C group, the patients were treated with captopril (1 mg/kg/day) at the time period 96-48 h prior to the operation control group. Each drug treatment group included a corresponding placebo treatment. The variables pulmonary vascular resistance (PVR) and A-aDO2 were measured prior to CPB and at 1, 3, 6 and 12 h after CPB. Pulmonary neutrophil (PMN) count in the left and right atrium blood as well as SOD malondialdehyde (MDA), NO, angiotensin II (AngII) value in the left atrium blood, were measured 30 min prior to and after CPB. The PVR parameters of the telmisartan and captopril groups were significantly lower than those of the placebo group (Ptelmisartan and captopril groups were significantly lower than those in the placebo group at 1, 3 and 6 h following CPB treatment. The difference between the right and left atrium blood PMN was significantly lower in the telmisartan and captopril intervention groups compared to that in the placebo group 30 min following CPB treatment. The left atrium blood SOD and NO values were significantly higher, whereas the MDA value was significantly lower in the telmisartan group compared to the control group 30 min following CPB treatment. As for AngII, there was no difference between the C and T groups, compared with the P group. In the two groups 30 min after treatment with CPB, 24 patients experienced varying degrees of cough, with the telmisartan group showing a significant difference (Ptelmisartan group than the captopril and placebo groups (Ptelmisartan (1 mg

  10. Effect of tone mapping operators on visual attention deployment

    Science.gov (United States)

    Narwaria, Manish; Perreira Da Silva, Matthieu; Le Callet, Patrick; Pepion, Romuald

    2012-10-01

    High Dynamic Range (HDR) images/videos require the use of a tone mapping operator (TMO) when visualized on Low Dynamic Range (LDR) displays. From an artistic intention point of view, TMOs are not necessarily transparent and might induce different behavior to view the content. In this paper, we investigate and quantify how TMOs modify visual attention (VA). To that end both objective and subjective tests in the form of eye-tracking experiments have been conducted on several still image content that have been processed by 11 different TMOs. Our studies confirm that TMOs can indeed modify human attention and fixation behavior significantly. Therefore our studies suggest that VA needs consideration for evaluating the overall perceptual impact of TMOs on HDR content. Since the existing studies so far have only considered the quality or aesthetic appeal angle, this study brings in a new perspective regarding the importance of VA in HDR content processing for visualization on LDR displays.

  11. Effects of the uncertainty of energy price and water availability forecasts on the operation of Alpine hydropower reservoir systems

    Science.gov (United States)

    Anghileri, D.; Castelletti, A.; Burlando, P.

    2016-12-01

    European energy markets have experienced dramatic changes in the last years because of the massive introduction of Variable Renewable Sources (VRSs), such as wind and solar power sources, in the generation portfolios in many countries. VRSs i) are intermittent, i.e., their production is highly variable and only partially predictable, ii) are characterized by no correlation between production and demand, iii) have negligible costs of production, and iv) have been largely subsidized. These features result in lower energy prices, but, at the same time, in increased price volatility, and in network stability issues, which pose a threat to traditional power sources because of smaller incomes and higher maintenance costs associated to a more flexible operation of power systems. Storage hydropower systems play an important role in compensating production peaks, both in term of excess and shortage of energy. Traditionally, most of the research effort in hydropower reservoir operation has focused on modeling and forecasting reservoir inflow as well as designing reservoir operation accordingly. Nowadays, price variability may be the largest source of uncertainty in the context of hydropower systems, especially when considering medium-to-large reservoirs, whose storage can easily buffer small inflow fluctuations. In this work, we compare the effects of uncertain inflow and energy price forecasts on hydropower production and profitability. By adding noise to historic inflow and price trajectories, we build a set of synthetic forecasts corresponding to different levels of predictability and assess their impact on reservoir operating policies and performances. The study is conducted on different hydropower systems, including storage systems and pumped-storage systems, with different characteristics, e.g., different inflow-capacity ratios. The analysis focuses on Alpine hydropower systems where the hydrological regime ranges from purely ice and snow-melt dominated to mixed snow

  12. Knife mill operating factors effect on switchgrass particle size distributions.

    Science.gov (United States)

    Bitra, Venkata S P; Womac, Alvin R; Yang, Yuechuan T; Igathinathane, C; Miu, Petre I; Chevanan, Nehru; Sokhansanj, Shahab

