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Sample records for modal parameter extraction

  1. Consolidation of Modal Parameters from Several Extraction Sets

    SciTech Connect

    MAYES,RANDALL L.; KLENKE,SCOTT E.

    2000-10-24

    Experienced experimentalists have gone through the process of attempting to identify a final set of modal parameters from several different sets of extracted parameters. Usually, this is done by visually examining the mode shapes. With the advent of automated modal parameter extraction algorithms such as SMAC (Synthesize Modes and Correlate), very accurate extractions can be made to high frequencies. However, this process may generate several hundred modes that then must be consolidated into a final set of modal information. This has motivated the authors to generate a set of tools to speed the process of consolidating modal parameters by mathematical (instead of visual) means. These tools help quickly identify the best modal parameter extraction associated with several extractions of the same mode. The tools also indicate how many different modes have been extracted in a nominal frequency range and from which references. The mathematics are presented to achieve the best modal extraction of multiple modes at the same nominal frequency. Improvements in the SMAC graphical user interface and database are discussed that speed and improve the entire extraction process.

  2. The SMAC Modal Parameter Extraction Package

    SciTech Connect

    Klenke, S.E.; Mayes, R.L.

    1998-10-21

    After the basic theory for SMAC is presented below, two applications of the algorithm with real hardware will be presented. The first moderate-damping application is a system with approximately 50 modes in the bandwidth with up to 5 percent damping. The second application has at least 70 modes in the bandwidth, but damping is always below 3 percent. In addition to the improved implementation of the SMAC root finder, coding has been written to extract the mode shapes based on quadrature fit, and this is described herein.

  3. Modal Parameter Extraction Using Natural Excitation Response Data

    SciTech Connect

    Barney, P.; Carne, T.

    1998-10-21

    The use of natural excitation response data for the extraction of modal parameters has been an alluring idea for many years, The primary reason is that it offers the real world inputs (both spatial and temporal) and the associated responses of the system without the cost of a complex excitation system. The use of NExT allows for a linear representation of the system at operating levels, which is ideal for predictive linear simulation. The NExT parameter estimation methods have relied on using standard modal parameter extraction routines that do not exploit the special model form of NExT data. A parameter estimation method is developed here that is consistent with the form, thereby providing a more robust estimator in the presence of noise. This paper presents the basic methods used in NExT as well as some of the critical issues when using NExT.

  4. Extraction of Modal Parameters from Spacecraft Flight Data

    NASA Technical Reports Server (NTRS)

    James, George H.; Cao, Timothy T.; Fogt, Vincent A.; Wilson, Robert L.; Bartkowicz, Theodore J.

    2010-01-01

    The modeled response of spacecraft systems must be validated using flight data as ground tests cannot adequately represent the flight. Tools from the field of operational modal analysis would typically be brought to bear on such structures. However, spacecraft systems have several complicated issues: 1. High amplitudes of loads; 2. Compressive loads on the vehicle in flight; 3. Lack of generous time-synchronized flight data; 4. Changing properties during the flight; and 5. Major vehicle changes due to staging. A particularly vexing parameter to extract is modal damping. Damping estimation has become a more critical issue as new mass-driven vehicle designs seek to use the highest damping value possible. The paper will focus on recent efforts to utilize spacecraft flight data to extract system parameters, with a special interest on modal damping. This work utilizes the analysis of correlation functions derived from a sliding window technique applied to the time record. Four different case studies are reported in the sequence that drove the authors understanding. The insights derived from these four exercises are preliminary conclusions for the general state-of-the-art, but may be of specific utility to similar problems approached with similar tools.

  5. Modal parameter extraction from large operating structures using ambient excitation

    SciTech Connect

    James, G.H. III; Carne, T.G.; Mayes, R.L.

    1995-12-31

    A technique called the Natural Excitation Technique or has been developed to response extract response parameters from large operational structure when subjected to random and unmeasured forces such as wind, road noise, aerodynamics, or waves. Six applications of NExT to ambient excitation testing and NExT analysis are surveyed in this paper with a minimum of technical detail. In the first application, NExT was applied to a controlled-yaw Horizontal-Axis Wind Turbine (HAWT). By controlling the yaw degree of freedom an important class of rotating coordinate system effects are reduced. A new shape extraction procedure was applied to this data set with good results. The second application was to a free-yaw HAWT. The complexity of the response has prompted further analytical studies and the development of a specialized visualization package. The third application of NExT was to a parked three-bladed Vertical-Axis Wind Turbine (VAWT) in which traditional modal testing could not excite all modes of interest. The shape extraction process used cross-correlation functions directly in a time-domain shape-fitting routine. The fourth application was to ground transportation systems. Ongoing work to improve driver and passenger comfort in tractor-trailer vehicles and to refine automobile body and tire models will use NExT. NExT has been used to process ambient vibration data for Finite Element Model correlation and is being used to study Structural Health Monitoring with ambient excitation. Shape fitting was performed using amplitude and phase information taken directly from the cross-spectra. The final application is to an offshore structure. This work is on-going, however initial studies have found a high-modal density, high noise content, and sparse data set.

  6. Applications of the Automated SMAC Modal Parameter Extraction Package

    SciTech Connect

    MAYES,RANDALL L.; DORRELL,LARRY R.; KLENKE,SCOTT E.

    1999-10-29

    An algorithm known as SMAC (Synthesize Modes And Correlate), based on principles of modal filtering, has been in development for a few years. The new capabilities of the automated version are demonstrated on test data from a complex shell/payload system. Examples of extractions from impact and shaker data are shown. The automated algorithm extracts 30 to 50 modes in the bandwidth from each column of the frequency response function matrix. Examples of the synthesized Mode Indicator Functions (MIFs) compared with the actual MIFs show the accuracy of the technique. A data set for one input and 170 accelerometer outputs can typically be reduced in an hour. Application to a test with some complex modes is also demonstrated.

  7. A modal parameter extraction procedure applicable to linear time-invariant dynamic systems

    NASA Technical Reports Server (NTRS)

    Kurdila, A. J.; Craig, R. R., Jr.

    1985-01-01

    Modal analysis has emerged as a valuable tool in many phases of the engineering design process. Complex vibration and acoustic problems in new designs can often be remedied through use of the method. Moreover, the technique has been used to enhance the conceptual understanding of structures by serving to verify analytical models. A new modal parameter estimation procedure is presented. The technique is applicable to linear, time-invariant systems and accommodates multiple input excitations. In order to provide a background for the derivation of the method, some modal parameter extraction procedures currently in use are described. Key features implemented in the new technique are elaborated upon.

  8. Extraction of modal parameters with the aid of predicted analytical mode shapes

    SciTech Connect

    Mayes, R.L.; Carne, T.G.

    1996-02-01

    The extraction of the modal parameters for closely spaced modes in the frequency domain is a common problem. However, it is made more difficult if the damping for the closely spaced modes is high. Data from a structure with more than three percent viscous damping is presented which exhibits this phenomenon. Traditional experimental techniques failed to identify all the modal parameters of three closely spaced modes. Mode shapes from an analytical model are manipulated to produce a modal filter which is used to calculate enhanced frequency response functions from which the modal parameters can be more readily identified. Discussion of the advantages and disadvantages of this technique as compared with traditional frequency response function enhancement techniques will be presented.

  9. Automation and Other Extensions of the SMAC Modal Parameter Extraction Package

    SciTech Connect

    KLENKE,SCOTT E.; MAYES,RANDALL L.

    1999-11-01

    As model validation techniques gain more acceptance and increase in power, the demands on the modal parameter extractions increase. The estimation accuracy, the number of modes desired, and the data reduction efficiency are required features. An algorithm known as SMAC (Synthesize Modes And Correlate), based on principles of modal filtering, has been in development for a few years. SMAC has now been extended in two main areas. First, it has now been automated. Second, it has been extended to fit complex modes as well as real modes. These extensions have enhanced the power of modal extraction so that, typically, the analyst needs to manually fit only 10 percent of the modes in the desired bandwidth, whereas the automated routines will fit 90 percent of the modes. SMAC could be successfully automated because it generally does not produce computational roots.

  10. Monitoring a 5 MW offshore wind energy converter—Condition parameters and triangulation based extraction of modal parameters

    NASA Astrophysics Data System (ADS)

    Häckell, Moritz W.; Rolfes, Raimund

    2013-10-01

    The test field alpha ventus is the first operating German offshore parks for wind energy. Twelve Wind Energy Converters (WECs) of the 5 MW-class are installed, both, for commercial and research reasons. Due to upcoming mass production and uncertainties in loads and behaviour, monitoring the foundation of these structures was desired. Two goals addressed are the extraction of modal parameters for model validation and the estimation of condition parameters to allow a hypothesis of the system's state. In a first step the largedatabase is classified by Environmental and Operational Conditions (EOCs) through affinity propagation which is a new approach for Structural Health Monitoring (SHM) on wind turbines. Further, system identification through data driven stochastic subspace identification (SSI) is performed. A new, automated approach called triangulation-based extraction of modal parapeters (TEMP), using stability diagrams, is a key focus of the presented research. Finally, extraction of condition parameters for tower accelerations classified by EOCs, based on covariance driven SSI and Vector Auto-Regressive (VAR) Models, is performed for several observation periods from one to 16 weeks. These parameters and their distributions provide a base line for long term observations.

  11. The Natural Excitation Technique (NExT) for modal parameter extraction from operating wind turbines

    SciTech Connect

    James, G.H. III; Carne, T.G.; Lauffer, J.P.

    1993-02-01

    The Natural Excitation Technique (NExT) is a method of modal testing that allows structures to be tested in their ambient environments. This report is a compilation of developments and results since 1990, and contains a new theoretical derivation of NExT, as well as a verification using analytically generated data. In addition, we compare results from NExT with conventional modal testing for a parked, vertical-axis wind turbine, and, for a rotating turbine, NExT is used to calculate the model parameters as functions of the rotation speed, since substantial damping is derived from the aeroelastic interactions during operation. Finally, we compare experimental results calculated using NExT with analytical predictions of damping using aeroelastic theory.

  12. Estimation of Modal Parameters Using a Wavelet-Based Approach

    NASA Technical Reports Server (NTRS)

    Lind, Rick; Brenner, Marty; Haley, Sidney M.

    1997-01-01

    Modal stability parameters are extracted directly from aeroservoelastic flight test data by decomposition of accelerometer response signals into time-frequency atoms. Logarithmic sweeps and sinusoidal pulses are used to generate DAST closed loop excitation data. Novel wavelets constructed to extract modal damping and frequency explicitly from the data are introduced. The so-called Haley and Laplace wavelets are used to track time-varying modal damping and frequency in a matching pursuit algorithm. Estimation of the trend to aeroservoelastic instability is demonstrated successfully from analysis of the DAST data.

  13. Determination of rolling tyre modal parameters using Finite Element techniques and Operational Modal Analysis

    NASA Astrophysics Data System (ADS)

    Palanivelu, Sakthivel; Narasimha Rao, K. V.; Ramarathnam, Krishna Kumar

    2015-12-01

    In order to address various noise generation mechanisms and noise propagation phenomena of a tyre, it is necessary to study the tyre dynamic behaviour in terms of modal parameters. This paper enumerates a novel method of finding the modal parameters of a rolling tyre using an Explicit Finite Element Analysis and Operational Modal Analysis (OMA). ABAQUS Explicit, a commercial Finite Element (FE) software code has been used to simulate the experiment, a tyre rolling over a semi-circular straight and inclined cleat. The acceleration responses obtained from these simulations are used as input to the OMA. LMS test lab has been used for carrying out the Operational Modal Analysis. The modal results are compared with the published results of Kindt [22] and validated. Also, the modal results obtained from OMA are compared with FE modal results of stationary unloaded tyre, stationary loaded tyre and Steady State Transport rolling tyre.

  14. Constrained maximum likelihood modal parameter identification applied to structural dynamics

    NASA Astrophysics Data System (ADS)

    El-Kafafy, Mahmoud; Peeters, Bart; Guillaume, Patrick; De Troyer, Tim

    2016-05-01

    A new modal parameter estimation method to directly establish modal models of structural dynamic systems satisfying two physically motivated constraints will be presented. The constraints imposed in the identified modal model are the reciprocity of the frequency response functions (FRFs) and the estimation of normal (real) modes. The motivation behind the first constraint (i.e. reciprocity) comes from the fact that modal analysis theory shows that the FRF matrix and therefore the residue matrices are symmetric for non-gyroscopic, non-circulatory, and passive mechanical systems. In other words, such types of systems are expected to obey Maxwell-Betti's reciprocity principle. The second constraint (i.e. real mode shapes) is motivated by the fact that analytical models of structures are assumed to either be undamped or proportional damped. Therefore, normal (real) modes are needed for comparison with these analytical models. The work done in this paper is a further development of a recently introduced modal parameter identification method called ML-MM that enables us to establish modal model that satisfies such motivated constraints. The proposed constrained ML-MM method is applied to two real experimental datasets measured on fully trimmed cars. This type of data is still considered as a significant challenge in modal analysis. The results clearly demonstrate the applicability of the method to real structures with significant non-proportional damping and high modal densities.

  15. Modal Parameter Identification of ATV STM Using Modal and Base Excitation Approaches

    NASA Astrophysics Data System (ADS)

    Wagner, Mark; Grillenbeck, Anton, , Dr.

    2004-08-01

    In 2002, a modal survey and a dynamic qualification test were performed on the structural-thermal model (STM) of the Automated Transfer Vehicle (ATV). These tests were conducted by the European Test Services (ETS) with support of IABG at the test facilities of ESTEC in Noordwijk by order of EADS ST. In order to minimize test duration and set-up complexity, the dynamic qualification test and a classical modal test were planned to be performed within one combined test campaign. The objectives of these tests were the experimental dynamic characteri- zation of the ATV STM structure and its qualification with respect to the ARIANE 5 flight loads.. The results of this dynamic characterization had to be used to verify, respectively to update the mathematical models. This paper focuses on the modal characterisation aspects of these tests. Considering the excitability of the vibration modes of this large test article and the demand to accomplish the modal survey and qualification test in very short time, it was foreseen to combine the modal and the vibration test in a manner, such that with minimum effort, an optimum of modal characterisation could be achieved. In the first part of the test campaign, with its main objective to determine the modal parameters of the lateral ATV modes, the ATV STM was excited by using locally distributed electrodynamic shakers. The modal parameters were determined by applying tuned sine excitation and in addition by a modal analysis of the measured frequency response functions. In the second test sequence, in which the qualification test was performed, the ATV STM was mounted onto the HYDRA vibration test facility. The modal parameter identification for mainly the longitudinal ATV modes was performed by using modal analysis of the recorded structural responses resulting from the applied longitudinal base excitation. Also, the responses of the lateral vibration tests were available for a modal analysis. This paper describes the test set-ups and

  16. Noise reduction for modal parameters estimation using algorithm of solving partially described inverse singular value problem

    NASA Astrophysics Data System (ADS)

    Bao, Xingxian; Cao, Aixia; Zhang, Jing

    2016-07-01

    Modal parameters estimation plays an important role for structural health monitoring. Accurately estimating the modal parameters of structures is more challenging as the measured vibration response signals are contaminated with noise. This study develops a mathematical algorithm of solving the partially described inverse singular value problem (PDISVP) combined with the complex exponential (CE) method to estimate the modal parameters. The PDISVP solving method is to reconstruct an L2-norm optimized (filtered) data matrix from the measured (noisy) data matrix, when the prescribed data constraints are one or several sets of singular triplets of the matrix. The measured data matrix is Hankel structured, which is constructed based on the measured impulse response function (IRF). The reconstructed matrix must maintain the Hankel structure, and be lowered in rank as well. Once the filtered IRF is obtained, the CE method can be applied to extract the modal parameters. Two physical experiments, including a steel cantilever beam with 10 accelerometers mounted, and a steel plate with 30 accelerometers mounted, excited by an impulsive load, respectively, are investigated to test the applicability of the proposed scheme. In addition, the consistency diagram is proposed to exam the agreement among the modal parameters estimated from those different accelerometers. Results indicate that the PDISVP-CE method can significantly remove noise from measured signals and accurately estimate the modal frequencies and damping ratios.

  17. Parameter testing for lattice filter based adaptive modal control systems

    NASA Technical Reports Server (NTRS)

    Sundararajan, N.; Williams, J. P.; Montgomery, R. C.

    1983-01-01

    For Large Space Structures (LSS), an adaptive control system is highly desirable. The present investigation is concerned with an 'indirect' adaptive control scheme wherein the system order, mode shapes, and modal amplitudes are estimated on-line using an identification scheme based on recursive, least-squares, lattice filters. Using the identified model parameters, a modal control law based on a pole-placement scheme with the objective of vibration suppression is employed. A method is presented for closed loop adaptive control of a flexible free-free beam. The adaptive control scheme consists of a two stage identification scheme working in series and a modal pole placement control scheme. The main conclusion from the current study is that the identified parameters cannot be directly used for controller design purposes.

  18. Parameter testing for lattice filter based adaptive modal control systems

    NASA Technical Reports Server (NTRS)

    Sundararajan, N.; Williams, J. P.; Montgomery, R. C.

    1983-01-01

    For Large Space Structures (LSS), an adaptive control system is highly desirable. The present investigation is concerned with an 'indirect' adaptive control scheme wherein the system order, mode shapes, and modal amplitudes are estimated on-line using an identification scheme based on recursive, least-squares, lattice filters. Using the identified model parameters, a modal control law based on a pole-placement scheme with the objective of vibration suppression is employed. A method is presented for closed loop adaptive control of a flexible free-free beam. The adaptive control scheme consists of a two stage identification scheme working in series and a modal pole placement control scheme. The main conclusion from the current study is that the identified parameters cannot be directly used for controller design purposes.

  19. Experimental evaluation of a modal parameter based system identification procedure

    NASA Astrophysics Data System (ADS)

    Yu, Minli; Feng, Ningsheng; Hahn, Eric J.

    2016-02-01

    Correct modelling of the foundation of a rotor bearing foundation system (RBFS) is an invaluable asset for the balancing and efficient running of turbomachinery. Numerical experiments have shown that a modal parameter based identification approach could be feasible for this purpose but there is a lack of experimental verification of the suitability of such a modal approach for even the simplest systems. In this paper the approach is tested on a simple experimental rig comprising a clamped horizontal bar with lumped masses. It is shown that apart from damping, the proposed approach can identify reasonably accurately the relevant modal parameters of the rig; and that the resulting equivalent system can predict reasonably well the frequency response of the rig. Hence, the proposed approach shows promise but further testing is required, since application to identifying the foundation of an RBFS involves the additional problem of accurately obtaining the force excitation from motion measurements.

  20. Variability of modal parameters measured on the Alamosa Canyon Bridge

    SciTech Connect

    Farrar, C.R.; Doebling, S.W.; Cornwell, P.J.; Straser, E.G.

    1996-12-31

    A significant amount of work has been reported in technical literature regarding the use of changes in modal parameters to identify the location and extent of damage in structures. Curiously absent, and critically important to the practical implementation of this work, is an accurate characterization of the natural variability of these modal parameters caused by effects other than damage. To examine this issue, a two-lane, seven-span, composite slab-on-girder bridge near the town of Truth or Consequences in southern New Mexico was tested several times over a period of nine months. Environmental effects common to this location that could potentially produce changes in the measured modal properties include changes in temperature, high winds, and changes to the supporting soil medium. In addition to environmental effects, variabilities in modal testing procedures and data reduction can also cause changes in the identified dynamic properties of the structure. In this paper the natural variability of the frequencies and mode shapes of the Alamosa Canyon bridge that result from changes in time of day when the test was performed, amount of traffic, and environmental conditions will be discussed. Because this bridge has not been in active use throughout the testing period, it is assumed that any change in the observed modal properties are the result of the factors listed above rather than deterioration of the structure itself.

  1. Extraction parameters for metabolomics from cell extracts

    PubMed Central

    Ser, Zheng; Liu, Xiaojing; Tang, Ngoc Nu; Locasale, Jason W

    2015-01-01

    The successful extraction of metabolites is a critical step in metabolite profiling. By optimizing metabolite extraction, the range and quantitative capacity of metabolomics studies can be improved. We considered eight separate extraction protocols for the preparation of a metabolite extract from cultured mammalian cells. Parameters considered included temperature, pH, and cell washing before extraction. The effects on metabolite recovery were studied using a high resolution liquid chromatography mass spectrometry (LC-HRMS) platform that measures metabolites of diverse chemical classes including among others amino acids, lipids, and sugar derivatives. The temperature considered during the extraction or the presence of formic acid, a commonly used additive, was shown to have minimal effects on the measured ion intensities of metabolites. However, washing of samples before metabolite extraction whether with water or PBS (both commonly considered practices) exhibited dramatic effects on measured intensities of both intra- and extra-cellular metabolites. Together these findings present a systematic assessment of extraction conditions for metabolite profiling. PMID:25613493

  2. Modal Parameter Identification of a Flexible Arm System

    NASA Technical Reports Server (NTRS)

    Barrington, Jason; Lew, Jiann-Shiun; Korbieh, Edward; Wade, Montanez; Tantaris, Richard

    1998-01-01

    In this paper an experiment is designed for the modal parameter identification of a flexible arm system. This experiment uses a function generator to provide input signal and an oscilloscope to save input and output response data. For each vibrational mode, many sets of sine-wave inputs with frequencies close to the natural frequency of the arm system are used to excite the vibration of this mode. Then a least-squares technique is used to analyze the experimental input/output data to obtain the identified parameters for this mode. The identified results are compared with the analytical model obtained by applying finite element analysis.

  3. Estimation of uncertain material parameters using modal test data

    SciTech Connect

    Veers, P.S.; Laird, D.L.; Carne, T.G.; Sagartz, M.J.

    1997-11-01

    Analytical models of wind turbine blades have many uncertainties, particularly with composite construction where material properties and cross-sectional dimension may not be known or precisely controllable. In this paper the authors demonstrate how modal testing can be used to estimate important material parameters and to update and improve a finite-element (FE) model of a prototype wind turbine blade. An example of prototype blade is used here to demonstrate how model parameters can be identified. The starting point is an FE model of the blade, using best estimates for the material constants. Frequencies of the lowest fourteen modes are used as the basis for comparisons between model predictions and test data. Natural frequencies and mode shapes calculated with the FE model are used in an optimal test design code to select instrumentation (accelerometer) and excitation locations that capture all the desired mode shapes. The FE model is also used to calculate sensitivities of the modal frequencies to each of the uncertain material parameters. These parameters are estimated, or updated, using a weighted least-squares technique to minimize the difference between test frequencies and predicted results. Updated material properties are determined for axial, transverse, and shear moduli in two separate regions of the blade cross section: in the central box, and in the leading and trailing panels. Static FE analyses are then conducted with the updated material parameters to determine changes in effective beam stiffness and buckling loads.

  4. A robust methodology for modal parameters estimation applied to SHM

    NASA Astrophysics Data System (ADS)

    Cardoso, Rharã; Cury, Alexandre; Barbosa, Flávio

    2017-10-01

    The subject of structural health monitoring is drawing more and more attention over the last years. Many vibration-based techniques aiming at detecting small structural changes or even damage have been developed or enhanced through successive researches. Lately, several studies have focused on the use of raw dynamic data to assess information about structural condition. Despite this trend and much skepticism, many methods still rely on the use of modal parameters as fundamental data for damage detection. Therefore, it is of utmost importance that modal identification procedures are performed with a sufficient level of precision and automation. To fulfill these requirements, this paper presents a novel automated time-domain methodology to identify modal parameters based on a two-step clustering analysis. The first step consists in clustering modes estimates from parametric models of different orders, usually presented in stabilization diagrams. In an automated manner, the first clustering analysis indicates which estimates correspond to physical modes. To circumvent the detection of spurious modes or the loss of physical ones, a second clustering step is then performed. The second step consists in the data mining of information gathered from the first step. To attest the robustness and efficiency of the proposed methodology, numerically generated signals as well as experimental data obtained from a simply supported beam tested in laboratory and from a railway bridge are utilized. The results appeared to be more robust and accurate comparing to those obtained from methods based on one-step clustering analysis.

  5. Modal parameters estimation using ant colony optimisation algorithm

    NASA Astrophysics Data System (ADS)

    Sitarz, Piotr; Powałka, Bartosz

    2016-08-01

    The paper puts forward a new estimation method of modal parameters for dynamical systems. The problem of parameter estimation has been simplified to optimisation which is carried out using the ant colony system algorithm. The proposed method significantly constrains the solution space, determined on the basis of frequency plots of the receptance FRFs (frequency response functions) for objects presented in the frequency domain. The constantly growing computing power of readily accessible PCs makes this novel approach a viable solution. The combination of deterministic constraints of the solution space with modified ant colony system algorithms produced excellent results for systems in which mode shapes are defined by distinctly different natural frequencies and for those in which natural frequencies are similar. The proposed method is fully autonomous and the user does not need to select a model order. The last section of the paper gives estimation results for two sample frequency plots, conducted with the proposed method and the PolyMAX algorithm.

  6. Parameter extraction and transistor models

    NASA Technical Reports Server (NTRS)

    Rykken, Charles; Meiser, Verena; Turner, Greg; Wang, QI

    1985-01-01

    Using specified mathematical models of the MOSFET device, the optimal values of the model-dependent parameters were extracted from data provided by the Jet Propulsion Laboratory (JPL). Three MOSFET models, all one-dimensional were used. One of the models took into account diffusion (as well as convection) currents. The sensitivity of the models was assessed for variations of the parameters from their optimal values. Lines of future inquiry are suggested on the basis of the behavior of the devices, of the limitations of the proposed models, and of the complexity of the required numerical investigations.

  7. Modal parameters estimation in the Z-domain

    NASA Astrophysics Data System (ADS)

    Fasana, Alessandro

    2009-01-01

    This paper aims to explain in a clear, plain and detailed way a modal parameter estimation method in the frequency domain, or similarly in the Z-domain, valid for multi degrees-of-freedom systems. The technique is based on the rational fraction polynomials (RFP) representation of the frequency-response function (FRF) of a single input single output (SISO) system but is simply extended to multi input multi output (MIMO) and output only problems. A least-squares approach is adopted to take into account the information of all the FRFs but, when large data sets are used, the solution of the resulting system of algebraic linear equations can be a long and difficult task. A procedure to drastically reduce the problem dimensions is then adopted and fully explained; some practical hints are also given in order to achieve well-conditioned matrices. The method is validated through numerical and experimental examples.

  8. Modal parameter estimation via shaker vs speaker excitation

    SciTech Connect

    Weaver, H.J.; Burdick, R.B.

    1984-05-01

    When dynamically testing delicate laser components (e.g. an elliptical glass laser disc) it is often impossible to provide a direct contact excitation source such as an impact hammer or shaker. This is because of the delicate and/or brittle nature of the material from which the components are constructed. The alternate approach that is often used in a test of this type is to excite the component with an acoustic speaker. In this paper we describe a small series of tests in which we compare the modal parameters obtained by using a speaker as an excitation source with those obtained on the same object when the excitation was provided by a shaker.

  9. Modal parameter identification of stay cables from output-only measurements

    NASA Astrophysics Data System (ADS)

    Lardies, Joseph; Minh-Ngi, Ta

    2011-01-01

    Stay cables are one of the most critical structural components in modern cable-stayed bridges and the cable tension plays an important role in the construction, control and monitoring of cable-stayed bridges. We propose a time domain and a time-frequency domain approaches for modal parameter identification of stay cables using output-only measurements. The time domain approach uses the subspace algorithm which is improved with a new modal coherence indicator. The time-frequency approach uses the wavelet transform of signals which is improved with a new analyzing wavelet. The wavelet transform is applied to the free response of ambient vibration which is obtained using the random decrement technique. Two experiments of stay cables are presented. The first experiment concerns a stay cable in laboratory where the external load is applied through an impact hammer and the vibratory signals are acquired through four accelerometers. The second experiment concerns the Jinma cable-stayed bridge that connects Guangzhou and Zhaoqing in China. It is a single tower, double row cable-stayed bridge supported by 112 stay cables. Ambient vibration of each stay cable is carried out using accelerometers. From output-only measurements, the modal parameters of stay cables are extracted. Once the eigenfrequencies and the damping coefficients are obtained, the cable forces and the Scruton number are derived. In a continuous monitoring and modal analysis process, the tension forces and Scruton numbers could be used to assess the health of stay cables in cable-stayed bridges.

  10. Uncertainty calculation for modal parameters used with stochastic subspace identification: an application to a bridge structure

    NASA Astrophysics Data System (ADS)

    Hsu, Wei-Ting; Loh, Chin-Hsiung; Chao, Shu-Hsien

    2015-03-01

    Stochastic subspace identification method (SSI) has been proven to be an efficient algorithm for the identification of liner-time-invariant system using multivariate measurements. Generally, the estimated modal parameters through SSI may be afflicted with statistical uncertainty, e.g. undefined measurement noises, non-stationary excitation, finite number of data samples etc. Therefore, the identified results are subjected to variance errors. Accordingly, the concept of the stabilization diagram can help users to identify the correct model, i.e. through removing the spurious modes. Modal parameters are estimated at successive model orders where the physical modes of the system are extracted and separated from the spurious modes. Besides, an uncertainty computation scheme was derived for the calculation of uncertainty bounds for modal parameters at some given model order. The uncertainty bounds of damping ratios are particularly interesting, as the estimation of damping ratios are difficult to obtain. In this paper, an automated stochastic subspace identification algorithm is addressed. First, the identification of modal parameters through covariance-driven stochastic subspace identification from the output-only measurements is used for discussion. A systematic way of investigation on the criteria for the stabilization diagram is presented. Secondly, an automated algorithm of post-processing on stabilization diagram is demonstrated. Finally, the computation of uncertainty bounds for each mode with all model order in the stabilization diagram is utilized to determine system natural frequencies and damping ratios. Demonstration of this study on the system identification of a three-span steel bridge under operation condition is presented. It is shown that the proposed new operation procedure for the automated covariance-driven stochastic subspace identification can enhance the robustness and reliability in structural health monitoring.

  11. Modality.

    ERIC Educational Resources Information Center

    Barbe, Walter B.; Milone, Michael N., Jr.

    1980-01-01

    This article explains to teachers how they can identify their personal modality strength (auditory, visual, or kinesthetic) and how this orientation affects their classroom style. Techniques are also suggested for providing reading help to auditory, visual, and kinesthetic learners. (SJL)

  12. A modal test of a space-truss for structural parameter identification

    SciTech Connect

    Carne, T.G.; Mayes, R.L. ); Levine-West, M.B. )

    1992-01-01

    The Jet Propulsion Laboratory is developing a large space-truss to support a micro-precision interferometer. A finite element model will be used to design and place passive and active elements in the truss to suppress vibration. To improve the model's predictive capability, it is desirable to identify uncertain structural parameters in the model by utilizing experimental modal data. Testing of both the components and the system was performed to obtain the data necessary to identify the structural parameters. Extracting a modal model, absent of bias errors, from measured data requires great care in test design and implementation. Testing procedures that are discussed include: verification of non-constraining shaker attachment, quantification of the non-linear structural response, and the design and effects of suspension systems used to simulate a free structure. In addition to these procedures, the accuracy of the measured frequency response functions are evaluated by comparing functions measured with random excitation, using various frequency resolutions, and with step sine excitation.

  13. A modal test of a space-truss for structural parameter identification

    SciTech Connect

    Carne, T.G.; Mayes, R.L.; Levine-West, M.B.

    1992-12-01

    The Jet Propulsion Laboratory is developing a large space-truss to support a micro-precision interferometer. A finite element model will be used to design and place passive and active elements in the truss to suppress vibration. To improve the model`s predictive capability, it is desirable to identify uncertain structural parameters in the model by utilizing experimental modal data. Testing of both the components and the system was performed to obtain the data necessary to identify the structural parameters. Extracting a modal model, absent of bias errors, from measured data requires great care in test design and implementation. Testing procedures that are discussed include: verification of non-constraining shaker attachment, quantification of the non-linear structural response, and the design and effects of suspension systems used to simulate a free structure. In addition to these procedures, the accuracy of the measured frequency response functions are evaluated by comparing functions measured with random excitation, using various frequency resolutions, and with step sine excitation.

  14. Mathematical correlation of modal parameter identification methods via system realization theory

    NASA Technical Reports Server (NTRS)

    Juang, J. N.

    1986-01-01

    A unified approach is introduced using system realization theory to derive and correlate modal parameter identification methods for flexible structures. Several different time-domain and frequency-domain methods are analyzed and treated. A basic mathematical foundation is presented which provides insight into the field of modal parameter identification for comparison and evaluation. The relation among various existing methods is established and discussed. This report serves as a starting point to stimulate additional research towards the unification of the many possible approaches for modal parameter identification.

  15. Roll maneuvering of flexible aircraft with distributed-parameter actuation via modal synthesis

    NASA Astrophysics Data System (ADS)

    Oz, Hayrani; Khot, Narendra S.

    1999-06-01

    The focus is on obtaining and identifying optimal distributed- parameter-control equivalent actuation profiles for desired roll maneuvers by a modal synthesis approach. The solution for distributed-parameter-control of an aeroelastic system is developed by synthesis of modal-state-space controllers designed via the globally power optimal Independent Modal- Space Control (IMSC) technique. The desired maneuver (set- point) control performance is achieved by a modal-performance- output synthesis (MPOS) approach. The MPOS approach requires that each independent modal controller be allocated a desired portion of the total desired output performance. In view of this, a modal performance-output allocation optimization problem is also defined, which minimizes a hybrid measure of control power and elastic strain energy of the structure during aeroelastic control. Insight to distributed-parameter- control equivalent actuation solutions are sought by considering the aeroservoelastic interactions among vehicle motion, aerodynamics, structural flexibility and control actuators from the perspective of work-energy, control power, and control loading requirements. The modal synthesis approach is illustrated for a flight vehicle wing design to achieve a 90 deg/sec roll-rate in a Mach 2 flight condition at altitude (20000 ft) via distributed-parameter equivalent actuation. The preliminary results indicate that such a roll-rate maneuver can be accomplished via distributed-parameter actuation with feasible levels of control power, work-energy, and control loadings through eliciting favorable aeroservoelastic interactions.

  16. Extraction of SUSY Parameters from Collider Data

    SciTech Connect

    Zerwas, Dirk

    2008-11-23

    The extraction of the parameters of the supersymmetric Lagrangian is discussed. Particular emphasis is put on the rigorous treatment of experimental and theoretical errors. While the LHC can provide a valuable first estimate of the parameters, the combination of LHC and ILC will be necessary to determine with high precision the parameters of the MSSM.

  17. Time-varying modal parameters identification of a spacecraft with rotating flexible appendage by recursive algorithm

    NASA Astrophysics Data System (ADS)

    Ni, Zhiyu; Mu, Ruinan; Xun, Guangbin; Wu, Zhigang

    2016-01-01

    The rotation of spacecraft flexible appendage may cause changes in modal parameters. For this time-varying system, the computation cost of the frequently-used singular value decomposition (SVD) identification method is high. Some control problems, such as the self-adaptive control, need the latest modal parameters to update the controller parameters in time. In this paper, the projection approximation subspace tracking (PAST) recursive algorithm is applied as an alternative method to identify the time-varying modal parameters. This method avoids the SVD by signal subspace projection and improves the computational efficiency. To verify the ability of this recursive algorithm in spacecraft modal parameters identification, a spacecraft model with rapid rotational appendage, Soil Moisture Active/Passive (SMAP) satellite, is established, and the time-varying modal parameters of the satellite are identified recursively by designing the input and output signals. The results illustrate that this recursive algorithm can obtain the modal parameters in the high signal noise ratio (SNR) and it has better computational efficiency than the SVD method. Moreover, to improve the identification precision of this recursive algorithm in the low SNR, the wavelet de-noising technology is used to decrease the effect of noises.

  18. Large Margin Multi-Modal Multi-Task Feature Extraction for Image Classification.

    PubMed

    Yong Luo; Yonggang Wen; Dacheng Tao; Jie Gui; Chao Xu

    2016-01-01

    The features used in many image analysis-based applications are frequently of very high dimension. Feature extraction offers several advantages in high-dimensional cases, and many recent studies have used multi-task feature extraction approaches, which often outperform single-task feature extraction approaches. However, most of these methods are limited in that they only consider data represented by a single type of feature, even though features usually represent images from multiple modalities. We, therefore, propose a novel large margin multi-modal multi-task feature extraction (LM3FE) framework for handling multi-modal features for image classification. In particular, LM3FE simultaneously learns the feature extraction matrix for each modality and the modality combination coefficients. In this way, LM3FE not only handles correlated and noisy features, but also utilizes the complementarity of different modalities to further help reduce feature redundancy in each modality. The large margin principle employed also helps to extract strongly predictive features, so that they are more suitable for prediction (e.g., classification). An alternating algorithm is developed for problem optimization, and each subproblem can be efficiently solved. Experiments on two challenging real-world image data sets demonstrate the effectiveness and superiority of the proposed method.

  19. An Eigensystem Realization Algorithm (ERA) for modal parameter identification and model reduction

    NASA Technical Reports Server (NTRS)

    Juang, J. N.; Pappa, R. S.

    1985-01-01

    A method, called the Eigensystem Realization Algorithm (ERA), is developed for modal parameter identification and model reduction of dynamic systems from test data. A new approach is introduced in conjunction with the singular value decomposition technique to derive the basic formulation of minimum order realization which is an extended version of the Ho-Kalman algorithm. The basic formulation is then transformed into modal space for modal parameter identification. Two accuracy indicators are developed to quantitatively identify the system modes and noise modes. For illustration of the algorithm, examples are shown using simulation data and experimental data for a rectangular grid structure.

  20. A quasi-modal parameter based system identification procedure with non-proportional hysteretic damping

    NASA Astrophysics Data System (ADS)

    Yu, Minli; Hahn, Eric J.; Liu, Jike; Lu, Zhongrong

    2016-11-01

    This paper introduced a modal parameter based identification procedure to identify the equivalent system of structures under harmonic excitations. The developed identification technique assumed non-proportional hysteretic damping in the equivalent system, which would be applicable in identifying more general structures. By introducing quasi-modal parameter, modal analysis equation was decoupled under physical coordinate; hence, the modal parameters of each vibration mode are identified independently. Double iteration algorithm was developed to solve the derived non-linear identification equation with complex unknowns. The developed identification procedure was applied to identify the equivalent system of a numerical model in order to evaluate the feasibility of the technique in practice. The identification procedure was also applied to identify an experimental mass and bar rig for validation purpose. Identification results showed that the identification procedure could identify accurately and robustly the equivalent system with non-proportional hysteretic damping assumption; hence, it is likely to be applicable in the field.

  1. Determination of Modal Parameters from Experimental Frequency Response Data.

    DTIC Science & Technology

    1978-12-01

    MILLERUNCLASSIFIED AFITCTC 1A NL mhhIhIIIIIIIIu Il lllllllllfl EIIEIIEIIIEEI IIIIIIIIIIIIIu IEEEEEIIIIIIIE IIEEEE-EI-EII -iii1 � 11jW8 1 2... TIPLER OF DAMPING MATR- 5 PARAMETER ESTIMATION 7. ERROR w 0.97242 0.0 Ci 0.11493 0.0 2 0.28362 0.0 C2 0.14715 0.0 mode F0.05735 /-347.521 0.02M 1 L 1 0T 0

  2. Identification of Rotor-Bearing Systems in the Frequency Domain Part II: Estimation of Modal Parameters

    NASA Astrophysics Data System (ADS)

    Peeters, Frank; Pintelon, Rik; Schoukens, Johan; Rolain, Yves

    2001-07-01

    This paper discusses the parametric identification of multiple-input-multiple-output (MIMO) rotor-bearing systems in the frequency domain on the basis of the maximum likelihood estimator (MLE). An identification procedure, considering noise on both inputs and outputs (errors-in variables model), is developed for real as well as for complex modal testing. Quantitative measures for the uncertainties (covariances) of the estimated parameters were to be obtained. It is shown that the MLE solution of real and complex modal analysis is fully equivalent. It follows that, in case of complex modal testing, reduction of the system is not allowed in general when noise information is taken into account. A comparison between random and broadband periodic (multisine) excitations is made. Measurements on a rotor test rig demonstrated that multisines yield more accurate estimates of the modal parameters (as compared to random excitation).

  3. A generalized multiple-input, multiple-output modal parameter estimation algorithm

    NASA Technical Reports Server (NTRS)

    Craig, R. R., Jr.; Blair, M. A.

    1984-01-01

    A new method for experimental determination of the modal parameters of a structure is presented. The method allows for multiple input forces to be applied simultaneously, and for an arbitrary number of acceleration response measurements to be employed. These data are used to form the equations of motion for a damped linear elastic structure. The modal parameters are then obtained through an eigenvalue technique. In conjunction with the development of the equations, an extensive computer simulation study was performed. The results of the study show a marked improvement in the mode shape identification for closely-spaced modes as the number of applied forces is increased. Also demonstrated is the influence of noise on the method's ability to identify accurate modal parameters. Here again, an increase in the number of exciters leads to a significant improvement in the identified parameters.

  4. Application of Cauchy wavelet transformation to identify time-variant modal parameters of structures

    NASA Astrophysics Data System (ADS)

    Huang, C. S.; Liu, C. Y.; Su, W. C.

    2016-12-01

    This work proposes a procedure for accurately identifying instantaneous modal parameters of a linear time-varying system using a time-varying autoregressive with exogenous input (TVARX) model with the continuous Cauchy wavelet transform (CCWT). An appropriate TVARX model is established using the velocity and displacement responses of the system under consideration. The time-varying coefficients of the TVARX are expanded as piecewise polynomial functions. CCWTs with various scale parameters are then applied to the TVARX model to evaluate the instantaneous modal parameters of different modes. The CCWTs of the velocity and displacement responses are analytically obtained from the CCWT of the measured acceleration responses. The effectiveness and accuracy of the proposed procedure are validated by numerical simulations of single and multiple degrees of freedom systems that have periodically varying and sharply varying stiffness and damping coefficients. The effects of noise, the Cauchy wavelet function and the order of the polynomial on the evaluation of the modal parameters are explored in processing the numerically simulated acceleration responses of systems with a single degree of freedom subjected to base excitation. Finally, the proposed procedure is adopted to determine the modal parameters of a five-story symmetric steel frame from its measured acceleration responses in a shaking table test. The measured strains reveal the yielding of columns in the first story. The variations of the identified instantaneous natural frequencies and modal damping ratios with time are consistent with the physical phenomena that are observed from the measured strains and base excitation acceleration.

