Sample records for experimental studies estimation

  1. It Pays to Compare: An Experimental Study on Computational Estimation (United States)

    Star, Jon R.; Rittle-Johnson, Bethany


    Comparing and contrasting examples is a core cognitive process that supports learning in children and adults across a variety of topics. In this experimental study, we evaluated the benefits of supporting comparison in a classroom context for children learning about computational estimation. Fifth- and sixth-grade students (N = 157) learned about…

  2. Experimental Study on MUSIC-Based DOA Estimation by Using Universal Steering Vector (United States)

    Yuan, Qiaowei; Chen, Qiang; Sawaya, Kunio

    MUSIC-based estimation of direction of arrival (DOA) using universal steering vector (USV) is experimentally studied. A four-element array antenna and a four-channel receiver are employed for the experiment. In order to improve the accuracy of DOA estimation, USV which has already included the effect of mutual coupling between array elements and effect of array elements themselves is compensated to further include the electric delay and loss of four channels in the receiver. The compensated USV (C-USV) approach proposed in this paper does not need the time-consuming measurement of array element pattern because the compensating matrix for USV is obtained by measuring the S parameters between RF input ports of the feeding cables and IF output ports of the receiver. The experimental results of MUSIC-based DOA estimation show that C-USV approach is an accurate, effective and practical method for the MUSIC-based DOA estimation.

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

    Directory of Open Access Journals (Sweden)

    Fei Yang


    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.


    Directory of Open Access Journals (Sweden)

    M. Ganesh Madhan


    Full Text Available In real life situations, location estimation of moving objects, armed personnel are of great importance. In this paper, we have attempted to locate targets which are mobile in a Wi-Fi environment. Radio Frequency (RF localization techniques based on Received Signal Strength Indication (RSSI algorithms are used. This study utilises Wireless Mon tool, software to provide complete technical information regarding received signal strength obtained from different wireless access points available in a campus Wi-Fi environment, considered for the study. All simulations have been done in MATLAB. The target location estimated by this approach agrees well with the actual GPS data.

  5. Fracture Energy Estimation of DCB Specimens Made of Glass/Epoxy: An Experimental Study

    Directory of Open Access Journals (Sweden)

    V. Alfred Franklin


    Full Text Available This paper examines critical load and corresponding displacement of double cantilever beam (DCB composite specimens made of glass/epoxy of three different layups. Experiments were conducted on these laminates, and the fracture energy, GIc, was evaluated considering the root rotation at the crack tip. The present model requires the applied load-displacement history and crack extension to estimate fracture energy. Reduction schemes based on cubic and power law are also proposed to determine Young’s modulus and energy release rate and found good agreement with the published and test results.

  6. Experimental Feasibility Study of Estimation of the Normalized Central Blood Pressure Waveform from Radial Photoplethysmogram

    Directory of Open Access Journals (Sweden)

    Edmond Zahedi


    Full Text Available The feasibility of a novel system to reliably estimate the normalized central blood pressure (CBPN from the radial photoplethysmogram (PPG is investigated. Right-wrist radial blood pressure and left-wrist PPG were simultaneously recorded in five different days. An industry-standard applanation tonometer was employed for recording radial blood pressure. The CBP waveform was amplitude-normalized to determine CBPN. A total of fifteen second-order autoregressive models with exogenous input were investigated using system identification techniques. Among these 15 models, the model producing the lowest coefficient of variation (CV of the fitness during the five days was selected as the reference model. Results show that the proposed model is able to faithfully reproduce CBPN (mean fitness = 85.2% ± 2.5% from the radial PPG for all 15 segments during the five recording days. The low CV value of 3.35% suggests a stable model valid for different recording days.

  7. Media influences on body size estimation in anorexia and bulimia. An experimental study. (United States)

    Hamilton, K; Waller, G


    Anorexic and bulimic women overestimate their body sizes substantially more than comparison women, but little is known about the factors that influence this overestimation. This study examined the influence of media portrayal of idealized female bodies in women's fashion magazines. Comparison women were not affected by the nature of the photographs that they saw, but eating-disordered women were--they overestimated more when they had seen the pictures of women than when they saw photographs of neutral objects.

  8. On the conditional logistic estimator in two-arm experimental studies with non-compliance and before-after binary outcomes. (United States)

    Bartolucci, Francesco


    The behavior of the conditional logistic estimator is analyzed under a causal model for two-arm experimental studies with possible non-compliance in which the effect of the treatment is measured by a binary response variable. We show that, when non-compliance may only be observed in the treatment arm, the effect (measured on the logit scale) of the treatment on compliers and that of the control on non-compliers can be identified and consistently estimated under mild conditions. The same does not happen for the effect of the control on compliers. A simple correction of the conditional logistic estimator is then proposed, which allows us to considerably reduce the bias in estimating this quantity and the causal effect of the treatment over control on compliers. A two-step estimator results on the basis of which we can also set up a Wald test for the hypothesis of absence of a causal effect of the treatment. The asymptotic properties of the estimator are studied by exploiting the general theory on maximum likelihood estimation of misspecified models. Finite-sample properties of the estimator and of the related Wald test are studied by simulation. The extension of the approach to the case of missing responses is also outlined. The approach is illustrated by an application to a dataset deriving from a study on the efficacy of a training course on the breast self examination practice. Copyright (c) 2010 John Wiley & Sons, Ltd.

  9. Experimental study on the method of estimating the vertical design wave force acting on a submerged dual horizontal plate

    Directory of Open Access Journals (Sweden)

    Hyuck-Min Kweon


    Full Text Available A steel-type breakwater that uses a submerged dual horizontal porous plate was originally proposed by Kweon et al. (2005, and its hydrodynamic characteristics and design methodology were investigated in a series of subsequent researches. In particular, Kweon et al. (2011 proposed a method of estimating the vertical uplift force that acts on the horizontal plate, applicable to the design of the pile uplift drag force. However, the difference between the method proposed by Kweon et al. (2011, and the wave force measured at a different time without a phase difference, have not yet been clearly analyzed. In this study, such difference according to the method of estimating the wave force was analyzed, by measuring the wave pressure acting on a breakwater model. The hydraulic model test was conducted in a two-dimensional wave flume of 60.0 m length, 1.5 m height and 1.0 m width. The steepness range of the selected waves is 0.01~0.03, with regular and random signals. 20 pressure gauges were used for the measurement. The analysis results showed that the wave force estimate in the method of Kweon et al. (2011 was smaller than the wave force calculated from the maximum pressure at individual points, under a random wave action. Meanwhile, the method of Goda (1974 that was applied to the horizontal plate produced a smaller wave force, than the method of Kweon et al. (2011. The method of Kweon (2011 was already verified in the real sea test of Kweon et al. (2012, where the safety factor of the pile uplift force was found to be greater than 2.0. Based on these results, it was concluded that the method of estimating the wave force by Kweon et al. (2011 can be satisfactorily used for estimating the uplift force of a pile.

  10. Cost estimate of initial SSC experimental equipment

    Energy Technology Data Exchange (ETDEWEB)



    The cost of the initial detector complement at recently constructed colliding beam facilities (or at those under construction) has been a significant fraction of the cost of the accelerator complex. Because of the complexity of large modern-day detectors, the time-scale for their design and construction is comparable to the time-scale needed for accelerator design and construction. For these reasons it is appropriate to estimate the cost of the anticipated detector complement in parallel with the cost estimates of the collider itself. The fundamental difficulty with this procedure is that, whereas a firm conceptual design of the collider does exist, comparable information is unavailable for the detectors. Traditionally, these have been built by the high energy physics user community according to their perception of the key scientific problems that need to be addressed. The role of the accelerator laboratory in that process has involved technical and managerial coordination and the allocation of running time and local facilities among the proposed experiments. It seems proper that the basic spirit of experimentation reflecting the scientific judgment of the community should be preserved at the SSC. Furthermore, the formal process of initiation of detector proposals can only start once the SSC has been approved as a construction project and a formal laboratory administration put in place. Thus an ad hoc mechanism had to be created to estimate the range of potential detector needs, potential detector costs, and associated computing equipment.

  11. Experimental Wind Field Estimation and Aircraft Identification


    Condomines, Jean-Philippe; Bronz, Murat; Hattenberger, Gautier; Erdelyi, Jean-François


    International audience; The presented work is focusing on the wind estimation and airframe identification based on real flight experiments as part of the SkyScanner project. The overall objective of this project is to estimate the local wind field in order to study the formation of cumulus-type clouds with a fleet of autonomous mini-UAVs involving many aspects including flight control and energy harvesting. For this purpose, a small UAV has been equipped with airspeed and angle of attack sens...

  12. Firing distance estimation through the analysis of the gunshot residue deposit pattern around the bullet entrance hole by inductively coupled plasma-mass spectrometry: an experimental study. (United States)

    Santos, Agostinho; Magalhães, Teresa; Vieira, Duarte Nuno; Almeida, Agostinho A; Sousa, António V


    The use of inductively coupled plasma-mass spectrometry (ICP-MS) in the study of gunshot residues (GSR) is relatively recent, and only a few studies have been published on the subject. In the present paper, this instrumental technique has been used to study the deposit pattern of the GSR around the bullet entrance hole, through the analysis of antimony (Sb), barium (Ba), and lead (Pb). The data obtained were used to establish a mathematical model for estimating the firing distance. Test shots using a 6.35-mm pistol were made against a target of cotton tissue, and the amounts of Sb, Ba, and Pb deposited in quadrangular pieces of the target, cut from 4 radial positions, were determined by ICP-MS. In these experimental conditions, it was possible to estimate the firing distance on the interval [20-80] cm. The best linear correlation between ln m and d, where m is the mass of Sb, Ba, or Pb in the samples, expressed in mug/g of target tissue, and d the firing distance, was obtained at radial distances between 3.5 cm and 4.5 cm from the entrance hole. The best regression curve which adjusted to the data was a linear multiple regression between the firing distance and the logarithm of the mass of each element: d = a + b(1)X(1) + b(2)X(2) + b(3)X(3), where X(1) = ln m (Sb), X(2) = ln m(Ba) and X(3) = ln m (Pb). The accuracy of firing distance estimation using only 1 or 2 elements was not significantly different from the one obtained with the 3 elements.

  13. Theoretical and experimental estimates of the Peierls stress

    CSIR Research Space (South Africa)

    Nabarro, FRN


    Full Text Available an error of a factor of 2 in this exponent in Peierls's original estimate. A revised estimate by Huntington introduced a further factor of 2. Three experimental estimates are available, from the Bordoni peaks (which agrees with the Huntington theory), from...

  14. Experimental Demonstration of a Cheap and Accurate Phase Estimation (United States)

    Rudinger, Kenneth; Kimmel, Shelby; Lobser, Daniel; Maunz, Peter


    We demonstrate an experimental implementation of robust phase estimation (RPE) to learn the phase of a single-qubit rotation on a trapped Yb+ ion qubit. We show this phase can be estimated with an uncertainty below 4 ×10-4 rad using as few as 176 total experimental samples, and our estimates exhibit Heisenberg scaling. Unlike standard phase estimation protocols, RPE neither assumes perfect state preparation and measurement, nor requires access to ancillae. We crossvalidate the results of RPE with the more resource-intensive protocol of gate set tomography.

  15. Experimental investigation of synthetic aperture flow angle estimation

    DEFF Research Database (Denmark)

    Oddershede, Niels; Jensen, Jørgen Arendt


    -correlation as a function of velocity and angle. This paper presents an experimental investigation of this velocity angle estimation method based on a set of synthetic aperture flow data measured using our RASMUS experimental ultrasound system. The measurements are performed for flow angles of 60, 75, and 90 deg...... for the experiments, and the emitted pulse is a 20 micro sec. chirp, linearly sweeping frequencies from approximately 3.5 to 10.5 MHz. The flow angle could be estimated with an average bias up to 5.0 deg., and a average standard deviation between 0.2 deg. and 5.2 deg. Using the angle estimates, the velocity...

  16. Assessing Methods for Generalizing Experimental Impact Estimates to Target Populations (United States)

    Kern, Holger L.; Stuart, Elizabeth A.; Hill, Jennifer; Green, Donald P.


    Randomized experiments are considered the gold standard for causal inference because they can provide unbiased estimates of treatment effects for the experimental participants. However, researchers and policymakers are often interested in using a specific experiment to inform decisions about other target populations. In education research,…

  17. Experimental Bayesian Quantum Phase Estimation on a Silicon Photonic Chip. (United States)

    Paesani, S; Gentile, A A; Santagati, R; Wang, J; Wiebe, N; Tew, D P; O'Brien, J L; Thompson, M G


    Quantum phase estimation is a fundamental subroutine in many quantum algorithms, including Shor's factorization algorithm and quantum simulation. However, so far results have cast doubt on its practicability for near-term, nonfault tolerant, quantum devices. Here we report experimental results demonstrating that this intuition need not be true. We implement a recently proposed adaptive Bayesian approach to quantum phase estimation and use it to simulate molecular energies on a silicon quantum photonic device. The approach is verified to be well suited for prethreshold quantum processors by investigating its superior robustness to noise and decoherence compared to the iterative phase estimation algorithm. This shows a promising route to unlock the power of quantum phase estimation much sooner than previously believed.

  18. Experimental investigation of transverse flow estimation using transverse oscillation

    DEFF Research Database (Denmark)

    Udesen, Jesper; Jensen, Jørgen Arendt


    Conventional ultrasound scanners can only display the blood velocity component parallel to the ultrasound beam. Introducing a laterally oscillating field gives signals from which the transverse velocity component can be estimated using 2:1 parallel receive beamformers. To yield the performance...... with a mean relative bias of 6.3% and a mean relative standard deviation of 5.4% over the entire vessel length. With the experimental ultrasound scanner RASMUS the simulations are reproduced in an experimental flow phantom using a linear array transducer and vessel characteristics as in the simulations....... The flow is generated with the Compuflow 1000 programmable flow pump giving a parabolic velocity profile of the blood mimicking fluid in the flow phantom. The profiles are estimated for 310 trials each containing of 32 data vectors. The relative mean bias over entire blood vessel is found to be 10...

  19. UAV-based Estimation of Carbon Exports from Heterogeneous Soil Landscapes - A Case Study from the CarboZALF Experimental Area (United States)

    Wehrhan, Marc; Rauneker, Philipp; Sommer, Michael


    The advantages of remote sensing using Unmanned Aerial Vehicles (UAVs) are a high spatial resolution of images, temporal flexibility and narrow-band spectral data from different wavelengths domains. This enables the detection of spatio-temporal dynamics of environmental variables, like plant-related carbon dynamics in agricultural landscapes. In this paper we quantify spatial patterns of fresh phytomass and related carbon (C) export using imagery captured by a 12-band multispectral camera mounted on the fixed wing UAV Carolo P360. The study was performed in 2014 at the experimental area CarboZALF-D in NE Germany. From radiometrically corrected and calibrated images of lucerne (Medicago sativa), the performance of four commonly used vegetation indices (VIs) was tested using band combinations of six near-infrared bands. The highest correlation (R² = 0.88) between ground-based measurements of fresh phytomass of lucerne and VIs was obtained for the Enhanced Vegetation Index (EVI) using near-infrared band 11 (899 nm). The resulting map was transformed into dry phytomass and finally upscaled to total C export by harvest. The observed spatial variability (75-225 g C m-2) at field- and plot-scale could be attributed to small-scale soil heterogeneity in part. Soil effects were suppressed by the nearly optimal weather conditions for plant growth in 2014.

  20. UAV-Based Estimation of Carbon Exports from Heterogeneous Soil Landscapes—A Case Study from the CarboZALF Experimental Area (United States)

    Wehrhan, Marc; Rauneker, Philipp; Sommer, Michael


    The advantages of remote sensing using Unmanned Aerial Vehicles (UAVs) are a high spatial resolution of images, temporal flexibility and narrow-band spectral data from different wavelengths domains. This enables the detection of spatio-temporal dynamics of environmental variables, like plant-related carbon dynamics in agricultural landscapes. In this paper, we quantify spatial patterns of fresh phytomass and related carbon (C) export using imagery captured by a 12-band multispectral camera mounted on the fixed wing UAV Carolo P360. The study was performed in 2014 at the experimental area CarboZALF-D in NE Germany. From radiometrically corrected and calibrated images of lucerne (Medicago sativa), the performance of four commonly used vegetation indices (VIs) was tested using band combinations of six near-infrared bands. The highest correlation between ground-based measurements of fresh phytomass of lucerne and VIs was obtained for the Enhanced Vegetation Index (EVI) using near-infrared band b899. The resulting map was transformed into dry phytomass and finally upscaled to total C export by harvest. The observed spatial variability at field- and plot-scale could be attributed to small-scale soil heterogeneity in part. PMID:26907284

  1. UAV-Based Estimation of Carbon Exports from Heterogeneous Soil Landscapes--A Case Study from the CarboZALF Experimental Area. (United States)

    Wehrhan, Marc; Rauneker, Philipp; Sommer, Michael


    The advantages of remote sensing using Unmanned Aerial Vehicles (UAVs) are a high spatial resolution of images, temporal flexibility and narrow-band spectral data from different wavelengths domains. This enables the detection of spatio-temporal dynamics of environmental variables, like plant-related carbon dynamics in agricultural landscapes. In this paper, we quantify spatial patterns of fresh phytomass and related carbon (C) export using imagery captured by a 12-band multispectral camera mounted on the fixed wing UAV Carolo P360. The study was performed in 2014 at the experimental area CarboZALF-D in NE Germany. From radiometrically corrected and calibrated images of lucerne (Medicago sativa), the performance of four commonly used vegetation indices (VIs) was tested using band combinations of six near-infrared bands. The highest correlation between ground-based measurements of fresh phytomass of lucerne and VIs was obtained for the Enhanced Vegetation Index (EVI) using near-infrared band b899. The resulting map was transformed into dry phytomass and finally upscaled to total C export by harvest. The observed spatial variability at field- and plot-scale could be attributed to small-scale soil heterogeneity in part.

  2. UAV-Based Estimation of Carbon Exports from Heterogeneous Soil Landscapes—A Case Study from the CarboZALF Experimental Area

    Directory of Open Access Journals (Sweden)

    Marc Wehrhan


    Full Text Available The advantages of remote sensing using Unmanned Aerial Vehicles (UAVs are a high spatial resolution of images, temporal flexibility and narrow-band spectral data from different wavelengths domains. This enables the detection of spatio-temporal dynamics of environmental variables, like plant-related carbon dynamics in agricultural landscapes. In this paper, we quantify spatial patterns of fresh phytomass and related carbon (C export using imagery captured by a 12-band multispectral camera mounted on the fixed wing UAV Carolo P360. The study was performed in 2014 at the experimental area CarboZALF-D in NE Germany. From radiometrically corrected and calibrated images of lucerne (Medicago sativa, the performance of four commonly used vegetation indices (VIs was tested using band combinations of six near-infrared bands. The highest correlation between ground-based measurements of fresh phytomass of lucerne and VIs was obtained for the Enhanced Vegetation Index (EVI using near-infrared band b899. The resulting map was transformed into dry phytomass and finally upscaled to total C export by harvest. The observed spatial variability at field- and plot-scale could be attributed to small-scale soil heterogeneity in part.

  3. Effects of Experimental Conditions on Estimation Uncertainty of Weibull Distribution: Applications for Crack Initiation Testing

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jae Phil; Bahn, Chi Bum [Pusan National University, Busan (Korea, Republic of)


    It is well known that stress corrosion cracking (SCC) is one of the main material-related issues in operating nuclear reactors. To predict the initiation time of SCC, the Weibull distribution is widely used as a statistical model representing SCC reliability. The typical experimental procedure of an SCC initiation test involves an interval-censored cracking test with several specimens. From the result of the test, the experimenters can estimate the parameters of Weibull distribution by maximum likelihood estimation (MLE) or median rank regression (MRR). However, in order to obtain the sufficient accuracy of the Weibull estimators, it is hard for experimenters to determine the proper number of test specimens and censoring intervals. Therefore, in this work, the effects of some experimental conditions on estimation uncertainties of Weibull distribution were studied through the Monte Carlo simulation. The main goal of this work is to suggest quantitative estimation uncertainties for experimenters who want to develop probabilistic SCC initiation model by a cracking test. Widely used MRR and MLE are considered as estimation methods of Weibull distribution. By using a Monte Carlo simulation, uncertainties of MRR and ML estimators were quantified in various experimental cases. And we compared the uncertainties between the TDCI and TICI cases.

  4. Theoretical and Experimental Investigation of Force Estimation Errors Using Active Magnetic Bearings with Embedded Hall Sensors

    DEFF Research Database (Denmark)

    Voigt, Andreas Jauernik; Santos, Ilmar


    to ∼ 20% of the nominal air gap the force estimation error is found to be reduced by the linearized force equation as compared to the quadratic force equation, which is supported by experimental results. Additionally the FE model is employed in a comparative study of the force estimation error behavior...... of AMBs by embedding Hall sensors instead of mounting these directly on the pole surfaces, force estimation errors are investigated both numerically and experimentally. A linearized version of the conventionally applied quadratic correspondence between measured Hall voltage and applied AMB force...

  5. Experimental FSO network availability estimation using interactive fog condition monitoring (United States)

    Turán, Ján.; Ovseník, Łuboš


    Free Space Optics (FSO) is a license free Line of Sight (LOS) telecommunication technology which offers full duplex connectivity. FSO uses infrared beams of light to provide optical broadband connection and it can be installed literally in a few hours. Data rates go through from several hundreds of Mb/s to several Gb/s and range is from several 100 m up to several km. FSO link advantages: Easy connection establishment, License free communication, No excavation are needed, Highly secure and safe, Allows through window connectivity and single customer service and Compliments fiber by accelerating the first and last mile. FSO link disadvantages: Transmission media is air, Weather and climate dependence, Attenuation due to rain, snow and fog, Scattering of laser beam, Absorption of laser beam, Building motion and Air pollution. In this paper FSO availability evaluation is based on long term measured data from Fog sensor developed and installed at TUKE experimental FSO network in TUKE campus, Košice, Slovakia. Our FSO experimental network has three links with different physical distances between each FSO heads. Weather conditions have a tremendous impact on FSO operation in terms of FSO availability. FSO link availability is the percentage of time over a year that the FSO link will be operational. It is necessary to evaluate the climate and weather at the actual geographical location where FSO link is going to be mounted. It is important to determine the impact of a light scattering, absorption, turbulence and receiving optical power at the particular FSO link. Visibility has one of the most critical influences on the quality of an FSO optical transmission channel. FSO link availability is usually estimated using visibility information collected from nearby airport weather stations. Raw data from fog sensor (Fog Density, Relative Humidity, Temperature measured at each ms) are collected and processed by FSO Simulator software package developed at our Department. Based


    African Journals Online (AJOL)


    The study of thermal and ventilation parameters, obtained in a transient, laminar solar chimney of reduced dimensions, (1 < m <3) m with a square collector (side = 2m) is presented. Experimental measurements has been made to determine the temperature of the absorber and the fluid in the collector, it is shown that at the ...

  7. Bias Corrections for Standardized Effect Size Estimates Used with Single-Subject Experimental Designs (United States)

    Ugille, Maaike; Moeyaert, Mariola; Beretvas, S. Natasha; Ferron, John M.; Van den Noortgate, Wim


    A multilevel meta-analysis can combine the results of several single-subject experimental design studies. However, the estimated effects are biased if the effect sizes are standardized and the number of measurement occasions is small. In this study, the authors investigated 4 approaches to correct for this bias. First, the standardized effect…

  8. Experimental study of vortex diffusers

    Energy Technology Data Exchange (ETDEWEB)

    Shakerin, S.; Miller, P.L. [National Renewable Energy Lab., Golden, CO (United States)


    This report documents experimental research performed on vortex diffusers used in ventilation and air-conditioning systems. The main objectives of the research were (1) to study the flow characteristics of isothermal jets issuing from vortex diffusers, (2) to compare the vortex diffuser`s performance with that of a conventional diffuser, and (3) to prepare a report that disseminates the results to the designers of ventilation and air-conditioning systems. The researchers considered three diffusers: a conventional round ceiling diffuser and two different styles of vortex diffusers. Overall, the vortex diffusers create slightly more induction of ambient air in comparison to the conventional diffuser.

  9. Experimental study of snow friction (United States)

    Cohen, Caroline; Canale, Luca; Siria, Alessandro; Quere, David; Bocquet, Lyderic; Clanet, Christophe


    Snow friction results from the interplay of different physical processes: solid friction of granular material, phase change and lubrication, heat transport, capillarity, elasticity and plasticity. The multiple conditions of temperature, humidity and density of the snow result in different regimes of friction. In particular, there is an optimal amount of melted water to lubricate the contact between the ski sole and the snow grains. The thickness of the water layer depends on temperature, speed... A huge variety of waxes have been empirically developed to adapt the amount of water to the conditions of skiing, but remain mysterious. In these study, we investigate experimentally the mechanisms of snow friction at different scales: first, the friction of a ski on snow is measured on a test bench, depending on the snow characteristics and for different waxes. Then microscopic experiments are led in order to understand the friction at the ice crystals scale.

  10. Theoretical and Experimental Estimations of Volumetric Inductive Phase Shift in Breast Cancer Tissue (United States)

    González, C. A.; Lozano, L. M.; Uscanga, M. C.; Silva, J. G.; Polo, S. M.


    Impedance measurements based on magnetic induction for breast cancer detection has been proposed in some studies. This study evaluates theoretical and experimentally the use of a non-invasive technique based on magnetic induction for detection of patho-physiological conditions in breast cancer tissue associated to its volumetric electrical conductivity changes through inductive phase shift measurements. An induction coils-breast 3D pixel model was designed and tested. The model involves two circular coils coaxially centered and a human breast volume centrally placed with respect to the coils. A time-harmonic numerical simulation study addressed the effects of frequency-dependent electrical properties of tumoral tissue on the volumetric inductive phase shift of the breast model measured with the circular coils as inductor and sensor elements. Experimentally; five female volunteer patients with infiltrating ductal carcinoma previously diagnosed by the radiology and oncology departments of the Specialty Clinic for Women of the Mexican Army were measured by an experimental inductive spectrometer and the use of an ergonomic inductor-sensor coil designed to estimate the volumetric inductive phase shift in human breast tissue. Theoretical and experimental inductive phase shift estimations were developed at four frequencies: 0.01, 0.1, 1 and 10 MHz. The theoretical estimations were qualitatively in agreement with the experimental findings. Important increments in volumetric inductive phase shift measurements were evident at 0.01MHz in theoretical and experimental observations. The results suggest that the tested technique has the potential to detect pathological conditions in breast tissue associated to cancer by non-invasive monitoring. Further complementary studies are warranted to confirm the observations.

  11. Stochastic estimation of human shoulder impedance with robots: an experimental design. (United States)

    Park, Kyungbin; Chang, Pyung Hun


    Previous studies assumed the shoulder as a hinge joint during human arm impedance measurement. This is obviously a vast simplification since the shoulder is a complex of several joints with multiple degrees of freedom. In the present work, a practical methodology for more general and realistic estimation of human shoulder impedance is proposed and validated with a spring array. It includes a gravity compensation scheme, which is developed and used for the experiments with a spatial three degrees of freedom PUMA-type robot. The experimental results were accurate and reliable, and thus it has shown a strong potential of the proposed methodology in the estimation of human shoulder impedance. © 2011 IEEE

  12. Fully Bayesian Experimental Design for Pharmacokinetic Studies

    Directory of Open Access Journals (Sweden)

    Elizabeth G. Ryan


    Full Text Available Utility functions in Bayesian experimental design are usually based on the posterior distribution. When the posterior is found by simulation, it must be sampled from for each future dataset drawn from the prior predictive distribution. Many thousands of posterior distributions are often required. A popular technique in the Bayesian experimental design literature, which rapidly obtains samples from the posterior, is importance sampling, using the prior as the importance distribution. However, importance sampling from the prior will tend to break down if there is a reasonable number of experimental observations. In this paper, we explore the use of Laplace approximations in the design setting to overcome this drawback. Furthermore, we consider using the Laplace approximation to form the importance distribution to obtain a more efficient importance distribution than the prior. The methodology is motivated by a pharmacokinetic study, which investigates the effect of extracorporeal membrane oxygenation on the pharmacokinetics of antibiotics in sheep. The design problem is to find 10 near optimal plasma sampling times that produce precise estimates of pharmacokinetic model parameters/measures of interest. We consider several different utility functions of interest in these studies, which involve the posterior distribution of parameter functions.

  13. Experimental Results for Direction of Arrival Estimation with a Single Acoustic Vector Sensor in Shallow Water

    Directory of Open Access Journals (Sweden)

    Alper Bereketli


    Full Text Available We study the performances of several computationally efficient and simple techniques for estimating direction of arrival (DOA of an underwater acoustic source using a single acoustic vector sensor (AVS in shallow water. Underwater AVS is a compact device, which consists of one hydrophone and three accelerometers in a packaged form, measuring scalar pressure and three-dimensional acceleration simultaneously at a single position. A very controlled experimental setup is prepared to test how well-known techniques, namely, arctan-based, intensity-based, time domain beamforming, and frequency domain beamforming methods, perform in estimating DOA of a source in different circumstances. Experimental results reveal that for almost all cases beamforming techniques perform best. Moreover, arctan-based method, which is the simplest of all, provides satisfactory results for practical purposes.

  14. Experimental investigation of transverse velocity estimation using cross-correlation

    DEFF Research Database (Denmark)

    Bjerngaard, Rasmus; Jensen, Jørgen Arendt


    /s. The volume flow was determined by a Danfoss MAG 1100 flow meter. The velocity profiles were measured for different beam-to-flow angles of 90, 65, and 45 degrees. A Harming apodized beam focused at the vessel was transmitted using 64 elements and the received signals on all elements were sampled at 40 MHz......A technique for estimating the full flow velocity vector has previously been presented by our group. Unlike conventional estimators, that only detect the axial component of the flow, this new method is capable of estimating the transverse velocity component. The method uses focusing along the flow...... direction to produce signals that are influenced by the shift of the scatterer's position. The signals are then cross-correllated to find the shift in position and thereby the velocity. The performance of the method is investigated using both a flow phantom and in-vivo measurements. A flow phantom capable...

  15. IC space radiation effects experimental simulation and estimation methods

    CERN Document Server

    Chumakov, A I; Telets, V A; Gerasimov, V F; Yanenko, A V; Sogoyan, A V


    Laboratory test simulation methods are developed for IC response prediction to space radiation. The minimum set of radiation simulators is proposed to investigate IC failures and upsets under space radiation. The accelerated test technique of MOS ICs degradation estimation are developed for low intensity irradiation taking into account temperature variations as well as latent degradation effects. Two-parameter cross section functions are adapted to describe the ion- and proton-induced single event upsets. Non-focused laser irradiation is found to be applicable for single event latchup threshold estimation.

  16. Experimental estimation of mutation rates in a wheat population with a gene genealogy approach. (United States)

    Raquin, Anne-Laure; Depaulis, Frantz; Lambert, Amaury; Galic, Nathalie; Brabant, Philippe; Goldringer, Isabelle


    Microsatellite markers are extensively used to evaluate genetic diversity in natural or experimental evolving populations. Their high degree of polymorphism reflects their high mutation rates. Estimates of the mutation rates are therefore necessary when characterizing diversity in populations. As a complement to the classical experimental designs, we propose to use experimental populations, where the initial state is entirely known and some intermediate states have been thoroughly surveyed, thus providing a short timescale estimation together with a large number of cumulated meioses. In this article, we derived four original gene genealogy-based methods to assess mutation rates with limited bias due to relevant model assumptions incorporating the initial state, the number of new alleles, and the genetic effective population size. We studied the evolution of genetic diversity at 21 microsatellite markers, after 15 generations in an experimental wheat population. Compared to the parents, 23 new alleles were found in generation 15 at 9 of the 21 loci studied. We provide evidence that they arose by mutation. Corresponding estimates of the mutation rates ranged from 0 to 4.97 x 10(-3) per generation (i.e., year). Sequences of several alleles revealed that length polymorphism was only due to variation in the core of the microsatellite. Among different microsatellite characteristics, both the motif repeat number and an independent estimation of the Nei diversity were correlated with the novel diversity. Despite a reduced genetic effective size, global diversity at microsatellite markers increased in this population, suggesting that microsatellite diversity should be used with caution as an indicator in biodiversity conservation issues.

  17. Experimental Infrasound Studies in Nevada (United States)

    Herrin, E. T.; Negraru, P. T.; Golden, P.; Williams, A.


    An experimental propagation study was carried out in Nevada in June 2009 on Julian days 173-177. During this field experiment we deployed 16 single channel digital infrasound recorders to monitor the munitions disposal activities near Hawthorne, NV. The sensors were deployed in a single line and placed approximately 12 km apart at distances ranging from 2 to 177 km. A four element semi-permanent infrasound array named FNIAR was installed approximately 154 km north of the detonation site in line with the individual temporary recorders. Tropospheric arrivals were observed during all days of the experiment, but during day 176 the observed arrivals had very large amplitudes. A large signal was observed at 58 km from the detonation site with amplitude as large as 4 Pascals, while at 94 km no signal was observed. At FNIAR the amplitude of the tropospheric arrival was 1 Pascal. During this day meteorological data acquired in the propagation path showed a strong jet stream to the north. On day 177 we were not able to identify tropospheric arrivals beyond 34 km, but at stations beyond 152 km we observed stratospheric arrivals. Continuous monitoring of these signals at FNIAR shows that stratospheric arrivals are the most numerous. In a two month period, from 06/15/2009 to 08/15/2009 there were 35 operational days at the Hawthorne disposal facility resulting in 212 explosions with known origin times. Based on the celerity values there were 115 explosions that have only stratospheric arrivals (celerities of 300-275 m/s), 72 explosions with both tropospheric (celerities above 330 m/s) and stratospheric arrivals, 20 explosions that were not detected and five explosions that have only tropospheric arrivals.

  18. Comparison of estimated and experimental subaqueous seed transport. (United States)

    Scott Markwith; David Leigh


    We compare the estimates from the relative bed stability (RBS) equation that indicates incipient bed movement, and the inertial settling (‘Impact’) law and Wu and Wang (2006) settling velocity equations that indicate suspended particle movement, to flume and settling velocity observations to confirm the utility of the equations for subaqueous hydrochory analyses, and...


    African Journals Online (AJOL)


    climatic conditions are favorable for the development of solar chimneys for the production of electrical energy or the drying of agro-food products. 1.1 Experimental models. The first prototype tower was built in Manzanares in. 1981, thanks to the team of Professor Schlaich, Haaf et al., (1983); Haaf et al., (1984), in Spain.

  20. Organ models in wound ballistics: experimental study. (United States)

    Ozer, Mustafa Tahir; Oğünç, Gökhan; Eryilmaz, Mehmet; Yiğit, Taner; Menteş, Mustafa Oner; Dakak, Mehmet; Uzar, Ali Ihsan; Oner, Köksal


    Effects of various types and diameters of guns and related treatment principles are different. Our study was performed to experimentally demonstrate the effects of different gunshots in body tissues. 9x19 mm hand-gun and 7.62x51 mm G-3 infantry rifle were used in the study. Injury models were created through hand-gun and rifle shootings at isolated soft tissue, lower extremity, liver and intestine tissue simulants made of ballistic candle. High-speed cameras were used to capture 1000 frames per second. Images were examined and wound mechanisms were evaluated. It was observed that the colon content distributed more within the surrounding tissues by the rifle shootings comparing with hand-gun shootings and could be an infection source due to the large size of the cavity in the colon. Especially when the bullets hitting the bone were investigated, it was seen that much more tissue injury occurs with high speed bullets due to bullet deformation and fragmentation. However, no significant difference was found between the effect of hand-gun and rifle bullets passing through the extremity without hitting the bone. To know the type of the gun that caused the injury and its characteristics will allow to estimate severity and size of the injury before the treatment and to focus on different alternatives of treatment. Therefore, use of appropriate models is required in experimental studies.

  1. Experimental and empirical technique to estimate energy decreasing at heating in an oval furnace

    Directory of Open Access Journals (Sweden)

    A. A. Minea


    Full Text Available In this paper an experimental and empirical methods are proposed to estimate the heat transfer enhancement in industrial heating processes in oval furnaces. An investigation was conducted to study the suitability of inserting radiant panels of different positions and radiation surface. Two case studies were considered. The maximum energy saving was obtained for case 5: 32,89 % off from the standard experiment (with no panels. The minimum energy saving was obtained for case 10: 11,72 % off from the standard experiment (with no panels. Finally, based on the results of this study, a correlation was developed to predict the inner configuration of an oval furnace.

  2. A Transverse Oscillation Approach for Estimation of Three-Dimensional Velocity Vectors, Part II: Experimental Validation

    DEFF Research Database (Denmark)

    Pihl, Michael Johannes; Stuart, Matthias Bo; Tomov, Borislav Gueorguiev


    The 3-D transverse oscillation method is investigated by estimating 3-D velocities in an experimental flowrigsystem. Measurements of the synthesized transverse oscillatingfields are presented as well. The method employs a 2-D transducer; decouples the velocity estimation; and estimates the axial,...

  3. Experimental uncertainty estimation and statistics for data having interval uncertainty.

    Energy Technology Data Exchange (ETDEWEB)

    Kreinovich, Vladik (Applied Biomathematics, Setauket, New York); Oberkampf, William Louis (Applied Biomathematics, Setauket, New York); Ginzburg, Lev (Applied Biomathematics, Setauket, New York); Ferson, Scott (Applied Biomathematics, Setauket, New York); Hajagos, Janos (Applied Biomathematics, Setauket, New York)


    This report addresses the characterization of measurements that include epistemic uncertainties in the form of intervals. It reviews the application of basic descriptive statistics to data sets which contain intervals rather than exclusively point estimates. It describes algorithms to compute various means, the median and other percentiles, variance, interquartile range, moments, confidence limits, and other important statistics and summarizes the computability of these statistics as a function of sample size and characteristics of the intervals in the data (degree of overlap, size and regularity of widths, etc.). It also reviews the prospects for analyzing such data sets with the methods of inferential statistics such as outlier detection and regressions. The report explores the tradeoff between measurement precision and sample size in statistical results that are sensitive to both. It also argues that an approach based on interval statistics could be a reasonable alternative to current standard methods for evaluating, expressing and propagating measurement uncertainties.

  4. Fundamental contradictions among observational and experimental estimates of non-trophic species interactions. (United States)

    Barner, Allison K; Coblentz, Kyle E; Hacker, Sally D; Menge, Bruce A


    The difficulty of experimentally quantifying non-trophic species interactions has long troubled ecologists. Increasingly, a new application of the classic "checkerboard distribution" approach is used to infer interactions by examining the pairwise frequency at which species are found to spatially co-occur. However, the link between spatial associations, as estimated from observational co-occurrence, and species interactions has not been tested. Here we used nine common statistical methods to estimate associations from surveys of rocky intertidal communities in the Northeast Pacific Ocean. We compared those inferred associations with a new data set of experimentally determined net and direct species interactions. Although association methods generated networks with aggregate structure similar to previously published interaction networks, each method detected a different set of species associations from the same data set. Moreover, although association methods generally performed better than a random model, associations rarely matched empirical net or direct species interactions, with high rates of false positives and true positives, and many false negatives. Our findings cast doubt on studies that equate species co-occurrences to species interactions and highlight a persistent, unanswered question: how do we interpret spatial patterns in communities? We suggest future research directions to unify the observational and experimental study of species interactions, and discuss the need for community standards and best practices in association analysis. © 2018 by the Ecological Society of America.

  5. Scaling Factor Estimation Using Optimized Mass Change Strategy, Part 2: Experimental Results

    DEFF Research Database (Denmark)

    Fernández, Pelayo Fernández; Aenlle, Manuel López; Garcia, Luis M. Villa


    of the structure. On the other hand, the aforementioned objectives are difficult to achieve for all modes simultaneously. Thus, a study of the number, magnitude and location of the masses must be performed previously to the modal tests. In this paper, the mass change method was applied to estimate the scaling......The mass change method is used to estimate the scaling factors, the uncertainty is reduced when, for each mode, the frequency shift is maximized and the changes in the mode shapes are minimized, which in turn, depends on the mass change strategy chosen to modify the dynamic behavior...... factors of a steel cantilever beam. The effect of the mass change strategy was experimentally studied by performing several modal tests in which the magnitude, the location and the number of the attached masses were changed....

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

    CERN Document Server

    Berger, Julien; Mendes, Nathan


    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. Experimental study of potential neutron moderator materials (United States)

    Mocko, M.; Daemen, L. L.; Hartl, M. A.; Huegle, Th.; Muhrer, G.


    We present an experimental investigation of thermal neutron energy spectra produced by lead and bismuth hydroxides (Pb(OH) 2, and Bi(OH) 3). The experimental energy spectra are compared with a thermal neutron energy spectrum produced by water measured in the same geometry. We developed an MCNPX geometry model designed to help with the interpretation of the experimental data. We demonstrate a very good reproduction of the experimental thermal neutron energy spectrum produced by the water moderator in our tightly coupled geometry. We study our experimental results for Pb(OH) 2 and Bi(OH) 3 using thermal neutron scattering kernels for hydrogen, bismuth, and lead.


    Directory of Open Access Journals (Sweden)

    Yu. B. Yurasova


    Full Text Available Research is devoted an experimental estimation of osteoinductive properties of demineralized bone implants (DBA made on technology CITO with use of lyophilization and radiating sterilization by stream of fast electrons. As experimental animals, white rats on ectopic osteogenesis model for a period of 40 days and rabbits to which DBA implanted into defect of the jaw with terms of experiment 10, 20, 30, 60 and 90 days have been chosen. Results of morphological researches testified to absence of toxicity, presence of high indicators of biointegration and osteoinductance studied DBA. The offered technology of processing of a bone tissue allows to keep biological activity of tissues and to receive biological materials with the expressed plastic properties. Obtained among other data were the bases for the decision of use of these materials in clinic of different bone pathologies.

  9. Experimental evaluation of regression model-based walking speed estimation using lower body-mounted IMU. (United States)

    Zihajehzadeh, Shaghayegh; Park, Edward J


    This study provides a concurrent comparison of regression model-based walking speed estimation accuracy using lower body mounted inertial sensors. The comparison is based on different sets of variables, features, mounting locations and regression methods. An experimental evaluation was performed on 15 healthy subjects during free walking trials. Our results show better accuracy of Gaussian process regression compared to least square regression using Lasso. Among the variables, external acceleration tends to provide improved accuracy. By using both time-domain and frequency-domain features, waist and ankle-mounted sensors result in similar accuracies: 4.5% for the waist and 4.9% for the ankle. When using only frequency-domain features, estimation accuracy based on a waist-mounted sensor suffers more compared to the one from ankle.

  10. Metabolic Desynchronization in Critical Conditions: Experimental Study

    Directory of Open Access Journals (Sweden)

    G. V. Livanov


    Full Text Available Objective. To conduct an experimental study of the impact of the time of administration of succinic acid preparations on central nervous system (CNS function and gas exchange while simulating metabolic therapy for severe poisoning by ethyl alcohol. The study was performed on 74 male albino rats weighing 140—180 g. Acute severe and very severe intoxication was simulated, by intraabdominally administering 30% ethanol to the rats. Cytoflavin was used to simulate experimental therapy. The rate of gas exchange was estimated by the oxygen uptake determined by the closed chamber method in a Regnault apparatus (Germany. Spontaneous bioelectrical activity was recorded in the frontooccipital lead by the routine procedure. External pain stimulation and rhythmical photostimulation were employed to evaluate cerebral responsiveness. Heterodirectional EEG changes in the «early» and «late» administration of succinate were not followed by the similar alterations of gas exchange: oxygen consumption in both the «early» and «late» administration of succinate remained significantly lower than in the control animals. With the late administration of succinate to the animals with mixed (toxic and hypoxic coma, the so-called discrepancy between the noticeably increased energy production and brutally diminished metabolism occurred. It may be just the pathological mechanism that was the basis for higher mortality in the late succinate administration group. The findings and their analysis make it possible to advance a hypothesis that succinate may cause metabolic desynchronization if activation of metabolic processes takes place under severe tissue respiratory tissue depression. In these cases, there is a severe damage to tissue and chiefly the brain. This manifests itself as EEG epileptiform activity splashes preceding the animals’ death. Therefore, resuscitation aimed at restoring the transport of oxygen and its involvement in tissue energy processes should

  11. Experimental studies of neutrino oscillations

    CERN Document Server

    Kajita, Takaaki


    The 2015 Nobel Prize in physics has been awarded to Takaaki Kajita and Arthur McDonald "for the discovery of neutrino oscillations, which shows that neutrinos have mass". Takaaki Kajita of Tokyo University is a Japanese physicist, known for neutrino experiments at the Kamiokande and its successor, Super-Kamiokande. This volume of collected works of Kajita on neutrino oscillations provides a good glimpse into as well as a record of the rise and the role of Asian research in the frontiers of neutrino physics. Japan is now a major force in the study of the 3 families of neutrinos. Much remains to be done to clarify the Dirac vs. Majorana nature of the neutrino, and the cosmological implications of the neutrino. The collected works of Kajita and his Super-Kamiokande group will leave an indelible foot-print in the history of big and better science.


    Directory of Open Access Journals (Sweden)

    Cuzdriorean Dan Dacian


    Full Text Available This empirical study extends the study conducted by Vladu, Grosanu and Cuzdriorean (2012 and reached similar conclusions. This particular research was conducted with the scope of assessing the impact of: positive bias, persuasive language, creative visual manipulation and performance comparisons over the unsophisticated users of accounting opinion. We have chosen this particular category since retail investors have been identified as relying on the information provided in corporate annual reports for decision making (Wills, 2008. Based on their relative inexperience and limited knowledge of these investors it is plausible that they can be mislead easily comparing to more sophisticated users of accounting information, as financial analysts. The main argument for conducting such a research is the fact that little research was conducted so far and the effects of creative disclosure on investment decision cannot be assessed so far. Based on this, we conducted a laboratory experiment where participants where provided with an informational set of financial data and required to make an investment decision. Our results document that the users perceptions is strongly affected by creative disclosure, contradictory with previous results documented in the literature, that their opinion cannot be influenced since they relay mostly on numerical information and less on the narrative segments of the financial statements. Even if our sample compressed few participants, we consider the results conclusive. A further research can extend the sample and test if our research hypothesis can be validated. Another possible spring of research can deal with the assessing of the opinion of the users of accounting information that are not considered unsophisticated, as financial analysts.

  13. Optimal experimental designs for estimating Henry's law constants via the method of phase ratio variation. (United States)

    Kapelner, Adam; Krieger, Abba; Blanford, William J


    When measuring Henry's law constants (kH) using the phase ratio variation (PRV) method via headspace gas chromatography (GC), the value of kH of the compound under investigation is calculated from the ratio of the slope to the intercept of a linear regression of the inverse GC response versus the ratio of gas to liquid volumes of a series of vials drawn from the same parent solution. Thus, an experimenter collects measurements consisting of the independent variable (the gas/liquid volume ratio) and dependent variable (the GC-1 peak area). A review of the literature found that the common design is a simple uniform spacing of liquid volumes. We present an optimal experimental design which estimates kH with minimum error and provides multiple means for building confidence intervals for such estimates. We illustrate performance improvements of our design with an example measuring the kH for Naphthalene in aqueous solution as well as simulations on previous studies. Our designs are most applicable after a trial run defines the linear GC response and the linear phase ratio to the GC-1 region (where the PRV method is suitable) after which a practitioner can collect measurements in bulk. The designs can be easily computed using our open source software optDesignSlopeInt, an R package on CRAN. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Experimental Studies on the Hypolipidemic and Haematological ...

    African Journals Online (AJOL)



    Jan 14, 2011 ... Experimental Studies on the Hypolipidemic and. Haematological Properties of Aqueous ... lipid and haematological profile of serum and blood samples collected were determined respectively. Results: Treatment with simvastatin (10 ..... pathway for cholesterol homeostasis. Science. (Washington, DC) 1986 ...

  15. Biomass thermochemical gasification: Experimental studies and modeling (United States)

    Kumar, Ajay

    The overall goals of this research were to study the biomass thermochemical gasification using experimental and modeling techniques, and to evaluate the cost of industrial gas production and combined heat and power generation. This dissertation includes an extensive review of progresses in biomass thermochemical gasification. Product gases from biomass gasification can be converted to biopower, biofuels and chemicals. However, for its viable commercial applications, the study summarizes the technical challenges in the gasification and downstream processing of product gas. Corn stover and dried distillers grains with solubles (DDGS), a non-fermentable byproduct of ethanol production, were used as the biomass feedstocks. One of the objectives was to determine selected physical and chemical properties of corn stover related to thermochemical conversion. The parameters of the reaction kinetics for weight loss were obtained. The next objective was to investigate the effects of temperature, steam to biomass ratio and equivalence ratio on gas composition and efficiencies. DDGS gasification was performed on a lab-scale fluidized-bed gasifier with steam and air as fluidizing and oxidizing agents. Increasing the temperature resulted in increases in hydrogen and methane contents and efficiencies. A model was developed to simulate the performance of a lab-scale gasifier using Aspen Plus(TM) software. Mass balance, energy balance and minimization of Gibbs free energy were applied for the gasification to determine the product gas composition. The final objective was to optimize the process by maximizing the net energy efficiency, and to estimate the cost of industrial gas, and combined heat and power (CHP) at a biomass feedrate of 2000 kg/h. The selling price of gas was estimated to be 11.49/GJ for corn stover, and 13.08/GJ for DDGS. For CHP generation, the electrical and net efficiencies were 37 and 86%, respectively for corn stover, and 34 and 78%, respectively for DDGS. For

  16. Optimal experimental design for improving the estimation of growth parameters of Lactobacillus viridescens from data under non-isothermal conditions. (United States)

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


    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

  17. 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)


    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)

  18. Estimation of boundary heat flux using experimental temperature data in turbulent forced convection flow (United States)

    Parwani, Ajit K.; Talukdar, Prabal; Subbarao, P. M. V.


    Heat flux at the boundary of a duct is estimated using the inverse technique based on conjugate gradient method (CGM) with an adjoint equation. A two-dimensional inverse forced convection hydrodynamically fully developed turbulent flow is considered. The simulations are performed with temperature data measured in the experimental test performed on a wind tunnel. The results show that the present numerical model with CGM is robust and accurate enough to estimate the strength and position of boundary heat flux.

  19. ANN Approach for State Estimation of Hybrid Systems and Its Experimental Validation

    Directory of Open Access Journals (Sweden)

    Shijoh Vellayikot


    Full Text Available A novel artificial neural network based state estimator has been proposed to ensure the robustness in the state estimation of autonomous switching hybrid systems under various uncertainties. Taking the autonomous switching three-tank system as benchmark hybrid model working under various additive and multiplicative uncertainties such as process noise, measurement error, process–model parameter variation, initial state mismatch, and hand valve faults, real-time performance evaluation by the comparison of it with other state estimators such as extended Kalman filter and unscented Kalman Filter was carried out. The experimental results reported with the proposed approach show considerable improvement in the robustness in performance under the considered uncertainties.


    African Journals Online (AJOL)


    Jun 30, 2010 ... could supply enough hydrogen to operate a fuel cell vehicle. In our study [23] an experimental study is done in the Center of Development of the Renewable Energy,. Algiers, Algeria; hydrogen is produced using a Proton Exchange Membrane (PEM) electrolyser supplied by PV panel; when an electric ...

  1. Experimental study on the wall jet over a riblet surface. ; Measurement of mean and fluctuating velocities and estimation of drag reduction. Riburetto men ni sou hekimen funryu ni kansuru jikkenteki kenkyu. ; Heikin-hendo sokudoba to teiko gensho no hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Yamashita, S. (Gifu Univ., Gifu (Japan). Faculty of Engineering); Hayashimoto, H. (Gifu Univ., Gifu (Japan). Graduate School); Inoue, Y. (Suzuka National College of Technology, Mie (Japan)); Iwakami, Y.


    A wall-jet has a wide range of application such as to control of the boundary layer of a wing of an aeroplane, control of temperature of the vanes of a gas turbine and flow inside a fluid control device. This field of flow comprises a wall layer on the wall side having the characteristics of a boundary layer and an outer layer on the external side which is like a free jet, the two layers being separated by a boundary where the flow is at a maximum speed. This study was carried out to clarify the effect of riblets experimentally using as a base jet a wall jet which was one of basic shearing flows. In particular, studied were the degrees of change in the mean and fluctuating velocities near the wall surface and reduction of drag. The following results were obtained. A significant difference was recognized in the vicinity of the wall in the mean velocity distribution between the mean velocities on the riblet surface and on the smooth surface. The fluctuating velocity component in the x direction on the riblet surface decreased by about a maximum of 20% when compared with that on the smooth surface. In contrast, the fluctuating velocity in the y direction and Reynolds shearing stress both on the riblet and smooth surfaces were substantially in agreement with each other within the range of this experiment. 28 refs., 12 figs., 1 tab.

  2. An experimental case study to estimate Pre-harvest Wheat Acreage/Production in Hilly and Plain region of Uttarakhand state: Challenges and solutions of problems by using satellite data (United States)

    Uniyal, D.; Kimothi, M. M.; Bhagya, N.; Ram, R. D.; Patel, N. K.; Dhaundiya, V. K.


    Wheat is an economically important Rabi crop for the state, which is grown on around 26 % of total available agriculture area in the state. There is a variation in productivity of wheat crop in hilly and tarai region. The agricultural productivity is less in hilly region in comparison of tarai region due to terrace cultivation, traditional system of agriculture, small land holdings, variation in physiography, top soil erosion, lack of proper irrigation system etc. Pre-harvest acreage/yield/production estimation of major crops is being done with the help of conventional crop cutting method, which is biased, inaccurate and time consuming. Remote Sensing data with multi-temporal and multi-spectral capabilities has shown new dimension in crop discrimination analysis and acreage/yield/production estimation in recent years. In view of this, Uttarakhand Space Applications Centre (USAC), Dehradun with the collaboration of Space Applications Centre (SAC), ISRO, Ahmedabad and Uttarakhand State Agriculture Department, have developed different techniques for the discrimination of crops and estimation of pre-harvest wheat acreage/yield/production. In the 1st phase, five districts (Dehradun, Almora, Udham Singh Nagar, Pauri Garhwal and Haridwar) with distinct physiography i.e. hilly and plain regions, have been selected for testing and verification of techniques using IRS (Indian Remote Sensing Satellites), LISS-III, LISS-IV satellite data of Rabi season for the year 2008-09 and whole 13 districts of the Uttarakhand state from 2009-14 along with ground data were used for detailed analysis. Five methods have been developed i.e. NDVI (Normalized Differential Vegetation Index), Supervised classification, Spatial modeling, Masking out method and Programming on visual basics methods using multitemporal satellite data of Rabi season along with the collateral and ground data. These methods were used for wheat discriminations and preharvest acreage estimations and subsequently results

  3. Optimal experimental design to estimate statistically significant periods of oscillations in time course data.

    Directory of Open Access Journals (Sweden)

    Márcio Mourão

    Full Text Available We investigated commonly used methods (Autocorrelation, Enright, and Discrete Fourier Transform to estimate the periodicity of oscillatory data and determine which method most accurately estimated periods while being least vulnerable to the presence of noise. Both simulated and experimental data were used in the analysis performed. We determined the significance of calculated periods by applying these methods to several random permutations of the data and then calculating the probability of obtaining the period's peak in the corresponding periodograms. Our analysis suggests that the Enright method is the most accurate for estimating the period of oscillatory data. We further show that to accurately estimate the period of oscillatory data, it is necessary that at least five cycles of data are sampled, using at least four data points per cycle. These results suggest that the Enright method should be more widely applied in order to improve the analysis of oscillatory data.

  4. Laparoscopic ureterocalicostomy in pigs - experimental study


    Caldas, Paulo Fernando de Oliveira; Rocha, Luiz Carlos de Almeida; Oliveira, Marília Teresa de; Ataíde, Michelli Westphal de; Spagnolo, Julio David; Feranti, João Pedro Scussel; Souza, Fernando Wiecheteck de; Silva, Marco Augusto Machado; Brun, Maurício Veloso


    This study aimed to evaluated laparoscopic ureterocalicostomy as treatment of experimental ureteropelvic junction (UPJ) obstruction in pigs. Ten male Large White pigs weighting approximately 28.4 (±1.43) kg were used in the current study. The UPJ obstruction was created laparoscopically by double-clipping of the left ureter. After 14 days the animals underwent laparoscopic ureterocalicostomy f The animals were sacrificed for subsequent retrograde pyelography in order to assess the anastomotic...

  5. Feasibility study of the AOSTA experimental campaign

    Directory of Open Access Journals (Sweden)

    Carta M.


    Full Text Available The reduction of the nuclear waste is one of the most important nuclear issues. The high radiotoxicity of the spent fuel is due to plutonium and some minor actinides (MAs such as neptunium, americium and curium, above all. One way to reduce their hazard is to destroy by fission MAs in appropriate nuclear reactors. To allow the MAs destruction an important effort have been done on the nuclear data due to the poor knowledge in this field. In the framework of one of the NEA Expert Group on Integral Experiments for Minor Actinide Management an analysis of the feasibility of MAs irradiation campaign in the TAPIRO fast research reactor is carried out. This paper provides preliminary results obtained by calculations modelling the irradiation, in different TAPIRO irradiation channels, of some CEA samples coming from the French experimental campaign OSMOSE, loaded with different contents of MAs, in order to access, through particular peak spectrometry, to their capture cross section. On the basis of neutron transport calculation results, obtained by both deterministic and Monte Carlo methods, an estimate of the irradiated samples counting levels from the AOSTA (Activation of OSMOSE Samples in TAPIRO experimental campaign is provided.

  6. Experimental and computational study of thaumasite structure

    Energy Technology Data Exchange (ETDEWEB)

    Scholtzová, Eva, E-mail: [Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 36 Bratislava (Slovakia); Kucková, Lenka; Kožíšek, Jozef [Department of Physical Chemistry, Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 812 37 Bratislava (Slovakia); Pálková, Helena [Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 36 Bratislava (Slovakia); Tunega, Daniel [Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 36 Bratislava (Slovakia); Institute for Soil Science, University of Natural Resources and Life Sciences, Peter-Jordanstrasse 82, A-1190 Wien (Austria)


    The structure of thaumasite has been studied experimentally by means of a single crystal X-ray diffraction and FTIR methods, and theoretically using density functional theory (DFT) method. Very good agreement was achieved between calculated and experimental structural parameters. In addition, calculations offered the refinement of the positions of the hydrogen atoms. The detailed analysis of the hydrogen bonds existing in the thaumasite structure has been performed. Several types of hydrogen bonds have been classified. The water molecules coordinating Ca{sup 2+} cation act as proton donors in moderate O-H···O hydrogen bonds formed with CO₃⁻²and SO₄⁻² anions. The multiple O-H···O hydrogen bonds exist among water molecules themselves. Finally, relatively weak hydrogen bonds form water molecules with the OH groups from the coordination sphere of the Si(OH)₆⁻² anion. Further, calculated vibrational spectrum allowed complete assignment of all vibrational modes which are not available from the experimental spectrum that has a complex structure with overlapped bands, especially below 1500 cm⁻¹. Highlights: • The thaumasite structure was studied experimentally and using DFT method. • We used DFT method for the refinement of the positions of hydrogen atoms. • A detailed analysis of the hydrogen bonds was done. • A complete assignment of all bands to particular types of vibrations was done.


    Directory of Open Access Journals (Sweden)

    P.M. Udiyani


    Full Text Available Experimental power reactor (RDE which is planned to be constructed by BATAN is a kind of High Temperature Gas Cooled Reactor (HTGR with 10 MWth power. HTGR is a helium gas-cooled reactor with TRISO-coated fuel that is able to confine fission products remained in the core. Although the fission products released into the environment are very small, in order to comply the regulations the study about environmental radiation on normal or routine operation condition need to be performed. Estimation of radiology in the environment involves the source term released into the environment under routine operation condition. The purpose of this study is to estimate the source term released into the environment based on postulation of normal or routine operations of RDE. The research approach starts with an assumption that there are defects and impurities in the TRISO fuel because of limitation during the fabrication. Mechanism of fission products release from the fuel to the environment was created based on the safety features design of RDE. Radionuclides inventories in the reactor were calculated using ORIGEN-2 whose library has been modified for HTGR type, and the assumptions of defects of the TRISO fuel and release fraction for each compartment of RDE safety system used a reference parameter. The results showed that the important source terms of RDE are group of noble gases (Kr and Xe, halogen (I, Sr, Cs, H-3, and Ag. Activities of RDE source terms for routine operations have no significant difference with the HTGR source terms with the same power. Keywords: routine discharge, radionuclide, source term, RDE, HTGR

  8. Cost and schedule estimation study report (United States)

    Condon, Steve; Regardie, Myrna; Stark, Mike; Waligora, Sharon


    This report describes the analysis performed and the findings of a study of the software development cost and schedule estimation models used by the Flight Dynamics Division (FDD), Goddard Space Flight Center. The study analyzes typical FDD projects, focusing primarily on those developed since 1982. The study reconfirms the standard SEL effort estimation model that is based on size adjusted for reuse; however, guidelines for the productivity and growth parameters in the baseline effort model have been updated. The study also produced a schedule prediction model based on empirical data that varies depending on application type. Models for the distribution of effort and schedule by life-cycle phase are also presented. Finally, this report explains how to use these models to plan SEL projects.

