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Sample records for experimental parameters influencing

  1. Experimental investigation of cutting parameters influence on ...

    Indian Academy of Sciences (India)

    The relationship between the variables and the technological parameters is determined through the response surface methodology (RSM), using a quadratic regression model. Results show how much surface roughness is mainly influenced by feed rate and cutting speed. The depth of cut exhibits maximum influence on ...

  2. Experimental investigation of cutting parameters influence on ...

    Indian Academy of Sciences (India)

    rough turning, heat treatment, and then grinding process. Hard turning eliminates the series of .... slide-lathing grade X38CrMoV5-1 steel treated at 50 HRC by a CBN 7020 tool to reveal the influences of cutting ... Turning experiments were performed in dry conditions using lathe type SN 40C with 6.6 KW spindle power.

  3. ANOVA parameters influence in LCF experimental data and simulation results

    Science.gov (United States)

    Delprete, C.; Sesanaa, R.; Vercelli, A.

    2010-06-01

    The virtual design of components undergoing thermo mechanical fatigue (TMF) and plastic strains is usually run in many phases. The numerical finite element method gives a useful instrument which becomes increasingly effective as the geometrical and numerical modelling gets more accurate. The constitutive model definition plays an important role in the effectiveness of the numerical simulation [1, 2] as, for example, shown in Figure 1. In this picture it is shown how a good cyclic plasticity constitutive model can simulate a cyclic load experiment. The component life estimation is the subsequent phase and it needs complex damage and life estimation models [3-5] which take into account of several parameters and phenomena contributing to damage and life duration. The calibration of these constitutive and damage models requires an accurate testing activity. In the present paper the main topic of the research activity is to investigate whether the parameters, which result to be influent in the experimental activity, influence the numerical simulations, thus defining the effectiveness of the models in taking into account of all the phenomena actually influencing the life of the component. To obtain this aim a procedure to tune the parameters needed to estimate the life of mechanical components undergoing TMF and plastic strains is presented for commercial steel. This procedure aims to be easy and to allow calibrating both material constitutive model (for the numerical structural simulation) and the damage and life model (for life assessment). The procedure has been applied to specimens. The experimental activity has been developed on three sets of tests run at several temperatures: static tests, high cycle fatigue (HCF) tests, low cycle fatigue (LCF) tests. The numerical structural FEM simulations have been run on a commercial non linear solver, ABAQUS®6.8. The simulations replied the experimental tests. The stress, strain, thermal results from the thermo structural FEM

  4. ANOVA parameters influence in LCF experimental data and simulation results

    Directory of Open Access Journals (Sweden)

    Vercelli A.

    2010-06-01

    Full Text Available The virtual design of components undergoing thermo mechanical fatigue (TMF and plastic strains is usually run in many phases. The numerical finite element method gives a useful instrument which becomes increasingly effective as the geometrical and numerical modelling gets more accurate. The constitutive model definition plays an important role in the effectiveness of the numerical simulation [1, 2] as, for example, shown in Figure 1. In this picture it is shown how a good cyclic plasticity constitutive model can simulate a cyclic load experiment. The component life estimation is the subsequent phase and it needs complex damage and life estimation models [3-5] which take into account of several parameters and phenomena contributing to damage and life duration. The calibration of these constitutive and damage models requires an accurate testing activity. In the present paper the main topic of the research activity is to investigate whether the parameters, which result to be influent in the experimental activity, influence the numerical simulations, thus defining the effectiveness of the models in taking into account of all the phenomena actually influencing the life of the component. To obtain this aim a procedure to tune the parameters needed to estimate the life of mechanical components undergoing TMF and plastic strains is presented for commercial steel. This procedure aims to be easy and to allow calibrating both material constitutive model (for the numerical structural simulation and the damage and life model (for life assessment. The procedure has been applied to specimens. The experimental activity has been developed on three sets of tests run at several temperatures: static tests, high cycle fatigue (HCF tests, low cycle fatigue (LCF tests. The numerical structural FEM simulations have been run on a commercial non linear solver, ABAQUS®6.8. The simulations replied the experimental tests. The stress, strain, thermal results from the thermo

  5. Influence of several experimental parameters on As and Se leaching from coal fly ash samples

    Energy Technology Data Exchange (ETDEWEB)

    Otero-Rey, Jose R. [Department of Analytical Chemistry, Faculty of Sciences, University of A Coruna, Campus da Zapateira s/n, E-15071 A Coruna (Spain); Mato-Fernandez, Maria J. [Department of Analytical Chemistry, Faculty of Sciences, University of A Coruna, Campus da Zapateira s/n, E-15071 A Coruna (Spain); Moreda-Pineiro, Jorge [Department of Analytical Chemistry, Faculty of Sciences, University of A Coruna, Campus da Zapateira s/n, E-15071 A Coruna (Spain); Alonso-Rodriguez, Elia [Department of Analytical Chemistry, Faculty of Sciences, University of A Coruna, Campus da Zapateira s/n, E-15071 A Coruna (Spain)]. E-mail: elia@udc.es; Muniategui-Lorenzo, Soledad [Department of Analytical Chemistry, Faculty of Sciences, University of A Coruna, Campus da Zapateira s/n, E-15071 A Coruna (Spain); Lopez-Mahia, Purificacion [Department of Analytical Chemistry, Faculty of Sciences, University of A Coruna, Campus da Zapateira s/n, E-15071 A Coruna (Spain); Prada-Rodriguez, Dario [Department of Analytical Chemistry, Faculty of Sciences, University of A Coruna, Campus da Zapateira s/n, E-15071 A Coruna (Spain)

    2005-02-28

    Coal fly ash leaching process for As and Se is studied. Environmental parameters such as pH, temperature, solid-liquid ratio, particle size and leaching time are taken into account in order to simulate As and Se leaching process for disposal coal fly ash. Analysis of reference materials was carried out by using of hydride generation coupled to atomic fluorescence spectrometry. Plackett-Burman experimental design is used to know the significative parameters, and Box-Behnken experimental design is used to refine the results obtained for these significative parameters. pH and temperature shown a hardly influence in leaching process. Furthermore, leaching time was also significative. According our results, it may be assumed that percentage of As and Se leaching in experimental conditions tested is relatively low for acidic fly ashes.

  6. Tailoring laser wakefield accelerated electron beams. An experimental study on the influence of experimental conditions on electron beam parameters

    Energy Technology Data Exchange (ETDEWEB)

    Couperus, Jurjen P.; Koehler, Alexander; Zarini, Omid; Huebl, Axel; Schramm, Ulrich [Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf (Germany); Technische Universitaet Dresden (Germany); Jochmann, Axel; Debus, Alexander; Irman, Arie [Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf (Germany)

    2016-07-01

    Laser wakefield acceleration (LWFA) has emerged as a promising concept for the next generation of high energy electron accelerators. In LFWA a high intensity ultrashort laser pulse drives plasma density waves, inducing a high accelerating field gradient in the order of GV/m. To create stable reproducible electron beams, tailoring of experimental parameters like gas density, laser energy and laser pulse duration is required. In this talk we present an overview of our experimental studies with the DRACO (3 J on target, 30 fs) laser on ultrasonic gas-jet targets (He and He-N{sub 2} mixtures). We discuss the influence of experimental parameters on beam parameters like beam charge, shot-to-shot stability and energy distribution, both in the self-injecting bubble regime as well as in the ionisation injection regime.

  7. Experimental Investigation of process parameters influence on machining Inconel 800 in the Electrical Spark Eroding Machine

    Science.gov (United States)

    Karunakaran, K.; Chandrasekaran, M.

    2016-11-01

    The Electrical Spark Eroding Machining is an entrenched sophisticated machining process for producing complex geometry with close tolerances in hard materials like super alloy which are extremely difficult-to-machine by using conventional machining processes. It is sometimes offered as a better alternative or sometimes as an only alternative for generating accurate 3D complex shapes of macro, micro and nano-features in such difficult-to-machine materials among other advanced machining processes. The accomplishment of such challenging task by use of Electrical Spark Eroding Machining or Electrical Discharge Machining (EDM) is depending upon selection of apt process parameters. This paper is about analyzing the influencing of parameter in electrical eroding machining for Inconel 800 with electrolytic copper as a tool. The experimental runs were performed with various input conditions to process Inconel 800 nickel based super alloy for analyzing the response of material removal rate, surface roughness and tool wear rate. These are the measures of performance of individual experimental value of parameters such as pulse on time, Pulse off time, peak current. Taguchi full factorial Design by using Minitab release 14 software was employed to meet the manufacture requirements of preparing process parameter selection card for Inconel 800 jobs. The individual parameter's contribution towards surface roughness was observed from 13.68% to 64.66%.

  8. Experimental study of the coupling parameters influencing the terminal effects of thoracic blunt ballistic impacts.

    Science.gov (United States)

    Pavier, Julien; Langlet, André; Eches, Nicolas; Prat, Nicolas; Bailly, Patrice; Jacquet, Jean-François

    2015-07-01

    The objective of the study is to better understand how blunt projectile ballistic parameters and material properties influence the events leading to injuries. The present work focuses on lateral thoracic impacts and follows an experimental approach. The projectiles are made with a soft foam nose assembled with a rigid rear plastic part. The dynamic properties of the foams were first determined using the Split Hopkinson Pressure Bar (SHPB) system. The impact forces on a rigid wall were then measured to provide reference load data. Lastly, shots were made on isolated thoraxes of porcine cadavers to investigate the response in the vicinity of the impact (wall displacements, rib accelerations and strains, rib fractures). Results show that the severity of the response appears to be mainly correlated with the impulse and with the pre-impact momentum. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  9. An Experimental Investigation of the Effects of Femtosecond Laser Helical Drilling: Influence of Process Parameters

    Science.gov (United States)

    You, Yancheng; Dong, Yiwei; Li, Xiaoji; Zhao, Qi; Wang, Ertai; Yin, Chunping

    2017-11-01

    Femtosecond laser pulses used in micro-drilling, which allows precise and thermal-damage-free removal of material, has progressed remarkably in recent years to become an essential tool for microhole drilling. Helical drilling is the most common method for processing high-precision microholes. Compared to multi-pulse drilling or circular scanning drilling, it is more convenient to process the requested radius and needed depth hole. The mechanism of interaction between the ultra-fast laser and materials is very complex. Exploring the influence of processing parameters on the drilling process not only helps to guide the actual processing, but also helps our understanding of the mechanism. In this study, laser processing parameters for drilling microholes in three materials are investigated. The influence of processing parameters on hole drilling is analysed, and the relationship between the overlapping rate influence on drilling depth and ablation threshold is explored.

  10. Influence of Experimental Parameters on Fatigue Crack Growth and Heat Build-Up in Rubber.

    Science.gov (United States)

    Stadlbauer, Franziska; Koch, Thomas; Archodoulaki, Vasiliki-Maria; Planitzer, Florian; Fidi, Wolfgang; Holzner, Armin

    2013-11-27

    Loading parameters (frequency, amplitude ratio and waveform) are varied to determine their influence on fatigue crack growth in rubber. Up to three different rubber blends are investigated: one actual engineering material and two model materials. Fatigue crack growth curves and strain distributions of pure shear and faint waist pure shear samples are compared for a model material. Fatigue behavior is studied for three different frequencies (1 Hz, 3 Hz and 5 Hz). Amplitude ratio appears to be another important influence factor concerning fatigue crack growth in rubber. The beneficial effect of positive amplitude ratios (tensional loading conditions) is shown for different materials. However, fatigue crack growth is considerably increased for negative amplitude ratios (tensional-compressional loading conditions). Furthermore, the influence of the waveform is determined for three different waveform shapes. One is sinusoidal, and two have a square shape, including dwell periods and sinusoidal slopes. Special focus lies on heat build-up, which is substantial, especially for large loads, high frequencies and/or highly filled rubber blends. Plateau temperatures are determined for various loading conditions and rubber blends. A very simple linear relationship with dissipated energy per time and unit area is obtained. Results gathered with dynamic mechanical analyses show, likewise, a linear trend, but the heat build-up is very small, due to different sample geometries.

  11. Theoretical and experimental analysis of the laser irradiation parameters influence on the LIDT of optical coatings

    Science.gov (United States)

    Gallais, Laurent; Capoulade, Jérémie; Natoli, Jean-Yves; Commandré, Mireille

    2008-09-01

    We describe in this paper a model to link laser damage initiators properties (nature, size distribution, density) to measured Laser Induced Damage Threshold (LIDT). It is based on calculation of light absorption in nanoabsorbers and subsequent heating, coupled to laser damage statistics in order to obtain the laser damage probability as a function of laser fluence. Applications to the case of optical coatings are then presented. We study the influence of laser irradiation parameters and coatings properties on LIDT measurements. By coupling this multiscale study to our model, we show that information on the initiating defects properties and the physical damage mechanisms involved can be obtained: discrimination between different defects, estimation of densities, size and nature of defects, evolution of the defects under multiple irradiation. Implication of this approach for physical understanding and metrology applications are discussed.

  12. Theoretical and experimental research on the influence of multiple piezoelectric effects on physical parameters of piezoelectric actuator

    Science.gov (United States)

    Shi, Liping; Zhou, Haimin; Huang, Jie; Tan, Jiliang

    2015-04-01

    Compared with the traditional actuator of machinery and electricity, the piezoelectric actuator has the advantages of a compact structure, small volume, no mechanical friction, athermancy and no electromagnetic interference. Therefore, it has high application value in the fields of MEMS, bioengineering, medical science and so on. This article draws conclusions from the influence of multiple piezoelectric effects on the physical parameters (dielectric coefficient, equivalent capacity, energy conversion and piezoelectric coefficient) of piezoelectric actuators. These data from theoretical and experimental research show the following: (1) The rate between the dielectric coefficient of piezoelectric in mechanical freedom and clamping is obtained from the secondary direct piezoelectric effect, which enhances the dielectric property, increases the dielectric coefficient and decreases the coefficient of dielectric isolation; (2) Under external field, En ( ex ) = E 1 , exterior stress T = 0, that is to say, under the boundary condition of mechanical freedom, piezoelectric can store electric energy and elasticity, which obtains power density, elastic density and an electromechanical coupling factor; (3) According to the piezoelectric strain Si ( 1 ) , piezoelectric displacement Dm ( 2 ) and piezoelectric strain Si ( 3 ) of multiple piezoelectric effects, when the dielectric coefficient of the first converse piezoelectric effect ɛ33 is 1326 and the dielectric coefficient of the secondary direct piezoelectric effect increases to 3336, the dielectric coefficient of the ceramic chip increases. When the piezoelectric coefficient of the first converse piezoelectric effect d33 is 595 and the piezoelectric coefficient of the secondary direct piezoelectric effect decreases to 240, the piezoelectric coefficient of the ceramic chip will decrease. It is of major significance both in the applications and in basic theory to research the influence of multiple piezoelectric effects on the

  13. Theoretical and experimental research on the influence of multiple piezoelectric effects on physical parameters of piezoelectric actuator

    Directory of Open Access Journals (Sweden)

    Liping Shi

    2015-04-01

    Full Text Available Compared with the traditional actuator of machinery and electricity, the piezoelectric actuator has the advantages of a compact structure, small volume, no mechanical friction, athermancy and no electromagnetic interference. Therefore, it has high application value in the fields of MEMS, bioengineering, medical science and so on. This article draws conclusions from the influence of multiple piezoelectric effects on the physical parameters (dielectric coefficient, equivalent capacity, energy conversion and piezoelectric coefficient of piezoelectric actuators. These data from theoretical and experimental research show the following: (1 The rate between the dielectric coefficient of piezoelectric in mechanical freedom and clamping is obtained from the secondary direct piezoelectric effect, which enhances the dielectric property, increases the dielectric coefficient and decreases the coefficient of dielectric isolation; (2 Under external field, E n ( ex = E 1 , exterior stress T = 0, that is to say, under the boundary condition of mechanical freedom, piezoelectric can store electric energy and elasticity, which obtains power density, elastic density and an electromechanical coupling factor; (3 According to the piezoelectric strain S i ( 1 , piezoelectric displacement D m ( 2 and piezoelectric strain S i ( 3 of multiple piezoelectric effects, when the dielectric coefficient of the first converse piezoelectric effect ε33 is 1326 and the dielectric coefficient of the secondary direct piezoelectric effect increases to 3336, the dielectric coefficient of the ceramic chip increases. When the piezoelectric coefficient of the first converse piezoelectric effect d33 is 595 and the piezoelectric coefficient of the secondary direct piezoelectric effect decreases to 240, the piezoelectric coefficient of the ceramic chip will decrease. It is of major significance both in the applications and in basic theory to research the influence of multiple piezoelectric

  14. Influence of the operational parameters on bioelectricity generation in continuous microbial fuel cell, experimental and computational fluid dynamics modelling

    Science.gov (United States)

    Sobieszuk, Paweł; Zamojska-Jaroszewicz, Anna; Makowski, Łukasz

    2017-12-01

    The influence of the organic loading rate (also known as active anodic chamber volume) on bioelectricity generation in a continuous, two-chamber microbial fuel cell for the treatment of synthetic wastewater, with glucose as the only carbon source, was examined. Ten sets of experiments with different combinations of hydraulic retention times (0.24-1.14 d) and influent chemical oxygen demand concentrations were performed to verify the impact of organic loading rate on the voltage generation capacity of a simple dual-chamber microbial fuel cell working in continuous mode. We found that there is an optimal hydraulic retention time value at which the maximum voltage is generated: 0.41 d. However, there were no similar effects, in terms of voltage generation, when a constant hydraulic retention time with different influent chemical oxygen demand of wastewater was used. The obtained maximal voltage value (600 mV) has also been compared to literature data. Computational fluid dynamics (CFD) was used to calculate the fluid flow and the exit age distribution of fluid elements in the reactor to explain the obtained experimental results and identify the crucial parameters for the design of bioreactors on an industrial scale.

  15. Experimental investigation of urea injection parameters influence on NOx emissions from blended biodiesel-fueled diesel engines.

    Science.gov (United States)

    Mehregan, Mina; Moghiman, Mohammad

    2017-11-27

    The present work submits an investigation about the effect of urea injection parameters on NOx emissions from a four-stroke four-cylinder diesel engine fueled with B20 blended biodiesel. An L9(34) Taguchi orthogonal array was used to design the test plan. The results reveal that increasing urea concentration leads to lower NOx emissions. Urea flow rate increment has the same influence on NOx emission. The same result is obtained by an increase in spray angle. Also, according to the analysis of variance (ANOVA), urea concentration and then urea flow rate are the most effective design parameters on NOx emissions, while spray angle and mixing length have less influence on this pollutant emission. Finally, since the result of confirmation test is in good agreement with the predicted value based on the Taguchi technique, the predictive capability of this method in the present study could be deduced.

  16. Optimization of Experimental Parameters in preparing ...

    African Journals Online (AJOL)

    The anodic oxidation method has been applied to the preparation of multinanoporous TiO2 thin films. The experimental parameters, including the electrolyte nature, oxidation voltage, and oxidation time have been carefully controlled. Their influence on the structure, morphology and photocatalytic activity of the prepared ...

  17. The influence of melatonin and agomelatine on urodynamic parameters in experimental overactive bladder model – preliminary results

    Directory of Open Access Journals (Sweden)

    Łukasz Dobrek

    2011-11-01

    Full Text Available Introduction:Overactive bladder (OAB is a common disease entity with complex pathogenesis that involves neurogenic, myogenic and abnormal paracrine urothelial activity mechanisms. Our objective was to estimate bladder functioning in urodynamic studies in experimental, both acute (AOAB and chronic (COAB cyclophosphamide (CYP-evoked OAB model in response to melatonin (MLT; antioxidant and MT receptor agonist or agomelatine (AMT; MT receptor agonist and 5HT2C receptor antagonist.Material/Methods:Seven groups were studied: 1 – control, 2–4 – MLT treated AOAB and COAB rats, 5–7 – AMT treated AOAB and COAB rats. AOAB model was evoked by single CYP administration (IP 200 mg/kg body weight, while COAB one was induced by a four-time administration of CYP (IP 75 mg/kg body weight. Each group underwent urethane anesthesia to perform urodynamic recordings in resting conditions and after administration 50 (group 2 or 5, 75 (group 3 or 6 or 100 mg/kg (group 4 or 7 of melatonin (groups 2–4 or agomelatine (groups 5–7, followed by classical urodynamic parameters assessment.Results:Neither melatonin nor agomelatine did not affect urodynamic parameters in the AOAB rats. In COAB model, after 75 and 100 mg/kg of MLT we revealed an improvement in urodynamic parameters. AMT (75 and 100 mg/kg administration caused deterioration of urodynamic findings suggesting bladder overactivity exacerbation.Disscussion:In summary, melatonin ameliorates bladder overactivity in cyclophosphamide-induced COAB. Agomelatine, contrary to melatonin, aggravates bladder dysfunction in this group. These findings suggest that the improvement in urodynamic parameters after melatonin administration may be due to its antioxidative profile and is not related to MT receptors activation. However, agomelatine’s unfavorable action on the bladder, resulting in its overactivity in COAB group, may not only be the result of MT receptor activation without the concomitant antioxidative

  18. Experimental assessment of the influence of welding process parameters on Lamb wave transmission across ultrasonically welded thermoplastic composite joints

    Science.gov (United States)

    Ochôa, Pedro; Fernandez Villegas, Irene; Groves, Roger M.; Benedictus, Rinze

    2018-01-01

    One of the advantages of thermoplastic composites relative to their thermoset counterparts is the possibility of assembling components through welding. Ultrasonic welding in particular is very promising for industrialization. However, uncertainty in the fatigue and fracture behaviour of composites is still an obstacle to the full utilisation of these materials. Health monitoring is then of vital importance, and Lamb wave techniques have been widely recognised as some of the most promising approaches for that end. This paper presents the first experimental study about the influence of welding travel on the transmission of Lamb waves across ultrasonically welded thermoplastic composite joints in single-lap configuration. The main aim of this research is to start to understand how guided waves interact with the internal structure of ultrasonic welds, so that benign, manufacturing-related structural features can be distinguished from damaging ones in signal interpretation. The power transmission coefficient and the correlation coefficient proved to be suitable for analysing the wave propagation phenomena, allowing quantitative identification of small variations of weld-line thickness and intermolecular diffusion at the weld interface. The conclusions are used to develop a tentative damage detection criterion which can later on assist the design of a Lamb wave based structural health monitoring system for thermoplastic composite structures. The Lamb wave test results are backed up by phased-array inspections, which also provide some extra insight on the internal structure of ultrasonic welds.

  19. Influence of temperature regime on endocrine parameters and vitellogenesis during experimental maturation of European eel (Anguilla anguilla) females

    NARCIS (Netherlands)

    Perez, L.; Penaranda, D.S.; Dufour, S.; Baloche, S.; Palstra, A.P.; Thillart, G.E.E.J.M.; Asturiano, J.F.

    2011-01-01

    We examined the effect of temperature in European silver eels during their maturation induced by injections of carp pituitary extract on endocrine parameters: pituitary fshß and lhß expression, plasma 17ß-estradiol (E2) and vitellogenin, estrogen receptor 1 (esr1), and vitellogenin 2 (vtg2)

  20. Influence of experimental parameters on sonochemistry dosimetries: KI oxidation, Fricke reaction and H{sub 2}O{sub 2} production

    Energy Technology Data Exchange (ETDEWEB)

    Merouani, Slimane [Laboratory of Environmental Engineering, Department of Process Engineering, Faculty of Engineering, University of Annaba, P.O. Box 12, 23000 Annaba (Algeria); Hamdaoui, Oualid, E-mail: ohamdaoui@yahoo.fr [Laboratory of Environmental Engineering, Department of Process Engineering, Faculty of Engineering, University of Annaba, P.O. Box 12, 23000 Annaba (Algeria); Saoudi, Fethi; Chiha, Mahdi [Laboratory of Environmental Engineering, Department of Process Engineering, Faculty of Engineering, University of Annaba, P.O. Box 12, 23000 Annaba (Algeria)

    2010-06-15

    Central events of the ultrasonic action are the cavitation bubbles that can be considered as microreactors. Adiabatic collapse of cavitation bubbles leads to the formation of reactive species such as hydroxyl radicals ({center_dot}OH), hydrogen peroxide (H{sub 2}O{sub 2}) and hydroperoxyl radicals (HOO{center_dot}). Several chemical methods were used to detect the production of these reactive moieties in sonochemistry. In this work, the influence of several operational parameters on the sonochemistry dosimetries namely KI oxidation, Fricke reaction and H{sub 2}O{sub 2} production using 300 kHz ultrasound was investigated. The main experimental parameters showing significant effect in KI oxidation dosimetry were initial KI concentration, acoustic power and pH. The solution temperature showed restricted influence on KI oxidation. The acoustic power and liquid temperature highly affected Fricke reaction dosimetry. Operational conditions having important influence on H{sub 2}O{sub 2} formation were acoustic power, solution temperature and pH. For the three tested dosimetries, the sonochemical efficiency was independent of liquid volume.

  1. Theoretical and experimental influence of aerosol assisted CVD parameters on the microstructural properties of magnetite nanoparticles and their response on the removal efficiency of arsenic

    Energy Technology Data Exchange (ETDEWEB)

    Hernández-Salcedo, P.G.; Amézaga-Madrid, P., E-mail: patricia.amezaga@cimav.edu.mx; Monárrez-Cordero, B.E.; Antúnez-Flores, W.; Pizá-Ruiz, P.; Leyva-Porras, C.; Ornelas-Gutiérrez, C.; Miki-Yoshida, M.

    2015-09-15

    The development and optimization of methodologies to generate magnetite nanoparticles is currently an innovation topic. For a desired application such as arsenic removal from waste water, the generation of these nanostructures with specific microstructural properties is determinant. Therefore, it is necessary to understand the phenomenon during the nanoparticles formation process. Thus, in this work it is reported the influence of synthesis parameters of AACVD technique on the formation of magnetite nanoparticles. Parameters were according to: (1) synthesis temperature, (2) tubular reactor diameter, (3) concentration of the precursor solution and type of solvent, (4) carrier gas flow and (5) solvent type in the collection process. The effect of these synthesis parameters on the morphology, size and microstructure are discussed in detail and related with the mechanism of formation of the particles. Theoretical simulations were performed on two of these parameters (1 and 4). The microstructure and surface morphology of the different nanostructures obtained were characterized by field emission scanning electron and transmission electron microscopy. Subsequently two materials, were selected for further microstructural analysis. Finally, to determine the removal efficiency in the two materials the arsenic adsorption was evaluated. A major contribution of this work was the calculation of the number of spherical particles formed from a single drop of precursor solution. This calculation matched with the value found experimentally.

  2. THE EXPERIMENTAL SETUP FOR RESEARCH OF THE INFLUENCE OF MECHANICAL VIBRATIONS ON THE OUTPUT PARAMETERS OF ELECTRONIC SYSTEMS BASED ON FLEXIBLE MODULES

    Directory of Open Access Journals (Sweden)

    S. P. Novoselov

    2015-01-01

    Full Text Available Periodic vibration in the form of distorted sine wave or other complex shapes are most common in the real moving objects, where the device can be exploited on the basis of flexible modules. This kind of exposure directly affects the reliability of the construction in general. The objective of the work was the creation of an experimental device for the study of mechanical vibrations and the dependencies of their impact on the operated device.Research of mechanical vibrations and the dependencies of their influence on the device will allow finding solutions to the problems of reliability of radio electronic devices. It developed an experimental device and automatic adaptive system for control own resonant frequency of the flexible module. As a result of the experiments has been identified according to mechanical influences on the output parameters of the devices. This will take into account and to apply this experience in the design and manufacture of devices with the use of flexible printed circuit boards. 

  3. Harnessing Aquatic Physicochemical Parameters Influencing ...

    African Journals Online (AJOL)

    The management-oriented background for harnessing aquatic physicochemical parameters influencing macro invertebrate fauna of Anambra River basin for sustainable fish productivity was studied. The intra seasonal variability in the water quality of the river revealed mean transparency of 1.79 cm, Conductivity of 28.81 ...

  4. Experimental investigations on the influence of the photocathode laser pulse parameters on the electron bunch quality in an RF-photoelectron source

    Energy Technology Data Exchange (ETDEWEB)

    Haenel, Marc

    2010-07-15

    Free Electron Lasers based on the SASE principle like the European XFEL require electron bunches having peak currents of several kiloamperes as well as very low transverse emittance. While high peak currents can be generated using longitudinal bunch compression techniques, the transverse emittance must have values as low as 1mmmrad already at the source. The development of electron sources fulfilling these demanding specifications is the goal of the Photo Injector Test Facility (PITZ) in DESY, Zeuthen site. The key component of a photoinjector is the electron gun cavity where the electrons bunches are generated and immediately accelerated. The extraction of the electrons is based on the photoelectric effect of the cathode which requires a laser system having special capabilities. In the first part of the thesis, measurements are presented which were performed to investigate whether the laser and the laser transport system fulfill these requirements. The second part of the thesis is dedicated to simulations as well as experimental studies on the impact of the temporal and spatial parameters of the laser pulses on the electron bunch quality. This influence is possible because the response time of the Cs{sub 2}Te photocathode is short compared to the laser pulse duration. Based on these investigations, suggestions for improvements are given and tolerances for the laser pulse properties are defined. (orig.)

  5. An experimental study on effect of process parameters in deep ...

    African Journals Online (AJOL)

    The effects of various deep drawing process parameters were determined by experimental study with the use of Taguchi fractional factorial design and analysis of variance for AA6111 Aluminum alloy. The optimum process parameters were determined based on their influence on the thickness variation at different regions ...

  6. Statistical approach for uncertainty quantification of experimental modal model parameters

    DEFF Research Database (Denmark)

    Luczak, M.; Peeters, B.; Kahsin, M.

    2014-01-01

    . This paper aims at a systematic approach for uncertainty quantification of the parameters of the modal models estimated from experimentally obtained data. Statistical analysis of modal parameters is implemented to derive an assessment of the entire modal model uncertainty measure. Investigated structures...... estimates obtained from vibration experiments. Modal testing results are influenced by numerous factors introducing uncertainty to the measurement results. Different experimental techniques applied to the same test item or testing numerous nominally identical specimens yields different test results...

  7. Experimental Studies and FEM Analysis Regarding the Influence of Geometric Parameters on Strain, Thickness Reduction and Forces in Incremental Forming Process

    Directory of Open Access Journals (Sweden)

    Adrian Blaga

    2011-10-01

    Full Text Available The purpose of this study was to investigate the influence of geometrical parameters on the distribution of the principal strains and relative thinning and determination of forces in two directions in single point incremental forming process. For this purpose we have chosen a straight grove piece type. The parameters were taken into account are the punch diameter and step down in z direction. Were conducted the tests on two thickness sheet metal of the same material but having different mechanical characteristics. To determine the distribution of strains we used an optical method and to determine the forces a dynamometer was used. We have made two types of FEM analyses, one to determine the strains distribution and another to determine the forces.

  8. [Determination of deuterium concentration in foods and influence of water with modified isotopic composition on oxidation parameters and heavy hydrogen isotopes content in experimental animals].

    Science.gov (United States)

    Basov, A A; Bykov, I M; Baryshev, M G; Dzhimak, S S; Bykov, M I

    2014-01-01

    The article presents the results of the study of the deuterium (D) content in food products as well as the influence of deuterium depleted water (DDW) on the concentration of heavy hydrogen isotopes in the blood and lyophilized tissues of rats. The most significant difference in the content of D was found between potato and pork fat, which indexes the standard delta notation (δ) D in promille, related to the international standard SMOW (Standard Mean Ocean of Water) amounted to -83,2 per thousand and -250,7 per thousand, respectively (pdeuterium concentration ranged from -75,5 per thousand (Narzan) to +72,1 per thousand (Kubai), that indicates the ability of some food products to increase the concentration of heavy hydrogen atoms in the body. The data obtained in the experimental modeling of the diet of male Wistar rats in the age of 5-6 mo (weight 235 ± 16 g) using DDW (δD = -743,2 per thousand) instead of drinking water (δD = -37,0 per thousand) with identical mineral composition showed that after 2 weeks significant (p deuterium-protium, D/H) gradient in the body is possible. Changing the direction of isotopic D/H gradient in laboratory animals in comparison with its physiological indicators (72-127 per thousand, "plasma>tissue") is due to different rates ofisotopic exchange reactions in plasma and tissues (liver, kidney, heart), which can be explained by entering into the composition of a modified diet of organic substrates with more than DDW concentration D, which are involved in the construction of cellular structures and eventually lead to a redistribution of D and change direction of D/H gradient "plasma

  9. Experimental methods for screening parameters influencing the growth to product yield (Y(x/CH4 of a biological methane production (BMP process performed with Methanothermobacter marburgensis

    Directory of Open Access Journals (Sweden)

    Sébastien Bernacchi

    2014-12-01

    Full Text Available 1. Specht M, Brellochs J, Frick V, et al. (2010 Storage of renewable energy in the natural gas grid. Erdoel, Erdgas, Kohle 126: 342-345.2. Thauer RK, Kaster AK, Goenrich M, et al. (2010 Hydrogenases from methanogenic archaea, nickel, a novel cofactor, and H2 storage. Annu Rev Biochem 79: 507-536.3. Liu Y, Whitman WB (2008 Metabolic, phylogenetic, and ecological diversity of the methanogenic archaea. Ann N Y Acad Sci 1125: 171-189.4. Kaster AK, Goenrich M, Seedorf H, et al. (2011 More than 200 genes required for methane formation from H2 and CO2 and energy conservation are present in Methanothermobacter marburgensis and Methanothermobacter thermautotrophicus. Archaea ID 973848: 1-23.5. Seifert AH, Rittmann S, Herwig C (2014 Analysis of process related factors to increase volumetric productivity and quality of biomethane with Methanothermobacter marburgensis Appl Energ 132: 155-162.6. Bernacchi S, Weissgram M, Wukovits W, et al. (2014 Process efficiency simulation for key process parameters in biological methanogenesis. AIMS bioengineering 1: 53-71.7. Thauer RK, Kaster AK, Seedorf H, et al. (2008 Methanogenic archaea: ecologically relevant differences in energy conservation. Nat Rev Microbiol 6: 579-591.8. Schill N, van Gulik WM, Voisard D, et al. (1996 Continuous cultures limited by a gaseous substrate: development of a simple, unstructure mathematical model and experimental verification with Methanobacterium thermoautotrophicum. Biotechnol Bioeng 51: 645-658.9. Jud G, Schneider K, Bachofen R (1997 The role of hydrogen mass transfer for the growth kinetics of Methanobacterium thermoautotrophicum in batch and chemostat cultures. J Ind Microbiol Biotechnol 19: 246-251.10. Tsao JH, Kaneshiro SM, Yu SS, et al. (1994 Continuous culture of Methanococcus jannaschii, an extremely thermophilic methanogen. Biotechnol Bioeng 43: 258-261.11. Schill N, van Gulik WM, Voisard D, et al. (1996 Continuous cultures limited by a gaseous substrate: development of a

  10. Graft copolymerization of acrylic acid to cassava starch-Evaluation of the influences of process parameters by an experimental design method

    NARCIS (Netherlands)

    Witono, J. R.; Noordergraaf, I. W.; Heeres, H. J.; Janssen, L. P. B. M.

    2012-01-01

    The graft copolymerization of cassava starch with acrylic acid was investigated using a free radical initiator system (Fe2+/H2O2 redox system) in water. A comprehensive understanding of the important variables and their interaction has been obtained by applying an experimental design method. In this

  11. Assessing influence of experimental parameters on formation of PCDD/F from ash derived from fires of CCA-treated wood.

    Science.gov (United States)

    Tame, N W; Dlugogorski, B Z; Kennedy, E M

    2003-09-15

    Ash residues from fires of radiata pine timber, both untreated and treated with chromated copper arsenate (CCA), were analyzed for the presence of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F). Fire conditions were simulated using a cone calorimeter. The sensitivity of the magnitude and profile of PCDD/F in the ash under controlled experimental conditions were examined to gain an insight into the formation of PCDD/F in a system containing CCA. The total amount of PCDD/F increased from 2.0 ng/kg of ash (0.05 ng of TE/kg of ash, using WHO-TEF) for untreated radiata pine to a maximum of 2700 ng/kg of ash (78 ng of TE/kg of ash) for 0.94% CCA. Ash containing CCA showed a distinct preference for formation of PCDFs, particularly the tetrachloro homologue. It is concluded that PCDD/F formation predominantly occurred via de novo synthesis during smoldering of the char rather than during the initial flaming and pyrolysis. Furthermore, the composition of the CCA constituents present in the timber was controlled to assess whether the physical presence of Cu, a known catalyst in PCDD/F production, was sufficient to account for the formation of PCDD/F in fires of timber impregnated with CCA.

  12. Experimental determination of mechanical parameters in sensorless ...

    Indian Academy of Sciences (India)

    V S S PAVAN KUMAR HARI

    11]. Several methods have been reported in literature to measure and/or estimate the mechanical parameters for servo-motor drives and permanent magnet synchronous machine. (PMSM)-based drives [1, 10–15]. Retardation test has been.

  13. Simultaneous estimation of experimental and material parameters

    CSIR Research Space (South Africa)

    Jansen van Rensburg, GJ

    2012-07-01

    Full Text Available This conference contribution focusses on the invertibility of non-ideal material tests to accurately determine material parameters. This is done by attempting to model non-ideal test cases and comparing strains as well as force history...

  14. Experimental study on HVAC sound parameters

    Science.gov (United States)

    Bujoreanu, C.; Benchea, M.

    2016-08-01

    HVAC system represent major source of buildings internal noise and therefore they are designed to provide a human acoustic comfort besides the thermal and air quality requirements. The paper experimentally investigates three types of commercial air handler units (AHU) with different ducts cross-section sizes and inlet-outlet configuration. The measurements are performed in an anechoic room. The measurements are carried out at different fan's speeds, ranging the power-charge from 30-100% while the duct air flow is slowly adjusted from full open to full closed, between 0-500 Pa. The sound pressure levels of the radiant units are rated using NR curves. Also, the supply and the outdoor ducts sound levels are compared in order to point the frequencies where the noise must be reduced. Third-octave band analysis of random noise of an air handling unit from a HVAC system is realized, using measurement procedures that agrees the requirements of the ISO 3744:2011 and ISO 5136:2010 standards. The comparatively results highlight the effects of the geometry, air flow pressure and power-charging dependencies upon the sound level. This is the start for a noise reduction strategy.

  15. Numerical and experimental study of the influence of the operational parameters on the formation mechanisms of oxides of nitrogen during the combustion of mixtures of cellulosic and plastic materials; Etude experimentale et numerique de l'influence des parametres operatoires sur les mecanismes de formation des oxydes d'azote lors de la combustion de melanges de materiaux cellulosiques et plastiques

    Energy Technology Data Exchange (ETDEWEB)

    Andzi Barhe, T.

    2004-10-15

    The current thesis was performed within a collaboration between the Laboratoire de Combustion et de Detonique (LCD of the University of Poitiers) and the Laboratoire de Physique et de Chimie d'Environnement (LPCE) of the University of Ouagadougou. It was financed by Agency for Environment and Energy Management (ADEME). The principle object of this study is the optimisation of the combustion process during the incineration of waste. This optimisation is aimed at the reduction of the polluting emissions, principally CO and NO, during the incineration of cellulosic and plastic materials. It involves the analysis of the influence of the operational parameters on the polluting emissions and the control of reaction mechanisms of formation and reduction of these pollutants during the combustion process. Consequently, the study was performed in two parts: an experimental part and a numerical part. The experimental part was realised using a fixed bed counterflow reactor. This setup simulates the combustion within an industrial waste incinerator. The reactor allows the combustion of a vertical layer of waste mixture (wood, cardboard, PET, polyamide) to be followed. Three model mixtures representative of the makeup of household waste were studied in order to determine the influence of the composition of the waste on the emission of pollutants (CO and NO). The obtained results show that this parameter has a practically negligible influence within the tested parameter range. Consequently the formation of pollutants depends on the operating parameters - the equivalence ratio and the temperature. A numerical study of the influence of these parameters in order to show their impact on the mechanisms of pollutant formation and to determine the chemical mechanisms involved in the formation of oxides of nitrogen. The numerical study was performed with software developed at the LCD. This programme based on a detailed chemical model coupled to a simple physical model. It uses the

  16. Polymerization Parameters Influencing the QCM Response Characteristics of BSA MIP

    Directory of Open Access Journals (Sweden)

    Nam V. H. Phan

    2014-06-01

    Full Text Available Designing Molecularly Imprinted Polymers for sensing proteins is still a somewhat empirical process due to the inherent complexity of protein imprinting. Based on Bovine Serum Albumin as a model analyte, we explored the influence of a range of experimental parameters on the final sensor responses. The optimized polymer contains 70% cross linker. Lower amounts lead to higher sensitivity, but also sensor response times substantially increase (to up to 10 h at constant imprinting effect (signal ratio MIP/NIP on quartz crystal microbalance—QCM. However, by shifting the polymer properties to more hydrophilic by replacing methacrylic acid by acrylic acid, part of the decreased sensitivity can be recovered leading to appreciable sensor responses. Changing polymer morphology by bulk imprinting and nanoparticle approaches has much lower influence on sensitivity.

  17. An experimental study on effect of process parameters in deep ...

    African Journals Online (AJOL)

    DR OKE

    The effects of various deep drawing process parameters were determined by experimental study with the use of Taguchi fractional factorial .... have used Taguchi method to optimize the turning operation of S45C steel bars using tungsten carbide cutting tools and reported .... The Nd:YAG laser with oxygen cutting gas were.

  18. Numerical and experimental investigation of geometric parameters in projection welding

    DEFF Research Database (Denmark)

    Kristensen, Lars; Zhang, Wenqi; Bay, Niels

    2000-01-01

    Resistance projection welding is widely used for joining of workpieces with almost any geometric combination. This makes standardization of projection welding impossible. In order to facilitate industrial applications of projection welding, systematic investigations are carried out on the geometric...... parameters by numerical modeling and experimental studies. SORPAS, an FEM program for numerical modeling of resistance welding, is developed as a tool to help in the phase of product design and process optimization in both spot and projection welding. A systematic experimental investigation of projection...... on the numerical and experimental investigations of the geometric parameters in projection welding, guidelines for selection of the geometry and material combinations in product design are proposed. These will be useful and applicable to industry....

  19. Process parameters influencing tannase production by Aspergillus ...

    African Journals Online (AJOL)

    Rhizophora apiculata bark is a tannin-rich waste material obtained from charcoal industry. This industrial waste was used as solid substrate in the study for the production of tannase and at the same time, help in minimizing the country's industrial wastes. This study was carried out to optimize the physical parameters for the ...

  20. Influence of pulse electrodeposition parameters on microhardness ...

    Indian Academy of Sciences (India)

    forced by SiO2 nanoparticles was processed by electro- deposition method and effects of electrodeposition parameters such as average current density, pulse frequency and duty cycle on microhardness and grain size of nanocomposite coating were investigated. There were insufficient reports about effect of current density ...

  1. Influence of pulse electrodeposition parameters on microhardness ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 39; Issue 5. Influence of ... size rose. The optimum value for pulse frequency was about 25 Hz. Results showed that microhardness of nanocomposite coatings which were produced by pulse current method was higher than that of produced by direct currentmethod.

  2. Optimizing experimental parameters for tracking of diffusing particles

    DEFF Research Database (Denmark)

    Vestergaard, Christian L.

    2016-01-01

    We describe how a single-particle tracking experiment should be designed in order for its recorded trajectories to contain the most information about a tracked particle's diffusion coefficient. The precision of estimators for the diffusion coefficient is affected by motion blur, limited photon...... statistics, and the length of recorded time series. We demonstrate for a particle undergoing free diffusion that precision is negligibly affected by motion blur in typical experiments, while optimizing photon counts and the number of recorded frames is the key to precision. Building on these results, we...... describe for a wide range of experimental scenarios how to choose experimental parameters in order to optimize the precision. Generally, one should choose quantity over quality: experiments should be designed to maximize the number of frames recorded in a time series, even if this means lower information...

  3. Experimental Investigations on Performance and Design Parameters of Solar Chimney

    Directory of Open Access Journals (Sweden)

    İbrahim ÜÇGÜL

    2010-03-01

    Full Text Available In this study, a solar chimney system, which is suitable for climate conditions of Isparta and its surroundings, is designed theoretically. With the aim of studying experimentally as based on that design, a prototype solar chimney has been constructed in the university campus area of Süleyman Demirel University-RACRER (Research and Application Center for Renewable Energy Resources. Additionally, after the experimental studies, the system is modelled theoretically with depending on the design. Then, this model constituted the basis for developed computer programme and performance parameters of the system are obtained. The obtained findings showed that the solar chimney, which is suitable for climate conditions of Isparta and its surroundings, are sufficient for determining design and performance parameters. The results showed that electricity generation with solar chimney is suitable for areas which have high solar incident and long sunshine duration and similar climate conditions as such as Isparta and its surroundings. When the results are evaluated, it is seen that electricity generation power of solar chimney depends on the region solar data, the chimney height and the size of greenhouse area.

  4. Experimental study of physical parameters significant in fullerene synthesis

    Directory of Open Access Journals (Sweden)

    T. NENADOVIC

    2003-07-01

    Full Text Available In this work, the effect of physical parameters on the yield of fullerene, synthesized in a hollow cathode plasma reactor is investigated. The experimental investigations done previously have shown that the fullerene yield depended on tehcnical parameters - the current intensity, inert gas pressure, type of gas and interelectrode gap. The aim of this work was to show that the fullerene yield depends on physical parameters - carbon concentration, carbon flow rate from the interelectrode gap, axial temperature and temperature gradient between the arc channel and the chamber walls as well. It was found that fullerene synthesis occurs in an inert heat bath with dimensions determined by the temperature gradient. The lower temperature limit is around 2000 K and the value of the upper limit is the value of the axis temperature which depends on the discharge conditions. The synthesis of fullerenes is more effective if the carbon concentration in the heat bath is large and the carbon flow rate from that zone to colder parts of chamber is small.

  5. Parameter space of experimental chaotic circuits with high-precision control parameters

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, Francisco F. G. de; Rubinger, Rero M. [Instituto de Física e Química, Universidade Federal de Itajubá, Itajubá, MG (Brazil); Sartorelli, José C., E-mail: sartorelli@if.usp.br [Universidade de São Paulo, São Paulo, SP (Brazil); Albuquerque, Holokx A. [Departamento de Física, Universidade do Estado de Santa Catarina, Joinville, SC (Brazil); Baptista, Murilo S. [Institute of Complex Systems and Mathematical Biology, SUPA, University of Aberdeen, Aberdeen (United Kingdom)

    2016-08-15

    We report high-resolution measurements that experimentally confirm a spiral cascade structure and a scaling relationship of shrimps in the Chua's circuit. Circuits constructed using this component allow for a comprehensive characterization of the circuit behaviors through high resolution parameter spaces. To illustrate the power of our technological development for the creation and the study of chaotic circuits, we constructed a Chua circuit and study its high resolution parameter space. The reliability and stability of the designed component allowed us to obtain data for long periods of time (∼21 weeks), a data set from which an accurate estimation of Lyapunov exponents for the circuit characterization was possible. Moreover, this data, rigorously characterized by the Lyapunov exponents, allows us to reassure experimentally that the shrimps, stable islands embedded in a domain of chaos in the parameter spaces, can be observed in the laboratory. Finally, we confirm that their sizes decay exponentially with the period of the attractor, a result expected to be found in maps of the quadratic family.

  6. Parametric analysis of rail vehicle parameters influencing ride ...

    African Journals Online (AJOL)

    It is seen from parametric analysis that car body mass, secondary suspension vertical damping, primary suspension vertical damping and wheel base are the most sensitive parameters influencing vertical ride. While lateral ride is significantly influenced by car body mass, roll & yaw mass moment of inertia and secondary ...

  7. Experimental investigation of design parameters on dry powder inhaler performance.

    Science.gov (United States)

    Ngoc, Nguyen Thi Quynh; Chang, Lusi; Jia, Xinli; Lau, Raymond

    2013-11-30

    The study aims to investigate the impact of various design parameters of a dry powder inhaler on the turbulence intensities generated and the performance of the dry powder inhaler. The flow fields and turbulence intensities in the dry powder inhaler are measured using particle image velocimetry (PIV) techniques. In vitro aerosolization and deposition a blend of budesonide and lactose are measured using an Andersen Cascade Impactor. Design parameters such as inhaler grid hole diameter, grid voidage and chamber length are considered. The experimental results reveal that the hole diameter on the grid has negligible impact on the turbulence intensity generated in the chamber. On the other hand, hole diameters smaller than a critical size can lead to performance degradation due to excessive particle-grid collisions. An increase in grid voidage can improve the inhaler performance but the effect diminishes at high grid voidage. An increase in the chamber length can enhance the turbulence intensity generated but also increases the powder adhesion on the inhaler wall. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Optimization of Experimental Model Parameter Identification for Energy Storage Systems

    Directory of Open Access Journals (Sweden)

    Rosario Morello

    2013-09-01

    Full Text Available The smart grid approach is envisioned to take advantage of all available modern technologies in transforming the current power system to provide benefits to all stakeholders in the fields of efficient energy utilisation and of wide integration of renewable sources. Energy storage systems could help to solve some issues that stem from renewable energy usage in terms of stabilizing the intermittent energy production, power quality and power peak mitigation. With the integration of energy storage systems into the smart grids, their accurate modeling becomes a necessity, in order to gain robust real-time control on the network, in terms of stability and energy supply forecasting. In this framework, this paper proposes a procedure to identify the values of the battery model parameters in order to best fit experimental data and integrate it, along with models of energy sources and electrical loads, in a complete framework which represents a real time smart grid management system. The proposed method is based on a hybrid optimisation technique, which makes combined use of a stochastic and a deterministic algorithm, with low computational burden and can therefore be repeated over time in order to account for parameter variations due to the battery’s age and usage.

  9. Influence of breed and environmental factors on litter parameters of ...

    African Journals Online (AJOL)

    The influence of breed and environmental factors such as season, temperature, relative humidity, sunshine hours and wind speed on litter parameters of rabbits raised in a semi-humid environment was investigated using two hundred and twenty four (224) litter records collected between 1991 and 1997. New Zealand White ...

  10. The influence of boar breed and season on semen parameters ...

    African Journals Online (AJOL)

    The aim of the present study was to demonstrate the influence of boar breed and season on semen parameters. The research material consisted of 31 boars: Polish Large White (PLW), Polish Landrace (PL), and Duroc × Pietrain (D × P), aged 8 to 24 months. The analysed material consisted of 1390 ejaculates, collected ...

  11. Influence of Thyroxine on Blood Parameters and Liver Enzymes in ...

    African Journals Online (AJOL)

    This study investigated and compared the influence of exogenous thyroxine with restricted feeding and sex on the blood parameters and liver enzymes in adult male and female Wistar rats. Twelve adult wistar rats (six males and females) were given thyroxine in drinking water at dosage of 50mg/100ml of water/pair/day with ...

  12. Influence of process parameters on the cup drawing of aluminium ...

    African Journals Online (AJOL)

    In this study, the significance of three important deep drawing process parameters namely blank temperature, die arc radius and punch velocity on the deep drawing characteristics of aluminium 7075 sheet was determined. The combination of finite element method and Taguchi analysis was used to determine the influence ...

  13. Influence of pulmonary lesions on some haemotological parameters ...

    African Journals Online (AJOL)

    Blood samples from external jugular vein of camels presented for slaughter at randomly selected slaughter houses in northwestern Nigeria were collected. This is to determine some haematological baseline data and to investigate the influence of pulmonary lesions on the blood parameters studied. Accordingly blood ...

  14. An experimental study of opinion influenceability

    CERN Document Server

    Grabowicz, Przemyslaw A; Lins, Theo; de Polavieja, Gonzalo G; Benevenuto, Fabrício; Gummadi, Krishna P

    2015-01-01

    Humans, like many other animal species, often make choices under social influence. Experiments in ants and fishes have shown that individuals choose according to estimations of which option to take given private and social information. Principled approaches based on probabilistic estimations by agents give mathematical formulas explaining experiments in these species. Here we test whether the same principled approaches can explain social influence in humans. We conduct a large online field experiment in which we measure opinion influenced by public comments about short movies in the most popular video-sharing website. We show that the basic principles of social influence in other species also apply to humans, with the added complexity that humans are heterogenous. We infer influenceability of each participant of the experiment, finding that individuals prone to social influence tend to agree with social feedback, read less comments, and are less educated than the persons who resist influence. We believe that ...

  15. Experimental studies of parameters affecting the heat generation in friction stir welding process

    Directory of Open Access Journals (Sweden)

    Mijajlović Miroslav M.

    2012-01-01

    Full Text Available Heat generation is a complex process of transformation of a specific type of energy into heat. During friction stir welding, one part of mechanical energy delivered to the welding tool is consumed in the welding process, another is used for deformational processes etc., and the rest of the energy is transformed into heat. The analytical procedure for the estimation of heat generated during friction stir welding is very complex because it includes a significant number of variables and parameters, and many of them cannot be fully mathematically explained. Because of that, the analytical model for the estimation of heat generated during friction stir welding defines variables and parameters that dominantly affect heat generation. These parameters are numerous and some of them, e. g. loads, friction coefficient, torque, temperature, are estimated experimentally. Due to the complex geometry of the friction stir welding process and requirements of the measuring equipment, adequate measuring configurations and specific constructional solutions that provide adequate measuring positions are necessary. This paper gives an overview of the process of heat generation during friction stir welding, the most influencing parameters on heat generation, constructional solutions for the measuring equipment needed for these experimental researches and examples of measured values.

  16. Experimental and numerical analysis for optimal design parameters ...

    Indian Academy of Sciences (India)

    Rajneesh Kaushal

    Finally, the relations established are confirmed experimentally to validate the models. The relations thus established are ... Additionally, the present study is among the first attempts to reveal the effect of humidity on the performance of falling film evaporator. .... and accuracies of instruments used. 2.2 Experimental procedure.

  17. Influence of Synbiotics on Selected Oxidative Stress Parameters

    Science.gov (United States)

    2017-01-01

    The aim of the present study was to assess synbiotic (Lactobacillus casei + inulin) influence on oxidative stress parameters such as concentrations of malondialdehyde (MDA), hydrogen peroxide (H2O2), glutathione, and free sulfhydryl groups content. Experiments were carried out on healthy volunteers (n = 32). The subjects were divided into women group (n = 16) and men group (n = 16) and randomly assigned to synbiotic and control groups. Blood samples were collected before synbiotic supplementation and after 7 wks, at the end of the study. The administration of synbiotic resulted in a significant decrease in MDA (p inulin may have positive influence on selected oxidative stress markers. PMID:28286605

  18. The Influence of Seismic Parameters on Site Response

    Directory of Open Access Journals (Sweden)

    Asakereh A.

    2015-09-01

    Full Text Available Geotechnical earthquake engineers have been trying to determine the most appropriate solution techniques for ground response analysis under earthquake loadings. This paper presents the importance of the adequate soil behavior model to simulate earthquake site response analysis. The influence of nonlinearity and linearity of soils on the site response is also investigated. Many methods have been proposed for the analysis of one-dimensional ground response such as nonlinear methods and equivalent linear with reduced modulus. Using 13 well known earthquake records and geotechnical information of sand in the Qeshm Island (Iran and classification of earthquakes based on seismic parameters, the influence of each parameter on the Response spectra and Fourier Spectrum of surface of ground becomes evident. Analysis was done using two softwares; EERA (equivalent linear analysis and NERA (nonlinear analysis and compared. Finally, output of the software is compared with the reference result on site.

  19. Influence of Process Parameters on Nitrogen Oxide Formation in

    DEFF Research Database (Denmark)

    Lans, Robert Pieter Van Der; Glarborg, Peter; Dam-Johansen, Kim

    1997-01-01

    This paper describes the influence of burner operating conditions, burner geometry and fuel parameters on the formation of nitrogen oxide during combustion of pulverized coal. Main attention has been paid to combustion test facilities with self-sustaining flames, while extensions have been made...... to full scale boilers and furnace modeling. Since coal combustion and flame aerodynamics have been reviewed earlier, these phenomena are only treated briefly....

  20. Experimentally Verified Parameter Sets for Modelling Heterogeneous Neocortical Pyramidal-Cell Populations.

    Directory of Open Access Journals (Sweden)

    Paul M Harrison

    2015-08-01

    Full Text Available Models of neocortical networks are increasingly including the diversity of excitatory and inhibitory neuronal classes. Significant variability in cellular properties are also seen within a nominal neuronal class and this heterogeneity can be expected to influence the population response and information processing in networks. Recent studies have examined the population and network effects of variability in a particular neuronal parameter with some plausibly chosen distribution. However, the empirical variability and covariance seen across multiple parameters are rarely included, partly due to the lack of data on parameter correlations in forms convenient for model construction. To addess this we quantify the heterogeneity within and between the neocortical pyramidal-cell classes in layers 2/3, 4, and the slender-tufted and thick-tufted pyramidal cells of layer 5 using a combination of intracellular recordings, single-neuron modelling and statistical analyses. From the response to both square-pulse and naturalistic fluctuating stimuli, we examined the class-dependent variance and covariance of electrophysiological parameters and identify the role of the h current in generating parameter correlations. A byproduct of the dynamic I-V method we employed is the straightforward extraction of reduced neuron models from experiment. Empirically these models took the refractory exponential integrate-and-fire form and provide an accurate fit to the perisomatic voltage responses of the diverse pyramidal-cell populations when the class-dependent statistics of the model parameters were respected. By quantifying the parameter statistics we obtained an algorithm which generates populations of model neurons, for each of the four pyramidal-cell classes, that adhere to experimentally observed marginal distributions and parameter correlations. As well as providing this tool, which we hope will be of use for exploring the effects of heterogeneity in neocortical

  1. Probability of detection as a function of multiple influencing parameters

    Energy Technology Data Exchange (ETDEWEB)

    Pavlovic, Mato

    2014-10-15

    Non-destructive testing is subject to measurement uncertainties. In safety critical applications the reliability assessment of its capability to detect flaws is therefore necessary. In most applications, the flaw size is the single most important parameter that influences the probability of detection (POD) of the flaw. That is why the POD is typically calculated and expressed as a function of the flaw size. The capability of the inspection system to detect flaws is established by comparing the size of reliably detected flaw with the size of the flaw that is critical for the structural integrity. Applications where several factors have an important influence on the POD are investigated in this dissertation. To devise a reliable estimation of the NDT system capability it is necessary to express the POD as a function of all these factors. A multi-parameter POD model is developed. It enables POD to be calculated and expressed as a function of several influencing parameters. The model was tested on the data from the ultrasonic inspection of copper and cast iron components with artificial flaws. Also, a technique to spatially present POD data called the volume POD is developed. The fusion of the POD data coming from multiple inspections of the same component with different sensors is performed to reach the overall POD of the inspection system.

  2. The influence of experimental infection of gilts with swine H1N2 influenza A virus during the second month of gestation on the course of pregnancy, reproduction parameters and clinical status.

    Science.gov (United States)

    Kwit, Krzysztof; Pomorska-Mól, Małgorzata; Markowska-Daniel, Iwona

    2014-06-04

    The course of swine influenza in pigs is reported to be similar to human influenza. Occasionally abortions and other reproduction disorders have been associated with influenza A virus (IAV) infection in pigs. Abortions may be a consequence of high fever, pro-inflammatory cytokines or transplacental transmission of the virus.The role of IAV in the complications observed during pregnancy has been scanty and the true importance of this agent as a cause of reproductive problems in swine is not known. The aim was to determine the possible involvement of swine H1N2 IAV strain on reproductive disorders in pregnant gilts under experimental conditions. The gestation length was from 113 to 116 days, no abortion or any other reproduction disorders were noted. A PCR assay confirms the presence of IAV in the nasal swabs taken from inoculated gilts between 1 and 5 dpi. In the nasal swabs from control gilts and newborn piglets, no IAV genetic material was found. No viral RNA was detected in samples of blood taken from gilts and piglets, placentas, lungs and tracheas taken from piglets euthanized after delivery. The significant decrease in the number and percentage of lymphocytes without leukopenia was observed at 4 dpi in inoculated gilts. The percentage of granulocytes increased significantly at 4 dpi in inoculated pigs. The concentration of IL-6, IL-10 and TNF-α were higher in inoculated gilts, while IL-4 and IFN-γ were not detected in the serum of any of animals. The serum concentrations of C-reactive protein remained stable during study, while haptoglobin concentrations increased significantly after inoculation. The results of the study indicate that infection of pregnant gilts with swine H1N2 IAV in the second month of pregnancy does not cause abortion and other reproduction disorders. No evidence for transplacental transmission of swine H1N2 IAV was found. However, due to subclinical course of influenza in the present experiment caution should be taken in extrapolating

  3. Propagation of a channelized debris-flow: experimental investigation and parameters identification for numerical modelling

    Science.gov (United States)

    Termini, Donatella

    2013-04-01

    Recent catastrophic events due to intense rainfalls have mobilized large amount of sediments causing extensive damages in vast areas. These events have highlighted how debris-flows runout estimations are of crucial importance to delineate the potentially hazardous areas and to make reliable assessment of the level of risk of the territory. Especially in recent years, several researches have been conducted in order to define predicitive models. But, existing runout estimation methods need input parameters that can be difficult to estimate. Recent experimental researches have also allowed the assessment of the physics of the debris flows. But, the major part of the experimental studies analyze the basic kinematic conditions which determine the phenomenon evolution. Experimental program has been recently conducted at the Hydraulic laboratory of the Department of Civil, Environmental, Aerospatial and of Materials (DICAM) - University of Palermo (Italy). The experiments, carried out in a laboratory flume appositely constructed, were planned in order to evaluate the influence of different geometrical parameters (such as the slope and the geometrical characteristics of the confluences to the main channel) on the propagation phenomenon of the debris flow and its deposition. Thus, the aim of the present work is to give a contribution to defining input parameters in runout estimation by numerical modeling. The propagation phenomenon is analyzed for different concentrations of solid materials. Particular attention is devoted to the identification of the stopping distance of the debris flow and of the involved parameters (volume, angle of depositions, type of material) in the empirical predictive equations available in literature (Rickenmanm, 1999; Bethurst et al. 1997). Bethurst J.C., Burton A., Ward T.J. 1997. Debris flow run-out and landslide sediment delivery model tests. Journal of hydraulic Engineering, ASCE, 123(5), 419-429 Rickenmann D. 1999. Empirical relationships

  4. Experimental Verification of a Systematic Method for Identifying Contact-Dynamics Model Parameters

    National Research Council Canada - National Science Library

    Ma, Ou; Kim, Jong; Martinez, Lucas

    2007-01-01

    This project is aimed at conducting an experimental test of a new and systematic method for identifying the key parameters of a general multiple-point contact dynamics model using a robotics-based experimental testbed...

  5. An experimental study on effect of process parameters in deep ...

    African Journals Online (AJOL)

    DR OKE

    Deep drawing experiments on axi-symmetric cup production were carried out according to central composite design. The optimum .... evaluation process consisting of system design, parameter design and tolerance design. System ... The S/N equation depends on the criteria for the quality characteristic to be optimized.

  6. Biochemical blood parameters in semi-adult rabbits experimentally ...

    African Journals Online (AJOL)

    Biochemical parameters in blood specimens obtained from semi-adult rabbits of both sexes fed crude oil contaminated diets were examined. The diets had crude oil inclusions of 0, 0.05, 0.10, 0.15 and 0.20%. Blood samples were obtained from the marginal ear vein of representatives in each treatment group and assayed ...

  7. Influence of operating parameters on cake formation in pilot scale pulse-jet bag filter

    OpenAIRE

    Saleem, Mahmood; Krammer, Gernot; Khan, Rafi Ullah; Tahir, M. Suleman

    2012-01-01

    Bag filters are commonly used for fine particles removal in off-gas purification. There dust laden gas pervades through permeable filter media starting at a lower pressure drop limit leaving dust (called filter cake) on the filter media. The filter cakeformation is influenced by many factors including filtration velocity, dust concentration, pressure drop limits, and filter media resistance. Effect of the stated parameters is investigated experimentally in a pilot scale pulse-jet bag filter t...

  8. Experimental Studies of the Transport Parameters of Warm Dense Matter

    Energy Technology Data Exchange (ETDEWEB)

    Chouffani, Khalid [Idaho State Univ., Pocatello, ID (United States)

    2014-12-01

    There is a need to establish fundamental properties of matter and energy under extreme physical conditions. Although high energy density physics (HEDP) research spans a wide range of plasma conditions, there is one unifying regime that is of particular importance and complexity: that of warm dense matter, the transitional state between solid state condensed matter and energetic plasmas. Most laboratory experimental conditions, including inertial confinement implosion, fall into this regime. Because all aspects of laboratory-created high-energy-density plasmas transition through the warm dense matter regime, understanding the fundamental properties to determine how matter and energy interact in this regime is an important aspect of major research efforts in HEDP. Improved understanding of warm dense matter would have significant and wide-ranging impact on HEDP science, from helping to explain wire initiation studies on the Sandia Z machine to increasing the predictive power of inertial confinement fusion modeling. The central goal or objective of our proposed research is to experimentally determine the electrical resistivity, temperature, density, and average ionization state of a variety of materials in the warm dense matter regime, without the use of theoretical calculations. Since the lack of an accurate energy of state (EOS) model is primarily due to the lack of experimental data, we propose an experimental study of the transport coefficients of warm dense matter.

  9. Experimental and numerical analysis for optimal design parameters ...

    Indian Academy of Sciences (India)

    Later, the response surface curves are studied using ANOVA. Finally, the relations established are confirmed experimentally to validate the models. The relations thus established are beneficent in furtherance of designing evaporators. Additionally, the presentstudy is among the first attempts to reveal the effect of humidity ...

  10. Influence of atmospheric forcing parameters on land surface simulation

    Science.gov (United States)

    Nayak, H. P.; Mandal, M.; Bhattacharya, A.

    2015-12-01

    The quality of atmospheric forcing plays important role on land surface simulation using decoupled land surface modeling system. In the present study, the influence of the various atmospheric forcing parameters on land surface simulation is assessed through sensitivity experiments. Numerical experiments are conducted towards preparation of land surface analysis for the period Jan-2011 - Dec-2013 using offline 2D-Noah land surface model (LSM) based land data assimilation system (LDAS) over Indian region (5 - 39N, 60 - 100E) hereafter referred as LDASI. The surface temperature, specific humidity, horizontal winds and pressure as atmospheric forcing parameters are derived from Modern-Era Retrospective Analysis for Research and Applications (MERRA). The downward (solar and thermal) radiation and precipitation is obtained from European Centre for Medium Range Forecast (ECMWF) and Tropical Rainfall Measuring Mission (TRMM) respectively. The sensitivity experiments are conducted by introducing perturbation in one atmospheric forcing parameter at a time keeping the other parameters unchanged. Influence of temperature, specific humidity, downward (shortwave and long wave) radiation, rain-rate and wind speed is investigated by conducted 13 numerical experiments. It is observed that the land surface analysis from LDASI is most sensitive to the downward longwave radiation and least sensitive to wind speed. The analysis is also substantially influenced by the surface air temperature. The annual mean soil moisture at 5 cm is decreased by 12-15% if the downward long-wave radiation is increased by 20% and it is increased by 15% if the downward long-wave radiation is decreased by 20%. The influence is even more in the Himalayan region but the increase in long-wave radiation leads to increase in soil moisture and similar influence on decrease because downward long-wave radiation leads glacier melting. The annual mean soil temperature in the analysis is increased by 2.2 K if surface

  11. Influence of Music on Preoperative Anxiety and Physiologic Parameters in Women Undergoing Gynecologic Surgery.

    Science.gov (United States)

    Labrague, Leodoro J; McEnroe-Petitte, Denise M

    2016-04-01

    The aim of this study was to determine the influence of music on anxiety levels and physiologic parameters in women undergoing gynecologic surgery. This study employed a pre- and posttest experimental design with nonrandom assignment. Ninety-seven women undergoing gynecologic surgery were included in the study, where 49 were allocated to the control group (nonmusic group) and 48 were assigned to the experimental group (music group). Preoperative anxiety was measured using the State Trait Anxiety Inventory (STAI) while noninvasive instruments were used in measuring the patients' physiologic parameters (blood pressure [BP], pulse [P], and respiration [R]) at two time periods. Women allocated in the experimental group had lower STAI scores (t = 17.41, p music during the preoperative period in reducing anxiety and unpleasant symptoms in women undergoing gynecologic surgery. © The Author(s) 2014.

  12. Experimental study of effect of stenosis geometry on flow parameters

    Directory of Open Access Journals (Sweden)

    Veselý Ondřej

    2015-01-01

    Full Text Available A stenosis is a narrowing in a tubular organ or structure. In medicine, vessel stenosis poses health risks for people. In this work, experimental investigations of pressure loss coefficient for varying stenosis eccentricity and shape were performed. Five models of different geometry were studied; all models were stenosis of 75 % area reduction. The flow conditions approximate physiological flow. The measuring range of Reynolds number was from 130 to 2730, measured values of pressure loss coefficient were from 12 to 20. The steady experimental results indicated that static pressure loss coefficient is affected by the shape of stenosis, but it was affected more significantly by the eccentricity. Visualization experiments have been performed in Polycarbonate models.

  13. Influence of Welding Parameters on the Weld Pool Dimensions and Shape in a TIG Configuration

    Directory of Open Access Journals (Sweden)

    Marine Stadler

    2017-04-01

    Full Text Available The weld pool shape created by the plasma arc interaction on a workpiece depends on many geometrical and physical parameters and on the operating conditions. Theoretical models are developed in such a way as to predict and to characterize the material. However, these models first need to be validated. Experimental results are hence proposed with parametric studies. Nevertheless, the interaction time is often short and the weld pool shape evolution not presented. In this work, the experimental setup and the diagnostic methods characterizing the workpiece are presented. The weld pool shape was evaluated versus time according to several parameters such as the current intensity value, the distance between the two electrodes, the cathode tip angle or the plasma gas nature. The results show that the depth-to-width ratio alone is not enough to compare the impact of the parameters. The analysis points out the great influence of the current intensity on the increase of the width and depth compared to the influence of the value of the cathode tip angle. The rise of the arc length leads to an increase of the power through a higher arc voltage; nevertheless, for distances of three and five millimeters and a characteristic time of the welding process of one second, this parameter has a weak influence on the energy transferred. The use of helium leads to a bigger volume of the weld pool due to an increase of width and depth.