  5. Ranking vocal fold model parameters by their influence on modal frequencies

    PubMed Central

    Cook, Douglas D.; Nauman, Eric; Mongeau, Luc

    2009-01-01

    The purpose of this study was to identify, using computational models, the vocal fold parameters which are most influential in determining the vibratory characteristics of the vocal folds. The sensitivities of vocal folds modal frequencies to variations model parameters were used to determine the most influential parameters. A detailed finite element model of the human vocal fold was created. The model was defined by eight geometric and six material parameters. The model included transitional boundary regions to idealize the complex physiological structure of real human subjects. Parameters were simultaneously varied over ranges representative of actual human vocal folds. Three separate statistical analysis techniques were used to identify the most and least sensitive model parameters with respect to modal frequency. The results from all three methods consistently suggest that a set of five parameters are most influential in determining the vibratory characteristics of the vocal folds. PMID:19813811

  6. Dynamic measurement via laser interferometry: crystal growth monitoring and modal parameter analysis

    NASA Astrophysics Data System (ADS)

    Yang, Chong; Fu, Yu; Zhao, Jing; Miao, Hong; Zhu, Changchun; Zhang, Ping

    2015-03-01

    Generally there are two categories of noncontact laser interferometric methods commonly used in dynamic measurement, camera-based full-field interferometry and photo-sensor-based laser Doppler interferometry. The two methods have different advantages and disadvantages thus are suitable for different applications. The camera-based interferometry enjoys the valuable merit of full-field observation and measurement. In this paper, one typical full-field interferometry, digital holography, is employed to monitor the growth process of aqueous sodium chlorate crystals. The phase proportional to the solution concentration is retrieved from the holograms captured by CCD camera in real time. There exist no phase ambiguity problem in holography compared with other optical interferometric methods. On the other hand, laser Doppler interferometry is usually a point-wise measurement but with a very high temporal sampling rate. A multipoint laser Doppler interferometer is proposed for modal parameter measurement in this paper. The multiple transient vibration signals of spatially separated points on a beam structure subjected to a shock excitation are recorded synchronously. The natural frequencies and mode shapes are extracted in the signal processing stage. This paper shows that laser interferometry is able to contribute more to the practical applications in dynamic measurement related fields.

  7. Effect of damage on the modal parameters of a cylindrical shell

    SciTech Connect

    Srinivasan, M.G.; Kot, C.A.

    1992-02-01

    The objective of the study was to investigate the feasibility of assessing damage to structural systems by measuring the changes in the dynamic characteristics of a thin circular cylindrical shell with both ends open. Theoretical and experimental modal analyses were performed for the shell. Subsequently, a notch was machined into the shell simulating a small amount of damage. The shell with the notch was again subjected to experimental modal analysis. A comparison of the modal parameters determined from the tests before and after the shell was damaged showed that the natural frequencies were not sensitive to the crack introduced. However, some of the mode shapes showed significant changes, establishing that the mode shapes were the more sensitive parameters for damage detection.

  8. Effect of damage on the modal parameters of a cylindrical shell

    SciTech Connect

    Srinivasan, M.G.; Kot, C.A.

    1992-01-01

    The objective of the study was to investigate the feasibility of assessing damage to structural systems by measuring the changes in the dynamic characteristics of a thin circular cylindrical shell with both ends open. Theoretical and experimental modal analyses were performed for the shell. Subsequently, a notch was machined into the shell simulating a small amount of damage. The shell with the notch was again subjected to experimental modal analysis. A comparison of the modal parameters determined from the tests before and after the shell was damaged showed that the natural frequencies were not sensitive to the crack introduced. However, some of the mode shapes showed significant changes, establishing that the mode shapes were the more sensitive parameters for damage detection.

  9. Mechanomyographic parameter extraction methods: an appraisal for clinical applications.

    PubMed

    Ibitoye, Morufu Olusola; Hamzaid, Nur Azah; Zuniga, Jorge M; Hasnan, Nazirah; Wahab, Ahmad Khairi Abdul

    2014-12-03

    The research conducted in the last three decades has collectively demonstrated that the skeletal muscle performance can be alternatively assessed by mechanomyographic signal (MMG) parameters. Indices of muscle performance, not limited to force, power, work, endurance and the related physiological processes underlying muscle activities during contraction have been evaluated in the light of the signal features. As a non-stationary signal that reflects several distinctive patterns of muscle actions, the illustrations obtained from the literature support the reliability of MMG in the analysis of muscles under voluntary and stimulus evoked contractions. An appraisal of the standard practice including the measurement theories of the methods used to extract parameters of the signal is vital to the application of the signal during experimental and clinical practices, especially in areas where electromyograms are contraindicated or have limited application. As we highlight the underpinning technical guidelines and domains where each method is well-suited, the limitations of the methods are also presented to position the state of the art in MMG parameters extraction, thus providing the theoretical framework for improvement on the current practices to widen the opportunity for new insights and discoveries. Since the signal modality has not been widely deployed due partly to the limited information extractable from the signals when compared with other classical techniques used to assess muscle performance, this survey is particularly relevant to the projected future of MMG applications in the realm of musculoskeletal assessments and in the real time detection of muscle activity.

  10. Structural modal parameter identification and damage diagnosis based on Hilbert-Huang transform

    NASA Astrophysics Data System (ADS)

    Han, Jianping; Zheng, Peijuan; Wang, Hongtao

    2014-03-01

    Traditional modal parameter identification methods have many disadvantages, especially when used for processing nonlinear and non-stationary signals. In addition, they are usually not able to accurately identify the damping ratio and damage. In this study, methods based on the Hilbert-Huang transform (HHT) are investigated for structural modal parameter identification and damage diagnosis. First, mirror extension and prediction via a radial basis function (RBF) neural network are used to restrain the troublesome end-effect issue in empirical mode decomposition (EMD), which is a crucial part of HHT. Then, the approaches based on HHT combined with other techniques, such as the random decrement technique (RDT), natural excitation technique (NExT) and stochastic subspace identification (SSI), are proposed to identify modal parameters of structures. Furthermore, a damage diagnosis method based on the HHT is also proposed. Time-varying instantaneous frequency and instantaneous energy are used to identify the damage evolution of the structure. The relative amplitude of the Hilbert marginal spectrum is used to identify the damage location of the structure. Finally, acceleration records at gauge points from shaking table testing of a 12-story reinforced concrete frame model are taken to validate the proposed approaches. The results show that the proposed approaches based on HHT for modal parameter identification and damage diagnosis are reliable and practical.

  11. A system theory approach to multi-input multi-output modal parameters identification methods

    NASA Astrophysics Data System (ADS)

    Yang, Q. J.; Zhang, P. Q.; Li, C. Q.; Wu, X. P.

    1994-03-01

    In this paper, a new theory of multi-input multi-output (MIMO) modal parameters identification technique is developed from the view of system theory. In the first part of the paper, the necessity of the MIMO identification is introduced from controllability and observability theory. Then, by linear transformation of system state equations, a mathematical model which describes the relation between a vibration system's MIMO, is given; when the model parameters are estimated from the measurement of the vibration system's input and output, the modal parameters can be identified by means of reconstructing the system state equations. Formulae on the identification are also presented in the paper. This theory can serve as a unifying approach, as many well known identifying methods, such as the direct parameter model, polyreference, Ibrahim time domain method and Eigensystem realisation algorithm can be derived as special forms. These are presented in the last part of the paper, and the relationship among all these methods are shown.

  12. The sensitivity of identified modal parameters to sensor placement errors and construction tolerances

    NASA Technical Reports Server (NTRS)

    Hinkle, Jason; Bullock, Steven J.

    1993-01-01

    This paper examines the sensitivity of experimentally measured modal frequencies and mode shapes to structural reassembly and sensor placement errors on a suspended three-bay truss. The statistical variations of identified mode shapes and frequencies are measured by repeated experiments. Both parameters are shown to vary measurably more with reassembly than sensor placement errors. Also, a directional stiffness in the truss joints was found to cause a parameter dependence on member orientation during reconstruction.

  13. Estimating free-body modal parameters from tests of a constrained structure

    NASA Technical Reports Server (NTRS)

    Cooley, Victor M.

    1993-01-01

    Hardware advances in suspension technology for ground tests of large space structures provide near on-orbit boundary conditions for modal testing. Further advances in determining free-body modal properties of constrained large space structures have been made, on the analysis side, by using time domain parameter estimation and perturbing the stiffness of the constraints over multiple sub-tests. In this manner, passive suspension constraint forces, which are fully correlated and therefore not usable for spectral averaging techniques, are made effectively uncorrelated. The technique is demonstrated with simulated test data.

  14. Modal parameter identification by an iterative approach and by the state space model

    NASA Astrophysics Data System (ADS)

    Lardiès, Joseph

    2017-10-01

    The problem of estimating a spectral representation of exponentially decaying signals from a set of sampled data is of considerable interest in several applications such as in vibration analysis of mechanical systems. In this paper we present a nonparametric and a parametric method for modal parameter identification of vibrating systems when only output data is available. The nonparametric method uses an iterative adaptive algorithm based in the formation of a two dimensional grid mesh, both in frequency and damping domains. We formulate the identification problem as an optimization problem where the signal energy is obtained from each frequency grid point and damping grid point. The modal parameters are then obtained by minimizing the signal energy from all grid points other than the grid point which contains the modal parameters of the system. The parametric approach uses the state space model and properties of the controllability matrix to obtain the state transition matrix which contains all modal information. We discuss and illustrate the benefits of the proposed algorithms using a numerical and two experimental tests and we conclude that the nonparametric approach is very time consuming when a large number of samples is considered and does not outperform the parametric approach.

  15. A new procedure of modal parameter estimation for high-speed digital image correlation

    NASA Astrophysics Data System (ADS)

    Huňady, Róbert; Hagara, Martin

    2017-09-01

    The paper deals with the use of 3D digital image correlation in determining modal parameters of mechanical systems. It is a non-contact optical method, which for the measurement of full-field spatial displacements and strains of bodies uses precise digital cameras with high image resolution. Most often this method is utilized for testing of components or determination of material properties of various specimens. In the case of using high-speed cameras for measurement, the correlation system is capable of capturing various dynamic behaviors, including vibration. This enables the potential use of the mentioned method in experimental modal analysis. For that purpose, the authors proposed a measuring chain for the correlation system Q-450 and developed a software application called DICMAN 3D, which allows the direct use of this system in the area of modal testing. The created application provides the post-processing of measured data and the estimation of modal parameters. It has its own graphical user interface, in which several algorithms for the determination of natural frequencies, mode shapes and damping of particular modes of vibration are implemented. The paper describes the basic principle of the new estimation procedure which is crucial in the light of post-processing. Since the FRF matrix resulting from the measurement is usually relatively large, the estimation of modal parameters directly from the FRF matrix may be time-consuming and may occupy a large part of computer memory. The procedure implemented in DICMAN 3D provides a significant reduction in memory requirements and computational time while achieving a high accuracy of modal parameters. Its computational efficiency is particularly evident when the FRF matrix consists of thousands of measurement DOFs. The functionality of the created software application is presented on a practical example in which the modal parameters of a composite plate excited by an impact hammer were determined. For the

  16. Single-Mode Projection Filters for Modal Parameter Identification for Flexible Structures

    NASA Technical Reports Server (NTRS)

    Huang, Jen-Kuang; Chen, Chung-Wen

    1988-01-01

    Single-mode projection filters are developed for eigensystem parameter identification from both analytical results and test data. Explicit formulations of these projection filters are derived using the orthogonal matrices of the controllability and observability matrices in the general sense. A global minimum optimization algorithm is applied to update the filter parameters by using the interval analysis method. The updated modal parameters represent the characteristics of the test data. For illustration of this new approach, a numerical simulation for the MAST beam structure is shown by using a one-dimensional global optimization algorithm to identify modal frequencies and damping. Another numerical simulation of a ten-mode structure is also presented by using a two-dimensional global optimization algorithm to illustrate the feasibility of the new method. The projection filters are practical for parallel processing implementation.

  17. Semi-analytical formulation of modal dispersion parameter of an optical fiber with Kerr nonlinearity and using a novel fundamental modal field approximation

    NASA Astrophysics Data System (ADS)

    Choudhury, Raja Roy; Choudhury, Arundhati Roy; Ghose, Mrinal Kanti

    2013-09-01

    To characterize nonlinear optical fiber, a semi-analytical formulation using variational principle and the Nelder-Mead Simplex method for nonlinear unconstrained minimization is proposed. The number of optimizing parameters in order to optimize core parameter U has been increased to incorporate more flexibility in the formulation of an innovative form of fundamental modal field. This formulation provides accurate analytical expressions for modal dispersion parameter (g) of optical fiber with Kerr nonlinearity. The minimization of core parameter (U), which involves Kerr nonlinearity through the nonstationary expression of propagation constant, is carried out by the Nelder-Mead Simplex method of nonlinear unconstrained minimization, suitable for problems with nonsmooth functions as the method does not require any derivative information. This formulation has less computational burden for calculation of modal parameters than full numerical methods.

  18. Comparative evaluation of soft tissue changes in Class I borderline patients treated with extraction and nonextraction modalities

    PubMed Central

    Yashwant V., Aniruddh; K., Ravi; Arumugam, Edeinton

    2016-01-01

    Abstract Objective: To compare soft tissue changes in Class I borderline cases treated with extraction and nonextraction modalities. Methods: A parent sample of 150 patients with Class I dental and skeletal malocclusion (89 patients treated with premolar extraction and 61 patients without extraction) was randomly selected and subjected to discriminant analysis which identified the borderline sample of 44 patients (22 extraction and 22 nonextraction patients). Pretreatment and post-treatment cephalograms of the borderline subsample were analyzed using 22 soft tissue parameters. Results: Upper and lower lips were more retracted and thickness of the upper lip increased more in the borderline extraction cases (p < 0.01). The nasolabial angle became more obtuse and the interlabial gap was reduced in the borderline extraction cases (p < 0.01). Lower lip, interlabial gap and nasolabial angle showed no changes in the borderline nonextraction cases. Conclusion: The soft tissue parameters which can be used as guideline in decision making to choose either extraction or nonextraction in Class I borderline cases are upper and lower lip protrusion in relation to the E-plane and Sn-Pg' line, lower lip protrusion in relation to the true vertical line (TVL), upper lip thickness, nasolabial angle and interlabial gap. PMID:27653264

  19. Comparative evaluation of soft tissue changes in Class I borderline patients treated with extraction and nonextraction modalities.

    PubMed

    Yashwant V, Aniruddh; K, Ravi; Arumugam, Edeinton

    2016-01-01

    To compare soft tissue changes in Class I borderline cases treated with extraction and nonextraction modalities. A parent sample of 150 patients with Class I dental and skeletal malocclusion (89 patients treated with premolar extraction and 61 patients without extraction) was randomly selected and subjected to discriminant analysis which identified the borderline sample of 44 patients (22 extraction and 22 nonextraction patients). Pretreatment and post-treatment cephalograms of the borderline subsample were analyzed using 22 soft tissue parameters. Upper and lower lips were more retracted and thickness of the upper lip increased more in the borderline extraction cases (p < 0.01). The nasolabial angle became more obtuse and the interlabial gap was reduced in the borderline extraction cases (p < 0.01). Lower lip, interlabial gap and nasolabial angle showed no changes in the borderline nonextraction cases. The soft tissue parameters which can be used as guideline in decision making to choose either extraction or nonextraction in Class I borderline cases are upper and lower lip protrusion in relation to the E-plane and Sn-Pg' line, lower lip protrusion in relation to the true vertical line (TVL), upper lip thickness, nasolabial angle and interlabial gap.

  20. An eigensystem realization algorithm using data correlations (ERA/DC) for modal parameter identification

    NASA Technical Reports Server (NTRS)

    Juang, Jer-Nan; Cooper, J. E.; Wright, J. R.

    1987-01-01

    A modification to the Eigensystem Realization Algorithm (ERA) for modal parameter identification is presented in this paper. The ERA minimum order realization approach using singular value decomposition is combined with the philosophy of the Correlation Fit method in state space form such that response data correlations rather than actual response values are used for modal parameter identification. This new method, the ERA using data correlations (ERA/DC), reduces bias errors due to noise corruption significantly without the need for model overspecification. This method is tested using simulated five-degree-of-freedom system responses corrupted by measurement noise. It is found for this case that, when model overspecification is permitted and a minimum order solution obtained via singular value truncation, the results from the two methods are of similar quality.

  1. Variance and bias confidence criteria for ERA modal parameter identification. [Eigensystem Realization Algorithm

    NASA Technical Reports Server (NTRS)

    Longman, Richard W.; Bergmann, Martin; Juang, Jer-Nan

    1988-01-01

    For the ERA system identification algorithm, perturbation methods are used to develop expressions for variance and bias of the identified modal parameters. Based on the statistics of the measurement noise, the variance results serve as confidence criteria by indicating how likely the true parameters are to lie within any chosen interval about their identified values. This replaces the use of expensive and time-consuming Monte Carlo computer runs to obtain similar information. The bias estimates help guide the ERA user in his choice of which data points to use and how much data to use in order to obtain the best results, performing the trade-off between the bias and scatter. Also, when the uncertainty in the bias is sufficiently small, the bias information can be used to correct the ERA results. In addition, expressions for the variance and bias of the singular values serve as tools to help the ERA user decide the proper modal order.

  2. Variance and bias confidence criteria for ERA modal parameter identification. [Eigensystem Realization Algorithm

    NASA Technical Reports Server (NTRS)

    Longman, Richard W.; Bergmann, Martin; Juang, Jer-Nan

    1988-01-01

    For the ERA system identification algorithm, perturbation methods are used to develop expressions for variance and bias of the identified modal parameters. Based on the statistics of the measurement noise, the variance results serve as confidence criteria by indicating how likely the true parameters are to lie within any chosen interval about their identified values. This replaces the use of expensive and time-consuming Monte Carlo computer runs to obtain similar information. The bias estimates help guide the ERA user in his choice of which data points to use and how much data to use in order to obtain the best results, performing the trade-off between the bias and scatter. Also, when the uncertainty in the bias is sufficiently small, the bias information can be used to correct the ERA results. In addition, expressions for the variance and bias of the singular values serve as tools to help the ERA user decide the proper modal order.

  3. Constitutive parameter extraction for heated materials

    NASA Technical Reports Server (NTRS)

    Munk, J.; Dominek, A.

    1991-01-01

    The focus is the determination of the electrical constitutive paramaters of materials with general complex epsilon and mu values at elevated temperatures. Measurement fixtures and techniques are evaluated for frequencies between 8 and 12 GHz using a rectangular waveguide with the sample completely filling the fixture. Three different measurement techniques are evaluated to obtain the necessary measured quantities for parameter extraction. The most desirable technique used two reflection measurements from material samples of different thickness backed with a short. Temperatures up to 600 F were investigated.

  4. A new scenario-based approach to damage detection using operational modal parameter estimates

    NASA Astrophysics Data System (ADS)

    Hansen, J. B.; Brincker, R.; López-Aenlle, M.; Overgaard, C. F.; Kloborg, K.

    2017-09-01

    In this paper a vibration-based damage localization and quantification method, based on natural frequencies and mode shapes, is presented. The proposed technique is inspired by a damage assessment methodology based solely on the sensitivity of mass-normalized experimental determined mode shapes. The present method differs by being based on modal data extracted by means of Operational Modal Analysis (OMA) combined with a reasonable Finite Element (FE) representation of the test structure and implemented in a scenario-based framework. Besides a review of the basic methodology this paper addresses fundamental theoretical as well as practical considerations which are crucial to the applicability of a given vibration-based damage assessment configuration. Lastly, the technique is demonstrated on an experimental test case using automated OMA. Both the numerical study as well as the experimental test case presented in this paper are restricted to perturbations concerning mass change.

  5. Stochastic finite element method for random harmonic analysis of composite plates with uncertain modal damping parameters

    NASA Astrophysics Data System (ADS)

    Sepahvand, K.

    2017-07-01

    Damping parameters of fiber-reinforced composite possess significant uncertainty due to the structural complexity of such materials. Considering the parameters as random variables, this paper uses the generalized polynomial chaos (gPC) expansion to capture the uncertainty in the damping and frequency response function of composite plate structures. A spectral stochastic finite element formulation for damped vibration analysis of laminate plates is employed. Experimental modal data for samples of plates is used to identify and realize the range and probability distributions of uncertain damping parameters. The constructed gPC expansions for the uncertain parameters are used as inputs to a deterministic finite element model to realize random frequency responses on a few numbers of collocation points generated in random space. The realizations then are employed to estimate the unknown deterministic functions of the gPC expansion approximating the responses. Employing modal superposition method to solve harmonic analysis problem yields an efficient sparse gPC expansion representing the responses. The results show while the responses are influenced by the damping uncertainties at the mid and high frequency ranges, the impact in low frequency modes can be safely ignored. Utilizing a few random collocation points, the method indicates also a very good agreement compared to the sampling-based Monte Carlo simulations with large number of realizations. As the deterministic finite element model serves as black-box solver, the procedure can be efficiently adopted to complex structural systems with uncertain parameters in terms of computational time.

  6. Stability, structure and scale: improvements in multi-modal vessel extraction for SEEG trajectory planning.

    PubMed

    Zuluaga, Maria A; Rodionov, Roman; Nowell, Mark; Achhala, Sufyan; Zombori, Gergely; Mendelson, Alex F; Cardoso, M Jorge; Miserocchi, Anna; McEvoy, Andrew W; Duncan, John S; Ourselin, Sébastien

    2015-08-01

    Brain vessels are among the most critical landmarks that need to be assessed for mitigating surgical risks in stereo-electroencephalography (SEEG) implantation. Intracranial haemorrhage is the most common complication associated with implantation, carrying significantly associated morbidity. SEEG planning is done pre-operatively to identify avascular trajectories for the electrodes. In current practice, neurosurgeons have no assistance in the planning of electrode trajectories. There is great interest in developing computer-assisted planning systems that can optimise the safety profile of electrode trajectories, maximising the distance to critical structures. This paper presents a method that integrates the concepts of scale, neighbourhood structure and feature stability with the aim of improving robustness and accuracy of vessel extraction within a SEEG planning system. The developed method accounts for scale and vicinity of a voxel by formulating the problem within a multi-scale tensor voting framework. Feature stability is achieved through a similarity measure that evaluates the multi-modal consistency in vesselness responses. The proposed measurement allows the combination of multiple images modalities into a single image that is used within the planning system to visualise critical vessels. Twelve paired data sets from two image modalities available within the planning system were used for evaluation. The mean Dice similarity coefficient was 0.89 ± 0.04, representing a statistically significantly improvement when compared to a semi-automated single human rater, single-modality segmentation protocol used in clinical practice (0.80 ± 0.03). Multi-modal vessel extraction is superior to semi-automated single-modality segmentation, indicating the possibility of safer SEEG planning, with reduced patient morbidity.

  7. Exploring vibration control strategies for a footbridge with time-varying modal parameters

    NASA Astrophysics Data System (ADS)

    Soria, Jose M.; Díaz, Ivan M.; Pereira, Emiliano; García-Palacios, Jaime H.; Wang, Xidong

    2016-09-01

    This paper explores different vibration control strategies for the cancellation of human-induced vibration of a structure with time-varying modal parameters. The motivation of this study is an urban stress-ribbon footbridge (Pedro Gomez Bosque, Valladolid, Spain) that, after a whole-year monitoring, it has been obtained that the natural frequency of a vibration mode at approximately 1.8 Hz (within the normal range of walking) changes up to 20%, mainly due to temperature variations. Thus, this paper takes the annual modal parameter estimates (aprox. 14000 estimations) of this mode and designs three control strategies: a) a tuned mass damper (TMD) tuned to the aforementioned mode using its most-repeated modal properties, b) a semi-active TMD with an on-off control law for the TMD damping, and c) an active mass damper designed using the well-known velocity feedback control strategy with a saturation nonlinearity. Illustrative results have been reported from this preliminary study.

  8. Study of modal parameters and vibration signatures of notched concrete prisms

    SciTech Connect

    Borsaikia, A.; Talukdar, S. . E-mail: staluk@iitg.ernet.in; Dutta, A.

    2006-03-15

    In the present study, vibration tests have been carried out on notched concrete prisms. The tests have been conducted to study modal parameters and vibration signatures in order to enhance the knowledge of monitoring concrete structures. Notch (artificially introduced crack) of constant widths and varying depths has been introduced in the concrete prisms at different locations. The specimens have been subjected to impact excitations by dropping a specific weight from a fixed height and at a particular location. The natural frequencies of notched and intact prisms have been experimentally measured. The frequency response functions (FRF) as obtained from multichannel pulse analyzer have been synthesized to evaluate the fundamental mode shape of vibration of the prisms by a curve fitting method. These curves have been further post-processed to obtain the modal curvature values. Pattern Recognition Scheme is applied to synthesize vibration signatures for the evaluation of the curvature differential values. The curvature differential values corresponding to different sensor locations in both intact and notched specimens have been obtained. Experimental results with different depth of flaws suggest that natural frequency alone cannot be a reliable parameter for the detection of damage in concrete beams with shallow depth of flaws. The modal curvature values have been found to be a reasonably good indicator of the location of the damage. The curvature differential values show the extent of damage but found to be dependent on the sensor location from the position of notch.

  9. Propellant Sloshing Parameter Extraction from CFD Analysis

    NASA Technical Reports Server (NTRS)

    Yang, H. Q.; Peugeot, John

    2010-01-01

    Propellant slosh is a potential source of disturbance critical to the stability of space vehicle. The sloshing dynamics is typically represented by a mechanical model of spring mass damper. This mechanical model is then included in the equation of motion of the entire vehicle for Guidance, Navigation and Control analysis. The typical parameters required by the mechanical model include natural frequency of the sloshing, sloshing mass, sloshing mass center coordinates, and critical damping coefficient. During the 1960 s US space program, these parameters were either computed from analytical solution for simple geometry or by experimental testing for the sub-scaled configurations. The purpose of this work is to demonstrate the soundness of a CFD approach in modeling the detailed fluid dynamics of tank sloshing and the excellent accuracy in extracting mechanical properties for different tank configurations and at different fill levels. The validation studies included straight cylinder against analytical solution, and sub-scaled Centaur LOX and LH2 tanks with and without baffles against experimental results. This effort shows that CFD technology can provide accurate mechanical parameters for any tank configuration, and is especially valuable to the future design of propellant tanks, as there is no previous experimental data available for the same size and configuration.

  10. Energy dissipation and absorption capacity influence on experimental modal parameters of a PC girder

    NASA Astrophysics Data System (ADS)

    Luna Vera, O. S.; Kim, C. W.; Oshima, Y.

    2017-05-01

    This experimental investigation focuses on collecting vibration data after different loading scenarios in a PC girder while measuring the performance at the same time. The vibration data is used for modal analysis and since several samples were taken in each scenario with different impact hammer tips, a comparison of the outcomes is also possible. The performance is based on recorded displacements along the bottom surface of the girder, information that makes possible the calculation of energy absorbed before cracking and the energy dissipation that takes place after cracking. Furthermore, two major damage events, a tendon breakage and cracking, were induced and monitored respectively. This study also clarified the influence of change in energy on changes in modal parameters.

  11. Planetary gear modal vibration experiments and correlation against lumped-parameter and finite element models

    NASA Astrophysics Data System (ADS)

    Ericson, Tristan M.; Parker, Robert G.

    2013-04-01

    Experimental modal analysis techniques are applied to characterize the planar dynamic behavior of two spur planetary gears. Rotational and translational vibrations of the sun gear, carrier, and planet gears are measured. Experimentally obtained natural frequencies, mode shapes, and dynamic response are compared to the results from lumped-parameter and finite element models. Two qualitatively different classes of mode shapes in distinct frequency ranges are observed in the experiments and confirmed by the lumped-parameter model, which considers the accessory shafts and fixtures in the system to capture all of the natural frequencies and modes. The finite element model estimates the high-frequency modes that have significant tooth mesh deflection without considering the shafts and fixtures. The lumped-parameter and finite element models accurately predict the natural frequencies and modal properties established by experimentation. Rotational, translational, and planet mode types presented in published mathematical studies are confirmed experimentally. The number and types of modes in the low-frequency and high-frequency bands depend on the degrees of freedom in the central members and planet gears, respectively. The accuracy of natural frequency prediction is improved when the planet bearings have differing stiffnesses in the tangential and radial directions, consistent with the bearing load direction.

  12. Advanced system identification techniques for wind turbine structures with special emphasis on modal parameters

    NASA Astrophysics Data System (ADS)

    Bialasiewicz, J. T.

    1995-06-01

    The goal is to develop advanced system identification techniques that can be used to accurately measure the frequency response functions of a wind-turbine structure immersed in wind noise. To allow for accurate identification, the authors have developed a special test signal called the pseudo-random binary sequence (PRBS). The Matlab program that generates this signal allows the user to interactively tailor its parameters for the frequency range of interest based on the response of the wind turbine under test. By controlling NREL's Mobile Hydraulic Shaker System, which is attached to the wind turbine structure, the PRBS signal produces the wide-band excitation necessary to perform system identification in the presence of wind noise. The techniques presented here will enable researchers to obtain modal parameters from an operating wind turbine, including frequencies, damping coefficients, and mode shapes. More importantly, the algorithms they have developed and tested (so far using input-output data from a simulated structure) permit state-space representation of the system under test, particularly the modal state space representation. This is the only system description that reveals the internal behavior of the system, such as the interaction between the physical parameters, and which, in contrast to transfer functions, is valid for non-zero initial conditions.

  13. Mono-modal feature extraction for bonding quality detection of explosive clad structure with optimized dual-tree complex wavelet transform

    NASA Astrophysics Data System (ADS)

    Si, Yue; Zhang, Zhousuo; Wang, Hongfang; Yuan, Feichen

    2017-03-01

    Bonding quality detection of explosive clad structure is significant to prevent catastrophic accidents. Multi-modal features related to bonding quality are contained in structural vibration response signal. Different modal feature has different sensitivity to the bonding quality. Extracting the desired mono-modal feature from the vibration response signal is necessary. Due to the mode aliasing easily appeared in the process of extracting the desired mono-modal feature, there is no effective method for this task. Dual-tree complex wavelet with attractive properties such as shift invariance and reduced spectral aliasing may provide a better way to extract the mono-modal feature. However, the fixed basis functions independent of the analyzed signal may weak the advantage of the method and even reduce the accuracy of detection result. To overcome this shortcoming, a technique called optimized dual-tree complex wavelet transform (ODTCWT) is proposed in this paper. Based on the analyzed signal, the optimized dual-tree complex wavelet basis function is constructed by searching for the proper parameters of vanishing moment K and the order of filter L. The optimized dual-tree complex wavelet with improved wavelet filters can best matched the modal frequencies of the analyzed signal. The ODTCWT can extract the mono-modal feature from vibration response signal with lower mode aliasing. The feasibility and effectiveness of the method of constructing ODTCWT is illustrated by the simulated signal. The proposed ODTCWT is combined with time entropy to detecting bonding quality of explosive clad pipes. For comparison, un-optimized dual-tree complex wavelet transform (UODTCWT), second-generation wavelet transform (SGWT) and band-pass filter (BPF) are also used for this task to demonstrate the validity of ODTCWT.

  14. Variance estimation of modal parameters from output-only and input/output subspace-based system identification

    NASA Astrophysics Data System (ADS)

    Mellinger, Philippe; Döhler, Michael; Mevel, Laurent

    2016-09-01

    An important step in the operational modal analysis of a structure is to infer on its dynamic behavior through its modal parameters. They can be estimated by various modal identification algorithms that fit a theoretical model to measured data. When output-only data is available, i.e. measured responses of the structure, frequencies, damping ratios and mode shapes can be identified assuming that ambient sources like wind or traffic excite the system sufficiently. When also input data is available, i.e. signals used to excite the structure, input/output identification algorithms are used. The use of input information usually provides better modal estimates in a desired frequency range. While the identification of the modal mass is not considered in this paper, we focus on the estimation of the frequencies, damping ratios and mode shapes, relevant for example for modal analysis during in-flight monitoring of aircrafts. When identifying the modal parameters from noisy measurement data, the information on their uncertainty is most relevant. In this paper, new variance computation schemes for modal parameters are developed for four subspace algorithms, including output-only and input/output methods, as well as data-driven and covariance-driven methods. For the input/output methods, the known inputs are considered as realizations of a stochastic process. Based on Monte Carlo validations, the quality of identification, accuracy of variance estimations and sensor noise robustness are discussed. Finally these algorithms are applied on real measured data obtained during vibrations tests of an aircraft.

  15. Modal parameter identification of flexible spacecraft using the covariance-driven stochastic subspace identification (SSI-COV) method

    NASA Astrophysics Data System (ADS)

    Xie, Yong; Liu, Pan; Cai, Guo-Ping

    2016-08-01

    In this paper, the on-orbit identification of modal parameters for a spacecraft is investigated. Firstly, the coupled dynamic equation of the system is established with the Lagrange method and the stochastic state-space model of the system is obtained. Then, the covariance-driven stochastic subspace identification (SSI-COV) algorithm is adopted to identify the modal parameters of the system. In this algorithm, it just needs the covariance of output data of the system under ambient excitation to construct a Toeplitz matrix, thus the system matrices are obtained by the singular value decomposition on the Toeplitz matrix and the modal parameters of the system can be found from the system matrices. Finally, numerical simulations are carried out to demonstrate the validity of the SSI-COV algorithm. Simulation results indicate that the SSI-COV algorithm is effective in identifying the modal parameters of the spacecraft only using the output data of the system under ambient excitation.

  16. Modal parameter determination of a lightweight aerospace panel using laser Doppler vibrometer measurements

    NASA Astrophysics Data System (ADS)

    de Sousa, Kleverson C.; Domingues, Allan C.; Pereira, Pedro P. de S.; Carneiro, Sergio H.; de Morais, Marcus V. G.; Fabro, Adriano T.

    2016-06-01

    The experimental determination of modal parameters, i.e. natural frequencies, mode shapes and damping ratio, are key in characterizing the dynamic behaviour of structures. Typically, such parameters are obtained from dynamic measurements using one or a set of accelerometers, for response measurements, along with force transducers from an impact hammer or an electrodynamic actuator, i.e. a shaker. However, lightweight structures, commonly applied in the aerospace industry, can be significantly affected by the added mass from accelerometers. Therefore, non-contact measurement techniques, like Laser Doppler Vibrometer (LDV), are a more suitable approach in determining the dynamic characteristics of such structures. In this article, the procedures and results of a modal test for a honeycomb sandwich panel for aerospace applications are presented and discussed. The main objectives of the test are the identification of natural frequencies and mode shapes in order to validate a numerical model, as well as the identification of the damping characteristics of the panel. A validated numerical model will be necessary for future detailed response analysis of the satellite, including vibroacoustic investigations to account for acoustic excitations encountered during launching. The numerical model using homogenised material properties is updated to fit the experimental results and very good agreement between experimental and numerically obtained natural frequencies and mode shapes.

  17. Long-term bridge health monitoring focusing on the Mahalanobis Distance of modal parameters

    NASA Astrophysics Data System (ADS)

    Kim, Chul-Woo; Morita, Tomoaki; Wang, Ziran; Sugiura, Kunitomo

    2015-07-01

    Maintaining civil infrastructure, including bridges, has been a keen technical issue in developed countries and will surely be one in developing countries in the near future. An effective maintenance strategy strongly depends on timely decisions on the health condition of the structure. Bridge health monitoring (BHM) using vibration data is widely recognized to be one of the effective technologies that aid decision-making on bridge maintenance. This research focuses on long-term BHM expecting that changes in physical properties of the bridge subject to aged-deterioration progress slowly. In the practical application of the long-term BHM, one of the difficulties is that the observed vibration data includes environmental influences such as temperature change. In order to achieve high accuracy in evaluating modal parameters of the bridge, other influencing variables have to be taken into consideration. In this study, temperature is considered as the main environmental factor by means of a regression analysis. The Mahalanobis distance (MD), a multivariate statistical distance, is adopted to emphasize potential changes in the identified modal parameters. The validity of the proposed approach is investigated utilizing vibration data measured at a real bridge in service.

  18. RESONANT EXTRACTION PARAMETERS FOR THE AGS BOOSTER.

    SciTech Connect

    BROWN,K.A.; CULLEN,J.; GLENN,J.W.; MAPES,M.; MARNERIS,I.; TSOUPAS,N.; SNYDSTRUP,L.; VAN ASSELT,W.

    2001-06-18

    Brookhaven's AGS Booster is the injector for the AGS. It is being modified to send resonant extracted heavy ions to a new beam line, the Booster Applications Facility (BAF). The design of the resonant extraction system for BAF was described in [1]. This note will give a more detailed description of the system and describe the predicted resonant beam time structure. We will describe tune space manipulations necessary to extract the resonant beam at the maximum Booster rigidity, schemes for performing resonant extraction, and describe the modifications required to perform bunched beam extraction to the BAF facility.

  19. Hybrid parameter identification of a multi-modal underwater soft robot.

    PubMed

    Giorgio-Serchi, F; Arienti, A; Corucci, F; Giorelli, M; Laschi, C

    2017-02-28

    We introduce an octopus-inspired, underwater, soft-bodied robot capable of performing waterborne pulsed-jet propulsion and benthic legged-locomotion. This vehicle consists for as much as 80% of its volume of rubber-like materials so that structural flexibility is exploited as a key element during both modes of locomotion. The high bodily softness, the unconventional morphology and the non-stationary nature of its propulsion mechanisms require dynamic characterization of this robot to be dealt with by ad hoc techniques. We perform parameter identification by resorting to a hybrid optimization approach where the characterization of the dual ambulatory strategies of the robot is performed in a segregated fashion. A least squares-based method coupled with a genetic algorithm-based method is employed for the swimming and the crawling phases, respectively. The outcomes bring evidence that compartmentalized parameter identification represents a viable protocol for multi-modal vehicles characterization. However, the use of static thrust recordings as the input signal in the dynamic determination of shape-changing self-propelled vehicles is responsible for the critical underestimation of the quadratic drag coefficient.

  20. Dynamic Testing of a Pre-stretched Flexible Tube for Identifying the Factors Affecting Modal Parameter Estimation

    NASA Astrophysics Data System (ADS)

    Unnikrishnan, Madhusudanan; Rajan, Akash; Basanthvihar Raghunathan, Binulal; Kochupillai, Jayaraj

    2017-08-01

    Experimental modal analysis is the primary tool for obtaining the fundamental dynamic characteristics like natural frequency, mode shape and modal damping ratio that determine the behaviour of any structure under dynamic loading conditions. This paper discusses about a carefully designed experimental method for calculating the dynamic characteristics of a pre-stretched horizontal flexible tube made of polyurethane material. The factors that affect the modal parameter estimation like the application time of shaker excitation, pause time between successive excitation cycles, averaging and windowing of measured signal, as well as the precautions to be taken during the experiment are explained in detail. The modal parameter estimation is done using MEscopeVESTM software. A finite element based pre-stressed modal analysis of the flexible tube is also done using ANSYS ver.14.0 software. The experimental and analytical results agreed well. The proposed experimental methodology may be extended for carrying out the modal analysis of many flexible structures like inflatables, tires and membranes.

  1. Continuous Scan, a method for performing modal testing using meaningful measurement parameters; Part I

    NASA Astrophysics Data System (ADS)

    Di Maio, D.; Ewins, D. J.

    2011-11-01

    This paper presents the first part of a work about modal testing using meaningful measurement parameters. Scanning Laser Doppler Vibrometer (SLDV) systems are becoming largely used both in industry and university for performing vibration measurements. A reason for the success of SLDV systems can be found in their capability of measuring vibration remotely and under different environmental conditions which, when hostile, can inhibit other transducers to work correctly. Hence, SLDV system can be very practical and useful in many engineering applications. SLDV systems are being used as a contactless transducer measuring vibrations from a discrete number of measurement positions marked on the specimen whenever an optical access to it is available. Hence, the advantage of a modal test carried out using accelerometers and one carried out using a SLDV system can be: (i) the automation of the measurements and (ii) the increase of the spatial resolution of the measured modes. This suggests that SLDV systems can be used as a practical replacement of accelerometers operating the same measurement method. Continuous Scanning method is a novel approach of using contactless transducers for measuring vibrations. The most important difference between a discrete and a continuous approach is the method of measuring a vibration pattern. A discrete method measures the level of vibrations at discrete positions on a structure whereas a continuous method captures the modulation of the vibrations produced by the excited modes. This is possible when a transducer can travel across a vibrating surface. This first part of the work presents a new approach of continuous scanning measurement method using a multi-tonal excitation waveform. The paper starts from a comparison between a step and continuous scan mode to introduce a novel approach of continuous scan and multi-tonal excitation waveform. The objective of this first part of work is to present and understand that measurement parameters

  2. Parameter extraction from I-V characteristics of PV devices

    SciTech Connect

    Macabebe, Erees Queen B.; Sheppard, Charles J.; Dyk, E. Ernest van

    2011-01-15

    Device parameters such as series and shunt resistances, saturation current and diode ideality factor influence the behaviour of the current-voltage (I-V) characteristics of solar cells and photovoltaic modules. It is necessary to determine these parameters since performance parameters are derived from the I-V curve and information provided by the device parameters are useful in analyzing performance losses. This contribution presents device parameters of CuIn(Se,S){sub 2}- and Cu(In,Ga)(Se,S){sub 2}-based solar cells, as well as, CuInSe{sub 2}, mono- and multicrystalline silicon modules determined using a parameter extraction routine that employs Particle Swarm Optimization. The device parameters of the CuIn(Se,S){sub 2}- and Cu(In,Ga)(Se,S){sub 2}-based solar cells show that the contribution of recombination mechanisms exhibited by high saturation current when coupled with the effects of parasitic resistances result in lower maximum power and conversion efficiency. Device parameters of photovoltaic modules extracted from I-V characteristics obtained at higher temperature show increased saturation current. The extracted values also reflect the adverse effect of temperature on parasitic resistances. The parameters extracted from I-V curves offer an understanding of the different mechanisms involved in the operation of the devices. The parameter extraction routine utilized in this study is a useful tool in determining the device parameters which reveal the mechanisms affecting device performance. (author)

  3. A consistent model reduction of measured modal parameters for reduced-order active control

    NASA Technical Reports Server (NTRS)

    Alvin, K. F.; Park, K. C.; Peterson, L. D.

    1993-01-01

    The problem of synthesizing reduced-order linear models of vibrating structures for the design of fixed-order dynamic feedback control is investigated. The present technique builds on a recently developed procedure for constructing an objective set of mass and stiffness matrices from measured modal parameters that are akin to the Craig-Bampton synthesized ones obtained from finite element models. The constructed mass and stiffness matrices are determined directly from the identification of experimental data, however, rather than through correlation or reconciliation of a finite element model. A model truncation criterion is then applied to the identified minimum-order mass and stiffness model to satisfy certain observability/controllability requirements for the reduced model. Numerical examples illustrate the effectiveness of the proposed technique for synthesizing reduced-order controllers from system realizations of experimental data. The dynamic performance of the resulting closed-loop models is assessed using the known full-order structural dynamics and compared with existing model reduction techniques.

  4. Extraction of the Susy and Higgs parameters

    SciTech Connect

    Adam-Bourdarios, Claire

    2010-02-10

    If supersymmetry is discovered by the next generation of collider experiments, it will be crucial to determine its fundamental high-scale parameters. Three scenarios have been recently investigated by the SFitter collaboration : the case where the LHC 'only' measures a light Higgs like signal, the case where SUSY signal are discovered at the LHC, and the dream scenario, where LHC and ILC measurements can be combined.

  5. Numerical determination of statistical energy analysis parameters of directly coupled composite plates using a modal-based approach

    NASA Astrophysics Data System (ADS)

    Seçgin, Abdullah

    2013-01-01

    Statistical energy analysis (SEA) parameters such as average modal spacing, coupling loss factor and input power are numerically determined for point connected, directly coupled symmetrically laminated composite plates using a modal-based approach. The approach is an enhancement of classical wave transmission formula. Unlike most of the existing numerical or experimental techniques, the approach uses uncoupled plate modal information and treats substructure by means of averaged modal impedances. The procedure introduced here is verified using analytical definitions of infinite orthotropic plates which physically resemble to laminated plates for (under) specific conditions, and is tested by performing experimental power injection method (PIM) for an actual, right-angled composite structure. In the development process, force and moment transmissions are individually considered in order to be consistent with analytical formulations. Modal information of composite plates is statistically evaluated by the discrete singular convolution method with random boundary conditions. Proposed methodology not only provides an efficient use of SEA method in high frequency vibration analysis of composite structures, but also enhances SEA accuracy in mid frequency region in which conventional SEA fails. Furthermore, the effect of orientation angles of laminations on SEA parameters are also discussed in mid and high frequency regions.