    2009-11-01

    Biomass particle size impacts handling, storage, conversion, and dust control systems. Switchgrass (Panicum virgatum L.) particle size distributions created by a knife mill were determined for integral classifying screen sizes from 12.7 to 50.8 mm, operating speeds from 250 to 500 rpm, and mass input rates from 2 to 11 kg/min. Particle distributions were classified with standardized sieves for forage analysis that included horizontal sieving motion with machined-aluminum sieves of thickness proportional to sieve opening dimensions. Then, a wide range of analytical descriptors were examined to mathematically represent the range of particle sizes in the distributions. Correlation coefficient of geometric mean length with knife mill screen size, feed rate, and speed were 0.872, 0.349, and 0.037, respectively. Hence, knife mill screen size largely determined particle size of switchgrass chop. Feed rate had an unexpected influence on particle size, though to a lesser degree than screen size. The Rosin-Rammler function fit the chopped switchgrass size distribution data with an R(2)>0.982. Mass relative span was greater than 1, which indicated a wide distribution of particle sizes. Uniformity coefficient was more than 4.0, which indicated a large assortment of particles and also represented a well-graded particle size distribution. Knife mill chopping of switchgrass produced 'strongly fine skewed mesokurtic' particles with 12.7-25.4 mm screens and 'fine skewed mesokurtic' particles with 50.8 mm screen. Results of this extensive analysis of particle sizes can be applied to selection of knife mill operating parameters to produce a particular size of switchgrass chop, and will serve as a guide for relations among the various analytic descriptors of biomass particle distributions.

  13. Effect of operating microscope light on brain temperature during craniotomy.

    Science.gov (United States)

    Gayatri, Parthasarathi; Menon, Girish G; Suneel, Puthuvassery R

    2013-07-01

    Operating microscopes used during neurosurgery are fitted with xenon light. Burn injuries have been reported because of xenon microscope lighting as the intensity of xenon light is 300 W. We designed this study to find out if the light of operating microscope causes an increase in temperature of the brain tissue, which is exposed underneath. Twenty-one adult patients scheduled for elective craniotomies were enrolled. Distal esophageal temperature (T Eso), brain temperature under the microscope light (T Brain), and brain temperature under dura mater (T Dura) were measured continuously at 15-minute intervals during microscope use. The irrigation fluid temperature, room temperature, intensity of the microscope light, and the distance of the microscope from the brain surface were kept constant. The average age of the patients was 44±15 years (18 males and 3 females). The mean duration of microscope use was 140±39 minutes. There were no significant changes in T Brain and T Dura and T Eso over time. T Dura was significantly lower than T Brain both at time 0 and 60 minutes but not at 90 minutes. T Brain was significantly lower than T Eso both at time 0 and 60 minutes but not at 90 minutes. The T Dura remained significantly lower than T Eso at 0, 60, and 90 minutes. Our study shows that there is no significant rise in brain temperature under xenon microscope light up to 120 minutes duration, at intensity of 60% to 70%, from a distance of 20 to 25 cm from the brain surface.

  14. Effect of peri-operative intravenous infusion of lignocaine on haemodynamic responses to intubation, extubation and post-operative analgesia

    Institute of Scientific and Technical Information of China (English)

    Yu-Mei Peng; An-Min Shao

    2016-01-01

    Objective: To study the effect of peri-operative intravenous infusion of lignocaine on haemodynamic responses to intubation, extubation and post-operative analgesia. Methods:A total of 90 patients performed with elective laparoscopic cholecystectomy under total anesthesia were randomly divided into three groups with 30 patients in each group. In Group A, patients received 6 mL normal saline as bolus over 10 min followed by 6 mL/h infusion, whereas in Group B, patients were intravenously injected with 2%lignocaine at the rate of 1 mg/kg intravenous injection, 10 min later, conducting intravenous infusion at the rate of 1 mg/kg/h until an hour after operation. In Group C, patients were intravenously injected with 2%lignocaine at a rate of 1.5 mL/kg intravenous injection, 10 min later, conducting intravenous infusion at a rate of 1.5 mL/kg/h until an hour after operation. We recorded the heart rate (HR)and mean arterial pressure (MAP)of before infusion lignocaine (T0), before induction (T1), intubation (T2), 3 min after intubation (T3), 10 min after intubation (T4), extubation (T5), 3 min after extubation (T6)and 10 min after extubation (T7). We also recorded the total injection dosage of ketorolac and pentazocine. Results:The HR and MAP of Group A on T2 and T5 were higher than T0, whereas, the HR and MAP in Groups B and C on T2 and T5 were lower than that of in Group A. The pain-free period in Groups B and C was longer than Group A. The ketorolac and pentazocine requirement in Groups B and C were lower than Group A. Conclusions:Patients were administrated with 2%lignocaine before operation at a rate of 1 mg/kg intravenous injection bolus, 10 min later at the rate of 1 mL/kg/h or 1.5 mL/kg intravenous infusion until an hour after operation. Administration of lignocaine can effectively prevent the change of haemodynamics resulting from intubation and extubation. Furthermore, it can significantly relieve the postoperative pain and reduce the usage amount of analgesic

  15. Perceiving blocks of emotional pictures and sounds:Effects on physiological variables

    Directory of Open Access Journals (Sweden)