  14. [Lipemia and bilirubin influences for twenty-four biochemical parameters measurement].

    Science.gov (United States)

    Ali, Damien; Sacchetto, Émilie; Reigner, Arnaud; Le Carrer, Didier; Orsonneau, Jean-Luc; Delaroche, Odile; Bigot-Corbel, Édith

    2015-01-01

    The study of the influence of the lipemia and icterus was performed experimentally for twenty-four biochemistry parameters on the Roche Cobas 6000 CE analyzer. Overloads in Intralipid(®) or ditaurate of bilirubin were performed on several plasma pools. The limit of 10% was chosen to define interference on the measurement. The parameters studied were classified into different categories depending on their measurement is affected or not. Knowledge of these data allows the biologist to adapt its reporting procedures in the case of lactescent and/or icteric samples.

  15. Influences of image resolution on herbaceous root morphological parameters

    Directory of Open Access Journals (Sweden)

    ZHANG Zeyou

    2014-06-01

    Full Text Available Root images of four herbaceous species (including Plantago virginica,Solidago canadensis,Conyza canadensis and Erigeron philadelphicus were obtained by using EPSON V7000 scanner with different resolutions.Root morphological parameters including root length,diameter,volume and area were determined by using a WinRhizo root analyzing software.The results show a distinct influence of image resolution on root morphological parameter.For different herbaceous species,the optimal resolutions of root images,which would produce an acceptable precision with relative short time,vary with different species.For example,a resolution of 200 dpi was recommended for the root images of Plantago virginica and S.Canadensis, while 400 dpi for Conyza canadensis and Erigeron philadelphicus.

  16. Do breastfeeding and bottle feeding influence occlusal parameters?

    Science.gov (United States)

    Galán-Gónzalez, Antonio F; Aznar-Martín, Teresa; Cabrera-Domínguez, Maria E; Domínguez-Reyes, Antonia

    2014-01-01

    A study was made of the influence of breastfeeding and bottle feeding on development of the dental arches and occlusion in an infant population. In total, 298 infants (163 girls and 135 boys) were selected from a series of 1,643 preschool children in Seville, Spain, evaluating the type of feeding received after birth (breastfeeding only or bottle feeding only), the duration of such feeding, and its influence upon the parameters that define occlusion of the dental arches. The study comprised a full exploration of the stomatognathic system of the infants and a questionnaire for the parents. SPSS Statistical Package software (SPSS, Inc., Chicago, IL) was used to analyze the results. In total, 109 children were exclusively breastfed (36.6%) for an average of 6.8±5.8 months, whereas 189 children were exclusively bottle fed (63.4%) for an average of 17.99±11.5 months. On comparing the occlusal parameters of the two groups, the most beneficial effects (straight terminal plane, canine class I relationship, diastemas, and primate spaces) corresponded to the infants who were breastfed. Breastfed infants show better development of the dental arches and a lesser incidence of dental occlusion disorders than bottle-fed infants.

  17. The influence of frequency of visual disorders on stabilographic parameters.

    Science.gov (United States)

    Michnik, Robert; Jurkojć, Jacek; Wodarski, Piotr; Gzik, Marek; Jochymczyk-Woźniak, Katarzyna; Bieniek, Andrzej

    2016-01-01

    Defining the influence of parameters of visual disorders on ability of balancing turns out to be an important process in effective diagnostics. Current diagnostic methods relating mainly to determination of the coefficient of BRUTM (Balance Rehabilitation Unit Trade Mark) depend on lots of tests carried out in a disturbed environment created by Virtual Reality Technology. The aim of this study is to determine the effect of the frequency of visual disturbances on stabilographic values in the virtual reality environment. The study was carried out involving one research group in Virtual Cave. There were induced visual disturbances with different frequencies and with the change of frequency during measuring the position of the center of pressure (COP) in the test. Before each test the reference test was performed. All tests were performed with disorders in two different sceneries: closed and open scenery. All measurements were carried out on an immobile Zebris platform which enables determination of feet pressure distribution. From the measured values of the position of the COP Short Time Fourier Transform (STFT) was calculated. The results of calculation are shown in graphs. Their analysis showed that changing the parameters of disorder frequency in world created using Virtual Reality Technology affects stabilographic parameters. The intensity of these changes is also affected by applied research scenery. Conditions have been set out to carry out similar studies in order to obtain reliable results. The study is the first step in a project to develop a system for diagnosis and rehabilitation of human movement using Virtual Reality Technology.

  18. Oscillation regimes produced by an alto saxophone: Influence of the control parameters and the bore inharmonicity.

    Science.gov (United States)

    Doc, Jean-Baptiste; Vergez, Christophe

    2015-04-01

    The aim of this work is to highlight experimentally how inharmonicity of the bore resonance frequencies of an alto saxophone influences the nature of the oscillation regimes. A variable volume branching from the neck of an alto sax at an appropriate position allows one to change the frequency of the first resonance independently from the second. A blowing machine with artificial lips is used to make the saxophone play while controlling independently the control parameters: the blowing pressure and an embouchure parameter. Values of these parameters are estimated experimentally through the measurement of the nonlinear characteristics linking the mean air flow blown into the instrument to the static pressure difference across the reed. Experiments with different values of the control parameters as well as of the inharmonicity produce different kinds of oscillation regimes. These regimes are categorized through the analysis of the pressure signal inside the mouthpiece. The resulting maps demonstrate that the emergence of quasi-periodic regimes, and their extent, depend on the level of inharmonicity, but also on the values of the control parameters. Periodic regimes playable by choosing appropriate values of the control parameters also differ according to the level of inharmonicity, a higher inharmonicity facilitating the emergence of the third register.

  19. Experimental critical parameters of plutonium metal cylinders flooded with water

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-07-01

    Forty-nine critical configurations are reported for experiments involving arrays of 3 kg plutonium metal cylinders moderated and reflected by water. Thirty-four of these describe systems assembled in the laboratory, while 15 others are derived critical parameters inferred from 46 subcritical cases. The arrays included 2x2xN, N = 2, 3, 4, and 5, in one program and 3x3x3 configurations in a later study. All were three-dimensional, nearly square arrays with equal horizontal lattice spacings but a different vertical lattice spacing. Horizontal spacings ranged from units in contact to 180 mm center-to-center; and vertical spacings ranged from about 80 mm to almost 400 mm center-to-center. Several nearly-equilateral 3x3x3 arrays exhibit an extremely sensitive dependence upon horizontal separation for identical vertical spacings. A line array of unreflected and essentially unmoderated canned plutonium metal units appeared to be well subcritical based on measurements made to assure safety during the manual assembly operations. All experiments were performed at two widely separated times in the mid-1970s and early 1980s under two programs at the Rocky Flats Plant`s Critical Mass Laboratory.

  20. Experimental setimeted of the some parameters of the conveyor belts

    Directory of Open Access Journals (Sweden)

    Marasová Daniela

    2001-12-01

    Full Text Available At present one of the most spread methods able to solve non-linear problems of the mechanics is theis the finite-element method. When solving problems of hyperelasticity by the finite-element method (FEM for introducing the input materials' constants of the body investigated, best - thought-out Money-Rivlin's theory is used. It is the method describing the behaviour of hyper-elastic materials with large elastic (reversible deformations. For the description of behaviour of the hyperelastic materials, can be used also the development from more members, comprising 5 or 9 materials' constants. The problem with the determining the hyperelastic materials' characteristics is one of the most important factors effecting the accuracy of the calculation result. The material's constants A and B are det-rmined experimentally from the practical tests, e.g.tensile, compressive or other and have to meet certain conditions. The paper shows the possibility how to determinate these matherials´ charakteris-tics and their verification by the mathematical model ANSYS.

  1. Experimental and numerical limits in parameter studies of a hydro-aeroelastic vibration phenomenon

    Science.gov (United States)

    Seidel, Christian

    2017-07-01

    Rain-wind induced vibrations are a hydro-aeroelastic vibration phenomenon that occurs when rain and wind act simultaneously on cables, hangars and ropes. The vibration phenomena may induce oscillations with large amplitudes, thus the fatigue of construction elements is possible. The paper presents a possible fluid-mechanical interpretation of rain-wind induced vibrations. Based on this interpretation a mechanical model is deduced, in order to enable numerical investigations. In order to account for the unsteady aerodynamics a hybrid method is used, which records the lift and drag coefficients as well as the distributions of pressure and shear stress from experiments in the wind tunnel. The complex system of nonlinear differential equations is analysed concerning the stability of solutions. As an example demonstrating the border zones between numerical and experimental investigations, a parameter study for the influence of the cylinder diameter on the onset wind velocity is shown.

  2. Design Parameters Influencing Reliability of CCGA Assembly: A Sensitivity Analysis

    Science.gov (United States)

    Tasooji, Amaneh; Ghaffarian, Reza; Rinaldi, Antonio

    2006-01-01

    Area Array microelectronic packages with small pitch and large I/O counts are now widely used in microelectronics packaging. The impact of various package design and materials/process parameters on reliability has been studied through extensive literature review. Reliability of Ceramic Column Grid Array (CCGA) package assemblies has been evaluated using JPL thermal cycle test results (-50(deg)/75(deg)C, -55(deg)/100(deg)C, and -55(deg)/125(deg)C), as well as those reported by other investigators. A sensitivity analysis has been performed using the literature da to study the impact of design parameters and global/local stress conditions on assembly reliability. The applicability of various life-prediction models for CCGA design has been investigated by comparing model's predictions with the experimental thermal cycling data. Finite Element Method (FEM) analysis has been conducted to assess the state of the stress/strain in CCGA assembly under different thermal cycling, and to explain the different failure modes and locations observed in JPL test assemblies.

  3. BACTERIAL LEACHING OF ELECTRONIC SCRAP: INFLUENCE OF PROCESS PARAMETERS

    Directory of Open Access Journals (Sweden)

    Luciana Harue Yamane

    2013-03-01

    Full Text Available The application of bacterial leaching in the ore treatment is already known and also can be applied such as treatment of electronic waste to copper recovery. This paper investigates the influence of process parameters (pulp density, inoculums volume, rotation speed and initial concentration of ferrous iron on bacterial leaching of copper from printed circuit board of computers using the bacterium Acidithiobacillus ferrooxidans–LR. Printed circuit boards from computers were comminuted using a hammer mill. The powder obtained was magnetically separated and the non-magnetic material used in this study. A shake flask study was carried out on the non-magnetic material using a shaker. The results show that Acidithiobacillus ferrooxidans–LR can leach 99% of copper from printed circuit boards (non–magnetic material under the determined conditions through of the studies.

  4. Influence of celestial parameters on Mercury's perihelion shift

    Science.gov (United States)

    Krizek, Michal

    2017-07-01

    This paper considers the influence of numerical values of the celestial parameters on the indeterminacy of the perihelion shift of Mercury's orbit. This shift is thought to be one of the fundamental tests of the validity of the general theory of relativity. In the current (astro)physical community, it is generally accepted that the additional relativistic perihelion shift of Mercury is the difference between its observed perihelion shift and the one predicted by Newtonian mechanics, and that this difference equals 43'' per century. However, as it results from the subtraction of two quite inexact numbers of almost equal magnitude, it is subject to cancellation errors. As such, the above accepted value is highly uncertain and may not correspond to reality. We present a thorough numerical analysis of this problem.

  5. Influence of Earthquake Parameters on Tsunami Wave Height and Inundation

    Science.gov (United States)

    Kulangara Madham Subrahmanian, D.; Sri Ganesh, J.; Venkata Ramana Murthy, M.; V, R. M.

    2014-12-01

    After Indian Ocean Tsunami (IOT) on 26th December, 2004, attempts are being made to assess the threat of tsunami originating from different sources for different parts of India. The Andaman - Sumatra trench is segmented by transcurrent faults and differences in the rate of subduction which is low in the north and increases southward. Therefore key board model with initial deformation calculated using different strike directions, slip rates, are used. This results in uncertainties in the earthquake parameters. This study is made to identify the location of origin of most destructive tsunami for Southeast coast of India and to infer the influence of the earthquake parameters in tsunami wave height travel time in deep ocean as well as in the shelf and inundation in the coast. Five tsunamigenic sources were considered in the Andaman - Sumatra trench taking into consideration the tectonic characters of the trench described by various authors and the modeling was carried out using TUNAMI N2 code. The model results were validated using the travel time and runup in the coastal areas and comparing the water elevation along Jason - 1's satellite track. The inundation results are compared from the field data. The assessment of the tsunami threat for the area south of Chennai city the metropolitan city of South India shows that a tsunami originating in Car Nicobar segment of the Andaman - Sumatra subduction zone can generate the most destructive tsunami. Sensitivity analysis in the modelling indicates that fault length influences the results significantly and the tsunami reaches early and with higher amplitude. Strike angle is also modifying the tsunami followed by amount of slip.

  6. Filtration Parameters Influencing Circulating Tumor Cell Enrichment from Whole Blood

    Science.gov (United States)

    Beck, Markus; Terstappen, Leon W. M. M.

    2013-01-01

    Filtration can achieve circulating tumor cell (CTC) enrichment from blood. Key parameters such as flow-rate, applied pressure, and fixation, vary largely between assays and their influence is not well understood. Here, we used a filtration system, to monitor these parameters and determine their relationships. Whole blood, or its components, with and without spiked tumor cells were filtered through track-etched filters. We characterize cells passing through filter pores by their apparent viscosity; the viscosity of a fluid that would pass with the same flow. We measured a ratio of 5·104∶102∶1 for the apparent viscosities of 15 µm diameter MDA-231 cells, 10 µm white cells and 90 fl red cells passing through a 5 µm pore. Fixation increases the pressure needed to pass cells through 8 µm pores 25-fold and halves the recovery of spiked tumor cells. Filtration should be performed on unfixed samples at a pressure of ∼10 mbar for a 1 cm2 track-etched filter with 5 µm pores. At this pressure MDA-231 cells move through the filter in 1 hour. If fixation is needed for sample preservation, a gentle fixative should be selected. The difference in apparent viscosity between CTC and blood cells is key in optimizing recovery of CTC. PMID:23658615

  7. The influence of structural parameters on the permeability of ceramic foams

    Directory of Open Access Journals (Sweden)

    Moreira E. A.

    2004-01-01

    Full Text Available Ceramic foams are a new structural material, characterized by a high porosity and a large surface area and made of megapores interconnected by filaments. This results in a structure with low resistance to fluid flow, making them appropriate for use as a filter. This work studies the influence of several structural parameters, such as porosity, tortuosity, surface area and pore diameter, in predicting the permeability of ceramic foams. Foams with different pore densities were used as porous media. Permeability was measured utilizing water as the flowing fluid. The results show that the predicted permeability scatters widely with the parameters under study. Pore diameter was the structural parameter that best represented the media. An Ergun-type correlation was fitted to the data and represented very well the permeability of the media in all foams under the experimental conditions studied.

  8. Experimental Parameter Tuning of Artificial Neural Network in Customer Churn Prediction

    National Research Council Canada - National Science Library

    Martin Fridrich

    2017-01-01

    Abstract Purpose of the article: The paper aim is to examine classification models, based on artificial neural networks through experimental parameter tuning, in domain of customer churn prediction in e-commerce retail...

  9. Parameters influencing AIS 1 neck injury outcome in frontal impacts.

    Science.gov (United States)

    Jakobsson, Lotta; Norin, Hans; Svensson, Mats Y

    2004-06-01

    In order to gain more knowledge of the neck injury scenario in frontal impacts, a statistical study of parameters influencing incidences of AIS 1 neck injuries was performed. The data set consisted of 616 occupants in Volvo cars. Information regarding the crash, the safety systems, occupant characteristics (including prior neck problems), behavior and sitting posture at the time of impact, and neck symptoms (including duration) was collected and analyzed. Occupant characteristics (mainly gender, weight, and age), kinematics (head impacts) and behavior at the time of impact were identified as the most prominent parameter areas with regard to AIS 1 neck injury outcome. Specifically, women had a significantly higher AIS 1 neck injury rate as compared to men, occupants under the age of 50 had a significantly higher AIS 1 neck injury rate as compared to those above 50 and occupants weighing less than 65 kg have a significantly higher AIS 1 neck injury rate than heavier occupants. Drivers stating that they impacted their head against a frontal interior structure had a significantly higher AIS 1 neck injury rate than those without head impact. Also, occupants who stated they had tensed their neck muscles at the time of impact, had a significantly higher AIS 1 neck injury rate as compared to occupants who did not. Occupant activities, such as tightly gripping the steering wheel or straightening their arms showed a significantly increased AIS 1 neck injury rate, indicating that occupant behavior at time of impact could be influential with respect to AIS 1 neck injury outcome. Also, occupants reporting prior neck problems had a higher rate of persistent symptoms (>1 year) but no difference with respect to passing symptoms (<3 months) as compared to those without prior neck problems. Additionally, there was no distinct pattern for the duration of neck symptoms.

  10. Modelling and experimental investigation of process parameters in WEDM of WC-5.3 % Co using response surface methodology

    Directory of Open Access Journals (Sweden)

    K. Jangra

    2012-11-01

    Full Text Available Tungsten carbide-cobalt (WC-Co composite is a difficult-to-machine material owing to its excellent strength and hardness at elevated temperature. Wire electrical discharge machining (WEDM is a best alternative for machining of WC-Co composite into intricate and complex shapes. Efficient machining of WC-Co composite on WEDM is a challenging task since it involves large numbers of parameters. Therefore, in present work, experimental investigation has been carried out to determine the influence of important WEDM parameters on machining performance of WC-Co composite. Response surface methodology, which is a collection of mathematical and experimental techniques, was utilised to obtain the experimental data. Using face-centered central composite design, experiments were conducted to investigate and correlate the four input parameters: pulse-on time, pulse-off time, servo voltage and wire feed for three output performance characteristics – cutting speed (CS, surface roughness (SR and radial overcut (RoC. Using analysis of variance on experimental data, quadratic vs. two-factor interaction (2FI models have been suggested for CS and RoC while two-factor interaction (2FI has been proposed for SR. Using these mathematical models, optimal parameters can be determined easily for desired performance characteristics, and hence a trade-off can be made among different performance characteristics.

  11. Bioremediation treatment of hydrocarbon-contaminated Arctic soils: influencing parameters.

    Science.gov (United States)

    Naseri, Masoud; Barabadi, Abbas; Barabady, Javad

    2014-10-01

    The Arctic environment is very vulnerable and sensitive to hydrocarbon pollutants. Soil bioremediation is attracting interest as a promising and cost-effective clean-up and soil decontamination technology in the Arctic regions. However, remoteness, lack of appropriate infrastructure, the harsh climatic conditions in the Arctic and some physical and chemical properties of Arctic soils may reduce the performance and limit the application of this technology. Therefore, understanding the weaknesses and bottlenecks in the treatment plans, identifying their associated hazards, and providing precautionary measures are essential to improve the overall efficiency and performance of a bioremediation strategy. The aim of this paper is to review the bioremediation techniques and strategies using microorganisms for treatment of hydrocarbon-contaminated Arctic soils. It takes account of Arctic operational conditions and discusses the factors influencing the performance of a bioremediation treatment plan. Preliminary hazard analysis is used as a technique to identify and assess the hazards that threaten the reliability and maintainability of a bioremediation treatment technology. Some key parameters with regard to the feasibility of the suggested preventive/corrective measures are described as well.

  12. An Experimental Study of the Modal Parameters of a Damaged Cantilever

    DEFF Research Database (Denmark)

    Rytter, A.; Brincker, Rune; Kirkegaard, Poul Henning

    of results from experimental tests with six hollow section steel cantilevers containing a fatigue crack introduced from a narrow laser cut slot. The modal parameters have been identified for different size and location of a crack. The modal parameters have been estimated by mean of frequency domain and time...

  13. Radiometric parameters in freshwater samples of Centro Experimental Aramar (CTMSP/Brazil)

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Marco Antonio P.V. [Laboratorio Radioecologico (LARE), Ipero, SP (Brazil). Dept. de Seguranca Nuclear; Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Experimental results are described obtained with gamma spectrometry, alpha and beta gross counts, liquid scintillation and fluorometry techniques for the measurement of background radiation in surface water samples, collected in Centro Experimental Aramar and surroundings, from 1988 to 2009. The estimated average background radiation concentrations in water samples in this region are low, related to the low level detection limits of the techniques, and indicates good water quality parameters, and low interference in the environment in Centro Experimental Aramar and region. (author)

  14. Influence of fission spectra uncertainties on calculated fast reactor parameters

    Energy Technology Data Exchange (ETDEWEB)

    Lucius, J.L.; Marable, J.H.

    1979-01-01

    The effect of fission spectra uncertainties on calculated fast reactor parameters is studied by (1) considering the sensitivities to fission spectrum parameters of four performance parameters in the fast reactor benchmark ZPR-6/7, (2) estimating the uncertainties in these calculated performance parameters due to uncertainties in the fission spectra, (3) reporting the change in ZPR-6/7 calculated performance parameters due to fission spectra changes going from ENDF/B-IV to proposed ENDF/B-VP, and (4) determining what fast benchmark integral experiments are trying to tell us about ENDF/B-IV fission spectrum parameters as variables in a least squares adjustment procedure.

  15. INFLUENCE OF UTILIZED LOAD OF DRIVE OF COMPRESSING STATION UPON PARAMETERS OF GTP

    Directory of Open Access Journals (Sweden)

    A. A. Abrazovski

    2014-01-01

    Full Text Available Today it is required to use secondary energy resources (STR, which we have in gas-transport system of the country, more efficiently. In this system (STR smoke gases of gas transforming aggregates with turbogas drive installations are presented primarily.For using STR of turbogas drives it is necessary to forecast heat exchange equipment installation, this causes the growth of aerodynamic resistance of exhaust channel. This influences on all plant’s work. It was experimentally proved that the usage of utilized equipment influences upon increasing  of power efficiency. For this reason the perturbation method was used, which allow to determine rate of influence. Convenience of this method is that the solution can be obtained in the form of evident analytical dependence and it does not depend on formulated problem, number of variable and definite relations between them.Using the perturbation method influence efficiency was obtained, which influences on exhaust channel resistance changes and as a result changes power efficiency and in the whole plant’s efficiency. Besides, in this article the dependence of influence efficiency from stating parameters of cycle was presented in graphs: temperature of burning products before turbine and air compression.

  16. Influence of Geant4 parameters on proton dose distribution

    Directory of Open Access Journals (Sweden)

    Asad Merouani

    2015-09-01

    Full Text Available Purpose: The proton therapy presents a great precision during the radiation dose delivery. It is useful when the tumor is located in a sensitive area like brain or eyes. The Monte Carlo (MC simulations are usually used in treatment planning system (TPS to estimate the radiation dose. In this paper we are interested in estimating the proton dose statistical uncertainty generated by the MC simulations. Methods: Geant4 was used in the simulation of the eye’s treatment room for 62 MeV protons therapy, installed in the Istituto Nazionale Fisica Nucleare Laboratori Nazionali del Sud (LNS-INFN facility in Catania. This code is a Monte Carlo based on software dedicated to simulate the passage of particles through the matter. In this work, we are interested in optimizing the Geant4 parameters on energy deposit distribution by proton to achieve the spatial resolution of dose distribution required for cancer therapy. We propose various simulations and compare the corresponding dose distribution inside water to evaluate the statistical uncertainties. Results: The simulated Bragg peak, based on facility model is in agreement with the experimental data, The calculations show that the mean statistical uncertainty is less than 1% for a simulation set with 5 × 104 events, 10-3 mm production threshold and a 10-2 mm step limit. Conclusion: The set of Geant4 cut and step limit values can be chosen in combination with the number of events to reach precision recommended from International Commission on Radiation Units and measurements (ICRU in Monte Carlo codes for proton therapy treatment.

  17. Neoadjuvant chemoradiotherapy of rectal carcinoma. Baseline hematologic parameters influencing outcomes

    Energy Technology Data Exchange (ETDEWEB)

    Hodek, Miroslav; Sirak, Igor; Paluska, Petr; Kopecky, Jindrich; Petera, Jiri; Vosmik, Milan [University Hospital in Hradec Kralove, Department of Oncology and Radiotherapy, Hradec Kralove (Czech Republic); Ferko, Alexander; Oerhalmi, Julius [University Hospital in Hradec Kralove, Department of Surgery, Hradec Kralove (Czech Republic); Hovorkova, Eva; Hadzi Nikolov, Dimitar [University Hospital in Hradec Kralove, Fingerland Department of Pathology, Hradec Kralove (Czech Republic)

    2016-09-15

    The link between the blood count and a systemic inflammatory response (SIR) is indisputable and well described. Pretreatment hematological parameters may predict the overall clinical outcomes in many types of cancer. Thus, this study aims to systematically evaluate the relationship between baseline blood count levels and treatment response in rectal cancer patients treated with neoadjuvant chemoradiotherapy. From 2009-2015, 173 patients with locally advanced rectal cancer were retrospectively enrolled in the study and analyzed. The baseline blood count was recorded in all patients 1 week before chemoradiation. Tumor response was evaluated through pathologic findings. Blood count levels which included RBC (red blood cells), Hb (hemoglobin), PLT (platelet count), neutrophil count, WBC (white blood cells), NLR (neutrophil-to-lymphocyte ratio), and PLR (platelet-to-lymphocyte ratio) were analyzed in relation to tumor downstaging, pCR (pathologic complete response), OS (overall survival), and DFS (disease-free survival). Hb levels were associated with a response in logistic regression analysis: pCR (p = 0.05; OR 1.04, 95 % CI 1.00-1.07); T downstaging (p = 0.006; OR 1.03, 95 % CI 1.01-1.05); N downstaging (p = 0.09; OR 1.02, 95 % CI 1.00-1.04); T or N downstaging (p = 0.007; OR 1.04, 95 % CI 1.01-1.07); T and N downstaging (p = 0.02; OR 1.02, 95 % CI 1.00-1.04); Hb and RBC were the most significant parameters influencing OS; PLT was a negative prognostic factor for OS and DFS (p = 0.008 for OS); an NLR value of 2.8 was associated with the greatest significance for OS (p = 0.03) and primary tumor downstaging (p = 0.02). Knowledge of pretreatment hematological parameters appears to be an important prognostic factor in patients with rectal carcinoma. (orig.) [German] Die Verbindung zwischen dem Blutbild und der systemischen Entzuendungsreaktion (''systemic inflammatory response'', SIR) ist unbestreitbar und gut beschrieben. Aufgrund der

  18. Evaluation of some biotechnological parameters influencing the Pleurotus ostreatus biomass production by submerged cultivation

    Directory of Open Access Journals (Sweden)

    Vicenţiu-Bogdan HORINCAR

    2015-12-01

    Full Text Available The submerged culture of mushrooms represents a future for biotechnological processes at industrial level, in order to obtain biomass with economical value (food and ingredients, nutraceuticals and pharmaceuticals. Pleurotus ostreatus is well known worldwide for its culinary and medicinal value. The aim of the present study was to evaluate the most important biotechnological parameters that have influence on the biomass production of P. ostreatus, by cultivation in submerged conditions. Applying the Plackett-Burman experimental design, the significant parameters influencing the P. ostreatus biomass production were found to be the concentration of dextrose and yeast extract and time of cultivation. The best results in terms of maximising the biomass production (25.71 g·L-1 were obtained when the “+1” level of each independent variables was used in the Plackett-Burman experimental design. Analysis of variance (ANOVA exhibited a high correlation coefficient (R2 value of 0.9908, which certifies that the mathematical model was relevant for the biotechnological process.

  19. Biofuel and Hydrogen Influence for Operation Parameters of Spark Ignition Engine

    Directory of Open Access Journals (Sweden)

    Martynas Damaševičius

    2016-12-01

    Full Text Available Paper presents research of efficient and ecological parameters of gasoline engine working with biobuthanol (10% and 20% by volume and addi-tionaly supplying oxygen and hydrogen (HHO gas mixture (3.6 l/min, which was obtained from from water by electrolysis. Biobuthanol addition decreases rate of heat release, the combustion temperature and pressure are lower, which has an influence on lower nitrous oxide (NOx emission in exhaust gases. However, biobuthanol increases carbon monoxide (CO concentration. Biobuthanol fuel has a simplier molecular structure, therefore the concentration of HC in the exhaust gas is decreasing. Due to lower heating value of biobuthanol fuel and slower combustion process, the engine efficiency decreases and specific fuel consumptions increase. The change of engine energetical indicators due to biobuthanol, can be compensated with advanced ignition angle. Using experimental investigation, it was determined, that negative biobuthanol influence for the combustion process and engine efficient inicators can be compensated also by additional supplied HHO gas, in which the hydrogen element iprove fuel mixture com-bustion. Fuel combustion process analysis was carried out using AVL BOOST software. Experimental research and combustion process numerical simulation showed that using balanced biobuthanol and hydrogen addition, optimal efficient and ecological parameters could be achieved, when engine is working for petrol fuel typical optimal spark timing.

  20. INFLUENCE OF TECHNOLOGICAL PARAMETERS ON AGROTEXTILES WATER ABSORBENCY USING ANOVA MODEL

    Directory of Open Access Journals (Sweden)

    LUPU Iuliana G.

    2016-05-01

    Full Text Available Agrotextiles are now days extensively being used in horticulture, farming and other agricultural activities. Agriculture and textiles are the largest industries in the world providing basic needs such as food and clothing. Agrotextiles plays a significant role to help control environment for crop protection, eliminate variations in climate, weather change and generate optimum condition for plant growth. Water absorptive capacity is a very important property of needle-punched nonwovens used as irrigation substrate in horticulture. Nonwovens used as watering substrate distribute water uniformly and act as slight water buffer owing to the absorbent capacity. The paper analyzes the influence of needling process parameters on water absorptive capacity of needle-punched nonwovens by using ANOVA model. The model allows the identification of optimal action parameters in a shorter time and with less material expenses than by experimental research. The frequency of needle board and needle depth penetration has been used as independent variables while the water absorptive capacity as dependent variable for ANOVA regression model. Based on employed ANOVA model we have established that there is a significant influence of needling parameters on water absorbent capacity. The higher of depth needle penetration and needle board frequency, the higher is the compactness of fabric. A less porous structure has a lower water absorptive capacity.

  1. Analysis of temperature influence on the informative parameters of single-coil eddy current sensors

    Science.gov (United States)

    Borovik, S. Yu.; Kuteynikova, M. M.; Sekisov, Yu. N.; Skobelev, O. P.

    2017-07-01

    This paper describes the study of temperature in the flowing part of a turbine on the informative parameters (equivalent inductances of primary windings of matching transformers) of single-coil eddy-current sensors with a sensitive element in the form of a conductor section, which are used as part of automation systems for testing gas-turbine engines. In this case, the objects of temperature influences are both sensors and controlled turbine blades. The existing model of electromagnetic interaction of a sensitive element with the end part of a controlled blade is used to obtain quantitative estimates of temperature changes of equivalent inductances of sensitive elements and primary windings of matching transformers. This model is also used to determine the corresponding changes of the informative parameter of the sensor in the process of experimental studies of temperature influences on it (in the absence of blades in the sensitive region). This paper also presents transformations in the form of relationships of informative parameters with radial and axial displacements at normal (20 °C) and nominal (1000 °C) temperatures, and their difference is used to determine the families of dominant functions of temperature, which characterize possible temperature errors for any radial and axial displacements in the ranges of their variation.

  2. Methodology to estimate parameters of an excitation system based on experimental conditions

    Energy Technology Data Exchange (ETDEWEB)

    Saavedra-Montes, A.J. [Carrera 80 No 65-223, Bloque M8 oficina 113, Escuela de Mecatronica, Universidad Nacional de Colombia, Medellin (Colombia); Calle 13 No 100-00, Escuela de Ingenieria Electrica y Electronica, Universidad del Valle, Cali, Valle (Colombia); Ramirez-Scarpetta, J.M. [Calle 13 No 100-00, Escuela de Ingenieria Electrica y Electronica, Universidad del Valle, Cali, Valle (Colombia); Malik, O.P. [2500 University Drive N.W., Electrical and Computer Engineering Department, University of Calgary, Calgary, Alberta (Canada)

    2011-01-15

    A methodology to estimate the parameters of a potential-source controlled rectifier excitation system model is presented in this paper. The proposed parameter estimation methodology is based on the characteristics of the excitation system. A comparison of two pseudo random binary signals, two sampling periods for each one, and three estimation algorithms is also presented. Simulation results from an excitation control system model and experimental results from an excitation system of a power laboratory setup are obtained. To apply the proposed methodology, the excitation system parameters are identified at two different levels of the generator saturation curve. The results show that it is possible to estimate the parameters of the standard model of an excitation system, recording two signals and the system operating in closed loop with the generator. The normalized sum of squared error obtained with experimental data is below 10%, and with simulation data is below 5%. (author)

  3. Experimental investigation on the influence of instrument settings on pixel size and nonlinearity in SEM image formation

    DEFF Research Database (Denmark)

    Carli, Lorenzo; Genta, Gianfranco; Cantatore, Angela

    2010-01-01

    The work deals with an experimental investigation on the influence of three Scanning Electron Microscope (SEM) instrument settings, accelerating voltage, spot size and magnification, on the image formation process. Pixel size and nonlinearity were chosen as output parameters related to image...... quality and resolution. A silicon grating calibrated artifact was employed to investigate qualitatively and quantitatively, through a designed experiment approach, the parameters relevance. SEM magnification was found to account by far for the largest contribution on both parameters under consideration...

  4. Experimental Parameter Tuning of Artificial Neural Network in Customer Churn Prediction

    OpenAIRE

    Martin Fridrich

    2017-01-01

    Abstract Purpose of the article: The paper aim is to examine classification models, based on artificial neural networks through experimental parameter tuning, in domain of customer churn prediction in e-commerce retail. Methodology/methods: Key methods used are artificial neural network and conditional inference tree for further meta-analysis of the results. Fundamental logical methods such as deduction are also used. Scientific aim: To present and execute experimental design for per...

  5. Influence of Thyroxine on Blood Parameters and Liver Enzymes in ...

    African Journals Online (AJOL)

    Dr Olaleye

    et al (1990) who found that exogenous thyroxine increased the body weight of the treated rats significantly. The results of these earlier studies with different results have not made it possible for one to state clearly the influence that thyroid hormones have on body weights in rats. Data from animal studies on the influence that.

  6. Uncertainty in wind climate parameters and their influence on wind turbine fatigue loads

    DEFF Research Database (Denmark)

    Toft, Henrik Stensgaard; Svenningsen, Lasse; Sørensen, John Dalsgaard

    2016-01-01

    Highlights • Probabilistic framework for reliability assessment of site specific wind turbines. • Uncertainty in wind climate parameters propagated to structural loads directly. • Sensitivity analysis to estimate wind climate parameters influence on reliability.......Highlights • Probabilistic framework for reliability assessment of site specific wind turbines. • Uncertainty in wind climate parameters propagated to structural loads directly. • Sensitivity analysis to estimate wind climate parameters influence on reliability....

  7. Experimental determination of detonation parameters of explosives based on ammonium nitrate

    Science.gov (United States)

    Utkin, Alexander; Lavrov, Vladimir; Mochalova, Valentina

    2012-03-01

    Laser interferometer VISAR was used for investigation of the reaction zone structure and determination of detonation parameters in two different kinds of explosives based on ammonium nitrate: emulsion explosives and composite explosives with plastic binder. The influence of ammonium particles size, structure and charge diameter on detonation velocity and distribution of parameters inside of the reaction zone has been investigated for composite explosives. The effect of aging time of emulsion matrix with different storage time was found.

  8. Influence of surface roughness on the measurement of acoustic nonlinearity parameter of solids using contact piezoelectric transducers.

    Science.gov (United States)

    Chakrapani, Sunil Kishore; Howard, Alexander; Barnard, Daniel

    2017-10-28

    The current article reports on the experimental study of the influence of surface roughness on the measurement of the acoustic nonlinearity parameter. The nonlinearity parameter was measured using contact piezoelectric transducers, which were calibrated using the reciprocity based technique. Aluminum and steel samples were chosen to study the influence of hardness of the sample on the measurement of the nonlinearity parameter. While, lower Ra value (average asperity height) aluminum samples were more susceptible to surface deformation and scratches from coupling the transducer to the sample, the same could not be observed for steel samples. Results demonstrate a large variation in nonlinearity parameter for aluminum (∼35%) compared to steel (∼2%) between two consecutive experiments, suggesting flattening of asperities after the first experiment. Experiments were also performed with 3 different setup configurations; (1) receiver and transmitter on rough sides, (2) receiver on smooth and transmitter on rough side and (3) receiver on rough and transmitter on smooth side. Results show that least variation in the measured nonlinearity parameter was observed when the receiver was placed on the smooth side, and a 10% variation was observed between the three setup configurations. Finally, a comparison of relative nonlinearity parameter calculated using current or voltage ratio and absolute nonlinearity parameter showed large discrepancies. Conclusions were drawn from the experimental observations. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Influence of Pilot Flame Parameters on the Stability of Turbulent Jet Flames

    KAUST Repository

    Guiberti, Thibault F.

    2016-11-08

    This paper presents a comprehensive study of the effects of pilot parameters on flame stability in a turbulent jet flame. The Sydney inhomogeneous piloted burner is employed as the experimental platform with two main fuels, namely, compressed natural gas and liquefied petroleum gas. Various concentrations of five gases are used in the pilot stream, hydrogen, acetylene, oxygen, nitrogen, and argon, to enable a sufficient range in exploring the following parameters: pilot heat release, temperature, burnt gas velocity, equivalence ratio, and H/C ratio. The experimental results are mainly presented in the form of blow-off limits and supported by simple calculations, which simulate various conditions of the pilot–mixture interface. It is found that increasing the pilot adiabatic flame temperature benefits the flame stability and has an even greater influence than the heat release, which is also known to enhance the blow-off limits. Conversely, increasing the pilot burnt gas velocity reduces the blow-off velocity, except for the limiting case when the jet is fully non-premixed. The H/C ratio has negligible effects, while resorting to lean pilots significantly increases the stability of globally rich partially premixed and premixed jets. Such findings are consistent with trends obtained from laminar flame calculations for rich fuel/air mixtures issuing against hot combustion products to simulate the pilot stream.

  10. The Influence of Physico-Chemical Parameters on the Zooplankton ...

    African Journals Online (AJOL)

    Zooplankton studies of Kusalla Reservoir in Karaye Local Government Area of Kano State were carried out over a period of twelve months from June, 2006 to May, 2007. Alongside the physicochemical parameters of the reservoir was also determined in relation to the distribution of the zooplankton. Physico-chemical ...

  11. The Influence of Malaria on Some Haematological Parameters in ...

    African Journals Online (AJOL)

    Venous blood samples were collected, during the second trimester of pregnancy, from one hundred (100) febrile pregnant women, and one hundred (100) nonfebrile pregnant women. The blood films were stained, examined and evaluated for malaria parasites. Haematological parameters like packed cell volume (PCV), ...

  12. Influence of laser parameters on laser ultrasonic efficiency

    CSIR Research Space (South Africa)

    Forbes, A

    2007-01-01

    Full Text Available parameters, such as output couplers and gas mixture, and the impact these choices have on the laser chemistry. The authors present a theory for the catalytic recombination of the gas which shows excellent agreement with experiment. Finally, an operating laser...

  13. Formulation parameters influencing self-stratification of coatings

    NARCIS (Netherlands)

    Vink, P.; Bots, T.L.

    1996-01-01

    Research was carried out aimed at the development of self-stratifying paints for steel which after application during film formation spontaneously form two well established layers of primer and top coat. The parameters affecting stratification were investigated for combinations of epoxy resins and

  14. Effect of Experimental Parameters on Nanofiber Diameter from Electrospinning with Wire Electrodes

    Science.gov (United States)

    Zhu, Guocheng; Zhao, L. Y.; Zhu, L. T.; Deng, X. Y.; Chen, W. L.

    2017-09-01

    Polyvinylidene Fluoride (PVDF) nanofibers were electrospun by Nanospider equipment with wire electrodes. The parameters which would influence the fiber diameter were investigated in terms of solution concentration, cartridge speed (feed rate of solution), voltage, electrode distance, rotating wire speed, winding speed and slit diameter. The morphology and diameter of fibers were observed by scanning electron microscope. The results revealed that the solution concentration had significant influence on both fiber morphology and fiber diameter; the cartridge speed, voltage, electrode distance and slit diameter had slight effect on fiber diameter since the standard deviations were large; the rotating wire speed and the winding speed had insignificant influence on fiber diameter.

  15. Residual waters treatment by heterogeneous photocatalysis: a study of experimental parameters applied to the photoelectrocatalysis

    Directory of Open Access Journals (Sweden)

    Henrique de Santana

    2006-02-01

    Full Text Available In this paper, the use of electrochemically-assisted heterogeneous photo-catalysis will be discussed. Several operational parameters will also be discussed, in order to achieve optimum efficiency of this photo-degradation system, such as: the influence of variables as support electrolyte, applied potential, dye initial concentration, pH and choice of a UV source on dye degradation.

  16. Experimental Verification of Statistically Optimized Parameters for Low-Pressure Cold Spray Coating of Titanium

    Directory of Open Access Journals (Sweden)

    Damilola Isaac Adebiyi

    2016-06-01

    Full Text Available The cold spray coating process involves many process parameters which make the process very complex, and highly dependent and sensitive to small changes in these parameters. This results in a small operational window of the parameters. Consequently, mathematical optimization of the process parameters is key, not only to achieving deposition but also improving the coating quality. This study focuses on the mathematical identification and experimental justification of the optimum process parameters for cold spray coating of titanium alloy with silicon carbide (SiC. The continuity, momentum and the energy equations governing the flow through the low-pressure cold spray nozzle were solved by introducing a constitutive equation to close the system. This was used to calculate the critical velocity for the deposition of SiC. In order to determine the input temperature that yields the calculated velocity, the distribution of velocity, temperature, and pressure in the cold spray nozzle were analyzed, and the exit values were predicted using the meshing tool of Solidworks. Coatings fabricated using the optimized parameters and some non-optimized parameters are compared. The coating of the CFD-optimized parameters yielded lower porosity and higher hardness.

  17. Vine Nutrition and Extraction Parameters Can Influence Winegrape YAN

    Science.gov (United States)

    This article covered the initial portion of our exploration of how altered vine nutrient regimes and sample preparation methods influence 'Pinot noir' grape nitrogen (N) content and composition. We mainly focused on ammonia and free amino acids and recalculated these values as YAN (yeast assimilable...

  18. Procedure for statistical analysis of one-parameter discrepant experimental data.

    Science.gov (United States)

    Badikov, Sergey A; Chechev, Valery P

    2012-09-01

    A new, Mandel-Paule-type procedure for statistical processing of one-parameter discrepant experimental data is described. The procedure enables one to estimate a contribution of unrecognized experimental errors into the total experimental uncertainty as well as to include it in analysis. A definition of discrepant experimental data for an arbitrary number of measurements is introduced as an accompanying result. In the case of negligible unrecognized experimental errors, the procedure simply reduces to the calculation of the weighted average and its internal uncertainty. The procedure was applied to the statistical analysis of half-life experimental data; Mean half-lives for 20 actinides were calculated and results were compared to the ENSDF and DDEP evaluations. On the whole, the calculated half-lives are consistent with the ENSDF and DDEP evaluations. However, the uncertainties calculated in this work essentially exceed the ENSDF and DDEP evaluations for discrepant experimental data. This effect can be explained by adequately taking into account unrecognized experimental errors. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Geometrical parameters influence on the stiffness of steel sandwich plates with web-core

    Science.gov (United States)

    Jiang, X. X.; Ji, H.; Rejab, M. R. M.; Zhang, S.; Ishak, M.; Zhu, L.

    2017-10-01

    Laser welded sandwich plates with web-core have found their position in the marine and land vehicles. To implement such design accurately, knowledge about the influence of geometrical parameters on the stiffness is necessary. In this paper, the over-hanging three points bending tests were performed on the laser welded web-core steel sandwich plate under quasi-static conditions, together with the finite element (FE) simulations. The following parameters were analysed: the thickness of the face plate, the spacing of the two core plates and the height of the core plates. The agreement between experimental measurements and FE results was considered to be good. It is shown that changes of these parameters can contribute to increase or decrease of the stiffness of web-core sandwich plate, but the height of the core plate has no effect on the shear stiffness as the spacing of the two core plates is known. There are linear, exponential and polynomial fitted relationships between the geometrical and the stiffness of the web-core sandwich plates.

  20. Influence of red jersey color on physical parameters in combat sports.

    Science.gov (United States)

    Dreiskaemper, Dennis; Strauss, Bernd; Hagemann, Norbert; Büsch, Dirk

    2013-02-01

    Hill and Barton (2005) showed that fighters in tae kwon do, boxing, and wrestling who wore red jerseys during the 2004 Olympic Games won more often than those wearing blue jerseys. Regarding these results, this study investigated the effects of jersey color during a combat situation on fighters' physical parameters of strength and heart rate. An artificial, experimental combat situation was created in which the color of sport attire was assigned randomly. Fourteen pairs of male athletes matched for weight, height, and age had to fight each other: once in a red jersey and once in a blue. Heart rate (before, during, and after the fight) and strength (before the fight) were tested wearing the blue and the red jerseys. Participants wearing red jerseys had significantly higher heart rates and significantly higher pre-contest values on the strength test. Results showed that participants' body functions are influenced by wearing red equipment.

  1. INFLUENCE OF PARAMETERS OF CRYSTALLIZATION ON MODIFYING OF AN ALLOY

    Directory of Open Access Journals (Sweden)

    V. Yu. Stetsenko

    2015-01-01

    Full Text Available It is shown that extent of modifying of an alloy is proportional to overcooling at its hardening, viscosity of fusion and interphase superficial energy of crystals of the leading phase. The key technological parameters of modifying of an alloy are the speed of its hardening, viscosity of fusion and extent of refinement from surface-active elements. Their adsorption on crystals of the leading phase interferes with modifying of an alloy.

  2. Influence of Fermentation Methods on Neutral Detergent Fiber Degradation Parameters

    DEFF Research Database (Denmark)

    Bossen, D; Mertens, D R; Weisbjerg, M R

    2008-01-01

    The effect of 3 fermentation methods, in situ (IS) in 4 lactating cows (average pH of 5.8), in vitro (IVn) with media pH of 6.8, or in vitro (IVa) with media pH adjusted to 6.0 using citric acid, on fiber degradation parameters was studied using feeds ground to different particle sizes. Corn silage...

  3. Experimental Verification of the Behavioral Foundation of Bacterial Transport Parameters Using Microfluidics

    Science.gov (United States)

    Ahmed, Tanvir; Stocker, Roman

    2008-01-01

    We present novel microfluidic experiments to quantify population-scale transport parameters (chemotactic sensitivity χ0 and random motility μ) of a population of bacteria. Previously, transport parameters have been derived theoretically from single-cell swimming behavior using probabilistic models, yet the mechanistic foundations of this upscaling process have not been verified experimentally. We designed a microfluidic capillary assay to generate and accurately measure gradients of chemoattractant (α-methylaspartate) while simultaneously capturing the swimming trajectories of individual Escherichia coli bacteria using videomicroscopy and cell tracking. By measuring swimming speed and bias in the swimming direction of single cells for a range of chemoattractant concentrations and concentration gradients, we directly computed the chemotactic velocity VC and the associated chemotactic sensitivity χ0. We then show how μ can also be readily determined using microfluidics but that a population-scale microfluidic approach is experimentally more convenient than a single-cell analysis in this case. Measured values of both χ0 [(12.4 ± 2.0) × 10−4 cm2 s−1] and μ [(3.3 ± 0.8) × 10−6 cm2 s−1] are comparable to literature results. This microscale approach to bacterial chemotaxis lends experimental support to theoretical derivations of population-scale transport parameters from single-cell behavior. Furthermore, this study shows that microfluidic platforms can go beyond traditional chemotaxis assays and enable the quantification of bacterial transport parameters. PMID:18658218

  4. Bridges Dynamic Parameters Identification Based On Experimental and Numerical Method Comparison in Regard with Traffic Seismicity

    Science.gov (United States)

    Krkošková, Katarína; Papán, Daniel; Papánová, Zuzana

    2017-10-01

    The technical seismicity negatively affects the environment, buildings and structures. Technical seismicity means seismic shakes caused by force impulse, random process and unnatural origin. The vibration influence on buildings is evaluated in the Eurocode 8 in Slovak Republic, however, the Slovak Technical Standard STN 73 0036 includes solution of the technical seismicity. This standard also classes bridges into the group of structures that are significant in light of the technical seismicity – the group “U”. Using the case studies analysis by FEM simulation and comparison is necessary because of brief norm evaluation of this issue. In this article, determinate dynamic parameters by experimental measuring and numerical method on two real bridges are compared. First bridge, (D201 – 00) is Scaffold Bridge on the road I/11 leading to the city of Čadca and is situated in the city of Žilina. It is eleven – span concrete road bridge. The railway is the obstacle, which this bridge spans. Second bridge (M5973 Brodno) is situated in the part of Žilina City on the road of I/11. It is concrete three – span road bridge built as box girder. The computing part includes 3D computational models of the bridges. First bridge (D201 – 00) was modelled in the software of IDA Nexis as the slab – wall model. The model outputs are natural frequencies and natural vibration modes. Second bridge (M5973 Brodno) was modelled in the software of VisualFEA. The technical seismicity corresponds with the force impulse, which was put into this model. The model outputs are vibration displacements, velocities and accelerations. The aim of the experiments was measuring of the vibration acceleration time record of bridges, and there was need to systematic placement of accelerometers. The vibration acceleration time record is important during the under – bridge train crossing, about the first bridge (D201 – 00) and the vibration acceleration time domain is important during

  5. The Influence of Seismic Parameters on Site Response

    OpenAIRE

    Asakereh A.; Jamali H.; Naderi E.

    2015-01-01

    Geotechnical earthquake engineers have been trying to determine the most appropriate solution techniques for ground response analysis under earthquake loadings. This paper presents the importance of the adequate soil behavior model to simulate earthquake site response analysis. The influence of nonlinearity and linearity of soils on the site response is also investigated. Many methods have been proposed for the analysis of one-dimensional ground response such as nonlinear methods and equivale...

  6. Influence of Extraction Parameters on Hydroalcohol Extracts of the ...

    African Journals Online (AJOL)

    Methods: A 33 factorial design was used to evaluate the influence of alcohol concentration (50, 70 and 90 % v/v), extraction time (2, 6 and 10 h), and particle size of the herbal drug (0.25, 0.5 and 1.0 mm) on the pH, dry residue and myrsinoic acid B (MAB) content of hydroalcoholic extracts by high performance liquid ...

  7. The influence of joint parameters on normal fault evolution and geometry: a parameter study using analogue modeling

    Science.gov (United States)

    Kettermann, Michael; von Hagke, Christoph; Urai, Janos L.

    2017-04-01

    Dilatant faults often form in rocks containing pre-existing joints, but the effects of joints on fault segment linkage and fracture connectivity is not well understood. Studying evolution of dilatancy and influence of fractures on fault development provides insights into geometry of fault zones in brittle rocks and will eventually allow for predicting their subsurface appearance. In an earlier study we recognized the effect of different angles between strike direction of vertical joints and a basement fault on the geometry of a developing fault zone. We now systematically extend the results by varying geometric joint parameters such as joint spacing and vertical extent of the joints and measuring fracture density and connectivity. A reproducibility study shows a small error-range for the measurements, allowing for a confident use of the experimental setup. Analogue models were carried out in a manually driven deformation box (30x28x20 cm) with a 60° dipping pre-defined basement fault and 4.5 cm of displacement. To produce open joints prior to faulting, sheets of paper were mounted in the box to a depth of 5 cm at a spacing of 2.5 cm. We varied the vertical extent of the joints from 5 to 50 mm. Powder was then sieved into the box, embedding the paper almost entirely (column height of 19 cm), and the paper was removed. During deformation we captured structural information by time-lapse photography that allows particle imaging velocimetry analyses (PIV) to detect localized deformation at every increment of displacement. Post-mortem photogrammetry preserves the final 3-dimensional structure of the fault zone. A counterintuitive result is that joint depth is of only minor importance for the evolution of the fault zone. Even very shallow joints form weak areas at which the fault starts to form and propagate. More important is joint spacing. Very large joint spacing leads to faults and secondary fractures that form subparallel to the basement fault. In contrast, small

  8. Influence of acquisition parameters on MV-CBCT image quality.

    Science.gov (United States)

    Gayou, Olivier

    2012-01-05

    The production of high quality pretreatment images plays an increasing role in image-guided radiotherapy (IGRT) and adaptive radiation therapy (ART). Megavoltage cone-beam computed tomography (MV-CBCT) is the simplest solution of all the commercially available volumetric imaging systems for localization. It also suffers the most from relatively poor contrast due to the energy range of the imaging photons. Several avenues can be investigated to improve MV-CBCT image quality while maintaining an acceptable patient exposure: beam generation, detector technology, reconstruction parameters, and acquisition parameters. This article presents a study of the effects of the acquisition scan length and number of projections of a Siemens Artiste MV-CBCT system on image quality within the range provided by the manufacturer. It also discusses other aspects not related to image quality one should consider when selecting an acquisition protocol. Noise and uniformity were measured on the image of a cylindrical water phantom. Spatial resolution was measured using the same phantom half filled with water to provide a sharp water/air interface to derive the modulation transfer function (MTF). Contrast-to-noise ratio (CNR) was measured on a pelvis-shaped phantom with four inserts of different electron densities relative to water (1.043, 1.117, 1.513, and 0.459). Uniformity was independent of acquisition protocol. Noise decreased from 1.96% to 1.64% when the total number of projections was increased from 100 to 600 for a total exposure of 13.5 MU. The CNR showed a ± 5% dependence on the number of projections and 10% dependence on the scan length. However, these variations were not statistically significant. The spatial resolution was unaffected by the arc length or the sampling rate. Acquisition parameters have little to no effect on the image quality of the MV-CBCT system within the range of parameters available on the system. Considerations other than image quality, such as memory

  9. N/Z influence on the level density parameter

    Directory of Open Access Journals (Sweden)

    Ademard G.

    2015-01-01

    Full Text Available A completely exclusive experiment was performed by the INDRA collaboration to study the isospin dependence of the level density parameter. Over a large N/Z range, the fusion-evaporation charged products of 34,36,40Ar+58,60,64Ni reactions were measured and identified both in charge and mass by coupling INDRA and VAMOS spectrometer. Preliminary results obtained by combining data of both detectors are presented for the 36Ar+58Ni at 13.3 A MeV. The analysis method of relevant observables for such an ambitious investigation are discussed and the progress of the data analysis are reviewed.

  10. Consumer perception of dry-cured sheep meat products: Influence of process parameters under different evoked contexts.

    Science.gov (United States)

    de Andrade, Juliana Cunha; Nalério, Elen Silveira; Giongo, Citieli; de Barcellos, Marcia Dutra; Ares, Gastón; Deliza, Rosires

    2017-08-01

    The development of high-quality air-dried cured sheep meat products adapted to meet consumer demands represent an interesting option to add value to the meat of adult animals. The present study aimed to evaluate the influence of process parameters on consumer choice of two products from sheep meat under different evoked contexts, considering product concepts. A total of 375 Brazilian participants completed a choice-based conjoint task with three 2-level variables for each product: maturation time, smoking, and sodium reduction for dry-cured sheep ham, and natural antioxidant, smoking, and sodium reduction for sheep meat coppa. A between-subjects experimental design was used to evaluate the influence of consumption context on consumer choices. All the process parameters significantly influenced consumer choice. However, their relative importance was affected by evoked context. Copyright © 2017. Published by Elsevier Ltd.

  11. Inferring the temperature dependence of population parameters: the effects of experimental design and inference algorithm.

    Science.gov (United States)

    Palamara, Gian Marco; Childs, Dylan Z; Clements, Christopher F; Petchey, Owen L; Plebani, Marco; Smith, Matthew J

    2014-12-01

    Understanding and quantifying the temperature dependence of population parameters, such as intrinsic growth rate and carrying capacity, is critical for predicting the ecological responses to environmental change. Many studies provide empirical estimates of such temperature dependencies, but a thorough investigation of the methods used to infer them has not been performed yet. We created artificial population time series using a stochastic logistic model parameterized with the Arrhenius equation, so that activation energy drives the temperature dependence of population parameters. We simulated different experimental designs and used different inference methods, varying the likelihood functions and other aspects of the parameter estimation methods. Finally, we applied the best performing inference methods to real data for the species Paramecium caudatum. The relative error of the estimates of activation energy varied between 5% and 30%. The fraction of habitat sampled played the most important role in determining the relative error; sampling at least 1% of the habitat kept it below 50%. We found that methods that simultaneously use all time series data (direct methods) and methods that estimate population parameters separately for each temperature (indirect methods) are complementary. Indirect methods provide a clearer insight into the shape of the functional form describing the temperature dependence of population parameters; direct methods enable a more accurate estimation of the parameters of such functional forms. Using both methods, we found that growth rate and carrying capacity of Paramecium caudatum scale with temperature according to different activation energies. Our study shows how careful choice of experimental design and inference methods can increase the accuracy of the inferred relationships between temperature and population parameters. The comparison of estimation methods provided here can increase the accuracy of model predictions, with important

  12. Influence of drug concentration on the diffusion parameters of caffeine

    Science.gov (United States)

    Mustapha, R.Ben; Lafforgue, C.; Fenina, N.; Marty, J.P.

    2011-01-01

    Background and Objectives: In the fields of the pharmaceutical and cosmetic industries and in toxicology, the study of the skin penetration of molecules is very interesting. Various studies have considered the impact of different physicochemical drug characteristics, skin thickness, and formulations, on the transition from the surface of the skin to the underlying tissues or to the systemic circulation; however, the influence of drug concentration on the permeation flux of molecules has rarely been raised. Our study aims to discover the influence of caffeine concentration in a formulation on the percutaneous penetration from gels, as a result of different dose applications to polysulfate membrane and human skin. Materials and Methods: For this purpose, three identical base gels were used at 1, 3, and 5% of caffeine, to evaluate the effect of the concentration of caffeine on in vitro release through the synthetic membrane and ex vivo permeation through the human skin, using diffusion FranzTM cells. Results: The diffusion through the epidermal tissue was significantly slower than through the synthetic membrane, which recorded an increase of flux with an increase in the concentration of caffeine. The skin permeation study showed that diffusion depended not only on the concentration, but also on the deposited amount of gel. Nevertheless, for the same amount of caffeine applied, the flux was more significant from the less concentrated gel. Conclusion: Among all the different concentrations of caffeine examined, 1% gel of caffeine applied at 5 mg / cm2 showed the highest absorption characteristics across human skin. PMID:21572649

  13. Influence of compression parameters on mechanical behavior of mozzarella cheese.

    Science.gov (United States)

    Fogaça, Davi Novaes Ladeia; da Silva, William Soares; Rodrigues, Luciano Brito

    2017-10-01

    Studies on the interaction between direction and degree of compression in the Texture Profile Analysis (TPA) of cheeses are limited. For this reason the present study aimed to evaluate the mechanical properties of Mozzarella cheese by TPA at different compression degrees (65, 75, and 85%) and directions (axes X, Y, and Z). Data obtained were compared in order to identify possible interaction between both factors. Compression direction did not affect any mechanical variable, or rather, the cheese had an isotropic behavior for TPA. Compression degree had a significant influence (p manufacturing is another factor that may directly influence the mechanical properties of food. This can be seen, for instance, in stretched curd cheese, such as Mozzarella. Knowledge on such mechanical properties is highly relevant for food industries due to the mechanical resistance in piling, pressing, manufacture of packages, and food transport, or to melting features presented by the food at high temperatures in preparation of several foods, such as pizzas, snacks, sandwiches, and appetizers. © 2016 Wiley Periodicals, Inc.

  14. The reaction between iodine and organic coatings under severe PWR accident conditions. An experimental parameter study

    Energy Technology Data Exchange (ETDEWEB)

    Hellmann, S.; Funke, F.; Greger, G.U.; Bleier, A.; Morell, W. [Siemens AG, Power Generation Group, Erlangen (Germany)

    1996-12-01

    An extensive experimental parameter study was performed on the deposition and on the resuspension kinetics in the reaction system iodine/organically coated surfaces. Both reactions in the gas phase and in the liquid phase were investigated and kinetic rate constants suitable for modelling were derived. Previous experimental studies on the reaction of iodine with organic coated surfaces were mostly limited to temperatures below 100{sup o}C. Thus, this parameter study aims at filling a gap and providing kinetic data on heterogeneous reactions with organic surfaces in the accident-relevant temperature range of 100-160{sup o}C. Two types of laboratory experiments carried out at Siemens/KWU using coatings representative for German power plants (epoxy-tape paint), namely gas phase tests and liquid phase tests. (author) 6 figs., 6 tabs., 5 refs.

  15. Influence of fermentation methods on neutral detergent fiber degradation parameters.

    Science.gov (United States)

    Bossen, D; Mertens, D R; Weisbjerg, M R

    2008-04-01

    The effect of 3 fermentation methods, in situ (IS) in 4 lactating cows (average pH of 5.8), in vitro (IVn) with media pH of 6.8, or in vitro (IVa) with media pH adjusted to 6.0 using citric acid, on fiber degradation parameters was studied using feeds ground to different particle sizes. Corn silage (CS), grass silage (GS), barley grain (B), sugar beet pulp (BP), and rapeseed cake (RC) were ground using a shear mill. Silages were ground through 8-, 4-, 2-, or 1-mm screens, B and BP through 4-, 2-, or 1-mm screens, and RC through 2- or 1-mm screens. The amylase-treated NDF (aNDF) content of samples ground using a 1-mm screen was 399, 431, 197, 480, and 251 g/kg of DM for CS, GS, B, BP, and RC, respectively, but increased with increasing screen size. Materials were incubated for 0, 6, 12, 24, 48, and 96 h IS, IVn, or IVa. Inoculum for IVn and IVa was prepared as a composite from the cows used for IS. The potentially degradable aNDF (D(0)), indegradable aNDF (I), lag time (L), and fractional rate of degradation of potential degradable aNDF (k(d)) were estimated using PROC NLIN in SAS. Except for RC, fermentation methods affected most degradation parameters, especially k(d) and L. The IVn, IVa, and IS methods resulted in k(d) values of 0.291, 0.105, 0.080 h(-1) and 0.262, 0.107, 0.103 h(-1) for BP and RC, respectively, demonstrating a decreasing rate of degradation for these feeds when fermented under suboptimal pH. In CS, GS, and B, no difference was found in k(d) between the IVn and IVa methods, which suggests that differences in pH did not alter k(d) in vitro. The k(d) values obtained for CS, GS, and B were 0.058, 0.109, 0.168, and 0.028, 0.054, and 0.069 h(-1) for the IVn and IS methods, respectively, indicating that the IS method using cows fed at production levels can underestimate the potential rate of NDF degradation. Using the IVa method, L was 12.1, 9.1, 7.8, and 2.5 h for CS, GS, BP, and RC, respectively, which was higher than L obtained from the IVn and IS

  16. The Influence of Boundary Layer Parameters on Interior Noise

    Science.gov (United States)

    Palumbo, Daniel L.; Rocha, Joana

    2012-01-01

    Predictions of the wall pressure in the turbulent boundary of an aerospace vehicle can differ substantially from measurement due to phenomena that are not well understood. Characterizing the phenomena will require additional testing at considerable cost. Before expending scarce resources, it is desired to quantify the effect of the uncertainty in wall pressure predictions and measurements on structural response and acoustic radiation. A sensitivity analysis is performed on four parameters of the Corcos cross spectrum model: power spectrum, streamwise and cross stream coherence lengths and Mach number. It is found that at lower frequencies where high power levels and long coherence lengths exist, the radiated sound power prediction has up to 7 dB of uncertainty in power spectrum levels with streamwise and cross stream coherence lengths contributing equally to the total.

  17. Influence of heating experiments on parameters of Schumann resonances

    Directory of Open Access Journals (Sweden)

    Agranat Irina

    2017-01-01

    Full Text Available Recently the significant increase in intensity of researches in the field of the fissile impact on geophysical processes in various environments is noted. Special attention is paid to a research of impact on an ionosphere of a potent short-wave radio emission of heating stands. Today experiments on change of an ionosphere are made generally at stands HAARP, EISCAT in Tromse (Norway. Within the Russian campaign (Tomsk EISCAT/heating (AARI_HFOX made from October 19 to October 30, 2016 experiments on impact on an ionosphere F-layer by the radiation potent HF. For assessment of impact of these experiments on geophysical processes mathematical methods carried out the analysis of change of the parameters of the Schumann resonances received on the basis of data from the station of constant observation of the Schumann resonances in the city of Tomsk, the Tomsk State University (Russia.

  18. Manufacturing of anode supported SOFCs: Processing parameters and their influence

    DEFF Research Database (Denmark)

    Ramousse, Severine; Menon, Mohan; Brodersen, Karen

    2007-01-01

    contains a complex microstructure. In order to improve the cell performance as well as reducing the processing costs, it has been found necessary to consider the process chain holistically, because successful manufacture of such a cell and the achievement of optimal final properties depend on each......The establishment of low cost, highly reliable and reproducible manufacturing processes has been focused for commercialization of SOFC technology. A major challenge in the production chain is the manufacture of anode-supported planar SOFC's single cells in which each layer in a layered structure...... of the processing steps and their interdependence. A large database for several thousand anode-supported SOFCs manufactured annually at the Risoe National Laboratory in collaboration with Topsoe Fuel Cell A/S has been constructed. This enables a statistical analysis of the various controlling parameters. Some...

  19. Influence of Process Parameters on Coal Combustion Performance

    DEFF Research Database (Denmark)

    Lans, Robert Pieter Van Der

    investigated experimentally in a 400 MWe corner fired boiler with over fire air, a 350 MWe opposed fired boiler, and in a 160 kWt pilot scale test rig. Three different coals were fired in each of the furnaces as part of the activities in group 3 of the European Union JOULE 2 Extension project "Atmospheric...... between coal type and NO concentrations were identical in all three furnaces. No clear trends have been observed between coal type and carbon in ash content. This is mainly due to the fact that the burnout in large furnaces is high, and differences between coals become small.A simple, one...... study has been performed in order to initiate an investigation of the potential of chemical engineering models to predict NO from pulverized fuel burners. The success of chemical engineering modeling is strongly connected to the simplification of the flow pattern into a reactor configuration...

  20. Phase-contrast tomography of sciatic nerves: image quality and experimental parameters

    Science.gov (United States)

    Töpperwien, M.; Krenkel, M.; Ruhwedel, T.; Möbius, W.; Pacureanu, A.; Cloetens, P.; Salditt, T.

    2017-06-01

    We present propagation-based phase-contrast tomography of mouse sciatic nerves stained with osmium, leading to an enhanced contrast in the myelin sheath around the axons, in order to visualize the threedimensional (3D) structure of the nerve. We compare different experimental parameters and show that contrast and resolution are high enough to identify single axons in the nerve, including characteristic functional structures such as Schmidt-Lanterman incisures.

  1. Kinematic Viscosities for Ether + Alkane Mixtures: Experimental Results and UNIFAC-VISCO Parameters

    Science.gov (United States)

    Bandrés, I.; Lahuerta, C.; Villares, A.; Martín, S.; Lafuente, Carlos

    2008-04-01

    Kinematic viscosities for the binary mixtures of diisopropylether, dibutylether or methyl ter-butyl ether with 3-methylpentane, hexane or heptane have been measured at 283.15 K, 298.15 K, and 313.15 K. The experimental values have been correlated by the McAllister equation. Using these results, new UNIFAC-VISCO parameters, Oether-CH2 and Oether-CH3, have been calculated.

  2. Influence of Pyrolysis Parameters on the Performance of CMSM

    Directory of Open Access Journals (Sweden)

    Marta C. Campo

    2009-01-01

    Full Text Available Carbon hollow fiber membranes have been prepared by pyrolysis of a P84/S-PEEK blend. Proximate analysis of the precursor was performed using thermogravimetry (TGA, and a carbon yield of approximately 40% can be obtained. This study aimed at understanding the influence of pyrolysis parameters—end temperature, quenching effect, and soaking time—on the membrane properties. Permeation experiments were performed with N2, He, and CO2. Scanning electron microscopy (SEM has been done for all carbon hollow fibers. The highest permeances were obtained for the membrane submitted to an end temperature of 750°C and the highest ideal selectivities for an end temperature of 700°C. In both cases, the membranes were quenched to room temperature.