  6. Extraction of exposure parameters by using neural networks

    NASA Astrophysics Data System (ADS)

    Jeon, Kyoung-Ah; Kim, Hyoung-Hee; Yoo, Ji-Yong; Park, Jun-Taek; Oh, Hye-Keun

    2003-06-01

    Dill"s ABC parameters are key parameters for the simulation of photolithography patterning. The exposure parameters of each resist should be exactly known to simulate the desired pattern. In ordinary extracting methods of Dill"s ABC parameters, the changed refractive index and the absorption coefficient of photoresist are needed during exposure process. Generally, these methods are not easy to be applied in a normal fab because of a difficulty of in-situ measuring. An empirical E0 (dose-to-clear) swing curve is used to extract ABC exposure parameters previously by our group. Dill"s ABC parameters are not independent from each other and different values of them would cause the dose to clear swing curve variation. By using the known relationship of ABC parameters, the experimental swing curves are to be matched with the simulated ones in order to extract the parameters. But sometimes this method is not easy in matching the procedure and performing simulation. This procedure would take much time for matching between the experimental data and the simulation by the naked eyes, and also the simulations are performed over and over again for different conditions. In this paper, Dill"s ABC parameters were extracted by applying the values, which are quantitatively determined by measuring the mean value, period, slope, and amplitude of the swing curve, to the neural network algorithm. As a result, Dill"s ABC parameters were able to rapidly and accurately extracted with some of the quantified values of the swing curve. This method of extracting the exposure parameters can be used in a normal fab so that any engineer can easily obtain the exposure parameters and apply them to the simulation tools.

  7. Development of an on-line parameter estimation system using the discrete modal filter

    NASA Technical Reports Server (NTRS)

    Shelley, S. J.; Freudinger, L. C.; Allemang, R. J.

    1992-01-01

    Ongoing development of an automated system for monitoring the frequency and damping of time varying structural systems is discussed. A spatial filtering technique called the discrete modal filter is used to uncouple multiple response measurements into modal coordinate responses. Since the modal coordinate responses are the responses of single-degree-of-freedom systems, the frequency and damping may be accurately estimated with short data records. An on-line monitoring system is discussed which may be useful in a variety of applications. The focus in this paper is on the application to aircraft flight flutter testing.

  8. Damage evaluation on a multi-story framed structures: comparison of results retrieved from algorithms based on modal and non-modal parameters

    NASA Astrophysics Data System (ADS)

    Auletta, Gianluca; Ditommaso, Rocco; Iacovino, Chiara; Carlo Ponzo, Felice; Pina Limongelli, Maria

    2016-04-01

    Continuous monitoring based on vibrational identification methods is increasingly employed with the aim of evaluate the state of the health of existing structures and infrastructures and to evaluate the performance of safety interventions over time. In case of earthquakes, data acquired by means of continuous monitoring systems can be used to localize and quantify a possible damage occurred on a monitored structure using appropriate algorithms based on the variations of structural parameters. Most of the damage identification methods are based on the variation of few modal and/or non-modal parameters: the former, are strictly related to the structural eigenfrequencies, equivalent viscous damping factors and mode shapes; the latter, are based on the variation of parameters related to the geometric characteristics of the monitored structure whose variations could be correlated related to damage. In this work results retrieved from the application of a curvature evolution based method and an interpolation error based method are compared. The first method is based on the evaluation of the curvature variation (related to the fundamental mode of vibration) over time and compares the variations before, during and after the earthquake. The Interpolation Method is based on the detection of localized reductions of smoothness in the Operational Deformed Shapes (ODSs) of the structure. A damage feature is defined in terms of the error related to the use of a spline function in interpolating the ODSs of the structure: statistically significant variations of the interpolation error between two successive inspections of the structure indicate the onset of damage. Both methods have been applied using both numerical data retrieved from nonlinear FE models and experimental tests on scaled structures carried out on the shaking table of the University of Basilicata. Acknowledgements This study was partially funded by the Italian Civil Protection Department within the project DPC

  9. Parameter extraction of solar cells using particle swarm optimization

    NASA Astrophysics Data System (ADS)

    Ye, Meiying; Wang, Xiaodong; Xu, Yousheng

    2009-05-01

    In this article, particle swarm optimization (PSO) was applied to extract the solar cell parameters from illuminated current-voltage characteristics. The performance of the PSO was compared with the genetic algorithms (GAs) for the single and double diode models. Based on synthetic and experimental current-voltage data, it has been confirmed that the proposed method can obtain higher parameter precision with better computational efficiency than the GA method. Compared with conventional gradient-based methods, even without a good initial guess, the PSO method can obtain the parameters of solar cells as close as possible to the practical parameters only based on a broad range specified for each of the parameters.

  10. Modal amplitude extraction of guided waves in rails using scanning laser vibrometer measurements

    NASA Astrophysics Data System (ADS)

    Loveday, P. W.; Long, C. S.

    2012-05-01

    It is advantageous to be able to measure the amplitude of the individual modes of propagation during the development of guided wave systems for rail monitoring. This paper addresses the problem of extracting modal amplitudes from scanning laser vibrometer measurements. The wave propagation characteristics of the rail are computed using the semi-analytical finite element method, and are used to represent the frequency response at a set of measurement locations (with unknown amplitude coefficients). Experimental frequency responses are measured and the amplitude of each mode is estimated using a pseudo-inverse technique. The selection of measurement points is investigated. A set of measureable points is defined based on accessibility and scanning angles. A technique is proposed for selecting appropriate measurement points, from within this set, to yield a well conditioned problem. It is shown that there exists a number of points, above which additional points do not add to the accuracy of the process. The method is demonstrated on a 5 m length of rail excited by a piezoelectric transducer in the lab.

  11. Bayesian Modal Estimation of the Four-Parameter Item Response Model in Real, Realistic, and Idealized Data Sets.

    PubMed

    Waller, Niels G; Feuerstahler, Leah

    2017-01-01

    In this study, we explored item and person parameter recovery of the four-parameter model (4PM) in over 24,000 real, realistic, and idealized data sets. In the first analyses, we fit the 4PM and three alternative models to data from three Minnesota Multiphasic Personality Inventory-Adolescent form factor scales using Bayesian modal estimation (BME). Our results indicated that the 4PM fits these scales better than simpler item Response Theory (IRT) models. Next, using the parameter estimates from these real data analyses, we estimated 4PM item parameters in 6,000 realistic data sets to establish minimum sample size requirements for accurate item and person parameter recovery. Using a factorial design that crossed discrete levels of item parameters, sample size, and test length, we also fit the 4PM to an additional 18,000 idealized data sets to extend our parameter recovery findings. Our combined results demonstrated that 4PM item parameters and parameter functions (e.g., item response functions) can be accurately estimated using BME in moderate to large samples (N ⩾ 5, 000) and person parameters can be accurately estimated in smaller samples (N ⩾ 1, 000). In the supplemental files, we report annotated [Formula: see text] code that shows how to estimate 4PM item and person parameters in [Formula: see text] (Chalmers, 2012 ).

  12. Physical parameter identification method based on modal analysis for two-axis on-road vehicles: Theory and simulation

    NASA Astrophysics Data System (ADS)

    Zheng, Minyi; Zhang, Bangji; Zhang, Jie; Zhang, Nong

    2016-07-01

    Physical parameters are very important for vehicle dynamic modeling and analysis. However, most of physical parameter identification methods are assuming some physical parameters of vehicle are known, and the other unknown parameters can be identified. In order to identify physical parameters of vehicle in the case that all physical parameters are unknown, a methodology based on the State Variable Method(SVM) for physical parameter identification of two-axis on-road vehicle is presented. The modal parameters of the vehicle are identified by the SVM, furthermore, the physical parameters of the vehicle are estimated by least squares method. In numerical simulations, physical parameters of Ford Granada are chosen as parameters of vehicle model, and half-sine bump function is chosen to simulate tire stimulated by impulse excitation. The first numerical simulation shows that the present method can identify all of the physical parameters and the largest absolute value of percentage error of the identified physical parameter is 0.205%; and the effect of the errors of additional mass, structural parameter and measurement noise are discussed in the following simulations, the results shows that when signal contains 30 dB noise, the largest absolute value of percentage error of the identification is 3.78%. These simulations verify that the presented method is effective and accurate for physical parameter identification of two-axis on-road vehicles. The proposed methodology can identify all physical parameters of 7-DOF vehicle model by using free-decay responses of vehicle without need to assume some physical parameters are known.

  13. Study on variability of modal parameters of concrete structure: humidity and moisture effect

    NASA Astrophysics Data System (ADS)

    Zhou, W.; Li, H.; Nasser, H.

    2008-03-01

    The complex external environment for civil engineering structures results in the structural vibration properties varying with external conditions, such as humidity and temperature. For the vibration-based structural health monitoring techniques, for example damage identification, modal updating etc., above characteristics will result in the vibration-based techniques invalid. Other researchers have reported that modal frequencies varied significantly due to temperature change, but the humidity affect structural vibration properties in another manner. This paper discusses the variation of frequencies and mode shapes with respect to humidity and temperature changes for concrete structures, for which the changing of moisture will affect the density of materials, and the changing of temperature will affect the stiffness of structures. This paper models these two factors with finite element model approach based on the theoretical analysis, and numerical results obtained on the FE model of a concrete bridge deck are reported.

  14. Photoresist Exposure Parameter Extraction from Refractive Index Change during Exposure

    NASA Astrophysics Data System (ADS)

    Sohn, Young-Soo; Sung, Moon-Gyu; Lee, Young-Mi; Lee, Eun-Mi; Oh, Jin-Kyung; Byun, Sung-Hwan; Jeong, Yeon-Un; Oh, Hye-Keun; An, Ilsin; Lee, Kun-Sang; Park, In-Ho; Cho, Joon-Yeon; Lee, Sang-Ho

    1998-12-01

    The refractive indices of photoresist are usually measured byan ellipsometer or spectrophotometer, but the values are limited to pre-exposure. It is known thatthe real and imaginary indices are changed during the exposure.But there is little report on these variations since itis difficult to measure this refractive index change at deep ultraviolet. The DillABC parameters show a significant variation with the resist and substrate thicknessas well as the experimental conditions.A method is suggested to extract the parameters from the refractive index changes.We can get the refractive index change and extract the Dill ABC exposure parameters from that.The multiple thin film interference calculation is used to fit the measured transmittance data.The results of our experiments and calculations for several resists including193 nm chemically amplified resists are compared with other methods.The results are agreed well with the full multilayer thin film simulation.

  15. Extraction of exposure modeling parameters of thick resist

    NASA Astrophysics Data System (ADS)

    Liu, Chi; Du, Jinglei; Liu, Shijie; Duan, Xi; Luo, Boliang; Zhu, Jianhua; Guo, Yongkang; Du, Chunlei

    2004-12-01

    Experimental and theoretical analysis indicates that many nonlinear factors existing in the exposure process of thick resist can remarkably affect the PAC concentration distribution in the resist. So the effects should be fully considered in the exposure model of thick resist, and exposure parameters should not be treated as constants because there exists certain relationship between the parameters and resist thickness. In this paper, an enhanced Dill model for the exposure process of thick resist is presented, and the experimental setup for measuring exposure parameters of thick resist is developed. We measure the intensity transmittance curve of thick resist AZ4562 under different processing conditions, and extract the corresponding exposure parameters based on the experiment results and the calculations from the beam propagation matrix of the resist films. With these modified modeling parameters and enhanced Dill model, simulation of thick-resist exposure process can be effectively developed in the future.

  16. The registration of dual-modality ship target images based on edge extraction

    NASA Astrophysics Data System (ADS)

    Zhang, Weimin; Wang, Risheng; Zhou, Fugen

    2014-11-01

    In this paper, we study the problem of visible and IR(infrared) ship target image registration with scale changes. We mainly focus on the infrared and visible image feature extraction and matching method. A method based on Force Field Transformation is used to determine the ship target contour area. Canny edge detection method is applied to obtain the edge features. During the process of image registration, we take the cross-correlation as the similarity measure and propose an improved Powell algorithm based on multi-scale searching to optimize the registration parameters. Through the edge fusion results, we can see the corresponding edges are almost overlapped, indicating that the method could achieve satisfying results. Also the average error distance of match is less than one pixel.

  17. Extracting cosmological and evolutionary parameters from distant galaxy observations

    NASA Astrophysics Data System (ADS)

    Bruzual, Gustavo A.

    Models of the galaxy number counts and color distribution in SA 68 (Koo 1986) built according to a non-negative least squares (NNLS) algorithm (Lawson and Hanson 1974) are discussed. The value of chi(red) squared that characterizes each model can be used as a goodness of fit indicator to decide in favor of a model over another, providing an objective and unbiased criterion to extract cosmological and evolutionary parameters from a data set.

  18. A variance based confidence criterion for ERA identified modal parameters. [Eigensystem Realization Algorithm

    NASA Technical Reports Server (NTRS)

    Longman, Richard W.; Juang, Jer-Nan

    1988-01-01

    The realization theory is developed in a systematic manner for the Eigensystem Realization Algorithm (ERA) used for system identification. First, perturbation results are obtained which describe the linearized changes in the identified parameters resulting from small change in the data. Formulas are then derived that can be used to evaluate the variance of each of the identified parameters, assuming that the noise level is sufficiently low to allow the application of linearized results. These variances can be converted to give confidence intervals for each of the parameters for any chosen confidence level.

  19. A variance based confidence criterion for ERA identified modal parameters. [Eigensystem Realization Algorithm

    NASA Technical Reports Server (NTRS)

    Longman, Richard W.; Juang, Jer-Nan

    1988-01-01

    The realization theory is developed in a systematic manner for the Eigensystem Realization Algorithm (ERA) used for system identification. First, perturbation results are obtained which describe the linearized changes in the identified parameters resulting from small change in the data. Formulas are then derived that can be used to evaluate the variance of each of the identified parameters, assuming that the noise level is sufficiently low to allow the application of linearized results. These variances can be converted to give confidence intervals for each of the parameters for any chosen confidence level.

  20. An Optimised Pseudo-Inverse Algorithm (opia) for Multi-Input Multi-Output Modal Parameter Identification

    NASA Astrophysics Data System (ADS)

    Bazán, Fermín. S. V.; Bavastri, Carlos A.

    1996-07-01

    A multi-input multi-output (MIMO) algorithm for modal parameter identification is developed based on linear prediction theory and its numerical efficiency compared to that of the well known Eigensystem realisation algorithm ERA. The problem of determining the correct system's order is analysed through perturbation theory of singular values of oversized Hankel-block matrices. The popular technique of using overdetermined models to mitigate the effects of external noise on the quality of the estimated parameters is justified here by showing analytically that the system's singular values are enhanced when oversized Hankel matrices are used. Numerical experiments illustrating the performance of the proposed algorithm on both simulated and real mechanical systems, are included.

  1. Dynamic Characteristics of Prosthetic Feet: A Comparison Between Modal Parameters of Walking, Running and Sprinting Foot

    NASA Astrophysics Data System (ADS)

    Noroozi, S.; Rahman, A. G. A.; Dupac, M.; Vinney, J. E.

    Current methods of evaluating the performance of Energy Storing and Returning (ESR) prosthesis are subjective and rely on VO2 consumption. Current prosthetic feet are designed for specific applications and the majority are designed for walking and moderate running. These mechanical feet have fixed mechanical and dynamic characteristics. They have to be selected to meet the requirement of the task and any use outside the domain of the task can result in extreme/severe lack of gait symmetry and loss of energy. Poor gait symmetry results is excess consumption of energy, back pain or fatigue. To investigate if a multipurpose foot can be designed to passively adapt to the walking or running condition one must first understand the different dynamics that are involved and are required from the task specific foot. Static tests have shown these feet to have non-linear stiffness, making the prediction of their dynamic response difficult. The most reliable method to test for dynamic characteristics is drop and modal testing. A method approach has been developed as part of this research to test and compare the dynamic characteristics of three different types of foot (natural frequency, mode shapes and damping). This is needed to explore the differences in the responses of these feet that allow one to be used for walking, one to be used for running and one to be used for sprinting with ease.

  2. Extraction of exchange parameters in transition-metal perovskites

    DOE PAGES

    Furrer, A.; Podlesnyak, A.; Krämer, K. W.

    2015-09-15

    When extracting exchange parameters from measured spin-wave dispersion relations there are severe limitations particularly for magnetic compounds such as the transition-metal perovskites, where the nearest-neighbor exchange parameter usually dominates the couplings between the further-distant-neighbor spins. Very precise exchange parameters beyond the nearest-neighbor spins can be obtained by neutron spectroscopic investigations of the magnetic excitation spectra of isolated multimers in magnetically diluted compounds. Moreover, this is exemplified for manganese trimers in the mixed three-and two-dimensional perovskite compounds KMnxZn1-xF3 and K2MnxZn1-xF4, respectively. We show that the small exchange couplings between the second-nearest-neighbor and the third-nearest-neighbor spins can be determined unambiguously and withmore » equal precision as the dominating nearest-neighbor exchange coupling.« less

  3. Comparison of Sexual Function and Hormonal Parameters Between Mood Stabilizer Treatment Modalities in Bipolar Disorder

    PubMed Central

    KESEBİR, Sermin; TOPRAK, Burak; BAYKARAN, Burak; HARİRİ, Aytül; BİLİCİ, Mustafa

    2014-01-01

    Introduction The aim of this study was to determine the differences between lithium and atypical antipsychotics (quetiapine and olanzapine) with regard to their effects on sexual functions and hormonal variables and to assess the findings in term of gender differences, in patients with bipolar disorder. Method 28 female and 29 male patients diagnosed as having bipolar disorder type I according to the DSM-IV, using lithium or quetiapine and quetiapine+lithium or olanzapine and olanzapine+lithium were evaluated consecutively. Being in remission period and given informed consent were set as inclusion criteria in these cases. Interviews with the patients were carried out using the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I) and SKIP-TURK. Sexual functions and satisfaction were evaluated with the Arizona Sexual Experiences Scale (ASEX) and the Golombok Rust Inventory of Sexual Satisfaction (GRISS). Blood samples of the patients were taken in order to determine prolactin (PRL), follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), and free testosterone (T) levels. Results GRISS scores in male patients were higher than in female patients (p=.001). The number of manic, depressive and total episodes, and functionality levels were similar between the treatment groups, both in female and male patients. No differences were found between treatment modalities in terms of hormone levels both in female and male patients. Among females, ASEX scores of the patients treated with lithium monotherapy were less than the ones treated with quetiapine and olanzapine. Among patients with quetiapine monotherapy, GRISS scores in male patients were higher than in female patients. Conclusion There are some evidences showing gender-based differences in the side effects of atypical antipsychotic drugs. Future studies with a specific focus on this topic are needed in order to have a better understanding of the basic mechanisms of gender differences

  4. Modal parameter identification and damping ratio estimation from the full-scale measurements of a typical Tibetan wooden structure

    NASA Astrophysics Data System (ADS)

    Dai, Lu; Yang, Na; Law, S. S.; Yang, Qingshan

    2016-12-01

    Tibetan heritage buildings have a high historical and cultural value. They have endured adverse environmental loadings over hundreds of years without significant damage. However, there are few reports on their structural characteristics under normal environmental loadings and their behavior under dynamic loadings. In this research, a typical Tibetan wooden wall-frame building is selected to study its dynamic characteristics. Field measurements of the structure were conducted under environmental excitation to collect acceleration responses. The stochastic subspace identification (SSI) method was adopted to calculate the structural modal parameters and obtain the out-of-plane vibration characteristics of the slab and frames. The results indicated that the wall-frame structure had a lower out-of-plane stiffness and greater in-plane stiffness due to the presence of stone walls. Due to poor identified damping ratio estimates from the SSI method, a method based on the variance upper bound was proposed to complement the existing variance lower bound method for estimating the modal damping ratio to address the significant damping variability obtained from different points and measurements. The feasibility of the proposed method was illustrated with the measured data from the floor slab of the structure. The variance lower and upper bound methods both provided consistent results compared to those from the traditional SSI method.

  5. Measurement of extraction and absorption parameters in GaN-based photonic-crystal light-emitting diodes

    SciTech Connect

    Matioli, Elison; Fleury, Blaise; Rangel, Elizabeth; Hu, Evelyn L.; Speck, J. S.; Weisbuch, Claude

    2010-01-01

    The light extraction efficiency of photonic-crystal (PhC) light-emitting diodes (LEDs) relies on the competition between the PhC extraction and dissipation mechanisms of the guided light within the LED. This work presents the experimental determination of the PhC extraction length of each guided mode and the absorption coefficient of the active region (AR) and quantum wells (QWs) from the observation of the LED far-field emission using a high-resolution angle-spectrum-resolved measurement. The angular and spectral linewidths of the extracted guided modes reveal, depending on the spectral range, the modal extraction length of the PhCs, the AR absorption length, or a combination of both. Modes with a high confinement with the QWs presented a shorter absorption length compared with their extraction length by a shallow surface PhC (95-nm-deep), meaning that the AR absorption was a more efficient mechanism than the PhC extraction. The measured modal extraction length of the shallow surface PhC varied in the range of 55–120 μm, which determines the minimum dimensions of the device and the maximum acceptable dissipation length for an efficient extraction of the guided light by the PhCs. This paper presents also a discussion on the PhC designs that yield PhC extraction lengths shorter than other dissipation lengths, a fundamental requirement for high-efficiency PhCLEDs. The same technique was also applied to estimate the absorption coefficient of the InGaN-based QWs, and can be extended to experimentally determine losses by metallic layers from electrical contacts or other dissipation mechanisms, which are parameters of interest to a broader class of optoelectronic devices, not only PhCLEDs.

  6. Role of Hansen solubility parameters in solid phase extraction.

    PubMed

    Bielicka-Daszkiewicz, K; Voelkel, A; Pietrzyńska, M; Héberger, K

    2010-08-27

    The sorbent-eluent systems combined from eight polymeric sorbents and seven solvents as eluents were used for the extraction of phenol and its oxidation products from water samples. The individual interactions between sorbents, eluents and analytes were characterized by Hansen solubility parameters. Principal components analysis (PCA) was used for revealing the dominant interactions (dispersive, polar, and hydrogen bonding type) in sorbent-analyte-eluent systems. The importance of solubility parameters was also determined by a novel procedure based on sum of ranking differences (SRD). Although PCA and ranking by SRD are based on different principles and calculations, they have provided very similar results. The recovery in a given system has been predicted from the magnitudes of mutual interactions (sorbent-analyte, sorbent-eluent, analyte-eluent) by multiple linear regression.

  7. Exploration of LWFA Parameter Regimes Using Truncated Azimuthal Modal Geometry in the OSIRIS Simulation Framework

    NASA Astrophysics Data System (ADS)

    Davidson, Asher

    2014-10-01

    In plasma based accelerators (LWFA and PWFA), the methods of injecting high quality electron bunches into the accelerating wakefield is of utmost importance for various applications. Numerous particle-in-cell (PIC) simulations are conducted in order to study various methods of injection and the ideal parameters thereof. 2D slab-geometry simulations are computationally inexpensive, but they are quantitatively, and sometimes even qualitatively inaccurate. One method for reducing the computational load of a 3D simulation is by utilizing a truncated azimuthal mode expansion into the OSIRIS simulation framework. Comparison with 3D LWFA simulations shows a great degree of consistency in the characteristics of the self-trapped beam. In addition, higher order cylindrical modes may capture effects such as beam hosing and asymmetric spot size modulation. With this highly efficient 2D-hybrid algorithm it is possible to simulate parameter regimes and scaling laws that are difficult to do in a full 3D Cartesian simulation. Relativistic spot-size self-focusing, which cannot be accurately described in a 2D slab geometry, is also studied.

  8. Modal Analysis of S809 Wind Turbine Blade Considering Different Geometrical and Material Parameters

    NASA Astrophysics Data System (ADS)

    Gangele, A.; Ahmed, S.

    2013-10-01

    In recent years wind energy has been the world's fastest growing source of energy. The wind turbine industry is booming and is spending a lot on research for improving the performance of its present machines and increasing their capacity. The purpose of this paper is to investigate the dynamic behavior characteristic of 1.5 MW wind turbine system (WTS) and carries out the analysis considering different geometrical and material parameters. Vibration of the blade of the WTS on the flap and edge section of the blade that is one of the most important elements of dynamic characteristic of WTS is evaluated. Natural frequency and mode shape are calculated by the finite element analysis, with commercial program (ANSYS). The results are compared which are performed by the finite element analysis with commercial FEM program (ANSYS) on the basis of the natural frequency and mode shape.

  9. Extraction of exchange parameters in transition-metal perovskites

    SciTech Connect

    Furrer, A.; Podlesnyak, A.; Krämer, K. W.

    2015-09-15

    When extracting exchange parameters from measured spin-wave dispersion relations there are severe limitations particularly for magnetic compounds such as the transition-metal perovskites, where the nearest-neighbor exchange parameter usually dominates the couplings between the further-distant-neighbor spins. Very precise exchange parameters beyond the nearest-neighbor spins can be obtained by neutron spectroscopic investigations of the magnetic excitation spectra of isolated multimers in magnetically diluted compounds. Moreover, this is exemplified for manganese trimers in the mixed three-and two-dimensional perovskite compounds KMnxZn1-xF3 and K2MnxZn1-xF4, respectively. We show that the small exchange couplings between the second-nearest-neighbor and the third-nearest-neighbor spins can be determined unambiguously and with equal precision as the dominating nearest-neighbor exchange coupling.

  10. Panel labels extraction from multi-panel figures for facilitating multi-modal information retrieval

    NASA Astrophysics Data System (ADS)

    Ali, Mushtaq; Dong, Le; Liang, Yan; He, Ling; Feng, Ning

    2015-07-01

    The association of subfigures in the multi-panel figure with related text in the accompanying caption and research article is necessary for the implementation of multi-modal information retrieval system. The panel labels in the multipanel figure are used as a source for making this kind of association. In this paper, we propose a novel method for the detection of panel labels in the multi-panel figures. The proposed method uses segmentation of multi-panel figure and its accompanying caption into subfigures and sub captions, respectively, as a preprocessing step. Next, the features of panel label, i.e., area and its distance from the borders in the upper left most subfigure of the multi panel figure are computed. These features are then used for detecting panel labels located in the rest of subfigures of the same multi-panel figure. Experiments on multi-panel figures selected from imageCLEF2013 dataset show promising results.

  11. Ares I-X In-Flight Modal Identification

    NASA Technical Reports Server (NTRS)

    Bartkowicz, Theodore J.; James, George H., III

    2011-01-01

    Operational modal analysis is a procedure that allows the extraction of modal parameters of a structure in its operating environment. It is based on the idealized premise that input to the structure is white noise. In some cases, when free decay responses are corrupted by unmeasured random disturbances, the response data can be processed into cross-correlation functions that approximate free decay responses. Modal parameters can be computed from these functions by time domain identification methods such as the Eigenvalue Realization Algorithm (ERA). The extracted modal parameters have the same characteristics as impulse response functions of the original system. Operational modal analysis is performed on Ares I-X in-flight data. Since the dynamic system is not stationary due to propellant mass loss, modal identification is only possible by analyzing the system as a series of linearized models over short periods of time via a sliding time-window of short time intervals. A time-domain zooming technique was also employed to enhance the modal parameter extraction. Results of this study demonstrate that free-decay time domain modal identification methods can be successfully employed for in-flight launch vehicle modal extraction.

  12. Extracting Cu Diffusion Parameters in Polycrystalline CdTe

    SciTech Connect

    Akis, Richard; Brinkman, Daniel; Sankin, Igor; Fang, Tian; Guo, Da; Dragica, Vasileska; Ringhofer, Christian

    2014-06-13

    It is well known that Cu plays an important role in CdTe solar cell performance as a dopant. In this work, a finite-difference method is developed and used to simulate Cu diffusion in CdTe solar cells. In the simulations, which are done on a two-dimensional (2D) domain, the CdTe is assumed to be polycrystal-line, with the individual grains separated by grain boundaries. When used to fit experimental Cu concentration data, bulk and grain boundary diffusion coefficients and activation energies for CdTe can be extracted. In the past, diffusion coefficients have been typically obtained by fitting data to simple functional forms of limited validity. By doing full simulations, the simplifying assumptions used in those analytical models are avoided and diffusion parameters can thus be determined more accurately.

  13. A method of extracting operating parameters of a quantum circuit

    NASA Astrophysics Data System (ADS)

    Sete, Eyob A.; Block, Maxwell; Scheer, Michael; Zanoci, Cris; Vahidpour, Mehrnoosh; Thompson, Dane; Rigetti, Chad

    Rigorous simulation-driven design methods are an essential component of traditional integrated circuit design. We adapt these techniques to the design and development of superconducting quantum integrated circuits by combining classical finite element analysis in the microwave domain with Brune circuit synthesis by Solgun [PhD thesis 2014] and BKD Hamiltonian analysis by Burkard et al. [Phys. Rev. B 69, 064503 (2004)]. Using the Hamiltonian of the quantum circuit, constructed using the synthesized equivalent linear circuit and the nonlinear Josephson junctions' contributions, we extract operating parameters of the quantum circuit such as resonance coupling strength, dispersive shift, qubit anharmonicitiy, and decoherence rates for single-and multi-port quantum circuits. This approach has been experimentally validated and allows the closed-loop iterative simulation-driven development of quantum information processing devices.

  14. Calendula extract: effects on mechanical parameters of human skin.

    PubMed

    Akhtar, Naveed; Zaman, Shahiq Uz; Khan, Barkat Ali; Amir, Muhammad Naeem; Ebrahimzadeh, Muhammad Ali

    2011-01-01

    The aim of this study was to evaluate the effects of newly formulated topical cream of Calendula officinalis extract on the mechanical parameters of the skin by using the cutometer. The Cutometer 580 MPA is a device that is designed to measure the mechanical properties of the skin in response to the application of negative pressure. This non-invasive method can be useful for objective and quantitative investigation of age related changes in skin, skin elasticity, skin fatigue, skin hydration, and evaluation of the effects of cosmetic and antiaging topical products. Two creams (base and formulation) were prepared for the study. Both the creams were applied to the cheeks of 21 healthy human volunteers for a period of eight weeks. Every individual was asked to come on week 1, 2, 3, 4, 5, 6, 7, and 8 and measurements were taken by using Cutometer MPA 580 every week. Different mechanical parameters of the skin measured by the cutometer were; R0, R1, R2, R5, R6, R7, and R8. These were then evaluated statistically to measure the effects produced by these creams. Using ANOVA, and t-test it was found that R0, and R6 were significant (p <0.05) whereas R1, R2, R5, R7, R8 were insignificant (p > 0.05). The instrumental measurements produced by formulation reflected significant improvements in hydration and firmness of skin.

  15. Excimer laser lead extraction catheter with increased laser parameters

    NASA Astrophysics Data System (ADS)

    Coe, M. Sean; Taylor, Kevin D.; Lippincott, Rebecca A.; Sorokoumov, Oleg; Papaioannou, Thanassis

    2001-05-01

    A fiber optic catheter connected to a pulsed excimer laser (308 nm) is currently used to extract chronically implanted pacemaker and defibrillator leads at Fluence of 60 mJ/mm2 and repetition rate of 40 Hz. The object of this study was to determine the effect of higher repetition rates (80 Hz) in the catheter's cutting performance. The penetration rate (micrometers /sec), and the associated mechanical and thermal effects were measured in soft (porcine myocardium) and hard tissue (bovine tendon) at 60 mJ/mm2-80 Hz, and were compared to the corresponding values at commercially available laser parameters (60 mJ/mm2-40 Hz). Ablation rates were measured with perforation experiments and the extent of thermal and mechanical damage was measured under polarized light microscopy. For hard (soft) tissue, the laser catheter demonstrated penetration speed of 106 +/- 32 (302 +/- 101) micrometers /sec at 40 Hz and 343 +/- 120 (830 +/- 364) micrometers /sec at 80 Hz. Maximum extent of thermal effects at 40 Hz and 80 Hz was 114 +/- 35 micrometers (72 +/- 18) and 233 +/- 63 micrometers (71 +/- 16) respectively. Maximum extent of mechanical effects at 40 Hz and 80 Hz was 188 +/- 63 micrometers (590 +/- 237) and 386 +/- 100 micrometers (767 +/- 160) respectively. In vitro testing of the laser catheter with 80 Hz laser parameters has demonstrated increased penetration speed in both soft and hard fibrous tissue, while maintaining associated thermal and mechanical effects within limited ranges.

  16. Assessment of environmental and nondestructive earthquake effects on modal parameters of an office building based on long-term vibration measurements

    NASA Astrophysics Data System (ADS)

    Wu, Wen-Hwa; Wang, Sheng-Wei; Chen, Chien-Chou; Lai, Gwolong

    2017-05-01

    Identification for the modal parameters of an instrumented office building using ambient vibration measurements is conducted in this study based on a recently developed stochastic subspace identification methodology equipped with an alternative stabilization diagram and a hierarchical sifting process. The identified results are then deliberately examined to recognize the dynamic features for quite a few dominant modes of this building structure including three pairs of closely-spaced modes. Making use of the collected three-month data including three seismic events, the analyzed results show that the root-mean-square vibration response is directly related to the wind speed and indirectly related to the air temperature under a specific condition. More importantly, it is discovered that the root-mean-square response is the dominant factor to induce the variation of modal parameters. Except for the torsional modes, all the other modal frequencies are highly correlated with the root-mean-square acceleration in a negative manner and the corresponding damping ratios also clearly display a positive correlation. Another crucial observation from this assessment is that the percentages of frequency variation in three months for most of the identified modes go beyond 10%. The effects of three nondestructive earthquakes are further traced to observe the tendencies of reducing the modal frequencies and raising the damping ratios, both with a variation level possibly increasing with the seismic intensity. But different from the effects of environmental factors, the changes in modal parameters caused by nondestructive earthquakes will vanish right after the seismic events.

  17. Modeling parameter extraction for DNQ-novolak thick film resists

    NASA Astrophysics Data System (ADS)

    Henderson, Clifford L.; Scheer, Steven A.; Tsiartas, Pavlos C.; Rathsack, Benjamen M.; Sagan, John P.; Dammel, Ralph R.; Erdmann, Andreas; Willson, C. Grant

    1998-06-01

    Optical lithography with special thick film DNQ-novolac photoresists have been practiced for many years to fabricate microstructures that require feature heights ranging from several to hundreds of microns such as thin film magnetic heads. It is common in these thick film photoresist systems to observe interesting non-uniform profiles with narrow regions near the top surface of the film that transition into broader and more concave shapes near the bottom of the resist profile. A number of explanations have been proposed for these various observations including the formation of `dry skins' at the resist surface and the presence of solvent gradients in the film which serve to modify the local development rate of the photoresist. There have been few detailed experimental studies of the development behavior of thick films resists. This has been due to part to the difficulty in studying these films with conventional dissolution rate monitors (DRMs). In general, this lack of experimental data along with other factors has made simulation and modeling of thick film resist performance difficult. As applications such as thin film head manufacturing drive to smaller features with higher aspect ratios, the need for accurate thick film simulation capability continues to grow. A new multi-wavelength DRM tool has been constructed and used in conjunction with a resist bleaching tool and rigorous parameter extraction techniques to establish exposure and development parameters for two thick film resists, AZTM 4330-RS and AZTM 9200. Simulations based on these parameters show good agreement to resist profiles for these two resists.

  18. Modal Test Experiences with a Jet Engine Fan Model

    NASA Astrophysics Data System (ADS)

    HOLLKAMP, J. J.; GORDON, R. W.

    2001-11-01

    High cycle fatigue in jet engine blades is caused by excessive vibration. Understanding the dynamic response of the bladed disk system is important in determining vibration levels. Modal testing is a useful tool in understanding the dynamic behavior of structures. However, modal tests are not conducted on bladed disks because of the difficulties involved. One problem is that the overall dynamic behavior is sensitive to small perturbations. Another problem is that multiple inputs and high-resolution techniques are required to separate modes that are nearly repeated. Two studies of engine blade response were recently completed in which bench modal tests were successfully performed on simplified fan models. The modal test procedures for the first study were successful in extracting the modal parameters. But the tests in the second study were more demanding. Ultimately, an approach was devised that accurately extracted the modal parameters. This paper describes the challenges and the evolution of the test procedures.

  19. Analytical modelling and extraction of the modal behaviour of a cantilever beam in fluid interaction

    NASA Astrophysics Data System (ADS)

    Gorman, Daniel G.; Trendafilova, Irina; Mulholland, Anthony J.; Horáček, Jaromír

    2007-11-01

    When carrying out vibration health monitoring (VHM) of a structure it is usually assumed that the structure is in the absence of fluid interaction and/or that any environmental effects which can cause changes in the vibration response of the structure either remain constant or are negligible. In general, the natural frequencies of a structure are the first candidates to be considered for damage features. But the natural frequencies would also change as a result of the interaction of the structure with a fluid/gas environment. For the purpose of VHM, one needs the pure structural natural frequencies corresponding to conditions when the structure does not interact with the environment. Therefore, in certain cases when the above assumptions cannot be made it becomes necessary to extract values of natural frequencies of the structure if it were in the absence of fluid interaction from those values measured. This paper considers the case of a cantilever beam in contact with a fluid cavity giving rise to strong structural/fluid vibration interaction and develops a method by which the natural frequencies of the beam in the absence of fluid interaction can be obtained from those of the beam in interaction.

  20. Operational modal identification using variational Bayes

    NASA Astrophysics Data System (ADS)

    Li, Binbin; Der Kiureghian, Armen

    2017-05-01

    Operational modal analysis is the primary tool for modal parameter identification in civil engineering. Bayesian statistics offers an ideal framework for analyzing uncertainties associated with the identified modal parameters. However, the exact Bayesian formulation is usually intractable due to the high computational demand in obtaining the posterior distributions of modal parameters. In this paper, the variational Bayes method is employed to provide an approximate solution. Unlike the Laplace approximation and Monte Carlo sampling, the variational Bayes approach provides a gradient-free algorithm to analytically approximate the posterior distributions. Working with the state-space representation of a dynamical system, the variational Bayes approach for identification of modal parameters is derived by ignoring statistical correlation between latent variables and the model parameters. In this approach, the joint distribution of the state-transition and observation matrices as well as the joint distribution of the process noise and measurement error are firstly calculated analytically using conjugate priors. The distribution of modal parameters is extracted from these obtained joint distributions using a first-order Taylor series expansion. A robust implementation of the method is discussed by using square-root filtering and Cholesky decomposition. The proposed approach is illustrated by its application to an example mass-spring system and the One Rincon Hill Tower in San Francisco.

  1. NIF Periscope Wall Modal Study Comparison of Results for 2 FEA Models with 2 Modal Tests

    SciTech Connect

    Eli, M W; Gerhard, M A; Lee, C L; Sommer, S C; Woehrle, T G

    2000-10-26

    This report summarizes experimentally and numerically determined modal properties for one of the reinforced concrete end walls of the NIF Periscope Support Structure in Laser Bay 1. Two methods were used to determine these modal properties: (1) Computational finite-element analyses (modal extraction process); and (2) Experimental modal analysis based on measured test data. This report also includes experimentally determined modal properties for a prototype LM3/Polarizer line-replaceable unit (LRU) and a prototype PEPC LRU. Two important parameters, used during the design phase, are validated through testing [ref 1]. These parameters are the natural frequencies and modal damping (of the system in question) for the first several global modes of vibration. Experimental modal testing provides these modal values, along with the corresponding mode shapes. Another important parameter, the input excitation (expected during normal operation of the NIF laser system) [ref 1], can be verified by performing a series of ambient vibration measurements in the vicinity of the particular system (or subsystem) of interest. The topic of ambient input excitation will be covered in a separate report. Due to the large mass of the Periscope Pedestal, it is difficult to excite the entire series of Periscope Pedestal Walls all at once. It was decided that the experimental modal tests would be performed on just one Periscope End Wall in Laser Bay 1. Experimental modal properties for the Periscope End Wall have been used to validate and update the FE analyses. Results from the analyses and modal tests support the conclusion that the Periscope Pedestal will not exceed the stability budget, which is described in reference 1. The results of the modal tests for the Periscope End Wall in Laser Bay 1 have provided examples of modal properties that can be derived from future modal tests of the entire Periscope Assembly (excluding the LRU's). This next series of larger modal tests can be performed

  2. Modeling and Extraction of Parasitic Thermal Conductance and Intrinsic Model Parameters of Thermoelectric Modules

    NASA Astrophysics Data System (ADS)

    Sim, Minseob; Park, Hyunbin; Kim, Shiho

    2015-11-01

    We have presented both modeling and a method for extracting parasitic thermal conductance as well as intrinsic device parameters of a thermoelectric module based on information readily available in vendor datasheets. An equivalent circuit model that is compatible with circuit simulators is derived, followed by a methodology for extracting both intrinsic and parasitic model parameters. For the first time, the effective thermal resistance of the ceramic and copper interconnect layers of the thermoelectric module is extracted using only parameters listed in vendor datasheets. In the experimental condition, including under condition of varying electric current, the parameters extracted from the model accurately reproduce the performance of commercial thermoelectric modules.

  3. Petermann I and II spot size: Accurate semi analytical description involving Nelder-Mead method of nonlinear unconstrained optimization and three parameter fundamental modal field

    NASA Astrophysics Data System (ADS)

    Roy Choudhury, Raja; Roy Choudhury, Arundhati; Kanti Ghose, Mrinal

    2013-01-01

    A semi-analytical model with three optimizing parameters and a novel non-Gaussian function as the fundamental modal field solution has been proposed to arrive at an accurate solution to predict various propagation parameters of graded-index fibers with less computational burden than numerical methods. In our semi analytical formulation the optimization of core parameter U which is usually uncertain, noisy or even discontinuous, is being calculated by Nelder-Mead method of nonlinear unconstrained minimizations as it is an efficient and compact direct search method and does not need any derivative information. Three optimizing parameters are included in the formulation of fundamental modal field of an optical fiber to make it more flexible and accurate than other available approximations. Employing variational technique, Petermann I and II spot sizes have been evaluated for triangular and trapezoidal-index fibers with the proposed fundamental modal field. It has been demonstrated that, the results of the proposed solution identically match with the numerical results over a wide range of normalized frequencies. This approximation can also be used in the study of doped and nonlinear fiber amplifier.