  9. Experimental Study on Permeability of Concrete (United States)

    Yang, Honglu; Liu, Rentai; Zheng, Zhuo; Liu, Haojie; Gao, Yan; Liu, Yankai


    To study the influencing factors on permeability of pervious concrete, by adding inorganic organic composite materials obtained experimental results show that different aggregate size, aggregate cement ratio of different, different water cement ratio on the permeability performance. The permeability of the concrete was tested by using the self - made permeable device. The experimental results showed that the permeation coefficient of the experiment was obtained and the factors influencing the permeability of the concrete were compared and analyzed. At the same time, the porosity of pervious concrete was measured, the influence of various variables on porosity was studied, and the influence of various factors on the permeability of voids was found. Finally, through comprehensive analysis of a variety of factors, the optimal water cement ratio is 0.28. At this time, the pervious performance of concrete is optimal.

  10. Experimental studies on transitional separated boundary layers


    Serna Serrano, José


    Separated transitional boundary layers appear on key aeronautical processes such as the flow around wings or turbomachinery blades. The aim of this thesis is the study of these flows in representative scenarios of technological applications, gaining knowledge about phenomenology and physical processes that occur there and, developing a simple model for scaling them. To achieve this goal, experimental measurements have been carried out in a low speed facility, ensuring the flow homogeneity and...

  11. Do Choice Experiments Generate Reliable Willingness to Pay Estimates Theory and Experimental Evidence (United States)


    paper we set up a three-stage experimental and theoretical framework to investigate strategic behaviour and design induced status quo bias in choice...enable researchers to estimate the potential economic benefits from the good or program being valued as well as consumers ’ willingness to pay (WTP) for...various attributes of the good or program. Initially applied to problems in marketing (Louviere and Woodworth 1983), the methodology has been

  12. Estimating Intervention Effects across Different Types of Single-Subject Experimental Designs: Empirical Illustration (United States)

    Moeyaert, Mariola; Ugille, Maaike; Ferron, John M.; Onghena, Patrick; Heyvaert, Mieke; Beretvas, S. Natasha; Van den Noortgate, Wim


    The purpose of this study is to illustrate the multilevel meta-analysis of results from single-subject experimental designs of different types, including AB phase designs, multiple-baseline designs, ABAB reversal designs, and alternating treatment designs. Current methodological work on the meta-analysis of single-subject experimental designs…

  13. Experimental holographic movie to estimate picture quality for holographic television (III) (United States)

    Higuchi, Kazuhito; Ishikawa, Jun; Hiyama, Shigeo


    Holographic movies can be seen as a tool to estimate the picture quality of moving holographic images as a step towards holographic television. The authors have previously developed two versions of an experimental holographic movie system, and this paper is a report on an improved version 3 of the system. The new version features a newly-developed recording system which utilizes a pulsed Nd:YAG laser with an injection seeder, and an automatic film driver unit which moves perforated 35 mm holographic film intermittently. The system is mounted on a dolly to which a hydraulic lifter is attached. A twin diamond-shaped hologram format, developed for an earlier version of the system, is adopted for the films. After the films are developed, they are driven intermittently with a shutter, illuminated by the LD pumped CW Nd:YAG laser, and viewed through twin diamond-shaped windows. This version 3 system makes it possible to record live scenes, including those of the human body, flowing liquids, smoke, etc., which was impossible in the version 1 and version 3 systems. As a consequence, the characteristics of holographic 3D images with motion can be studied over an area covered by both eyes, and the labor required of animators in taking holograms is greatly reduced.

  14. Experimental 3-D Vector Velocity Estimation with Row-Column Addressed Arrays

    DEFF Research Database (Denmark)

    Holbek, Simon; Stuart, Matthias Bo; Jensen, Jørgen Arendt


    Experimental 3-D vector flow estimates obtained with a 62+62 2-D row-column (RC) array with integrated apodization are presented. A transverse oscillation (TO) velocity estimator is implemented on a 3.0 MHz RC array, to yield realtime 3-D vector flow in a cross-sectional scan plane at 750 frames...... rates. The flow rate measured from five cycles is 2.3 mL/stroke ± 0.1 mL/stroke giving a negative 9.7% bias compared to the pump settings. It is concluded that 124 elements are sufficient to estimate 3-D vector flow, if they are positioned in a row-column wise manner....

  15. Experimental study of natural circulation circuit

    Energy Technology Data Exchange (ETDEWEB)

    Lemos, Wanderley F.; Su, Jian, E-mail:, E-mail: [Coordenacao dos Programas de Pos-Graduacao de Engenharia (LASME/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Simulacao e Metodos Numericos; Faccini, Jose L.H., E-mail: [Instituto de Engenharia Nuclear (LTE/IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. de Termo-Hidraulica Experimental


    This work presents an experimental study about fluid flows behavior in natural circulation, under conditions of single-phase flow. The experiment was performed through experimental thermal-hydraulic circuit built at IEN. This test equipment has performance similar to passive system of residual heat removal present in Advanced Pressurized Water Reactors (APWR). This experimental study aims to observing and analyzing the natural circulation phenomenon, using this experimental circuit that was dimensioned and built based on concepts of similarity and scale. This philosophy allows the analysis of natural circulation behavior in single-phase flow conditions proportionally to the functioning real conditions of a nuclear reactor. The experiment was performed through procedures to initialization of hydraulic feeding of primary and secondary circuits and electrical energizing of resistors installed inside heater. Power controller has availability to adjust values of electrical power to feeding resistors, in order to portray several conditions of energy decay of nuclear reactor in a steady state. Data acquisition system allows the measurement and monitoring of the evolution of the temperature in various points through thermocouples installed in strategic points along hydraulic circuit. The behavior of the natural circulation phenomenon was monitored by graphical interface on computer screen, showing the temperature evolutions of measuring points and results stored in digital spreadsheets. The results stored in digital spreadsheets allowed the getting of data to graphic construction and discussion about natural circulation phenomenon. Finally, the calculus of Reynolds number allowed the establishment for a correlation of friction in function of geometric scales of length, heights and cross section of tubing, considering a natural circulation flow throughout in the region of hot leg. (author)

  16. a comparative study of some robust ridge and liu estimators

    African Journals Online (AJOL)

    Dr A.B.Ahmed

    , Ogbomoso, Oyo State, Nigeria. ... Liu Estimator, Robust Estimator, Robust Ridge Regression. Estimator, Robust Liu Estimator. 1.0. INTRODUCTION. Regression analysis is used to study the ..... in Probability and Mathematical Statistics.Wiley ...

  17. Experimental study on partial coherence source

    CERN Document Server

    Zhao Xue Qing; Yuan Xiao; LiuJingRu; Wang Long Hua; Tang Ying; Huang, Kerson


    Partial coherence source is a key part in the laser system using echelon-free introduced spatial incoherence beam smoothing technique. Different kinds of partial coherence sources have been studied experimentally for improving the uniformity of laser intensity distribution. It is found that the source produced by excimer laser scattering on the surface of a teflon plate is ideal. The properties of this kind of source are studied. As a result, the uniformity of source beam intensity distribution, the beam spatial coherence and energy transfer efficiency of the source are obtained

  18. Reservoir capacity estimates in shale plays based on experimental adsorption data (United States)

    Ngo, Tan

    from different measurement techniques using representative fluids (such as CH4 and CO2) at elevated pressures, and the adsorbed density can range anywhere between the liquid and the solid state of the adsorbate. Whether these discrepancies are associated with the inherent heterogeneity of mudrocks and/or with poor data quality requires more experiments under well-controlled conditions. Nevertheless, it has been found in this study that methane GIP estimates can vary between 10-45% and 10-30%, respectively, depending on whether the free or the total amount of gas is considered. Accordingly, CO2 storage estimates range between 30-90% and 15-50%, due to the larger adsorption capacity and gas density at similar pressure and temperature conditions. A manometric system has been designed and built that allows measuring the adsorption of supercritical fluids in microporous materials. Preliminary adsorption tests have been performed using a microporous 13X zeolite and CO 2 as an adsorbing gas at a temperature of 25oC and 35oC and at pressures up to 500 psi. Under these conditions, adsorption is quantified with a precision of +/- 3%. However, relative differences up to 15-20% have been observed with respect to data published in the literature on the same adsorbent and at similar experimental conditions. While it cannot be fully explained with uncertainty analysis, this discrepancy can be reduced by improving experiment practice, thus including the application of a higher adsorbent's regeneration temperature, of longer equilibrium times and of a careful flushing of the system between the various experimental steps. Based on the results on 13X zeolite, virtual tests have been conducted to predict the performance of the manometric system to measure adsorption on less adsorbing materials, such as mudrocks. The results show that uncertainties in the estimated adsorbed amount are much more significant in shale material and they increase with increasing pressure. In fact, relative

  19. A Study on Crack Initiation Test Condition by Uncertainty Evaluation of Weibull Estimation Methods

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jae Phil; Bahn, Chi Bum [Pusan National University, Busan (Korea, Republic of)


    The goal of this work is to suggest proper experimental conditions for experimenters who want to develop probabilistic SCC initiation model by cracking test. Widely used MRR and MLE are considered as estimation methods of Weibull distribution. Stress Corrosion Cracking (SCC) is one of the main materials-related issues in operating nuclear reactors. From the result of the test, experimenters can estimate the parameters of Weibull distribution by Maximum Likelihood Estimation (MLE) or Median Rank Regression (MRR). However, in order to obtain the sufficient accuracy of the estimated Weibull model, it is hard for experimenters to determine the proper number of test specimens and censoring intervals. In this work, a comparison of MLE and MRR is performed by Monte Carlo simulation to quantify the effect of total number of specimen, test duration, censoring interval and shape parameter of the assumed true Weibull distribution. By using a Monte Carlo simulation, uncertainties of MRR and MLE estimators were quantified in various conditions of experimental cases. The following conclusions could be informative for the experimenters: 1) For all range of the simulation study, estimated scale parameters were more reliable than estimated shape parameters, especially for at high βtrue. 2) It is likely that the shape parameter is overestimated when the number of specimen is less than 25. For scale parameter estimation, MLE estimators have small bias as compared to the MRR estimators.

  20. Experimental support and estimate of the accuracy of the water flow model in structured soils (United States)

    Nikulina, M.


    The set of models of water flow and solute transport was developed. It takes into account spatial and time variability of soil properties and a complex structure of a soil pore space. However, its limited by physically justified methods of experimental definition of parameters. The important stage of the work with the models is checking their adequacy to described processes. It is possible only at a presence of the qualitative experi-mental data received under conditions, reproduced by model. According to this, the aim of the work is the support of methods of experimental maintenance of water flow models with taking into account of structure of soil porosity and evaluation of conditions of application of mathematical models of a dif-ferent level. The field experiments were conducted in Suzdal (Russia, Vladimirskaja oblast), in June and July 1997. The soil cover of this region has high complexity, in which grey forest soils are dominant. Genetic horizons of the grey forest soils are well structured, this causes the presence in soil profile the macropores. The field investigation consisted of three big parts: (1) the morphological research of the genetic horizons of the grey forest soil; (2) investigation of the soil filtration properties by the tube with a constant head and vacuum-infiltrometer methods; (3) study of water movement at different intensity of the irrigation. Experiments were conducted on three sets called , and . The plots had 1m x 1m a size and were equipped with the hole for measurement of soil water content by the neutron hygrometer and by the tensiometers. In labo-ratory conditions the following properties of soil were determined: density of soil, texture, porosity of the aggregates, shrinkage characteristics of soil fraction in diameter of 3-5 mm. For the simulation the model "MACRO" (Jarvis et al, 1991) was used in the work. Adequacy of the model descriptions of the field data were estimated by visual comparison of measured and calculated data



    Shrama, Gopal Dutt; Tripathi, S. N.


    SUMMARY Water soluble fraction of total alcoholic in the treatment of bronchial asthma 1.2. The same fraction is studied here on frog heart and on blood pressure and respiration of dog, to screen its action on cardio vascular and respiratory systems experimentally. The paper deals with the above experiments with their observations and results. In nut shell the drug is found to have cardiac depresent action an isolated frog heart as well as on frog heart in situ. The drug also possesses potent...

  2. Experimental study of rf pulsed heating

    CERN Document Server

    Laurent, L; Nantista, C; Dolgashev, V; Higashi, Y; Aicheler, M; Tantawi, S; Wuensch, W


    Cyclic thermal stresses produced by rf pulsed heating can be the limiting factor on the attainable reliable gradients for room temperature linear accelerators. This is especially true for structures that have complicated features for wakefield damping. These limits could be pushed higher by using special types of copper, copper alloys, or other conducting metals in constructing partial or complete accelerator structures. Here we present an experimental study aimed at determining the potential of these materials for tolerating cyclic thermal fatigue due to rf magnetic fields. A special cavity that has no electric field on the surface was employed in these studies. The cavity shape concentrates the magnetic field on one flat surface where the test material is placed. The materials tested in this study have included oxygen free electronic grade copper, copper zirconium, copper chromium, hot isostatically pressed copper, single crystal copper, electroplated copper, Glidcop (R), copper silver, and silver plated co...

  3. Estimates of power generated from synchrotron radiation in the HL-LHC experimental insertion regions

    CERN Document Server

    Rossi, Adriana; CERN. Geneva. ATS Department


    The power generated in single magnets of the HL-LHC experimental regions is estimated for collision optics HLLHCV1.2 β*=15 cm Round and HLLHCV1.2 Flat. Note that the layout used for the computations presented here is that before the recent change of baseline. These values should serve as input to Monte-Carlo codes (i.e., PHOTON [ ], Synrad [ ] or others), able to calculate the heat load distribution along the machine and in particular the Long Straight Sections (LSS).

  4. Experimental factors affecting PCR-based estimates of microbial species richness and evenness

    Energy Technology Data Exchange (ETDEWEB)

    Engelbrektson, Anna; Kunin, Victor; Wrighton, Kelly C.; Zvenigorodsky, Natasha; Chen, Feng; Ochman, Howard; Hugenholtz, Philip


    Pyrosequencing of 16S rRNA gene amplicons for microbial community profiling can, for equivalent costs, yield greater than two orders of magnitude more sensitivity than traditional PCR-cloning and Sanger sequencing. With this increased sensitivity and the ability to analyze multiple samples in parallel, it has become possible to evaluate several technical aspects of PCRbased community structure profiling methods. We tested the effect of amplicon length and primer pair on estimates of species richness number of species and evenness relative abundance of species by assessing the potentially tractable microbial community residing in the termite hindgut. Two regions of the 16S rRNA gene were sequenced from one of two common priming sites, spanning the V1-V2 or V8 regions, using amplicons ranging n length from 352 to 1443 bp. Our results demonstrate that both amplicon length and primer pair markedly influence estimates of richness and evenness. However, estimates of species evenness are consistent among different primer pairs targeting the same region. These results highlight the importance of experimental methodology when comparing diversity estimates across communities.

  5. An Experimental Study of Soft Lubrication (United States)

    Wu, Qianhong; Gacka, Thomas; Nathan, Rungun; Wu, Li-Zhu; Cbmss Team


    Lift generation in soft porous media, as a planing surface glides over it, is a new topic in porous media flow with superior potential for lubrication and squeeze damping. This paper presents the first experimental study of this phenomenon. The experimental setup consists of a running conveyer belt covered with a soft porous sheet, and a stationary instrumented inclined planar upper board. Twelve pressure transducers mounted on the upper board captured the pore pressure generation, while a load cell was used to capture the total lifting force, arising from both the pore pressure and the compression of the solid fibers. One finds that the pore pressure distribution is consistent with theoretical predictions (Feng and Weinbaum, JFM, 2000; Wu et al., MSSE, 2006, 2011), and depends on the running belt velocity, U, the mechanical properties of the porous material, and the compression ratios of the porous layer. For a typical trial (h2/h1=5,h2/h0=1, U=3.8 m/s, where h2, h1, and h0 are the leading edge, trailing edge, and undeformed porous layer thicknesses, respectively), 68% of the lifting force was generated by the pore pressure. It conclusively demonstrates the validity of using soft porous materials for super lubrication. applications. Villanova Cellular Biomechanics and Sports Science Laboratory.

  6. Experimental Study of Separate Type Thermosyphon (United States)

    Hirashima, Masao; Kawahata, Kenya; Negishi, Kanji

    The passages of vapor flow and the returning liquid flow are perfectly partitioned in a separate type thermosyphon. Therefore the flooding limit can be eliminated and practicability based on its construction is highly evaluated. The carry-over of the liquid into the condensing section accompanied with the rising vapor flow should be avoided in the separate type thermosyphon, since it causes to decrease the heat transfer coefficient on the heat transfer surface in the condenser. In the present work, the effect of liquid level, the heat input into the evaporating section, the charging rate of the liquid, and the dimension of the adiabatic section supposed on the generation of carry-over were studied experimentally. The frequency of the bumping and the velocity of the vapor in the adiabatic section were examined as the function of the termination of the carry-over. The experimental correlation representing the relation among the elapsed time, the liquid temperature and the charging rate of the liquid were also derived.

  7. Contribution to the experimental study of the hydraulic jump in ...

    African Journals Online (AJOL)

    The purpose of this study is to study experimentally the hydraulic jump evolving in a symmetric trapezoidal channel with a positive slope, requires the use of an experimental protocol, and to find experimental relations linking the characteristics of the formed projection. The experimental study investigated the variation of the ...

  8. [Endodontics in horses. An experimental study]. (United States)

    Garcia, F; Sanromán, F; Llorens, M P


    A total of 44 experimental endodontic treatments were performed in incisors of eight horses of different ages. Four different endodontic pastes were used: Cloropercha, AH26 De Trey, Eugenol-Endometasone, and Universal N2. Gutta-percha points were also included in the last two treatments. Access to the pulp cavity of incisors was gained through their vestibular and occlusal faces. Holes drilled in vestibular faces were sealed with composite and those drilled in occlusal faces were sealed with Amalgama. Animals were observed during eighteen months at least after endodontics. Radiographic controls were done just after surgery and before slaughtering. Treated incisors and alveoli were studied histopathologically. During the experiment all animals were in good condition. They ate apparently without trouble, and neither clinical nor radiological signs were present.

  9. An experimental study of reactive turbulent mixing (United States)

    Cooper, L. P.; Marek, C. J.; Strehlow, R. A.


    An experimental study of the turbulent mixing of two coaxial gas streams, which react very rapidly (pseudo-hypergolic chemical kinetics), was performed to investigate the mixing characteristics of turbulent flow fields. The center stream consisted of a CO-N2 mixture and the outer annular stream consisted of air vitiated by H2 combustion. The streams were at equal velocity (50 m/sec) and temperature (1280 K). Turbulence measurements were obtained using hot film anemometry. A sampling probe was used to obtain time averaged gas compositions. Six different turbulence generators were placed in the annular passage to alter the flow field mixing characteristics. The turbulence generators affected the bulk mixing of the streams and the extent of CO conversion to different degrees. The effects can be related to the average eddy size and the bulk mixing. Higher extents of conversion of CO to CO2 were found by increasing the bulk mixing and decreasing the average eddy size.

  10. Experimental plan for the Single-Family Study

    Energy Technology Data Exchange (ETDEWEB)

    Berry, L.G.; Brown, M.A.; Wright, T.; White, D.L.


    The national evaluation of the Weatherization Assistance Program (WAP) consists of five separate studies. The Single-Family Study is one of three studies that will estimate program energy savings and cost effectiveness in principal WAP submarkets. This report presents the experimental plan for the Single-Family Study, which will be implemented over the next three years (1991--1993). The Single-Family Study will directly estimate energy savings for a nationally representative sample of single-family and small multifamily homes weatherized in the 1989 program year. Savings will be estimated from gas and electric utility billing records using the Princeton Scorekeeping Method (PRISM). The study will also assess nonenergy impacts (e.g., health, comfort, safety, and housing affordability), estimate cost effectiveness, and analyze factors influencing these outcomes. For homes using fuels such as wood, coal, fuel oil, kerosene, and propane as the primary source of space conditioning, energy savings will be studied indirectly. The study will assemble a large nationally representative data base. A cluster sampling approach will be used, in which about 400 subgrantees are selected in a first stage and weatherized homes are selected in a second range. To ensure that the Single-Family Study is able to identify promising opportunities for future program development, two purposively selected groups of subgrantees will be included: (1) subgrantees that install cooling measures (such as more efficient air conditioning equipment or radiant barriers), and (2) exemplary subgrantees that use state-of-the-art technologies and service delivery procedures (such as advanced audit techniques, blower door tests, infrared scanners, extensive client education, etc.). These two groups of subgrantees will be analyzed to identify the most effective program elements in specific circumstances. 14 refs., 4 figs., 3 tabs.



    K. Jayapratha; M. Muthamizharasan


    Software Cost Estimation is one of the most important part in software development. It involves in estimating the effort and cost in terms of money to complete the software development. Software Cost Estimation is very important when lines of code for the particular project exceeds certain limit, also when the software deployed with too many bugs and uncovered requirements the project will go incomplete. Software cost estimation of a project plays a vital role in acceptance or rejection of it...

  12. Experimental and theoretical study of reflux condensation

    Energy Technology Data Exchange (ETDEWEB)

    Bakke, Knut


    This thesis studies the separation of gas mixtures in a reflux condenser. also called a dephlegmator. Reflux condensation is separation of a gas mixture, in reflux flow with condensing liquid, under continuous heat removal. A numerical model of a dephlegmator for binary mixtures was developed. The model may readily be extended to multi-component mixtures, as the solution method is based on a matrix solver. Separation of a binary mixture in a reflux condenser test rig is demonstrated. The test facility contains a single-tube test section that was designed and built as part of the project. Test mixtures of propane and n-butane were used, and a total of 15 experiments are reported. Limited degree of separation was achieved due to limited heat transfer area and narrow boiling point range of the test mixture. The numerical model reproduces the experimental data within reasonable accuracy. Deviation between calculated and measured properties is less than 6% of the measured temperature and less than 5% of the measured flow rate. The model is based on mechanistic models of physical processes and is not calibrated or tuned to fit the experimental data. The numerical model is applied to a number of separation processes. These case studies show that the required heat transfer area increases rapidly with increments in top product composition (light component). Flooding limits the amount of reflux liquid. The dephlegmator is suitable for separation of feed mixtures that are rich in light components. The gliding temperature in the dephlegmation process enables utilization of top product as refrigerant, with subsequent energy saving as a result. 61 refs., 50 figs., 34 tabs.

  13. Experimental studies of ongoing conscious experience. (United States)

    Singer, J L


    A research programme designed to find ways of applying a variety of methods in psychological science to studying the seemingly ephemeral phenomena of the human stream of consciousness and its manifestations in daydreams, interior monologues, imagery and related private experiences is described. Approaches include psychometric studies to establish normative information on daydreaming and experimental studies using signal-detection paradigms to capture the ongoing stream of thought. Recent experiments involve thought-sampling methods for identifying the determinants of the content of the stream of thought in adolescents or the ways in which self-beliefs and emotions are manifested in a group of cocaine and heroin abusers. Children's pretend play is studied as a possible forerunner of adult consciousness. It is proposed that the human condition involves a continuing tension between processing information generated from the physical and social milieu and the continuous operation of centrally generated material from long-term memory in the form of reminiscences, wishes, current concerns, expectancies and fantasies. This concept has implications for personality variation, affective arousal and adaptive behaviour.

  14. A transverse oscillation approach for estimation of three-dimensional velocity vectors, part II: experimental validation. (United States)

    Pihl, Michael Johannes; Stuart, Matthias Bo; Tomov, Borislav Gueorguiev; Rasmussen, Morten Fischer; Jensen, Jørgen Arendt


    The 3-D transverse oscillation method is investigated by estimating 3-D velocities in an experimental flow-rig system. Measurements of the synthesized transverse oscillating fields are presented as well. The method employs a 2-D transducer; decouples the velocity estimation; and estimates the axial, transverse, and elevation velocity components simultaneously. Data are acquired using a research ultrasound scanner. The velocity measurements are conducted with steady flow in sixteen different directions. For a specific flow direction with [α, ß] = [45, 15]°, the mean estimated velocity vector at the center of the vessel is (v(x), v(y), v(z)) = (33.8, 34.5, 15.2) ± (4.6, 5.0, 0.6) cm/s where the expected velocity is (34.2, 34.2, 13.0) cm/s. The velocity magnitude is 50.6 ± 5.2 cm/s with a bias of 0.7 cm/s. The flow angles α and ß are estimated as 45.6 ± 4.9° and 17.6 ± 1.0°. Subsequently, the precision and accuracy are calculated over the entire velocity profiles. On average for all direction, the relative mean bias of the velocity magnitude is -0.08%. For α and ß, the mean bias is -0.2° and -1.5°. The relative standard deviations of the velocity magnitude ranges from 8 to 16%. For the flow angles, the ranges of the mean angular deviations are 5° to 16° and 0.7° and 8°.

  15. Comparing the accuracy of experimental estimates to guessing: a new perspective on replication and the "Crisis of Confidence" in psychology. (United States)

    Davis-Stober, Clintin P; Dana, Jason


    We develop a general measure of estimation accuracy for fundamental research designs, called v. The v measure compares the estimation accuracy of the ubiquitous ordinary least squares (OLS) estimator, which includes sample means as a special case, with a benchmark estimator that randomizes the direction of treatment effects. For sample and effect sizes common to experimental psychology, v suggests that OLS produces estimates that are insufficiently accurate for the type of hypotheses being tested. We demonstrate how v can be used to determine sample sizes to obtain minimum acceptable estimation accuracy. Software for calculating v is included as online supplemental material (R Core Team, 2012).

  16. Experimental Study of Alluvial Fan Formation (United States)

    Delorme, P.; Devauchelle, O.; Barrier, L.; Métivier, F.


    At the outlet of mountain ranges, rivers flow onto flatter lowlands. The associated change of slope causes sediment deposition. As the river is free to move laterally, it builds conical sedimentary structures called alluvial fans. Their location at the interface between erosional and depositional areas makes them valuable sedimentary archives. To decipher these sedimentary records, we need to understand the dynamics of their growth. Most natural fans are built by braided streams. However, to avoid the complexity of braided rivers, we develop a small-scale experiment in which an alluvial fan is formed by a single channel. We use a mixture of water and glycerol to produce a laminar river. The fluid is mixed with corindon sand (~ 300 μm) in a tilted channel and left free to form a fan around its outlet. The sediment and water discharges are constant during an experimental run. We record the fan progradation and the channel morphology with top-view pictures. We also generate an elevation map with an optical method based on the deformation of a moiré pattern. We observe that, to leading order, the fan remains self-affine as it grows, with a constant slope. We compare two recent studies about the formation of one-dimensionnal fan [Guerit et al. 2014] and threshold rivers [Seizilles et al. 2013] to our experimental findings. In particular, we propose a theory witch relates the fan morphology to the control parameters ( fluid and sediment discharges, grain size). Our observation accord with the predictions, suggesting that the fan is built near the threshold of sediment motion. Finally, we intend to expand our interpretation to alluvial fans build by single-thread channels ( Okavango, Bostwana; Taquari and Paraguay, Brasil; Pastaza, Peru).

  17. Estimation of break-lock in PLL synthesizers for monopulse radar applications: Experimental and simulation approach

    Directory of Open Access Journals (Sweden)

    Harikrishna Paik


    Full Text Available This work presents and estimates the break-lock in phase locked loop (PLL synthesizers for monopulse radar applications through experimental measurements and computer simulation. Sinusoidal continuous wave (CW and linear frequency modulated (LFM signals are used as repeater jamming signals. The CW jamming signal power as a function of radar echo signal power at break-lock is estimated for different values of frequency difference between these two signals, and from these results the jammer to echo signal power (J/S ratio (in dB is computed. Break-lock is achieved at a J/S ratio of 1.9 dB (measured at 1.8 dB for a typical echo signal power of −5 dBm with a 1 MHz frequency difference. The frequency deviation as a function of J/S ratio required to break-lock is estimated for different modulation rates in the presence of LFM jamming signal. Break-lock is achieved at a frequency deviation of 0.34 MHz (measured at 0.32 MHz for a J/S ratio of 2 dB and 200 kHz modulation rate. The simulation models are proposed accordingly to the data obtained from the experimental setups. Good and consistent agreements between the measured and simulated results are observed and can be useful in the design of CW and LFM jammers in the target platform.

  18. Hot forming of composite prepreg : Experimental study (United States)

    Tardif, Xavier; Duthille, Bertrand; Bechtel, Stephane; le Pinru, Louis; Campagne, Benjamin; Destombes, Gautier; Deshors, Antoine; Marchand, Christophe; Azzouzi, Khalid El; Moro, Tanguy


    The hot forming of thermoset prepreg consists in bending an uncured composite part by applying a mechanical constrain on the hot laminate. Most of the time, the mold is inserted in a vacuum box and the mechanical constrain is applied on the composite laminate by a single membrane or a double-membrane. But the performance improvement products resulted in forming increasingly complex parts with advanced materials having a less formability. These new complex parts require a finer comprehension of the process and an optimization of the key parameters to get acceptable quality. In this work, an experimental study has been carried out to identify the process conditions that do not lead to unacceptable defaults: undulations of fibers. In the present study, downward-bending has been evaluated with an original light mechanical forming concept, for a given stacking sequence. The influence of the part's temperature and the part's bending speed are investigated. To carry this study out, a hot forming test bench has been designed and manufactured to have a precise supervision of the process conditions. It is able to bend parts of 1500 mm length x 600 mm width x 20 mm thick.

  19. Experimental study of rf pulsed heating

    Directory of Open Access Journals (Sweden)

    Lisa Laurent


    Full Text Available Cyclic thermal stresses produced by rf pulsed heating can be the limiting factor on the attainable reliable gradients for room temperature linear accelerators. This is especially true for structures that have complicated features for wakefield damping. These limits could be pushed higher by using special types of copper, copper alloys, or other conducting metals in constructing partial or complete accelerator structures. Here we present an experimental study aimed at determining the potential of these materials for tolerating cyclic thermal fatigue due to rf magnetic fields. A special cavity that has no electric field on the surface was employed in these studies. The cavity shape concentrates the magnetic field on one flat surface where the test material is placed. The materials tested in this study have included oxygen free electronic grade copper, copper zirconium, copper chromium, hot isostatically pressed copper, single crystal copper, electroplated copper, Glidcop®, copper silver, and silver plated copper. The samples were exposed to different machining and heat treatment processes prior to rf processing. Each sample was tested to a peak pulsed heating temperature of approximately 110°C and remained at this temperature for approximately 10×10^{6} rf pulses. In general, the results showed the possibility of pushing the gradient limits due to pulsed heating fatigue by the use of copper zirconium and copper chromium alloys.

  20. Comparative Study of Online Open Circuit Voltage Estimation Techniques for State of Charge Estimation of Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Hicham Chaoui


    Full Text Available Online estimation techniques are extensively used to determine the parameters of various uncertain dynamic systems. In this paper, online estimation of the open-circuit voltage (OCV of lithium-ion batteries is proposed by two different adaptive filtering methods (i.e., recursive least square, RLS, and least mean square, LMS, along with an adaptive observer. The proposed techniques use the battery’s terminal voltage and current to estimate the OCV, which is correlated to the state of charge (SOC. Experimental results highlight the effectiveness of the proposed methods in online estimation at different charge/discharge conditions and temperatures. The comparative study illustrates the advantages and limitations of each online estimation method.

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

    Directory of Open Access Journals (Sweden)

    Zahra Shourgashti


    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.

  2. Theoretical and experimental studies on the foundation theoretical and experimental studies on the foundation of mesomechanics (United States)

    Chudnovsky, A.; Wu, S.


    The report summarizes a closely coupled experimental and theoretical investigation of various stages of Fracture Process: (1) accumulation of 'damage' on submicroscopical and microscopical scales leading to crack initiation; (2) slow (subcritical) crack growth and an evolution of the damage zone; (3) transition to dynamic crack growth and the catastrophic failure. The experimental part of the program is focused on the observation and quantitative characterization of damage preceding and accompanying crack initiation and growth. A special experimental setup for studying the fracture process under variable stress field is reported in Chapter 2. A leading role of crack-damage interaction in fracture process is well documented. A new formalism for solution of crack-microcrack array interaction problem and its successful implementation in the evaluation of crack layer driving forces is presented in Chapter 3. A new model of the process zone, which generalizes the well-known Dagdale-Barenblatt model is presented in Chapter 4. A new measure for material toughness and the prediction of R-curve behavior illustrate the practical application of our model. Experimental examinations of our model under various test conditions are reported in Chapters 4, 5 and 6. The development of the constitutive equations for Crack Layer evolution and their experimental examinations under stress relaxation, fatigue and creep conditions are reported in Chapters 5 and 6. An accelerated test procedure and the formulation of crack layer instability criteria as a substitution for the conventional fracture toughness parameters are also discussed in Chapter 6.

  3. Experimental studies of herbicide drift characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Renne, D.S.; Wolf, M.A.


    A knowledge of the drift characteristics of herbicides and pesticides released from ground and aerial rigs is important in forestry and agricultural applications so that methods for minimizing damage to downwind systems sensitive to these chamicals can be developed. A field experiment was undertaken on the Hanford Reservation in eastern Washington State during 1975 to study techniques for maximizing herbicide applications from a spray airplane on the intended area and minimizing drift. Several early morning experiments comparing drift characteristics of a fixed with a test application for various nozzle systems and herbicide concentrations were made. The results of these experiments have shown that the initial drift and drift deposit components varied by only a factor of two or so, depending on the production of smaller droplets, as various techniques were used to put the herbicides down from the aircraft. Meteorological conditions become increasingly important at greater downwind distances from the source. Furthermore, drift reduction was most effective under conditions of high relative humidities and cool temperatures. At large distances from the source, ground level drift was higher on stable than on unstable days. Comments on methods for improving the experimental design, and applications of studies such as these to forestry will be made.

  4. Experimental studies of fiber concrete creep

    Directory of Open Access Journals (Sweden)

    Korneeva Irina


    Full Text Available The results of two-stage experimental studies of the strength and deformation characteristics of fibrous concrete reinforced with steel fiber. In the experiments we used steel fiber with bent ends, which practically does not form "hedgehogs", which allows to achieve an even distribution of the fiber by volume. At the first stage, the cube and prismatic strength, deformability at central compression, a number of special characteristics are determined: water absorption, frost resistance, abrasion; the optimal percentage of fiber reinforcement and the maximum size of the coarse aggregate fraction were selected. Fiber reinforcement led to an increase in the strength of concrete at compression by 1,35 times and an increase in the tensile strength at bending by 3,4 times. At the second stage, the creep of fibrous concrete and plain concrete of similar composition at different stress levels was researched. Creep curves are plotted. It is shown that the use of fiber reinforcement leads to a decrease in creep strain by 21 to 30 percent, depending on the stress level.

  5. Experimental study of finite Larmor radius effects

    Energy Technology Data Exchange (ETDEWEB)

    Struve, K.W.


    Linear Z-pinches in Ar, Kr, Xe, N/sub 2/, and He are experimentally studied in regimes where strong finite Larmor radius effects could provide a significant stabilizing effect. Scaling arguments show that for deuterium such a pinch has an electron line density of order 2 x 10/sup 15//cm. For higher Z plasmas a higher line density is allowed, the exact value of which depends on the average ion charge. The pinch is formed by puffing gas axially through the cathode towards the anode of an evacuated pinch chamber. When the gas reaches the anode, the pinch bank is fired. The pinch current rises in 2 to 3 to a maximum of 100 to 200 kA. The pinch bank capacitance is 900, and the external inductance is 100 nH. Additionally, the bank is fused to increase dI/dt. The primary diagnostics are a framing camera, a spatially resolved Mach-Zehnder interferometer, and X-ray absorption.

  6. The experimental studies of thermoacoustic cooler. (United States)

    Sakamoto, Shin-ichi; Watanabe, Yoshiaki


    The experimental studies of thermoacoustic cooler consisting of acoustic loop-tube were carried out. The loop-tube was filled with the mixture of air and helium gas or air at atmospheric pressure. The dimensions of the loop-tube were 3.3 m of length, 44 mm of inner diameter and 4 mm of thickness. A pair of stacks (stack 1 and stack 2) which were sandwiched between two heat exchangers was placed symmetrically in the loop-tube. Stack 1 was employed as a prime mover and stack 2 as a heat pump. The self-sustained sound generated by the thermoacoustic effect and the cooling phenomena at the stack 2 were observed. The distribution of the sound pressures and the waveforms in the loop-tube were measured, and the frequency component of the self-sustained sound was investigated at the starting phase. The fundamental frequency component was confirmed and it was developing as the sound pressure increasing. The higher harmonics frequency components were generated and they were also developing.

  7. Experimental study of trimethyl aluminum decomposition (United States)

    Zhang, Zhi; Pan, Yang; Yang, Jiuzhong; Jiang, Zhiming; Fang, Haisheng


    Trimethyl aluminum (TMA) is an important precursor used for metal-organic chemical vapor deposition (MOCVD) of most Al-containing structures, in particular of nitride structures. The reaction mechanism of TMA with ammonia is neither clear nor certain due to its complexity. Pyrolysis of trimethyl metal is the start of series of reactions, thus significantly affecting the growth. Experimental study of TMA pyrolysis, however, has not yet been conducted in detail. In this paper, a reflectron time-of-flight mass spectrometer is adopted to measure the TMA decomposition from room temperature to 800 °C in a special pyrolysis furnace, activated by soft X-ray from the synchrotron radiation. The results show that generation of methyl, ethane and monomethyl aluminum (MMA) indicates the start of the pyrolysis process. In the low temperature range from 25 °C to 700 °C, the main product is dimethyl aluminum (DMA) from decomposition of TMA. For temperatures larger than 700 °C, the main products are MMA, DMA, methyl and ethane.

  8. Learning, forecasting and optimizing : An experimental study

    NARCIS (Netherlands)

    Bao, Te; Duffy, John; Hommes, Cars

    Rational Expectations (RE) models have two crucial dimensions: (i) agents on average correctly forecast future prices given all available information, and (ii) given expectations, agents solve optimization problems and these solutions in turn determine actual price realizations. Experimental tests

  9. Evapotranspiration studies for protective barriers: Experimental plans

    Energy Technology Data Exchange (ETDEWEB)

    Link, S.O.; Waugh, W.J.


    This document describes a general theory and experimental plans for predicting evapotranspiration in support of the Protective Barrier Program. Evapotranspiration is the combined loss of water from plants and soil surfaces to the atmosphere. 45 refs., 1 fig., 4 tabs.

  10. Systematic review of survival time in experimental mouse stroke with impact on reliability of infarct estimation

    DEFF Research Database (Denmark)

    Klarskov, Carina Kirstine; Klarskov, Mikkel Buster; Hasseldam, Henrik


    and a comparison of correction methods will be discussed. Method: Relevant terms were searched in the National Library of Medicine PubMed database. A method for classification of infarct measurement methods was made using a naming convention. Conclusion: Our study shows that infarct size estimations are often...


    Directory of Open Access Journals (Sweden)

    O. V. Murav’eva


    Full Text Available Measuring the characteristics of process fluids allows us to evaluate their quality, biological tissues – to differentiate healthy tissues and tissues with pathologies. Measuring the characteristics of process fluids allows us to evaluate their quality, biological tissues – to differentiate healthy tissues and tissues with pathologies. One of the complex acoustic parameters is the impedance, which allows one to fully evaluate the characteristics of viscoelastic media. Most of impedance methods of measurements require using two or more reference media and the availability of calibrated acoustic transducers. The aim of this work ware introduced a methods and construction for the experimental evaluation of the longitudinal and shear impedance of viscoelastic media based on measuring the parameters of the amplitude-frequency characteristics and calculating the elements of the electric circuit for replacing the piezoelectric element which vibrating in the test medium.The paper introduces a methods and construction of the experimental evaluation of the impedances of viscoelastic media. The suggested methods is allowed measuring longitudinal and shear impedances and determining velocities of longitudinal and transverse ultrasonic waves and the values of the elastic moduli of viscoelastic media, including in various aggregate states. The technique is fairly simple to implement and can be reproduced using simple laboratory equipment.The obtained values of the acoustic impedances of the investigated media are in satisfactory agreement with their reference data. In contrast to the known methods for determining the acoustic impedance, the developed technique allows us to estimate with sufficient accuracy the parameter of the shear impedance of viscoelastic media that is difficult to measure at the frequencies of the megahertz range, which determines the shear modulus of the material and characterizes its resistance to shear deformations. The results of

  12. Experimental and computational studies of nanofluids (United States)

    Vajjha, Ravikanth S.

    The goals of this dissertation were (i) to experimentally investigate the fluid dynamic and heat transfer performance of nanofluids in a circular tube, (ii) to study the influence of temperature and particle volumetric concentration of nanofluids on thermophysical properties, heat transfer and pumping power, (iii) to measure the rheological properties of various nanofluids and (iv) to investigate using a computational fluid dynamic (CFD) technique the performance of nanofluids in the flat tube of a radiator. Nanofluids are a new class of fluids prepared by dispersing nanoparticles with average sizes of less than 100 nm in traditional heat transfer fluids such as water, oil, ethylene glycol and propylene glycol. In cold regions of the world, the choice of base fluid for heat transfer applications is an ethylene glycol or propylene glycol mixed with water in different proportions. In the present research, a 60% ethylene glycol (EG) or propylene glycol (PG) and 40% water (W) by mass fluid mixture (60:40 EG/W or 60:40 PG/W) was used as a base fluid, which provides freeze protection to a very low level of temperature. Experiments were conducted to measure the convective heat transfer coefficient and pressure loss of nanofluids flowing in a circular tube in the fully developed turbulent regime. The experimental measurements were carried out for aluminum oxide (Al2O3), copper oxide (CuO) and silicon dioxide (SiO2) nanoparticles dispersed in 60:40 EG/W base fluid. Experiments revealed that the heat transfer coefficient of nanofluids showed an increase with the particle volumetric concentration. Pressure loss was also observed to increase with the nanoparticle volumetric concentration. New correlations for the Nusselt number and the friction factor were developed. The effects of temperature and particle volumetric concentration on different thermophysical properties (e.g. viscosity, thermal conductivity, specific heat and density) and subsequently on the Prandtl number

  13. Preliminary experimental studies of waste coal gasification

    Energy Technology Data Exchange (ETDEWEB)

    Su, S.; Jin, Y.G.; Yu, X.X.; Worrall, R. [CSIRO, Brisbane, QLD (Australia). Advanced Coal Technology


    Coal mining is one of Australia's most important industries. It was estimated that coal washery rejects from black coal mining was approximately 1.82 billion tonnes from 1960 to 2009 in Australia, and is projected to produce another one billion tonnes by 2018 at the current production rate. To ensure sustainability of the Australian coal industry, we have explored a new potential pathway to create value from the coal waste through production of liquid fuels or power generation using produced syngas from waste coal gasification. Consequently, environmental and community impacts of the solid waste could be minimized. However, the development of an effective waste coal gasification process is a key to the new pathway. An Australian mine site with a large reserve of waste coal was selected for the study, where raw waste coal samples including coarse rejects and tailings were collected. After investigating the initial raw waste coal samples, float/sink testing was conducted to achieve a desired ash target for laboratory-scale steam gasification testing and performance evaluation. The preliminary gasification test results show that carbon conversions of waste coal gradually increase as the reaction proceeds, which indicates that waste coal can be gasified by a steam gasification process. However, the carbon conversion rates are relatively low, only reaching to 20-30%. Furthermore, the reactivity of waste coal samples with a variety of ash contents under N{sub 2}/air atmosphere have been studied by a home-made thermogravimetric analysis (TGA) apparatus that can make the sample reach the reaction temperature instantly.

  14. Experimental estimation of moderator temperature coefficient of reactivity of the IPEN/MB-01 research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Rubens C. da; Bitelli, Ulysses D.; Mura, Luiz Ernesto C., E-mail:, E-mail:, E-mail: [Universidade de Sao Paulo (PNV/POLI/USP), SP (Brazil). Arquitetura Naval e Departamento de Engenharia Oceanica; Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)


    The aim of this article is to present the procedure for the experimental estimation of the Moderator Temperature Coefficient of Reactivity of the IPEN/MB-01 Research Reactor, a parameter that has an important role in the physics and the control operations of any reactor facility. At the experiment, the IPEN/MB-01 reactor went critical at the power of 1W (1% of its total power), and whose core configuration was 28 x 26 rectangular array of UO{sub 2} fuel rods, inside a light water (moderator) tank. In addition, there was a heavy water (D{sub 2}O) reflector installed in the West side of the core to obtain an adequate neutron reflection along the experiment. The moderator temperature was increased in steps of 4 °C, and the measurement of the mean moderator temperature was acquired using twelve calibrated thermocouples, placed around the reactor core. As a result, the mean value of -4.81 pcm/°C was obtained for such coefficient. The curves of ρ(T) (Reactivity x Temperature) and α{sup M}{sub T}(T)(Moderator Temperature Coefficient of Reactivity x Temperature) were developed using data from an experimental measurement of the integral reactivity curves through the Stable Period and Inverse Kinetics Methods, that was carried out at the reactor with the same core configuration. Such curves were compared and showed a very similar behavior between them. (author)

  15. Experimental estimation of average fidelity of a Clifford gate on a 7-qubit quantum processor. (United States)

    Lu, Dawei; Li, Hang; Trottier, Denis-Alexandre; Li, Jun; Brodutch, Aharon; Krismanich, Anthony P; Ghavami, Ahmad; Dmitrienko, Gary I; Long, Guilu; Baugh, Jonathan; Laflamme, Raymond


    One of the major experimental achievements in the past decades is the ability to control quantum systems to high levels of precision. To quantify the level of control we need to characterize the dynamical evolution. Full characterization via quantum process tomography is impractical and often unnecessary. For most practical purposes, it is enough to estimate more general quantities such as the average fidelity. Here we use a unitary 2-design and twirling protocol for efficiently estimating the average fidelity of Clifford gates, to certify a 7-qubit entangling gate in a nuclear magnetic resonance quantum processor. Compared with more than 10^{8} experiments required by full process tomography, we conducted 1656 experiments to satisfy a statistical confidence level of 99%. The average fidelity of this Clifford gate in experiment is 55.1%, and rises to at least 87.5% if the signal's decay due to decoherence is taken into account. The entire protocol of certifying Clifford gates is efficient and scalable, and can easily be extended to any general quantum information processor with minor modifications.

  16. Methods for estimating Curie temperatures of titanomaghemites from experimental J s-T data (United States)

    Moskowitz, Bruce M.


    Methods for determining the Curie temperature ( T c) of titanomaghemites from experimental saturation magnetization-temperature ( J s-T ) data are reviewed. J s-T curves for many submarine basalts and synthetic titanomaghemites are irreversible and determining Curie temperatures from these curves is not a straightforward procedure. Subsequently, differences of sometimes over 100°C in the values of T c may result just from the method of calculation. Two methods for determining T c will be discussed: (1) the graphical method, and (2) the extrapolation method. The graphical method is the most common method employed for determining Curie temperatures of submarine basalts and synthetic titanomaghemites. The extrapolation method based on the quantum mechanical and thermodynamic aspects of the temperature variation of saturation magnetization near T c, although not new to solid state physics, has not been used for estimating Curie temperatures of submarine basalts. The extrapolation method is more objective than the graphical method and uses the actual magnetization data in estimating T c.

  17. AMPS/AAm/AAc Terpolymerization: Experimental Verification of the EVM Framework for Ternary Reactivity Ratio Estimation

    Directory of Open Access Journals (Sweden)

    Alison J. Scott


    Full Text Available The complete error-in-variables-model (EVM framework, consisting of both design of experiments and parameter estimation stages, is applied to the terpolymerization of 2-acrylamido-2-methylpropane sulfonic acid (AMPS, M1, acrylamide (AAm, M2 and acrylic acid (AAc, M3. This water-soluble terpolymer has potential for applications in enhanced oil recovery, but the associated terpolymerization kinetic characteristics are largely unstudied. In the current paper, EVM is used to design optimal experiments (for the first time in the literature, and reactivity ratios are subsequently estimated based on both low and medium-high conversion data. The results from the medium-high conversion data are more precise than those from the low conversion data, and are therefore used next to predict the terpolymer composition trajectory over the full course of conversion. Good agreement is seen between experimental data and model predictions, which confirms the accuracy of the newly determined ternary reactivity ratios: r12 = 0.66, r21 = 0.82, r13 = 0.82, r31 = 0.61, r23 = 1.61, r32 = 0.25.

  18. Ovine and Caprine Toxoplasmosis: Experimental Study

    Directory of Open Access Journals (Sweden)

    Shawkat Q. Lafi


    Full Text Available Eighteen mature ewes of the Mytilene breed and 18 mature Local- Damascus crossbred goats, seronegative for Toxoplasma gondii (T. gondii by ELISA were used. All animals were mated after synchronization of estrus. On day 90 of pregnancy, animals were randomly assigned to 3 experimental groups; 6 ewes (S1 and 6 goats (G1 were orally inoculated by stomach tube with 1000 oocysts; 6 ewes (S2 and 6 goats (G2 were orally inoculated with a non-infected control inoculum. On day 140+2 of pregnancy, the remaining 6 ewes (S3 and 6 goats (G3 were inoculated by stomach tube with 3000 oocysts. Positive T. godii DNA was detected in 94% of fetal and maternal blood, 95% fetal tissue, 89% pre-colostral udder secretions and 12.5% milk samples using Polymerase Chain Reaction (PCR. Infected animals and their live newborns was seropositive (ELISA until the end of the study. PCR was able to detect T. gondii DNA in maternal blood of infected animals 3-5 days before abortion occurred. This time period may be used to implement preventive and therapeutic measure to reduce abortion rate and associated economic losses. Since milk and milk products are important food sources in rural areas and in many cases it is used unpasteurized before consumption. The T. gondii DNA, detected by PCR in milk samples of infected animals, increases the possibility that the parasite is transmitted through consumption of unpasteurized milk which is a highly relevant result for public health considerations and providing valuable information for future research.

  19. A comparison of experimental and estimated data analyses of solar radiation, in Adiyaman, Turkey


    Bozkurt, Ismail; Calis, Nazif; Sogukpinar, Haci


    The world's main energy source is the sun. Other energy sources are caused directly or indirectly from the sun. Turkey has a rich potential in terms of solar energy and interest in solar power systems is increasing in the rapidly evolving technology. In all of the solar energy studies needs solar radiation data but solar radiation measurements are not possible on each area. Therefore, estimation of the solar radiation by using a variety of methods are emerging importance. In this study, ...

  20. Experimental Study of the WEPTOS Wave Energy Converter

    DEFF Research Database (Denmark)

    Pecher, Arthur; Kofoed, Jens Peter; Marchalot, Tanguy

    This report presents the results of an experimental study on the power conversion capabilities and structural loads of the WEPTOS wave energy converter. The investigation focuses mainly at identifying the performance of the WEPTOS prototype in a wide range of production wave states...... and at the mooring forces and structural bending moments in extreme wave conditions, in order to estimate the performance and structural loads of larger WEPTOS machines being located at various offshore locations of interest. The following aspects were the main subjects of investigation: Performance of the prototype...... under a constant and linear PTO loading, the opening angle of the device, the effect of alterations to the wave conditions, and mooring forces and structural bending moments in production and extreme wave states. During the study, a highly realistic scale model was supplied by the client, WEPTOS, which...

  1. Experimental Study of the Weptos Wave Energy Converter

    DEFF Research Database (Denmark)

    Pecher, Arthur; Kofoed, Jens Peter; Larsen, Tommy


    This paper presents the power performance results of the experimental study of the WEPTOS wave energy converter (WEC). This novel device combines an established and efficient wave energy absorbing mechanism with an adjustable structure that can regulate the amount of incoming wave energy and reduce...... loads in extreme wave conditions. This A-shaped floating structure absorbs the energy in the waves through a multitude of rotors, the shape of which is based on the renowned Salter’s Duck. These rotors pivot around a common axle, one for each leg of the structure, to which the rotors transfer...... the absorbed wave energy and which is connected to a common power take off system (one for each leg). The study investigates the performance of the device in a large range of wave states and estimates the performance in terms of mechanical power available to the power take off system of the WEPTOS WEC for two...

  2. Computatonal and experimental study of laminar flames

    Energy Technology Data Exchange (ETDEWEB)

    Smooke, M.D.; Long, M.B. [Yale Univ., New Haven, CT (United States)


    This research has centered on an investigation of the effects of complex chemistry and detailed transport on the structure and extinction of hydrocarbon flames in counterflow, cylindrical and coflowing axisymmetric configurations. The authors have pursued both computational and experimental aspects of the research in parallel. The computational work has focused on the application of accurate and efficient numerical methods for the solution of the one and two-dimensional nonlinear boundary value problems describing the various reacting systems. Detailed experimental measurements were performed on axisymmetric coflow flames using two-dimensional imaging techniques. In particular, spontaneous Raman scattering and laser induced fluorescence were used to measure the temperature, major and minor species profiles.

  3. An experimental evaluation of electrical skin conductivity changes in postmortem interval and its assessment for time of death estimation. (United States)

    Cantürk, İsmail; Karabiber, Fethullah; Çelik, Safa; Şahin, M Feyzi; Yağmur, Fatih; Kara, Sadık


    In forensic medicine, estimation of the time of death (ToD) is one of the most important and challenging medico-legal problems. Despite the partial accomplishments in ToD estimations to date, the error margin of ToD estimation is still too large. In this study, electrical conductivity changes were experimentally investigated in the postmortem interval in human cases. Electrical conductivity measurements give some promising clues about the postmortem interval. A living human has a natural electrical conductivity; in the postmortem interval, intracellular fluids gradually leak out of cells. These leaked fluids combine with extra-cellular fluids in tissues and since both fluids are electrolytic, intracellular fluids help increase conductivity. Thus, the level of electrical conductivity is expected to increase with increased time after death. In this study, electrical conductivity tests were applied for six hours. The electrical conductivity of the cases exponentially increased during the tested time period, indicating a positive relationship between electrical conductivity and the postmortem interval. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Experimental Study of a Thermoelectric Generation System

    DEFF Research Database (Denmark)

    Zhu, Junpeng; Gao, Junling; Chen, Min


    A flat wall-like thermoelectric generation system is developed for applications in exhaust heat of kilns. The design of the whole experimental setup is presented. The essential performance of the thermoelectric generation system is tested, including open-circuit voltage, output power, and system ...

  5. Economic principles in communication: An experimental study

    NARCIS (Netherlands)

    De Jaegher, K.; Rosenkranz, S.; Weitzel, G.U.


    This paper experimentally investigates how economic principles affect communication. In a simple sender–receiver game with common interests over payoffs, the sender can send a signal without a pre-given meaning in an infrequent or frequent state of the world. When the signal is costly, several

  6. Blast mitigation experimental and numerical studies

    CERN Document Server


    Presents experimental methods of material and structural response to dynamic blast loads Includes computational analysis of material and structural response to dynamic blast loads Offers mitigation measures for structures in various environments Relates lab experiments to larger field tests Features more than 150 illustrations

  7. An experimental study of passive regenerator geometries

    DEFF Research Database (Denmark)

    Engelbrecht, Kurt; Nielsen, Kaspar Kirstein; Pryds, Nini


    experimental uncertainty associated with magnetocaloric material properties, all regenerators are made of aluminum. The performance of corrugated plates and dimpled plates are compared to traditional flat plate regenerators for a range of cycle times and utilizations. Each regenerator is built using 18...

  8. Experimental estimation of convective heat transfer coefficient from pulsating semi-confined impingement air slot jet by using inverse method (United States)

    Farahani, Somayeh Davoodabadi; Kowsary, Farshad


    An experimental study on pulsating impingement semi-confined slot jet has been performed. The effect of pulsations frequency was examined for various Reynolds numbers and Nozzle to plate distances. Convective heat transfer coefficient is estimated using the measured temperatures in the target plate and conjugate gradient method with adjoint equation. Heat transfer coefficient in Re 3000), heat transfer coefficient is affected by the pulsation from particular frequency. In this study, the threshold Strouhal number (St) is 0.11. No significant heat transfer enhancement was obtained for St resistance is smaller each time due to the newly forming thermal boundary layers. Heat transfer coefficient increases due to decrease thermal resistance. This study shows that maximum enhancement in heat transfer due to pulsations occurs in St = 0.169. Results show the configuration geometry has an important effect on the heat transfer performances in pulsed impinging jet. Heat transfer enhancement can be described to reflect flow by the confinement plate.

  9. An experimental study on pump clogging (United States)

    Isono, M.; Nohmi, M.; Uchida, H.; Kawai, M.; Kudo, H.; Kawahara, T.; Miyagawa, K.; Saito, S.


    For sewage pump that various foreign substance is flowed into, anti-clogging performance is a factor as important as pump efficiency in order to avoid clogging trouble by foreign substance. Many investigations about pump inner flow and pump efficiency estimation have been carried out conventionally in order to realize coexistence with anti-clogging performance and pump performance. And these results have been reflected in construction of the running water section design method. As a index of anti-clogging performance, "impeller passage diameter" which is diameter of spherical solid that can pass through the pump is used widely. And there are various type of the sewage pump which have large impeller passage diameter. However real cause of clog is not a solid, and it is fibrous material such as towel and clothes, vinyl and paper diaper. In most case these material accumulate in the pump, so that clog is occurred. In this study, for the purpose of quantification of anti-clogging performance against fibrous materials, the factor that affect to clogging of pump was investigated by pump model test using a string. The test is done based on Taguchi method. In this test, type of the pump model, diameter of the string, material of the string, length of the string and flow rate are selected for the factor, and the effect that they have on the clogging of the pump was investigated. As a result of this test, it was made clear that length of the string has a strong influence on the clogging of the pump. And from the result of this test, evaluation method of anti-clogging performance of the pump against fibrous material by using string was considered. According to the result of above test based on Taguchi method, it was assumed that quantification of anti-clogging performance against fibrous materials is possible by flowing plural strings into the pump and calculating the probability of passing. Plurality sewage pumps of different types were evaluated based on this assumption


    African Journals Online (AJOL)

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    experimental and theoretical data have showed that the molecular geometry and the ... 1D and 2D hetero- and homonuclear NMR methods enable to ... The essence of this study is briefly to report experimental and theoretical NMR features of.

  11. Model refinement for offshore platforms: Experimental study (United States)

    Zhang, Min; Chen, Zongli; Wu, Yanjian


    Offshore jacket platforms are widely used in offshore oil and gas exploitation. Finite element models of such structures need to have many degrees of freedom (DOFs) to represent the geometrical detail of complex structures, thereby leading to incompatibility in the number of DOFs of experimental models. To bring them both to the same order while ensuring that the essential eigen- properties of the refined model match those of experimental models, an extended model refinement procedure is presented in this paper. Vibration testing of an offshore jacket platform model is performed to validate the applicability of the proposed approach. A full-order finite element model of the platform is established and then tuned to meet the measured modal properties identified from the acceleration signals. Both model reduction and modal expansion methods are investigated, as well as various scenarios of sensor arrangements. Upon completion of the refinement, the updated jacket platform model matches the natural frequencies of the measured model well.

  12. Experimental studies of Steel Corrugated Constructions

    Directory of Open Access Journals (Sweden)

    Lazarev Yuriy


    Full Text Available The purpose of this particular article is to assess existing calculations of steel corrugated constructions. Steel Corrugated Construction is a perspective type of constructions, which is exhibiting numerous advantages in comparison with one that currently applied in automobile and railroad networks (reinforced concrete water-throughput pipes, reinforced concrete frame bridges. The evaluation of experimental data on models of constructions of this particular type has been carried out in order to improve calculations of Steel Corrugated Constructions.

  13. Uncertainty in techno-economic estimates of cellulosic ethanol production due to experimental measurement uncertainty

    Directory of Open Access Journals (Sweden)

    Vicari Kristin J


    Full Text Available Abstract Background Cost-effective production of lignocellulosic biofuels remains a major financial and technical challenge at the industrial scale. A critical tool in biofuels process development is the techno-economic (TE model, which calculates biofuel production costs using a process model and an economic model. The process model solves mass and energy balances for each unit, and the economic model estimates capital and operating costs from the process model based on economic assumptions. The process model inputs include experimental data on the feedstock composition and intermediate product yields for each unit. These experimental yield data are calculated from primary measurements. Uncertainty in these primary measurements is propagated to the calculated yields, to the process model, and ultimately to the economic model. Thus, outputs of the TE model have a minimum uncertainty associated with the uncertainty in the primary measurements. Results We calculate the uncertainty in the Minimum Ethanol Selling Price (MESP estimate for lignocellulosic ethanol production via a biochemical conversion process: dilute sulfuric acid pretreatment of corn stover followed by enzymatic hydrolysis and co-fermentation of the resulting sugars to ethanol. We perform a sensitivity analysis on the TE model and identify the feedstock composition and conversion yields from three unit operations (xylose from pretreatment, glucose from enzymatic hydrolysis, and ethanol from fermentation as the most important variables. The uncertainty in the pretreatment xylose yield arises from multiple measurements, whereas the glucose and ethanol yields from enzymatic hydrolysis and fermentation, respectively, are dominated by a single measurement: the fraction of insoluble solids (fIS in the biomass slurries. Conclusions We calculate a $0.15/gal uncertainty in MESP from the TE model due to uncertainties in primary measurements. This result sets a lower bound on the error bars of

  14. An experimental study of opinion influenceability

    CERN Document Server

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


    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. Probabilistic evidential assessment of gunshot residue particle evidence (Part II): Bayesian parameter estimation for experimental count data. (United States)

    Biedermann, A; Bozza, S; Taroni, F


    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.