  3. Influence of laser ablation parameters on trueness of imaging

    Energy Technology Data Exchange (ETDEWEB)

    Vaculovič, T.; Warchilová, T. [Department of Chemistry, Faculty of Science, Masaryk University, Kotlářská 2, Brno 61137 (Czech Republic); CEITEC, Masaryk University, Kamenice 5, Brno 62500 (Czech Republic); Čadková, Z.; Száková, J.; Tlustoš, P. [Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcka 129, Praha 16521 (Czech Republic); Otruba, V. [Department of Chemistry, Faculty of Science, Masaryk University, Kotlářská 2, Brno 61137 (Czech Republic); Kanický, V., E-mail: viktork@chemi.muni.cz [Department of Chemistry, Faculty of Science, Masaryk University, Kotlářská 2, Brno 61137 (Czech Republic); CEITEC, Masaryk University, Kamenice 5, Brno 62500 (Czech Republic)

    2015-10-01

    Highlights: • Laser ablation conditions vs. quality of LA-ICP-MS imaging (resolution, detection). • Increase in laser spot size improves detection limit, while deteriorates resolution. • Decrease in scan speed improves resolution but prolongs time of analysis. • Compromise spot size and scan speed meet required quality of imaging. • Metal-enriched/depleted zones in tapeworm sections were resolved by LA-ICP-MS. - Abstract: Influence of laser ablation conditions on limit of detection, spatial resolution and time of analysis was studied for laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) applied to elemental mapping. Laser repetition rate and laser fluence were investigated in tapeworm thin section to attain optimum ablation rate, yielding appropriately low detection limit which complies with elemental contents in the tissue. Effect of combinations of laser spot size and scan speed on relative broadening (Δw{sub rel}) of image of the ablated pattern (line) was investigated with the aim to quantify the trueness of imaging. Ink lines printed on paper were employed for the study of influence of spot size and scan speed on limit of detection, relative broadening of elemental image and duration of elemental mapping. An uneven distribution of copper in a printed line (coffee stain effect) was observed. The Δw{sub rel} is strongly reduced (down to 2%) at low scan speed (10 μm s{sup −1}) and laser spot diameter of 10 μm but resulting in unacceptably long time of mapping (up to 3000 min). Finally, tapeworm thin-section elemental maps (4 mm × 5 mm) were obtained at the laser spot diameter of 65 μm and the scan speed of 65 μm s{sup −1} within 100 min. A dissimilar lateral distribution of Pb was observed in comparison with that of Cu or Zn due to different pathways of element uptake.

  4. Experimental determination of chosen document elements parameters from raster graphics sources

    Directory of Open Access Journals (Sweden)

    Jiří Rybička

    2010-01-01

    Full Text Available Visual appearance of documents and their formal quality is considered to be as important as the content quality. Formal and typographical quality of documents can be evaluated by an automated system that processes raster images of documents. A document is described by a formal model that treats a page as an object and also as a set of elements, whereas page elements include text and graphic object. All elements are described by their parameters depending on elements’ type. For future evaluation, mainly text objects are important. This paper describes the experimental determination of chosen document elements parameters from raster images. Techniques for image processing are used, where an image is represented as a matrix of dots and parameter values are extracted. Algorithms for parameter extraction from raster images were designed and were aimed mainly at typographical parameters like indentation, alignment, font size or spacing. Algorithms were tested on a set of 100 images of paragraphs or pages and provide very good results. Extracted parameters can be directly used for typographical quality evaluation.

  5. Influence of psychological and coronary parameters on coronary patient rehospitalization

    Directory of Open Access Journals (Sweden)

    Nikolić Gordana

    2010-01-01

    Full Text Available Introduction. Psychological reactions are often comorbid with coronary risk factors and could be important for a six-month outcome. Objective. Determination of anxiety level, depression and aggression, persistence of risk health behaviour, stress life events, and coronary risk factors after coronary event and a predictive value of those parameters for six-month rehospitalization. Methods. In the group with Angina Pectoris (E1=30 and the group with Acute Myocardial Infarction (E2=33, there were applied, at baseline and after 6 months, the following: Semistructured Clinical Interview based on ICD-10, for depressive episode and anxiety disorder, Hamilton Anxiety Scale (HAMA, Hamilton Depression Scale (HAMD, KON-6 sigma Scale for aggression, Holms-Rahe Scale (H-R for stress events and Questionnaire for risk behaviour: alcohol consumption, smoking, lack of physical activity. Group differences were assessed by t-test and chi-square test, p<0.05, regression analysis for assessing initial variables, a predictive value for six month rehospitalization. Results. After acute coronary event, the anxiety and depression levels were mild and aggression was low in E1 and mild in E2. Stress event score was significantly higher in E2 (H-R=115.18 than in E1 (H-R=72.20, p<0.05. After 6 months, the results were the same except for a significantly lower stress event score in E1 (H-R=49.48, and in E2 (H-R=91.65, but still significantly higher than in E1. Coronary parameters were reduced, smokers' rate was increased in E1. Alcohol consumption, hypercholesterolaemia and hereditary tendency were predictive for six- month rehospitalization. Conclusion. After acute cardiac event, hospitalized coronary patients had a mild anxiety, depression and aggression level as well as after six months. The infarct patients had experienced more stress life events in the previous year than the angina patients. Risk health behaviour did not change in the following six months, with the

  6. [Principles and experimental analysis of a measuring system for measuring spacesuit joint's damping parameters].

    Science.gov (United States)

    Wang, Hao; Jin, Ming-he; Liu, Hong; Gao, Xiao-hui; Li, Tan-qiu; Zhao, Yong-jun

    2003-10-01

    To measure the damping parameters of the spacesuit joint. The principles of the passive robot system for measuring spacesuit joint's damping parameters were presented. Basing on its special mechanical structure, a 3 DOF model of the flexible IVA (intra-vehicular activity) spacesuit's sleeve was built. The optimal approximation of inverse calculation based on 6 dimension space interval was described. The damping parameters of an actual IVA spacesuit's sleeve were measured on the actual testbed. Also, the potential application of the measuring system was discussed. The model of spacesuit sleeve and the forward/inverse kinematics were proved by experimental measurements and real time 3D simulation. The principles and the proposed method of the measurement were testified.

  7. Influence of Differing Analgesic Formulations of Aspirin on Pharmacokinetic Parameters

    Directory of Open Access Journals (Sweden)

    Kunal Kanani

    2015-08-01

    Full Text Available Aspirin has been used therapeutically for over 100 years. As the originator and an important marketer of aspirin-containing products, Bayer’s clinical trial database contains numerous reports of the pharmacokinetics of various aspirin formulations. These include evaluations of plain tablets, effervescent tablets, granules, chewable tablets, and fast-release tablets. This publication seeks to expand upon the available pharmacokinetic information concerning aspirin formulations. In the pre-systemic circulation, acetylsalicylic acid (ASA is rapidly converted into its main active metabolite, salicylic acid (SA. Therefore, both substances are measured in plasma and reported in the results. The 500 mg strength of each formulation was chosen for analysis as this is the most commonly used for analgesia. A total of 22 studies were included in the analysis. All formulations of 500 mg aspirin result in comparable plasma exposure to ASA and SA as evidenced by AUC. Tablets and dry granules provide a consistently lower Cmax compared to effervescent, granules in suspension and fast release tablets. Effervescent tablets, fast release tablets, and granules in suspension provide a consistently lower median Tmax compared to dry granules and tablets for both ASA and SA. This report reinforces the importance of formulation differences and their impact on pharmacokinetic parameters.

  8. Influence of different carbon monolith preparation parameters on pesticide adsorption

    Directory of Open Access Journals (Sweden)

    Vukčević Marija

    2013-01-01

    Full Text Available The capacity of carbon monolith for pesticide removal from water, and the mechanism of pesticide interaction with carbon surface were examined. Different carbon monolith samples were obtained by varying the carbonization and activation parameters. In order to examine the role of surface oxygen groups in pesticide adsorption, carbon monolith surface was functionalized by chemical treatment in HNO3, H2O2 and KOH. The surface properties of the obtained samples were investigated by BET surface area, pore size distribution and temperature-programmed desorption. Adsorption of pesticides from aqueous solution onto activated carbon monolith samples was studied by using five pesticides belonging to different chemical groups (acetamiprid, dimethoate, nicosulfuron, carbofuran and atrazine. Presented results show that higher temperature of carbonization and the amount of activating agent allow obtaining microporous carbon monolith with higher amount of surface functional groups. Adsorption properties of the activated carbon monolith were more readily affected by the amount of the surface functional groups than by specific surface area. Results obtained by carbon monolith functionalisation showed that π-π interactions were the main force for adsorption of pesticides with aromatic structure, while acidic groups play an important role in adsorption of pesticides with no aromatic ring in the chemical structure.

  9. The Influence of Parameters Affecting Boron Removal by Electrocoagulation Process

    KAUST Repository

    Zeboudji, B.

    2013-04-01

    Boron removal in seawater desalination presents a particular challenge. In seawater reverse osmosis (SWRO) systems boron removal at low concentration (<0.5 mg/L) is usually achieved by a second pass using brackish water RO membranes. However, this process requires chemical addition and important additional investment, operation and maintenance, and energy costs. Electrocoagulation (EC) process can be used to achieve such low boron concentration. In this work, the removal of boron from aqueous solution was carried out by EC process using aluminum and iron electrodes. Several operating parameters on the removal efficiency such as initial pH, current density, initial boron ion concentration, feed concentration, gap between electrodes, and electrode material, were investigated. In the case of bipolar electrocoagulation (BEC), an optimum removal efficiency of 96% corresponding to a final boron concentration of 0.4 mg/L was achieved at a current density of 6 mA/cm2 and pH = 8 using aluminum electrodes. The concentration of NaCl was 2,500 mg/L and the gap between the electrodes of 0.5 cm. Furthermore, a comparison between monopolar electrocoagulation (MEC) and BEC using both aluminum and iron electrodes was carried out. Results showed that the BEC process has reduced the current density applied to obtain high level of boron removal in a short reaction time compared to MEC process. The high performance of the EC showed that the process could be used to reduce boron concentration to acceptable levels at low-cost and more environmentally friendly. © 2013 Copyright Taylor and Francis Group, LLC.

  10. Influence of shear cutting parameters on the fatigue behavior of a dual-phase steel

    Science.gov (United States)

    Paetzold, I.; Dittmann, F.; Feistle, M.; Golle, R.; Haefele, P.; Hoffmann, H.; Volk, W.

    2017-09-01

    The influence of the edge condition of car body and chassis components made of steel sheet on fatigue behavior under dynamic loading presents a major challenge for automotive manufacturers and suppliers. The calculated lifetime is based on material data determined by the fatigue testing of specimens with polished edges. Prototype components are often manufactured by milling or laser cutting, whereby in practice, the series components are produced by shear cutting due to its cost-efficiency. Since the fatigue crack in such components usually starts from a shear cut edge, the calculated and experimental determined lifetime will vary due to the different conditions at the shear cut edges. Therefore, the material data determined with polished edges can result in a non-conservative component design. The aim of this study is to understand the relationship between the shear cutting process and the fatigue behavior of a dual-phase steel sheet. The geometry of the shear cut edge as well as the depth and degree of work hardening in the shear affected zone can be adjusted by using specific shear cutting parameters, such as die clearance and cutting edge radius. Stress-controlled fatigue tests of unnotched specimens were carried out to compare the fatigue behavior of different edge conditions. By evaluating the results of the fatigue experiments, influential shear cutting parameters on fatigue behavior were identified. It was possible to assess investigated shear cutting strategies regarding the fatigue behavior of a high-strength steel DP800.

  11. Parameters influencing deposit estimation when using water sensitive papers

    Directory of Open Access Journals (Sweden)

    Emanuele Cerruto

    2013-10-01

    Full Text Available The aim of the study was to assess the possibility of using water sensitive papers (WSP to estimate the amount of deposit on the target when varying the spray characteristics. To identify the main quantities influencing the deposit, some simplifying hypotheses were applied to simulate WSP behaviour: log-normal distribution of the diameters of the drops and circular stains randomly placed on the images. A very large number (4704 of images of WSPs were produced by means of simulation. The images were obtained by simulating drops of different arithmetic mean diameter (40-300 μm, different coefficient of variation (0.1-1.5, and different percentage of covered surface (2-100%, not considering overlaps. These images were considered to be effective WSP images and then analysed using image processing software in order to measure the percentage of covered surface, the number of particles, and the area of each particle; the deposit was then calculated. These data were correlated with those used to produce the images, varying the spray characteristics. As far as the drop populations are concerned, a classification based on the volume median diameter only should be avoided, especially in case of high variability. This, in fact, results in classifying sprays with very low arithmetic mean diameter as extremely or ultra coarse. The WSP image analysis shows that the relation between simulated and computed percentage of covered surface is independent of the type of spray, whereas impact density and unitary deposit can be estimated from the computed percentage of covered surface only if the spray characteristics (arithmetic mean and coefficient of variation of the drop diameters are known. These data can be estimated by analysing the particles on the WSP images. The results of a validation test show good agreement between simulated and computed deposits, testified by a high (0.93 coefficient of determination.

  12. Coupling Influence on Signal Readout of a Dual-Parameter LC Resonant System

    Directory of Open Access Journals (Sweden)

    Jijun Xiong

    2015-01-01

    Full Text Available Dual-parameter inductive-capacitive (LC resonant sensor is gradually becoming the measurement trend in complex harsh environments; however, the coupling between inductors greatly affects the readout signal, which becomes very difficult to resolve by means of simple mathematical tools. By changing the values of specific variables in a MATLAB code, the influence of coupling between coils on the readout signal is analyzed. Our preliminary conclusions underline that changing the coupling to antenna greatly affects the readout signal, but it simultaneously influences the other signal. When f01=f02, it is better to broaden the difference between the two coupling coefficients k1 and k2. On the other side, when f01 is smaller than f02, it is better to decrease the coupling between sensor inductors k12, in order to obtain two readout signals averaged in strength. Finally, a test system including a discrete capacitor soldered to a printed circuit board (PCB based planar spiral coil is built, and the readout signals under different relative inductors positions are analyzed. All experimental results are in good agreement with the results of the MATLAB simulation.

  13. Experimental analysis of influence of cutting conditions on machinability of waspaloy

    Science.gov (United States)

    Caruso, Serafino; Rinaldi, Sergio; Franchi, Rodolfo; Del Prete, Antonio; Umbrello, Domenico

    2017-10-01

    Taking into account the main importance of nickel-based superalloy in aerospace, marine and chemical industries concerning the production of high performance artifacts, in this paper experimental results of cutting forces, chip morphology, tool wear and temperatures were investigated during orthogonal machining of Waspaloy (45 HRC). All the experiments were performed in dry and lubricated cutting conditions, analyzing and comparing the collected results for a range of different cutting parameters: cutting speed and feed rate. The results show a good trends coherence, highlighting the influence of lubrication during machining.

  14. Electromagnetic radiation influence on clinical course of experimental wound infection

    Directory of Open Access Journals (Sweden)

    Pronina Е.А.

    2010-09-01

    Full Text Available The article gives close attention to the study of electromagnetic radiation influence (EMR at the frequency of molecular spectrum absorption and radiation (MSAR of nitric oxide (150 GHz and atmospheric oxygen (129 GHz on the clinical course of experimental wound infection caused by antibiotic-sensitive and antibiotic-resistant strains of Pseudomonas aeruginosa. The panoramic spectrometric measuring complex, developed in Saratov Scientific Research Institute of Measuring Equipment was used while carrying out the research. Electromagnetic vibrations of extremely high frequencies were stimulated in this complex imitating the atmospheric oxygen and nitric oxide absorption and radiation molecular spectrum structure. The experiments proved the fact that exposure to radiation at the frequency of molecular spectrum absorption and radiation (MSAR of nitric oxide and atmospheric oxygen had positive impact on the course of traumatic process

  15. The influence of experimentally induced pain on shoulder muscle activity

    DEFF Research Database (Denmark)

    Diederichsen, Louise Pyndt; Winther, Annika; Dyhre-Poulsen, Poul

    2009-01-01

    Muscle function is altered in painful shoulder conditions. However, the influence of shoulder pain on muscle coordination of the shoulder has not been fully clarified. The aim of the present study was to examine the effect of experimentally induced shoulder pain on shoulder muscle function. Eleven...... healthy men (range 22-27 years), with no history of shoulder or cervical problems, were included in the study. Pain was induced by 5% hypertonic saline injections into the supraspinatus muscle or subacromially. Seated in a shoulder machine, subjects performed standardized concentric abduction (0 degrees...... -105 degrees) at a speed of approximately 120 degrees/s, controlled by a metronome. During abduction, electromyographic (EMG) activity was recorded by intramuscular wire electrodes inserted in two deeply located shoulder muscles and by surface-electrodes over six superficially located shoulder muscles...

  16. The influence of experimentally induced pain on shoulder muscle activity

    DEFF Research Database (Denmark)

    Diederichsen, L.P.; Winther, A.; Dyhre-Poulsen, P.

    2009-01-01

    Muscle function is altered in painful shoulder conditions. However, the influence of shoulder pain on muscle coordination of the shoulder has not been fully clarified. The aim of the present study was to examine the effect of experimentally induced shoulder pain on shoulder muscle function. Eleven...... healthy men (range 22-27 years), with no history of shoulder or cervical problems, were included in the study. Pain was induced by 5% hypertonic saline injections into the supraspinatus muscle or subacromially. Seated in a shoulder machine, subjects performed standardized concentric abduction (0A degrees......-105A degrees) at a speed of approximately 120A degrees/s, controlled by a metronome. During abduction, electromyographic (EMG) activity was recorded by intramuscular wire electrodes inserted in two deeply located shoulder muscles and by surface-electrodes over six superficially located shoulder...

  17. Using Modified Intelligent Experimental Design in Parameter Estimation of Chaotic Systems

    Directory of Open Access Journals (Sweden)

    Zahra Shourgashti

    2017-01-01

    Full Text Available Computational modeling plays an important role in prediction and optimization of real systems and processes. Models usually have some parameters which should be set up to the proper value. Therefore, parameter estimation is known as an important part of the modeling and system identification. It usually refers to the process of using sampled data to estimate the optimum values of parameters. The accuracy of model can be increased by adjusting its parameters to the optimum value which need a richer dataset. One simple solution for having a richer dataset is increasing the amount of data, but that can be costly and time consuming. When using data from animals or people, it is especially important to have a proper plan. There are several available methods for parameter estimation in dynamical systems; however there are some basic differences in chaotic systems due to their sensitivity to initial condition (butterfly effect. Accordingly, in this paper, a new cost function which is proper for chaotic systems is applied to the chaotic one-dimensional map. Then the efficiency of a newly introduced intelligent method experimental design in extracting proper data is investigated. The results show the success of the proposed method.

  18. Influences of petrographic parameters on technological properties of greywackes used for crushed stone production

    Science.gov (United States)

    Prikryl, Richard; Cermak, Martin; Krutilova, Katerina

    2014-05-01

    This study focuses on the influence of petrographic parameters on technological properties of greywackes. These sedimentary rocks make about 27 % of crushed stone market in the Czech Republic. Mainly in Moravia (eastern part of the Czech Republic), greywackes represent almost exclusive high quality aggregate. The behaviour of greywackes varies, however, from quarry to quarry. In this study, we have selected the most important deposits that cover major lithological variation of local greywackes. Studied greywackes were analysed for their petrographic parameters quantitatively (using image analysis of thin sections). The pore space characteristics were determined by using fluorescent dye - epoxy resin impregnated specimens. The studied rocks are composed of subangular and angular quartz grains, lithoclasts (stable rocks: quartzites, and unstable rocks: phylites, metaphylites, siltstones, slates, greywackes, and less frequently acid eruptive rocks), feldspars (orthoclas, microcline, plagioclase), and detrital micas. Detrital and authigenic chlorite has been found as well. The matrix which represents the largest volume of rock-forming components contains a mixture of sericite, chlorite, clay minerals, cements, and clasts in aleuropelitic size. Based on the microscopic examination, all studied rock types were classified as greywacke with fine- to medium-grained massive rock fabric. Only specimen from Bělkovice has shown partly layered structure. Alteration of feldspars and unstable rock fragments represents common feature. Diagenetic features included pressure dissolution of quartz clasts and formation of siliceous and/or calcite cements. Based on the experimental study of technological performance of studied greywackes and its correlation to petrographic features, the average size of clasts and volume of matrix make the driving factors affecting the LA values. The LA values decrease with the increasing of volume of matrix (R = 0.61) and with decreasing average grain

  19. A study on the influence of hot press forming process parameters on ...

    African Journals Online (AJOL)

    Hence an attempt is made in this work to improve the mechanical properties of green composites by optimizing the hot press forming process parameters using Taguchi experimental design. Process parameters such as temperature, pressure, heating time, cooling system and recrystallization soak time were chosen for ...

  20. Study of the influence of design parameters of MAPS for the ALICE ITS Upgrade: Project Report

    CERN Document Server

    Munteanu, Laura-Iuliana

    2016-01-01

    This report illustrates the results of measurements performed on various MAPS chips used during the R&D phase for the ALICE ITS Upgrade. It lists the influence that pixel design parameters have on the performance of the chips.

  1. Experimental determination of critical parameters for gas-condensate-oil systems

    Energy Technology Data Exchange (ETDEWEB)

    Ramazanova, Z.E.; Yagubov, A.S.; Razamat, M.S.; Babaev, R.D.

    1971-01-01

    An experimental study was conducted to determine the effect of crude oil quantity and quality on changes of critical parameters in gas-condensate-oil systems. Experiments were performed at 40/sup 0/, 100/sup 0/, and 140/sup 0/C, and pressures up to 1,000 kg/sq cm. The 3 components of the system were gas, condensate, and crude oil. Isotherms of condensation were determined to the left and right of the critical point, reaching one-phase zones for liquid and gas. Experimental values of critical parameters varied widely from calculated values. Even insignificant changes in composition caused sharp changes in the critical parameters. For example by changing the weight fraction of crude oil from 0.499 to 0.503, critical temperature changed from 40/sup 0/ to 140/sup 0/C and critical pressure from 640 to 780 kg/sq cm. This type of occurrence must be kept in mind when exploiting gas-oil reservoirs near the critical range.

  2. Influence of Cutting Parameters on the Surface Roughness and Hole Diameter of Drilling Making Parts of Alluminium Alloy

    Directory of Open Access Journals (Sweden)

    Andrius Stasiūnas

    2013-02-01

    Full Text Available The article researches the drilling process of an aluminium alloy. The paper is aimed at analyzing the influence of cutting speed, feed and hole depth considering hole diameter and hole surface roughness of aluminum alloy 6082 in the dry drilling process and at making empirical formulas for cutting parameters. The article also describes experimental techniques and equipment, tools and measuring devices. Experimental studies have been carried out using different cutting parameters. The obtained results have been analyzed using computer software. According to the existing techniques for measuring, surface roughness and hole diameters have been measured, empirical models have been created and the results of the conducted experiments have been inspected. The findings and recommendations are presented at the end of the work.Artcile in Lithuanian

  3. Influence of Cutting Parameters on the Surface Roughness and Hole Diameter of Drilling Making Parts of Alluminium Alloy

    Directory of Open Access Journals (Sweden)

    Andrius Stasiūnas

    2012-12-01

    Full Text Available The article researches the drilling process of an aluminium alloy. The paper is aimed at analyzing the influence of cutting speed, feed and hole depth considering hole diameter and hole surface roughness of aluminum alloy 6082 in the dry drilling process and at making empirical formulas for cutting parameters. The article also describes experimental techniques and equipment, tools and measuring devices. Experimental studies have been carried out using different cutting parameters. The obtained results have been analyzed using computer software. According to the existing techniques for measuring, surface roughness and hole diameters have been measured, empirical models have been created and the results of the conducted experiments have been inspected. The findings and recommendations are presented at the end of the work.Artcile in Lithuanian

  4. The Intramolecular Pressure and the Extension of the Critical Point’s Influence Zone on the Order Parameter

    Directory of Open Access Journals (Sweden)

    Jose Luis Rivera

    2015-01-01

    Full Text Available The critical point affects the coexistence behavior of the vapor-liquid equilibrium densities. The length of the critical influence zone is under debate because for some properties, like shear viscosity, the extension is only a few degrees, while for others, such as the density order parameter, the critical influence zone covers up to hundreds of degrees below the critical temperature. Here we show that, for ethane, the experimental critical influence zone covers a wide zone of tens of degrees (below the critical temperature down to a transition temperature, at which the apparent critical influence zone vanishes, and the transition temperature can be predicted through a pressure analysis of the coexisting bulk liquid phase, using a simple molecular potential. The liquid phases within the apparent critical influence zone show low densities, making them behave internally like their corresponding vapor phases. Therefore, Molecular Dynamics simulations reveal that the experimentally observed wide extension of the critical influence zone is the result of a vapor-like effect due to low bulk liquid phase densities.

  5. Three-dimensional FEM model of FBGs in PANDA fibers with experimentally determined model parameters

    Science.gov (United States)

    Lindner, Markus; Hopf, Barbara; Koch, Alexander W.; Roths, Johannes

    2017-04-01

    A 3D-FEM model has been developed to improve the understanding of multi-parameter sensing with Bragg gratings in attached or embedded polarization maintaining fibers. The material properties of the fiber, especially Young's modulus and Poisson's ratio of the fiber's stress applying parts, are crucial for accurate simulations, but are usually not provided by the manufacturers. A methodology is presented to determine the unknown parameters by using experimental characterizations of the fiber and iterative FEM simulations. The resulting 3D-Model is capable of describing the change in birefringence of the free fiber when exposed to longitudinal strain. In future studies the 3D-FEM model will be employed to study the interaction of PANDA fibers with the surrounding materials in which they are embedded.

  6. On the optimal experimental design for heat and moisture parameter estimation

    CERN Document Server

    Berger, Julien; Mendes, Nathan

    2016-01-01

    In the context of estimating material properties of porous walls based on in-site measurements and identification method, this paper presents the concept of Optimal Experiment Design (OED). It aims at searching the best experimental conditions in terms of quantity and position of sensors and boundary conditions imposed to the material. These optimal conditions ensure to provide the maximum accuracy of the identification method and thus the estimated parameters. The search of the OED is done by using the Fisher information matrix and a priori knowledge of the parameters. The methodology is applied for two case studies. The first one deals with purely conductive heat transfer. The concept of optimal experiment design is detailed and verified with 100 inverse problems for different experiment designs. The second case study combines a strong coupling between heat and moisture transfer through a porous building material. The methodology presented is based on a scientific formalism for efficient planning of experim...

  7. Evaluation of Experimental Parameters in the Accelerated Aging of Closed-Cell Foam Insulation

    Energy Technology Data Exchange (ETDEWEB)

    Stovall, Therese K [ORNL; Vanderlan, Michael [ORNL; Atchley, Jerald Allen [ORNL

    2012-12-01

    The thermal conductivity of many closed-cell foam insulation products changes over time as production gases diffuse out of the cell matrix and atmospheric gases diffuse into the cells. Thin slicing has been shown to be an effective means of accelerating this process in such a way as to produce meaningful results. Efforts to produce a more prescriptive version of the ASTM C1303 standard test method led to the ruggedness test described here. This test program included the aging of full size insulation specimens for time periods of five years for direct comparison to the predicted results. Experimental parameters under investigation include: slice thickness, slice origin (at the surface or from the core of the slab), thin slice stack composition, product facings, original product thickness, product density, and product type. The test protocol has been completed and this report provides a detailed evaluation of the impact of the test parameters on the accuracy of the 5-year thermal conductivity prediction.

  8. On the IR/UV mixing and experimental limits on the parameters of canonical noncommutative spacetimes

    CERN Document Server

    Amelino-Camelia, G; Yoshida, K; Amelino-Camelia, Giovanni; Mandanici, Gianluca; Yoshida, Kensuke

    2004-01-01

    We investigate some issues that are relevant for the derivation of experimental limits on the parameters of canonical noncommutative spacetimes. By analyzing a simple Wess-Zumino-type model in canonical noncommutative spacetime with soft supersymmetry breaking we explore the implications of ultraviolet supersymmetry on low-energy phenomenology. The fact that new physics in the ultraviolet can modify low-energy predictions affects significantly the derivation of limits on the noncommutativity parameters based on low-energy data. These are, in an appropriate sense here discussed, ``conditional limits''. We also find that some standard techniques for an effective low-energy description of theories with non-locality at short distance scales are only applicable in a regime where theories in canonical noncommutative spacetime lack any predictivity, because of the strong sensitivity to unknown UV physics. It appears useful to combine high-energy data, from astrophysics, with the more readily available low-energy dat...

  9. Experimental Characterization of Ultra-Wideband Channel Parameter Measurements in an Underground Mine

    Directory of Open Access Journals (Sweden)

    B. Nkakanou

    2011-01-01

    Full Text Available Experimental results for an ultra-wideband (UWB channel parameters in an underground mining environment over a frequency range of 3 GHz to 10 GHz are reported. The measurements were taken both in LOS and NLOS cases in two different size mine galleries. In the NLOS case, results were acquired for different corridor obstruction angles. The results were obtained during an extensive measurement campaign in the UWB frequency, and the measurement procedure allows both the large- and small-scale parameters such as the path loss exponent, coherence bandwidth, and so forth, to be quantified. The capacity of the UWB channel as a function of the physical depth of the mine gallery has also been recorded for comparison purposes.

  10. 2000 CKM-triangle analysis a critical review with updated experimental inputs and theoretical parameters

    Energy Technology Data Exchange (ETDEWEB)

    Roudeau, P.; Stocchi, A. [Laboratoire de l' Accelerateur Lineaire, 91 - Orsay (France); Ciuchini, M.; Lubicz, V. [Rome Univ., INFN (Italy); D' Agostini, G.; Franco, E.; Martinelli, G. [Rome Univ. La Sapienza and Sezione INFN, (Italy); Parodi, F. [Universita di Genova and INFN, Dipt. di Fisica (Italy)

    2000-12-01

    Within the Standard Model, a review of the current determination of the sides and angles of the CKM unitarity triangle is presented, using experimental constraints from the measurements of |{epsilon}{sub K}|, |V{sub ub}/V{sub cb}|, {delta}m{sub d} and from the limit on {delta}m{sub s}, available in September 2000. Results from the experimental search for B{sup 0}{sub s}-B-bar{sup 0}{sub s} oscillations are introduced in the present analysis using the likelihood. Special attention is devoted to the determination of the theoretical uncertainties. The purpose of the analysis is to infer regions where the parameters of interest lie with given probabilities. The BaBar '95% C.L. scanning' method is also commented. (authors)

  11. On the Viscoelastic Parameters of Gussasphalt Mixture Based on Modified Burgers Model: Deviation and Experimental Verification

    Directory of Open Access Journals (Sweden)

    Faxiang Xie

    2017-01-01

    Full Text Available Viscoelasticity is an important characteristic of gussasphalt mixtures. The aim of this study is to find the correct viscoelastic material parameters of the novel gussasphalt applied in the 4th Yangtze River Bridge based on the modified Burgers model. This study firstly derives the explicit Prony series form of the shear relaxation modulus of viscoelastic material from Laplace transformation, to fulfill the parameter inputting requirements of commonly used finite element software suites. Secondly, a kind of uniaxial penetration creep experiment on the gussasphalt mixtures is conducted. By fitting the creep compliance, the viscoelastic parameters characterized by the modified Burgers model are obtained. And thirdly, based on the viscoelastic test data of asphalt mixtures, the Prony series formula derived in this study is verified through the finite element simulation. The comparison results of the relative errors between the finite element simulation and the theoretical calculation confirm the reliability of the Prony series formulas deduced in this research. And finally, a stress-correcting method is proposed, which can significantly improve the accuracy of model parameters identification and reduce the relative error between the finite element simulation and the experimental data.

  12. Experimental determination of spin-transfer torque nonadiabaticity parameter and spin polarization in permalloy

    Science.gov (United States)

    Lepadatu, S.; Hickey, M. C.; Potenza, A.; Marchetto, H.; Charlton, T. R.; Langridge, S.; Dhesi, S. S.; Marrows, C. H.

    2009-03-01

    The domain-wall depinning boundary, showing the variation in critical current density with magnetic field, is measured for notched permalloy wires using pulsed-current measurements. The structure of domain walls trapped at the pinning potential provided by the notch is imaged using photoemission electron microscopy. The experimental depinning boundary is compared with those obtained by micromagnetic simulations including the adiabatic and nonadiabatic spin-torque terms. This method allows for the determination of both the nonadiabaticity parameter β and spin current polarization P , which we obtain as β=0.040±0.005 and P=0.40±0.02 at room temperature.

  13. Experimental Parameter Effect on Ceramic Coating Film on LY12 Alloy by Micro-arc Oxidation

    Science.gov (United States)

    Zhao, H.; Yang, J. H.; Wang, X. H.

    2017-09-01

    Ceramic coatings were fabricated on the surface of LY12 aluminum alloy by micro-arc oxidation (MAO) method in NaSiO3-NaOH solution. Effect of experimental parameter on the MAO film was investigated. The results show that the ceramic layers formed on the surface of the alloy show different surface morphologies, and thickness of MAO film increases with the increase of voltage and oxidation time. These films contain two layers, an outer porous layer and an inner barrier layer, which consists mainly of γ-Al2O3 phase and a small amount of α-Al2O3 phase..

  14. Estimate the contribution of incubation parameters influence egg hatchability using multiple linear regression analysis

    OpenAIRE

    Khalil, Mohamed H.; Shebl, Mostafa K.; Kosba, Mohamed A.; El-Sabrout, Karim; Zaki, Nesma

    2016-01-01

    Aim: This research was conducted to determine the most affecting parameters on hatchability of indigenous and improved local chickens’ eggs. Materials and Methods: Five parameters were studied (fertility, early and late embryonic mortalities, shape index, egg weight, and egg weight loss) on four strains, namely Fayoumi, Alexandria, Matrouh, and Montazah. Multiple linear regression was performed on the studied parameters to determine the most influencing one on hatchability. Results: The...

  15. Influence of structure parameters of reinforcing rib to mechanical properties of plastic well cover

    OpenAIRE

    Pengbiao HAN; Chao SUN; Lei MA

    2016-01-01

    In order to study the influence of structure parameters of the reinforcing rib to the mechanical properties of plastic well covers, according to the theory of elasticity, the stress situation of the plastic well cover with reinforcing rib is analyzed with finite element method. The load simulation of the plastic well cover with different reinforcing rib structure parameters is conducted with Abaqus software, and the relationship between the structure parameters of the reinforcing rib and the ...

  16. Study of the influences of laser parameters on laser assisted machining processes

    OpenAIRE

    Tagliaferri, Flaviana; Leopardi, Giacomo; Semmler, Ulrich; Kuhl, Michael; Palumbo, Biagio

    2013-01-01

    Hybrid machining processes using additional energy sources such as laser assisted machining (LAM) have increased considerably during the last years. The benefits of LAM for reducing tool wear and cutting forces are well known, especially for superalloys. However, optimal machining results depend on both the laser parameters and the cutting process parameters. It is difficult to find optimal LAM settings due to the complexity of the influencing parameters and their mutual interactions. The aim...

  17. Global performance parameters for different pneumatic bioreactors operating with water and glycerol solution: experimental data and CFD simulation.

    Science.gov (United States)

    Rodriguez, G Y; Valverde-Ramírez, M; Mendes, C E; Béttega, R; Badino, A C

    2015-11-01

    Global variables play a key role in evaluation of the performance of pneumatic bioreactors and provide criteria to assist in system selection and design. The purpose of this work was to use experimental data and computational fluid dynamics (CFD) simulations to determine the global performance parameters gas holdup ([Formula: see text]) and volumetric oxygen transfer coefficient (k L a), and conduct an analysis of liquid circulation velocity, for three different geometries of pneumatic bioreactors: bubble column, concentric-tube airlift, and split tube airlift. All the systems had 5 L working volumes and two Newtonian fluids of different viscosities were used in the experiments: distilled water and 10 cP glycerol solution. Considering the high oxygen demand in certain types of aerobic fermentations, the assays were carried out at high flow rates. In the present study, the performances of three pneumatic bioreactors with different geometries and operating with two different Newtonian fluids were compared. A new CFD modeling procedure was implemented, and the simulation results were compared with the experimental data. The findings indicated that the concentric-tube airlift design was the best choice in terms of both gas holdup and volumetric oxygen transfer coefficient. The CFD results for gas holdup were consistent with the experimental data, and indicated that k L a was strongly influenced by bubble diameter and shape.

  18. Measuring saliency in images: which experimental parameters for the assessment of image quality?

    Science.gov (United States)

    Fredembach, Clement; Woolfe, Geoff; Wang, Jue

    2012-01-01

    Predicting which areas of an image are perceptually salient or attended to has become an essential pre-requisite of many computer vision applications. Because observers are notoriously unreliable in remembering where they look a posteriori, and because asking where they look while observing the image necessarily in uences the results, ground truth about saliency and visual attention has to be obtained by gaze tracking methods. From the early work of Buswell and Yarbus to the most recent forays in computer vision there has been, perhaps unfortunately, little agreement on standardisation of eye tracking protocols for measuring visual attention. As the number of parameters involved in experimental methodology can be large, their individual in uence on the nal results is not well understood. Consequently, the performance of saliency algorithms, when assessed by correlation techniques, varies greatly across the literature. In this paper, we concern ourselves with the problem of image quality. Specically: where people look when judging images. We show that in this case, the performance gap between existing saliency prediction algorithms and experimental results is signicantly larger than otherwise reported. To understand this discrepancy, we rst devise an experimental protocol that is adapted to the task of measuring image quality. In a second step, we compare our experimental parameters with the ones of existing methods and show that a lot of the variability can directly be ascribed to these dierences in experimental methodology and choice of variables. In particular, the choice of a task, e.g., judging image quality vs. free viewing, has a great impact on measured saliency maps, suggesting that even for a mildly cognitive task, ground truth obtained by free viewing does not adapt well. Careful analysis of the prior art also reveals that systematic bias can occur depending on instrumental calibration and the choice of test images. We conclude this work by proposing a

  19. Influence of position and stimulation parameters on intracortical inhibition and facilitation in human tongue motor cortex

    DEFF Research Database (Denmark)

    Kothari, Mohit; Svensson, Peter; Nielsen, Jørgen Feldbæk

    2014-01-01

    Paired-pulse transcranial magnetic stimulation (ppTMS) can be used to assess short-interval intracortical inhibitory (SICI) and facilitatory (ICF) networks. Many methodological parameters may however influence the outcome. The aim of the study was to examine the influence of body positions (recline...

  20. The influence of technological parameters on the dynamic behavior of "liquid wood" samples obtained by injection molding

    Science.gov (United States)

    Plavanescu Mazurchevici, Simona; Carausu, Constantin; Comaneci, Radu; Nedelcu, Dumitru

    2017-10-01

    The plastic products contribute to environmental pollution. Replacing the plastic materials with biodegradable materials with superior properties is an absolute necessity and important research direction for the near future. The first steps in this regard were the creation of composite materials containing natural fibers with positive effects on the environment that have penetrated in different fields. The bioplastics and biocomposites made from natural fibers is a topical solution. The next step was made towards obtaining biodegradable and recyclable materials based on cellulose, lignin and no carcinogens. In this category fall the "liquid wood" with a use up to five times without affecting the mechanical properties. "Liquid wood" is a high quality thermoplastic biocomposite. "Liquid wood" is a biopolymer composite divided in three categories, ARBOFORM®, ARBOBLEND® and ARBOFILL®, which have differed composition in terms of lignin percentage, being delivered by Tecnaro, as granules, [1]. The paper's research was focus on Arboform L V3 Nature and Arboform L V3 Nature reinforced with aramid fiber. In the experimental plan were taken into account six parameters (Dinj - direction of injection [°]; Ttop - melting temperature [°C]; Pinj - injection pressure [MPa] Ss - speed [m/min]; tinj - injection time [s] and tc - cooling time [s]) each with two levels, research carried on by Taguchi methodology. Processing Taguchi method allowed both Taguchi setting work parameters influence on storage modulus and damping as the size and influence their ranking. Experimental research concerning the influence technological parameters on storage modulus of samples obtained by injection from Arboform L V3 Nature yielded an average of 6055MPa and descending order as follows: Trac, Ss, Pinj, Dinj and Ttop. The average of model for reinforced material was 6419MPa and descending order of parameters influence such as: Dinj, Trac, Ttop, tinj, Ss and Pinj.

  1. The influence of experimentally induced pain on shoulder muscle activity.

    Science.gov (United States)

    Diederichsen, Louise Pyndt; Winther, Annika; Dyhre-Poulsen, Poul; Krogsgaard, Michael R; Nørregaard, Jesper

    2009-04-01

    Muscle function is altered in painful shoulder conditions. However, the influence of shoulder pain on muscle coordination of the shoulder has not been fully clarified. The aim of the present study was to examine the effect of experimentally induced shoulder pain on shoulder muscle function. Eleven healthy men (range 22-27 years), with no history of shoulder or cervical problems, were included in the study. Pain was induced by 5% hypertonic saline injections into the supraspinatus muscle or subacromially. Seated in a shoulder machine, subjects performed standardized concentric abduction (0 degrees -105 degrees) at a speed of approximately 120 degrees/s, controlled by a metronome. During abduction, electromyographic (EMG) activity was recorded by intramuscular wire electrodes inserted in two deeply located shoulder muscles and by surface-electrodes over six superficially located shoulder muscles. EMG was recorded before pain, during pain and after pain had subsided and pain intensity was continuously scored on a visual analog scale (VAS). During abduction, experimentally induced pain in the supraspinatus muscle caused a significant decrease in activity of the anterior deltoid, upper trapezius and the infraspinatus and an increase in activity of lower trapezius and latissimus dorsi muscles. Following subacromial injection a significantly increased muscle activity was seen in the lower trapezius, the serratus anterior and the latissimus dorsi muscles. In conclusion, this study shows that acute pain both subacromially and in the supraspinatus muscle modulates coordination of the shoulder muscles during voluntary movements. During painful conditions, an increased activity was detected in the antagonist (latissimus), which support the idea that localized pain affects muscle activation in a way that protects the painful structure. Further, the changes in muscle activity following subacromial pain induction tend to expand the subacromial space and thereby decrease the load

  2. The Influence of Process Parameters on the Characteristics of Electrospun 3D Nanostructures

    Science.gov (United States)

    Bertea, A.; Manea, L. R.; Popa, A.; Bertea, A.

    2017-06-01

    Electrospinning is a fast developing technique that employs electrostatic repulsive forces to produce ultrafine fibres with application in fields like environment protection, medicine, sensors and many others. The characteristics of the polymer jet and the properties of the electrospun nanofibres are highly influenced by technological and environmental parameters. This paper offers a report on the main processing parameters that may influence the characteristics of the obtained nanofibres. The influence of flow rate, spinneret to collector distance and applied voltage on maximum fibre length, average fibre diameter, diameter uniformity and nanofibre quality is reviewed.

  3. Distributed parameter model and experimental validation of a compressive-mode energy harvester under harmonic excitations

    Energy Technology Data Exchange (ETDEWEB)

    Li, H.T. [Department of Engineering Mechanics, Northwestern Polytechnical University, Xian (China); Department of Mechanical & Industrial Engineering, University of Toronto, Toronto, Ontario (Canada); Yang, Z.; Zu, J. [Department of Mechanical & Industrial Engineering, University of Toronto, Toronto, Ontario (Canada); Qin, W. Y., E-mail: qinweiyang67@gmail.com [Department of Engineering Mechanics, Northwestern Polytechnical University, Xian (China)

    2016-08-15

    This paper presents the modeling and parametric analysis of the recently proposed nonlinear compressive-mode energy harvester (HC-PEH) under harmonic excitation. Both theoretical and experimental investigations are performed in this study over a range of excitation frequencies. Specially, a distributed parameter electro-elastic model is analytically developed by means of the energy-based method and the extended Hamilton’s principle. An analytical formulation of bending and stretching forces are derived to gain insight on the source of nonlinearity. Furthermore, the analytical model is validated against with experimental data and a good agreement is achieved. Both numerical simulations and experiment illustrate that the harvester exhibits a hardening nonlinearity and hence a broad frequency bandwidth, multiple coexisting solutions and a large-amplitude voltage response. Using the derived model, a parametric study is carried out to examine the effect of various parameters on the harvester voltage response. It is also shown from parametric analysis that the harvester’s performance can be further improved by selecting the proper length of elastic beams, proof mass and reducing the mechanical damping.

  4. Optimizing experimental parameters for the projection requirement in HAADF-STEM tomography

    Energy Technology Data Exchange (ETDEWEB)

    Aveyard, R., E-mail: r.a.aveyard@tudelft.nl [Department of Imaging Physics, Delft University of Technology, 2628CJ Delft (Netherlands); Zhong, Z.; Batenburg, K.J. [Centrum Wiskunde and Informatica, Science Park 123, NL-1098 XG Amsterdam (Netherlands); Rieger, B., E-mail: b.rieger@tudelft.nl [Department of Imaging Physics, Delft University of Technology, 2628CJ Delft (Netherlands)

    2017-06-15

    Highlights: • The extent to which HAADF-STEM meets the projection requirement has been studied. • Multislice simulations used to model beam propagation and study signal linearity. • Propagation in crystalline and amorphous materials considered. • Optimal experimental set-up for the projection requirement is discussed. - Abstract: Tomographic reconstruction algorithms offer a means by which a tilt-series of transmission images can be combined to yield a three dimensional model of the specimen. Conventional reconstruction algorithms assume that the measured signal is a linear projection of some property, typically the density, of the material. Here we report the use of multislice simulations to investigate the extent to which this assumption is met in HAADF-STEM imaging. The use of simulations allows for a systematic survey of a range of materials and microscope parameters to inform optimal experimental design. Using this approach it is demonstrated that the imaging of amorphous materials is in good agreement with the projection assumption in most cases. Images of crystalline specimens taken along zone-axes are found to be poorly suited for conventional linear reconstruction algorithms due to channelling effects which produce enhanced intensities compared with off-axis images, and poor compliance with the projection requirement. Off-axis images are found to be suitable for reconstruction, though they do not strictly meet the linearity requirement in most cases. It is demonstrated that microscope parameters can be selected to yield improved compliance with the projection requirement.

  5. An Empirical Study of Parameter Estimation for Stated Preference Experimental Design

    Directory of Open Access Journals (Sweden)

    Fei Yang

    2014-01-01

    Full Text Available The stated preference experimental design can affect the reliability of the parameters estimation in discrete choice model. Some scholars have proposed some new experimental designs, such as D-efficient, Bayesian D-efficient. But insufficient empirical research has been conducted on the effectiveness of these new designs and there has been little comparative analysis of the new designs against the traditional designs. In this paper, a new metro connecting Chengdu and its satellite cities is taken as the research subject to demonstrate the validity of the D-efficient and Bayesian D-efficient design. Comparisons between these new designs and orthogonal design were made by the fit of model and standard deviation of parameters estimation; then the best model result is obtained to analyze the travel choice behavior. The results indicate that Bayesian D-efficient design works better than D-efficient design. Some of the variables can affect significantly the choice behavior of people, including the waiting time and arrival time. The D-efficient and Bayesian D-efficient design for MNL can acquire reliability result in ML model, but the ML model cannot develop the theory advantages of these two designs. Finally, the metro can handle over 40% passengers flow if the metro will be operated in the future.

  6. Experimentally Studied Influence of the Bullet Head Shape on Dispersion Characteristics at Subsonic Airspeeds

    Directory of Open Access Journals (Sweden)

    S. N. Ilukhin

    2015-01-01

    Full Text Available The article presents description and results of experiments on a ballistic track and subsonic wind tunnel. The subject of study is important an issue such as the assessment of the influence of the bullet head shape on the accuracy of shooting parameters at subsonic muzzle velocity. The article points to the features of examined precision of guided and unguided aircraft, refers to the main disturbing factors. In addition, it outlines the most well known ways to improve the flight precision of unguided munitions. The article presents the geometric parameters of bullets and their scale models used in the experiments. It describes the experimental facilities and the studies themselves. Particular attention is paid to the analysis of experimental air-gun firings. Results for different muzzle velocities of flight are compared. The paper notes an ambiguity in comparison of accuracy and head drag coefficient. The results are clearly aligned with the data purging in the little turbulent subsonic wind tunnel. The article describes in detail the use of the method for visualizing a structure of the flow for the delimitation of attached flow and estimation of stagnation zone. A revealed physical picture has comprehensive theoretical underpinning. The conclusions of the work also give a advices on selecting a bullet to have the best dispersion parameters.

  7. Influence of Radial Stress Gradient on Strainbursts: An Experimental Study

    Science.gov (United States)

    Su, Guoshao; Zhai, Shaobin; Jiang, Jianqing; Zhang, Gangliang; Yan, Liubin

    2017-10-01

    Strainbursts, which are violent disasters that are accompanied by the ejection failure of rocks, usually occur in hard brittle rocks around highly stressed underground openings. The release of the radial stress at excavation boundaries is one of the major inducing factors for strainbursts in tunnels. After excavation, the radial stress usually exhibits different but apparent gradient variations along the radial direction near the boundary within a certain depth under different in situ stress conditions. In this study, the influence of the radial stress gradient on strainbursts of granite was investigated using an improved true-triaxial rockburst testing system, which was equipped with an acoustic emission monitoring system. The stress state and boundary conditions (i.e., one face free, other faces loaded and increasing tangential stress) of the representative rock element in the vicinity of the excavation boundary were simulated. High-speed cameras were used to capture the ejection failure processes during strainbursts, and the kinetic energy of ejected fragments was quantitatively estimated by analyzing the recorded videos. The experimental results indicate that with an increasing radial stress gradient, the strength increases, the apparent yield platform prior to the peak stress on the stress-strain curves decreases, the failure mode changes from strainburst characterized by tensile splitting to strainburst characterized by shear rupture, and the kinetic energy of ejected fragments during strainbursts significantly increases.

  8. Influence of plectrum shape and jack velocity on the sound of the harpsichord: An experimental study.

    Science.gov (United States)

    Paté, Arthur; Le Carrou, Jean-Loïc; Givois, Arthur; Roy, Alexandre

    2017-03-01

    A controversial discussion in the musical community regards the ability of the harpsichord to produce sound level or timbre changes. The jack velocity (controlled in real time within a musical context) and the plectrum shape (modified by the musician or maker prior to the performance) appear to be the two control parameters at the disposal of the harpsichord makers and players for shaping the sound. This article initiates the acoustical study of the control parameters of the harpsichord, presenting a framework for the investigation of these two parameters with means of experimental mechanics measurement. A robotic finger is used for producing repeatable plucks with various jack velocities and plectrum shapes. The plectrum bending, vibrating string's initial conditions, and radiated sound are recorded and analysed. First, results are obtained from measurements carried out on one string, for four plectrum shapes and four jack velocities. The plectrum shape has been found to have an influence on its bending behavior when interacting with the string; on the string's initial conditions (position and velocity); and on the resulting sound (sound level, spectral centroid, and decay time). The jack velocity does not have an influence on any of the measured quantities.

  9. Influence of experimental conditions on data variability in the liver comet assay.

    Science.gov (United States)

    Guérard, M; Marchand, C; Plappert-Helbig, U

    2014-03-01

    The in vivo comet assay has increasingly been used for regulatory genotoxicity testing in recent years. While it has been demonstrated that the experimental execution of the assay, for example, electrophoresis or scoring, can have a strong impact on the results; little is known on how initial steps, that is, from tissue sampling during necropsy up to slide preparation, can influence the comet assay results. Therefore, we investigated which of the multitude of steps in processing the liver for the comet assay are most critical. All together eight parameters were assessed by using liver samples of untreated animals. In addition, two of those parameters (temperature and storage time of liver before embedding into agarose) were further investigated in animals given a single oral dose of ethyl methanesulfonate at dose levels of 50, 100, and 200 mg/kg, 3 hr prior to necropsy. The results showed that sample cooling emerged as the predominant influence factor, whereas variations in other elements of the procedure (e.g., size of the liver piece sampled, time needed to process the liver tissue post-mortem, agarose temperature, or time of lysis) seem to be of little relevance. Storing of liver samples of up to 6 hr under cooled conditions did not cause an increase in tail intensity. In contrast, storing the tissue at room temperature, resulted in a considerable time-dependent increase in comet parameters. Copyright © 2013 Wiley Periodicals, Inc.

  10. Influence of operating parameters on electrocoagulation of C.I. disperse yellow 3

    Directory of Open Access Journals (Sweden)

    Djamel Ghernaout

    2014-12-01

    Full Text Available This work deals with the electrocoagulation (EC process for an organic dye removal. The chosen organic dye is C.I. disperse yellow 3 (DY which is used in textile industry. Experiments were performed in batch mode using Al electrodes and for comparison purposes Fe electrodes. The experimental set-up was composed of 1 L beaker, two identical electrodes which are separated 2 cm from each other. The main operating parameters influencing EC process were examined such as pH, supporting electrolyte concentration CNaCl, current density i, and DY concentration. High performance EC process was shown during 45 min for 200 mg/L dye concentration at i = 350 A m-2 (applied voltage 12 V and CNaCl = 1 g L-1 reaching 98 % for pHs 3 and 10 and 99 % for pH 6. After 10 min, DY was also efficiently removed (86 % showing that EC process may be conveniently applied for textile industry wastewater treatment. EC using Fe electrodes exhibited slightly lower performance comparing EC using Al electrodes.

  11. Influences of operational parameters on phosphorus removal in batch and continuous electrocoagulation process performance.

    Science.gov (United States)

    Nguyen, Dinh Duc; Yoon, Yong Soo; Bui, Xuan Thanh; Kim, Sung Su; Chang, Soon Woong; Guo, Wenshan; Ngo, Huu Hao

    2017-09-21

    Performance of an electrocoagulation (EC) process in batch and continuous operating modes was thoroughly investigated and evaluated for enhancing wastewater phosphorus removal under various operating conditions, individually or combined with initial phosphorus concentration, wastewater conductivity, current density, and electrolysis times. The results revealed excellent phosphorus removal (72.7-100%) for both processes within 3-6 min of electrolysis, with relatively low energy requirements, i.e., less than 0.5 kWh/m(3) for treated wastewater. However, the removal efficiency of phosphorus in the continuous EC operation mode was better than that in batch mode within the scope of the study. Additionally, the rate and efficiency of phosphorus removal strongly depended on operational parameters, including wastewater conductivity, initial phosphorus concentration, current density, and electrolysis time. Based on experimental data, statistical model verification of the response surface methodology (RSM) (multiple factor optimization) was also established to provide further insights and accurately describe the interactive relationship between the process variables, thus optimizing the EC process performance. The EC process using iron electrodes is promising for improving wastewater phosphorus removal efficiency, and RSM can be a sustainable tool for predicting the performance of the EC process and explaining the influence of the process variables.

  12. Influence of local parameters on the dispersion of traffic-related pollutants within street canyons

    Science.gov (United States)

    Karra, Styliani; Malki-Epshtein, Liora; Martin Hyde Collaboration

    2011-11-01

    Ventilation within urban cities and street canyons and the associated air quality is a problem of increasing interest in the last decades. It is important for to minimise exposure of the population to traffic-related pollutants at street level. The residence time of pollutants within the street canyons depends on the meteorological conditions such as wind speed and direction, geometry layout and local parameters (position of traffic lane within the street). An experimental study was carried out to investigate the influence of traffic lane position on the dispersion of traffic-related pollutants within different street canyons geometries: symmetrical (equal building heights on both sides of the street), non-symmetrical (uniform building heights but lower on one side of the street) and heterogeneous (non-uniform building heights on both sides of the street) under constant meteorological conditions. Laboratory experiments were carried out within a water channel and simultaneous measurements of velocity field and concentration scalar levels within and above the street canyons using PIV and PLIF techniques. Traffic -related emissions were simulated using a line emission source. Two positions were examined for all street geometries: line emission source was placed in the centre of the street canyon; line emission source was placed off the centre of the street. TSI Incorporated.

  13. A Comparative Survey on Parameters Influencing on Hexavalent Chromium Measurement as an Occupational Carcinogen

    Directory of Open Access Journals (Sweden)

    A. Tirgar

    2008-07-01

    Full Text Available Introduction & Objective: Hexavalent chromium, Cr+6, is a very harmful pollutant and a relatively unstable compound that is present in many industries. It is a known human respiratory carcinogen and occupational exposure to this chemical is associated with different health hazards. The purpose of this study was to evaluate the effects of four parameters including: type of sampling head, sampling height from the surface of electroplating solution, sampling duration, and sample storage duration on Cr+6 mist monitoring.Materials & Methods: To evaluate the influence of the main parameters as an experimental study, the 24 factorial design was applied at constant electroplating condition. A chromium electroplating bath with the ability to produce homogenous mist was used to create Cr+6 mist in laboratory setting. The National Institute for Occupational Safety and Health (NIOSH method 7600 was used to determine the Cr+6 concentration. Results: The results of 48 Cr+6 mist samples showed that Cr+6 concentration was higher: (1 for sampling by closed-face filter cassettes than for sampling by open-face filter cassettes (P<0.001; (2 for samples collected at 35 cm above the electroplating solution surface than for samples collected at 50 cm (P <0.001; (3 for sampling duration of 30 minutes than for sampling duration of 180 minutes (P <0.001; and, (4 for samples extracted immediately after sampling than for samples with delayed extraction (24 hours after sampling (P <0.001. Conclusion: It is concluded that the accuracy of Cr+6 mist sampling in electroplating shops will be enhanced when: (1 a closed-face filter cassette is used to prevent liquid splash contamination; (2 the sampling height is suitable as determined by further research; (3 the sampling duration is short (approximately 30 minutes; and, (4 the extraction of the Cr+6 sample is performed as soon as the sampling is completed.

  14. The Influence of Inner Component and Topographical Properties on Tribological Parameters of Injection-Moulded Microparts

    Directory of Open Access Journals (Sweden)

    Christopher Fischer

    2014-10-01

    Full Text Available Tribological parameters are dependent upon inter alia, inner component properties which may vary with the temperature-time behaviour of the polymer melt used. This temperature-time behaviour can be influenced by dynamic mould temperature control. The present paper presents a new dynamic tempering concept, which enables a targeted temperature-time control via shifting a mould cavity within two different tempered mould areas at a defined point in time. By influencing the temperature-time development by means of a mould temperature and isothermal holding time variation, micro tensile bars with different inner component properties are produced. To show the influence of inner component properties on tribological parameters, pin-on-disc wear tests are performed. Furthermore, tribological tests with different surface topographies are performed to show the influence of topographical properties on tribological parameters. Results indicate that the tribological properties of microparts are mainly influenced by the nature of the skin near layers, which can be influenced by the application of different mould temperatures. Variations in the isothermal holding time show no significant impact on the material examined. A more distinct roughness of the disc surface topography not only shows higher values for the measured tribological parameters but also different wear behaviour in general.

  15. Experimental Investigation on the Fatigue Mechanical Properties of Intermittently Jointed Rock Models Under Cyclic Uniaxial Compression with Different Loading Parameters

    Science.gov (United States)

    Liu, Yi; Dai, Feng; Dong, Lu; Xu, Nuwen; Feng, Peng

    2018-01-01

    Intermittently jointed rocks, widely existing in many mining and civil engineering structures, are quite susceptible to cyclic loading. Understanding the fatigue mechanism of jointed rocks is vital to the rational design and the long-term stability analysis of rock structures. In this study, the fatigue mechanical properties of synthetic jointed rock models under different cyclic conditions are systematically investigated in the laboratory, including four loading frequencies, four maximum stresses, and four amplitudes. Our experimental results reveal the influence of the three cyclic loading parameters on the mechanical properties of jointed rock models, regarding the fatigue deformation characteristics, the fatigue energy and damage evolution, and the fatigue failure and progressive failure behavior. Under lower loading frequency or higher maximum stress and amplitude, the jointed specimen is characterized by higher fatigue deformation moduli and higher dissipated hysteresis energy, resulting in higher cumulative damage and lower fatigue life. However, the fatigue failure modes of jointed specimens are independent of cyclic loading parameters; all tested jointed specimens exhibit a prominent tensile splitting failure mode. Three different crack coalescence patterns are classified between two adjacent joints. Furthermore, different from the progressive failure under static monotonic loading, the jointed rock specimens under cyclic compression fail more abruptly without evident preceding signs. The tensile cracks on the front surface of jointed specimens always initiate from the joint tips and then propagate at a certain angle with the joints toward the direction of maximum compression.

  16. Experimental validation of analytical models for a rapid determination of cycle parameters in thermoplastic injection molding

    Science.gov (United States)

    Pignon, Baptiste; Sobotka, Vincent; Boyard, Nicolas; Delaunay, Didier

    2017-10-01

    Two different analytical models were presented to determine cycle parameters of thermoplastics injection process. The aim of these models was to provide quickly a first set of data for mold temperature and cooling time. The first model is specific to amorphous polymers and the second one is dedicated to semi-crystalline polymers taking the crystallization into account. In both cases, the nature of the contact between the polymer and the mold could be considered as perfect or not (thermal contact resistance was considered). Results from models are compared with experimental data obtained with an instrumented mold for an acrylonitrile butadiene styrene (ABS) and a polypropylene (PP). Good agreements were obtained for mold temperature variation and for heat flux. In the case of the PP, the analytical crystallization times were compared with those given by a coupled model between heat transfer and crystallization kinetics.

  17. Experimental determination of the x-ray atomic fundamental parameters of nickel

    Science.gov (United States)

    Ménesguen, Y.; Lépy, M.-C.; Hönicke, P.; Müller, M.; Unterumsberger, R.; Beckhoff, B.; Hoszowska, J.; Dousse, J.-Cl; Błachucki, W.; Ito, Y.; Yamashita, M.; Fukushima, S.

    2018-02-01

    The x-ray atomic properties of nickel (Ni) were investigated in a unique approach combining different experimental techniques to obtain new, useful and reliable values of atomic fundamental parameters for x-ray spectrometric purposes and for comparison with theoretical predictions. We determined the mass attenuation coefficients in an energy range covering the L- and K-absorption edges, the K-shell fluorescence yield and the Kβ/Kα and Kβ1, 3/Kα1, 2 transition probability ratios. The obtained line profiles and linewidths of the Kα and Kβ transitions in Ni can be considered as the contribution of the satellite lines arising from the [KM] shake processes suggested by Deutsch et al (1995 Phys. Rev. A 51 283) and Ito et al (2016 Phys. Rev. A 94 042506). Comparison of the new data with several databases showed good agreement, but also discrepancies were found with existing tabulated values.

  18. CFD analysis and experimental investigations towards optimizing the parameters of Ranque-Hilsch vortex tube

    Energy Technology Data Exchange (ETDEWEB)

    Behera, U.; Paul, P.J. [Indian Institute of Science, Bangalore (India). Department of Aerospace Engineering; Kasthurirengan, S.; Karunanithi, R.; Ram, S.N.; Dinesh, K.; Jacob, S. [Indian Institute of Science, Bangalore (India). Centre for Cryogenic Technology

    2005-05-01

    Computational fluid dynamics (CFD) and experimental studies are conducted towards the optimization of the Ranque-Hilsch vortex tubes. Different types of nozzle profiles and number of nozzles are evaluated by CFD analysis. The swirl velocity, axial velocity and radial velocity components as well as the flow patterns including secondary circulation flow have been evaluated. The optimum cold end diameter (d{sub c}) and the length to diameter (L/D) ratios and optimum parameters for obtaining the maximum hot gas temperature and minimum cold gas temperature are obtained through CFD analysis and validated through experiments. The coefficient of performance (COP) of the vortex tube as a heat engine and as a refrigerator has been calculated. (author)

  19. Analysis of Experimental Fuel Rod Parameters using 3D Modelling of PCMI with MPS Defect

    Energy Technology Data Exchange (ETDEWEB)

    Casagranda, Albert [Idaho National Laboratory; Spencer, Benjamin Whiting [Idaho National Laboratory; Pastore, Giovanni [Idaho National Laboratory; Novascone, Stephen Rhead [Idaho National Laboratory; Hales, Jason Dean [Idaho National Laboratory; Williamson, Richard L [Idaho National Laboratory; Martineau, Richard Charles [Idaho National Laboratory

    2016-06-01

    An in-reactor experiment is being designed in order to validate the pellet-cladding mechanical interaction (PCMI) behavior of the BISON fuel performance code. The experimental parameters for the test rod being placed in the Halden Research Reactor are being determined using BISON simulations. The 3D model includes a missing pellet surface (MPS) defect to generate large local cladding deformations, which should be measureable after typical burnup times. The BISON fuel performance code is being developed at Idaho National Laboratory (INL) and is built on the Multiphysics Object-Oriented Simulation Environment (MOOSE) framework. BISON supports both 2D and 3D finite elements and solves the fully coupled equations for solid mechanics, heat conduction and species diffusion. A number of fuel performance effects are included using models for swelling, densification, creep, relocation and fission gas production & release. In addition, the mechanical and thermal contact between the fuel and cladding is explicitly modelled using a master-slave based contact algorithm. In order to accurately predict PCMI effects, the BISON code includes the relevant physics involved and provides a scalable and robust solution procedure. The depth of the proposed MPS defect is being varied in the BISON model to establish an optimum value for the experiment. The experiment will be interrupted approximately every 6 months to measure cladding radial deformation and provide data to validate BISON. The complete rodlet (~20 discrete pellets) is being simulated using a 180° half symmetry 3D model with MPS defects at two axial locations. In addition, annular pellets will be used at the top and bottom of the pellet stack to allow thermocouples within the rod to measure the fuel centerline temperature. Simulation results will be presented to illustrate the expected PCMI behavior and support the chosen experimental design parameters.

  20. Determination of Experimental Fuel Rod Parameters using 3D Modelling of PCMI with MPS Defect

    Energy Technology Data Exchange (ETDEWEB)

    Casagranda, Albert [Idaho National Laboratory; Spencer, Benjamin Whiting [Idaho National Laboratory; Pastore, Giovanni [Idaho National Laboratory; Novascone, Stephen Rhead [Idaho National Laboratory; Hales, Jason Dean [Idaho National Laboratory; Williamson, Richard L [Idaho National Laboratory; Martineau, Richard Charles [Idaho National Laboratory

    2016-05-01

    An in-reactor experiment is being designed in order to validate the pellet-cladding mechanical interaction (PCMI) behavior of the BISON fuel performance code. The experimental parameters for the test rod being placed in the Halden Research Reactor are being determined using BISON simulations. The 3D model includes a missing pellet surface (MPS) defect to generate large local cladding deformations, which should be measureable after typical burnup times. The BISON fuel performance code is being developed at Idaho National Laboratory (INL) and is built on the Multiphysics Object-Oriented Simulation Environment (MOOSE) framework. BISON supports both 2D and 3D finite elements and solves the fully coupled equations for solid mechanics, heat conduction and species diffusion. A number of fuel performance effects are included using models for swelling, densification, creep, relocation and fission gas production & release. In addition, the mechanical and thermal contact between the fuel and cladding is explicitly modelled using a master-slave based contact algorithm. In order to accurately predict PCMI effects, the BISON code includes the relevant physics involved and provides a scalable and robust solution procedure. The depth of the proposed MPS defect is being varied in the BISON model to establish an optimum value for the experiment. The experiment will be interrupted approximately every 6 months to measure cladding radial deformation and provide data to validate BISON. The complete rodlet (~20 discrete pellets) is being simulated using a 180° half symmetry 3D model with MPS defects at two axial locations. In addition, annular pellets will be used at the top and bottom of the pellet stack to allow thermocouples within the rod to measure the fuel centerline temperature. Simulation results will be presented to illustrate the expected PCMI behavior and support the chosen experimental design parameters.

  1. Optimal experimental design for improving the estimation of growth parameters of Lactobacillus viridescens from data under non-isothermal conditions.

    Science.gov (United States)

    Longhi, Daniel Angelo; Martins, Wiaslan Figueiredo; da Silva, Nathália Buss; Carciofi, Bruno Augusto Mattar; de Aragão, Gláucia Maria Falcão; Laurindo, João Borges

    2017-01-02

    In predictive microbiology, the model parameters have been estimated using the sequential two-step modeling (TSM) approach, in which primary models are fitted to the microbial growth data, and then secondary models are fitted to the primary model parameters to represent their dependence with the environmental variables (e.g., temperature). The Optimal Experimental Design (OED) approach allows reducing the experimental workload and costs, and the improvement of model identifiability because primary and secondary models are fitted simultaneously from non-isothermal data. Lactobacillus viridescens was selected to this study because it is a lactic acid bacterium of great interest to meat products preservation. The objectives of this study were to estimate the growth parameters of L. viridescens in culture medium from TSM and OED approaches and to evaluate both the number of experimental data and the time needed in each approach and the confidence intervals of the model parameters. Experimental data for estimating the model parameters with TSM approach were obtained at six temperatures (total experimental time of 3540h and 196 experimental data of microbial growth). Data for OED approach were obtained from four optimal non-isothermal profiles (total experimental time of 588h and 60 experimental data of microbial growth), two profiles with increasing temperatures (IT) and two with decreasing temperatures (DT). The Baranyi and Roberts primary model and the square root secondary model were used to describe the microbial growth, in which the parameters b and Tmin (±95% confidence interval) were estimated from the experimental data. The parameters obtained from TSM approach were b=0.0290 (±0.0020) [1/(h(0.5)°C)] and Tmin=-1.33 (±1.26) [°C], with R(2)=0.986 and RMSE=0.581, and the parameters obtained with the OED approach were b=0.0316 (±0.0013) [1/(h(0.5)°C)] and Tmin=-0.24 (±0.55) [°C], with R(2)=0.990 and RMSE=0.436. The parameters obtained from OED approach

  2. Kinematic parameters that influence the aesthetic perception of beauty in contemporary dance.

    Science.gov (United States)

    Torrents, Carlota; Castañer, Marta; Jofre, Toni; Morey, Gaspar; Reverter, Ferran

    2013-01-01

    Some experiments have stablished that certain kinematic parameters can influence the subjective aesthetic perception of the dance audience. Neave, McCarty, Freynik, Caplan, Hönekopp, and Fink (2010, Biology Letters 7 221-224) reported eleven movement parameters in non-expert male dancers, showing a significant positive correlation with perceived dance quality. We aim to identify some of the kinematic parameters of expert dancers' movements that influence the subjective aesthetic perception of observers in relation to specific skills of contemporary dance. Four experienced contemporary dancers performed three repetitions of four dance-related motor skills. Motion was captured by a VICON-MX system. The resulting 48 animations were viewed by 108 observers. The observers judged beauty using a semantic differential. The data were then subjected to multiple factor analysis. The results suggested that there were strong associations between higher beauty scores and certain kinematic parameters, especially those related to amplitude of movement.