  4. Comments on extracting the resonance strength parameter from yield data

    DOE PAGES

    Croft, Stephen; Favalli, Andrea

    2015-06-23

    The F(α,n) reaction is the focus of on-going research in part because it is an important source of neutrons in the nuclear fuel cycle which can be exploited to assay nuclear materials, especially uranium in the form of UF6. At the present time there remains some considerable uncertainty (of the order of ± 20%) in the thick target integrated over angle (α,n) yield from 19F (100% natural abundance) and its compounds as discussed. An important thin target cross-section measurement is that of Wrean and Kavanagh who explore the region from below threshold (2.36 MeV) to approximately 3.1 MeV with finemore » energy resolution. Integration of their cross-section data over the slowing down history of a stopping α-particle allows the thick target yield to be calculated for incident energies up to 3.1 MeV. This trend can then be combined with data from other sources to obtain a thick target yield curve over the wider range of interest to the fuel cycle (roughly threshold to 10 MeV to include all relevant α-emitters). To estimate the thickness of the CaF2 target they used, Wrean and Kavanagh separately measured the integrated yield of the 6.129 MeV γ-rays from the resonance at 340.5 keV (laboratory α-particle kinetic energy) in the 19F(p,αγ) reaction. To interpret the data they adopted a resonance strength parameter of (22.3 ± 0.8) eV based on a determination by Becker et al. The value and its uncertainty directly affects the thickness estimate and the extracted (α,n) cross-section values. In their citation to Becker et al's work, Wrean and Kavanagh comment that they did not make use of an alternative value of (23.7±1.0) eV reported by Croft because they were unable to reproduce the value from the data given in that paper. The value they calculated for the resonance strength from the thick target yield given by Croft was 21.4 eV. The purpose of this communication is to revisit the paper by Croft published in this journal and specifically to explain the origin of

  5. Comments on extracting the resonance strength parameter from yield data

    NASA Astrophysics Data System (ADS)

    Croft, Stephen; Favalli, Andrea

    2015-10-01

    The F(α,n) reaction is the focus of on-going research in part because it is an important source of neutrons in the nuclear fuel cycle which can be exploited to assay nuclear materials, especially uranium in the form of UF6 [1,2]. At the present time there remains some considerable uncertainty (of the order of ±20%) in the thick target integrated over angle (α,n) yield from 19F (100% natural abundance) and its compounds as discussed in [3,4]. An important thin target cross-section measurement is that of Wrean and Kavanagh [5] who explore the region from below threshold (2.36 MeV) to approximately 3.1 MeV with fine energy resolution. Integration of their cross-section data over the slowing down history of a stopping α-particle allows the thick target yield to be calculated for incident energies up to 3.1 MeV. This trend can then be combined with data from other sources to obtain a thick target yield curve over the wider range of interest to the fuel cycle (roughly threshold to 10 MeV to include all relevant α-emitters). To estimate the thickness of the CaF2 target they used, Wrean and Kavanagh separately measured the integrated yield of the 6.129 MeV γ-rays from the resonance at 340.5 keV (laboratory α-particle kinetic energy) in the 19F(p,αγ) reaction. To interpret the data they adopted a resonance strength parameter of (22.3±0.8) eV based on a determination by Becker et al [6]. The value and its uncertainty directly affects the thickness estimate and the extracted (α,n) cross-section values. In their citation to Becker et al's work, Wrean and Kavanagh comment that they did not make use of an alternative value of (23.7±1.0) eV reported by Croft [7] because they were unable to reproduce the value from the data given in that paper. The value they calculated for the resonance strength from the thick target yield given by Croft was 21.4 eV. The purpose of this communication is to revisit the paper by Croft published in this journal and specifically to

  6. Comments on extracting the resonance strength parameter from yield data

    SciTech Connect

    Croft, Stephen; Favalli, Andrea

    2015-06-23

    The F(α,n) reaction is the focus of on-going research in part because it is an important source of neutrons in the nuclear fuel cycle which can be exploited to assay nuclear materials, especially uranium in the form of UF6. At the present time there remains some considerable uncertainty (of the order of ± 20%) in the thick target integrated over angle (α,n) yield from 19F (100% natural abundance) and its compounds as discussed. An important thin target cross-section measurement is that of Wrean and Kavanagh who explore the region from below threshold (2.36 MeV) to approximately 3.1 MeV with fine energy resolution. Integration of their cross-section data over the slowing down history of a stopping α-particle allows the thick target yield to be calculated for incident energies up to 3.1 MeV. This trend can then be combined with data from other sources to obtain a thick target yield curve over the wider range of interest to the fuel cycle (roughly threshold to 10 MeV to include all relevant α-emitters). To estimate the thickness of the CaF2 target they used, Wrean and Kavanagh separately measured the integrated yield of the 6.129 MeV γ-rays from the resonance at 340.5 keV (laboratory α-particle kinetic energy) in the 19F(p,αγ) reaction. To interpret the data they adopted a resonance strength parameter of (22.3 ± 0.8) eV based on a determination by Becker et al. The value and its uncertainty directly affects the thickness estimate and the extracted (α,n) cross-section values. In their citation to Becker et al's work, Wrean and Kavanagh comment that they did not make use of an alternative value of (23.7±1.0) eV reported by Croft because they were unable to reproduce the value from the data given in that paper. The value they calculated for the resonance strength from the thick target yield given by Croft was 21.4 eV. The purpose of this communication is to revisit the paper by Croft published in this journal and

  7. Extraction of Cole parameters from the electrical bioimpedance spectrum using stochastic optimization algorithms.

    PubMed

    Gholami-Boroujeny, Shiva; Bolic, Miodrag

    2016-04-01

    Fitting the measured bioimpedance spectroscopy (BIS) data to the Cole model and then extracting the Cole parameters is a common practice in BIS applications. The extracted Cole parameters then can be analysed as descriptors of tissue electrical properties. To have a better evaluation of physiological or pathological properties of biological tissue, accurate extraction of Cole parameters is of great importance. This paper proposes an improved Cole parameter extraction based on bacterial foraging optimization (BFO) algorithm. We employed simulated datasets to test the performance of the BFO fitting method regarding parameter extraction accuracy and noise sensitivity, and we compared the results with those of a least squares (LS) fitting method. The BFO method showed better robustness to the noise and higher accuracy in terms of extracted parameters. In addition, we applied our method to experimental data where bioimpedance measurements were obtained from forearm in three different positions of the arm. The goal of the experiment was to explore how robust Cole parameters are in classifying position of the arm for different people, and measured at different times. The extracted Cole parameters obtained by LS and BFO methods were applied to different classifiers. Two other evolutionary algorithms, GA and PSO were also used for comparison purpose. We showed that when the classifiers are fed with the extracted feature sets by BFO fitting method, higher accuracy is obtained both when applying on training data and test data.

  8. Select modalities.

    PubMed

    Canapp, Debra A

    2007-11-01

    Physical rehabilitation modalities such as therapeutic ultrasound (TU), transcutaneous electrical neuromuscular stimulation (TENS), neuromuscular electrical stimulation (NMES), cold or low-level laser therapy (LLLT), and pulsed magnetic field therapy (PMF) can all, when used properly, assist in treating orthopedic injuries, neurological conditions, and chronic conditions brought about by normal aging in our small animal companions. TU uses sound waves to produce both thermal and nonthermal effects that aid in tissue healing, repair, and function. TENS uses different frequencies of electrical current to decrease pain and inflammation. NMES also uses an electrical current to stimulate muscle contraction to assist in normal neuromuscular function in postorthopedic and neurological injuries. LLLT uses light energy to reduce pain, decrease inflammation, and stimulate healing at a cellular level. PMF uses magnetic field to stimulate normal cellular ion exchange and oxygen utilization and promote generalized healing of tissues. These modalities are discussed in detail covering mechanism of action, parameters, settings, and indications/contraindications of use in our small animals. Although these modalities are important in the physical rehabilitation of small animals, they need to be incorporated with a proper diagnosis, manual therapy, and home exercise program into a specific and individualized patient treatment protocol.

  9. Modal parameter identification of a compression-loaded CFRP stiffened plate and correlation with its buckling behaviour

    NASA Astrophysics Data System (ADS)

    Chaves-Vargas, M.; Dafnis, A.; Reimerdes, H.-G.; Schröder, K.-U.

    2015-10-01

    In order to study the dynamic response and the buckling behaviour of several load-carrying structural components of civil aircraft when subjected to transient load scenarios such as gusts or a landing impact, a generic mid-size aircraft is defined within the European research project DAEDALOS. From this aircraft, several sections or panels in different regions such as wing, vertical tailplane and fuselage are defined. The stiffened carbon-fibre-reinforced plastic (CFRP) plate investigated within the present work represents a simplified version of the wing panel selected from the generic aircraft. As part of the current work, the buckling behaviour and the modal properties of the stiffened plate under the effect of a static in-plane compression load are studied. This is accomplished by means of a test series including quasi-static buckling tests and an experimental modal analysis (EMA). One of the key objectives pursued is the correlation of the modal properties to the buckling behaviour by studying the relationship between the natural frequencies of the stiffened plate and its corresponding buckling load. The experimental work is verified by a finite element analysis.

  10. Extraction and fusion of spectral parameters for face recognition

    NASA Astrophysics Data System (ADS)

    Boisier, B.; Billiot, B.; Abdessalem, Z.; Gouton, P.; Hardeberg, J. Y.

    2011-03-01

    Many methods have been developed in image processing for face recognition, especially in recent years with the increase of biometric technologies. However, most of these techniques are used on grayscale images acquired in the visible range of the electromagnetic spectrum. The aims of our study are to improve existing tools and to develop new methods for face recognition. The techniques used take advantage of the different spectral ranges, the visible, optical infrared and thermal infrared, by either combining them or analyzing them separately in order to extract the most appropriate information for face recognition. We also verify the consistency of several keypoints extraction techniques in the Near Infrared (NIR) and in the Visible Spectrum.

  11. Extracting source parameters from beam monitors on a chopper spectrometer

    SciTech Connect

    Abernathy, Douglas L; Niedziela, Jennifer L; Stone, Matthew B

    2015-01-01

    The intensity distributions of beam monitors in direct-geometry time-of-flight neutron spectrometers provide important information about the instrument resolution. For short-pulse spallation neutron sources in particular, the asymmetry of the source pulse may be extracted and compared to Monte Carlo source simulations. An explicit formula using a Gaussian-convolved Ikeda-Carpenter distribution is given and compared to data from the ARCS instrument at the Spallation Neutron Source.

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

    NASA Astrophysics Data System (ADS)

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

    2017-08-01

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

  13. Investigation of erosion rill parameters extracted from digital terrain models

    NASA Astrophysics Data System (ADS)

    Eltner, Anette; Baumgart, Philipp

    2015-04-01

    Rill erosion is a significant factor contributing to soil loss and subsequent land degradation. Erosion rills exhibit a complex genesis influenced by rill hydraulics and soil detachment processes. Precise measurement of rills with high spatial and temporal resolution is necessary to investigate rill development. However, established field methods are time consuming, labor intense or restricted to few rills only. Furthermore, rill capturing is accompanied by surface impact, which inherits multi-temporal observation. These limitations can be resolved due to recent advances in digital surface mapping technologies - e.g. structure-from-motion (SfM) algorithms and unmanned aerial vehicle (UAV) platforms - allowing for fast and flexible measurement of detailed digital elevation models (DEM). However, automatic procedures are needed to extract relevant data and hence exploit the high information potential arising from the DEM. In this study a workflow is presented to obtain rill characteristics with minimal manual input from high-resolution DEM calculated from UAV images. Rill extraction is performed using methods that evolve from image processing. Edge detection is conducted with the Canny operator utilizing intensity changes of the DEM raster height values. Rills are extracted at the position where the rill wall is steepest. Further data processing is necessary to estimate the upper edge of the erosion rill considering height changes in the immediate neighborhood of the detected Canny edge. Thereby, significant slope changes indicate the end of the rill wall. The developed rill extraction method enables rill measurement with at least cm-resolution. The detected rill walls and the DEM are used for the calculation of rill depth, width and cross section area. Surface roughness of the area enclosing the rill is estimated to account for possible runoff impacts. Erosion volumes per rill are also measured. Investigation of the rill evolution at field scale on loess soil

  14. Inverting chaos: Extracting system parameters from experimental data

    NASA Astrophysics Data System (ADS)

    Baker, G. L.; Gollub, J. P.; Blackburn, J. A.

    1996-12-01

    Given a set of experimental or numerical chaotic data and a set of model differential equations with several parameters, is it possible to determine the numerical values for these parameters using a least-squares approach, and thereby to test the model against the data? We explore this question (a) with simulated data from model equations for the Rossler, Lorenz, and pendulum attractors, and (b) with experimental data produced by a physical chaotic pendulum. For the systems considered in this paper, the least-squares approach provides values of model parameters that agree well with values obtained in other ways, even in the presence of modest amounts of added noise. For experimental data, the ``fitted'' and experimental attractors are found to have the same correlation dimension and the same positive Lyapunov exponent.

  15. A simple and accurate resist parameter extraction method for sub-80-nm DRAM patterns

    NASA Astrophysics Data System (ADS)

    Lee, Sook; Hwang, Chan; Park, Dong-Woon; Kim, In-Sung; Kim, Ho-Chul; Woo, Sang-Gyun; Cho, Han-Ku; Moon, Joo-Tae

    2004-05-01

    Due to the polarization effect of high NA lithography, the consideration of resist effect in lithography simulation becomes increasingly important. In spite of the importance of resist simulation, many process engineers are reluctant to consider resist effect in lithography simulation due to time-consuming procedure to extract required resist parameters and the uncertainty of measurement of some parameters. Weiss suggested simplified development model, and this model does not require the complex kinetic parameters. For the device fabrication engineers, there is a simple and accurate parameter extraction and optimizing method using Weiss model. This method needs refractive index, Dill"s parameters and development rate monitoring (DRM) data in parameter extraction. The parameters extracted using referred sequence is not accurate, so that we have to optimize the parameters to fit the critical dimension scanning electron microscopy (CD SEM) data of line and space patterns. Hence, the FiRM of Sigma-C is utilized as a resist parameter-optimizing program. According to our study, the illumination shape, the aberration and the pupil mesh point have a large effect on the accuracy of resist parameter in optimization. To obtain the optimum parameters, we need to find the saturated mesh points in terms of normalized intensity log slope (NILS) prior to an optimization. The simulation results using the optimized parameters by this method shows good agreement with experiments for iso-dense bias, Focus-Exposure Matrix data and sub 80nm device pattern simulation.

  16. Revisiting The Effect Of Sine Sweep Rate On Modal Identification

    NASA Astrophysics Data System (ADS)

    Roy, Nicolas; Girard, Alain

    2012-07-01

    Sine-sweep base excitation vibration tests are performed to qualify spacecraft structures in the low-frequency environment where the dynamic behavior can be characterized by a small number of modes. These modes can be extracted from the measured frequency response functions (FRF) by various modal identification methods, and then used for model validation purposes. If the sweep rate is too high, the steady-state response is not reached and the resulting FRF profile will be modified by the presence of transients. This has a direct effect on the modal parameters extracted from the FRF.Several authors have examined the effect of the sweep rate based on the response of a one-degree-of-freedom system. The goal of this paper is to adapt the approach to base-excitation vibration tests. Both increasing and decreasing exponential sweep rates are considered. The effect on the three principal modal parameters (natural frequency, damping and modal effective parameters) is examined.

  17. A simple and efficient solar cell parameter extraction method from a single current-voltage curve

    NASA Astrophysics Data System (ADS)

    Zhang, Chunfu; Zhang, Jincheng; Hao, Yue; Lin, Zhenhua; Zhu, Chunxiang

    2011-09-01

    In this work, a simple and efficient method for the extraction of all the parameters of a solar cell from a single current-voltage (I-V) curve under the constant illumination level is proposed. With the help of the Lambert W function, the explicit analytic expression for I is obtained. By reducing the number of the parameters, the expression for I only depends on the ideality factor n, the series resistance Rs, and the shunt resistance Rsh. This analytic expression is directly used to fit the experimental data and extract the device parameters. This simple solar cell parameter extraction method can be directly applied for all kinds of solar cells whose I-V characteristics follow the single-diode model. The parameters of various solar devices including silicon solar cells, silicon solar modules, dye-sensitized solar cells, and organic solar cells with standalone, tandem, and multi-junction structures have been successfully extracted by using our proposed method.

  18. Power extraction calculation improvement when local parameters are included

    NASA Astrophysics Data System (ADS)

    Flores-Mateos, L. M.; Hartnett, M.

    2016-02-01

    The improvement of the tidal resource assessment will be studied by comparing two approaches in a two-dimensional, finite difference, hydrodynamic model DIVAST-ADI; in a channel of non-varying cross-sectional area that connects two large basins. The first strategy, considers a constant trust coefficient; the second one, use the local field parameters around the turbine. These parameters are obtained after applying the open channel theory in the tidal stream and after considering the turbine as a linear momentum actuator disk. The parameters correspond to the upstream and downstream, with respect to the turbine, speeds and depths; also the blockage ratio, the wake velocity and the bypass coefficients and they have already been incorporated in the model. The figure (a) shows the numerical configuration at high tide developed with DIVAST-ADI. The experiment undertakes two open boundary conditions. The first one is a sinusoidal forcing introduced as a water level located at (I, J=1) and the second one, indicate that a zero velocity and a constant water depth were kept (I, J=362); when the turbine is introduced it is placed in the middle of the channel (I=161, J=181). The influence of the turbine in the velocity and elevation around the turbine region is evident; figure (b) and (c) shows that the turbine produces a discontinuity in the depth and velocity profile, when we plot a transect along the channel. Finally, the configuration implemented reproduced with satisfactory accuracy the quasi-steady flow condition, even without presenting shock-capturing capability. Also, the range of the parameters 0.01<α 4<0.55, $0

  19. Advanced lithography parameters extraction by using scatterometry system: part II

    NASA Astrophysics Data System (ADS)

    Zhou, Wenzhan; Hsieh, Michael; Koh, Huipeng; Zhou, Meisheng

    2008-03-01

    As the advanced IC device process shrinks to below sub-micron dimensions (65nm, 45 nm and beyond), the overall CD error budget becomes more and more challenging. The impact of lithography process parameters other than exposure energy and defocus on final CD results cannot be ignored any more. In this paper we continue the development of the advanced lithography parameters model which we presented last year. This year we achieved to decouple 4 lithography parameters: exposure, focus, PEB temperature and laser bandwidth (or z-blur). To improve the accuracy and precision of the model, new scatterometry marks are designed to reduce the pitch dependent accuracy impact of sidewall angle and photoresist height for scatterometry metrology. The concept of this kind of scatterometry mark design is from T.A. Brunner's paper "Process Monitor Gating" [SPIE Vol. 6518, 2007]. With this concept, new scatterometry marks are designed to increase the accuracy of scatterometry measurement without sacrificing the process sensitivity and thus improve the model prediction accuracy.

  20. Multi-modal, Multi-measure, and Multi-class Discrimination of ADHD with Hierarchical Feature Extraction and Extreme Learning Machine Using Structural and Functional Brain MRI

    PubMed Central

    Qureshi, Muhammad Naveed Iqbal; Oh, Jooyoung; Min, Beomjun; Jo, Hang Joon; Lee, Boreom

    2017-01-01

    Structural and functional MRI unveil many hidden properties of the human brain. We performed this multi-class classification study on selected subjects from the publically available attention deficit hyperactivity disorder ADHD-200 dataset of patients and healthy children. The dataset has three groups, namely, ADHD inattentive, ADHD combined, and typically developing. We calculated the global averaged functional connectivity maps across the whole cortex to extract anatomical atlas parcellation based features from the resting-state fMRI (rs-fMRI) data and cortical parcellation based features from the structural MRI (sMRI) data. In addition, the preprocessed image volumes from both of these modalities followed an ANOVA analysis separately using all the voxels. This study utilized the average measure from the most significant regions acquired from ANOVA as features for classification in addition to the multi-modal and multi-measure features of structural and functional MRI data. We extracted most discriminative features by hierarchical sparse feature elimination and selection algorithm. These features include cortical thickness, image intensity, volume, cortical thickness standard deviation, surface area, and ANOVA based features respectively. An extreme learning machine performed both the binary and multi-class classifications in comparison with support vector machines. This article reports prediction accuracy of both unimodal and multi-modal features from test data. We achieved 76.190% (p < 0.0001) classification accuracy in multi-class settings as well as 92.857% (p < 0.0001) classification accuracy in binary settings. In addition, we found ANOVA-based significant regions of the brain that also play a vital role in the classification of ADHD. Thus, from a clinical perspective, this multi-modal group analysis approach with multi-measure features may improve the accuracy of the ADHD differential diagnosis. PMID:28420972

  1. Multi-modal, Multi-measure, and Multi-class Discrimination of ADHD with Hierarchical Feature Extraction and Extreme Learning Machine Using Structural and Functional Brain MRI.

    PubMed

    Qureshi, Muhammad Naveed Iqbal; Oh, Jooyoung; Min, Beomjun; Jo, Hang Joon; Lee, Boreom

    2017-01-01

    Structural and functional MRI unveil many hidden properties of the human brain. We performed this multi-class classification study on selected subjects from the publically available attention deficit hyperactivity disorder ADHD-200 dataset of patients and healthy children. The dataset has three groups, namely, ADHD inattentive, ADHD combined, and typically developing. We calculated the global averaged functional connectivity maps across the whole cortex to extract anatomical atlas parcellation based features from the resting-state fMRI (rs-fMRI) data and cortical parcellation based features from the structural MRI (sMRI) data. In addition, the preprocessed image volumes from both of these modalities followed an ANOVA analysis separately using all the voxels. This study utilized the average measure from the most significant regions acquired from ANOVA as features for classification in addition to the multi-modal and multi-measure features of structural and functional MRI data. We extracted most discriminative features by hierarchical sparse feature elimination and selection algorithm. These features include cortical thickness, image intensity, volume, cortical thickness standard deviation, surface area, and ANOVA based features respectively. An extreme learning machine performed both the binary and multi-class classifications in comparison with support vector machines. This article reports prediction accuracy of both unimodal and multi-modal features from test data. We achieved 76.190% (p < 0.0001) classification accuracy in multi-class settings as well as 92.857% (p < 0.0001) classification accuracy in binary settings. In addition, we found ANOVA-based significant regions of the brain that also play a vital role in the classification of ADHD. Thus, from a clinical perspective, this multi-modal group analysis approach with multi-measure features may improve the accuracy of the ADHD differential diagnosis.

  2. Extracting Structure Parameters of Dimers for Molecular Tunneling Ionization Model

    NASA Astrophysics Data System (ADS)

    Song-Feng, Zhao; Fang, Huang; Guo-Li, Wang; Xiao-Xin, Zhou

    2016-03-01

    We determine structure parameters of the highest occupied molecular orbital (HOMO) of 27 dimers for the molecular tunneling ionization (so called MO-ADK) model of Tong et al. [Phys. Rev. A 66 (2002) 033402]. The molecular wave functions with correct asymptotic behavior are obtained by solving the time-independent Schrödinger equation with B-spline functions and molecular potentials which are numerically created using the density functional theory. We examine the alignment-dependent tunneling ionization probabilities from MO-ADK model for several molecules by comparing with the molecular strong-field approximation (MO-SFA) calculations. We show the molecular Perelomov-Popov-Terent'ev (MO-PPT) can successfully give the laser wavelength dependence of ionization rates (or probabilities). Based on the MO-PPT model, two diatomic molecules having valence orbital with antibonding systems (i.e., Cl2, Ne2) show strong ionization suppression when compared with their corresponding closest companion atoms. Supported by National Natural Science Foundation of China under Grant Nos. 11164025, 11264036, 11465016, 11364038, the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No. 20116203120001, and the Basic Scientific Research Foundation for Institution of Higher Learning of Gansu Province

  3. Information Extraction of High Resolution Remote Sensing Images Based on the Calculation of Optimal Segmentation Parameters.

    PubMed

    Zhu, Hongchun; Cai, Lijie; Liu, Haiying; Huang, Wei

    2016-01-01

    Multi-scale image segmentation and the selection of optimal segmentation parameters are the key processes in the object-oriented information extraction of high-resolution remote sensing images. The accuracy of remote sensing special subject information depends on this extraction. On the basis of WorldView-2 high-resolution data, the optimal segmentation parameters methodof object-oriented image segmentation and high-resolution image information extraction, the following processes were conducted in this study. Firstly, the best combination of the bands and weights was determined for the information extraction of high-resolution remote sensing image. An improved weighted mean-variance method was proposed andused to calculatethe optimal segmentation scale. Thereafter, the best shape factor parameter and compact factor parameters were computed with the use of the control variables and the combination of the heterogeneity and homogeneity indexes. Different types of image segmentation parameters were obtained according to the surface features. The high-resolution remote sensing images were multi-scale segmented with the optimal segmentation parameters. Ahierarchical network structure was established by setting the information extraction rules to achieve object-oriented information extraction. This study presents an effective and practical method that can explain expert input judgment by reproducible quantitative measurements. Furthermore the results of this procedure may be incorporated into a classification scheme.

  4. Information Extraction of High Resolution Remote Sensing Images Based on the Calculation of Optimal Segmentation Parameters

    PubMed Central

    Zhu, Hongchun; Cai, Lijie; Liu, Haiying; Huang, Wei

    2016-01-01

    Multi-scale image segmentation and the selection of optimal segmentation parameters are the key processes in the object-oriented information extraction of high-resolution remote sensing images. The accuracy of remote sensing special subject information depends on this extraction. On the basis of WorldView-2 high-resolution data, the optimal segmentation parameters methodof object-oriented image segmentation and high-resolution image information extraction, the following processes were conducted in this study. Firstly, the best combination of the bands and weights was determined for the information extraction of high-resolution remote sensing image. An improved weighted mean-variance method was proposed andused to calculatethe optimal segmentation scale. Thereafter, the best shape factor parameter and compact factor parameters were computed with the use of the control variables and the combination of the heterogeneity and homogeneity indexes. Different types of image segmentation parameters were obtained according to the surface features. The high-resolution remote sensing images were multi-scale segmented with the optimal segmentation parameters. Ahierarchical network structure was established by setting the information extraction rules to achieve object-oriented information extraction. This study presents an effective and practical method that can explain expert input judgment by reproducible quantitative measurements. Furthermore the results of this procedure may be incorporated into a classification scheme. PMID:27362762

  5. Effect of Supercritical Carbon Dioxide Extraction Parameters on the Biological Activities and Metabolites Present in Extracts from Arthrospira platensis

    PubMed Central

    Esquivel-Hernández, Diego A.; Rodríguez-Rodríguez, José; Cuéllar-Bermúdez, Sara P.; García-Pérez, J. Saúl; Mancera-Andrade, Elena I.; Núñez-Echevarría, Jade E.; Ontiveros-Valencia, Aura; Rostro-Alanis, Magdalena; García-García, Rebeca M.; Torres, J. Antonio; Chen, Wei Ning; Parra-Saldívar, Roberto

    2017-01-01

    Arthrospira platensis was used to obtain functional extracts through supercritical carbon dioxide extraction (SFE-CO2). Pressure (P), temperature (T), co-solvent (CX), static extraction (SX), dispersant (Di) and dynamic extraction (DX) were evaluated as process parameters through a Plackett–Burman design. The maximum extract yield obtained was 7.48 ± 0.15% w/w. The maximum contents of bioactive metabolites in extracts were 0.69 ± 0.09 µg/g of riboflavin, 5.49 ± 0.10 µg/g of α-tocopherol, 524.46 ± 0.10 µg/g of β-carotene, 1.44 ± 0.10 µg/g of lutein and 32.11 ± 0.12 mg/g of fatty acids with 39.38% of palmitic acid, 20.63% of linoleic acid and 30.27% of γ-linolenic acid. A. platensis extracts had an antioxidant activity of 76.47 ± 0.71 µg GAE/g by Folin–Ciocalteu assay, 0.52 ± 0.02, 0.40 ± 0.01 and 1.47 ± 0.02 µmol TE/g by DPPH, FRAP and TEAC assays, respectively. These extracts showed antimicrobial activity against Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922 and Candida albicans ATCC 10231. Overall, co-solvent was the most significant factor for all measured effects (p < 0.05). Arthrospira platensis represents a sustainable source of bioactive compounds through SFE using the following extraction parameters P: 450 bar, CX: 11 g/min, SX: 15 min, DX: 25 min, T: 60 °C and Di: 35 g. PMID:28604646

  6. Effect of Supercritical Carbon Dioxide Extraction Parameters on the Biological Activities and Metabolites Present in Extracts from Arthrospira platensis.

    PubMed

    Esquivel-Hernández, Diego A; Rodríguez-Rodríguez, José; Cuéllar-Bermúdez, Sara P; García-Pérez, J Saúl; Mancera-Andrade, Elena I; Núñez-Echevarría, Jade E; Ontiveros-Valencia, Aura; Rostro-Alanis, Magdalena; García-García, Rebeca M; Torres, J Antonio; Chen, Wei Ning; Parra-Saldívar, Roberto

    2017-06-12

    Arthrospira platensis was used to obtain functional extracts through supercritical carbon dioxide extraction (SFE-CO₂). Pressure (P), temperature (T), co-solvent (CX), static extraction (SX), dispersant (Di) and dynamic extraction (DX) were evaluated as process parameters through a Plackett-Burman design. The maximum extract yield obtained was 7.48 ± 0.15% w/w. The maximum contents of bioactive metabolites in extracts were 0.69 ± 0.09 µg/g of riboflavin, 5.49 ± 0.10 µg/g of α-tocopherol, 524.46 ± 0.10 µg/g of β-carotene, 1.44 ± 0.10 µg/g of lutein and 32.11 ± 0.12 mg/g of fatty acids with 39.38% of palmitic acid, 20.63% of linoleic acid and 30.27% of γ-linolenic acid. A. platensis extracts had an antioxidant activity of 76.47 ± 0.71 µg GAE/g by Folin-Ciocalteu assay, 0.52 ± 0.02, 0.40 ± 0.01 and 1.47 ± 0.02 µmol TE/g by DPPH, FRAP and TEAC assays, respectively. These extracts showed antimicrobial activity against Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922 and Candida albicans ATCC 10231. Overall, co-solvent was the most significant factor for all measured effects (p < 0.05). Arthrospira platensis represents a sustainable source of bioactive compounds through SFE using the following extraction parameters P: 450 bar, CX: 11 g/min, SX: 15 min, DX: 25 min, T: 60 °C and Di: 35 g.

  7. [A study of coordinates transform iterative fitting method to extract bio-impedance model parameters bio-impedance model parameters].

    PubMed

    Zhou, Liming; Yang, Yuxing; Yuan, Shiying

    2006-02-01

    A new algorithm, the coordinates transform iterative optimizing method based on the least square curve fitting model, is presented. This arithmetic is used for extracting the bio-impedance model parameters. It is superior to other methods, for example, its speed of the convergence is quicker, and its calculating precision is higher. The objective to extract the model parameters, such as Ri, Re, Cm and alpha, has been realized rapidly and accurately. With the aim at lowering the power consumption, decreasing the price and improving the price-to-performance ratio, a practical bio-impedance measure system with double CPUs has been built. It can be drawn from the preliminary results that the intracellular resistance Ri increased largely with an increase in working load during sitting, which reflects the ischemic change of lower limbs.

  8. Extraction of thermal parameters of microbolometer infrared detectors using electrical measurement

    NASA Astrophysics Data System (ADS)

    Karunasiri, R. P. G.; Xu, Gu; Chen, G. X.; Sridhar, U.

    1998-10-01

    The performance of microbolometer infrared sensors is typically characterized by its thermal time constant, heat capacitance, and thermal conductance. Therefore, the determination of these parameters accurately and efficiently is of considerable interest for the design and operation of microbolometer infrared sensors. Usually, the thermal time constant is obtained by measuring the frequency response of microbolometers under infrared excitation and the thermal conductance and capacity are extracted using electrical measurement. In this paper, a technique is described to extract all three parameters using a single electrical measurement. In the measurement, we have employed a Wheatstone Bridge consisting of a bolometer and three reference resistors. The resistance of the bolometer changes as a result of self-heating under an external bias which in turn generates an output voltage across the Bridge. The time dependence of the output voltage was used to extract thermal parameters of the bolometer. We believe this technique is useful in determining the thermal parameters of microbolometer based sensors.

  9. ECG characterization of paroxysmal atrial fibrillation: parameter extraction and automatic diagnosis algorithm.

    PubMed

    Ros, E; Mota, S; Fernández, F J; Toro, F J; Bernier, J L

    2004-12-01

    Paroxysmal atrial fibrillation (PAF) is one of the most common heart arrhythmias. It is very difficult to detect unless an explicit Atrial Fibrillation episode occurs during the exploration. The present paper describes a number of low level parameters extracted from ECG traces where no Atrial Fibrillation process is present. The ability of this parameter set to characterize PAF patients is studied and discussed. Based on these parameters a modular automatic classification algorithm for PAF diagnosis is developed and evaluated.

  10. Extraction of the Michel parameters from muon decay by a maximum likelihood method

    SciTech Connect

    McKee, R.J.

    1980-01-01

    A maximum likelihood method was developed for extracting the Michel parameters, which describe the decay spectrum of stopped polarized muons. The method was applied successfully in a Monte Carlo simulation of apparatus. A complete error matrix for the set of Michel parameters was also obtained. In an experiment of 10/sup 8/ muon decays the statistical errors can be reduced by more than an order of magnitude over the currently accepted limits on the Michel parameters. 5 tables.

  11. Factors influencing particle number concentrations, size distributions and modal parameters at a roof-level and roadside site in Leicester, UK.

    PubMed

    Agus, Emily L; Young, David T; Lingard, Justin J N; Smalley, Robert J; Tate, James E; Goodman, Paul S; Tomlin, Alison S

    2007-11-01

    Measurements of urban particle number concentrations and size distributions in the range 5-1000 nm were taken at elevated (roof-level) and roadside sampling sites on Narborough Road in Leicester, UK, along with simultaneous measurements of traffic, NO(x), CO and 1,3-butadiene concentrations and meteorological parameters. A fitting program was used to determine the characteristics of up to five modal groups present in the particle size distributions. All particle modal concentrations peaked during the morning and evening rush hours. Additional events associated with the smallest mode, that were not observed to be connected to primary emissions, were also present suggesting that this mode consisted of newly formed secondary particles. These events included peaks in concentration which coincided with peaks in solar radiation, and lower concentrations of the larger modes. Investigation into the relationships between traffic flow and occupancy indicated three flow regimes; free-flow, unstable and congested. During free-flow conditions, positive linear relationships existed between traffic flow and particle modal number concentrations. However, during unstable and congested periods, this relationship was shown to break-down. Similar trends were observed for concentrations of the gas phase pollutants NO(x), CO and 1,3-butadiene. Strong linear relationships existed between NO(x), CO, 1,3-butadiene concentrations, nucleation and Aitken mode concentrations at both sampling locations, indicating a local traffic related emission source. At the roadside, both nucleation and Aitken mode are best represented by a decreasing exponential function with wind speed, whereas at the roof-level this relationship only occurred for Aitken mode particles. The differing relationships at the two sampling locations are most likely due to a combination of meteorological factors and distance from the local emission source.

  12. Optimization of Process Parameters and Kinetic Model of Enzymatic Extraction of Polyphenols from Lonicerae Flos

    PubMed Central

    Kong, Fansheng; Yu, Shujuan; Bi, Yongguang; Huang, Xiaojun; Huang, Mengqian

    2016-01-01

    Objective: To optimize and verify the cellulase extraction of polyphenols from honeysuckle and provide a reference for enzymatic extracting polyphenols from honeysuckle. Materials and Methods: The uniform design was used According to Fick's first law and kinetic model, fitting analysis of the dynamic process of enzymatic extracting polyphenols was conducted. Results: The optimum enzymatic extraction parameters for polyphenols from honeysuckle are found to be 80% (v/v) of alcohol, 35:1 (mL/g) of liquid-solid ratio, 80°C of extraction temperature, 8.5 of pH, 6.0 mg of enzyme levels, and 130 min of extraction time. Under the optimal conditions, the extraction rate of polyphenols was 3.03%. The kinetic experiments indicated kinetic equation had a good linear relationship with t even under the conditions of different levels of enzyme and temperature, which means fitting curve tallies well with the experimental values. Conclusion: The results of quantification showed that the results provide a reference for enzymatic extracting polyphenols from honeysuckle. SUMMARY Lonicerae flos (Lonicera japonica Thunb.) is a material of traditional Chinese medicine and healthy drinks, of which active compounds mainly is polyphenols. At present, plant polyphenols are the hotspots centents of food, cosmetic and medicine, because it has strong bioactivity. Several traditional methods are available for the extraction of plant polyphenols including impregnation, solvent extraction, ultrasonic extraction, hot-water extraction, alkaline dilute alcohol or alkaline water extraction, microwave extraction and Supercritical CO2 extraction. But now, an increasing number of research on using cellulase to extract active ingredients from plants. Enzymatic method is widely used for enzyme have excellent properties of high reaction efficiency and specificity, moderate reaction conditions, shorter extraction time and easier to control, less damage to the active ingredient. At present, the enzymatic

  13. Influence of process parameters on the extraction of soluble substances from OFMSW and methane production.

    PubMed

    Campuzano, Rosalinda; González-Martínez, Simón

    2017-04-01

    Microorganisms involved in anaerobic digestion require dissolved substrates to transport them through the cell wall to different processing units and finally to be disposed as waste, such as methane and carbon dioxide. In order to increase methane production, this work proposes to separate the soluble substances from OFMSW and analyse methane production from extracts and OFMSW. Using water as solvent, four extraction parameters were proposed: (1) Number of consecutive extractions, (2) Duration of mixing for every consecutive extraction, (3) OFMSW to water mass ratios 1:1, 1:2, and 1:3 and, (4) The influence of temperature on the extraction process. Results indicated that is possible to separate 40% of VS from OFMSW with only three consecutive extraction with mixing of 30min in every extraction using ambient temperature water. For every OFMSW to water combination, the first three consecutive extracts were analysed for biochemical methane potential test during 21days at 35°C; OFMSW was also tested as reference. Methane production from all substrates is highest during the first day and then it slowly decreases to increase again during a second stage. This was identified as diauxic behaviour. Specific methane production at day 21 increased with increasing water content of the extracts where OFMSW methane production was the lowest of all with 535NL/kgVS. These results indicate that it is feasible to rapidly produce methane from extracted substances. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. A Unified Genetic Algorithm for Deep-submicron MOSFET Model Parameter Extraction

    NASA Astrophysics Data System (ADS)

    Li, Yiming; Cho, Yen-Yu Cho

    2002-08-01

    Genetic algorithm is a stochastic-based optimization strategy which was usually applied for solving complex physical problem and parameter extraction. To characterize the device transport properties accurately, various MOSFET compact models, such as BSIM3, MosM9, and EKV models have been proposed for deep-submicron and nanoscale MOSFET device simulation. Each model consists of diverse governing equations and parameters. It leads to a multivariable optimization problem to be solved and extracted efficiently for the device applications. Different approaches, for instance the direct method and numerical method have been applied to extract and optimize the model parameters. In this paper we present a unified multiobject evolutionary approach for models parameter extraction. In contract to conventional time-consuming large-scale approach, our genetic algorithm includes: (1) a physical-based weight function; (2) a novel encoding scheme; (3) floating-point operators; and (4) dynamic mutation techniques solves the problem efficiently. The proposed method outputs a set of optimal parameters for device simulation; in our simulation experiences, this method is stable and accurate. Parallelization of the method shows an excellent performance for a typical optimization problem. Comprehensive comparisons among models are reported for the parameters sensitivity test. Simulations and measurements for MOSFETs models are examined to show the accuracy and robustness of the method.

  15. Changes in Corneal Deformation Parameters after Lenticule Creation and Extraction during Small Incision Lenticule Extraction (SMILE) Procedure

    PubMed Central

    Shen, Yang; Zhao, Jing; Yao, Peijun; Miao, Huamao; Niu, Lingling

    2014-01-01

    Purpose To investigate the effects of lenticule creation and subsequent corneal lenticule extraction on corneal deformation parameters during small incision lenticule extraction (SMILE) procedure. Materials and Methods In this prospective study, 18 eyes of 10 patients (27.90±7.11 years, −5.64±2.45 diopters) scheduled for SMILE procedure were enrolled. Changes in the corneal deformation parameters, including deformation amplitude (DA), applanation time(AT1 and AT2), applanation length(AL1 and AL2), corneal velocity(CV1 and CV2), peak distance(P.Dist.), radius and intraocular pressure values were measured preoperatively, immediately after lenticule creation and subsequent to corneal lenticule extraction in all eyes with the Corvis Scheimpflug Technology (Corvis ST, OCULUS, Wetzlar, Germany). Repeated measures analysis of variance (ANOVA) with bonferroni-adjusted post hoc comparisons was performed to investigate changes following each step of the procedure. Results All surgical procedures were uneventful. A significant difference was detected among the three time points (pre-operation, post-lenticule creation and post lenticule extraction) for AT1 (P<0.001), AT2 (P = 0.001), DA(P<0.001), and IOP(P = 0.002). Bonferroni-adjusted post hoc comparisons indicated that there was no significant change in AT1, AT2, DA, or IOP after lenticule creation (post hoc P>0.05), but there was a significant change in these parameters following subsequent corneal lenticule extraction (post hoc P<0.01), when compared to values obtained pre-operatively. The scheimpflug camera of the Corvis ST demonstrated the intralamellar small gas bubbles formed from the vaporisation of tissue after lenticule creation and a gray zone was observed between the cap and the residual stromal bed after lenticule extraction. Conclusions There is a significant change in corneal deformation parameters following SMILE procedure. The changes may be caused predominantly by stromal lenticule extraction

  16. Extraction of linear anisotropic parameters using optical coherence tomography and hybrid Mueller matrix formalism.

    PubMed

    Liao, Chia-Chi; Lo, Yu-Lung

    2015-04-20

    A method is proposed for extracting the linear birefringence (LB) and linear dichroism (LD) properties of an anisotropic optical sample using reflection-mode optical coherence tomography (OCT) and a hybrid Mueller matrix formalism. To ensure the accuracy of the extracted parameter values, a method is proposed for calibrating and compensating the polarization distortion effect induced by the beam splitters in the OCT system using a composite quarter-waveplate / half-waveplate / quarter-waveplate structure. The validity of the proposed method is confirmed by extracting the LB and LD properties of a quarter-wave plate and a defective polarizer. To the best of the authors' knowledge, the method proposed in this study represents the first reported attempt to utilize an inverse Mueller matrix formalism and a reflection-mode OCT structure to extract the LB and LD parameters of optically anisotropic samples.

  17. Extraction of battery parameters of the equivalent circuit model using a multi-objective genetic algorithm

    NASA Astrophysics Data System (ADS)

    Brand, Jonathan; Zhang, Zheming; Agarwal, Ramesh K.

    2014-02-01

    A simple but reasonably accurate battery model is required for simulating the performance of electrical systems that employ a battery for example an electric vehicle, as well as for investigating their potential as an energy storage device. In this paper, a relatively simple equivalent circuit based model is employed for modeling the performance of a battery. A computer code utilizing a multi-objective genetic algorithm is developed for the purpose of extracting the battery performance parameters. The code is applied to several existing industrial batteries as well as to two recently proposed high performance batteries which are currently in early research and development stage. The results demonstrate that with the optimally extracted performance parameters, the equivalent circuit based battery model can accurately predict the performance of various batteries of different sizes, capacities, and materials. Several test cases demonstrate that the multi-objective genetic algorithm can serve as a robust and reliable tool for extracting the battery performance parameters.

  18. Full gate voltage range Lambert-function based methodology for FDSOI MOSFET parameter extraction

    NASA Astrophysics Data System (ADS)

    Karatsori, T. A.; Theodorou, C. G.; Ioannidis, E. G.; Haendler, S.; Josse, E.; Dimitriadis, C. A.; Ghibaudo, G.

    2015-09-01

    A new full gate voltage range methodology using a Lambert W function based inversion charge model, for extracting the electrical parameters in FDSOI nano-MOSFET devices, has been developed. Split capacitance-voltage measurements carried out on 14 nm technology FDSOI devices show that the inversion charge variation with gate voltage can be well described by a Lambert W function. Based on the drain current equation in the linear region including the inversion charge described by the Lambert function of gate voltage and the standard mobility equation enables five electrical MOSFET parameters to be extracted from experimental Id-Vg measurements (ideality factor, threshold voltage, low field mobility, first and second order mobility attenuation factors). The extracted parameters were compared with those extracted by the well-known Y-function in strong inversion region. The present methodology for extracting the electrical MOSFET parameters was verified over a wide range of channel lengths on nano-scale FDSOI devices, demonstrating its simplicity, accuracy and robustness.