  16. Demographic aspects of Chrysomya megacephala (Diptera, Calliphoridae adults maintained under experimental conditions: reproductive rate estimates

    Directory of Open Access Journals (Sweden)

    Marcelo Henrique de Carvalho


    Full Text Available The objective of this work was to evaluate some aspects of the populational ecology of Chrysomya megacephala, analyzing demographic aspects of adults kept under experimental conditions. Cages of C. megacephala adults were prepared with four different larval densities (100, 200, 400 and 800. For each cage, two tables were made: one with demographic parameters for the life expectancy estimate at the initial age (e0, and another with the reproductive rate and average reproduction age estimates. Populational parameters such as the intrinsic growth rate (r and the finite growth rate (lambda were calculated as well.Chrysomya megacephala (Fabricius (Diptera, Calliphoridae é uma espécie de mosca-varejeira de considerável importância médico-sanitária que foi introduzida acidentalmente no Brasil nos anos 70. O objetivo do presente trabalho foi avaliar alguns aspectos da ecologia populacional desta espécie, analisando aspectos demográficos de adultos mantidos sob condições experimentais. Gaiolas de C. megacephala foram montadas com quatro diferentes densidades larvais (100, 200, 400 e 800. Para cada gaiola, foram confeccionadas duas tabelas: uma com parâmetros demográficos para a estimativa da expectativa de vida na idade inicial (e0, e outra com as estimativas de taxa reprodutiva e idade média de reprodução. Parâmetros populacionais tais como a taxa intrínseca de crescimento (r e a taxa finita de crescimento (lambda foram também calculados.

  17. Oxygenation level and hemoglobin concentration in experimental tumor estimated by diffuse optical spectroscopy (United States)

    Orlova, A. G.; Kirillin, M. Yu.; Volovetsky, A. B.; Shilyagina, N. Yu.; Sergeeva, E. A.; Golubiatnikov, G. Yu.; Turchin, I. V.


    Using diffuse optical spectroscopy the level of oxygenation and hemoglobin concentration in experimental tumor in comparison with normal muscle tissue of mice have been studied. Subcutaneously growing SKBR-3 was used as a tumor model. Continuous wave fiber probe diffuse optical spectroscopy system was employed. Optical properties extraction approach was based on diffusion approximation. Decreased blood oxygen saturation level and increased total hemoglobin content were demonstrated in the neoplasm. The main reason of such differences between tumor and norm was significant elevation of deoxyhemoglobin concentration in SKBR-3. The method can be useful for diagnosis of tumors as well as for study of blood flow parameters of tumor models with different angiogenic properties.

  18. Automated estimation of hip prosthesis migration: a feasibility study (United States)

    Vandemeulebroucke, Jef; Deklerck, Rudi; Temmermans, Frederik; Van Gompel, Gert; Buls, Nico; Scheerlinck, Thierry; de Mey, Johan


    A common complication associated with hip arthoplasty is prosthesis migration, and for most cemented components a migration greater than 0.85 mm within the first six months after surgery, are an indicator for prosthesis failure. Currently, prosthesis migration is evaluated using X-ray images, which can only reliably estimate migrations larger than 5 mm. We propose an automated method for estimating prosthesis migration more accurately, using CT images and image registration techniques. We report on the results obtained using an experimental set-up, in which a metal prosthesis can be translated and rotated with respect to a cadaver femur, over distances and angles applied using a combination of positioning stages. Images are first preprocessed to reduce artefacts. Bone and prosthesis are extracted using consecutive thresholding and morphological operations. Two registrations are performed, one aligning the bones and the other aligning the prostheses. The migration is estimated as the difference between the found transformations. We use a robust, multi-resolution, stochastic optimization approach, and compare the mean squared intensity differences (MS) to mutual information (MI). 30 high-resolution helical CT scans were acquired for prosthesis translations ranging from 0.05 mm to 4 mm, and rotations ranging from 0.3° to 3° . For the translations, the mean 3D registration error was found to be 0.22 mm for MS, and 0.15 mm for MI. For the rotations, the standard deviation of the estimation error was 0.18° for MS, and 0.08° for MI. The results show that the proposed approach is feasible and that clinically acceptable accuracies can be obtained. Clinical validation studies on patient images will now be undertaken.

  19. Orientational order parameter estimated from molecular polarizabilities - an optical study (United States)

    Lalitha Kumari, J.; Datta Prasad, P. V.; Madhavi Latha, D.; Pisipati, V. G. K. M.


    An optical study of N-(p-n-alkyloxybenzylidene)-p-n-butyloxyanilines, nO.O4 compounds with the alkoxy chain number n = 1, 3, 6, 7, and 10 has been carried out by measuring the refractive indices using modified spectrometer and direct measurement of birefringence employing the Newton's rings method. Further, the molecular polarizability anisotropies are evaluated using Lippincott δ-function model, the molecular vibration method, Haller's extrapolation method, and scaling factor method. The molecular polarizabilities α e and α 0 are calculated using Vuk's isotropic and Neugebauer anisotropic local field models. The order parameter S is estimated by employing the molecular polarizability values determined from experimental refractive indices and density data and the polarizability anisotropy values. Further, the order parameter S is also obtained directly from the birefringence data. A comparison has been carried out among the order parameter obtained from different ways and the results are compared with the body of the data available in the literature.

  20. Theoretical and experimental estimation of geometric relationship of non-parallel conjugate normal faults (United States)

    Yu, Fusheng; Koyi, Hemin


    Intersecting and crossing conjugate normal faults develop at different scales. Equations of geometric parameters of non-parallel conjugate normal faults can be deduced from their trigonometric relations. Physical models can also be used to verify the theoretical calculations and compared with natural examples. In this study, we have used a theoretical approach to outline some key geometric parameters of conjugate normal faults (intersection angles, plunge of intersection line, and vertical and horizontal distances of the intersection point, etc.) and compared them to equivalent geometric values in scaled analogue models. The comparison shows that theoretical plots used for geometric estimation of conjugate normal faults constrain reasonably the geometric parameters in natural cases. Data from the Lufeng Sag of Pearl River Mouth Basin in the northern part of South China Sea, where conjugate non-parallel basement faults propagate and intersect in cover units are compatible with the theoretical geometric estimation.

  1. Experimental study of the nucleon spin structure

    Energy Technology Data Exchange (ETDEWEB)

    Litmaath, M.F.


    After introducing the theoretical framework, which includes DIS, the Quark Parton Model (QPM) and QCD, we describe the implementation of the experiment. The SMC uses a beam of 190 GeV naturally polarized muons, scattering off nucleons in a large cryogenic target containing protons or deuterons that are polarized through Dynamic Nuclear Polarization (DNP). The target material is located in two cells in a row, with opposite polarizations. Every 5 hours the polarizations of both cells are reversed. The target polarization is measured by an NMR system. The polarization of the beam is measured in a polarimeter, located downstream of the main experimental setup. (orig.).

  2. Experimental Studies of Coaxial Plasma Gun Current (United States)


    insertion into experimental systems (117-133), fueling for proposed thermonuclear reactors (134-138], breeding fissionable material [139, 140] and...Center Top Level Linear Exponential Yield Current Current Extrap . Extrap . (MA) (MA) Current Current (MA) (MA) 02901 2.8106 0.18 0.05 D3001 1.2x107...Exponential Yield Current Current Extrap . Extrap . (MA) (MA) Current Current (MA) (MA) 30703 1.610 8 1.57 0.64 0.54 0.59 J0706 4.040O 1.46 0.85 0.80 0.82 J

  3. Experimental Results of Novel DoA Estimation Algorithms for Compact Reconfigurable Antennas

    Directory of Open Access Journals (Sweden)

    Henna Paaso


    Full Text Available Reconfigurable antenna systems have gained much attention for potential use in the next generation wireless systems. However, conventional direction-of-arrival (DoA estimation algorithms for antenna arrays cannot be used directly in reconfigurable antennas due to different design of the antennas. In this paper, we present an adjacent pattern power ratio (APPR algorithm for two-port composite right/left-handed (CRLH reconfigurable leaky-wave antennas (LWAs. Additionally, we compare the performances of the APPR algorithm and LWA-based MUSIC algorithms. We study how the computational complexity and the performance of the algorithms depend on number of selected radiation patterns. In addition, we evaluate the performance of the APPR and MUSIC algorithms with numerical simulations as well as with real world indoor measurements having both line-of-sight and non-line-of-sight components. Our performance evaluations show that the DoA estimates are in a considerably good agreement with the real DoAs, especially with the APPR algorithm. In summary, the APPR and MUSIC algorithms for DoA estimation along with the planar and compact LWA layout can be a valuable solution to enhance the performance of the wireless communication in the next generation systems.



    Udiyani, P.M; Sri Kuntjoro


    Experimental power reactor (RDE) which is planned to be constructed by BATAN is a kind of High Temperature Gas Cooled Reactor (HTGR) with 10 MWth power. HTGR is a helium gas-cooled reactor with TRISO-coated fuel that is able to confine fission products remained in the core. Although the fission products released into the environment are very small, in order to comply the regulations the study about environmental radiation on normal or routine operation condition need to be performed. Estimati...

  5. Experimental study of external fuel vaporization (United States)

    Szetela, E. J.; Tevelde, J. A.


    The fuel properties used in the design of a flash vaporization system for aircraft gas turbine engines were evaluated in experiments using a flowing system to determine critical temperature and pressure, boiling points, dew points, heat transfer coefficients, deposit formation rates, and deposit removal. Three fuels were included in the experiments: Jet-A, an experimental referree broad specification fuel, and a premium No. 2 diesel fuel. Engine conditions representing a NASA Energy Efficient Engine at sea-level take-off, cruise, and idle were simulated in the vaporization system and it was found that single phase flow was maintained in the heat exchanger and downstream of the throttle. Deposits encountered in the heat exchanger represented a thermal resistance as high as 1300 sq M K/watt and a deposit formation rate over 1000 gC/sq cm hr.

  6. Experimental Study of the Sampled Labyrinth Chaos

    Directory of Open Access Journals (Sweden)

    J. Petrzela


    Full Text Available In this paper, some new numerical as well as experimental results connected with the so-called labyrinth chaos are presented. This very unusual chaotic motion can be generated by mathematical model involving the scalar goniometrical functions which makes a three-dimensional autonomous dynamical system strongly nonlinear. Final circuitry implementation with analog core and digital parts can be used for modeling Brownian motion. From the viewpoint of generating chaotic motion by some electronic circuit, first step is to solve problems associated with the two-port nonlinear transfer functions synthesis. In the case of labyrinth chaos the finite dynamical range of the input variables introduced by the used active elements usually limits the performance greatly, similarly as it holds for the multi-grid spiral attractors. This paper shows an elegant way how to remove these obstacles by using uni-versal multiple-port with internal digital signal processing.

  7. Experimental Study of Pollutant Transfer within Dwellings

    CERN Document Server

    Koffi, Juslin; Allard, Francis; Husaunndee, Ahmad


    A mechanical ventilation principle used in French residential buildings was tested in the experimental house of the CSTB research centre. The experiments dealt with pollutant removal efficiency of this ventilation principle, mainly with air tightness and the influence of internal doors. Tracer gas constant injection method was used to simulate the pollution source in the living room. SF6 concentrations were measured in several rooms. The results showed that the air flow routes were in agreement with the theory as long as internal doors were closed. When doors were open, the air pattern was disturbed a lot; a great quantity of the emitted pollutant was measured in the bedrooms. Besides, stack effect promotes the pollutant moving towards the bedrooms under higher indoor-outdoor air temperature differences. In addition, the results showed that if the opening of the bedroom window increases the air change rate, it does not guarantee a good indoor air quality.

  8. Computational and experimental study of laminar flames

    Energy Technology Data Exchange (ETDEWEB)

    Smooke, Mitchell [Yale Univ., New Haven, CT (United States)


    During the past three years, our research has centered on an investigation of the effects of complex chemistry and detailed transport on the structure and extinction of hydrocarbon flames in coflowing axisymmetric configurations. We have pursued both computational and experimental aspects of the research in parallel on both steady-state and time-dependent systems. The computational work has focused on the application of accurate and efficient numerical methods for the solution of the steady-state and time-dependent boundary value problems describing the various reacting systems. Detailed experimental measurements were performed on axisymmetric coflow flames using two-dimensional imaging techniques. Previously, spontaneous Raman scattering, chemiluminescence, and laser-induced fluorescence were used to measure the temperature, major and minor species profiles. Particle image velocimetry (PIV) has been used to investigate velocity distributions and for calibration of time-varying flames. Laser-induced incandescence (LII) with an extinction calibration was used to determine soot volume fractions, while soot surface temperatures were measured with three-color optical pyrometry using a color digital camera. A blackbody calibration of the camera allows for determination of soot volume fraction as well, which can be compared with the LII measurements. More recently, we have concentrated on a detailed characterization of soot using a variety of techniques including time-resolved LII (TiRe-LII) for soot primary particles sizes, multi-angle light scattering (MALS) for soot radius of gyration, and spectrally-resolved line of sight attenuation (spec-LOSA). Combining the information from all of these soot measurements can be used to determine the soot optical properties, which are observed to vary significantly depending on spatial location and fuel dilution. Our goal has been to obtain a more fundamental understanding of the important fluid dynamic and chemical interactions in

  9. Experimental study on HVAC sound parameters (United States)

    Bujoreanu, C.; Benchea, M.


    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.

  10. Experimental study of asymmetric heart valve prototype (United States)

    Vukicevic, M.; Fortini, S.; Querzoli, G.; Cenedese, A.; Pedrizzetti, G.


    The mechanical heart valves (MHVs) are extremely important medical devices, commonly used for diseased heart valves replacement. Despite the long term of use and constant design refinement, the MHVs are very far from ideal and their performance is very diverse from that of the native ones. It has been approved that small variations in geometry of valvular leaflets influence the significant change in the intraventricular vortical flow, known as one of the most important factors for the overall functionality of the heart. We have experimentally examined the home-made heart valve prototypes, exclusively modeled for the mitral valve replacement. The performance and energetic properties of the prototypes have been compared with those in the presence of standard MHVs. The analysis was based on the testing of intraventricular fluid dynamics, usually missing criteria for the quality of the valve performance. It has been shown that the asymmetric prototype, with unequal leaflets and D-shaped orifice produces flow patterns and energetic properties close to those found in the healthy subjects. Thus, the break of symmetry in the standard bi-leaflet MHV prosthesis, at least from the fluid dynamics point of view, is worthwhile to be considered for the design of MHVs for the mitral valve replacement.

  11. Estimating valence from the sound of a word: Computational, experimental, and cross-linguistic evidence. (United States)

    Louwerse, Max; Qu, Zhan


    It is assumed linguistic symbols must be grounded in perceptual information to attain meaning, because the sound of a word in a language has an arbitrary relation with its referent. This paper demonstrates that a strong arbitrariness claim should be reconsidered. In a computational study, we showed that one phonological feature (nasals in the beginning of a word) predicted negative valence in three European languages (English, Dutch, and German) and positive valence in Chinese. In three experiments, we tested whether participants used this feature in estimating the valence of a word. In Experiment 1, Chinese and Dutch participants rated the valence of written valence-neutral words, with Chinese participants rating the nasal-first neutral-valence words more positive and the Dutch participants rating nasal-first neutral-valence words more negative. In Experiment 2, Chinese (and Dutch) participants rated the valence of Dutch (and Chinese) written valence-neutral words without being able to understand the meaning of these words. The patterns replicated the valence patterns from Experiment 1. When the written words from Experiment 2 were transformed into spoken words, results in Experiment 3 again showed that participants estimated the valence of words on the basis of the sound of the word. The computational study and psycholinguistic experiments indicated that language users can bootstrap meaning from the sound of a word.

  12. Economic principles in communication: an experimental study. (United States)

    De Jaegher, Kris; Rosenkranz, Stephanie; Weitzel, Utz


    This paper experimentally investigates how economic principles affect communication. In a simple sender-receiver game with common interests over payoffs, the sender can send a signal without a pre-given meaning in an infrequent or frequent state of the world. When the signal is costly, several theories (focal point theory, the intuitive criterion, evolutionary game theory) predict an efficient separating equilibrium, where the signal is sent in the infrequent state of the world (also referred to as Horn׳s rule). To analyze whether Horn׳s rule applies, and if so, which theory best explains it, we develop and test variants of the sender-receiver game where the theories generate discriminatory hypotheses. In costly signaling variants, our participants follow Horn׳s rule most of the time, in a manner that is best explained by focal point theory. In costless signaling variants, evolutionary game theory best explains our results. Here participants coordinate significantly more (less) often on a separating equilibrium where the signal is sent in the frequent state if they are primed to associate the absence of a signal with the infrequent (frequent) state of the world. We also find indications that a similar priming effect applies to costly signals. Thus, while the frequency with which participants follow Horn׳s rule in costly signaling variants is best explained by Horn׳s rule, the priming effect shows that some of our participants׳ behavior is best explained by evolutionary game theory even when signals are costly. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Experimental studies of local scour in the pressurized OCF below a ...

    Indian Academy of Sciences (India)

    The proposed study examined and reviewed the published experimental results related to clear water scour below a cylinder across the flow. It also highlighted the limitations of existing methods for estimating the scour depth below a submerged cylinder. In the present study, experiments were performed for 50% and 75% ...

  14. Comparing apples and pears in studies on magnitude estimations. (United States)

    Ebersbach, Mirjam; Luwel, Koen; Verschaffel, Lieven


    The present article is concerned with studies on magnitude estimations that strived to uncover the underlying mental representation(s) of magnitudes. We point out a number of methodological differences and shortcomings that make it difficult drawing general conclusions. To solve this problem, we propose a taxonomy by which those studies could be classified, taking into account central methodological aspects of magnitude estimation tasks. Finally, we suggest perspectives for future research on magnitude estimations, which might abandon the hunt for the mathematical model that explains estimations best and turn, instead, to investigate the underlying principles of estimations (e.g., strategies) and ways of their improvement.

  15. Comparing apples and pears in studies on magnitude estimations

    Directory of Open Access Journals (Sweden)

    Mirjam eEbersbach


    Full Text Available The present article is concerned with studies on magnitude estimations that strived to uncover the underlying mental representation(s of magnitudes. We point out a number of methodological differences and shortcomings that make it difficult drawing general conclusions. To solve this problem, we propose a taxonomy by which those studies could be classified, taking into account central methodological aspects of magnitude estimation tasks. Finally, we suggest perspectives for future research on magnitude estimations, which might abandon the hunt for the mathematical model that explains estimations best and turn, instead, to investigate the underlying principles of estimations (e.g., strategies and ways of their improvement.

  16. Experimental Verification for Cable Force Estimation Using Handheld Shooting of Smartphones

    Directory of Open Access Journals (Sweden)

    Xuefeng Zhao


    Full Text Available Currently, due to the rapid development and popularization of smartphones, the usage of ubiquitous smartphones has attracted growing interest in the field of structural health monitoring (SHM. The portable and rapid cable force measurement for cable-supported structures, such as a cable-stayed bridge and a suspension bridge, has an important and practical significance in the evaluation of initial damage and the recovery of transportation networks. The extraction of dynamic characteristics (natural frequencies of cable is considered as an essential issue in the cable force estimation. Therefore, in this study, a vision-based approach is proposed for identifying the natural frequencies of cable using handheld shooting of smartphone camera. The boundary of cable is selected as a target to be tracked in the region of interest (ROI of video image sequence captured by smartphone camera, and the dynamic characteristics of cable are identified according to its dynamic displacement responses in frequency domain. The moving average is adopted to eliminate the noise associated with the shaking of smartphone camera during measurement. A laboratory scale cable model test and a pedestrian cable-stayed bridge test are carried out to evaluate the proposed approach. The results demonstrate the feasibility of using smartphone camera for cable force estimation.

  17. Theoretical & Experimental Studies of Elementary Particles

    Energy Technology Data Exchange (ETDEWEB)

    McFarland, Kevin [Univ. of Rochester, NY (United States)


    Abstract High energy physics has been one of the signature research programs at the University of Rochester for over 60 years. The group has made leading contributions to experimental discoveries at accelerators and in cosmic rays and has played major roles in developing the theoretical framework that gives us our ``standard model'' of fundamental interactions today. This award from the Department of Energy funded a major portion of that research for more than 20 years. During this time, highlights of the supported work included the discovery of the top quark at the Fermilab Tevatron, the completion of a broad program of physics measurements that verified the electroweak unified theory, the measurement of three generations of neutrino flavor oscillations, and the first observation of a ``Higgs like'' boson at the Large Hadron Collider. The work has resulted in more than 2000 publications over the period of the grant. The principal investigators supported on this grant have been recognized as leaders in the field of elementary particle physics by their peers through numerous awards and leadership positions. Most notable among them is the APS W.K.H. Panofsky Prize awarded to Arie Bodek in 2004, the J.J. Sakurai Prizes awarded to Susumu Okubo and C. Richard Hagen in 2005 and 2010, respectively, the Wigner medal awarded to Susumu Okubo in 2006, and five principal investigators (Das, Demina, McFarland, Orr, Tipton) who received Department of Energy Outstanding Junior Investigator awards during the period of this grant. The University of Rochester Department of Physics and Astronomy, which houses the research group, provides primary salary support for the faculty and has waived most tuition costs for graduate students during the period of this grant. The group also benefits significantly from technical support and infrastructure available at the University which supports the work. The research work of the group has provided educational opportunities

  18. Dynamic transport of suspended sediment by solitary wave: Experimental study (United States)

    cho, JaeNam; Kim, DongHyun; Hwang, KyuNam; Lee, SeungOh


    Solitary waves are able to transport a large amount of suspended sediment when approaching on the beach, which sometimes causes - serious beach erosion, especially in the east and south coastal lines in Korea. But it has rarely been known about the method how to evaluate or estimate the amount of beach erosion caused by solitary waves. Experimental assessment is necessary to comprehend the process of sediment transport on a slope. The prismatic rectangular channel is 12 m long, 0.8 m wide, and 0.75 m high. A sluice gate is applied at prismatic channel in order to produce the solitary waves. Upstream water depth is more than channel water depth and the sluice gate is suddenly opened to simulate conditions of solitary waves. A sand slope with a 1/6 and a sediment thickness is 0.03 m. The experimental sediments are used anthracite (d_50=1.547 mm ,C_u=1.38) and Jumoonjin sand (d_50=0.627 mm ,C_u=1.68). Specific laboratory equipment are designed to collect suspended sediment samples at the same time along the wave propagation at 5 points with evenly space. Each amount of sampling is approximately 25 ml and they are completely dried in oven over 24 hours according to the USGS (Guideline and standard techniques and method 3-C4). Two video cameras (Model No. : Sony, HDR-XR550) are mounted for capturing images at top and side-view when the processes of solitary wave and run up/down on slope. Also, this study are analyzed the correlation between Suspended sediment concentration and turbidity. Also, this study are analyzed the correlation between suspended sediment concentration and turbidity. Turbidity is used to verify suspended sediment concentration. Dimensionless analyses of experimental results carried out in this study. One dimensionless parameter is expressed with pressure of solitary wave on a slope to suspended sediment concentration, which is concerned about lifting force. The other is relate to drag force presenting with run up/down velocity on a slope and

  19. Experimental Study of Current-Driven Turbulence During Magnetic Reconnection

    Energy Technology Data Exchange (ETDEWEB)

    Porkolab, Miklos; Egedal-Pedersen, Jan; Fox, William


    CMPD Final Report Experimental Study of Current-Driven Turbulence During Magnetic Reconnection Miklos Porkolab, PI, Jan Egedal, co-PI, William Fox, graduate student. This is the final report for Grant DE-FC02-04ER54786, MIT Participation in the Center for Multiscale Plasma Dynamics, which was active from 8/1/2004 to 7/31/2010. This Grant supported the thesis work of one MIT graduate student, William Fox, The thesis research consisted of an experimental study of the fluctuations arising during magnetic reconnection in plasmas on the Versatile Toroidal Facility (VTF) at MIT Plasma Science and Fusion Center (PSFC). The thesis was submitted and accepted by the MIT physics Department,. Fox, Experimental Study of Current-Driven Turbulence During Magnetic Reconnection, Ph.D. Thesis, MIT (2009). In the VTF experiment reconnection and current-sheet formation is driven by quickly changing currents in a specially arranged set of internal conductors. Previous work on this device [Egedal, et al, PRL 98, 015003, (2007)] identified a spontaneous reconnection regime. In this work fluctuations were studied using impedance-matched, high-bandwidth Langmuir probes. Strong, broadband fluctuations, with frequencies extending from near the lower-hybrid frequency [fLH = (fcefci)1/2] to the electron cyclotron frequency fce were found to arise during the reconnection events. Based on frequency and wavelength measurements, lower-hybrid waves and Trivelpiece-Gould waves were identified. The lower-hybrid waves are easiest to drive with strong perpendicular drifts or gradients which arise due to the reconnection events; an appealing possibility is strong temperature gradients. The Trivelpiece-Gould modes can result from kinetic, bump-on-tail instability of a runaway electron population energized by the reconnection events. We also observed that the turbulence is often spiky, consisting of discrete positive-potential spikes, which were identified as electron phase-space holes, a class of

  20. Estimating frontal and parietal involvement in cognitive estimation: a study of focal neurodegenerative diseases

    Directory of Open Access Journals (Sweden)

    Teagan Ann Bisbing


    Full Text Available We often estimate an unknown value based on available relevant information, a process known as cognitive estimation. In this study, we assess the cognitive and neuroanatomic basis for quantitative estimation by examining deficits in patients with focal neurodegenerative disease in frontal and parietal cortex. Executive function and number knowledge are key components in cognitive estimation. Prefrontal cortex has been implicated in multilevel reasoning and planning processes, and parietal cortex has been associated with number knowledge required for such estimations. We administered the Biber Cognitive Estimation Test (BCET to assess cognitive estimation in 22 patients with prefrontal disease due to behavioral variant frontotemporal dementia (bvFTD, to 17 patients with parietal disease due to corticobasal syndrome (CBS or posterior cortical atrophy (PCA and 11 patients with mild cognitive impairment (MCI. Both bvFTD and CBS/PCA patients had significantly more difficulty with cognitive estimation than controls. MCI were not impaired on BCET relative to controls. Regression analyses related BCET performance to gray matter atrophy in right lateral prefrontal and orbital frontal cortices in bvFTD, and to atrophy in right inferior parietal cortex, right insula and fusiform cortices in CBS/PCA. These results are consistent with the hypothesis that a frontal-parietal network plays a crucial role in cognitive estimation.

  1. An experimental result of estimating an application volume by machine learning techniques. (United States)

    Hasegawa, Tatsuhito; Koshino, Makoto; Kimura, Haruhiko


    In this study, we improved the usability of smartphones by automating a user's operations. We developed an intelligent system using machine learning techniques that periodically detects a user's context on a smartphone. We selected the Android operating system because it has the largest market share and highest flexibility of its development environment. In this paper, we describe an application that automatically adjusts application volume. Adjusting the volume can be easily forgotten because users need to push the volume buttons to alter the volume depending on the given situation. Therefore, we developed an application that automatically adjusts the volume based on learned user settings. Application volume can be set differently from ringtone volume on Android devices, and these volume settings are associated with each specific application including games. Our application records a user's location, the volume setting, the foreground application name and other such attributes as learning data, thereby estimating whether the volume should be adjusted using machine learning techniques via Weka.


    Directory of Open Access Journals (Sweden)

    O. M. Ustarkhanov


    Full Text Available The paper deals a new structural solution of reinforced glued wooden beam and results ofexperimental studies of the bearing capacity of reinforced beams in a special way. We presentthedesign parameters ofprototypebeams, description ofthe experimental setup, results of experimental studies and comparative analysis ofthe stresses anddeflectionsdepending on how the pinching inclined armature.

  3. Experimental studies of auroral arc generators

    Energy Technology Data Exchange (ETDEWEB)

    Suszcynsky, D.M.; Borovsky, J.E.; Thomsen, M.F. [and others


    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). An all-sky video camera system was deployed in Eagle, Alaska at the foot of the magnetic field line that threads geosynchronous satellite 1989-046 as part of a campaign to study correlations of ground-based auroral activity with satellite-based plasma and energetic particle measurements. The overall intent of the project was to study magnetosphere-ionosphere coupling as it relates to the aurora, and, in particular, to look for signatures that may help to identify various auroral generator mechanism(s). During this study, our efforts were primarily directed towards identifying the generator mechanism(s) for pulsating aurora. Our data, though not conclusive, are found to support theories that propose a cyclotron resonance mechanism for the generation of auroral pulsations.

  4. Experimental studies of actinides in molten salts

    Energy Technology Data Exchange (ETDEWEB)

    Reavis, J.G.


    This review stresses techniques used in studies of molten salts containing multigram amounts of actinides exhibiting intense alpha activity but little or no penetrating gamma radiation. The preponderance of studies have used halides because oxygen-containing actinide compounds (other than oxides) are generally unstable at high temperatures. Topics discussed here include special enclosures, materials problems, preparation and purification of actinide elements and compounds, and measurements of various properties of the molten volts. Property measurements discussed are phase relationships, vapor pressure, density, viscosity, absorption spectra, electromotive force, and conductance. 188 refs., 17 figs., 6 tabs.

  5. Experimental Study on Gastric Juice Secretion by ...

    African Journals Online (AJOL)



    May 29, 2012 ... reduced (P < 0.05) when acupuncture at zusanli was applied after treatment with cimetidine. Therefore, our study shows that when electroacupuncture at zusanli is applied, the gastric electrical frequency increased and gastric electrical amplitude reduced, while the flux of gastric juice secretion increased.

  6. Experimental and computational studies of polar solvation

    Energy Technology Data Exchange (ETDEWEB)


    Many articles and papers were published; a few are still in preparation or will be published. The solvation dynamics studies will be extended to ionic solutions. Computer simulations were also performed. A new line of research was begun on excited-state proton-transfer reactions catalyzed by alcohol solvents. (DLC)

  7. An experimental approach to estimation of human information processing capacity for diagnosis tasks in NPPs

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Tae


    The objectives of this research are 1) to determine the human's information processing capacity and 2) to describe the relationship between the information processing capacity and human factors. This research centers on the relationship, as experimentally determined, between an operator's mental workload and information flow during accident diagnosis tasks at nuclear power plants (NPPs). The relationship between the information flow rate and operator's mental workload is investigated experimentally. According to this relationship, the operator's information processing capacity can be established. Once the information processing capacity of a main control room (MCR) operator in a NPP is known, it is possible to apply it 1) to predict the operator's performance, 2) to design diagnosis tasks, and 3) to design human-machine interface. In advanced MCR, an operator's mental activity is more important than his or her physical activity. The mental workload is the portion of the operator's limited capacity that is actually required to perform a particular task. A high mental workload may cause an operator to make a mistake and consequently affect that the safe operation of NPPs. Thus, to predict an operator's performance is very important for the nuclear safety. The information processing capacity is the operator's ability to manage the amount of bits per second when an operator is diagnosing tasks or accidents. We can estimate the information processing capacity using the relationship between the information flow rate and human performance. That is, if the operator's performance decreases rapidly as the information flow rate (bit/sec) is increased, it is possible to determine the operator's information processing capacity. A diagnosis task is one of the most complex and mentally demanding tasks as well as a crucial part in maintaining the safe operation of NPPs. Diagnosis tasks refer to the overall tasks of finding the

  8. An Experimental Study to Control Scour at River Confluence (United States)

    Wuppukondur, A.; Chandra, V.


    The aim of present study is finding a method to control sediment erosion at river confluence. The confluences are mixture of two different flows and are common occurrences along the river. River confluences are sites of natural scour phenomenon and also influence reservoir sedimentation. The river confluence is associated with a separation zone, stagnation zone and a mixing layer along which the scour hole is observed. The eroded sediment creates potential problems by depositing at unwanted downstream locations such as barrages, weirs, check dams, reservoirs etc. As per the literature, the storage capacity of major reservoirs in India is going to be reduced nearly half of the storage capacity by 2020. Hence, an experimental study has been conducted on mobile bed (d50=0.28 mm) with a confluence angle of 90o for a discharge ratio (Qr) of 0.5, where, Qr is defined as the ratio between lateral flow discharge (Ql) and main flow discharge (Qm). Circular shape pile models of same diameter are arranged in a systematic manner with constant spacing (5 cm, 10 cm and 15 cm) to change the flow pattern for reducing scour at the confluence. Two types of pile models (8 mm ϕ and 12 mm ϕ) are used to conduct the experiments. The experimental results show that maximum scour depth at confluence is reduced by 60%. In addition, the bed profile modifications are also reported. Keywords: Reservoir sedimentation, River confluence, Mobile bed, Scour, Vanes. References:1. Borghei, S. M., and Sahebari, A. J. (2010). "Local Scour at Open-Channel Junctions", Journal of Hydraulic Research, 48(4), 37 - 41. 2. Kothyari, U. C. (1996). "Methods for Estimation Sediment Yield from Catchments", Proc., Int. Sem. On Civil Engg. Practices in Twenty First Century, Roorkee, India, 1071-1086. 3. Mosley, M. P. (1976) "An Experimental Study of Channel Confluences". The Journal of Geology, 84(55), 532-562. 4. Ouyang, H. T. (2009). "Investigation on the dimensions and shape of a submerged vane for sediment

  9. Experimental study of highly viscous impinging jets

    Energy Technology Data Exchange (ETDEWEB)

    Gomon, M. [Univ. of Texas, Austin, TX (United States). Dept. of Mechanical Engineering


    The objective of this research is to study the behavior of highly viscous gravity-driven jets filling a container. Matters of interest are the formation of voids in the fluid pool during the filling process and the unstable behavior of the fluid in the landing region which manifests itself as an oscillating motion. The working fluids used in this research are intended to simulate the flow behavior of molten glass. Qualitative and quantitative results are obtained in a parametric study. The fraction of voids present in the fluid pool after the filling of the container is measured for different parameter values of viscosity and mass flow rate. Likewise, frequencies of the oscillating jet are measured. Results are inconclusive with regard to a correlation between parameter settings and void fractions. As for frequencies, power law correlations are established.

  10. Experimental Study of Flow in a Bifurcation (United States)

    Fresconi, Frank; Prasad, Ajay


    An instability known as the Dean vortex occurs in curved pipes with a longitudinal pressure gradient. A similar effect is manifest in the flow in a converging or diverging bifurcation, such as those found in the human respiratory airways. The goal of this study is to characterize secondary flows in a bifurcation. Particle image velocimetry (PIV) and laser-induced fluorescence (LIF) experiments were performed in a clear, plastic model. Results show the strength and migration of secondary vortices. Primary velocity features are also presented along with dispersion patterns from dye visualization. Unsteadiness, associated with a hairpin vortex, was also found at higher Re. This work can be used to assess the dispersion of particles in the lung. Medical delivery systems and pollution effect studies would profit from such an understanding.

  11. Experimental studies in non-equilibrium physics (United States)

    Cressman, John Robert, Jr.

    This work is a collection of three experiments aimed at studying different facets of non-equilibrium dynamics. Chapter I concerns strongly compressible turbulence, which turns out to be very different from incompressible turbulence. The focus is on the dispersion of contaminants in such a flow. This type of turbulence can be studied, at very low mach number, by measuring the velocity fields of particles that float on a turbulently stirred body of water. It turns out that in the absence of incompressibility, the turbulence causes particles to cluster rather than to disperse. The implications of the observations are far reaching and include the transport of pollutants on the oceans surface, phytoplankton growth, as well as industrial applications. Chapter II deals with the effects of polymer additives on drag reduction and turbulent suppression, a well-known phenomenon that is not yet understood. In an attempt to simplify the problem, the effects of a polymer additive were investigated in a vortex street formed in a flowing soap film. Measurements suggest that an increase in elongational viscosity is responsible for a substantial reduction in periodic velocity fluctuations. This study also helps to illuminate the mechanism responsible for vortex separation in the wake of a bluff body. Chapter III describes an experiment designed to test a theoretical approach aimed at generalizing the classical fluctuation dissipation theorem (FDT). This theorem applies to systems driven only slightly away from thermal equilibrium, whereas ours, a liquid crystal under-going electroconvection, is so strongly driven, that the FDT does not apply. Both theory and experiment focus on the flux in global power fluctuations. Physical limitations did not permit a direct test of the theory, however it was possible to establish several interesting characteristics of the system: the source of the fluctuations is the transient defect structures that are generated when the system is driven hard

  12. An experimental study of rip channel flow

    DEFF Research Database (Denmark)

    Drønen, Nils Kjetil; Karunarathna, H.; Fredsøe, Jørgen


    A laboratory study of the flow over a bar with a single rip channel has been performed. First, the well-known pattern of a bar circulation cell with a strong offshore-directed current out through the rip channel and a weaker onshore-directed return flow over the bar is documented. Then measurements...... of the three-dimensional structure of the flow in the area where the rip channel, the bar and the trough meet and well inside the rip channel are presented. These measurements reveal that 3D effects play an important role, and that a depth-integrated viewpoint may not always be sufficient for predicting...

  13. The influence of the design matrix on treatment effect estimates in the quantitative analyses of single-subject experimental design research. (United States)

    Moeyaert, Mariola; Ugille, Maaike; Ferron, John M; Beretvas, S Natasha; Van den Noortgate, Wim


    The quantitative methods for analyzing single-subject experimental data have expanded during the last decade, including the use of regression models to statistically analyze the data, but still a lot of questions remain. One question is how to specify predictors in a regression model to account for the specifics of the design and estimate the effect size of interest. These quantitative effect sizes are used in retrospective analyses and allow synthesis of single-subject experimental study results which is informative for evidence-based decision making, research and theory building, and policy discussions. We discuss different design matrices that can be used for the most common single-subject experimental designs (SSEDs), namely, the multiple-baseline designs, reversal designs, and alternating treatment designs, and provide empirical illustrations. The purpose of this article is to guide single-subject experimental data analysts interested in analyzing and meta-analyzing SSED data. © The Author(s) 2014.

  14. Experimental Study of Methane Hydrates in Coal

    Directory of Open Access Journals (Sweden)

    Smirnov Vyacheslav


    Full Text Available The possibility of gas hydrate formation in porous space of coal has been studied. The experiments conducted have proven the possibility of methane gas hydrate formation in moist coal. It has been demonstrated that the decomposition points of methane gas hydrates in coal are near to the phase equilibrium curve for bulk methane hydrate. Only part of water absorbed by coal can be involved in the methane gas hydrate formation. With the increase in gas pressure increases the amount of gas hydrate formed in natural coal. For formation of hydrates at a positive temperature, the pressure in the system has to be at least 2 MPa. At the same time the speed of formation and decomposition of gas hydrates in coal is big enough.

  15. Experimental techniques for cement hydration studies

    Directory of Open Access Journals (Sweden)

    Andreas Luttge


    Full Text Available Cement hydration kinetics is a complex problem of dissolution, nucleation and growth that is still not well understood, particularly in a quantitative way. While cement systems are unique in certain aspects they are also comparable to natural mineral systems. Therefore, geochemistry and particularly the study of mineral dissolution and growth may be able to provide insight and methods that can be utilized in cement hydration research. Here, we review mainly what is not known or what is currently used and applied in a problematic way. Examples are the typical Avrami approach, the application of Transition State Theory (TST to overall reaction kinetics and the problem of reactive surface area. Finally, we suggest an integrated approach that combines vertical scanning interferometry (VSI with other sophisticated analytical techniques such as atomic force microscopy (AFM and theoretical model calculations based on a stochastic treatment.

  16. ESP Teaching for Tourism. An Experimental Study

    Directory of Open Access Journals (Sweden)

    Buzarna-Tihenea (Gălbează Alina


    Full Text Available This paper is focused on those teaching and learning methods and techniques which can improve the practical use of English for work-related purposes, this giving the students the opportunity to develop their language skills by means of attractive, motivating and useful learning activities. The paper aims at providing an in-depth knowledge about ways of studying and applying English for Specific Purposes in the Tourism field, as well as types of activities to be used in the classroom in order to assist learners overcome language difficulties. It is of great importance to emphasize the specific tasks and strategies used while teaching ESP for Tourism classes, strategies that differ from the ones used in a traditional English language classroom. The main purpose of all these ESP methods and approaches is to prepare students for their future jobs so that they can perform effectively in their area of work.

  17. Experimental Study of Liquid Fuel Spray Combustion

    DEFF Research Database (Denmark)

    Westlye, Fredrik Ree

    by the Danish Council for Strategic Research. Other supporters of the project have been MAN Diesel & Turbo A/S, DTU Mechanical Engineering, DTU Chemical Engineering, Sandia National Laboratories USA, Norwegian University of Science & Technology (NTNU) and University of Nottingham, Malaysia Campus....... The continuing stringency of emission regulations for marine diesel engines forces a deeper understanding of the complex physical processes occurring inside the engine cylinder. A deeper understanding can lead to higher accuracy of predictive numerical models, thereby enabling evaluation of multiple engine...... the specific physical quantities needed in CFD validation of these types of flames. This work is a testament to that fact. The first part of this thesis is an extensive study of optical combustion diagnostics applied to complex transient sprayflames in a high temperature and pressure environment...

  18. Flapless implant surgery: an experimental study. (United States)

    Jeong, Seung-Mi; Choi, Byung-Ho; Li, Jingxu; Kim, Han-Sung; Ko, Chang-Yong; Jung, Jae-Hyung; Lee, Hyeon-Jung; Lee, Seoung-Ho; Engelke, Wilfried


    The purpose of this study was to examine the effect of flapless implant surgery on crestal bone loss and osseointegration in a canine mandible model. In 6 mongrel dogs, bilateral, edentulated, flat alveolar ridges were created in the mandible. After 3 months of healing, 2 implants in each side were placed by either flap or flapless procedures. After a healing period of 8 weeks, microcomputerized tomography at the implantation site was performed. Osseointegration was calculated as percentage of implant surface in contact with bone. Additionally, bone height was measured in the peri-implant bone. The mean osseointegration was greater at flapless sites (70.4%) than at sites with flaps (59.5%) (P flapless sites (10.1 mm) than at sites with flaps (9.0 mm) (P Flapless surgery can achieve results superior to surgery with reflected flaps. The specific improvements of this technique include enhanced osseointegration of dental implants and increased bone height.

  19. Experimental and clinical studies with intraoperative radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Sindelar, W.F.; Kinsella, T.; Tepper, J.; Travis, E.L.; Rosenberg, S.A.; Glatstein, E.


    Studies of normal tissue tolerance to intraoperative radiotherapy were done upon 65 dogs subjected to laparotomy and 11 million electron volt electron irradiation in doses ranging from zero to 5,000 rads. Results of studies indicated that intact aorta and vena cava tolerate up to 5,000 rads without loss of structural integrity. Ureteral fibrosis and stenosis develop at doses of 3,000 rads or more. Arterial anastomoses heal after doses of 4,500 rads, but fibrosis can lead to occlusion. Intestinal suture lines heal after doses of 4,500 rads. Bile duct fibrosis and stenosis develop at doses of 2,000 rads or more. Biliary-enteric anastomoses fail to heal at any dose level. A clinical trial of intraoperative radiotherapy combined with radical surgery was performed upon 20 patients with advanced malignant tumors which were considered unlikely to be cured by conventional therapies and which included carcinomas of the stomach, carcinomas of the pancreas, carcinomas involving the hilus of the liver, retroperitoneal sarcomas and osteosarcomas of the pelvis. All patients underwent resection of gross tumor, followed by intraoperative irradiation of the tumor bed and regional nodal basins. Some patients received additional postoperative external beam radiotherapy. Treatment mortality for combined operation and radiotherapy occurred in four of 20 patients. Postoperative complications occurred in four of the 16 surviving patients. Local tumor control was achieved in 11 of the 16 surviving patients, with an over-all median follow-up period of 18 months. The clinical trial suggested that intraoperative radiotherapy is a feasible adjunct to resection in locally advanced tumors, that the resulting mortality and morbidity is similar to that expected from operation alone and that local tumor control may be improved.

  20. Experimental study of forearm compartmental pressures. (United States)

    Ardolino, Antonella; Zeineh, Nedal; O'Connor, David


    Chronic compartment syndrome is well recognized, although it is rare in the forearm. Diagnosis is based on history, clinical examination, and compartment pressure readings. Existing normal pressure ranges for the forearm are based on lower limb measurements. This study aimed to establish normal pre- and post-exercise forearm compartment pressures. Using a Stryker intracompartmental pressure monitor (Stryker, Kalamazoo, MI), 41 volunteers had pressure measurements of the extensor and flexor forearm compartments before and after exercise. Normal ranges were established for pre-exercise extensor compartment (2-27 mm Hg; upper confidence interval [CI] 18.8-25.2 mm Hg), post-exercise extensor compartment (2-24 mm Hg; upper CI 16.8-22.8 mm Hg), pre-exercise flexor compartment (1-19 mm Hg; upper CI 13.3-17.4 mm Hg), and post-exercise flexor compartment (0-19 mm Hg; upper CI 16-21.4 mm Hg) pressures. No significant difference was found between pressures before and after exercise. There was no correlation between whether pressures increased or decreased following exercise. There was a significant gender difference. Normal ranges were 0 to 25.2 mm Hg for the extensor compartment and 0 to 21.4 mm Hg for the flexor compartment. This study has shown a significant difference in normal forearm compartment pressures between genders. A normal reference range of flexor and extensor forearm compartment pressures to aid diagnosis of chronic compartment syndrome has been determined. This might also prove useful in aiding the diagnosis of acute forearm compartment syndrome. Copyright © 2010 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  1. Risk estimates for silicosis: comparison of animal and human studies

    Energy Technology Data Exchange (ETDEWEB)

    Tran, C.L.; Miller, B.G.; Soutar, C.A.


    A risk assessment has been conducted for lung fibrosis from inhaled crystalline silica that follows the traditional approach of extrapolation from animal studies, and the results compared with observed human risks based on epidemiological studies. Bio-mathematical modelling was applied to the available animal data to estimate the NOAEL for inflammation. The resulting estimate for the rat is 0.1 mg.m{sup -3}. Conventional scaling and extrapolation methods recommended by the US EPA have then been applied to estimate a human acceptable average exposure limit. This resulted in an estimate of about 0.001 mg.m{sup -3}. The risk estimates were compared with human risk estimates for fibrosis based on epidemiological data. These comprised ACGIH summary conclusions on the risk estimates provided by epidemiological studies, and the risks demonstrated by one epidemiological study, of Scottish coalworkers, with unusually detailed exposure information. The average exposure limits implied by the risk estimates from the epidemiological studies ranged from 0.01 mg.m{sup -3} to about 0.05 mg.m{sup -3}, some 9 to 45 times higher than the limits derived from the animal studies. The conventional uncertainty factors applied in the animal-based risk estimates may be over-precautionary. Extension of the biomathematical model to extrapolate from animals to humans would provide a sounder basis for extrapolation than the present uncertainty factors. 18 refs., 5 figs., 5 tabs., 2 apps.

  2. Directional velocity estimation using focusing along the flow direction II: Experimental investigation

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt; Bjerngaard, R.


    A new method for directional velocity estimation is investigated through a number of flow rig measurements. The method uses beamformation along the flow direction to generate data, where the correct velocity magnitude can directly be estimated from the shift in position of the received consecutiv...

  3. Experimental study of flow through compressor Cascade

    Directory of Open Access Journals (Sweden)

    Satyam Panchal


    Full Text Available The objective of this research work is to study the behaviour of flow at the inlet, within the blade passage and at the exit of a compressor cascade. For this purpose, a cascade with six numbers of aerofoil blades was designed and constructed. The cascade was fitted on the cascade test tunnel. Out of six blades two were instrumented for measuring the pressure distribution on the pressure and suction surface. The blades had a parabolic camber line, with a maximum camber position at 40% of the chord from the leading edge of the blade. The profile of the blade was C4, height of the blade was 160 mm, chord length was 80 mm, camber angle was 45° and stagger angle was 30°. Similarly, the length of the cascade was 300 mm, span was 160 mm, pitch was 60 mm, the actual chord of the cascade was 80 mm, the axial chord of the cascade was 70 mm, the stagger angle of the cascade was 30° and the pitch-chord ratio was 0.75. The data was taken and analyzed at −500% of the axial chord before the cascade, −25% of the axial chord before the leading edge, 25%, 50%, 75% and 150% of the axial chord from the leading edge of the blade. The readings were taken from the cascade wall to the mid span position along the pitch wise direction. The angle of incidence was also changed during the experiment and varied from i=−50°, −30°, −10° to 5°.

  4. Medical waste to energy: experimental study. (United States)

    Arcuri, C; Luciani, F; Piva, P; Bartuli, F N; Ottria, L; Mecheri, B; Licoccia, S


    Although waste is traditionally assessed as a pollutant which needs to be reduced or lessened, its management is certainly necessary. Nowadays, biological fuel cells, through the direct conversion of organic matter to electricity using biocatalysts, represent a technology able to produce sustainable energy by means of waste treatment. This study aims to propose a mean to generate energy from blood and saliva, that are common risk-infectious medical waste. Material employed (purchased by Sigma-Aldrich) were: Glucose oxidase (GOx), Nafion perfluorinated resin solution at 5% in a mixture of lower aliphatic alcohols and water, Polyethylene oxide. Stock solutions of D (+) glucose were prepared in a 0.1 M phosphate buffer solution and stored at 4 °C for at least 24 h before use. Carbon cloth electrode ELAT HT 140 E-W with a platinum loading of 5 gm-2 was purchased by E-Tek. Electrospun Nafion fibers were obtained as follows. Scanning electron microscopy was used to characterize the electrode morphologies. In order to develop an effective immobilization strategy of GOx on the electrode surface, Nafion fibers (a fully fluorinated ion conducting polymer used as a membrane material in enzymatic fuel cells - EFC) were selected as immobilizing polymer matrix. In this work, exploiting the nafion fibers capability of being able to cathalize Gox activity, we have tried to produce an enzymatic fuel cell which could produce energy from the blood and the saliva within medical-dental waste. Medical waste refers to all those materials produced by the interaction among doctor and patient, such as blood and saliva. During our research we will try to complete an EFC prototype able to produce energy from blood and saliva inside the risk-infectious medical waste in order to contribute to the energy requirements of a consulting room.


    Rhoads, C P


    Through the kindness of Dr. W. H. Park we have been enabled to study a horse antipoliomyelitic serum. This preparation has been supplied us in three forms: citrated blood plasma, serum, and globulin concentrate. We have tested these preparations in vitro and in vivo for inactivating or neutralizing or, to use perhaps a better term, antiviral effects against a constant, potent, filtrate virus of poliomyelitis. The preparations exhibited these effects when combined in vitro. Their action in this respect appears to be greater and more constant than that found by Stewart and Haselbauer for the Pettit antipoliomyelitic horse serum. On the other hand, in vivo tests carried out by us were less successful. In comparison with the constancy of action, under given conditions, of convalescent monkey and human sera, the antipoliomyelitic horse serum displayed striking irregularity, and certain preparations were devoid of protective power. The precise nature of the inactivating substances in the horse antiserum and their relation to the corresponding substances in convalescent sera have still, to be determined. As far as one absorption test carried out by us indicates, precipitin does not play a major rôle in the inactivating process. When an active globulin concentrate was filtered through Berkefeld candles, it lost its in vitro inactivating power. This is not true of convalescent sera in the native state. No tests have, however, been made with globulin concentrates from such sera. The experiments described in this paper raise the question whether, therapeutically considered, the antipoliomyelitic horse serum should be regarded as an exact equivalent of, and hence employed as a perfect substitute for, convalescent serum. This question can only be answered by further experiment and observation.

  6. Markets and morals: an experimental survey study.

    Directory of Open Access Journals (Sweden)

    Julio J Elias

    Full Text Available Most societies prohibit some market transactions based on moral concerns, even when the exchanges would benefit the parties involved and would not create negative externalities. A prominent example is given by payments for human organs for transplantation, banned virtually everywhere despite long waiting lists and many deaths of patients who cannot find a donor. Recent research, however, has shown that individuals significantly increase their stated support for a regulated market for human organs when provided with information about the organ shortage and the potential beneficial effects a price mechanism. In this study we focused on payments for human organs and on another "repugnant" transaction, indoor prostitution, to address two questions: (A Does providing general information on the welfare properties of prices and markets modify attitudes toward repugnant trades? (B Does additional knowledge on the benefits of a price mechanism in a specific context affect attitudes toward price-based transactions in another context? By answering these questions, we can assess whether eliciting a market-oriented approach may lead to a relaxation of moral opposition to markets, and whether there is a cross-effect of information, in particular for morally controversial activities that, although different, share a reference to the "commercialization" of the human body. Relying on an online survey experiment with 5,324 U.S. residents, we found no effect of general information about market efficiency, consistent with morally controversial markets being accepted only when they are seen as a solution to a specific problem. We also found some cross-effects of information about a transaction on the acceptance of the other; however, the responses were mediated by the gender and (to a lesser extent religiosity of the respondent--in particular, women exposed to information about legalizing prostitution reduced their stated support for regulated organ payments. We

  7. Injury Based on Its Study in Experimental Models

    Directory of Open Access Journals (Sweden)

    M. Mendes-Braz


    Full Text Available The present review focuses on the numerous experimental models used to study the complexity of hepatic ischemia/reperfusion (I/R injury. Although experimental models of hepatic I/R injury represent a compromise between the clinical reality and experimental simplification, the clinical transfer of experimental results is problematic because of anatomical and physiological differences and the inevitable simplification of experimental work. In this review, the strengths and limitations of the various models of hepatic I/R are discussed. Several strategies to protect the liver from I/R injury have been developed in animal models and, some of these, might find their way into clinical practice. We also attempt to highlight the fact that the mechanisms responsible for hepatic I/R injury depend on the experimental model used, and therefore the therapeutic strategies also differ according to the model used. Thus, the choice of model must therefore be adapted to the clinical question being answered.

  8. Experimental Study of Rectangular Labyrinth Weir

    Directory of Open Access Journals (Sweden)

    M. Rezaee


    Full Text Available Introduction: Labyrinth weirs compare with straight weirs had required less freeboard in upstream so they are more appropriate for the irrigation networks. So they could maked more space to sotrage water and restrained foold with higher discharge. Labyrinths weirs have three generally form triangles, trapezoidal and rectangular that Tullis et al. (15 presented formula (3 for discharge coefficient of labyrinth weirs (triangles and rectangular and a few studiescarried out on rectangular shape and its hydraulic characteristics are not specified.Therefore main aim of this paper study and characterized hydraulic characteristics of rectangular labyrinth weirs by using laboratory data. Materials and Methods: In this study rectangular labyrinth weir discharge and coefficient discharge relationships used dimensional analysis and experiment on hydraulic modeling, constant coefficient was defined. Laboratory flume is shown in Figure 2 (0.5 m wide x 12 m long x 0.8 m deep. Models was made from clear plexiglass plate with 10 cm thickness thatcuted using leaserdevice and the crest manualy shaped quadrant with radius 10 cm, all models using silicon glue install in the flume. The upstream depth readership by point gauge that installed in upstream of models. Discharge calcutaed byupsterm depth of triangular weir that installed in down stream of flume.Data were analyzed by SPSS software and to compare relationships with each other used two parameter root mean square error and correlation coefficient and charts darw in Excel Results and Discussion: discharge coefficient formula (11 carried out by using SPSS software that compared with formula (3. Results showed (Tables 2 and 3 that the correlation coefficient of formula (11 was more than a formula (3 and formula (11 RSME was less than formula (3 RSME except in first and fifth hydraulic model (rectengular1 and 5 that they were almost equal. So the formula (11 was more accurate than a formula (3 to peredict

  9. Theoretical and Experimental Studies in Accelerator Physics

    Energy Technology Data Exchange (ETDEWEB)

    Rosenzweig, James [Univ. of California, Los Angeles, CA (United States). Dept. of Physics and Astronomy


    . We note also that PBPL graduates remain as close elaborators for the program after leaving UCLA. The UCLA PBPL program is a foremost developer of on-campus facilities, such as the Neptune and Pegasus Laboratories, providing a uniquely strong environment for student-based research. In addition, the PBPL is a strong user of off-campus national lab facilities, such as SLAC FACET and NLCTA, and the BNL ATF. UCLA has also vigorously participated in the development of these facilities. The dual emphases on off- and on-campus opportunities permit the PBPL to address in an agile way a wide selection of cutting-edge research topics. The topics embraced by this proposal illustrate this program aspect well. These include: GV/m dielectric wakefield acceleration/coherent Cerenkov radiation experiments at FACET (E-201) and the ATF; synergistic laser-excited dielectric accelerator and light source development; plasma wakefield (PWFA) experiments on “Trojan horse” ionization injection (FACET E-210), quasi-nonlinear PWFA at BNL and the production at Neptune high transformer ratio plasma wakes; the inauguration of a new type of RF photoinjector termed “hybrid” at UCLA, and application to PWFA; space-charge dominated beam and cathode/near cathode physics; the study of advanced IFEL systems, for very high energy gain and utilization of novel OAM modes; the physcis of inverse Compton scattering (ICS), with applications to e+ production and γγ colliders; electron diffraction; and advanced beam diagnostics using coherent imaging techniques. These subjects are addressed under the leadership of PBPL director Prof. James Rosenzweig in Task A, and Prof. Pietro Musumeci in Task J, which was initiated following his OHEP Outstanding Junior Investigator award.

  10. A Comparative Study Of Source Location And Depth Estimates From ...

    African Journals Online (AJOL)

    A Comparative Study Of Source Location And Depth Estimates From Total Intensity And Reduced-To-The Pole Magnetic Data. ... Ife Journal of Science ... In this study, a synthetic magnetic field due to four buried dipoles was analysed to show that estimates of source location and depth can be improved significantly by ...

  11. The experimental study of seed dispersal by fish (ichthyochory)

    NARCIS (Netherlands)

    Pollux, B.J.A.


    1.The last few years have seen an increased interest in the experimental study of seed dispersal by fish (ichthyochory). This paper reviews such experiments, aiming to determine what functional aspects of ichthyochory have been investigated, what experimental designs have been used and what the

  12. Influence of Radial Stress Gradient on Strainbursts: An Experimental Study (United States)

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


    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.

  13. Bipolar mood disorder, creativity and schizotypy: an experimental study. (United States)

    Rybakowski, Janusz K; Klonowska, Paulina


    Our purpose was to make an experimental assessment of the elements of creativity and the features of schizotypy in patients with bipolar disorder, compared with healthy control subjects and to investigate the effect of an acute affective episode (depressed or manic) and the features of schizotypy on the measurements of creativity. Forty patients with bipolar disorder, and 48 age- and gender-matched control subjects were studied. For the assessment of creativity the Revised Art Scale and the 'inventiveness' part of the Berlin Intelligence Structure Test (BIS) were used. The Oxford-Liverpool Inventory of Feelings and Experiences was applied for estimation of schizotypy. The bipolar patients did not differ on the RAS scale from the control subjects but obtained significantly higher scores on the BIS-total as well as on the verbal part of the test. Their scores on the BIS scale during depression were significantly lower than in remission. The bipolar patients obtained significantly higher scores on all dimensions of schizotypy compared with the controls. These results confirm previous data showing higher scores on some creativity scales in bipolar patients compared with healthy subjects. They also corroborate a relationship between the features of schizotypy and creativity scores in bipolar patients. Copyright © 2011 S. Karger AG, Basel.

  14. Pilot study of the Korean Parent Training Program using a partial group randomized experimental study (United States)

    Kim, Eunjung; Cain, Kevin; Boutain, Doris; Chun, Jin-Joo; Kim, Sangho; Im, Hyesang


    Problems Korean American (KA) children experience mental health problems due to difficulties in parenting dysfunction complicated by living in two cultures. Methods Korean Parent Training Program (KPTP) was pilot tested with 48 KA mothers of children (ages 3–8) using partial group randomized controlled experimental study design. Self-report survey and observation data were gathered. Findings Analyses using generalized estimating equation indicated the intervention group mothers increased effective parenting and their children decreased behavior problems and reported less acculturation conflict with mothers. Conclusions The KPTP is a promising way to promote effective parenting and increase positive child mental health in KA families. PMID:24645901

  15. Evaluating uncertainty in 7Be-based soil erosion estimates: an experimental plot approach (United States)

    Blake, Will; Taylor, Alex; Abdelli, Wahid; Gaspar, Leticia; Barri, Bashar Al; Ryken, Nick; Mabit, Lionel


    Soil erosion remains a major concern for the international community and there is a growing need to improve the sustainability of agriculture to support future food security. High resolution soil erosion data are a fundamental requirement for underpinning soil conservation and management strategies but representative data on soil erosion rates are difficult to achieve by conventional means without interfering with farming practice and hence compromising the representativeness of results. Fallout radionuclide (FRN) tracer technology offers a solution since FRN tracers are delivered to the soil surface by natural processes and, where irreversible binding can be demonstrated, redistributed in association with soil particles. While much work has demonstrated the potential of short-lived 7Be (half-life 53 days), particularly in quantification of short-term inter-rill erosion, less attention has focussed on sources of uncertainty in derived erosion measurements and sampling strategies to minimise these. This poster outlines and discusses potential sources of uncertainty in 7Be-based soil erosion estimates and the experimental design considerations taken to quantify these in the context of a plot-scale validation experiment. Traditionally, gamma counting statistics have been the main element of uncertainty propagated and reported but recent work has shown that other factors may be more important such as: (i) spatial variability in the relaxation mass depth that describes the shape of the 7Be depth distribution for an uneroded point; (ii) spatial variability in fallout (linked to rainfall patterns and shadowing) over both reference site and plot; (iii) particle size sorting effects; (iv) preferential mobility of fallout over active runoff contributing areas. To explore these aspects in more detail, a plot of 4 x 35 m was ploughed and tilled to create a bare, sloped soil surface at the beginning of winter 2013/2014 in southwest UK. The lower edge of the plot was bounded by

  16. Inner detached frequency response curves: an experimental study (United States)

    Gatti, Gianluca; Brennan, Michael J.