  3. Using GA-Ridge regression to select hydro-geological parameters influencing groundwater pollution vulnerability.

    Science.gov (United States)

    Ahn, Jae Joon; Kim, Young Min; Yoo, Keunje; Park, Joonhong; Oh, Kyong Joo

    2012-11-01

    For groundwater conservation and management, it is important to accurately assess groundwater pollution vulnerability. This study proposed an integrated model using ridge regression and a genetic algorithm (GA) to effectively select the major hydro-geological parameters influencing groundwater pollution vulnerability in an aquifer. The GA-Ridge regression method determined that depth to water, net recharge, topography, and the impact of vadose zone media were the hydro-geological parameters that influenced trichloroethene pollution vulnerability in a Korean aquifer. When using these selected hydro-geological parameters, the accuracy was improved for various statistical nonlinear and artificial intelligence (AI) techniques, such as multinomial logistic regression, decision trees, artificial neural networks, and case-based reasoning. These results provide a proof of concept that the GA-Ridge regression is effective at determining influential hydro-geological parameters for the pollution vulnerability of an aquifer, and in turn, improves the AI performance in assessing groundwater pollution vulnerability.

  4. The Influence of Thermal Spray Process Technological Parameters on the Properties of Coatings

    Directory of Open Access Journals (Sweden)

    Aleksandr Lebedev

    2017-01-01

    Full Text Available The article deals with the plasma sprayed Ni-based coating on aluminum alloy substrates. Before spraying, the surfaces of substrates were modified employing sandblasting and its combination with preheating. The coatings were sprayed under variation of spray process parameters. The study involves coating microstructure, porosity and adhesion tests. The influence of spray parameters and substrate pre-treatment on the properties of coating were evaluated.

  5. Gimbal Influence on the Stability of Exterior Orientation Parameters of UAV Acquired Images

    OpenAIRE

    Mateo Gašparović; Luka Jurjević

    2017-01-01

    In this paper, results from the analysis of the gimbal impact on the determination of the camera exterior orientation parameters of an Unmanned Aerial Vehicle (UAV) are presented and interpreted. Additionally, a new approach and methodology for testing the influence of gimbals on the exterior orientation parameters of UAV acquired images is presented. The main motive of this study is to examine the possibility of obtaining better geometry and favorable spatial bundles of rays of images in UAV...

  6. Influence of geometrical parameters of the VVER-1000 reactor construction elements to internals irradiation conditions

    Directory of Open Access Journals (Sweden)

    О. M. Pugach

    2015-07-01

    Full Text Available Investigations to determine the influences of geometrical parameters of the calculational VVER-1000 reactor model to the results of internal irradiation condition determination are carried out. It is shown that the values of appropriate sensitivity matrix elements are not dependent on a height coordinate for any core level, but there is their azimuthal dependence. Maximum possible relative biases of neutron fluence due to inexact knowledge of internal geometrical parameters are obtained for the baffle and the barrel.

  7. Use of Hoy's solubility parameters to predict water sorption/solubility of experimental primers and adhesives.

    Science.gov (United States)

    Nishitani, Yoshihiro; Yoshiyama, Masahiro; Hosaka, Keiichi; Tagami, Junji; Donnelly, Adam; Carrilho, Marcela; Tay, Franklin R; Pashley, David H

    2007-02-01

    Self-etching primers and adhesives contain very hydrophilic acidic monomers that result in high water sorption/solubilities of their polymers. However, the chemical composition of these products varies widely. The purpose of this work was to vary the chemical composition of experimental self-etching primers and adhesives to determine if the water sorption/solubility of the polymers were affected in a predictable manner. The Hoy's solubility parameters of these mixtures were calculated to permit ranking of the degree of hydrophilicity of the polymers. Water sorption/solubility was measured according to ISO 4049. The results showed highly significant (R(2) = 0.86, P solubility parameter for polar forces (delta(p)) of the polymers. Similar correlations were obtained between polymer solubility and delta(p). When these results were compared with previously published results obtained with more hydrophobic resins, excellent correlations were obtained, indicating that Hoy's delta(p) values may be used to predict the water sorption behavior of methylmethacrylate polymers.

  8. Experimental Active Vibration Control in Truss Structures Considering Uncertainties in System Parameters

    Directory of Open Access Journals (Sweden)

    Douglas Domingues Bueno

    2008-01-01

    Full Text Available This paper deals with the study of algorithms for robust active vibration control in flexible structures considering uncertainties in system parameters. It became an area of enormous interest, mainly due to the countless demands of optimal performance in mechanical systems as aircraft, aerospace, and automotive structures. An important and difficult problem for designing active vibration control is to get a representative dynamic model. Generally, this model can be obtained using finite element method (FEM or an identification method using experimental data. Actuators and sensors may affect the dynamics properties of the structure, for instance, electromechanical coupling of piezoelectric material must be considered in FEM formulation for flexible and lightly damping structure. The nonlinearities and uncertainties involved in these structures make it a difficult task, mainly for complex structures as spatial truss structures. On the other hand, by using an identification method, it is possible to obtain the dynamic model represented through a state space realization considering this coupling. This paper proposes an experimental methodology for vibration control in a 3D truss structure using PZT wafer stacks and a robust control algorithm solved by linear matrix inequalities.

  9. INFECTIOUS PATHOLOGY OF MOTHER AND ITS INFLUENCE ON THE ANTHROPOMETRIC PARAMETERS OF NEWBORNS

    Directory of Open Access Journals (Sweden)

    Markovsky V. D.

    2014-01-01

    Full Text Available The presence in pregnant woman foci of latent, chronic infection of any localization is an important cause of various complications during pregnancy, childbirth, a wide range of perinatal pathology. The purpose of this study was to reveal the influence of mother infectious diseases on the anthropometric parameters of newborns. The authors set up an experiment on WAG rats on modeling subacute (prolonged peritonitis in females in order to study the influence of this infectiousinflammatory process in the organism of mother on the anthropometric parameters of newborns. The study found that the presence of infectious-inflammatory diseases in mother is not always leads to inflammatory changes in the placenta, but involutive- degenerative and dyscirculatory changes are taking place in all cases. In newborns from mothers with infectious pathology revealed significantly reduced anthropometric parameters in comparison with newborns from healthy mothers. Anthropometric parameters of newborns from mothers with infectious pathology depend on the infective dose (the higher the dose of agent, the less neonatal anthropometric parameters. Negative influence of infectious extragenital pathology of mother on newborn anthropometric parameters requires improving the quality of pregravidal training aimed at early detection and sanitation of foci of infection.

  10. Experimental Investigation of Process Parameters in Drilling LM25 Composites Coated with Multi Wall Carbon Nano Tubes Using Sonication Process

    Directory of Open Access Journals (Sweden)

    Sangeetha M.

    2017-09-01

    Full Text Available Aluminium based metal matrix composites are widely used in automobile components such as cardan shaft of Chevrolet corvette, disc brake and engine push rod. In this experiment a Hybrid Metal Matrix Composites (HMMC are fabricated and drilled. Drilling is the process of making slots in disc brake and thread in the engine parts. The surface quality of the drilled specimen depends on the speed, feed, drill type and the thrust force. Thrust force plays the major role in drilling the specimen. In this experiment HMMCs are fabricated using two processes-called, sonication and casting. Sonication is the process of coating the carbon nanotubes over the silicon carbide particles (SiCp. Semisolid stir casting is used to reinforce the coated SiCp in the LM 25 alloy. A drilling process is performed on HMMC to analyse the extent to which the input parameters influence the thrust force and Ovality. The tools used for drilling are solid carbide tools of three different diameters. Taguchi’s experimental design is adopted for the drilling operation. A mathematical model is used to determine the influence of input parameters on the outputs thrust force and ovality. This paper proves the combination of N3, f1 and d1 of the carbide tool results in the lowest value of thrust force and ovality while drilling HMMCs. In this work the HMMC is prepared by coating the abrasive nature, silicon carbide particle and there is a good interfacial bonding between the reinforced particle and matrix and the drilling process becomes smoother. The new being of this article is the treated ceramics, SiCp with carbon nanotubes. This HMMC shows the improved mechanical properties compared to other metal matrix composites surveyed in the literatures.

  11. Isometric force production parameters during normal and experimental low back pain conditions

    Directory of Open Access Journals (Sweden)

    Blouin Jean-Sébastien

    2005-02-01

    Full Text Available Abstract Background The control of force and its between-trial variability are often taken as critical determinants of motor performance. Subjects performed isometric trunk flexion and extension forces without and with experiment pain to examine if pain yields changes in the control of trunk forces. The objective of this study is to determine if experimental low back pain modifies trunk isometric force production. Methods Ten control subjects participated in this study. They were required to exert 50 and 75% of their isometric maximal trunk flexion and extension torque. In a learning phase preceding the non painful and painful trials, visual and verbal feedbacks were provided. Then, subjects were asked to perform 10 trials without any feedback. Time to peak torque, time to peak torque variability, peak torque variability as well as constant and absolute error in peak torque were calculated. Time to peak and peak dF/dt were computed to determine if the first peak of dF/dt could predict the peak torque achieved. Results Absolute and constant errors were higher in the presence of a painful electrical stimulation. Furthermore, peak torque variability for the higher level of force was increased with in the presence of experimental pain. The linear regressions between peak dF/dt, time to peak dF/dt and peak torque were similar for both conditions. Experimental low back pain yielded increased absolute and constant errors as well as a greater peak torque variability for the higher levels of force. The control strategy, however, remained the same between the non painful and painful condition. Cutaneous pain affects some isometric force production parameters but modifications of motor control strategies are not implemented spontaneously. Conclusions It is hypothesized that adaptation of motor strategies to low back pain is implemented gradually over time. This would enable LBP patients to perform their daily tasks with presumably less pain and more

  12. Gait parameters database for young children: The influences of age and walking speed

    OpenAIRE

    Van Hamme, Angèle; El Habachi, Aimad; SAMSON, William; Dumas, Raphaël; Cheze, Laurence; DOHIN, Bruno

    2015-01-01

    Background. Reference databases are mandatory in orthopaedics because they enable the detection of gait abnormalities in patients. Such databases rarely include data on children under seven years of age. In young children, gait is principally influenced by age and walking speed. The influence of the age-speed interaction has not been well established. Therefore, the objective of the present study is to propose normative values for biomechanical gait parameters in children taking into account ...

  13. Laser Treatment of Wood Surfaces for Ski Cores: An Experimental Parameter Study

    Directory of Open Access Journals (Sweden)

    Alexander Petutschnigg

    2013-01-01

    Full Text Available Recently, the production of skis with wooden cores has increased due to changes in customer awareness concerning ecological issues and rising raw material costs for mineral oil resources. The preparation of ski surfaces is one of the main expense factors in the production of skis. Thus, one perspective of the AMER SPORTS CORPORATION is to treat wood surfaces with laser beams to develop new aesthetic possibilities in ski design. This study deals with different laser treatments for samples from various wood species: beech, ash, lime, and spruce. The parameters investigated are laser beam intensity and number of laser points on the surface. To evaluate the aesthetic changes, the CIELab color measurements were applied. Changes in the main wood components were observed by the Fourier transform infrared spectroscopy (FTIR using an ATR (attenuated total reflectance unit. The results show that the laser treatments on wood surfaces have an influence on wood color and the chemical composition. Especially the intensity of laser beams affects the color changes in different patterns for the parameters observed. These findings will be useful to develop innovative design possibilities of wood surfaces for ski cores as well as for further product design applications (e.g., mass customization.

  14. Experimental Investigation and Optimization of TIG Welding Parameters on Aluminum 6061 Alloy Using Firefly Algorithm

    Science.gov (United States)

    Kumar, Rishi; Mevada, N. Ramesh; Rathore, Santosh; Agarwal, Nitin; Rajput, Vinod; Sinh Barad, AjayPal

    2017-08-01

    To improve Welding quality of aluminum (Al) plate, the TIG Welding system has been prepared, by which Welding current, Shielding gas flow rate and Current polarity can be controlled during Welding process. In the present work, an attempt has been made to study the effect of Welding current, current polarity, and shielding gas flow rate on the tensile strength of the weld joint. Based on the number of parameters and their levels, the Response Surface Methodology technique has been selected as the Design of Experiment. For understanding the influence of input parameters on Ultimate tensile strength of weldment, ANOVA analysis has been carried out. Also to describe and optimize TIG Welding using a new metaheuristic Nature - inspired algorithm which is called as Firefly algorithm which was developed by Dr. Xin-She Yang at Cambridge University in 2007. A general formulation of firefly algorithm is presented together with an analytical, mathematical modeling to optimize the TIG Welding process by a single equivalent objective function.

  15. EXPERIMENTAL DETERMINATION OF PARAMETERS OF THE LAW GOVERNING DISTRIBUTION OF TIME PROBABILITIES BY PRECISE OPERATION OF AN ELECTRONIC APPARATUS,

    Science.gov (United States)

    For experimental determination of parameters of the law of time probability distribution of correct operation the demarcation of failures by causes...shows practically no effect on reliability. Parameters of the law of probabilities distribution, determined by numerical values of dispersion and

  16. Experimental and numerical investigations of oscillations in extracted material parameters for finite Bragg stacks using the NRW method

    DEFF Research Database (Denmark)

    Clausen, Niels Christian Jerichau; Arslanagic, Samel; Breinbjerg, Olav

    2012-01-01

    A 1D dielectric finite Bragg stack situated in a rectangular waveguide and illuminated by the fundamental TE10 mode is examined analytically, numerically, and experimentally. Calculated as well as measured scattering parameters are used to extract the effective/equivalent material parameters for ...

  17. The influence of sensor and flight parameters on texture in radar images

    Science.gov (United States)

    Frost, V. S.; Shanmugan, K. S.; Holtzman, J. C.

    1984-01-01

    Texture is known to be important in the analysis of radar images for geologic applications. It has previously been shown that texture features derived from the grey level co-occurrence matrix (GLCM) can be used to separate large scale texture in radar images. Here the influence of sensor parameters, specifically the spatial and radiometric resolution and flight parameters, i.e., the orientation of the surface structure relative to the sensor, on the ability to classify texture based on the GLCM features is investigated. It was found that changing these sensor and flight parameters greatly affects the usefulness of the GLCM for classifying texture on radar images.

  18. Experimental investigation of the influence of blade height and blade number on the performance of low head axial flow turbines

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Punit; Nestmann, Franz [Institute for Water and River Basin Management (IWG), University of Karlsruhe, Kaiser Str. 12, D 76128, Karlsruhe (Germany)

    2011-01-15

    Investigations regarding the influence of design parameters in low head axial flow turbines like blade profiles, blade height and blade number for micro-hydro application continue to be inadequate, even though there is a need and potential for the application of such turbines. This inadequacy provides a good ground to make a detailed experimental study to characterize these influences. The paper presents a holistic theoretical model that attempts to bring out a functionality of the internal performance parameters of the runner and attempts to establish a physical relationship between the two design parameters (blade height and blade number) and the performance parameters. The experimental results on 3 runners showed that with an increase in the number of blades, the efficiency of the runner dropped drastically due to the change in direction of the relative flow vector at the runner exit, which decreased the net rotational momentum and increased the axial flow velocity. The decrease of blade height on the other hand decreased the overall runner loss coefficient quite drastically but this could not result in major performance gains. The study concluded that the influence of blade number is more dominating compared to that of the blade height and that choice of blade number should be carefully made. On the hydraulic level, the study found interesting effects like the slip phenomenon and loss mechanisms within the runner. The paper also looks into the possible errors within the theoretical model developed and the extent of their influence on the conclusions. The paper suggests more experimental studies to separately study the effects of blade number and blade height. It further makes a strong case to initiate a computational work to validate all the experimental findings, fill the gaps in the theoretical model and use it as an optimization and standardization tool for axial flow turbines in the specialized application of micro-hydro. (author)

  19. The Numerical Calculation and Experimental Measurement of the Inductance Parameters for Permanent Magnet Synchronous Motor in Electric Vehicle

    Science.gov (United States)

    Jiang, Chao; Qiao, Mingzhong; Zhu, Peng

    2017-12-01

    A permanent magnet synchronous motor with radial magnetic circuit and built-in permanent magnet is designed for the electric vehicle. Finite element numerical calculation and experimental measurement are adopted to obtain the direct axis and quadrature axis inductance parameters of the motor which are vital important for the motor control. The calculation method is simple, the measuring principle is clear, the results of numerical calculation and experimental measurement are mutual confirmation. A quick and effective method is provided to obtain the direct axis and quadrature axis inductance parameters of the motor, and then improve the design of motor or adjust the control parameters of the motor controller.

  20. Permeability of concrete under thermal and compressive stress influence; an experimental study

    Directory of Open Access Journals (Sweden)

    Lun H.

    2013-09-01

    Full Text Available In recent years the permeability was found as one of the main parameters affecting the durability of concrete. Especially in concrete at high temperatures in case of fire loading, the interaction of thermal/mechanical loading and fluid transfer strongly influences degradation of mechanical properties within concrete and spalling of near-surface concrete layers. To understand the change in transport properties of concrete, a new experimental setup was developed, allowing us to conduct permeability tests under uniaxial compressive loading up to 20 MPa and thermal condition up to 350 °C. Based on the obtained results, the effect of both mechanical and thermal loading on the effective transport properties is highlighted and relations to more simplified test setups, disregarding mechanical loading and/or conducting the permeability test at room temperature giving the residual permeability, are established.

  1. Influence of process parameters on the weld lines of a micro injection molded component

    DEFF Research Database (Denmark)

    Tosello, Guido; Gava, Alberto; Hansen, Hans Nørgaard

    2007-01-01

    The insufficient entanglement of the molecular chains and the stress amplification at the v-notch of a weld line compromise the mechanical strength of a plastic product, also in the micro scale. To investigate the influence of process parameters on the weld lines formation, a special micro cavity...... by mold temperature and injection speed....

  2. Influence of design and mode parameters on pump performance curve of heat generating aggregate

    Science.gov (United States)

    Barykin, O.; Kovalyov, S.; Ovcharenko, M.; Papchenko, A.

    2017-08-01

    Classification of multi-functional heat generating aggregates according to the function is considered in this article. Analysis of operating process mathematical model was implemented and methods for its refinement were proposed. Results of physical investigation of heat generating aggregate design and mode parameters influence on its power and head were presented.

  3. Application of grey system theory on the influencing parameters of aerobic granulation in SBR.

    Science.gov (United States)

    Bindhu, B K; Madhu, G

    2017-09-01

    Aerobic granulation is a promising technology for wastewater treatment. Four operational parameters were selected as influencing factors for this study. Aerobic granulation was experimented with three different values of organic loading rate (3, 6 and 9 kg COD m-3 d-1), superficial upflow air velocity (SUAV) (2, 3 and 4 cm s-1), settling time (3, 5 and 10 min) and volume exchange ratio (25%, 50% and 75%) in sequencing batch reactor in nine trials for the optimal performance of aerobic granulation. The influence of compared parameters on five reference parameters (sludge volume index (SVI), time taken for the appearance of granules, size and specific gravity of granules and chemical oxygen demand (COD) removal) was analyzed using grey system theory. The grey relational coefficients and grey entropy relational grade of each parameter were calculated. Hydrodynamic shear force in terms of SUAV was found to have the greatest influence on granule appearance, specific gravity of granules and COD removal efficiency. SVI is greatly affected by settling time. The optimal scopes of all the compared parameters were found.

  4. The influence of arc plasma parameters on the form of a welding pool

    Science.gov (United States)

    Frolov, V. Ya.; Toropchin, A. I.

    2015-07-01

    The influence of the Marangoni force on the form of a welding pool has been considered. Results of computer simulation of the processes of welding arc generation with a non-consumable tungsten electrode in inert gas are shown. The experimental results are reported and comparatively analyzed. The calculations were carried out in a package of applied programs at various currents.

  5. Hot cracking during laser welding of steel: influence of the welding parameters and prevention of cracks

    Science.gov (United States)

    Schaefer, Marcel; Kessler, Steffen; Scheible, Philipp; Speker, Nicolai; Harrer, Thomas

    2017-02-01

    In continuous wave keyhole-mode laser welding of high strength steel alloys hot cracking can occur. The hot crack susceptibility depends on the mutual interaction of several factors like the welding parameters, the alloy composition and the weld fixturing. In this paper we focus on the influence of the welding parameters and investigate the dependency of the laser power, the welding speed and the laser wavelength on the crack formation. X-ray images are used to visualize the hot crack patterns, which exhibit a pronounced periodicity. To influence the hot crack formation, the incident energy input into the process was adapted. For specific welding parameters, we show exemplarily the prevention of hot cracking by the use of a twin-spot optics.

  6. The influence of terminal substituents of diphenylbutadiene on the parameters of intra- and intermolecular interactions

    Science.gov (United States)

    Kompaneets, V. V.; Vasil'eva, I. A.

    2017-04-01

    We have analyzed the parameters of the Franck-Condon and Herzberg-Teller interactions, which form the fine-structure spectra of diphenylbutadiene substituted derivatives with the general formula X-Ph-(C=C)2-Ph-Y (where X, Y = H, NO2, N(CH3)2, and NH2 are the substituents in different combinations) in solutions of n-paraffins at 4.2 K. The influence of substituents on the vibronic parameters of characteristic bands that describe the states (vibrations, types of deformations upon excitation) of the phenyl rings and diphenylbutadiene polyene bridge has been considered. Data on the influence of the H, NO2, N(CH3)2, or NH2 terminal fragment on the parameters of the intra- and intermolecular interactions of diphenylbutadiene substituted derivatives have been presented.

  7. Accidental release of toxic chemicals: influence of the main input parameters on consequence calculation.

    Science.gov (United States)

    Bubbico, Roberto; Mazzarotta, Barbara

    2008-03-01

    In the present paper the accidental release of toxic chemicals has been taken into consideration, and a sensitivity analysis study of the corresponding consequences calculation has been carried out. Four different toxic chemicals have been chosen for the simulations, and the effect of the variability of the main input parameters on the extension of the impact areas has been assessed. The results show that the influence of these parameters depends on the physical properties of the released substance and that not always the widely known rules of thumb, such as the positive influence of the wind velocity on gas dispersion, apply. In particular, the boiling temperature of the chemical has revealed to be the main parameter affecting the type of dependence of the impact distances on the input variables.

  8. Influence of novel gallium complexes on the homeostasis of some biochemical and hematological parameters in rats.

    Science.gov (United States)

    Gârban, Gabriela; Silaghi-Dumitrescu, Radu; Ioniţă, Hortensia; Gârban, Zeno; Hădărugă, Nicoleta-Gabriela; Ghibu, George-Daniel; Baltă, Cornel; Simiz, Florin-Dan; Mitar, Carmen

    2013-12-01

    The aim of this study was to detect possible homeostasis changes in some biochemical and hematological parameters after the administration of gallium (Ga) complexes C (24) and C (85) on an experimental animal model (Wistar strain rats). In order to observe chronobiological aspects, a morning (m) and an evening (e) animal series were constituted. Further on, each series were divided into three groups: control (C), experimental I (EI), and experimental II (EII). Both Ga complexes were solubilized in a carrier solution containing polyethylene glycol (PEG) 400, water, and ethanol. Animals of the C groups received the carrier solution by intraperitoneal injection, those from the EI groups received the solubilized C(24) gallium complex, and those of the EII groups received the solubilized C(85) gallium complex. At the end of the experiment, blood and tissue samples were taken and the following parameters were determined: serum concentration of the nonprotein nitrogenous compounds (uric acid, creatinine, and blood urea nitrogen), hematological parameters (erythrocytes, hemoglobin, leukocytes, and platelets), and the kidney tissue concentration of three essential trace elements (Fe, Cu, and Zn). With the exception of uric acid, the results revealed increased concentrations of the nonprotein nitrogenous compounds both in the morning and in the evening experimental groups. Hematological data showed increased levels of erythrocytes, hemoglobin, and leukocytes and decreased platelet levels in the experimental group given the C(24) gallium complex in the morning (EI-m) group; increased levels of leukocytes and decreased levels of the other parameters in the experimental group given the C(24) gallium complex in the evening (EI-e) group; and increased levels of all hematological parameters in the experimental groups receiving the C(85) gallium complex in the morning (EII-m) group and in the evening (EII-e) group. Decreased kidney tissue concentrations of metals were found in all

  9. Influence of Choice of Null Network on Small-World Parameters of Structural Correlation Networks

    Science.gov (United States)

    Hosseini, S. M. Hadi; Kesler, Shelli R.

    2013-01-01

    In recent years, coordinated variations in brain morphology (e.g., volume, thickness) have been employed as a measure of structural association between brain regions to infer large-scale structural correlation networks. Recent evidence suggests that brain networks constructed in this manner are inherently more clustered than random networks of the same size and degree. Thus, null networks constructed by randomizing topology are not a good choice for benchmarking small-world parameters of these networks. In the present report, we investigated the influence of choice of null networks on small-world parameters of gray matter correlation networks in healthy individuals and survivors of acute lymphoblastic leukemia. Three types of null networks were studied: 1) networks constructed by topology randomization (TOP), 2) networks matched to the distributional properties of the observed covariance matrix (HQS), and 3) networks generated from correlation of randomized input data (COR). The results revealed that the choice of null network not only influences the estimated small-world parameters, it also influences the results of between-group differences in small-world parameters. In addition, at higher network densities, the choice of null network influences the direction of group differences in network measures. Our data suggest that the choice of null network is quite crucial for interpretation of group differences in small-world parameters of structural correlation networks. We argue that none of the available null models is perfect for estimation of small-world parameters for correlation networks and the relative strengths and weaknesses of the selected model should be carefully considered with respect to obtained network measures. PMID:23840672

  10. Influence of process and system parameters on the local oxidation of alkyl-terminated silicon

    Energy Technology Data Exchange (ETDEWEB)

    Baumgaertel, Thomas; Graaf, Harald; Borczyskowski, Christian von [Center for Nanostructured Materials and Analytics, Institut fuer Physik, TU Chemnitz, 09107 Chemnitz (Germany)

    2011-07-01

    The local anodic oxidation (LAO) of silicon substrates by an atomic force microscope (AFM) is an electrochemical process which is influenced by multiple parameters. These can be divided into two major groups: system parameters and process parameters. Process parameters such as oxidation voltage, duration and ambient humidity can be tuned over a wide range of values during the experiment. System parameters on the other hand depend on equipment and materials themselves and are only difficult to control e.g. AFM tip shape, substrate conductivity and surface hydrophobicity. We investigated the influence of these parameters on the LAO process of silicon which is passivated by a self-assembled alkyl monolayer. Such monolayers are not only characterized by high molecular order and an excellent physical and chemical stability but offer also a neat way to tune the surface properties by variation of the head groups of the alkenes. A detailed understanding of the dependencies of the LAO process is essential for the controlled generation of silicon oxide nanostructures which can be used to build up functional nanostructures by a combined bottom-up (anchoring of functional molecules) and top-down (AFM LAO lithography) approach.

  11. Influence of Impeller Geometry on the Unsteady Flow in a Centrifugal Fan: Numerical and Experimental Analyses

    Directory of Open Access Journals (Sweden)

    M. Younsi

    2007-01-01

    Full Text Available The aim of this study is to evaluate the influence of design parameters on the unsteady flow in a forward-curved centrifugal fan and their impact on the aeroacoustic behavior. To do so, numerical and experimental studies have been carried out on four centrifugal impellers designed with various geometrical parameters. The same volute casing has been used to study these impellers. The effects on the unsteady flow behavior related to irregular blade spacing, blade count and radial distance between the impeller periphery and the volute tongue have been studied. The numerical simulations of the unsteady flow have been carried out using computational fluid dynamics (CFD tools based on the unsteady Reynolds averaged Navier Stokes (URANS approach. The study is focused on the unsteadiness induced by the aerodynamic interaction between the volute and the rotating impeller blades. In order to predict the acoustic pressure at far field, the unsteady flow variables provided by the CFD calculations have been used as inputs in the Ffowcs Williams-Hawkings equations (FW-H. The experimental part of this work concerns measurement of aerodynamic performance of the fans using a test bench built according to ISO 5801 (1997 standard. In addition to this, pressure microphones have been flush mounted on the volute tongue surface in order to measure the wall pressure fluctuations. The sound pressure level (SPL measurements have been carried out in an anechoic room in order to remove undesired noise reflections. Finally, the numerical results have been compared with the experimental measurements and a correlation between the wall pressure fluctuations and the far field noise signals has been found.

  12. Building an experimental model of the human body with non-physiological parameters.

    Science.gov (United States)

    Labuz, Joseph M; Moraes, Christopher; Mertz, David R; Leung, Brendan M; Takayama, Shuichi

    2017-03-01

    New advances in engineering and biomedical technology have enabled recent efforts to capture essential aspects of human physiology in microscale, in-vitro systems. The application of these advances to experimentally model complex processes in an integrated platform - commonly called a 'human-on-a-chip (HOC)' - requires that relevant compartments and parameters be sized correctly relative to each other and to the system as a whole. Empirical observation, theoretical treatments of resource distribution systems and natural experiments can all be used to inform rational design of such a system, but technical and fundamental challenges (e.g. small system blood volumes and context-dependent cell metabolism, respectively) pose substantial, unaddressed obstacles. Here, we put forth two fundamental principles for HOC design: inducing in-vivo-like cellular metabolic rates is necessary and may be accomplished in-vitro by limiting O2 availability and that the effects of increased blood volumes on drug concentration can be mitigated through pharmacokinetics-based treatments of solute distribution. Combining these principles with natural observation and engineering workarounds, we derive a complete set of design criteria for a practically realizable, physiologically faithful, five-organ millionth-scale (× 10-6) microfluidic model of the human body.

  13. [Spectrum diagnostics for optimization of experimental parameters in thin films deposited by magnetron sputtering].

    Science.gov (United States)

    Guo, Qing-Lin; Cui, Yong-Liang; Chen, Jian-Hui; Zhang, Jin-Ping; Huai, Su-Fang; Liu, Bao-Ting; Chen, Jin-Zhong

    2010-12-01

    The plasma emission spectra generated during the deposition process of Si-based thin films by radio frequency (RF) magnetron sputtering using Cu and Al targets in an argon atmosphere were acquired by the plasma analysis system, which consists of a magnetron sputtering apparatus, an Omni-lambda300 series grating spectrometer, a CCD data acquisition system and an optical fiber transmission system. The variation in Cu and Al plasma emission spectra intensity depending on sputtering conditions, such as sputtering time, sputtering power, the target-to-substrate distance and deposition pressure, was studied by using the analysis lines Cu I 324. 754 nm, Cu I 327. 396 nm, Cu I 333. 784 nm, Cu I 353. 039 nm, Al I 394. 403 nm and Al I 396. 153 nm. Compared with the option of experimental parameters of thin films deposited by RF magnetron sputtering, it was shown that emission spectra analysis methods play a guiding role in optimizing the deposition conditions of thin films in RF magnetron sputtering.

  14. Experimental Investigation into the Effect of Ball End Milling Parameters on Surface Integrity of Inconel 718

    Science.gov (United States)

    Bhopale, Nandkumar N.; Joshi, Suhas S.; Pawade, Raju S.

    2015-02-01

    In machining of Inconel 718, various difficulties such as increased tool wear and poor machined surface quality are frequently encountered due to its high temperature strength and poor thermal properties. This work considers the effect of number of passes and the machining environment on the machined surface quality in ball end milling of Inconel 718, which hitherto has not been adequately understood. To this effect, extensive experimentation has been carried out to analyze machined surface quality and integrity in terms of surface roughness, surface damage, and microhardness variation in the machined surfaces. The machined surfaces show formation of distinct bands as a function of instantaneous machining parameters along the periphery of cutting tool edge. A distinct variation is also observed in the measured values of surface roughness and microhardness in these regions. The minimum surface roughness is obtained in the stable cutting zone and it increases toward the periphery of the cutter on band #2 and band #3. Microhardness of depth beneath the machined surface shows that the machining affected zone varies from 60 to 100 µm in ball end milling under various machining conditions.

  15. Experimental studies on the effects of bolt parameters on the bearing characteristics of reinforced rock.

    Science.gov (United States)

    Cheng, Liang; Zhang, Yidong; Ji, Ming; Zhang, Kai; Zhang, Minglei

    2016-01-01

    Roadways supported by bolts contain support structures that are built into the rock surrounding the roadway, referred to as reinforced rocks in this paper. Using physical model simulation, the paper investigates the bearing characteristics of the reinforced rock under different bolt parameters with incrementally increased load. The experimental results show that the stress at the measurement point inside the structure varies with the kinetic pressure. The stress increases slowly as the load is initially applied, displays accelerated growth in the middle of the loading application, and decreases or remains constant in the later stage of the loading application. The change in displacement of the surrounding rock exhibits the following characteristics: a slow increase when the load is first applied, accelerated growth in the middle stage, and violent growth in the later stage. There is a good correlation between the change in the measured stress and the change in the surrounding rock displacement. Increasing the density of the bolt support and the length and diameter of the bolt improves the load-bearing performance of the reinforced rock, including its strength, internal peak stress, and residual stress. Bolting improves the internal structure of the surrounding rocks, and the deterioration of the surrounding rock decreases with the distance between the bolt supports.

  16. Drying of a tape-cast layer: Numerical investigation of influencing parameters

    DEFF Research Database (Denmark)

    Jabbaribehnam, Mirmasoud; Shojaee Nasirabadi, Parizad; Jambhekar, V. A.

    2017-01-01

    In this study, the evaporation of water from a ceramic-water mixture is investigated numerically with the purpose of understanding the drying process of the thin sheets produced by the tape casting process. In the scope of this work, a Representative Elementary Volume (REV) scale model concept...... for coupling non-isothermal multi-phase compositional porous-media flow and single-phase compositional laminar free-flow developed by Jabbari et al. (2016), is used for a thorough analysis of the influential parameters. Specifically, we investigate the influence of ventilation speed magnitude, vmax...... analysis based on numerical experiments in combination with a fractional factorial design of the aforementioned parameters. The analysis accounts for the effects of parameters on the characteristic drying curves of a thin ceramic layer. The effects of varying each of the parameters as well as their mutual...

  17. Influence of parameters detuning on induction motor NFO shaft-sensorless scheme

    Directory of Open Access Journals (Sweden)

    KULIC, F.

    2010-11-01

    Full Text Available In this paper, the parameter sensitivity analysis of shaft-sensorless induction motor drive with natural field orientation (NFO scheme is performed. NFO scheme calculates rotor flux position using the rotor flux vector reference only, does not require significant processor power and therefore it is suitable for low cost shaft sensorless drives. This concept also eliminates the need for sensitive stator voltage vector integration and it is usable in low rotor speed range. However, low speeds are coupled with low stator voltage amplitudes, which inflate the NFO scheme sensitivity to an error in stator resistance parameter. Similar problems can also take place if mutual inductance parameter is detuned, but this time in whole speed range. This paper investigates the influence of each parameter error on the NFO control steady state characteristics and dynamic performance.

  18. The influence of 3D kinematic and electromyographical parameters on cycling economy.

    Science.gov (United States)

    Sinclair, Jonathan; Hebron, Jack; Atkins, Stephen; Hurst, Howard; Taylor, Paul J

    2014-01-01

    Economy is considered to be a key factor for the determination of performance in endurance events such as cycling. There have been no investigations which have related cycling economy to simultaneous measurements of 3D kinematics and muscular activation. This study examined selected biomechanical and neuromuscular parameters which have the strongest association with cycling economy. Twenty-five trained cyclists (31.27 ± 3.19 years) completed steady state cycling time trials at a workload of 180 W. Simultaneous measurements of 3D kinematics and electromyographical parameters were obtained. Continuous measurements of expired gases were used to provide a measure of cycling economy. A multiple regression analysis showed that key parameters of peak knee extension velocity and mean activity of the rectus femoris muscles were significant predictors of VO2 during steady state cycling (P economy. As economy has been shown to influence aerobic performance, future work should focus on optimising these parameters to improve cycling economy.

  19. Coupled 1D-2D hydrodynamic inundation model for sewer overflow: Influence of modeling parameters

    Directory of Open Access Journals (Sweden)

    Adeniyi Ganiyu Adeogun

    2015-10-01

    Full Text Available This paper presents outcome of our investigation on the influence of modeling parameters on 1D-2D hydrodynamic inundation model for sewer overflow, developed through coupling of an existing 1D sewer network model (SWMM and 2D inundation model (BREZO. The 1D-2D hydrodynamic model was developed for the purpose of examining flood incidence due to surcharged water on overland surface. The investigation was carried out by performing sensitivity analysis on the developed model. For the sensitivity analysis, modeling parameters, such as mesh resolution Digital Elevation Model (DEM resolution and roughness were considered. The outcome of the study shows the model is sensitive to changes in these parameters. The performance of the model is significantly influenced, by the Manning's friction value, the DEM resolution and the area of the triangular mesh. Also, changes in the aforementioned modeling parameters influence the Flood characteristics, such as the inundation extent, the flow depth and the velocity across the model domain.

  20. Biobanking of Fresh-Frozen Human Adenocarcinomatous and Normal Colon Tissues: Which Parameters Influence RNA Quality?

    Directory of Open Access Journals (Sweden)

    Thibaut Galissier

    Full Text Available Medical research projects become increasingly dependent on biobanked tissue of high quality because the reliability of gene expression is affected by the quality of extracted RNA. Hence, the present study aimed to determine if clinical, surgical, histological, and molecular parameters influence RNA quality of normal and tumoral frozen colonic tissues. RNA Quality Index (RQI was evaluated on 241 adenocarcinomas and 115 matched normal frozen colon tissues collected between October 2006 and December 2012. RQI results were compared to patients' age and sex, tumor site, kind of surgery, anastomosis failure, adenocarcinoma type and grade, tumor cell percentage, necrosis extent, HIF-1α and cleaved caspase-3 immunohistochemistry, and BRAF, KRAS and microsatellites status. The RQI was significantly higher in colon cancer tissue than in matched normal tissue. RQI from left-sided colonic cancers was significantly higher than RQI from right-sided cancers. The RNA quality was not affected by ischemia and storage duration. According to histological control, 7.9% of the samples were unsatisfactory because of inadequate sampling. Biobanked tumoral tissues with RQI ≥5 had lower malignant cells to stromal cells ratio than samples with RQI <5 (p <0.05. Cellularity, necrosis extent and mucinous component did not influence RQI results. Cleaved caspase-3 and HIF-1α immunolabelling were not correlated to RQI. BRAF, KRAS and microsatellites molecular status did not influence RNA quality. Multivariate analysis revealed that the tumor location, the surgical approach (laparoscopy versus open colectomy and the occurrence of anastomotic leakage were the only parameters influencing significantly RQI results of tumor samples. We failed to identify parameter influencing RQI of normal colon samples. These data suggest that RNA quality of colonic adenocarcinoma biospecimens is determined by clinical and surgical parameters. More attention should be paid during the biobanking

  1. An experimental hut study to quantify the effect of DDT and airborne pyrethroids on entomological parameters of malaria transmission

    Science.gov (United States)

    2014-01-01

    Background Current malaria vector control programmes rely on insecticides with rapid contact toxicity. However, spatial repellents can also be applied to reduce man-vector contact, which might ultimately impact malaria transmission. The aim of this study was to quantify effects of airborne pyrethroids from coils and DDT used an indoor residual spray (IRS) on entomological parameters that influence malaria transmission. Methods The effect of Transfluthrin and Metofluthrin coils compared to DDT on house entry, exit and indoor feeding behaviour of Anopheles gambiae sensu lato were measured in experimental huts in the field and in the semi-field. Outcomes were deterrence - reduction in house entry of mosquitoes; irritancy or excito-repellency – induced premature exit of mosquitoes; blood feeding inhibition and effect on mosquito fecundity. Results Transfluthrin coils, Metofluthrin coils and DDT reduced human vector contact through deterrence by 38%, 30% and 8%, respectively and induced half of the mosquitoes to leave huts before feeding (56%, 55% and 48%, respectively). Almost all mosquitoes inside huts with Metofluthrin and Transfluthrin coils and more than three quarters of mosquitoes in the DDT hut did not feed, almost none laid eggs and 67%, 72% and 70% of all mosquitoes collected from Transfluthrin, Metofluthrin and DDT huts, respectively had died after 24 hours. Conclusion This study highlights that airborne pyrethroids and DDT affect a range of anopheline mosquito behaviours that are important parameters in malaria transmission, namely deterrence, irritancy/excito-repellency and blood-feeding inhibition. These effects are in addition to significant toxicity and reduced mosquito fecundity that affect mosquito densities and, therefore, provide community protection against diseases for both users and non-users. Airborne insecticides and freshly applied DDT had similar effects on deterrence, irritancy and feeding inhibition. Therefore, it is suggested that

  2. Gait parameters database for young children: The influences of age and walking speed.

    Science.gov (United States)

    Van Hamme, A; El Habachi, A; Samson, W; Dumas, R; Chèze, L; Dohin, B

    2015-07-01

    Reference databases are mandatory in orthopaedics because they enable the detection of gait abnormalities in patients. Such databases rarely include data on children under seven years of age. In young children, gait is principally influenced by age and walking speed. The influence of the age-speed interaction has not been well established. Therefore, the objective of the present study is to propose normative values for biomechanical gait parameters in children taking into account age, walking speed, and the age-speed interaction. Gait analyses were performed on 106 healthy children over a large age range (between one and seven years of age) during gait trials at a self-selected speed. From these gait cycles, biomechanical parameters, such as the joint angles and joint power of the lower limbs, were computed. Specific peak values and the times of occurrence of each biomechanical gait parameter were identified. Linear regressions are proposed for studying the influence of age, walking speed and the age-speed interaction. Most of the regressions achieved good accuracy in fitting the curve peaks and times of occurrence, and the normal reference targets of biomechanical parameters could be deduced from these regressions. The biomechanical gait parameters of a pathological case were plotted against the normal reference targets to illustrate the relevance of the proposed targeting method. The normal reference targets for biomechanical gait parameters based on age-speed regressions in a large database might help clinicians detect gait abnormalities in children from one to seven years of age. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Influence on muscle oxygenation to EMG parameters at different skeletal muscle contraction

    Science.gov (United States)

    Zhang, Li; Song, Gaoqing

    2010-02-01

    The purpose of this study is to investigate the influence of muscle oxygenation on EMG parameters during isometric and incremental exercises and to observe the relationship between EMG parameters and muscle oxygenation. Twelve rowers took part in the tests. Near infrared spectrometer was utilized for measurements of muscle oxygenation on lateral quadriceps. sEMG measurement is performed for EMG parameters during isometric and incremental exercises. Results indicated that Oxy-Hb decrease significantly correlated with IEMG, E/T ratio and frequency of impulse signal during 1/3 MVC and 2/3 MVC isometric exercise, and it is also correlated with IEMG, E/T ratio and frequency of impulse signal. Increase of IEMG occurred at the time after Oxy-Hb decrease during incremental exercise and highly correlated with BLa. It is concluded that no matter how heavy the intensity is, Oxy-Hb dissociation may play an important role in affecting EMG parameters of muscle fatigue during isometric exercise. 2) EMG parameters may be influenced by Oxy-Hb dissociation and blood lactate concentration during dynamic exercise.

  4. Evaluation of cyclone geometry and its influence on performance parameters by computational fluid dynamics (CFD

    Directory of Open Access Journals (Sweden)

    W. P. Martignoni

    2007-03-01

    Full Text Available Cyclone models have been used without relevant modifications for more than a century. Most of the attention has been focused on finding new methods to improve performance parameters. Recently, some studies were conducted to improve equipment performance by evaluating geometric effects on projects. In this work, the effect of cyclone geometry was studied through the creation of a symmetrical inlet and a volute scroll outlet section in an experimental cyclone and comparison to an ordinary single tangential inlet. The study was performed for gas-solid flow, based on an experimental study available in the literature, where a conventional cyclone model was used. Numerical experiments were performed by using CFX 5.7.1. The axial and tangential velocity components were evaluated using RSM and LES turbulence models. Results showed that these new designs can improve the cyclone performance parameters significantly and very interesting details were found on cyclone fluid dynamics properties using RSM and LES.

  5. Extraction of equivalent circuit parameters of solar cell: influence of temperature

    Science.gov (United States)

    Khalis, M.; Mir, Y.; Hemine, J.; Zazoui, M.

    2011-04-01

    A new method to evaluate the five parameters of illuminated solar cells is described. The method is based on nonlinear least squares approach. On calculating the lsqcurvefit-function with constraints, between the experimental current-voltage I(V) characteristic and a theoretical arbitrary characteristic based on Lambert W-function. The used model is implemented as a MATLAB® script which yields the I(V) characteristics of the LILT under test. The model has been validated against by applying it to experimental I(V) characteristics. Some parameters of the model have been measured directly whereas others have been evaluated by means of direct computation on the data sheet or by means of best-fit on the measured data. The results have been compared and an analysis of the errors is presented.

  6. Influence of the section size and holding time on the graphite parameters of ductile iron production

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    S. Bockus

    2009-01-01

    Full Text Available This work was conducted to establish the conditions required to produce a desirable structure of the castings of various section sizes. This investigation was focused on the study of the influence of cooling rate or section size and holding time on graphite parameters of the ductile iron. Plates having thickness between 3 and 50mm were cast in sand molds using the same melt. The present investigation has shown that the section size of ductile iron castings and holding time had strong effect on the graphite parameters of the castings.

  7. The influence of orlistat (Xenical therapy on the parameters of lipid metabolism in patients with obesity

    Directory of Open Access Journals (Sweden)

    N V Mazurina

    2009-06-01

    Full Text Available One of the main goals in treatment of obesity is descending of overall cardiometabolic risk, which is mostly defined by atherogenic changes in blood lipid spectrum. Scientific data, presented in this review confirm that orlistat is effective for treatment of obesity, its introduction significantly increases proportion of patients who reach clinically valuable results. The mechanism of action of orlistat explains its influence on parameters of blood lipids, which doesn't directly depend on the decrease of body mass during treatment. Improvement of cardiometabolic parameters during orlistsat treatment allows to consider this therapy as one of the methods for correction of dyslipidemia

  8. Influence Coefficients of Constructive Parameters of Meander Slow-Wave System with Additional Shields

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    Metlevskis Edvardas

    2016-12-01

    Full Text Available Constructions of meander slow-wave systems with additional shields grounded at different positions are presented. The construction of meander slow-wave systems with additional shields grounded at both edges is investigated in detail. The influence of the main constructive parameters on the electrical characteristics of meander slow-wave systems with additional shields grounded at both edges is evaluated. The main constructive parameters of the investigated system are: the length of the conductor, the width of meander conductor, the width of additional shield, and the width of the gap between adjacent meander conductors.

  9. Influence of the cutting parameters on the workpiece temperature during face milling

    Directory of Open Access Journals (Sweden)

    Nowakowski Lukasz

    2017-01-01

    Full Text Available This thesis presents the outcome of experimental research of the impact of changes in cutting speed and volume of material processed during a face milling process on the temperature of the processed object made of copper of M1Ez4 class. Measurement of the temperature of the processed object was conducted in six points with K-type thermocouples. The theoretical amount of released heat per unit of time for particular parameters of machining was also calculated.

  10. The reaction between iodine and silver under severe PWR accident conditions. An experimental parameter study

    Energy Technology Data Exchange (ETDEWEB)

    Funke, F.; Greger, G.U.; Bleier, A.; Hellmann, S.; Morell, W. [Siemens AG, Power Generation Group, Erlangen (Germany)

    1996-12-01

    An extensive experimental parameter study was performed on the kinetics in the reaction system I{sub 2}/Ag and I{sup -}/Ag in a laboratory-scale apparatus.Starting with I{sub 2} or I{sup -} solutions and silver powder suspensions, the decrease of soluted I{sub 2} or I{sup -}, respectively, due to fixation on the silver particles, was monitored as function of time using the radioactive tracer I-131. The measured data were analyzed using a model of first order kinetics with respect to the iodine concentration. However, the analysis using first order kinetics had to be performed separately in an early, fast reaction phase and in a late, slow reaction phase. The reason for this unexpected behaviour was not identified. Thus, rate constant, two for each test, were deduced from 14 I{sub 2}/Ag main tests and from 36 I{sup -}/Ag tests. No dependencies of the rate constants were found on the parameters temperature, initial iodine concentration, presence of boric acid, type of silver educt, and pretreatment of the silver educt prior to the tests. However, the stirring of the reaction solution generally enhanced the kinetics highlighting the importance of mass transfer. The I{sup -}/Ag reaction proceeded only if there was no inertization of the reaction solution by sparging with nitrogen. The temperature-independent rate constant for the early, fast I{sub 2}/Ag reaction phase is 2E-5 m/s. However, a smaller rate constant of 6E-6 m/s is recommended for use in source term calculations with IMPAIR, which already contains a first order model. Analogously, the temperature-independent I{sup -}/Ag reaction rate constant is 8E-6 m/s in an early, fast reaction phase. For use in source term calculations, a smaller rate constant of 2E-6 m/s is recommended. The lower bound of the I{sup -}/Ag rate constant was 3E-8 m/s which could be used in very conservative source term calculations. (author) 20 figs., 6 tabs., 15 refs.

  11. Electroacupuncture-Induced Attenuation of Experimental Epilepsy: A Comparative Evaluation of Acupoints and Stimulation Parameters

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    Xuezhi Kang

    2013-01-01

    Full Text Available The efficacy of electroacupuncture (EA on epilepsy remains to be verified because of previous controversies that might be due to the complexity of the effects induced by different acupoints and stimulation approaches adopted. Therefore, we investigated the effects of EA on epilepsy to determine the specific acupoints and optimal stimulation parameters in this work. Experimental epilepsy was induced by injecting kainic acid to the lateral cerebral ventricle of adult male SD rats. EA with a low-frequency (10 Hz/1 mA or high-frequency (100 Hz/1 mA current was applied to the epileptic model for 30 minutes starting at 0.5 hour after the injection. Four pairs of acupoints were tested, that is, Shuigou (DU26 + Dazhui (DU14, Jinsuo (DU8 + Yaoqi (EXB9, Neiguan (PC6 + Quchi (LI11, and Fenglong (ST40 + Yongquan (KI1. We found that (1 low- or high-frequency EA at different acupoints reduced epileptic seizures (P<0.05 versus the control with an exception of low-frequency EA at Neiguan (PC6 and Quchi (LI11; (2 low-frequency EA induced a better effect at Fenglong (ST40 plus Yongquan (KI1 than that of the other acupoints (P<0.05; (3 there is no significant difference in the effects of high-frequency EA at these acupoints; and (4 the high-frequency EA elicited a greater effect than that of low-frequency EA in all groups (P<0.05, with an exception at Jinsuo (DU8 + Yaoqi (EXB9. The EA-induced attenuation appeared 1–1.5 hours after EA with no appreciable effect in the first hour after EA in either the EEG or the behavioral tests. We conclude that EA attenuation of epileptic seizures is dependent on the stimulation parameters and acupoints and that the delay in appearance of the EA effect could be a reflection of the time required by the EA signal to regulate neural function in the central nervous system.

  12. Influence of process parameters on threshold voltage and leakage current in 18nm NMOS device

    Science.gov (United States)

    Atan, Norani Binti; Ahmad, Ibrahim Bin; Majlis, Burhanuddin Bin Yeop; Fauzi, Izzati Binti Ahmad

    2015-04-01

    The process parameters are very crucial factor in the development of transistors. There are many process parameters that influenced in the development of the transistors. In this research, we investigate the effects of the process parameters variation on response characteristics such as threshold voltage (VTH) and sub-threshold leakage current (IOFF) in 18nm NMOS device. The technique to identify semiconductor process parameters whose variability would impact most on the device characteristic is realized through the process by using Taguchi robust design method. This paper presents the process parameters that influenced in threshold voltage (VTH) and sub-threshold leakage current (IOFF) which includes the Halo Implantation, Compensation Implantation, Adjustment Threshold voltage Implantation and Source/Drain Implantation. The design, fabrication and characterization of 18nm HfO2/TiSi2 NMOS device is simulated and performed via a tool called Virtual Wafer Fabrication (VWF) Silvaco TCAD Tool known as ATHENA and ATLAS simulators. These two simulators were combined with Taguchi L9 Orthogonal method to aid in the design and the optimization of the process parameters to achieve the optimum average of threshold voltage (VTH) and sub-threshold leakage current, (IOFF) in 18nm device. Results from this research were obtained; where Halo Implantation dose was identified as one of the process parameter that has the strongest effect on the response characteristics. Whereby the Compensation Implantation dose was identified as an adjustment factor to get the nominal values of threshold voltage VTH, and sub-threshold leakage current, IOFF for 18nm NMOS devices equal to 0.302849 volts and 1.9123×10-16 A/μm respectively. The design values are referred to ITRS 2011 prediction.

  13. Effect of Experimental Parameters on the Hydrothermal Synthesis of Bi2WO6 Nanostructures.

    Science.gov (United States)

    Cui, Ziming; Yang, Hua; Wang, Bin; Li, Ruishan; Wang, Xiangxian

    2016-12-01

    Bi2WO6 nanostructures were synthesized by a hydrothermal route, where the effect of various experimental parameters on the products was investigated. It is demonstrated that the sample morphology and size is highly dependent on the NaOH content (or pH value). At C NaOH = 0-0.0175 mol (pH range of 1-4), the prepared samples present flower-like hierarchical microspheres which are constructed from thin nanosheets via the self-assembly process. The size of the hierarchical microspheres exhibits a decreasing trend with increasing the NaOH content, from 7 μm at C NaOH = 0 mol to 1.5 μm at C NaOH = 0.0175 mol. At C NaOH = 0.03-0.0545 mol (pH: 5-9), the prepared samples exhibit irregular flake-like structures, and their size increases with the increase in NaOH content. At C NaOH = 0.055-0.05525 mol (pH: 10-11), the prepared samples are composed of uniform sphere-like particles with an average size of 85 nm. Compared to the NaOH content, the reaction temperature and time has a relatively small effect on the product morphology and size. The photocatalytic activity of the samples was evaluated by degrading rhodamine B (RhB) under irradiation of simulated sunlight. Among these samples, the samples composed of flower-like hierarchical microspheres have relatively high photocatalytic activity. In particular, the microspheres prepared at C NaOH = 0.01 mol exhibit the highest photocatalytic activity, and the degradation percentage reaches 99 % after 2 h of irradiation.

  14. Influence of Sandwich-Type Constrained Layer Damper Design Parameters on Damping Strength

    Directory of Open Access Journals (Sweden)

    Inaki Merideno

    2016-01-01

    Full Text Available This paper presents a theoretical study of the parameters that influence sandwich-type constrained layer damper design. Although there are different ways to reduce the noise generated by a railway wheel, most devices are based on the mechanism of increasing wheel damping. Sandwich-type constrained layer dampers can be designed so their resonance frequencies coincide with the wheel’s resonant vibration frequencies, and thus the damping effect can be concentrated within the frequency ranges of interest. However, the influence of design parameters has not yet been studied. Based on a number of numerical simulations, this paper provides recommendations for the design stages of sandwich-type constrained layer dampers.

  15. Variation of biometric parameters in corn cobs under the influence of nitrogen fertilization

    Science.gov (United States)

    Gigel, Prisecaru; Florin, Sala

    2017-07-01

    Biometric parameters as elements of productivity on corn cobs, along with plant density per unit area (ha) are essential in achieving production. The influence of differentiated fertilization with nitrogen was evaluated at the level of productivity elements on corn cobs, Andreea hybrid. Biometric parameters of the corn cobs (total length - L; usable length - l; uncoated length with corn kernels - lu; diameter at the base - Db, middle - Dm, and top of the corn cobs - Dt; corn cob weight - Cw, grain weight - Gw) were directly influenced by the doses of nitrogen. Regression analysis has facilitated the prediction of grain weight as the main element of productivity under different statistical certainty based on nitrogen doses (R2 = 0.962, pcorn cobs (R2 = 0.985, pcorn cobs (R2 = 0.996, pcorn cobs (R2 = 0.824, pcorn cobs (R2 = 0.807, pcorn kernels (R2 = 0.624, pcorn cobs (R2 = 0.384, p=0.015).

  16. Evolving trends in cryopreservation and parameters influencing semen extender preparation - a prospective review.

    Science.gov (United States)

    Sridharan, T B; Vickram, A S

    2016-01-01

    Cryopreservation is a technique by which, semen can be preserved to subzero temperature, usually at -196° C. The freezing of semen desires vitrification mediators that diminish wreck to the cells (spermatozoan) during the freeze and thaw process. Using cryopreservation, the quality of the semen has been increased in the latest years, by which the achievement rate for the insemination techniques has increased in an agreed way. The area need to be focused is to enhance the quality of the semen extender preparation before cryopreservation. Many researchers are working in the area of cryopreservation of human semen with different semen extenders. Several parameters influence the properties of semen extender essential for better post thaw results. This review is mainly focused on a range of parameters which influence the best semen extender for cryopreservation that includes glycerol and its importance, buffer and novel usage of antimicrobial peptides as antimicrobial agents.

  17. THE INFLUENCE OF OREGANO ESSENTIAL OIL AND BEE PRODUCTS ON QUALITATIVE PARAMETERS AND MICROBIOLOGICAL INDICATORS OF TABLE EGGS CONTENT

    Directory of Open Access Journals (Sweden)

    Henrieta Arpášová

    2013-02-01

    Full Text Available Phytobiotics are a new group of natural products. They are defined as products derived from plants, which may have a beneficial effect on the gastrointestinal microflora of animals, performance and quality of animal products. In this experiment the effects of supplementation of the diet for laying hens with oregano essential oil, propolis and pollen extract addition on physical and microbiological egg parameters were studied. Hens of laying hybrid Hy-Line Brown (n=40 were randomly divided into 4 groups (n=10 and fed for 23 weeks with diets with oregano essential oiland propolis or pollen supplemented. In the control group hens received feed mixture with no additions. The diets in the first experimental groups was supplemented with 0.5 g/kg oregano essential oil. The feed for second and third experimental groups of birds consisted of basal diet supplemented with propolis extract and pollen extract of the same dose at 0.5 g/kg. The results suggest that the most of qualitative parameters of egg internal content were not significantly influenced with oregano oil or bee products addition (P>0.05. A statistically significant differencein favor of the experimental groups compared with the control group was observed in two indicators of albumen quality. In the index of albumen and in the Haugh Units was significantly higher difference in favor of the experimental group with addition of oregano essential oilat a dose of0.5 g/kg and in the group with pollen supplement (P<0.05. The highest total number of bacteria and count of coliforms bacteria was found in the control group. The number of lactobacilli was zero in all groups.

  18. Experimental and Computational Method for Determining Parameters of Stress-Strain State from the Data Obtainable by Interference Optical Techniques

    Directory of Open Access Journals (Sweden)

    Razumovsky I.

    2010-06-01

    Full Text Available Experimental and computational method for determining parameters of stress-strain state is proposed which is based on estimation of compliance between the data sets obtained experimentally and the results of numerical calculations of the boundary problems in formulation of which all distinctive features of area geometry, character of the loads being considered and deformation characteristics of materials are taken into account. The procedure proposed was checked at a number of practically important problems.

  19. The influence of orlistat (Xenical) therapy on the parameters of lipid metabolism in patients with obesity

    OpenAIRE

    N V Mazurina; N V Masurina

    2009-01-01

    One of the main goals in treatment of obesity is descending of overall cardiometabolic risk, which is mostly defined by atherogenic changes in blood lipid spectrum. Scientific data, presented in this review confirm that orlistat is effective for treatment of obesity, its introduction significantly increases proportion of patients who reach clinically valuable results. The mechanism of action of orlistat explains its influence on parameters of blood lipids, which doesn't directly depend on the...

  20. The influence of chosen modifiers on stereological parameters of carbides of chromium cast iron

    Directory of Open Access Journals (Sweden)

    A. Studnicki

    2011-07-01

    Full Text Available The results of investigations of stereological carbides in the modified wear resistance chromium cast iron resistant were introduced in the article. There were following elements: boron, niobium, vanadium, cerium and lanthanum (RE, nitrogen in the composition of modifiers. The influence of used modifiers on such stereological parameters of carbides as: size, perimeter, shape coefficient and volume fraction was showed in tables and on diagrams.

  1. Influence of Population Variation of Physiological Parameters in Computational Models of Space Physiology

    Science.gov (United States)

    Myers, J. G.; Feola, A.; Werner, C.; Nelson, E. S.; Raykin, J.; Samuels, B.; Ethier, C. R.

    2016-01-01

    The earliest manifestations of Visual Impairment and Intracranial Pressure (VIIP) syndrome become evident after months of spaceflight and include a variety of ophthalmic changes, including posterior globe flattening and distension of the optic nerve sheath. Prevailing evidence links the occurrence of VIIP to the cephalic fluid shift induced by microgravity and the subsequent pressure changes around the optic nerve and eye. Deducing the etiology of VIIP is challenging due to the wide range of physiological parameters that may be influenced by spaceflight and are required to address a realistic spectrum of physiological responses. Here, we report on the application of an efficient approach to interrogating physiological parameter space through computational modeling. Specifically, we assess the influence of uncertainty in input parameters for two models of VIIP syndrome: a lumped-parameter model (LPM) of the cardiovascular and central nervous systems, and a finite-element model (FEM) of the posterior eye, optic nerve head (ONH) and optic nerve sheath. Methods: To investigate the parameter space in each model, we employed Latin hypercube sampling partial rank correlation coefficient (LHSPRCC) strategies. LHS techniques outperform Monte Carlo approaches by enforcing efficient sampling across the entire range of all parameters. The PRCC method estimates the sensitivity of model outputs to these parameters while adjusting for the linear effects of all other inputs. The LPM analysis addressed uncertainties in 42 physiological parameters, such as initial compartmental volume and nominal compartment percentage of total cardiac output in the supine state, while the FEM evaluated the effects on biomechanical strain from uncertainties in 23 material and pressure parameters for the ocular anatomy. Results and Conclusion: The LPM analysis identified several key factors including high sensitivity to the initial fluid distribution. The FEM study found that intraocular pressure and

  2. Influence of search parameters and criteria on compound selection, promiscuity, and pan assay interference characteristics.

    Science.gov (United States)

    Hu, Ye; Bajorath, Jürgen

    2014-11-24

    Compound activity data grow at unprecedented rates, and their complexity increases. This challenges compound data mining efforts and makes it difficult to draw reliable conclusions from data analysis. We have aimed to investigate the influence of individual parameters and data confidence levels on compound selection and property assessment. Therefore, alternative sets of bioactive compounds were systematically extracted from ChEMBL on the basis of iteratively expanding selection criteria with increasing stringency covering a variety of search parameters. The sequential application of criteria for the selection of high-confidence compound data was order-independent, as expected. Furthermore, the influence of separately applied selection criteria was analyzed. Criteria that largely influenced compound selection and compound promiscuity rates were identified. In the presence of stringent selection criteria and high data confidence, many compounds with likely assay artifacts or liabilities were eliminated from further consideration. Taken together, the findings of our analysis emphasize the need to carefully consider search parameters related to target organisms, confidence level of activity, and activity measurements and suggest reliable protocols for compound data mining.

  3. Estimate the contribution of incubation parameters influence egg hatchability using multiple linear regression analysis.

    Science.gov (United States)

    Khalil, Mohamed H; Shebl, Mostafa K; Kosba, Mohamed A; El-Sabrout, Karim; Zaki, Nesma

    2016-08-01

    This research was conducted to determine the most affecting parameters on hatchability of indigenous and improved local chickens' eggs. Five parameters were studied (fertility, early and late embryonic mortalities, shape index, egg weight, and egg weight loss) on four strains, namely Fayoumi, Alexandria, Matrouh, and Montazah. Multiple linear regression was performed on the studied parameters to determine the most influencing one on hatchability. The results showed significant differences in commercial and scientific hatchability among strains. Alexandria strain has the highest significant commercial hatchability (80.70%). Regarding the studied strains, highly significant differences in hatching chick weight among strains were observed. Using multiple linear regression analysis, fertility made the greatest percent contribution (71.31%) to hatchability, and the lowest percent contributions were made by shape index and egg weight loss. A prediction of hatchability using multiple regression analysis could be a good tool to improve hatchability percentage in chickens.

  4. Influence of Wire Electrical Discharge Machining (WEDM) process parameters on surface roughness

    Science.gov (United States)

    Yeakub Ali, Mohammad; Banu, Asfana; Abu Bakar, Mazilah

    2018-01-01

    In obtaining the best quality of engineering components, the quality of machined parts surface plays an important role. It improves the fatigue strength, wear resistance, and corrosion of workpiece. This paper investigates the effects of wire electrical discharge machining (WEDM) process parameters on surface roughness of stainless steel using distilled water as dielectric fluid and brass wire as tool electrode. The parameters selected are voltage open, wire speed, wire tension, voltage gap, and off time. Empirical model was developed for the estimation of surface roughness. The analysis revealed that off time has a major influence on surface roughness. The optimum machining parameters for minimum surface roughness were found to be at a 10 V open voltage, 2.84 μs off time, 12 m/min wire speed, 6.3 N wire tension, and 54.91 V voltage gap.

  5. Influence of mixing and extraction parameters on virgin olive oil quality

    Directory of Open Access Journals (Sweden)

    Pasqualone, A.

    2001-08-01

    Full Text Available The mixing time, the temperature and the degree of dilution of olive paste are the main parameters liable to change during mixing and oil ext raction. They can greatly differ from a processing run to another, with variations being observed in Tuscan oil mills, between 26ºC and 36ºC, 40’ and 90’, and 10% and 50% respectively, for the temperature, the mixing time and the water added during the centrifugal extraction. This note reports on the results of some experimental trials run during the 1998 olive oil year in Tuscany. The mixing time and temperature as well as the olive paste dilution were changed one at a time and were assessed for their influence on extraction yield and oil quality. The best conditions to optimise the product yield and quality were identified.El tiempo de batido, la temperatura y el grado de dilución de la pasta de aceituna, son los principales parámetros que pueden sufrir cambios durante el batido y la extracción del aceite. Estos pueden diferir mucho de un proceso a otro, habiendo sido observadas variaciones en los aceites de molino de Toscana, entre 26ºC y 36ºC, 40’ y 90’, y 10% y 50% respectivamente, para la temperatura, el tiempo de batido y el agua añadida durante la extracción por centrifugación. Este artículo presenta los resultados de algunos ensayos experimentales realizados durante el año 1998 con aceite de oliva de Toscana. El tiempo de batido y la temperatura, así como la dilución de la pasta de aceitunas, se variaron uno a uno y se evaluaron por su influencia en el rendimiento de la extracción y la calidad del aceite. Las mejores condiciones para optimizar el rendimiento y la calidad del producto fueron identificadas.

  6. Motorcycle On-Road Driving Parameters Influencing Fuel Consumption and Emissions on Congested Signalized Urban Corridor

    Directory of Open Access Journals (Sweden)

    Atthapol Seedam

    2017-01-01

    Full Text Available This study aims to find the on-road driving parameters influencing fuel consumption and emissions of motorcycle driving on a congested signalized urban corridor. A motorcycle onboard measurement system was developed to measure instantaneously and continuously record on-road driving data, including speed-time profile, emissions, and fuel consumption, by the second. The test motorcycles were driven by 30 sample motorcyclists on a signalized urban corridor in Khon Kaen City, Thailand, to collect their on-road driving behavior during the morning peak period. Cluster analysis was applied to analyze collected driving data and to categorize the drivers by level of fuel consumption and on-road driver behavior. The on-road driving parameter influencing fuel consumption and emissions was then determined. Results revealed that proportion of idle time significantly influenced fuel consumption and emissions of motorcycle driving on a congested signalized urban corridor, though aggressive driving behavior, hard acceleration and deceleration, did not have the same kind of influence.

  7. Experimental Research on the Influence of Vibration on Knee Mobility

    Directory of Open Access Journals (Sweden)

    Radu Panaitescu-Liess

    2013-09-01

    Full Text Available Besides hand - arm system, the vibration can enter in the human body through the feet, too. In these case - when the subject was in a standing position and the vibrations have a vertical component - longer exposures may cause disease of joints, lower extremity and serious disorders of the cerebral blood vessels, internal organs and circulatory system. This paper focused on the influence of vibration on knee mobility. We used a MediTouch system which consists of a motion capture device (an ergonomic leg brace and a dedicated software.

  8. Influence of Combustion Parameters on Fouling Composition after Wood Pellet Burning in a Lab-Scale Low-Power Boiler

    Directory of Open Access Journals (Sweden)

    Lara Febrero

    2015-09-01

    Full Text Available The present study aims to evaluate the effect of different operating conditions on fouling composition after woody biomass combustion in an experimental low-power fixed-bed boiler. The boiler was built specifically for research purposes and allows easy removal of areas susceptible to fouling and the control, modification and registry of combustion parameters. The influences of the total airflow supplied and the deposition probe temperature were studied in fouling; differentiating between the layers of fouling adhered to the tube and those deposited over the tube. Thermogravimetry and Differential Scanning Calorimetry (TG-DSC and Scanning Electron Microscopy with Energy Dispersive X-Ray Spectroscopy (SEM-EDS were performed in order to determine a relationship between the fouling composition and the combustion parameters used. Upon increasing the total airflow supplied and the deposition probe temperature, the amount of organic matter, namely unburned carbon, decreased, indicating a better combustion efficiency. Chemical analysis results of fouling deposits showed that inorganic elements presented different behaviors depending on the collection area and the combustion parameters. Non-volatile elements such as Si and Ca were mostly found in the coarse fraction of the bottom ash and minor amounts were deposited over the tube. Small amounts of Cl in biomass generated serious deposition problems, especially during combustions with low airflow rates.