  19. Effects of Watercress (Nasturtium nasturtium) extract on selected immunological parameters of rainbow trout (Oncorhynchus mykiss)

    PubMed Central

    Asadi, M.S.; Mirvaghefei, A.R.; Nematollahi, M.A.; Banaee, M.; Ahmadi, K.

    2012-01-01

    Watercress (Nasturtium nasturtium) is a medical plant containing diverse chemically-active substances with biological properties. The present study was conducted to investigate the immunomodulatory effects of watercress extract on immunological and hematological parameters of rainbow trout (Oncorhynchus mykiss). Fish were fed for 21 days with diet supplemented with 0.1% and 1% of watercress extract per 1 kg food and with a normal diet as control. Hematological parameters such as red blood cells (RBC) and white blood cells (WBC), hematocrit (Hct), hemoglobin (Hb), RBC index like mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) as well as immunological parameters such as peroxidase, lysozyme and complement activities, total protein, albumin and globulin levels were measured after 21 days of watercress extract treatment. The results indicated that oral administration of 1 % watercress extract in fish may enhance some hematological and immunological parameters including Hb and MCHC, lysozyme and complement activities, total protein and globulin levels, compared to the controls after 21 days of experimental period. In conclusion, on the basis of these results, oral administration of watercress extract may be useful to improve fish’s immune system. PMID:26623289

  20. Effects of Watercress (Nasturtium nasturtium) extract on selected immunological parameters of rainbow trout (Oncorhynchus mykiss).

    PubMed

    Asadi, M S; Mirvaghefei, A R; Nematollahi, M A; Banaee, M; Ahmadi, K

    2012-01-01

    Watercress (Nasturtium nasturtium) is a medical plant containing diverse chemically-active substances with biological properties. The present study was conducted to investigate the immunomodulatory effects of watercress extract on immunological and hematological parameters of rainbow trout (Oncorhynchus mykiss). Fish were fed for 21 days with diet supplemented with 0.1% and 1% of watercress extract per 1 kg food and with a normal diet as control. Hematological parameters such as red blood cells (RBC) and white blood cells (WBC), hematocrit (Hct), hemoglobin (Hb), RBC index like mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) as well as immunological parameters such as peroxidase, lysozyme and complement activities, total protein, albumin and globulin levels were measured after 21 days of watercress extract treatment. The results indicated that oral administration of 1 % watercress extract in fish may enhance some hematological and immunological parameters including Hb and MCHC, lysozyme and complement activities, total protein and globulin levels, compared to the controls after 21 days of experimental period. In conclusion, on the basis of these results, oral administration of watercress extract may be useful to improve fish's immune system.

  1. Glacier parameter extraction using Landsat 8 images in the eastern Karakorum

    NASA Astrophysics Data System (ADS)

    Wang, H.; Yang, R.; LI, X.; CAO, S.

    2017-02-01

    Changes in glacial melt and river runoff directly impact upon water resources and utilization. Glacier area data provide the basis of analysing glacier change. In this study, Landsat images from the end of the 2014 melt season were analysed using remote sensing and geographic information systems (GIS) technology. We compared the band ratio method and Normalized Difference Snow Index (NDSI) method for extracting glacial parameters. The results show that the band ratio method is better for glacier boundary extraction. However, for debris covered glaciers, textural analysis is needed for area extraction and needed to revise boundary extraction results through the visual interpretation of the remote sensing image Accurate area extraction is particularly important for glaciers, as these are major contributors to runoff.

  2. A new approach to extracting the RF parameters of asymmetric DG MOSFETs with the NQS effect

    NASA Astrophysics Data System (ADS)

    Pati, Sudhansu Kumar; Koley, Kalyan; Dutta, Arka; Mohankumar, N.; Sarkar, Chandan Kumar

    2013-11-01

    In analog circuit design an important parameter, from the perspective of superior device performance, is linearity. The DG MOSFET in asymmetric mode operation has been found to present a better linearity. In addition to that it provides, at the discretion of analog circuit designer, an additional degree of freedom, by providing independent bias control for the front and the back gates. Here a non-quasi-static (NQS) small signal model for DGMOSFET with asymmetric gate bias is proposed for extracting the parameters of the device using TCAD simulations. The parameters extracted here for analysis are the intrinsic front and back gate to drain capacitance, Cgd1 and Cgd2, the intrinsic front and back distributed channel resistance, Rgd1 and Rgd2 respectively, the transport delay, τm, and the inductance, Lsd. The parameter extraction model for an asymmetric DG MOSFET is validated with pre-established extracted parameter data, for symmetric DG MOSFET devices, from the available literature. The device simulation is performed with respect to frequency up to 100 GHz.

  3. An algorithm for automatic parameter adjustment for brain extraction in BrainSuite

    NASA Astrophysics Data System (ADS)

    Rajagopal, Gautham; Joshi, Anand A.; Leahy, Richard M.

    2017-02-01

    Brain Extraction (classification of brain and non-brain tissue) of MRI brain images is a crucial pre-processing step necessary for imaging-based anatomical studies of the human brain. Several automated methods and software tools are available for performing this task, but differences in MR image parameters (pulse sequence, resolution) and instrumentand subject-dependent noise and artefacts affect the performance of these automated methods. We describe and evaluate a method that automatically adapts the default parameters of the Brain Surface Extraction (BSE) algorithm to optimize a cost function chosen to reflect accurate brain extraction. BSE uses a combination of anisotropic filtering, Marr-Hildreth edge detection, and binary morphology for brain extraction. Our algorithm automatically adapts four parameters associated with these steps to maximize the brain surface area to volume ratio. We evaluate the method on a total of 109 brain volumes with ground truth brain masks generated by an expert user. A quantitative evaluation of the performance of the proposed algorithm showed an improvement in the mean (s.d.) Dice coefficient from 0.8969 (0.0376) for default parameters to 0.9509 (0.0504) for the optimized case. These results indicate that automatic parameter optimization can result in significant improvements in definition of the brain mask.

  4. Optimization of extraction parameters on the antioxidant properties of banana waste.

    PubMed

    Toh, Pui Yee; Leong, Fei Shan; Chang, Sui Kiat; Khoo, Hock Eng; Yim, Hip Seng

    2016-01-01

    Banana is grown worldwide and consumed as ripe fruit or used for culinary purposes. Peels form about 18-33% of the whole fruit and are discarded as a waste product. With a view to exploiting banana peel as a source of valuable compounds, this study was undertaken to evaluate the effect of different extraction parameters on the antioxidant activities of the industrial by-product of banana waste (peel). Influence of different extraction parameters such as types of solvent, percentages of solvent, and extraction times on total phenolic content (TPC) and antioxidant activity of mature and green peels of Pisang Abu (PA), Pisang Berangan (PB), and Pisang Mas (PM) were investigated. The best extraction parameters were initially selected based on different percentages of ethanol (0-100% v/v), extraction time (1-5 hr), and extraction temperature (25-60°C) for extraction of antioxidants in the banana peels. Total phenolic content (TPC) was evaluated using Folin-Ciocalteu reagent assay while antioxidant activities (AA) of banana peel were accessed by DPPH, ABTS, and β-carotene bleaching (BCB) assays at optimum extraction conditions. Based on different extraction solvents and percentages of solvents used, 70% and 90% of acetone had yielded the highest TPC for the mature and green PA peels, respectively; 90% of ethanol and methanol has yielded the highest TPC for the mature and green PB peels, respectively; while 90% ethanol for the mature and green PM peels. Similar extraction conditions were found for the antioxidant activities for the banana peel assessed using DPPH assay except for green PB peel, which 70% methanol had contributed to the highest AA. Highest TPC and AA were obtained by applying 4, 1, and 2 hrs extraction for the peels of PA, PB and PM, respectively. The best extraction conditions were also used for determination of AAs using ABTS and β-carotene bleaching assays. Therefore, the best extraction conditions used have given the highest TPC and AAs. By

  5. Analytical parameters and vital signs in patients subjected to dental extraction

    PubMed Central

    Jané-Pallí, Enric; Arranz-Obispo, Carlos; González-Navarro, Beatriz; Murat, Jesús; Ayuso-Montero, Raúl; Rojas, Santiago; Santamaría, Amparo; Jané-Salas, Enric

    2017-01-01

    Background Dental consultation may provoke stress to the patient, especially when a dental surgery is going to be performed, stressful situations can cause a reaction in the sympathetic nervous system that could lead to cardiovascular alterations. Blood pressure and cardiac frequency are used often as an indirect measurement and this parameters combined can serve as good indicators of stress. Objective: Analyze the changes in vital signs and analytical parameters induced by a dental extraction. Material and Methods 24 healthy patients who required a simple dental extraction underwent to a blood test and motorization of their pre- and post-extraction vital signs before, at 2 and 48 hours after the procedure. Data analysis was performed by means of repeated measures one way ANOVA followed by multiple comparisons Bonferroni’s Post-hoc test. Results The evaluated patients were 13 women and 11 men with an average age of 35.1. Thirteen patients (54.17% of the sample) were smokers and five were regular drinkers (20.8%). No significant differences were observed in the vital signs with the exception of diastolic blood pressure and cardiac rate that were slightly lower after extraction. Only two analytical parameters showed statistical significant changes. Total bilirubin was significantly higher at 48 hours after extraction and leukocyte count was significantly lower at this time. In any case, the magnitude of the changes observed was very low. The analytical parameters and the vital signs did not show any relevant change. Conclusions Eventual alterations found after simple tooth extraction should not be attributed to the procedure. Key words:Blood pressure, heart rate, monitoring physiologic, oxygen saturation, tooth extraction. PMID:28210440

  6. Extraction of bowing parameters from violin performance combining motion capture and sensors.

    PubMed

    Schoonderwaldt, E; Demoucron, M

    2009-11-01

    A method is described for measurement of a complete set of bowing parameters in violin performance. Optical motion capture was combined with sensors for accurate measurement of the main bowing parameters (bow position, bow velocity, bow acceleration, bow-bridge distance, and bow force) as well as secondary control parameters (skewness, inclination, and tilt of the bow). In addition, other performance features (moments of on/off in bow-string contact, string played, and bowing direction) were extracted. Detailed descriptions of the calculations of the bowing parameters, features, and calibrations are given. The described system is capable of measuring all bowing parameters without disturbing the player, allowing for detailed studies of musically relevant aspects of bow control and coordination of bowing parameters in bowed-string instrument performance.

  7. Fundamental parameters in extraction of lipids from wastewater-grown microalgal biomass

    SciTech Connect

    Enssani, E.

    1987-01-01

    To obtain data required the following steps: (1) Selection and design of a quick and simple laboratory procedure for the extraction of microalgal lipids to provide a basis for the scale-up operation. (2) Identification of the fundamental process parameters that influence the extraction of lipids from microalgae. (3) Selection of different levels for these parameters and their respective values. (4) Examination of the effects of these factors on the extraction process. (5) Development of the final technique resulting from these studies. In the studies, maximum percent lipids extracted by the devised procedures was 17.3% of the biomass volatile weight. An acidic soxhlet extraction method, released almost 25% of the biomass volatile weight as lipids. Residual oil, CC, was defined as the amount of oil remained in the lipid-free (inert) volatile weight of biomass after each extraction period. It was revealed that four factors; solvent type, pretreatment, concentration of microalgae, and solvent to microalgae ratio, influence the residual oil values at all the ten extraction time levels selected, between 5 and 1440 minutes. The minimum residual oil was obtained when: chloroform-methanol 2:1 was used as the solvent, the microalgal cells were mechanically disrupted to release the tightly bound lipids and then freeze-dried, 50 mls of solvent was used per gram volatile weight of biomass, temperature was 25C and no mixing involved. The value of residual oil under the above-mentioned conditions and after 30 minutes of extraction was 0.100 grams per gram inert volatile weight of biomass. After a 24-hour period of extraction, it was reduced only 9% to a value of 0.0909.

  8. Metabolic tumor volume by positron emission tomography/computed tomography as a clinical parameter to determine therapeutic modality for early stage Hodgkin's lymphoma.

    PubMed

    Song, Moo-Kon; Chung, Joo-Seop; Lee, Je-Jung; Jeong, Shin Young; Lee, Sang-Min; Hong, Jun-Shik; Chong, Ari; Moon, Joon-Ho; Kim, Ji-Hyun; Lee, Seok-Mo; Kim, Seong Jang; Shin, Ho-Jin

    2013-12-01

    Recent studies have shown that metabolic tumor volume (MTV) by positron emission tomography/computed tomography (PET/CT) is an important prognostic parameter in patients with non-Hodgkin's lymphoma. However, it is unknown whether doxorubicin, bleomycin, vinblastine, dacarbazine (ABVD) alone in early stage Hodgkin's lymphoma would lead to similar disease control as combined modality therapy (CMT) using MTV by PET/CT. One hundred and twenty-seven patients with early stage Hodgkin's lymphoma who underwent PET/CT at diagnosis were enrolled. The MTV was delineated on PET/CT by the area ≥SUV(max), 2.5 (standardized uptake value [SUV]). Sixty-six patients received six cycles of ABVD only. The other 61 patients received CMT (involved-field radiotherapy after 4-6 cycles of ABVD). The calculated MTV cut-off value was 198 cm(3) . Clinical outcomes were compared according to several prognostic factors (i.e. age ≥50 years, male, performance status ≥2, stage II, B symptoms, ≥4 involved sites, extranodal site, large mediastinal mass, CMT, elevated erythrocyte sedimentation rate and high MTV). Older age (progression-free survival [PFS], P = 0.003; overall survival [OS], P = 0.007), B symptoms (PFS, P = 0.006; OS, P = 0.036) and high MTV (PFS, P = 0.008; OS, P = 0.007) were significant independent prognostic factors. Survival of two high MTV groups treated with ABVD only and CMT were lower than the low MTV groups (PFS, P < 0.012; OS, P < 0.045). ABVD alone was sufficient to control disease in those with low MTV status. However, survival was poor, even if the CMT was assigned a high MTV status. The MTV would be helpful for deciding the therapeutic modality in patients with early stage Hodgkin's lymphoma. © 2013 Japanese Cancer Association.

  9. Simulation-based Extraction of Key Material Parameters from Atomic Force Microscopy

    NASA Astrophysics Data System (ADS)

    Alsafi, Huseen; Peninngton, Gray

    Models for the atomic force microscopy (AFM) tip and sample interaction contain numerous material parameters that are often poorly known. This is especially true when dealing with novel material systems or when imaging samples that are exposed to complicated interactions with the local environment. In this work we use Monte Carlo methods to extract sample material parameters from the experimental AFM analysis of a test sample. The parameterized theoretical model that we use is based on the Virtual Environment for Dynamic AFM (VEDA) [1]. The extracted material parameters are then compared with the accepted values for our test sample. Using this procedure, we suggest a method that can be used to successfully determine unknown material properties in novel and complicated material systems. We acknowledge Fisher Endowment Grant support from the Jess and Mildred Fisher College of Science and Mathematics,Towson University.

  10. Effects of J couplings and unobservable minor states on kinetics parameters extracted from CEST data

    NASA Astrophysics Data System (ADS)

    Zhou, Yang; Yang, Daiwen

    2014-12-01

    Chemical exchange saturation transfer (CEST) experiments have emerged as a powerful tool for characterizing dynamics and sparse populated conformers of protein in slow exchanging systems. We show that J couplings and 'invisible' minor states can cause systematic errors in kinetics parameters and chemical shifts extracted from CEST data. For weakly coupled spin systems, the J coupling effect can be removed using an approximation method. This method is warranted through detailed theoretical derivation, supported by results from simulations and experiments on an acyl carrier protein domain. Simulations demonstrate that the effect of 'invisible' minor states on the extracted kinetics parameters depends on the chemical shifts, populations, exchange rates of the 'invisible' states to the observed major or minor state and exchange models. Moreover, the extracted chemical shifts of the observed minor state can also be influenced by the "invisible" minor states. The presence of an off-pathway folding intermediate in the acyl carrier protein domain explains why the exchange rates obtained with a two-state model from individual residues that displayed only two obvious CEST dips varied significantly and the extracted exchange rates for 15N and 13CO spins located in the same peptide bond could be very different. The approximation method described here simplifies CEST data analysis in many situations where the coupling effect cannot be ignored and decoupling techniques are not desirable. In addition, this study also raises alerts for 'invisible' minor states which can cause errors in not only kinetics parameters but also chemical shifts of the observed minor state.

  11. Effects of the main extraction parameters on chemical and microbial characteristics of compost tea.

    PubMed

    Islam, M K; Yaseen, T; Traversa, A; Ben Kheder, M; Brunetti, G; Cocozza, C

    2016-06-01

    The rising popularity of compost tea as fertilizer or foliar spray against pathogens has encouraged many researchers to evaluate its performance without standardizing its quality, so obtaining inconsistent and controversial results. The fertilizing and pesticide-like effects of compost tea are due to its chemical and microbiological properties. Therefore, this study aimed to identify the best combination of the compost tea extraction parameters for exalting both chemical and microbiological features. A factorial design was adopted to evaluate the effects of compost/water ratio, extraction time, storage duration and storage temperature in different combination on physical, chemical and microbiological characteristics of compost tea, and the results were elaborated through different statistical analyses. Compost tea nutrients and microorganisms were influenced by compost/water ratio and extraction time. In addition, the storage duration affected the microbial populations, whereas the storage temperature influenced only the fungal population of compost tea. Results suggested that the best combination of the studied parameters was: 1:2.5 compost/water ratio, 2days of extraction time and the compost tea should be utilized immediately after the extraction, since the storage reduced the microbial populations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Effects of Kaempferia parviflora extracts on reproductive parameters and spermatic blood flow in male rats.

    PubMed

    Chaturapanich, G; Chaiyakul, S; Verawatnapakul, V; Pholpramool, C

    2008-10-01

    Krachaidum (KD, Kaempferia parviflora Wall. Ex. Baker), a native plant of Southeast Asia, is traditionally used to enhance male sexual function. However, only few scientific data in support of this anecdote have been reported. The present study investigated the effects of feeding three different extracts of KD (alcohol, hexane, and water extracts) for 3-5 weeks on the reproductive organs, the aphrodisiac activity, fertility, sperm motility, and blood flow to the testis of male rats. Sexual performances (mount latency, mount frequency, ejaculatory latency, post-ejaculatory latency) and sperm motility were assessed by a video camera and computer-assisted sperm analysis respectively, while blood flow to the testis was measured by a directional pulsed Doppler flowmeter. The results showed that all extracts of KD had virtually no effect on the reproductive organ weights even after 5 weeks. However, administration of the alcohol extract at a dose of 70 mg/kg body weight (BW)/day for 4 weeks significantly decreased mount and ejaculatory latencies when compared with the control. By contrast, hexane and water extracts had no influence on any sexual behavior parameters. All types of extracts of KD had no effect on fertility or sperm motility. On the other hand, alcohol extract produced a significant increase in blood flow to the testis without affecting the heart rate and mean arterial blood pressure. In a separate study, an acute effect of alcohol extract of KD on blood flow to the testis was investigated. Intravenous injection of KD at doses of 10, 20, and 40 mg/kg BW caused dose-dependent increases in blood flow to the testis. The results indicate that alcohol extract of KD had an aphrodisiac activity probably via a marked increase in blood flow to the testis.

  13. [Effect of Bergenia crassifolia extract on specific immune response parameters under extremal conditions].

    PubMed

    Churin, A A; Masnaia, N V; Sherstoboev, E Yu; Suslov, N I

    2005-01-01

    The influence of a dry extract from Bergenia crassifolia (Fritsch) on the specific immune response parameters was studied under extremal conditions of model immunodepressive states induced by immobilization stress or cyclophosphamide injections. The drug produced normalizing effect on the content of antibody-forming cells in the spleen of experimental mice under the conditions of humoral response stimulation by antigen and in both immunodepression models. The bergenia extract decreases expression of inflammatory processes under delayed hypersensitivity reaction conditions, by preventing the accumulation of T-lymphocytes in the inflammation focus and reducing the ability of cells to produce anti-inflammatory cytokines.

  14. Exploration of Genetic Programming Optimal Parameters for Feature Extraction from Remote Sensed Imagery

    NASA Astrophysics Data System (ADS)

    Gao, P.; Shetty, S.; Momm, H. G.

    2014-11-01

    Evolutionary computation is used for improved information extraction from high-resolution satellite imagery. The utilization of evolutionary computation is based on stochastic selection of input parameters often defined in a trial-and-error approach. However, exploration of optimal input parameters can yield improved candidate solutions while requiring reduced computation resources. In this study, the design and implementation of a system that investigates the optimal input parameters was researched in the problem of feature extraction from remotely sensed imagery. The two primary assessment criteria were the highest fitness value and the overall computational time. The parameters explored include the population size and the percentage and order of mutation and crossover. The proposed system has two major subsystems; (i) data preparation: the generation of random candidate solutions; and (ii) data processing: evolutionary process based on genetic programming, which is used to spectrally distinguish the features of interest from the remaining image background of remote sensed imagery. The results demonstrate that the optimal generation number is around 1500, the optimal percentage of mutation and crossover ranges from 35% to 40% and 5% to 0%, respectively. Based on our findings the sequence that yielded better results was mutation over crossover. These findings are conducive to improving the efficacy of utilizing genetic programming for feature extraction from remotely sensed imagery.

  15. Accurate optical parameter extraction procedure for broadband near-infrared spectroscopy of brain matter

    PubMed Central

    Najafizadeh, Laleh; Gandjbakhche, Amir H.; Pourrezaei, Kambiz; Daryoush, Afshin

    2013-01-01

    Abstract. Modeling behavior of broadband (30 to 1000 MHz) frequency modulated near-infrared (NIR) photons through a phantom is the basis for accurate extraction of optical absorption and scattering parameters of biological turbid media. Photon dynamics in a phantom are predicted using both analytical and numerical simulation and are related to the measured insertion loss (IL) and insertion phase (IP) for a given geometry based on phantom optical parameters. Accuracy of the extracted optical parameters using finite element method (FEM) simulation is compared to baseline analytical calculations from the diffusion equation (DE) for homogenous brain phantoms. NIR spectroscopy is performed using custom-designed, broadband, free-space optical transmitter (Tx) and receiver (Rx) modules that are developed for photon migration at wavelengths of 680, 780, and 820 nm. Differential detection between two optical Rx locations separated by 0.3 cm is employed to eliminate systemic artifacts associated with interfaces of the optical Tx and Rx with the phantoms. Optical parameter extraction is achieved for four solid phantom samples using the least-square-error method in MATLAB (for DE) and COMSOL (for FEM) simulation by fitting data to measured results over broadband and narrowband frequency modulation. Confidence in numerical modeling of the photonic behavior using FEM has been established here by comparing the transmission mode’s experimental results with the predictions made by DE and FEM for known commercial solid brain phantoms. PMID:23322361

  16. Extraction of static parameters to extend the EKV model to cryogenic temperatures

    NASA Astrophysics Data System (ADS)

    Fonseca, Germano S.; de Sá, Leonardo B.; Mesquita, Antonio C.

    2016-05-01

    The electric simulation models of CMOS devices provided by the foundries are valid at the standard temperature range of -55 to 125°C. These models are not suitable to the design of circuits intended to operate at cryogenic temperatures as is the case of cooled infrared readout circuits. To generate a library of CMOS electric simulation models valid at cryogenic temperatures, the characterization of wide and long CMOS transistors are investigated. The EKV2.6 model, which is an industry-standard compact simulation model for CMOS transistors, is used in this characterization. Due to its relatively small number of parameters the EKV2.6 model is well suited to the parameter extraction procedures when not disposing of an expensive automated parameter extraction system. It is shown that to provide an appropriate IV-characteristic fit to cryogenic temperature range it is sufficient to extract only five parameters - threshold voltage VT0, body effect GAMMA, Fermi potential PHI, transconductance factor KP, and the vertical characteristic field for mobility reduction E0. The proposed approach is tested in a standard 0.35μm/3.3V CMOS technology, employing extraction procedures recommended in the literature. Simulations are made with a BSIM3V3 standard library provided by the foundry changing the temperature parameter and with the generated library. The results are compared with the measurements. As expected, the simulations made with the generated library show a best agreement with the performed measurements at 77K than the simulations with the BSIM3V3 model. The proposed methodology is shown to be particularly effective above strong freeze-out temperature.

  17. Optimization of subcritical fluid extraction of bioactive compounds using Hansen solubility parameters.

    PubMed

    Srinivas, K; King, J W; Monrad, J K; Howard, L R; Hansen, C M

    2009-08-01

    Process engineering operations in food and nutraceutical industries pertaining to the design of extraction of value-added products from biomass using pressurized liquids involve a careful selection of the solvent and optimal temperature conditions to achieve maximum yield. Complex molecular structure and limited physical property data in the literature of biological solutes extracted from biomass compounds have necessitated the process modeling of such operations. In this study, we have applied the Hansen 3-dimensional solubility parameter concept to optimize the extraction of molecularly complex solutes using subcritical fluid solvents. Hansen solubility spheres characterized by the relative energy differences (RED) have been used to characterize and quantify the solute-subcritical solvent interactions as a function of temperature. The solvent power of subcritical water and compressed hydroethanolic mixtures above their boiling points has been characterized using the above-mentioned method. The use of group contribution methods in collaboration with computerized algorithms to plot the Hansen spheres provides a quantitative prediction tool for optimizing the design of extraction conditions. The method can be used to estimate conditions for solute-solvent miscibility, an optimum temperature range for conducting extractions under pressurized conditions, and approximate extraction conditions of solutes from natural matrices.

  18. Effect of aroma and magnum hops extracts and paracetamol on antioxidant liver parameters in mice.

    PubMed

    Jakovljevic, Vida; Popovic, Mira; Raskovic, Aleksandar; Sabo, Ana; Horvat, Olga; Mitic, Radoslav; Vasic, Radica

    2009-01-01

    Hop varieties that are mainly grown in Serbia are Magnum (German variety) and Aroma, which is grown only in the Vojvodina region. About the use of hops extracts as an auxiliary remedy there are divergent opinions. Our findings indicate that extracts of Magnum and Aroma varieties, among the others, enhance and prolong the analgesic action of paracetamol. For this reason we undertook a study of the effects of these extracts alone and in combination with paracetamol, along with the action of paracetamol alone, on the activity of the antioxidant enzymes GSHPx, CAT, Px, XOD, GSHR, glutathione content, LPx intensity, as well as activities of AST and ALT. Paracetamol in the dose applied exerted no influence on the investigated parameters and neither did ethanolic extract of Magnum variety. On the other hand, ethanolic extract of Aroma hops caused a significant reduction of GSH content. In combination with paracetamol, extracts of both Magnum and Aroma varieties reduced significantly the LPx intensity, activities of CAT and GSHPx, as well as GSH content in the liver homogenate. A significant increase in the AST value with respect to control was also observed. These findings indicate the disturbance in the functioning of hepatocytes, probably by decelarating metabolism and elimination of paracetamol.

  19. Effect of aroma and magnum hops extracts and paracetamol on antioxidant liver parameters in mice.

    PubMed

    Jakovljevic, Vida; Popovic, Mira; Raskovic, Aleksandar; Sabo, Ana; Vasic, Radica

    2008-01-01

    Hop varieties that are mainly grown in Serbia are Magnum (German variety) and Aroma, which is grown only in the Vojvodina region. About the use of hops extracts as an auxiliary remedy there are divergent opinions. Our findings indicate that extracts of Magnum and Aroma varieties, among the others, enhance and prolong the analgesic action of paracetamol. For this reason we undertook a study of the effects of these extracts alone and in combination with paracetamol, along with the action of paracetamol alone, on the activity of the antioxidant enzymes GSHPx, CAT, Px, XOD, GSHR, glutathione content, LPx intensity, as well as activities of AST and ALT. Paracetamol in the dose applied exerted no influence on the investigated parameters and neither did ethanolic extract of Magnum variety. On the other hand, ethanolic extract of Aroma hops caused a significant reduction of GSH content. In combination with paracetamol, extracts of both Magnum and Aroma varieties reduced significantly the LPx intensity, activities of CAT and GSHPx, as well as GSH content in the liver homogenate. A significant increase in the AST value with respect to control was also observed. These findings indicate the disturbance in the functioning of hepatocytes, probably by decelarating metabolism and elimination of paracetamol.

  20. Effects of Rutherford Cable Parameters on Nb3Sn Extracted Strand Deformation and Performance

    SciTech Connect

    Turrioni, Daniele; Barzi, Emanuela; Bossert, M.; Collings, E.W.; Nazareth, V.; Sumptions, M.D.; Yamada, R.; Zlobin, A.V.; /Fermilab

    2008-06-01

    In order to optimize parameters for Rutherford cables used in accelerator magnets, a number of cables were fabricated with different keystone angles, packing factors and numbers of strands. The effect of these parameters was measured on Nb{sub 3}Sn strand performance and deformation for two different RRP designs. High and low field current carrying capabilities and RRR were measured for the extracted strands. To correlate strand deformation with performance, the former was measured for several cables and conditions as a function of the strand location in the cable cross section.

  1. Lateral aerodynamic parameters extracted from flight data for the F-8C airplane in maneuvering flight

    NASA Technical Reports Server (NTRS)

    Suit, W. T.

    1977-01-01

    Flight test data are used to extract the lateral aerodynamic parameters of the F-8C airplane at moderate to high angles of attack. The data were obtained during perturbations of the airplane from steady turns with trim normal accelerations from 1.5g to 3.0g. The angle-of-attack variation from trim was negligible. The aerodynamic coefficients extracted from flight data were compared with several other sets of coefficients, and the extracted coefficients resulted in characteristics for the Dutch roll mode (at the highest angles of attack) similar to those of a set of coefficients that have been the basis of several simulations of the F-8C.

  2. Beam Losses in the NLC Extraction Line for High Luminosity Beam Parameters (LCC-0049)

    SciTech Connect

    Nosochkov, Y

    2004-03-19

    In this note we present results of beam tracking in the NLC extraction line for the NLC option with high luminosity beam parameters (option H). Particle losses for 0.5 TeV and 1 TeV cms energy beams have been computed and examined as a function of beam offset at the interaction point (IP). Updated tracking results for the NLC option A are presented as well.

  3. Bio-inspired optimization algorithms for optical parameter extraction of dielectric materials: A comparative study

    NASA Astrophysics Data System (ADS)

    Ghulam Saber, Md; Arif Shahriar, Kh; Ahmed, Ashik; Hasan Sagor, Rakibul

    2016-10-01

    Particle swarm optimization (PSO) and invasive weed optimization (IWO) algorithms are used for extracting the modeling parameters of materials useful for optics and photonics research community. These two bio-inspired algorithms are used here for the first time in this particular field to the best of our knowledge. The algorithms are used for modeling graphene oxide and the performances of the two are compared. Two objective functions are used for different boundary values. Root mean square (RMS) deviation is determined and compared.

  4. Extraction of effective parameters of turbid media utilizing the Mueller matrix approach: study of glucose sensing.

    PubMed

    Pham, Thi-Thu-Hien; Lo, Yu-Lung

    2012-09-01

    An analytical technique based on Stokes polarimetry and the Mueller matrix method is proposed for extracting the effective linear birefringence, linear dichroism, circular birefringence, circular dichroism, linear depolarization, and circular depolarization properties of turbid media. In contrast to existing analytical models, the model proposed extracts the effective parameters in a decoupled manner and considers not only the circular dichroism properties of the sample, but also the depolarization properties. The results show that the proposed method enables all of the effective parameters to be measured over the full range. Moreover, it is shown that the extracted value of the depolarization index is unaffected by the order in which the depolarizing Mueller matrix is decomposed during the extraction procedure. Finally, a method is proposed for calibrating the optical rotation angle of a polystyrene microsphere suspension containing dissolved D-glucose (C6H12O6) powder in accordance with the distance between the sample and the detector. The experimental results show that the sensitivity of the resulting D-glucose measurement is equal to approximately 1.73  deg/M.

  5. Phase Behavior and Thermodynamic Model Parameters in Simulations of Extractive Distillation for Azeotrope Separation.

    PubMed

    Li, Min; Xu, Xicai; Li, Xin; Ma, Kang; Qin, Bin; Zhu, Zhaoyou; Wang, Yinglong

    2017-08-25

    Extractive distillation (ED) processes for separating ternary mixtures of benzene-cyclohexane-toluene with dimethyl formamide (DMF) and N-methyl-2-pyrrolidone (NMP) were studied using Aspen Plus and PRO/II simulators. The Aspen Plus built-in binary interaction parameters for the toluene-DMF, benzene-NMP and cyclohexane-NMP systems resulted in inaccurate phase behavior calculations. The vapor-liquid equilibrium (VLE) for the three binary systems was regressed to illustrate the importance of using accurate model parameters. The obtained binary interaction parameters described the phase behavior more accurately compared with the built-in binary interaction parameters in Aspen Plus. In this study, the effects of the regressed and built-in binary interaction parameters on the ED process design are presented. The total annual cost (TAC) was calculated to further illustrate the importance of the regressed binary interaction parameters. The results show that phase behavior and thermodynamic model parameters should receive more attention during the research and development of ED processes.

  6. Linearly Supporting Feature Extraction for Automated Estimation of Stellar Atmospheric Parameters

    NASA Astrophysics Data System (ADS)

    Li, Xiangru; Lu, Yu; Comte, Georges; Luo, Ali; Zhao, Yongheng; Wang, Yongjun

    2015-05-01

    We describe a scheme to extract linearly supporting (LSU) features from stellar spectra to automatically estimate the atmospheric parameters {{T}{\\tt{eff} }}, log g, and [Fe/H]. “Linearly supporting” means that the atmospheric parameters can be accurately estimated from the extracted features through a linear model. The successive steps of the process are as follow: first, decompose the spectrum using a wavelet packet (WP) and represent it by the derived decomposition coefficients; second, detect representative spectral features from the decomposition coefficients using the proposed method Least Absolute Shrinkage and Selection Operator (LARS)bs; third, estimate the atmospheric parameters {{T}{\\tt{eff} }}, log g, and [Fe/H] from the detected features using a linear regression method. One prominent characteristic of this scheme is its ability to evaluate quantitatively the contribution of each detected feature to the atmospheric parameter estimate and also to trace back the physical significance of that feature. This work also shows that the usefulness of a component depends on both the wavelength and frequency. The proposed scheme has been evaluated on both real spectra from the Sloan Digital Sky Survey (SDSS)/SEGUE and synthetic spectra calculated from Kurucz's NEWODF models. On real spectra, we extracted 23 features to estimate {{T}{\\tt{eff} }}, 62 features for log g, and 68 features for [Fe/H]. Test consistencies between our estimates and those provided by the Spectroscopic Parameter Pipeline of SDSS show that the mean absolute errors (MAEs) are 0.0062 dex for log {{T}{\\tt{eff} }} (83 K for {{T}{\\tt{eff} }}), 0.2345 dex for log g, and 0.1564 dex for [Fe/H]. For the synthetic spectra, the MAE test accuracies are 0.0022 dex for log {{T}{\\tt{eff} }} (32 K for {{T}{\\tt{eff} }}), 0.0337 dex for log g, and 0.0268 dex for [Fe/H].

  7. Gait parameters extraction by using mobile robot equipped with Kinect v2

    NASA Astrophysics Data System (ADS)

    Ogawa, Ami; Mita, Akira; Yorozu, Ayanori; Takahashi, Masaki

    2016-04-01

    The needs for monitoring systems to be used in houses are getting stronger because of the increase of the single household population due to the low birth rate and longevity. Among others, gait parameters are under the spotlight to be examined as the relations with several diseases have been reported. It is known that the gait parameters obtained at a walk test are different from those obtained under the daily life. Thus, the system which can measure the gait parameters in the real living environment is needed. Generally, gait abilities are evaluated by a measurement test, such as Timed Up and Go test and 6-minute walking test. However, these methods need measurers, so the accuracy depends on them and the lack of objectivity is pointed out. Although, a precise motion capture system is used for more objective measurement, it is hard to be used in daily measurement, because the subjects have to put the markers on their body. To solve this problem, marker less sensors, such as Kinect, are developed and used for gait information acquisition. When they are attached to a mobile robot, there is no limitation of distance. However, they still have challenges of calibration for gait parameters, and the important gait parameters to be acquired are not well examined. Therefore, in this study, we extract the important parameters for gait analysis, which have correlations with diseases and age differences, and suggest the gait parameters extraction from depth data by Kinect v2 which is mounted on a mobile robot aiming at applying to the living environment.

  8. Modal identification using the frequency-scale domain decomposition technique of ambient vibration responses

    NASA Astrophysics Data System (ADS)

    Le, Thien-Phu; Argoul, Pierre

    2016-12-01

    This paper proposes a new modal identification method of ambient vibration responses. The application of the singular value decomposition to continuous wavelet transform of power spectral density matrix gives singular values and singular vectors in frequency-scale domain. Analytical development shows a direct relation between local maxima in frequency-scale representation of singular values and modal parameters. This relation is then carried on for the identification of modal parameters via a complete practical procedure. The main novelties of this work involve the new formulation in frequency-scale domain and the capacity for the identification of modal parameters without the step of ridges extraction in comparison with previous wavelet-based modal identification methods.

  9. Influence of ultrasound-assisted extraction on the pyrolysis characteristics and kinetic parameters of eucalyptus.

    PubMed

    Wang, Zhenyu; He, Zhengbin; Zhao, Zijian; Yi, Songlin; Mu, Jun

    2017-07-01

    In this study, the influence of ultrasound-assisted extraction on eucalyptus samples with special focus on pyrolysis characteristics and kinetic parameters was explored. Ultrasound and Soxhlet extraction were used to pretreat samples respectively, then samples were assayed by component analysis, TG-FTIR, and kinetic analysis. Ultrasound-assisted extraction did change the physiochemical characteristics of eucalyptus samples, particularly in regards to the quantity of extractives obtained. In TG and DTG curves, ultrasound-extracted samples reflected lower residual weight ratio (17.77%) and higher maximum weight loss rate (-22.92%/min), and were accompanied by a slight shift in the weight loss rate peak to lower temperature (366°C). The volatiles produced during pyrolysis and the discrepancies of product distribution between experimental and controlled groups were explored based on TG-FTIR spectra. According to kinetic analysis results, ultrasound-treated samples showed higher activation energy at the primary portion of thermal degradation with an average of 206.09kJ/mol. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Impact of Extraction Parameters on the Recovery of Lipolytic Activity from Fermented Babassu Cake

    PubMed Central

    Silva, Jaqueline N.; Godoy, Mateus G.; Gutarra, Melissa L. E.; Freire, Denise M. G.

    2014-01-01

    Enzyme extraction from solid matrix is as important step in solid-state fermentation to obtain soluble enzymes for further immobilization and application in biocatalysis. A method for the recovery of a pool of lipases from Penicillium simplicissimum produced by solid-state fermentation was developed. For lipase recovery different extraction solution was used and phosphate buffer containing Tween 80 and NaCl showed the best results, yielding lipase activity of 85.7 U/g and 65.7 U/g, respectively. The parameters with great impacts on enzyme extraction detected by the Plackett-Burman analysis were studied by Central Composite Rotatable experimental designs where a quadratic model was built showing maximum predicted lipase activity (160 U/g) at 25°C, Tween 80 0.5% (w/v), pH 8.0 and extraction solution 7 mL/g, maintaining constant buffer molarity of 0.1 M and 200 rpm. After the optimization process a 2.5 fold increase in lipase activity in the crude extract was obtained, comparing the intial value (64 U/g) with the experimental design (160 U/g), thus improving the overall productivity of the process. PMID:25090644

  11. Extraction of quasi-linear viscoelastic parameters for lower limb soft tissues from manual indentation experiment.

    PubMed

    Zheng, Y P; Mak, A F

    1999-06-01

    A manual indentation protocol was established to assess the quasi-linear viscoelastic (QLV) properties of lower limb soft tissues. The QLV parameters were extracted using a curve-fitting procedure on the experimental indentation data. The load-indentation responses were obtained using an ultrasound indentation apparatus with a hand-held pen-sized probe. Limb soft tissues at four sites of eight normal young subjects were tested in three body postures. Four QLV model parameters were extracted from the experimental data. The initial modulus E0 ranged from 0.22 kPa to 58.4 kPa. The nonlinear factor E1 ranged from 21.7 kPa to 547 kPa. The time constant tau ranged from 0.05 s to 8.93 s. The time-dependent materials parameter alpha ranged from 0.029 to 0.277. Large variations of the parameters were noted among subjects, sites, and postures.

  12. SEMICONDUCTOR DEVICES: Small-signal model parameter extraction for microwave SiGe HBTs based on Y- and Z-parameter characterization

    NASA Astrophysics Data System (ADS)

    Jun, Fu

    2009-08-01

    High frequency intrinsic small-signal model parameter extraction for microwave SiGe heterojunction bipolar transistors is studied, with a focus on the main feedback elements including the emitter series resistor, internal and external base-collector capacitors as well as the base series resistor, all of which are important in determining the behavior of the device equivalent circuit. In accordance with the respective features of definition of the Y- and Z-parameters, a novel combined use of them succeeds in reasonably simplifying the device equivalent circuit and thus decoupling the extraction of base-collector capacitances from other model parameters. As a result, a very simple direct extraction method is proposed. The proposed method is applied for determining the SiGe HBT small-signal model parameters by taking numerically simulated Y- and Z-parameters as nominal “measurement data" with the help of a Taurus-device simulator. The validity of the method is preliminarily confirmed by the observation of certain linear relations of device frequency behavior as predicted by the corresponding theoretical analysis. Furthermore, the extraction results can be used to reasonably account for the dependence of the extracted model parameters on device geometry and process parameters, reflecting the explicit physical meanings of parameters, and especially revealing the distributed nature of the base series resistor and its complex interactions with base-collector capacitors. Finally, the accuracy of our model parameter extraction method is further validated by comparing the modeled and simulated S-parameters as a function of frequency.

  13. Effects of lichen extracts on haematological parameters of rats with experimental insulin-dependent diabetes mellitus.

    PubMed

    Colak, Suat; Geyikoğlu, Fatime; Aslan, Ali; Deniz, Gülşah Yıldız

    2014-11-01

    The prevalence of diabetes mellitus in the world is steadily increasing. Oxidative stress contributes to the development of diabetic complications, including diabetic haematological changes. Lichens are used as food supplements and are also used as possible natural antioxidant, antimicrobial and anticancer agents. We hypothesized that antioxidant activity of lichens may decrease hyperglycaemia-induced oxidative stress and prevent the development of diabetic complications, including abnormality in haematological condition. Therefore, the effects of Cetraria islandica water extract (CIWE) and Pseudevernia furfuracea water extract (PFWE) on the haematological parameters of rats with type 1 DM were investigated for the first time in the present study. Control Sprague-Dawley or streptozotocin (STZ)-induced diabetic rats were either untreated or treated with water lichen extracts (5-500 mg/kg body weight (bw)/day) for 2 weeks, starting at 72 h after STZ injection. On day 14, animals were anaesthetized and haematological and metabolic parameters were determined between control and experimental groups. In addition, the total oxidative stress (TOS), a specific indicator of oxidative stress, and the total antioxidant capacity (TAC) were measured by biochemical studies. In diabetic rats, CIWE of 250-500 mg/kg bw dose showed more prominent results when compared with doses of PFWE for TAC. The results obtained in the present study suggested that the antioxidant activities of lichens might be the possible reason behind the observed antihaematological status. However, the protective effect of lichen extracts were inadequate on diabetes-induced microcytic hypochromic anaemia. In addition, the extracts have no effect on metabolic complications. Our experimental data showed that high doses of CIWE and PFWE alone have no detrimental effect on blood cells and TOS status of plasma. Hence, they are safe and suitable for different administration routes.