    Certain nonlinear vibrating systems have frequency response curves (FRCs), in which isolated detached curves exist inside the main continuous FRC. The behavior of these systems has hitherto been studied analytically and numerically, but to the authors' knowledge, there is no record of an inner detached FRC being detected experimentally. These curves may be hidden by numerical or experimental analysis, particularly when a system is subject to swept or stepped-sine excitation. Their existence may thus lead to unexpected dramatic changes in the amplitude of the system response. This paper presents an experimental study that involves the design, construction and testing of a specific system that has an isolated detached FRC inside the main continuous FRC. The experimental design of the test rig is supported by multibody dynamic simulations, and in the experimental tests the existence of a detached FRC was verified.

  17. 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.


    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

  18. Estimations of isoprenoid emission capacity from enclosure studies: measurements, data processing, quality and standardized measurement protocols

    Directory of Open Access Journals (Sweden)

    Ü. Niinemets


    Full Text Available The capacity for volatile isoprenoid production under standardized environmental conditions at a certain time (ES, the emission factor is a key characteristic in constructing isoprenoid emission inventories. However, there is large variation in published ES estimates for any given species partly driven by dynamic modifications in ES due to acclimation and stress responses. Here we review additional sources of variation in ES estimates that are due to measurement and analytical techniques and calculation and averaging procedures, and demonstrate that estimations of ES critically depend on applied experimental protocols and on data processing and reporting. A great variety of experimental setups has been used in the past, contributing to study-to-study variations in ES estimates. We suggest that past experimental data should be distributed into broad quality classes depending on whether the data can or cannot be considered quantitative based on rigorous experimental standards. Apart from analytical issues, the accuracy of ES values is strongly driven by extrapolation and integration errors introduced during data processing. Additional sources of error, especially in meta-database construction, can further arise from inconsistent use of units and expression bases of ES. We propose a standardized experimental protocol for BVOC estimations and highlight basic meta-information that we strongly recommend to report with any ES measurement. We conclude that standardization of experimental and calculation protocols and critical examination of past reports is essential for development of accurate emission factor databases.

  19. Studies on pathogenesis and treatment of experimental immune complex glomerulonephrtis.

    NARCIS (Netherlands)

    Fleuren, Gerard Johannes Maria


    Chapter 1. In this thesis an investigation into pathogenetic mechanisms of epimembranous immune complex depostion in the glomeruli was described. For this study we used two related models of experimental immune complex glemerulonephritis: the heterologous and the autologous immune complex

  20. Experimental study of convective flows in the freezer

    Directory of Open Access Journals (Sweden)

    Krasnoshlykov Alexander


    Full Text Available The article discusses an experimental study of convective heat transfer in the amount of air and water in the freezer, under various operating conditions of the refrigeration unit.

  1. Experimental geothermal research facilities study (Phase 0). Volume 1

    Energy Technology Data Exchange (ETDEWEB)


    The study comprises Phase 0 of a project for Experimental Geothermal Research Facilities. The study focuses on identification of a representative liquid-dominated geothermal reservoir of moderate temperature and salinity, preliminary engineering design of an appropriate energy conversion system, identification of critical technology, and planning for implementation of experimental facilities. The objectives included development of liaison with the industrial sector, to ensure responsiveness to their views in facility requirements and planning, and incorporation of environmental and socioeconomic factors. This Phase 0 report covers problem definition and systems requirements. Facilities will incorporate capability for research in component, system, and materials technology and a nominal 10 MWe experimental, binary cycle, power generating plant.

  2. Experimental Study on the Langlee Wave Energy Converter

    DEFF Research Database (Denmark)

    Lavelle, John; Kofoed, Jens Peter

    This report concerns the experimental study of the 1:20 scale model of the Langlee Wave Energy Converter (WEC) carried out at Aalborg University’s wave basin during the summer of 2010.......This report concerns the experimental study of the 1:20 scale model of the Langlee Wave Energy Converter (WEC) carried out at Aalborg University’s wave basin during the summer of 2010....

  3. Experimental Demonstration of a Cognitive Quality of Transmission Estimator for Optical Communication Systems

    DEFF Research Database (Denmark)

    Caballero Jambrina, Antonio; Aguado, Juan Carlos; Borkowski, Robert


    We report on the experimental performance of a case-based reasoning technique to predict whether optical channels fulfill quality of transmission requirements, thus supporting impairment-aware networking. Validation is performed in a WDM 80 Gb/s PDM-QPSK testbed....

  4. Experimental estimation of mismatch uncertainty in radio – frequency power and attenuation measurements

    Directory of Open Access Journals (Sweden)

    Patel Kamlesh


    Full Text Available In this paper, the effects of the input quantity representations in linear and complex forms are analyzed to estimate mismatch uncertainty separately for one-port and two-port components. The mismatch uncertainties in power and attenuation measurements are evaluated for direct, ratio and substitution techniques with the use of a vector network analyzer system in the range of 1 to 18 GHz. The estimated mismatch uncertainties were compared for the same device under test and these values have verified that their evaluation is dependent on the representations of input quantities. In power measurements, the mismatch uncertainty is reduced when evaluating from the voltage standing wave ratio or reflection coefficient magnitudes in comparison to the complex reflection coefficients. The mismatch uncertainty in the attenuation measurements, are found higher and linearly increasing while estimating from the linear magnitude values than those from the S-parameters of the attenuator. Thus in practice, the mismatch uncertainty is estimated more accurately using the quantities measured in the same representations as of measuring quantity.

  5. Experimental demonstration of a cognitive quality of transmission estimator for optical communication systems

    DEFF Research Database (Denmark)

    Caballero Jambrina, Antonio; Aguado, Juan Carlos; Borkowski, Robert


    The impact of physical layer impairments in optical network design and operation has received significant attention in the last years, thereby requiring estimation techniques to predict the quality of transmission (QoT) of optical connections before being established. In this paper, we report on ...

  6. A theoretical and experimental study of coplanar waveguide shunt stubs (United States)

    Dib, Nihad I.; Ponchak, George E.; Katehi, Linda P. B.


    A comprehensive theoretical and experimental study of straight and bent coplanar waveguide (CPW) shunt stubs is presented. In the theoretical analysis, the CPW is assumed to be inside a cavity while, the experiments are performed on open structures. For the analysis of CPW discontinuities with air-bridges, a hybrid technique was developed which was validated through extensive theoretical and experimental comparisons. The effect of the cavity resonances on the behavior of the stubs with and without air-bridges is investigated. In addition, the encountered radiation loss due to the discontinuities is evaluated experimentally.

  7. Experimental study of the robust global synchronization of Brockett oscillators (United States)

    Ahmed, Hafiz; Ushirobira, Rosane; Efimov, Denis


    This article studies the experimental synchronization of a family of a recently proposed oscillator model, i.e. the Brockett oscillator [R. Brockett, Synchronization without periodicity, in Mathematical Systems Theory, A Volume in Honor of U. Helmke, edited by K. Huper, J. Trumpf (CreateSpace, Seattle, USA, 2013), pp. 65-74]. Due to its structural property, Brockett oscillator can be considered as a promising benchmark nonlinear model for investigating synchronization and the consensus phenomena. Our experimental setup consists of analog circuit realizations of a network of Brockett oscillators. Experimental results obtained in this work correspond to the prior theoretical findings.

  8. Comparison of Experimental Methods for Estimating Matrix Diffusion Coefficients for Contaminant Transport Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Telfeyan, Katherine Christina [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ware, Stuart Douglas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Reimus, Paul William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Birdsell, Kay Hanson [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    Diffusion cell and diffusion wafer experiments were conducted to compare methods for estimating matrix diffusion coefficients in rock core samples from Pahute Mesa at the Nevada Nuclear Security Site (NNSS). A diffusion wafer method, in which a solute diffuses out of a rock matrix that is pre-saturated with water containing the solute, is presented as a simpler alternative to the traditional through-diffusion (diffusion cell) method. Both methods yielded estimates of matrix diffusion coefficients that were within the range of values previously reported for NNSS volcanic rocks. The difference between the estimates of the two methods ranged from 14 to 30%, and there was no systematic high or low bias of one method relative to the other. From a transport modeling perspective, these differences are relatively minor when one considers that other variables (e.g., fracture apertures, fracture spacings) influence matrix diffusion to a greater degree and tend to have greater uncertainty than diffusion coefficients. For the same relative random errors in concentration measurements, the diffusion cell method yields diffusion coefficient estimates that have less uncertainty than the wafer method. However, the wafer method is easier and less costly to implement and yields estimates more quickly, thus allowing a greater number of samples to be analyzed for the same cost and time. Given the relatively good agreement between the methods, and the lack of any apparent bias between the methods, the diffusion wafer method appears to offer advantages over the diffusion cell method if better statistical representation of a given set of rock samples is desired.

  9. Comparison of experimental methods for estimating matrix diffusion coefficients for contaminant transport modeling. (United States)

    Telfeyan, Katherine; Ware, S Doug; Reimus, Paul W; Birdsell, Kay H


    Diffusion cell and diffusion wafer experiments were conducted to compare methods for estimating effective matrix diffusion coefficients in rock core samples from Pahute Mesa at the Nevada Nuclear Security Site (NNSS). A diffusion wafer method, in which a solute diffuses out of a rock matrix that is pre-saturated with water containing the solute, is presented as a simpler alternative to the traditional through-diffusion (diffusion cell) method. Both methods yielded estimates of effective matrix diffusion coefficients that were within the range of values previously reported for NNSS volcanic rocks. The difference between the estimates of the two methods ranged from 14 to 30%, and there was no systematic high or low bias of one method relative to the other. From a transport modeling perspective, these differences are relatively minor when one considers that other variables (e.g., fracture apertures, fracture spacings) influence matrix diffusion to a greater degree and tend to have greater uncertainty than effective matrix diffusion coefficients. For the same relative random errors in concentration measurements, the diffusion cell method yields effective matrix diffusion coefficient estimates that have less uncertainty than the wafer method. However, the wafer method is easier and less costly to implement and yields estimates more quickly, thus allowing a greater number of samples to be analyzed for the same cost and time. Given the relatively good agreement between the methods, and the lack of any apparent bias between the methods, the diffusion wafer method appears to offer advantages over the diffusion cell method if better statistical representation of a given set of rock samples is desired. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Using an experimental model for the study of therapeutic touch. (United States)

    dos Santos, Daniella Soares; Marta, Ilda Estéfani Ribeiro; Cárnio, Evelin Capellari; de Quadros, Andreza Urba; Cunha, Thiago Mattar; de Carvalho, Emilia Campos


    to verify whether the Paw Edema Model can be used in investigations about the effects of Therapeutic Touch on inflammation by measuring the variables pain, edema and neutrophil migration. this is a pilot and experimental study, involving ten male mice of the same genetic strain and divided into experimental and control group, submitted to the chemical induction of local inflammation in the right back paw. The experimental group received a daily administration of Therapeutic Touch for 15 minutes during three days. the data showed statistically significant differences in the nociceptive threshold and in the paw circumference of the animals from the experimental group on the second day of the experiment. the experiment model involving animals can contribute to study the effects of Therapeutic Touch on inflammation, and adjustments are suggested in the treatment duration, number of sessions and experiment duration.

  11. Experimental Test of the State Estimation-Reversal Tradeoff Relation in General Quantum Measurements

    Directory of Open Access Journals (Sweden)

    Geng Chen


    Full Text Available When a measurement has limited strength, only partial information, regarding the initial state, is extracted, and, correspondingly, there is a probability to reverse its effect on the system and retrieve the original state. Recently, a clear and direct quantitative description of this complementary relationship, in terms of a tradeoff relation, was developed by Y. K. Cheong and S. W. Lee. [Phys. Rev. Lett. 109, 150402 (2012]. Here, this tradeoff relation is experimentally verified using polarization-encoded single photons from a quantum dot. Measurement operators representing a complete range, from not affecting the system to a projection to a single polarization state, are realized. In addition, for each measurement operator, an optimal reversal operator is also implemented. The upper bound of the tradeoff relation is mapped to experimental parameters representing the measurement strength. Our results complement the theoretical work and provide a hands-on characterization of general quantum measurements.

  12. A Comparative Study of Distribution System Parameter Estimation Methods

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yannan; Williams, Tess L.; Gourisetti, Sri Nikhil Gup


    In this paper, we compare two parameter estimation methods for distribution systems: residual sensitivity analysis and state-vector augmentation with a Kalman filter. These two methods were originally proposed for transmission systems, and are still the most commonly used methods for parameter estimation. Distribution systems have much lower measurement redundancy than transmission systems. Therefore, estimating parameters is much more difficult. To increase the robustness of parameter estimation, the two methods are applied with combined measurement snapshots (measurement sets taken at different points in time), so that the redundancy for computing the parameter values is increased. The advantages and disadvantages of both methods are discussed. The results of this paper show that state-vector augmentation is a better approach for parameter estimation in distribution systems. Simulation studies are done on a modified version of IEEE 13-Node Test Feeder with varying levels of measurement noise and non-zero error in the other system model parameters.

  13. Fast Estimation of Expected Information Gain for Bayesian Experimental Design Based on Laplace Approximation

    KAUST Repository

    Long, Quan


    Shannon-type expected information gain is an important utility in evaluating the usefulness of a proposed experiment that involves uncertainty. Its estimation, however, cannot rely solely on Monte Carlo sampling methods, that are generally too computationally expensive for realistic physical models, especially for those involving the solution of stochastic partial differential equations. In this work we present a new methodology, based on the Laplace approximation of the posterior probability density function, to accelerate the estimation of expected information gain in the model parameters and predictive quantities of interest. Furthermore, in order to deal with the issue of dimensionality in a complex problem, we use sparse quadratures for the integration over the prior. We show the accuracy and efficiency of the proposed method via several nonlinear numerical examples, including a single parameter design of one dimensional cubic polynomial function and the current pattern for impedance tomography.

  14. Experimental and theoretical analysis on the procedure for estimating geo-stresses by the Kaiser effect (United States)

    Li, Yuan-Hui; Yang, Yu-Jiang; Liu, Jian-Po; Zhao, Xing-Dong


    Acoustic emission tests of the core specimens retrieved from boreholes at the depth over 1000 m in Hongtoushan Copper Mine were carried out under uniaxial compressive loading, and the numerical test was also done by using the rock failure process analysis (RFPA2D) code, based on the procedure for estimating geo-stresses by the Kaiser effect under uniaxial compression. According to the statistical damage mechanics theory, the Kaiser effect mechanism was analyzed. Based on these analyses, it is indicted that the traditional method of estimating geo-stresses by the Kaiser effect is not appropriate, and the result is usually smaller than the real one. Furthermore, the greater confining compression in the rock mass may result in a larger difference between the Kaiser effect stresses acquired from uniaxial loading in laboratory and the real in-situ stresses.

  15. Experimental estimation of dij coefficients of piezoelectric materials by means of optical microscopy

    Directory of Open Access Journals (Sweden)

    Stamopoulos D.


    Full Text Available The properties of multiferroic and specifically piezoelectric (PE materials are, nowadays, intensively investigated by means of well established, however relatively complicate methods. In this work we present a method for the direct visual demonstration of the underlying electro-mechanical processes occurring in PE materials and the estimation of the respective coefficients dij. The method is based on the utilization of optical microscopy for the local observation of the deformation of a PE specimen upon application of an electric field. The direct comparison of the snapshots obtained before and after application of the electric field and simple algebraic calculations enables the estimation of the dij coefficients. The method was evaluated in unpoled single crystals of 0.71Pb(Mg1/3Nb2/3O3–0.29PbTiO3, at room temperature. Various locations of each crystal surface were surveyed. Non-homogeneous electro-mechanical response was observed. Accordingly, the estimated dij coefficients depended on the specific location of the crystal surface. Specifically, the dzx coefficient ranged within 500-1000 pm/V over the investigated locations (for electric fields E<1kV/mm. The present method directly unveils non-homogeneous electro-mechanical processes occurring at the surface of PE crystals and clarifies how these observations can be quantified through the respective dij coefficients.

  16. Fast estimation of expected information gains for Bayesian experimental designs based on Laplace approximations

    KAUST Repository

    Long, Quan


    Shannon-type expected information gain can be used to evaluate the relevance of a proposed experiment subjected to uncertainty. The estimation of such gain, however, relies on a double-loop integration. Moreover, its numerical integration in multi-dimensional cases, e.g., when using Monte Carlo sampling methods, is therefore computationally too expensive for realistic physical models, especially for those involving the solution of partial differential equations. In this work, we present a new methodology, based on the Laplace approximation for the integration of the posterior probability density function (pdf), to accelerate the estimation of the expected information gains in the model parameters and predictive quantities of interest. We obtain a closed-form approximation of the inner integral and the corresponding dominant error term in the cases where parameters are determined by the experiment, such that only a single-loop integration is needed to carry out the estimation of the expected information gain. To deal with the issue of dimensionality in a complex problem, we use a sparse quadrature for the integration over the prior pdf. We demonstrate the accuracy, efficiency and robustness of the proposed method via several nonlinear numerical examples, including the designs of the scalar parameter in a one-dimensional cubic polynomial function, the design of the same scalar in a modified function with two indistinguishable parameters, the resolution width and measurement time for a blurred single peak spectrum, and the boundary source locations for impedance tomography in a square domain. © 2013 Elsevier B.V.

  17. Real-time estimation of projectile roll angle using magnetometers: in-lab experimental validation (United States)

    Changey, S.; Pecheur, E.; Wey, P.; Sommer, E.


    The knowledge of the roll angle of a projectile is decisive to apply guidance and control law. For example, the goal of ISL's project GSP (Guided Supersonic Projectile) is to change the flight path of an airdefence projectile in order to correct the aim error due to the target manoeuvres. The originality of the concept is based on pyrotechnical actuators and onboard sensors which control the angular motion of the projectile. First of all, the control of the actuators requires the precise control of the roll angle of the projectile. To estimate the roll angle of the projectile, two magnetometers are embedded in the projectile to measure the projection of the Earth magnetic field along radial axes of the projectiles. Then, an extended Kalman filter (EKF) is used to compute the roll angle estimation. As the rolling frequency of the GSP is about 22 Hz, it was easy to test the navigation algorithm in laboratory. In a previous paper [1], the In-Lab demonstration of this concept showed that the roll angle estimation was possible with an accuracy of about 1◦ . In this paper, the demonstration is extended to high-speed roll rate, up to 1000 Hz. Thus, two magnetometers, a DSP (Digital Signal Processor) and a LED (Light Eminent Diode), are rotated using a pneumatic motor; the DSP runs an EKF and a guidance algorithm to compute the trigger times of the LED. By using a high-speed camera, the accuracy of the method can be observed and improved.

  18. Study of n-Butyl Acrylate Self-Initiation Reaction Experimentally and via Macroscopic Mechanistic Modeling

    Directory of Open Access Journals (Sweden)

    Ahmad Arabi Shamsabadi


    Full Text Available This paper presents an experimental study of the self-initiation reaction of n-butyl acrylate (n-BA in free-radical polymerization. For the first time, the frequency factor and activation energy of the monomer self-initiation reaction are estimated from measurements of n-BA conversion in free-radical homo-polymerization initiated only by the monomer. The estimation was carried out using a macroscopic mechanistic mathematical model of the reactor. In addition to already-known reactions that contribute to the polymerization, the model considers a n-BA self-initiation reaction mechanism that is based on our previous electronic-level first-principles theoretical study of the self-initiation reaction. Reaction rate equations are derived using the method of moments. The reaction-rate parameter estimates obtained from conversion measurements agree well with estimates obtained via our purely-theoretical quantum chemical calculations.

  19. Experimental demonstration of OFDM/OQAM transmission with DFT-based channel estimation for visible laser light communications (United States)

    He, Jing; Shi, Jin; Deng, Rui; Chen, Lin


    Recently, visible light communication (VLC) based on light-emitting diodes (LEDs) is considered as a candidate technology for fifth-generation (5G) communications, VLC is free of electromagnetic interference and it can simplify the integration of VLC into heterogeneous wireless networks. Due to the data rates of VLC system limited by the low pumping efficiency, small output power and narrow modulation bandwidth, visible laser light communication (VLLC) system with laser diode (LD) has paid more attention. In addition, orthogonal frequency division multiplexing/offset quadrature amplitude modulation (OFDM/OQAM) is currently attracting attention in optical communications. Due to the non-requirement of cyclic prefix (CP) and time-frequency domain well-localized pulse shapes, it can achieve high spectral efficiency. Moreover, OFDM/OQAM has lower out-of-band power leakage so that it increases the system robustness against inter-carrier interference (ICI) and frequency offset. In this paper, a Discrete Fourier Transform (DFT)-based channel estimation scheme combined with the interference approximation method (IAM) is proposed and experimentally demonstrated for VLLC OFDM/OQAM system. The performance of VLLC OFDM/OQAM system with and without DFT-based channel estimation is investigated. Moreover, the proposed DFT-based channel estimation scheme and the intra-symbol frequency-domain averaging (ISFA)-based method are also compared for the VLLC OFDM/OQAM system. The experimental results show that, the performance of EVM using the DFT-based channel estimation scheme is improved about 3dB compared with the conventional IAM method. In addition, the DFT-based channel estimation scheme can resist the channel noise effectively than that of the ISFA-based method.

  20. Multilevel meta-analysis of single-subject experimental designs: a simulation study. (United States)

    Ugille, Maaike; Moeyaert, Mariola; Beretvas, S Natasha; Ferron, John; Van den Noortgate, Wim


    One way to combine data from single-subject experimental design studies is by performing a multilevel meta-analysis, with unstandardized or standardized regression coefficients as the effect size metrics. This study evaluates the performance of this approach. The results indicate that a multilevel meta-analysis of unstandardized effect sizes results in good estimates of the effect. The multilevel meta-analysis of standardized effect sizes, on the other hand, is suitable only when the number of measurement occasions for each subject is 20 or more. The effect of the treatment on the intercept is estimated with enough power when the studies are homogeneous or when the number of studies is large; the power of the effect on the slope is estimated with enough power only when the number of studies and the number of measurement occasions are large.

  1. Experimental plan for the fuel-oil study

    Energy Technology Data Exchange (ETDEWEB)

    Ternes, M.P.; Levins, W.P.; Brown, M.A.


    An up-to-date assessment of the Weatherization Assistance Program (WAP) is being performed by the US Department of Energy WAP Division and the Oak Ridge National Laboratory. Five studies form the evaluation. Major goals of the Fuel-Oil Study are to estimate the fuel oil saved by the WAP in the Northeast during the 1990 and 1991 program years, identify and quantify non-energy impacts of the WAP, assess the cost effectiveness of the WAP within this submarket, and assess factors which may cause savings and cost effectiveness to vary. The study will only analyze single-family houses in the nine states in the Northeast census region and will be carried out over two heating seasons (1990 and 1991 WAP program years). A split-winter, pre- and post-weatherization experimental design with a control group will be used. Houses will be monitored over one winter. Energy conservation measures will be installed in the weatherized houses in January of each winter by the local WAP subgrantee. One hundred twenty five weatherized houses and 75 control houses will be monitored over the 1990--1991 winter; a different set of 200 houses will be monitored over the 1991--1992 winter. The houses will be evenly distributed among 25 subgrantees. Space-heating fuel-oil consumption, indoor temperature, and outdoor temperature data will be collected for all houses. Fuel-oil delivery data will be collected for each house monitored over the 1990--1991 winter for at least a year before weatherization. The delivery data will be analyzed to determine if the accuracy of the study can be improved by collecting fuel-oil delivery data on a larger sample of houses over the 1991--1992 winter. Detailed survey information will be obtained on all the houses. This information includes descriptive details of the house and its mechanical systems, details on household size and other demographics, and occupant answers to questions regarding comfort, safety, and operation of their space-heating system and house.

  2. Experimental study of mechanical properties of friction welded AISI ...

    Indian Academy of Sciences (India)

    Friction welding is widely used as a mass production method in various industries. In the present study, an experimental set-up was designed in order to achieve friction welding of plastically deformed AISI 1021 steels. In this study, low alloy steel (AISI 1021) was welded under different welding parameters and afterwards ...

  3. Experimental study of mechanical properties of friction welded AISI ...

    Indian Academy of Sciences (India)

    Abstract. Friction welding is widely used as a mass production method in vari- ous industries. In the present study, an experimental set-up was designed in order to achieve friction welding of plastically deformed AISI 1021 steels. In this study, low alloy steel (AISI 1021) was welded under different welding parameters and ...

  4. Infections in orthopaedic surgery : clinical and experimental studies

    NARCIS (Netherlands)

    Vogely, Henri Charles


    The diagnostic difficulties, variability in outcome and the heterogeinity of the problem of orthopaedic infections stimulated the author to a study of the literature, and several clinical and experimental studies. The diagnosis prosthesis-related infection can only be reached with an acceptable

  5. Systematic review of experimental studies on intestinal anastomosis

    NARCIS (Netherlands)

    Yauw, S.T.K.; Wever, K.E.; Hoesseini, A.; Ritskes-Hoitinga, M.; Goor, H. van


    BACKGROUND: The contribution of animal research to a reduction in clinical intestinal anastomotic leakage is unknown, despite numerous experimental studies. In view of the current societal call to replace, reduce and refine animal experiments, this study examined the quality of animal research

  6. What Shapes the Intention to Study Abroad? An Experimental Approach (United States)

    Petzold, Knut; Moog, Petra


    In contrast to previous studies, this investigation aims to get deeper insights into the causes of the intention to study abroad by using an experimental approach. Although international experience is often considered as important, many students at German universities do not even consider abroad. Referring to the Theory of Rational Choice (RCT)…

  7. Experimental Study of the Production of Solar Hydrogen in Algeria ...

    African Journals Online (AJOL)

    Hydrogen is a sustainable fuel option and one of the potential solutions for the current energy and environmental problems. In this study hydrogen is produced using a hydrogen generator with a Proton Exchange Membrane (PEM) electrolyser. An experimental study is done in the Center of Development of the Renewable ...

  8. Experimental Studies on Electronic Portfolios in Turkey: A Literature Review (United States)

    Alan, Selahattin; Sünbül, Ali Murat


    In this study, a literature review was conducted about an individual's selected efforts, products stored in electronic format, and electronic portfolios that reflect the development and capacity of multimedia systems. In this context, relevant experimental studies performed in Turkey are collected to show e-portfolio application forms, their…

  9. Radiation efficiency during slow crack propagation: an experimental study. (United States)

    Jestin, Camille; Lengliné, Olivier; Schmittbuhl, Jean


    Creeping faults are known to host a significant aseismic deformation. However, the observations of micro-earthquake activity related to creeping faults (e.g. San Andreas Faults, North Anatolian Fault) suggest the presence of strong lateral variabilities of the energy partitioning between radiated and fracture energies. The seismic over aseismic slip ratio is rather difficult to image over time and at depth because of observational limitations (spatial resolution, sufficiently broad band instruments, etc.). In this study, we aim to capture in great details the energy partitioning during the slow propagation of mode I fracture along a heterogeneous interface, where the toughness is strongly varying in space.We lead experiments at laboratory scale on a rock analog model (PMMA) enabling a precise monitoring of fracture pinning and depinning on local asperities in the brittle-creep regime. Indeed, optical imaging through the transparent material allows the high resolution description of the fracture front position and velocity during its propagation. At the same time, acoustic emissions are also measured by accelerometers positioned around the rupture. Combining acoustic records, measurements of the crack front position and the loading curve, we compute the total radiated energy and the fracture energy. We deduce from them the radiation efficiency, ηR, characterizing the proportion of the available energy that is radiated in form of seismic wave. We show an increase of ηR with the crack rupture speed computed for each of our experiments in the sub-critical crack propagation domain. Our experimental estimates of ηR are larger than the theoretical model proposed by Freund, stating that the radiation efficiency of crack propagation in homogeneous media is proportional to the crack velocity. Our results are demonstrated to be in agreement with existing studies which showed that the distribution of crack front velocity in a heterogeneous medium can be well described by a

  10. Targeted Maximum Likelihood Estimation for Causal Inference in Observational Studies. (United States)

    Schuler, Megan S; Rose, Sherri


    Estimation of causal effects using observational data continues to grow in popularity in the epidemiologic literature. While many applications of causal effect estimation use propensity score methods or G-computation, targeted maximum likelihood estimation (TMLE) is a well-established alternative method with desirable statistical properties. TMLE is a doubly robust maximum-likelihood-based approach that includes a secondary "targeting" step that optimizes the bias-variance tradeoff for the target parameter. Under standard causal assumptions, estimates can be interpreted as causal effects. Because TMLE has not been as widely implemented in epidemiologic research, we aim to provide an accessible presentation of TMLE for applied researchers. We give step-by-step instructions for using TMLE to estimate the average treatment effect in the context of an observational study. We discuss conceptual similarities and differences between TMLE and 2 common estimation approaches (G-computation and inverse probability weighting) and present findings on their relative performance using simulated data. Our simulation study compares methods under parametric regression misspecification; our results highlight TMLE's property of double robustness. Additionally, we discuss best practices for TMLE implementation, particularly the use of ensembled machine learning algorithms. Our simulation study demonstrates all methods using super learning, highlighting that incorporation of machine learning may outperform parametric regression in observational data settings. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail:

  11. Dense Descriptors for Optical Flow Estimation: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Ahmadreza Baghaie


    Full Text Available Estimating the displacements of intensity patterns between sequential frames is a very well-studied problem, which is usually referred to as optical flow estimation. The first assumption among many of the methods in the field is the brightness constancy during movements of pixels between frames. This assumption is proven to be not true in general, and therefore, the use of photometric invariant constraints has been studied in the past. One other solution can be sought by use of structural descriptors rather than pixels for estimating the optical flow. Unlike sparse feature detection/description techniques and since the problem of optical flow estimation tries to find a dense flow field, a dense structural representation of individual pixels and their neighbors is computed and then used for matching and optical flow estimation. Here, a comparative study is carried out by extending the framework of SIFT-flow to include more dense descriptors, and comprehensive comparisons are given. Overall, the work can be considered as a baseline for stimulating more interest in the use of dense descriptors for optical flow estimation.

  12. Experimental Estimation of Slipping in the Supporting Point of a Biped Robot

    Directory of Open Access Journals (Sweden)

    J.A. Vázquez


    Full Text Available When developing a gait cycle on a low-friction surface, a biped robot eventually tends to slip. In general, it is commonto overcome this problem by means of either slow movements or physical adaptations of the robot at the contact pointwith the walking surface in order to increase the frictional characteristics. In the case of slipping, several types ofsensors have been used to identify the relative displacement at the contact point of the supporting leg with the walkingsurface for control purposes. This work is focused on the experimental implementation of a low-cost force sensor as ameasurement system of the slipping phenomenon. It is shown how, supported on a suitable change of coordinates,the force measurement at the contact point is used to obtain the total displacement at the supporting point due to thelow-friction conditions. This is an important issue when an accurate Cartesian task is required.

  13. Experimental Estimation of Slipping in the Supporting Point of a Biped Robot

    Directory of Open Access Journals (Sweden)

    J.A. Vázquez


    Full Text Available When developing a gait cycle on a low-friction surface, a biped robot eventually tends to slip. In general, it is common to overcome this problem by means of either slow movements or physical adaptations of the robot at the contact point with the walking surface in order to increase the frictional characteristics. In the case of slipping, several types of sensors have been used to identify the relative displacement at the contact point of the supporting leg with the walking surface for control purposes. This work is focused on the experimental implementation of a low-cost force sensor as a measurement system of the slipping phenomenon. It is shown how, supported on a suitable change of coordinates, the force measurement at the contact point is used to obtain the total displacement at the supporting point due to the low-friction conditions. This is an important issue when an accurate Cartesian task is required.

  14. Diffusion in liquids a theoretical and experimental study

    CERN Document Server

    Tyrrell, H J V


    Diffusion in Liquids: A Theoretical and Experimental Study aims to discuss the principles, applications, and advances in the field of diffusion, thermal diffusion, and thermal conduction in liquid systems. The book covers topics such as the principles of non-equilibrium thermodynamics; diffusion in binary and multicompetent systems; and experimental methods of studying diffusion processes in liquids. Also covered in the book are topics such as the theoretical interpretations of diffusion coefficients; hydrodynamic and kinetic theories; and diffusion in electrolyte systems. The text is recommen

  15. Analytical and Experimental Study of Residual Stresses in CFRP

    Directory of Open Access Journals (Sweden)

    Chia-Chin Chiang


    Full Text Available Fiber Bragg Grating sensors (FBGs have been utilized in various engineering and photoelectric fields because of their good environment tolerance. In this research, residual stresses of carbon fiber reinforced polymer composites (CFRP were studied using both experimental and analytical approach. The FBGs were embedded inside middle layers of CFRP to study the formation of residual stress during curing process. Finite element analysis was performed using ABAQUS software to simulate the CFRP curing process. Both experimental and simulation results showed that the residual stress appeared during cooling process and the residual stresses could be released when the CFRP was machined to a different shape.

  16. Estimated cognitive decline in patients with schizophrenia: A multicenter study. (United States)

    Fujino, Haruo; Sumiyoshi, Chika; Yasuda, Yuka; Yamamori, Hidenaga; Fujimoto, Michiko; Fukunaga, Masaki; Miura, Kenichiro; Takebayashi, Yuto; Okada, Naohiro; Isomura, Shuichi; Kawano, Naoko; Toyomaki, Atsuhito; Kuga, Hironori; Isobe, Masanori; Oya, Kazuto; Okahisa, Yuko; Takaki, Manabu; Hashimoto, Naoki; Kato, Masaki; Onitsuka, Toshiaki; Ueno, Takefumi; Ohnuma, Tohru; Kasai, Kiyoto; Ozaki, Norio; Sumiyoshi, Tomiki; Imura, Osamu; Hashimoto, Ryota


    Studies have reported that cognitive decline occurs after the onset of schizophrenia despite heterogeneity in cognitive function among patients. The aim of this study was to investigate the degree of estimated cognitive decline in patients with schizophrenia by comparing estimated premorbid intellectual functioning and current intellectual functioning. A total of 446 patients with schizophrenia (228 male, 218 female), consisting of three sample sets obtained from 11 psychiatric facilities, and 686 healthy controls participated in this study. The Wechsler Adult Intelligence Scale-III (WAIS-III) was used to measure the participants' current full-scale IQ (FSIQ). The premorbid IQ was estimated using the Japanese Adult Reading Test-25. Estimated cognitive decline (difference score) was defined as the difference between the estimated premorbid IQ and the current FSIQ. Patients with schizophrenia showed greater estimated cognitive decline, a lower FSIQ, and a lower premorbid IQ compared with the healthy controls. The mean difference score, FSIQ, and estimated premorbid IQ were -16.3, 84.2, and 100.5, respectively, in patients with schizophrenia. Furthermore, 39.7% of the patients had a difference score of 20 points or greater decline. A discriminant analysis showed that the difference score accurately predicted 81.6% of the patients and healthy controls. These results show the distribution of difference score in patients with schizophrenia. These findings may contribute to assessing the severity of estimated cognitive decline and identifying patients with schizophrenia who suffer from cognitive decline. © 2016 The Authors. Psychiatry and Clinical Neurosciences published by John Wiley & Sons Australia, Ltd on behalf of Japanese Society of Psychiatry and Neurology.

  17. An experimental estimate of the electron-tunneling distance for some outer-sphere electrochemical reactions (United States)

    Hupp, J. T.; Weaver, M. J.


    Estimates of the reaction zone thickness over which electron tunneling can effectively occur for the outer-sphere electrochemical reduction of some Cr(III) complexes are obtained by comparing the observed work-corrected rate constants with unimolecular rate constants for the electroreduction of structurally similar surface-bound Cr(III) reactants. Effective reaction zone thicknesses of ca. 0.1-0.3 A and ca. 5 A are obtained for outer-sphere electron transfer with Cr(III) reactants containing predominantly aquo or ammine ligands, respectively. This indicates that the former reactions are marginally nonadiabatic whereas the latter are decidedly adiabatic at their respective places of closest approach. These findings are compatible with the greater reactant-electrode separation distances previously noted for Cr(III) aquo relative to ammine complexes resulting from the more extensive hydration sheath surrounding the former reactants.

  18. Comparative study of sound absorption coefficient determination using FEM method and experimental tests on Kundt's tube (United States)

    Deaconu, Marius; Toma, Adina Cristina; Dragasanu, Luminita Ioana; Mihai, Dragos


    Sound absorption coefficient is a commonly used parameter to characterize the acoustic properties of sound absorbing materials that plays an important role in noise attenuation. For this study a specific material has been chosen in order to be evaluated experimentally and compared with the simulated results. Both simulation and experimental assessments used to estimate the sound absorption coefficient are based on transfer function method in accordance with standard SR EN JSO 10354-2. Results are obtained for 15, 30, 45 mm material sample thickness in order to assess the relationship between absorption coefficient, thickness and frequency response. Comparative analysis is performed to determine differences given by the two approaches.

  19. Conceptual studies of toroidal field magnets for the tokamak experimental power reactor. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Buncher, B.R.; Chi, J.W.H.; Fernandez, R.


    This report documents the principal results of a Conceptual Design Study for the Superconducting Toroidal Field System for a Tokamak Experimental Power Reactor. Two concepts are described for peak operating fields at the windings of 8 tesla, and 12 tesla, respectively. The design and manufacturing considerations are treated in sufficient detail that cost and schedule estimates could be developed. Major uncertainties in the design are identified and their potential impact discussed, along with recommendations for the necessary research and development programs to minimize these uncertainties. The minimum dimensions of a sub-size test coil for experimental qualification of the full size design are developed and a test program is recommended.

  20. Experimental study of lithium target under high power load

    Energy Technology Data Exchange (ETDEWEB)

    Khripunov, B.I. E-mail:; Petrov, V.B.; Shapkin, V.V.; Pleshakov, A.S.; Rupyshev, A.S.; Antonov, N.V.; Litnovsky, A.M.; Romanov, P.V.; Shpansky, Yu.S.; Evtikhin, V.A.; Lyublinsky, I.E.; Vertkov, A.V


    This paper presents experimental research on simulation of a free liquid lithium surface under high heat flux impact for divertor application. Capillary porous structure (CPS) was taken to form the free liquid metal surface imitating divertor target plate. Experiments were performed in the SPRUT-4 linear plasma device with electron beam as power source. Lithium-filled targets were investigated at 1-50 MW/m{sup 2} heat loads in steady state. Lithium evaporation, energy and mass balance, surface temperature, vapor ionization, lithium plasma parameters and radiation were studied. Detailed thermal analysis was made to study heat flows in the target and their correspondence with experimental observations. Durable operation of the setup was possible in the range 1-20 MW/m{sup 2} without damage of the structure. The relevance of the experimental performance to divertor condition is analyzed.

  1. Conversion of eugenol to methyleugenol: Computational study and experimental (United States)

    Kurniawan, Muhammad Arsyik; Matsjeh, Sabirin; Triono, Sugeng


    This study provides comprehensive benchmark calculations for the computational study and experimental research on conversion of eugenol to methyleugenol with different pathway of the transition state compounds. First-principle calculation (DFT) were used to generate the structure optimization, energies of species. The calculation parameter are used to predict reactant, product and transition state species as guide to predict the experimental development of chemical characterization method including NMR and IR. The calculation showed significant effect of NaOH in formation of transition state in reaction. Experimentally, the step was nucleophilic substitution reaction of eugenolate ion to dimethylsulfate compound, it was obtained methyleugenol compound with purity of 90.73 %, which analyzed by Infrared and H-NMR spectrometer.

  2. Estimating the intake of abused methamphetamines using experimenter-administered deuterium labeled R-methamphetamine: selection of the R-methamphetamine dose. (United States)

    Li, Linghui; Lopez, Juan Carlos; Galloway, Gantt P; Baggott, Matthew J; Everhart, Tom; Mendelson, John


    All addictive drugs produce tolerance and addicts compensate by increasing drug exposure. Thus, the quantity of illicit drug ingested is related to the severity of addiction. Unfortunately, there are no objective methods to estimate intake for most addictive drugs. Using experimenter-administered doses of deuterium-labeled R-methamphetamine (R-[-]-MA-d3), we have developed a method to estimate the amount of abused methamphetamine intake in addicts enrolled in clinical trials. This study assessed the pharmacokinetics, pharmacodynamics, and tolerability of single oral doses of R-MA in healthy adults to select a dose of R-MA-d3 to be used as a biomarker for estimation the amount of methamphetamine abuse. This was a five-session randomized, double-blind, placebo-controlled, balanced crossover study in eight subjects. Oral R-(-)-MA was dosed at 0 mg, 1 mg, 2.5 mg, 5 mg, or 10 mg; bioavailability was estimated by slow intravenous dosing (30 minutes) of 2.5 mg R-(-)-MA-d3 given with the 2.5 mg R-(-)-MA oral dose condition. Pharmacokinetic and pharmacodynamic measures were obtained. No serious adverse events occurred during the study and all doses of R-MA were well tolerated. Linear pharmacokinetics was observed within our oral dose range of 1 to 10 mg. Complete bioavailability and pharmacologic inactivity were found for all oral doses. These characteristics indicate the advantage of using a small oral R-(-)-MA-d3 dose as a biomarker to estimate exposure to abused methamphetamine. Based on these results, 5 mg R-(-)-MA-d3 has been selected as the biomarker dose in future studies. Preliminary findings from our study indicate that experimenter-administered oral R-(-)-MA-d3 may allow estimation of abused methamphetamine intake and exposure. Knowledge of the quantity of methamphetamine intake may allow better estimation of disease severity and treatment efficacy. Experience gained from this study also can be applied to the management of other drug dependence problems such as

  3. Labeled experimental choice design for estimating attribute and availability cross effects with N attributes and specific brand attribute levels

    DEFF Research Database (Denmark)

    Nguyen, Thong Tien


    , orthogonal design is not available for every situation. Instead, efficient design based on computerized design algorithm is always available. This paper presents the method of efficient design for estimating brand models having attribute and availability cross effects. The paper gives a framework...... for implementing designs that is efficient enough to estimate model with N brands, each brand have K attributes, and brand attribute has specific levels. The paper also illustrates an example in food consumption study....

  4. Experimental Study on Impact Load on a Dam Due to Debris Flow (United States)

    lwao Miyoshi


    When a dam is struck by mud or debris flow, it is put under a great impact load and sometimes is destroyed. To prevent such destruction, it is important to perform basic research about the impact load on a dam due to debris flow. Thus, we have made an experimental study and tried to establish a method to estimate such a impact load on the dam. The experiment was...

  5. Approach to Operational Experimental Estimation of Static Stresses of Elements of Mechanical Structures (United States)

    Sedov, A. V.; Kalinchuk, V. V.; Bocharova, O. V.


    The evaluation of static stresses and strength of units and components is a crucial task for increasing reliability in the operation of vehicles and equipment, to prevent emergencies, especially in structures made of metal and composite materials. At the stage of creation and commissioning of structures to control the quality of manufacturing of individual elements and components, diagnostic control methods are widely used. They are acoustic, ultrasonic, X-ray, radiation methods and others. The using of these methods to control the residual life and the degree of static stresses of units and parts during operation is fraught with great difficulties both in methodology and in instrumentation. In this paper, the authors propose an effective approach of operative control of the degree of static stresses of units and parts of mechanical structures which are in working condition, based on recording the changing in the surface wave properties of a system consisting of a sensor and a controlled environment (unit, part). The proposed approach of low-frequency diagnostics of static stresses presupposes a new adaptive-spectral analysis of a surface wave created by external action (impact). It is possible to estimate implicit stresses of structures in the experiment due to this approach.

  6. Location estimation in a smart home: system implementation and evaluation using experimental data. (United States)

    Rahal, Youcef; Pigot, Hélène; Mabilleau, Philippe


    In the context of a constantly increasing aging population with cognitive deficiencies, insuring the autonomy of the elders at home becomes a priority. The DOMUS laboratory is addressing this issue by conceiving a smart home which can both assist people and preserve their quality of life. Obviously, the ability to monitor properly the occupant's activities and thus provide the pertinent assistance depends highly on location information inside the smart home. This paper proposes a solution to localize the occupant thanks to Bayesian filtering and a set of anonymous sensors disseminated throughout the house. The localization system is designed for a single person inside the house. It could however be used in conjunction with other localization systems in case more people are present. Our solution is functional in real conditions. We conceived an experiment to estimate precisely its accuracy and evaluate its robustness. The experiment consists of a scenario of daily routine meant to maximize the occupant's motion in meaningful activities. It was performed by 14 subjects, one subject at a time. The results are satisfactory: the system's accuracy exceeds 85% and is independent of the occupant's profile. The system works in real time and behaves well in presence of noise.

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

    Directory of Open Access Journals (Sweden)

    Predmirskyi V. S.


    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.

  8. Concept of the Cooling System of the ITS for ALICE: Technical Proposals, Theoretical Estimates, Experimental Results

    CERN Document Server

    Godisov, O N; Yudkin, M I; Gerasimov, S F; Feofilov, G A


    Contradictory demands raised by the application of different types of sensitive detectors in 5 layers of the Inner Tracking System (ITS) for ALICE stipulate the simultaneous use of different schemes of heat drain: gaseous cooling of the 1st layer (uniform heat production over the sensitive surface) and evaporative cooling for the 2nd-5th layers (localised heat production). The last system is also a must for the thermostabilization of Si-drift detectors within 0.1 degree C. Theoretical estimates of gaseous, evaporative and liquid cooling systems are done for all ITS layers. The results of the experiments done for evaporative and liquid heat drain systems are presented and discussed. The major technical problems of the evaporative systems' design are being considered: i) control of liquid supply; ii) vapour pressure control. Two concepts of the evaporative systems are proposed: 1) One channel system for joint transfer of two phases (liquid + gas); 2) Two channels system with separate transfer of phases. Both sy...

  9. Kernel bandwidth estimation for non-parametric density estimation: a comparative study

    CSIR Research Space (South Africa)

    Van der Walt, CM


    Full Text Available We investigate the performance of conventional bandwidth estimators for non-parametric kernel density estimation on a number of representative pattern-recognition tasks, to gain a better understanding of the behaviour of these estimators in high...

  10. Experimental study of hole cleaning performance in underbalanced

    African Journals Online (AJOL)


    factors affecting cost, time and drilling quality can be significantly hindered due to poor hole cleaning performance. Experimental study of hole cleaning performance in underbalanced drilling at downhole temperatures260C, 400C and 600C and water influx of 0.25m3/s in a simulated vertical well using gasified mud was ...

  11. 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.

  12. Experimental studies of the transient fluctuation theorem using liquid ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 72; Issue 5. Experimental studies of the transient ... Recently a fluctuation theorem, known as the transient fluctuation theorem (TFT), which generalizes the second law of thermodynamics to small systems has been proposed. This theorem has been tested in small ...

  13. Premium auctions and risk preferences: an experimental study

    NARCIS (Netherlands)

    Brunner, C.; Hu, A.; Oechssler, J.


    In premium auctions, the highest losing bidder receives a reward from the seller. This paper studies the private value English premium auction (EPA) for different risk attitudes of bidders. We explicitly derive the symmetric equilibrium for bidders with CARA utilities and conduct an experimental

  14. Sciara as an experimental model for studies on the evolutionary ...

    Indian Academy of Sciences (India)

    Sciara as an experimental model for studies on the evolutionary relationships between the zygotic, maternal and environmental primary signals for sexual development. Lucas Sánchez. Review Article Volume ... Lucas Sánchez1. Centro de Investigaciones Biol´ogicas (C. S. I. C.), Ramiro de Maeztu 9, 28040 Madrid, Spain ...

  15. Experimental Study of Cloud Formation from Rapidly Opened Containers

    Energy Technology Data Exchange (ETDEWEB)

    Wooldridge, C.E. [Stanford Research Institute; Amaro, A.J. [Stanford Research Institute; Kier, R.J. [Stanford Research Institute


    This report presents the results of an experimental study of droplet size emanating from a rapidly-opened container of volatile liquid, of the internal dynamics of the cavitation process inside such a container, & of the evaporation time of propane drops.

  16. Experimental study in natural convection | Ousmane | Global Journal ...

    African Journals Online (AJOL)

    The study of thermal and ventilation parameters, obtained in a transient, laminar solar chimney of reduced dimensions, (1 < m <3) m with a square collector (side = 2m) is presented. Experimental measurements has been made to determine the temperature of the absorber and the fluid in the collector, it is shown that at the ...

  17. Synthesis, experimental and theoretical studies of two cocrystals in 1 ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 127; Issue 11. Synthesis, experimental and theoretical studies of two cocrystals in 1:1 stoichiometric ratio from 4,4'-bithiazole-2,2'-diamine with two hydrogen acceptor molecules. Zohreh Rashidi Ranjbar Ali Morsali. Articles Volume 127 Issue 11 November 2015 pp ...

  18. Experimental studies on an indigenous coconut shell based ...

    Indian Academy of Sciences (India)

    Satyabrata Sahoo

    Abstract. Experimental studies are carried out to characterize an indigenous, coconut shell based, activated carbon suitable for storage of natural gas. Properties such as BET surface area, micropore volume, average pore diameter and pore size distribution are obtained by using suitable instruments and techniques.

  19. Experimental Study on a Rotor for WEPTOS Wave Energy Converter

    DEFF Research Database (Denmark)

    Pecher, Arthur; Kofoed, Jens Peter; Marchalot, Tanguy

    This report presents the results of an experimental study of the power conversion capabilities of one single rotor of the WEPTOS wave energy converter. The investigation focuses mainly on defining the optimal weight distribution in the rotor in order to improve the hydraulic performance through...

  20. Real versus Simulated Mobile Phone Exposures in Experimental Studies

    Directory of Open Access Journals (Sweden)

    Dimitris J. Panagopoulos


    Full Text Available We examined whether exposures to mobile phone radiation in biological/clinical experiments should be performed with real-life Electromagnetic Fields (EMFs emitted by commercially available mobile phone handsets, instead of simulated EMFs emitted by generators or test phones. Real mobile phone emissions are constantly and unpredictably varying and thus are very different from simulated emissions which employ fixed parameters and no variability. This variability is an important parameter that makes real emissions more bioactive. Living organisms seem to have decreased defense against environmental stressors of high variability. While experimental studies employing simulated EMF-emissions present a strong inconsistency among their results with less than 50% of them reporting effects, studies employing real mobile phone exposures demonstrate an almost 100% consistency in showing adverse effects. This consistency is in agreement with studies showing association with brain tumors, symptoms of unwellness, and declines in animal populations. Average dosimetry in studies with real emissions can be reliable with increased number of field measurements, and variation in experimental outcomes due to exposure variability becomes less significant with increased number of experimental replications. We conclude that, in order for experimental findings to reflect reality, it is crucially important that exposures be performed by commercially available mobile phone handsets.

  1. Chemometric Optimization Studies in Catalysis Employing High-Throughput Experimentation

    NARCIS (Netherlands)

    Pereira, S.R.M.


    The main topic of this thesis is the investigation of the synergies between High-Throughput Experimentation (HTE) and Chemometric Optimization methodologies in Catalysis research and of the use of such methodologies to maximize the advantages of using HTE methods. Several case studies were analysed

  2. Experimental and modeling studies of mass transfer in ...

    African Journals Online (AJOL)

    Gaining a better understanding of mass transfer problems in encapsulated cell systems and in tissue engineering requires both experimental investigations and mathematical modelling. Specific mass transfer studies are reviewed including oxygen transfer in immobilised animal cell culture systems, modelling of ...

  3. Experimental study of buoyancy driven natural ventilation through horizontal openings

    DEFF Research Database (Denmark)

    Heiselberg, Per; Li, Zhigang


    An experimental study of buoyancy driven natural ventilation through single-sided horizontal openings was performed in a full-scale laboratory test rig. Measurements were made for opening ratios L/D range from 0.027 to 4.455, where L and D are the length and the diameter of the opening, respectiv...

  4. 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 ...

  5. Experimental study on imaging spectrometer focusing formula in orbit (United States)

    Ma, Hong-tao; Jin, Hui


    Experimental verification for a focusing mechanism of imaging spectrometer is studied. The mechanism uses stepper motor driven precision harmonic drive. Wave generator is composed of elliptical cam and a flexible bearing. The output end is connected with the ball screw rotary motion into linear motion, which drives the focusing lens linear guide reciprocating motion. In view of the practical application of the mechanism in the imaging spectrometer, the thermal optical experimental imaging spectrometer has been focusing the formula. Data show that the focus formula ensures linear relationship between the focal plane position and temperature. The linear relationship shows that the imaging spectrometer onboard the variation with temperature and automatic focusing is very important.

  6. Experimental study on beam for composite CES structural system (United States)

    Matsui, Tomoya


    Development study on Concrete Encase Steel (CES) composite structure system has been continuously conducted toward the practical use. CES structure is composed of steel and fiber reinforced concrete. In previous study, it was found that CES structure has good seismic performance from experimental study of columns, beam - column joints, shear walls and a two story two span frame. However, as fundamental study on CES beam could be lacking, it is necessary to understand the structural performance of CES beam. In this study, static loading tests of CES beams were conducted with experimental valuable of steel size, the presence or absence of slab and thickness of slab. And restoring characteristics, failure behavior, deformation behavior, and strength evaluation method of CES beam were investigated. As the results, it was found that CES beam showed stable hysteresis behavior. Furthermore it was found that the flexural strength of the CES beam could be evaluated by superposition strength theory.

  7. Experimental and numerical study on condensation in transonic steam flow

    Directory of Open Access Journals (Sweden)

    Majkut Mirosław


    Full Text Available The present paper describes an experimental and numerical study of steam condensing flow in a linear cascade of turbine stator blades. The experimental research was performed on the facility of a small scale steam power plant located at Silesian University of Technology in Gliwice, Poland. The test rig of the facility allows us to perform the tests of steam transonic flows for the conditions corresponding to these which prevail in the low-pressure (LP condensing steam turbine stages. The experimental data of steam condensing flow through the blade-to- blade stator channel were compared with numerical results obtained using the in-house CFD numerical code TraCoFlow. Obtained results confirmed a good quality of the performed experiment and numerical calculations.

  8. Mechanical properties of jennite: A theoretical and experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Juhyuk, E-mail: [Civil Engineering Program, Department of Mechanical Engineering, Stony Brook University, NY 11794 (United States); Yoon, Seyoon [School of Engineering, Kings College, University of Aberdeen, Aberdeen AB24 3UE (United Kingdom); Monteiro, Paulo J.M. [Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720 (United States)


    The objective of this study is to determine the mechanical properties of jennite. To date, several hypotheses have been proposed to predict the structural properties of jennite. For the first time as reported herein, the isothermal bulk modulus of jennite was measured experimentally. Synchrotron-based high-pressure x-ray diffraction experiments were performed to observe the variation of lattice parameters under pressure. First-principles calculations were applied to compare with the experimental results and predict additional structural properties. Accurately measured isothermal bulk modulus herein (K{sub 0} = 64(2) GPa) and the statistical assessment on experimental and theoretical results suggest reliable mechanical properties of shear and Young's modulus, Poisson's ratio, and elastic tensor coefficients. Determination of these fundamental structural properties is the first step toward greater understanding of calcium–silicate–hydrate, as well as provides a sound foundation for forthcoming atomic level simulations.

  9. Experimental dehydration of natural obsidian and estimation of DH2O at low water contents (United States)

    Jambon, A.; Zhang, Y.; Stolper, E. M.


    Water diffusion experiments were carried out by dehydrating rhyolitic obsidian from Valles Caldera (New Mexico, USA) at 510-980 degrees C. The starting glass wafers contained approximately 0.114 wt% total water, lower than any glasses previously investigated for water diffusion. Weight loss due to dehydration was measured as a function of experiment duration, which permits determination of mean bulk water diffusivity, mean Dw. These diffusivities are in the range of 2.6 to 18 X 10(-14) m2/s and can be fit with the following Arrhenius equation: ln mean Dw (m2/s) = -(25.10 +/- 1.29) - (46,480 +/- 11,400) (J/mol) / RT, except for two replicate runs at 510 degrees C which give mean Dw values much lower than that defined by the above equation. When interpreted according to a model of water speciation in which molecular H2O is the diffusing species with concentration-independent diffusivity while OH units do not contribute to the transport but react to provide H2O, the data (except for the 510 degrees C data) are in agreement with extrapolation from previous results and hence extend the previous data base and provide a test of the applicability of the model to very low water contents. Mean bulk water diffusivities are about two orders of magnitude less than molecular H2O diffusivities because the fraction of molecular H2O out of total water is very small at 0.114 wt% total water and less. The 510 degrees C experimental results can be interpreted as due to slow kinetics of OH to H2O interconversion at low temperatures.

  10. Experimental model for non-Newtonian fluid viscosity estimation: Fit to mathematical expressions

    Directory of Open Access Journals (Sweden)

    Guillem Masoliver i Marcos


    Full Text Available The  construction  process  of  a  viscometer,  developed  in  collaboration  with  a  final  project  student,  is  here  presented.  It  is  intended  to  be  used  by   first  year's  students  to  know  the  viscosity  as  a  fluid  property, for  both  Newtonian  and  non-Newtonian  flows.  Viscosity  determination  is  crucial  for  the  fluids  behaviour knowledge  related  to  their  reologic  and  physical  properties.  These  have  great  implications  in  engineering aspects  such  as  friction  or  lubrication.  With  the  present  experimental  model  device  three  different fluids are  analyzed  (water,  kétchup  and  a  mixture  with  cornstarch  and  water.  Tangential stress is measured versus velocity in order to characterize all the fluids in different thermal conditions. A mathematical fit process is proposed to be done in order to adjust the results to expected analytical expressions, obtaining good results for these fittings, with R2 greater than 0.88 in any case.

  11. A New Extant Respirometric Assay to Estimate Intrinsic Growth Parameters Applied to Study Plasmid Metabolic Burden

    DEFF Research Database (Denmark)

    Seoane, Jose Miguel; Sin, Gürkan; Lardon, Laurent


    Start-Lip phenomena in microbial biokinetic assays are not captured by the most commonly used growth-related equations. In this Study we propose a new respirometric experimental design to estimate intrinsic growth parameters that allow us to avoid these limitations without data omission, separate...... the plasmid contributing equally to the overall effect. Biotechnol. Bioeng. 2010;105: 141-149. (C) 2009 Wiley Periodicals, Inc....

  12. Pseudoepitheliomatous hyperplasia after diode laser oral surgery. An experimental study (United States)

    Seoane, Juan; González-Mosquera, Antonio; García-Martín, José-Manuel; García-Caballero, Lucía; Varela-Centelles, Pablo


    Background To examine the process of epithelial reparation in a surgical wound caused by diode laser. Material and Methods An experimental study with 27 Sprage-Dawley rats was undertaken. The animals were randomly allocated to two experimental groups, whose individuals underwent glossectomy by means of a diode laser at different wattages, and a control group treated using a number 15 scalpel blade. The animals were slaughtered at the 2nd, 7th, and 14th day after glossectomy. The specimens were independently studied by two pathologists (blinded for the specimens’ group). Results At the 7th day, re-epithelisation was slightly faster for the control group (conventional scalpel) (p=0.011). At the 14th day, complete re-epithelization was observed for all groups. The experimental groups displayed a pseudoepitheliomatous hyperplasia. Conclusions It is concluded that, considering the limitations of this kind of experimental studies, early re-epithelisation occurs slightly faster when a conventional scalpel is used for incision, although re-epithelisation is completed in two weeks no matter the instrument used. In addition, pseudoepitheliomatous hyperplasia is a potential event after oral mucosa surgery with diode laser. Knowledge about this phenomenon (not previously described) may prevent diagnostic mistakes and inadequate treatment approaches, particularly when dealing with potentially malignant oral lesions. Key words:Diode laser, animal model, oral biopsy, oral cancer, oral precancer, pseudoepitheliomatous hyperplasia. PMID:26116841

  13. Experimental estimation of the heat energy dissipated in a volume surrounding the tip of a fatigue crack

    Directory of Open Access Journals (Sweden)

    G. Meneghetti


    Full Text Available Fatigue crack initiation and propagation involve plastic strains that require some work to be done on the material. Most of this irreversible energy is dissipated as heat and consequently the material temperature increases. The heat being an indicator of the intense plastic strains occurring at the tip of a propagating fatigue crack, when combined with the Neuber’s structural volume concept, it might be used as an experimentally measurable parameter to assess the fatigue damage accumulation rate of cracked components. On the basis of a theoretical model published previously, in this work the heat energy dissipated in a volume surrounding the crack tip is estimated experimentally on the basis of the radial temperature profiles measured by means of an infrared camera. The definition of the structural volume in a fatigue sense is beyond the scope of the present paper. The experimental crack propagation tests were carried out on hot-rolled, 6-mm-thick AISI 304L stainless steel specimens subject to completely reversed axial fatigue loading.

  14. Lateral ankle ligament injury : an experimental and clinical study

    NARCIS (Netherlands)

    F.W.C. van der Ent (Frederik Willem Charles)


    textabstractSport has become one of the most popular methods of spending freetime and consequently is of great social importance. fn recent studies concerning sports injuries in the Netherlands (BoersmaSIUtter et al. - 1979, v.Rens 1982) it was estimated that about 20% of all registered sportsmen

  15. Experimental Study on Volume for Fly Ash of Building Block


    Ling Wang; He Sun; Zhihui Sun; Enqing Ma


    Fly ash is a waste substance from thermal power plants, steel mills, etc. That is found in abundance in the world. It has polluted the environment, wasting the cultivated land. This study introduces an experimental research on fly ash being reused effectively, the study introduces raw materials of fly ash brick, production process and product inspection, fly ash content could be amounted to 40%~75%. High doping fly ash bricks are manufactured, which selects wet fly ash from the power plants, ...