    Anne-Marie eBrouwer

    2013-06-01

    Full Text Available Most studies on physiological effects of emotion inducing images and sounds examine stimulus locked variables reflecting a state of at most a few seconds. We here aimed to induce longer lasting emotional states using blocks of repetitive visual, auditory and bimodal stimuli corresponding to specific valence and arousal levels. The duration of these blocks enabled us to reliably measure heart rate variability as a possible indicator of arousal. In addition, heart rate and skin conductance were determined without taking stimulus timing into account. Heart rate was higher for pleasant and low arousal stimuli compared to unpleasant and high arousal stimuli. Heart rate variability and skin conductance increased with arousal. Effects of valence and arousal on cardiovascular measures habituated or remained the same over 2-minute intervals whereas the arousal effect on skin conductance increased. We did not find any effect of stimulus modality. Our results indicate that blocks of images and sounds of specific valence and arousal levels consistently influence different physiological parameters. These parameters need not be stimulus locked. We found no evidence for differences in emotion induction between visual and auditory stimuli, nor did we find bimodal stimuli to be more potent than unimodal stimuli. The latter could be (partly due to the fact that our bimodal stimuli were not optimally congruent.

  16. The Effect of Visual Merchandising on Impulsive Buying with Impulsive Buying Tendency As Moderating Variable

    Directory of Open Access Journals (Sweden)

    Jessica Novia

    2015-03-01

    Full Text Available This research aims to classify the female consumer demographic segments linked by impulsive buying, to determine the effect of visual merchandising on impulsive buying, and to determine the effect of visual merchandising on impulsive buying with impulsive buying tendency as moderating variable on customers of Gaudi in Taman Anggrek Mall. This research is quantitative research with a total sample of 100 people. Data were obtained by distributing questionnaires to the respondents by cross sectional. Research used Cluster Analysis and Moderated Regression Analysis. Data processing was performed using SPSS software for Windows version 20. Research found that customers of Gaudi were divided into three groups: the way of the world, sufficient money, and promotions. Then, research found that visual merchandising affected impulsive buying. In addition, there visual merchandising had also an effect on impulsive buying with impulsive buying tendency as moderating variable. As a conclusion, moderating variable strengthens the effect of visual merchandising on impulse buying.

  17. Empirical Likelihood for Mixed-effects Error-in-variables Model

    Institute of Scientific and Technical Information of China (English)

    Qiu-hua Chen; Ping-shou Zhong; Heng-jian Cui

    2009-01-01

    This paper mainly introduces the method of empirical likelihood and its applications on two dif-ferent models.We discuss the empirical likelihood inference on fixed-effect parameter in mixed-effects model with error-in-variables.We first consider a linear mixed-effects model with measurement errors in both fixed and random effects.We construct the empirical likelihood confidence regions for the fixed-effects parameters and the mean parameters of random-effects.The limiting distribution of the empirical log likelihood ratio at the true parameter is χ2p+q,where p,q are dimension of fixed and random effects respectively.Then we discuss empirical likelihood inference in a semi-linear error-in-variable mixed-effects model.Under certain conditions,it is shown that the empirical log likelihood ratio at the true parameter also converges to χ2p+q.Simulations illustrate that the proposed confidence region has a coverage probability more closer to the nominal level than normal approximation based confidence region.

  18. Analysis of the sensitivity to rainfall spatio-temporal variability of an operational urban rainfall-runoff model in a multifractal framework

    Science.gov (United States)

    Gires, A.; Tchiguirinskaia, I.; Schertzer, D. J.; Lovejoy, S.

    2011-12-01

    In large urban areas, storm water management is a challenge with enlarging impervious areas. Many cities have implemented real time control (RTC) of their urban drainage system to either reduce overflow or limit urban contamination. A basic component of RTC is hydraulic/hydrologic model. In this paper we use the multifractal framework to suggest an innovative way to test the sensitivity of such a model to the spatio-temporal variability of its rainfall input. Indeed the rainfall variability is often neglected in urban context, being considered as a non-relevant issue at the scales involve. Our results show that on the contrary the rainfall variability should be taken into account. Universal multifractals (UM) rely on the concept of multiplicative cascade and are a standard tool to analyze and simulate with a reduced number of parameters geophysical processes that are extremely variable over a wide range of scales. This study is conducted on a 3 400 ha urban area located in Seine-Saint-Denis, in the North of Paris (France). We use the operational semi-distributed model that was calibrated by the local authority (Direction Eau et Assainnissement du 93) that is in charge of urban drainage. The rainfall data comes from the C-Band radar of Trappes operated by Météo-France. The rainfall event of February 9th, 2009 was used. A stochastic ensemble approach was implemented to quantify the uncertainty on discharge associated to the rainfall variability occurring at scales smaller than 1 km x 1 km x 5 min that is usually available with C-band radar networks. An analysis of the quantiles of the simulated peak flow showed that the uncertainty exceeds 20 % for upstream links. To evaluate a potential gain from a direct use of the rainfall data available at the resolution of X-band radar, we performed similar analysis of the rainfall fields of the degraded resolution of 9 km x 9 km x 20 min. The results show a clear decrease in uncertainty when the original resolution of C

  19. Evaluating the effect of internal aperture variability on transport in kilometer scale discrete fracture networks

    Science.gov (United States)

    Makedonska, Nataliia; Hyman, Jeffrey D.; Karra, Satish; Painter, Scott L.; Gable, Carl W.; Viswanathan, Hari S.