  14. Sensor-Based Gait Parameter Extraction With Deep Convolutional Neural Networks.

    PubMed

    Hannink, Julius; Kautz, Thomas; Pasluosta, Cristian F; Gasmann, Karl-Gunter; Klucken, Jochen; Eskofier, Bjoern M

    2017-01-01

    Measurement of stride-related, biomechanical parameters is the common rationale for objective gait impairment scoring. State-of-the-art double-integration approaches to extract these parameters from inertial sensor data are, however, limited in their clinical applicability due to the underlying assumptions. To overcome this, we present a method to translate the abstract information provided by wearable sensors to context-related expert features based on deep convolutional neural networks. Regarding mobile gait analysis, this enables integration-free and data-driven extraction of a set of eight spatio-temporal stride parameters. To this end, two modeling approaches are compared: a combined network estimating all parameters of interest and an ensemble approach that spawns less complex networks for each parameter individually. The ensemble approach is outperforming the combined modeling in the current application. On a clinically relevant and publicly available benchmark dataset, we estimate stride length, width and medio-lateral change in foot angle up to -0.15 ± 6.09 cm, -0.09 ± 4.22 cm and 0.13 ± 3.78° respectively. Stride, swing and stance time as well as heel and toe contact times are estimated up to ±0.07, ±0.05, ±0.07, ±0.07 and ±0.12 s respectively. This is comparable to and in parts outperforming or defining state of the art. Our results further indicate that the proposed change in the methodology could substitute assumption-driven double-integration methods and enable mobile assessment of spatio-temporal stride parameters in clinically critical situations as, e.g., in the case of spastic gait impairments.

  15. Extraction of Spatial Parameters from Classified LIDAR Data and Aerial Photograph for Sound Modeling

    NASA Astrophysics Data System (ADS)

    Biswas, S.; Lohani, B.

    2012-07-01

    Prediction of outdoor sound levels in 3D space is important for noise management, soundscaping etc. Sound levels at outdoor can be predicted using sound propagation models which need terrain parameters. The existing practices of incorporating terrain parameters into models are often limited due to inadequate data or inability to determine accurate sound transmission paths through a terrain. This leads to poor accuracy in modelling. LIDAR data and Aerial Photograph (or Satellite Images) provide opportunity to incorporate high resolution data into sound models. To realize this, identification of building and other objects and their use for extraction of terrain parameters are fundamental. However, development of a suitable technique, to incorporate terrain parameters from classified LIDAR data and Aerial Photograph, for sound modelling is a challenge. Determination of terrain parameters along various transmission paths of sound from sound source to a receiver becomes very complex in an urban environment due to the presence of varied and complex urban features. This paper presents a technique to identify the principal paths through which sound transmits from source to receiver. Further, the identified principal paths are incorporated inside the sound model for sound prediction. Techniques based on plane cutting and line tracing are developed for determining principal paths and terrain parameters, which use various information, e.g., building corner and edges, triangulated ground, tree points and locations of source and receiver. The techniques developed are validated through a field experiment. Finally efficacy of the proposed technique is demonstrated by developing a noise map for a test site.

  16. A modal test design strategy for model correlation

    SciTech Connect

    Carne, T.G.; Dohrmann, C.R.

    1994-12-01

    When a modal test is to be performed for purposes of correlation with a finite element model, one needs to design the test so that the resulting measurements will provide the data needed for the correlation. There are numerous issues to consider in the design of a modal test; two important ones are the number and location of response sensors, and the number, location, and orientation of input excitation. From a model correlation perspective, one would like to select the response locations to allow a definitive, one-to-one correspondence between the measured modes and the predicted modes. Further, the excitation must be designed to excite all the modes of interest at a sufficiently high level so that the modal estimation algorithms can accurately extract the modal parameters. In this paper these two issues are examined in the context of model correlation with methodologies presented for obtaining an experiment design.

  17. Effect of interpolation on parameters extracted from seating interface pressure arrays.

    PubMed

    Wininger, Michael; Crane, Barbara

    2014-01-01

    Interpolation is a common data processing step in the study of interface pressure data collected at the wheelchair seating interface. However, there has been no focused study on the effect of interpolation on features extracted from these pressure maps, nor on whether these parameters are sensitive to the manner in which the interpolation is implemented. Here, two different interpolation paradigms, bilinear versus bicubic spline, are tested for their influence on parameters extracted from pressure array data and compared against a conventional low-pass filtering operation. Additionally, analysis of the effect of tandem filtering and interpolation, as well as the interpolation degree (interpolating to 2, 4, and 8 times sampling density), was undertaken. The following recommendations are made regarding approaches that minimized distortion of features extracted from the pressure maps: (1) filter prior to interpolate (strong effect); (2) use of cubic interpolation versus linear (slight effect); and (3) nominal difference between interpolation orders of 2, 4, and 8 times (negligible effect). We invite other investigators to perform similar benchmark analyses on their own data in the interest of establishing a community consensus of best practices in pressure array data processing.

  18. Reconfigurable Special Test Circuit of physics-based IGBT models parameter extraction

    NASA Astrophysics Data System (ADS)

    Rodríguez, Marco A.; Claudio, Abraham; Cotorogea, Maria; González, Leobardo H.; Aguayo, Jesús

    2010-11-01

    Physics-based models of power electronic devices are the most accurate for circuit simulation purposes. However, many parameters of such models are related to device physics and structure and are not directly available for the user. The IGBT is still the most used power semiconductor device for applications at medium power and frequency ranges, due to its good compromise between on-state loss, switching loss, and ease of control. This paper presents a procedure for extracting the most important parameters of the IGBT, with physical background and electrical measurements. The goal is to develop a deeply understanding of the device-structure and to simulate correctly both steady-state and transient period with any circuit simulation software without the IGBT model provided by the manufacturer. The method consists of seven test setups and seven algorithms for extracting 13 physical and structural parameters needed in most physics-based IGBT models; by using only one Reconfigurable Special Test Circuit in order to achieve the different test setups conditions.

  19. Model independent extraction of the axial mass parameter in CCQE anti neutrino-nucleon scattering

    NASA Astrophysics Data System (ADS)

    Grebe, Heather

    2013-10-01

    Neutrino oscillation studies depend on a consistent value for the axial mass. For this reason, a model-independent extraction of this parameter from quasielastic (anti)neutrino-nucleon scattering data is vital. While most studies employ a model-dependent extraction using the dipole model of the axial form factor, we present a model-independent description using the z expansion of the axial form factor. Quasielastic antineutrino scattering data on C-12 from the MiniBooNE experiment are analyzed using this model-independent description. The value found, mA = 0 .85-0 . 06 + 0 . 13 +/- 0 . 13 GeV, differs significantly from the value utilized by the MiniBooNE Collaboration, mA = 1 . 35 GeV. Advisor: Dr. Gil Paz Wayne State Univerity.

  20. Automatic modal identification of cable-supported bridges instrumented with a long-term monitoring system

    NASA Astrophysics Data System (ADS)

    Ni, Y. Q.; Fan, K. Q.; Zheng, G.; Chan, T. H. T.; Ko, J. M.

    2003-08-01

    An automatic modal identification program is developed for continuous extraction of modal parameters of three cable-supported bridges in Hong Kong which are instrumented with a long-term monitoring system. The program employs the Complex Modal Indication Function (CMIF) algorithm to identify modal properties from continuous ambient vibration measurements in an on-line manner. By using the LabVIEW graphical programming language, the software realizes the algorithm in Virtual Instrument (VI) style. The applicability and implementation issues of the developed software are demonstrated by using one-year measurement data acquired from 67 channels of accelerometers deployed on the cable-stayed Ting Kau Bridge. With the continuously identified results, normal variability of modal vectors caused by varying environmental and operational conditions is observed. Such observation is very helpful for selection of appropriate measured modal vectors for structural health monitoring applications.

  1. Small-signal modeling with direct parameter extraction for impact ionization effect in high-electron-mobility transistors

    SciTech Connect

    Guan, He; Lv, Hongliang; Guo, Hui Zhang, Yuming

    2015-11-21

    Impact ionization affects the radio-frequency (RF) behavior of high-electron-mobility transistors (HEMTs), which have narrow-bandgap semiconductor channels, and this necessitates complex parameter extraction procedures for HEMT modeling. In this paper, an enhanced small-signal equivalent circuit model is developed to investigate the impact ionization, and an improved method is presented in detail for direct extraction of intrinsic parameters using two-step measurements in low-frequency and high-frequency regimes. The practicability of the enhanced model and the proposed direct parameter extraction method are verified by comparing the simulated S-parameters with published experimental data from an InAs/AlSb HEMT operating over a wide frequency range. The results demonstrate that the enhanced model with optimal intrinsic parameter values that were obtained by the direct extraction approach can effectively characterize the effects of impact ionization on the RF performance of HEMTs.

  2. Radio frequency spectral characterization and model parameters extraction of high Q optical resonators

    PubMed Central

    Abdallah, Zeina; Boucher, Yann G.; Fernandez, Arnaud; Balac, Stéphane; Llopis, Olivier

    2016-01-01

    A microwave domain characterization approach is proposed to determine the properties of high quality factor optical resonators. This approach features a very high precision in frequency and aims to acquire a full knowledge of the complex transfer function (amplitude and phase) characterizing an optical resonator using a microwave vector network analyzer. It is able to discriminate between the different coupling regimes, from the under-coupling to the selective amplification, and it is used together with a model from which the main resonator parameters are extracted, i.e. coupling factor, intrinsic losses, phase slope, intrinsic and external quality factor. PMID:27251460

  3. A method extracting solar cell parameters from spectral response by inverse laplace transform

    NASA Astrophysics Data System (ADS)

    Tuominen, E.; Acerbis, M.; Hovinen, A.; Siirtola, T.; Sinkkonen, J.

    1997-01-01

    A mathematical method to interpret spectral responses measured from solar cells has been developed. Taking an inverse Laplace transform from the spectral response of a solar cell the spatial dependent collection efficiency of the cell can be obtained. Several important material parameters of the solar cell can be extracted from this function. Applying this method the properties of the solar cell can be investigated without applying characterization methods to the cell itself. We have applied the method both to simulated solar cells andto real solar cells.

  4. Extracting S-parameters of bilateral electro-optic network for lightwave component analyzer calibration

    NASA Astrophysics Data System (ADS)

    Frolov, D.; Levchenko, A.; Korotkov, K.

    2015-11-01

    A new method for extracting E/O and O/E S-parameters of a bilateral electro-optic network (BEON) is theoretically proposed. It is based on measuring reflection coefficients from three optical loads: an absorber and two mirrors. This technique includes two series of reflections measurements: first when loads are connected to optical port of BEON directly and second when loads are connected in series with optical waveguide of fixed length. Using two BEONs and this calibration technique allows to make calibrated lightwave measurements with a standard microwave network analyzer without using additional electro-optical equipment such as lightwave component analyzer or optical heterodyne techniques.

  5. Diagnostic modalities.

    PubMed

    Elstob, Alison; Gonsalves, Michael; Patel, Uday

    2016-12-01

    The incidental detection of small renal masses on imaging undertaken to evaluate unrelated symptoms or conditions is an increasingly common occurrence. Accurate imaging characterisation is fundamental to determining optimum patient management. The goals of imaging small renal masses include determining whether a lesion is solid or cystic, if there are signs of biological aggressiveness and whether the lesion is likely benign or malignant. The current imaging practices and the evidence supporting the use of different imaging modalities for the characterisation of small renal masses are discussed. CT remains the primary imaging modality and is able to classify most masses into surgical or non-surgical lesions. MRI and contrast enhanced ultrasound are most often employed to problem solve in lesions deemed indeterminate on contrast enhanced CT or for patients in which CECT is contraindicated. Percutaneous biopsy should be considered in lesions that remain indeterminate after initial imaging investigations. Given the central role of imaging in the management of small renal masses, all multidisciplinary team members involved in renal cancer care should have an understanding of the performance of the different imaging modalities.

  6. Robust parameter extraction for decision support using multimodal intensive care data

    PubMed Central

    Clifford, G.D.; Long, W.J.; Moody, G.B.; Szolovits, P.

    2008-01-01

    Digital information flow within the intensive care unit (ICU) continues to grow, with advances in technology and computational biology. Recent developments in the integration and archiving of these data have resulted in new opportunities for data analysis and clinical feedback. New problems associated with ICU databases have also arisen. ICU data are high-dimensional, often sparse, asynchronous and irregularly sampled, as well as being non-stationary, noisy and subject to frequent exogenous perturbations by clinical staff. Relationships between different physiological parameters are usually nonlinear (except within restricted ranges), and the equipment used to measure the observables is often inherently error-prone and biased. The prior probabilities associated with an individual's genetics, pre-existing conditions, lifestyle and ongoing medical treatment all affect prediction and classification accuracy. In this paper, we describe some of the key problems and associated methods that hold promise for robust parameter extraction and data fusion for use in clinical decision support in the ICU. PMID:18936019

  7. Method for extracting relevant electrical parameters from graphene field-effect transistors using a physical model

    SciTech Connect

    Boscá, A.; Pedrós, J.; Martínez, J.; Calle, F.

    2015-01-28

    Due to its intrinsic high mobility, graphene has proved to be a suitable material for high-speed electronics, where graphene field-effect transistor (GFET) has shown excellent properties. In this work, we present a method for extracting relevant electrical parameters from GFET devices using a simple electrical characterization and a model fitting. With experimental data from the device output characteristics, the method allows to calculate parameters such as the mobility, the contact resistance, and the fixed charge. Differentiated electron and hole mobilities and direct connection with intrinsic material properties are some of the key aspects of this method. Moreover, the method output values can be correlated with several issues during key fabrication steps such as the graphene growth and transfer, the lithographic steps, or the metalization processes, providing a flexible tool for quality control in GFET fabrication, as well as a valuable feedback for improving the material-growth process.

  8. Fixed Base Modal Survey of the MPCV Orion European Service Module Structural Test Article

    NASA Technical Reports Server (NTRS)

    Winkel, James P.; Akers, J. C.; Suarez, Vicente J.; Staab, Lucas D.; Napolitano, Kevin L.

    2017-01-01

    Recently, the MPCV Orion European Service Module Structural Test Article (E-STA) underwent sine vibration testing using the multi-axis shaker system at NASA GRC Plum Brook Station Mechanical Vibration Facility (MVF). An innovative approach using measured constraint shapes at the interface of E-STA to the MVF allowed high-quality fixed base modal parameters of the E-STA to be extracted, which have been used to update the E-STA finite element model (FEM), without the need for a traditional fixed base modal survey. This innovative approach provided considerable program cost and test schedule savings. This paper documents this modal survey, which includes the modal pretest analysis sensor selection, the fixed base methodology using measured constraint shapes as virtual references and measured frequency response functions, and post-survey comparison between measured and analysis fixed base modal parameters.

  9. An automatic recognition and parameter extraction method for structural planes in borehole image

    NASA Astrophysics Data System (ADS)

    Wang, Chuanying; Zou, Xianjian; Han, Zengqiang; Wang, Yiteng; Wang, Jinchao

    2016-12-01

    As a breakthrough in borehole imaging technology, digital panoramic borehole camera technology has been widely employed. The high-resolution panoramic borehole images can accurately reproduce the geometric features of structural planes. However, the detection of these features is usually done manually, which is both time-consuming and introduces human errors. To solve this problem, this paper presents a method for the automatic recognition and parameter extraction of borehole geometric features of camera images. In this method, the image's gray and gradient level, and also their projection on the depth axis are used to identify the locations of structural planes. Afterwards, iterative matching is employed by using a template of sinusoidal function to search for structural planes in the identified image blocks. Finally, optimal sine curves are selected as the feature curves of structural planes, and their related parameters are converted into structural plane parameters required for engineering, such as their positions, dip directions, dip angles and fracture widths. The method can automatically identify all of structural planes throughout the whole borehole camera image in a continuous and rapid manner, and obtain the corresponding structural parameters. It has proven highly reliable, accurate and efficient.

  10. Observations of urban airborne particle number concentrations during rush-hour conditions: analysis of the number based size distributions and modal parameters.

    PubMed

    Lingard, Justin J N; Agus, Emily L; Young, David T; Andrews, Gordon E; Tomlin, Alison S

    2006-12-01

    A summertime study of the number concentration and the size distribution of combustion derived nanometre sized particles (termed nanoparticles) from diesel and spark-ignition (SI) engine emissions were made under rush-hour and free-flow traffic conditions at an urban roadside location in Leeds, UK in July 2003. The measured total particle number concentrations (N(TOTAL)) were of the order 1.8 x 10(4) to 3.4 x 10(4) cm(-3), and tended to follow the diurnal traffic flow patterns. The N(TOTAL) was dominated by particles < or =100 nm in diameter which accounted for between 89-93% of the measured particle number. By use of a log-normal fitting procedure, the modal parameters of the number based particle size distribution of urban airborne particulates were derived from the roadside measurements. Four component modes were identified. Two nucleation modes were found, with a smaller, more minor, mode composed principally of sub-11 nm particles, believed to be derived from particles formed from the nucleation of gaseous species in the atmosphere. A second mode, much larger in terms of number, was composed of particles within the size range of 10-20 nm. This second mode was believed to be principally derived from the condensation of the unburned fuel and lube oil (the solvent organic fraction or SOF) as it cooled on leaving the engine exhaust. Third and fourth modes were noted within the size ranges of 28-65 nm and 100-160 nm, respectively. The third mode was believed to be representative of internally mixed Aitken mode particles composed of a soot/ash core with an adsorbed layer of readily volatilisable material. The fourth mode was believed to be composed of chemically aged, secondary particles. The larger nucleation and Aitken modes accounted for between 80-90% of the measured N(TOTAL), and the particles in these modes were believed to be derived from SI and diesel engine emissions. The overall size distribution, particularly in modes II-IV, was observed to be strongly

  11. Active control and sound synthesis--two different ways to investigate the influence of the modal parameters of a guitar on its sound.

    PubMed

    Benacchio, Simon; Mamou-Mani, Adrien; Chomette, Baptiste; Finel, Victor

    2016-03-01

    The vibrational behavior of musical instruments is usually studied using physical modeling and simulations. Recently, active control has proven its efficiency to experimentally modify the dynamical behavior of musical instruments. This approach could also be used as an experimental tool to systematically study fine physical phenomena. This paper proposes to use modal active control as an alternative to sound simulation to study the complex case of the coupling between classical guitar strings and soundboard. A comparison between modal active control and sound simulation investigates the advantages, the drawbacks, and the limits of these two approaches.

  12. A Method to Extract the Redshift Distortion β Parameter in Configuration Space from Minimal Cosmological Assumptions

    NASA Astrophysics Data System (ADS)

    Tocchini-Valentini, Domenico; Barnard, Michael; Bennett, Charles L.; Szalay, Alexander S.

    2012-10-01

    We present a method to extract the redshift-space distortion β parameter in configuration space with a minimal set of cosmological assumptions. We show that a novel combination of the observed monopole and quadrupole correlation functions can remove efficiently the impact of mild nonlinearities and redshift errors. The method offers a series of convenient properties: it does not depend on the theoretical linear correlation function, the mean galaxy density is irrelevant, only convolutions are used, and there is no explicit dependence on linear bias. Analyses based on dark matter N-body simulations and Fisher matrix demonstrate that errors of a few percent on β are possible with a full-sky, 1 (h -1 Gpc)3 survey centered at a redshift of unity and with negligible shot noise. We also find a baryonic feature in the normalized quadrupole in configuration space that should complicate the extraction of the growth parameter from the linear theory asymptote, but that does not have a major impact on our method.

  13. Variation in available cesium concentration with parameters during temperature induced extraction of cesium from soil.

    PubMed

    Parajuli, Durga; Takahashi, Akira; Tanaka, Hisashi; Sato, Mutsuto; Fukuda, Shigeharu; Kamimura, Ryuichi; Kawamoto, Tohru

    2015-02-01

    Cesium extraction behavior of brown forest type soil collected from paddy fields in Fukushima nuclear accident affected areas was studied. In nitric acid or sulfuric acid solutions at elevated temperature, the concentration of Cs in soil available for extraction, m0, has been estimated on the basis of modified canonical equation and the equations derived from assumed equilibria. With the variation in temperature, mixing time, and soil to solvent ratio, the observed m0 values in 0.5 M acid solution ranged between 1.5 and 2.9 mg cesium per kilogram of soil. By increasing the acid concentration to 3 M, the value of m0 could be sharply increased to 5.1 mg/kg even at 95 °C. This variation in the extractable concentration of cesium with the parameters signifies the existence of different binding sites in the soil matrix. The results observed for uncontaminated sample could be reproduced with the radioactive cesium contaminated sample belonging to the same soil group.

  14. A new correlation parameter extraction method for searching mode sea clutter restraint

    NASA Astrophysics Data System (ADS)

    Yuan, Xujin; Chen, Yong; Wang, Chao; Yin, Hongcheng; Yao, Jingping; Xu, Zhiming; Lu, Yongge

    2014-11-01

    Correlation characteristics are important for sea clutter restraint in radar image processing, which is universal in certain features for both radar and optical image. The spatial-temporal dispersion relation contained in sea clutter, which usually fits into the sum of wind friction linear item and gravity wave item, is proved effective for sea clutter restraint recently. A sea clutter restraint method for mobile searching mode observation point, which is prevalent in maritime air-borne platform, is developed from a former restraint method for shore-based stationary radar. A new extraction method for intrinsic dispersion linear item parameter of sea clutter aiming at range profile of searching mode radar system is proposed, which forms the core of the restraint method. The statistical model is founded on spatial-temporal dispersion relation and radar illumination geometry. Simulation results shows Doppler shift of measured wind linear item have a bias from the sum of sea wind and radar platform velocity. A systematic study suggests the bias could be attributed to interaction between wind friction and gravity wave item, and a rather good fitting result is obtained. CFAR detection processing for a set of experimental clutter data shows that this intrinsic dispersion extraction method formula is found to be effective in detection probability enhancement. The restraint method based on the proposed dispersion extraction method could be utilized in mobile maritime surveillance equipments.

  15. The influence of supplementation with artichoke (Cynara scolymus L.) extract on selected redox parameters in rowers.

    PubMed

    Skarpanska-Stejnborn, Anna; Pilaczynska-Szczesniak, Lucia; Basta, Piotr; Deskur-Smielcka, Ewa; Horoszkiewicz-Hassan, Magorzata

    2008-06-01

    High-intensity physical exercise decreases intracellular antioxidant potential. An enhanced antioxidant defense system is desirable in people subjected to exhaustive exercise. The aim of this study was to investigate the influence of supplementation with artichoke-leaf extract on parameters describing balance between oxidants and antioxidants in competitive rowers. This double-blinded study was carried out in 22 members of the Polish rowing team who were randomly assigned to a supplemented group (n = 12), receiving 1 gelatin capsule containing 400 mg of artichoke-leaf extract 3 times a day for 5 wk, or a placebo group (n = 10). At the beginning and end of the study participants performed a 2,000-m maximal test on a rowing ergometer. Before each exercise test, 1 min after the test completion, and after a 24-hr restitution period blood samples were taken from antecubital vein. The following redox parameters were assessed in red blood cells: superoxide dismutase activity, glutathione peroxidase activity, glutathione reductase activity, reduced glutathione levels, and thiobarbituric-acid-reactive-substances concentrations. Creatine kinase activity and total antioxidant capacity (TAC) were measured in plasma samples, lactate levels were determined in capillary blood samples, and serum lipid profiles were assessed. During restitution, plasma TAC was significantly higher (p < .05) in the supplemented group than in the placebo group. Serum total cholesterol levels at the end of the study were significantly (p < .05) lower in the supplemented group than in the placebo group. In conclusion, consuming artichoke-leaf extract, a natural vegetable preparation of high antioxidant potential, resulted in higher plasma TAC than placebo but did not limit oxidative damage to erythrocytes in competitive rowers subjected to strenuous training.

  16. Optimization of subcritical water extraction parameters of antioxidant polyphenols from sea buckthorn (Hippophaë rhamnoides L.) seed residue.

    PubMed

    Gong, Ying; Zhang, Xiaofei; He, Li; Yan, Qiuli; Yuan, Fang; Gao, Yanxiang

    2015-03-01

    Polyphenols was extracted with subcritical water from the sea buckthorn seed residue (after oil recovery), and the extraction parameters were optimized using response surface methodology (RSM). The independent processing variables were extraction temperature, extraction time and the ratio of water to solid. The optimal extraction parameters for the extracts with highest ABTS radical scavenging activity were 120 °C, 36 min and the water to solid ratio of 20, and the maximize antioxidant capacity value was 32.42 mmol Trolox equivalent (TE)/100 g. Under the optimal conditions, the yield of total phenolics, total flavonoids and proanthocyanidins was 36.62 mg gallic acid equivalents (GAE)/g, 19.98 mg rutin equivalent (RE)/g and 10.76 mg catechin equivalents (CE)/g, respectively.

  17. Consistency in Al/CuPc/ n-Si Heterojunction Diode Parameters Extracted Using Different Techniques

    NASA Astrophysics Data System (ADS)

    Ullah, Irfan; Shah, Mutabar; Khan, Majid; Wahab, Fazal

    2016-02-01

    This paper reports fabrication and characterization of an Al/CuPc/ n-Si heterojunction diode. The heterojunction was fabricated by depositing the active organic semiconducting material copper phthalocyanine (CuPc) on the n-Si substrate using the thermal vacuum evaporation technique. Electrical characterization of the fabricated heterojunction was carried out at ambient conditions. Various diode parameters, such as the ideality factor ( n), barrier height (Φ_{{b}}), and series resistance ( R s), were extracted from the current-voltage ( I- V) characteristic curve. These parameters are consistent with techniques used by Cheung, Norde and Hernandez et al. Furthermore these parameters are consistent with capacitance-voltage (C-V) characterization method. The conduction mechanism at the interface of CuPc and n-Si was also investigated. The surface morphology of the CuPc film was studied using atomic force microscopy and scanning electron microscopy. The optical bandgap of the CuPc film was calculated from the absorption spectrum using Tauc's law.

  18. Three-dimensional fluorescence spectra of mineral oil and extraction method of characteristic parameters

    NASA Astrophysics Data System (ADS)

    Shang, Liping; Liu, Xianyong; Xu, Xiaoxuan; Xu, Jingjun

    2005-02-01

    To realize the on-line fluorescence monitoring of mineral oil pollution in water, three-dimensional spectral characteristic of oil-water intermixtures must be studied and the characteristic must be extracted. Using excitation wavelength, fluorescence wavelength and fluorescence intensity as three-dimensional system of coordinate, through sampling and surface fitting, three-dimensional fluorogram is gotten, which can provide gist for oil discrimination when presented in contour chart (finger-print map of oils). But there is little difference between characteristics of three-dimensional fluorogram because of the similarity of constituent and structure of similar oils. Therefore this paper introduces quantitative analysis method-characteristic parameter method which starts with analyzing statistical characteristic of three-dimensional fluorogram. Using RFPC fluorescence spectrometer (Shimadzu, Japan), three-dimensional fluorescence spectra of diesel oil, machine oil, gasoline oil, crude oil are measured and parameterized. The result shows that as a quantitative classified discrimination method of three-dimensional fluorescence spectra, the parameter of characteristic parameter method possesses definiteness for three-dimensional fluorescence spectra, and it is applicable, available when used in oil discrimination.

  19. Effects of Temperature and Concentration Mono and Polycrystalline Silicon Solar Cells: Extraction Parameters

    NASA Astrophysics Data System (ADS)

    Khalis, M.; Masrour, R.; Khrypunov, G.; Kirichenko, M.; Kudiy, D.; Zazoui, M.

    2016-10-01

    The simple and efficient method for the extraction of all the parameters of a solar cell from a single current-voltage curve under one constant illumination level based on the Lambert W function. On calculating the lsqcurvefit function with constraints, between the experimental current-voltage characteristic and a theoretical arbitrary characteristic based on Lambert W-function. It is significant to understand the effect of the light intensity and temperature on output performance of the crystalline solar cells. The effect of light intensity and temperature on performance parameters of mc-si and pc-si solar cells is discusses. The experiments have been carried out under a solar simulator for various intensity levels in the range 1-2.5 sun and 25-60°C, respectively. The experiment was carried out employing solar cell simulator with varying cell temperature at constant light intensity. The results show that cell temperature has a significant effect on the photovoltaic parameters and it controls the quality and performance of the solar cell. The maximum power and efficiency are found to be decreased with cell temperature and the temperature coefficient of the efficiency and maximum output power is found to be negative.

  20. Extraction Of Hydrological Parameters Using High Spatial Resolution Remote Sensing For KINEROS2 Model

    NASA Astrophysics Data System (ADS)

    Sadeh, Yuval; Blumberg, Dan G.; Cohen, Hai; Morin, Efrat; Maman, Shimrit

    2016-04-01

    Arid and semi-arid environments cover more than one-third of Earth's land surface; these environments are especially vulnerable to flash flood hazards due to the poor understanding of the phenomenon and the lack of meteorological, geomorphological, and hydrological data. For many years, catchment characteristics have been observed using point-based measurements such as rain gauges and soil sample analysis. Furthermore, flood modeling techniques are not always available in ungauged catchments or in regions where data are sparse. In comparison to point-based observations, using remote sensing technologies can provide continuous spatial hydrological parameters and variables. The advances in remote sensing technologies including weather radar-based quantitative precipitation estimation (QPE) and Earth observing satellites, provide new geo-spatial data using high spatial and temporal resolution for basin-scale geomorphological analysis and hydrological models. This study used high spatial resolution remote sensing to extract some of the main input parameters of Kinematic Runoff and Erosion Model (KINEROS2), for the arid medium size Rahaf watershed (76 km^2}), located in the Judean Desert, Israel. During the research a high resolution land cover map of Rahaf basin was created using WorldView-2 multispectral satellite imageries; surface roughness was estimated using SIR-C and COSMO-SkyMed Synthetic Aperture Radar (SAR) spaceborne sensors; and rainstorm characteristics were extracted from ground-based meteorological radar. Finally, all the remotely sensed extracted data were used as inputs for the KINEROS2 through Automated Geospatial Watershed Assessment (AGWA) tool. The model-simulated peak flow and volume were then compared to runoff measurements from the watershed's pouring point. This research demonstrates the ability of using remotely sensed extracted data as inputs for the KINEROS2 model. Using AGWA, each simulated storm was successfully calibrated, when the average

  1. Modalities of Thinking: State and Trait Effects on Cross-Frequency Functional Independent Brain Networks.

    PubMed

    Milz, Patricia; Pascual-Marqui, Roberto D; Lehmann, Dietrich; Faber, Pascal L

    2016-05-01

    Functional states of the brain are constituted by the temporally attuned activity of spatially distributed neural networks. Such networks can be identified by independent component analysis (ICA) applied to frequency-dependent source-localized EEG data. This methodology allows the identification of networks at high temporal resolution in frequency bands of established location-specific physiological functions. EEG measurements are sensitive to neural activity changes in cortical areas of modality-specific processing. We tested effects of modality-specific processing on functional brain networks. Phasic modality-specific processing was induced via tasks (state effects) and tonic processing was assessed via modality-specific person parameters (trait effects). Modality-specific person parameters and 64-channel EEG were obtained from 70 male, right-handed students. Person parameters were obtained using cognitive style questionnaires, cognitive tests, and thinking modality self-reports. EEG was recorded during four conditions: spatial visualization, object visualization, verbalization, and resting. Twelve cross-frequency networks were extracted from source-localized EEG across six frequency bands using ICA. RMANOVAs, Pearson correlations, and path modelling examined effects of tasks and person parameters on networks. Results identified distinct state- and trait-dependent functional networks. State-dependent networks were characterized by decreased, trait-dependent networks by increased alpha activity in sub-regions of modality-specific pathways. Pathways of competing modalities showed opposing alpha changes. State- and trait-dependent alpha were associated with inhibitory and automated processing, respectively. Antagonistic alpha modulations in areas of competing modalities likely prevent intruding effects of modality-irrelevant processing. Considerable research suggested alpha modulations related to modality-specific states and traits. This study identified the

  2. Evaluation and Optimization of Downstream Process Parameters for Extraction of Betulinic Acid from the Bark of Ziziphus jujubae L.

    PubMed Central

    Dubey, Kashyap Kumar; Goel, Nitika

    2013-01-01

    Present work investigated an apposite and efficient method for extraction of betulinic acid (BA) from the bark of Ziziphus jujubae. Various extraction methods like stirring extraction, soxhlet extraction, ultrasonic extraction, and microwave assisted extraction (MAE) were evaluated for increasing recovery percentage of BA. From the raffinate so obtained, BA was isolated. Thin layer chromatography (TLC) was used to analyze the extract and high performance liquid chromatography (HPLC) for quantification. The results revealed that the percentage extraction of BA from Z. jujubae by MAE was more proficient. As recovery percentage of BA by MAE technique turned out to be maximum, by using response surface methodology (RSM), three process parameters (pH, temperature, and time) were optimized by MAE and it was observed that the optimum parameters (pH 6.5, temp. 70.23°C, and time 3.5 min) gave the maximum recovery of BA (0.44% w/w). To validate the RSM model, experiments were performed and the highest recovery of BA was found to be 0.4% w/w which is ±0.04% to the predicted value. Henceforth the extraction efficiency and the substantial saving of time by MAE was more capable than the other extraction techniques. PMID:24324374

  3. Extraction of Forest Stands Parameters from Aster Data in Open Forest

    NASA Astrophysics Data System (ADS)

    Abbasi, M.; Riyahi Bakhtyarib, H. R.

    2012-07-01

    Tree crown size (CS) and stem number per hectare (SN) has become increasingly important for forest management and ecosystem monitoring. Tree crown size is also strongly related to other canopy structural parameters, such as diameter at breast height, tree height and biomass. For both issues, remote sensing data are attractive for their large-area and up-to-date mapping capacities. The QuickBird and ASTER imagery used in this study was acquired over Zagros Forests in southern Zagros region, Fars province of Iran on 1 August 2005 and 1 July 2005, respectively. For the forest site investigated in this study, we concentrated on stands of Quercus Persica which is the dominant species in Zagros region. This study was conducted to investigate the capabilities of ASTER-L1B data to estimate some of forest parameters at individual tree and stand level in dry area. The forest stand parameters are crown area, crown density, average crown area. Obtaining the accuracy of classification the ground truth map was prepared by tree crown delineation using the panchromatic band of QuickBird data. Individual tree crowns were automatically delineated by color segmentation of QuickBird imagery. Simple linear regression procedure was used to show the relationships between spectral variables and the individual trees and forest stand parameters. With decreasing the crown density the effects of background will increase. Our results indicated that crown size could be accurately extracted from panchromatic band of QuickBird images especially for open forest stands. This paper demonstrates that using high-resolution satellite imagery in the open forest offers a unique opportunity for deriving single tree attributes and allowing reliable ground truth map to estimate stand structure. ASTER data and its indices showed good capability to estimate crown area in this study.

  4. Automated extraction and validation of children's gait parameters with the Kinect.

    PubMed

    Motiian, Saeid; Pergami, Paola; Guffey, Keegan; Mancinelli, Corrie A; Doretto, Gianfranco

    2015-12-02

    Gait analysis for therapy regimen prescription and monitoring requires patients to physically access clinics with specialized equipment. The timely availability of such infrastructure at the right frequency is especially important for small children. Besides being very costly, this is a challenge for many children living in rural areas. This is why this work develops a low-cost, portable, and automated approach for in-home gait analysis, based on the Microsoft Kinect. A robust and efficient method for extracting gait parameters is introduced, which copes with the high variability of noisy Kinect skeleton tracking data experienced across the population of young children. This is achieved by temporally segmenting the data with an approach based on coupling a probabilistic matching of stride template models, learned offline, with the estimation of their global and local temporal scaling. A preliminary study conducted on healthy children between 2 and 4 years of age is performed to analyze the accuracy, precision, repeatability, and concurrent validity of the proposed method against the GAITRite when measuring several spatial and temporal children's gait parameters. The method has excellent accuracy and good precision, with segmenting temporal sequences of body joint locations into stride and step cycles. Also, the spatial and temporal gait parameters, estimated automatically, exhibit good concurrent validity with those provided by the GAITRite, as well as very good repeatability. In particular, on a range of nine gait parameters, the relative and absolute agreements were found to be good and excellent, and the overall agreements were found to be good and moderate. This work enables and validates the automated use of the Kinect for children's gait analysis in healthy subjects. In particular, the approach makes a step forward towards developing a low-cost, portable, parent-operated in-home tool for clinicians assisting young children.

  5. Multishaker modal testing

    NASA Technical Reports Server (NTRS)

    Craig, Roy R., Jr.

    1987-01-01

    The major accomplishments of this research are: (1) the refinement and documentation of a multi-input, multi-output modal parameter estimation algorithm which is applicable to general linear, time-invariant dynamic systems; (2) the development and testing of an unsymmetric block-Lanzcos algorithm for reduced-order modeling of linear systems with arbitrary damping; and (3) the development of a control-structure-interaction (CSI) test facility.

  6. Evaluation of concepts and methods for extraction of flow parameters from laser transit anemometry data

    NASA Technical Reports Server (NTRS)

    Humphreys, W. M., Jr.; Hunter, W. W., Jr.

    1988-01-01

    A Monte-Carlo type simulation system was developed to test concepts and associated algorithms proposed by Mayo and Smart (1984) for the extraction of two-dimensional flow parameters from laser transit anemometry data sets. The Monte-Carlo LTA simulation program models a flow field as well as the sample volume geometry of the LTA system, thereby permitting simulation of two-dimensional data acquisition in a three-dimensional flow field. The results of these tests on the proposed processing concepts suggest that the instrument is capable of measuring mean velocities to less than +0.15 percent error and flow angles to less then +0.3 percent for turbulence intensities of up to 15.0 percent.

  7. Robust extraction of channel parameters from HRSC data of Warrego Valles

    NASA Astrophysics Data System (ADS)

    Koenders, R.; Lindenbergh, R. C.

    2011-10-01

    Detailed and regional studies of Martian hydrolandforms and modelling of the process responsible for those landforms have been performed in the last decades, but a global understanding of the evolution of water systematics of Mars requires a global and systematic analysis and integration of the tell-tale signs of water at the surface. In the coming years HRSC will obtain high-resolution stereo-imagery with near-global coverage of Mars. This will result in an unprecedented detailed look of the morphology of the Martian surface. In anticipation of this we have developed an algorithm to systematically and quantitatively extract the relevant morphological parameters to identify the formative process classes of Martian hydro-landforms from these data. At this conference we will present our first results through a case study of the Warrego Valles system.

  8. The influence of supplementation with Rhodiola rosea L. extract on selected redox parameters in professional rowers.

    PubMed

    Skarpanska-Stejnborn, Ana; Pilaczynska-Szczesniak, Lucja; Basta, Piotr; Deskur-Smielecka, Ewa

    2009-04-01

    The aim of this study was to investigate the effect of Rhodiola rosea supplementation on the balance of oxidants and antioxidants in the serum and erythrocytes of competitive rowers. This double-blinded study included 22 members of the Polish Rowing Team who were participating in a preparatory camp. Participants were randomly assigned to the supplemented group (n = 11), who received 100 mg of R. rosea extract twice daily for 4 wk, or the placebo group (n = 11). At the beginning and end of the study, participants performed a 2,000-m maximum test on a rowing ergometer. Blood samples were taken from the antecubital vein before each exercise test, 1 min after completing the test, and after a 24-hr restitution period. The following redox parameters were assessed in erythrocytes: superoxide dismutase activity, glutathione peroxidase activity, and thiobarbituric-acid-reactive substances concentrations. In addition, creatine kinase activity and total antioxidant capacity were measured in plasma samples, lactate levels were determined in capillary blood samples, and uric acid concentrations were measured in serum. After supplementation, the total plasma antioxidant capacity was significantly higher (p = .0002) in the supplemented group than in the placebo group, and superoxide dismutase activity in erythrocytes directly after and 24 hr after the ergometry was significantly (p = .0461) lower in athletes receiving R. rosea extracts than in the placebo group. In conclusion, supplementation with R. rosea increased antioxidant levels in the plasma of professional rowers but had no effect on oxidative damage induced by exhaustive exercise.

  9. Exploring the effects of pulsed electric field processing parameters on polyacetylene extraction from carrot slices.

    PubMed

    Aguiló-Aguayo, Ingrid; Abreu, Corina; Hossain, Mohammad B; Altisent, Rosa; Brunton, Nigel; Viñas, Inmaculada; Rai, Dilip K

    2015-03-02

    The effects of various pulsed electric field (PEF) parameters on the extraction of polyacetylenes from carrot slices were investigated. Optimised conditions with regard to electric field strength (1-4 kV/cm), number of pulses (100-1500), pulse frequency (10-200 Hz) and pulse width (10-30 μs) were identified using response surface methodology (RSM) to maximise the extraction of falcarinol (FaOH), falcarindiol (FaDOH) and falcarindiol-3-acetate (FaDOAc) from carrot slices. Data obtained from RSM and experiments fitted significantly (p < 0.0001) the proposed second-order response functions with high regression coefficients (R2) ranging from 0.82 to 0.75. Maximal FaOH (188%), FaDOH (164.9%) and FaDOAc (166.8%) levels relative to untreated samples were obtained from carrot slices after applying PEF treatments at 4 kV/cm with 100 number of pulses of 10 μs at 10 Hz. The predicted values from the developed quadratic polynomial equation were in close agreement with the actual experimental values with low average mean deviations (E%) ranging from 0.68% to 3.58%.

  10. Intensification of extraction of curcumin from Curcuma amada using ultrasound assisted approach: Effect of different operating parameters.

    PubMed

    Shirsath, S R; Sable, S S; Gaikwad, S G; Sonawane, S H; Saini, D R; Gogate, P R

    2017-09-01

    Curcumin, a dietary phytochemical, has been extracted from rhizomes of Curcuma amada using ultrasound assisted extraction (UAE) and the results compared with the conventional extraction approach to establish the process intensification benefits. The effect of operating parameters such as type of solvent, extraction time, extraction temperature, solid to solvent ratio, particle size and ultrasonic power on the extraction yield have been investigated in details for the approach UAE. The maximum extraction yield as 72% was obtained in 1h under optimized conditions of 35°C temperature, solid to solvent ratio of 1:25, particle size of 0.09mm, ultrasonic power of 250W and ultrasound frequency of 22kHz with ethanol as the solvent. The obtained yield was significantly higher as compared to the batch extraction where only about 62% yield was achieved in 8h of treatment. Peleg's model was used to describe the kinetics of UAE and the model showed a good agreement with the experimental results. Overall, ultrasound has been established to be a green process for extraction of curcumin with benefits of reduction in time as compared to batch extraction and the operating temperature as compared to Soxhlet extraction. Copyright © 2017. Published by Elsevier B.V.

  11. Noise elimination algorithm for modal analysis

    SciTech Connect

    Bao, X. X.; Li, C. L.; Xiong, C. B.