  16. Experimental and Analytical Studies of Solar System Chemistry (United States)

    Burnett, Donald S.


    The cosmochemistry research funded by this grant resulted in the publications given in the attached Publication List. The research focused in three areas: (1) Experimental studies of trace element partitioning. (2) Studies of the minor element chemistry and O isotopic compositions of MgAlO4 spinels from Ca-Al-Rich Inclusions in carbonaceous chondrite meteorites, and (3) The abundances and chemical fractionations of Th and U in chondritic meteorites.

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

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  18. Experimental study of the formation of steep waves and breakers

    Directory of Open Access Journals (Sweden)

    Stanis³aw R. Massel


    Full Text Available Breaking waves (whitecaps are one of the most important and least understood processes associated with the evolution of the surface gravity wave field in the open sea. This process is the principal means by which energy and momentum are transferred away from a developing sea. However, an estimation of the frequency of breaking waves or the fraction of sea surface covered by whitecaps and the amount of dissipated energy induced by breaking is very difficult to carry out under real sea conditions. A controlled experiment, funded by the European Commission under the Improving Human Potential Access Infrastructures programme, was carried out in the Ocean Basin Laboratory at MARINTEK, Trondheim (Norway. Simulation of random waves of the prescribed spectra by wave makers provided a very realistic pattern of the sea surface. The number of breaking waves was estimated by photographing the sea surface and recording the noise caused by the breaking waves. The experimental data will serve for calibration of the theoretical models of the sea surface fraction related to the whitecaps.

  19. Monte Carlo Approach for Reliability Estimations in Generalizability Studies. (United States)

    Dimitrov, Dimiter M.

    A Monte Carlo approach is proposed, using the Statistical Analysis System (SAS) programming language, for estimating reliability coefficients in generalizability theory studies. Test scores are generated by a probabilistic model that considers the probability for a person with a given ability score to answer an item with a given difficulty…

  20. Experimental and Theoretical Studies in Hydrogen-Bonding Organocatalysis

    Directory of Open Access Journals (Sweden)

    Matej Žabka


    Full Text Available Chiral thioureas and squaramides are among the most prominent hydrogen-bond bifunctional organocatalysts now extensively used for various transformations, including aldol, Michael, Mannich and Diels-Alder reactions. More importantly, the experimental and computational study of the mode of activation has begun to attract considerable attention. Various experimental, spectroscopic and calculation methods are now frequently used, often as an integrated approach, to establish the reaction mechanism, the mode of activation or explain the stereochemical outcome of the reaction. This article comprises several case studies, sorted according to the method used in their study. The aim of this review is to give the investigators an overview of the methods currently utilized for mechanistic investigations in hydrogen-bonding organocatalysis.

  1. Informing Estimates of Program Effects for Studies of Mathematics Professional Development Using Teacher Content Knowledge Outcomes. (United States)

    Phelps, Geoffrey; Kelcey, Benjamin; Jones, Nathan; Liu, Shuangshuang


    Mathematics professional development is widely offered, typically with the goal of improving teachers' content knowledge, the quality of teaching, and ultimately students' achievement. Recently, new assessments focused on mathematical knowledge for teaching (MKT) have been developed to assist in the evaluation and improvement of mathematics professional development. This study presents empirical estimates of average program change in MKT and its variation with the goal of supporting the design of experimental trials that are adequately powered to detect a specified program effect. The study drew on a large database representing five different assessments of MKT and collectively 326 professional development programs and 9,365 teachers. Results from cross-classified hierarchical growth models found that standardized average change estimates across the five assessments ranged from a low of 0.16 standard deviations (SDs) to a high of 0.26 SDs. Power analyses using the estimated pre- and posttest change estimates indicated that hundreds of teachers are needed to detect changes in knowledge at the lower end of the distribution. Even studies powered to detect effects at the higher end of the distribution will require substantial resources to conduct rigorous experimental trials. Empirical benchmarks that describe average program change and its variation provide a useful preliminary resource for interpreting the relative magnitude of effect sizes associated with professional development programs and for designing adequately powered trials. © The Author(s) 2016.

  2. Comparison of two acoustic analogies applied to experimental PIV data for cavity sound emission estimation

    NARCIS (Netherlands)

    Koschatzky, V.; Westerweel, J.; Boersma, B.J.


    The aim of the present study is to compare two different acoustic analogies applied to time-resolved particle image velocimetry (PIV) data for the prediction of the acoustic far-field generated by the flow over a rectangular cavity. Recent developments in laser and camera technology allow the

  3. Fusion reactor design studies: standard accounts for cost estimates

    Energy Technology Data Exchange (ETDEWEB)

    Schulte, S.C.; Willke, T.L.; Young, J.R.


    The fusion reactor design studies--standard accounts for cost estimates provides a common format from which to assess the economic character of magnetically confined fusion reactor design concepts. The format will aid designers in the preparation of design concept costs estimates and also provide policymakers with a tool to assist in appraising which design concept may be economically promising. The format sets forth a categorization and accounting procedure to be used when estimating fusion reactor busbar energy cost that can be easily and consistently applied. Reasons for developing the procedure, explanations of the procedure, justifications for assumptions made in the procedure, and the applicability of the procedure are described in this document. Adherence to the format when evaluating prospective fusion reactor design concepts will result in the identification of the more promising design concepts thus enabling the fusion power alternatives with better economic potential to be quickly and efficiently developed.

  4. Validation of the finite element simulation to estimate the rolling resistance of a non-driving wheel with experimental tests

    Directory of Open Access Journals (Sweden)

    N Dibagar


    Full Text Available Introduction: Encountering soil from the viewpoint of management and product manufacturing has always been considered important, and an attempt is always made hat the tools and contrasting methods of soil be designed in such a way that itself prevents, as much as possible, the destructive consequences or energy waste that include economical or environmental limitations. Enhancing the soil encountering methods, quality reformation, and its related equipment, requires performing reliable tests in actual soil conditions. Considering the complexity and variety of variables in soil and machine contrast, this is a hard task. Hence, the numeral simulations are the key of all optimizations that illustrate efficient models by removing the costly farm tests and reducing research time. Tire is one of the main factors engaged with soil, and it is one of those tools that are discussable in both farms, and software environments. Despite the complexities in soil behavior, and tire geometry, modeling, tire movement on the soil has been the researchers’ objective from the past. Materials and methods: A non-linear finite element (FE model of the interaction of a non-driving tire with soil surface was developed to investigate the influence of the forward speed, tire inflation pressure and vertical load on rolling resistance using ABAQUS/Explicit code. In this research numerical and experimental tests were done under different conditions in order to estimate tire rolling resistance. In numerical tests, the soil part was simulated as a one-layer viscous-elastic material with a Drucker-Prager model by considering realistic soil properties. These properties included elastic and plastic properties which were obtained in the soil laboratory using relevant tests. The soil samples were prepared from the soil which was inside the soil bin. The same soil was utilized in experimental tests. Finite strain hyper elasticity model is developed to model nearly incompressible

  5. Evaluation of Lithium-Ion Battery Equivalent Circuit Models for State of Charge Estimation by an Experimental Approach

    Directory of Open Access Journals (Sweden)

    Jinxin Fan


    Full Text Available To improve the use of lithium-ion batteries in electric vehicle (EV applications, evaluations and comparisons of different equivalent circuit models are presented in this paper. Based on an analysis of the traditional lithium-ion battery equivalent circuit models such as the Rint, RC, Thevenin and PNGV models, an improved Thevenin model, named dual polarization (DP model, is put forward by adding an extra RC to simulate the electrochemical polarization and concentration polarization separately. The model parameters are identified with a genetic algorithm, which is used to find the optimal time constant of the model, and the experimental data from a Hybrid Pulse Power Characterization (HPPC test on a LiMn2O4 battery module. Evaluations on the five models are carried out from the point of view of the dynamic performance and the state of charge (SoC estimation. The dynamic performances of the five models are obtained by conducting the Dynamic Stress Test (DST and the accuracy of SoC estimation with the Robust Extended Kalman Filter (REKF approach is determined by performing a Federal Urban Driving Schedules (FUDS experiment. By comparison, the DP model has the best dynamic performance and provides the most accurate SoC estimation. Finally, sensitivity of the different SoC initial values is investigated based on the accuracy of SoC estimation with the REKF approach based on the DP model. It is clear that the errors resulting from the SoC initial value are significantly reduced and the true SoC is convergent within an acceptable error.

  6. Composite likelihood and two-stage estimation in family studies

    DEFF Research Database (Denmark)

    Andersen, Elisabeth Anne Wreford


    In this paper register based family studies provide the motivation for linking a two-stage estimation procedure in copula models for multivariate failure time data with a composite likelihood approach. The asymptotic properties of the estimators in both parametric and semi-parametric models...... in this last case where very flexible modelling is possible. The suggested method is also studied in simulations and found to be efficient compared to maximum likelihood. Finally, the suggested method is applied to a family study of deep venous thromboembolism where it is seen that the association between ages...... are derived, combining the approaches of Parner (2001) and Andersen (2003). The method is mainly studied when the families consist of groups of exchangeable members (e.g. siblings) or members at different levels (e.g. parents and children). The advantages of the proposed method are especially clear...

  7. Biases in Estimating Treatment Effects Due to Attrition in Randomized Controlled Trials and Cluster Randomized Controlled Trials: A Simulation Study (United States)

    Dong, Nianbo; Lipsey, Mark W.


    Attrition occurs when study participants who were assigned to the treatment and control conditions do not provide outcome data and thus do not contribute to the estimation of the treatment effects. It is very common in experimental studies in education as illustrated, for instance, in a meta-analysis studying "the effects of attrition on baseline…

  8. Experimental estimation of in vacuo structural admittance using random sources in a non-anechoic room. (United States)

    Williams, Earl G; Tippmann, Jeffery D; Rakotonarivo, Sandrine T; Waters, Zachary J; Roux, Philippe; Kuperman, W A


    Identification of unexploded ordinance buried in the sediment in the littoral waters throughout the world is a problem of great concern. When illuminated by low-frequency sonar some of these targets exhibit an elastic response that can be used to identify them. This elastic behavior is embodied and identified by a quantity called the in vacuo structural admittance matrix Ys, a relationship between the sonar-induced forces and resulting vibration on its surface. When it is known it can be combined with surface impedances to predict the three-dimensional bistatic scattering in any fluid-like media and for any burial state (depth and orientation). At the heart of this is the measurement of Ys and it is demonstrated in this paper that this can be accomplished by studying the target in a simple (acoustically unaltered) in-air laboratory environment. The target chosen in this study is a thick spherical shell that was illuminated by a nearly spatially isotropic array of remote loudspeakers. Ys is constructed from ensemble averages of the cross-correlations of eight collocated accelerometers and microphones placed on the surface of the object. The structural admittance determined from the data showed excellent agreement with theory.

  9. Estimation of surface soil moisture and roughness from multi-angular ASAR imagery in the Watershed Allied Telemetry Experimental Research (WATER

    Directory of Open Access Journals (Sweden)

    S. G. Wang


    Full Text Available Radar remote sensing has demonstrated its applicability to the retrieval of basin-scale soil moisture. The mechanism of radar backscattering from soils is complicated and strongly influenced by surface roughness. Additionally, retrieval of soil moisture using AIEM (advanced integrated equation model-like models is a classic example of underdetermined problem due to a lack of credible known soil roughness distributions at a regional scale. Characterization of this roughness is therefore crucial for an accurate derivation of soil moisture based on backscattering models. This study aims to simultaneously obtain surface roughness parameters (standard deviation of surface height σ and correlation length cl along with soil moisture from multi-angular ASAR images by using a two-step retrieval scheme based on the AIEM. The method firstly used a semi-empirical relationship that relates the roughness slope, Zs (Zs = σ2/cl and the difference in backscattering coefficient (Δσ from two ASAR images acquired with different incidence angles. Meanwhile, by using an experimental statistical relationship between σ and cl, both these parameters can be estimated. Then, the deduced roughness parameters were used for the retrieval of soil moisture in association with the AIEM. An evaluation of the proposed method was performed in an experimental area in the middle stream of the Heihe River Basin, where the Watershed Allied Telemetry Experimental Research (WATER was taken place. It is demonstrated that the proposed method is feasible to achieve reliable estimation of soil water content. The key challenge is the presence of vegetation cover, which significantly impacts the estimates of surface roughness and soil moisture.

  10. Numerical and Experimental Case Study of Blasting Works Effect (United States)

    Papán, Daniel; Valašková, Veronika; Drusa, Marian


    This article introduces the theoretical and experimental case study of dynamic monitoring of the geological environment above constructed highway tunnel. The monitored structure is in this case a very important water supply pipeline, which crosses the tunnel and was made from steel tubes with a diameter of 800 mm. The basic dynamic parameters had been monitored during blasting works, and were compared with the FEM (Finite Element Method) calculations and checked by the Slovak standard limits. A calibrated FEM model based on the experimental measurement data results was created and used in order to receive more realistic results in further predictions, time and space extrapolations. This case study was required and demanded by the general contractor company and also by the owner of water pipeline, and it was an answer of public safety evaluation of risks during tunnel construction.

  11. Lung Morphological Changes in Closed Chest Injury (an experimental study

    Directory of Open Access Journals (Sweden)

    A. M. Golubev


    Full Text Available Objective: to study lung morphological changes in a closed chest injury model in laboratory animals. Material and methods. Experiments were carried out in 30 male albino nonbred rats weighing 350—380 g. Closed chest injury was simulated, by exposing the chest of anesthetized rats to a 300-g metal cylinder falling from a height of 30 cm. The observation periods were 1, 3, 6, and 24 hours. Results. The signs of evident perivenular edema that was uncharas-teristic to acute respiratory distress syndrome induced by other causes are an important peculiarity of lung morphological changes in this experimental model of closed chest injury. Conclusion. The experimental studies clarified the pattern of lung morphological changes in the early period after closed chest injury. Key words: closed chest injury, pulmonary edema.

  12. Comparative study of experimental signals for multipactor and breakdown.

    CERN Document Server

    Dehler, Micha; Wuensch, Walter; Faus-Golfe, Angeles; Gimeno Martinez, Benito; Kovermann, Jan; Boria, Vicente; Raboso, David


    Performance limiting high-power rf phenomenon occur in both transmitter systems in satellites and high-gradient accelerating structures in particle accelerators. In satellites the predominant effect is multipactor while in accelerators it is breakdown. Both communities have studied their respective phenomena extensively and developed particular simulation tools and experimental techniques. A series of experiments to directly compare measurements made under multipactor and breakdown conditions has been initiated with the objective to crosscheck and compare the physics, simulation tools and measurement techniques.

  13. Experimental and theoretical study of horizontal-axis wind turbines


    Anderson, Michael Broughton


    An experimental and theoretical study of horizontal-axis wind turbines is undertaken. The theoretical analyses cover the four major areas of aerodynamics, turbulence. aeroelasticity and blade optimisation. EXisting aerodynamic theories based on blade-element theory for predicting the loads on a wind turbine blade are reviewed and extended to include non-uniform flow, tip losses and the 'turbulent wake' state. A theoretical model based on a free vortex representation of a ...

  14. Composition of intraocular foreign bodies: experimental study of ultrasonographic presentation


    Márcio Augusto Nogueira Costa; Patrícia Novita Garcia; Letícia Fernandes Barroso; Marco Antonio Ferreira; Érika Araki Okuda; Norma Allemann


    PURPOSE: To investigate the reliability of ultrasound in determining the size and identify the sonographic features and artifacts generated by intraocular foreign bodies of different materials. METHODS: Experimental study using 36 enucleated porcine eyes. Fragments of nine different compositions (wood, glass, plastic, cardboard, iron, aluminum, lead, powder and concrete) and similar dimensions (4 mm) were implanted via scleral incision into the vitreous cavity of 36 porcine eyes, four eyes we...

  15. Respecifying lab ethnography an ethnomethodological study of experimental physics

    CERN Document Server

    Sormani, Philippe


    Respecifying Lab Ethnography delivers the first ethnomethodological study of current experimental physics in action, describing the disciplinary orientation of lab work and exploring the discipline in its social order, formal stringency and skilful performance - in situ and in vivo. In bringing together two major strands of ethnomethodological inquiry, reflexive ethnography and video analysis, which have hitherto existed in parallel, Respecifying Lab Ethnography introduces a practice-based video analysis. In doing so, the book recasts conventional distinctions to shed fresh light on methodolog

  16. Experimental study on durability of small wind turbine (United States)

    Bao, Daorina; Shang, Wei; Wang, Huan


    Through the basic theory of durability test technology for small and medium sized wind power generation units, and the durability of 3KW wind turbine, this paper analyzed the test method of time available rate of unit and studied the power generation capability of the wind turbine. No power attenuation trend has been found, and a lot of experimental data and rich experience in engineering practice has been obtained with the success of experiments.

  17. Experimental studies toward the characterization of Inmetro's circulating water channel (United States)

    Santos, A. M.; Alho, A. T. P.; Garcia, D. A.; Farias, M. H.; Massari, P. L.; Silva, V. V. S.


    Circulating water channels are facilities which can be used for conducting environmental, metrological and engineering studies. The Brazilian National Institute of Metrology-INMETRO has a water channel of innovative design, and the present work deals with the prior experimental investigation of its hydrodynamics performance. By using the optical technique PIV - Particle Image Velocimetry, under certain conditions, the velocity profile behavior in a region inside the channel was analyzed in order to evaluate the scope of applicability of such bench.

  18. Estimation Methods of the Point Spread Function Axial Position: A Comparative Computational Study

    Directory of Open Access Journals (Sweden)

    Javier Eduardo Diaz Zamboni


    Full Text Available The precise knowledge of the point spread function is central for any imaging system characterization. In fluorescence microscopy, point spread function (PSF determination has become a common and obligatory task for each new experimental device, mainly due to its strong dependence on acquisition conditions. During the last decade, algorithms have been developed for the precise calculation of the PSF, which fit model parameters that describe image formation on the microscope to experimental data. In order to contribute to this subject, a comparative study of three parameter estimation methods is reported, namely: I-divergence minimization (MIDIV, maximum likelihood (ML and non-linear least square (LSQR. They were applied to the estimation of the point source position on the optical axis, using a physical model. Methods’ performance was evaluated under different conditions and noise levels using synthetic images and considering success percentage, iteration number, computation time, accuracy and precision. The main results showed that the axial position estimation requires a high SNR to achieve an acceptable success level and higher still to be close to the estimation error lower bound. ML achieved a higher success percentage at lower SNR compared to MIDIV and LSQR with an intrinsic noise source. Only the ML and MIDIV methods achieved the error lower bound, but only with data belonging to the optical axis and high SNR. Extrinsic noise sources worsened the success percentage, but no difference was found between noise sources for the same method for all methods studied.

  19. Study on the Computational Estimation Performance and Computational Estimation Attitude of Elementary School Fifth Graders in Taiwan (United States)

    Tsao, Yea-Ling; Pan, Ting-Rung


    Main purpose of this study is to investigate what level of computational estimation performance is possessed by fifth graders and explore computational estimation attitude towards fifth graders. Two hundred and thirty-five Grade-5 students from four elementary schools in Taipei City were selected for "Computational Estimation Test" and…

  20. Experimental and numerical studies of two arterial wall delamination modes. (United States)

    Leng, Xiaochang; Zhou, Boran; Deng, Xiaomin; Davis, Lindsey; Lessner, Susan M; Sutton, Michael A; Shazly, Tarek


    Arterial wall dissection, which results from various pathophysiological processes, can lead to the occurrence of large area delamination in the aortic wall that can potentially block blood flow and lead to deleterious clinical conditions. Despite its critical clinical relevance, few studies have focused on investigating the failure mode of delamination in the arterial wall. In this study, we quantify the energy release rate of the medial layer of a porcine abdominal aorta via two delamination experiments: the mixed-mode delamination experiment and the "T"-shaped delamination experiment. A cohesive zone model (CZM) is applied to simulate the arterial wall delamination and Holzapfel-Gasser-Ogden (HGO) material model is used to capture the bulk arterial material behavior. A set of parameter values for the HGO and CZM models are identified through matching simulation predictions of the load vs. load-point displacement curve with experimental measurements. Then the parameter values and critical energy release rates obtained from experiments are used as input data for simulation predictions for two arterial wall delamination experiments. The simulation predictions show that the delamination front matches well with experimental measurements. Moreover, the mixed-mode delamination experiment reveals a shear mode-dominated failure event, whereas the "T"-shaped delamination experiment is an opening failure process. The integration of experimental data and numerical predictions of arterial delamination events provides a comprehensive description of distinct failure modes and aids in the prediction of aortic dissection. Copyright © 2017. Published by Elsevier Ltd.

  1. Analytical and experimental studies of wakes behind circularly capped bubbles (United States)

    Bessler, W. F.

    The wakes behind circularly capped bubbles are examined by means of an experimental and analytical study. A single two-inch diameter bubble is injected into a six by three foot fluid column, one half inch thick, producing an essentially two-dimensional flow. Aspirin powder placed in the fluid column just prior to bubble release highlights the structure of the flow field before dissolving. High speed film and sequenced photographs are taken to document the observed results. Pressure-time measurements are made with sensitive capacitive transducers mounted in the rear column wall and are synchronized with photographs using a high speed clock. Experimental fluids, prepared by mixing water and glycerine in varying proportions, are used to study the effects of viscosity on bubble shape and wake structure. Testing is performed over a range of Reynolds numbers from 14 to 29,655 which includes the transition from circularly capped to ellipsoidal bubble shape. Experimental data is reduced and summarized in convenient dimensionless form to permit comparison with analytical predictions.

  2. An experimental study on recovering heat from domestic drain water (United States)

    Ramadan, Mohamad; Al Shaer, Ali; Haddad, Ahmad; Khaled, Mahmoud


    This paper concerns an experimental study on a system of heat recovery applied to domestic drain water pipes. The concept suggested consists of using the heat still present in the drain water as a preheating/heating source to the cold water supply of the building. To proceed, an appropriate experimental setup is developed and a coil heat exchanger is used as heat transfer device in the recovery system. Several scenarios are simulated and corresponding parameters are recorded and analyzed. It was shown that the suggested recovery concept can considerably preheat the cold water supply and then decrease the energy consumption. Particularly, up to 8.6 kW of heat were recovered when the cold water supply is initially at 3 °C.

  3. Experimental and theoretical study of metal combustion in oxygen flows

    CERN Document Server

    El-Rabii, Hazem; Muller, Maryse


    The effects of oxygen flow speed and pressure on the iron and mild steel combustion are investigated experimentally and theoretically. The studied specimens are vertical cylindrical rods subjected to an axial oxygen flow and ignited at the upper end by laser irradiation. Three main stages of the combustion process have been identified experimentally: (1) Induction period, during which the rod is heated until an intensive metal oxidation begins at its upper end; (2) Static combustion, during which a laminar liquid "cap" slowly grows on the upper rod end; and, after the liquid cap detachment from the sample, (3) Dynamic combustion, which is characterized by a rapid metal consumption and turbulent liquid motions. An analytical description of these stages is given. In particular, a model of the dynamic combustion is constructed based on the turbulent oxygen transport through the liquid metal-oxide flow. This model yields a simple expression for the fraction of metal burned in the process, and allows one to calcul...

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

    Directory of Open Access Journals (Sweden)

    Veselý Ondřej


    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.

  5. Experimental study of hydronic panels system and its environment

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, Nestor Fonseca [University of Liege Belgium, Thermodynamics Laboratory, Campus du Sart Tilman, Bat: B49 - P33, B-4000 Liege (Belgium); Universidad Tecnologica de Pereira, Facultad de Ingenieria Mecanica (Colombia)


    An experimental analysis of hydronic cooling or heating ceiling panels coupled to the building is present in this investigation as a part of the commissioning study of this system. Two test chambers are adapted in a way to reproduce the interaction of the system to the building (windows, internal thermal loads distribution, building structure and ventilation). A series of experimental tests were performed in which the main objective is to observe the influence of parameters such as the water mass flow rate, supply water temperature, thermal load distribution, window and ventilation system effects on the hydronic ceiling capacity and comfort conditions. Test results show that the influence of asymmetric surfaces temperatures inside the room, especially the window effect is not negligible. Then, it is clear that the cooling hydronic ceiling must be evaluated coupled to the building systems and structure. (author)

  6. Experimental study of hydronic panels system and its environment

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca Diaz, Nestor, E-mail: [University of Liege Belgium, Thermodynamics Laboratory, Campus du Sart Tilman, Bat: B49 - P33, B-4000 Liege (Belgium); Universidad Tecnologica de Pereira, Facultad de Ingenieria Mecanica (Colombia)


    An experimental analysis of hydronic cooling or heating ceiling panels coupled to the building is present in this investigation as a part of the commissioning study of this system. Two test chambers are adapted in a way to reproduce the interaction of the system to the building (windows, internal thermal loads distribution, building structure and ventilation). A series of experimental tests were performed in which the main objective is to observe the influence of parameters such as the water mass flow rate, supply water temperature, thermal load distribution, window and ventilation system effects on the hydronic ceiling capacity and comfort conditions. Test results show that the influence of asymmetric surfaces temperatures inside the room, especially the window effect is not negligible. Then, it is clear that the cooling hydronic ceiling must be evaluated coupled to the building systems and structure.

  7. Experimental study of heat transfer to falling liquid films (United States)

    Fagerholm, N. E.; Kivioja, K.; Ghazanfari, A. R.; Jaervinen, E.


    This project was initiated in order to obtain more knowledge about thermal design of falling film heat exchangers and to find methods to improve heat transfer in film flow. A short literature survey of film flow characteristics and heat transfer is presented. An experimental apparatus designed and built for studying falling film evaporation is described. The first experiments were made with smooth Cu tube 25/22 mm and refrigerant R114 as evaporating liquid. A significant amount of droplet entrainment was observed during the tests. The measured average heat transfer coefficient varied from 1000 to 1800 W/m K when Re=1300 to 11000 respectively and when the transfer mode is surface evaporation. This could be predicted accurately with the experimental correlation of Chun and Seban. When nucleate boiling is dominant the heat transfer could be predicted well with pool boiling correlation of VDI-84.

  8. Experimental Study on the WavePiston Wave Energy Converter

    DEFF Research Database (Denmark)

    Pecher, Arthur; Kofoed, Jens Peter; Angelelli, E.

    This report presents the results of an experimental study of the power performance of the WavePiston wave energy converter. It focuses mainly on evaluating the power generating capabilities of the device and the effect of the following issues: Scaling ratios PTO loading Wave height and wave period...... dependency Oblique incoming waves Distance between plates During the study, the model supplied by the client, WavePiston, has been rigorously tested as all the anticipated tests have been done thoroughly and during all tests, good quality data has been obtained from all the sensors....

  9. Game theory and experimental games the study of strategic interaction

    CERN Document Server

    Colman, Andrew M


    Game Theory and Experimental Games: The Study of Strategic Interaction is a critical survey of the essential ideas of game theory and the findings of empirical research on strategic interaction. Some experiments using lifelike simulations of familiar kinds of strategic interactions are presented, and applications of game theory to the study of voting, the theory of evolution, and moral philosophy are discussed.Comprised of 13 chapters, this volume begins with an informal definition of game theory and an outline of the types of social situations to which it applies. Games of skill, games of cha

  10. Dental age estimation using Willems method: A digital orthopantomographic study

    Directory of Open Access Journals (Sweden)

    Rezwana Begum Mohammed


    Full Text Available In recent years, age estimation has become increasingly important in living people for a variety of reasons, including identifying criminal and legal responsibility, and for many other social events such as a birth certificate, marriage, beginning a job, joining the army, and retirement. Objectives: The aim of this study was to assess the developmental stages of left seven mandibular teeth for estimation of dental age (DA in different age groups and to evaluate the possible correlation between DA and chronological age (CA in South Indian population using Willems method. Materials and Methods: Digital Orthopantomogram of 332 subjects (166 males, 166 females who fit the study and the criteria were obtained. Assessment of mandibular teeth (from central incisor to the second molar on left quadrant development was undertaken and DA was assessed using Willems method. Results and Discussion: The present study showed a significant correlation between DA and CA in both males (r = 0.71 and females (r = 0.88. The overall mean difference between the estimated DA and CA for males was 0.69 ± 2.14 years (P 0.05. Willems method underestimated the mean age of males by 0.69 years and females by 0.08 years and showed that females mature earlier than males in selected population. The mean difference between DA and CA according to Willems method was 0.39 years and is statistically significant (P < 0.05. Conclusion: This study showed significant relation between DA and CA. Thus, digital radiographic assessment of mandibular teeth development can be used to generate mean DA using Willems method and also the estimated age range for an individual of unknown CA.

  11. Experimental Study of Axially Tension Cold Formed Steel Channel Members (United States)

    Apriani, Widya; Lubis, Fadrizal; Angraini, Muthia


    Experimental testing is commonly used as one of the steps to determine the cause of the collapse of a building structure. The collapse of structures can be due to low quality materials. Although material samples have passed laboratory tests and the existing technical specifications have been met but there may be undetected defects and known material after failure. In this paper will be presented Experimental Testing of Axially Tension Cold Formed Steel Channel Members to determine the cause of the collapse of a building roof truss x in Pekanbaru. Test of tensile strength material cold formed channel sections was performed to obtain the main characteristics of Cold Formed steel material, namely ultimate tensile strength loads that can be held by members and the yield stress possessed by channel sections used in construction. Analysis of axially tension cold formed steel channel section presents in this paper was conducted through experimental study based on specificationsAnnualBook of ASTM Standards: Metal Test methods and Analitical Procedures, Section 3 (1991). The result of capacity loads experimental test was compared with design based on SNI 03-7971-2013standard of Indonesia for the design of cold formed steel structural members. The results of the yield stress of the material will be seen against the minimum allowable allowable stress range. After the test, the percentace of ultimate axial tension capacity theory has a result that is 16.46% larger than the ultimate axial tension capacity experimental. When compared with the load that must be borne 5.673 kN/m it can be concluded that 2 specimens do not meet. Yield stress of member has fulfilled requirement that wass bigger than 550 MPa. Based on the curve obtained ultimate axial tension capacity theory, results greater than experimental. The greatest voltage value (fu) is achieved under the same conditions as its yield stress. For this specimen with a melting voltage value fy = 571.5068 MPa has fulfilled the

  12. Manipulation of pain catastrophizing: An experimental study of healthy participants

    Directory of Open Access Journals (Sweden)

    Joel E Bialosky


    Full Text Available Joel E Bialosky1*, Adam T Hirsh2,3, Michael E Robinson2,3, Steven Z George1,3*1Department of Physical Therapy; 2Department of Clinical and Health Psychology; 3Center for Pain Research and Behavioral Health, University of Florida, Gainesville, Florida, USAAbstract: Pain catastrophizing is associated with the pain experience; however, causation has not been established. Studies which specifically manipulate catastrophizing are necessary to establish causation. The present study enrolled 100 healthy individuals. Participants were randomly assigned to repeat a positive, neutral, or one of three catastrophizing statements during a cold pressor task (CPT. Outcome measures of pain tolerance and pain intensity were recorded. No change was noted in catastrophizing immediately following the CPT (F(1,84 = 0.10, p = 0.75, partial η2 < 0.01 independent of group assignment (F(4,84 = 0.78, p = 0.54, partial η2 = 0.04. Pain tolerance (F(4 = 0.67, p = 0.62, partial η2 = 0.03 and pain intensity (F(4 = 0.73, p = 0.58, partial η2 = 0.03 did not differ by group. This study suggests catastrophizing may be difficult to manipulate through experimental pain procedures and repetition of specific catastrophizing statements was not sufficient to change levels of catastrophizing. Additionally, pain tolerance and pain intensity did not differ by group assignment. This study has implications for future studies attempting to experimentally manipulate pain catastrophizing.Keywords: pain, catastrophizing, experimental, cold pressor task, pain catastrophizing scale

  13. Numerical and experimental study in piping system dead legs

    Energy Technology Data Exchange (ETDEWEB)

    Deutsch, E.; Barcouda, M.; Rousset, J.L. [Electricite de France (EDF), 78 - Chatou (France). Lab. National d`Hydraulique; Mallez, C.


    This paper deals with an experimental and numerical study of the isothermal flow at the junction of a zero flow-rate pipe connected to high Reynolds number piping system. The motivation is to understand and model the hydraulic behaviour of various auxiliary lines connected to the primary circuit of Pressurised Water Reactors. Experimental data have been obtained on a hydraulic mock-up using flow visualisation method and particle image velocimetry (PIV). These qualitative results show an helicoidal flow extending along the auxiliary pipe. Numerical calculations performed with the 3D ESTET code are presented and contrast the performance of the k-epsilon eddy viscosity model and a second moment closure turbulence model. Fine (1 500 000) mesh were used. The numerical results obtained using the second moment closure turbulence model confirm the swirl flow structure into the dead leg observed on the mock-up. On the other hand the k-epsilon eddy viscosity model is not able to predict the vortex penetration along the auxiliary pipe. These results illustrate the necessity to use second moment closure turbulence model to simulate flows in piping system dead legs. Unfortunately the powerful of the vortex is very sensitive to geometric details of the junction and gives difficulties for quantitative comparisons of the numerical results with experimental data. (author)

  14. Nonlocal Regularized Algebraic Reconstruction Techniques for MRI: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Xin Li


    Full Text Available We attempt to revitalize researchers' interest in algebraic reconstruction techniques (ART by expanding their capabilities and demonstrating their potential in speeding up the process of MRI acquisition. Using a continuous-to-discrete model, we experimentally study the application of ART into MRI reconstruction which unifies previous nonuniform-fast-Fourier-transform- (NUFFT- based and gridding-based approaches. Under the framework of ART, we advocate the use of nonlocal regularization techniques which are leveraged from our previous research on modeling photographic images. It is experimentally shown that nonlocal regularization ART (NR-ART can often outperform their local counterparts in terms of both subjective and objective qualities of reconstructed images. On one real-world k-space data set, we find that nonlocal regularization can achieve satisfactory reconstruction from as few as one-third of samples. We also address an issue related to image reconstruction from real-world k-space data but overlooked in the open literature: the consistency of reconstructed images across different resolutions. A resolution-consistent extension of NR-ART is developed and shown to effectively suppress the artifacts arising from frequency extrapolation. Both source codes and experimental results of this work are made fully reproducible.

  15. Experimental Method For Studying Habitual Behavior In Food Consumption

    Directory of Open Access Journals (Sweden)

    Naziha Kasraoui


    Full Text Available Abstract To investigate the process of habit formation in everyday life a sample of 126 participants students chooses an eating and drinking for three periods weeks. They completed the self-report habit each period and we have recorded their choices. All participants provided sufficient data for analysis and collected experimental data were examined over the study periods 3 weeks. Experimental analysis was used to examine the persistence of habit formation process in the behavior of participants. The game is carried out with 126 students and repeated for three periods. Using experimental laboratory data approach and economic analysis elasticity results show that into the presence of labor income and for 126 students of whom approximately 70 showed that habit formation process is persist in their behaviors along the three periods. The rest 30 of them who dont present habit formation in their behavior for the three periods did not materially affect our conclusion about the assumption of habit formation process. Participants to the game persistently spend too much in early periods they learn rapidly from their own experience to consume the same choice of meals and drinks. Their spending is closely linked to optimal consumption non conditional on earlier spending and they choose the same basket of goods in the future horizon which shows that theres a habit formation in the behaviors of participants.

  16. The Experimental Study Of Effects Of Irradiation On Osseointegration

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kwan Soo; Lee, Sang Rae; Hwang, Eui Hwan [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Kyunghee University, Seoul (Korea, Republic of)


    The purpose of this study was to investigate the effects of the Co-60 gamma irradiation on the osseointegration. 2.0 mm titanium alloy screw implants were placed in the tibial metaphysics of the rabbits, bilaterally. The mean length of the implants was 6.0 mm. The right tibia was irradiated with a single dose of 15 Gy from 6{sup 0C}o teletherapic machine at 5th postoperative day. The experimental group was irradiated tibia. The control group was non-irradiated tibia. To observe the phase of bone formation, the bone labeling by intramuscular injection of 20 mg/Kg of Tetracycline, Calcein, Alizarin red S, was performed. The rabbits were sacrificed on the 1st, 2nd, 4th, 6th, 8th week and the tibia including implants were taken, and then the specimens were examined by the microradiography, light microscopy, and fluorescent microscopy.The obtained results were as follows; 1. There were connective tissue between bone and titanium at 1st week, in both group. Especially, the many empty lacunae without nucleus and obscure cytoplasm in experimental group, were observed. 2. The osteons were observed at 4th week in control group, and at 6th week in experimental group. The bone formation in experimental group was retarded as compared to the control group. 3. In fluorescent microscopy, bone labelling band was observed as linear, arc or concentric shape. Occasionary interrupted labelling band was observed, which is demonstrated bone remodeling. 4. In microradiographic examination, the radiolucent image was found between bone and implant with widening of bone marrow spaces as compared to the control group.

  17. Study on analyses of experimental data at DCA

    Energy Technology Data Exchange (ETDEWEB)

    Min, Byung Joo; Suk, Ho Chun; Hazama, T. [Korea Atomic Energy Research Institute, Taejon (Korea)


    In this report, the lattice characteristics of DCA are calculated to validate WIMS-AECL code for the lattice analysis of CANDU core by using experimental data of DCA and JNC. These results are compared with those of WIMS-ATR code. Analytical studies of some critical experiments had been performed to analyze the effects of fuel composition and lattice pitch. Different items of reactor physics such as local power peaking factor (LPF), effective multiplication factor (Keff) and coolant void reactivity were calculated for two coolant void fractions (0% and 100%). LPFs calculated by WIMS-ATR code are in close agreement with the experimental results. LPFs calculated by WIMS-AECL code with WINFRITH and ENDF/B-V libraries have similar values for both libraries but the differences between experimental data and results of WIMS-AECL code are larger than those of WIMS-ATR code. The maximum difference between the values calculated by WIMS-ATR and experimental values of LPFs are within 1.3%. LPF of Pu fuel cluster is found to be higher than that of the uranium fuel cluster. The coupled code systems WIMS-ATR and CITATION used in this analysis predict Keff within 1% {delta}K and coolant void reactivity within 4%{delta}K/K in all cases. The coolant void reactivity of uranium fuel is found to be positive for two lattice pitches (25.0 and 28.3 cm). Presence of plutonium fuel makes it more negative compare to uranium fuel. To validate WIMS-AECL code, the core characteristics of DCA shall be calculated by WIMS-AECL and CITATION codes in the future. 8 refs., 8 figs., 12 tabs. (Author)

  18. An experimental design approach for optimization of spectrophotometric method for estimation of cefixime trihydrate using ninhydrin as derivatizing reagent in bulk and pharmaceutical formulation

    Directory of Open Access Journals (Sweden)

    Yogita B. Wani


    Full Text Available The aim of the present work is to use experimental design to screen and optimize experimental variables for developing a spectrophotometric method for determining cefixime trihydrate content using ninhydrin as a derivatizing reagent. The method is based on the reaction of the amino group of cefixime with ninhydrin in an alkaline medium to form a yellow-colored derivative (λmax 436 nm. A two-level full factorial design was utilized to screen the effect of ninhydrin reagent concentration (X1, volume of ninhydrin reagent (X2, heating temperature (X3 and heating time (X4 on the formation of the cefixime–ninhydrin complex Y (absorbance. One way ANOVA and Pareto ranking analyses have shown that the ninhydrin reagent concentration (X1, volume of ninhydrin reagent (X2 and heating temperature (X3 were statistically significant factors (P < 0.05 affecting the formation of the cefixime–ninhydrin complex Y (absorbance. A Box-Behnken experimental design with response surface methodology was then utilized to evaluate the main, interaction and quadratic effects of these three factors on the selected response. With the help of a response surface plot and contour plot the optimum values of the selected factors were determined and used for further experiments. These values were a ninhydrin reagent concentration (X1 of 0.2% w/v, volume of ninhydrin reagent (X2 of 1 mL and heating temperature (X3 of 80 °C. The proposed method was validated according to the ICH Q2 (R1 method validation guidelines. The results of the present study have clearly shown that an experimental design concept may be effectively applied to the optimization of a spectrophotometric method for estimating the cefixime trihydrate content in bulk and pharmaceutical formulation with the least number of experimental runs possible.

  19. Seismic vulnerability of the Himalayan half-dressed rubble stone masonry structures, experimental and analytical studies

    Directory of Open Access Journals (Sweden)

    N. Ahmad


    Full Text Available Half-Dressed rubble stone (DS masonry structures as found in the Himalayan region are investigated using experimental and analytical studies. The experimental study included a shake table test on a one-third scaled structural model, a representative of DS masonry structure employed for public critical facilities, e.g. school buildings, offices, health care units, etc. The aim of the experimental study was to understand the damage mechanism of the model, develop damage scale towards deformation-based assessment and retrieve the lateral force-deformation response of the model besides its elastic dynamic properties, i.e. fundamental vibration period and elastic damping. The analytical study included fragility analysis of building prototypes using a fully probabilistic nonlinear dynamic method. The prototypes are designed as SDOF systems assigned with lateral, force-deformation constitutive law (obtained experimentally. Uncertainties in the constitutive law, i.e. lateral stiffness, strength and deformation limits, are considered through random Monte Carlo simulation. Fifty prototype buildings are analyzed using a suite of ten natural accelerograms and an incremental dynamic analysis technique. Fragility and vulnerability functions are derived for the damageability assessment of structures, economic loss and casualty estimation during an earthquake given the ground shaking intensity, essential within the context of risk assessment of existing stock aiming towards risk mitigation and disaster risk reduction.

  20. Experimental studies of pion-nucleus interactions at intermediate energies

    Energy Technology Data Exchange (ETDEWEB)


    This report summarizes the work on experimental research in intermediate energy nuclear physics carried out at New Mexico State University in 1991 under a great from the US Department of Energy. Most of these studies have involved investigations of various pion-nucleus interactions. The work has been carried out both with the LAMPF accelerator at the Los Alamos National Laboratory and with the cyclotron at the Paul Scherrer Institute (PSI) near Zurich, Switzerland. Part of the experimental work involves measurements of new data on double-charge-exchange scattering, using facilities at LAMPF which we helped modify, and on pion absorption, using a new detector system at PSI that covers nearly the full solid-angle region which we helped construct. Other work involved preparation for future experiments using polarized nuclear targets and a new high-resolution spectrometer system for detecting {pi}{sup 0} mesons. We also presented several proposals for works to be done in future years, involving studies related to pi-mesonic atoms, fundamental pion-nucleon interactions, studies of the difference between charged and neutral pion interactions with the nucleon, studies of the isospin structure of pion-nucleus interactions, and pion scattering from polarized {sup 3}He targets. This work is aimed at improving our understanding of the pion-nucleon interaction, of the pion-nucleus interaction mechanism, and of nuclear structure.

  1. Models for the estimation of thermodynamic properties of layered double hydroxides: application to the study of their anion exchange characteristics

    Directory of Open Access Journals (Sweden)

    Bravo-Suárez Juan J.


    Full Text Available Several models for the estimation of thermodynamic properties of layered double hydroxides (LDHs are presented. The predicted thermodynamic quantities calculated by the proposed models agree with experimental thermodynamic data. A thermodynamic study of the anion exchange process on LDHs is also made using the described models. Tables for the prediction of monovalent anion exchange selectivities on LDHs are provided. Reasonable agreement is found between the predicted and the experimental monovalent anion exchange selectivities.

  2. Study of landmarks estimation stability produced by AAM (United States)

    Glebov, Victor; Lashmanov, Oleg


    Active Appearance Model (AAM) is an accurate and robust tool and is suitable when it's needed to estimate shape of object when its' approximate shape is known but varies within a certain range from instance to instance. An AAM allows complex models of shape (for example human face) and appearance to be matched to new images rapidly. An AAM contains a statistical model of the shape and gray level or color appearance of an object of interest. The associated search algorithm exploits the locally linear relationship between model parameter displacements and the residual errors between model instance and image. AAM is widely used but the research of its' accuracy and stability still remains an important and not fully learned issue. In this paper, we study landmarks stability and error estimation produced by AAM in different lightning conditions and signal-to-noise ratio (SNR).

  3. On Distributed PV Hosting Capacity Estimation, Sensitivity Study, and Improvement

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Fei; Mather, Barry


    This paper first studies the estimated distributed PV hosting capacities of seventeen utility distribution feeders using the Monte Carlo simulation based stochastic analysis, and then analyzes the sensitivity of PV hosting capacity to both feeder and photovoltaic system characteristics. Furthermore, an active distribution network management approach is proposed to maximize PV hosting capacity by optimally switching capacitors, adjusting voltage regulator taps, managing controllable branch switches and controlling smart PV inverters. The approach is formulated as a mixed-integer nonlinear optimization problem and a genetic algorithm is developed to obtain the solution. Multiple simulation cases are studied and the effectiveness of the proposed approach on increasing PV hosting capacity is demonstrated.

  4. Experimental study of microtabs in smart blades for wind turbines


    Senosiain Suescun, David; Morales Goicoechea, Joseba


    The goal of this thesis is to carry out an experimental study of the performance of smart blades reducing extreme and/or cyclic loads for their use in wind turbines. First of all, theoretical research about wind turbines and smart blades was done. Some of this information is explained in the thesis in order to set the background and make it more readable and understandable (Chapters 1 to 3). The next step was to choose a blade profile that would fit well the requirements of ...

  5. Experimental study of temperature effects on air gun signatures

    Energy Technology Data Exchange (ETDEWEB)

    Langhammer, J.; Landroe, M.


    The effect of varying the water temperature between 5[sup o]C and 46[sup o]C upon seismic air gun signatures has been studied experimentally. The experiments were carried out in a 850 litres water tank. Increasing the water temperature from 5[sup o]C to 29[sup o]C leads to 10% increase in the primary to bubble ratio, given that the signatures are filtered with a 0-128 Hz high cut filter. The bubble time period increases with 1 ms, or 4 % within the same temperature range. 7 refs., 28 figs., 3 tabs.

  6. A numerical and experimental study of confined swirling jets (United States)

    Nikjooy, M.; Mongia, H. C.; Samuelsen, G. S.; Mcdonell, V. G.


    A numerical and experimental study of a confined strong swirling flow is presented. Detailed velocity measurements are made using a two-component laser Doppler velocimeter (LDV) technique. Computations are performed using a differential second-moment (DSM) closure. The effect of inlet dissipation rate on calculated mean and turbulence fields is investigated. Various model constants are employed in the pressure-strain model to demonstrate their influences on the predicted results. Finally, comparison of the DSM calculations with the algebraic second-monent (ASM) closure results shows that the DSM is better suited for complex swirling flow analysis.

  7. Experimental studies of ionospheric irregularities and related plasma processes (United States)

    Baker, Kay D.


    Utah State University (USU) continued its program of measuring and interpreting electron density and its variations in a variety of ionospheric conditions with the Experimental Studies of Ionospheric Irregularities and Related Plasma Processes program. The program represented a nearly ten year effort to provide key measurements of electron density and its fluctuations using sounding rockets. The program also involved the joint interpretation of the results in terms of ionospheric processes. A complete campaign summary and a brief description of the major rocket campaigns are also included.

  8. Experimental study of flapping jets in a soap film (United States)

    Lee, Julia; Kim, Ildoo; Mandre, Shreyas


    Plateau and Rayleigh's observation and explanation on jet instability have inspired us over the years and there has been a significant advance in understanding the jet dynamics. Here, we present a quasi-two-dimensional experimental study of flapping jets in a soap film. Newtonian and non-Newtonian solutions are injected in a flowing soap film. Thinning, break-ups, and beads-on-a-string of the jets, and axisymmetric vortices shredded from the flapping jets are visualized. We employ PIV of the flow motion around the jets to gain an understanding of the roles of instabilities in the flow.

  9. Experimental study of dynamic stall on Darrieus wind turbine blades (United States)

    Brochier, G.; Fraunie, P.; Beguier, C.; Paraschivoiu, I.


    An experimental study of periodic vortex phenomena was performed on a model of a two straight-bladed Darrieus wind turbine under controlled-rotation conditions in the IMST water tunnel. The main focus of interest was the tip-speed ratios at which dynamic stall appears. Observations of this phenomenon from dye emission and the formation of hydrogen bubbles were made in the form of photographs, film and video recordings. Velocity measurements were obtained using the Laser-Doppler Velocimeter and components of velocity fluctuations could be determined quantitatively.

  10. Experimental and theoretical study on the electrospinning nanoporous fibers process

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jianghui; Si, Na [National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou (China); Xu, Lan, E-mail: [National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou (China); Nantong Textile Institute of Soochow University, Nantong (China); Tang, Xiaopeng; Song, Yanhua; Sun, Zhaoyang [National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou (China)


    Porous materials can be prepared by sol–gel method, hydrothermal synthesis method, electrospinning and other methods. In this paper, electrospun porous nanofibers were prepared by adjusting electrospinning parameters. And the properties of obtained porous nanofiber mats were investigated. Theoretical analysis and experiment research were carried out to research mechanical mechanism of electrospun porous nanofibers, and could be used to optimize and control the porous structure. The theoretical analysis results were further verified according to the experimental data. In addition, Bernoulli equation was used to study the electrospinning “splaying” process. We found the ratio of pore width to pore length was varied along with the variation of the internal pressure of the jet, and the internal pressure of the jet increases with the velocity of the charged jet decreases. - Highlights: • Mechanical mechanism of electrospun porous nanofibers process was studied. • A simplifying gas–liquid two-phase flow model was established. • Bernoulli equation was used to study the electrospinning “splaying” process. • The theoretical results were in good agreement with the experimental data. • The electrospinning parameters affected the surface morphology of charged jet.


    Directory of Open Access Journals (Sweden)

    W. Bendaikha


    Full Text Available Hydrogen is a sustainable fuel option and one of the potential solutions for the current energy and environmental problems. In this study hydrogen is produced using a hydrogen generator with a Proton Exchange Membrane (PEM electrolyser. An experimental study is done in the Center of Development of the Renewable Energy, Algiers, Algeria.The experimental device contains essentially a photovoltaic module, a PEM electrolyser, a gasometer and the devices of measures of characteristics of the PEM electrolyser as well as two pyranometers for the horizontal and diffuse global radiance registration. This system in pilots scale is permitted on the one hand, to measured and analyzed the characteristics: of the PEM electrolyser for two different pressures of working (Patm and P=3 bar, on the other hand, to study the volume of hydrogen produces in the time with different sources of electrical power (generator, photovoltaic module, fluorescent lamp, the efficiency for every case is calculated and compared. We present in this paper the variation of the solar hydrogen flow rate produced according to the global radiance and according to the time for a typical day’s of August.


    Directory of Open Access Journals (Sweden)

    Yulia Alexandrowna Griber


    Full Text Available The objective of the study was informal social norms of urban culture. The paper contains the detailed description of the experimental situation and the main steps of the field research, focused on the observance of informal social norms in the sphere of urban coloristics. The experiment was conducted in three districts of Smolensk (Russia – Leninskiy, Zadneprovskiy and Promyshlennyy. Particular attention was paid to the analysis of the results of the field research, including evaluation of reaction of participants (residents of multi-storied houses, breakers of informal norms of urban coloristics (experimenters and casual experiment witnesses (neighbors and passersby. In addition, the accuracy of results “forecasting”, done before the beginning of the experiment, is analyzed. The research was conducted using the methodology of breaking experiment that is one of the most provocative ways of studying informal norms in sociology and social psychology. The experiment allowed to draw a number of important conclusions. It showed that urban coloristics is regulated by strict informal norms, that are not noticed by citizens until a violation occurs. The power of informal norms is significantly underestimated by citizens, and their break causes a negative reaction and protest. The most important contribution to the study of informal norms of urban culture was the comparison of the reaction degree by men and women, by the residents of different districts (central, residential or blue-collar neighborhoods, by different age groups.

  13. Experimental studies of electron-phonon interactions in gallium nitride

    CERN Document Server

    Stanton, N M


    This thesis presents an experimental investigation of the electron-phonon interaction in GaN. Bulk epilayers, grown by MBE, and AIGaN/GaN heterostructure grown by MOCVD, have been studied. The energy relaxation rate for hot electrons has been measured over a wide range of temperatures, allowing both acoustic and optic phonon emission to be studied in GaN epilayers. Direct phonon measurements, both studying the emission and absorption processes, have been performed. Detection of phonons emitted when hot electrons relax their excess energy complements the measurements of relaxation rates. Absorption of acoustic phonons by the epilayers, using both fixed and extended metal film phonon sources, allowed investigation into the effectiveness of the 2k sub F cutoff in the low mobility layers. The experimental findings are compared with the predictions of theory. AIGaN/GaN heterostructures were characterised and measurements of the energy relaxation rate in the temperature range 4K-40K obtained. Excellent agreement wi...

  14. Experimental study of friction in aluminium bolted joints

    Directory of Open Access Journals (Sweden)

    Vincenzi N.


    Full Text Available This study aims at developing an experimental tool useful to define accurately the friction coefficients in bolted joints and, therefore, at relating precisely the tightening torque to the bolt preloading force in some special components used in front motorbike suspensions. The components under investigation are some clamped joints made of aluminium alloy. The preloading force is achieved by applying a torque wrench to the bolt head. Some specific specimens have been appropriately designed and realized in order to study the tribological aspects of the tightening phase. Experimental tests have been performed by applying the Design of Experiment (DOE method in order to obtain a mathematical model for the friction coefficients. Three replicas of a full factorial DOE at two levels for each variable have been carried out. The levels include cast versus forged aluminium alloy, anodized versus spray-painted surface, lubricated versus unlubricated screw, and first tightening (fresh unspoiled surfaces versus sixth tightening (spoiled surfaces. The study considers M8x1.25 8.8 galvanized screws.

  15. Using Two Pedotransfer Functions to Estimate Soil Moisture Retention Curves From One Experimental Site of ​​South Moravia

    Directory of Open Access Journals (Sweden)

    Ivana Kameníčková


    Full Text Available The soil moisture retention curves (SMRCs were measured in laboratory conditions. The sand table and pressure extractor method were used to obtain a 9-point SMRCs for undisturbed soil samples taken from 20 cm depth. The data points of the individual retention curves were parameterized using the RETC computer program. For the same soil, the SMRCs were estimated by two models of pedotransfer functions (PTFs. In the first part of the study the Rosetta program with the model of artificial neural network (Schaap et al., 1998 was used. The PTFs derived by Wösten et al. (1998 were used in the second part of the study. The reliability of selected PTFs models were tested on local soils from one site of the South Moravia. The quality of estimated retention curves was evaluated using the coefficient for correlation R between the measured and the estimated soil water content at several pF values and the root mean squared error RMSE. Of the two models of PTFs, which have been tested in the study, Wösten’s model showed better agreement with the measured retention curves (RMSESch = 0.0383 (−3, RMSEW = 0.0264 (−3.

  16. Multivariate dynamic linear models for estimating the effect of experimental interventions in an evolutionary operations setup in dairy herds

    DEFF Research Database (Denmark)

    Stygar, Anna Helena; Krogh, Mogens Agerbo; Kristensen, Troels


    Evolutionary operations is a method to exploit the association of often small changes in process variables, planned during systematic experimentation and occurring during the normal production flow, to production characteristics to find a way to alter the production process to be more efficient...... from a herd, and an intervention effect on a given day. The model was constructed to handle any number of cows, experimental interventions, different data sources, or presence of control groups. In this study, data from 2 commercial Danish herds were used. In herd 1, data on 98,046 and 12,133 milkings......,471) were used. In herd 1, the manager wanted to explore the possibility of reducing the amount of concentrate provided to the cows in an AMS. In herd 2, the manager wanted to know if the milk yield could be increased by elevating the energy level provided to the cows in a total mixed ration. The experiment...

  17. Experimental Studies of Phase Equilibria of Meteorites and Planetary Bodies (United States)

    Stolper, Edward M.


    The primary theme of this project was the application of experimental petrology and geochemistry to a variety of problems in meteoritics and planetary geology. The studies were designed to help develop constraints on the histories of primitive meteorites and their components, the environments in which they formed and evolved, and to understand quantitatively the processes involved in the evolution of igneous rocks on the earth and other planetary bodies. We undertook several projects relating to the origin of CAIs and chondrules. Systematics in the thermodynamic properties of CAI-like liquids were investigated and used to elucidate speciation of multi-valent cations and sulfide capacity of silicate melts and to constrain redox conditions and the vapor pressures of volatile species over molten chondrules. We experimentally determined vanadium speciation in meteoritic pyroxenes and in pyroxenes crystallized from CAI-like melts under very reducing conditions. We also found that bulk oxygen isotope compositions of chondrules in the moderately unequilibrated LL chondrites are related to the relative timing of plagioclase crystallization. We completed an experimental study on the vaporization of beta-SiC and SiO2 (glass or cristobalite) in reducing gases and established the conditions under which these presolar grains could have survived in the solar nebula. We expanded our technique for determining the thermodynamic properties of minerals and liquids to iron-bearing systems. We determined activity-composition relationships in Pt-Fe, Pt-Cr and Pt-Fe-Cr alloys. Results were used to determine the thermodynamic properties of chromite-picrochromite spinels including the free energy of formation of end-member FeCr2O4. We also established a new approach for evaluating Pt-Fe saturation experiments. We calculated the T-fO2 relationships in equilibrated ordinary chondrites and thereby constrained the conditions of metamorphism in their parent bodies.

  18. Immunotoxicology of arc welding fume: worker and experimental animal studies. (United States)

    Zeidler-Erdely, Patti C; Erdely, Aaron; Antonini, James M


    Arc welding processes generate complex aerosols composed of potentially hazardous metal fumes and gases. Millions of workers worldwide are exposed to welding aerosols daily. A health effect of welding that is of concern to the occupational health community is the development of immune system dysfunction. Increased severity, frequency, and duration of upper and lower respiratory tract infections have been reported among welders. Specifically, multiple studies have observed an excess mortality from pneumonia in welders and workers exposed to metal fumes. Although several welder cohort and experimental animal studies investigating the adverse effects of welding fume exposure on immune function have been performed, the potential mechanisms responsible for these effects are limited. The objective of this report was to review both human and animal studies that have examined the effect of welding fume pulmonary exposure on local and systemic immune responses.

  19. Experimental and trial-based study of Resilient Packet Ring (United States)

    Ramnath, Vasudha; Cheng, Heng Seng; Ngoh, Lek Heng


    An experimental study of the Resilient Packet Ring (RPR) media access control (MAC) technology that is optimized for IP traffic in the metropolitan-area-network (MAN) environment is described. The study involved the deployment and trials of a RPR testbed encompassing a public optical fiber infrastructure in which Cisco Systems' Dynamic Packet Transport (DPT) Ring Technology - a prestandard RPR implementation - was used. We focus on a number of important RPR protocol features that are vital to the future success of RPR as a MAN/wide-area-network (WAN) network technology. Related research on RPR/DPT has been done so far through simulation studies only. Standardization of RPR is currently being performed by the Institute of Electrical and Electronics Engineers (IEEE) 802.17 working group and is expected to be completed in 2003. Also, we present and discuss the experiments and tests performed to investigate the key features of RPR, along with the results obtained.

  20. Immunotoxicology of arc welding fume: Worker and experimental animal studies (United States)

    Zeidler-Erdely, Patti C.; Erdely, Aaron; Antonini, James M.


    Arc welding processes generate complex aerosols composed of potentially hazardous metal fumes and gases. Millions of workers worldwide are exposed to welding aerosols daily. A health effect of welding that is of concern to the occupational health community is the development of immune system dysfunction. Increased severity, frequency, and duration of upper and lower respiratory tract infections have been reported among welders. Specifically, multiple studies have observed an excess mortality from pneumonia in welders and workers exposed to metal fumes. Although several welder cohort and experimental animal studies investigating the adverse effects of welding fume exposure on immune function have been performed, the potential mechanisms responsible for these effects are limited. The objective of this report was to review both human and animal studies that have examined the effect of welding fume pulmonary exposure on local and systemic immune responses. PMID:22734811

  1. Design of an experimental set up for convective drying: experimental studies at different drying temperature (United States)

    Mohan, V. P. Chandra; Talukdar, Prabal


    An experimental setup is designed to investigate the convective drying of moist object experimentally. All the design data, components of setup, materials and specifications are presented. Transient moisture content of a rectangular shaped potato slice (4 × 2 × 2 cm) is measured at different air temperatures of 40, 50, 60 and 70 °C with an air velocity of 2 m/s. Two different drying rate periods are observed. Results are compared with available results from literature.