    2016-08-01

    The apertures of natural fractures in fractured rock are highly heterogeneous. However, in-fracture aperture variability is often neglected in flow and transport modeling and individual fractures are assumed to have uniform aperture distribution. The relative importance of in-fracture variability in flow and transport modeling within kilometer-scale field-scale fracture networks has been under a matter of debate for a long time because the flow in each single fracture is controlled not only by in-fracture variability but also by boundary conditions. Computational limitations have previously prohibited researchers from investigating the relative importance of in-fracture variability in flow and transport modeling within large-scale fracture networks. We address this question by incorporating internal heterogeneity of individual fractures into flow simulations within kilometer scale three-dimensional fracture networks, where fracture intensity, P32 (ratio between total fracture area and domain volume) is between 0.027 and 0.031 [1/m]. A recently developed discrete fracture network (DFN) simulation capability, dfnWorks, is used to generate DFNs that include in-fracture aperture variability represented by a stationary log-normal stochastic field with various correlation lengths and variances. The Lagrangian transport parameters, non-reacting travel time and cumulative retention, are calculated along particles streamlines. It is observed that due to local flow channeling early particle travel times are more sensitive to in-fracture variability than the tails of travel time distributions, where no significant effect of the in-fracture transmissivity variations and spatial correlation length is observed.

  20. Electroencephalogram-based scaling of multifocal visual evoked potentials: effect on intersubject amplitude variability.

    Science.gov (United States)

    Klistorner, A I; Graham, S L

    2001-08-01

    The interindividual variability of the visual evoked potential (VEP) has been recognized as a problem for interpretation of clinical results. This study examines whether VEP variability can be reduced by scaling responses according to underlying electroencephalogram (EEG) activity. A multifocal objective perimeter provided different random check patterns to each of 58 points extending out to 32 degrees nasally. A multichannel VEP was recorded (bipolar occipital cross electrodes, 7 min/eye). One hundred normal subjects (age 58.9 +/- 10.7 years) were tested. The amplitude and inter-eye asymmetry coefficient for each point of the field was calculated. VEP signals were then normalized according to underlying EEG activity recorded using Fourier transform to quantify EEG levels. High alpha-rhythm and electrocardiogram contamination were removed before scaling. High intersubject variability was present in the multifocal VEP, with amplitude in women on average 33% larger than in men. The variability for all left eyes was 42.2% +/- 3.9%, for right eyes 41.7% +/- 4.4% (coefficient of variability [CV]). There was a strong correlation between EEG activity and the amplitude of the VEP (left eye, r = 0.83; P < 0.001; right eye, r = 0.82; P < 0.001). When this was used to normalize VEP results, the CVs dropped to 24.6% +/- 3.1% (P < 0.0001) and 24.0% +/- 3.2% (P < 0.0001), respectively. The gender difference was effectively removed. Using underlying EEG amplitudes to normalize an individual's VEP substantially reduces intersubject variability, including differences between men and women. This renders the use of a normal database more reliable when applying the multifocal VEP in the clinical detection of visual field changes.

  1. Effects of various Prāṇāyāma on cardiovascular and autonomic variables

    Directory of Open Access Journals (Sweden)

    L Nivethitha

    2016-01-01

    Full Text Available Cardiovascular functions are controlled by neural factors, temperature, hormones, etc., Of these, neural factors primarily concern the autonomic nervous system, which plays a major role in maintaining and regulating cardiac functions, e.g., blood pressure and heart rate. Prāṇāyāma is one of the most important yogic practices. There are various review articles on Yoga and its effects but, though Prāṇāyāma is a part of yoga, there is lack of review articles. To the best of our knowledge there is no known review article on effect of various Prāṇāyāma on cardiovascular and autonomic variables. To provide a general overview about the effect of various prāṇāyāma (breathing techniques on cardiovascular and autonomic variables. A narrative review was performed based on the available scientific literature. An electronic data search was performed in Medline/PubMed database to review relevant articles, using keywords such as “Prāṇāyāma, Yogic breathing techniques, Unilateral nostril breathing, Alternate nostril breathing, Kapalbhati, Bhastrika and Bhramari Pranayama”. All the relevant articles published from 1988 to 06-04-2016 were included in this review. Slow type of yogic breathing technique was reported to produce beneficial effect on cardiovascular and autonomic variables while fast breathing techniques do not produce such effects. There is lack of consistency in the results of specific nostril yogic breathing techniques and the mechanisms behind the effects of various prāṇāyāma. This review suggests that different types of Prāṇāyāma techniques produce different effects and the mechanisms behind these effects are not fully understood.