    2015-07-27

    Modal analysis is an ongoing interdisciplinary physical issue. Modal parameters estimation is applied to determine the dynamic characteristics of structures under vibration excitation. Modal analysis is more challenging for the measured vibration response signals are contaminated with noise. This study develops a mathematical algorithm of structured low rank approximation combined with the complex exponential method to estimate the modal parameters. Physical experiments using a steel cantilever beam with ten accelerometers mounted, excited by an impulse load, demonstrate that this method can significantly eliminate noise from measured signals and accurately identify the modal frequencies and damping ratios. This study provides a fundamental mechanism of noise elimination using structured low rank approximation in physical fields.

  12. Real-time extraction of plasma equilibrium parameters in KSTAR tokamak using statistical methods

    NASA Astrophysics Data System (ADS)

    Na, Yong-Su; Jeon, Young-Mu; Hong, S. H.; Hwang, Y. S.

    2001-02-01

    To improve inherent shortcomings of statistical methods and apply them to the extraction of plasma equilibrium parameters in a fast timescale for real-time plasma control, new concepts of statistical methods such as principal component analysis-based neural network (NN), functional parametrization (FP)-based NN and double network are introduced by modifying NN and FP. These new methods are benchmarked and compared with the conventional techniques of NN and FP in a simple single-filament system. As a result of their applications to identification of plasma equilibrium parameters in the Korea Superconducting Tokamak Advanced Research tokamak, particularly, the double network concept among them has successfully achieved the improvement of drawbacks in the conventional methods. It is shown that more reliable results from the double network method can be obtained by combining several different statistical treatments as a primary network. Even in the case of nonoptimized methods united as a primary network, quite acceptable results can be achieved in the double network method.

  13. Simultaneously Extracting Multiple Parameters via Fitting One Single Autocorrelation Function Curve in Diffuse Correlation Spectroscopy

    PubMed Central

    Dong, Lixin; He, Lian; Lin, Yu; Shang, Yu; Yu, Guoqiang

    2015-01-01

    Near-infrared diffuse correlation spectroscopy (DCS) has recently been employed for noninvasive acquisition of blood flow information in deep tissues. Based on the established correlation diffusion equation, the light intensity autocorrelation function detected by DCS is determined by a blood flow index αDB, tissue absorption coefficient μa, reduced scattering coefficient μs’, and a coherence factor β. The present study is designed to investigate the possibility of extracting multiple parameters such as μa, μs’, β, and αDB through fitting one single autocorrelation function curve and evaluate the performance of different fitting methods. For this purpose, computer simulations, tissue-like phantom experiments and in-vivo tissue measurements were utilized. The results suggest that it is impractical to simultaneously fit αDB and μa or αDB and μs’ from one single autocorrelation function curve due to the large crosstalk between these paired parameters. However, simultaneously fitting β and αDB is feasible and generates more accurate estimation with smaller standard deviation compared to the conventional two-step fitting method (i.e., first calculating β and then fitting αDB). The outcomes from this study provide a crucial guidance for DCS data analysis. PMID:23193446

  14. Supercritical carbon dioxide extraction of compounds with antimicrobial activity from Origanum vulgare L.: determination of optimal extraction parameters.

    PubMed

    Santoyo, S; Cavero, S; Jaime, L; Ibañez, E; Señoráns, F J; Reglero, G

    2006-02-01

    Oregano leaves were extracted using a pilot-scale supercritical fluid extraction plant under a wide range of extraction conditions, with the goal of determining the extraction and fractionation conditions to obtain extracts with optimal antimicrobial activity. In this investigation, the essential oil-rich fractions were selectively precipitated in the second separator, and their chemical composition and antimicrobial activity were investigated. Gas chromatography-mass spectrometry analysis of the various fractions resulted in the identification of 27 compounds of the essential oil. The main components of these fractions were carvacrol, trans-sabinene hydrate, cis-piperitol, borneol, terpinen-4-ol, and linalool. Antimicrobial activity was investigated by the disk diffusion and broth dilution methods against six different microbial species, including two gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), two gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa), a yeast (Candida albicans), and a fungus (Aspergillus niger). All of the supercritical fluid extraction fractions obtained showed antimicrobial activity against all of the microorganisms tested, although the most active fraction was the one obtained in experiment 5 (fraction was obtained with 7% ethanol at 150 bar and 40 degrees C). C. albicans was the most sensitive microorganism to the oregano extracts, whereas the least susceptible was A. niger. Carvacrol, sabinene hydrate, borneol, and linalool standards also showed antimicrobial activity against all of the microorganisms tested, with carvacrol being the most effective. Consequently, it was confirmed that essential oil from experiment 5, with the best antimicrobial activity, also presented the highest quantity of carvacrol.

  15. Optimization of Polycyclic Aromatic Hydrocarbon (PAH) Extraction Efficiency Parameters for Sub- and Supercritical Water Extraction (SCWE) Instrument

    NASA Technical Reports Server (NTRS)

    Okada, Asahi A.

    2005-01-01

    Polycyclic aromatic hydrocarbons are a class of molecules composed of multiple, bonded benzene rings. As PAHS are believed to be present on Mars, positive confirmation of their presence on Mars is highly desirable. To extract PAHS, which have low volatility, a fluid extraction method is ideal, and one that does not utilize organic solvents is especially ideal for in situ instrumental analysis. The use of water as a solvent, which at subcritical pressures and temperatures is relatively non-Polar, has significant potential. As SCWE instruments have not yet been commercialized, all instruments are individually-built research prototypes: thus, initial efforts were intended to determine if extraction efficiencies on the JPL-built laboratory-scale SCWE instrument are comparable to differing designs built elsewhere. Samples of soil with certified reference concentrations of PAHs were extracted using SCWE as well as conventional Soxhlet extraction. Continuation of the work would involve extractions on JPL'S newer, portable SCWE instrument prototype to determine its efficiency in extracting PAHs.

  16. LiDAR DTMs and anthropogenic feature extraction: testing the feasibility of geomorphometric parameters in floodplains

    NASA Astrophysics Data System (ADS)

    Sofia, G.; Tarolli, P.; Dalla Fontana, G.

    2012-04-01

    resolution topography have been proven to be reliable for feasible applications. The use of statistical operators as thresholds for these geomorphic parameters, furthermore, showed a high reliability for feature extraction in mountainous environments. The goal of this research is to test if these morphological indicators and objective thresholds can be feasible also in floodplains, where features assume different characteristics and other artificial disturbances might be present. In the work, three different geomorphic parameters are tested and applied at different scales on a LiDAR DTM of typical alluvial plain's area in the North East of Italy. The box-plot is applied to identify the threshold for feature extraction, and a filtering procedure is proposed, to improve the quality of the final results. The effectiveness of the different geomorphic parameters is analyzed, comparing automatically derived features with the surveyed ones. The results highlight the capability of high resolution topography, geomorphic indicators and statistical thresholds for anthropogenic features extraction and characterization in a floodplains context.

  17. Operational modal analysis applied to the concert harp

    NASA Astrophysics Data System (ADS)

    Chomette, B.; Le Carrou, J.-L.

    2015-05-01

    Operational modal analysis (OMA) methods are useful to extract modal parameters of operating systems. These methods seem to be particularly interesting to investigate the modal basis of string instruments during operation to avoid certain disadvantages due to conventional methods. However, the excitation in the case of string instruments is not optimal for OMA due to the presence of damped harmonic components and low noise in the disturbance signal. Therefore, the present study investigates the least-square complex exponential (LSCE) and the modified least-square complex exponential methods in the case of a string instrument to identify modal parameters of the instrument when it is played. The efficiency of the approach is experimentally demonstrated on a concert harp excited by some of its strings and the two methods are compared to a conventional modal analysis. The results show that OMA allows us to identify modes particularly present in the instrument's response with a good estimation especially if they are close to the excitation frequency with the modified LSCE method.

  18. An improved model and parameters extraction for photovoltaic cells using only three state points at standard test condition

    NASA Astrophysics Data System (ADS)

    Peng, Lele; Sun, Yize; Meng, Zhuo

    2014-02-01

    In this paper, a comprehensive modeling and parameters extraction method is proposed to describe the current-voltage and power-voltage characteristic of photovoltaic cells. This method is based on data commonly issued by commercial photovoltaic data sheet. By using Lambert W function, the improved model of solar cells is given. Meanwhile, the current-voltage and power-voltage curves of photovoltaic cells are calculated. To extract the model parameters from only three state points at standard test conditions, an optimized approach using iterative method and approximate method is presented. Compared to the popular Rp model and experimental data, the proposed method shows excellent agreement between the current-voltages points. It is found that the proposed modeling and parameters extraction method has less error at the maximum power point state. Moreover, the proposed model is more realistic when subjected to ideality factors variations.

  19. Effects of wheat bran extract containing arabinoxylan oligosaccharides on gastrointestinal parameters in healthy preadolescent children.

    PubMed

    François, Isabelle E J A; Lescroart, Olivier; Veraverbeke, Wim S; Marzorati, Massimo; Possemiers, Sam; Hamer, Henrike; Windey, Karen; Welling, Gjalt W; Delcour, Jan A; Courtin, Christophe M; Verbeke, Kristin; Broekaert, Willem F

    2014-05-01

    We assessed whether wheat bran extract (WBE) containing arabinoxylan-oligosaccharides (AXOS) elicited a prebiotic effect and modulated gastrointestinal (GI) parameters in healthy preadolescent children upon consumption in a beverage. This double-blind randomized placebo-controlled crossover trial evaluated the effects of consuming WBE at 0 (control) or 5.0 g/day for 3 weeks in 29 healthy children (8-12 years). Fecal levels of microbiota, short-chain fatty acids, branched-chain fatty acids, ammonia, moisture, and fecal pH were assessed at the end of each treatment and at the end of a 1-week run-in (RI) period. In addition, the subjects completed questionnaires scoring distress severity of 3 surveyed GI symptoms. Finally, subjects recorded defecation frequency and stool consistency. Nominal fecal bifidobacteria levels tended to increase after 5 g/day WBE consumption (P = 0.069), whereas bifidobacteria expressed as percentage of total fecal microbiota was significantly higher upon 5 g/day WBE intake (P = 0.002). Additionally, 5 g/day WBE intake induced a significant decrease in fecal content of isobutyric acid and isovaleric acid (P < 0.01), markers of protein fermentation. WBE intake did not cause a change in distress severity of the 3 surveyed GI symptoms (flatulence, abdominal pain/cramps, and urge to vomit) (P > 0.1). WBE is well tolerated at doses up to 5 g/day in healthy preadolescent children. In addition, the intake of 5 g/day exerts beneficial effects on gut parameters, in particular an increase in fecal bifidobacteria levels relative to total fecal microbiota, and reduction of colonic protein fermentation.

  20. Synergistic improvement of gas sensing performance by micro-gravimetrically extracted kinetic/thermodynamic parameters.

    PubMed

    Guo, Shuanbao; Xu, Pengcheng; Yu, Haitao; Cheng, Zhenxing; Li, Xinxin

    2015-03-10

    A novel method is explored for comprehensive design/optimization of organophosphorus sensing material, which is loaded on mass-type microcantilever sensor. Conventionally, by directly observing the gas sensing response, it is difficult to build quantitative relationship with the intrinsic structure of the material. To break through this difficulty, resonant cantilever is employed as gravimetric tool to implement molecule adsorption experiment. Based on the sensing data, key kinetic/thermodynamic parameters of the material to the molecule, including adsorption heat -ΔH°, adsorption/desorption rate constants Ka and Kd, active-site number per unit mass N' and surface coverage θ, can be quantitatively extracted according to physical-chemistry theories. With gaseous DMMP (simulant of organophosphorus agents) as sensing target, the optimization route for three sensing materials is successfully demonstrated. Firstly, a hyper-branched polymer is evaluated. Though suffering low sensitivity due to insufficient N', the bis(4-hydroxyphenyl)-hexafluoropropane (BHPF) sensing-group exhibits satisfactory reproducibility due to appropriate -ΔH°. To achieve more sensing-sites, KIT-5 mesoporous-silica with higher surface-area is assessed, resulting in good sensitivity but too high -ΔH° that brings poor repeatability. After comprehensive consideration, the confirmed BHPF sensing-group is grafted on the KIT-5 carrier to form an optimized DMMP sensing nanomaterial. Experimental results indicate that, featuring appropriate kinetic/thermodynamic parameters of -ΔH°, Ka, Kd, N' and θ, the BHPF-functionalized KIT-5 mesoporous silica exhibits synergistic improvement among reproducibility, sensitivity and response/recovery speed. The optimized material shows complete signal recovery, 55% sensitivity improvement than the hyper-branched polymer and 2∼3 folds faster response/recovery speed than the KIT-5 mesoporous silica.

  1. 3D numerical simulations of negative hydrogen ion extraction using realistic plasma parameters, geometry of the extraction aperture and full 3D magnetic field map

    NASA Astrophysics Data System (ADS)

    Mochalskyy, S.; Wünderlich, D.; Ruf, B.; Franzen, P.; Fantz, U.; Minea, T.

    2014-02-01

    Decreasing the co-extracted electron current while simultaneously keeping negative ion (NI) current sufficiently high is a crucial issue on the development plasma source system for ITER Neutral Beam Injector. To support finding the best extraction conditions the 3D Particle-in-Cell Monte Carlo Collision electrostatic code ONIX (Orsay Negative Ion eXtraction) has been developed. Close collaboration with experiments and other numerical models allows performing realistic simulations with relevant input parameters: plasma properties, geometry of the extraction aperture, full 3D magnetic field map, etc. For the first time ONIX has been benchmarked with commercial positive ions tracing code KOBRA3D. A very good agreement in terms of the meniscus position and depth has been found. Simulation of NI extraction with different e/NI ratio in bulk plasma shows high relevance of the direct negative ion extraction from the surface produced NI in order to obtain extracted NI current as in the experimental results from BATMAN testbed.

  2. Effects of methanolic extract of Moringa oleifera leaves on semen and biochemical parameters in cryptorchid rats.

    PubMed

    Afolabi, Ayobami Oladele; Aderoju, Hameed Adeola; Alagbonsi, Isiaka Abdullateef

    2013-01-01

    While anti-oxidant effects of Moringa oleifera in much oxidative stress related diseases have been well reported, cryptorchidism on the other hand has been shown to cause oxidative stress. However, study is scanty on the likely role of Moringa oleifera in reducing cryptorchidism-induced oxidative stress in rats has not been studied. The present study looked into the effects of methanolic extract of Moringa oleifera leaves (MEMO) on semen and biochemical parameters in cryptorchid rats. Twenty male albino rats (200-250 g) were randomly divided into 4 groups (n=5 each). Groups A and B were sham-operated and treated with corn-oil and 200 mg/kg of MEMO respectively, while groups C and D were rendered cryptorchid and also treated with corn-oil and 200 mg/kg of MEMO respectively. Cryptorchid rats had lower testicular weight, sperm count, germ cell count, testicular superoxide dismutase (SOD) concentration, testicular total protein and higher testicular malondialdehyde (MDA) concentration compared to sham-operated rats. MEMO had no significant effect on testicular weight and MDA concentration, while it significantly increased sperm count, germ cell count, testicular SOD and total protein in the cryptorchid rats. The present study suggests that MEMO ameliorates cryptorchidism associated germ cell loss and oxidative stress.

  3. Implementation and comparative analysis of the optimisations produced by evolutionary algorithms for the parameter extraction of PSP MOSFET model

    NASA Astrophysics Data System (ADS)

    Hadia, Sarman K.; Thakker, R. A.; Bhatt, Kirit R.

    2016-05-01

    The study proposes an application of evolutionary algorithms, specifically an artificial bee colony (ABC), variant ABC and particle swarm optimisation (PSO), to extract the parameters of metal oxide semiconductor field effect transistor (MOSFET) model. These algorithms are applied for the MOSFET parameter extraction problem using a Pennsylvania surface potential model. MOSFET parameter extraction procedures involve reducing the error between measured and modelled data. This study shows that ABC algorithm optimises the parameter values based on intelligent activities of honey bee swarms. Some modifications have also been applied to the basic ABC algorithm. Particle swarm optimisation is a population-based stochastic optimisation method that is based on bird flocking activities. The performances of these algorithms are compared with respect to the quality of the solutions. The simulation results of this study show that the PSO algorithm performs better than the variant ABC and basic ABC algorithm for the parameter extraction of the MOSFET model; also the implementation of the ABC algorithm is shown to be simpler than that of the PSO algorithm.

  4. Antioxidant effect of supercritical CO2 extracted Nigella sativa L. seed extract on deep fried oil quality parameters.

    PubMed

    Solati, Zeinab; Baharin, Badlishah Sham

    2015-06-01

    Effect of supercritical CO2 extracted Nigella sativa L. seed extract (NE) on frying performance of sunflower oil and refined, bleached and deodorized (RBD) palm olein was investigated at concentrations of 1.2 % and 1.0 % respectively. Two frying systems containing 0 % N. sativa L. extract (Control) and 0.02 % butylated hydroxytoluene (BHT) were used for comparison. Physicochemical properties such as fatty acid composition (FAC), Peroxide Value (PV), Anisidine Value (AV), Totox Value (TV), Total Polar Content (TPC), C18:2/C16:0 ratio and viscosity of frying oils were determined during five consecutive days of frying. Results have shown that N. sativa L. extract was able to improve the oxidative stability of both frying oils during the frying process compared to control. The stabilizing effect of antioxidants were in the order of BHT > NE. RBD palm olein was found to be more stable than sunflower oil based on the ratio of linoleic acid (C18:2) to palmitic acid (C16:0) and fatty acid composition.

  5. Parasitic Parameters Extraction for InP DHBT Based on EM Method and Validation up to H-Band

    NASA Astrophysics Data System (ADS)

    Li, Oupeng; Zhang, Yong; Wang, Lei; Xu, Ruimin; Cheng, Wei; Wang, Yuan; Lu, Haiyan

    2017-05-01

    This paper presents a small-signal model for InGaAs/InP double heterojunction bipolar transistor (DHBT). Parasitic parameters of access via and electrode finger are extracted by 3-D electromagnetic (EM) simulation. By analyzing the equivalent circuit of seven special structures and using the EM simulation results, the parasitic parameters are extracted systematically. Compared with multi-port s-parameter EM model, the equivalent circuit model has clear physical intension and avoids the complex internal ports setting. The model is validated on a 0.5 × 7 μm2 InP DHBT up to 325 GHz. The model provides a good fitting result between measured and simulated multi-bias s-parameters in full band. At last, an H-band amplifier is designed and fabricated for further verification. The measured amplifier performance is highly agreed with the model prediction, which indicates the model has good accuracy in submillimeterwave band.

  6. Parasitic Parameters Extraction for InP DHBT Based on EM Method and Validation up to H-Band

    NASA Astrophysics Data System (ADS)

    Li, Oupeng; Zhang, Yong; Wang, Lei; Xu, Ruimin; Cheng, Wei; Wang, Yuan; Lu, Haiyan

    2017-01-01

    This paper presents a small-signal model for InGaAs/InP double heterojunction bipolar transistor (DHBT). Parasitic parameters of access via and electrode finger are extracted by 3-D electromagnetic (EM) simulation. By analyzing the equivalent circuit of seven special structures and using the EM simulation results, the parasitic parameters are extracted systematically. Compared with multi-port s-parameter EM model, the equivalent circuit model has clear physical intension and avoids the complex internal ports setting. The model is validated on a 0.5 × 7 μm2 InP DHBT up to 325 GHz. The model provides a good fitting result between measured and simulated multi-bias s-parameters in full band. At last, an H-band amplifier is designed and fabricated for further verification. The measured amplifier performance is highly agreed with the model prediction, which indicates the model has good accuracy in submillimeterwave band.

  7. International Space Station Modal Correction Analysis

    NASA Technical Reports Server (NTRS)

    Fotz[atrocl. Lrostom; Grugoer. < ocjae; Laible, Michael; Sugavanam, Sujatha

    2012-01-01

    This paper summarizes the on-orbit modal test and the related modal analysis, model validation and correlation performed for the ISS Stage ULF4, DTF S4-1A, October 11,2010, GMT 284/06:13:00.00. The objective of this analysis is to validate and correlate analytical models with the intent to verify the ISS critical interface dynamic loads and improve fatigue life prediction. For the ISS configurations under consideration, on-orbit dynamic responses were collected with Russian vehicles attached and without the Orbiter attached to the ISS. ISS instrumentation systems that were used to collect the dynamic responses during the DTF S4-1A included the Internal Wireless Instrumentation System (IWIS), External Wireless Instrumentation System (EWIS), Structural Dynamic Measurement System (SDMS), Space Acceleration Measurement System (SAMS), Inertial Measurement Unit (IMU) and ISS External Cameras. Experimental modal analyses were performed on the measured data to extract modal parameters including frequency, damping and mode shape information. Correlation and comparisons between test and analytical modal parameters were performed to assess the accuracy of models for the ISS configuration under consideration. Based on the frequency comparisons, the accuracy of the mathematical models is assessed and model refinement recommendations are given. Section 2.0 of this report presents the math model used in the analysis. This section also describes the ISS configuration under consideration and summarizes the associated primary modes of interest along with the fundamental appendage modes. Section 3.0 discusses the details of the ISS Stage ULF4 DTF S4-1A test. Section 4.0 discusses the on-orbit instrumentation systems that were used in the collection of the data analyzed in this paper. The modal analysis approach and results used in the analysis of the collected data are summarized in Section 5.0. The model correlation and validation effort is reported in Section 6.0. Conclusions and

  8. Theoretical uncertainties in extracting cosmic-ray diffusion parameters: the boron-to-carbon ratio

    NASA Astrophysics Data System (ADS)

    Genolini, Y.; Putze, A.; Salati, P.; Serpico, P. D.

    2015-08-01

    distribution marginally alters the central value of the diffusion coefficient normalisation (at the 10%, 1σ level). However, the index of the diffusion coefficient δ is basically unaltered, as well as the goodness of fit. Conclusions: Our study suggests that, differently for instance from the leptonic case, realistic modelling of the geometry of the Galaxy and of the source distribution are of minor importance to correctly reproduce B/C data at high energies and thus, to a large extent, for the extraction of diffusion parameters. The ansatz on the lack of primary injection of boron represents the most serious bias and requires multi-messenger studies to be addressed. If this uncertainty could be lifted, nuclear uncertainties would still represent a serious concern; they degrade the systematic error on the inferred parameters to the 20% level, or three times the estimated experimental sensitivity. To reduce this, a new nuclear cross-section measurement campaign might be required.

  9. Modal characterization of the ASCIE segmented optics testbed: New algorithms and experimental results

    NASA Technical Reports Server (NTRS)

    Carrier, Alain C.; Aubrun, Jean-Noel

    1993-01-01

    New frequency response measurement procedures, on-line modal tuning techniques, and off-line modal identification algorithms are developed and applied to the modal identification of the Advanced Structures/Controls Integrated Experiment (ASCIE), a generic segmented optics telescope test-bed representative of future complex space structures. The frequency response measurement procedure uses all the actuators simultaneously to excite the structure and all the sensors to measure the structural response so that all the transfer functions are measured simultaneously. Structural responses to sinusoidal excitations are measured and analyzed to calculate spectral responses. The spectral responses in turn are analyzed as the spectral data become available and, which is new, the results are used to maintain high quality measurements. Data acquisition, processing, and checking procedures are fully automated. As the acquisition of the frequency response progresses, an on-line algorithm keeps track of the actuator force distribution that maximizes the structural response to automatically tune to a structural mode when approaching a resonant frequency. This tuning is insensitive to delays, ill-conditioning, and nonproportional damping. Experimental results show that is useful for modal surveys even in high modal density regions. For thorough modeling, a constructive procedure is proposed to identify the dynamics of a complex system from its frequency response with the minimization of a least-squares cost function as a desirable objective. This procedure relies on off-line modal separation algorithms to extract modal information and on least-squares parameter subset optimization to combine the modal results and globally fit the modal parameters to the measured data. The modal separation algorithms resolved modal density of 5 modes/Hz in the ASCIE experiment. They promise to be useful in many challenging applications.

  10. Direct extraction of the isovector deformation parameter β(1)2 from the (p, n) reaction of 56Fe

    NASA Astrophysics Data System (ADS)

    Orihara, H.; Murakami, T.; Nishihara, S.; Nakagawa, T.; Maeda, K.; Miura, K.; Ohnuma, H.

    1981-11-01

    The reaction 56Fe(p, n) 56Co leading to the analog of the ground state and the first excited 2 + state of 56Fe has been studied at Ep=20, 28, 32 and35MeV. The direct process dominates at higher energies, thus the direct extraction of the isovector deformation parameter β(1)2 is feasible. It is found that β(1)2 is about three times larger than β(0)2, the isoscalar deformation parameter.

  11. Dynamic modal estimation using instrumental variables

    NASA Technical Reports Server (NTRS)

    Salzwedel, H.

    1980-01-01

    A method to determine the modes of dynamical systems is described. The inputs and outputs of a system are Fourier transformed and averaged to reduce the error level. An instrumental variable method that estimates modal parameters from multiple correlations between responses of single input, multiple output systems is applied to estimate aircraft, spacecraft, and off-shore platform modal parameters.

  12. Comparative analyses of universal extraction buffers for assay of stress related biochemical and physiological parameters.

    PubMed

    Han, Chunyu; Chan, Zhulong; Yang, Fan

    2015-01-01

    Comparative efficiency of three extraction solutions, including the universal sodium phosphate buffer (USPB), the Tris-HCl buffer (UTHB), and the specific buffers, were compared for assays of soluble protein, free proline, superoxide radical (O2∙-), hydrogen peroxide (H2O2), and the antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (POD), ascorbate peroxidase (APX), glutathione peroxidase (GPX), and glutathione reductase (GR) in Populus deltoide. Significant differences for protein extraction were detected via sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and two-dimensional electrophoresis (2-DE). Between the two universal extraction buffers, the USPB showed higher efficiency for extraction of soluble protein, CAT, GR, O2∙-, GPX, SOD, and free proline, while the UTHB had higher efficiency for extraction of APX, POD, and H2O2. When compared with the specific buffers, the USPB showed higher extraction efficiency for measurement of soluble protein, CAT, GR, and O2∙-, parallel extraction efficiency for GPX, SOD, free proline, and H2O2, and lower extraction efficiency for APX and POD, whereas the UTHB had higher extraction efficiency for measurement of POD and H2O2. Further comparisons proved that 100 mM USPB buffer showed the highest extraction efficiencies. These results indicated that USPB would be suitable and efficient for extraction of soluble protein, CAT, GR, GPX, SOD, H2O2, O2∙-, and free proline.

  13. A Novel Validation Algorithm Allows for Automated Cell Tracking and the Extraction of Biologically Meaningful Parameters

    PubMed Central

    Madany Mamlouk, Amir; Schicktanz, Simone; Kruse, Charli

    2011-01-01

    Automated microscopy is currently the only method to non-invasively and label-free observe complex multi-cellular processes, such as cell migration, cell cycle, and cell differentiation. Extracting biological information from a time-series of micrographs requires each cell to be recognized and followed through sequential microscopic snapshots. Although recent attempts to automatize this process resulted in ever improving cell detection rates, manual identification of identical cells is still the most reliable technique. However, its tedious and subjective nature prevented tracking from becoming a standardized tool for the investigation of cell cultures. Here, we present a novel method to accomplish automated cell tracking with a reliability comparable to manual tracking. Previously, automated cell tracking could not rival the reliability of manual tracking because, in contrast to the human way of solving this task, none of the algorithms had an independent quality control mechanism; they missed validation. Thus, instead of trying to improve the cell detection or tracking rates, we proceeded from the idea to automatically inspect the tracking results and accept only those of high trustworthiness, while rejecting all other results. This validation algorithm works independently of the quality of cell detection and tracking through a systematic search for tracking errors. It is based only on very general assumptions about the spatiotemporal contiguity of cell paths. While traditional tracking often aims to yield genealogic information about single cells, the natural outcome of a validated cell tracking algorithm turns out to be a set of complete, but often unconnected cell paths, i.e. records of cells from mitosis to mitosis. This is a consequence of the fact that the validation algorithm takes complete paths as the unit of rejection/acceptance. The resulting set of complete paths can be used to automatically extract important biological parameters with high

  14. [Modalities of mechanical ventilation].

    PubMed

    Subirana, M; Bazan, P

    2000-01-01

    Mechanical ventilation improves the symptoms and reduces complications of acute respiratory failure. Recent advances in microprocessor technology have increased the sophistication of mechanical ventilators, thus leading to new ventilation modalities. This article describes the ventilation modalities available, grouping them as conventional, alternative and new modalities. Conventional ventilation includes the most widely used modalities, alternative ventilation includes less frequently used modalities, and new ventilation modalities include recently introduced options that are available on the latest-generation mechanical ventilators.

  15. Comparison of clinical parameters and environmental noise levels between regular surgery and piezosurgery for extraction of impacted third molars.

    PubMed

    Chang, Hao-Hueng; Lee, Ming-Shu; Hsu, You-Chyun; Tsai, Shang-Jye; Lin, Chun-Pin

    2015-10-01

    Impacted third molars can be extracted by regular surgery or piezosurgery. The aim of this study was to compare clinical parameters and device-produced noise levels between regular surgery and piezosurgery for the extraction of impacted third molars. Twenty patients (18 women and 2 men, 17-29 years of age) with bilateral symmetrical impacted mandibular or maxillary third molars of the same level were included in this randomized crossover clinical trial. The 40 impacted third molars were divided into a control group (n = 20), in which the third molar was extracted by regular surgery using a high-speed handpiece and an elevator, and an experimental group (n = 20), in which the third molar was extracted by piezosurgery using a high-speed handpiece and a piezotome. The clinical parameters were evaluated by a self-reported questionnaire. The noise levels produced by the high-speed handpiece and piezotome were measured and compared between the experimental and control groups. Patients in the experimental group had a better feeling about tooth extraction and force delivery during extraction and less facial swelling than patients in the control group. However, there were no significant differences in noise-related disturbance, extraction period, degree of facial swelling, pain score, pain duration, any noise levels produced by the devices under different circumstances during tooth extraction between the control and experimental groups. The piezosurgery device produced noise levels similar to or lower than those of the high-speed drilling device. However, piezosurgery provides advantages of increased patient comfort during extraction of impacted third molars. Copyright © 2014. Published by Elsevier B.V.

  16. Multishaker modal testing

    NASA Technical Reports Server (NTRS)

    Craig, R. R., Jr.

    1985-01-01

    A component mode synthesis method for damped structures was developed and modal test methods were explored which could be employed to determine the relevant parameters required by the component mode synthesis method. Research was conducted on the following topics: (1) Development of a generalized time-domain component mode synthesis technique for damped systems; (2) Development of a frequency-domain component mode synthesis method for damped systems; and (3) Development of a system identification algorithm applicable to general damped systems. Abstracts are presented of the major publications which have been previously issued on these topics.

  17. Letter-Matrix of Compact Representation of two-Dimensional Data Multitude for Visualization of Modal Parameters' Time-History With Implication to Seismic Survey of Life-Time and Characteristics of Excited Modal States of a Wide Range of Dynamic Structures

    NASA Astrophysics Data System (ADS)

    Zaurov, D.

    2013-12-01

    The PSWT technique assumes definition of modal parameters on the basis of modal differential equation by processing of a segment of seismic response with stationary properties by a set of modulate functions. Thus, calculating necessary convolution integrals in the limits of the time-window with a modulate function and its claimed derivatives fixed within the window with zero values on its edges and having a limited transparent spectral window, a system of algebraic equation regard to looking for parameters can be formed. Leading correct conception of moving window analysis, total parametric scanning of the records in both time and frequency domains when the time-window should be moving by a certain step while varying its width in some boundaries that corresponds to shifting the spectral window in frequency domain allowing to find dominant filtration of the fundamental mode, should be proceeded. Revealed time segments with steady series of parameters' estimations are evidence of stationary of the modal state and that trial estimations are true, otherwise, non-stationary of dynamic properties and, or ill-filtration on some segments are the cause of the series of estimations to be dispersed. Final numeric output of the scanning require a vast storage paper space and it is time consuming of its graphic representation and interpretation. But the following idea allows the representation to be a completely formalized one. Thus, the numeric multitude of estimations should be grouping for each parameter and represented by corresponding compact symbolic, letter fields. Symbolic conform representation can be accomplished by assuming a quantum symbolic scale limited by accepted set of 53 symbols: +ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!?#$%&@(/{<|>})*- which is coherent to appropriate domain of continuous numeric measure scale of each parameter estimations' multitude. A certain step is admitted for quantization, and a respective symbol is assigned in sequence to each quantum

  18. Ultra-Low Noise HEMT Device Models: Application of On-Wafer Cryogenic Noise Analysis and Improved Parameter Extraction Techniques

    NASA Technical Reports Server (NTRS)

    Bautista, J. J.; Hamai, M.; Nishimoto, M.; Laskar, J.; Szydlik, P.; Lai, R.

    1995-01-01

    Significant advances in the development of HEMT technology have resulted in high performance cryogenic low noise amplifiers whose noise temperatures are within an order of magnitude of the quantum noise limit. Key to the identification of optimum HEMT structures at cryogenic temperatures is the development of on-wafer noise and device parameter extraction techniques. Techniques and results are described.

  19. Development of Measurement and Extraction Technique of Complex Permittivity Using Transmission Parameter S 21 for Millimeter Wave Frequencies

    NASA Astrophysics Data System (ADS)

    Ozturk, Turgut; Hudlička, Martin; Uluer, İhsan

    2017-07-01

    This study provides an overview of measured S-parameters and its processing to extract the dielectric properties of materials such as Teflon, PMMA, and PVC which are preferred for materials characterization process. In addition, a correction model is presented for transmission parameter (S 21) to obtain the dielectric constant with high accuracy. A non-destructive and non-contact free space measurement method has been used to measure S-parameters of thin samples in the low THz frequency range. S-parameters are measured in free space by vector network analyzer supported with two frequency extenders. Additionally, the parabolic mirrors are used to collimate the generated beam in wide frequency range. Furthermore, a standard filter process is performed to remove the undesired ripples in signal using singular spectrum analyzer before the implementation of extraction process. Newton-Raphson extraction technique is used to extract the material complex permittivity as a function of the frequency in Y-band (325-500 GHz).

  20. Modal Analysis and Model Correlation of the Mir Space Station

    NASA Technical Reports Server (NTRS)

    Kim, Hyoung M.; Kaouk, Mohamed

    2000-01-01

    This paper will discuss on-orbit dynamic tests, modal analysis, and model refinement studies performed as part of the Mir Structural Dynamics Experiment (MiSDE). Mir is the Russian permanently manned Space Station whose construction first started in 1986. The MiSDE was sponsored by the NASA International Space Station (ISS) Phase 1 Office and was part of the Shuttle-Mir Risk Mitigation Experiment (RME). One of the main objectives for MiSDE is to demonstrate the feasibility of performing on-orbit modal testing on large space structures to extract modal parameters that will be used to correlate mathematical models. The experiment was performed over a one-year span on the Mir-alone and Mir with a Shuttle docked. A total of 45 test sessions were performed including: Shuttle and Mir thruster firings, Shuttle-Mir and Progress-Mir dockings, crew exercise and pushoffs, and ambient noise during night-to-day and day-to-night orbital transitions. Test data were recorded with a variety of existing and new instrumentation systems that included: the MiSDE Mir Auxiliary Sensor Unit (MASU), the Space Acceleration Measurement System (SAMS), the Russian Mir Structural Dynamic Measurement System (SDMS), the Mir and Shuttle Inertial Measurement Units (IMUs), and the Shuttle payload bay video cameras. Modal analysis was performed on the collected test data to extract modal parameters, i.e. frequencies, damping factors, and mode shapes. A special time-domain modal identification procedure was used on free-decay structural responses. The results from this study show that modal testing and analysis of large space structures is feasible within operational constraints. Model refinements were performed on both the Mir alone and the Shuttle-Mir mated configurations. The design sensitivity approach was used for refinement, which adjusts structural properties in order to match analytical and test modal parameters. To verify the refinement results, the analytical responses calculated using

  1. Effect of aqueous leaves extract of Ocimum gratissimum on hematological parameters in rats

    PubMed Central

    Ofem, OE; Ani, EJ; Eno, AE

    2012-01-01

    Objective: This study aims to elucidate the effect of Ocimum gratissimum on hematological parameters in rats. Materials and Methods: Thirty male albino Wistar rats were randomly assigned into three groups of ten rats each. Group 1 was control, while groups 2 (LD) and 3 (HD) received 500 mg/kg and 1000 mg/kg body weight, respectively, of the extract orally once daily. Rats in all three groups received normal rat chow and drinking water ad libitum for 28 days. Complete blood count was done using an automatic counter. Results: The HD group had significantly (P<.05) higher red blood cell (RBC) counts, packed cell volume (PCV), hemoglobin (Hb), and platelet counts as compared with the control and LD groups. No significant changes were observed in the total white blood cell (WBC) count of the three groups, but significantly (P<.05) lower lymphocyte and higher neutrophil counts were observed in the HD group compared with the LD group. The mean platelet volume (MPV), platelet–large cell ratio (P–LCR), and platelet distribution width (PDW) were significantly (P<.05) reduced in the HD compared with the LD group. The mean corpuscular volume (MCV) and RBC distribution width–standard deviation were significantly (P<.05) lower in the HD group than in control. No significant changes were observed in levels of mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and RBC distribution width–coefficient of variation among the groups. Conclusion: We conclude that oral administration of O gratissimum increases RBC, PCV, Hb, platelet count, and neutrophils and also leads to a decrease in platelet indices (i.e., MPV, P–LCR, and PDW). PMID:23776807

  2. Citrus peel polymethoxylated flavones extract modulates liver and heart function parameters in diet induced hypercholesterolemic rats.

    PubMed

    Green, Curtis O; Wheatley, Andrew O; McGrowder, Donovan A; Dilworth, Lowell L; Asemota, Helen N

    2013-01-01

    The primary aim of this study was to investigate the effects of Ortanique peel polymethoxylated flavones extract (PMF(ort)) on organ function parameters in the serum of hypercholesterolemic and normal rats. Thirty Sprague-Dawley rats were fed high cholesterol diets supplemented with 1.5% PMF(ort) and niacin respectively for 49days. Hypercholesterolemic rats fed PMF(ort) had significant reductions in the activities of aspartate aminotransferase and alkaline phosphatase (69.12±3.34 and 87.22±8.42U/L respectively) compared to the untreated hypercholesterolemic group (118.61±4.85 and 132.62±10.62U/L respectively, p<0.05). Supplementation of the diet with niacin or PMF(ort) resulted in no significant differences in the serum levels of creatinine or urea in any of the groups. Total bilirubin was highest in the untreated hypercholesterolemic group. Supplementation of the diets of hypercholesterolemic rats with PMF(ort) resulted in significant reductions in the activities of serum creatine kinase and lactate dehydrogenase (119.3±25.3; 222.5±50.3U/L, p<0.05) respectively relative to the untreated hypercholesterolemic group (257.2±48.3; 648.8±103U/L, p<0.05). The results would suggest that PMF(ort) modulates hypercholesterolemia-associated organ injury in rats. PMF(ort) could therefore be a suitable candidate for prophylactic and therapeutic treatment of hypercholesterolemia-associated organ injury. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Extracting Physical Parameters for the First Galaxies from the Cosmic Dawn Global 21-cm Spectrum

    NASA Astrophysics Data System (ADS)

    Burns, Jack O.; Mirocha, Jordan; harker, geraint; Tauscher, Keith; Datta, Abhirup

    2016-01-01

    The all-sky or global redshifted 21-cm HI signal is a potentially powerful probe of the first luminous objects and their environs during the transition from the Dark Ages to Cosmic Dawn (35 > z > 6). The first stars, black holes, and galaxies heat and ionize the surrounding intergalactic medium, composed mainly of neutral hydrogen, so the hyperfine 21-cm transition can be used to indirectly study these early radiation sources. The properties of these objects can be examined via the broad absorption and emission features that are expected in the spectrum. The Dark Ages Radio Explorer (DARE) is proposed to conduct these observations at low radio astronomy frequencies, 40-120 MHz, in a 125 km orbit about the Moon. The Moon occults both the Earth and the Sun as DARE makes observations above the lunar farside, thus eliminating the corrupting effects from Earth's ionosphere, radio frequency interference, and solar nanoflares. The signal is extracted from the galactic/extragalactic foreground employing Bayesian methods, including Markov Chain Monte Carlo (MCMC) techniques. Theory indicates that the 21-cm signal is well described by a model in which the evolution of various physical quantities follows a hyperbolic tangent (tanh) function of redshift. We show that this approach accurately captures degeneracies and covariances between parameters, including those related to the signal, foreground, and the instrument. Furthermore, we also demonstrate that MCMC fits will set meaningful constraints on the Ly-α, ionizing, and X-ray backgrounds along with the minimum virial temperature of the first star-forming halos.

  4. Ulmus davidiana extract improves lumbar vertebral parameters in ovariectomized osteopenic rats

    PubMed Central

    Zhuang, Xinming; Fu, Changfeng; Liu, Wanguo; Wang, Yuanyi; Xu, Feng; Zhang, Qi; Liu, Yadong; Liu, Yi

    2016-01-01

    The aim of this study was to determine the skeletal effect of total ethanolic extract from the stem-bark of Ulmus davidiana (UDE) in a rat model of postmenopausal bone loss. Effective dose of UDE was determined in adult female Sprague-Dawley (SD) rats by measuring bone regeneration at fracture site. UDE (250 mg/kg p.o.) was administered to ovariectomized (OVX) osteopenic SD rats for 12 weeks. OVX rats treated with vehicle or 17β-estradiol, and sham-operated rats treated with vehicle served as various controls. Bone mineral density (BMD), microarchitecture, biomechanical strength, turnover markers, and uterotrophic effect were studied. Bioactive markers in UDE were analyzed by HPLC. Human osteoblasts was used to study the effect of compounds on differentiation by alkaline phosphase assay. One-way ANOVA was used to test significance of effects. OVX+UDE group showed BMD, microarchitectural parameters and compressive strength at lumbar vertebra (L5) comparable to sham. At proximal femur, OVX+UDE group exhibited significantly higher BMD, better microarchitecture and compressive strength compared with OVX+vehicle. OVX-induced decrease in Ca/P ratio was completely restored at both skeletal sites by UDE treatment. Serum procollagen N-terminal propeptide and carboxy-terminal collagen crosslinks were respectively higher and lower in OVX+UDE group compared with OVX+vehicle group. Osteogenic genes were upregulated in L5 and anti-resorptive genes were suppressed in proximal femur of OVX+UDE group compared with OVX+vehicle. UDE had no uterine estrogenicity. Analysis of markers yielded two osteogenic isoforms of catechin. In conclusion, UDE completely restored vertebral trabecular bones and strength in osteopenic rats by an osteogenic mechanism and prevented bone loss at proximal femur. PMID:27158327

  5. Optimization of parameters for the supercritical fluid extraction in the determination of N-nitrosamines in rubbers.

    PubMed

    Rech, F; Garrigós, M C; Marín, M L; Cantó, A; Jiménez, A

    2002-07-19

    The study of the possibilities of supercritical fluid extraction (SFE) with N-nitrosamines in rubbers has been carried out. Home-made materials fortified with several N-nitrosamines were prepared in order to optimize the SFE parameters. A Plackett-Burman design was employed to evaluate the influence of those parameters to be controlled in SFE, such as pressure, temperature, static and dynamic time, restrictor temperature and volume of modifier while CO2 was used as the extraction fluid. An extra central composite design for the main factors (according to the previously obtained results) was also developed in order to refine the best supercritical conditions for the extraction of N-nitrosamines from rubbers. Gas chromatography with a nitrogen and phosphorus sensitive detector was used to achieve sensitivity and limits of detection for the concentrations expected in plastic materials. The proposed analytical method has shown to be useful in the determination of N-nitrosamines even for complex matrices.