  2. Biofouling in forward osmosis systems: An experimental and numerical study

    KAUST Repository

    Bucs, Szilard


    This study evaluates with numerical simulations supported by experimental data the impact of biofouling on membrane performance in a cross-flow forward osmosis (FO) system. The two-dimensional numerical model couples liquid flow with solute transport in the FO feed and draw channels, in the FO membrane support layer and in the biofilm developed on one or both sides of the membrane. The developed model was tested against experimental measurements at various osmotic pressure differences and in batch operation without and with the presence of biofilm on the membrane active layer. Numerical studies explored the effect of biofilm properties (thickness, hydraulic permeability and porosity), biofilm membrane surface coverage, and biofilm location on salt external concentration polarization and on the permeation flux. The numerical simulations revealed that (i) when biofouling occurs, external concentration polarization became important, (ii) the biofilm hydraulic permeability and membrane surface coverage have the highest impact on water flux, and (iii) the biofilm formed in the draw channel impacts the process performance more than when formed in the feed channel. The proposed mathematical model helps to understand the impact of biofouling in FO membrane systems and to develop possible strategies to reduce and control biofouling. © 2016 Elsevier Ltd

  3. Experimental and numerical studies of rotating drum grate furnace

    Directory of Open Access Journals (Sweden)

    Basista Grzegorz


    Full Text Available Waste material from the meat industry can be taken into account as a biofuel. Studies confirm, that calorific value is higher and ash content is lower comparing to some conventional fuels. EU directives regulate details of thermal disposal of the waste material from the meat industry - especially in range of the process temperature and time of the particle presence in area of the combustion zone. The paper describes design of the rotating drum grate stove, dedicated to thermal disposal of the meat wastes as well as solid biomass (pellet, small bricket, wood chips combustion. Device has been developed in frames of cooperation between AGH University of Science and Technology (Krakow, Poland and producer focused on technologies of energy utilization of biomass in distributed generation. Results of measurements of selected operational parameters performed during startup of the furnace have been presented and discussed. Furthermore, numerical model of the combustion process has been developed to complement experimental results in range of the temperature and oxygen distribution in the area of the combustion chamber. ANSYS CFX solver has been applied to perform simulations including rotational domain related with specifics of operation of the device. Results of numerical modelling and experimental studies have been summarized and compared.

  4. Experimental studies of irradiated and hydrogen implantation damaged reactor steels

    Energy Technology Data Exchange (ETDEWEB)

    Slugeň, Vladimír, E-mail:; Pecko, Stanislav; Sojak, Stanislav


    Radiation degradation of nuclear materials can be experimentally simulated via ion implantation. In our case, German reactor pressure vessel (RPV) steels were studied by positron annihilation lifetime spectroscopy (PALS). This unique non-destructive method can be effectively applied for the evaluation of microstructural changes and for the analysis of degradation of reactor steels due to neutron irradiation and proton implantation. Studied specimens of German reactor pressure vessel steels are originally from CARINA/CARISMA program. Eight specimens were measured in as-received state and two specimens were irradiated by neutrons in German experimental reactor VAK (Versuchsatomkraftwerk Kahl) in the 1980s. One of the specimens which was in as-received and neutron irradiated condition was also used for simulation of neutron damage by hydrogen nuclei implantation. Defects with the size of about 1–2 vacancies with relatively small contribution (with intensity on the level of 20–40 %) were observed in “as-received” steels. A significant increase in the size of the induced defects due to neutron damage was observed in the irradiated specimens resulting in 2–3 vacancies. The size and intensity of defects reached a similar level as in the specimens irradiated in the nuclear reactor due to the implantation of hydrogen ions with energies of 100 keV (up to the depth <500 nm).

  5. Experimental Study of a Pulse Detonation Engine Driven Ejector (United States)

    Santoro, Robert J.; Pal, Sibtosh; Shehadeh, R.; Saretto, S.; Lee, S.-Y.


    Results of an experimental effort on pulse detonation driven ejectors are presented and discussed. The experiments were conducted using a pulse detonation engine (PDE)/ejector setup that was specifically designed for the study. The results of various experiments designed to probe different aspects of the PDE/ejector setup are reported. The baseline PDE was operated using ethylene (C2H4) as the fuel and an oxygen/nitrogen (O2 + N2) mixture at an equivalence ratio of one. The PDE only experiments included propellant mixture characterization using a laser absorption technique, high fidelity thrust measurements using an integrated spring-damper system, and shadowgraph imaging of the detonation/shock wave structure emanating from the tube. The baseline PDE thrust measurement results are in excellent agreement with experimental and modeling results reported in the literature. These PDE setup results were then used as a basis for quantifying thrust augmentation for various PDE/ejector setups with constant diameter ejector tubes and various detonation tube/ejector tube overlap distances. The results show that for the geometries studied here, a maximum thrust augmentation of 24% is achieved. Further increases are possible by tailoring the ejector geometry based on CFD predictions conducted elsewhere. The thrust augmentation results are complemented by shadowgraph imaging of the flowfield in the ejector tube inlet area and high frequency pressure transducer measurements along the length of the ejector tube.

  6. Experimental and analytical studies on pedestrian induced footbridge vibrations

    DEFF Research Database (Denmark)

    Gudmundsson, Gudmundur Valur; Ingólfsson, Einar Thór; Einarsson, Baldvin


    This paper presents results from experimental study on human-induced vibrations of three lively footbridges in Reykjavik. The project was funded by the Icelandic Public Roads Administration with two main focus areas; validating the FE-models used at the design stage in terms of dynamic characteri......This paper presents results from experimental study on human-induced vibrations of three lively footbridges in Reykjavik. The project was funded by the Icelandic Public Roads Administration with two main focus areas; validating the FE-models used at the design stage in terms of dynamic...... with two equal spans crossing the same highway and was built in 2000. A commercially available finite element program (SAP2000) was used in the design phase to model the bridges. The FE-models were updated after the initial tests in order to have the frequencies and damping of the fundamental vibration...... modes corresponding to the measured values. The models were subsequently used to calculate the predicted acceleration according to the preliminary version of the Eurocode (ENV 1992-2: Concrete bridges) using time-history analysis with a moving load as representative for a single pedestrian. The load...

  7. Biofouling in forward osmosis systems: An experimental and numerical study. (United States)

    Bucs, Szilárd S; Valladares Linares, Rodrigo; Vrouwenvelder, Johannes S; Picioreanu, Cristian


    This study evaluates with numerical simulations supported by experimental data the impact of biofouling on membrane performance in a cross-flow forward osmosis (FO) system. The two-dimensional numerical model couples liquid flow with solute transport in the FO feed and draw channels, in the FO membrane support layer and in the biofilm developed on one or both sides of the membrane. The developed model was tested against experimental measurements at various osmotic pressure differences and in batch operation without and with the presence of biofilm on the membrane active layer. Numerical studies explored the effect of biofilm properties (thickness, hydraulic permeability and porosity), biofilm membrane surface coverage, and biofilm location on salt external concentration polarization and on the permeation flux. The numerical simulations revealed that (i) when biofouling occurs, external concentration polarization became important, (ii) the biofilm hydraulic permeability and membrane surface coverage have the highest impact on water flux, and (iii) the biofilm formed in the draw channel impacts the process performance more than when formed in the feed channel. The proposed mathematical model helps to understand the impact of biofouling in FO membrane systems and to develop possible strategies to reduce and control biofouling. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Thermodynamic and experimental study of UC powders ignition

    Energy Technology Data Exchange (ETDEWEB)

    Le Guyadec, F., E-mail: fabienne.leguyadec@cea.f [Commissariat a l' Energie Atomique CEA-MARCOULE, DEN/DTEC/SDTC/Laboratoire d' Etude des Materiaux en Environnement, BP 17171, 30207 Bagnols sur Ceze (France); Rado, C.; Joffre, S.; Coullomb, S. [Commissariat a l' Energie Atomique CEA-MARCOULE, DEN/DTEC/SDTC/Laboratoire d' Etude des Materiaux en Environnement, BP 17171, 30207 Bagnols sur Ceze (France); Chatillon, C.; Blanquet, E. [SIMAP, Sciences et Ingenierie des Materiaux et Procedes, INPG-CNRS-UJF ENSEEG, BP 75, 38402 St Martin-d' Heres (France)


    Mixed plutonium and uranium carbide (UPuC) is considered as a possible fuel material for future nuclear reactors. However, UPuC is pyrophoric and fine powders of UPuC are subject to temperature increase due to oxidation with air and possible ignition during conditioning and handling. In a first approach and to allow easier experimental conditions, this study was undertaken on uranium monocarbide (UC) with the aim to determine safe handling conditions for the production and reprocessing of uranium carbide fuels. The reactivity of uranium monocarbide in oxidizing atmosphere was studied in order to analyze the ignition process. Experimental thermogravimetric analysis (TGA) and differential thermal analysis (DTA) revealed that UC powder obtained by arc melting and milling is highly reactive in air at about 200 deg. C. The phases formed at the various observed stages of the oxidation process were analyzed by X-ray diffraction. At the same time, ignition was analyzed thermodynamically along isothermal sections of the U-C-O ternary diagram and the pressure of the gas produced by the UC + O{sub 2} reaction was calculated. Two possible oxidation schemes were identified on the U-C-O phase diagram and assumptions are proposed concerning the overall oxidation and ignition paths. It is particularly important to understand the mechanisms involved since temperatures as high as 2500 deg. C could be reached, leading to CO(g) production and possibly to a blast effect.

  9. Thermodynamic and experimental study of UC powders ignition (United States)

    Le Guyadec, F.; Rado, C.; Joffre, S.; Coullomb, S.; Chatillon, C.; Blanquet, E.


    Mixed plutonium and uranium carbide (UPuC) is considered as a possible fuel material for future nuclear reactors. However, UPuC is pyrophoric and fine powders of UPuC are subject to temperature increase due to oxidation with air and possible ignition during conditioning and handling. In a first approach and to allow easier experimental conditions, this study was undertaken on uranium monocarbide (UC) with the aim to determine safe handling conditions for the production and reprocessing of uranium carbide fuels. The reactivity of uranium monocarbide in oxidizing atmosphere was studied in order to analyze the ignition process. Experimental thermogravimetric analysis (TGA) and differential thermal analysis (DTA) revealed that UC powder obtained by arc melting and milling is highly reactive in air at about 200 °C. The phases formed at the various observed stages of the oxidation process were analyzed by X-ray diffraction. At the same time, ignition was analyzed thermodynamically along isothermal sections of the U-C-O ternary diagram and the pressure of the gas produced by the UC + O 2 reaction was calculated. Two possible oxidation schemes were identified on the U-C-O phase diagram and assumptions are proposed concerning the overall oxidation and ignition paths. It is particularly important to understand the mechanisms involved since temperatures as high as 2500 °C could be reached, leading to CO(g) production and possibly to a blast effect.

  10. Experimental studies of irradiated and hydrogen implantation damaged reactor steels (United States)

    Slugeň, Vladimír; Pecko, Stanislav; Sojak, Stanislav


    Radiation degradation of nuclear materials can be experimentally simulated via ion implantation. In our case, German reactor pressure vessel (RPV) steels were studied by positron annihilation lifetime spectroscopy (PALS). This unique non-destructive method can be effectively applied for the evaluation of microstructural changes and for the analysis of degradation of reactor steels due to neutron irradiation and proton implantation. Studied specimens of German reactor pressure vessel steels are originally from CARINA/CARISMA program. Eight specimens were measured in as-received state and two specimens were irradiated by neutrons in German experimental reactor VAK (Versuchsatomkraftwerk Kahl) in the 1980s. One of the specimens which was in as-received and neutron irradiated condition was also used for simulation of neutron damage by hydrogen nuclei implantation. Defects with the size of about 1-2 vacancies with relatively small contribution (with intensity on the level of 20-40 %) were observed in "as-received" steels. A significant increase in the size of the induced defects due to neutron damage was observed in the irradiated specimens resulting in 2-3 vacancies. The size and intensity of defects reached a similar level as in the specimens irradiated in the nuclear reactor due to the implantation of hydrogen ions with energies of 100 keV (up to the depth <500 nm).

  11. Experimental and numerical investigations of soil water balance at the hinterland of the Badain Jaran Desert for groundwater recharge estimation (United States)

    Hou, Lizhu; Wang, Xu-Sheng; Hu, Bill X.; Shang, Jie; Wan, Li


    Quantification of groundwater recharge from precipitation in the huge sand dunes is an issue in accounting for regional water balance in the Badain Jaran Desert (BJD) where about 100 lakes exist between dunes. In this study, field observations were conducted on a sand dune near a large saline lake in the BJD to investigate soil water movement through a thick vadose zone for groundwater estimation. The hydraulic properties of the soils at the site were determined using in situ experiments and laboratory measurements. A HYDRUS-1D model was built up for simulating the coupling processes of vertical water-vapor movement and heat transport in the desert soil. The model was well calibrated and validated using the site measurements of the soil water and temperature at various depths. Then, the model was applied to simulate the vertical flow across a 3-m-depth soil during a 53-year period under variable climate conditions. The simulated flow rate at the depth is an approximate estimation of groundwater recharge from the precipitation in the desert. It was found that the annual groundwater recharge would be 11-30 mm during 1983-2012, while the annual precipitation varied from 68 to 172 mm in the same period. The recharge rates are significantly higher than those estimated from the previous studies using chemical information. The modeling results highlight the role of the local precipitation as an essential source of groundwater in the BJD.

  12. Experimental study on neon refrigeration system using commercial helium compressor (United States)

    Ko, Junseok; Kim, Hyobong; Hong, Yong-Ju; Yeom, Hankil; Koh, Deuk-Yong; Park, Seong-Je


    In this study, we developed neon refrigeration system using commercial helium compressor which was originally designed for GM cryocooler. We performed this research as precedent study before developing neon refrigeration system for small-scale hydrogen liquefaction system. The developed system is based on precooled Linde-Hampson system with liquid nitrogen as precoolant. Design parameters of heat exchangers are determined from thermodynamic cycle analysis with operating pressure of 2 MPa and 0.4 MPa. Heat exchangers have concentric-tube heat exchanger configuration and orifice is used as Joule- Thomson expansion device. In experiments, pressure, temperature, mass flow rate and compressor input power are measured as charging pressure. With experimental results, the characteristics of heat exchanger, Joule-Thomson expansion and refrigeration effect are discussed. The developed neon refrigeration system shows the lowest temperature of 43.9 K.

  13. Experimental study on a natural circulation driven HPLWR

    Energy Technology Data Exchange (ETDEWEB)

    T' Joen, C.; Rohde, M. [Delft Univ. of Tech., Delft (Netherlands)


    The large density change through the core of a supercritical water reactor could be used as the driving force for circulating the coolant. To study such a natural circulation system, a scaled experimental setup was developed using Freon R23. This paper presents the first power-flow measurements for single core heating as well as 3 core heating (HPLWR power distribution) indicating that natural circulation occurs. A numerical model was developed to further study the impact of geometric and system parameters. This model shows good qualitative agreement with the experiment. By further refining the proposed model to include the pressure drop over the heat exchanger, a better quantitative agreement could be obtained. (author)

  14. Reverse running pumps analytical, experimental and computational study: A review

    Energy Technology Data Exchange (ETDEWEB)

    Nautiyal, Himanshu; Varun; Kumar, Anoop [Department of Mechanical Engineering, National Institute of Technology, Hamirpur (India)


    A pump can be used as turbine and has good application in micro-hydropower schemes. Pump as turbine (PAT) is one of the best alternatives for fulfilling the energy demands and providing the electricity in remote and rural areas. In this study a review on the work done in the area of pump working as turbine has been explained. Based upon the literature survey, analytical, experimental and computational works on pump as turbine have been discussed. Several methods for predicting the behaviour of pumps in turbine mode have been developed but no method is appropriate for the entire range of specific speeds. Computational fluid dynamics (CFD) is also used to study the reverse operation of centrifugal pumps, but still results are not yet acceptable. (author)

  15. Experimental studies with low transition energy optics in the SPS

    CERN Document Server

    Bartosik, H; Bohl, T; Cettour Cave, S; Esteban Muller, J; Cornelis, K; Papaphilippou, Y; Rumolo, G; Salvant, B; Shaposhnikova, E; Wenninger, J


    The optics of the SPS can be tuned to lower transition energy such that the slippage factor at injection is raised by a factor of almost 3. From theory, an increase of the intensity thresholds for transverse mode coupling, longitudinal coupled bunch and longitudinal instabilities due to the loss of Landau damping can be expected. In this paper, experimental studies in the SPS with single bunches of protons with intensities of up to 3.5e11 p/b on the flat bottom and at 450 GeV/c are presented. Longitudinal instabilities were studied with LHC-type beams with 50 ns spacing and injected intensities up to 1.8e11 p/b. The measurements address the increase of intensity thresholds and the achievable transverse emittances in the new low gamma transition optics with respect to the nominal SPS optics. The obtained results are compared with numerical simulations.

  16. Experimental study of rectenna coupling at low power level (United States)

    Douyère, A.; Alicalapa, F.; Rivière, S.; Luk, J.-D. Lan Sun


    The experimental results presented in this paper focus on the performance of a rectenna array by studying the effect of mutual coupling between two rectennas. The measurements in several planes of the space are investigated and used to help us to define the minimum distance for future rectenna arrays that can be used at a low power density level. The single element chosen for the array is composed of a rectifier circuit and a CSPA (Circular Slot Patch Antenna). This study shows that at a distance greater than 6cm (λ/2) between two rectennas in reception, we observe that the DC received voltage is constant in the Y plane, while in the X plane, the DC received voltage remains constant whatever the distance. We deduce that these rectennas are uncoupled in this case. We can consider each rectenna like an independent system.

  17. An experimental study of laser supported hydrogen plasmas (United States)

    Vanzandt, D. M.; Mccay, T. D.; Eskridge, R. H.


    The rudiments of a rocket thruster which receives its enthalpy from an energy source which is remotely beamed from a laser is described. An experimental study now partially complete is discussed which will eventually provide a detailed understanding of the physics for assessing the feasibility of using hydrogen plasmas for accepting and converting this energy to enthalpy. A plasma ignition scheme which uses a pulsed CO2 laser has been developed and the properties of the ignition spark documented, including breakdown intensities in hydrogen. A complete diagnostic system capable of determining plasma temperature and the plasma absorptivity for subsequent steady state absorption of a high power CO2 laser beam are developed and demonstrative use is discussed for the preliminary case study, a two atmosphere laser supported argon plasma.

  18. Experimental Study on the Langlee Wave Energy Converter

    DEFF Research Database (Denmark)

    Pecher, Arthur; Kofoed, Jens Peter; Weisz, A.

    This report presents the results of an experimental study of the wave energy converting abilities of the Langlee wave energy converter (WEC). It focused mainly on evaluating the power generating capabilities of the device, including investigations of the following issues: Scaling ratiosPTO loadingWave...... height and wave period dependencyOblique incoming waves and directional spreading of waves (3D waves)Damping platesMooring forces and fixed structure setupPitch, surge and heave motion During the study the model supplied by the client (Langlee Wave Power AS) has been heavily instrumented - up to 23...... different instruments was deployed to measure and record data. Tests were performed at scales of 1:30 and 1:20 based on the realized reference wave states....

  19. Experimental study of visual training effects in shooting initiation. (United States)

    Quevedo, Lluïsa; Solé, Joan; Palmi, Joan; Planas, Antoni; Soana, Carlos


    INTRODUCTION: The present study was conducted to investigate the influence of specific visual training in shooting initiation performance. METHODS: Seventy-one first-year university students were divided randomly into two groups. The experimental group followed a nine-session shooting training program that included technical, physical and psychological components, along with specific visual exercises. The control group followed the same program with one difference: this group received theoretical lectures on psychological training techniques instead of doing visual exercises. Pre- and post-test results were obtained for shooting, concentration, saccades and visual acuity. RESULTS: Statistical analysis indicated significant gains in the four mentioned variables for the experimental group. The control group also showed significant differences in the three first variables but no significant improvement in visual acuity. No significant differences in shooting performance were observed between groups. CONCLUSIONS: The effect of vision training on sports initiation performance is still not clear. It cannot be assumed that the improvement is transferable to the performance of precision shooting at the stage of sports initiation.

  20. Experimental Study of Hysteretic Steel Damper for Energy Dissipation Capacity

    Directory of Open Access Journals (Sweden)

    Daniel R. Teruna


    Full Text Available This study aims to evaluate energy absorption capacity of hysteretic steel damper for earthquake protection of structures. These types of steel dampers are fabricated from mild steel plate with different geometrical shapes on the side part, namely, straight, concave, and convex shapes. The performance of the proposed device was verified experimentally by a series of tests under increasing in-plane cyclic load. The overall test results indicated that the proposed steel dampers have similar hysteretic curves, but the specimen with convex-shaped side not only showed stable hysteretic behavior but also showed excellent energy dissipation capabilities and ductility factor. Furthermore, the load-deformation relation of these steel dampers can be decomposed into three parts, namely, skeleton curve, Bauschinger part, and elastic unloading part. The skeleton curve is commonly used to obtain the main parameters, which describe the behavior of steel damper, namely, yield strength, elastic stiffness, and postyield stiffness ratio. Moreover, the effective stiffness, effective damping ratio, cumulative plastic strain energy, and cumulative ductility factor were also derived from the results. Finally, an approximation trilinear hysteretic model was developed based on skeleton curve obtained from experimental results.

  1. Experimental Vertical Stability Studies for ITER Performance and Design Guidance

    Energy Technology Data Exchange (ETDEWEB)

    Humphreys, D A; Casper, T A; Eidietis, N; Ferrera, M; Gates, D A; Hutchinson, I H; Jackson, G L; Kolemen, E; Leuer, J A; Lister, J; LoDestro, L L; Meyer, W H; Pearlstein, L D; Sartori, F; Walker, M L; Welander, A S; Wolfe, S M


    Operating experimental devices have provided key inputs to the design process for ITER axisymmetric control. In particular, experiments have quantified controllability and robustness requirements in the presence of realistic noise and disturbance environments, which are difficult or impossible to characterize with modeling and simulation alone. This kind of information is particularly critical for ITER vertical control, which poses some of the highest demands on poloidal field system performance, since the consequences of loss of vertical control can be very severe. The present work describes results of multi-machine studies performed under a joint ITPA experiment on fundamental vertical control performance and controllability limits. We present experimental results from Alcator C-Mod, DIII-D, NSTX, TCV, and JET, along with analysis of these data to provide vertical control performance guidance to ITER. Useful metrics to quantify this control performance include the stability margin and maximum controllable vertical displacement. Theoretical analysis of the maximum controllable vertical displacement suggests effective approaches to improving performance in terms of this metric, with implications for ITER design modifications. Typical levels of noise in the vertical position measurement which can challenge the vertical control loop are assessed and analyzed.


    Directory of Open Access Journals (Sweden)

    Selcuk Selimli


    Full Text Available The subject of this study is the seawater distillation process enhancement through integration of the solar vacuum tube into the system. Positive effects on the rate of distillated freshwater achieved by means of the enhanced system have been investigated experimentally. Experiments were done in the Turkish city of Samsun in the Black Sea region. A distillation pond setup having the volume of 0.015m3 and a water surface area of 0.24m2 was constructed. The distillation pond is covered with a condensation glass and also equipped with a 0.15m solar vacuum tube that is inclined at an angle of 30o to the ground, a feed water tank connected with a ball cock, and distillated fresh water tank. Experimental results have shown that the rate of distilled fresh water was enhanced for about 62.5% by integrating the solar vacuum tube and the natural distillation pond. Isolation of the condensation glass not only prevents the light transmission to the pond but also heat loss from the pond; hence the rate of the distillated fresh water is increased for about 137.5% due to the natural distillation.

  3. Scintigraphic and Radiographic Study of the Experimental Periapical Lesions

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Youn Sik; Park, Tae Won [Dept. of Oral Radiology, College of Dentistry, Seoul National University, Seoul (Korea, Republic of)


    The purpose of this study was to clarify that scintigram was a more effective method than radiogram in the early detection of periapical lesion. Periapical lesions were produced artificially by the opening of the pulp chambers of the lower right 3rd and 4th premolars in 6 dogs. The serial bone scintigrams using 99m-Tc-MDP and periapical radiograms were taken weekly. The uptake counts of the 99-Tc-MDP in the experimental side were compared with those in the control side. The periapical radiograms were interpreted with the joint evaluation by three dental radiologists. The following results were obtained.; 1. The radioactivity in the experimental side was increased at the 1st week except one animal in which the radioactivity was increased at the 2nd week. 2. It was observed that increasing amount of radioactivity per week was prominent from the 1st day of experiment to the 1st week, and the 3rd week to the 4th week. 3. The radiographic evidence of the periapical lesions was observed at the 3rd week and became more apparent at the 4th week. 4. Histologically, proliferation of blood vessels and infiltration of chronic inflammatory cells were observed at the 1st week and osteoblasts were found after the 3rd week.

  4. A comprehensive experimental and modeling study of 2-methylbutanol combustion

    KAUST Repository

    Park, Sungwoo


    2-Methylbutanol (2-methyl-1-butanol) is one of several next-generation biofuels that can be used as an alternative fuel or blending component for combustion engines. This paper presents new experimental data for 2-methylbutanol, including ignition delay times in a high-pressure shock tube and premixed laminar flame speeds in a constant volume combustion vessel. Shock tube ignition delay times were measured for 2-methylbutanol/air mixtures at three equivalence ratios, temperatures ranging from 750 to 1250. K, and at nominal pressures near 20 and 40. bar. Laminar flame speed data were obtained using the spherically propagating premixed flame configuration at pressures of 1, 2, and 5. bar. A detailed chemical kinetic model for 2-methylbutanol oxidation was developed including high- and low-temperature chemistry based on previous modeling studies on butanol and pentanol isomers. The proposed model was tested against new and existing experimental data at pressures of 1-40. atm, temperatures of 740-1636. K, equivalence ratios of 0.25-2.0. Reaction path and sensitivity analyses were conducted for identifying key reactions at various combustion conditions, and to obtain better understanding of the combustion characteristics of larger alcohols.

  5. Experimental study of moving throat plug in a shock tunnel (United States)

    Lee, J. K.; Park, C.; Kwon, O. J.


    An experimental study has been carried out to investigate the flow in the KAIST shock tunnel with two moving throat plugs at a primary shock velocity of 1.19 km/s. The nozzle reservoir pressure and the Pitot pressure at the exit of the nozzle were measured to examine the influence of the moving throat plugs on the shock tunnel flow. To assess the present experimental results, comparisons with previous work using a stationary throat plug were made. The mechanism for closing the moving throat plug was developed and verified. The source of the force to move the plug was the pressure generated when the primary shock was reflected at the bottom of the plug. It was observed that the two plugs terminated the shock tunnel flow after the steady flow. .The time for the plugs to terminate the flow showed good agreement with the calculation of the proposed simple analytic solution. There was a negligible difference in flow values such as the reflected pressure and the Pitot pressure between the moving and the stationary plugs.

  6. Equilibrium p-T phase diagram of boron: experimental study and thermodynamic analysis. (United States)

    Solozhenko, Vladimir L; Kurakevych, Oleksandr O


    Solid-state phase transformations and melting of high-purity crystalline boron have been in situ and ex situ studied at pressures to 20 GPa in the 1500-2500 K temperature range where diffusion processes become fast and lead to formation of thermodynamically stable phases. The equilibrium phase diagram of boron has been constructed based on thermodynamic analysis of experimental and literature data. The high-temperature part of the diagram contains p-T domains of thermodynamic stability of rhombohedral β-B106, orthorhombic γ-B28, pseudo-cubic (tetragonal) t'-B52, and liquid boron (L). The positions of two triple points have been experimentally estimated, i.e. β-t'-L at ~ 8.0 GPa and ~ 2490 K; and β-γ-t' at ~ 9.6 GPa and ~ 2230 K. Finally, the proposed phase diagram explains all thermodynamic aspects of boron allotropy and significantly improves our understanding of the fifth element.

  7. Experimental and modelling study of plutonium uptake by suspended matter in aquatic environments from southern Spain. (United States)

    Mrabet, R E; Abril, J M; Manjón, G; Tenorio, R G


    Kinetic transfer coefficients are important parameters to understand and reliably model the behaviour of non-conservative radionuclides in aquatic environments. This report pertains to a series of five radiotracer experiments on Pu uptake in natural aqueous suspensions of unfiltered waters from three aquatic systems in the south of Spain (Gergal reservoir, the Guadalquivir river, and the estuary of the Tinto river). The experimental procedure ensured the simulation of environmental conditions. Pu activity was measured by a liquid scintillation technique. The uptake curves, covering a period up to one week, are discussed with respect to numerical uptake kinetics models. The data suggest that in our experimental setting the main pathways for Pu uptake consist of two parallel and reversible reactions followed by a consecutive non-reversible reaction. Kinetic transfer coefficients were estimated by a fitting procedure and a comparative study was followed.

  8. Exoplanet Yield Estimation for Decadal Study Concepts using EXOSIMS (United States)

    Morgan, Rhonda; Lowrance, Patrick; Savransky, Dmitry; Garrett, Daniel


    The anticipated upcoming large mission study concepts for the direct imaging of exo-earths present an exciting opportunity for exoplanet discovery and characterization. While these telescope concepts would also be capable of conducting a broad range of astrophysical investigations, the most difficult technology challenges are driven by the requirements for imaging exo-earths. The exoplanet science yield for these mission concepts will drive design trades and mission concept comparisons.To assist in these trade studies, the Exoplanet Exploration Program Office (ExEP) is developing a yield estimation tool that emphasizes transparency and consistent comparison of various design concepts. The tool will provide a parametric estimate of science yield of various mission concepts using contrast curves from physics-based model codes and Monte Carlo simulations of design reference missions using realistic constraints, such as solar avoidance angles, the observatory orbit, propulsion limitations of star shades, the accessibility of candidate targets, local and background zodiacal light levels, and background confusion by stars and galaxies. The python tool utilizes Dmitry Savransky's EXOSIMS (Exoplanet Open-Source Imaging Mission Simulator) design reference mission simulator that is being developed for the WFIRST Preliminary Science program. ExEP is extending and validating the tool for future mission concepts under consideration for the upcoming 2020 decadal review. We present a validation plan and preliminary yield results for a point design.

  9. Sequential recruitment of study participants may inflate genetic heritability estimates. (United States)

    Noce, Damia; Gögele, Martin; Schwienbacher, Christine; Caprioli, Giulia; De Grandi, Alessandro; Foco, Luisa; Platzgummer, Stefan; Pramstaller, Peter P; Pattaro, Cristian


    After the success of genome-wide association studies to uncover complex trait loci, attempts to explain the remaining genetic heritability (h (2)) are mainly focused on unraveling rare variant associations and gene-gene or gene-environment interactions. Little attention is paid to the possibility that h (2) estimates are inflated as a consequence of the epidemiological study design. We studied the time series of 54 biochemical traits in 4373 individuals from the Cooperative Health Research In South Tyrol (CHRIS) study, a pedigree-based study enrolling ten participants/day over several years, with close relatives preferentially invited within the same day. We observed distributional changes of measured traits over time. We hypothesized that the combination of such changes with the pedigree structure might generate a shared-environment component with consequent h (2) inflation. We performed variance components (VC) h (2) estimation for all traits after accounting for the enrollment period in a linear mixed model (two-stage approach). Accounting for the enrollment period caused a median h (2) reduction of 4%. For 9 traits, the reduction was of >20%. Results were confirmed by a Bayesian Markov chain Monte Carlo analysis with all VCs included at the same time (one-stage approach). The electrolytes were the traits most affected by the enrollment period. The h (2) inflation was independent of the h (2) magnitude, laboratory protocol changes, and length of the enrollment period. The enrollment process may induce shared-environment effects even under very stringent and standardized operating procedures, causing h (2) inflation. Including the day of participation as a random effect is a sensitive way to avoid overestimation.

  10. Experimental techniques for deflection and radiation studies with bent crystals

    CERN Document Server

    Hasan, Said


    What happens when a high energy charged particle crosses an amorphous material? It loses energy by ionization and its trajectory is affected by the multiple Coulomb scattering, being these phenomena originated by uncorrelated collisions with the atoms. If the atoms of the target were distributed according to an ordered scheme, the uncorrelated collisions would turn into a coherent interaction with the whole atomic structure. This is the case of an aligned crystal that, depending on the orientation, is seen as a set of atomic planes or strings by the impinging particles. Planes and strings produce potential wells able to confine the charged particles in a transversal region of the crystal, in the so called channeling condition, so that, bending the crystal, particles are forced to follow the curvature, being deflected. This simple and powerful idea, dating 1979, is at the basis of many theoretical and experimental studies that have proven bent crystals effectiveness, described their possible applications and ...

  11. A Transmission Electron Microscope Study of Experimentally Shocked Pregraphitic Carbon (United States)

    Rietmeijer, Frans J. M.


    A transmission electron microscope study of experimental shock metamorphism in natural pre-graphitic carbon simulates the response of the most common natural carbons to increased shock pressure. The d-spacings of this carbon are insensitive to the shock pressure and have no apparent diagnostic value, but progressive comminution occurs in response to increased shock pressure up to 59.6 GPa. The function, P = 869.1 x (size(sub minimum )(exp -0.83), describes the relationship between the minimum root-mean-square subgrain size (nm) and shock pressure (GPa). While a subgrain texture of natural pregraphitic carbons carries little information when pre-shock textures are unknown, this texture may go unnoticed as a shock metamorphic feature.

  12. Experimental study of coherent betatron resonances with a Paul trap

    Directory of Open Access Journals (Sweden)

    S. Ohtsubo


    Full Text Available Linear and nonlinear resonant instabilities of charged-particle beams traveling in periodic quadrupole focusing channels are studied experimentally with a compact non-neutral plasma trap. The present experiments are based on the idea that the collective motion of a beam in an accelerator is physically similar to that of a one-component plasma in a trap. A linear Paul trap system named “S-POD” (simulator for particle orbit dynamics was developed to explore a variety of space-charge-induced phenomena. To emulate lattice-dependent effects, periodic perturbations are applied to quadrupole electrodes, which gives rise to additional resonance stop bands that shift depending on the plasma density. It is confirmed that an mth-order resonance takes place when the corresponding tune of an mth-order collective mode Ω_{m} is close to a half integer.

  13. Modular hybrid total hip arthroplasty. Experimental study in dogs

    Directory of Open Access Journals (Sweden)

    Ranzani José JT


    Full Text Available Abstract Background This prospective experimental study evaluated the surgical procedure and results of modular hybrid total hip arthroplasty in dogs. Methods Ten skeletally mature healthy mongrel dogs with weights varying between 19 and 27 kg were used. Cemented modular femoral stems and uncemented porous-coated acetabular cups were employed. Clinical and radiographic evaluations were performed before surgery and at 30, 60, 90, 120, 180 and 360 days post-operation. Results Excellent weight bearing was noticed in the operated limb in seven dogs. Dislocation followed by loosening of the prosthesis was noticed in two dogs, which were therefore properly treated with a femoral head osteotomy. Femoral fracture occurred in one dog, which was promptly treated with full implant removal and femoral osteosynthesis. Conclusions The canine modular hybrid total hip arthroplasty provided excellent functionality of the operated limb.

  14. An experimental study of rotor-filter pump performance

    Energy Technology Data Exchange (ETDEWEB)

    Marshek, K.M.; Naja, M.R.


    The performance of a rotor-filter pump has been studied experimentally. To develop an understanding of pump performance, and in particular to discern the mechanism of hydraulic pulsing, flow visualization in the rotor, vibration analyses of the pump, frequency analysis of the pump hydraulic pressure pulsation, and analyses of flow characteristics for different pick-up tubes in combination with different impellers and cover plates were conducted. The frequencies of the pump's hydraulic pulsation is shown to be a function of the number of pick-up arms and the motor speed. The pump vibration and its pulsation amplitude were reduced by increasing the number of pick-up arms or by adding a radial impeller. These actions increased the lowest frequency of pulsation and decreased the chance of excitation of the pump system parts.

  15. Numerical and Experimental Study of Friction Loss in Hydrostatic Motor

    DEFF Research Database (Denmark)

    Sørensen, Rasmus Mørk; Hansen, Michael R.; Mouritsen, Ole Ø.


    This paper presents a numerical and experimental study of the losses in a hydrostatic motor principle. The motor is designed so that the structural de ections and lubricating regimes between moving surfaces and, subsequently, the leakage and friction losses, can be controlled during operation....... This is done by means of additional pressure volumes that in uence the stator de ection. These pressures are referred to as compensation pressures and the main emphasis is on friction or torque loss modeling of the motor as a function of the compensation pressures and the high and low pressures related...... to the load torque. The torque loss modeling is identied as a Stribeck curve which depends on gap height. The asperity friction is decreasing exponentially with an increase in gap height. The parameters of the torque loss model are based on prototype measurements that include the structural de ections...

  16. Experimental study of equilibrium in a bumpy torus

    Energy Technology Data Exchange (ETDEWEB)

    Hiroe, S.; Cobble, J.A.; Colchin, R.J.; Chen, G.L.; Connor, K.A.; Goyer, J.R.; Solensten, L.


    Plasma equilibrium in the ELMO Bumpy Torus (EBT) was studied experimentally by measurements of the electrostatic potential structure. Before an electron tail population is formed, the electric field is found, roughly speaking, to be in the vertical direction. The appearance of a high-energy electron tail signals the formation of a negative potential well, and the potential contours start to nest. The potential contours are shifted inward with respect to the center of the conducting wall. The electric field between the plasma and the conducting wall forces the plasma inward, balancing the outward expansion force. This force balance provides a horizontal electric field that cancels the concentric radial electric field locally at the separatrix of the potential contour and leads to convective energy loss.

  17. Experimental study of a rotating packed bed distillation column

    Directory of Open Access Journals (Sweden)

    J. V. S. Nascimento


    Full Text Available The purpose of this work was to study the mass transfer performance of rotating packed beds applying the "Higee" process. The operations were carried out with the n-hexane/n-heptane distilling system at atmospheric pressure and under total reflux conditions. The rotating speed could be varied between 300 and 2500 rpm, which provided centrifugal forces from 5 to 316 times the Earth's gravity. The effects of concentration, vapor velocity, rotating speed and packing type (two different Raschig ring sizes and structured wire mesh packing on mass transfer behavior were analyzed. Experimental results showed that the mass transfer coefficient depends on the liquid flow rates and rotating speed. The equipment had high separation efficiency in a reduced bed volume.

  18. Numerical and Experimental Study of Pump Sump Flows

    Directory of Open Access Journals (Sweden)

    Wei-Liang Chuang


    Full Text Available The present study analyzes pump sump flows with various discharges and gate submergence. Investigations using a three-dimensional large eddy simulation model and an acoustic Doppler velocimeter are performed. Flow patterns and velocity profiles in the approaching flow are shown to describe the flow features caused by various discharges and gate submergence. The variation of a large-scale spanwise vortex behind a sluice gate is examined and discussed. The suction effect on approaching flow near the pipe column is examined using numerical modeling. To gain more understanding of the vortices variation, a comparison between time-averaged and instantaneous flow patterns is numerically conducted. Additionally, swirl angle, a widely used index for evaluating pump efficiency, is experimentally and numerically examined under various flow conditions. The results indicate that the pump becomes less efficient with increasing discharge and gate submergence. The fluctuation of the free surface over the pump sump is also discussed.

  19. Experimental Study of a 45-MHz Array for Radio Astronomy (United States)

    Alvarez, H.; Aparici, J.; May, J.; Olmos, F.


    The University of Chile transit radiotelescope is a 528-dipole array operating at 45 MHz. We present a comparison of an experimental study of the antenna radiation pattern with the basic theoretical pattern in three dimensions. We concentrate in the meridian plane diagram since this is particularly difficult to measure for an array like ours. The comparison shows excellent agreement. We have measured several important antenna parameters like the effective area as a function of zenith distance, the orientation of the plane of the array and the pointing accuracy. We include a detailed treatment of these subjects since not much information related to low frequency arrays for radio astronomy can be found in the literature. We discuss the importance of knowing these parameters in the preparation of the 45-MHz Sky Survey under way at the University of Chile Radio Observatory.

  20. Numerical simulation and experimental study of explosive projectile devices (United States)

    Selivanov, V. V.; Gryaznov, E. F.; Goldenko, N. A.; Sudomoev, A. D.; Feldstein, V. A.


    A study of explosive-throwing device (ETD) was undertaken to simulate the hypervelocity impact of space debris fragments (SDF) and meteoroids with spacecrafts. The principle of operation of an ETD is based on the cumulative effect in combination with the cut-off head of the cumulative jet, which enables one to simulate a compact particle, such as a meteoroid or a fragment of space debris. Different design schemes of ETD with different composition explosive charge initiation schemes with notably low speeds of the jet cut-off are explored, and a method to control the particle velocity is proposed. Numerical simulation of device modes and basic technical characteristics of experimental testing are investigated.

  1. Experimental and simulated study of a composite structure metamaterial absorber (United States)

    Li, Shengyong; Ai, Xiaochuan; Wu, Ronghua; Chen, Jiajun


    In this paper, a high performance metamaterial absorber is designed and experimental studied. Measured results indicate that a perfect absorption band and a short-wavelength absorption peak are achieved in the near-infrared spectrum. Current strength distributions reveal that the absorption band is excited by the cavity resonance. And electric field distributions show that the short-wavelength absorption peak is excited by the horizontal coupled of localized surface plasmon (LSP) modes near hole edges. On the one hand, the absorption property of the measured metamaterial absorber can be enhanced through optimizing the structural parameters (a, w, and H). On the other hand, the absorption property is sensitive to the change of refractive index of environmental medias. A sensing scheme is proposed for refractive index detecting based on the figure of merit (FOM) value. Measured results indicate that the proposed sensing scheme can achieve high FOM value with different environmental medias (water, glucose solution).

  2. An experimental and modeling study of n-octanol combustion

    KAUST Repository

    Cai, Liming


    This study presents the first investigation on the combustion chemistry of n-octanol, a long chain alcohol. Ignition delay times were determined experimentally in a high-pressure shock tube, and stable species concentration profiles were obtained in a jet stirred reactor for a range of initial conditions. A detailed kinetic model was developed to describe the oxidation of n-octanol at both low and high temperatures, and the model shows good agreement with the present dataset. The fuel\\'s combustion characteristics are compared to those of n-alkanes and to short chain alcohols to illustrate the effects of the hydroxyl moiety and the carbon chain length on important combustion properties. Finally, the results are discussed in detail. © 2014 The Combustion Institute.

  3. Experimental study of infrared filaments under different initial conditions (United States)

    Mirell, Daniel Joseph

    In 1964, four years after the first working laser was constructed, long skinny damage tracks and fluorescence trails were seen inside of certain transparent media that were excited by intense light pulses [1]. What was so remarkable about these features was the narrowness of the spatial profile and their long propagation length in the beam in concert with the very high intensity of the light that would be necessary to produce them. A purely linear model of light propagation through such media was insufficient to explain the results of these experiments and hence a new area of nonlinear optics, latex coined filamentation (to describe the length, slimness, and intensity of the light field), was born. Filament studies begin with a medium that has a nonlinear index of refraction, n¯2, that interacts with an intense beam of light so as to cause it to self-focus. The n¯2 of liquid and solid transparent media is much higher than the n¯ 2 of gases and therefore a much higher intensity of laser source would need to be invented to begin the study of filaments in air. With the advent of the Ti-Sapphire Kerr-lens modelocked laser [2], working in combination with the development of the chirped pulse amplifier system in the mid-1990's, light intensities sufficient to produce filaments in air was realized. Since that time much experimental and theoretical work has been done to better understand some of the additional complexities that arise specifically in the filamentation of light in air using several different wavelengths (UV to IR) and pulsewidths (femto- to pico-seconds). Many theoretical models exist each with a different emphasis on the various physical mechanisms that may produce the features experimentally observed in filaments. The experimental work has sought to give the theoretician better data on some of the properties of filaments such as the: (a) spatial and temporal structure of the beam and of the produced plasma (that arises due to the high intensity light

  4. Experimental study of drag reduction in flumes and spillway tunnels

    Directory of Open Access Journals (Sweden)

    Ying-kui Wang


    Full Text Available Experiments in an open flume model and spillway tunnel model were carried out using drag reduction techniques. Two drag reduction techniques were adopted in the experiments: polymer addition and coating. The drag reduction effect of a polyacrylamide (PAM solution and dimethyl silicone oil coating were studied in the flume model experiments, and the results were analyzed. Experiments were then carried out with a model of the Xiluodu Hydropower Station, the second largest dam in China. In order to reduce the resistance, the spillway tunnels were internally coated with dimethyl silicone oil. This is the first time that these drag reduction techniques have been applied to so large a hydraulic model. The experimental results show that the coating technique can effectively increase flood discharge. The outlet velocity and the jet trajectory distance are also increased, which enhances the energy dissipation of the spillway tunnel.

  5. An experimental study on improvement of Savonius rotor performance

    Directory of Open Access Journals (Sweden)

    N.H. Mahmoud


    In this work different geometries of Savonius wind turbine are experimentally studied in order to determine the most effective operation parameters. It was found that, the two blades rotor is more efficient than three and four ones. The rotor with end plates gives higher efficiency than those of without end plates. Double stage rotors have higher performance compared to single stage rotors. The rotors without overlap ratio (β are better in operation than those with overlap. The results show also that the power coefficient increases with rising the aspect ratio (α. The conclusions from the measurements of the static torque for each rotor at different wind speeds verify the above summarized results of this work.

  6. Perceptions of unfairness in price increases: an experimental study

    Directory of Open Access Journals (Sweden)

    Verônica Feder Mayer


    Full Text Available This experimental study investigates antecedents and consequences of perceptions of price unfairness in a price increase situation. The proposed theoretical model states that consumer dependence on the service provider as well as the relevance the consumer attributes to the service (for the consumer's life will affect his/her degree of (a unfairness price perception, (b anger, and (c intention to complain and retaliate. The results support all the hypotheses specified in the model. The findings not only indicate that some situations of unfairness price perception lead to stronger emotions and more dramatic reactions from consumers, but also allow us to predict which situations of perceived unfairness offer greater risks and have greater potential for conflict.

  7. The role of bibliotherapy in health anxiety: an experimental study. (United States)

    Jones, Freda A


    Despite its high prevalence and implications for health care resources, health anxiety is generally considered difficult and expensive to manage. Structured self-help materials (bibliotherapy) using a cognitive behaviour therapy (CBT) treatment approach have been shown to be clinically effective. This experimental study investigated the effects of bibliotherapy on patients who had been identified as demonstrating health concerns. The 40 participants (patients drawn from GP surgeries) were randomly allocated to two groups, one receiving bibliotherapy and the other not. Half the patients had a medically diagnosed problem. Anxiety was assessed before and after the bibliotherapy intervention, which took the form of a cognitive-behavioural self-help booklet for health anxiety sufferers. Patients in the bibliotherapy group showed reduced levels of anxiety at post-test, even when they also had an identifiable physical problem. These results are consistent with the idea that self-help materials can be an effective and accessible intervention in CBT, although further research is recommended.

  8. Simulation and experimental study of resin flow in fibre fabrics (United States)

    Yan, Fei; Yan, Shilin; Li, Yongjing


    Liquid Composite Moulding (LCM) is gradually becoming the most competitive manufacturing technology for producing large composite parts with complex geometry with high quality and low cost. These parts include those for airplanes, wind turbine blades and automobile components. Fibre fabrics in liquid composite moulding can be considered as dual-scale porous media. In different gap scales, an unsaturated flow is produced during the mould filling process. This particular flow behaviour deviates from the traditional Darcy’s law, which is used to calculate the filling pressure and will cause errors. According to sink theory, the unsaturated flow characteristics of this dual-scale porous media were studied in this paper, and a FEM solution program was developed. The results showed that the pressure curves against the position which simulated by sink functions were departure from the position of traditional theory. In addition, the simulation results of partially-saturated region were consistent with the experimental data.

  9. An experimental study on particle effects in liquid sheets

    Directory of Open Access Journals (Sweden)

    Sauret Alban


    Full Text Available Many industrial processes, such as surface coating or liquid transport in tubes, involve liquid sheets or thin films of suspensions. In these situations, the thickness of the liquid film becomes comparable to the particle size, which leads to unexpected dynamics. In addition, the classical constitutive rheological law for suspensions cannot be applied as the continuum approximation is no longer valid. Here, we consider experimentally a transient particle-laden liquid sheet that expands radially. We characterize the influence of the particles on the shape of the liquid film and the atomization process. We highlight that the presence of particles modifies the thickness and stability of the liquid sheet. Our study suggests that the influence of particles through capillary effects can modify significantly the dynamics of processes that involve suspensions and particles confined in liquid films.

  10. Theoretical and experimental study of 15N NMR protonation shifts. (United States)

    Semenov, Valentin A; Samultsev, Dmitry O; Krivdin, Leonid B


    A combined theoretical and experimental study revealed that the nature of the upfield (shielding) protonation effect in 15N NMR originates in the change of the contribution of the sp(2)-hybridized nitrogen lone pair on protonation resulting in a marked shielding of nitrogen of about 100 ppm. On the contrary, for amine-type nitrogen, protonation of the nitrogen lone pair results in the deshielding protonation effect of about 25 ppm, so that the total deshielding protonation effect of about 10 ppm is due to the interplay of the contributions of adjacent natural bond orbitals. A versatile computational scheme for the calculation of 15N NMR chemical shifts of protonated nitrogen species and their neutral precursors is proposed at the density functional theory level taking into account solvent effects within the supermolecule solvation model. Copyright © 2015 John Wiley & Sons, Ltd.

  11. Experimental study on silicon micro-heat pipe arrays

    Energy Technology Data Exchange (ETDEWEB)

    Launay, S.; Sartre, V.; Lallemand, M. [Institut National des Sciences Appliquees, Villeurbanne (France). Centre de Thermique


    In this study, micro-heat pipe arrays etched into silicon wafers have been investigated for electronic cooling purposes. Micro-heat pipes of triangular cross-section and with liquid arteries were fabricated by wet anisotropic etching with a KOH solution. The microchannels (230 {mu}m wide) are closed by molecular bonding of a plain wafer with the grooved one. A test bench was developed for the micro-heat pipe filling and the thermal characterisation. The temperature profile on the silicon surface is deduced from experimental measurements. The results show that with the artery micro-heat pipe array, filled with methanol, the effective thermal conductivity of the silicon wafer is significantly improved compared to massive silicon. (author)

  12. [Pathomorphological studies of experimental thiazole-80 poisoning in sheep]. (United States)

    Petkov, P


    Investigations on the pathomorphological changes occurring in the organisms of 4 sheep poisoned experimentally by varying Thiazole-80 doses applied orally were made. It was established macroscopically that after opening the rumen a smell of sulfuric hydrogen is felt. The abomasum was with rusty brown haemorrhages and liver distrophy as well as enlarged gall bladder were observed. The histological studies of parenchymal organs revealed vascular disturbances, hyperemia, oedema and intervascular haemolysis. A heavy diffuse nephrosis, hyaline and protein cylinders were found in the kidney cortex, while in the ganglial cells of medula oblongata were evident degenerative changes. Histochemically, in sheep poisoned by thiazole-80, a well expressed reaction to iron in the lungs, leptomeniges and distrophic hepatocytes were established. Glycogen quantity in the liver was considerably reduced.


    Directory of Open Access Journals (Sweden)

    Dogaru Gabriela


    Full Text Available Pulsed short waves are short electromagnetic waves emitted as intermittent trains with a fixed duration, separated by free intervals of variable duration. The biological effects of pulsed short waves could be explained according to most of the authors by an activation of cellular enzymatic reactions, a stimulation of energy metabolism, a stimulation of liver function, of adrenal gland function and of the reticulocyte system, changes in cell permeability, by an increase of peripheral blood flow through the enhancement of local vascularization. This research aimed to investigate the biological effects of exposure to pulsed short waves at different doses on the adrenal glands of experimental animals, by structural and ultrastructural studies. The study included 35 animals assigned to 4 groups. Group I included 10 experimental animals exposed to radiation at a dose of 1/80 impulses/sec, group II, 10 animals exposed to a dose of 4/400 impulses/sec, group III, 10 animals exposed to a dose of 6/600 impulses/sec, for 10 min/day, and the control group consisted of 5 unexposed animals. Structural and ultrastructural changes of adrenal glands induced by the dose of 4/400 impulses/sec, compared to the unexposed control group and the dose of 1/80 impulses/sec, include an intensification of protein synthesis processes, an enhancement of energy metabolism in providing the energy required for an increased production of hormones, an intensification of collagen fiber synthesis processes in the capsule, necessary for healing. It was demonstrated that this dose induced an intensification of hormone synthesis and secretion, a stimulation of adrenal function. At the dose of 6/600 cycles/sec, a slight diminution of hormone synthesis and secretion activity was found, which was not below the limits existing in the unexposed control group, but was comparable to group II. This dose is probably too strong for experimental animals, inducing them a state of stress. The

  14. A comparative study of some robust ridge and liu estimators ...

    African Journals Online (AJOL)

    In multiple linear regression analysis, multicollinearity and outliers are two main problems. When multicollinearity exists, biased estimation techniques such as Ridge and Liu Estimators are preferable to Ordinary Least Square. On the other hand, when outliers exist in the data, robust estimators like M, MM, LTS and S ...

  15. Estimating heritability for cause specific mortality based on twin studies

    DEFF Research Database (Denmark)

    Scheike, Thomas; Holst, Klaus K.; Hjelmborg, Jacob B.


    There has been considerable interest in studying the magnitude and type of inheritance of specific diseases. This is typically derived from family or twin studies, where the basic idea is to compare the correlation for different pairs that share different amount of genes. We here consider data from...... the Danish twin registry and discuss how to define heritability for cancer occurrence. The key point is that this should be done taking censoring as well as competing risks due to e.g.  death into account. We describe the dependence between twins on the probability scale and show that various models can...... be used to achieve sensible estimates of the dependence within monozygotic and dizygotic twin pairs that may vary over time. These dependence measures can subsequently be decomposed into a genetic and environmental component using random effects models. We here present several novel models that in essence...

  16. Direct and diffuse solar radiation components estimation based on RBF model: Case study

    Directory of Open Access Journals (Sweden)

    Abdelaziz RABEHI


    Full Text Available The current study, propose a new application of radial basis functions neural network for estimating direct normal radiation (DNR and diffuse solar radiation (DSR components based on different inputs parameters. The proposed methodology was validated and tested on limited data set recorded over three years (2014-2016 in a semi-arid climate in Algeria.The experimental results show that RBF-model was highly qualified for estimating DNR and DSR with high performance accuracy. The obtained statistical parameters of Normalized Root Mean Square Error (NRMSE, Determination Coefficient (R2 and Correlation Coefficient (r for DNR and DSR are: 0.030, 97.30 %, 98.60% and 0.044, 94.34%, 97.61%, respectively.

  17. Experimental Study on the Flow Characteristics in a Bare Rod Bundle Array

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Seok Kyu; Kim, Bok Deuk; Moon, Sang Ki [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)


    Structure of a rod bundle array in thermal-hydraulic environment is widely used and very important issues in the industrial field. Especially, in nuclear power plant, this structure is essential in the reactor and steam generator. Because of such an industrial importance, there have been many experimental studies on the flow characteristics in a rod bundle array. During two decades from 1970, fundamental studies on the flow mixing in a bare rod bundle have been frequently performed. Rowe et al. measured the axial and some lateral velocities and their turbulence intensities by using 2-D LDV system. They found the existence of the longitudinal macro-scale and the dominant frequency of turbulence in a sub-channel mixing. Neti et al. also performed the LDV measurements for a 3x3 rod array and presented the lateral fluctuations were about 1% magnitudes of the axial flow. Renksizbulut et al. measured the shear stress of the rod surface and estimates the secondary flow in a sub-channel and Vonka also confirmed the secondary flow in his experimental work. In spite of many experimental studies on the flow mixing in a sub-channel geometry on a bare rod bundle, there were no full measurement information in a subchannel. This study attempted to the detailed full measurement of the lateral velocities as well as the axial velocities in a sub-channel geometry on a 5x5 rod bundle.

  18. Experimental studies and modeling on concentration polarization in forward osmosis. (United States)

    Qin, Jian-Jun; Chen, Sijie; Oo, Maung Htun; Kekre, Kiran A; Cornelissen, Emile R; Ruiken, Chris J


    Concentration polarization (CP) is an important issue in forward osmosis (FO) processes and it is believed that the coupled effect of dilutive internal CP (DICP) and concentrative external CP (CECP) limits FO flux. The objective of this study was to distinguish individual contribution of different types of DICP and CECP via modeling and to validate it by pilot studies. The influence of DICP/CECP on FO flux has been investigated in this study. The CP model presented in this work was derived from a previous study and evaluated by bench-scale FO experiments. Experiments were conducted with drinking water as the feed and NaCl/MgSO(4) as draw solutions at different concentrations and velocities. Modeling results indicated that DICP contributed to a flux reduction by 99.9% for 0.5 M NaCl as a draw solution although the flow pattern of both feed and draw solutions was turbulent. DICP could be improved via selection of the draw solution. The modeling results were well fit with the experimental data. It was concluded that the model could be used for selection of the draw solution and prediction of water flux under similar situation. A draw solution with greater diffusion coefficient or a thinner substrate of an asymmetric FO membrane resulted in a higher flux.

  19. Experimental verification of a method for estimating energy for domestic hot water production in a 2-stage district heating substation

    Energy Technology Data Exchange (ETDEWEB)

    Yliniemi, Kimmo; Delsing, Jerker; van Deventer, Jan [Luleaa University of Technology, Department of Computer Science and Electrical Engineering, Division EISLAB, 971 87 Luleaa (Sweden)


    In this paper we compare our estimate of energy consumption for domestic hot water production in a building with the measured value. The energy consumption for hot water production is estimated from the measured total power consumption. The estimation method was developed using computer simulations, and it is based on the assumption that hot water production causes rapid and detectable changes in power consumption. A comparison of our estimates with measurements indicates that the uncertainty in estimation of hot water energy consumption is {+-}10%. Thus, the estimate is comparable to class 3 energy meter measurements, which have an uncertainty of {+-}2-10%. (author)


    Directory of Open Access Journals (Sweden)

    Héctor José Peinado-Guevara


    Full Text Available Hydraulic conductivity is a basic element in the advancement of knowledge of a geological environment in both the flow and transport processes of pollutants for conservation projects, managementand environmental management and also for the development of public policies for protection of ecosystems, among others. The aim of this paper is to obtain the hydraulic conductivity (K and the finescontent (C of saturated granular half using two empirical laws. One correlates the electrical conductivity of saturated granular media σo and water saturated σw which depends on the formation factor(F, cation exchange capacity (CEC and the fines content in the saturated soil. Using data obtained from materials of 18 samples from 6 wells the relationships between F-C and CEC-C were obtained,so the equation reduces to a σo function in terms of σw and C, with a correlation coefficient of R = 0.97. A second experimental law is the one that results from the experimental relationship between K and C,being 1.4054 K 0.1804.C with a correlation coefficient of R = 0.96. From both experimental expressions relationships between K and C, a and C,and C are created so from every pair knowing one of them you get to know the other one. Under the scheme outlined electrical conductivity sections for the saturated medium and fines content are obtained,finding that the groundwater in the study area consists of a thin top layer and beneath it there is a predominantly sandy environment.

  1. A Novel Approach to Experimental Studies of Mineral Dissolution Kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Chen Zhu; William E. Seyfried


    Currently, DOE is conducting pilot CO{sub 2} injection tests to evaluate the concept of geological sequestration. One strategy that potentially enhances CO{sub 2} solubility and reduces the risk of CO{sub 2} leak back to the surface is dissolution of indigenous minerals in the geological formation and precipitation of secondary carbonate phases, which increases the brine pH and immobilizes CO{sub 2}. Clearly, the rates at which these dissolution and precipitation reactions occur directly determine the efficiency of this strategy. However, one of the fundamental problems in modern geochemistry is the persistent two to five orders of magnitude discrepancy between laboratory-measured and field derived feldspar dissolution rates. To date, there is no real guidance as to how to predict silicate reaction rates for use in quantitative models. Current models for assessment of geological carbon sequestration have generally opted to use laboratory rates, in spite of the dearth of such data for compositionally complex systems, and the persistent disconnect between lab and field applications. Therefore, a firm scientific basis for predicting silicate reaction kinetics in CO{sub 2} injected geological formations is urgently needed to assure the reliability of the geochemical models used for the assessments of carbon sequestration strategies. The funded experimental and theoretical study attempts to resolve this outstanding scientific issue by novel experimental design and theoretical interpretation to measure silicate dissolution rates and iron carbonate precipitation rates at conditions pertinent to geological carbon sequestration. In the first year of the project, we have successfully developed a sample preparation method and completed three batch feldspar dissolution experiments at 200 C and 300 bars. The changes of solution chemistry as dissolution experiments progressed were monitored with on-line sampling of the aqueous phase at the constant temperature and pressure

  2. Experimental studies of light emission phenomena in superconducting RF cavities

    Energy Technology Data Exchange (ETDEWEB)

    Anthony, P.L. [SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Delayen, J.R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport, News, VA 23606 (United States); Center for Accelerator Science, Old Dominion University, Norfolk, VA, 23529 (United States); Fryberger, D., E-mail: fryberger@slac.stanford.ed [SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Goree, W.S. [2G Enterprises, Pacific Grove, CA 93950 (United States); Mammosser, J. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport, News, VA 23606 (United States); Szalata, Z.M.; Weisend, J.G. [SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States)


    Experimental studies of light emission phenomena in superconducting RF cavities, which we categorize under the general heading of cavity lights, are described. The cavity lights data, which were obtained using a small CCD video camera, were collected in a series of nine experimental runs ranging from approx1/2 to approx2 h in duration. The video data were recorded on a standard VHS tape. As the runs progressed, additional instrumentation was added. For the last three runs a LabVIEW-controlled data acquisition system was included. These runs furnish evidence for several, possibly related, light emission phenomena. The most intriguing of these is what appear to be small luminous objects <=1.5 mm in size, freely moving about in the vacuum space, generally without wall contact, as verified by reflections of the tracks in the cavity walls. In addition, on a number of occasions, these objects were observed to bounce off of the cavity walls. The wall-bounce aspect of most of these events was clearly confirmed by pre-bounce and post-bounce reflections concurrent with the tracks. In one of the later runs, a mode of behavior was observed that was qualitatively different from anything observed in the earlier runs. Perhaps the most perplexing aspect of this new mode was the observation of as many as seven luminous objects arrayed in what might be described as a macromolecular formation, coherently moving about in the interior of the cavity for extended periods of time, evidently without any wall contact. It is suggested that these mobile luminous objects are without explanation within the realm of established physics. Some remarks about more exotic theoretical possibilities are made, and future plans are discussed.