  2. L² approaches in several complex variables development of Oka–Cartan theory by L² estimates for the d-bar operator

    CERN Document Server

    Ohsawa, Takeo

    2015-01-01

    The purpose of this monograph is to present the current status of a rapidly developing part of several complex variables, motivated by the applicability of effective results to algebraic geometry and differential geometry. Highlighted are the new precise results on the L² extension of holomorphic functions. In Chapter 1, the classical questions of several complex variables motivating the development of this field are reviewed after necessary preparations from the basic notions of those variables and of complex manifolds such as holomorphic functions, pseudoconvexity, differential forms, and cohomology. In Chapter 2, the L² method of solving the d-bar equation is presented emphasizing its differential geometric aspect. In Chapter 3, a refinement of the Oka–Cartan theory is given by this method. The L² extension theorem with an optimal constant is included, obtained recently by Z. Błocki and by Q.-A. Guan and X.-Y. Zhou separately. In Chapter 4, various results on the Bergman kernel are presented, includi...

  3. Individual Difference Variables and the Occurrence and Effectiveness of Faking Behavior in Interviews

    Directory of Open Access Journals (Sweden)

    Anne-Kathrin Buehl

    2017-05-01

    Full Text Available There is widespread fear that applicants can fake during selection interviews and that this impairs the quality of selection decisions. Several theories assume that faking occurrence is influenced by personality and attitudes, which together influence applicants’ motivation to show faking behavior. However, for faking behavior to be effective, interviewees also need certain skills and abilities. To investigate the impact of several relevant individual difference variables on faking behavior and interview success, we conducted two studies. In Study 1, we surveyed 222 individuals to assess different personality variables, attitude toward faking, cognitive ability, self-reported faking behavior, and success in previous interviews, and in Study 2, we assessed cognitive ability, social skills, faking behavior, and interview performance in an interview simulation with 108 participants. Taken together, personality, as well as attitude toward faking, influenced who showed faking behavior in an interview, but there was no evidence for the assumed moderating effect of cognitive ability or social skills on interview success.

  4. Contact-dependent performance variability of monolayer MoS{sub 2} field-effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Han, Gyuchull; Yoon, Youngki, E-mail: youngki.yoon@uwaterloo.ca [Department of Electrical and Computer Engineering and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

    2014-11-24

    Using self-consistent quantum transport simulations, we investigate the performance variability of monolayer molybdenum disulfide (MoS{sub 2}) field-effect transistors (FETs) with various contact properties. Varying the Schottky barrier in MoS{sub 2} FETs affects the output characteristics more significantly than the transfer characteristics. If doped contacts are realized, the performance variation due to non-ideal contacts becomes negligible; otherwise, channel doping can effectively suppress the performance variability in metal-contact devices. Our scaling study also reveals that for sub-10-nm channels, doped-contact devices can be more robust in terms of switching, while metal-contact MoS{sub 2} FETs can undergo the smaller penalty in output conductance.

  5. Effect of Particle Size and Soil Compaction on Gas Transport Parameters in Variably Saturated, Sandy Soils

    DEFF Research Database (Denmark)

    Hamamoto, Shoichiro; Møldrup, Per; Kawamoto, Ken

    2009-01-01

    the water retention curve), both exhibiting similar and exponential relationships with D50. Under variably saturated conditions, higher Dp and ka in coarser sand (larger D50) were observed due to rapid gas diffusion and advection through the less tortuous large-pore networks. In addition, soil compaction......The soil gas diffusion coefficient (Dp) and air permeability (ka) and their dependency on soil air content ( ) control gas diffusion and advection in soils. This study investigated the effects of average particle size (D50) and dry bulk density ( b) on Dp and ka for six sandy soils under variably...... saturated conditions. Data showed that particle size markedly affects the effective diameter of the drained pores active in leading gas through the sample at –100 cm H2O of soil water matric potential (calculated from Dp and ka) as well as the average pore diameter at half saturation (calculated from...

  6. Effects of robotically modulating kinematic variability on motor skill learning and motivation.

    Science.gov (United States)

    Duarte, Jaime E; Reinkensmeyer, David J

    2015-04-01

    It is unclear how the variability of kinematic errors experienced during motor training affects skill retention and motivation. We used force fields produced by a haptic robot to modulate the kinematic errors of 30 healthy adults during a period of practice in a virtual simulation of golf putting. On day 1, participants became relatively skilled at putting to a near and far target by first practicing without force fields. On day 2, they warmed up at the task without force fields, then practiced with force fields that either reduced or augmented their kinematic errors and were finally assessed without the force fields active. On day 3, they returned for a long-term assessment, again without force fields. A control group practiced without force fields. We quantified motor skill as the variability in impact velocity at which participants putted the ball. We quantified motivation using a self-reported, standardized scale. Only individuals who were initially less skilled benefited from training; for these people, practicing with reduced kinematic variability improved skill more than practicing in the control condition. This reduced kinematic variability also improved self-reports of competence and satisfaction. Practice with increased kinematic variability worsened these self-reports as well as enjoyment. These negative motivational effects persisted on day 3 in a way that was uncorrelated with actual skill. In summary, robotically reducing kinematic errors in a golf putting training session improved putting skill more for less skilled putters. Robotically increasing kinematic errors had no performance effect, but decreased motivation in a persistent way.