  9. Influence of process parameters on physical dimensions of AA6063 aluminium alloy coating on mild steel in friction surfacing

    Directory of Open Access Journals (Sweden)

    B. Vijaya Kumar

    2015-09-01

    Full Text Available An attempt is made in the present study to obtain the relationships among process parameters and physical dimensions of AA6063 aluminium alloy coating on IS2062 mild steel obtained through friction surfacing and their impact on strength and ductility of the coating. Factorial experimental design technique was used to investigate and select the parameter combination to achieve a coating with adequate strength and ductility. Spindle speed, axial force and table traverse speed were observed to be the most significant factors on physical dimensions. It was observed that the thickness of the coating decreased as the coating width increased. In addition, the width and thickness of the coatings are higher at low and high torques. At intermediate torque values, when the force is high, the width of the coating is high, and its thickness is thin; and when the force is low, the width and thickness are low. The interaction effect between axial force (F – table traverse speed (Vx and spindle speed (N – table traverse speed (Vx produced an increasing effect on coating width and thickness, but other interactions exhibited decreasing influence. It has also been observed that sound coatings could be obtained in a narrow set of parameter range as the substrate-coating materials are metallurgically incompatible and have a propensity to form brittle intermetallics.

  10. Design and formulation of nano-sized spray dried efavirenz-part I: influence of formulation parameters

    Science.gov (United States)

    Katata, Lebogang; Tshweu, Lesego; Naidoo, Saloshnee; Kalombo, Lonji; Swai, Hulda

    2012-11-01

    Efavirenz (EFV) is one of the first-line antiretroviral drugs recommended by the World Health Organisation for treating HIV. It is a hydrophobic drug that suffers from low aqueous solubility (4 μg/mL), which leads to a limited oral absorption and low bioavailability. In order to improve its oral bioavailability, nano-sized polymeric delivery systems are suggested. Spray dried polycaprolactone-efavirenz (PCL-EFV) nanoparticles were prepared by the double emulsion method. The Taguchi method, a statistical design with an L8 orthogonal array, was implemented to optimise the formulation parameters of PCL-EFV nanoparticles. The types of sugar (lactose or trehalose), surfactant concentration and solvent (dichloromethane and ethyl acetate) were chosen as significant parameters affecting the particle size and polydispersity index (PDI). Small nanoparticles with an average particle size of less than 254 ± 0.95 nm in the case of ethyl acetate as organic solvent were obtained as compared to more than 360 ± 19.96 nm for dichloromethane. In this study, the type of solvent and sugar were the most influencing parameters of the particle size and PDI. Taguchi method proved to be a quick, valuable tool in optimising the particle size and PDI of PCL-EFV nanoparticles. The optimised experimental values for the nanoparticle size and PDI were 217 ± 2.48 nm and 0.093 ± 0.02.

  11. Design and formulation of nano-sized spray dried efavirenz-part I: influence of formulation parameters

    Energy Technology Data Exchange (ETDEWEB)

    Katata, Lebogang, E-mail: lebzakate@yahoo.com; Tshweu, Lesego; Naidoo, Saloshnee; Kalombo, Lonji; Swai, Hulda [Materials Science and Manufacturing, Centre of Polymers and Composites, Council for Scientific and Industrial Research (South Africa)

    2012-11-15

    Efavirenz (EFV) is one of the first-line antiretroviral drugs recommended by the World Health Organisation for treating HIV. It is a hydrophobic drug that suffers from low aqueous solubility (4 {mu}g/mL), which leads to a limited oral absorption and low bioavailability. In order to improve its oral bioavailability, nano-sized polymeric delivery systems are suggested. Spray dried polycaprolactone-efavirenz (PCL-EFV) nanoparticles were prepared by the double emulsion method. The Taguchi method, a statistical design with an L{sub 8} orthogonal array, was implemented to optimise the formulation parameters of PCL-EFV nanoparticles. The types of sugar (lactose or trehalose), surfactant concentration and solvent (dichloromethane and ethyl acetate) were chosen as significant parameters affecting the particle size and polydispersity index (PDI). Small nanoparticles with an average particle size of less than 254 {+-} 0.95 nm in the case of ethyl acetate as organic solvent were obtained as compared to more than 360 {+-} 19.96 nm for dichloromethane. In this study, the type of solvent and sugar were the most influencing parameters of the particle size and PDI. Taguchi method proved to be a quick, valuable tool in optimising the particle size and PDI of PCL-EFV nanoparticles. The optimised experimental values for the nanoparticle size and PDI were 217 {+-} 2.48 nm and 0.093 {+-} 0.02.

  12. Experimental study on relationship between processing parameters and stress wave propagation during automated fiber placement process

    Science.gov (United States)

    Fu, H. Y.; Li, W. Q.; Sun, S. Z.; Han, Z. Y.

    2017-06-01

    Automated fiber placement (AFP) is an important manufacturing method of composites, which has been widely used in the field of aerospace. Unreasonable processing parameters could lead to some manufacturing defects including pores, bubbles and cracks. In this paper, the propagation characteristics of stress waves are believed to be closely related to the defects during AFP process. Experiments are conducted to collect stress wave signal under different processing parameters (pressure, velocity and temperature) during manufacturing process. And the relationship between the processing parameters and the characteristics of stress waves is explored by Control Variate Method (CVM). Finally, the effects of laying parameters on stress amplitude, response speed and duration are summarized.

  13. Gas migration in KBS-3 buffer bentonite. Sensitivity of test parameters to experimental boundary conditions

    Energy Technology Data Exchange (ETDEWEB)

    Harrington, J.F.; Horseman, S.T. [British Geological Survey, Nottingham (United Kingdom)

    2003-01-01

    In the current Swedish repository design concept, hydrogen gas can be generated inside a waste canister by anaerobic corrosion of the ferrous metal liner. If the gas generation rate exceeds the diffusion rate of gas molecules in the buffer porewater, gas will accumulate in the void-space of a canister until its pressure becomes large enough for it to enter the bentonite as a discrete gaseous phase. Three long tenn gas injection tests have been performed on cylinders of pre-compacted MX80 bentonite. Two of these tests were undertaken using a custom-designed constant volume and radial flow (CVRF) apparatus. Gas was injected at a centrally located porous filter installed in the clay before hydration. Arrangements were made for gas to flow to three independently monitored sink-filter arrays mounted around the specimen. Axial and radial total stresses and internal porewater pressures were continuously monitored. Breakthrough and peak gas pressures were substantially larger than the sum of the swelling pressure and the external porewater. The third test was performed. using an apparatus which radially constrains the specimen during gas flow. Observed sensitivity of the breakthrough and peak gas pressures to the test boundary conditions suggests that gas entry must be accompanied by dilation of the bentonite fabric. In other words, there is a tendency for the volume of the specimen to increase during this process. The experimental evidence is consistent with the flow of gas along a relatively small number of crack-like pathways which propagate through the clay as gas pressure increases. Gas entry and breakthrough under constant volume boundary conditions causes a substantial increase in the total stress and the internal porewater pressure. It is possible to determine the point at which gas enters the clay by monitoring changes in these parameters. Localisation of gas flow within multiple pathways results, in nonuniform discharge rates at the sinks. When gas injection

  14. Investigation of the Influence of Hydrocyclone Geometric and Flow Parameters on Its Performance Using CFD

    Directory of Open Access Journals (Sweden)

    Oboetswe Seraga Motsamai

    2010-01-01

    Full Text Available Effectiveness and efficiency of hydro-cyclone separators are highly dependent on their geometrical parameters and flow characteristics. Performance of the hydro-cyclone can, therefore, be improved by modifying the geometrical parameters or flow characteristics. The mining and chemical industries are faced with problems of separating ore-rich stones from the nonore-rich stones. Due to this problem a certain amount of precious metals is lost to the dumping sites. Plant managers try to solve these problems by stockpiling what could be useless stones, so that they can be reprocessed in the future. Reprocessing is not a sustainable approach, because the reprocessed material would give lower yield as compared to the production costs. Particulate separation in a hydro-cyclone has been investigated in this paper, by using computational fluid dynamics. The paper investigated the influence of various flow and geometric parameters on particulate separation. Optimal parameters for efficient separation have been determined for the density of fluid, diameter of the spigot, and diameter of the vortex finder. The principal contribution of this paper is that key parameters for design optimization of the hydro-cyclone have been investigated.

  15. Influence оf 2d Vibratory Motion Conveyed to Billet on Force And Timing Parameters of its Contact Interaction With Sawing Disc

    Directory of Open Access Journals (Sweden)

    M. G. Kiselev

    2014-01-01

    Full Text Available The paper presents an experimental investigation on influence of 2D vibratory dimension conveyed to a billet on force and timing parameters of its contact interaction with a sawing disc. Description of the modernized sawing section ensuring conveyance of 2D vibratory motion to a billet, methodology and  hardware facilities applied for normal force measurement of its impact with the disc and longevity of their contact for the period of the billet circulation motion. The paper provides, analyzes and generalizes experimentally obtained dependences reflecting influence of gap clearance between a boom and an upper stop on the mentioned force and timing parameters of the billet contact interaction with the sawing disc.

  16. Allergen specific immunotherapy has no influence on standard chemistry and hematology laboratory parameters in clinical studies.

    Science.gov (United States)

    Häfner, Dietrich; Gödicke, Viola; Narkus, Annemie

    2014-01-01

    A set of standard clinical chemistry and hematology parameters are usually measured during clinical studies. The major outcome of these standard tests is to control that the drug investigated does not lead to pathophysiological changes in respective organs or blood. In some cases based on scientific rationale such tests may not be needed. In this paper we report on a standard set of clinical chemistry and hematology laboratory parameters measured before and after treatment in three different immunotherapy studies, representing different routes of administration and different formulations. Thirteen hematological laboratory parameters and eight clinical chemistry parameters were evaluated from three double-blind, placebo-controlled, randomized, multi-centre, phase III studies. The three studies include one with sublingual immunotherapy (n = 185), one subcutaneous immunotherapy trial with an aluminium hydroxide-adsorbed recombinant hypoallergenic Bet v1-FV (n = 211) and one with pre-seasonal subcutaneous immunotherapy with a 6-grass pollen allergoid (n = 154). Allergen specific immunotherapy with both administration forms and formulations respectively did not show any influence on any of the 21 laboratory parameters analyzed. Few patients had a change in laboratory parameters from within normal range at baseline to either below or above at end-of-treatment. No differences between active and placebo were seen with respect to number of patients with such a change. This study with different preparations and routes of application indicates that the value of repeated measurements of standard clinical chemistry and hematology parameters during allergen immunotherapy should be discussed further.

  17. Experimental study of the influence of flow passage subtle variation on mixed-flow pump performance

    Science.gov (United States)

    Bing, Hao; Cao, Shuliang

    2014-05-01

    In the mixed-flow pump design, the shape of the flow passage can directly affect the flow capacity and the internal flow, thus influencing hydraulic performance, cavitation performance and operation stability of the mixed-flow pump. However, there is currently a lack of experimental research on the influence mechanism. Therefore, in order to analyze the effects of subtle variations of the flow passage on the mixed-flow pump performance, the frustum cone surface of the end part of inlet contraction flow passage of the mixed-flow pump is processed into a cylindrical surface and a test rig is built to carry out the hydraulic performance experiment. In this experiment, parameters, such as the head, the efficiency, and the shaft power, are measured, and the pressure fluctuation and the noise signal are also collected. The research results suggest that after processing the inlet flow passage, the head of the mixed-flow pump significantly goes down; the best efficiency of the mixed-flow pump drops by approximately 1.5%, the efficiency decreases more significantly under the large flow rate; the shaft power slightly increases under the large flow rate, slightly decreases under the small flow rate. In addition, the pressure fluctuation amplitudes on both the impeller inlet and the diffuser outlet increase significantly with more drastic pressure fluctuations and significantly lower stability of the internal flow of the mixed-flow pump. At the same time, the noise dramatically increases. Overall speaking, the subtle variation of the inlet flow passage leads to a significant change of the mixed-flow pump performance, thus suggesting a special attention to the optimization of flow passage. This paper investigates the influence of the flow passage variation on the mixed-flow pump performance by experiment, which will benefit the optimal design of the flow passage of the mixed-flow pump.

  18. Experimental and Numerical Investigation of Design Parameters for Hydronic Embedded Thermally Active Surfaces

    DEFF Research Database (Denmark)

    Marcos-Meson, Victor; Pomianowski, Michal Zbigniew; E. Poulsen, Søren

    2015-01-01

    This paper evaluates the principal design parameters affecting the thermal performance of embedded hydronic Thermally Active Surfaces (TAS), combining the Response Surface Method (RSM) with the Finite Elements Method (FEM). The study ranks the combined effects of the parameters on the heat flux i...

  19. Analysis of agro-climatic parameters and their influence on maize production in South Africa

    Science.gov (United States)

    Adisa, Omolola M.; Botai, Christina M.; Botai, Joel O.; Hassen, Abubeker; Darkey, Daniel; Tesfamariam, Eyob; Adisa, Alex F.; Adeola, Abiodun M.; Ncongwane, Katlego P.

    2017-11-01

    This study analyzed the variability of the agro-climatic parameters that impact maize production across different seasons in South Africa. To achieve this, four agro-climatic variables (precipitation, potential evapotranspiration, minimum, and maximum temperatures) were considered for the period spanning 1986-2015, covering the North West, Free State, Mpumalanga, and KwaZulu-Natal (KZN) provinces. Results illustrate that there is a negative trend in precipitation for North West and Free State provinces and positive trend in maximum temperature for all the provinces over the study period. Furthermore, the results showed that among other agro-climatic parameters, minimum temperature had the most influence on maize production in North West, potential evapotranspiration (combination of the agro-climatic parameters), minimum and maximum temperature influenced maize production in KZN while maximum temperature influenced maize production in Mpumalanga and Free State. In general, the agro-climatic parameters were found to contribute 7.79, 21.85, 32.52, and 44.39% to variation in maize production during the study period in North West, Free State, Mpumalanga, and KZN, respectively. The variation in maize production among the provinces under investigation could most likely attribute to the variation in the size of the cultivated land among other factors including soil type and land tenure system. There were also difference in yield per hectare between the provinces; KZN and Mpumalanga being located in the humid subtropical areas of South Africa had the highest yield per hectare 5.61 and 4.99 tons, respectively, while Free State and North West which are in the semi-arid region had the lowest yield per hectare 3.86 and 3.03 tons, respectively. Understanding the nature and interaction of the dominant agro-climatic parameters discussed in the present study as well as their impact on maize production will help farmers and agricultural policy makers to understand how climate change

  20. The influence of working memory capacity on experimental heat pain.

    Science.gov (United States)

    Nakae, Aya; Endo, Kaori; Adachi, Tomonori; Ikeda, Takashi; Hagihira, Satoshi; Mashimo, Takashi; Osaka, Mariko

    2013-10-01

    Pain processing and attention have a bidirectional interaction that depends upon one's relative ability to use limited-capacity resources. However, correlations between the size of limited-capacity resources and pain have not been evaluated. Working memory capacity, which is a cognitive resource, can be measured using the reading span task (RST). In this study, we hypothesized that an individual's potential working memory capacity and subjective pain intensity are related. To test this hypothesis, we evaluated 31 healthy participants' potential working memory capacity using the RST, and then applied continuous experimental heat stimulation using the listening span test (LST), which is a modified version of the RST. Subjective pain intensities were significantly lower during the challenging parts of the RST. The pain intensity under conditions where memorizing tasks were performed was compared with that under the control condition, and it showed a correlation with potential working memory capacity. These results indicate that working memory capacity reflects the ability to process information, including precise evaluations of changes in pain perception. In this work, we present data suggesting that changes in subjective pain intensity are related, depending upon individual potential working memory capacities. Individual working memory capacity may be a phenotype that reflects sensitivity to changes in pain perception. Copyright © 2013 American Pain Society. Published by Elsevier Inc. All rights reserved.

  1. Experimental evidence for the influence of cognitions on compulsive buying.

    Science.gov (United States)

    McQueen, Paul; Moulding, Richard; Kyrios, Michael

    2014-12-01

    Compulsive buying is a disabling condition, where individuals are unable to resist or control their buying behavior, leading to substantial social and financial problems. Cognitive models implicate the role of beliefs as one factor in buying behavior, for example, "this item is unique and will help me improve my life". This study experimentally examined the contribution of such beliefs to the disorder, in individuals who compulsively buy (N = 18) and in non-clinical controls (N = 17). Participants were presented with photographs of idiosyncratically appealing and unappealing items, in the context of imagined scenarios that either minimized or maximized aspects relevant to hypothesized "compulsive buying beliefs" (i.e., beliefs that acquisition can compensate for negative feelings, beliefs regarding uniqueness and lost opportunities, and emotional reasons for buying). It was found that individuals who compulsively buy demonstrated stronger urges to purchase than control participants, regardless of context, but the overall strength of these urges was responsive to manipulations of beliefs about consumer items said to be associated with compulsive buying. The main limitation of the study was a small sample size, potentially reducing power. Nonetheless, these findings provide insights into the processes underlying compulsive phenomena, in particular supporting the role of cognitions in compulsive buying. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Influence analysis of design parameters of suspensions on the technical specifications of conveyor with suspended belt and distributed drive

    Directory of Open Access Journals (Sweden)

    Lagerev A.V.

    2016-09-01

    Full Text Available Using the basic design of the conveyor with suspended belt and distributed drive, a series of numerical calculations was performed. As a result, the influence of friction and mass-dimensional design parameters of suspensions on the main technical parameters of the conveyor was established. Recommendations on the choice of rational parameters were formulated.

  3. Environmental parameters influence non-viral transfection of human mesenchymal stem cells for tissue engineering applications

    Science.gov (United States)

    King, William J.; Kouris, Nicholas A.; Choi, Siyoung; Ogle, Brenda M.; Murphy, William L.

    2012-01-01

    Non-viral transfection is a promising technique which could be used to increase the therapeutic potential of stem cells. The purpose of this study was to explore practical culture parameters of relevance in potential human mesenchymal stem cell (hMSC) clinical and tissue engineering applications, including type of polycationic transfection reagent, N/P ratio and dose of polycation/pDNA polyplexes, cell passage number, cell density, and cell proliferation. The non-viral transfection efficiency was significantly influenced by N/P ratio, polyplex dose, cell density, and cell passage number. hMSC culture conditions that inhibited cell division also decreased transfection efficiency, suggesting that strategies to promote hMSC proliferation may be useful to enhance transfection efficiency in future tissue engineering studies. Non-viral transfection treatments influenced hMSC phenotype, including the expression level of the hMSC marker CD105, and the ability of hMSCs to differentiate down the osteogenic and adipogenic lineages. The parameters found here to promote hMSC transfection efficiency, minimize toxicity, and influence hMSC phenotype may be instructive in future non-viral transfection studies and tissue engineering applications. PMID:22277991

  4. INFLUENCE OF MICROBIOTA IN EXPERIMENTAL CUTANEOUS LEISHMANIASIS IN SWISS MICE

    Directory of Open Access Journals (Sweden)

    OLIVEIRA Marcia Rosa de

    1999-01-01

    Full Text Available Infection of Swiss/NIH mice with Leishmania major was compared with infection in isogenic resistant C57BL/6 and susceptible BALB/c mice. Swiss/NIH mice showed self-controlled lesions in the injected foot pad. The production of high levels of interferon-g (IFN-g and low levels of interleukin-4 (IL-4 by cells from these animals suggests that they mount a Th1-type immune response. The importance of the indigenous microbiota on the development of murine leishmaniasis was investigated by infecting germfree Swiss/NIH in the hind footpad with L. major and conventionalizing after 3 weeks of infection. Lesions from conventionalized Swiss/NIH mice were significantly larger than conventional mice. Histopathological analysis of lesions from conventionalized animals showed abscesses of variable shapes and sizes and high numbers of parasitized macrophages. In the lesions from conventional mice, besides the absence of abscess formation, parasites were rarely observed. On the other hand, cells from conventional and conventionalized mice produced similar Th1-type response characterized by high levels of IFN-g and low levels of IL-4. In this study, we demonstrated that Swiss/NIH mice are resistant to L. major infection and that the absence of the normal microbiota at the beginning of infection significantly influenced the lesion size and the inflammatory response at the site of infection.

  5. Influence of Powder Injection Parameters in High-Pressure Cold Spray

    Science.gov (United States)

    Ozdemir, Ozan C.; Widener, Christian A.

    2017-10-01

    High-pressure cold spray systems are becoming widely accepted for use in the structural repair of surface defects of expensive machinery parts used in industrial and military equipment. The deposition quality of cold spray repairs is typically validated using coupon testing and through destructive analysis of mock-ups or first articles for a defined set of parameters. In order to provide a reliable repair, it is important to not only maintain the same processing parameters, but also to have optimum fixed parameters, such as the particle injection location. This study is intended to provide insight into the sensitivity of the way that the powder is injected upstream of supersonic nozzles in high-pressure cold spray systems and the effects of variations in injection parameters on the nature of the powder particle kinetics. Experimentally validated three-dimensional computational fluid dynamics (3D CFD) models are implemented to study the particle impact conditions for varying powder feeder tube size, powder feeder tube axial misalignment, and radial powder feeder injection location on the particle velocity and the deposition shape of aluminum alloy 6061. Outputs of the models are statistically analyzed to explore the shape of the spray plume distribution and resulting coating buildup.

  6. Nor-isoprenoids profile during port wine ageing—influence of some technological parameters

    OpenAIRE

    Ferreira, António César Silva; Pinho, Paula Guedes de

    2004-01-01

    Nor-isoprenoid compounds, such as β-damascenone, β-ionone, 2,2,6-trimethylcyclohexanone (TCH), 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN) and vitispirane were determined in 14 young port wines and 45 old port wines. As between the two groups of wines levels of these compounds are quite different, an experimental protocol was performed in order to determine which technological parameter (dissolved O2, free SO2 levels, pH and time/temperature) was related with the formation/consumption of the...

  7. Microgravity-Induced Physiological Fluid Redistribution: Computational Analysis to Assess Influence of Physiological Parameters

    Science.gov (United States)

    Myers, J. G.; Eke, Chika; Werner, C.; Nelson, E. S.; Mulugeta, L.; Feola, A.; Raykin, J.; Samuels, B.; Ethier, C. R.

    2016-01-01

    Space flight impacts human physiology in many ways, the most immediate being the marked cephalad (headward) shift of fluid upon introduction into the microgravity environment. This physiological response to microgravity points to the redistribution of blood and interstitial fluid as a major factor in the loss of venous tone and reduction in heart muscle efficiency which impact astronaut performance. In addition, researchers have hypothesized that a reduction in astronaut visual acuity, part of the Visual Impairment and Intracranial Pressure (VIIP) syndrome, is associated with this redistribution of fluid. VIIP arises within several months of beginning space flight and includes a variety of ophthalmic changes including posterior globe flattening, distension of the optic nerve sheath, and kinking of the optic nerve. We utilize a suite of lumped parameter models to simulate microgravity-induced fluid redistribution in the cardiovascular, central nervous and ocular systems to provide initial and boundary data to a 3D finite element simulation of ocular biomechanics in VIIP. Specifically, the lumped parameter cardiovascular model acts as the primary means of establishing how microgravity, and the associated lack of hydrostatic gradient, impacts fluid redistribution. The cardiovascular model consists of 16 compartments, including three cerebrospinal fluid (CSF) compartments, three cranial blood compartments, and 10 thoracic and lower limb blood compartments. To assess the models capability to address variations in physiological parameters, we completed a formal uncertainty and sensitivity analysis that evaluated the relative importance of 42 input parameters required in the model on relative compartment flows and compartment pressures. Utilizing the model in a pulsatile flow configuration, the sensitivity analysis identified the ten parameters that most influenced each compartment pressure. Generally, each compartment responded appropriately to parameter variations

  8. Influence of isoproterenol on myocardial energetics. Experimental and clinical investigations.

    Science.gov (United States)

    Hasenfuss, G; Holubarsch, C; Blanchard, E M; Mulieri, L A; Alpert, N R; Just, H

    1989-01-01

    The influence of isoproterenol on myocardial performance and energetics was investigated in normal guinea pig myocardium and in patients with normal left ventricular function. The in vitro experiments were performed by simultaneous isometric force and heat measurements using sensitive antimony-bismuth thermopiles. Following the application of isoproterenol (10(-8) M) isometric peak twitch tension and tension-time integral increased significantly by 185% and 142%, respectively. Tension-independent heat which reflects high energy phosphate hydrolysis of excitation-contraction coupling increased by 183%. Tension-dependent heat reflecting the high energy phosphate hydrolysis of the crossbridges increased by 417%. The ratio of tension-dependent heat to tension-time integral increased by 131%. The recovery/initial heat ratio, reflecting the efficiency of the recovery metabolism, and the resting metabolism did not significantly change. In the patients the effect of isoproterenol on myocardial energetics was evaluated in terms of myocardial efficiency. Following isoproterenol administration, left ventricular systolic stress-time integral decreased by 49% due to reductions in end-diastolic pressure, end-diastolic volume and duration of systole. Pressure-volume work remained unchanged. Myocardial oxygen consumption per minute increased in proportion to heart rate. The ratio of myocardial oxygen consumption per beat to left ventricular systolic stress-time integral increased significantly by 95%. External myocardial efficiency was unaltered. Thus, isoproterenol increases the energy turnover of excitation-contraction coupling and increases the energy consumption of the crossbridges disproportionately to developed tension-time integral in the guinea pig heart.

  9. Parameter extraction using global particle swarm optimization approach and the influence of polymer processing temperature on the solar cell parameters

    Science.gov (United States)

    Kumar, S.; Singh, A.; Dhar, A.

    2017-08-01

    The accurate estimation of the photovoltaic parameters is fundamental to gain an insight of the physical processes occurring inside a photovoltaic device and thereby to optimize its design, fabrication processes, and quality. A simulative approach of accurately determining the device parameters is crucial for cell array and module simulation when applied in practical on-field applications. In this work, we have developed a global particle swarm optimization (GPSO) approach to estimate the different solar cell parameters viz., ideality factor (η), short circuit current (Isc), open circuit voltage (Voc), shunt resistant (Rsh), and series resistance (Rs) with wide a search range of over ±100 % for each model parameter. After validating the accurateness and global search power of the proposed approach with synthetic and noisy data, we applied the technique to the extract the PV parameters of ZnO/PCDTBT based hybrid solar cells (HSCs) prepared under different annealing conditions. Further, we examine the variation of extracted model parameters to unveil the physical processes occurring when different annealing temperatures are employed during the device fabrication and establish the role of improved charge transport in polymer films from independent FET measurements. The evolution of surface morphology, optical absorption, and chemical compositional behaviour of PCDTBT co-polymer films as a function of processing temperature has also been captured in the study and correlated with the findings from the PV parameters extracted using GPSO approach.

  10. Experimental and ab initio study of the hyperfine parameters of ZnFe {sub 2}O{sub 4} with defects

    Energy Technology Data Exchange (ETDEWEB)

    Quintero, J. Melo; Salcedo Rodríguez, K. L.; Pasquevich, G. A.; Zélis, P. Mendoza; Stewart, S. J., E-mail: stewart@fisica.unlp.edu.ar; Rodríguez Torres, C. E.; Errico, L. A. [Universidad Nacional de La Plata, IFLP-CCT- La Plata-CONICET and Departamento de Física, Facultad de Ciencias Exactas, C. C. 67 (Argentina)

    2016-12-15

    We present a combined Mössbauer and ab initio study on the influence of oxygen-vacancies on the hyperfine and magnetic properties of the ZnFe {sub 2}O{sub 4} spinel ferrite. Samples with different degree of oxygen-vacancies were obtained from zinc ferrite powder that was thermally treated at different temperatures up to 650 {sup ∘}C under vacuum.Theoretical calculations of the hyperfine parameters, magnetic moments and magnetic alignment have been carried out considering different defects such as oxygen vacancies and cation inversion. We show how theoretical and experimental approaches are complementary to characterize the local structure around Fe atoms and interpret the observed changes in the hyperfine parameters as the level of defects increases.

  11. Influence of multiple bioprocess parameters on production of lipase from Pseudomonas sp. BWS-5

    Directory of Open Access Journals (Sweden)

    Balwinder Singh Sooch

    2013-10-01

    Full Text Available The aim of the present work was to study the influence of multiple bioprocess parameters for the maximum production of lipase from Pseudomonas sp. BWS-5. The culture reached the stationary phase of growth after 36h of incubation when the maximum lipase production was obtained at flask level. The different media components such as carbon sources, nitrogen sources, trace elements and process parameters such as the pH of the medium, temperature and time of incubation, agitation/stationary conditions, etc. were optimized at flask level and at bioreactor level. The maximum enzyme production of 298 IU/mL was obtained with the use of simple medium with pH 6.5 containing glucose (1 %, w/v, peptone (3 %, w/v and KCl (0.05 %, w/v after 30h of incubation at 37°C under agitation (200 rpm conditions with 0.75 vvm of air supply.

  12. Influences of some parameters on the performance of a small vertical axis wind turbine

    Directory of Open Access Journals (Sweden)

    Dumitrache Alexandru

    2016-01-01

    Full Text Available The effects of various parameters on the performance of a straight bladed vertical axis wind turbine, using the vortex model, have been numerically investigated. A vortex model has been used to evaluate the performance of a vertical axis wind turbine, by means of aerodynamic characteristics of different airfoils for Reynolds numbers between 105 and 106. Parameters such as the thickness and the camber of the blade airfoil, the solidity, the type of blade profile, the number of blades and the pitch angle, which influence the power coefficient, CP, and the start-up regime. This study can be used in the designing an optimal vertical axis wind turbine in a specific location, when the prevailed wind regime is known.

  13. Powder properties and compaction parameters that influence punch sticking propensity of pharmaceuticals.

    Science.gov (United States)

    Paul, Shubhajit; Taylor, Lisa J; Murphy, Brendan; Krzyzaniak, Joseph F; Dawson, Neil; Mullarney, Matthew P; Meenan, Paul; Sun, Changquan Calvin

    2017-04-15

    Punch sticking is a frequently occurring problem that challenges successful tablet manufacturing. A mechanistic understanding of the punch sticking phenomenon facilitates the design of effective strategies to solve punch sticking problems of a drug. The first step in this effort is to identify process parameters and particle properties that can profoundly affect sticking performance. This work was aimed at elucidating the key material properties and compaction parameters that influence punch sticking by statistically analyzing punch sticking data of 24 chemically diverse compounds obtained using a set of tooling with removable upper punch tip. Partial least square (PLS) analysis of the data revealed that particle surface area and tablet tensile strength are the most significant factors attributed to punch sticking. Die-wall pressure, ejection force, and take-off force also correlate with sticking, but to a lesser extent. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Musculoskeletal simulations to investigate the influence of vertebral geometrical parameters on lumbar spine loading

    DEFF Research Database (Denmark)

    Putzer, Michael; Rasmussen, John; Penzkofer, Rainer

    Musculoskeletal simulations of subject-specific loads in the lumbar spine are computed by using subject-specific geometrical data. However this data has an inherent inaccuracy. This study evaluates the influence of defined geometrical parameters on lumbar spine loading utilizing the Any......Body Modeling System and a parameterized musculoskeletal lumbar spine model for four different postures: upright standing, flexion (50°), torsion (10°) and lateral bending (15°). The linear dimensions of the vertebral body, the posterior parts of the vertebrae as well as the disc height, the orientation...... of the facet joints and the curvature of the lumbar spine have been varied. Figure 1 depicts the used musculoskeletal model in the flexed posture and a lumbar vertebra labeled with all relevant linear dimensions except the disc height. Additionally, all combinations of the three parameters vertebral body...

  15. On the Viscoelastic Parameters of Gussasphalt Mixture Based on Modified Burgers Model: Deviation and Experimental Verification

    OpenAIRE

    Faxiang Xie; Dengjing Zhang; Ao Zhou; Bohai Ji; Lin Chen

    2017-01-01

    Viscoelasticity is an important characteristic of gussasphalt mixtures. The aim of this study is to find the correct viscoelastic material parameters of the novel gussasphalt applied in the 4th Yangtze River Bridge based on the modified Burgers model. This study firstly derives the explicit Prony series form of the shear relaxation modulus of viscoelastic material from Laplace transformation, to fulfill the parameter inputting requirements of commonly used finite element software suites. Seco...

  16. Experimental determination of cascade parameters of a hearing-aid microphone via the two-load method.

    Science.gov (United States)

    Egolf, D P; Haley, B T; Bauer, K M; Howell, H C; Larson, V D

    1988-06-01

    Presented in this article is a computer-aided experimental method for obtaining the cascade parameters of the two-port model of a miniature hearing-aid microphone. The method is an adaptation of the "two-load" method [D.P. Egolf and R.G. Leonard, J. Acoust. Soc. Am. 62, 1013-1023 (1977)] to acoustoelectric, rather than electroacoustic, transducers. The cascade parameters of a particular microphone, determined by this method, were within 2.5 dB of the manufacturer's published open-circuit sensitivity data. In an attempt to further verify the numerical cascade-parameter data, a two-port model of the microphone was used to simulate experimental voltages developed across two different complex electrical load impedances attached to the microphone. The results showed experimental/simulation differences of no greater than 3.0 dB at any frequency. The two-port microphone model and associated cascade parameters are currently being incorporated into a computer-based plan for mathematical simulation of an entire in situ hearing aid.

  17. Different atmospheric parameters influence on spectral UV radiation (measurements and modelling)

    Energy Technology Data Exchange (ETDEWEB)

    Chubarova, N.Y. [Moscow State Univ. (Russian Federation). Meteorological Observatory; Krotkov, N.A. [Maryland Univ., MD (United States). JCESS/Meteorology Dept.; Geogdzhaev, I.V.; Bushnev, S.V.; Kondranin, T.V. [SUMGF/MIPT, Dolgoprudny (Russian Federation); Khattatov, V.U. [Central Aerological Observatory, Dolgoprudny (Russian Federation)

    1995-12-31

    The ultraviolet (UV) radiation plays a vital role in the biophysical processes despite its small portion in the total solar flux. UV radiation is subject to large variations at the Earth surface depending greatly on solar elevation, ozone and cloud amount, aerosols and surface albedo. The analysis of atmospheric parameters influence is based on the spectral archive data of three spectral instruments: NSF spectroradiometer (Barrow network) (NSF Polar Programs UV Spectroradiometer Network 1991-1992,1992), spectrophotometer (SUVS-M) of Central Aerological Observatory CAO, spectroradiometer of Meteorological Observatory of the Moscow State University (MO MSU) and model simulations based on delta-Eddington approximation

  18. [The influence of swimming activity on lung function parameters among smoking and non-smoking youth].

    Science.gov (United States)

    Michalak, Katarzyna; Gatkiewicz, Maciej; Pawlicka-Lisowska, Agnieszka; Poziomska-Piatkowska, Elzbieta

    2012-07-01

    The aim of the study was to evaluate the influence of regularswimming activity on the respiratory system of smokers and non-smokers. The study included 107 students, aged 19 to 24, attending weekly swimming classes. The study was composed of the following elements: measurement of selected respiratory parameters (FVC, FEV,, MIP, MEP), the percentage concentration of blood carboxyhemoglobin (%COHb) and a survey. After 10 months of regular swimming activity in the entire study population statistically significant increase in maximal expiratory pressure MEP (alpha importance of promoting physical activity, especially swimming, among cigarette smokers.

  19. Influence of Processing Parameters on the Flow Path in Friction Stir Welding

    Science.gov (United States)

    Schneider, J. A.; Nunes, A. C., Jr.

    2006-01-01

    Friction stir welding (FSW) is a solid phase welding process that unites thermal and mechanical aspects to produce a high quality joint. The process variables are rpm, translational weld speed, and downward plunge force. The strain-temperature history of a metal element at each point on the cross-section of the weld is determined by the individual flow path taken by the particular filament of metal flowing around the tool as influenced by the process variables. The resulting properties of the weld are determined by the strain-temperature history. Thus to control FSW properties, improved understanding of the processing parameters on the metal flow path is necessary.

  20. Influence of electromagnetic radiation of industrial frequency on the peripheral blood hematological parameters of the rodents

    Directory of Open Access Journals (Sweden)

    Solovyev Vladimir Sergeevich

    2016-06-01

    Full Text Available The authors studied the hematological parameters of peripheral blood in outbred white mice, which were exposed to electromagnetic radiation of industrial frequency. It was shown that the long-term staying in the zone affected by this factor causes the shift in an erythron system and the change in the total number of leucocytes in animals’ blood. The effects caused by electromagnetic action are not specific and can reflect the general reaction of an organism to the extreme physical and chemical influence. Sensitivity to the studied factor depends on animal’s sex.

  1. Influence of measuring parameters on the accuracy of atomic force microscope in industrial applications

    DEFF Research Database (Denmark)

    Tosello, Guido; Antico, Andrea; Hansen, Hans Nørgaard

    2009-01-01

    as in the evaluation of final product characteristics. The paper considers quantitative application of AFM measurements for industrial applications. In particular the influence and subsequent optimization of scanning parameters on the precision of AFM maps is discussed, with particular attention to scan speed...... and interaction force when measuring a one-dimensional grating with triangular profile. The aim is then maximization of information from collected data and minimization of measurement variability and scan time. Optimized scan setting is then applied to measure surface defects of micro injection moulded components...

  2. Influence of kinetic effects on a sheath potential and divertor plasma parameters in ITER

    Energy Technology Data Exchange (ETDEWEB)

    Krasheninnikov, S.I.; Soboleva, T.K.; Igitkhanov, Yu.L.; Runov, A.M. (Kurchatov Institute, Moscow (Russian Federation))

    1991-01-01

    It was already noted that strong inhomogeneity of ITER divertor plasma parameters may be a reason of a pronounced deviation of a sheath potential U[sub d] at a plasma-divertor plate contact from the local value U[sub d][approx]3.5T[sub d] (T[sub d] is an electron temperature in a vicinity of the divertor plate). This effect may badly influence the divertor plates sputtering resulting in a plasma contamination. (author) 6 refs., 5 figs.

  3. Influence of electromagnetic field parameters on the morphology of graphite in grey cast iron

    Directory of Open Access Journals (Sweden)

    J. Szajnar

    2009-01-01

    Full Text Available One way to improve the unification of the casting structure may be the application of forced convection of liquid metal during thecrystallization in the form or continuous casting mould. This paper presents the results describing the influence of selected parameters of rotating electromagnetic field enforcing the movement of liquid metal in the form on the morphology of graphite in grey cast iron. The results were fragmented graphite flakes in conditions of regulating the rate of cooling in the range of temperature TZAL

  4. Parameters Influencing Wave Run-Up on a Rubble Mound Breakwater

    DEFF Research Database (Denmark)

    Walle, Björn Van de; Rouck, Julien De; Damme, Luc Van

    2002-01-01

    Full scale wave run-up measurements have been performed on the Zebrugge rubble mound breakwater. Wave run-up also has been investigated on various small scale models of the Zeebrugge breakwater. A significant difference between the results has been noticed. Additional small scale model testing has...... been carried out on a slightly modified scale model: a regular armour unit pattern has been applied in stead of an irregular pattern as in full scale. The aim of the additional laboratory tests was to investigate the influence of the spectral width parameter and the influence of the position...... of the wave run-up step gauge with respect to the armour unit pattern and the water level....

  5. Thermoforming of glass fibre reinforced polypropylene: A study on the influence of different process parameters

    Science.gov (United States)

    Schug, Alexander; Winkelbauer, Jonas; Hinterhölzl, Roland; Drechsler, Klaus

    2017-10-01

    The aim of this study was to analyse the forming behaviour of glass fibre reinforced polypropylene and to identify the influence of several process parameters on the resulting part quality. For this purpose, a complex forming tool was designed, consisting of several areas with single and double curvature. The specimens were produced from unidirectional (UD) tape using the Fiberforge RELAY2000® automated tape laying machine and a subsequent consolidation step. They were then fixed in a support frame, pre-heated in an infrared oven, and formed in the forming tool, which was mounted into a hydraulic heating press. The investigated process parameters were the number and force of the springs in the support frame, the tool temperature and the forming pressure and speed. The layups of the specimens were [0/90/0/90/0¯]s and [0/45/90/-45/0¯]s. After the forming process, the parts were analysed in terms of their quality, with a special focus on wrinkles, undulations, gaps and surface roughness. In addition to optical analysis with a statistical evaluation of the results, 3D scans of the specimens at different steps of the forming process were made to gain an impression of the forming mechanisms and the development of failures. The ATOS system of GOM was used for these 3D scans. The results show that the undulations were influenced by the tool temperature and the spring force. By contrast, the surface quality was most strongly dependent on the forming pressure, which also influenced the size and the number of gaps. The forming speed affected the gaps as well. The tool temperature had the largest influence on the development of wrinkles. As expected, the quasi-isotropic layup showed distinctly more wrinkles and undulations, but it also presented a better surface quality than the orthotropic layup.

  6. Numerical simulation of cavitation effects influenced by centrifugal pump inlet parameters

    Science.gov (United States)

    Zhao, L. F.; Wang, Y.; Ning, C.; Liu, Z. C.; Zhu, Z. T.; Xie, S. F.

    2015-01-01

    Cavitation has great influence on performance of the centrifugal pump. However, there is still no effective design to overcome this problem. Blade leading edge of centrifugal pump impeller is the initial position of cavitation. The leading edge geometry shape not only has a great influence on the cavitation inception and its development, but also a great influence on the flow state near the impeller inlet. In this paper, the numerical simulation method is adopted. Cavitation of four different models (including rectangular-shape blade model, circular-arc-shape blade model, elliptical-shape blade model and cusp-shape blade model) are simulated under the same condition by changing the NPSHA value. The influence of different blade models on cavitation performance is analyzed. The results show that the deviation between the simulated data and experimental data is within the deviation range. The head of rectangular-shape blade model and circular-arc-shape blade model are higher than those of elliptical-shape blade model and cusp-shape blade model. However, the head of rectangular-shape blade model and circular-arc-shape blade model is smaller than the latter under the low effective cavitation margin. What's more, the head of the models with trimmed blade are higher than the head of the models with untrimmed blade under the working condition but are smaller under the low effective cavitation margin.

  7. Comparison of different morphological parameters with duration of obstruction created experimentally in unilateral upper ureters: An animal model

    Directory of Open Access Journals (Sweden)

    Shasanka Shekhar Panda

    2014-01-01

    Full Text Available Background: The objective of the following study is to determine and to compare the different morphological parameters with duration of obstruction created experimentally in unilateral upper ureters of rats. Materials and Methods: Unilateral upper ureteric obstruction was created in 60 adult Wistar rats that were reversed after predetermined intervals. Rats were sacrificed and ipsilateral kidneys were subjected for analysis of morphological parameters such as renal height, cranio-caudal diameter, antero-posterior diameter, lateral diameter, volume of the pelvis and average cortical thickness: Renal height. Results: Renal height and cranio-caudal diameter of renal pelvis after ipsilateral upper ureteric obstruction started rising as early as 7 days of creating obstruction and were affected earlier than antero-posterior and lateral diameter and also were reversed earlier than other parameters after reversal of obstruction. Renal cortical thickness and volume of the pelvis were affected after prolonged obstruction (> 3 weeks and were the late parameters to be reversed after reversal of obstruction. Conclusions: Cranio-caudal diameter and renal height were the early morphological parameters to be affected and reversed after reversal of obstruction in experimentally created ipsilateral upper ureteric obstruction.

  8. Prediction of drug-polymer miscibility through the use of solubility parameter based Flory-Huggins interaction parameter and the experimental validation: PEG as model polymer.

    Science.gov (United States)

    Thakral, Seema; Thakral, Naveen K

    2013-07-01

    Important consideration for developing physically stable solid dispersion is miscibility of drug in carrier matrix. It is possible to predict thermodynamics of binary system through free energy calculations based on Flory-Huggins interaction parameter (χ(dp)). In present study, PEG 6000 as model polymer and dataset comprising commonly used drugs/excipients was selected. The three-dimensional solubility parameter based on group contribution method was utilized for systemic calculation of χ(dp) of the polymer with each compound in data set. On the basis of the values of χ(dp), it was possible to categorize all the compounds into three distinct categories, Types I and II: compounds predicted to be miscible and immiscible respectively with the polymer in all proportions and Type III: compounds expected to exhibit composition dependent miscibility behavior. The Bagley plot showed that majority of points for Type I fall in a region, which can approximately be delimited by a circle. Experimental verification through thermal analysis revealed that though it was possible to predict correctly miscibility behavior of Type II class compounds, distinction between Types I and III was less evident. Hence, solubility parameter based χ(dp) may be used as an initial tool for fast screening of immiscible combination of polymer and drug. Copyright © 2013 Wiley Periodicals, Inc.

  9. Experimental research of shock wave processes influence on machineless gas flow energy separation effect

    Science.gov (United States)

    Vinogradov, Y. A.; Zditovets, A. G.; Leontiev, A. I.; Popovich, S. S.; Strongin, M. M.

    2017-11-01

    Experimental results for artificially initiated shock wave influence on machineless gas flow energy separation effect are presented. The working principle of the technique is based on interaction of supersonic and subsonic flows through the heat-conducting wall. In result at output there are two flows with different temperature – heated supersonic air flow and cooled subsonic one. Shock waves were initiated by conic ribs placed along the supersonic channel. During the research varied parameters included uni-flow and counter-flow air moving direction in subsonic and supersonic channels, subsonic flow rate divided by supersonic one (from 0 to 0.9), stagnation flow temperature (298, 313 and 343K) and initial Mach number (1.9, 2.5). The research was carried out with the use of infrared thermal imaging, thermocouples, total and static pressure probes, National Instruments automation equipment. Energy separation effect is increasing with the growth of Mach number and stagnation flow temperature. Rib placement in supersonic channel causes rise of static pressure and wall temperature and results in decreasing of energy separation effect at output of the device by less than 12%. Operability of the device with shock wave generation is remained.

  10. Experimental study of laser-induced plasma: Influence of laser fluence and pulse duration

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Xueshi; Ma, Qianli; Perrier, Maxime; Motto-Ros, Vincent [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne cedex (France); Sabourdy, David; Nguyen, Luc; Jalocha, Alain [CILAS Laser Company, Photonics Department, 45000 Orléans (France); Yu, Jin, E-mail: jin.yu@univ-lyon1.fr [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne cedex (France)

    2013-09-01

    Influence of laser fluence and pulse duration on the morphology and the internal structure of plasma induced by infrared nanosecond laser pulse on an aluminum target placed in an argon ambient gas of one atmosphere pressure was experimentally studied. Dual-wavelength differential spectroscopic imaging was used in the experiment, which allowed observing the detailed structure inside of the ablation plume with distributions of species evaporated from the target as well as contributed by the ambient gas. Different regimes of post-ablation interaction were investigated using different laser fluences and pulse durations. We demonstrate in particular that plasma shielding due to various species localized in different zones inside of the plume leads to different morphologies and internal structures of the plasma. At moderate fluence, the plasma shielding due to the ablation vapor localized in the central part of the plume leads to its nearly spherical expansion with a layered structure of the distribution of different species. At higher fluence, the plasma shielding becomes strongly contributed by ionized ambient gas localized in the propagation front of the plume. An elongated morphology of the plume is observed with a zone of mixing between different species evaporated from the target or contributed by the ambient gas. Finally with extremely strong plasma shielding by ionized ambient gas in the case of a long duration pulse at high fluence, a delayed evaporation from the target is observed due to the ejection of melted material by splashing. - Highlights: • Morphology and internal structure of a plasma were experimentally determined. • Laser fluence and pulse duration are critical parameters for plasma structure. • Plasma shielding due to various species leads to different plasma structures. • Different regimes of laser-support absorption wave are used for interpretation. • Splashing ejection is observed for strong plasma shielding with long pulse.

  11. INFLUENCE OF ROLLING STOCK VIBROACOUSTICAL PARAMETERS ON THE CHOICE OF RATIONAL VALUES OF LOCOMOTIVE RUNNING GEAR

    Directory of Open Access Journals (Sweden)

    Yu. V. Zelenko

    2016-06-01

    Full Text Available Purpose.The success of the traffic on the railways of Ukraine depends on the number and the operational fleet of electric locomotives. Today, the locomotive depot exploit physically and morally outdated locomotives that have low reliability. Modernization of electric locomotives is not economically justified. The aim of this study is to improve the safety of the traction rolling stock by the frequency analysis of dynamical systems, which allows conducting the calculation of the natural (of resonant frequencies of the design and related forms of vibrations.Methodology.The study was conducted by methods of analytical mechanics and mathematical modeling of operating loads of freight locomotive when driving at different speeds on the straight and curved track sections. The theoretical value of the work is the technique of choice of constructive schemes and rational parameters of perspective electric locomotive taking into account the electric inertia ratios and stiffness coefficients of Lagrange second-order equations.Findings. The problems of theoretical research and the development of a mathematical model of the spatial electric vibrations are solved. The theoretical studies of the effect of inertia ratios and stiffness coefficients on the dynamic values and the parameter values of electric locomotive undercarriages are presented.Originality.The set of developed regulations and obtained results is a practical solution to selecting rational parameters of bogies of the freight mainline locomotive for railways of Ukraine. A concept of choice of constructive scheme and rational parameters of perspective locomotive is formulated. It is developed the method of calculation of spatial electric locomotive oscillations to determine its dynamic performance. The software complex for processing the data of experimental studies of dynamic parameters of electric locomotive and comparing the results of the theoretical calculations with the data of full

  12. The Influence on Modal Parameters of Thin Cylindrical Shell under Bolt Looseness Boundary

    Directory of Open Access Journals (Sweden)

    Hui Li

    2016-01-01

    Full Text Available The influence on modal parameters of thin cylindrical shell (TCS under bolt looseness boundary is investigated. Firstly, bolt looseness boundary of the shell is divided into two types, that is, different bolt looseness numbers and different bolt looseness levels, and natural frequencies and mode shapes are calculated by finite element method to roughly master vibration characteristics of TCS under these conditions. Then, the following measurements and identification techniques are used to get precise frequency, damping, and shape results; for example, noncontact laser Doppler vibrometer and vibration shaker with excitation level being precisely controlled are used in the test system; “preexperiment” is adopted to determine the required tightening torque and verify fixed constraint boundary; the small-segment FFT processing technique is employed to accurately measure nature frequency and laser rotating scanning technique is used to get shape results with high efficiency. Finally, based on the measured results obtained by the above techniques, the influence on modal parameters of TCS under two types of bolt looseness boundaries is analyzed and discussed. It can be found that bolt looseness boundary can significantly affect frequency and damping results which might be caused by changes of nonlinear stiffness and damping and in bolt looseness positions.

  13. [Photosynthetic parameters and physiological indexes of Paris polyphylla var. yunnanensis influenced by arbuscular mycorrhizal fungi].

    Science.gov (United States)

    Wei, Zheng-xin; Guo, Dong-qin; Li, Hai-feng; Ding, Bo; Zhang, Jie; Zhou, Nong; Yu, Jie

    2015-10-01

    Through potted inoculation test at room temperature and indoor analysis, the photosynthetic parameters and physiological and biochemical indexes of Paris polyphylla var. yunnanensis were observed after 28 arbuscular mycorrhizal (AM) fungi were injected into the P. polyphylla var. yunnanensis growing in a sterile soil environment. The results showed that AM fungi established a good symbiosis with P. polyphylla var. yunnanensis. The AM fungi influenced the photosynthetic parameters and physiological and biochemical indexes of P. polyphylla var. yunnanensis. And the influences were varied depending on different AM fungi. The application of AM fungi improved photosynthesis intensity of P. polyphylla var. yunnanensis mesophyll cells, the contents of soluble protein and soluble sugar, protective enzyme activity of P. polyphylla var. yunnanensis leaf, which was beneficial to resist the adverse environment and promote the growth of P. polyphylla var. yunnanensis. Otherwise, there was a certain mutual selectivity between P. polyphylla var. yunnanensis and AM fungi. From the comprehensive effect of inoculation, Racocetra coralloidea, Scutellospora calospora, Claroideoglomus claroideum, S. pellucida and Rhizophagus clarus were the most suitable AM fungi to P. polyphylla var. yunnanensis when P. polyphylla var. yunnanensis was planted in the field.

  14. Numerical Methods for a Multicomponent Two-Phase Interface Model with Geometric Mean Influence Parameters

    KAUST Repository

    Kou, Jisheng

    2015-07-16

    In this paper, we consider an interface model for multicomponent two-phase fluids with geometric mean influence parameters, which is popularly used to model and predict surface tension in practical applications. For this model, there are two major challenges in theoretical analysis and numerical simulation: the first one is that the influence parameter matrix is not positive definite; the second one is the complicated structure of the energy function, which requires us to find out a physically consistent treatment. To overcome these two challenging problems, we reduce the formulation of the energy function by employing a linear transformation and a weighted molar density, and furthermore, we propose a local minimum grand potential energy condition to establish the relation between the weighted molar density and mixture compositions. From this, we prove the existence of the solution under proper conditions and prove the maximum principle of the weighted molar density. For numerical simulation, we propose a modified Newton\\'s method for solving this nonlinear model and analyze its properties; we also analyze a finite element method with a physical-based adaptive mesh-refinement technique. Numerical examples are tested to verify the theoretical results and the efficiency of the proposed methods.

  15. Influence of process parameters on the formability of bead stamping part using advanced models

    Science.gov (United States)

    Cha, W.; Müller, S.; Bursac, N.; Albers, A.; Volk, W.

    2017-09-01

    Beads are applied to deep drawn sheet metal parts to increase its stiffness. In order to form the bead, a two-stage manufacturing process including at least deep drawing and beading is performed. Thus, reductions of sheet metal thickness and consequently weight reduction can be effectively reached by numeric optimization. In order to apply the optimization algorithm to the production of non-virtual actual parts, the forming limits of the parts must be considered in both manufacturing steps. Bead formability is affected by process parameters such as blank holding force and lubrication. One way to investigate these influences is to use an accurate simulation model. In this study, the yield function named Yld2000-2D under non-associated flow rule is used to express anisotropic material behavior of blank and the Generalized Forming Limit Concept (GFLC) considering nonlinear strain paths is used to determine the formability. These models are validated by comparing the strain and bead forming limits measured in the Nakajima experiment. Then, the influences of mentioned process parameters are investigated by the validated model.

  16. Influence of Process Parameters in n-PMEDM of Inconel 800 with Electrode and Coated Electrodes

    Directory of Open Access Journals (Sweden)

    Karunakaran K.

    2017-01-01

    Full Text Available By considering the unique performances, the Powder Mixed Electrical Discharge Machining (PMEDM mostly encounter choice for machining the hard materials with job features like intricate shapes with grater accuracy and those materials are difficult to cut in conventional machining processes. This Research aimed to prepare parameter index chart for machining nickel based super alloy - Inconel 800 for various requirements. To achieve the aim, In this experimental study on machining of Inconel 800 in PMEDM with electrolyte copper electrode as well as silver coated electrolyte copper electrode is focused. Taguchi full factorial design derived from MINITAB release-16 software was used to design the experimentation. The factors like pulse off time, Current and Pulse on Time were considered. The responses like amount of Tool Wear, Quantity of material removal, surface finishes were noted against each case. In the same experimental conditions the coated electrode increased the MRR by 36.67% with minor increment of maximum surface roughness to 16.11%.

  17. Influence of matching solubility parameter of polymer matrix and CNT on electrical conductivity of CNT/rubber composite

    National Research Council Canada - National Science Library

    Ata, Seisuke; Mizuno, Takaaki; Nishizawa, Ayumi; Subramaniam, Chandramouli; Futaba, Don N; Hata, Kenji

    2014-01-01

    .... By using arbitrary nine kinds of rubbers as matrices, we experimentally demonstrate that the matching the solubility parameter of CNTs and the rubber matrix is important to achieve higher electrical...

  18. Experimental estimation of technology parameters of TWT slow-wave structure elements manufacture

    Directory of Open Access Journals (Sweden)

    Predmirskyi V. S.

    2017-04-01

    Full Text Available During the test of traveling wave tubes it was ascertained the direct dependence of the thermal conductivity of the slow wave structure from accuracy of manufacturing and from porosity of ceramic support rods. It is allowed to define the need to improve the accuracy of their production and the presorting by porosity. In this paper it is solved the problem of fastening of the ceramic rods in the process of processing by coolant instead of adhesive layer. The list of technological parameters and modes of machining support rods held by molecular cohesion forces are defined. The developed system of experiments allowed to determine the processing parameters required for the calculation of the bond strength (due to the liquid layer of the ceramic support rod with a mandrel in the process of machining. This makes possible to determine the technological process parameters of ceramic supporting bars polishing for TWT slow-wave structure. It is shown the possibility of power approach to the estimation of process parameters.

  19. Experimental determination of solubility parameters of oils as a function of pressure

    DEFF Research Database (Denmark)

    Verdier, Sylvain Charles Roland; Duong, Diep; Andersen, Simon Ivar

    2005-01-01

    In this work, the solubility parameter of dead and live crude oils was measured at 303.15 K and up to 300 bar, using the internal pressure approach. An indirect technique was chosen, using thermal expansivities (determined from microcalorimetric measurements) and isothermal compressibilities...

  20. Experimental design for parameter estimation of two time-scale model of photosynthesis and photoinhibition in microalgae

    Czech Academy of Sciences Publication Activity Database

    Papáček, Š.; Čelikovský, Sergej; Rehák, Branislav; Štys, D.

    2010-01-01

    Roč. 80, č. 6 (2010), s. 1302-1309 ISSN 0378-4754 R&D Projects: GA ČR(CZ) GA102/08/0186 Institutional research plan: CEZ:AV0Z10750506 Keywords : Photosynthetic factory * Experimental design * Parameter estimation * Two-scale modeling Subject RIV: BC - Control Systems Theory Impact factor: 0.812, year: 2010 http://library.utia.cas.cz/separaty/2010/TR/celikovsky-0341543.pdf

  1. Experimental study and empirical prediction of fuel flow parameters under air evolution conditions

    Science.gov (United States)

    Kitanina, E. E.; Kitanin, E. L.; Bondarenko, D. A.; Kravtsov, P. A.; Peganova, M. M.; Stepanov, S. G.; Zherebzov, V. L.

    2017-11-01

    Air evolution in kerosene under the effect of gravity flow with various hydraulic resistances in the pipeline was studied experimentally. The study was conducted at pressure ranging from 0.2 to 1.0 bar and temperature varying between -20°C and +20°C. Through these experiments, the oversaturation limit beyond which dissolved air starts evolving intensively from the fuel was established and the correlations for the calculation of pressure losses and air evolution on local loss elements were obtained. A method of calculating two-phase flow behaviour in a titled pipeline segment with very low mass flow quality and fairly high volume flow quality was developed. The complete set of empirical correlations obtained by experimental analysis was implemented in the engineering code. The software simulation results were repeatedly verified against our experimental findings and Airbus test data to show that the two-phase flow simulation agrees quite well with the experimental results obtained in the complex branched pipelines.

  2. Compaction of enteric-coated pellets: influence of formulation and process parameters on tablet properties and in vivo evaluation.

    Science.gov (United States)

    Debunne, Ann; Vervaet, Chris; Mangelings, Debby; Remon, Jean-Paul

    2004-07-01

    The aim of this study was to investigate the influence of formulation and compression parameters on the properties of tablets, containing enteric-coated pellets, and on the integrity of the enteric polymer of the individual pellets after compression. In addition the piroxicam plasma concentrations were determined after single and multiple oral administration of powder, pellet and tablet formulations at a dose of 0.3 mg piroxicam/kg bodyweight to dogs. Tablets consisted of enteric-coated pellets (containing 2.5% (w/w) piroxicam in combination with microcrystalline cellulose and sodium carboxymethylcellulose (using Avicel PH 101 and Avicel CL 611 in a ratio of 1-3), cushioning waxy pellets and 10% Kollidon CL (as an external disintegrator). From the D-optimality experimental design it was concluded that the ratio of coated pellets to cushioning pellets (CoP/CuP) affected all tablet properties evaluated. Variation of the pellet size and the CoP/CuP ratio resulted in different in vitro tablet disintegration times. Enteric coating of the pellets or compression of the coated pellets did not have a significant influence (P >0.05) on AUC(0-->72 h). Cmax values obtained after oral administration of coated pellets and compressed coated pellets were significantly lower than for the other formulations. Differences in in vitro tablet disintegration times were not reflected in the onset of the piroxicam plasma concentrations. A dosing interval of 48 h prevented piroxicam accumulation following multiple dose administration.

  3. Influence of TiB2 particles on machinability and machining parameter optimization of TiB2/Al MMCs

    Directory of Open Access Journals (Sweden)

    Ruisong JIANG

    2018-01-01

    Full Text Available In situ formed TiB2 particle reinforced aluminum matrix composites (TiB2/Al MMCs have some extraordinary properties which make them be a promising material for high performance aero-engine blade. Due to the influence of TiB2 particles, the machinability is still a problem which restricts the application of TiB2/Al MMCs. In order to meet the industrial requirements, the influence of TiB2 particles on the machinability of TiB2/Al MMCs was investigated experimentally. Moreover, the optimal machining conditions for this kind of MMCs were investigated in this study. The major conclusions are: (1 the machining force of TiB2/Al MMCs is bigger than that of non-reinforced alloy and mainly controlled by feed rate; (2 the residual stress of TiB2/Al MMCs is compressive while that of non-reinforced alloy is nearly neutral; (3 the surface roughness of TiB2/Al MMCs is smaller than that of non-reinforced alloy under the same cutting speed, but reverse result was observed when the feed rate increased; (4 a multi-objective optimization model for surface roughness and material removal rate (MRR was established, and a set of optimal parameter combinations of the machining was obtained. The results show a great difference from SiC particle reinforced MMCs and provide a useful guide for a better control of machining process of this material.

  4. Continuous melt granulation: Influence of process and formulation parameters upon granule and tablet properties.

    Science.gov (United States)

    Monteyne, Tinne; Vancoillie, Jochem; Remon, Jean-Paul; Vervaet, Chris; De Beer, Thomas

    2016-10-01

    The pharmaceutical industry has a growing interest in alternative manufacturing models allowing automation and continuous production in order to improve process efficiency and reduce costs. Implementing a switch from batch to continuous processing requires fundamental process understanding and the implementation of quality-by-design (QbD) principles. The aim of this study was to examine the relationship between formulation-parameters (type binder, binder concentration, drug-binder miscibility), process-parameters (screw speed, powder feed rate and granulation temperature), granule properties (size, size distribution, shape, friability, true density, flowability) and tablet properties (tensile strength, friability, dissolution rate) of four different drug-binder formulations using Design of experiments (DOE). Two binders (polyethylene glycol (PEG) and Soluplus®) with a different solid state, semi-crystalline vs amorphous respectively, were combined with two model-drugs, metoprolol tartrate (MPT) and caffeine anhydrous (CAF), both having a contrasting miscibility with the binders. This research revealed that the granule properties of miscible drug-binder systems depended on the powder feed rate and barrel filling degree of the granulator whereas the granule properties of immiscible systems were mainly influenced by binder concentration. Using an amorphous binder, the tablet tensile strength depended on the granule size. In contrast, granule friability was more important for tablet quality using a brittle binder. However, this was not the case for caffeine-containing blends, since these phenomena were dominated by the enhanced compression properties of caffeine Form I, which was formed during granulation. Hence, it is important to gain knowledge about formulation behavior during processing since this influences the effect of process parameters onto the granule and tablet properties. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Properties of electrodeposited Co–Mn films: Influence of deposition parameters

    Energy Technology Data Exchange (ETDEWEB)

    Karpuz, Ali, E-mail: alikarpuz@kmu.edu.tr [Physics Department, Kamil Ozdag Science Faculty, Karamanoglu Mehmetbey University, Karaman (Turkey); Kockar, Hakan [Physics Department, Science & Literature Faculty, Balikesir University, Balikesir (Turkey); Alper, Mursel [Physics Department, Science & Literature Faculty, Uludag University, Bursa (Turkey)

    2015-12-15

    , influence of the deposition parameters affect H{sub c} is in order of the electrolyte pH, the Mn concentration in the electrolyte and the film thickness (from high to low influence). As it is observed that the magnetic properties are sensible to the deposition parameters and the Co–Mn films may have the potential applications in magnetic recording and sensors technologies.

  6. Gimbal Influence on the Stability of Exterior Orientation Parameters of UAV Acquired Images

    Science.gov (United States)

    Gašparović, Mateo; Jurjević, Luka

    2017-01-01

    In this paper, results from the analysis of the gimbal impact on the determination of the camera exterior orientation parameters of an Unmanned Aerial Vehicle (UAV) are presented and interpreted. Additionally, a new approach and methodology for testing the influence of gimbals on the exterior orientation parameters of UAV acquired images is presented. The main motive of this study is to examine the possibility of obtaining better geometry and favorable spatial bundles of rays of images in UAV photogrammetric surveying. The subject is a 3-axis brushless gimbal based on a controller board (Storm32). Only two gimbal axes are taken into consideration: roll and pitch axes. Testing was done in a flight simulation, and in indoor and outdoor flight mode, to analyze the Inertial Measurement Unit (IMU) and photogrammetric data. Within these tests the change of the exterior orientation parameters without the use of a gimbal is determined, as well as the potential accuracy of the stabilization with the use of a gimbal. The results show that using a gimbal has huge potential. Significantly, smaller discrepancies between data are noticed when a gimbal is used in flight simulation mode, even four times smaller than in other test modes. In this test the potential accuracy of a low budget gimbal for application in real conditions is determined. PMID:28218699

  7. Gimbal Influence on the Stability of Exterior Orientation Parameters of UAV Acquired Images

    Directory of Open Access Journals (Sweden)

    Mateo Gašparović

    2017-02-01

    Full Text Available In this paper, results from the analysis of the gimbal impact on the determination of the camera exterior orientation parameters of an Unmanned Aerial Vehicle (UAV are presented and interpreted. Additionally, a new approach and methodology for testing the influence of gimbals on the exterior orientation parameters of UAV acquired images is presented. The main motive of this study is to examine the possibility of obtaining better geometry and favorable spatial bundles of rays of images in UAV photogrammetric surveying. The subject is a 3-axis brushless gimbal based on a controller board (Storm32. Only two gimbal axes are taken into consideration: roll and pitch axes. Testing was done in a flight simulation, and in indoor and outdoor flight mode, to analyze the Inertial Measurement Unit (IMU and photogrammetric data. Within these tests the change of the exterior orientation parameters without the use of a gimbal is determined, as well as the potential accuracy of the stabilization with the use of a gimbal. The results show that using a gimbal has huge potential. Significantly, smaller discrepancies between data are noticed when a gimbal is used in flight simulation mode, even four times smaller than in other test modes. In this test the potential accuracy of a low budget gimbal for application in real conditions is determined.

  8. Influence of autoclave sterilization on the surface parameters and mechanical properties of six orthodontic wires.

    Science.gov (United States)

    Pernier, C; Grosgogeat, B; Ponsonnet, L; Benay, G; Lissac, M

    2005-02-01

    Orthodontic wires are frequently packaged in individual sealed bags in order to avoid cross-contamination. The instructions on the wrapper generally advise autoclave sterilization of the package and its contents if additional protection is desired. However, sterilization can modify the surface parameters and the mechanical properties of many types of material. The aim of this research was to determine the influence of one of the most widely used sterilization processes, autoclaving (18 minutes at 134 degrees C, as recommended by the French Ministry of Health), on the surface parameters and mechanical properties of six wires currently used in orthodontics (one stainless steel alloy: Tru-Chrome RMO; two nickel-titanium shape memory alloys: Neo Sentalloy and Neo Sentalloy with Ionguard GAC; and three titanium-molybdenum alloys: TMA(R) and Low Friction TMA Ormco and Resolve GAC). The alloys were analysed on receipt and after sterilization, using surface structure observation techniques, including optical, scanning electron and atomic force microscopy and profilometry. The mechanical properties were assessed by three-point bending tests. The results showed that autoclave sterilization had no adverse effects on the surface parameters or on the selected mechanical properties. This supports the possibility for practitioners to systematically sterilize wires before placing them in the oral environment.

  9. Gimbal Influence on the Stability of Exterior Orientation Parameters of UAV Acquired Images.

    Science.gov (United States)

    Gašparović, Mateo; Jurjević, Luka

    2017-02-18

    In this paper, results from the analysis of the gimbal impact on the determination of the camera exterior orientation parameters of an Unmanned Aerial Vehicle (UAV) are presented and interpreted. Additionally, a new approach and methodology for testing the influence of gimbals on the exterior orientation parameters of UAV acquired images is presented. The main motive of this study is to examine the possibility of obtaining better geometry and favorable spatial bundles of rays of images in UAV photogrammetric surveying. The subject is a 3-axis brushless gimbal based on a controller board (Storm32). Only two gimbal axes are taken into consideration: roll and pitch axes. Testing was done in a flight simulation, and in indoor and outdoor flight mode, to analyze the Inertial Measurement Unit (IMU) and photogrammetric data. Within these tests the change of the exterior orientation parameters without the use of a gimbal is determined, as well as the potential accuracy of the stabilization with the use of a gimbal. The results show that using a gimbal has huge potential. Significantly, smaller discrepancies between data are noticed when a gimbal is used in flight simulation mode, even four times smaller than in other test modes. In this test the potential accuracy of a low budget gimbal for application in real conditions is determined.

  10. Influence of laser parameters on selective retinal treatment using single-phase heat transfer analyses.

    Science.gov (United States)

    Banerjee, Rupak K; Zhu, Liang; Gopalakrishnan, Pradeep; Kazmierczak, Michael J

    2007-05-01

    Selective thermal treatment to retina is induced by short pulsed lasers to denaturize retinal pigment epithelium (RPE) selectively, while sparing the sensitive photoreceptors. The problem associated with the usage of short pulsed laser is the difficulty in determining the correct dosimetry parameters. This study quantifies the influence of laser parameters over the therapeutic range. The laser-tissue interaction is numerically investigated by analyzing the transient temperature in ocular tissues during the treatment. The rate process analysis for thermal injury is employed to estimate the selective damage of retina. The contours of Arrhenius integral value (Omeg/ Omegamax) presented in this study show both the area and magnitude of damage caused by various laser parameters. Results reveal that the 2 micros pulsed laser with green wavelength and Gaussian profile is relatively more effective for selective retinal treatment. The repetition frequency of 100 Hz is found to produce selectively RPE damage, while higher frequencies produce collateral damage to neural retina and choroid located within 2 microm from the RPE interface.