  3. Overview: Experimental studies of crystal nucleation: Metals and colloids (United States)

    Herlach, Dieter M.; Palberg, Thomas; Klassen, Ina; Klein, Stefan; Kobold, Raphael


    Crystallization is one of the most important phase transformations of first order. In the case of metals and alloys, the liquid phase is the parent phase of materials production. The conditions of the crystallization process control the as-solidified material in its chemical and physical properties. Nucleation initiates the crystallization of a liquid. It selects the crystallographic phase, stable or meta-stable. Its detailed knowledge is therefore mandatory for the design of materials. We present techniques of containerless processing for nucleation studies of metals and alloys. Experimental results demonstrate the power of these methods not only for crystal nucleation of stable solids but in particular also for investigations of crystal nucleation of metastable solids at extreme undercooling. This concerns the physical nature of heterogeneous versus homogeneous nucleation and nucleation of phases nucleated under non-equilibrium conditions. The results are analyzed within classical nucleation theory that defines the activation energy of homogeneous nucleation in terms of the interfacial energy and the difference of Gibbs free energies of solid and liquid. The interfacial energy acts as barrier for the nucleation process. Its experimental determination is difficult in the case of metals. In the second part of this work we therefore explore the potential of colloidal suspensions as model systems for the crystallization process. The nucleation process of colloids is observed in situ by optical observation and ultra-small angle X-ray diffraction using high intensity synchrotron radiation. It allows an unambiguous discrimination of homogeneous and heterogeneous nucleation as well as the determination of the interfacial free energy of the solid-liquid interface. Our results are used to construct Turnbull plots of colloids, which are discussed in relation to Turnbull plots of metals and support the hypothesis that colloids are useful model systems to investigate crystal

  4. Experimental Studies of Light Emission Phenomena in Superconducting RF Cavitites

    Energy Technology Data Exchange (ETDEWEB)

    Anthony, P.L.; /SLAC; Delayen, J.R.; /Jefferson Lab; Fryberger, D.; /SLAC; Goree, W.S.; Mammosser, J.; /Jefferson Lab /SNS Project, Oak Ridge; Szalata, Z.M.; II, J.G.Weisend /SLAC


    Experimental studies of light emission phenomena in superconducting RF cavities, which we categorize under the general heading of cavity lights, are described. The cavity lights data, which were obtained using a small CCD video camera, were collected in a series of nine experimental runs ranging from {approx} 1/2 to {approx} 2 h in duration. The video data were recorded on a standard VHS tape. As the runs progressed, additional instrumentation was added. For the last three runs a LabVIEW controlled data acquisition system was included. These runs furnish evidence for several, possibly related, light emission phenomena. The most intriguing of these is what appear to be small luminous objects {le} 1.5 mm in size, freely moving about in the vacuum space, generally without wall contact, as verified by reflections of the tracks in the cavity walls. In addition, on a number of occasions, these objects were observed to bounce off of the cavity walls. The wall-bounce aspect of most of these events was clearly confirmed by pre-bounce and post-bounce reflections concurrent with the tracks. In one of the later runs, a mode of behavior was observed that was qualitatively different from anything observed in the earlier runs. Perhaps the most perplexing aspect of this new mode was the observation of as many as seven luminous objects arrayed in what might be described as a macromolecular formation, coherently moving about in the interior of the cavity for extended periods of time, evidently without any wall contact. It is suggested that these mobile luminous objects are without explanation within the realm of established physics. Some remarks about more exotic theoretical possibilities are made, and future plans are discussed.

  5. Experimental study of vortex breakdown in a cylindrical, swirling flow (United States)

    Stevens, J. L.; Celik, Z. Z.; Cantwell, B. J.; Lopez, J. M.


    The stability of a steady, vortical flow in a cylindrical container with one rotating endwall has been experimentally examined to gain insight into the process of vortex breakdowwn. The dynamics of the flow are governed by the Reynolds number (Re) and the aspect ratio of the cylinder. Re is given by Omega R(sup 2)/nu, where Omega is the speed of rotation of the endwall, R is the cylinder radius, and nu is the kinematic viscosity of the fluid filling the cylinder. The aspect ratio is H/R, where H is the height of the cylinder. Numerical simulation studies disagree whether or not the steady breakdown is stable beyond a critical Reynolds number, Re(sub c). Previous experimental researches have considered the steady and unsteady flows near Re(sub c), but have not explored the stability of the steady breakdown structures beyond this value. In this investigation, laser induced fluorescence was utilized to observe both steady and unsteady vortex breakdown at a fixed H/R of 2.5 with Re varying around Re(sub c). When the Re of a steady flow was slowly increased beyond Re(sub c), the breakdown structure remained steady even though unsteadiness was possible. In addition, a number of hysteresis events involving the oscillation periods of the unsteady flow were noted. The results show that both steady and unsteady vortex breakdown occur for a limited range of Re above Re(sub c). Also, with increasing Re, complex flow transformations take place that alter the period at which the unsteady flow oscillates.

  6. Epidural blood patch: A study on an experimental model

    Directory of Open Access Journals (Sweden)

    S K Sengupta


    Full Text Available Aim: Epidural blood patch has been used to treat spinal headache with varying success. An experimental model was designed to ascertain whether an epidural blood patch can be used to seal the needle puncture sites in dural repair. Materials and Methods: Bovine dura was secured to the lower end of an open-ended calibrated plastic cylinder. Multiple interrupted stitches were applied over a 02 cm length of the dura without any incision. The cylinder was filled with colored saline gradually with the dura placed in a dependent position. Height of the water column at which sutured dura leaked was recorded. A layer of fresh blood was laid over the dura and allowed to clot. The test was repeated and the hydrostatic pressure at which leak took place was noted again. The test was repeated three times. Similar studies were done with two specimens with 02-cm dural incisions repaired with interrupted stitches of 4-0 silk in one specimen and 4-0 prolene in another, and three specimens with 3-mm unsutured dural rent in one and dural punctures made with 23-G and 26-G spinal needles in the other two. Results: All the dural preparations leaked, at a very low hydrostatic pressure (<30 mm of H 2 O. By covering the needle puncture sites with clotted blood, a watertight closure could be achieved, that can withstand a much higher hydrostatic pressure (mean of 180 mm of H 2 O. Conclusion : The experimental findings indicate that an epidural blood patch does enhance the ability of a dural closure to prevent a leak; however, its utility in clinical setting is questionable.

  7. Experimental study of a single channel alluvial fan (United States)

    Delorme, Pauline; Devauchelle, Olivier; Barrier, Laurie; Métivier, François


    At the outlet of mountain ranges, rivers reach a flat plain and start to depose their sediment load into a conical sedimentary structure called alluvial fan. To decipher these sedimentary records, we need to understand the dynamics of their growth. Most natural fans are built by braided streams. However, to avoid the complexity of braided rivers, we develop a small-scale experiment in which an alluvial fan is formed by a single channel. We use a mixture of water and glycerol to produce a laminar river. The fluid is mixed with corindon sand (~ 300 μm) in a tilted channel and left free to form a fan around its outlet. The sediment and water discharges are constant during an experimental run. We record the fan progradation and the channel morphology with top-view pictures. We also generate an elevation map with an optical method based on the deformation of a moiré pattern. We observe that, to leading order, the fan remains self-affine as it grows, with a constant slope. We compare two recent studies about the formation of one-dimensionnal fan [Guerit et al. 2014] and threshold rivers [Seizilles et al. 2013] to our experimental findings. In particular, we propose a theory witch relates the fan morphology to the control parameters (fluid and sediment discharges, grain size). Our observations accord with the predictions, suggesting that the fan is built near the threshold of sediment motion. At the first order, the fan profile is linear and control by the water discharge. The downstream decrease in sediment discharge add a curvature to this profile. Finally, we intend to expand our interpretation to alluvial fans build by single-thread channels ( Okavango, Bostwana; Taquari and Paraguay, Brasil).

  8. Proteomic Studies on Human and Experimental Cerebral Malaria

    KAUST Repository

    Moussa, Ehab


    Cerebral malaria (CM) is a severe neurological complication of malaria infection that results from interrelated pathologies. Despite extensive research efforts, the mechanism of the disease is not completely understood. Clinical studies, postmortem analysis, and animal models have been the main research arenas in CM. In this thesis, shotgun proteomics approach was used to further understand the pathology of human and experimental CM. The mechanism by which CM turns fatal is yet to be identified. A clinical proteomics study was conducted on pooled plasma samples from children with reversible or fatal CM from the Gambia. The results show that depletion of coagulation factors and increased levels of circulating proteasomes are associated with fatal pediatric CM. This data suggests that the ongoing coagulation during CM might be a disseminated intravascular coagulation state that eventually causes depletion of the coagulation factors leading to petechial hemorrhages. In addition, the mechanism(s) by which blood transfusion benefits CM in children was investigated. To that end, the concentration and multimerization pattern of von-willebrand factor, and the concentration of haptoglobin in the plasma of children with CM who received blood transfusions were measured. In addition to clinical studies, experimental cerebral malaria (ECM) in mice has been long used as a model for the disease. A shotgun proteomics workflow was optimized to identify the proteomic signature of the brain tissue of mice with ECM.Because of the utmost importance of membrane proteins in the pathology of the disease, sample fractionation and filter aided sample preparation were used to recover them. The proteomic signature of the brains of mice infected with P. berghei ANKA that developed neurological syndrome, mice infected with P. berghei NK56 that developed severe malaria but without neurological signs, and non-infected mice, were compared to identify CM specific proteins. Among the differentially

  9. [Crystalline lens photodisruption using femtosecond laser: experimental study]. (United States)

    Chatoux, O; Touboul, D; Buestel, C; Balcou, P; Colin, J


    The aim of this study was to analyze the interactions during femtosecond (fs) laser photodisruption in ex vivo porcine crystalline lenses and to study the parameters for laser interaction optimization. An experimental femtosecond laser was used. The laser characteristics were: 1030 nm wavelength; pulse duration, 400 fs; and numerical aperture, 0.13. Specific software was created to custom and monitor any type of photoablation pattern for treatment purposes. Porcine crystalline lenses were placed in an open sky holder filled with physiological liquid (BSS) covered by a glass plate. A numerical camera was associated with metrological software in order to magnify and quantify the results. Transmission electron microscopy (TEM) was performed on some samples to identify the microscopic plasma interactions with the lens. The optimization of parameters was investigated in terms of the optical breakdown threshold, the sizing of interactions, and the best pattern for alignments. More than 150 crystalline lenses of freshly enucleated pigs were treated. The optical breakdown threshold (OBT) was defined as the minimal energy level per pulse necessary to observe a physical interaction. In our study, the OBT varied according to the following parameters: the crystalline lens itself, varying from 4.2 to 7.6 μJ (mean, 5.1 μJ), and the depth of laser focus, varying up to 1 μJ, increasing in the depth of the tissue. Analyzing the distance between impacts, we observed that the closer the impacts were the less power was needed to create a clear well-drawn defect pattern (lines), i.e., with a 4-μJ optimized OBT, when the impacts were placed every 2 μm for the x,y directions and 60 μm for the z direction. Coalescent bubbles created by plasma formation always disappeared in less than 24h. The nonthermal effect of plasma and the innocuousness on surrounding tissues were proven by the TEM results. The crystalline lens photodisruption by the femtosecond laser seems an innovative

  10. Experimental study on mechanical properties of aircraft honeycomb sandwich structures

    Directory of Open Access Journals (Sweden)

    Talebi Mazraehshahi H.


    Full Text Available Mechanical behaviour of sandwich panels under different conditions have been exprimentally studied in this research to increase the knowledge of aircraft sandwich panel structures and facilitate design criteria for aircraft structures. Tests were concentrated on the honeycomb sandwich structures under different loads including flexural, insert shear, flat wise tension and compression loads. Furthermore, effect of core density and face material on mechanical behavior of different samples were investigated and compared with analytical and FEM method. Effects of skin thickness on strength of honycomb sandwhich panels under shear pull out and moments have also been considerd in this study. According to this investigation, insert strength and flexural test under different load conditions is strongly affected by face thickness, but compression and tearoff (falt wise tensile properties of a sandwich panel depends on core material. The study concludes that the correlation between experimental results and the analytical predictions will enable the designer to predict the mechanical behaviour and strength of a sandwich beam; however, applied formula may lead engineers to unreliable results for shear modulus.

  11. Designing Awe in Virtual Reality: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Alice Chirico


    Full Text Available Awe is a little-studied emotion with a great transformative potential. Therefore, the interest toward the study of awe’s underlying mechanisms has been increased. Specifically, researchers have been interested in how to reproduce intense feelings of awe within laboratory conditions. It has been proposed that the use of virtual reality (VR could be an effective way to induce awe in controlled experimental settings, thanks to its ability of providing participants with a sense of “presence,” that is, the subjective feeling of being displaced in another physical or imaginary place. However, the potential of VR as awe-inducing medium has not been fully tested yet. In the present study, we provided an evidence-based design and a validation of four immersive virtual environments (VEs involving 36 participants in a within-subject design. Of these, three VEs were designed to induce awe, whereas the fourth VE was targeted as an emotionally neutral stimulus. Participants self-reported the extent to which they felt awe, general affect and sense of presence related to each environment. As expected, results showed that awe-VEs could induce significantly higher levels of awe and presence as compared to the neutral VE. Furthermore, these VEs induced significantly more positive than negative affect. These findings supported the potential of immersive VR for inducing awe and provide useful indications for the design of awe-inspiring virtual environments.

  12. Theoretical and experimental study of fiber-optic fluorescence immunosensors (United States)

    Cao, He

    This dissertation investigates the optical detection of antigens (in this case, food pathogens such as Salmonella) with fiber-optic immunosensors. The major techniques used for this optical detection include: (1)Linking the antigens to some physical tracers that can be optically detected; (2)Collecting and transmitting the optical signal to an optical detector. From an optical point of view, the problem is a nonimaging-optics problem to collect a fluorescent signal from an extended Lambertian source and deliver it to an optical detection system with maximum energy transfer and distinct wavelength separation. A raytrace model of the optical detection system was used for numerical simulations to analyze and optimize the optical design. The result leads to an improvement of the optical detection. Related physical problems such as magnetic focusing effect, fluorescence detection, and wavelength separation have also been studied in detail. With the adoption of a single-step immunomagnetic assay, experimental studies have been conducted for the detection of Salmonella, with a dual- fiber optical probe and tapered tubular waveguide probes. The test results have shown that the detection system gives detection limit of approximately 106 CFU/ml with dual-fiber optical probes, and 105 CFU/ml with improved tubular waveguide probes. The system developed for this research project is designed as a cost-effective portable instrument that may be used for field-testing. Rapid and on-site detection, low cost instrumentation and a reusable optical probe have been emphasized throughout the study.

  13. [Comparative estimation of antilithogenic activity of porcine kidney derived biomedical substance and sodium citrate in experimental urolithiasis]. (United States)

    Pavlyashik, G V; Zharikov, A Yu; Kiselev, V I


    to compare the anti-lithogenic activity of biomedical substance derived from freeze-dried porcine kidney and sodium citrate. The experiments were conducted on Wistar rats divided into three groups of 15 animals each: control group (disease control), comparison group (sodium citrate treatment) and experimental group (treatment with biomedical substance from porcine kidneys). Experimental urolithiasis was modeled using the ethylene glycol model. On every 7th day of the 6 week experiment testing was done calcium and oxalate urine concentration and the activity of marker enzymes of renal epithelial damage: lactate dehydrogenase (LDH), -glutamyl transferase (GGT), and N-acetyl--D-glucosaminidase (NAG). At the end of the experiment, a part of the rats were decapitated and the renal tissue was tested for the oxidant status indicators of (renal thiobarbiturate reactive product content, TBRP, and total prooxidant activity, TPA) and antioxidant enzyme activities: glutathione peroxidase (GPO), superoxide dismutase (SOD) and catalase (CAT). To measure the number and size of calcium deposits formed in the renal papillary area, the Koss histochemical method was used. The experimental findings showed developing oxalate nephrolithiasis in the control group, as indicated by urinary supersaturation of oxalate ion, increased activity of marker enzymes, oxidative stress and the formation of numerous calcium deposits in the renal papillary area. In the comparison group, the 3-week use of sodium citrate contributed to a significant decrease in nephrolithiasis: a 3 to 4-fold decrease in the activity of marker enzymes in the urine, a 3.8-fold increase in the concentration of TBRP, normalization of GPO activity; the number and size of urinary calcium deposits decreased by 3.4 and 1.9 times, respectively. In the experimental group, using biomedical substance led to an even greater therapeutic effect. LDH activity and concentration of TPRP showed 1.9 times and by 26.2% greater decrease than

  14. Insights on the role of accurate state estimation in coupled model parameter estimation by a conceptual climate model study (United States)

    Yu, Xiaolin; Zhang, Shaoqing; Lin, Xiaopei; Li, Mingkui


    The uncertainties in values of coupled model parameters are an important source of model bias that causes model climate drift. The values can be calibrated by a parameter estimation procedure that projects observational information onto model parameters. The signal-to-noise ratio of error covariance between the model state and the parameter being estimated directly determines whether the parameter estimation succeeds or not. With a conceptual climate model that couples the stochastic atmosphere and slow-varying ocean, this study examines the sensitivity of state-parameter covariance on the accuracy of estimated model states in different model components of a coupled system. Due to the interaction of multiple timescales, the fast-varying atmosphere with a chaotic nature is the major source of the inaccuracy of estimated state-parameter covariance. Thus, enhancing the estimation accuracy of atmospheric states is very important for the success of coupled model parameter estimation, especially for the parameters in the air-sea interaction processes. The impact of chaotic-to-periodic ratio in state variability on parameter estimation is also discussed. This simple model study provides a guideline when real observations are used to optimize model parameters in a coupled general circulation model for improving climate analysis and predictions.

  15. Studies on experimental models used for nutritional and biological ...

    African Journals Online (AJOL)

    The anatomical location for a successful implantation in order to reduce complications to the hearest minimum has been suggested . The maintenance of the implanted cannulae for the purpose of keeping the modified experimental model in perfect health is discussed. Key Words: Experimental Models, Nutritional Biological ...

  16. An Experimental Study on Wall Thickness Distribution in Thermoforming

    Directory of Open Access Journals (Sweden)

    Sencer Süreyya Karabeyoglu


    Full Text Available In this work, Polystyrene (PS sheets were thermoformed in predetermined conditions. Wall thickness distributions obtained by experimental method in PS thermoformed products. Then same thickness distributions were predicted by using Geometric Element Analysis (GEA. The thickness results which obtained experimentally, compared to thickness distributions which were predicted by GEA. It has been found that GEA does not reveal thickness distributions precisely.

  17. [Study on spectrum characteristics of cotton leaf and its estimating with remote sensing under aphid stress]. (United States)

    Chen, Bing; Wang, Ke-ru; Li, Shao-kun; Jing, Xia; Chen, Jiang-lu; Su, Yi


    The spectrum and physical-chemical parameters were measured on cotton leaves infected by aphid with different severity levels (SL) at main cotton growth periods. Meanwhile, the reflectance and physical-chemical parameters of cotton leaves infected by aphid were analyzed and compared in different cotton growth periods and varieties. The sensitivity wave bands of cotton leaves infected by aphid were confirmed, and the estimating models of leaves infected by aphid were established. The results showed that there was a significant difference in the spectrum and physical-chemical parameters of cotton leaves infected by aphid. The thickness, water and Chl. b increased, while Chla, Chl. a+b and Cars content decreased in leaves infected by aphid. Besides, in visible region, the reflectance of cotton leaves infected by aphid has shown going up first and then down in different cotton growth periods and varieties with increasing of SL. However, in NIR region, it has shown discrepancy in varieties. The 434-727 and 648 nm can be used as sensitive and optimal aphid-band for cotton leaves. Estimation models for leaves infected by aphid were all in significant correlation. Among all the models, the model of (R1 589-R648)/ (R1 589+R648) had the best estimation precision, RE was the smallest (0.128), and it was commended as best models to estimate SL of leaves infected by aphid. The study provides an experimental reference for monitoring spectrum of cotton infected by aphid with remote sensing in large areas.

  18. A "self adhering" prosthesis for hernia repair: experimental study. (United States)

    Champault, G; Polliand, C; Dufour, F; Ziol, M; Behr, L


    Prosthetic reinforcement is now routine in the management of inguinal and incisional hernia, and it significantly reduces the risk of recurrence. After surgery, chronic pain is often attributed to the characteristics of the mesh and to the method of fixation in the wound, with a potential risk of nerve or muscle injuries. To evaluate the properties of a new "self adhering" prosthesis in an experimental animal study. The self adhering prosthesis, a lightweight (40 mg/m(2)) polypropylene mesh coated with a synthetic glue on one side, was implanted laparoscopically in pigs. Removal of the prosthesis was performed at one day, one week and one month post operatively. A macroscopic and microscopic evaluation was performed. The results, using a quantitative score, were compared to those of a control group using the same polypropylene mesh without glue, but fixed by staples. The operative time was significantly lower in the self adhering group: 23 min (15-32) versus 31 min (21-40) (P = 0.01). The average time interval from the introduction of the mesh into the preperitoneal space until the appearance of the first tough adhesion was 3 min (2-4). In the control group, the mesh handling time was 8.3 min (5-14) (P = 0.01). At the time of implantation, the score was at a maximum value in all cases for the self adhering prostheses, especially concerning handling and adhesiveness. Upon removal, this score was noted to be good or very good in 90-100% of the cases. There was a good integration in the muscle confirmed histologically, and there was no shrinkage, no mobilisation and no migration. At one month, the thickness of the fibrosis at the limits of the meshes was significantly higher for the self adhering prostheses (P = 0.02). In this experimental study, the self adhering prosthesis demonstrated its adhesive properties and its ability to be well tolerated, with a good macroscopic and microscopic integration into the abdominal wound. This should allow us to perform a clinical

  19. Experimental and theoretical study of delayed ettringite damage in concrete (United States)

    Ramadan, Elsaid Osman


    An experimental study is conducted to investigate the effect of a range of parameters on concrete expansion and premature deterioration associated with delayed ettringite formation (DEF). These parameters were identified from a comprehensive literature review; they include concrete curing conditions and cement chemistry. Specifically, the study investigated the effect of potassium and magnesium contents as well as the effect of water and steam curing conditions on concrete damage associated with DEF. An accelerated test method for DEF was evaluated and modifications are suggested. Concrete specimens were prepared with varying amounts of potassium and magnesium and subjected to different curing conditions. To accelerate any potential expansion, a beat cycle was employed. The change in length of the specimens was monitored for the duration of the study. Specimens were analyzed using the scanning electron microscope, x-ray dispersive analysis, and x-ray diffraction to determine the mechanism responsible for deterioration. Computed tomography x-ray was also employed as a non-destructive method for examining the internal crack patterns associated with expansion. The expansion data is fitted using the Kohnogorov-Avrami-Johenson-Mehl (KAJM) equation. This theory makes it possible to identify individual expansion processes and to identify the contribution of different expansion mechanisms. All concretes showed expansion following the beat cycle. Subjecting concrete to the heat cycle has a primary role in accelerating expansion. The age at which concrete is subjected to the beat cycle as well as the sample dimensions have a profound effect on the resulting expansion. The use of the concrete prisms as suggested in the modified test method offers a better alternative to cores suggested by Duggan. Increasing the potassium content has a deleterious effect on concrete expansion and premature deterioration and is also associated with dramatic reduction in compressive strength

  20. Theoretical and Experimental Study of Bimetal-Pipe Hydroforming. (United States)

    Dezhi, Zeng; Kuanhai, Deng; Taihe, Shi; Yuanhua, Lin; Hongjun, Zhu; Tianlei, Li; Yongxing, Sun


    The corrosion of oil country tubular goods (OCTG) gets more and more serious especially in the acidic environment. So, it is very important to develop a perfect anticorrosion technology for exploring sour oil and gas fields economically and safely. Analysis indicates that the bimetal-pipe (BP) which consists of the base layer of low carbon steel and a corrosion resistant alloy (CRA) cladding layer is an economic and reliable anticorrosion technology and has broad application prospects in the transportation of acid medium. However, theoretical study of hydraulic expansion mechanism for BP is not enough. In this paper, the deformation compatibility condition of BP was obtained by studying the deformation rule of the (CRA) liner and the outer pipe of carbon steel in the forming process; the mechanical model which can compute the hydroforming pressure of BP has been established based on the nonlinear kinematic hardening characteristics of material; furthermore, based on the stress strain curve of inner pipe simultaneously, the calculation method of the plastic hardening stress has been proposed. Thus, the accurate method for computing the forming pressure was obtained. The experimental data show that results are consistent with results of the proposed model. It indicates that the model can be used to provide theoretical guidance for the design and production as well as use of BP.

  1. Laser Experimental Study of the Surface Vibrations of EMUS Sensor (United States)

    Wilkie-Chancellier, N.; Wang, Y.; Martinez, L.; Roucaries, B.; Serfaty, S.

    In order to ensure a comprehensive monitoring of the material structuration in liquid phase, the traditional ultrasonic techniques require excitation in contact which is often inadequate for online tracking. To monitor the material evolution remotely, a new electromagnetic ultrasonic sensor (EMUS) was successfully developed in our laboratory. The EMUS transducer is based on a resonant thickness shear mode sensor (TSM) magnetically coupled to a high frequency antenna. The TSM resonator consists in a piezoelectric AT-cut quartz plate with metal electrodes on opposite sides. The application of a radio frequency electrical signal gives rise to the excitation of a shear mechanical resonance. The work presented here allows characterizing the acoustic behavior of the EMUS. A laser vibrometer is used to scan the surface of the TSM resonator and visualize the propagation of the generated surface waves. This study shows a good agreement between experimental and theoretical results which encourages the study of acoustic interaction between the TSM resonator and a material in contact with the quartz surface. They therefore suggest that this non-destructive technique can be used to extract the viscoelastic properties of materials.

  2. A Perspective on the Experimental Techniques for Studying Lamins

    Directory of Open Access Journals (Sweden)

    Ilaria Pecorari


    Full Text Available Lamins are type V intermediate filaments that collectively form a meshwork underneath the inner nuclear membrane, called nuclear lamina. Furthermore, they are also present in the nucleoplasm. Lamins are experiencing a growing interest, since a wide range of diseases are induced by mutations in the gene coding for A-type lamins, globally known as laminopathies. Moreover, it has been demonstrated that lamins are involved in other pathological conditions, like cancer. The role of lamins has been studied from several perspectives, exploiting different techniques and procedures. This multidisciplinary approach has contributed to resolving the unique features of lamins and has provided a thorough insight in their role in living organisms. Yet, there are still many unanswered questions, which constantly generate research in the field. The present work is aimed to review some interesting experimental techniques performed so far to study lamins. Scientists can take advantage of this collection for their novel investigations, being aware of the already pursued and consolidated methodologies. Hopefully, advances in these research directions will provide insights to achieve better diagnostic procedures and effective therapeutic options.

  3. [Muscular control of scapholunate instability. An experimental study]. (United States)

    León-López, M M; García-Elías, M; Salvà-Coll, G; Llusá-Perez, M; Lluch-Bergadà, A


    As long as the neuromuscular stabilizers are intact, a lesion of the scapholunate ligament may or may not progress to a carpal instability. The mechanisms by which the muscles compensate this defect are not very well known. We designed an experimental study with the aim of clarifying these mechanisms. Using 10 fresh wrists, with no pre-existing lesions, we studied the movements of the scaphoid, triquetrum and capitate produced by the isometrical loading of the muscles which move the wrist, each of them isolated or combined, before and after cutting off the scapholunate ligaments. To do this, we placed sensors in each of these bones and used the Fastrack system to record these movements. The simultaneous loading of the muscles of the wrist produce rotational movements in flexion and supination of the proximal carpal row. After cutting off the scapholunate ligaments, the scaphoid rotates in pronation and flexion, while the triquetrum rotates in pronation and extension. In this situation of a scapholunate lesion, the muscles that worsen the carpal dexasation are the extensor carpi ulnaris and flexor carpi ulnaris. On the other hand, the isolated loading of the radial muscles reduce the scapholunate diastasis, thus improving the carpal alignment. In dynamic scapholunate instabilities, isometric contraction of the ulnar carpal muscles must be avoided, as it promotes the scapholunate diastasis. The rest of the muscles have the opposite effect, stabilizing the carpus when primary stabilizers have failed. Copyright © 2013 SECOT. Published by Elsevier Espana. All rights reserved.

  4. A retrievable nitinol endobronchial stent : an experimental study in dog

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Sang Jin; Park, Sang Soo; Yoon, Hyun Ki; Sung, Kyu Bo; Song, Ho Young [Asan Medical Center, Ulsan Univ. College of Medicine, Seoul (Korea, Republic of); Kang, Sung Gwon [Inha Univ. College of Medicine, Inchon (Korea, Republic of)


    The purpose of this study was to evaluate the safety and the retrievability of a new covered retrievable nitinol tracheobronchial stent. Stents were knitted from 0.2mm nitinol wire, covered with polyurethane, and were 20-22mm in diameter and 2cm in length. Under fluoroscopic guidance, a stent was placed in the normal right bronchus intermedius of ten dogs. Using a retrieval hook, stent retrieval was attempted after 1 month(N=5) or 2 months(N=5). After removal, the dogs were sacrificed and their their tracheobronchial trees were examined grossly and histologically. Eleven stents were successfully placed in ten dogs. Migration and expectoration occurred in four of ten stents in nine dogs(40%). Five stents were successfully removed from six dogs(83%). Without significant difference between the two groups, mild to moderate mucosal hyperplasia was noted at the sites of stents as well as above and below them. On microscopy, three of five dogs showed pneumonia in the right middle lobes, but none of the stents was covered with epithelium. Temporary placement of a covered expandable nitinol stent in the tracheobronchial tree is feasible, but to establish its efficacy, further experimental studies are needed.

  5. Cold-formed steel pallet rack connection: an experimental study (United States)

    Mohan, Vimal; Prabha, P.; Rajasankar, J.; Iyer, Nagesh R.; Raviswaran, N.; Nagendiran, V.; Kamalakannan, S. S.


    Industrial pallet rack systems are made up of three-dimensional structural arrangement using cold-formed steel members. The rack columns (upright) have perforations at prescribed intervals to facilitate the assemblage of beams with end connections. The tabs are used as connections which are engaged into the perforations and are in particular, highly semi-rigid in nature. Due to the diversity of rack systems, connecting member's stiffness and strength, it is almost impossible to develop a generalised model for analytical predication of the connection stiffness. This paper describes the beam-column connection tests carried out on a commercially available pallet rack system by adopting single cantilever test set-up. Thirty-five sets of combinations are identified based on the variation in upright profile and thickness, depth of beam and the connector to study the connection stiffness. Three tests were performed for each set to bring in uniformity in the result taking the total number of tests to 105. A full range parametric study is carried out to understand the influence of above said parameters on moment-rotation behaviour and the joint stiffness. The experimental results showed that an improved performance of the joint connection is achieved using connectors with more number of tabs, greater thickness and improved profile of the upright and larger depth of the beam.

  6. Estimating the parameters of the microheterogeneous structure of metal melts according to viscometric experimental data in terms of the absolute reaction rate theory (United States)

    Chikova, O. A.; Tsepelev, V. S.; Moskovskikh, O. P.


    The temperature dependences of the viscosity of microheterogeneous metal melts are analyzed in terms of the Frenkel-Eyring theory. Using viscometric experimental data, the sizes of dispersed particles in metal melts whose components undergo eutectic and monotectic interactions are numerically estimated.

  7. Nab: precise experimental study of unpolarized neutron beta decay (United States)

    Pocanic, Dinko; Nab Collaboration


    Nab, a program of experimental study of unpolarized neutron decays at the Spallation Neutron Source, Oak Ridge, TN, aims to determine a, the electron-neutrino correlation with precision of δa / a =10-3 , and b, the Fierz interference term, with uncertainty δb ~= 3 ×10-3 . Neutron beta decay's simple theoretical description in the Standard Model (SM) is overconstrained by the set of available observables, providing opportunities to search for evidence of SM extensions. Planned Nab results will lead to a new precise determination of the ratio λ =GA /GV , and to significant reductions in the allowed limits for both right- and left-handed scalar and tensor currents. Alternatively, the experiment may detect a discrepancy from SM predictions consistent with certain realizations of supersymmetry. An optimized, asymmetric spectrometer has been designed to achieve the narrow proton momentum response function required to meet the physics goals of the experiment. The apparatus is to be used in a follow-up measurement (ABba) of asymmetry observables A and B in polarized neutron decay. Nab is funded, now in the construction stage, with planned beam readiness in 2016. We discuss the experiment's motivation, expected reach, design and method. Nab, a program of experimental study of unpolarized neutron decays at the Spallation Neutron Source, Oak Ridge, TN, aims to determine a, the electron-neutrino correlation with precision of δa / a =10-3 , and b, the Fierz interference term, with uncertainty δb ~= 3 ×10-3 . Neutron beta decay's simple theoretical description in the Standard Model (SM) is overconstrained by the set of available observables, providing opportunities to search for evidence of SM extensions. Planned Nab results will lead to a new precise determination of the ratio λ =GA /GV , and to significant reductions in the allowed limits for both right- and left-handed scalar and tensor currents. Alternatively, the experiment may detect a discrepancy from SM

  8. Experimental and numeric study of aluminum wire explosion in vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Tkachenko, S.I.; Khattatov, T.A.; Tilikin, I.N. [MIPT, Dolgoprudny, Moscow Region (Russian Federation); Romanova, V.M.; Mingaleev, A.R.; Ter-Oganesyan, A.E.; Shelkovenko, T.A.; Pikuz, S.A. [P.N. Lebedev Physical Institute RAS, Moscow (Russian Federation); Olhovskaya, O.G.; Krukovskij, A.Y.; Gasilov, V.A.; Novikov, V.G. [IMM RAS, Moscow (Russian Federation)


    Full text of publication follows: Distribution of matter in the discharge channel formed upon a nanosecond electrical explosion of Al wire in vacuum was studied experimentally and theoretically. Several series of experiments with 25 {mu}m diameter 12 mm long wires were performed; the charging voltage, the current amplitude and current rise rate were U{sub 0} = 20 kV, Imax {approx} 10 kA and dI/dt = 50 A/ns, respectively [1]. 'Shadow and Schlieren' images of the discharge channel were obtained using optical probing at the second harmonic of a YAG: Nd{sup +3} laser ({lambda} = 0.532 {mu}m, {tau} {approx} 70 ps). Simultaneous use of optical and UV diagnostics made it possible to distinguish qualitatively different regions of the discharge channel, such as the current-carrying plasma layers and the region occupied by a weakly conducting cold matter. The simulations were performed using a program containing the Braginsky two temperature magnetic gas-dynamic model: Lagrange-Euler code RAZRYAD-2.5 [2] on the basis of homogeneous, conservative and implicit differences of MHD schemes. Radiation energy exchange is accounted for in a multi-group (from the spectrum) approximation, using a radiation diffusion model. Heat- and electro- conductivity anisotropy in magnetic field is taken into account. Tables of thermal-physical and optical properties of aluminum were used in calculations in the present work [3]. The influence of radiation on the distribution of the parameters of matter (temperature, density) and current density in the discharge channel was studied. Several variants with differing amounts of radiation of spectral groups were evaluated. The obtained results are compared with experimental data. This work was supported in part by the RFBR 08-08-00688, 09-02-01532, and the ESC FIAN.; [1]. S.I. Tkachenko et. al., Plasma Physics Reports, 2009, Vol. 35, No. 9, pp. 734-753; [2]. V.A. Gasilov et. al., Mathematical Modelling, 2003, v. 15, No 9, pp. 107-124; [3]. A

  9. Numerical and experimental studies of droplet-gas flow

    Energy Technology Data Exchange (ETDEWEB)

    Joesang, Aage Ingebret


    This thesis considers droplet-gas flow by the use of numerical methods and experimental verification. A commercial vane separator was studied both numerical and by experiment. In addition some efforts are put into the numerical analysis of cyclones. The experimental part contains detailed measurements of the flow field between a pair of vanes in a vane separator and droplet size measurements. LDA (Laser Doppler Anemometry) was used to measure the velocity in two dimensions and corresponding turbulence quantities. The results from the LDA measurements are considered to be of high quality and are compared to numerical results obtained from a CFD (Computational Fluid Dynamics) analysis. The simulation showed good agreement between the numerical and experimental results. Combinations of different turbulence models; the standard k-epsilon model and the Reynold Stress Mode, different schemes; first order and higher order scheme and different near wall treatment of the turbulence; the Law of the wall and the Two-Layer Zonal model were used in the simulations. The Reynold Stress Model together with a higher order scheme performed rather poorly. The recirculation in parts of the separator was overpredicted in this case. For the other cases the overall predictions are satisfactory. PDA (Phase Doppler Anemometry) measurements were used to study the changes in the droplet size distribution through the vane separator. The PDA measurements show that smaller droplets are found at the outlet than present at the inlet. In the literature there exists different mechanisms for explaining the re-entrainment and generation of new droplets. The re-entrainments mechanisms are divided into four groups where droplet-droplet interaction, droplet break-up, splashing of impinging droplet and re-entrainment from the film are defined as the groups of re-entrainment mechanisms. Models for these groups are found in the literature and these models are tested for re-entrainment using the operational

  10. Experimental designs for evaluation of genetic variability and selection of ancient grapevine varieties: a simulation study. (United States)

    Gonçalves, E; St Aubyn, A; Martins, A


    Classical methodologies for grapevine selection used in the vine-growing world are generally based on comparisons among a small number of clones. This does not take advantage of the entire genetic variability within ancient varieties, and therefore limits selection challenges. Using the general principles of plant breeding and of quantitative genetics, we propose new breeding strategies, focussed on conservation and quantification of genetic variability by performing a cycle of mass genotypic selection prior to clonal selection. To exploit a sufficiently large amount of genetic variability, initial selection trials must be generally very large. The use of experimental designs adequate for those field trials has been intensively recommended for numerous species. However, their use in initial trials of grapevines has not been studied. With the aim of identifying the most suitable experimental designs for quantification of genetic variability and selection of ancient varieties, a study was carried out to assess through simulation the comparative efficiency of various experimental designs (randomized complete block design, alpha design and row-column (RC) design). The results indicated a greater efficiency for alpha and RC designs, enabling more precise estimates of genotypic variance, greater precision in the prediction of genetic gain and consequently greater efficiency in genotypic mass selection.

  11. Study Design Rigor in Animal-Experimental Research Published in Anesthesia Journals. (United States)

    Hoerauf, Janine M; Moss, Angela F; Fernandez-Bustamante, Ana; Bartels, Karsten


    Lack of reproducibility of preclinical studies has been identified as an impediment for translation of basic mechanistic research into effective clinical therapies. Indeed, the National Institutes of Health has revised its grant application process to require more rigorous study design, including sample size calculations, blinding procedures, and randomization steps. We hypothesized that the reporting of such metrics of study design rigor has increased over time for animal-experimental research published in anesthesia journals. PubMed was searched for animal-experimental studies published in 2005, 2010, and 2015 in primarily English-language anesthesia journals. A total of 1466 publications were graded on the performance of sample size estimation, randomization, and blinding. Cochran-Armitage test was used to assess linear trends over time for the primary outcome of whether or not a metric was reported. Interrater agreement for each of the 3 metrics (power, randomization, and blinding) was assessed using the weighted κ coefficient in a 10% random sample of articles rerated by a second investigator blinded to the ratings of the first investigator. A total of 1466 manuscripts were analyzed. Reporting for all 3 metrics of experimental design rigor increased over time (2005 to 2010 to 2015): for power analysis, from 5% (27/516), to 12% (59/485), to 17% (77/465); for randomization, from 41% (213/516), to 50% (243/485), to 54% (253/465); and for blinding, from 26% (135/516), to 38% (186/485), to 47% (217/465). The weighted κ coefficients and 98.3% confidence interval indicate almost perfect agreement between the 2 raters beyond that which occurs by chance alone (power, 0.93 [0.85, 1.0], randomization, 0.91 [0.85, 0.98], and blinding, 0.90 [0.84, 0.96]). Our hypothesis that reported metrics of rigor in animal-experimental studies in anesthesia journals have increased during the past decade was confirmed. More consistent reporting, or explicit justification for absence

  12. Sustaining a Global Social Network: a quasi-experimental study. (United States)

    Benton, D C; Ferguson, S L


    To examine the longer term impact on the social network of participating nurses in the Global Nursing Leadership Institute (GNLI2013) through using differing frequencies of follow-up to assess impact on maintenance of network cohesion. Social network analysis is increasingly been used by nurse researchers, however, studies tend to use single point-in-time descriptive methods. This study utilizes a repeated measures, block group, control-intervention, quasi-experimental design. Twenty-eight nurse leaders, competitively selected through a double-blind peer review process, were allocated to five action learning-based learning groups. Network architecture, measures of cohesion and node degree frequency were all used to assess programme impact. The programme initiated and sustained connections between nurse leaders drawn from a geographically dispersed heterogeneous group. Modest inputs of two to three e-mails over a 6-month period seem sufficient to maintain connectivity as indicated by measures of network density, diameter and path length. Due to the teaching methodology used, the study sample was relatively small and the follow-up data collection took place after a relatively short time. Replication and further cohort data collection would be advantageous. In an era where many policy solutions are being debated and initiated at the global level, action learning leadership development that utilizes new technology follow-up appears to show significant impact and is worthy of wider application. The approach warrants further inquiry and testing as to its longer term effects on nursing's influence on policy formulation and implementation. © 2016 International Council of Nurses.

  13. X-Ray Fluorescence to Estimate the Maximum Temperature Reached at Soil Surface during Experimental Slash-and-Burn Fires. (United States)

    Melquiades, Fábio L; Thomaz, Edivaldo L


    An important aspect for the evaluation of fire effects in slash-and-burn agricultural system, as well as in wildfire, is the soil burn severity. The objective of this study is to estimate the maximum temperature reached in real soil burn events using energy dispersive X-ray fluorescence (EDXRF) as an analytical tool, combined with partial least square (PLS) regression. Muffle-heated soil samples were used for PLS regression model calibration and two real slash-and-burn soils were tested as external samples in the model. It was possible to associate EDXRF spectra alterations to the maximum temperature reached in the heat affected soils with about 17% relative standard deviation. The results are promising since the analysis is fast, nondestructive, and conducted after the burn event, although local calibration for each type of burned soil is necessary. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  14. Landfill Lifespan Estimation: A Case Study | Akyen | Ghana Mining ...

    African Journals Online (AJOL)

    Mathematical models or expressions have also been suggested in literature as an alternative approach to the estimation of landfills lifespan. This research used the future value of money equation to estimate the lifespan of the Aboso landfill in Tarkwa, Ghana. The result showed that the landfill could operate for the next ...

  15. Experimental Liquefaction Study of Southern Yogyakarta Using Shaking Table

    Directory of Open Access Journals (Sweden)

    Lindung Zalbuin Mase


    Full Text Available An experimental study using shaking table was conducted to learn liquefaction. Samples used were sandy soils from South of Yogyakarta Special Region Province. Analysis of liquefaction potential was performed by considering several factors, i.e. peak ground acceleration (PGA of 0.3 g to 0.4 g, vibrational frequency of 1.8 Hz, and vibration duration of 8, 16, and 32 seconds which reflect earthquake magnitudes of 5, 6, and 7. The pore water pressure was measured by using a pressure transducer. Liquefaction potential was determined by using the parameter of excess pore water pressure ratio (ru. Liquefaction potentially occurred when ru > 1, whereas ru < 1 indicated liquefaction didn’t occur. The results of test showed that liquefaction potentially occur in each applied dynamic load, that maximum excess pore wate pressure (ru max measured was equal to or larger than 1. The larger peak ground acceleration applied, the faster beginning time of liquefaction. The bigger peak ground acceleration applied, the slower dissipation time of pore water pressure. The duration of liquefaction become longer, along with the increase of applied peak ground acceleration. The bigger applied peak ground acceleration, the larger maximum excess pore water pressure.

  16. Experimental Study of Fast Neutron Irradiation on Si Transistor

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Sung Ho; Sun, Gwang Min; Baek, Ha ni; Jin, Seong Bok; Hoang, Sy Minh Tuan [KAERI, Daejeon (Korea, Republic of)


    Bipolar junction transistors (BJTs) are applied in many industrial fields. BJT is a three-terminal device with an important feature in that the current through two terminals can be controlled by small changes we make in the current or voltage at the third terminal. This control feature allows us to amplify small AC signals or to switch the device from an on state and off state and back. These two operations, amplification and switching, are the basis of a host of electronic functions. This study will investigate the electrical characteristics of a p-n-p BJT, such as the base current and collector current for fast neutron irradiation. Fast neutron irradiation can cause displacement damage in the Si bulk. In this paper, the electrical characteristics of a p-n-p BJT such as a base current and collector current are investigated for fast neutron irradiation. The experimental results show that the base current is increased and the collector current is decreased after fast neutron irradiation. These results indicate that the displacement damage caused by fast neutron irradiation increases the recombination rate of minority carriers and resistors.

  17. Experimental study of two-phase natural circulation circuit

    Energy Technology Data Exchange (ETDEWEB)

    Lemos, Wanderley Freitas; Su, Jian, E-mail:, E-mail: [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Faccini, Jose Luiz Horacio, E-mail: [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), RIo de Janeiro, RJ (Brazil). Lab. de Termo-Hidraulica Experimental


    This paper reports an experimental study on the behavior of fluid flow in natural circulation under single-and two-phase flow conditions. The natural circulation circuit was designed based on concepts of similarity and scale in proportion to the actual operating conditions of a nuclear reactor. This test equipment has similar performance to the passive system for removal of residual heat presents in Advanced Pressurized Water Reactors (A PWR). The experiment was carried out by supplying water to primary and secondary circuits, as well as electrical power resistors installed inside the heater. Power controller has available to adjust the values for supply of electrical power resistors, in order to simulate conditions of decay of power from the nuclear reactor in steady state. Data acquisition system allows the measurement and control of the temperature at different points by means of thermocouples installed at several points along the circuit. The behavior of the phenomenon of natural circulation was monitored by a software with graphical interface, showing the evolution of temperature measurement points and the results stored in digital format spreadsheets. Besides, the natural circulation flow rate was measured by a flowmeter installed on the hot leg. A flow visualization technique was used the for identifying vertical flow regimes of two-phase natural circulation. Finally, the Reynolds Number was calculated for the establishment of a friction factor correlation dependent on the scale geometrical length, height and diameter of the pipe. (author)

  18. A molecular machine biosensor: construction, predictive models and experimental studies. (United States)

    Moradi-Monfared, Sahar; Krishnamurthy, Vikram; Cornell, Bruce


    This paper describes the construction, operation and predictive modeling of a molecular machine, functioning as a high sensitivity biosensor. Embedded gramicidin A (gA) ionchannels in a self-assembled tethered lipid bilayer act as biological switches in response to target molecules and provide a signal amplification mechanism that results in high sensitivity molecular detection. The biosensor can be used as a rapid and sensitive point of care diagnostic device in different media such as human serum, plasma and whole blood without the need for pre and post processing steps required in an enzyme-linked immunosorbent assay. The electrical reader of the device provides the added advantage of objective measurement. Novel ideas in the construction of the molecular machine, including fabrication of biochip arrays, and experimental studies of its ability to detect analyte molecules over a wide range of concentrations are presented. Remarkably, despite the complexity of the device, it is shown that the response can be predicted by modeling the analyte fluid flow and surface chemical reactions. The derived predictive models for the sensing dynamics also facilitate determining important variables in the design of a molecular machine such as the ion channel lifetime and diffusion dynamics within the bilayer lipid membrane as well as the bio-molecular interaction rate constants. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Experimental study on behavior of steel channel strengthened with CFRP

    Directory of Open Access Journals (Sweden)

    Tang Hongyuan


    Full Text Available This paper describes the behaviour of axially loaded long and eccentrically loaded short thin-walled steel channels, strengthened with transversely bonded carbon fibre reinforced polymer (CFRP sheets. Seven long members, each 1400 mm long, and seven short members, each 750mmlong, were tested. The main parameters were the number of CFRP plies (one or two and the clear spacing between the CFRP strips (50, 100 or 150 mm. The effect of CFRP sheet layer and clear spacing was studied. All the ultimate load capacity of the reinforced members was improved in different extent. A maximum strength gain of 9.13% was achieved for long members with two CFRP layers and 50 mm spacing of CFRP strips. The experimental results show that the global buckling happens to all the long specimens. For short members, the maximum strength gain of 12.1% was achieved with two CFRP layers and 50 mm spacing of CFRP strips. With the exception of the most heavily reinforced (2 plies at 50 and 100 mm, local buckling was observed prior to global buckling for short members, which was completely opposite of the control specimens. Meanwhile, when the clear spacing of CFRP strips is greater than theweb height of steel channel, the transversely bonded CFRP does not have a significant improvement in buckling load capacity of the short- and long-channel components. While the clear spacing is less than the web height, the more number of CFRP layer, the more enhancement of buckling load capacity.

  20. Augmented reality in bone tumour resection: An experimental study. (United States)

    Cho, H S; Park, Y K; Gupta, S; Yoon, C; Han, I; Kim, H-S; Choi, H; Hong, J


    We evaluated the accuracy of augmented reality (AR)-based navigation assistance through simulation of bone tumours in a pig femur model. We developed an AR-based navigation system for bone tumour resection, which could be used on a tablet PC. To simulate a bone tumour in the pig femur, a cortical window was made in the diaphysis and bone cement was inserted. A total of 133 pig femurs were used and tumour resection was simulated with AR-assisted resection (164 resection in 82 femurs, half by an orthropaedic oncology expert and half by an orthopaedic resident) and resection with the conventional method (82 resection in 41 femurs). In the conventional group, resection was performed after measuring the distance from the edge of the condyle to the expected resection margin with a ruler as per routine clinical practice. The mean error of 164 resections in 82 femurs in the AR group was 1.71 mm (0 to 6). The mean error of 82 resections in 41 femurs in the conventional resection group was 2.64 mm (0 to 11) (p Augmented reality in bone tumour resection: An experimental study. Bone Joint Res 2017;6:137-143. © 2017 Cho et al.

  1. Inflation of stressed cylindrical tubes: an experimental study (United States)

    Guo, Zhiming; Wang, Shibin; Li, Linan; Ji, Hongwei; Wang, Zhiyong; Cai, Songbao


    The inflation of an initially stressed cylindrical shell provides a good illustration of the phenomenon of the initiation and propagation of an instability, which shares the same mathematical and mechanical features with a variety of other strain localization phenomena in engineering structures and materials. The high speed CCD camera and digital image processing system were used to measure the 3D shape of the inflated cylindrical tube. The localized bulge of a cylindrical tube with closed ends forms when the internal pressure reaches a critical value Pcr. As more air is filled into the tube, the pressure drops but the radius at the centre of the bulge will increase until it reaches a maximum value rmax. With continued inflation, the pressure stays at a constant value Pp. The purpose of this study is to investigate the critical and propagation pressures in the tubes and the profile outside when the shells under axial tension and internal pressure were inflating. We focus on the influence of the axial tension on the critical pressure. In this paper the problem is explored through experimental efforts. A series of experiments were conducted on commercially available natural rubber latex tubes involving different geometries and initial axial tensions, which were regarded as isotropic, homogeneous, incompressible and hyper-elastic materials.

  2. Experimental Study on Effect of Electrode Location on Ion Current

    Directory of Open Access Journals (Sweden)

    Xu Hanqing


    Full Text Available In an attempt to use ion current method on a suction flame holder for combustion diagnosis, the position of the detection electrode that has the significant effect on ion current, should be investigated. The objective of this study was to experimentally investigate the ion current distribution in different combustion zones by changing the electrode length and streamwise location. An ion current acquisition system was built on basis of the principle of Langmuir probe, and experiments were conducted under different fuel-air ratios ranging from 0.008~0.022. The results suggest that the ion current distribution obeys the same regulation at different fuel-air ratios. With the electrode length increasing, the ion current increases first, then decreases, and finally presents a unimodal curve. As the electrode streamwise location increases, the ion current demonstrates a linear decrease rule. The maximum ion current is obtained in the case that the electrode length and streamwise location equals 60mm and 0.75. Since the larger ion current provides the wider range for setting the misfire threshold, the position where the maximum ion current occurs can be a better choice for arranging the electrode.

  3. Experimental studies on power transformer model winding provided with MOVs

    Directory of Open Access Journals (Sweden)

    G.H. Kusumadevi


    Full Text Available Surge voltage distribution across a HV transformer winding due to appearance of very fast rise time (rise time of order 1 μs transient voltages is highly non-uniform along the length of the winding for initial time instant of occurrence of surge. In order to achieve nearly uniform initial time instant voltage distribution along the length of the HV winding, investigations have been carried out on transformer model winding. By connecting similar type of metal oxide varistors across sections of HV transformer model winding, it is possible to improve initial time instant surge voltage distribution across length of the HV transformer winding. Transformer windings with α values 5.3, 9.5 and 19 have been analyzed. The experimental studies have been carried out using high speed oscilloscope of good accuracy. The initial time instant voltage distribution across sections of winding with MOV remains nearly uniform along length of the winding. Also results of fault diagnostics carried out with and without connection of MOVs across sections of winding are reported.

  4. Attentional bias in snus users: an experimental study.

    Directory of Open Access Journals (Sweden)

    Rune Aune Mentzoni

    Full Text Available The use of nicotine in the form of "snus" is substantial and increasing in some geographic areas, in particular among young people. It has previously been suggested that addictions may operate through a mechanism of attentional bias, in which stimuli representative of the dependent substance increase in salience, thus increasing the addictive behavior. However, this hypothesis has not been tested for the case of snus. The current experiment used a modified Stroop task and a dot-probe task to investigate whether 40 snus users show an attentional bias towards snus-relevant stimuli, compared to 40 non-snus users. There were no significant differences between the two groups on reaction times or accuracy on either Stroop or dot-probe task, thus failing to show an attentional bias towards snus-relevant stimuli for snus users. This could imply that other mechanisms may contribute to maintenance of snus use than for other addictions. However, this is the first experimental study investigating attentional bias in snus users, and more research is warranted.

  5. Experimental study of drop impacts on soap films (United States)

    Yawar, Ali; Basu, Saikat; Concha, Andres; Bandi, Mahesh


    Impinging drops on flowing and static soap films demonstrate at least three distinct types of impact regimes: (a) the drop bounces off the film surface, (b) it coalesces with the downstream flow for a moving film and for static films it gets assimilated within the film, and (c) it pierces through the film. The interaction presents a unique opportunity to explore the impact of a quasi one-dimensional object on a two-dimensional fluid, much like a comet impacting on a thin atmosphere. We present a detailed experimental study of droplet impacts on soap film flow, for a number of film inclination angles and falling heights of the drop. Imaging techniques employed include sodium lamp interferometry to measure film thickness fluctuations and particle tracking velocimetry to measure the velocity field. Film thickness measures approximately 10 microns and the drop diameter is 1 mm. We mostly observe the bouncing-off regime for smaller inclination angles. However, at higher impact angles, puncturing of the film becomes a more common occurrence. We show that when the drop bounces off the film, there is a momentum transfer leading to vortex dipole shedding, along with the generation of capillary waves; an impulsive regime that may share correspondence with the locomotion of water striders.

  6. Immunology and Homeopathy. 3. Experimental Studies on Animal Models

    Directory of Open Access Journals (Sweden)

    Paolo Bellavite


    Full Text Available A search of the literature and the experiments carried out by the authors of this review show that there are a number of animal models where the effect of homeopathic dilutions or the principles of homeopathic medicine have been tested. The results relate to the immunostimulation by ultralow doses of antigens, the immunological models of the ‘simile’, the regulation of acute or chronic inflammatory processes and the use of homeopathic medicines in farming. The models utilized by different research groups are extremely etherogeneous and differ as the test medicines, the dilutions and the outcomes are concerned. Some experimental lines, particularly those utilizing mice models of immunomodulation and anti-inflammatory effects of homeopathic complex formulations, give support to a real effect of homeopathic high dilutions in animals, but often these data are of preliminary nature and have not been independently replicated. The evidence emerging from animal models is supporting the traditional ‘simile’ rule, according to which ultralow doses of compounds, that in high doses are pathogenic, may have paradoxically a protective or curative effect. Despite a few encouraging observational studies, the effectiveness of the homeopathic prevention or therapy of infections in veterinary medicine is not sufficiently supported by randomized and controlled trials.

  7. Ileoanal anastomosis with proximal ileal reservoir: an experimental study. (United States)

    Schraut, W H; Block, G E


    Endorectal ileoanal anastomosis with proximal interposition of an ileal reservoir was evaluated experimentally in dogs as an approach to retain sphincteric control of defecation after proctocolectomy. Two months after the operative procedure, eight animals with a reservoir had four to eight semisolid stools per day and were continent. In contrast, six animals with straight ileoanal anastomosis were incontinent with 10 to 14 evacuations per day. Motility studies demonstrated a reduction of propulsive peristalsis within the undistended reservoir, which is considered the responsible factor for increased intestinal transit time and reduced stool frequency. Filling of the reservoir to capacity elicited strong peristaltic contractions, which may assure a more complete evacuation of the reservoir during defecation. Reservoir capacity increased substantially (150% to 200%) within 2 months but only to a minor degree thereafter, indicating that the reservoir does not dilate progressively into an atonic viscus. Motility patterns remained unaltered as the reservoir became more complaint with time. Mucosal alterations (flattening of villi, submucosal inflammation) were detected in the reservoir but did not result in nutritional defects within an observation period of 1 year.

  8. Experimental study of liquid drop impact onto a powder surface

    KAUST Repository

    Marston, Jeremy


    The initial dynamics of liquid drop impact onto powder surfaces is studied experimentally using high-speed photography. For a range of bed packing fractions, φ, liquid physical properties and impact velocities, ui, we observe a variety of phenomena that can be representative of a hydrophobic surface, a rough surface or a porous medium. The solids packing fraction in the bed, 0.38≤φ≤0.65, and the impact Weber number, 3.5≤We=ρDui 2/φ≤750, (where ρ, D and φ are the drop density, diameter and surface tension respectively) are shown to be the critical parameters governing the outcome of an impact. For high packing fractions, φ≳0.5, we show that the observed spreading, rebound and splashing can be broadly characterised in terms of the Weber number while for looser packing fractions, φ≲0.5, we observe powder ejectas and provide a qualitative description of the granule nucleation at the centre of the impact sites. © 2010 Elsevier B.V.

  9. Experimental study on titanium wire drawing with ultrasonic vibration. (United States)

    Liu, Shen; Shan, Xiaobiao; Guo, Kai; Yang, Yuancai; Xie, Tao


    Titanium and its alloys have been widely used in aerospace and biomedical industries, however, they are classified as difficult-to-machine materials. In this paper, ultrasonic vibration is imposed on the die to overcome the difficulties during conventional titanium wire drawing processes at the room temperature. Numerical simulations were performed to investigate the variation of axial stress within the contacting region and study the change of the drawing stress with several factors in terms of the longitudinal amplitude and frequency of the applied ultrasonic vibration, the diameter reduction ratio, and the drawing force. An experimental testing equipment was established to measure the drawing torque and rotational velocity of the coiler drum during the wire drawing process. The result indicates the drawing force increases with the growth of the drawing velocity and the reduction ratio, whether with or without vibrations. Application of either form of ultrasonic vibrations contributes to the further decrease of the drawing force, especially the longitudinal vibration with larger amplitude. SEM was employed to detect the surface morphology of the processed wires drawn under the three circumstances. The surface quality of the drawn wires with ultrasonic vibrations was apparently improved compared with those using conventional method. In addition, the longitudinal and torsional composite vibration was more effective for surface quality improvement than pure longitudinal vibration, however, at the cost of weakened drawing force reduction effect. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Experimental Study Of Fog Water Harvesting By Stainless Steel Mesh

    Directory of Open Access Journals (Sweden)

    Nikhil R. Pawar


    Full Text Available The collection of fog water is a simple and sustainable technology to get hold of fresh water for various purposes. In areas where a substantial amount of fog can be obtained it is feasible to set up a stainless steel as well as black double layer plastic mesh structure for fog water harvesting. The mesh structure is directly exposed to the weather and the fog containing air is pushed through the active mesh surface by the wind. Afterward fog droplets are deposited on the active mesh area which combines to form superior droplets and run down into a gutter to storage by gravity. Fog water harvesting rates show a discrepancy from site to site. The scope of this experimental work is to review fog collection at SCOE Pune campus and to examine factors of success. This study is to synthesize the understanding of fog water harvesting in the institutional era and to analyze its benefits and boundaries for future development. The rate of fog water harvesting depends on the science of fog physics chemistry and its starring role in the hydrological cycle. This technology runs on zero energy and zeroes pollution level with cost of the benefit. The collected or treated clear water mainly could be used for different purposes as per requirement. For further development this technology public as well as government participation is needed.

  11. Numerical and experimental study of bistable plates for morphing structures (United States)

    Nicassio, F.; Scarselli, G.; Avanzini, G.; Del Core, G.