  7. Effect of relativistic acceleration on continuous variable quantum teleportation and dense coding

    OpenAIRE

    Grochowski, Piotr T.; Rajchel, Grzegorz; Kiałka, Filip; Dragan, Andrzej

    2017-01-01

    We investigate how relativistic acceleration of the observers can affect the performance of the quantum teleportation and dense coding for continuous variable states of localized wavepackets. Such protocols are typically optimized for symmetric resources prepared in an inertial frame of reference. A mismatch of the sender and the receiver's accelerations can introduce asymmetry to the shared entanglement, which has an effect on the efficiency of the protocol that goes beyond entanglement degr...

  8. Effects of Antecedent Variables on Disruptive Behavior and Accurate Responding in Young Children in Outpatient Settings

    OpenAIRE

    Boelter, Eric W; Wacker, David P.; Call, Nathan A; Ringdahl, Joel E; Kopelman, Todd; Gardner, Andrew W.

    2007-01-01

    The effects of manipulations of task variables on inaccurate responding and disruption were investigated with 3 children who engaged in noncompliance. With 2 children in an outpatient clinic, task directives were first manipulated to identify directives that guided accurate responding; then, additional dimensions of the task were manipulated to evaluate their influence on disruptive behavior. With a 3rd child, similar procedures were employed at school. Results showed one-step directives set ...

  9. Effects of Variable Spot Size on Human Exposure to 95 GHz Millimeter Wave Energy

    Science.gov (United States)

    2017-05-11

    AFRL-RH-FS-TR-2017-0017 Effects of Variable Spot Size on Human Exposure to 95-GHz Millimeter Wave Energy James E. Parker Eric J. Nelson...release by the 88th ABW Public Affairs Office and is available to the general public, including foreign nationals. Copies may be obtained from the...This report is published in the interest of scientific and technical information exchange , and its publication does not constitute the

  10. Thermal effects of variable material properties and metamorphic reactions in a three-component subducting slab

    DEFF Research Database (Denmark)

    Chemia, Zurab; Dolejš, David; Steinle-Neumann, Gerd

    2015-01-01

    We explore the effects of variable material properties, phase transformations, and metamorphic devolatilization reactions on the thermal structure of a subducting slab using thermodynamic phase equilibrium calculations combined with a thermal evolution model. The subducting slab is divided...... into three layers consisting of oceanic sediments, altered oceanic crust, and partially serpentinized or anhydrous harzburgite. Solid-fluid equilibria and material properties are computed for each layer individually to illustrate distinct thermal consequences when chemical and mechanical homogenization...

  11. Effect of design variables on starting torque of single phase flux-reversal machine

    Science.gov (United States)

    Won, Sung Hong; Kim, Tae Heoung; Jang, Ki-Bong; Choi, Seung-Kil; Oh, Won Seok; Lee, Ju

    2006-04-01

    This article introduces a single phase flux-reversal machine (FRM) and presents the design method to improve its starting torque. The effects of the design parameters on the characteristic and starting torque are analyzed by the finite element method. The design variables considered are tapered airgap, stepped airgap, slotted teeth, and asymmetric PM width. As a result, we can find the best model in producing starting torque of a single phase 2/3 FRM.

  12. Does the RR Lyrae variable DY And show the Blazhko effect?

    CERN Document Server

    Cano, Zachariah

    2009-01-01

    Data taken on the University of Sussex 0.46-m telescope in 2006 and 2007 are combined with previously published data to obtain a better defined light curve for the RRab-type variable DY And, a slightly improved period of 0.6030897 +0.0000006 -0.0000002 days and a new time of maximum. Evidence is presented that may indicate the Blazhko effect in this system. In addition, a new time of maximum has been obtained for VX Tri.

  13. An evaluation of the effect of recent temperature variability on the prediction of coral bleaching events.

    Science.gov (United States)

    Donner, Simon D

    2011-07-01

    Over the past 30 years, warm thermal disturbances have become commonplace on coral reefs worldwide. These periods of anomalous sea surface temperature (SST) can lead to coral bleaching, a breakdown of the symbiosis between the host coral and symbiotic dinoflagellates which reside in coral tissue. The onset of bleaching is typically predicted to occur when the SST exceeds a local climatological maximum by 1 degrees C for a month or more. However, recent evidence suggests that the threshold at which bleaching occurs may depend on thermal history. This study uses global SST data sets (HadISST and NOAA AVHRR) and mass coral bleaching reports (from Reefbase) to examine the effect of historical SST variability on the accuracy of bleaching prediction. Two variability-based bleaching prediction methods are developed from global analysis of seasonal and interannual SST variability. The first method employs a local bleaching threshold derived from the historical variability in maximum annual SST to account for spatial variability in past thermal disturbance frequency. The second method uses a different formula to estimate the local climatological maximum to account for the low seasonality of SST in the tropics. The new prediction methods are tested against the common globally fixed threshold method using the observed bleaching reports. The results find that estimating the bleaching threshold from local historical SST variability delivers the highest predictive power, but also a higher rate of Type I errors. The second method has the lowest predictive power globally, though regional analysis suggests that it may be applicable in equatorial regions. The historical data analysis suggests that the bleaching threshold may have appeared to be constant globally because the magnitude of interannual variability in maximum SST is similar for many of the world's coral reef ecosystems. For example, the results show that a SST anomaly of 1 degrees C is equivalent to 1.73-2.94 standard