  11. Influence of extrinsic operational parameters on salt diffusion during ultrasound assisted meat curing.

    Science.gov (United States)

    Inguglia, Elena S; Zhang, Zhihang; Burgess, Catherine; Kerry, Joseph P; Tiwari, Brijesh K

    2018-02-01

    The present study investigated the effect of geometric parameters of the ultrasound instrument during meat salting in order to enhance salt diffusion and salt distribution in pork meat on a lab scale. The effects of probe size (∅2.5 and 1.3cm) and of different distances between the transducer and the meat sample (0.3, 0.5, and 0.8cm) on NaCl diffusion were investigated. Changes in the moisture content and NaCl gain were used to evaluate salt distribution and diffusion in the samples, parallel and perpendicular to ultrasound propagation direction. Results showed that 0.3cm was the most efficient distance between the probe and the sample to ensure a higher salt diffusion rate. A distance of 0.5cm was however considered as a trade-off distance to ensure salt diffusion and maintenance of meat quality parameters. The enhancement of salt diffusion by ultrasound was observed to decrease with increased horizontal distance from the probe. This study is of valuable importance for meat processing industries willing to apply new technologies on a larger scale and with defined operational standards. The data suggest that the geometric parameters of ultrasound systems can have strong influence on the efficiency of ultrasonic enhancement of NaCl uptake in meat and can be a crucial element in determining salt uptake during meat processing. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. The influence of inertial sensor sampling frequency on the accuracy of measurement parameters in rearfoot running.

    Science.gov (United States)

    Mitschke, Christian; Zaumseil, Falk; Milani, Thomas L

    2017-09-26

    Increasingly, inertial sensors are being used for running analyses. The aim of this study was to systematically investigate the influence of inertial sensor sampling frequencies (SF) on the accuracy of kinematic, spatio-temporal, and kinetic parameters. We hypothesized that running analyses at lower SF result in less signal information and therefore the inability to sufficiently interpret measurement data. Twenty-one subjects participated in this study. Rearfoot strikers ran on an indoor running track at a velocity of 3.5 ± 0.1 ms(-1). A uniaxial accelerometer was attached at the tibia and an inertial measurement unit was mounted at the heel of the right shoe. All sensors were synchronized at the start and data was measured with 1000 Hz (reference SF). Datasets were reduced to 500, 333, 250, 200, and 100 Hz in post-processing. The results of this study showed that a minimum SF of 500 Hz should be used to accurately measure kinetic parameters (e.g. peak heel acceleration). In contrast, stride length showed accurate results even at 333 Hz. 200 Hz were required to calculate parameters accurately for peak tibial acceleration, stride duration, and all kinematic measurements. The information from this study is necessary to correctly interpret measurement data of existing investigations and to plan future studies.

  13. Assessment of reduced-order unscented Kalman filter for parameter identification in 1-dimensional blood flow models using experimental data.

    Science.gov (United States)

    Caiazzo, A; Caforio, Federica; Montecinos, Gino; Muller, Lucas O; Blanco, Pablo J; Toro, Eluterio F

    2016-10-25

    This work presents a detailed investigation of a parameter estimation approach on the basis of the reduced-order unscented Kalman filter (ROUKF) in the context of 1-dimensional blood flow models. In particular, the main aims of this study are (1) to investigate the effects of using real measurements versus synthetic data for the estimation procedure (i.e., numerical results of the same in silico model, perturbed with noise) and (2) to identify potential difficulties and limitations of the approach in clinically realistic applications to assess the applicability of the filter to such setups. For these purposes, the present numerical study is based on a recently published in vitro model of the arterial network, for which experimental flow and pressure measurements are available at few selected locations. To mimic clinically relevant situations, we focus on the estimation of terminal resistances and arterial wall parameters related to vessel mechanics (Young's modulus and wall thickness) using few experimental observations (at most a single pressure or flow measurement per vessel). In all cases, we first perform a theoretical identifiability analysis on the basis of the generalized sensitivity function, comparing then the results owith the ROUKF, using either synthetic or experimental data, to results obtained using reference parameters and to available measurements. Copyright © 2016 John Wiley & Sons, Ltd.

  14. Tire-road noise: an experimental study of tire and road design parameters

    NARCIS (Netherlands)

    Bekke, Dirk; Wijnant, Ysbrand H.; Weegerink, Thijs; de Boer, Andries

    2013-01-01

    It is widely known that road traffic noise has negative influences on human health. Hence, as tire-road noise is considered to be the most dominant cause of road traffic noise above 30-50 km/h, a lot of research is performed by the two involving industries: road authorities/manufacturers and tire

  15. Awareness of social influence on food intake. An analysis of two experimental studies.

    Science.gov (United States)

    Robinson, Eric; Field, Matt

    2015-02-01

    There is consistent evidence that the amount of food we consume can be influenced by the eating behaviour of other people. Some previous experimental studies reported that consumers are unaware of this influence on their behaviour. The present research tested whether people may be more aware of social influence on their eating than previously assumed. In two studies, participants (total n = 160) were exposed to information about the amount of snack food other people had been eating shortly before being served the same snack food and eating as much as they liked. After this, participants responded to questions regarding whether they thought their food intake had been socially influenced, and reported the reasons why they believed they had or had not been influenced. Of the 160 participants, 34% reported that they had been influenced, 10% were unsure and 56% reported they had not been influenced. Crucially, participants' reports of social influence appeared to be accurate; the food intake of participants reporting social influence was significantly affected by the amount of food other people had been eating, whereas the food intake of participants denying social influence was unaffected. Individuals may be more aware of the effect that social influence has on their eating behaviour than previously assumed. Further work is needed to identify the factors which determine whether people are susceptible to social influence on eating behaviour. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. The predicted influence of climate change on lesser prairie-chicken reproductive parameters.

    Directory of Open Access Journals (Sweden)

    Blake A Grisham

    Full Text Available The Southern High Plains is anticipated to experience significant changes in temperature and precipitation due to climate change. These changes may influence the lesser prairie-chicken (Tympanuchus pallidicinctus in positive or negative ways. We assessed the potential changes in clutch size, incubation start date, and nest survival for lesser prairie-chickens for the years 2050 and 2080 based on modeled predictions of climate change and reproductive data for lesser prairie-chickens from 2001-2011 on the Southern High Plains of Texas and New Mexico. We developed 9 a priori models to assess the relationship between reproductive parameters and biologically relevant weather conditions. We selected weather variable(s with the most model support and then obtained future predicted values from climatewizard.org. We conducted 1,000 simulations using each reproductive parameter's linear equation obtained from regression calculations, and the future predicted value for each weather variable to predict future reproductive parameter values for lesser prairie-chickens. There was a high degree of model uncertainty for each reproductive value. Winter temperature had the greatest effect size for all three parameters, suggesting a negative relationship between above-average winter temperature and reproductive output. The above-average winter temperatures are correlated to La Niña events, which negatively affect lesser prairie-chickens through resulting drought conditions. By 2050 and 2080, nest survival was predicted to be below levels considered viable for population persistence; however, our assessment did not consider annual survival of adults, chick survival, or the positive benefit of habitat management and conservation, which may ultimately offset the potentially negative effect of drought on nest survival.

  17. CFD and experimental investigation of sloshing parameters for the safety assessment of HLM reactors

    Energy Technology Data Exchange (ETDEWEB)

    Myrillas, Konstantinos, E-mail: myrillas@vki.ac.be [von Karman Institute for Fluid Dynamics, Chaussée de Waterloo 72, B-1640 Rhode-St-Genèse (Belgium); Planquart, Philippe, E-mail: philippe.planquart@vki.ac.be [von Karman Institute for Fluid Dynamics, Chaussée de Waterloo 72, B-1640 Rhode-St-Genèse (Belgium); Simonini, Alessia, E-mail: Simonini@vki.ac.be [von Karman Institute for Fluid Dynamics, Chaussée de Waterloo 72, B-1640 Rhode-St-Genèse (Belgium); Buchlin, Jean-Marie, E-mail: buchlin@vki.ac.be [von Karman Institute for Fluid Dynamics, Chaussée de Waterloo 72, B-1640 Rhode-St-Genèse (Belgium); Schyns, Marc, E-mail: mschyns@SCKCEN.BE [SCK-CEN, Boeretang 200, B-2400 Mol (Belgium)

    2017-02-15

    Highlights: • Comparison of sloshing behavior in cylindrical tank using mercury and water. • Flow visualization of liquid sloshing in resonance case. • CFD simulations of sloshing with OpenFOAM, using the VOF method. • Qualitative and quantitative comparison of experimental and numerical results. • Evaluation of sloshing forces on the tank walls from numerical simulations. - Abstract: For the safety assessment of Heavy Liquid Metal nuclear reactors under seismic excitation, sloshing phenomena can be of great concern. The earthquake motions are transferred to the liquid coolant which oscillates inside the vessel, exerting additional forces on the walls and internal structures. The present study examines the case of MYRRHA, a multi-purpose experimental reactor with LBE as coolant, developed by SCK·CEN. The sloshing behavior of liquid metals is studied through a comparison between mercury and water in a cylindrical tank. Experimental investigation of sloshing is carried out using optical techniques with the shaking table facility SHAKESPEARE at the von Karman Institute. Emphasis is given on the resonance case, where maximum forces occur on the tank walls. The experimental cases are reproduced numerically with the CFD software OpenFOAM, using the VOF method to track the liquid interface. The non-linear nature of sloshing is observed through visualization, where swirling is shown in the resonance case. The complex behavior is well reproduced by the CFD simulations, providing good qualitative validation of the numerical tools. A quantitative comparison of the maximum liquid elevation inside the tank shows higher values for the liquid metal than for water. Some discrepancies are revealed in CFD results and the differences are quantified. From simulations it is verified that the forces scale with the density ratio, following similar evolution in time. Overall, water is demonstrated to be a valid option as a working liquid in order to evaluate the sloshing

  18. Study of Parameters Effect on Hydrodynamics of a Gas-Solid Chamber Experimentally and Numerically

    Directory of Open Access Journals (Sweden)

    Rahimzadeh Hassan

    2012-04-01

    Full Text Available In this research, gas velocity, initial static bed height and particle size effect on hydrodynamics of a non-reactive gas–solid fluidized bed chamber were studied experimentally and computationally. A multi fluid Eulerian model incorporating the kinetic theory for solid particles was applied to simulate the unsteady state behavior of this chamber and momentum exchange coefficients were calculated by using the Syamlal- O’Brien drag functions. Simulation results were compared with the experimental data in order to validate the CFD model. Pressure drops predicted by the simulations at different particle sizes and initial static bed height were in good agreement with experimental measurements at superficial gas velocity higher than the minimum fluidization velocity. Simulation results also indicated that small bubbles were produced at the bottom of the bed. These bubbles collided with each other as they moved upwards forming larger bubbles. Furthermore, this comparison showed that the model can predict hydrodynamic behavior of gas solid fluidized bed chambers reasonably well.

  19. The influence of electron-beam welding parameters on heat-affected-zone microfissuring in INCOLOY 903

    Science.gov (United States)

    Richards, N. L.; Nakkalil, R.; Chaturvedi, M. C.

    1994-08-01

    The microfissuring in the heat-affected zone (HAZ) of electron-beam-(EB-) welded thermomechanically processed INCOLOY 903 has been studied with a view to reducing the incidence of microfissuring and to obtaining a better understanding of the influence of EB welding parameters on it. For a given heat of material, microfissuring susceptibility has been quantitatively related to EB welding parameters and the shape of the weld pool. Fractional factorial experimental study of welding parameters showed that a reduction in welding speed and an increase in EB current for a given heat input would minimize HAZ microfissuring in the alloy. It was observed that with lower travel speeds, bccause of the shallower temperature gradients in the HAZ, the amount of liquated grain boundary area is less, thus leading to decreased microfissuring. Considerable HAZ microfissuring was observed on the coarse grain boundaries of warm-worked grains. The microfissures appeared to initiate in regions slightly removed from the fusion line. Minimal microfissuring was observed on the grain boundaries of fine recrystallized grains. These boundaries, however, had a thickened appearance bccause of the formation of Nb-enriched y phase by the process of grain boundary liquid film migration (LFM). The origin of the liquid on the grain boundaries is suggested to be due to the constitutional liquation of preexisting primary carbides (partial), fine MC carbides, and MNP-type phosphides. It is suggested that substantial occurrence of LFM in the HAZ minimizes microfissuring by decreasing the total temperature range of solidification and also by enabling the grain boundary liquid to solidify without the occurrence of low-melting terminal eutectic reaction.

  20. The influence of energy migration on luminescence kinetics parameters in upconversion nanoparticles.

    Science.gov (United States)

    Alyatkin, Sergey; Asharchuk, Ilya; Khaydukov, Kirill; Nechaev, Andrey; Lebedev, Oleg; Vainer, Yuri; Semchishen, Vladimir; Khaydukov, Evgeny

    2017-01-20

    The mechanism of upconversion at the nanoscale is still under discussion. In this paper, we report on the experimental results of anti-Stokes luminescence kinetics in the upconversion nanoparticles of β-NaYF4: 20%Yb3+; 0.6%Tm3+. The parameters of the luminescence kinetics were found to be unambiguously dependent on the number of excitation quanta n, which are necessary for certain transitions between the energy states of thulium ions. The observed correlation has been explained by means of the long-lasting energy migration between the ytterbium ions. The spread in time between the luminescent maxima of the corresponding thulium transitions not only shows the nonlinear character of upconversion, but also reveals the time scale of energy migration as well. From these, we derive that the conventional Förster formalism applied to the estimation of energy transfer efficiency in UCNP-fluorophore pairs can provide misleading results.

  1. Influence on surface characteristics of electron beam melting process (EBM) by varying the process parameters

    Science.gov (United States)

    Dolimont, Adrien; Michotte, Sebastien; Rivière-Lorphèvre, Edouard; Ducobu, François; Vivès, Solange; Godet, Stéphane; Henkes, Tom; Filippi, Enrico

    2017-10-01

    The use of additive manufacturing processes keeps growing in aerospace and biomedical industry. Among the numerous existing technologies, the Electron Beam Melting process has advantages (good dimensional accuracy, fully dense parts) and disadvantages (powder handling, support structure, high surface roughness). Analyzes of the surface characteristics are interesting to get a better understanding of the EBM operations. But that kind of analyzes is not often found in the literature. The main goal of this study is to determine if it is possible to improve the surface roughness by modifying some parameters of the process (scan speed function, number of contours, order of contours, etc.) on samples with different thicknesses. The experimental work on the surface roughness leads to a statistical analysis of 586 measures of EBM simple geometry parts.

  2. The influence of energy migration on luminescence kinetics parameters in upconversion nanoparticles

    Science.gov (United States)

    Alyatkin, Sergey; Asharchuk, Ilya; Khaydukov, Kirill; Nechaev, Andrey; Lebedev, Oleg; Vainer, Yuri; Semchishen, Vladimir; Khaydukov, Evgeny

    2017-01-01

    The mechanism of upconversion at the nanoscale is still under discussion. In this paper, we report on the experimental results of anti-Stokes luminescence kinetics in the upconversion nanoparticles of β-NaYF4: 20%Yb3+; 0.6%Tm3+. The parameters of the luminescence kinetics were found to be unambiguously dependent on the number of excitation quanta n, which are necessary for certain transitions between the energy states of thulium ions. The observed correlation has been explained by means of the long-lasting energy migration between the ytterbium ions. The spread in time between the luminescent maxima of the corresponding thulium transitions not only shows the nonlinear character of upconversion, but also reveals the time scale of energy migration as well. From these, we derive that the conventional Förster formalism applied to the estimation of energy transfer efficiency in UCNP-fluorophore pairs can provide misleading results.

  3. Experimental verification and analytical approach to influence stator skew on electromagnetic performance of permanent magnet generators with multipole rotor

    Science.gov (United States)

    Choi, Jang-Young; Jang, Seok-Myeong; Ko, Kyoung-Jin

    2009-04-01

    This paper deals with experimental verification and analytical approach to influence stator skew on electromagnetic performance of a permanent magnet generator (PMG) with multipole rotor. The analytical expressions for magnetic field distributions are due to permanent magnets and the two-dimensional permeance function considering skew effects are established. On the basis of these analytical solutions, the analytical solutions for cogging torque and back-emf considering skew effects are also derived. Then, by applying estimated electrical parameters to a simple equivalent circuit of one phase for the PMG, output performances of the PMG with/without a skewed stator are investigated. Finally, by confirming that all analytical results are validated extensively by nonlinear finite element calculations and measurements, the validity of analysis methods presented in this paper is verified, and the influence stator skew on cogging torque, back-emf, and output performances of the PMG is also clearly described.

  4. Influence of newly designed monorail pressure sensor catheter on coronary diagnostic parameters: an in vitro study.

    Science.gov (United States)

    Banerjee, Rupak K; Peelukhana, Srikara V; Goswami, Ishan

    2014-02-07

    The decision to perform intervention on a patient with coronary stenosis is often based on functional diagnostic parameters obtained from pressure and flow measurements using sensor-tipped guidewire at maximal vasodilation (hyperemia). Recently, a rapid exchange Monorail Pressure Sensor catheter of 0.022″ diameter (MPS22), with pressure sensor at distal end has been developed for improved assessment of stenosis severity. The hollow shaft of the MPS22 is designed to slide over any standard 0.014″ guidewire (G14). Hence, influence of MPS22 diameter on coronary diagnostic parameters needs investigation. An in vitro experiment was conducted to replicate physiologic flows in three representative area stenosis (AS): mild (64% AS), intermediate (80% AS), and severe (90% AS), for two arterial diameters, 3mm (N2; more common) and 2.5mm (N1). Influence of MPS22 on diagnostic parameters: fractional flow reserve (FFR) and pressure drop coefficient (CDP) was evaluated both at hyperemic and basal conditions, while comparing it with G14. The FFR values decreased for the MPS22 in comparison to G14, (Mild: 0.87 vs 0.88, Intermediate: 0.68 vs 0.73, Severe: 0.48 vs 0.56) and CDP values increased (Mild: 16 vs 14, Intermediate: 75 vs 56, Severe: 370 vs 182) for N2. Similar trend was observed in the case of N1. The FFR values were found to be well above (mild) and below (intermediate and severe) the diagnostic cut-off of 0.75. Therefore, MPS22 catheter can be used as a possible alternative to G14. Further, irrespective of the MPS22 or G14, basal FFR (FFRb) had overlapping ranges in close proximity for clinically relevant mild and intermediate stenoses that will lead to diagnostic uncertainty under both N1 and N2. However, CDPb had distinct ranges for different stenosis severities and could be a potential diagnostic parameter under basal conditions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Significance of data treatment and experimental setup on the determination of copper complexing parameters by anodic stripping voltammetry.

    Science.gov (United States)

    Omanović, Dario; Garnier, Cédric; Louis, Yoann; Lenoble, Véronique; Mounier, Stéphane; Pizeta, Ivanka

    2010-04-07

    Different procedures of voltammetric peak intensities determination, as well as various experimental setups were systematically tested on simulated and real experimental data in order to identify critical points in the determination of copper complexation parameters (ligand concentration and conditional stability constant) by anodic stripping voltammetry (ASV). Varieties of titration data sets (Cu(measured)vs. Cu(total)) were fitted by models encompassing discrete sites distribution of one-class and two-class of binding ligands (by PROSECE software). Examination of different procedures for peak intensities determination applied on voltammograms with known preset values revealed that tangent fit (TF) routine should be avoided, as for both simulated and experimental titration data it produced an additional class of strong ligand (actually not present). Peak intensities determination by fitting of the whole voltammogram was found to be the most appropriate, as it provided most reliable complexation parameters. Tests performed on real seawater samples under different experimental conditions revealed that in addition to importance of proper peak intensities determination, an accumulation time (control of the sensitivity) and an equilibration time needed for complete complexation of added copper during titration (control of complexation kinetics) are the keypoints to obtain reliable results free of artefacts. The consequence of overestimation and underestimation of complexing parameters is supported and illustrated by the example of free copper concentrations (the most bioavailable/toxic specie) calculated for all studied cases. Errors up to 80% of underestimation of free copper concentration and almost two orders of magnitude overestimation of conditional stability constant were registered for the simulated case with two ligands. Copyright 2010 Elsevier B.V. All rights reserved.

  6. Accurate measurements of experimental parameters in supercritical fluid chromatography. I. Extent of variations of the mass and volumetric flow rates.

    Science.gov (United States)

    Tarafder, Abhijit; Guiochon, Georges

    2013-04-12

    Previous reports have highlighted the influence of the properties of the mobile phase flow rate on the column performance achieved in supercritical fluid chromatography (SFC). In SFC both the mass and the volumetric flow rates have unique influences on the chromatographic performance and the determination of their exact values is critical. It is well understood that the mass flow rate stays constant along an SFC system whereas the volumetric flow rate may vary considerably, but the extent of these variations and the role of the individual operating parameters in influencing these variations have not been clearly reported yet. The factors that control the mass and the volumetric flow rates in an SFC system are discussed and the possible extent of variations of these flow rates under different operating pressures and temperatures are demonstrate quantitatively. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Experimental Measures of Bus Comfort Levels Using Kinematic Parameters Recorded by Smartphone

    Energy Technology Data Exchange (ETDEWEB)

    Aquila, S. dell' ; Eboli, L.; Futia, G.; Mazzulla, G.; Pungillo, G.

    2016-07-01

    Comfort on board plays an essential role in the levels of satisfaction of a bus service perceived by passengers. The aim of this paper is to propose a measure of comfort based on two kinds of data: perceptions of passengers (subjective data) and accelerations of bus (objective data). For the collection of subjective data a questionnaire was addressed to a sample of university students, while a smartphone, equipped with GPS device and 3-axis accelerometer, was used to record the accelerations. Based on the recorded parameters, we determined the thresholds of the acceleration values beyond which the level of comfort cannot be considered as good.. (Author)

  8. Analysis and Experimental Evaluation of Power Line Transmission Parameters for Power Line Communication

    Science.gov (United States)

    Mlynek, P.; Misurec, J.; Koutny, M.; Fujdiak, R.; Jedlicka, T.

    2015-04-01

    The article describes a way of evaluating the power line channel frequency response and input impedance by means of the linear time-invariant (LTI) power line generator. Two possible methods are introduced for the calculation of primary parameters: the first method depends on the physical realization and physical dimension of the cable, and the second method is derived from the data provided by typical electrical cable manufacturers. Based on these methods, a comparison of transfer functions was made. This is followed by measurement evaluation and numerical verification on a simple topology

  9. Parameters for Viability Check on Gravitational Theories Regarding the Experimental Data

    Directory of Open Access Journals (Sweden)

    Celakoska E. G.

    2009-01-01

    Full Text Available Parameterized post-Newtonian formalism requires an existence of a symmetric metric in a gravitational theory in order to perform aviability check regarding the experimental data. The requirement of a symmetric metric is a strong constraint satisfied by very narrowclass of theories. In this letter we propose a viability check of a theory using the corresponding theory equations of motion. It issufficient that a connection exists, not necessarily a metrical one. The method is based on an analysis of the Lorentz invariant terms in the equations of motion. An example of the method is presented on the Einstein-Infeld-Hoffmann equations.

  10. Effects of different spray formulations on the reproductive parameters of engorged Rhipicephalus (Boophilus) microplus females detached from experimentally infested cattle.

    Science.gov (United States)

    Cruz, Breno Cayeiro; Buzzulini, Carolina; Lopes, Welber Daniel Zanetti; Maciel, Willian Giquelin; Bichuette, Murilo Abud; Felippelli, Gustavo; Teixeira, Weslen Fabricio Pires; Soares, Vando Edésio; Gomes, Lucas Vinicius Costa; Prando, Luciana; Campos, Gabriel Pimentel; da Costa, Alvimar José

    2015-11-01

    This present study aimed to evaluate the deleterious effects of some commercially available spray formulations (15% Cypermethrin+25% Chlorpyriphos+1% Citronellal and 8% Cypermethrin+60% Ethion) on the reproductive parameters of engorged Rhipicephalus (Boophilus) microplus females that detached from experimentally infested cattle. The following reproductive parameters of engorged female ticks were analyzed: female weight, egg mass weight, percentage of hatchability, percentage of reduction in oviposition, percentage of reduction in hatchability, reproductive efficiency and percent control/efficacy of formulations for reproductive parameters. Our findings showed that although the strain R. (B.) microplus used in both experiments was thought to be sensitive to the test compounds because of the acaricidal efficacy observed throughout these trials, it was not possible to observe overall deleterious effects on the reproductive parameters of this tick species with both spray formulations. However, the 8% Cypermethrin+60% Ethion showed short-term significant effects on the weight of female ticks between the 14th and 16th days post-treatment and the weight of female and the egg mass weight between the 20th and 22nd days post-treatment. New studies should be conducted to show if these results regarding the reproductive parameters of fully engorged R. (B.) microplus females, combined with the acaricidal efficacy can be sufficient to reduce the number of chemical treatments administered to cattle. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. An investigation into the influence of different parameters on the onset of boiling in minichannels

    Directory of Open Access Journals (Sweden)

    Piasecka Magdalena

    2013-02-01

    Full Text Available The paper presents experimental studies on boiling heat transfer in rectangular minichannels. The investigations focus on the transition from single phase forced convection to nucleate boiling, i.e., in the zone of boiling incipience. The experiment has been carried out with FC-72, R-123 and R-11 at the Reynolds number below 4700, corresponding to mass flow rate range 95-710 kg/(m s. The main part of the test section is a minichannel of pre-set depth from 0.7 to 2 mm and width (20, 40 and 60 mm, with different spatial orientations from vertical to horizontal and 30% inclination angle adjustment. The objective of the paper includes the impact of selected parameters (liquid flow velocity, pressure and inlet liquid subcooling, channel dimensions and spatial orientation on the boiling incipience in minichannels. The investigations are intended to develop a correlation for the calculations of the Nusselt number under the conditions of boiling incipience in the minichannel as a function of changeable parameters.

  12. An investigation into the influence of different parameters on the onset of boiling in minichannels

    Science.gov (United States)

    Piasecka, Magdalena

    2013-02-01

    The paper presents experimental studies on boiling heat transfer in rectangular minichannels. The investigations focus on the transition from single phase forced convection to nucleate boiling, i.e., in the zone of boiling incipience. The experiment has been carried out with FC-72, R-123 and R-11 at the Reynolds number below 4700, corresponding to mass flow rate range 95-710 kg/(m s). The main part of the test section is a minichannel of pre-set depth from 0.7 to 2 mm and width (20, 40 and 60 mm), with different spatial orientations from vertical to horizontal and 30% inclination angle adjustment. The objective of the paper includes the impact of selected parameters (liquid flow velocity, pressure and inlet liquid subcooling, channel dimensions and spatial orientation) on the boiling incipience in minichannels. The investigations are intended to develop a correlation for the calculations of the Nusselt number under the conditions of boiling incipience in the minichannel as a function of changeable parameters.

  13. Influence of proton bunch and plasma parameters on the AWAKE experiment

    Science.gov (United States)

    Moreira, Mariana; Vieira, Jorge; Muggli, Patric

    2017-10-01

    The Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) at CERN will test the concept underlying plasma wakefield acceleration using long proton beams that undergo the self-modulation instability. The effectiveness of the experiment hinges on the successful and predictable development of this instability, which fragments the initial proton bunch into smaller beamlets with lengths of the order of the plasma wavelength. Since the initial parameters of the experiment inevitably vary from event to event, this work will aim to understand the correlation between these variations and the resulting wakefield. Using both theoretical models and numerical particle-in-cell simulations, the influence of variations in initial bunch charge, bunch dimensions, bunch energy and plasma density profile on the excited accelerating gradients and on the final energies reached by the witness particles will be investigated. In addition, further options in the experiment setup will be explored with the aim of optimizing the results.

  14. Evaluation of parameters influencing the molecular delivery by biodegradable microsphere-mediated perforation using femtosecond laser.

    Science.gov (United States)

    Mitsuhashi, Tatsuki; Terakawa, Mitsuhiro

    2014-01-01

    The parameters critically influencing the delivery rate on the biodegradable microsphere-mediated femtosecond (fs) laser perforation are investigated in detail with the aim of developing efficient molecular delivery. Cell membrane was perforated by the irradiation of weakly focused fs laser pulses to the spherical polylactic acid microspheres conjugated to the cell membrane. The delivery of fluorescein isothiocyanate-dextran and fluorescent silica particles to A431 cells is investigated in detail. The increase in the number of irradiated laser pulses had resulted in the increase of delivery rate. The delivery rate depends on the size and functionalization of fluorescent silica particles in which silica particles of 100 nm in diameter were able to be delivered into 20% of the irradiated cells, suggesting that the pore sizes are large enough for the delivery of therapeutic agents into cells. These findings contribute to the development of an efficient and safe phototherapy and drug delivery.

  15. Improving adhesion of powder coating on PEEK composite: Influence of atmospheric plasma parameters

    Science.gov (United States)

    Dupuis, Aurélie; Ho, Thu Huong; Fahs, Ahmad; Lafabrier, Aurore; Louarn, Guy; Bacharouche, Jalal; Airoudj, Aissam; Aragon, Emmanuel; Chailan, Jean-François

    2015-12-01

    In aeronautic industries, powder coatings are increasingly used because of environmental considerations. During the deposition of such a coating on a substrate piece, the main objective is to obtain a good coating/substrate adhesion. In this study, the targeted substrate is a Poly-(Ether EtherKetone)-(PEEK) based composite material. Due to the poor surface energy of PEEK, a surface treatment is necessary in order to enhance its adhesion with the coating. In this purpose, atmospheric plasma treatment has been chosen and the influence of plasma parameters has been studied. Four scan speed nozzles and three gases (Air, N2 and Argon) plasma has been tested. The increase of adhesion with increasing wettability, polarity and nanoroughness has been evidenced. A particular study of the type of grafted polar functionalities according to gas nature allowed to better understand the plasma mechanism and the cross-impact of polarity and nanoroughness in adhesion enhancement.

  16. Influence of cookies composition on temperature profiles and qualitative parameters during baking

    Directory of Open Access Journals (Sweden)

    Ž. Kožul

    2014-01-01

    Full Text Available During baking of bakery products temperature of baking, temperature profiles, moisture content, volume and colour changes are strongly coupled. The objective of this paper was to study the influence of the cookies composition on temperature profiles and quality parameters (width and thickness, colour formation and textural properties: hardness, fracturability and work of breaking force during baking process. Composition of cookies differs due to flour type and initial moisture content. Cookies were baked at 205 °C and temperature was measured in the centre of samples which were 7 mm thick with a 60 mm diameter. The results of temperature profiles of the cookies during baking have shown the same trend for all of the 18 samples. Samples with the higher initial water content have lower values of total colour difference and also significantly affect textural properties.

  17. The influence of the deposition parameters on the porosity of thin alumina films on steel

    Directory of Open Access Journals (Sweden)

    DUSAN KICEVIC

    2004-03-01

    Full Text Available The influence of the deposition parameters on the porosity of thin alumina films electrophoretically deposited on steel from aqueous suspensions was investigated. The effects of the applied voltage, deposition time, suspension temperature and the solid content of the aqueous suspension on the porosity of the obtained alumina films have been determined using optical microscopy coupled with image analysis. It was shown that the lowest film porosity was obtained from a suspension containing 20 wt.% alumina powder at the lowest applied voltage (30 V, for a longer deposition time (10 min using a suspension temperature of 30 ºC. This behavior can be explained by the smaller amount of hydrogen evolved on the cathode during the electrophoretic deposition process.

  18. Influence of the vibratory test facility type and parameters upon the cavitation erosion evolution

    Science.gov (United States)

    Bordeasu, I.; Popoviciu, M. O.; Balasoiu, V.; Jurchela, A. D.; Karabenciov, A.

    2010-08-01

    Paper analyses the configuration of area and depth for the laboratory produced cavitation erosion. The affected zones were examined using both an optic microscope and a device for obtaining the cross-sectional profile of the eroded area. The cavitation was produced with a nickel tube magnetostrictive device (vibration amplitude 94 μm, vibration frequency 7 kHz, specimen diameter 14 mm and power 500 W) as well as with a standard piezoceramic crystals device (vibration amplitude 50 μm, vibration frequency 20 kHz, specimen diameter 16 mm and the power 500 W). The test specimens were manufactured from two different materials (steel and bronze). We found that the vibrations amplitude has greater influence upon the erosion (we obtained increase in the erosion maximum depth, in the total eroded mass and in the erosion velocity). Regardless of the running parameters, the way in which the deformations, the cracks and the dislocations are produced, is very similar.

  19. THE INFLUENCE OF THE NUTRITIONAL FACTORS ON SOME BIOPHYSICAL PARAMETERS OF THE RUMINAL FLUID

    Directory of Open Access Journals (Sweden)

    IULIANA CREłESCU

    2008-05-01

    Full Text Available At this hour, a large part of the products obtained through biotechnologies are used in animal fodder, thus contributing to the enhancement of the animal products obtained in economical conditions through optimising the nutrition. In the present study, we wanted to pursue the influence of a high level of cereal in fodder rations, as well as the effect of the yeast Saccharomyces cerevisiae, Yea Sacc1026 strain on some biophysical parameters of the ruminal fluid, such as: pH, density and superficial tension. It has been noted, that Yea Sacc1026 improves the pH and the superficial tension, which represents more stable ruminal fermentation when using fodder rations with a high level of barley.

  20. Influence of the parameters of a human triceps surae muscle model on the isometric torque-angle relationship

    NARCIS (Netherlands)

    Out, Lia; Vrijkotte, Tanja G M; Van Soest, Arthur J.; Bobbert, Maarten F.

    This study investigates the influence of parameter values of the human triceps surae muscle on the torque-angle relationship. The model used consisted of three units, each containing a contractile, a series elastic and a parallel elastic element. Parameter values were based on morphological

  1. Influence of the parameters of a human triceps surae muscle model on the isometric torque-angle relationship

    NARCIS (Netherlands)

    Out, L.; Vrijkotte, T. G.; van Soest, A. J.; Bobbert, M. F.

    1996-01-01

    This study investigates the influence of parameter values of the human triceps surae muscle on the torque-angle relationship. The model used consisted of three units, each containing a contractile, a series elastic and a parallel elastic element. Parameter values were based on morphological

  2. Alteration of Lysophosphatidylcholine-Related Metabolic Parameters in the Plasma of Mice with Experimental Sepsis.

    Science.gov (United States)

    Ahn, Won-Gyun; Jung, Jun-Sub; Kwon, Hyeok Yil; Song, Dong-Keun

    2017-04-01

    Plasma concentration of lysophosphatidylcholine (LPC) was reported to decrease in patients with sepsis. However, the mechanisms of sepsis-induced decrease in plasma LPC levels are not currently well known. In mice subjected to cecal ligation and puncture (CLP), a model of polymicrobial peritoneal sepsis, we examined alterations in LPC-related metabolic parameters in plasma, i.e., the plasma concentration of LPC-related substances (i.e., phosphatidylcholine (PC) and lysophosphatidic acid (LPA)), and activities or levels in the plasma of some enzymes that can be involved in the regulation of plasma LPC concentration (i.e., secretory phospholipase A2 (sPLA2), lecithin:cholesterol acyltransferase (LCAT), acyl-CoA:lysophosphatidylcholine acyltransferase (LPCAT), and autotaxin (ATX)), as well as plasma albumin concentration. We found that levels of LPC and albumin and enzyme activities of LCAT, ATX, and sPLA2 were decreased, whereas levels of PC, LPA, and LPCAT1-3 were increased in the plasma of mice subjected to CLP. Bacterial peritonitis led to alterations in all the measured LPC-related metabolic parameters in the plasma, which could potentially contribute to sepsis-induced decrease in plasma LPC levels. These findings could lead to the novel biomarkers of sepsis.

  3. An Experimental Investigation into Chosen Parameters of Diesel-Water Emulsion on Combustion Processes

    Directory of Open Access Journals (Sweden)

    Pradeep Kumar Arokiasamy Remigious

    2013-01-01

    Full Text Available The purpose of this research is to investigate the effect of mixing water with diesel to make an emulsified fuel considering the needs for the vehicle performance and its cleanest possible operation. The test fuels chosen for the investigation are termed Emulsion 1 (EM1 and Emulsion 2 (EM2. EM1 is prepared in the ratio of 91/8/1 which represents 91% diesel, 8% water, 0.5% surfactant (Span 20, and 0.5% cosurfactant (Tween 20 with continuous stirring. EM2 has a composition of 94% diesel, 5% water, 0.5% Span 20, and 0.5% Tween 20. The stability of the emulsified fuel is checked for 8 hours. The performance and emission characteristics of EM1 and EM2 are compared with diesel fuel. The emission parameters such as hydrocarbon emission, carbon monoxide (CO emission, smoke opacity, and oxides of nitrogen (NOx emission have been measured. To compare the difference in performance characteristics between diesel fuel and emulsified fuel, brake thermal efficiency has been taken into account as a measure. Appreciable reductions of emission parameters have been obtained, and hence the investigation assures that this research could be further extended to biodiesel fuel as it produces more NOx than diesel fuel.

  4. Experimental verification of internal parameter in magnetically coupled boost used as PV optimizer in parallel association

    Science.gov (United States)

    Sawicki, Jean-Paul; Saint-Eve, Frédéric; Petit, Pierre; Aillerie, Michel

    2017-02-01

    This paper presents results of experiments aimed to verify a formula able to compute duty cycle in the case of pulse width modulation control for a DC-DC converter designed and realized in laboratory. This converter, called Magnetically Coupled Boost (MCB) is sized to step up only one photovoltaic module voltage to supply directly grid inverters. Duty cycle formula will be checked in a first time by identifying internal parameter, auto-transformer ratio, and in a second time by checking stability of operating point on the side of photovoltaic module. Thinking on nature of generator source and load connected to converter leads to imagine additional experiments to decide if auto-transformer ratio parameter could be used with fixed value or on the contrary with adaptive value. Effects of load variations on converter behavior or impact of possible shading on photovoltaic module are also mentioned, with aim to design robust control laws, in the case of parallel association, designed to compensate unwanted effects due to output voltage coupling.

  5. Laboratory transport experiments with antibiotic sulfadiazine: Experimental results and parameter uncertainty analysis

    Science.gov (United States)

    Sittig, S.; Vrugt, J. A.; Kasteel, R.; Groeneweg, J.; Vereecken, H.

    2011-12-01

    Persistent antibiotics in the soil potentially contaminate the groundwater and affect the quality of drinking water. To improve our understanding of antibiotic transport in soils, we performed laboratory transport experiments in soil columns under constant irrigation conditions with repeated applications of chloride and radio-labeled SDZ. The tracers were incorporated in the first centimeter, either with pig manure or with solution. Breakthrough curves and concentration profiles of the parent compound and the main transformation products were measured. The goal is to describe the observed nonlinear and kinetic transport behavior of SDZ. Our analysis starts with synthetic transport data for the given laboratory flow conditions for tracers which exhibit increasingly complex interactions with the solid phase. This first step is necessary to benchmark our inverse modeling approach for ideal situations. Then we analyze the transport behavior using the column experiments in the laboratory. Our analysis uses a Markov chain Monte Carlo sampler (Differential Evolution Adaptive Metropolis algorithm, DREAM) to efficiently search the parameter space of an advective-dispersion model. Sorption of the antibiotics to the soil was described using a model regarding reversible as well as irreversible sorption. This presentation will discuss our initial findings. We will present the data of our laboratory experiments along with an analysis of parameter uncertainty.

  6. Influence of calibration protocols for a pressure-sensing walkway on kinetic and temporospatial parameters.

    Science.gov (United States)

    Agostinho, F S; Rahal, S C; Geraldo, B; Justolin, P L T; Teixeira, C R; Lins, F L M L; Monteiro, F O B

    2015-01-01

    To evaluate the influence on the kinetic and temporospatial parameters of calibration protocols with point and step techniques for a pressure-sensing walkway. Nine Labrador dogs were used. Two protocols of point calibration technique (C1 and C2) and eight protocols of step calibration technique (C3 to C10) were performed. In C1, weight was added to a stool to match the body mass of each dog. In C2, weight was added to the stool to match a 46.1 kg person. The other eight calibration protocols represented combinations of the following factors: 46.1 kg and 96.1 kg persons, barefoot or wearing sneakers, and stepping onto the platform with one or two feet. The calibration protocols did not affect the temporospatial variables or percentages of body weight (%BW) distribution. Significant differences were found in both PVI (peak vertical force) and VI (vertical impulse) between barefoot versus wearing sneakers, 46.1 kg versus 96.1 kg person, and stepping onto the platform with one foot versus two feet. When comparing C1 with other protocols, significant differences were observed in PVF and VI for both forelimbs and hindlimbs. When comparing C2 with other protocols, significant differences were observed in PVF and VI for both forelimbs and hindlimbs in all protocols. The PVF and VI were influenced by the calibration protocol used, but the %BW distribution and temporospatial parameters were not. Using the same calibration protocol for all dogs within the same group eliminated the variability of the kinetic data caused by the calibration.

  7. On the influence of water subcooling and melt jet parameters on debris formation

    Energy Technology Data Exchange (ETDEWEB)

    Manickam, Louis, E-mail: louis@safety.sci.kth.se; Kudinov, Pavel; Ma, Weimin; Bechta, Sevostian; Grishchenko, Dmitry

    2016-12-01

    Highlights: • Melt and water configuration effects on debris formation is studied experimentally. • Melt superheat and water subcooling are most influential compared to jet size. • Melt-water configuration and material properties influence particle fracture rate. • Results are compared with large scale experiments to study effect of spatial scales. - Abstract: Breakup of melt jet and formation of a porous debris bed at the base-mat of a flooded reactor cavity is expected during the late stages of a severe accident in light water reactors. Debris bed coolability is determined by the bed properties including particle size, morphology, bed height and shape as well as decay heat. Therefore understanding of the debris formation phenomena is important for assessment of debris bed coolability. A series of experiments was conducted in MISTEE-Jet facility by discharging binary-oxide mixtures of WO{sub 3}–Bi{sub 2}O{sub 3} and WO{sub 3}–ZrO{sub 2} into water in order to investigate properties of resulting debris. The effect of water subcooling, nozzle diameter and melt superheat was addressed in the tests. Experimental results reveal significant influence of water subcooling and melt superheat on debris size and morphology. Significant differences in size and morphology of the debris at different melt release conditions is attributed to the competition between hydrodynamic fragmentation of liquid melt and thermal fracture of the solidifying melt droplets. The particle fracture rate increases with increased subcooling. Further the results are compared with the data from larger scale experiments to discern the effects of spatial scales. The present work provides data that can be useful for validation of the codes used for the prediction of debris formation phenomena.

  8. Influence of Fasciola Hepatica on Serum Biochemical Parameters and Vascular and Biliary System of Sheep Liver

    Directory of Open Access Journals (Sweden)

    A Hodžić

    2013-03-01

    Full Text Available Background: The aim of this study was to evaluate the functional capacity of the liver based on the activity of specific enzymes and bilirubin in serum and also to investigate the influence of mechanical and toxic effects of Fasciola hepatica on the structures of the blood vessels and biliary tract in the sheep liver.Methods: Blood samples and liver of 63 indigenous sheep of Pramenka breed, slaughtered in the period from March to December 2009 were used. Based on parasitological findings in the liver, all animals were divided into two groups: control (n=34 and infected group (n=29. For investigation and description of pathological changes in sheep liver, naturally infected with F. hepatica, corrosion cast technique was used.Results: Biochemical analysis of tested parameters showed a significant elevation (P≤0.05 of serum gamma-glutamyl transferase (GGT, total bilirubin (TBIL and direct bilirubin (DBIL in infected sheep group comparing with the control group. No significant differences were observed for activity of aspartate aminotranferase (AST between groups. Vascular and biliary systems of the liver were found to be affected.Conclusion: Results of biochemical analysis are consistent with pathological findings and measuring of tested parameters could be used in early diagnosis of sheep fasciolosis and to test the effectiveness of anthelmintic therapy. Corrosion cast technique is very useful for investigation of pathological changes and neoangiogenesis of vascular and biliary system in sheep liver, caused by mechanical and toxic effects of F. hepatica.

  9. The influence of SBR parameters on the sludge toxicity of synthetic wastewater containing bisphenol A.

    Science.gov (United States)

    Chen, Xiurong; Zhao, Jianguo; Zhao, Jun; Yang, Na; Zhang, Fei; Jiang, Zijian

    2014-01-01

    Synthetic wastewater with bisphenol A (BPA) concentrations of 7.5, 20, and 40 mg/L was treated with activated sludge sequential batch reactors (SBRs). The sludge acute toxicity indicated by the inhibitory ratio to luminous bacteria T3 was evaluated. The influent COD was controlled at approximately 300 mg/L, and aerobic conditions were maintained in the SBR. It was found that the process of BPA biodegradation, as opposed to BPA adsorption, contributed to the formation of sludge toxicity; there was a positive relationship between sludge toxicity and influent BPA concentration, and the toxicity centralized in intracellular regions and the intersection of extracellular polymeric substances (EPS) in sludge flocs. Since the BPA biodegradation process dedicated to sludge toxicity, the influence of key operational parameters such as sludge retention time (SRT) and hydraulic retention time (HRT) on sludge toxicity were investigated. It was founded that sludge toxicity decreased significantly when SRT and HRT were shortened from 20 to 10 days and 12 to 8 h, respectively. The results of Pearson correlation analysis indicated that the Shannon index H of the bacterial community correlated significantly to sludge toxicity. The results from both similarity analysis and UPGMA indicated that influent quality characteristic contributes much more to bacterial community than operation parameters, and then leads to difference between blank and control sludge toxicity.

  10. Review on Parameters Influencing the Rice Breakage and Rubber Roll Wear in Sheller

    Directory of Open Access Journals (Sweden)

    Prabhakaran P.

    2017-09-01

    Full Text Available The present review deals with parameters influencing the rice breakage during rice milling operations and the effect of rubber roll Sheller in rice husk removal process. The main objective of rice milling system is to remove the husk and bran layer to produce the white rice. In this process, rubber roll sheller is used to remove husk from the grains by friction process. If the rubber material is too soft, there may not be sufficient shear force to husk the paddy. Wear will be minimum for rubber material with high hardness but indeed it pronounce the breakage of rice. Hence, for efficient husking the rubber roll material should possess the balance of physico-mechanical properties. Rice breakage depends on several other parameters like the type of harvest, drying temperature, drying methods, physical characteristics of paddy, husking characteristics, paddy moisture content, rubber roller speed, rubber roll pressure, paddy feed rate and fissures. Rubber roll wear depends on the type of rubber material attached to the roller, feed rate, roller speed, pressure etc.

  11. The influence of supplementation with artichoke (Cynara scolymus L.) extract on selected redox parameters in rowers.

    Science.gov (United States)

    Skarpanska-Stejnborn, Anna; Pilaczynska-Szczesniak, Lucia; Basta, Piotr; Deskur-Smielcka, Ewa; Horoszkiewicz-Hassan, Magorzata

    2008-06-01

    High-intensity physical exercise decreases intracellular antioxidant potential. An enhanced antioxidant defense system is desirable in people subjected to exhaustive exercise. The aim of this study was to investigate the influence of supplementation with artichoke-leaf extract on parameters describing balance between oxidants and antioxidants in competitive rowers. This double-blinded study was carried out in 22 members of the Polish rowing team who were randomly assigned to a supplemented group (n = 12), receiving 1 gelatin capsule containing 400 mg of artichoke-leaf extract 3 times a day for 5 wk, or a placebo group (n = 10). At the beginning and end of the study participants performed a 2,000-m maximal test on a rowing ergometer. Before each exercise test, 1 min after the test completion, and after a 24-hr restitution period blood samples were taken from antecubital vein. The following redox parameters were assessed in red blood cells: superoxide dismutase activity, glutathione peroxidase activity, glutathione reductase activity, reduced glutathione levels, and thiobarbituric-acid-reactive-substances concentrations. Creatine kinase activity and total antioxidant capacity (TAC) were measured in plasma samples, lactate levels were determined in capillary blood samples, and serum lipid profiles were assessed. During restitution, plasma TAC was significantly higher (p artichoke-leaf extract, a natural vegetable preparation of high antioxidant potential, resulted in higher plasma TAC than placebo but did not limit oxidative damage to erythrocytes in competitive rowers subjected to strenuous training.

  12. Influence of Fasciola hepatica on Serum Biochemical Parameters and Vascular and Biliary System of Sheep Liver

    Science.gov (United States)

    Hodžić, A; Zuko, A; Avdić, R; Alić, A; Omeragić, J; Jažić, A

    2013-01-01

    Background The aim of this study was to evaluate the functional capacity of the liver based on the activity of specific enzymes and bilirubin in serum and also to investigate the influence of mechanical and toxic effects of Fasciola hepatica on the structures of the blood vessels and biliary tract in the sheep liver. Methods Blood samples and liver of 63 indigenous sheep of Pramenka breed, slaughtered in the period from March to December 2009 were used. Based on parasitological findings in the liver, all animals were divided into two groups: control (n = 34) and infected group (n = 29). For investigation and description of pathological changes in sheep liver, naturally infected with F. hepatica, corrosion cast technique was used. Results Biochemical analysis of tested parameters showed a significant elevation (P≤0.05) of serum gamma-glutamyl transferase (GGT), total bilirubin (TBIL) and direct bilirubin (DBIL) in infected sheep group comparing with the control group. No significant differences were observed for activity of aspartate aminotranferase (AST) between groups. Vascular and biliary systems of the liver were found to be affected. Conclusion Results of biochemical analysis are consistent with pathological findings and measuring of tested parameters could be used in early diagnosis of sheep fasciolosis and to test the effectiveness of anthelmintic therapy. Corrosion cast technique is very useful for investigation of pathological changes and neoangiogenesis of vascular and biliary system in sheep liver, caused by mechanical and toxic effects of F. hepatica. PMID:23682266

  13. Influence of soil parameters on the skewness coefficient of the annual maximum flood peaks

    Science.gov (United States)

    Gioia, A.; Iacobellis, V.; Manfreda, S.; Fiorentino, M.

    2011-06-01

    Understanding the spatial variability of key parameters of flood probability distributions represents a strategy to provide insights on hydrologic similarity and building probabilistic models able to reduce the uncertainty in flood prediction in ungauged basins. In this work, we exploited the theoretically derived distribution of floods TCIF (Gioia et al., 2008), based on two different threshold mechanisms associated respectively to ordinary and extraordinary events. The model is based on the hypotheses that ordinary floods are generally due to rainfall events exceeding a threshold infiltration rate in a small source area, while the so-called outlier events, responsible of the high skewness of flood distributions, are triggered when severe rainfalls exceed a storage threshold over a large portion of the basin. Within this scheme, a sensitivity analysis was performed in order to analyze the effects of climatic and geomorphologic parameters on the skewness coefficient. In particular, the analysis was conducted investigating the influence on flood distribution of physical factors such as rainfall intensity, soil infiltration capacity, and basin area, in order to provide insights in catchment classification and process conceptualization.

  14. An Experimental Seismic Data and Parameter Exchange System for Tsunami Warning Systems

    Science.gov (United States)

    Hoffmann, T. L.; Hanka, W.; Saul, J.; Weber, B.; Becker, J.; Heinloo, A.; Hoffmann, M.

    2009-12-01

    For several years GFZ Potsdam is operating a global earthquake monitoring system. Since the beginning of 2008, this system is also used as an experimental seismic background data center for two different regional Tsunami Warning Systems (TWS), the IOTWS (Indian Ocean) and the interim NEAMTWS (NE Atlantic and Mediterranean). The SeisComP3 (SC3) software, developed within the GITEWS (German Indian Ocean Tsunami Early Warning System) project, capable to acquire, archive and process real-time data feeds, was extended for export and import of individual processing results within the two clusters of connected SC3 systems. Therefore not only real-time waveform data are routed to the attached warning centers through GFZ but also processing results. While the current experimental NEAMTWS cluster consists of SC3 systems in six designated national warning centers in Europe, the IOTWS cluster presently includes seven centers, with another three likely to join in 2009/10. For NEAMTWS purposes, the GFZ virtual real-time seismic network (GEOFON Extended Virtual Network -GEVN) in Europe was substantially extended by adding many stations from Western European countries optimizing the station distribution. In parallel to the data collection over the Internet, a GFZ VSAT hub for secured data collection of the EuroMED GEOFON and NEAMTWS backbone network stations became operational and first data links were established through this backbone. For the Southeast Asia region, a VSAT hub has been established in Jakarta already in 2006, with some other partner networks connecting to this backbone via the Internet. Since its establishment, the experimental system has had the opportunity to prove its performance in a number of relevant earthquakes. Reliable solutions derived from a minimum of 25 stations were very promising in terms of speed. For important events, automatic alerts were released and disseminated by emails and SMS. Manually verified solutions are added as soon as they become

  15. Variable Modal Parameter Identification for Non-Linear Mdof Systems. Part II: Experimental Validation and Advanced Case Study

    Directory of Open Access Journals (Sweden)

    Y.H. Chong

    2000-01-01

    Full Text Available The purpose of Part II is to provide an experimental validation of the methodology presented in Part I and to consider a representative engineering case, the study of which requires a relatively large numerical model. A beam system with cubic stiffness type non-linearity was used in the experimental study. The non-linear response was measured at three locations and the underlying linear system was obtained via linear modal analysis of low-excitation response data. The non-linear parameter variations were obtained as a function of the modal amplitude and the response of the system was generated for other force levels. The results were found to agree very well with the corresponding measurements, indicating the success of the non-linear modal analysis methodology, even in the presence of true experimental noise. An advanced numerical case study that included both inherent structural damping and non-linear friction damping, was considered next. The linear finite element model of a high-pressure turbine blade was used in conjunction with three local non-linear friction damper elements. It was shown that the response of the system could be predicted at any force level, provided that that non-linear modal parameters were available at some reference force level. The predicted response levels were compared against those obtained from reference simulations and very good agreement was achieved in all cases.

  16. Evaluation of the effect of conventionally prepared swarna makshika bhasma on different bio-chemical parameters in experimental animals

    Directory of Open Access Journals (Sweden)

    Sudhaldev Mohapatra

    2011-01-01

    Full Text Available Swarna makshika (chalcopyrite bhasma (SMB has been used for different therapeutic purposes since long in Ayurveda. The present study is conducted to evaluate the effect of conventionally prepared SMB on different bio-chemical parameters in experimental animals, for providing scientific data base for its logical use in clinical practice. The genuine SMB was prepared by following classical techniques of shodhana and marana most commonly used by different Ayurvedic drug manufacturers. Shodhana was done by roasting raw swarna makshika with lemon juice for three days and marana was performed by 11 putas . The experimental animals (rats were divided into two groups. SMB mixed with diluted honey was administered orally in therapeutic dose to Group SMB and diluted honey only was administered to vehicle control Group, for 30 days. The blood samples were collected twice, after 15 days and after 30 days of drug administration and different biochemical investigations were done. Biochemical parameters were chosen based on references from Ayurvedic classics and contemporary medicine. It was observed that Hb% was found significantly increased and LDL and VLDL were found significantly decreased in Group SMB when compared with vehicle control group. This experimental data will help the clinician for the logical use of SMB in different disease conditions with findings like low Hb% and high LDL, VLDL levels.

  17. Models for the UX-X Emission in AGN: Influence of Different Parameters

    Science.gov (United States)

    Coupé, S.; Artru, M.-C.; Collin, S.; Czerny, B.; Dumont, A.-M.

    We present the results of computations performed with a new photoionisation-transfer code designed for hot Compton thick media. Presently the code solves the transfer of the continuum with the Presently the code solves the transfer of the continuum with the Accelerated Lambda Iteration method (ALI) and that of the lines in a two stream Eddington approximation, without using the local escape probability formalism to approximate the line transfer. We show the influence that the approximations made in the treatment of the transfer and of the atomic data can have on the broad band UV-X spectrum and on the detailed spectral features (X-ray lines and ionization edges) emitted/absorbed by an X-ray irradiated medium. This transfer code is coupled with a Monte Carlo code which allows to take into account direct and inverse Compton diffusions, and to compute the spectrum emitted up to hundreds of keV energies. The influence of a few physical parameters is shown, and the importance of the density and pressure distribution (constant density, pressure equilibrium) is discussed.

  18. Influence of various growth parameters on fungal growth and volatile metabolite production by indoor molds.

    Science.gov (United States)

    Polizzi, Viviana; Adams, An; De Saeger, Sarah; Van Peteghem, Carlos; Moretti, Antonio; De Kimpe, Norbert

    2012-01-01

    A Penicillium polonicum, an Aspergillus ustus and a Periconia britannica strain were isolated from water-damaged environments and the production of microbial volatile organic compounds (MVOCs) was investigated by means of headspace solid-phase microextraction followed by GC-MS analysis. The most important MVOCs produced were 2-methylisoborneol, geosmin and daucane-type sesquiterpenes for P. polonicum, 1-octen-3-ol, 3-octanone, germacrene D, δ-cadinene and other sesquiterpenes for A. ustus and the volatile mycotoxin precursor aristolochene together with valencene, α-selinene and β-selinene for P. britannica. Different growth conditions (substrate, temperature, relative humidity) were selected, resembling indoor parameters, to investigate their influence on fungal metabolism in relation with the sick building syndrome and the results were compared with two other fungal strains previously analyzed under the same conditions. In general, the range of MVOCs and the emitted quantities were larger on malt extract agar than on wallpaper and plasterboard, but, overall, the main MVOC profile was conserved also on the two building materials tested. The influence of temperature and relative humidity on growth and metabolism is different for different fungal species, and two main patterns of behavior could be distinguished. Results show that, even at suboptimal conditions for growth, production of fungal volatiles can be significant. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Influence of daily individual meteorological parameters on the incidence of acute coronary syndrome.

    Science.gov (United States)

    Ravljen, Mirjam; Bilban, Marjan; Kajfež-Bogataj, Lučka; Hovelja, Tomaž; Vavpotič, Damjan

    2014-11-12

    A nationwide study was conducted to explore the short term association between daily individual meteorological parameters and the incidence of acute coronary syndrome (ACS) treated with coronary emergency catheter interventions in the Republic of Slovenia, a south-central European country. We linked meteorological data with daily ACS incidence for the entire population of Slovenia, for the population over 65 years of age and for the population under 65 years of age. Data were collected daily for a period of 4 years from 1 January 2008 to 31 December 2011. In line with existing studies, we used a main effect generalized linear model with a log-link-function and a Poisson distribution of ACS. Three of the studied meteorological factors (daily average temperature, atmospheric pressure and relative humidity) all have relevant and significant influences on ACS incidences for the entire population. However, the ACS incidence for the population over 65 is only affected by daily average temperature, while the ACS incidence for the population under 65 is affected by daily average pressure and humidity. In terms of ambient temperature, the overall findings of our study are in line with the findings of the majority of contemporary European studies, which also note a negative correlation. The results regarding atmospheric pressure and humidity are less in line, due to considerable variations in results. Additionally, the number of available European studies on atmospheric pressure and humidity is relatively low. The fourth studied variable-season-does not influence ACS incidence in a statistically significant way.

  20. ASPECTS OF THE INFLUENCE OF TECHNOLOGICAL PARAMETERS ON THE TENSION PROPERTIES OF THE YARNS

    Directory of Open Access Journals (Sweden)

    HRISTIAN Liliana

    2016-05-01

    Full Text Available This paper presents the results of some experiments performed using the power system bands directly from the card to the rotor spinning machine and the spinning system used by passing the lanes on two passages mill and fed to the spinning rotor. In this study we analized the influence of technological parameters of the preparation drawing on the assessing indicators for the tensile strength of the Nm20, Nm24, Nm27 Nm34 and Nm40 yarns. The fineness range studied was made of three fiber mixtures of different varieties of cotton, coded as follows: A1-85% Soviet cotton+15% Chinese cotton medium II; A2-100% Turkish cotton medium III; A3-100% American cotton mdium IV. The method of preparation of the bands which are to be powered to the rotor spinning machine, respectively with the aggregate pile-card and the powered bands directly to the rotor spinning machine and the adding of two rolling mill, detemines different structures of bands and different degrees of untangling and orientation of the fibers, which influences the quality of the obtained yarns. This study reveals a considerable improvement of the tensile properties when the yarns are made from rolled band, which is explained by the high degree of correction and parallelization of the fibers of the rolled band, which allows a greater participation of fibers with their resistance to the resistance of the yarns.

  1. Clinical-experimental data influence Speroton on the fertility parameters of ejaculate

    Directory of Open Access Journals (Sweden)

    O. B. Zhukov

    2015-01-01

    Full Text Available The article analyzes the experience of studying the properties of patients ejaculate. They were 30 men with normal semen, idiopathic infertility secretory type and varicocele in the postoperative period. The total number of patients was 30, 10 in each group. The study was conducted with dietary supplement Speroton (without the inclusion of ancillary components to the maximum effective concentration. Stages of the study consisted of the evaluation of the main indicators of semen (WHO, 5th edition. The study was conducted over 30 minutes, 1 hour, 3 hours and 24 hours after the addition of the dietary supplement Speroton. Set material was 3 months. The study dietary supplement Speroton was used in three different concentrations (1:100,1:200,1:1000. Was used to estimate the mobility, viability and morphology of spermatozoa within a specified time of incubation by mixing the dietary supplement and ejaculate. The study of sperm motility in groups separated by disease, showed the following changes: the best results were in group 1 – active mobility increase by 46 % in the first hour of incubation, total – 15 % for the first hour of incubation. In second place were indicators of mobility in the third group after surgery for varicocele – 22 and 14 %, respectively, in last place in the group, with a secretory infertility is increasing the activity and overall mobility was 14 %. The study of the dietary supplement in the experiment revealed Speroton positive effect on sperm motility active. Maximum effect was obtained at a dilution of 1:200 – active mobility increased by 27 % for the 1st hour experiment. The results obtained allow to recommend the dietary supplement Speroton as part of precomplex conservative therapy in patients referred for treatment methods of assisted reproductive technologies, as well as in patients with a change in fertility due to varicocele in the postoperative period and idiopathic patozoospermia.

  2. THE EXPERIMENTAL DIDACTIC STAND FOR DETERMINING THE PARAMETERS OF THE GEAR WITH MAGNETORHEOLOGICAL CLUTCH AND BRAKE

    Directory of Open Access Journals (Sweden)

    Jerzy BAJKOWSKI

    2014-03-01

    Full Text Available In this paper the laboratory stand, designed to be used as a part of the Laboratory of Machine Design and Research which is part of the subject Fundamentals of Machine Design, is presented. Originally the laboratory stand was designed as an element of one of the research projects, and the adopted for didactic purposes. The students have the chance to get familiar with unique type of fluids controlled by the magnetic field and their application in the special purpose devices. The laboratory stand allows to conduct individual measurements of the torque, for different coil currents which generate the magnetic field. In the final report students provide the results with the individual analysis of the system parameters.

  3. Experimental investigations on steel-concrete composite columns for varying parameters

    Science.gov (United States)

    Aparna, V.; Vivek, D.; Neelima, Kancharla; Karthikeyan, B.

    2017-07-01

    In this study, the experimental investigations on steel tubes filled with different types of concrete are presented. Steel tubes filled with fibre reinforced concrete using lathe waste and steel tube with concerned confined with steel mesh were investigated. The combinations were compared with steel tubes with conventional concrete. A total of 4 concrete filled steel tube (CFST) combinations were made with tubes of diameter 100 mm with wall thickness 1.6 mm and a height of 300 mm. Axial compression test to examine the resisting capacity of the columns and push-out test for noting the bond strength were performed. Coupon tests were also conducted to determine the mechanical properties of steel. The structural behaviour of the composite columns was evaluated from on the test results. It was observed that steel tube filled fibre reinforced possessed better bond strength and resistance to axial load.

  4. Experimental basis for parameters contributing to energy dissipation in piping systems

    Energy Technology Data Exchange (ETDEWEB)

    Ibanez, P.; Ware, A.G.

    1985-01-01

    The paper reviews several pipe testing programs to suggest the phenomena causing energy dissipation in piping systems. Such phenomena include material damping, plasticity, collision in gaps and between pipes, water dynamics, insulation straining, coupling slippage, restraints (snubbers, struts, etc.), and pipe/structure interaction. These observations are supported by a large experimental data base. Data are available from in-situ and laboratory tests (pipe diameters up to about 20 inches, response levels from milli-g's to responses causing yielding, and from excitation wave forms including sinusoid, snapback, random, and seismic). A variety of pipe configurations have been tested, including simple, bare, straight sections and complex lines with bends, snubbers, struts, and insulation. Tests have been performed with and without water and at zero to operating pressure. Both light water reactor and LMFBR piping have been tested.

  5. Influence of environmental parameters on the Kelvin-Helmholtz instability at the magnetopause

    Science.gov (United States)

    Leroy, Matthieu; Keppens, Rony

    2017-04-01

    Influence of environmental parameters on the Kelvin-Helmholtz instability at the magnetopause M. Leroy1, R. Keppens1 1 Centre for mathematical Plasma-Astrophysics, Department Wiskunde, KU Leuven, Celestijnenlaan 200B, bus 2400, B-3001 Leuven, Belgium The process dominating the development of a large boundary layer at the interface between the solar wind (SW) and the magnetosphere (MS) during northward interplanetary magnetic field is still not fully understood. However the Kelvin-Helmholtz instability (KHI), which can induce magnetic reconnection events through its non-linear phase vortices, being the major actor is in good agreement with the observations around the magnetopause so far. Numerous numerical studies have investigated the topic with many interesting results but most of these were considering two-dimensional situations with simplified magnetic configuration and often neglecting the inhomogeneities for the sake of clarity. Given the typical parameters at the SW/MS interface, the situation must be considered in the frame of Hall-MHD, due to the fact that the current layers widths and the gradient lengths can be in the order of the ion inertial length. As a consequence of Hall-MHD creating a third vector component from two planar ones, and also because flow and magnetic field variations in the equatorial plane can affect the field configuration at a distance in all directions and not only locally, the simulations must also be performed away from the equatorial plane and a three-dimensional treatment is necessary. In this work, different configurations than can occur in the KHI scenario are studied in a three-dimensional (3D) Hall-MHD setting, where the double mid-latitude reconnection (DMLR) process exposed by Faganello, Califano et al. is triggered by the equatorial roll-ups. Their previous work is extended here with in particular a larger simulation box and the addition of a density contrast and variations of the interface configuration. The influence of

  6. Fatiguing exercise intensity influences the relationship between parameters reflecting neuromuscular function and postural control variables.

    Directory of Open Access Journals (Sweden)

    Sébastien Boyas

    Full Text Available The purpose of this study was to investigate the influence of fatiguing exercise intensity on the nature and extent of fatigue-induced changes in neuromuscular function and postural stability in quiet standing. We also explored the contribution of selected neuromuscular mechanisms involved in force production to postural stability impairment observed following fatigue using an approach based on multivariate regressions. Eighteen young subjects performed 30-s postural trials on one leg with their eyes closed. Postural trials were performed before and after fatiguing exercises of different intensities: 25, 50 and 75% of maximal isometric plantarflexor torque. Fatiguing exercises consisted of sustaining a plantarflexor isometric contraction at the target intensity until task failure. Maximal isometric plantarflexor torque, electromyographic activity of plantarflexor and dorsiflexor muscles, activation level (twitch interpolation technique and twitch contractile properties of plantarflexors were used to characterize neuromuscular function. The 25% exercise was associated with greater central fatigue whereas the 50 and 75% exercises involved mostly peripheral fatigue. However, all fatiguing exercises induced similar alterations in postural stability, which was unexpected considering previous literature. Stepwise multiple regression analyses showed that fatigue-related changes in selected parameters related to neuromuscular function could explain more than half (0.51≤R(2≤0.82 of the changes in postural variables for the 25% exercise. On the other hand, regression models were less predictive (0.17≤R(2≤0.73 for the 50 and 75% exercises. This study suggests that fatiguing exercise intensity does not influence the extent of postural stability impairment, but does influence the type of fatigue induced and the neuromuscular function predictors explaining changes in postural variables.

  7. Evaluation of clinical parameters influencing the development of bone metastasis in breast cancer.

    Science.gov (United States)

    Diessner, Joachim; Wischnewsky, Manfred; Stüber, Tanja; Stein, Roland; Krockenberger, Mathias; Häusler, Sebastian; Janni, Wolfgang; Kreienberg, Rolf; Blettner, Maria; Schwentner, Lukas; Wöckel, Achim; Bartmann, Catharina

    2016-05-12

    The development of metastases is a negative prognostic parameter for the clinical outcome of breast cancer. Bone constitutes the first site of distant metastases for many affected women. The purpose of this retrospective multicentre study was to evaluate if and how different variables such as primary tumour stage, biological and histological subtype, age at primary diagnosis, tumour size, the number of affected lymph nodes as well as grading influence the development of bone-only metastases. This retrospective German multicentre study is based on the BRENDA collective and included 9625 patients with primary breast cancer recruited from 1992 to 2008. In this analysis, we investigated a subgroup of 226 patients with bone-only metastases. Association between bone-only relapse and clinico-pathological risk factors was assessed in multivariate models using the tree-building algorithms "exhausted CHAID (Chi-square Automatic Interaction Detectors)" and CART(Classification and Regression Tree), as well as radial basis function networks (RBF-net), feedforward multilayer perceptron networks (MLP) and logistic regression. Multivariate analysis demonstrated that breast cancer subtypes have the strongest influence on the development of bone-only metastases (χ2 = 28). 29.9 % of patients with luminal A or luminal B (ABC-patients) and 11.4 % with triple negative BC (TNBC) or HER2-overexpressing tumours had bone-only metastases (p bottom line of different mathematical models is the prior importance of subcategories of breast cancer and the age at primary diagnosis for the appearance of osseous metastases. The primary tumour stage, histological subtype, tumour size, the number of affected lymph nodes, grading and NPI seem to have only a minor influence on the development of bone-only metastases.