    This study is concerned with the activation energy threshold of bistable composite plates in order to tailor a bistable system for specific aeronautical applications. The aim is to explore potential configurations of the bistable plates and their dynamic behavior for designing novel morphing structure suitable for aerodynamic surfaces and, as a possible further application, for power harvesters. Bistable laminates have two stable mechanical shapes that can withstand aerodynamic loads without additional constraint forces or locking mechanisms. This kind of structures, when properly loaded, snap-through from one stable configuration to another, causing large strains that can also be used for power harvesting scopes. The transition between the stable states of the composite laminate can be triggered, in principle, simply by aerodynamic loads (pilot, disturbance or passive inputs) without the need of servo-activated control systems. Both numerical simulations based on Finite Element models and experimental testing based on different activating forcing spectra are used to validate this concept. The results show that dynamic activation of bistable plates depend on different parameters that need to be carefully managed for their use as aircraft passive wing flaps.

  12. Differential Responses to Food Price Changes by Personal Characteristic: A Systematic Review of Experimental Studies (United States)

    Mizdrak, Anja; Scarborough, Peter; Waterlander, Wilma E.; Rayner, Mike


    Background Fiscal interventions to improve population diet have been recommended for consideration by many organisations including the World Health Organisation and the United Nations and policies such as sugar-sweetened beverage taxes have been implemented at national and sub-national levels. However, concerns have been raised with respect to the differential impact of fiscal interventions on population sub-groups and this remains a barrier to implementation. Objective To examine how personal characteristics (such as socioeconomic status, sex, impulsivity, and income) moderate changes in purchases of targeted foods in response to food and beverage price changes in experimental settings. Design Systematic review Data Sources Online databases (PubMed, EMBASE, Web of Science, EconLit and PsycInfo), reference lists of previous reviews, and additional data from study authors. Study Selection We included randomised controlled trials where food and beverage prices were manipulated and reported differential effects of the intervention on participant sub-groups defined according to personal characteristics. Data Analysis Where possible, we extracted data to enable the calculation of price elasticities for the target foods by personal characteristic. Results 8 studies were included in the review. Across studies, the difference in price elasticity varied from 0.02 to 2.43 between groups within the same study. 11 out of the total of 18 comparisons of own-price elasticity estimates by personal characteristic differed by more than 0.2 between groups. Income related factors were the most commonly considered and there was an indication that own-price elasticity estimates do vary by income but the direction of this effect was not clear. Conclusion Experimental studies provide an opportunity to examine the differential effects of fiscal measures to improve population diets. Patterns in price sensitivity by personal characteristics are complex. General conclusions pertaining to the

  13. Scale dependence of acoustic velocities. An experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Gotusso, Angelamaria Pillitteri


    Reservoir and overburden data (e.g. seismic, sonic log and core data) are collected at different stages of field development, at different scales, and under different measurement conditions. A more precise reservoir characterization could be obtained by combining all the collected data. Reliable data may also be obtained from drill cuttings. This methodology can give data in quasi-real time, it is easily applicable, and cheap. It is then important, to understand the relationship between results obtained from measurements at different scales. In this Thesis acoustic velocities measured at several different laboratory scales are presented. This experimental study was made in order to give the base for the development of a model aiming to use/combine appropriately the data collected at different scales. The two main aspects analyzed are the experimental limitations due to the decrease in sample size and the significance of measurements in relation to material heterogeneities. Plexiglas, an isotropic, non-dispersive artificial material, with no expected scale effect, was used to evaluate the robustness of the measurement techniques. The results emphasize the importance of the wavelength used with respect to the sample length. If the sample length (L) is at least 5 time bigger than wavelength used ({lambda}), then the measured velocities do not depend on sample size. Leca stone, an artificial isotropic material containing spherical grains was used to evaluate the combined effects of technique, heterogeneities and sample length. The ratio between the scale of the heterogeneities and the sample length has to be taken in to account. In this case velocities increase with decreasing sample length when the ratio L/{lambda} is smaller than 10-15 and at the same time the ratio between sample length and grain size is greater than 10. Measurements on natural rocks demonstrate additional influence of grain mineralogy, shape and orientation. Firenzuola sandstone shows scale and

  14. Extremal quantum correlations: Experimental study with two-qubit states

    Energy Technology Data Exchange (ETDEWEB)

    Chiuri, A.; Mataloni, P. [Dipartimento di Fisica, Sapienza Universita di Roma, Piazzale Aldo Moro 5, I-00185 Roma (Italy); Istituto Nazionale di Ottica (INO-CNR), L.go E. Fermi 6, I-50125 Firenze (Italy); Vallone, G. [Dipartimento di Fisica, Sapienza Universita di Roma, Piazzale Aldo Moro 5, I-00185 Roma (Italy); Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Via Panisperna 89/A, Compendio del Viminale, I-00184 Roma (Italy); Paternostro, M. [Centre for Theoretical Atomic, Molecular, and Optical Physics, School of Mathematics and Physics, Queen' s University, Belfast BT7 1NN (United Kingdom)


    We explore experimentally the space of two-qubit quantum-correlated mixed states, including frontier states as defined by the use of quantum discord and von Neumann entropy. Our experimental setup is flexible enough to allow for high-quality generation of a vast variety of states. We address quantitatively the relation between quantum discord and a recently suggested alternative measure of quantum correlations.

  15. Bargaining Power in Relational Contracts: An Experimental Study


    Cordero Salas, Paula


    This paper provides experimental evidence of the economic impact from shifting bargaining power in relational contracts. I implement an experimental design that adjusts the bargaining power of sellers (agents) and the enforceability of the contract. I find that the vast majority of contracts take the form of efficiency wage contracts instead of contingent performance contracts when enforcement is partially incomplete and sellers have more bargaining power than buyers. The total contracted and...

  16. Mahayograj guggulu: Heavy metal estimation and safety studies. (United States)

    Lavekar, G S; Ravishankar, B; Gaidhani, S; Shukla, V J; Ashok, B K; Padhi, M M


    This study was conducted to estimate the heavy metal profile and determine the safety of Mahayograj guggulu, an Ayurvedic herbo-mineral preparation. Mahayograj guggulu, manufactured by Shree Baidynath Ayurved Bhawan Pvt. Ltd., Gwalior Road, Jhansi - 284 003 (of batch number-07 and manufacturing date October 2004) was procured from the local market. Heavy metal concentrations were measured using an atomic absorption spectrophotometer. A total of 40 Charles Foster strain albino rats of either sex with an average body weight of 160-250 g were divided into four groups (Groups I, II, III and IV), with 10 animals in each group. Group I served as the control, while Group II, III and IV rats received Mahayograj guggulu at a dose of 54 (dose equivalent to human therapeutic dose), 270 (five-times the dose equivalent to the human therapeutic dose) and 540 (10-times the dose equivalent to human therapeutic dose) mg/kg, p.o. for 120 days. The effect of drug administration was noted on the ponderal, biochemical, hematological and histopathological parameters. In addition, urine examination was also carried out. At the end of the study, only six rats per group were sacrificed as per the IAEC advice. Mahayograj guggulu was found to be safe at all dose levels tested. No significant behavioral changes were noted in any of the groups studied. The effect on food and water consumption and fecal and urine output remained unaffected in all groups during the study period. No major alterations were observed in hematology, serum biochemistry, necropsy and histopathology at the therapeutically advocated dose level. Heavy metal content measurement indicated levels of 25.8 µg/g for lead, 0.07 µg/g for mercury and 5.19 µg/g for arsenic. The test drug is well tolerated as no changes of a serious nature could be observed in any of the parameters assessed.

  17. Estimating Supply Response Function for Wheat: A Case Study

    Directory of Open Access Journals (Sweden)

    M.S. EI-Habbab


    Full Text Available To increase wheat production, governments can subsidize wheat farmers by purchasing their produce at a price higher than the world price. This policy did not succeed in increasing wheat production in the Irbid Governorate of Jordan, our case study area. The agricultural sector in the study area was characterized by risk in production and prices. In our study, the supply response function based on the Nerlovian Model was estimated for wheat produced in Irbid Governorate. Wheat area, in the model, was the dependent variable in the supply response function. The independent variables were: wheat planted area in Dunums in the current and previous year respectively, the weighted price of wheat in the previous year deflated by the Consumer Price Index (CPI, the holding fragmentation coefficient in the previous year, the yield risk, and the amount of rain in millimeters during the early months of the season (October, November, and December. The study reached the following conclusions: Firstly, holdings fragmentation was the major factor that negatively affects wheat production. Since the heritage system is the main factor that affects holding fragmentation, the policy makers need to find a way that can decrease this effect. Secondly, lagged weighted prices were found more suitable than the current weighted prices from an economic and statical point of view. Thirdly, the partial adjustment coefficient was low (i.e. less than one, which means that the farmers need more than one year to change their producing habits. Finally, the farmers were found to be risk-neutral, because their decisions depend mainly on the level and distribution of rainfall during the rainy season.

  18. Increasing the rate of recycled asphalt: an experimental study

    Directory of Open Access Journals (Sweden)

    Marjan TUŠAR


    Full Text Available Asphalt is material that can be recycled. In particular reclaimed asphalt (RA contains aged binder, which limits the reuse of RA. In this study the rate of recycled asphalt was increased by adding a rejuvenator containing paraffin. The authors investigated the effect of the rejuvenator in laboratory and in plant prepared samples of asphalt mixture. In laboratory samples with different percentage of RA (0%, 10%, 30%, 50% and rejuvenator were prepared. In asphalt plant only asphalt mixture with highest amount of RA and rejuvenator and control mixture without RA were prepared. On samples were conducted different tests, e.g. determining softening point, Fraass breaking point, penetration, indirect tensile strength. Results on extracted bitumen showed increase in softening point and decrease in Fraass breaking point with increasing percentage of RA and rejuvenator, meaning that service temperature of binders increased. Asphalt samples prepared in asphalt plant were laid on test field. Asphalt with RA and rejuvenator was built in at lower temperature (round 100 °C. Mixtures with RA and rejuvenator have better low temperature properties confirmed with Thermal Stress Restrained Specimen Test (TSRST method, but are less resistant to compaction and less sensitive to water than control mixture. For comparison of long term behaviour wheel tracking test was performed on mixtures built in test field. A week after paving, the control mixture showed better properties, but one year later the results were opposite, asphalt containing RA and rejuvenator was more resistant to rutting. From the results of this experimental study the following was concluded: the amount of RA can be increased by using rejuvenator and the quality of such asphalt mixture is in most cases equal or even better than asphalt mixture made of virgin materials. By using RA we preserve nature, reduce usage of virgin raw materials, but it is cost effective only if recycling degree is high

  19. Rheology of lava flows on Mercury: An analog experimental study (United States)

    Sehlke, A.; Whittington, A. G.


    We experimentally determined the rheological evolution of three basaltic analog compositions appropriate to Mercury's surface, during cooling, and crystallization. Investigated compositions are an enstatite basalt, and two magnesian basalts representing the compositional end-members of the northern volcanic plains with 0.19 wt % (NVP) and 6.26 wt % Na2O (NVP-Na). The viscosity-strain rate dependence of lava was quantified using concentric cylinder viscometry. We measured the viscosities of the crystal-free liquids from 1600°C down to the first detection of crystals. Liquidus temperatures of the three compositions studied are around 1360°C, and all three compositions are more viscous than Hawaiian basalt at the same temperature. The onset of pseudoplastic behavior was observed at crystal fractions ~0.05 to 0.10, which is consistent with previous studies on mafic lavas. We show that all lavas develop detectable yield strengths at crystal fractions around 0.20, beyond which the two-phase suspensions are better described as Herschel-Bulkley fluids. By analogy with the viscosity-strain rate conditions at which the pahoehoe to `a`a transition occurs in Kilauea basalt, this transition is predicted to occur at ~1260 ± 10°C for the enstatite basalt, at ~1285 ± 20°C for the NVP, and at ~1240 ± 40°C for the NVP-Na lavas. Our results indicate that Mercury lavas are broadly similar to terrestrial ones, which suggests that the extensive smooth lava plains of Mercury could be due to large effusion rates (flood basalts) and not to unusually fluid lavas.

  20. U-stitching splenorraphy technique: experimental and clinical study. (United States)

    Tsaroucha, Alexandra K; Pitiakoudis, Michail S; Chanos, Georgios; Chiotis, Anestis S; Argyropoulou, Paraskevi I; Prassopoulos, Panos; Simopoulos, Constantinos E


    The aim of the present study was to describe the laboratory development and the subsequent clinical utility of the U-stitching technique for splenorraphy over the recent years in a general non-trauma hospital. Patients with splenectomies and patients treated conservatively during the same time period, are also presented. In the 15-year period from September 1988 until September 2003, 65 patients were diagnosed with splenic injury following admission to 2nd Department of Surgery, Democritus University Hospital, after blunt abdominal trauma. During the first 3 years, 14 patients were admitted; one of them was treated conservatively and 13 had splenectomies. Because computed tomography (CT) was not available at that time, these 14 patients form a control group. During the remaining 12-year period, 51 patients (39 male and 12 female; age, 4-82 years; mean, 31.1 years; SD, 19.7 years) were treated conservatively or surgically, either with splenectomy or with splenorraphy. Splenorraphy was performed using the U-stitching technique. This alternative splenorraphy technique was first tested on experimental models at 2nd Department of Surgery, Democritus University Hospital, then followed by successful clinical application. The medical records for these patients were reviewed to extract the data for the present study. Thirty-six patients (70.6% of 51 patients) were treated surgically; of these, 21 (41.2% of 51 patients) had splenectomy and 15 (29.4% of 51 patients) had splenorraphy. Non-operative treatment was initially given to 15 patients (29.4% of 51 patients). Two of them had delayed rupture of the spleen and underwent splenectomy (at 8 and 40 days). The total number of preserved spleens was 28 of 51 (54.9%). None of the patients with conservative treatment or splenorraphy died. One patient with splenectomy died later from overwhelming sepsis. Splenic salvage is now a treatment goal. If the patient is haemodynamically unstable and splenorraphy is possible, the U

  1. Laser welding of biological tissue: experimental studies in ophthalmology (United States)

    Pini, Roberto; Rossi, Francesca; Menabuoni, Luca


    In this paper we present an original approach to laser welding of ocular media. Attention is focused on laser welding of the cornea and lens capsule. The process is based on the interaction of near infrared diode laser radiation (at 810 nm) with tissue that was previously stained with an Indocyanine Green solution in sterile water. The topical application of the chromophore makes possible a selective heating of the tissue, which results in a homogenous welding effect with low thermal damage to the surrounding tissue. Experimental tests were performed ex vivo on both capsule and cornea, and in vivo (rabbits) only on the cornea, in order to characterize the process as a whole. Spectrophotometric, biomechanical, and thermal measurements were carried out in order to study the laser-tissue interaction, while morphological, histological and auto-florescence microscopy analyses made during a follow-up study provided information on the healing process in welded rabbit corneas. The welding procedure was set up according to the type of tissue, with the staining procedure and irradiation conditions being optimized in each case. Our test indicated that: 1) laser welding of corneal wounds, which is a non contact technique performed at low continuous wave laser power (12 W/cm2), can be proposed as a support to or substitute for the standard suturing technique in cataract surgery and in penetrating keratoplasty (in corneal transplants); 2) laser welding of the lens capsule requires a "contact irradiating technique" in order to be efficiently performed, since the tissue is in underwater conditions, with single spot pulses of about 100 J/cm2 fluence and pulse duration around 100 ms. In the latter case, laser welding was proposed as a tool for assisting closure of the lens capsule after the lens refilling procedure (Phaco-ersatz), or for repairing capsular breaks induced by accidental traumas or produced intraoperatively.

  2. Study on planar blast waves initiated by gaseous detonations. I. Estimation of initiation energy

    Energy Technology Data Exchange (ETDEWEB)

    Ohyagi, S.; Yoshihashi, T.; Harigaya, Y.


    An experimental study has been made of the initiation of planar blast waves by gaseous detonations. A gaseous detonation initiated by a DDT process is submitted into a long tube filled with air at various initial pressures. The measurement of the decay process of a produced shock wave indicates that it can be treated as a plane source blast wave, although there exists a secondary shock wave, which may be a detonation wave reflected on an end wall of a driver tube, behind the blast wave front. As a result, the decay of a propagation Mach number and a peak overpressure of the wave front as a function of a distance from the initiation source and the initial pressure of the medium are described by the quasi-similar theory of the idealized plane source blast wave. Comparing the experimental results with the theory leads to the estimation of an initiation energy of the blast wave. The initiation energies of oxyhydrogen detonations for three different mixture strengths, three different initial pressures, and two different sizes of the driver tube are estimated to show that about 30-40 percent of the chemical energy contained initially in the driver tube is used to initiate the blast wave. 9 references.

  3. Mechanisms of Osteoarthritic Pain. Studies in Humans and Experimental Models

    Directory of Open Access Journals (Sweden)

    Annett Eitner


    Full Text Available Pain due to osteoarthritis (OA is one of the most frequent causes of chronic pain. However, the mechanisms of OA pain are poorly understood. This review addresses the mechanisms which are thought to be involved in OA pain, derived from studies on pain mechanisms in humans and in experimental models of OA. Three areas will be considered, namely local processes in the joint associated with OA pain, neuronal mechanisms involved in OA pain, and general factors which influence OA pain. Except the cartilage all structures of the joints are innervated by nociceptors. Although the hallmark of OA is the degradation of the cartilage, OA joints show multiple structural alterations of cartilage, bone and synovial tissue. In particular synovitis and bone marrow lesions have been proposed to determine OA pain whereas the contribution of the other pathologies to pain generation has been studied less. Concerning the peripheral neuronal mechanisms of OA pain, peripheral nociceptive sensitization was shown, and neuropathic mechanisms may be involved at some stages. Structural changes of joint innervation such as local loss and/or sprouting of nerve fibers were shown. In addition, central sensitization, reduction of descending inhibition, descending excitation and cortical atrophies were observed in OA. The combination of different neuronal mechanisms may define the particular pain phenotype in an OA patient. Among mediators involved in OA pain, nerve growth factor (NGF is in the focus because antibodies against NGF significantly reduce OA pain. Several studies show that neutralization of interleukin-1β and TNF may reduce OA pain. Many patients with OA exhibit comorbidities such as obesity, low grade systemic inflammation and diabetes mellitus. These comorbidities can significantly influence the course of OA, and pain research just began to study the significance of such factors in pain generation. In addition, psychologic and socioeconomic factors may aggravate

  4. Early differentiation of the Moon: Experimental and modeling studies and experimental and modeling studies of massif anorthosites (United States)

    Longhi, John


    NASA grant NAG9-329 was in effect from 3/1/89 to 8/31/94, the last 18 months being a no-cost extension. While the grant was in effect, the P.I., coworkers, and students gave 22 talks and poster sessions at professional meetings, published 12 articles in referred journals (one more is in press, and another is in review), and edited 2 workshop reports relevant to this project. Copies of all the publications are appended to this report. The major accomplishments during the grant period have derived from three quarters: 1) the application of quantitative models of fractional crystallization and partial melting to various problems in planetary science, such as the petrogenesis of picritic glasses and mare basalts and the implications of the SNC meteorites for martian evolution; 2) an experimental study of silicate liquid immiscibility relevant to early lunar differentiation and the petrogenesis of evolved highlands rocks; and 3) experimental studies of massif anorthosites and related rocks that provide terrestrial analogs for the proposed origin of lunar anorthosites by multistage processes. The low-pressure aspects of the quantitative models were developed by the P.I. in the 1980s with NASA support and culminated with a paper comparing the crystallization of terrestrial and lunar lavas. The basis for the high-pressure modifications to the quantitative models is a data set gleaned from high pressure melting experiments done at Lamont and is supplemented by published data from other labs that constrain the baric and compositional dependences of various liquidus phase boundaries such as olivine/orthopyroxene, relevant to the melting of the mantles of the terrestrial planets. With these models it is possible to predict not only the thermal and compositional evolution of magmatic liquids ranging in composition from lumar mare basalt to terrestrial calc-alkaline basalts, but also the small increments of fractional melting that are produced when mantle rises adiabatically

  5. Experimental study on anelasticty of polycrystalline material for seismological application (United States)

    Takei, Y.; Karasawa, F.


    Due to the recent progress in seismology, we can obtain highly-resolved seismic velocity structures in the upper mantle. In order to interpret the velocity structures in terms of temperature heterogeneity, chemical heterogeneity, and fluid/melt distribution, it is important to assess the quantitative effects of temperature, chemical composition, and fluid/melt on Vp and Vs. Although these effects at the ultrasonic frequencies (anharmonic effect, poroelastic effect) have been measured and assessed quantitatively, these effects at the seismic frequencies are subject to large uncertainty due to the uncertainty in rock anelasticity, which additionally causes modulus relaxation at lower frequencies (anelastic effect). Previous studies have shown that anelasticity of polycrystalline materials follows the similarity rule in which frequency normalized to the Maxwell frequency, f/fM, can be used as a master variable (Morris & Jackson, 2009a; McCarthy et al, 2012). The general applicability of this Maxwell frequency scaling shows that the anelastic relaxation in those experiments is caused by diffusionally accommodated grain boundary sliding (GBS) (Gribb & Cooper, 1998; McCarthy et al, 2012). However, normalized frequency of the existing experimental data is usually considerably lower than the seismic frequencies normalized to the Maxwell frequency of the upper mantle (f/fM=106-1010). Therefore, in order to clarify the mechanism and scaling law applicable to the seismic waves, we have to measure anelasticity at higher normalized frequencies. Theoretical models (e.g., Raj, 1975; Morris & Jackson, 2009b) predict that at higher normalized frequencies, dominant GBS mechanism changes from diffusionally accommodated GBS to elastically accommodated GBS. However, the transition frequency and total relaxation strength associated with the elastically accommodated GBS, which are important in the application to seismology, have so far been difficult to constrain theoretically

  6. An experimental study of light scattering by large, irregular particles (United States)

    Mcguire, Audrey F.; Hapke, Bruce W.


    The intensity and polarization of light scattered by a variety of types of artificial partices large compared to the wavelength were measured as a function of phase angle. Shape, surface roughness, absorption coefficient, and internal scattering coefficient were varied systematically and their effects studied. Scattering by clear, smooth-surfaced spheres is in quantitative agreement with the predictions of the geometrical optics (ray theory) approximation to physical optics (Mie theory). The phase functions of almost all of the particles measured have both forward and backward scattering lobes. A two-parameter, double Henyey-Greenstein function generally provides reasonably good descriptions of the data, while keeping the number of free parameters to the minimum necessary. On a double Henyey- Greenstein parameter plot all of the particles fall into an L-shaped area of restricted size in which the location is characteristic of the particle type. Formalisms based on the equivalent slab model are also given for estimating the scattering efficiency of a large, irregular particle. For most dielectric particles the transmitted, forward scattered light is partially negatively polarized. It is this component that is respopnsible for the well-known maximum in the polarization curves of planetary regoliths at phase angles around 100 deg. For phase angles between about 30 deg and 70 deg the internally scattered light is found to be randomly polarized in the particles studied here, so that the only contribution to the second component of the Stokes vector is by Fresnel reflection from the particle surface. If this empirical result is general, measurement of the second Stokes vector of the light scattered from a regolith at these angles may provide a method of remotely measuring the mean refractive index.

  7. An Experimental Study of Cutting Performances of Worn Picks (United States)

    Dogruoz, Cihan; Bolukbasi, Naci; Rostami, Jamal; Acar, Cemil


    The best means to assess rock cuttability and efficiency of cutting process for using mechanical excavation is specific energy (SE), measured in full-scale rock cutting test. This is especially true for the application of roadheaders, often fitted with drag-type cutting tools. Radial picks or drag bits are changed during the operation as they reach a certain amount of wear and become blunt. In this study, full-scale cutting tests in different sedimentary rock types with bits having various degree of wear were used to evaluate the influence of bit wear on cutting forces and specific energy. The relationship between the amount of wear as represented by the size of the wear flats at the tip of the bit, and cutting forces as well as specific energy was examined. The influence of various rock properties such as mineral content, uniaxial compressive strength, tensile strength, indentation index, shore hardness, Schmidt hammer hardness, and density with required SE of cutting using different levels of tool wear was also studied. The preliminary analysis of the data shows that the mean cutting forces increase 2-3 times and SE by 4-5 times when cutting with 4 mm wear flat as compared to cutting with new or sharp wedge shape bits. The grain size distribution of the muck for cutting different rock types and different level of bit wear was analyzed and discussed. The best fit prediction models for SE based on statistical analysis of laboratory test results are introduced. The model can be used for estimating the performance of mechanical excavators using radial tools, especially roadheaders, continuous miners and longwall drum shearers.

  8. Sphericity estimation bias for repeated measures designs in simulation studies. (United States)

    Bono, Roser; Arnau, Jaume; Blanca, María J; Alarcón, Rafael


    In this study, we explored the accuracy of sphericity estimation and analyzed how the sphericity of covariance matrices may be affected when the latter are derived from simulated data. We analyzed the consequences that normal and nonnormal data generated from an unstructured population covariance matrix-with low (ε = .57) and high (ε = .75) sphericity-can have on the sphericity of the matrix that is fitted to these data. To this end, data were generated for four types of distributions (normal, slightly skewed, moderately skewed, and severely skewed or log-normal), four sample sizes (very small, small, medium, and large), and four values of the within-subjects factor (K = 4, 6, 8, and 10). Normal data were generated using the Cholesky decomposition of the correlation matrix, whereas the Vale-Maurelli method was used to generate nonnormal data. The results indicate the extent to which sphericity is altered by recalculating the covariance matrix on the basis of simulated data. We concluded that bias is greater with spherical covariance matrices, nonnormal distributions, and small sample sizes, and that it increases in line with the value of K. An interaction was also observed between sample size and K: With very small samples, the observed bias was greater as the value of K increased.

  9. Experimental and numerical study of globe valve housing

    Directory of Open Access Journals (Sweden)

    Mitrovic Nenad R.


    Full Text Available Complex structure experimental analysis has always been a huge challenge for researchers. Conventional experimental methods (e.g., strain gauges give only limited data sets regarding measurement on critical areas with high geometrical discontinuities. A 3D Digital Image Correlation method is an optical method that overcomes the limitations of conventional methods and enables full-field displacement and strain measurement of geometrically complex structures. System Aramis, based on Digital Image Correlation method, is used for experimental analysis and numerical model verification in this paper. Investigated complex structure is sphere/cylinder junction on globe valve housing subjected to axial loading. The highest experimentally measured von Mises strain values around 0.15% are recorded on cylinder/sphere intersection. Von Mises strain values on cylindrical and spherical part are several times smaller than on intersection itself. It is important to emphasize that, to the authors’ best knowledge, this is the first paper showing experimental results of 3D full and strain field of geometrically complex structure (sphere/cylinder intersection on the intersection itself on pressure equipment. It is proven that 3D Digital Image Correlation method is fast and versatile method for recording strain during loading of complex structures. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR35031 and Grant no. TR35040

  10. A comprehensive experimental and modeling study of isobutene oxidation

    KAUST Repository

    Zhou, Chong-Wen


    Isobutene is an important intermediate in the pyrolysis and oxidation of higher-order branched alkanes, and it is also a component of commercial gasolines. To better understand its combustion characteristics, a series of ignition delay time (IDT) and laminar flame speed (LFS) measurements have been performed. In addition, flow reactor speciation data recorded for the pyrolysis and oxidation of isobutene is also reported. Predictions of an updated kinetic model described herein are compared with each of these data sets, as well as with existing jet-stirred reactor (JSR) species measurements. IDTs of isobutene oxidation were measured in four different shock tubes and in two rapid compression machines (RCMs) under conditions of relevance to practical combustors. The combination of shock tube and RCM data greatly expands the range of available validation data for isobutene oxidation models to pressures of 50 atm and temperatures in the range 666–1715 K. Isobutene flame speeds were measured experimentally at 1 atm and at unburned gas temperatures of 298–398 K over a wide range of equivalence ratios. For the flame speed results, there was good agreement between different facilities and the current model in the fuel-rich region. Ab initio chemical kinetics calculations were carried out to calculate rate constants for important reactions such as H-atom abstraction by hydroxyl and hydroperoxyl radicals and the decomposition of 2-methylallyl radicals. A comprehensive chemical kinetic mechanism has been developed to describe the combustion of isobutene and is validated by comparison to the presently considered experimental measurements. Important reactions, highlighted via flux and sensitivity analyses, include: (a) hydrogen atom abstraction from isobutene by hydroxyl and hydroperoxyl radicals, and molecular oxygen; (b) radical–radical recombination reactions, including 2-methylallyl radical self-recombination, the recombination of 2-methylallyl radicals with

  11. Rapidly resorbable vs. non-resorbable suture for experimental colonic anastomoses in rats--a randomized experimental study

    DEFF Research Database (Denmark)

    Klein, Mads; Pommergaard, Hans-Christian; Gögenur, Ismail


    Anastomotic dehiscence remains an important challenge for colorectal surgeons worldwide. Extensive research focused on performing a safe anastomosis is conducted with rats being the most used model when examining colorectal anastomoses. In daily clinical practice resorbable sutures are used when...... hand-sewn anastomoses are performed. However, in the experimental studies examining colorectal anastomoses, non-resorbable sutures have predominantly been used. The aim of this study was to compare a rapidly resorbable suture with a non-resorbable suture in experimental colorectal anastomoses....

  12. Experimental study on viscosity reduction for residual oil by ultrasonic. (United States)

    Huang, Xintong; Zhou, Cuihong; Suo, Quanyu; Zhang, Lanting; Wang, Shihan


    Because of characteristics of large density, high viscosity and poor mobility, the processing and transportation of residual oil are difficult and challenging, viscosity reduction of residual oil is of great significance. In this paper, the effects of different placement forms of ultrasonic transducers on the sound pressure distribution of ultrasonic inside a cubic container have been simulated, the characteristics of oil bath heating and ultrasonic viscosity reduction were compared, viscosity reduction rule of residual oil was experimentally analyzed by utilizing Response Surface Method under conditions of changing ultrasonic exposure time, power and action mode, the mechanism of viscosity reduction was studied by applying Fourier transform infrared spectrometer, the viscosity retentivity experiment was carried out at last. Experiments were conducted using two kinds of residual oil, and results show that ultrasonic effect on the viscosity reduction of residual oil is significant, the higher viscosity of residual oil, the better effect of ultrasonic, ultrasonic power and exposure time are the significant factors affecting the viscosity reduction rate of residual oil. The maximum viscosity reduction rate is obtained under condition of ultrasonic power is 900W, exposure time is 14min and action mode of exposure time is 2s and interrupting time is 2s, viscosity reduction rate reaching up to 63.95%. The infrared spectroscopy results show that light component in residual oil increased. The viscosity retentivity experiment results show that the viscosity reduction effect remains very well. This paper can provide data reference for the application of ultrasonic in the field of viscosity reduction for residual oil. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. An experimental study on cerebral paragonimiasis using cats

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seon Kyu; Chang, Kee Hyun; Goo, Jin Mo; Han, Moon Hee; Shin, Yong Moon; Choo, Sung Wook; Yu, In Kyu [Seoul National University College of Medicine, Seoul (Korea, Republic of); Cho, Seung Yull; Kong, Yoon [Chung-Ang University College of Medicine, Seoul (Korea, Republic of)


    It is important to diagnosis paragonimiasis in early active because it can be dared by chemotherapy. However, it is difficult to make a correct diagnosis of cerebral paragonimiasis in the early active stage, and the radiographic findings of cerebral paragonimiasis have been rarely reported. Thus, this experimental study was designed to produce early active cerebral paragonimiasis and to demonstrate radiologic-pathologic correlations. In 8 cats, 7-8 metacercariae of Paragonimus Westermani were directly introduced into brain parenchyma of each cat's after trephination of the skull. In another 16 cats, the juvenile worms and the adult worms that had developed for varying periods (2 weeks, 4 weeks, 6 weeks, 8 weeks and 12 weeks) in the lunges of another cats were introduced into the brain parenchyma of each cat's with the same procedure described above. Follow -up MR images and chest radiographs were obtained at 2 days, 1 weeks, 2 weeks, 4 weeks and 8 weeks after inoculation. The autopsies and histopathological examinations of the cat's brain were undertaken in 22 cats. In 9 cats that were suspected with pulmonary lesion on chest radiograph, the soft tissue radiographs of inflated-fixed lungs were obtained. In one cat with inoculation of adult worm, acute suppurative inflammation of the brain parenchyma was demonstrated. But the other cats with inoculation of adult worm or juvenile worm and the cats with intentional of metacercaris did not reveal any evidence of acute cerebral paragonimiasis. More than half of the introduce metacercariae (5 out of 8 cats) were found in the lung parenchyma, while only 25% (4 out of 16 cats) of the adult worm inoculated cats were. Acute suppurative inflammation suggesting acute stage cerebral paragonimiasis was obtained in one case of adult worm inoculated cat. Most of the inoculated metacercariae and some of the juvenile worms or adult worms were migrated to the lungs.

  14. Composition of intraocular foreign bodies: experimental study of ultrasonographic presentation. (United States)

    Costa, Márcio Augusto Nogueira; Garcia, Patrícia Novita; Barroso, Letícia Fernandes; Ferreira, Marco Antonio; Okuda, Érika Araki; Allemann, Norma


    To investigate the reliability of ultrasound in determining the size and identify the sonographic features and artifacts generated by intraocular foreign bodies of different materials. Experimental study using 36 enucleated porcine eyes. Fragments of nine different compositions (wood, glass, plastic, cardboard, iron, aluminum, lead, powder and concrete) and similar dimensions (4 mm) were implanted via scleral incision into the vitreous cavity of 36 porcine eyes, four eyes were used for each material. Ultrasound examination was performed in all eyes using the contact technique, conductive gel and 10-MHz transducer (EZScan, Sonomed). Considering the material fragments of gunpowder, lead, concrete, aluminum, wood and glass, the size determined by ultrasound was considered statistically similar to the actual size. The material iron presented ultrasound-determined dimension statistically smaller than its actual size. Cardboard and plastic materials showed ultrasound-determined measurements far greater than the actual. All fragments of intraocular foreign bodies demonstrated hyper-reflective interfaces, irrespective of their composition. Whereas the artifacts generated by different materials, it was found that the materials iron, aluminum and lead showed reverberation of great extent. The material wood showed no reverberation. The length of the reverberation artifact for the materials iron, glass, aluminum and cardboard was lower when compared to other materials. All materials presented posterior shadowing artifact, with the exception of aluminum. Ultrasonography was considered a reliable technique to determine the size of intraocular foreign bodies in pigs, with little influence caused by its composition. Ultrasound artifacts generated were considered material-dependent and can assist the examiner to identify the nature of a foreign body of unknown etiology. Ultrasonography aided the surgeon to identify, locate and measure the intraocular foreign body, directing

  15. Composition of intraocular foreign bodies: experimental study of ultrasonographic presentation

    Directory of Open Access Journals (Sweden)

    Márcio Augusto Nogueira Costa


    Full Text Available PURPOSE: To investigate the reliability of ultrasound in determining the size and identify the sonographic features and artifacts generated by intraocular foreign bodies of different materials. METHODS: Experimental study using 36 enucleated porcine eyes. Fragments of nine different compositions (wood, glass, plastic, cardboard, iron, aluminum, lead, powder and concrete and similar dimensions (4 mm were implanted via scleral incision into the vitreous cavity of 36 porcine eyes, four eyes were used for each material. Ultrasound examination was performed in all eyes using the contact technique, conductive gel and 10-MHz transducer (EZScan, Sonomed. RESULTS: Considering the material fragments of gunpowder, lead, concrete, aluminum, wood and glass, the size determined by ultrasound was considered statistically similar to the actual size. The material iron presented ultrasound-determined dimension statistically smaller than its actual size. Cardboard and plastic materials showed ultrasound-determined measurements far greater than the actual. All fragments of intraocular foreign bodies demonstrated hyper-reflective interfaces, irrespective of their composition. Whereas the artifacts generated by different materials, it was found that the materials iron, aluminum and lead showed reverberation of great extent. The material wood showed no reverberation. The length of the reverberation artifact for the materials iron, glass, aluminum and cardboard was lower when compared to other materials. All materials presented posterior shadowing artifact, with the exception of aluminum. CONCLUSION: Ultrasonography was considered a reliable technique to determine the size of intraocular foreign bodies in pigs, with little influence caused by its composition. Ultrasound artifacts generated were considered material-dependent and can assist the examiner to identify the nature of a foreign body of unknown etiology. Ultrasonography aided the surgeon to identify, locate and

  16. Experimental study of voltage fluctuations in a glow discharge (United States)

    Yunusov, R. F.; Garipov, M. M.


    The article is devoted to the experimental study of voltage pulsations in a glow discharge. The longitudinal discharge was ignited in a stream of air moving in a cylindrical discharge chamber (DC). Copper hollow electrodes were located at a distance of a = (2-8) cm from each other along the axis of the DC. The gas pressure P = (4.7 - 26) kPa and its flow rate G = (0-0.06) g/s were monitored. The discharge current and voltage varied accordingly in the ranges: I = (20-100) mA, U = (1, 5 - 4, 2) kV. The current-voltage characteristics of the discharge were measured. The voltage decreased with increasing current, which is typical for a given type of discharge. The oscillations of the discharge voltage were registered by an oscilloscope; the current-voltage characteristic of the discharge was recorded by a two-coordinate recorder. Three regions of the current-voltage characteristic were detected. The luminous positive discharge column (PC) occupied the entire interelectrode space in the current region I = (100-70) mA. In the current range I = (70-40) mA there is a smooth transition to the discharge without visible glow of the PC with a significant increase in the discharge voltage. With further reduction of the current intensity (the third region), the discharge exists almost at a constant voltage until its quenching. Low-frequency and high-frequency oscillations of the discharge voltage were observed at the boundary of the second and third regions of the current-voltage characteristic.

  17. Mechanisms of blast induced brain injuries, experimental studies in rats. (United States)

    Risling, M; Plantman, S; Angeria, M; Rostami, E; Bellander, B-M; Kirkegaard, M; Arborelius, U; Davidsson, J


    Traumatic brain injuries (TBI) potentially induced by blast waves from detonations result in significant diagnostic problems. It may be assumed that several mechanisms contribute to the injury. This study is an attempt to characterize the presumed components of the blast induced TBI. Our experimental models include a blast tube in which an anesthetized rat can be exposed to controlled detonations of explosives that result in a pressure wave with a magnitude between 130 and 260 kPa. In this model, the animal is fixed with a metal net to avoid head acceleration forces. The second model is a controlled penetration of a 2mm thick needle. In the third model the animal is subjected to a high-speed sagittal rotation angular acceleration. Immunohistochemical labeling for amyloid precursor protein revealed signs of diffuse axonal injury (DAI) in the penetration and rotation models. Signs of punctuate inflammation were observed after focal and rotation injury. Exposure in the blast tube did not induce DAI or detectable cell death, but functional changes. Affymetrix Gene arrays showed changes in the expression in a large number of gene families including cell death, inflammation and neurotransmitters in the hippocampus after both acceleration and penetration injuries. Exposure to the primary blast wave induced limited shifts in gene expression in the hippocampus. The most interesting findings were a downregulation of genes involved in neurogenesis and synaptic transmission. These experiments indicate that rotational acceleration may be a critical factor for DAI and other acute changes after blast TBI. The further exploration of the mechanisms of blast TBI will have to include a search for long-term effects. Copyright © 2010 Elsevier Inc. All rights reserved.

  18. An Experimental Toxoplasma gondii Dose Response Challenge Model to Study Therapeutic or Vaccine Efficacy in Cats (United States)

    Cornelissen, Jan B. W. J.; van der Giessen, Joke W. B.; Takumi, Katsuhisa; Teunis, Peter F. M.; Wisselink, Henk J.


    High numbers of Toxoplasma gondii oocysts in the environment are a risk factor to humans. The environmental contamination might be reduced by vaccinating the definitive host, cats. An experimental challenge model is necessary to quantitatively assess the efficacy of a vaccine or drug treatment. Previous studies have indicated that bradyzoites are highly infectious for cats. To infect cats, tissue cysts were isolated from the brains of mice infected with oocysts of T. gondii M4 strain, and bradyzoites were released by pepsin digestion. Free bradyzoites were counted and graded doses (1000, 100, 50, 10), and 250 intact tissue cysts were inoculated orally into three cats each. Oocysts shed by these five groups of cats were collected from faeces by flotation techniques, counted microscopically and estimated by real time PCR. Additionally, the number of T. gondii in heart, tongue and brains were estimated, and serology for anti T. gondii antibodies was performed. A Beta-Poisson dose-response model was used to estimate the infectivity of single bradyzoites and linear regression was used to determine the relation between inoculated dose and numbers of oocyst shed. We found that real time PCR was more sensitive than microscopic detection of oocysts, and oocysts were detected by PCR in faeces of cats fed 10 bradyzoites but by microscopic examination. Real time PCR may only detect fragments of T. gondii DNA without the presence of oocysts in low doses. Prevalence of tissue cysts of T. gondii in tongue, heart and brains, and anti T. gondii antibody concentrations were all found to depend on the inoculated bradyzoite dose. The combination of the experimental challenge model and the dose response analysis provides a suitable reference for quantifying the potential reduction in human health risk due to a treatment of domestic cats by vaccination or by therapeutic drug application. PMID:25184619

  19. Holding Strength of Suture: An Experimental Study Using Porcine Kidney (United States)

    Akpinar, Haluk; Karadag, Mert Ali; Dönmez, Muhammet İrfan; Altunrende, Fatih


    Background and Objectives: The search for the perfect suture is going on and has resulted in the introduction of many different suture types into the market. The purpose of this study is to investigate the holding strength (HS) of different sutures in the renal parenchyma in an experimental study on pig kidneys. Methods: The HS that caused sliding of the suture was investigated in 5 adult porcine kidneys with 7 suture variants. HS-caused tearing of the kidney was investigated with 3 suture types on 5 kidneys. The third investigation, performed on 5 porcine kidneys, was a comparison between 2-0 Vicryl sutures with a Hem-o-lok clip and 2-0 V-Loc sutures with 1 knot. The Friedman test was used to compare the groups. Post hoc analysis was performed with the Wilcoxon signed ranks test (Bonferroni corrected). Results: For HS causing sliding of the suture, the mean HSs of the tested sutures were as follows: 2-0 Vicryl with 1 Hem-o-lok clip, 3.26 ± 0.55 N; 2-0 Vicryl with 2 Hem-o-lok clips, 4.1 ± 0.46 N; 2-0 V-Loc, 2.52 ± 0.63 N; 4-0 V-Loc, 1.62 ± 0.17 N; 0 Quill, 0.48 ± 0.16 N; 2-0 Vicryl with 1 Hem-o-lok clip (halfway), 3.62 ± 0.66 N; and 2-0 V-Loc (halfway), 1.02 ± 0.40 N. For HS causing tearing of the kidney, the mean value of 2-way 2-0 Vicryl (Hem-o-lok in the middle) was 13.28 ± 1.38 N, 2-0 2-way Vicryl (Hem-o-lok at the end) was 5.86 ± 0.75 N, and 2-way 2-0 V-Loc was 3.98 ± 1.60 N. For the third group, the difference between the 2 suture variants was not statistically significant. Conclusion: Our study revealed that 2-0 Vicryl (polyglactin 910) sutures with 2 Hem-o-lok clips had the maximum HS in renal parenchyma when compared with other sutures. PMID:28729782

  20. Holding Strength of Suture: An Experimental Study Using Porcine Kidney. (United States)

    Özkuvanci, Ünsal; Akpinar, Haluk; Karadag, Mert Ali; Dönmez, Muhammet İrfan; Altunrende, Fatih


    The search for the perfect suture is going on and has resulted in the introduction of many different suture types into the market. The purpose of this study is to investigate the holding strength (HS) of different sutures in the renal parenchyma in an experimental study on pig kidneys. The HS that caused sliding of the suture was investigated in 5 adult porcine kidneys with 7 suture variants. HS-caused tearing of the kidney was investigated with 3 suture types on 5 kidneys. The third investigation, performed on 5 porcine kidneys, was a comparison between 2-0 Vicryl sutures with a Hem-o-lok clip and 2-0 V-Loc sutures with 1 knot. The Friedman test was used to compare the groups. Post hoc analysis was performed with the Wilcoxon signed ranks test (Bonferroni corrected). For HS causing sliding of the suture, the mean HSs of the tested sutures were as follows: 2-0 Vicryl with 1 Hem-o-lok clip, 3.26 ± 0.55 N; 2-0 Vicryl with 2 Hem-o-lok clips, 4.1 ± 0.46 N; 2-0 V-Loc, 2.52 ± 0.63 N; 4-0 V-Loc, 1.62 ± 0.17 N; 0 Quill, 0.48 ± 0.16 N; 2-0 Vicryl with 1 Hem-o-lok clip (halfway), 3.62 ± 0.66 N; and 2-0 V-Loc (halfway), 1.02 ± 0.40 N. For HS causing tearing of the kidney, the mean value of 2-way 2-0 Vicryl (Hem-o-lok in the middle) was 13.28 ± 1.38 N, 2-0 2-way Vicryl (Hem-o-lok at the end) was 5.86 ± 0.75 N, and 2-way 2-0 V-Loc was 3.98 ± 1.60 N. For the third group, the difference between the 2 suture variants was not statistically significant. Our study revealed that 2-0 Vicryl (polyglactin 910) sutures with 2 Hem-o-lok clips had the maximum HS in renal parenchyma when compared with other sutures.

  1. Experimental pragmatics: a Gricean turn in the study of language. (United States)

    Noveck, Ira A; Reboul, Anne


    Discerning the meaning of an utterance requires not only mastering grammar and knowing the meanings of words but also understanding the communicative (i.e., pragmatic) features of language. Although it has been an ever present aspect of linguistic analyses and discussions, it is only over the last ten years or so that cognitive scientists have been investigating--in a concerted fashion--the pragmatic features of language experimentally. We begin by highlighting Paul Grice's contributions to ordinary language philosophy and show how it has led to this active area of experimental investigation. We then focus on two exemplary phenomena--'scalar inference' and 'reference resolution'--before considering other topics that fit into the paradigm known as 'experimental pragmatics'.

  2. Experimental and numerical studies on pressure drop in reverse electrodialysis: Effect of unit cell configuration

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sung Kook; Choi, Kyung Soo [Advanced Combustion Laboratory, Korea Institute of Energy Research, Daejeon (Korea, Republic of); Kim, Chan Soo; Hwang, Kyo Sik; Han, Ji Hyung; Kim, Han Ki; Jeong, Nam Jo [Jeju Global Research Center, Korea Institute of Energy Research, Jeju (Korea, Republic of)


    Experimental and numerical studies on pressure drop in Reverse electrodialysis (RED) were performed. In this study, a module with 200 unit cells is considered for the demonstration of bench-scale RED module and two different unit cell configurations are utilized. Pressure drop through the module is measured by varying flow rates. For evaluating the hydrodynamic characteristics in the unit cell, a numerical simulation is also conducted and the simplified method using a porous media model is employed to simulate the channel filled with spacer. Due to the insertion of spacer and narrow channel, great pressure loss occurs along the unit cell. Based on estimated pressure data, high pressure difference between seawater and fresh water channel takes place locally in the unit cell configuration with crossflow direction, leading to a leakage problem through the membrane and finally degradation in the output power. Consequently, it is confirmed that the unit cell configuration is one of the important design parameters in a RED module.

  3. Organ hierarchy during low blood flow on-pump: a randomized experimental positron emission tomography study

    DEFF Research Database (Denmark)

    Thomassen, Sisse Anette; Kjærgaard, Benedict; Frøkiær, Jørgen

    knowledge this is the first study investigating organ hierarchy with dynamic PET-CT during profound systemic ischemia due to suboptimal blood flows during normothermic CPB. References 1. Murphy JM, Hessel II EA, Groom RC. Optimal perfusion during cardiopulmonary bypass: an Evidence-based approach. Anesth......].The purpose of this animal study is to investigate the organ hierarchy of brain, liver, kidney and muscle at normal and low blood flows by using dynamic positron tomography (PET-CT) during CPB. Methods CPB at different blood flows will be investigated in an experimental model of six 70 kg pigs...... will be measured with dynamic PET-CT before CPB and during the different blood flows. Systemic oxygen consumption will be estimated by measurement of mixed venous saturation and lactate, and regional muscle oxygen saturation (tSO2) with near infrared spectroscopy at the lower limb. Result: Preliminary data...

  4. Merging multiple longitudinal studies with study-specific missing covariates: A joint estimating function approach. (United States)

    Wang, Fei; Song, Peter X-K; Wang, Lu


    Merging multiple datasets collected from studies with identical or similar scientific objectives is often undertaken in practice to increase statistical power. This article concerns the development of an effective statistical method that enables to merge multiple longitudinal datasets subject to various heterogeneous characteristics, such as different follow-up schedules and study-specific missing covariates (e.g., covariates observed in some studies but missing in other studies). The presence of study-specific missing covariates presents great statistical methodology challenge in data merging and analysis. We propose a joint estimating function approach to addressing this challenge, in which a novel nonparametric estimating function constructed via splines-based sieve approximation is utilized to bridge estimating equations from studies with missing covariates to those with fully observed covariates. Under mild regularity conditions, we show that the proposed estimator is consistent and asymptotically normal. We evaluate finite-sample performances of the proposed method through simulation studies. In comparison to the conventional multiple imputation approach, our method exhibits smaller estimation bias. We provide an illustrative data analysis using longitudinal cohorts collected in Mexico City to assess the effect of lead exposures on children's somatic growth. © 2015, The International Biometric Society.

  5. No association between periodontitis, preterm birth, or intrauterine growth restriction: experimental study in Wistar rats. (United States)

    Fogacci, Mariana Fampa; Barbirato, Davi da Silva; Amaral, Cristine da Silva Furtado; da Silva, Priscilla Gonçalves; Coelho, Mariana de Oliveira; Bertozi, Giuliana; de Carvalho, Denise Pires; Leão, Anna Thereza Thomé


    The biologic plausibility of the possible association between periodontitis and adverse pregnancy outcomes has been assessed with the use of different experimental models. However, most experimental studies did not induce periodontitis in the animals but promoted an acute microbial challenge with selected periodontal pathogens or their products subcutaneous or intravenous or intraamniotic. The present study was then conducted to verify the biologic plausibility of such association by experimentally inducing periodontitis in Wistar rats. An experimental study on an animal model by the induction of periodontitis in 50% of sites and assessment of the presence of cytokines in the gingival tissue, serum, placenta, cord, and amniotic fluid was designed to test the null hypothesis that experimental periodontitis that is induced on rats does not result in adverse pregnancy outcomes. Forty female Wistar rats were included in 2 groups: a periodontally healthy (without ligatures) and an experimentally induced periodontitis group (test, with ligatures). Forty-five days after the induction, the mating was initiated. Males were placed with females in the ratio of 1:2 for a period of 12 hours. The bodyweight of the female, from then on, was recorded daily. When the pregnancy was confirmed on day 20, laparotomy was performed. The amniotic fluid, placenta, umbilical cord, blood (serum) and maternal and gingival tissue samples were subjected to quantitative analysis for interleukin 1α, -6, -10, -4, -12p70, and -17a, tumor necrosis factor-α, and interferon-γ by multiplex methods. Mean scores, standard deviations, and standard errors for estimated measures were calculated. For cytokines analyses, the Mann-Whitney test was conducted to compare the concentration of the analytes from control and test groups in the different tissues samples. For comparison of cytokines reduction from gingival tissue to serum and from serum to placenta, the Wilcoxon Test was performed. Spearman

  6. Experimental study of self-compacted concrete in hardened state (United States)

    Parra Costa, Carlos Jose

    The main aim of this work is to investigate the hardened behaviour of Self-Compacting Concrete (SCC). Self compacting Concrete is a special concrete that can flow in its gravity and fill in the formwork alone to its self-weight, passing through the bars and congested sections without the need of any internal or external vibration, while maintaining adequate homogeneity. SCC avoids most of the materials defects due to bleeding or segregation. With regard to its composition, SCC consists of the same components as traditional vibrated concrete (TC), but in different proportions. Thus, the high amount of superplasticizer and high powder content have to taken into account. The high workability of SCC does not allow to use traditional methods for measuring the fresh state properties, so new tests has developed (slump-flow, V-funnel, L-box, and others). The properties of the hardened SCC, which depend on the mix design, should be different from traditional concrete. In order to study the possible modifications of SCC hardened state properties, a review of the bibliography was done. The state of art was focused on the mechanical behaviour (compressive strength, tension strength and elastic modulus), on bond strength of reinforcement steel, and on material durability. The experimental program consisted in the production of two types of concretes: Self-Compacting Concrete and Traditional Concrete. Four different dosages was made with three different water/cement ratio and two strength types of Portland cement, in order to cover the ordinary strength used in construction. Based on this study it can be concluded that compressive strength of SCC and TC are similar (the differences are lesser than 10%), whereas the tensile strength of TC are up to 18% higher. The values of elastic modulus of both concrete are similar. On the other hand, in the ultimate state the bond strength of SCC and TC is similar, although SCC shows higher bond stiffness in the serviceability state (initial

  7. Toward quantitative estimation of material properties with dynamic mode atomic force microscopy: a comparative study (United States)

    Ghosal, Sayan; Gannepalli, Anil; Salapaka, Murti


    In this article, we explore methods that enable estimation of material properties with the dynamic mode atomic force microscopy suitable for soft matter investigation. The article presents the viewpoint of casting the system, comprising of a flexure probe interacting with the sample, as an equivalent cantilever system and compares a steady-state analysis based method with a recursive estimation technique for determining the parameters of the equivalent cantilever system in real time. The steady-state analysis of the equivalent cantilever model, which has been implicitly assumed in studies on material property determination, is validated analytically and experimentally. We show that the steady-state based technique yields results that quantitatively agree with the recursive method in the domain of its validity. The steady-state technique is considerably simpler to implement, however, slower compared to the recursive technique. The parameters of the equivalent system are utilized to interpret storage and dissipative properties of the sample. Finally, the article identifies key pitfalls that need to be avoided toward the quantitative estimation of material properties.

  8. Measuring the effect of inter-study variability on estimating prediction error.

    Directory of Open Access Journals (Sweden)

    Shuyi Ma

    Full Text Available The biomarker discovery field is replete with molecular signatures that have not translated into the clinic despite ostensibly promising performance in predicting disease phenotypes. One widely cited reason is lack of classification consistency, largely due to failure to maintain performance from study to study. This failure is widely attributed to variability in data collected for the same phenotype among disparate studies, due to technical factors unrelated to phenotypes (e.g., laboratory settings resulting in "batch-effects" and non-phenotype-associated biological variation in the underlying populations. These sources of variability persist in new data collection technologies.Here we quantify the impact of these combined "study-effects" on a disease signature's predictive performance by comparing two types of validation methods: ordinary randomized cross-validation (RCV, which extracts random subsets of samples for testing, and inter-study validation (ISV, which excludes an entire study for testing. Whereas RCV hardwires an assumption of training and testing on identically distributed data, this key property is lost in ISV, yielding systematic decreases in performance estimates relative to RCV. Measuring the RCV-ISV difference as a function of number of studies quantifies influence of study-effects on performance.As a case study, we gathered publicly available gene expression data from 1,470 microarray samples of 6 lung phenotypes from 26 independent experimental studies and 769 RNA-seq samples of 2 lung phenotypes from 4 independent studies. We find that the RCV-ISV performance discrepancy is greater in phenotypes with few studies, and that the ISV performance converges toward RCV performance as data from additional studies are incorporated into classification.We show that by examining how fast ISV performance approaches RCV as the number of studies is increased, one can estimate when "sufficient" diversity has been achieved for learning a

  9. Estimation of PKCδ autophosphorylation in U87 MG glioma cells: combination of experimental, conceptual and numerical approaches. (United States)

    Misuth, Matus; Joniova, Jaroslava; Belej, Dominik; Hrivnak, Stanislav; Horvath, Denis; Huntosova, Veronika


    Golgi apparatus (GA) is a center for lipid metabolism and the final target of ceramide pathway, which may result in apoptosis. In this work localization of highly hydrophobic hypericin is followed by time-resolved imaging of NBDC6 (fluorescent ceramide) in U87 MG glioma cells. Decrease of NBDC6 fluorescence lifetimes in cells indicates that hypericin can also follow this pathway. It is known that both, ceramide and hypericin can significantly influence protein kinase C (PKC) activity. Western blotting analysis shows increase of PKCδ autophosphorylation at Ser645 (p(S645)PKCδ) in glioma cells incubated with 500 nM hypericin and confocal-fluorescence microscopy distinguishes p(S645)PKCδ localization between GA related compartments and nucleus. Experimental and numerical methods are combined to study p(S645)PKCδ in U87 MG cell line. Image processing based on conceptual qualitative description is combined with numerical treatment via simple exponential saturation model which describes redistribution of p(S645)PKCδ between nucleus and GA related compartments after hypericin administration. These results suggest, that numerical methods can significantly improve quantification of biomacromolecules (p(S645)PKCδ) directly from the fluorescence images and such obtained outputs are complementary if not equal to typical used methods in biology. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Synthesis, experimental and theoretical vibrational studies of 1 ...

    Indian Academy of Sciences (India)

    M Drai

    DMPrIM. +][(CF3SO2)2N. −]). The under- standing of the vibrational structures is important to explain the influence of the methyl group at C2 posi- tion (effect of methylation) between the two synthesized. ILs. For this purpose, experimental and ...

  11. A Simplified Experimental Scheme for the Study of Mitosis. (United States)

    Gill, John


    A procedure is described for providing preparations of dividing cells from root apical meristems, requiring only inexpensive equipment and minimal experimental skill, and using 8-Hydroxyquinoline and Toluidene-blue as a chromosome stain. The method has been sucessfully tested in schools and yields permanent preparations of adequate quality for…

  12. Students' Experimental Research Competences in the Study of Physics (United States)

    Kurbanbekov, Bakytzhan A.; Turmambekov, Torebai A.; Baizak, Usen A.; Saidakhmetov, Pulat A.; Abdraimov, Rakhymzhan T.; Bekayeva, Aigerim E.; Orazbayeva, Kuldarkhan O.


    The actuality of the investigated problem is caused by the need for students' training at pedagogical high schools to meet the challenges of research activities and the insufficient development of the theoretical, content-technological, scientific and methodological aspects of the formation of their experimental research competencies at the…

  13. Experimental studies on multicellular GFRP bridge deck panels ...

    Indian Academy of Sciences (India)



    Nov 20, 2017 ... Abstract. This paper presents the experimental investigations carried out on hand lay-up prototype multi- cellular glass fibre reinforced polymer (GFRP) composite bridge deck panels under static and fatigue loading. Various sustainability aspects with regard to GFRP structural members were discussed.

  14. Experimental studies on multicellular GFRP bridge deck panels ...

    Indian Academy of Sciences (India)

    This paper presents the experimental investigations carried out on hand lay-up prototype multicellular glass fibre reinforced polymer (GFRP) composite bridge deck panels under static and fatigue loading. Various sustainability aspects with regard to GFRP structural members were discussed. The aspects include(i) social ...

  15. Experimental and numerical study of high intensity argon cluster beams

    Energy Technology Data Exchange (ETDEWEB)

    Korobeishchikov, N. G.; Kalyada, V. V.; Shmakov, A. A.; Zarvin, A. E. [Department of Applied Physics, Novosibirsk State University, 2, Pirogova str., Novosibirsk, 630090 (Russian Federation); Skovorodko, P. A. [Department of Applied Physics, Novosibirsk State University, 2, Pirogova str., Novosibirsk, 630090, Russia and Kutateladze Institute of Thermophysics SB RAS,1, Lavrentyev Ave., Novosibirsk, 630090 (Russian Federation)


    Experimental and numerical investigations of expansion of argon with homogeneous condensation in supersonic conical nozzle and in free jet behind it were carried out. Optimal parameters (stagnation pressure, nozzle-skimmer distance) for the formation of cluster beam with maximum intensity were determined. Two available models for nonequilibrium nucleation were tested. The numerical results are in satisfactory agreement with the measured data.

  16. Experimental Study of Heat Dissipation in Indoor Sports Shoes

    NARCIS (Netherlands)

    Dessing, O.; Jansen, A.J.; Leihitu, C.; Overhage, D.


    As indoor sports shoes are intensively used in a warm and sweaty environment for periods of up to three consecutive hours, the built-up heat inside is insufficiently released causing warm and perspiring feet. This results in an increased chance of blisters and skin irritations. Experimental research

  17. Nanoscale experimental study of the morphology of a microcrack in ...

    Indian Academy of Sciences (India)

    A microcrack in a silicon single crystal was experimentally investigated using highresolution transmission electron microscopy (HRTEM). In particular, the numerical Moiré (NM) method was used to visualize the deformations and defects. The lattice structure of the microcrack was carefully observed at the nanoscale. HRTEM ...

  18. Experimental study of yttrium barium copper oxide superconducting ...

    Indian Academy of Sciences (India)

    Abstract. Critical current (Ic) characteristics of 2G YBCO superconducting tape under the influ- ence of twisting moment was experimentally investigated at varying current ramp rates in the self-field. Under a uniform twist, the degradation in the current-carrying capacity of YBCO tape up to 30% was observed at 77 K. The ...

  19. Experimental and theoretical study of precast beam-slab construction

    African Journals Online (AJOL)

    The use of partially precast beam elements with shear connectors in slab construction relieves the requirement of extensive use of soffit formwork and props and will have the advantage of faster construction. It also reduces adverse effects associated deforestation. Experimental and theoretical investigations were conducted ...

  20. Numerical and Experimental Study of Electromagnetically Driven Vortical Flows

    NARCIS (Netherlands)

    Kenjeres, S.; Verdoold, J.; Tummers, M.J.; Hanjalic, K.; Kleijn, C.R.


    The paper reports on numerical and experimental investigations of electromagnetically driven vortical flows of an electrically conductive fluid in a generic setup. Two different configurations of permanent magnets are considered: a 3-magnet configuration in which the resulting Lorentz force is