  14. The effects of physicochemical wastewater treatment operations on forward osmosis.

    Science.gov (United States)

    Hey, Tobias; Bajraktari, Niada; Vogel, Jörg; Hélix Nielsen, Claus; la Cour Jansen, Jes; Jönsson, Karin

    2016-10-24

    Raw municipal wastewater from a full-scale wastewater treatment plant was physicochemically pretreated in a large pilot-scale system comprising coagulation, flocculation, microsieve and microfiltration operated in various configurations. The produced microsieve filtrates and microfiltration permeates were then concentrated using forward osmosis (FO). Aquaporin Inside(TM) FO membranes were used for both the microsieve filtrate and microfiltration permeates, and Hydration Technologies Inc.-thin-film composite membranes for the microfiltration permeate using only NaCl as the draw solution. The FO performance was evaluated in terms of the water flux, water flux decline and solute rejections of biochemical oxygen demand, and total and soluble phosphorus. The obtained results were compared with the results of FO after only mechanical pretreatment. The FO permeates satisfied the Swedish discharge demands for small and medium-sized wastewater treatment plants. The study demonstrates that physicochemical pretreatment can improve the FO water flux by up to 20%. In contrast, the solute rejection decreases significantly compared to the FO-treated wastewater with mechanical pretreatment.

  15. Effect of Drying Operating Conditions on Canola Oil Tocopherol Content

    Directory of Open Access Journals (Sweden)

    Daniela Laoretani

    2014-03-01

    Full Text Available The aim of this work was to evaluate two operating parameters of seed drying (temperature and initial moisture content on the tocopherol content of canola oil. The raw material was characterized by moisture, oil, protein, crude fiber and ash content. Seeds at 13.6% and 22.7% moisture content (dry basis, db were dried at temperatures in the range of 35–100 °C to a safe storage moisture of 7% db. Oil was extracted from each treated sample. The oil extracted from the samples dried at the extreme temperatures was analyzed by means of the acidity value, peroxide index and fatty acid composition, finding no significant differences among treatments or among untreated and treated samples. Tocopherol contents in the oils obtained for all the assayed temperatures were determined. Differences were found for the samples with 22.7% (db initial moisture content. Except at 35 °C, temperature affected negatively the oil tocopherol content. However, when 13.6% (db moisture seeds were processed, no significant differences were observed in the amount of this minor oil component among assays.

  16. Mandarin Tone and Vowel Recognition in Cochlear Implant Users: Effects of Talker Variability and Bimodal Hearing.

    Science.gov (United States)

    Chang, Yi-Ping; Chang, Ronald Y; Lin, Chun-Yi; Luo, Xin

    2016-01-01

    For cochlear implant (CI) users with residual low-frequency acoustic hearing in the nonimplanted ear, bimodal hearing combining the use of a CI and a contralateral hearing aid (HA) may provide more salient talker voice cues than CI alone to handle the variability of talker identity across trials. This study tested the effects of talker variability, bimodal hearing, and their interaction on response accuracy and time of CI users' Mandarin tone, vowel, and syllable recognition (i.e., combined Mandarin tone and vowel recognition in this study). Fifteen prelingually deafened native Mandarin-speaking CI users (at age 20 or lower) participated in this study. Four talkers each produced six Mandarin single-vowel syllables in four lexical tones. The stimuli were presented in quiet via a single loudspeaker. To study the effects of talker variability, Mandarin tone, vowel, and syllable recognition was tested in two presentation conditions: with stimuli blocked according to talker (blocked-talker condition) or mixed across talkers from trial to trial (mixed-talker condition). To explore the effects of bimodal hearing, two processor conditions were tested: CI alone or CI + HA. The cumulative response time was recorded as an indirect indicator of the cognitive load or listening effort in each condition. The correlations were computed between demographic/hearing factors (e.g., hearing thresholds in the nonimplanted ear) and bimodal performance/benefits (where bimodal benefits refer to the performance differences between CI alone and CI + HA). Mandarin tone recognition with both CI alone and CI + HA was significantly poorer in the mixed-talker condition than in the blocked-talker condition, while vowel recognition was comparable in the two presentation conditions. Bimodal hearing significantly improved Mandarin tone recognition but not vowel recognition. Mandarin syllable recognition was significantly affected by both talker variability and bimodal hearing. The cumulative response

  17. The effect of pre-operative administration of gabapentin on post-operative pain relief after herniorrhaphy

    Directory of Open Access Journals (Sweden)