  8. Experimental determination of drift and PM10 cooling tower emissions: Influence of components and operating conditions.

    Science.gov (United States)

    Ruiz, J; Kaiser, A S; Lucas, M

    2017-11-01

    Cooling tower emissions have become an increasingly common hazard to the environment (air polluting, ice formation and salts deposition) and to the health (Legionella disease) in the last decades. Several environmental policies have emerged in recent years limiting cooling tower emissions but they have not prevented an increasing intensity of outbreaks. Since the level of emissions depends mainly on cooling tower component design and the operating conditions, this paper deals with an experimental investigation of the amount of emissions, drift and PM10, emitted by a cooling tower with different configurations (drift eliminators and distribution systems) and working under several operating conditions. This objective is met by the measurement of cooling tower source emission parameters by means of the sensitive paper technique. Secondary objectives were to contextualize the observed emission rates according to international regulations. Our measurements showed that the drift rates included in the relevant international standards are significantly higher than the obtained results (an average of 100 times higher) and hence, the environmental problems may occur. Therefore, a revision of the standards is recommended with the aim of reducing the environmental and human health impact. By changing the operating conditions and the distribution system, emissions can be reduced by 52.03% and 82% on average. In the case of drift eliminators, the difference ranges from 18.18% to 98.43% on average. As the emissions level is clearly influenced by operating conditions and components, regulation tests should be referred to default conditions. Finally, guidelines to perform emission tests and a selection criterion of components and conditions for the tested cooling tower are proposed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Does Negative Mood Influence Self-Report Assessment of Individual and Relational Measures? An Experimental Analysis

    Science.gov (United States)

    Heene, Els; De Raedt, Rudi; Buysse, Ann; Van Oost, Paulette

    2007-01-01

    The present study was designed to test the influence of negative mood on the self-report of individual and relational correlates of depression and marital distress. The authors applied a combined experimental mood induction procedure, based on music, autobiographical recall, and environmental manipulation. Results showed that the mood manipulation…

  10. The influence of diet on Lawsonia intracellularis colonization in pigs upon experimental challenge

    DEFF Research Database (Denmark)

    Boesen, Henriette T.; Jensen, Tim Kåre; Schmidt, Anja S.

    2004-01-01

    The objective of this investigation was to study if different feeding strategies influence experimental infections of pigs with Lawsonia intracellularis, the causative agent of proliferative enteropathy. In three sequential trials, a total of 144 weaned pigs were fed five different diets all made...

  11. Experimentally Measured Susceptibility to Peer Influence and Adolescent Sexual Behavior Trajectories: A Preliminary Study

    Science.gov (United States)

    Choukas-Bradley, Sophia; Giletta, Matteo; Widman, Laura; Cohen, Geoffrey L.; Prinstein, Mitchell J.

    2014-01-01

    A performance-based measure of peer influence susceptibility was examined as a moderator of the longitudinal association between peer norms and trajectories of adolescents' number of sexual intercourse partners. Seventy-one 9th grade adolescents (52% female) participated in an experimental "chat room" paradigm involving…

  12. Experimentally measured susceptibility to peer influence and adolescent sexual behavior trajectories : A preliminary study

    NARCIS (Netherlands)

    Choukas-Bradley, S.; Giletta, M.; Widman, L.; Cohen, G.L.; Prinstein, M.J.

    2014-01-01

    A performance-based measure of peer influence susceptibility was examined as a moderator of the longitudinal association between peer norms and trajectories of adolescents' number of sexual intercourse partners. Seventy-one 9th grade adolescents (52% female) participated in an experimental "chat

  13. Simulation and Experimental Determination of Technological Liquid Molding Parameters of Tubing Basalt Insulation

    Directory of Open Access Journals (Sweden)

    Yu. V. Badanina

    2015-01-01

    Full Text Available The article is dedicated to one of the most important and urgent tasks in mechanical engineering development - the creation of low-density and environmentally-friendly thermoinsulation from available cheap basalt fibers for products to operate at temperatures up to 700°C.One of the most effective applications of such thermo-insulation is to develop and provide highly porous coatings from short basalt fibers by liquid filtration for tubing (T to supply superheated up to 420° C steam under pressure of 35 MPa in the deep layers with severe highviscosity oil. Tubing with the short low-density basalt insulation can be used for a greater depth than the vacuum-insulated tubing, which are also called "thermo-cases", and do not fully meet business needs for long-term reliability of oil vacuum tubes, too large mass per unit length of their design and, as a consequence, the impossibility to use such pipes for deep wells.The aim of the work is to simulate a liquid filtration process of short fibers and determine technological parameters of producing thermal insulation coatings of tubing pipes from basalt fibers and mineral binder shaped as cylinders and cylindrical shells. The paper proposes a mathematical model of free filtration deposition of short fibers from liquid slurry, which describes dynamics of creating thermal insulation products and allows us to determine the rational parameters of their manufacturing process. It shows methods to improve the products quality while forming the thermal insulation by filtration through additional vacuum deposition of a filtrate chamber and the final prepressing of sediment layer, giving dimensions and shape to the final product.The paper defines a prescription hydro mass composition. It shows that to increase the compressive strength of highly fibrous rings and cylindrical shells it is necessary to use based on oxide А12O3 5-7% by weight mineral binder, which fixes basalt fibers in places of their contacts. It

  14. An Experimental Seismic Data and Parameter Exchange System for Interim NEAMTWS

    Science.gov (United States)

    Hanka, W.; Hoffmann, T.; Weber, B.; Heinloo, A.; Hoffmann, M.; Müller-Wrana, T.; Saul, J.

    2009-04-01

    In 2008 GFZ Potsdam has started to operate its global earthquake monitoring system as an experimental seismic background data centre for the interim NEAMTWS (NE Atlantic and Mediterranean Tsunami Warning System). The SeisComP3 (SC3) software, developed within the GITEWS (German Indian Ocean Tsunami Early Warning System) project was extended to test the export and import of individual processing results within a cluster of SC3 systems. The initiated NEAMTWS SC3 cluster consists presently of the 24/7 seismic services at IMP, IGN, LDG/EMSC and KOERI, whereas INGV and NOA are still pending. The GFZ virtual real-time seismic network (GEOFON Extended Virtual Network - GEVN) was substantially extended by many stations from Western European countries optimizing the station distribution for NEAMTWS purposes. To amend the public seismic network (VEBSN - Virtual European Broadband Seismic Network) some attached centres provided additional private stations for NEAMTWS usage. In parallel to the data collection by Internet the GFZ VSAT hub for the secured data collection of the EuroMED GEOFON and NEAMTWS backbone network stations became operational and the first data links were established. In 2008 the experimental system could already prove its performance since a number of relevant earthquakes have happened in NEAMTWS area. The results are very promising in terms of speed as the automatic alerts (reliable solutions based on a minimum of 25 stations and disseminated by emails and SMS) were issued between 2 1/2 and 4 minutes for Greece and 5 minutes for Iceland. They are also promising in terms of accuracy since epicenter coordinates, depth and magnitude estimates were sufficiently accurate from the very beginning, usually don't differ substantially from the final solutions and provide a good starting point for the operations of the interim NEAMTWS. However, although an automatic seismic system is a good first step, 24/7 manned RTWCs are mandatory for regular manual verification

  15. INFLUENCE ANALYSES OF DESIGNED CHARACTERISTICS OF THE ELEVATOR TO THE PARAMETERS OF ITS DRIVE

    Directory of Open Access Journals (Sweden)

    V. M. Bohomaz

    2015-04-01

    Full Text Available Purpose. A drive behaves to the basic elements of scoop band elevators. To determine the drive power calculations are carried out according to standard methods, which take plenty of time. It is necessary to conduct the analysis of influence of project characteristics on the parameters of high-speed drive in a scoop bent elevator and to build the improved algorithm of speed-up determination of its drive power on project descriptions, that will take into account the type of load, rise height, necessary productivity, standard parameters of scoops and tape. Methodology. Using parametric dependences of elevators drive power on its project characteristics, received by the author earlier, the improved algorithm of speed-up determination of elevators high-speed drive power with deep and shallow scoops at set type of load, productivity, rise height was offered. Findings. The algorithm of drive power speed-up determination of high-speed vertical elevators with deep and shallow scoops depending on project parameters was offered. The example of such algorithm application is considered for an elevator that is intended for transporting of cement. Analytical dependences of drive power of such elevator are determined on the productivity and rise height. Corresponding graphic dependences were built and character of drive power changes during the size changing of any project characteristics was determined. Originality. The improved algorithm of drive power elevator determination at the given project characteristics (type of load, rise height, productivity that takes into account standard sizes, parameters of scoops and ribbons, was built at first time. Practical value. The use of an offered algorithm of calculation gives the possibility of relatively fast determination of reference value of high-speed elevators drive power with deep and shallow scoops, to build graphic dependences of drive power on the values of the productivity and rise height at the certain

  16. THE INFLUENCE OF THE MAIN PARAMETERS OF TRAIN TRAFFIC VOLUME ON TOTAL PROFITS OF RAILWAYS

    Directory of Open Access Journals (Sweden)

    H. YA. Mozolevich

    2015-04-01

    Full Text Available Purpose. The paper is aimed to influence analysis of parameters such as the number of trains on the section and the length of freight trains, the total profit of the railway and determination of total profit of Prydniprovsk railway for major parts of the trains handling; the determination of the specific rate of return on 1 kilometer operational length of each individual link in the rail network. Methodology. To achieve this goal the simulation models of the sections of railway polygon and the simulation of cargo trains have been developed. On the basis of obtained results the dependence of the main parameters of train traffic and their impact on the overall profit of the railway was determined. Findings. On the basis of the conducted studies the functions operating costs for each section were developed to determine the optimal routes crossing of trains and choice of rational parameters. The operating costs, revenue, total profit of railways and certain impact parameters of train traffic volume on the economic performance of railway transport were calculated with their help. It is determined that freight trains, length 53-56 of a conventional car is optimal to pass and loading area should be 75-85% of the available crossing capacity. Taking into account given results, the electrification of the sections with diesel traction (due to the significant cost of diesel fuel is the priority development of railway transport at the possible increase in size of the movement. Originality. Authors have improved the technology of determining the total profits of railways on the basis of variables train traffic volumes. For the first time the specific rate of profit on the 1 kilometer operational length of the section depending on the size of the average daily traffic is identified and proposed to use to determine the investment attractiveness of the railways. The simulation models of individual sections of the real train polygon at Prydniprovsk railway were

  17. More accurate macro-models of solid oxide fuel cells through electrochemical and microstructural parameter estimation - Part I: Experimentation

    Science.gov (United States)

    Boigues Muñoz, Carlos; Pumiglia, Davide; McPhail, Stephen J.; Montinaro, Dario; Comodi, Gabriele; Santori, Giulio; Carlini, Maurizio; Polonara, Fabio

    2015-10-01

    The distributed relaxation times (DRT) method has been employed in order to deconvolute the electrochemical impedance spectroscopy (EIS) measurements carried out on a Ni-YSZ|YSZ|Pr2NiO4+δ - GDC solid oxide fuel cell (SOFC). This has enabled to shed light on the diverse physicochemical processes occurring within the aforementioned cell by individuating the characteristic relaxation times of these by means of a specifically designed experimental campaign where temperature and gas compositions in anode and cathode were varied one at a time. A comprehensive equivalent circuit model (ECM) has thus been generated based on the processes observed in the DRT spectra. This ECM has proved to be instrumental for the obtainment of parameters which describe the microstructural and electrochemical properties of the SOFC when used contemporaneously with experimental results and modelling theory (described in Part II of this work).

  18. Experimental study on effects of drilling parameters on respirable dust production during roof bolting operations.

    Science.gov (United States)

    Jiang, Hua; Luo, Yi; McQuerrey, Joe

    2017-11-20

    Underground coalmine roof bolting operators exhibit a continued risk for overexposure to airborne levels of respirable coal and crystalline silica dust from the roof drilling operation. Inhaling these dusts can cause coal worker's pneumoconiosis and silicosis. This research explores the effect of drilling control parameters, specifically drilling bite depth, on the reduction of respirable dust generated during the drilling process. Laboratory drilling experiments were conducted and results demonstrated the feasibility of this dust control approach. Both the weight and size distribution of the dust particles collected from drilling tests with different bite depths were analyzed. The results showed that the amount of total inhalable and respirable dust was inversely proportional to the drilling bite depth. Therefore, control of the drilling process to achieve proper high bite depth for the rock can be an important approach to reducing the generation of harmful dust. Different from conventional passive engineering controls, such as mist drilling and ventilation approaches, this approach is proactive and can cut down the generation of respirable dust from the source. These findings can be used to develop an integrated drilling control algorithm to achieve the best drilling efficiency as well as reducing respirable dust and noise.

  19. Experimental examination of the relationships among chemico-osmotic, hydraulic, and diffusion parameters of Wakkanai mudstones

    Science.gov (United States)

    Takeda, M.; Hiratsuka, T.; Manaka, M.; Finsterle, S.; Ito, K.

    2014-05-01

    Sequential permeability and chemical osmosis experiments on Wakkanai mudstones were performed to explore the relationships between the semipermeability of clayey rocks and the hydraulic and diffusion parameters as well as the pore structure characteristics. The wide ranges in osmotic efficiency (0.0004-0.046) and intrinsic permeability (8.92 × 10-20 to 1.24 × 10-17 m2) reflect the variation in the pore size distributions of the Wakkanai mudstones. A regression analysis between osmotic efficiency and permeability shows that the osmotic efficiency is proportional to the inverse of permeability, suggesting that the permeability is indeed indicative of the degree of semipermeability. Osmotic efficiency was determined invariant with the effective diffusion coefficient for the Wakkanai mudstones (3.59-8.36 × 10-11 m2/s) due to their small osmotic efficiencies (≤0.046). The wide variation in osmotic efficiencies and pore structure characteristics of Wakkanai mudstones indicates that the nanoscale pores enable semipermeability in Wakkanai mudstones. However, the pressure evolution caused by chemical osmosis is limited by the connected wide pores that are the main conduits for water, thus dissipating the osmotic pressure buildup induced by the semipermeability of nanoscale pores.

  20. Effect of Small Intestine Strangulation Obstruction on Clinical and Histopathological Parameters An Experimental Study in Donkeys

    Directory of Open Access Journals (Sweden)

    Heba Mohamed M. Kuraa

    2011-06-01

    Full Text Available To study clinical and histopathological changes occur within the first 12 hours of strangulating obstruction of the small intestine in equine, twenty five adult donkeys were used in an experimental study. Strangulation obstruction of the small intestine was performed for 3, 6, 9 and 12 hours, respectively. Clinical examination was done before surgery and at 3 hours intervals postoperatively. After euthanasia, histopathological examination was made 10 cm, 1, 2 and 3 meters proximal to the strangulated part. Three hours postoperatively, the animals began to show signs of abdominal pain, they were looking around, stamping the hind feet, falling down suddenly. Nine hours postoperatively, animals showed signs of depression with intermittent nervous movements in the form of circle movement. After 12 hours, the animals were lying down; There were a significant reduction in the body temperature, respiratory rate, pulse rate, heart rate with significant increase in capillary refill time. Macroscopic changes of the strangulated part were congestion, edema, and dark red discoloration of the intestinal wall and mesentery. Distension of the intestine proximal to the strangulation extended more with increase the period of strangulation. Microscopic examination showed showed severe congestion, dark brown to blackish discoloration with fibrous shreds on the strangulated segment. Peticheal hemorrhages were observed in the intestinal wall and its mesentery for a distance up to 3 meters. The severity of signs varies according to the duration of obstruction which could give a remarkable justification of the prognosis of the patient and the availability of treatment.

  1. Preventive effects of hydroalcoholic extract of saffron on hematological parameters of experimental asthmatic rats

    Directory of Open Access Journals (Sweden)

    Somayyeh Vosooghi

    2013-05-01

    Full Text Available Objective: Asthma is a chronic inflammatory disease of the respiratory airways distinguished by edema and infiltration of inflammatory immune cells. To test our hypothesis about the anti-inflammatory effect of saffron, we examined effects of Crocus sativus (C. sativus extract as a prophylactic anti-inflammatory agent in sensitized rats. Materials and Methods: To induce experimental asthma, rats were sensitized with injection and inhalation of ovalbumin (OA. Forty male Wistar rats were divided into 5 groups (n=8 for each: control, sensitized (asthma, and sensitized and pretreated with three different concentrations of extract, 50, 100, and 200 mg/kg, 2 times a week (group asthma+50EX, group asthma+100EX, and group asthma+200EX. After 32 days, total white blood cells (WBC counts, red blood cells (RBC, and platelet counts in blood were examined. Results: Total WBC number and eosinophil and neutrophil percentage in blood were increased, but lymphocyte decreased in sensitized animals compared with those of control group (pConclusion: Our findings indicated that the extract of C. sativus could be useful to prevent asthma as an anti-inflammatory treatment.

  2. [Serological parameters for the diagnosis and follow-up of toxoplasmosis. Experimental models].

    Science.gov (United States)

    Acebes, M V; Díez, B; Nicolás, R; Martín, M T; Suñén, E; Cisterna, R

    1994-03-01

    Toxoplasmosis is a disease of increasing incidence. Its laboratory diagnosis is difficult, specially in acute toxoplasmosis. The data obtained in experimental models attempting to distinguish between acute and chronic toxoplasmosis by the simultaneous study of four serological tests: IgM and IgG antibodies, circulating antigens (CA) and antigens present in immune complexes (IC) are reported. The evolution of IgM and IgG antibodies, CA and IC was followed in 3 murine models in acute, subacute and chronic toxoplasmosis, compared with the use of the ELISA technique. Acute toxoplasmosis is characterized by the presence of CA and IC in 100% of the individuals at high concentrations with IgM and IgG only being detectable at low concentrations. In subacute and chronic toxoplasmosis the response to IgG antibodies (100% in animals) is prominent, with detection of IgM being variable and the detection of CA and IC being reduced to the phase considered as acute. The detection of IgM and IgG antibodies, circulating antigens and immune complexes may be of great usefulness in the differentiation of acute, recently acquired or chronic toxoplasmosis.

  3. THE INFLUENCE OF THE TOOL POINT ANGLE AND FEED RATE ON THE DYNAMIC PARAMETERS AT DRILLING COATED PARTICLEBOARD

    Directory of Open Access Journals (Sweden)

    Mihai ISPAS

    2015-12-01

    Full Text Available Pre-laminated (coated particleboards (PB are wood-based composites intensively used in the furniture industry. In order to prepare the PB for joining, drilling is the most commonly applied machining process. The surface quality and the dynamic parameters (thrust force and torque are significantly influenced by the tools characteristics and the machining parameters. The point/tip angle of the drill bit and the feed speed during drilling play a major role in gaining a good surface quality and minimizing the dynamic parameters. The objective of this study was to measure and analyze the influence of both the geometric and cinematic parameters on the dynamic parameters at drilling with twist (helical drills. The experiments were performed based on a factorial design. The results show that, a low feed rate generally minimizes both the drilling torque and the thrust force, while a small tip angle increases the drilling torque and minimizes the thrust force.

  4. THE INFLUENCE OF THE EXPERIMENTAL PROGRAMME OF PHYSICAL EDUCATION CURRICULUM ON SCHOOLGIRLS MOTOR ABILITIES

    Directory of Open Access Journals (Sweden)

    Nevenka Zrnzević

    2010-03-01

    Full Text Available The main purpose of this research was to determine the influence of the suggested experimental program of physical education on motor abilities of the experimental group of schoolgirls. The research purpose was also to determine the influence of the current curriculum concerning teaching physical education of motor abilities of the control group of schoolgirls. The experimental program was carried out on the sample of 97 first-grade schoolgirls of the elementary schools in Leposavic and Zvecan, age of 7 years ± 6 months. The applied experimental program was composed of athletics exercises, sports games, exercises on the pieces of equipment and on the floor, rhythmics and dancing exercises and some additional exercises. The control group was taught according to the current curriculum. 12 metrical instruments were used to estimate motor abilities. Multivariant and univariant analyses of variance for repeated measures (MANOVA and ANOVA – repeated measures were applied to determine the differences between the initial and final measuring within the groups. On the basis of the results and discussion, it can be concluded that the experimental program has statistically significant effects on the changes all of the motor abilities. Comparing the two programs, it was concluded that both of them caused the change in motor abilities, but the experimental program had statistically more significant effects.

  5. Parameter design and experimental study of a bifunctional isolator for optical payload protection and stabilization

    Science.gov (United States)

    Wang, Guang-yuan; Guan, Xin; Cao, Dong-jing; Tang, Shao-fan; Chen, Xiang; Liang, Lu; Zheng, Gang-tie

    2017-11-01

    requirement and the displacement restriction during launch are satisfied by tuning the nonlinear stiffness and damping parameters. A group of sample isolators are designed tested both statically and dynamically.

  6. The influence of coronary angiography and angioplasty on parameters of hemostasis and fibrinolysis.

    Science.gov (United States)

    Six, A J; Tjon, R M; Buys, E M; Haas, F; Hollander-van Zalk, A; Haverkate, F

    1990-08-13

    The influence of invasive investigations on parameters of hemostasis and fibrinolysis is generally unknown, although this has consequences for the design of prospective studies on the association between those parameters and regression or progression of atherosclerosis. We therefore determined hemostatic and fibrinolytic factors in 12 patients who were admitted to the hospital for coronary angiography (CAG; n = 5) or percutaneous transluminal coronary angioplasty (PTCA; n = 7). Blood samples were drawn under basal circumstances on the day before, the day of and the day after CAG or PTCA. Significant changes occur in the concentrations of platelets and white blood cells, hematocrit (Ht), von Willebrand factor antigen (vWF:ag), antithrombin III-activity (AT III-ag), antithrombin III-antigen (AT III-ant), fibrinogen, plasminogen, alpha2-antiplasmin (alpha2-AP), histidine-rich glycoprotein (HRG), and plasminogen activator inhibitor (PAI)-activity. Mean values of beta-thromboglobulin, platelet factor 4, factor VIII:C, tissue-type plasminogen activator activity (t-PA act) and euglobulin clot lysis time (ECLT) do not differ significantly. After correction for Ht, no significant differences exist between the day before and the day of the procedure; but on the day after CAG and PTCA significant differences occur in white blood cells, factor VIII:C, AT III-ag, alpha2-AP and PAI-act. It is concluded that principally blood samples for investigations on fibrinolysis may be taken on the day before or the day of CAG or PTCA without a loss of quality, if the values are corrected for Ht. Samples taken on the day after the procedure are not useful for such purposes.

  7. The influence of sputter deposition parameters on piezoelectric and mechanical properties of AlN thin films

    Energy Technology Data Exchange (ETDEWEB)

    Ababneh, A., E-mail: a.ababneh@lmm.uni-saarland.de [Department of Mechatronics, Saarland University, D-66123 Saarbruecken (Germany); Schmid, U. [Department of Microsystems Technology, Vienna University of Technology, Floragasse 7, 1040 Vienna (Austria); Hernando, J.; Sanchez-Rojas, J.L. [Departamento Ingenieria Electrica, Electronica, Automatica y Comunicaciones, E.T.S.I. Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain); Seidel, H. [Department of Mechatronics, Saarland University, D-66123 Saarbruecken (Germany)

    2010-09-15

    Aluminium nitride (AlN) reactively sputter-deposited from an aluminium target is an interesting piezoelectric thin film material with high CMOS compatibility. A good c-axis orientation is essential for obtaining high piezoelectric coefficients. Therefore, the influence of different sputtering conditions on the microstructure of AlN thin films with a typical thickness of about 500 nm was investigated. In this study it is demonstrated that highly c-axis oriented AlN thin films can be deposited on nominally unheated (1 0 0) silicon substrates, most preferentially when using a pure nitrogen atmosphere. The degree of c-axis orientation increases with higher nitrogen concentration and with decreasing the sputtering pressure, whereas the influence of plasma power on the microstructure was found to be negligible. A low sputtering pressure is also useful for minimizing the amount of oxygen contaminations in the deposition chamber and hence for reducing the incorporation of impurities into the AlN films. Intrinsic stress values of AlN thin films were determined by wafer bow measurements and were found to be between -3.5 and 750 MPa depending on choice of deposition parameters. Finally, the piezoelectric coefficients d{sub 33} and d{sub 31} were determined experimentally by laser scanning vibrometry in conjunction with a theoretical model. Effective values in c-axis oriented 500 nm films with FWHM of 0.33 deg. are 3.0 and -1.0 pm/V. For a film of 2.4 {mu}m thickness, values of 5.0 and -1.8 pm/V were measured, which are near the bulk values.

  8. Influence of process parameters on coal combustion performance. Review, experiments and engineering modeling

    Energy Technology Data Exchange (ETDEWEB)

    Lans, R.P. van der

    1997-04-01

    The objective of this study is to improve the understanding of nitrogen oxide formation and carbon burnout during the combustion of pulverized coal, and to contribute to addressing the potential of chemical engineering models for the prediction of furnace temperatures, NO emissions and the amount of carbon in ash. To this purpose, the effect of coal quality on NO and burnout has been investigated experimentally, a radiation heat balance has been developed based on a simple chemical engineering methodology, and a mixing study has been conducted in order to describe the near burner macro mixing in terms of a reactor configuration. The influence of coal type and process conditions on NO formation and carbon burnout has been investigated experimentally in a 400 MW{sub e} corner fired boiler with over fire air, a 350 MW{sub e} opposed fired boiler, and in a 160 kW{sub t} pilot scale test rig. Three different coals were fired in each of the furnaces as part of the activities in group 3 of the European Union JOULE 2 Extension project `Atmospheric Pressure Combustion of Pulverized Coal and Coal Based Blends for Power Generation`. On the pilot scale test both single stage and air staged tests were performed. A simple, one-dimensional combustion and radiation heat transfer model has been developed for the furnace of full scale boilers. The model has been applied to the two boilers mentioned above, and is validated against measured temperatures and carbon in ash concentrations. A mixing study has been performed in order to initiate an investigation of the potential of chemical engineering models to predict NO from pulverized fuel burners. (EG) 11 refs.

  9. Influence of image-capturing parameters on digital X-ray radiogrammetry.

    Science.gov (United States)

    Böttcher, Joachim; Pfeil, Alexander; Rosholm, Anders; Malich, Ansgar; Petrovitch, Alexander; Heinrich, Bianka; Lehmann, Gabriele; Mentzel, Hans-Joachim; Hein, Gert; Linss, Werner; Kaiser, Werner A

    2005-01-01

    The purpose of this study was to evaluate the importance of different image-capturing conditions, which might influence the characteristics of radiographs and, consequently, impact calculations of bone mineral density (BMD) and Metacarpal Index (MCI) using digital X-ray radiogrammetry (DXR). Radiographs of the left hand of deceased males were acquired three times using systematically varied parameters: 4-8 miliamp seconds (mA); 40-52 kV; film-focus distance (FFD); 90-130 cm; film sensitivity, 200/400; and different image modalities (conventional vs original digital radiographs as well as digital printouts). Furthermore, the interradiograph reproducibility using both conventional equipment and printouts vs originals of digital images and the intraradiograph reproducibility (either conventional or digital printouts) were evaluated. All BMD and MCI measurements were obtained with the DXR technology. The interradiograph reproducibility of DXR-BMD using conventional images under standardized conditions (6 mAs; 42 kV; 1 m FFD; film sensitivity of 200) was calculated to be coefficient of variation (CV) = 0.49% for Agfa Curix film and CV = 0.33% for Kodak T-MAT-Plus film, whereas reproducibility error using digital images ranged from CV = 0.57% (digital printouts; Philips) to CV = 1.50% (original digital images; Siemens). The intraradiograph reproducibility error was observed to be CV = 0.13% (conventional; Kodak film) vs CV = 0.27% (digital printouts; Philips). The BMD calculation was not noticeably affected by changes of FFD, exposure level, or film sensitivity/film brand, but was influenced by tube voltage (CV = 0.99% for Kodak film to CV = 2.05% for Siemens digital printouts). No significant differences were observed between the BMD and MCI data. DXR provides measurements of MCI and BMD with high precision and reproducibility. The measurements are unaffected by all tested image-capturing conditions, with the exception of tube voltage. In addition, different digital

  10. The influence of exposure parameters on jawbone model accuracy using cone beam CT and multislice CT.

    Science.gov (United States)

    Vandenberghe, B; Luchsinger, S; Hostens, J; Dhoore, E; Jacobs, R

    2012-09-01

    The main purpose of this study was to investigate the influence of exposure parameters on jawbone model accuracy when using cone beam CT (CBCT) and multislice CT (MSCT). A lower and an upper edentulous human cadaver jaw were scanned using micro-CT (Skyscan 1173 high energy spiral scan micro-CT; Skyscan NV, Kontich, Belgium) at 35 μm to serve as true reference. The in vitro samples were exposed using six CBCT units and one MSCT system. CBCT exposure protocols were chosen according to clinically available settings. The variables were kilovoltage, milliamperage, voxel size and/or scan time. Image segmentation was based on local thresholds using profile lines. The resulting jawbone segmentations were registered with the reference and image processing was done to internally fill the segmentations. A point-based distance calculation was performed between the three-dimensional objects and reference scans and deviation percentages were calculated for 2 mm, 1 mm and 0.5 mm intervals. All points of the MSCT surface models lay within a 1 mm deviation range and 98.5% within 0.5 mm compared with micro-CT. For the different CBCT systems, accuracy came close to MSCT with mean percentages of 98.9% within 1 mm deviation and 92.8% within 0.5 mm. A difference of approximately 1% between lower and upper jaws could be perceived. For the specific CBCT exposure protocols, only scan time and voxel size revealed certain significant differences. Jawbone model accuracy using CBCT was comparable with MSCT. The surface models of the upper jaws deviated slightly more than those for lower jaws. CBCT exposure settings had a limited influence on accuracy with scan time and voxel size as the main factors.

  11. Investigation of the influence of process parameters on adhesive wear under hot stamping conditions

    Science.gov (United States)

    Schwingenschlögl, P.; Weldi, M.; Merklein, M.

    2017-09-01

    Current challenges like increasing safety standards and reducing fuel consumption motivate lightweight construction in modern car bodies. Besides using lightweight workpiece materials like aluminum, hot stamping has been established as a key technology for producing safety relevant components. Producing hot stamped parts out of ultra-high strength steels offers the possibility to improve the crash performance. At the same time the weight of car structure is reduced by using thinner sheet thicknesses. In order to avoid oxide scale formation and ensure corrosion protection, AlSi coatings are commonly deposited on the sheet surfaces used for direct hot stamping. This workpiece coating has a critical impact on the tribological conditions within the forming process and, as a consequence, influences the quality of hot stamped parts as well as tool wear. AlSi coatings have been identified as major reason for adhesive wear, which represents the main wear mechanism in hot stamping. Within this study, the influence of the process parameters on adhesive wear are investigated in dependency of workpiece and tool temperatures, drawing velocities and contact pressures. The tribological behavior is analyzed based on strip drawing experiments under direct hot stamping conditions. The experiments are performed with AlSi coated 22MnB5 in contact with the hot working tool steel 1.2367. For analyzing the amount of adhesion on the friction jaws, the surfaces are characterized by optical measurements. The experiments indicate that higher workpiece temperatures cause severe adhesive wear on the tool surface, while an increase of drawing velocity or contact pressure led to reduced adhesion. The measured friction coefficients decreased with rising amount of adhesion and remained at a constant level after a certain adhesive layer was built up on the tool surface.

  12. Parameters influencing the regeneration of a green roof's retention capacity via evapotranspiration

    Science.gov (United States)

    Poë, Simon; Stovin, Virginia; Berretta, Christian

    2015-04-01

    The extent to which the finite hydrological capacity of a green roof is available for retention of a storm event largely determines the scale of its contribution as a Sustainable Drainage System (SuDS). Evapotranspiration (ET) regenerates the retention capacity at a rate that is variably influenced by climate, vegetation treatment, soil and residual moisture content. Experimental studies have been undertaken to monitor the drying cycle behaviour of 9 different extensive green roof configurations with 80 mm substrate depth. A climate-controlled chamber at the University of Sheffield replicated typical UK spring and summer diurnal cycles. The mass of each microcosm, initially at field capacity, was continuously recorded, with changes inferred to be moisture loss/gain (or ET/dew). The ranges of cumulative ET following a 28 day dry weather period (ADWP) were 0.6-1.0 mm/day in spring and 0.7-1.25 mm/day in summer. These ranges reflect the influence of configuration on ET. Cumulative ET was highest from substrates with the greatest storage capacity. Significant differences in ET existed between vegetated and non-vegetated configurations. Initially, seasonal mean ET was affected by climate. Losses were 2.0 mm/day in spring and 3.4 mm/day in summer. However, moisture availability constrained ET, which fell to 1.4 mm/day then 1.0 mm/day (with an ADWP of 7 and 14 days) in spring; compared to 1.0 mm/day and 0.5 mm/day in summer. A modelling approach, which factors Potential Evapotranspiration (PET) according to stored moisture content, predicts daily ET with very good accuracy (PBIAS = 2.0% [spring]; -0.8% [summer]).

  13. Influence of storage temperature on quality parameters, phenols and volatile compounds of Croatian virgin olive oils

    Directory of Open Access Journals (Sweden)

    Brkić Bubola, K.

    2014-09-01

    Full Text Available The influence of low storage temperature (+4 °C and -20 °C and conventional storage room temperature on the quality parameters, phenolic contents and volatile profiles of Buža, Črna and Rosinjola monovarietal virgin olive oils after 12 months of storage was investigated in this study. Virgin olive oils stored at low temperatures maintained better quality parameters than oils stored at room temperature. A negligible decrease in the total phenols was detected after 12 months of storage at all investigated temperatures. The total volatile compounds, aldehydes, alcohols and esters in almost all stored samples were unchanged compared to fresh oils. Total ketones increased after storage, although at a lower temperature these changes were less notable. An increase in the oxidation indicators hexanal and hexanal/E-2-hexenal ratio was the lowest in oils stored at +4 °C.Storage at temperatures lower than room temperature could help to prolong the shelf-life of extra virgin olive oil by maintaining high quality parameters and preserving the fresh oil’s volatile profile.Se ha estudiado la influencia, durante 12 meses, de temperaturas bajas (+4 °C y −20 °C y convencional (ambiente, sobre los parámetros de calidad, contenido fenólico y perfil de volátiles de aceites de oliva vírgenes monovarietales Buža, Črna y Rosinjola. Los aceites de oliva vírgenes almacenados a bajas temperaturas mantienen mejores propiedades de calidad que los aceites almacenados a temperatura ambiente. Se encontró una disminución no significativa de los fenoles totales después de 12 meses de almacenamiento a todas las temperaturas estudiadas. Los compuestos volátiles totales, aldehídos, alcoholes y ésteres, en casi todas las muestras almacenadas, se mantuvieron sin cambios en comparación con los aceites frescos. Las cetonas totales incrementaron tras el almacenamiento, aunque a temperaturasmas bajas estos cambios fueron menos notables. El incremento de los

  14. Influence of electrical resistivity and machining parameters on electrical discharge machining performance of engineering ceramics.

    Directory of Open Access Journals (Sweden)

    Renjie Ji

    Full Text Available Engineering ceramics have been widely used in modern industry for their excellent physical and mechanical properties, and they are difficult to machine owing to their high hardness and brittleness. Electrical discharge machining (EDM is the appropriate process for machining engineering ceramics provided they are electrically conducting. However, the electrical resistivity of the popular engineering ceramics is higher, and there has been no research on the relationship between the EDM parameters and the electrical resistivity of the engineering ceramics. This paper investigates the effects of the electrical resistivity and EDM parameters such as tool polarity, pulse interval, and electrode material, on the ZnO/Al2O3 ceramic's EDM performance, in terms of the material removal rate (MRR, electrode wear ratio (EWR, and surface roughness (SR. The results show that the electrical resistivity and the EDM parameters have the great influence on the EDM performance. The ZnO/Al2O3 ceramic with the electrical resistivity up to 3410 Ω·cm can be effectively machined by EDM with the copper electrode, the negative tool polarity, and the shorter pulse interval. Under most machining conditions, the MRR increases, and the SR decreases with the decrease of electrical resistivity. Moreover, the tool polarity, and pulse interval affect the EWR, respectively, and the electrical resistivity and electrode material have a combined effect on the EWR. Furthermore, the EDM performance of ZnO/Al2O3 ceramic with the electrical resistivity higher than 687 Ω·cm is obviously different from that with the electrical resistivity lower than 687 Ω·cm, when the electrode material changes. The microstructure character analysis of the machined ZnO/Al2O3 ceramic surface shows that the ZnO/Al2O3 ceramic is removed by melting, evaporation and thermal spalling, and the material from the working fluid and the graphite electrode can transfer to the workpiece surface during electrical

  15. Influence of electrical resistivity and machining parameters on electrical discharge machining performance of engineering ceramics.

    Science.gov (United States)

    Ji, Renjie; Liu, Yonghong; Diao, Ruiqiang; Xu, Chenchen; Li, Xiaopeng; Cai, Baoping; Zhang, Yanzhen

    2014-01-01

    Engineering ceramics have been widely used in modern industry for their excellent physical and mechanical properties, and they are difficult to machine owing to their high hardness and brittleness. Electrical discharge machining (EDM) is the appropriate process for machining engineering ceramics provided they are electrically conducting. However, the electrical resistivity of the popular engineering ceramics is higher, and there has been no research on the relationship between the EDM parameters and the electrical resistivity of the engineering ceramics. This paper investigates the effects of the electrical resistivity and EDM parameters such as tool polarity, pulse interval, and electrode material, on the ZnO/Al2O3 ceramic's EDM performance, in terms of the material removal rate (MRR), electrode wear ratio (EWR), and surface roughness (SR). The results show that the electrical resistivity and the EDM parameters have the great influence on the EDM performance. The ZnO/Al2O3 ceramic with the electrical resistivity up to 3410 Ω·cm can be effectively machined by EDM with the copper electrode, the negative tool polarity, and the shorter pulse interval. Under most machining conditions, the MRR increases, and the SR decreases with the decrease of electrical resistivity. Moreover, the tool polarity, and pulse interval affect the EWR, respectively, and the electrical resistivity and electrode material have a combined effect on the EWR. Furthermore, the EDM performance of ZnO/Al2O3 ceramic with the electrical resistivity higher than 687 Ω·cm is obviously different from that with the electrical resistivity lower than 687 Ω·cm, when the electrode material changes. The microstructure character analysis of the machined ZnO/Al2O3 ceramic surface shows that the ZnO/Al2O3 ceramic is removed by melting, evaporation and thermal spalling, and the material from the working fluid and the graphite electrode can transfer to the workpiece surface during electrical discharge

  16. Influence of friction stir welding parameters on properties of 2024 T3 aluminium alloy joints

    Directory of Open Access Journals (Sweden)

    Eramah Abdsalam M.

    2014-01-01

    Full Text Available The aim of this work is to analyse the process of friction stir welding (FSW of 3mm thick aluminium plates made of high strength aluminium alloy - 2024 T3, as well as to assess the mechanical properties of the produced joints. FSW is a modern procedure which enables joining of similar and dissimilar materials in the solid state, by the combined action of heat and mechanical work. This paper presents an analysis of the experimental results obtained by testing the butt welded joints. Tensile strength of the produced joints is assessed, as well as the distribution of hardness, micro-and macrostructure through the joints (in the base material, nugget, heat affected zone and thermo-mechanically affected zone. Different combinations of the tool rotation speed and the welding speed are used, and the dependence of the properties of the joints on these parameters of welding technology is determined. [Projekat Ministarstva nauke Republike Srbije, br. TR 34018 i br. TR 35006

  17. Echinacea as an antiinflammatory agent: the influence of physiologically relevant parameters.

    Science.gov (United States)

    Sharma, M; Schoop, R; Hudson, J B

    2009-06-01

    Numerous Echinacea preparations are available on the market for the prevention and treatment of cold and 'flu symptoms and inflammatory conditions associated with infections. Most of these preparations are consumed orally in the form of aqueous or ethanol extracts and tinctures. Since the recommended consumption normally involves a brief local exposure to the diluted preparation at an unspecified time in relation to the actual infection, then it is important that experimental models for the evaluation of Echinacea reflect these limitations. A line of human bronchial epithelial cells, in which rhinoviruses stimulate the production of pro-inflammatory cytokines, was used to evaluate several relevant parameters. The chemically characterized Echinacea preparation (Echinaforce) was capable of inhibiting completely the rhinovirus induced secretion of IL-6 (interleukin-6) and IL-8 (chemokine CXCL-8) in these cells, regardless of whether the Echinacea was added before or after virus infection, and in response to a range of virus doses. This inhibitory effect was also manifest under conditions resembling normal consumption with respect to the duration of exposure to Echinacea and the Echinacea dilution. It is concluded that under real life conditions of Echinacea consumption, the virus-induced stimulation of pro-inflammatory cytokines can be effectively reversed or alleviated. (c) 2008 John Wiley & Sons, Ltd.

  18. Optimization and influence of parameter affecting the compressive strength of geopolymer concrete containing recycled concrete aggregate: using full factorial design approach

    Science.gov (United States)

    Krishnan, Thulasirajan; Purushothaman, Revathi

    2017-07-01

    There are several parameters that influence the properties of geopolymer concrete, which contains recycled concrete aggregate as the coarse aggregate. In the present study, the vital parameters affecting the compressive strength of geopolymer concrete containing recycled concrete aggregate are analyzedby varying four parameters with two levels using full factorial design in statistical software Minitab® 17. The objective of the present work is to gain an idea on the optimization, main parameter effects, their interactions and the predicted response of the model generated using factorial design. The parameters such as molarity of sodium hydroxide (8M and 12M), curing time (6hrs and 24 hrs), curing temperature (60°C and 90°C) and percentage of recycled concrete aggregate (0% and 100%) are considered. The results show that the curing time, molarity of sodium hydroxide and curing temperature were the orderly significant parameters and the percentage of Recycled concrete aggregate (RCA) was statistically insignificant in the production of geopolymer concrete. Thus, it may be noticeable that the RCA content had negligible effect on the compressive strength of geopolymer concrete. The expected responses from the generated model showed a satisfactory and rational agreement to the experimental data with the R2 value of 97.70%. Thus, geopolymer concrete comprising recycled concrete aggregate can solve the major social and environmental concerns such as the depletion of the naturally available aggregate sources and disposal of construction and demolition waste into the landfill.

  19. Influence of physical parameters on radiation protection and image quality in intra-oral radiology

    Energy Technology Data Exchange (ETDEWEB)

    Belinato, W. [Instituto Federal de Ensino Basico, Tecnico e Tecnologico da Bahia, Av. Amazonas, 1350-45030-220, Zabele, Vitoria da Conquista, BA (Brazil); Departamento de Fisica, Universidade Federal de Sergipe, Av. Marechal Rondon s/n, 49100-000 Rosa Elze, Sao Cristovao, SE (Brazil); Souza, D.N., E-mail: divanizi@ufs.br [Departamento de Fisica, Universidade Federal de Sergipe, Av. Marechal Rondon s/n, 49100-000 Rosa Elze, Sao Cristovao, SE (Brazil)

    2011-10-01

    In the world of diagnostic imaging, radiography is an important supplementary method for dental diagnosis. In radiology, special attention must be paid to the radiological protection of patients and health professionals, and also to image quality for correct diagnosis. In Brazil, the national rules governing the operation of medical and dental radiology were specified in 1998 by the National Sanitary Surveillance Agency, complemented in 2005 by the guide 'Medical radiology: security and performance of equipment.' In this study, quality control tests were performed in public clinics with dental X-ray equipment in the State of Sergipe, Brazil, with consideration of the physical parameters that influence radiological protection and also the quality of images taken in intra-oral radiography. The accuracy of the exposure time was considered acceptable for equipment with digital timers. Exposure times and focal-spot size variations can lead to increased entrance dose. Increased dose has also been associated with visual processing of radiographic film, which often requires repeating the radiographic examination.

  20. The influence of genetic polymorphisms on performance and cardiac and hemodynamic parameters among Brazilian soccer players.

    Science.gov (United States)

    Dionísio, Thiago José; Thiengo, Carlos Rogério; Brozoski, Daniel Thomas; Dionísio, Evandro José; Talamoni, Guilherme Augusto; Silva, Roberto Braga; Garlet, Gustavo Pompermaier; Santos, Carlos Ferreira; Amaral, Sandra Lia

    2017-06-01

    This study investigated whether ACTN3 R577X, AMPD1 C34T, I/D ACE, and M235T AGT polymorphisms can affect performance tests such as jumping, sprinting, and endurance in 220 young male athletes from professional minor league soccer team from São Paulo Futebol Clube, Brazil. I/D ACE and M235T AGT polymorphisms were also analyzed according to cardiac and hemodynamic parameters. Athletes were grouped or not by age. DNA from saliva and Taqman assays were used for genotyping 220 athletes and the results were associated with performance tests. Ventricle mass, ventricle end-diastolic diameter, end-diastolic volume, and ejection fraction were assessed by echocardiogram. Arterial pressure, heart rate, and oximetry were assessed by a cardioscope. The main results of this study were that athletes who carried RR/RX (ACTN3) and DD (ACE) genotypes presented better performance during jump and sprint tests. On the other hand, athletes with ID/II genotype presented better results during endurance test, while AGT genotypes did not seem to favor the athletes during the evaluated physical tests. CC genotype (AMPD1) only favored the athletes during 10-m sprint test. Although there are environmental interactions influencing performance, the present results suggest that RR/RX ACTN3 and ACE DD genotypes may benefit athletes in activities that require strength and speed, while II ACE genotype may benefit athletes in endurance activities. This information could help coaches to plan the training session to improve the athletes' performance.

  1. Influence of physical parameters on radiation protection and image quality in intra-oral radiology

    Science.gov (United States)

    Belinato, W.; Souza, D. N.

    2011-10-01

    In the world of diagnostic imaging, radiography is an important supplementary method for dental diagnosis. In radiology, special attention must be paid to the radiological protection of patients and health professionals, and also to image quality for correct diagnosis. In Brazil, the national rules governing the operation of medical and dental radiology were specified in 1998 by the National Sanitary Surveillance Agency, complemented in 2005 by the guide "Medical radiology: security and performance of equipment." In this study, quality control tests were performed in public clinics with dental X-ray equipment in the State of Sergipe, Brazil, with consideration of the physical parameters that influence radiological protection and also the quality of images taken in intra-oral radiography. The accuracy of the exposure time was considered acceptable for equipment with digital timers. Exposure times and focal-spot size variations can lead to increased entrance dose. Increased dose has also been associated with visual processing of radiographic film, which often requires repeating the radiographic examination.

  2. Influence of Parameters of Screen Printing on Photoluminescence Properties of Nanophotonic Labels for Smart Packaging

    Directory of Open Access Journals (Sweden)

    Olha Hrytsenko

    2017-01-01

    Full Text Available Smart packaging is becoming more popular on world market as a new type of packaging able to react to changes in a packaged product during storage and informs a customer about the safety of consumption of packaged food. This article investigates the main technological issues of the use of nanophotonic printing inks based on ZnO/SiO2 nanoparticles and polyvinylpyrrolidone (PVP for printing active elements of smart packaging on paper substrates, concerning material properties and parameters of screen printing. It is determined that the use of ink compositions with medium content of ZnO/SiO2 nanoparticles allows obtaining blue-green and blue shades of luminescence color of screen printed images by changing ink layer thickness on papers with different contents of optical brightness agents (OBAs. The minimum content of ZnO/SiO2 nanoparticles in the developed fluorescent inks leads to blue luminescence colors regardless the contents of OBAs of the papers and ink layer thickness. The luminescence intensity is directly proportional to ink layer thickness and partly depends on the content of OBAs in the selected paper. In order to fabricate nanophotonic elements of smart packaging with predetermined photoluminescence properties, the influence of investigated factors on photoluminescence properties of printed nanophotonic labels should be taken into account.

  3. Recent Strategy of Biodiesel Production from Waste Cooking Oil and Process Influencing Parameters: A Review

    Directory of Open Access Journals (Sweden)

    A. Gnanaprakasam

    2013-01-01

    Full Text Available Cost of biodiesel produced from virgin vegetable oil through transesterification is higher than that of fossil fuel, because of high raw material cost. To minimize the biofuel cost, in recent days waste cooking oil was used as feedstock. Catalysts used in this process are usually acids, base, and lipase. Since lipase catalysts are much expensive, the usage of lipase in biodiesel production is limited. In most cases, NaOH is used as alkaline catalyst, because of its low cost and higher reaction rate. In the case of waste cooking oil containing high percentage of free fatty acid, alkaline catalyst reacts with free fatty acid and forms soap by saponification reaction. Also, it reduces the biodiesel conversions. In order to reduce the level of fatty acid content, waste cooking oil is pretreated with acid catalyst to undergo esterification reaction, which also requires high operating conditions. In this review paper, various parameters influencing the process of biofuel production such as reaction rate, catalyst concentration, temperature, stirrer speed, catalyst type, alcohol used, alcohol to oil ratio, free fatty acid content, and water content have been summarized.

  4. Music in CrossFit®—Influence on Performance, Physiological, and Psychological Parameters

    Directory of Open Access Journals (Sweden)

    Gavin Brupbacher

    2014-01-01

    Full Text Available Gaining increasing popularity within the fitness sector, CrossFit® serves as an appealing and efficient high intensity training approach to develop strength and endurance on a functional level; and music is often utilized to produce ergogenic effects. The present randomized, controlled, crossover study aimed at investigating the effects of music vs. non-music on performance, physiological and psychological outcomes. Thirteen (age: 27.5, standard deviation (SD 6.2 years, healthy, moderately trained subjects performed four identical workouts over two weeks. The order of the four workouts (two with, and two without music, 20 min each was randomly assigned for each individual. Acute responses in work output, heart rate, blood lactate, rate of perceived exertion, perceived pain, and affective reaction were measured at the 5th, 10th, 15th, and 20th min during the training sessions. Training with music resulted in a significantly lower work output (460.3 repetitions, SD 98.1 vs. 497.8 repetitions, SD 103.7; p = 0.03. All other parameters did not differ between both music conditions. This is partly in line with previous findings that instead of providing ergogenic effects, applying music during CrossFit® may serve as a more distractive stimulus. Future studies should separate the influence of music on a more individual basis with larger sample sizes.

  5. Influence of formulation and process parameters on pellet production by powder layering technique.

    Science.gov (United States)

    Nastruzzi, C; Cortesi, R; Esposito, E; Genovesi, A; Spadoni, A; Vecchio, C; Menegatti, E

    2000-05-06

    The goal of the present study was to evaluate the influence of the formulation and operating conditions on pellet preparation by pan technique. To this end, a new pelletization process, typified by the application of powdered drug on sugar-based cores using the GS coating system was studied. Inert cores were intermittently treated with micronized drug powder and adhesive solution. This treatment led to the formation of multiple layers of drug particles around an inert core resulting in the production of pellets that can further be coated by different polymers to obtain modified release formulations. Different procedures have been used to evaluate a series of important parameters such as initial core weight; speed of powder application; speed, type, and position of the atomizers; atomization degree; temperature; and air cap. Good yield of drug layering was obtained by adjusting the quantity of both the drug powder to apply and the binder solution. Pellets obtained following the optimal operating conditions (defined in a pre-formulation study) were film coated with the acrylic polymer Eudragit L30D in order to produce a model formulation consisting of enteric polymer-coated pellets containing ibuprofen. During its preparation, the formulation showed no degradation of the drug; moreover, a low percentage of residual humidity was obtained, indicating that this system is very efficient for the production of highly stable formulations. This study showed the good performance of the GS automated pan-coating system in obtaining enteric coated pellets prepared by powder layering technique using aqueous solutions.

  6. Influence of dimension parameters of the gravity heat pipe on the thermal performance

    Science.gov (United States)

    Kosa, Ľuboš; Nemec, Patrik; Jobb, Marián; Malcho, Milan

    2016-06-01

    Currently the problem with the increasing number of electronic devices is a problem with the outlet Joule heating. Joule heating, also known as ohmic heating and resistive heating, is the process by which the passage of an electric current through a conductor releases heat. Perfect dustproof cooling of electronic components ensures longer life of the equipment. One of more alternatives of heat transfer without the using of mechanical equipment is the use of the heat pipe. Heat pipes are easy to manufacture and maintenance of low input investment cost. The advantage of using the heat pipe is its use in hermetic closed electronic device which is separated exchange of air between the device and the environment. This experiment deals with the influence of changes in the working tube diameter and changing the working fluid on performance parameters. Changing the working fluid and the tube diameter changes the thermal performance of the heat pipe. The result of this paper is finding the optimal diameter with ideal working substance for the greatest heat transfer for 1cm2 sectional area tube.

  7. Influence of groundwater flow on the estimation of subsurface thermal parameters

    Science.gov (United States)

    Verdoya, Massimo; Chiozzi, Paolo

    2018-01-01

    We investigated the influence of groundwater flow on the thermal tests performed in borehole heat exchangers to infer the underground thermal properties. Temperature-time signals were simulated with a moving line source (MLS) model under different hypotheses of Darcy velocity. Periodic and random noise was included in the synthetic data obtained with this model in order to mimic high-frequency disturbances caused by several possible sources (e.g. equipment instability and changes in environmental conditions during the experiment) that often occur in real signals. The subsurface thermal conductivity, the Darcy velocity and the borehole thermal resistance were inferred by minimising the root-mean-square error between the synthetic dataset and the model. The calculated thermal and hydraulic parameters were consistent with the "a priori" values. The optimisation procedure results were then tested with the infinite line source (ILS) model. For a Darcy velocity exceeding 10-7 m s-1, ILS largely overestimates thermal conductivity. The approach relying on the MLS model was finally tested with real temperature-time data and produced reliable estimates of thermal conductivity, Darcy velocity and borehole thermal resistance. The inferred groundwater flow was cross checked by means of an independent method based on the analysis of temperature-depth logs recorded under thermal equilibrium conditions. Such a test validates the Darcy velocity inferred with the MLS approach.

  8. Influence of emphysema distribution on pulmonary function parameters in COPD patients

    Science.gov (United States)

    Bastos, Helder Novais e; Neves, Inês; Redondo, Margarida; Cunha, Rui; Pereira, José Miguel; Magalhães, Adriana; Fernandes, Gabriela

    2015-01-01

    ABSTRACT OBJECTIVE: To evaluate the impact that the distribution of emphysema has on clinical and functional severity in patients with COPD. METHODS: The distribution of the emphysema was analyzed in COPD patients, who were classified according to a 5-point visual classification system of lung CT findings. We assessed the influence of emphysema distribution type on the clinical and functional presentation of COPD. We also evaluated hypoxemia after the six-minute walk test (6MWT) and determined the six-minute walk distance (6MWD). RESULTS: Eighty-six patients were included. The mean age was 65.2 ± 12.2 years, 91.9% were male, and all but one were smokers (mean smoking history, 62.7 ± 38.4 pack-years). The emphysema distribution was categorized as obviously upper lung-predominant (type 1), in 36.0% of the patients; slightly upper lung-predominant (type 2), in 25.6%; homogeneous between the upper and lower lung (type 3), in 16.3%; and slightly lower lung-predominant (type 4), in 22.1%. Type 2 emphysema distribution was associated with lower FEV1, FVC, FEV1/FVC ratio, and DLCO. In comparison with the type 1 patients, the type 4 patients were more likely to have an FEV1 emphysema could have a major impact on functional parameters and should be considered in the evaluation of COPD patients. PMID:26785956

  9. Intraocular pressure and influencing systemic health parameters in a Korean population

    Directory of Open Access Journals (Sweden)

    Young Sang Han

    2014-01-01

    Full Text Available Aim: To evaluate the relationship between intraocular pressure (IOP and systemic health parameters such as age, gender, body mass index (BMI, total cholesterol, high density lipoprotein (HDL, and triglyceride (TG in a Korean population. Materials and Methods: A total of 30,893 healthy subjects underwent automated multiphasic tests, including non-contact tonometry, automated perimetry, fundus photography, and blood samplings for total cholesterol, HDL, and TG. Seven age groups were divided by decades ranging from 20 to 29 years to 80 + years. The association between IOP and BMI, plasma lipid profiles was examined using cross-sectional analysis. Results: The mean age of subjects was 47.7 years. The mean IOP of subjects was 15.4 ± 3.2 mmHg for both eyes. The mean IOP of men was significantly higher than women ( P = 0.000. By multiple linear regression analysis, IOP was positively associated with gender (male, BMI, total cholesterol, and TG and negatively associated with age ( P = 0.000. BMI, total cholesterol, and TG had significantly positive correlations with IOP after adjusting for age, gender, and other variables which can influence the IOP ( P = 0.000. Conclusions: In a Korean population, the mean IOP, total cholesterol, TG, and BMI values of men were higher than women. IOP was found to increase with total cholesterol, TG, BMI, and to decrease with only age regardless of sex.

  10. Influence of groundwater flow on the estimation of subsurface thermal parameters

    Science.gov (United States)

    Verdoya, Massimo; Chiozzi, Paolo

    2016-09-01

    We investigated the influence of groundwater flow on the thermal tests performed in borehole heat exchangers to infer the underground thermal properties. Temperature-time signals were simulated with a moving line source (MLS) model under different hypotheses of Darcy velocity. Periodic and random noise was included in the synthetic data obtained with this model in order to mimic high-frequency disturbances caused by several possible sources (e.g. equipment instability and changes in environmental conditions during the experiment) that often occur in real signals. The subsurface thermal conductivity, the Darcy velocity and the borehole thermal resistance were inferred by minimising the root-mean-square error between the synthetic dataset and the model. The calculated thermal and hydraulic parameters were consistent with the "a priori" values. The optimisation procedure results were then tested with the infinite line source (ILS) model. For a Darcy velocity exceeding 10-7 m s-1, ILS largely overestimates thermal conductivity. The approach relying on the MLS model was finally tested with real temperature-time data and produced reliable estimates of thermal conductivity, Darcy velocity and borehole thermal resistance. The inferred groundwater flow was cross checked by means of an independent method based on the analysis of temperature-depth logs recorded under thermal equilibrium conditions. Such a test validates the Darcy velocity inferred with the MLS approach.

  11. Influence of pellet seating on the external ballistic parameters of spring-piston air guns.

    Science.gov (United States)

    Werner, Ronald; Schultz, Benno; Frank, Matthias

    2016-09-01

    In firearm examiners' and forensic specialists' casework as well as in air gun proof testing, reliable measurement of the weapon's muzzle velocity is indispensable. While there are standardized and generally accepted procedures for testing the performance of air guns, the method of seating the diabolo pellets deeper into the breech of break barrel spring-piston air guns has not found its way into standardized test procedures. The influence of pellet seating on the external ballistic parameters was investigated using ten different break barrel spring-piston air guns. Test shots were performed with the diabolo pellets seated 2 mm deeper into the breech using a pellet seater. The results were then compared to reference shots with conventionally loaded diabolo pellets. Projectile velocity was measured with a high-precision redundant ballistic speed measurement system. In eight out of ten weapons, the muzzle energy increased significantly when the pellet seater was used. The average increase in kinetic energy was 31 % (range 9-96 %). To conclude, seating the pellet even slightly deeper into the breech of spring-piston air guns might significantly alter the muzzle energy. Therefore, it is strongly recommended that this effect is taken into account when accurate and reliable measurements of air gun muzzle velocity are necessary.

  12. Influences of growth parameters on the reaction pathway during GaN synthesis

    Science.gov (United States)

    Zhang, Zhi; Liu, Zhongyi; Fang, Haisheng

    2018-01-01

    Gallium nitride (GaN) film growth is a complicated physical and chemical process including fluid flow, heat transfer, species transport and chemical reaction. Study of the reaction mechanism, i.e., the reaction pathway, is important for optimizing the growth process in the actual manufacture. In the paper, the growth pathway of GaN in a closed-coupled showerhead metal-organic chemical vapor deposition (CCS-MOCVD) reactor is investigated in detail using computational fluid dynamics (CFD). Influences of the process parameters, such as the chamber pressure, the inlet temperature, the susceptor temperature and the pre-exponential factor, on the reaction pathway are examined. The results show that increases of the chamber pressure or the inlet temperature, as well as reductions of the susceptor temperature or the pre-exponential factor lead to the adduct route dominating the growth. The deposition rate contributed by the decomposition route, however, can be enhanced dramatically by increasing the inlet temperature, the susceptor temperature and the pre-exponential factor.

  13. Mathematical Model of Solid Food Pasteurization by Ohmic Heating: Influence of Process Parameters

    Directory of Open Access Journals (Sweden)

    Francesco Marra

    2014-01-01

    Full Text Available Pasteurization of a solid food undergoing ohmic heating has been analysed by means of a mathematical model, involving the simultaneous solution of Laplace’s equation, which describes the distribution of electrical potential within a food, the heat transfer equation, using a source term involving the displacement of electrical potential, the kinetics of inactivation of microorganisms likely to be contaminating the product. In the model, thermophysical and electrical properties as function of temperature are used. Previous works have shown the occurrence of heat loss from food products to the external environment during ohmic heating. The current model predicts that, when temperature gradients are established in the proximity of the outer ohmic cell surface, more cold areas are present at junctions of electrodes with lateral sample surface. For these reasons, colder external shells are the critical areas to be monitored, instead of internal points (typically geometrical center as in classical pure conductive heat transfer. Analysis is carried out in order to understand the influence of pasteurisation process parameters on this temperature distribution. A successful model helps to improve understanding of these processing phenomenon, which in turn will help to reduce the magnitude of the temperature differential within the product and ultimately provide a more uniformly pasteurized product.

  14. Influence of Growth Parameters on the Formation of Hydroxyapatite (HAp Nanostructures and Their Cell Viability Studies

    Directory of Open Access Journals (Sweden)

    Murugesan Manoj

    2015-02-01

    Full Text Available Morphology controlled hydroxyapatite (HAp nanostructures play a vital role in biomedical engineering, tissue regenerative medicine, biosensors, chemotherapeutic applications, environmental remediation, etc. The present work investigates the influence of temperature, pH and time on the growth of HAp nanostructures using a simple, cost effective and surfactant free chemical approach. The obtained HAp nanostructures were systematically investigated by analytical techniques such as XRD, FESEM, EDX, FTIR and Raman spectroscopy. The XRD analysis showed that the hexagonal structure of the hydroxyapatite and average crystallite size was estimated from this analysis. The electron microscopic analysis confirmed the different morphologies obtained by varying the synthesis parameters such as temperature, pH and time. The elemental composition was determined through EDS analysis. FTIR and Raman spectroscopic analysis confirmed the presence of functional groups and the purity and crystallinity of the samples. The biocompatibility and adhesion nature of samples was examined with mouse preosteoblast cells. The obtained results demonstrated good biocompatibility and excellent focal adhesion.

  15. Microstructural characterization and influence of manufacturing parameters on technological properties of vitreous ceramic materials

    Energy Technology Data Exchange (ETDEWEB)

    Njoya, D. [Laboratoire de Physico-chimie des Materiaux Mineraux, Departement de Chimie Inorganique, Faculte des Sciences, Universite de Yaounde I, B.P. 812, Yaounde (Cameroon); Laboratoire de Physico-chimie des Materiaux et Environnement, Departement de Chimie, Faculte des Sciences Semlalia, Universite Cadi Ayyad, B.P. 2390, Marrakech (Morocco); Hajjaji, M., E-mail: Hajjaji@ucam.ac.ma [Laboratoire de Physico-chimie des Materiaux et Environnement, Departement de Chimie, Faculte des Sciences Semlalia, Universite Cadi Ayyad, B.P. 2390, Marrakech (Morocco); Bacaoui, A. [Laboratoire de Chimie Organique Appliquee, Departement de Chimie, Faculte des Sciences Semlalia, Universite Cadi Ayyad, B.P. 2390, Marrakech (Morocco); Njopwouo, D. [Laboratoire de Physico-chimie des Materiaux Mineraux, Departement de Chimie Inorganique, Faculte des Sciences, Universite de Yaounde I, B.P. 812, Yaounde (Cameroon)

    2010-03-15

    Microstructure of vitreous ceramic samples manufactured from kaolinitic-clay and feldspars raw materials from Cameroon was investigated in the range 1150-1250 deg. C by X-ray diffraction and scanning electron microscopy and by measuring some technological properties. Moreover, the simultaneous influence of feldspars content, heating temperature and soaking time on water absorption and firing shrinkage was evaluated by adopting the response surface methodology (Doehlert matrix), using the New Efficient Methodology for Research using Optimal Design (NEMROD) software. The results show that a spinel phase, mullite, glassy phase and some amount of hematite were formed. However, the spinel phase and potassic feldspar, as compared to the sodic one, disappeared at moderate firing temperature and soaking time. Apparently, mullite developed from spinel phase, which is formed from the demixion of metakaolin. On the other hand, it is found that the effects of fluxing content and firing temperature on the measured properties were almost similar and more influent than soaking time. Antagonistic and synergetic interactions existed between the considered parameters, and their importance differed for the considered properties. By using this mathematical tool, suitable operating conditions for manufacturing vitreous bodies were determined.

  16. Quality parameters of wine grape varieties under the influence of different vine spacing and training systems

    Directory of Open Access Journals (Sweden)

    O. Tkachenko

    2017-06-01

    Full Text Available Physicochemical and biochemical indices, which characterize quality of white wine grape varieties Zagrey and Aromatnyi of selection of NNC «IV&W named after V. Ye. Tairov», (harvest of 2016 were determined. The field trial which includes various variants of planting density and vine training systems, made it possible to study the influence of viticulture practices on the criteria of carbohydrate-acid and phenolic complex, oxidative enzyme system of grapes. Low-density plantings of Aromatnyi variety (2222 vines per ha were characterized by harvest that slightly exceeded the grapes obtained from dense plantations (4000 vines per ha in terms of carbohydrate-acid and phenolic complexes. The most optimal in terms of the mass concentration of sugars, phenolic substances, polymer forms, macerating ability of must, activity of oxidizing enzyme system was cultivation of this variety on a 160 cm – high trunk. Growing grapes of Zagrey variety with vine spacing, corresponding to 4000 plants per ha, contributed to obtaining harvest with optimal parameters of carbohydrate-acid complex, low technological reserve and mass concentration of phenolic compounds, moderate macerating ability and activity of monophenol monooxygenase in must. Training vines of this variety on a 40 cm high trunk with vertical shoot positioning led to significant deterioration of grape quality due to increased content of phenolic substances and their polymer forms, high macerating capacity of must.

  17. [Influence of duration of menopause, anthropometric and hormonal parameters on metabolic syndrome].

    Science.gov (United States)

    Simoncig-Netjasov, Aleksandra; Vujović, Svetlana; Ivović, Miomira; Tancić-Gajić, Milina; Drezgić, Milka

    2010-01-01

    Hypoestrogenic status in the menopausal women shows a shift to a central android fat distribution and metabolic syndrome (MIS). Related metabolic changes and hypertension increase the risk for cardiovascular (CV) diseases. The aim of this study was to investigate the influence of duration of menopause, anthropometric and hormonal parameters on metabolic syndrome. 50 obese women were examined with BMI = 31.92 = 5.83 kg/m2, age 54.40 +/- 3.64, time since menopause 5.90 +/- 5.46 years. Control group consisted of 37 normal weight women with BMI = 23.50 +/- 2.13 kg/m2, age 53.92 +/- 3.95, time since menopause 5.96 +/- 4.92 years. Anthropometric characteristics and blood pressure were measured. Blood was taken at 8 am for: fasting glucose, triglycerides, cholesterol, HDL, LDL, apolipoprotein A (ApoA), apolipoprotein B (ApoB), lipoprotein(a) (Lp(a)), C-reactive protein (CRP), fibrinogen, FSH, LH, prolactin, estradiol, progesterone, testosterone and sex hormone binding globulin (SHBG). In obese women significant negative correlations were found for: BMI anid HDL (p menopause and waist/hip ratio (p menopause and HDL (p menopausal endocrine changes cause metabolic and hemodynamic imbalances, which contribute to risk for cardiovascular diseases.

  18. The Influence of Various Process Parameters on Dissolution Kinetics and Mechanism of Struvite Seed Crystals

    Science.gov (United States)

    Ariyanto, Eko; Ang, Ha Ming; Sen, Tushar Kanti

    2017-09-01

    The basic understanding of struvite dissolution chemistry is essential to designers and operators for anticipating struvite problem and remediating existing struvite damage in a wastewater treatment. The dissolution kinetic of struvite seed crystals is very important parameters to determine a solid substance entering in solvent to yield a solution. In this study the dissolution kinetics of struvite crystals (MgNH4PO4·6H2O) in deionized water was investigated in a batch crystallizer. The effects of stirrer speeds, temperature and seed crystals size on the dissolution rate were determined. The results showed that an increase of struvite dissolution rate with increasing stirring speed. Struvite dissolution occurred via a diffusion-controlled mechanism in the range of stirrer speeds 120-400 rpm but became interfacial-reaction-controlling at over 400 rpm. The influence of temperature on dissolution kinetic of struvite crystals was also investigated at stirrer speeds of 200 and 500 rpm. The dissolution rates increased with an increase in the temperature for both stirrer speeds. The change in activation energies at different stirrer speeds confirmed that the change of dissolution mechanism from a diffusion-controlled mechanism at low stirrer speeds to an interfacial-reaction-controlled mechanism at higher stirrer speeds. The dissolution rate of struvite crystals increased with smaller crystal sizes.

  19. Influence of controller parameters on the life of ball screw feed drives

    Directory of Open Access Journals (Sweden)

    Stefano Mauro

    2015-08-01

    Full Text Available The ball screws are the machine component most frequently used for transforming rotational into linear motion of a feed drive, to position the machine tool components carrying the cutting tool to the desired location. A failure of the ball screw usually leads to a total breakdown of the axis; therefore, the attainable life of this component is an important issue concerning the availability and productivity of modern machine tools. This article presents an approach to evaluate the influence of control parameters on the fatigue life of ball screws based on simulation, by means of a numerical model of a machine tool servo-axis. Ball screw life was evaluated with different conditions, varying the position loop main proportional gain and the kinematic limit conditions for trajectory generation. Furthermore, the mathematical model was used to evaluate optimal control gain and trajectory conditions for a machine tool based on the achievable life span of the ball screw feed drive system, with regard to the desirable performances, such as position accuracy, promptness, and cutoff frequency.

  20. The influence of environmental parameters on the optimal frequency in a shallow underwater acoustic channel

    Science.gov (United States)

    Zarnescu, George

    2015-02-01

    In a shallow underwater acoustic channel the delayed replicas of a transmitted signal are mainly due to the interactions with the sea surface and the bottom layer. If a specific underwater region on the globe is considered, for which the sedimentary layer structure is constant across the transmission distance, then the variability of the amplitude-delay profile is determined by daily and seasonal changes of the sound speed profile (SSP) and by weather changes, such as variations of the wind speed. Such a parameter will influence the attenuation at the surface, the noise level and the profile of the sea surface. The temporal variation of the impulse response in a shallow underwater acoustic channel determines the variability of the optimal transmission frequency. If the ways in which the optimal frequency changes can be predicted, then an adaptive analog transceiver can be easily designed for an underwater acoustic modem or it can be found when a communication link has high throughput. In this article it will be highlighted the way in which the amplitude-delay profile is affected by the sound speed profile, wind speed and channel depth and also will be emphasized the changes of the optimal transmission frequency in a configuration, where the transmitter and receiver are placed on the seafloor and the bathymetry profile will be considered flat, having a given composition.

  1. Optimal Experimental Designs For The Identification of Release and Transport Parameters of Reactive Solutes In Column Studies

    Science.gov (United States)

    Wehrer, M.; Totsche, K. U.; Huwe, B.

    Knowledge about the release and transport of contaminants in natural porous media plays a crucial role in the estimation of the risk of soil and groundwater pollution. Thus, robust and reliable experimental methods are necessary for the prediction of contaminant fate in soils and aquifers. In this context, soil column experiments are widely used to determine the reactive solute transport parameters. The scope of this work is to analyze (un)saturated column outflow experiments with respect to their suit- ability for the understanding of interaction processes and their properties. Employing numerical case studies, the effect of singular and composite processes (e.g. sorption, partitioning, dispersion) and properties (linearity of the interactions, rate constrictions) on the breakthrough curve are investigated. Numerical scenarios are based on real world data sets and further consider analytical constraints like limits of determina- tion, precision and accuracy. The results suggest that uniqueness problems arise in the identification and quantification of flow and transport parameters. These problems are caused by the lack of "usable information" in the column response to the rather simple input signal, i.e., the continuous feed or pulse type inflow boundary condition. In gen- eral, shape and curvature of the breakthrough curve - which are used to identify the governing processes - are affected by processes and properties which enforce, weaken or compensate each other. To eliminate this deficiency, we will propose different ex- perimental designs which help to improve our ability for parameter identification but simultaneously minimize both time and financial investments

  2. Effect Analysis of Geometric Parameters on Stainless Steel Stamping Multistage Pump by Experimental Test and Numerical Calculation

    Directory of Open Access Journals (Sweden)

    Chuan Wang

    2013-01-01

    Full Text Available In order to improve the efficiency of stainless steel stamping multistage pump, quadratic regression orthogonal test, hydraulic design, and computational fluid dynamics (CFD are used to analyze the effect of pump geometric parameters. Sixteen impellers are designed based on the quadratic regression orthogonal test, which have three factors including impeller outlet slope, impeller blade outlet stagger angle, and impeller blade outlet width. Through quadratic regression equation, the function relationship between efficiency values and three factors is established. The optimal combination of geometric parameters is found through the analysis of the regression equation. To further study the influence of blade thickness on the performance of multistage pump, numerical simulations of multistage pump with different blade thicknesses are carried out. The influence law of blade thickness on pump performance is built from the external characteristics and internal flow field. In conclusion, with the increase of blade thickness, the best efficiency point of the pump shifts to the small flow rate direction, and the vortex regions inside the pump at rated flow gradually increase, which is the main reason that pump efficiency decreases along with the increase of the blade thickness at rated flow.

  3. Experimental and One-Dimensional Mathematical Modeling of Different Operating Parameters in Direct Formic Acid Fuel Cells

    Directory of Open Access Journals (Sweden)

    Shingjiang Jessie Lue

    2017-11-01

    Full Text Available The purpose of this work is to develop a one-dimensional mathematical model for predicting the cell performance of a direct formic acid fuel cell and compare this with experimental results. The predicted model can be applied to direct formic acid fuel cells operated with different formic acid concentrations, temperatures, and with various electrolytes. Tafel kinetics at the electrodes, thermodynamic equations for formic acid solutions, and the mass-transport parameters of the reactants are used to predict the effective diffusion coefficients of the reactants (oxygen and formic acid in the porous gas diffusion layers and the associated limiting current densities to ensure the accuracy of the model. This model allows us to estimate fuel cell polarization curves for a wide range of operating conditions. Furthermore, the model is validated with experimental results from operating at 1–5 M of formic acid feed at 30–80 °C, and with Nafion-117 and silane-crosslinked sulfonated poly(styrene-ethylene/butylene-styrene (sSEBS membrane electrolytes reinforced in porous polytetrafluoroethylene (PTFE. The cell potential and power densities of experimental outcomes in direct formic acid fuel cells can be adequately predicted using the developed model.

  4. Influence of microkeratome parameters on the stromal bed and flap edge quality in laser in situ keratomileusis

    Directory of Open Access Journals (Sweden)

    Heichel J

    2013-12-01

    Full Text Available Jens Heichel,1 Frank Wilhelm,2 Kathleen S Kunert,3 Rabea Schlueter,4 Ute Stuhltraeger,1 Thomas Hammer5 1Department of Ophthalmology, University Hospital of Martin Luther University Halle/Wittenberg, Halle (Saale, Germany; 2Augen im Zentrum, Greifswald, Germany; 3Department of Ophthalmology, Helios Klinikum Erfurt, Erfurt, Germany; 4Institute of Microbiology, Ernst-Moritz-Arndt-University, Greifswald, Germany; 5Augenzentrum Frohe Zukunft, Halle (Saale, Germany Purpose: Femtosecond lasers have become the standard for laser-assisted in situ keratomileusis (LASIK flap creation, but advanced mechanical microkeratomes are still an alternative, more cost-effective way to create the flap. The SCHWIND Carriazo-Pendular microkeratome is one of the most commonly used microkeratomes. The influence of different cutting parameters (head-advance speeds, cutting heads on morphology of LASIK cuts was investigated. Setting: Experimental study performed at the University Eye Hospital of the Martin Luther University Halle/Wittenberg, Halle (Saale, Germany. Methods: The Carriazo-Pendular microkeratome was used on freshly enucleated porcine eyes for lamellar keratotomy. After flap removal, the cutting edge and stromal bed were evaluated from scanning electron micrographs using an individualized scoring system. Four different settings of microkeratome parameters were compared. For each setting, eight cuts were evaluated (n=32. Results: Different oscillation frequencies and head-advance speeds did not influence the cutting qualities. A higher oscillation/feed rate ratio seemed to be advantageous for a smoother interface. Concerning different cuttings heads, a deeper keratotomy led to sharper cutting edges. The thinner the flap, the more irregularities in the stromal bed appeared. Complications did not occur. Conclusion: The Carriazo-Pendular microkeratome is a safe tool with which to create a LASIK flap and is a good alternative to a costly femtosecond laser. Deeper

  5. Influence of metallurgical parameters on the electrochemical behavior of electrodeposited Ni and Ni–W nanocrystalline alloys

    Energy Technology Data Exchange (ETDEWEB)

    Shakibi Nia, N.; Creus, J.; Feaugas, X.; Savall, C., E-mail: csavall@univ-lr.fr

    2016-05-01

    Highlights: • Corrosion behavior of nickel and Ni–W coatings is studied in an acidic medium. • W addition implies grain refinement and other metallurgical parameters variation. • Annealing permitted to separate the W content influence from the grain size. • The W incorporation has an unfavorable effect on the passive film stability. - Abstract: The electrochemical behavior of electrodeposited nickel and Ni–W nanostructured alloys is discussed by studying the polarization curves in acidic medium. As tungsten content varies, several metallurgical parameters that can influence the electrochemical behavior are also modified, namely grain size, nature of grain boundaries, crystallographic texture and light element contamination. Comparing the behavior of Ni–W coatings with that of pure nickel and annealed coatings highlights that tungsten incorporation enhances anodic dissolution and has a detrimental influence on passive film, whereas grain size and grain boundary character behave as second-order parameters.

  6. Vaccination with IL-6 analogues induces autoantibodies to IL-6 and influences experimentally induced inflammation

    DEFF Research Database (Denmark)

    Galle, Pia; Jensen, Lene; Andersson, Christina

    2007-01-01

    ; yet they appear healthy and do not exhibit overt clinical or laboratory abnormalities. We induced comparable levels of aAb-IL-6 in different mouse strains by vaccination with immunogenic IL-6 analogues. We observed that the induced aAb-IL-6 protected against collagen-induced arthritis and experimental...... allergic encephalitis. Furthermore, aAb-IL-6 carrying mice displayed increased plasma TNFalpha concentrations upon challenge with LPS. Taken together, induction of IL-6 autoantibodies was possible in different mouse strains. The autoantibodies influenced experimental inflammation. This immunotherapeutic...

  7. Influence of waste managemental and technical planning parameters on plant costs; Einfluss abfallwirtschaftlicher und technischer Plannungsgroessen auf die Anlagenkosten

    Energy Technology Data Exchange (ETDEWEB)

    Beckmann, R. [Inst. fuer Umwelt, Sicherheits- und Energietechnik e.V., Oberhausen (Germany)

    1998-09-01

    The probable future costs of thermal waste treatment depend on a great number of influencing factors. One of the essential aims of the present contribution is to elaborate and present the sensitivity of costs to various parameters. [Deutsch] Die zukuenftig zu erwartenden Kosten der thermischen Abfallbehandlung haengen von einer Vielzahl von Einflussgroessen ab. Im Rahmen des Beitrags besteht daher ein wesentliches Ziel darin, die Sensitivitaet der Kosten hinsichtlich verschiedenster Parameter herauszuarbeiten und darzustellen. (orig./SR)

  8. Influence of constant magnetic field on the tribological parameters of rubbing couples steel-brass in surface active substances

    Directory of Open Access Journals (Sweden)

    М.М. Свирид

    2009-03-01

    Full Text Available  Maintainability of surfaces of sensitive pairs of friction is analysed in surroundings with high electrical resistance in the conditions of friction. The model of tribological unit, determining conditions and conformities to the law of formation of protective tribological pellicles, is worked out. The parameters of reparation of friction surfaces are determined by a tribomagnetic method. The parameters of renewal of sensitive tribopairs are also defined on uncollapsible technologies by joint influence of triboelectrochemical method and tribomagnetic components.

  9. Analysis of the influence of multiple parameters on the commercial categories of Extremadura virgin olive oils

    Directory of Open Access Journals (Sweden)

    Montaño, A.

    2014-12-01

    Full Text Available Although Extremadura is an important producing region of Spanish virgin olive oils, it has not been always known for the high quality of its oils. However, implementation of continuous extraction systems in most of its olive mills has shown a general improvement in the quality of most virgin olive oils, but not in all of them. The aim of the present study was to examine how different variables, such as fruit quality discrimination or payment system, affected the overall quality of virgin olive oils from Extremadura. To do so, a screening experimental design and the corresponding statistical analysis of the collected data were performed. Sixty Extremadura oil mills were evaluated (50.4% of the total by taking bottled virgin olive oil samples from each of them. Statistical relationships between physicochemical parameters and production process variables were evaluated, showing that only three of them (separation of ground- and tree-harvested fruits, differential payment according to acidity, and extraction process were significantly correlated with the quality index and acidity of virgin olive oils.Extremadura es una importante región productora de aceites de oliva vírgenes de España, aunque no siempre ha sido conocida por la producción de aceites de oliva de alta calidad. Sin embargo, desde la implantación de los sistemas continuos de extracción de aceite en la mayoría de sus almazaras, ha tenido lugar un aumento de la calidad en muchas de éstas. El objetivo de este trabajo ha sido estudiar cómo algunas variables, como la clasificación de las aceitunas por la calidad, o su sistema de remuneración, influye en la calidad global de los aceites de oliva vírgenes extremeños. Para ello, se ha hecho uso de un diseño experimental de barrido y el análisis estadístico del mismo. Sesenta almazaras fueron evaluadas en Extremadura (50,4% del total y se tomó una muestra de aceite de oliva virgen envasado de cada una de las almazaras. Los

  10. Effects of interferential therapy parameter combinations upon experimentally induced pain in pain-free participants: a randomized controlled trial.

    Science.gov (United States)

    Dounavi, Myrto D; Chesterton, Linda S; Sim, Julius

    2012-07-01

    Little evidence exists regarding parameter selection for hypoalgesia using interferential therapy (IFT). This study investigated segmental and extrasegmental hypoalgesic effects of different IFT parameter combinations upon experimentally induced pressure pain threshold (PPT) in pain-free volunteers. The participants were randomly assigned to 6 groups: control, placebo, bipolar constant amplitude modulation frequency (AMF), bipolar sweep AMF, quadripolar constant AMF, and quadripolar sweep AMF. The study was conducted in a university laboratory. One hundred eighty adults who were healthy and pain-free participated in the study. Interferential therapy was delivered to all groups at high, to-tolerance intensity and at high AMF. Stimulation to the dominant forearm was delivered for 30 minutes, with monitoring for a further 30 minutes. Pain pressure threshold was measured at the area of first dorsal interosseous muscle of the dominant and nondominant hands (segmental measurements) and over the tibialis anterior muscle (extrasegmental measurement) at baseline and at 10-minute intervals using a pressure algometer. Square root transformed PPT data were analyzed using repeated-measures analysis of variance. There was a significant change in PPT over time, but no significant between-subjects difference in segmental or extrasegmental PPT between any of the IFT groups and the placebo or control group. Thus, IFT delivered in any of these parameter combinations did not significantly affect the PPT of pain-free participants compared with the control or placebo group. Success of blinding was not evaluated. This study showed that IFT delivered at high, to-tolerance intensity and high AMF does not produce significant segmental and extrasegmental hypoalgesic effects on PPT in participants who were healthy compared with a control or placebo group. Further research is warranted to investigate the hypoalgesic effect of different IFT parameter combinations and to explain its possible

  11. Influence of the growth parameters on TiO2 thin films deposited using the MOCVD method

    Directory of Open Access Journals (Sweden)

    Bernardi M. I. B.

    2002-01-01

    Full Text Available In this work we report the synthesis of TiO2 thin films by the Organometallic Chemical Vapor Deposition (MOCVD method. The influence of deposition parameters used during the growth in the obtained structural characteristics was studied. Different temperatures of the organometallic bath, deposition time, temperature and type of the substrate were combined. Using Scanning Electron Microscopy associated to Electron Dispersive X-Ray Spectroscopy, Atomic Force Microscopy and X-ray Diffraction, the strong influence of these parameters in the thin films final microstructure was verified.

  12. Direct experimental manipulation of intestinal cells in Ascaris suum, with minor influences on the global transcriptome.

    Science.gov (United States)

    Rosa, Bruce A; McNulty, Samantha N; Mitreva, Makedonka; Jasmer, Douglas P

    2017-04-01

    Ascaris suum provides a powerful model for studying parasitic nematodes, including individual tissues such as the intestine, an established target for anthelmintic treatments. Here, we add a valuable experimental component to our existing functional, proteomic, transcriptomic and phylogenomic studies of the Ascaris suum intestine, by developing a method to manipulate intestinal cell functions via direct delivery of experimental treatments (in this case, double-stranded (ds)RNA) to the apical intestinal membrane. We developed an intestinal perfusion method for direct, controlled delivery of dsRNA/heterogeneous small interfering (hsi) RNA into the intestinal lumen for experimentation. RNA-Seq (22 samples) was used to assess influences of the method on global intestinal gene expression. Successful mRNA-specific knockdown in intestinal cells of adult A. suum was accomplished with this new experimental method. Global transcriptional profiling confirmed that targeted transcripts were knocked down more significantly than any others, with only 12 (0.07% of all genes) or 238 (1.3%) off-target gene transcripts consistently differentially regulated by dsRNA treatment or the perfusion experimental design, respectively (after 24h). The system supports controlled, effective delivery of treatments (dsRNA/hsiRNA) to the apical intestinal membrane with relatively minor off-target effects, and builds on our experimental model to dissect A. suum intestinal cell functions with broad relevance to parasitic nematodes. Copyright © 2017 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.

  13. Static vs. mobile sink: The influence of basic parameters on energy efficiency in wireless sensor networks.

    Science.gov (United States)

    Khan, Majid I; Gansterer, Wilfried N; Haring, Guenter

    2013-05-15

    Over the last decade a large number of routing protocols has been designed for achieving energy efficiency in data collecting wireless sensor networks. The drawbacks of using a static sink are well known. It has been argued in the literature that a mobile sink may improve the energy dissipation compared to a static one. Some authors focus on minimizing Emax , the maximum energy dissipation of any single node in the network, while others aim at minimizing Ebar , the average energy dissipation over all nodes. In our paper we take a more holistic view, considering both Emax and Ebar . The main contribution of this paper is to provide a simulation-based analysis of the energy efficiency of WSNs with static and mobile sinks. The focus is on two important configuration parameters: mobility path of the sink and duty cycling value of the nodes. On the one hand, it is well known that in the case of a mobile sink with fixed trajectory the choice of the mobility path influences energy efficiency. On the other hand, in some types of applications sensor nodes spend a rather large fraction of their total lifetime in idle mode, and therefore higher energy efficiency can be achieved by using the concept of reduced duty cycles. In particular, we quantitatively analyze the influence of duty cycling and the mobility radius of the sink as well as their interrelationship in terms of energy consumption for a well-defined model scenario. The analysis starts from general load considerations and is refined into a geometrical model. This model is validated by simulations which are more realistic in terms of duty cycling than previous work. It is illustrated that over all possible configuration scenarios in terms of duty cycle and mobility radius of the sink the energy dissipation in the WSN can vary up to a factor of nine in terms of Emax and up to a factor of 17 in terms of Ebar. It turns out that in general the choice of the duty cycle value is more important for achieving energy

  14. Static vs. mobile sink: The influence of basic parameters on energy efficiency in wireless sensor networks

    Science.gov (United States)

    Khan, Majid I.; Gansterer, Wilfried N.; Haring, Guenter

    2013-01-01

    Over the last decade a large number of routing protocols has been designed for achieving energy efficiency in data collecting wireless sensor networks. The drawbacks of using a static sink are well known. It has been argued in the literature that a mobile sink may improve the energy dissipation compared to a static one. Some authors focus on minimizing Emax, the maximum energy dissipation of any single node in the network, while others aim at minimizing Ebar, the average energy dissipation over all nodes. In our paper we take a more holistic view, considering both Emax and Ebar. The main contribution of this paper is to provide a simulation-based analysis of the energy efficiency of WSNs with static and mobile sinks. The focus is on two important configuration parameters: mobility path of the sink and duty cycling value of the nodes. On the one hand, it is well known that in the case of a mobile sink with fixed trajectory the choice of the mobility path influences energy efficiency. On the other hand, in some types of applications sensor nodes spend a rather large fraction of their total lifetime in idle mode, and therefore higher energy efficiency can be achieved by using the concept of reduced duty cycles. In particular, we quantitatively analyze the influence of duty cycling and the mobility radius of the sink as well as their interrelationship in terms of energy consumption for a well-defined model scenario. The analysis starts from general load considerations and is refined into a geometrical model. This model is validated by simulations which are more realistic in terms of duty cycling than previous work. It is illustrated that over all possible configuration scenarios in terms of duty cycle and mobility radius of the sink the energy dissipation in the WSN can vary up to a factor of nine in terms of Emax and up to a factor of 17 in terms of Ebar. It turns out that in general the choice of the duty cycle value is more important for achieving energy efficiency

  15. Quantitative assessments of mantle flow models against seismic observations: Influence of uncertainties in mineralogical parameters

    Science.gov (United States)

    Schuberth, Bernhard S. A.

    2017-04-01

    synthetic traveltime data can then be compared - on statistical grounds - to the traveltime variations observed on Earth. Here, we now investigate the influence of uncertainties in the various input parameters that enter our modelling. This is especially important for the material properties at high pressure and high temperature entering the mineralogical models. In particular, this concerns uncertainties that arise from relating measurements in the laboratory to Earth properties on a global scale. As one example, we will address the question on the influence of anelasticity on the variance of global synthetic traveltime residuals. Owing to the differences in seismic frequency content between laboratory measurements (MHz to GHz) and the Earth (mHz to Hz), the seismic velocities given in the mineralogical models need to be adjusted; that is, corrected for dispersion due to anelastic effects. This correction will increase the sensitivity of the seismic velocities to temperature variations. The magnitude of this increase depends on absolute temperature, frequency, the frequency dependence of attenuation and the activation enthalpy of the dissipative process. Especially the latter two are poorly known for mantle minerals and our results indicate that variations in activation enthalpy potentially produce the largest differences in temperature sensitivity with respect to the purely elastic case. We will present new wave propagation simulations and corresponding statistical analyses of traveltime measurements for different synthetic seismic models spanning the possible range of anelastic velocity conversions (while being based on the same mantle circulation model).

  16. Influence of deposition density on undrained shear strength parameters of mining sand

    Science.gov (United States)

    Chan, Chee-Ming

    2017-10-01

    Sand is widely used as the underlying soil for the construction of road embankments. The deposition density of sand is therefore of crucial importance to ensure long term stability of the overlying materials. The present study examined the effect of variation in density on the undrained shear strength parameters of a mining sand sample. The standard direct shear test apparatus was adopted for the measurements. The sand sample was prepared in loose (1400 kg/m3), medium dense (1600 kg/m3) and dense (1940 kg/m3) forms via the dry pulverization method. For the direct shear test, 3 vertical loads were applied to obtain the shear stress - displacement plots, i.e. σv = 25, 50 and 100 kPa. The results indicated significant influence of deposition density of the sand on the shear strength measurements, where higher density gave higher shear strength readings with greater frictional resistance mobilised. Besides, the peak shear strength recorded at failure (τf) for all samples were almost 4 times of those observed post-failure, i.e. residual shear strength, τF. the corresponding failure and residual shear strains, γf and γF respectively, showed marginal changes at σv = 25 kPa. Initial loose packing of the sand was also found to be detrimental post-failure with marginal residual shear strength locked in. All in all the findings point towards the importance of accurately identifying initial packing density of the sand to estimate the inherent shear resistance for load-bearing.

  17. Influence of morphological parameters on the development of gingival recession in class III malocclusion.

    Science.gov (United States)

    Warmuz, Justyna; Jagielak, Maciej; Botzenhart, Ute; Seeliger, Julia; Gedrange, Tomasz; Dominiak, Marzena

    2016-07-01

    Cephalometric analysis, including both basic cranio- and gnathometric measurements and detailed evaluation of the construction of skeletal, muscular and mucosal systems combined with estimation of the risk of recession's occurrence, can be used to determine the direction of therapy and ensure appropriate aesthetic-functional effects of treatment. The objective of the present study was to compare the influence of the chosen morphologic parameters on the development of gingival recession in the front part of the jaw in patients with Angle class III. The research material was based on the medical documentation of 1800 patients. Sixty generally healthy patients qualified for the research with prognathism. On the basis of the side-head cephalograms, measurements were carried out to describe the bone structure in the front section of the lower jaw. The lower incisor teeth set-up was also analyzed. Gum recession of the lower incisor teeth was assessed on the basis of the inside-mouth photos of the patients with class III malocclusion. The occurrence of recession in a further 4 patients resulted from such a positioning of the lower teeth. In patients in the first group, treated with complex ortho-surgical treatment, the lower incisor teeth were adjusted much more vertically in the alveola and, thus, recession occurred only in one patient. Complex orthodontic-surgical therapy contributes to recession development to a lesser degree than the sham treatment and makes it a safe alternative therapy in patients with high diathesis for occurrence or progression of an existing recession. Copyright © 2015 Elsevier GmbH. All rights reserved.

  18. Experimental and statistical models of impact determination of the electron beam parameters on surface layers properties of optical elements in precision instruments building

    Directory of Open Access Journals (Sweden)

    I.V. Yatsenko

    2016-05-01

    Full Text Available Modern devices with optical elements for measurement and thermal control of different physical nature objects subjected to intense external thermal actions. To prevent destruction of optical elements the electron beam methods of work surfaces finishing at the stage of manufacture has practical significance. These methods can improve the properties of the element surface layers and thus make them more resistant to external thermal and mechanical action. Aim: The aim is to determine the optimal ranges of parameters of the electron beam and the development of experimental and statistical models that will automatically generate database with improved properties of the surface layers of optical elements in real time mode after previous electron beam treatment. Materials and Methods: To study the influence of parameters of the electron beam on the properties of the surface layers of the optical elements used plates of optical glass (K8, K108, etc. and ceramics (KO1, KO2, etc.. The strip electron beam has the following characteristics: density of heat flow Fn = 5∙10^6…9∙10^8 W/m2 and rate of displacement V = 0…0.1 m/s. Determination of the surface layers properties of the optical elements before and after electron beam treatment was carried out by known methods of physical and chemical analysis. Results: It was established that under the influence of the electron beam on the surface of the optical element there is visible clearing of various impurities take place, various micro-defects that remain on it after standard processing methods (mechanical, chemical, etc. remove and also its smoothness significantly increases, i.e. height of residual asperities on the surface is reduced. It was also found that the processing of optical glass elements by electron beam their surface layers change their structure, which is close to the quartz. It is shown that the surface of the preprocessed electron beam elements able to withstand the critical value of

  19. The Parameters Selection of PSO Algorithm influencing On performance of Fault Diagnosis

    Directory of Open Access Journals (Sweden)

    He Yan

    2016-01-01

    Full Text Available The particle swarm optimization (PSO is an optimization algorithm based on intelligent optimization. Parameters selection of PSO will play an important role in performance and efficiency of the algorithm. In this paper, the performance of PSO is analyzed when the control parameters vary, including particle number, accelerate constant, inertia weight and maximum limited velocity. And then PSO with dynamic parameters has been applied on the neural network training for gearbox fault diagnosis, the results with different parameters of PSO are compared and analyzed. At last some suggestions for parameters selection are proposed to improve the performance of PSO.

  20. An investigation of the influence of reconceptualization of demonstrative experimental activities of optics in high school

    Directory of Open Access Journals (Sweden)

    Jair Lúcio Prados Ribeiro

    2013-08-01

    Full Text Available In this work, we analyze the influence that the use of demonstrative experiments can bring to the learning of optics. It is assumed that the development of experimental activities, when reconceptualized according to Hodson proposal, tends to contribute to the generation of cognitive conflicts when compared to traditional didactic experience. Justifications are given for an analysis of changes under a Piagetian bias, reconciled with Hodson proposal. The methodology used to structure the topics presentations was quasi-experimental, contrasting an experimental group with a control group. The measuring of the effectiveness of the suggested working method was made from a quantitative analysis, which identified some of the topics discussed had better results in learning, being more tied to the experiments carried out.

  1. Determination and Assessment of Parameters Influencing Rock Mass Cavability in Block Caving Mines Using the Probabilistic Rock Engineering System

    Science.gov (United States)

    Rafiee, Ramin; Ataei, Mohammad; Khalokakaie, Reza; Jalali, Seyed Mohammad Esmaeil; Sereshki, Farhang

    2015-05-01

    Mining methods such as block caving or sublevel caving rely on the characteristics of the rock mass to cave efficiently to fulfill an economical production. The identification of influencing parameters and cavability assessment are, thus, a prime geotechnical focus for all potential caving projects. In the caving operation, many factors, such as natural and induced factors, affect the caving performance. In this study, after discussing the caving process and identifying all effective parameters, the interaction matrix based on the rock engineering system (RES) is introduced to study the influencing parameters in rock mass cavability. The interaction matrix analyzes the interrelationship between the parameters affecting rock engineering activities. As the interaction matrix codes are not unique, probabilistic coding can be performed non-deterministically, allowing consideration of uncertainties in the RES analysis. As a result, the parameters with the highest probability of being dominant or subordinate, and also the parameters with the highest probability of being interactive, are introduced. The proposed approach could be a simple but efficient tool in the evaluation of the parameters affecting the cavability of rock mass in block caving mines and, hence, useful in decision-making under uncertainties.

  2. Experimental Study of Direct Laser Deposition of Ti-6Al-4V and Inconel 718 by Using Pulsed Parameters

    Directory of Open Access Journals (Sweden)

    Kamran Shah

    2014-01-01

    Full Text Available Laser direct metal deposition (LDMD has developed from a prototyping to a single metal manufacturing tool. Its potential for creating multimaterial and functionally graded structures is now beginning to be explored. This work is a first part of a study in which a single layer of Inconel 718 is deposited on Ti-6Al-4V substrate. Single layer tracks were built at a range of powder mass flow rates using a coaxial nozzle and 1.5 kW diode laser operating in both continuous and pulsed beam modes. This part of the study focused on the experimental findings during the deposition of Inconel 718 powder on Ti-6Al-4V substrate. Scanning electron microscopy (SEM and X-ray diffraction analysis were performed for characterization and phase identification. Residual stress measurement had been carried out to ascertain the effects of laser pulse parameters on the crack development during the deposition process.

  3. CO2 laser cutting: analytical dependence of the roughness of the cut edge on the experimental parameters and process monitoring

    Science.gov (United States)

    Sforza, Patrizia; Santacesaria, Vincenzo

    1994-09-01

    Over the last few years laser cutting has been widely introduced in industrial production lines, mainly due to the high processing speeds. In the present work a fundamental aspect of the cutting process of metals has been considered: the formation of periodic striations on the cut edge that greatly affects the quality of the treated samples. Therefore this paper is devoted to the study of the roughness of the cut surfaces with a particular attention to the dependence of this parameters on the working conditions. For a better understanding of the variables involved in the process, a comparison of the experimental data with the results of an analytical model has been performed. Furthermore a real time monitoring of the infrared emission coming from the interaction zone has been carried out by means of an electrooptic device properly developed for the measurements of the local temperature. A correlation between these data and the roughness measurements has been found.

  4. Determination of heat transfer parameters by use of finite integral transform and experimental data for regular geometric shapes

    Science.gov (United States)

    Talaghat, Mohammad Reza; Jokar, Seyyed Mohammad

    2017-12-01

    This article offers a study on estimation of heat transfer parameters (coefficient and thermal diffusivity) using analytical solutions and experimental data for regular geometric shapes (such as infinite slab, infinite cylinder, and sphere). Analytical solutions have a broad use in experimentally determining these parameters. Here, the method of Finite Integral Transform (FIT) was used for solutions of governing differential equations. The temperature change at centerline location of regular shapes was recorded to determine both the thermal diffusivity and heat transfer coefficient. Aluminum and brass were used for testing. Experiments were performed for different conditions such as in a highly agitated water medium ( T = 52 °C) and in air medium ( T = 25 °C). Then, with the known slope of the temperature ratio vs. time curve and thickness of slab or radius of the cylindrical or spherical materials, thermal diffusivity value and heat transfer coefficient may be determined. According to the method presented in this study, the estimated of thermal diffusivity of aluminum and brass is 8.395 × 10-5 and 3.42 × 10-5 for a slab, 8.367 × 10-5 and 3.41 × 10-5 for a cylindrical rod and 8.385 × 10-5 and 3.40 × 10-5 m2/s for a spherical shape, respectively. The results showed there is close agreement between the values estimated here and those already published in the literature. The TAAD% is 0.42 and 0.39 for thermal diffusivity of aluminum and brass, respectively.

  5. Experimental evidence that sexual conflict influences the opportunity, form and intensity of sexual selection.

    Science.gov (United States)

    Hall, Matthew D; Bussière, Luc F; Hunt, John; Brooks, Robert

    2008-09-01

    Sexual interactions are often rife with conflict. Conflict between members of the same sex over opportunities to mate has long been understood to effect evolution via sexual selection. Although conflict between males and females is now understood to be widespread, such conflict is seldom considered in the same light as a general agent of sexual selection. Any interaction between males or females that generates variation in fitness, whether due to conflict, competition or mate choice, can potentially influence sexual selection acting on a range of male traits. Here we seek to address a lack of direct experimental evidence for how sexual conflict influences sexual selection more broadly. We manipulate a major source of sexual conflict in the black field cricket, Teleogryllus commodus, and quantify the resulting changes in the nature of sexual selection using formal selection analysis to statistically compare multivariate fitness surfaces. In T. commodus, sexual conflict occurs over the attachment time of an external spermatophore. By experimentally manipulating the ability of males and females to influence spermatophore attachment, we found that sexual conflict significantly influences the opportunity, form, and intensity of sexual selection on male courtship call and body size. When males were able to harass females, the opportunity for selection was smaller, the form of selection changed, and sexual selection was weaker. We discuss the broader evolutionary implications of these findings, including the contributions of sexual conflict to fluctuating sexual selection and the maintenance of additive genetic variation.

  6. Influence of pre-injection control parameters on main-injection fuel quantity for an electronically controlled double-valve fuel injection system of diesel engine

    Science.gov (United States)

    Song, Enzhe; Fan, Liyun; Chen, Chao; Dong, Quan; Ma, Xiuzhen; Bai, Yun

    2013-09-01

    A simulation model of an electronically controlled two solenoid valve fuel injection system for a diesel engine is established in the AMESim environment. The accuracy of the model is validated through comparison with experimental data. The influence of pre-injection control parameters on main-injection quantity under different control modes is analyzed. In the spill control valve mode, main-injection fuel quantity decreases gradually and then reaches a stable level because of the increase in multi-injection dwell time. In the needle control valve mode, main-injection fuel quantity increases with rising multi-injection dwell time; this effect becomes more obvious at high-speed revolutions and large main-injection pulse widths. Pre-injection pulse width has no obvious influence on main-injection quantity under the two control modes; the variation in main-injection quantity is in the range of 1 mm3.

  7. Probabilistic evidential assessment of gunshot residue particle evidence (Part II): Bayesian parameter estimation for experimental count data.

    Science.gov (United States)

    Biedermann, A; Bozza, S; Taroni, F

    2011-03-20

    Part I of this series of articles focused on the construction of graphical probabilistic inference procedures, at various levels of detail, for assessing the evidential value of gunshot residue (GSR) particle evidence. The proposed models--in the form of Bayesian networks--address the issues of background presence of GSR particles, analytical performance (i.e., the efficiency of evidence searching and analysis procedures) and contamination. The use and practical implementation of Bayesian networks for case pre-assessment is also discussed. This paper, Part II, concentrates on Bayesian parameter estimation. This topic complements Part I in that it offers means for producing estimates usable for the numerical specification of the proposed probabilistic graphical models. Bayesian estimation procedures are given a primary focus of attention because they allow the scientist to combine (his/her) prior knowledge about the problem of interest with newly acquired experimental data. The present paper also considers further topics such as the sensitivity of the likelihood ratio due to uncertainty in parameters and the study of likelihood ratio values obtained for members of particular populations (e.g., individuals with or without exposure to GSR). Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  8. Experimental and simulation investigation of electrical and plasma parameters in a low pressure inductively coupled argon plasma

    Science.gov (United States)

    Jian, YANG; Angjian, WU; Xiaodong, LI; Yang, LIU; Fengsen, ZHU; Zhiliang, CHEN; Jianhua, YAN; Ruijuan, CHEN; Wangjun, SHEN

    2017-11-01

    The electrical and plasma parameters of a low pressure inductively coupled argon plasma are investigated over a wide range of parameters (RF power, flow rate and pressure) by diverse characterizations. The external antenna voltage and current increase with the augment of RF power, whereas decline with the enhancement of gas pressure and flow rate conversely. Compared with gas flow rate and pressure, the power transfer efficiency is significantly improved by RF power, and achieved its maximum value of 0.85 after RF power injected excess 125 W. Optical emission spectroscopy (OES) provides the local mean values of electron excited temperature and electron density in inductively coupled plasma (ICP) post regime, which vary in a range of 0.81 eV to 1.15 eV and 3.7× {10}16 {{{m}}}-3 to 8.7× {10}17 {{{m}}}-3, respectively. Numerical results of the average magnitudes of electron temperature and electron density in two-dimensional distribution exhibit similar variation trend with the experimental results under different operating condition by using COMSOL Multiphysics. By comprehensively understanding the characteristics in a low pressure ICP, optimized operating conditions could be anticipated aiming at different academic and industrial applications.

  9. Influence of sol-gel process parameters on the micro-structure and performance of hybrid silica membranes

    NARCIS (Netherlands)

    Qureshi, H.F.; Nijmeijer, Arian; Winnubst, Aloysius J.A.

    2013-01-01

    A facile, versatile and reproducible sol–gel process to make microporous organosilica membranes by using 1,2-bis (triethoxysilyl) ethane (BTESE) as a precursor is reported. The influence of process parameters on sol particle size and rheology of BETSE-derived sols was investigated to produce

  10. Investigating the links between the process parameters and their influence on the aesthetic evaluation of selective laser melted parts

    NARCIS (Netherlands)

    Galimberti, G.; Doubrovski, E.L.; Guagliano, M.; Previtali, B.; Verlinden, J.C.; Bourell, David L.; Crawford, Richard H.; Seepersad, Carolyn C.; Beaman, Joseph J.; Fish, Scott; Marcus, Harris

    2016-01-01

    This study is a precursor to gaining a deeper understanding of how each parameter of the Additive Manufacturing (AM) process influences the aesthetic properties of 3D printed products. Little research has been conducted on this specific aspect of AM. Using insights from the work presented in this

  11. The influence of precultivation parameters on the catabolism of branched-chain amino acids by Staphylococcus xylosus and Staphylococcus carnosus

    DEFF Research Database (Denmark)

    Olesen, Pelle Thonning; Stahnke, Louise Heller

    2003-01-01

    The influence of precultivation. parameters on the ability of Staphylococcus xylosus and Staphylococcus carnosus to convert branched-chain amino acids-leucine, isoleucine and valine-into volatile flavour compounds was investigated using resting cells in a defined reaction medium. The studied...

  12. Scientific Opinion on the influence of genetic parameters on the welfare and the resistance to stress of commercial broilers

    DEFF Research Database (Denmark)

    Morton, David; Oltenacu, Toni; Arnould, Cécile

    2010-01-01

      This scientific opinion describes the influence of genetic parameters that have affected the welfare of commercial broilers. There is a lack of robust scientific data for Europe on welfare outcome indicators and these should be recorded independently and made publicly available. The major welfa...

  13. Computation of adsorption parameters for the removal of dye from wastewater by microwave assisted sawdust: Theoretical and experimental analysis.

    Science.gov (United States)

    S, Suganya; P, Senthil Kumar; A, Saravanan; P, Sundar Rajan; C, Ravikumar

    2017-03-01

    In this research, the microwave assistance has been employed for the preparation of novel material from agro/natural bio-waste i.e. sawdust, for the effective removal of methylene blue (MB) dye from aqueous solution. The characterization of the newly prepared microwave assisted sawdust (MASD) material was performed by using FTIR, SEM and XRD analyses. In order to obtain the maximum removal of MB dye from wastewater, the adsorption experimental parameters such as initial dye concentration, contact time, solution pH and adsorbent dosage were optimized by trial and error approach. The obtained experimental results were applied to the different theoretical models to predict the system behaviour. The optimum conditions for the maximum removal MB dye from aqueous solution for an initial MB dye concentration of 25mg/L was calculated as: adsorbent dose of 3g/L, contact time of 90min, solution pH of 7.0 and at the temperature of 30°C. Freundlich and pseudo-second order models was best obeyed with the studied experimental data. Langmuir maximum monolayer adsorption capacity of MASD for MB dye removal was calculated as 58.14mg of MB dye/g of MASD. Adsorption diffusion model stated that the present adsorption system was controlled by intraparticle diffusion model. The obtained results proposed that, novel MASD was considered to be an effective and low-cost adsorbent material for the removal of dye from wastewater. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Theoretical and experimental evaluation of effective stress-induced sorption capacity change and its influence on coal permeability

    Science.gov (United States)

    Li, Chengwu; Dong, Lihui; Xu, Xiaomeng; Hu, Po; Tian, Jianwei; Zhang, Yihuai; Yang, Leilei

    2017-06-01

    The gas sorption effect is an important factor affecting the gas permeability of a coal seam, which has been proved in many previous experimental measurements and analytical permeability studies. However, the sorption capacity of coal is usually not static due to the complexity of external stress variation and internal gas media features. The stress-induced sorption capacity variation and its effect on the coal permeability change have not been fully identified yet. Thus, in this paper we present a preliminary evaluation of the stress-induced sorption capacity change by introducing the adsorption capacity modified term, and an experiment is carried out to verify the influence of the altered effective stress on coal permeability. Langmuir-like adsorption deformation constant parameters were combined into the modified coal permeability model and were given values to fully estimate the influence on permeability caused by the modification term. We found that different change modes of effective stress would yield different change effects on the permeability, that is, with the same effective stress change amount, the altered external stress-induced change had less influence than the altered-pore pressure-induced change; however, both modes demonstrated that the model taking sorption capacity change into consideration is more consistent with the experimental data. The effect of sorption capacity change on coal permeability variation was also found to be tightly connected with the physical and mechanical properties of the coal itself. It is proved that considering stress-induced sorption ability change has a critical role in characterizing the permeability variation of coal.

  15. Trace metals, melanin-based pigmentation and their interaction influence immune parameters in feral pigeons (Columba livia).

    Science.gov (United States)

    Chatelain, M; Gasparini, J; Frantz, A

    2016-04-01

    Understanding the effects of trace metals emitted by anthropogenic activities on wildlife is of great concern in urban ecology; yet, information on how they affect individuals, populations, communities and ecosystems remains scarce. In particular, trace metals may impact survival by altering the immune system response to parasites. Plumage melanin is assumed to influence the effects of trace metals on immunity owing to its ability to bind metal ions in feathers and its synthesis being coded by a pleiotropic gene. We thus hypothesized that trace metal exposure would interact with plumage colouration in shaping immune response. We experimentally investigated the interactive effect between exposure to an environmentally relevant range of zinc and/or lead and melanin-based plumage colouration on components of the immune system in feral pigeons (Columba livia). We found that zinc increased anti-keyhole limpet hemocyanin (KLH) IgY primary response maintenance, buffered the negative effect of lead on anti-KLH IgY secondary response maintenance and tended to increase T-cell mediated phytohaemagglutinin (PHA) skin response. Lead decreased the peak of the anti-KLH IgY secondary response. In addition, pheomelanic pigeons exhibited a higher secondary anti-KLH IgY response than did eumelanic ones. Finally, T-cell mediated PHA skin response decreased with increasing plumage eumelanin level of birds exposed to lead. Neither treatments nor plumage colouration correlated with endoparasite intensity. Overall, our study points out the effects of trace metals on some parameters of birds' immunity, independently from other confounding urbanization factors, and underlines the need to investigate their impacts on other life history traits and their consequences in the ecology and evolution of host-parasite interactions.

  16. Smoking experimentation among elementary school students in China: influences from peers, families, and the school environment.

    Directory of Open Access Journals (Sweden)

    Cheng Huang

    Full Text Available The aim of this study was to investigate experimentation with smoking among primary school students in China. Data were acquired from a recent survey of 4,073 students in grades 4 to 6 (ages 9-12 in 11 primary schools of Ningbo City. The questions were adapted from the Global Youth Tobacco Survey (GYTS. Results suggest that although the Chinese Ministry of Education (MOE encourages smoke-free schools, experimentation with cigarettes remains a serious problem among primary school students in China. Peers, family members, and the school environment play important roles in influencing smoking experimentation among students. Having a friend who smoked, seeing a family member smoke, and observing a teacher smoking on campus predicted a higher risk of experimentation with smoking; the exposure to anti-tobacco materials at school predicted a lower risk of experimentation with smoking. The evidence suggests that public health practitioners and policymakers should seek to ensure the implementation of smoke-free policies and that intervention should target young people, families, and communities to curb the commencement of smoking among children and adolescents in China.

  17. Influence of cultivation parameters on the composition of volatile compounds and physico-chemical characteristics of kiwi fruit.

    Science.gov (United States)

    Santoni, François; Barboni, Toussaint; Paolini, Julien; Costa, Jean

    2013-02-01

    The effect of four cultivation parameters (post-maturity harvest date, storage period at 0 °C and input of nitrogen or potassium fertilisers) on the physico-chemical characteristics and composition of volatile compounds in kiwi fruit (Actinidia deliciosa) were evaluated. Five physico-chemical parameters were selected, namely, pH, total acidity, dry matter, conductivity and refractive index. To our knowledge, no published data are available concerning the influence of nitrogen or potassium fertilisers on the volatile compounds and physico-chemical parameters in kiwi fruit. Except for total acidity, these parameters were only weakly influenced by cultivation parameters. The concentrations of five main volatile compounds [hexanal, (E)-hex-2-enal, hexan-2-ol, ethyl butyrate and hexanol] were also measured using gas chromatography and gas chromatography-mass spectrometry. This work showed that the total content of volatile compounds decreased with post-maturity harvest date and storage period of 3 months. In contrast, the input levels of nitrogen and potassium had little effect on the concentrations of volatile components This study demonstrates a high degree of difference in the physiochemical parameters and volatile composition of kiwi fruit, depending on the harvest date, the time of storage and the input of fertilisers. Copyright © 2012 Society of Chemical Industry.

  18. Influence of emphysema distribution on pulmonary function parameters in COPD patients

    Directory of Open Access Journals (Sweden)

    Helder Novais e Bastos

    2015-12-01

    Full Text Available ABSTRACT OBJECTIVE: To evaluate the impact that the distribution of emphysema has on clinical and functional severity in patients with COPD. METHODS: The distribution of the emphysema was analyzed in COPD patients, who were classified according to a 5-point visual classification system of lung CT findings. We assessed the influence of emphysema distribution type on the clinical and functional presentation of COPD. We also evaluated hypoxemia after the six-minute walk test (6MWT and determined the six-minute walk distance (6MWD. RESULTS: Eighty-six patients were included. The mean age was 65.2 ± 12.2 years, 91.9% were male, and all but one were smokers (mean smoking history, 62.7 ± 38.4 pack-years. The emphysema distribution was categorized as obviously upper lung-predominant (type 1, in 36.0% of the patients; slightly upper lung-predominant (type 2, in 25.6%; homogeneous between the upper and lower lung (type 3, in 16.3%; and slightly lower lung-predominant (type 4, in 22.1%. Type 2 emphysema distribution was associated with lower FEV1, FVC, FEV1/FVC ratio, and DLCO. In comparison with the type 1 patients, the type 4 patients were more likely to have an FEV1 < 65% of the predicted value (OR = 6.91, 95% CI: 1.43-33.45; p = 0.016, a 6MWD < 350 m (OR = 6.36, 95% CI: 1.26-32.18; p = 0.025, and post-6MWT hypoxemia (OR = 32.66, 95% CI: 3.26-326.84; p = 0.003. The type 3 patients had a higher RV/TLC ratio, although the difference was not significant. CONCLUSIONS: The severity of COPD appears to be greater in type 4 patients, and type 3 patients tend to have greater hyperinflation. The distribution of emphysema could have a major impact on functional parameters and should be considered in the evaluation of COPD patients.

  19. Cytological evaluation of inflammation of the uterus and influence of endometritis on selected reproductive parameters in dairy cows

    Directory of Open Access Journals (Sweden)

    Brodzki Piotr

    2014-06-01

    Full Text Available There were two aims of this study. One was to evaluate the postpartum state of the reproductive system in cows based on ultrasonography, bacterial culture, and cytological examination of the uterus. The other was to determine whether postpartum endometritis affects the subsequent state of the endometrium, and, in consequence, selected reproductive parameters in cows. The study was conducted on 60 cows: the experimental group of 30 cows with endometritis, and 30 cows free of uterine inflammation (control. The percentage of leukocytes in both groups was similar only on day 5 of postpartum. In all subsequent tests (26, 40, 61 d postpartum, the percentage of leukocytes in the experimental group was statistically significantly higher than in the control (P < 0.001, both in samples collected with a brush and in lavage samples. Involution of the uterus in the experimental group was also slower (P < 0.001. The analysed reproductive parameters were markedly less favourable in the experimental group than in the control. The study showed that postpartum inflammation of the uterus can persist for a long time in the form of endometritis, causing substantial deterioration of reproductive parameters in cows. The authors suggest that cytological evaluation of the uterus, preferably using a brush, should be performed as soon as possible after parturition, even before day 21, up to which time puerperal metritis may still persist. Evaluation of the inflammatory process based on the number of leukocytes and the quality of endometrial cells is important.

  20. Experimental study of the pH influence on the transport mechanisms of phenols in soil.

    Science.gov (United States)

    Fiore, Silvia; Zanetti, Maria Chiara; Genon, Giuseppe

    2003-01-01

    The study of the transport mechanisms connected to solid-liquid interactions is fundamental in the determination of the extension of the pollution of a site and in the evaluation of the best remediation process to be applied. The sorption of hydrophobic ionizable organic contaminants from the groundwaters is supervised not only by the physico-chemical properties of soil and pollutants, but also by the groundwaters pH, which deeply influences their solubility in the aqueous media, and consequently their transport mechanisms in the aquifer. In this work an experimental study of the sorption of phenol and 2-nitrophenol on two soils, different in particle-size distribution, CEC and organic carbon content, was realized. The sorption potential of the soils was evaluated by means of a physical, mineralogical and chemical characterization. The experimental data coming from some batch tests, performed at pH values equal to 4, 7 and 10 were fitted by means of linear, Freundlich and Langmuir isotherms models. The soil-contaminants interaction mechanisms that influence the isotherms shapes were then analyzed and discussed, and a comparison between the theoretical and experimental values of the partitioning coefficient KD was performed.

  1. Characterization of an erbium doped fiber amplifier starting from its experimental parameters; Caracterizacion de un amplificador de fibra dopada con erbio a partir de sus parametros experimentales

    Energy Technology Data Exchange (ETDEWEB)

    Bello J, M.; Kuzin, E.A.; Ibarra E, B. [Instituto Nacional de Astrofisica, Optica y Electronica (INAOE), Luis Enrique Erro No. 1, TonantzintIa, 72000 Puebla (Mexico); Tellez G, R. [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas No 152, Delegacion Gustavo A. Madero, 07730 Mexico D.F. (Mexico)]. e-mail: mabello@inaoep.mx

    2007-07-01

    In this paper we describe a method to characterize the gain of an erbium-doped fiber amplifier (EDFA) through the numerical simulation of the signal beam along the amplifier. The simulation is based on a model constituted by the propagation and rate equations for an erbium-doped fiber. The manipulation of these equations allows us to regroup the parameters present in an EDFA, which we have named the A, B, C, D parameters, and they can be obtained experimentally from an erbium-doped fiber. Experimental results show that the measurement of these parameters allow us to estimate with very good correspondence the amplifier gain. (Author)

  2. Estimation of the Influence of Power System Mathematical Model Parameter Uncertainty on PSS2A System Stabilizers

    Directory of Open Access Journals (Sweden)

    Adrian Nocoń

    2015-09-01

    Full Text Available This paper presents an analysis of the influence of uncertainty of power system mathematical model parameters on optimised parameters of PSS2A system stabilizers. Optimisation of power system stabilizer parameters was based on polyoptimisation (multi-criteria optimisation. Optimisation criteria were determined for disturbances occurring in a multi-machine power system, when taking into account transient waveforms associated with electromechanical swings (instantaneous power, angular speed and terminal voltage waveforms of generators. A genetic algorithm with floating-point encoding, tournament selection, mean crossover and perturbative mutations, modified for the needs of investigations, was used for optimisation. The impact of uncertainties on the quality of operation of power system stabilizers with optimised parameters has been evaluated using various deformation factors.

  3. Influence of helium puff on divertor asymmetry in experimental advanced superconducting tokamak

    DEFF Research Database (Denmark)

    Liu, S. C.; Guo, H. Y.; Xu, G. S.

    2014-01-01

    Divertor asymmetries with helium puffing are investigated in various divertor configurations on Experimental Advanced Superconducting Tokamak (EAST). The outer divertor electron temperature decreases significantly during the gas injection at the outer midplane. As soon as the gas is injected...... parameters are measured by reciprocating probes at the outer midplane, showing that the electron temperature and density increase but the parallel Mach number decreases significantly due to the gas injection. Effects of poloidal E × B drifts and parallel SOL flows on the divertor asymmetry observed in EAST...

  4. Influence of parameter estimation uncertainty in Kriging: Part 1 - Theoretical Development

    Directory of Open Access Journals (Sweden)

    E. Todini

    2001-01-01

    Full Text Available This paper deals with a theoretical approach to assessing the effects of parameter estimation uncertainty both on Kriging estimates and on their estimated error variance. Although a comprehensive treatment of parameter estimation uncertainty is covered by full Bayesian Kriging at the cost of extensive numerical integration, the proposed approach has a wide field of application, given its relative simplicity. The approach is based upon a truncated Taylor expansion approximation and, within the limits of the proposed approximation, the conventional Kriging estimates are shown to be biased for all variograms, the bias depending upon the second order derivatives with respect to the parameters times the variance-covariance matrix of the parameter estimates. A new Maximum Likelihood (ML estimator for semi-variogram parameters in ordinary Kriging, based upon the assumption of a multi-normal distribution of the Kriging cross-validation errors, is introduced as a mean for the estimation of the parameter variance-covariance matrix. Keywords: Kriging, maximum likelihood, parameter estimation, uncertainty

  5. Sensitivity analysis to identify key parameters influencing Salmonella infection dynamics in a pig batch.

    Science.gov (United States)

    Lurette, Amandine; Touzeau, Suzanne; Lamboni, Matieyendou; Monod, Hervé

    2009-05-07

    In the context of managed herds, epidemiological models usually take into account relatively complex interactions involving a high number of parameters. Some parameters may be uncertain and/or highly variable, especially epidemiological parameters. Their impact on the model outputs must then be assessed by a sensitivity analysis, allowing to identify key parameters. The prevalence over time is an output of particular interest in epidemiological models, so sensitivity analysis methods adapted to such dynamic output are needed. In this paper, such a sensitivity analysis method, based on a principal component analysis and on analysis of variance, is presented. It allows to compute a generalised sensitivity index for each parameter of a model representing Salmonella spread within a pig batch. The model is a stochastic discrete-time model describing the batch dynamics and movements between rearing rooms, from birth to slaughterhouse delivery. Four health states were introduced: Salmonella-free, seronegative shedder, seropositive shedder and seropositive carrier. The indirect transmission was modelled via an infection probability function depending on the quantity of Salmonella in the rearing room. Simulations were run according to a fractional factorial design enabling the estimation of main effects and two-factor interactions. For each of the 18 epidemiological parameters, four values were chosen, leading to 4096 scenarios. For each scenario, 15 replications were performed, leading to 61440 simulations. The sensitivity analysis was then conducted on the seroprevalence output. The parameters governing the infection probability function and residual room contaminations were identified as key parameters. To control the Salmonella seroprevalence, efficient measures should therefore aim at these parameters. Moreover, the shedding rate and maternal protective factor also had a major impact. Therefore, further investigation on the protective effect of maternal or post

  6. Influence of the welding parameters on the heat affected zone for aluminium welding

    Directory of Open Access Journals (Sweden)

    Meseguer-Valdenebro José L.

    2016-01-01

    Full Text Available This work analyzes the Heat Affected Zone in an aluminum alloy welded assembly using the Metal Inert Gas welding technique. Making use of numerical simulations of the involved thermal processes, the aluminum alloy cooling curve is calculated and the extension of the Heat Affected Zone is evaluated. The connection between this last parameter, the cooling rate, and the maximum obtained temperature is assessed. Additionally, the response surface method is exploited to fit the dependence of the Heat Affected Zone with the welding parameters and to optimize these parameters in order to minimize that region.

  7. Evaluation of nanoselenium (Nano-Se) effect on hematological and serum biochemical parameters of rat in experimentally lead poisoning.

    Science.gov (United States)

    Dehkordi, A Jafari; Mohebbi, A N; Aslani, M R; Ghoreyshi, S M

    2017-04-01

    The present study was designed to evaluate the effect of nanoselenium (Nano-Se) on hematological and biochemical parameters of rats experimentally intoxicated with lead (Pb). Thirty male rats were randomly divided into six groups as follows: the control, selenite, Nano-Se, Pb group, Pb + selenite, and Pb + Nano-Se groups. After 35 days, blood was collected from rats and hematology and serum biochemical parameters of oxidative stress were measured. The thiobarbituric acid reactive substances (TBARS) level of Pb group was significantly higher than other groups. Also, TBARS level was significantly lower in the Pb + Nano-Se group than Pb + selenite group. The serum superoxide dismutase activities were significantly lower in Pb group than the control, Pb + selenite, and Pb + Nano-Se groups. The catalase activities in the Pb group showed no significant change when compared to other groups. In the Pb group, packed cell volume was lower than the control group. A significant difference was observed between the control group and the Pb, Pb + selenite, and Pb + Nano-Se groups. In the Pb group, the numbers of white blood cell (WBC) decreased in comparison with the control group. Also, there was significant increase in WBC counts in the Pb + Nano-Se and Pb + selenite groups in comparison with Pb group. The number of lymphocytes in the Pb group decreased in comparison with the control group. By comparing the means of the Pb + Nano-Se and Pb + selenite groups together, it was determined that there were significant differences in the lymphocytes and neutrophil counts. In conclusion, usage of selenium compounds particularly Nano-Se particles inhibits the adverse effects of Pb on antioxidant activity and immune system function in the Pb poisoning.

  8. The Genetic Influences on Oxycodone Response Characteristics in Human Experimental Pain

    DEFF Research Database (Denmark)

    Olesen, Anne Estrup; Sato, Hiroe; Nielsen, Lecia Møller

    2015-01-01

    Human experimental pain studies are of value to study basic pain mechanisms under controlled conditions. The aim of this study was to investigate whether genetic variation across selected mu-, kappa- and delta-opioid receptor genes (OPRM1, OPRK1and OPRD1, respectively) influenced analgesic response...... PTT (n = 41) were included. Genetic associations with pain outcomes were explored. Nineteen opioid receptor genetic polymorphisms were included in this study. Variability in oxycodone response to skin heat was associated with OPRM1 single-nucleotide polymorphisms (SNPs) rs589046 (P ... to oxycodone in healthy volunteers. Experimental multimodal, multitissue pain data from previously published studies carried out in Caucasian volunteers were used. Data on thermal skin pain tolerance threshold (PTT) (n = 37), muscle pressure PTT (n = 31), mechanical visceral PTT (n = 43) and thermal visceral...

  9. Gender, experimenter gender and medium of report influence the content of autobiographical memory report.

    Science.gov (United States)

    Grysman, Azriel; Denney, Amelia

    2017-01-01

    In this study, we examined the role of context in autobiographical memory narratives, specifically as it pertains to gender among emerging adults. Male and female participants reported stressful events in their lives in the presence of an experimenter, and were randomly assigned either to report events verbally or type them, and to report in the presence of a male or female experimenter. Narratives were coded for factual and interpretive content. Results revealed that men verbally reporting to women reported longer narratives than all other groups. Women's narrative length did not vary by medium of report or conversational partner, but women used proportionally fewer internal state phrases when verbally reporting to men than when reporting to women. Women also used proportionally fewer evaluative statements in verbal reports than in typed narratives. Of these important interactions among context, gender, and experimenter gender, some findings, such as men's longer narratives and women's reduced internal states, were counter to expectations. These findings highlight the importance of methodological influences in autobiographical memory studies, in regard to both the context generated by experimental methods, and how gender differences are understood.

  10. Definition and use of the experimental sensible parameters to characterize sensitivity and precision of a generic oxygen optical sensor.

    Science.gov (United States)

    Badocco, Denis; Pastore, Paolo

    2008-03-15

    Experimental data, obtained with an oxygen optical sensor constituted by a polysulfone layer embedding ruthenium(II)(4,7-diphenyl-l,l0-phenanthroline)octylsulfate (Ru(dpp)OS), were rationalized by using the digital simulation technique and generalized for different sensors. The experimental, asymmetric, emission shape was used to define two sensible parameters, ASY (asymmetry factor) and DeltaI(%) (percent variation of emission intensity), to characterize the sensitivity of a generic oxygen optical sensor (represented by the Stern-Volmer constant, K'(sv)). Correlations between ASY and K'(sv) and between DeltaI(%) and K'(sv) were established, and a double working curve was proposed to evaluate with a single light emission measurement the K'(sv) value with the best precision. Sensitive membranes (-log K'(sv) = pK'(sv) 2.5) had constant but scarce precisions in a large %O(2) interval. For %O(2) up to 21% (air) good values are pK'(sv)= 0.5-1.0. In order to monitor a wider %O(2) range, pK'(sv) = 1.5-2.0 are good choices. A simple mathematical model allowed one to estimate the oxygen diffusion coefficient inside the layer, D(O2), and its solubility in the polymer matrix, s(O2), from the simple measurement of the membrane thickness, response time, t(90), and luminescence lifetime. D(O2) = 2 x 10(-8) cm2 s(-1) and s(O2) = 2.2 x 10(-3) mol atm(-1) dm(-3) [corrected] were estimated for our membranes. The proposed working curves gave very good results even with literature data.

  11. Influence of the key parameters of suspended structures on the inherent frequency of oil and gas pipelines

    Science.gov (United States)

    Tao, S. Y.; Liu, Q. Y.; Wang, G. R.; Jiang, J. C.

    2015-10-01

    Inherent frequency is an important parameter that reflects the dynamic stability of fluid-conveying pipelines. In engineering applications, the inherent frequency of pipelines is usually increased to improve their dynamic stability. The flow velocity and pressure of oil and gas pipelines cannot be altered freely. Among all of the parameters that affect the inherent frequency of suspended pipelines, the flexural stiffness of the stiffening girder, the tensile force of the cable system, and the pipe-axial precompression force are the most important. Revealing the influence laws of these three parameters could provide theoretical support for engineering designs. In this paper, a suspended crossing pipeline project was simplified as a Hetenyi's elastic foundation model. The flexural stiffness of the stiffening girder and the tensile force of the cable system were simplified as the foundation parameters G and K, respectively. The influence regularities of G, K, and the pipe-axial precompression force T on the pipeline inherent frequency were analyzed. According to the numerical simulation results, the ranks of these three parameters in descending order of importance were G, T, and K. During construction, G should be increased as much as possible. If the inherent frequency needs to be improved while pipelines have already been built up, it should be firstly considered to increase T, to values higher than zero if possible. On this basis, the further improvement of K could achieve a better result.

  12. Design and formulation of nano-sized spray dried efavirenz. Part I: Influence of formulation parameters

    CSIR Research Space (South Africa)

    Katata, L

    2012-10-01

    Full Text Available statistical design with an L8 orthogonal array, was implemented to optimise the formulation parameters of PCL-EFV nanoparticles. The types of sugar (lactose or trehalose), surfactant concentration and solvent (dichloromethane and ethyl acetate) were chosen...

  13. Influences of tropicamide on anterior segment parameters with Pentacam in healthy individuals.

    Science.gov (United States)

    Palamar, Melis; Alkan, Zerrin; Egrilmez, Sait; Yagci, Ayse

    2013-04-01

    This study aims to investigate the effects of tropicamide 1% on the main numerical parameters of anterior segment with the Pentacam rotating Scheimpflug camera in healthy individuals. Pentacam measurements of 50 (25 female and 25 male) healthy individuals before and after 25 min of tropicamide 1% instillation were performed and compared. For comparison of the test parameters, paired t-test was used in the groups. Mean age in the study group was 28.40±4.58 years (range 18-35 years). Measurements between 2 sessions were significantly different for the parameters of anterior chamber depth (ACD) and anterior chamber volume (ACV) (PTropicamide 1% instillation leads to a significant increment in ACD and ACV measurements. Effects of tropicamide on these parameters for Pentacam measurements should be considered to ensure exact clinical interpretation in ophthalmologic practice.

  14. Influence of water on alkali-silica reaction: Experimental study and numerical simulations

    Energy Technology Data Exchange (ETDEWEB)

    Poyet, Stephane [CEA Saclay, DEN/DANS/DPC/SCCME/LECBA, B158, 91191 Gif sur Yvette (France); Sellier, Alain [LMDC, INSA PS, 135 Avenue de Rangueil, 31077 Toulouse Cedex 4 (France); Capra, Bruno [Oxand SA, 36bis Avenue Franklin Roosevelt, 77210 Avon (France); Thevenin-Foray, Genevieve [Universite Lyon 1 2MS ETRA GC, 82 Boulevard Niels BOHR, Domaine Scientifique de la DOUA, 69622 Villeurbanne Cedex (France); Torrenti, Jean-Michel [IRSN, BP17, 92262 Fontenay aux Roses Cedex (France); Tournier-Cognon, Helene [DER DF, Les Renardieres, Route de Sens, Ecuelles, 77818 Moret sur Loing (France); Bourdarot, Eric [Direction de l' Equipement, CIH, Savoie Technolac, 73373 Le Bourget du Lac (France)

    2006-07-01

    Alkali-silica reaction (ASR) is a concrete pathology due to chemical reactions involving reactive silica from reactive aggregates and the inner solution of concrete. Main effects are swelling, cracking, and reduction in the mechanical properties of affected concretes. Water is very important for ASR; the more available water, the more expansion and degradation. This article presents new laws for modeling of the influence of water upon ASR. They are based on experimental results and then used to simulate results taken out of the scientific literature. (authors)

  15. Major histocompatibility complex-controlled protective influences on experimental autoimmune encephalomyelitis are peptide specific

    DEFF Research Database (Denmark)

    Issazadeh-Navikas, Shohreh; Kjellén, P; Olsson, T

    1997-01-01

    The myelin basic protein (MBP) peptide 63-88-induced experimental autoimmune encephalomyelitis (EAE) and its associated T cell cytokine profile are influenced by the rat major histocompatibility complex (MHC). There is an allele-specific protective influence of the MHC class I region, whereas...... the MHC class II region display either disease-protective or -promoting effects. To investigate if the MHC-associated protection is dependent on certain combinations of MBP peptide and MHC molecules, we have now used another peptide (MBP 89-101). A broader and different set of rat MHC alleles were......-101 peptide, except in LEW.1N (RT1 pi) rats which were relatively resistant. Only this strain responded with additional Th2-like and transforming growth factor-beta responses to the peptide in vitro. In vivo depletion of CD8+ cells aggravated the disease in this strain. We conclude that both MHC...

  16. Experimental study on influence of boundary on location of maximum velocity in open channel flows

    Directory of Open Access Journals (Sweden)

    Jing Yan

    2011-06-01

    Full Text Available The velocity dip phenomenon may occur in a part of or in the whole flow field of open channel flows due to the secondary flow effect. Based on rectangular flume experiments and the laser Doppler velocimetry, the influence of the distance to the sidewall and the aspect ratio on the velocity dip is investigated. Through application of statistical methods to the experimental results, it is proposed that the flow field may be divided into two regions, the relatively strong sidewall region and the relatively weak sidewall region. In the former region, the distance to the sidewall greatly affects the location of maximum velocity, and, in the latter region, both the distance to the sidewall and the aspect ratio influence the location of the maximum velocity.

  17. INFLUENCE OF AGE ON PARAMETERS FOR FEMOROACETABULAR IMPINGEMENT AND HIP DYSPLASIA IN X-RAYS

    OpenAIRE

    HOFMANN, ULF-KRISTER; IPACH, INGMAR; RONDAK, INA-CHRISTINE; SYHA, ROLAND; GÖTZE, MARCO; MITTAG, FALK

    2017-01-01

    ABSTRACT Objective: While several radiographic parameters have been established to describe the geometry and pathology of the hip, their reference values and clinical significance remain a matter of dispute. The present study tests the hypothesis that age has a relevant impact on radiographic hip parameters. Method: Pelvic antero-posterior views were measured for CE angle, Sharp’s angle, acetabular depth-to-width ratio, femoral head extrusion index, roof obliquity, caput-collum-diaphyseal (...

  18. Influence of parameter estimation uncertainty in Kriging: Part 1 - Theoretical Development

    OpenAIRE

    Todini, E.

    2001-01-01

    This paper deals with a theoretical approach to assessing the effects of parameter estimation uncertainty both on Kriging estimates and on their estimated error variance. Although a comprehensive treatment of parameter estimation uncertainty is covered by full Bayesian Kriging at the cost of extensive numerical integration, the proposed approach has a wide field of application, given its relative simplicity. The approach is based upon a truncated Taylor expansion approximation and, within the...

  19. The Influence of Age on Hemodynamic Parameters During Rest and Exercise in Healthy Individuals

    DEFF Research Database (Denmark)

    Wolsk, Emil; Bakkestrøm, Rine; Thomsen, Jacob H

    2017-01-01

    OBJECTIVES: The authors sought to obtain hemodynamic estimates across a wide age span and in both sexes for future reference and compare these estimates with current guideline diagnostic hemodynamic thresholds for abnormal filling pressure and pulmonary hypertension. BACKGROUND: At present....... Participants had hemodynamic parameters measured using right heart catheterization during rest, passive leg raise, and incremental exercise. RESULTS: During rest, all hemodynamic parameters were similar between age groups, apart from blood pressure. During leg raise and incremental exercise...

  20. Influence of current reuse LNA circuit parameters on its noise figure

    Directory of Open Access Journals (Sweden)

    Radić Jelena

    2009-01-01

    Full Text Available A 2.4 GHz low noise amplifier (LNA with a bias current reuse technique is proposed in this work. To obtain the optimum noise figure (NF value, dependence of NF on its most influential LNA parameters has been analyzed. Taking into account the LNA design requirements for other figures of merit, values of the circuit parameters are given for the optimum noise figure.