    Alireza Mahoori

    2014-01-01

    Full Text Available Background: Gabapentin, an anticonvulsant, recently has been suggested as an effective post-operative "analgesic" agent. The objective of the present study was to examine the analgesic effectiveness and opioid-sparing effects associated with the use of a single dose of gabapentin as a prophylactic analgesic. Materials and Methods: In a randomized double-blinded clinical trial, 50 American Society of Anesthesiologists I and II patients with an age range of 40-60 years who were the candidate for inguinal herniorrhaphy under spinal anesthesia were randomly assigned to receive 400 mg gabapentin or placebo 2 h prior to surgery. Post-operatively, the pain was assessed on a visual analog scale (VAS at 2, 4, 12 and 24 h at rest. Morphine 0.05 mg/kg intravenously was used to treat post-operative pain on patient′s demand. Total morphine consumption in the first 24 h after surgery was also recorded. Results: Patients in the gabapentin group had significantly lower VAS scores at the all-time intervals of study than those in the placebo group (P < 0.05. The total morphine consumption in the first 24 h after surgery was also significantly lower in gabapentin group than in the placebo group (0.9 ± 1.23 vs. 1.8 ± 1.5; P = 0.003. There was no significant difference between the first time of analgesic request among the two groups. Conclusion: In conclusion, prophylactic administration of gabapentin decreases pain scores and analgesic consumption in the first 24 h after repair of inguinal hernia.

  18. Sound and vibration: effects on infants' heart rate and heart rate variability during neonatal transport.

    Science.gov (United States)

    Karlsson, Björn-Markus; Lindkvist, Marie; Lindkvist, Markus; Karlsson, Marcus; Lundström, Ronnie; Håkansson, Stellan; Wiklund, Urban; van den Berg, Johannes

    2012-02-01

    To measure the effect of sound and whole-body vibration on infants' heart rate and heart rate variability during ground and air ambulance transport. Sixteen infants were transported by air ambulance with ground ambulance transport to and from the airports. Whole-body vibration and sound levels were recorded and heart parameters were obtained by ECG signal. Sound and whole-body vibration levels exceeded the recommended limits. Mean whole-body vibration and sound levels were 0.19 m/s(2) and 73 dBA, respectively. Higher whole-body vibration was associated with a lower heart rate (p < 0.05), and higher sound level was linked to a higher heart rate (p = 0.05). The heart rate variability was significantly higher at the end of the transport than at the beginning (p < 0.01). Poorer physiological status was associated with lower heart rate variability (p < 0.001) and a lower heart rate (p < 0.01). Infants wearing earmuffs had a lower heart rate (p < 0.05). Sound and whole-body vibration during neonatal transport exceed recommended levels for adults, and sound seem to have a more stressful effect on the infant than vibrations. Infants should wear earmuffs during neonatal transport because of the stress-reducing effect. © 2011 The Author(s)/Acta Paediatrica © 2011 Foundation Acta Paediatrica.

  19. The Effects of a Change in the Variability of Irrigation Water

    Science.gov (United States)

    Lyon, Kenneth S.

    1983-10-01

    This paper examines the short-run effects upon several variables of an increase in the variability of an input. The measure of an increase in the variability is the "mean preserving spread" suggested by Rothschild and Stiglitz (1970). The variables examined are real income (utility), expected profits, expected output, the quantity used of the controllable input, and the shadow price of the stochastic input. Four striking features of the results follow: (1) The concepts that have been useful in summarizing deterministic comparative static results are nearly absent when an input is stochastic. (2) Most of the signs of the partial derivatives depend upon more than concavity of the utility and production functions. (3) If the utility function is not "too" risk averse, then the risk-neutral results hold for the risk-aversion case. (4) If the production function is Cobb-Douglas, then definite results are achieved if the utility function is linear or if the "degree of risk-aversion" is "small."

  20. Effects of climate on variability in Lyme disease incidence in the northeastern United States.

    Science.gov (United States)

    Subak, Susan

    2003-03-15

    Numbers of reported Lyme disease cases have increased dramatically over the past decade in the northeastern United States, but the year-to-year variability is sizable (average standard deviation approximately 30% of the mean). An improved understanding of the causes of such variability would aid in prevention and control of the disease, which is transmitted by a spirochete carried in the "black-legged" tick, Ixodes scapularis. In this study, the variability in reported Lyme disease incidence between 1993 and 2001 in seven northeastern US states was analyzed as an outcome of weather variability. For all seven states analyzed, significant (p Hydrological Drought Index) in the region 2 years previously. The correlations may reflect enhanced nymph tick survival in wetter conditions. Few significant relations were found with same-year moisture index, which suggests that moisture has a greater effect on nymph tick survival following the insect's blood meal than before. In some states, significant correlations were observed related to warmer winter weather a year and a half prior to disease incidence, which may have been due to higher survival and activity levels of the white-footed mouse, the main host for Lyme disease-infected ticks.