  6. Influence of an aqueous extract of Ligustrum lucidum and an ethanol extract of Schisandra chinensis on parameters of antioxidative metabolism and spleen lymphocyte proliferation of broilers.

    PubMed

    Ma, Deying; Shan, Anshan; Li, Jianping; Zhao, Yun; Guo, Xiaoqiu

    2009-02-01

    The study was conducted to evaluate the effects of dietary supplementation with different levels of two extracts, an aqueous extract of Ligustrum lucidum (AELL), and an ethanol extract of Schisandra chinensis (EESC) on growth performance, parameters of antioxidative status and spleen lymphocyte proliferation of broilers, respectively. The results showed that neither AELL nor EESC had significant effects on growth performance of broilers. However, malondialdehyde concentration in heart and liver of the broilers were significantly decreased by feeding AELL or EESC. Superoxide dismutase activity in heart, liver, and kidney of broilers were improved by feeding different dosages of AELL or EESC. In contrast, glutathione reductase activity in serum, heart and kidney of broilers was not affected by experimental treatment. In addition, spleen lymphocyte proliferation of broilers was significantly enhanced by feeding different dosages of AELL or EESC. In conclusion, the results suggested that either AELL or EESC may improve antioxidant status and immune function of broilers.

  7. Evaluation of different parameters in the extraction of incurred pesticides and environmental contaminants in fish.

    PubMed

    Sapozhnikova, Yelena; Lehotay, Steven J

    2015-06-03

    Sample processing is often ignored during analytical method development and validation, but accurate results for real samples depend on all aspects of the analytical process. Also, validation is often conducted using only spiked samples, but extraction yields may be lower in incurred samples. In this study, different variables in extraction for incurred pesticides and environmental contaminants in fish were investigated. Among 207 analytes screened using low-pressure gas chromatography-tandem mass spectrometry, consisting of 150 pesticides, 15 polycyclic aromatic hydrocarbons (PAHs), 14 polychlorinated biphenyls (PCBs), 6 polybrominated diphenyl ethers (PBDEs), and 22 other flame retardants (FRs), 35 (16 pesticides, 9 PCBs, 5 PBDEs, and 5 PAHs) were identified for quantification in samples of salmon, croaker, and NIST Standard Reference Material 1947 (Lake Michigan Fish Tissue). Extraction efficiencies using different extraction devices (blending, vortexing, and vibrating) versus time, sample size, and sample/solvent ratio were determined. In comparison to blending results, use of a pulsed-vortexer for 1 min with 1/1 (g/mL) sample/acetonitrile ratio was generally sufficient to extract the incurred contaminants in the homogenized fish tissues. Conversely, extraction with a prototype vibration shaker often took 60 min to achieve 100% extraction efficiency. A main conclusion from this study is that accurate results for real samples can be obtained using batch extraction with a pulsed-vortexer in a simple and efficient method that achieves high sample throughput.

  8. Bidentate organophosphorus compound management of actinide and lanthanide extraction by changing structure and diluent parameter

    SciTech Connect

    Rozen, A.M.; Volk, V.I.; Zakharkin, B.S.; Nikolotova, Z.I.; Kartasheva, N.A.; Bochvar, A.A.

    1995-12-31

    Extraction of actinides and lanthanides by bidentate organophosphorus compounds (diphosphine dioxides and carbamoylphosphine oxides) can be managed by varying the polarity of diluent DP* in the range of 2--5 and by introducing aryl groups (tolyl) into an extractant molecule which results in improved extraction ability due to bidentate coordination and effect of the anomalous aryl strengthening (AAS) of the complexes. Disappearance of AAS effect upon carbamoylphosphine oxide extraction at the lower polarity of diluent (not observed toy diphosphine dioxides) is explained by an increase of the solvate number to three and transfer from bidentate coordination to monodentate one. Due to AAS effect the above mentioned extractants can be used for deep purification of waste to remove actinides without any preliminary conditioning of solutions.

  9. Relationship between wood color parameters measured by the CIELab system and extractive and phenol content in Acacia mangium and Vochysia guatemalensis from fast-growth plantations.

    PubMed

    Moya, Róger; Soto Fallas, Roy; Jiménez Bonilla, Pablo; Tenorio, Carolina

    2012-03-26

    The heterogeneity of color distribution between sapwood and heartwood limits the market for wood from fast-growth plantations of tropical species. Wood color is associated with wood extractives contents. This study presents the relationship between wood color parameters measured by the CIELab color system and total amount of extractives and phenolic-type extractives in ethanol-toluene and hot water extracts of wood from two fast-growth plantation species. The results demonstrated that the difference in sapwood and hardwood color in Vochysia guatemalensis and Acacia mangium is caused by lower concentrations of extractives in sapwood of both species. Additionally, variations in total extractive and phenolic content have different effects on the color parameters (L*, a* and b*) of both species studied. In Vochysia guatemalensis wood, parameter L* decreases as total extractive and phenolic content increases; however, parameter a* increases as the content of extractives and phenols increases. In Acacia mangium, the amount of phenols showed no relationship with the color parameters. The ethanol-toluene total extractive content, however, shows a relationship with several color parameters. An increase in the content of total extractives in water and ethanol-toluene increases parameter a*, but decreases parameter L*.

  10. Optimization of process parameters for supercritical fluid extraction of cholesterol from whole milk powder using ethanol as co-solvent.

    PubMed

    Dey Paul, Indira; Jayakumar, Chitra; Niwas Mishra, Hari

    2016-12-01

    In spite of being highly nutritious, the consumption of milk is hindered because of its high cholesterol content, which is responsible for numerous cardiac diseases. Supercritical carbon dioxide using ethanol as co-solvent was employed to extract cholesterol from whole milk powder (WMP). This study was undertaken to optimize the process parameters of supercritical fluid extraction (SCFE), viz. extraction temperature, pressure and volume of ethanol. The cholesterol content of WMP was quantified using high-performance liquid chromatography. The impact of the extraction conditions on the fat content (FC), solubility index (SI) and lightness (L*) of the SCFE-treated WMP were also investigated. The process parameters were optimized using response surface methodology. About 46% reduction in cholesterol was achieved at the optimized conditions of 48 °C, 17 MPa and 31 mL co-solvent; flow rate of expanded CO2 , static time and dynamic time of extraction were 6 L min(-1) , 10 min and 80 min respectively. The treated WMP retained its FC, SI, and L* at moderate limits of 183.67 g kg(-1) , 96.3% and 96.90, respectively. This study demonstrated the feasibility of ethanol-modified SCFE of cholesterol from WMP with negligible changes in its physicochemical properties. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  11. The effect of hydroalcoholic extract of P. crispum on sperm parameters, testis tissue and serum nitric oxide levels in mice

    PubMed Central

    Jalili, Cyrus; Salahshoor, Mohammad Reza; Naderi, Tahere

    2015-01-01

    Background: Sperm dysfunction is one of the main causes of male infertility. Petroselinum crispum (P. crispum) is a member of umbelliferae family that contains different vitamins and minerals and has numerous therapeutic properties. The aim of this study was to evaluate P. crispum effect on sperm parameters, testis tissue and serum nitric oxid levels in mice. Materials and Methods: Hydroalcoholic extract of P. crispum was prepared and administered intraperitoneally (0,100, 150 and 200 mg/kg) to 40 mice, which were divided into four groups (n = 10), one control group and three experimental groups, for 14 consequent days. The sperm parameter such as motility, sperm count, morphology, and seminiferous tubules diameter, and weight of prostate and testis, and serum nitric oxide levels were analyzed. Results: P. crispum administration (100, 150 and 200 mg/kg) significantly increased mean percentage of sperm motility, testis and prostate weight and serum nitric oxide compared to the control group (P < 0.05). However, no significant effect was reported for different doses of P. crispum extract on sperm parameters. Conclusion: Administrating hydroalcoholic extract of P. crispum has positive effects on some reproductive parameters. PMID:25789266

  12. Effect of various experimental parameters on the swelling and supercritical extraction properties of lignite

    SciTech Connect

    Hacimehmetoglu, S.; Sinag, A.; Tekes, A.T.; Misirlioglu, Z.; Canel, M.

    2007-07-01

    The original lignite sample, the samples swollen in dimethylsulfoxide (DMSO), dimethylformamide (DMF), pyridine, tetrahydrofuran (THF), acetone, ethylenediamine (EDA), N-methyl-2-pyrrolidone (NMP), tetrabutylammonium hydroxide (TBAH), the samples impregnated by ZnCl{sub 2} as catalyst and the samples both swollen in the solvents and impregnated by ZnCl{sub 2} were subjected to the supercritical toluene extraction and the effects of temperature, pressure, pre-swelling procedure, hydrogen donor solvent (tetralin), and catalyst on the extract yields were investigated.

  13. Toxicity of anthraquinones: differential effects of rumex seed extracts on rat organ weights and biochemical and haematological parameters.

    PubMed

    Islam, Rabigul; Mamat, Yultuz; Ismayil, Ilyar; Yan, Ming; Kadir, Mahsutjan; Abdugheny, Abdujilil; Rapkat, Haximjan; Niyaz, Mardan; Ali, Yusupjan; Abay, Sirapil

    2015-05-01

    The genus Rumex and related species such as Rheum and Polygonum are widely used as medicinal herbs and foods. They contain anthraquinones (AQ) such as emodin and chrysophanol as active ingredients, and there is concern about the toxicity of these compounds. This study evaluated the chronic effects of Rumex patientia seed aqueous and ethanolic extracts, in male and female rats separately, on organ weights and over 30 haematological, biochemical and histological parameters, immediately after 14-week administration and after a further period of 15 days without drug treatment. Adverse changes were associated with long-term AQ administration, and these focussed on the liver, lung and kidney, but after 15-day convalescence, most had reverted to normal. In general, male rats appeared to be more susceptible than female rats at similar doses. The water extract produced no irreversible changes, which may reflect the lower dose of the AQ constituents or the presence of different ancillary compounds, and supports the traditional method of extracting Rumex seeds with water. In conclusion, ethanolic extracts of R. patientia caused irreversible pathological changes at very high doses (4000mg/kg), but lower doses and aqueous extracts produced either non-significant or reversible changes. Long-term administration of high doses of AQ extracts over a long period of time should be avoided until further assurances can be given, and given other existing reports of reproductive toxicity, should be avoided altogether during pregnancy.

  14. Total soluble solids from banana: evaluation and optimization of extraction parameters.

    PubMed

    Carvalho, Giovani B M; Silva, Daniel P; Santos, Júlio C; Izário Filho, Hélcio J; Vicente, António A; Teixeira, José A; Felipe, Maria das Graças A; Almeida e Silva, João B

    2009-05-01

    Banana, an important component in the diet of the global population, is one of the most consumed fruits in the world. This fruit is also very favorable to industry processes (e.g., fermented beverages) due to its rich content on soluble solids and minerals, with low acidity. The main objective of this work was to evaluate the influence of factors such as banana weight and extraction time during a hot aqueous extraction process on the total soluble solids content of banana. The extract is to be used by the food and beverage industries. The experiments were performed with 105 mL of water, considering the moisture of the ripe banana (65%). Total sugar concentrations were obtained in a beer analyzer and the result expressed in degrees Plato (degrees P, which is the weight of the extract or the sugar equivalent in 100 g solution at 20 degrees C), aiming at facilitating the use of these results by the beverage industries. After previous studies of characterization of the fruit and of ripening performance, a 2(2) full-factorial star design was carried out, and a model was developed to describe the behavior of the dependent variable (total soluble solids) as a function of the factors (banana weight and extraction time), indicating as optimum conditions for extraction 38.5 g of banana at 39.7 min.

  15. A Model Parameter Extraction Method for Dielectric Barrier Discharge Ozone Chamber using Differential Evolution

    NASA Astrophysics Data System (ADS)

    Amjad, M.; Salam, Z.; Ishaque, K.

    2014-04-01

    In order to design an efficient resonant power supply for ozone gas generator, it is necessary to accurately determine the parameters of the ozone chamber. In the conventional method, the information from Lissajous plot is used to estimate the values of these parameters. However, the experimental setup for this purpose can only predict the parameters at one operating frequency and there is no guarantee that it results in the highest ozone gas yield. This paper proposes a new approach to determine the parameters using a search and optimization technique known as Differential Evolution (DE). The desired objective function of DE is set at the resonance condition and the chamber parameter values can be searched regardless of experimental constraints. The chamber parameters obtained from the DE technique are validated by experiment.

  16. Effect of Methanolic Leaf Extract of Talinum triangulare (Jacq). Willd. on Biochemical Parameters in Diet induced Dyslipidemia Wistar Rats

    PubMed Central

    Olorunnisola, Olubukola Sinbad; Adetutu, Adewale; Afolayan, Anthony Jide; Owoade, Abiodun Olusoji

    2016-01-01

    Objective: To investigate the effect of methanolic leaf extract of Talinum triangulare on hematological parameters, enzymatic and non-enzymatic antioxidant status, and serum lipid in Wistar rats fed standard laboratory, or 2% cholesterol-enrich diet. Material and Methods: Wistar rats (180-210g) divided into six groups of six animals (males) each were fed 2% cholesterol-enriched diet and orally treated with 0.9% saline or extract of Talinum triangulare (250, 500, and 1000 mg/kg per body weight) daily for eight weeks. Lipid profile, lipid peroxidation (MDA), hematological parameters, and their functional indices and serum antioxidant enzymes (catalase, glutathione -S-transferase, and superoxide dismutase) activities and glutathione status were assessed in normal and diet-induced hypercholesterolemic extract treated rats and compared with the rats treated with 100 mg/kg per bwt standard drug gemfibrozil. Results: A significant (P < 0.05) increase in lipid profile (total glyceride, total cholestrol, low-density lipoprotein, and very low-density lipoprotein), MDA and reduction (P < 0.05) in enzymatic and nonenzymatic antioxidant status coupled with alterations in hematological parameters was observed in the serum of hypercholesterolemic rats when compared with animals on a normal diet. Coadministration of methanolic leaf extracts of Talinum triangulare or gemfibrozil significantly (P < 0.05) restored the elevated serum lipid profile, MDA, and the deranged hematological parameters to near normal. The extract also protected against hypercholesterolemic-induced diminished enzymatic and nonenzymatic antioxidant status. The activities of the plant extract are dose (250, 500, and 1000 mg/kg) dependent and it compared favorably with the standard drug gemfibrozil. Conclusion: The present study suggested that the extract of Talinum triangulare might protect against hypercholesterolemic-induced altered lipid profiles, oxidative stress, and also improve the status of antioxidant

  17. Vector-algebra approach to extract Denavit-Hartenberg parameters of assembled robot arms

    NASA Technical Reports Server (NTRS)

    Barker, L. K.

    1983-01-01

    The Denavit-Hartenberg parameters characterize the joint axis systems in a robot arm and, naturally, appear in the transformation matrices from one joint axis system to another. These parameters are needed in the control of robot arms and in the passage of sensor information along the arm. This paper presents a vector algebra method to determine these parameters for any assembled robot arm. The idea is to measure the location of the robot hand (or extension) for different joint angles and then use these measurements to calculate the parameters.

  18. Identification of PV solar cells and modules parameters using the genetic algorithms: Application to maximum power extraction

    SciTech Connect

    Zagrouba, M.; Sellami, A.; Bouaicha, M.; Ksouri, M.

    2010-05-15

    In this paper, we propose to perform a numerical technique based on genetic algorithms (GAs) to identify the electrical parameters (I{sub s}, I{sub ph}, R{sub s}, R{sub sh}, and n) of photovoltaic (PV) solar cells and modules. These parameters were used to determine the corresponding maximum power point (MPP) from the illuminated current-voltage (I-V) characteristic. The one diode type approach is used to model the AM1.5 I-V characteristic of the solar cell. To extract electrical parameters, the approach is formulated as a non convex optimization problem. The GAs approach was used as a numerical technique in order to overcome problems involved in the local minima in the case of non convex optimization criteria. Compared to other methods, we find that the GAs is a very efficient technique to estimate the electrical parameters of PV solar cells and modules. Indeed, the race of the algorithm stopped after five generations in the case of PV solar cells and seven generations in the case of PV modules. The identified parameters are then used to extract the maximum power working points for both cell and module. (author)

  19. Ion beams extraction and measurements of plasma parameters on a multi-frequencies microwaves large bore ECRIS with permanent magnets

    SciTech Connect

    Nozaki, Dai; Kiriyama, Ryutaro; Takenaka, Tomoya; Kurisu, Yosuke; Yano, Keisuke; Sato, Fuminobu; Kato, Yushi; Iida, Toshiyuki

    2012-11-06

    We have developed an all-permanent magnet large bore electron cyclotron resonance ion source (ECRIS) for broad ion beam processing. The cylindrically comb-shaped magnetic field configuration is adopted for efficient plasma production and good magnetic confinement. To compensate for disadvantages of fixed magnetic configuration, a traveling wave tube amplifier (TWTA) is used. In the comb-shaped ECRIS, it is difficult to achieve controlling ion beam profiles in the whole inside the chamber by using even single frequency-controllable TWTA (11-13GHz), because of large bore size with all-magnets. We have tried controlling profiles of plasma parameters and then those of extracted ion beams by launching two largely different frequencies simultaneously, i.e., multi-frequencies microwaves. Here we report ion beam profiles and corresponding plasma parameters under various experimental conditions, dependence of ion beams against extraction voltages, and influence of different electrode positions on the electron density profile.

  20. Extraction parameters and capillary electrophoresis analysis of limonin glucoside and phlorin in citrus byproducts.

    PubMed

    Braddock, R J; Bryan, C R

    2001-12-01

    Limonin glucoside (LG) and phlorin were extracted from citrus fruit tissues and assayed by capillary electrophoresis (CE). LG was determined in dried [1.20 +/- 0.10 mg of dry weight (dw)] and wet peel residues (1.16 +/- 0.04 mg of dw), orange juice finisher pulp (0.58 +/- 0.03 mg of dw), dried grapefruit seeds (2.70 +/- 0.15 mg of dw), and 50 degrees Brix molasses (2225 +/- 68 mg/L). Phlorin was purified from orange peel residue and grapefruit albedo, and concentrations were determined in some citrus products. Phlorin and LG were extracted from residues with water/pectinase or with water solutions of methanol and ethanol. Efficient LG extraction from grapefruit seeds (2.40 +/- 0.15 mg/g) was achieved with 50-65% methanol, solvent polarity P' approximately equal to 7-8. Extracts were purified and concentrated by adsorptive resins and HPLC to obtain 95% pure compounds of LG and phlorin. CE analysis did not require extract purification beyond filtration. LG and phlorin migrated as anions in electropherograms containing peaks representing other citrus flavonoids and limonoid glucosides.

  1. Effect of Syzygium cumini and Bauhinia forficata aqueous-leaf extracts on oxidative and mitochondrial parameters in vitro

    PubMed Central

    Ecker, Assis; Araujo Vieira, Francielli; de Souza Prestes, Alessandro; Mulling dos Santos, Matheus; Ramos, Angelica; Dias Ferreira, Rafael; Teixeira de Macedo, Gabriel; Vargas Klimaczewski, Claudia; Lopes Seeger, Rodrigo; Teixeira da Rocha, João Batista; de Vargas Barbosa, Nilda B.

    2015-01-01

    Aqueous-leaf extract of Syzygium cumini and Bauhinia forficata are traditionally used in the treatment of diabetes and cancer, especially in South America, Africa, and Asia. In this study, we analyzed the effects of these extracts on oxidative and mitochondrial parameters in vitro, as well as their protective activities against toxic agents. Phytochemical screenings of the extracts were carried out by HPLC analysis. The in vitro antioxidant capacities were compared by DPPH radical scavenging and Fe2+ chelating activities. Mitochondrial parameters observed were swelling, lipid peroxidation and dehydrogenase activity. The major chemical constituent of S. cumini was rutin. In B. forficata were predominant quercetin and gallic acid. S. cumini reduced DPPH radical more than B. forficata, and showed iron chelating activity at all tested concentrations, while B. forficata had not similar property. In mitochondria, high concentrations of B. forficata alone induced a decrease in mitochondrial dehydrogenase activity, but low concentrations of this extract prevented the effect induced by Fe2++H2O2. This was also observed with high concentrations of S. cumini. Both extracts partially prevented the lipid peroxidation induced by Fe2+/citrate. S. cumini was effective against mitochondrial swelling induced by Ca2+, while B. forficata alone induced swelling more than Ca2+. This study suggests that leaf extract of S. cumini might represent a useful therapeutic for the treatment of diseases related with mitochondrial dysfunctions. On the other hand, the consumption of B. forficata should be avoided because mitochondrial damages were observed, and this possibly may pose risk to human health. PMID:27152111

  2. Effect of Syzygium cumini and Bauhinia forficata aqueous-leaf extracts on oxidative and mitochondrial parameters in vitro.

    PubMed

    Ecker, Assis; Araujo Vieira, Francielli; de Souza Prestes, Alessandro; Mulling Dos Santos, Matheus; Ramos, Angelica; Dias Ferreira, Rafael; Teixeira de Macedo, Gabriel; Vargas Klimaczewski, Claudia; Lopes Seeger, Rodrigo; Teixeira da Rocha, João Batista; de Vargas Barbosa, Nilda B

    2015-01-01

    Aqueous-leaf extract of Syzygium cumini and Bauhinia forficata are traditionally used in the treatment of diabetes and cancer, especially in South America, Africa, and Asia. In this study, we analyzed the effects of these extracts on oxidative and mitochondrial parameters in vitro, as well as their protective activities against toxic agents. Phytochemical screenings of the extracts were carried out by HPLC analysis. The in vitro antioxidant capacities were compared by DPPH radical scavenging and Fe(2+) chelating activities. Mitochondrial parameters observed were swelling, lipid peroxidation and dehydrogenase activity. The major chemical constituent of S. cumini was rutin. In B. forficata were predominant quercetin and gallic acid. S. cumini reduced DPPH radical more than B. forficata, and showed iron chelating activity at all tested concentrations, while B. forficata had not similar property. In mitochondria, high concentrations of B. forficata alone induced a decrease in mitochondrial dehydrogenase activity, but low concentrations of this extract prevented the effect induced by Fe(2+)+H2O2. This was also observed with high concentrations of S. cumini. Both extracts partially prevented the lipid peroxidation induced by Fe(2+)/citrate. S. cumini was effective against mitochondrial swelling induced by Ca(2+), while B. forficata alone induced swelling more than Ca(2+). This study suggests that leaf extract of S. cumini might represent a useful therapeutic for the treatment of diseases related with mitochondrial dysfunctions. On the other hand, the consumption of B. forficata should be avoided because mitochondrial damages were observed, and this possibly may pose risk to human health.

  3. Extracting Pore and Fracture Parameters of Porous Rocks Using a Method Based on Digital Image Analysis

    NASA Astrophysics Data System (ADS)

    Song, Z.; Song, Y.

    2015-12-01

    The characterization of pore and fracture is an important part of regional hydrological survey. Traditional methods (e.g. mercury intrusion, porosimetry, and pressure pulse) can effectively determine the parameters of pore and fracture for high-permeability rocks. However, these methods tend to fail for low-permeability rocks, especially quartz sandstone and granite. Thus, this work presented a novel method to determine the parameters of pore and fracture by analyzing the digital image of the casting thin sections under a microscope. Firstly, the size of representative elementary image was obtained by calculating pore parameters of different scales of samples. Then the method based on representative elementary image analyzed the casting thin sections of sandstone with low permeability, low anisotropy, and high water-binding capacity, and determined the parameters such as porosity, round-hole rate, roundness. Besides, this method analyzed the casting thin sections of low-permeability granite from Beishan, Gansu, China to determine more parameters such as fracture rate, length-width ratio of fracture, direction angle, and roundness. Finally, these parameters determined by the method were compared with those by transient pressure pulse method. The comparison demonstrated that the presented method can determine more high-accuracy parameters than transient pressure pulse method. Key words: digital image analysis, casting thin sections, pore, fracture, parameters analysis

  4. Effect of Causative Tooth Extraction on Clinical and Biological Parameters of Odontogenic Infection: A Prospective Clinical Trial.

    PubMed

    Igoumenakis, Dimosthenis; Giannakopoulos, Nikolaos-Nikitas; Parara, Eleni; Mourouzis, Constantinos; Rallis, George

    2015-07-01

    To prospectively compare changes of body temperature, white blood cell count, fibrinogen, and C-reactive protein between odontogenic infections in which the responsible tooth was removed and odontogenic infections in which the treatment included no extraction. The sample was composed of patients admitted to the authors' maxillofacial unit for odontogenic infection from 2010 through 2013. One hundred seventy-nine patients were categorized into an extraction or a non-extraction group based on whether the causative tooth was non-restorable or restorable, respectively. Non-restorable teeth were extracted at admission of the patient. Otherwise, the treatment protocol, including incision of the involved space in conjunction with intravenous antibiotics, was the same for the 2 groups. The parameters were measured and recorded at admission and 2 days later. Data records were statistically analyzed by comparing the change of the parameters studied between the extraction and non-extraction groups. P values less than .05 were regarded as statistically significant. One hundred seventy-nine patients fulfilled the inclusion criteria and were enrolled in the study. The mean age of the patients was 39.1 years (minimum, 14 yr; maximum, 81 yr; standard deviation, 15.4 yr). One hundred nine patients (60.9%) were male, and 70 (39.1%) were female. Differences in the mean decrease of axillary temperature, white blood cell count, fibrinogven, and C-reactive protein between the 2 groups were 0.178, 2,300, 1.01, and 0.64, respectively. All these differences were statistically significant (P =.02, .001, .001, and .001, respectively). Also, the mean hospital stay in the extraction group was 1.05 days shorter than in the non-extraction group, with the difference being statistically significant (P = .006). In odontogenic maxillofacial infections, extraction of the causative tooth is associated with a faster clinical and biological resolution of the infection. Copyright © 2015 American

  5. Extracting Kinematic Parameters for Monkey Bipedal Walking from Cortical Neuronal Ensemble Activity

    PubMed Central

    Fitzsimmons, Nathan A.; Lebedev, Mikhail A.; Peikon, Ian D.; Nicolelis, Miguel A. L.

    2009-01-01

    The ability to walk may be critically impacted as the result of neurological injury or disease. While recent advances in brain–machine interfaces (BMIs) have demonstrated the feasibility of upper-limb neuroprostheses, BMIs have not been evaluated as a means to restore walking. Here, we demonstrate that chronic recordings from ensembles of cortical neurons can be used to predict the kinematics of bipedal walking in rhesus macaques – both offline and in real time. Linear decoders extracted 3D coordinates of leg joints and leg muscle electromyograms from the activity of hundreds of cortical neurons. As more complex patterns of walking were produced by varying the gait speed and direction, larger neuronal populations were needed to accurately extract walking patterns. Extraction was further improved using a switching decoder which designated a submodel for each walking paradigm. We propose that BMIs may one day allow severely paralyzed patients to walk again. PMID:19404411

  6. Effect of experimental parameters in the pressurized solvent extraction of polyphenolic compounds from white grape marc.

    PubMed

    Álvarez-Casas, Marta; García-Jares, Carmen; Llompart, María; Lores, Marta

    2014-08-15

    A method based on pressurized solvent extraction (PSE) to determine main polyphenolic compounds in the grape marc obtained as a byproduct of the white winemaking process has been developed. As response variables in the optimisation process include main individual polyphenols, as well as spectrophotometric indexes. The optimised PSE procedure implies the use of 1 g of sample, without preliminary clean-up step, sea sand as dispersant, temperature of 105 °C, methanol (63%) in water as solvent, and 5 min of extraction time (2 static cycles). The performance of the proposed method has been assessed in terms of recovery (91-105%), linearity (R(2)>0.995) and precision. The applicability of the method was demonstrated by the analysis of bagasse samples collected from 12 wineries located in Galicia (NW Spain). Data of the in vitro antioxidant activities of the PSE extracts are also discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. On modality and complexity of affine embeddings

    SciTech Connect

    Arzhantsev, I V

    2001-08-31

    Let G be a reductive algebraic group and let H be a reductive subgroup of G. The modality of a G-variety X is the largest number of the parameters in a continuous family of G-orbits in X. A precise formula for the maximum value of the modality over all affine embeddings of the homogeneous space G/H is obtained.

  8. Rosa canina L. Fruit Hydro-Alcoholic Extract Effects on Some Immunological and Biochemical Parameters in Rats

    PubMed Central

    Sadigh-Eteghad, Saeed; Tayefi-Nasrabadi, Hossein; Aghdam, Zahra; Zarredar, Habib; Shanehbandi, Dariush; Khayyat, Leila; Seyyed-Piran, Seyyed-Hamed

    2011-01-01

    Introduction This research investigates the possible potential of Rosa canina (RC) as an immunomodulator in rats and its effects on some biochemical parameters. Methods In this experiment, 45 male Wistar rats were obtained and divided into three groups (n = 15). These groups received normal saline (10 mg/kg), RC fruit extract (250 mg/kg) and RC fruit extract (500 mg/kg) as oral gavages every day for a period of four weeks, respective-ly. After obtaining blood samples (at the end of each week), differential white blood cell (WBC) counts, phagocyte activity (number), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphates (ALP) albumin and globulins levels of sam-ples were obtained. The malondialdehyde (MDA) and glutathione (GSH) levels in the se-rum were determined only in day 28 of study. The radical scavenger activity (RSA) of the RC extract was measured spectrophotometrically. Results the gamma globulin level, neu-trophil and monocyte counts and phagocyte activity increased significantly in comparison with the normal saline group. ALT, AST and ALP had not significantly differences in compared to control group. RC extract significantly increased thiobarbituric acid reactive substances (TBARS) and also decreased GSH levels in comparing to control group in day 28. Conclusion the data suggest that the RC extract has been used in traditional medicine might have immunomodulatory effects. PMID:23678431

  9. Screening of Argentine plant extracts: impact on growth parameters and aflatoxin B1 accumulation by Aspergillus section Flavi.

    PubMed

    Bluma, R; Amaiden, M R; Etcheverry, M

    2008-02-29

    The effect of essential oils, ethanolic and aqueous extract of 41 vegetable species on Aspergillus section Flavi growth was evaluated. The in vitro screen was a two-stage process. A wide-spectrum initial screen which identified promising antifungal plant extracts was carried out first. After that, identified extracts were studied in more detail by in vitro assays. A total of 96 plant extracts were screened. Essential oils were found to be the most effective extract controlling aflatoxigenic strains. Clove, mountain thyme, poleo and eucalyptus essential oils were selected to study their antifungal effect. Studies on percentage of germination, germ-tube elongation rate, growth rate, and aflatoxin B1 accumulation were carried out. Clove, mountain thyme and poleo essential oils showed the most antifungal effect under all growth parameters analyzed as well as aflatoxin B1 accumulation. Our results suggest that mountain thyme and poleo, which are native vegetal species of Argentina, and clove essential oils could be used alone or in conjunction with other substances to control the presence of aflatoxigenic fungi in stored maize.

  10. Therapeutic effects of marshmallow (Althaea officinalis L.) extract on plasma biochemical parameters of common carp infected with Aeromonas hydrophila

    PubMed Central

    Banaee, Mahdi; Soleimany, Vahid; Nematdoost Haghi, Behzad

    2017-01-01

    This study evaluated preclinical and clinical safety of marshmallow (Althaea officinalis L.) extract as a naturopathic medicine in common carp deliberately infected with Aeromonas hydrophila. The fish were fed 0 (control), 2.50, 5.00 and 10.00 g of marshmallow extract for 60 days in a preclinical experiment and then, challenged with A. hydrophila for a 10-day experiment. Significant increases were observed in aspartate aminotransferase (AST), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), creatine phosphokinase (CPK) activities and plasma creatinine levels in fish fed 10 g marshmallow extract per kg feed. However, alanine aminotransferase (ALT) significantly decreased on day 60. The fish fed 2.50 g marshmallow extract per kg feed indicated increased levels of total protein and globulin. There were no significant changes in albumin levels (p > 0.05). 2.50 and 5.00 g marshmallow significantly decreased triglyceride and cholesterol levels and increased glucose levels (p < 0.05). A. hydrophila significantly increased AST, ALT, LDH, ALP and CPK activities and plasma glucose, cholesterol, triglycerides and creatinine levels after 10 days (p < 0.05). Total plasma protein, albumin and globulin levels in fish challenged with A. hydrophila were significantly lower than the control group (p < 0.05). Marshmallow extract at 5.00 and 10.00 g can adjust plasma biochemical parameters in fish challenged with A. hydrophila. The results of preclinical studies and pharmaceutical toxicity of marshmallow extract revealed that dietary levels lower than 5.00 g were safe and effective. The results of this clinical study demonstrated that marshmallow extract (5.00 g kg-1 feed) can protect fish against A. hydrophila. PMID:28785391

  11. Parameters affecting microwave-assisted extraction of organophosphorus pesticides from agricultural soil.

    PubMed

    Fuentes, Edwar; Báez, María E; Labra, Ronnie

    2007-10-26

    This work describes an optimised method for the determination of six representative organophosphorus pesticides (OPPs) (diazinon, parathion, methyl pirimiphos, methyl parathion, ethoprophos, and fenitrothion) in agricultural soils. The method is based on microwave-assisted extraction using a water-methanol modified mixture for desorption and simultaneous partitioning on n-hexane (MAEP), together with gas chromatography-flame photometric detection (GC-FPD). To improve GC-FPD signals (peak intensity and shape) olive oil was used effectively as a "matrix mimic". The optimisation of the extraction method was achieved in two steps: an initial approach through experimental design and principal component analysis where recovery of compounds using a water-methanol mixture ranged from 54 to 77%, and the second one by studying the addition of KH2PO4 to the extracting solution where recoveries were significantly increased, molecular replacing of OPPs from adsorption sites by phosphate being the probable extraction mechanism. Under optimised conditions, recoveries of pesticides from different soils were higher than 73%, except for methyl parathion in some soils, with SD equal or lower than 11% and detection limits ranging from 0.004 to 0.012 microg g(-1). The proposed method was used to determine OPPs in soil samples from different agricultural zones of Chile.

  12. Evaluation of different parameters in the extraction of incurred pesticides and environmental contaminants in fish

    USDA-ARS?s Scientific Manuscript database

    Sample processing is often ignored during analytical method development and validation, but accurate results for real samples depend on all aspects of the analytical process. Also, validation is often conducted only using spiked samples, but extraction yields may be lower in incurred samples. In thi...

  13. FPGA-based fused smart sensor for dynamic and vibration parameter extraction in industrial robot links.

    PubMed

    Rodriguez-Donate, Carlos; Morales-Velazquez, Luis; Osornio-Rios, Roque Alfredo; Herrera-Ruiz, Gilberto; de Jesus Romero-Troncoso, Rene

    2010-01-01

    Intelligent robotics demands the integration of smart sensors that allow the controller to efficiently measure physical quantities. Industrial manipulator robots require a constant monitoring of several parameters such as motion dynamics, inclination, and vibration. This work presents a novel smart sensor to estimate motion dynamics, inclination, and vibration parameters on industrial manipulator robot links based on two primary sensors: an encoder and a triaxial accelerometer. The proposed smart sensor implements a new methodology based on an oversampling technique, averaging decimation filters, FIR filters, finite differences and linear interpolation to estimate the interest parameters, which are computed online utilizing digital hardware signal processing based on field programmable gate arrays (FPGA).

  14. FPGA-Based Fused Smart Sensor for Dynamic and Vibration Parameter Extraction in Industrial Robot Links

    PubMed Central

    Rodriguez-Donate, Carlos; Morales-Velazquez, Luis; Osornio-Rios, Roque Alfredo; Herrera-Ruiz, Gilberto; de Jesus Romero-Troncoso, Rene

    2010-01-01

    Intelligent robotics demands the integration of smart sensors that allow the controller to efficiently measure physical quantities. Industrial manipulator robots require a constant monitoring of several parameters such as motion dynamics, inclination, and vibration. This work presents a novel smart sensor to estimate motion dynamics, inclination, and vibration parameters on industrial manipulator robot links based on two primary sensors: an encoder and a triaxial accelerometer. The proposed smart sensor implements a new methodology based on an oversampling technique, averaging decimation filters, FIR filters, finite differences and linear interpolation to estimate the interest parameters, which are computed online utilizing digital hardware signal processing based on field programmable gate arrays (FPGA). PMID:22319345

  15. Extraction of battery parameters using a multi-objective genetic algorithm with a non-linear circuit model

    NASA Astrophysics Data System (ADS)

    Malik, Aimun; Zhang, Zheming; Agarwal, Ramesh K.

    2014-08-01

    There is need for a battery model that can accurately describe the battery performance for an electrical system, such as the electric drive train of electric vehicles. In this paper, both linear and non-linear equivalent circuit models (ECM) are employed as a means of extracting the battery parameters that can be used to model the performance of a battery. The linear and non-linear equivalent circuit models differ in the numbers of capacitance and resistance; the non-linear model has an added circuit; however their numerical characteristics are equivalent. A multi-objective genetic algorithm is employed to accurately extract the values of the battery model parameters. The battery model parameters are obtained for several existing industrial batteries as well as for two recently proposed high performance batteries. Once the model parameters are optimally determined, the results demonstrate that both linear and non-linear equivalent circuit models can predict with acceptable accuracy the performance of various batteries of different sizes, characteristics, capacities, and materials. However, the comparisons of results with catalog and experimental data shows that the predictions of results using the non-linear equivalent circuit model are slightly better than those predicted by the linear model, calculating voltages that are closer to the manufacturers' values.

  16. EPIPOI: A user-friendly analytical tool for the extraction and visualization of temporal parameters from epidemiological time series

    PubMed Central

    2012-01-01

    Background There is an increasing need for processing and understanding relevant information generated by the systematic collection of public health data over time. However, the analysis of those time series usually requires advanced modeling techniques, which are not necessarily mastered by staff, technicians and researchers working on public health and epidemiology. Here a user-friendly tool, EPIPOI, is presented that facilitates the exploration and extraction of parameters describing trends, seasonality and anomalies that characterize epidemiological processes. It also enables the inspection of those parameters across geographic regions. Although the visual exploration and extraction of relevant parameters from time series data is crucial in epidemiological research, until now it had been largely restricted to specialists. Methods EPIPOI is freely available software developed in Matlab (The Mathworks Inc) that runs both on PC and Mac computers. Its friendly interface guides users intuitively through useful comparative analyses including the comparison of spatial patterns in temporal parameters. Results EPIPOI is able to handle complex analyses in an accessible way. A prototype has already been used to assist researchers in a variety of contexts from didactic use in public health workshops to the main analytical tool in published research. Conclusions EPIPOI can assist public health officials and students to explore time series data using a broad range of sophisticated analytical and visualization tools. It also provides an analytical environment where even advanced users can benefit by enabling a higher degree of control over model assumptions, such as those associated with detecting disease outbreaks and pandemics. PMID:23153033

  17. Extraction of crystal-field parameters for lanthanide ions from quantum-chemical calculations.

    PubMed

    Hu, Liusen; Reid, Michael F; Duan, Chang-Kui; Xia, Shangda; Yin, Min

    2011-02-02

    A simple method for constructing effective Hamiltonians for the 4f(N) and 4f(N - 1)5d energy levels of lanthanide ions in crystals from quantum-chemical calculations is presented. The method is demonstrated by deriving crystal-field and spin-orbit parameters for Ce(3 + ) ions doped in LiYF(4), Cs(2)NaYCl(6), CaF(2), KY(3)F(10) and YAG host crystals from quantum-chemical calculations based on the DV-Xα method. Good agreement between calculated and fitted values of the crystal-field parameters is obtained. The method can be used to calculate parameters even for low-symmetry sites where there are more parameters than energy levels.

  18. Extraction of crystal-field parameters for lanthanide ions from quantum-chemical calculations

    NASA Astrophysics Data System (ADS)

    Hu, Liusen; Reid, Michael F.; Duan, Chang-Kui; Xia, Shangda; Yin, Min

    2011-02-01

    A simple method for constructing effective Hamiltonians for the 4fN and 4fN - 15d energy levels of lanthanide ions in crystals from quantum-chemical calculations is presented. The method is demonstrated by deriving crystal-field and spin-orbit parameters for Ce3 + ions doped in LiYF4, Cs2NaYCl6, CaF2, KY3F10 and YAG host crystals from quantum-chemical calculations based on the DV-Xα method. Good agreement between calculated and fitted values of the crystal-field parameters is obtained. The method can be used to calculate parameters even for low-symmetry sites where there are more parameters than energy levels.

  19. Fast modal extraction in NASTRAN via the FEER computer program. [based on automatic matrix reduction method for lower modes of structures with many degrees of freedom

    NASA Technical Reports Server (NTRS)

    Newman, M. B.; Pipano, A.

    1973-01-01

    A new eigensolution routine, FEER (Fast Eigensolution Extraction Routine), used in conjunction with NASTRAN at Israel Aircraft Industries is described. The FEER program is based on an automatic matrix reduction scheme whereby the lower modes of structures with many degrees of freedom can be accurately extracted from a tridiagonal eigenvalue problem whose size is of the same order of magnitude as the number of required modes. The process is effected without arbitrary lumping of masses at selected node points or selection of nodes to be retained in the analysis set. The results of computational efficiency studies are presented, showing major arithmetic operation counts and actual computer run times of FEER as compared to other methods of eigenvalue extraction, including those available in the NASTRAN READ module. It is concluded that the tridiagonal reduction method used in FEER would serve as a valuable addition to NASTRAN for highly increased efficiency in obtaining structural vibration modes.

  20. Reliable gate stack and substrate parameter extraction based on C-V measurements for 14 nm node FDSOI technology

    NASA Astrophysics Data System (ADS)

    Mohamad, B.; Leroux, C.; Rideau, D.; Haond, M.; Reimbold, G.; Ghibaudo, G.

    2017-02-01

    Effective work function and equivalent oxide thickness are fundamental parameters for technology optimization. In this work, a comprehensive study is done on a large set of FDSOI devices. The extraction of the gate stack parameters is carried out by fitting experimental CV characteristics to quantum simulation, based on self-consistent solution of one dimensional Poisson and Schrodinger equations. A reliable methodology for gate stack parameters is proposed and validated. This study identifies the process modules that impact directly the effective work function from those that only affect the device threshold voltage, due to the device architecture. Moreover, the relative impacts of various process modules on channel thickness and gate oxide thickness are evidenced.

  1. Parameters of Density Distribution of Exotic Nuclei Extracted from a Data on Reaction Cross-section in the Glauber Model

    NASA Astrophysics Data System (ADS)

    Novikov, Ivan; Rueter, Keiti

    2016-09-01

    Parameters of density distribution of exotic nuclei with halo structure were extracted from the experimental data on the interaction cross-section using exact expressions obtained in the Glauber theory. Generally, to do so measured interaction cross-section is compared with a reaction cross-section calculated in optical approximation or using exact expressions of the Glauber theory. It was shown before that the parameters of nuclear density distribution depends on chosen density model (Gaussian, harmonic oscillator or Woods-Saxon) and on the used approximation of the Glauber theory (i.e. optical or rigid target). In the presented paper, we discuss the difference between reaction and interaction cross-sections calculated in various approximations, and how this difference affects the accuracy of the nuclear density parameters determination. As an example, we provide results of the analyzes of experimental data on interaction cross-section of 11Li, 16C and 31Ne nuclei on 12C target.

  2. Postoperative radiotherapy dose requirement in standard combined-modality practice for head and neck squamous cell carcinoma: Analysis of salient surgical and radiotherapy parameters in 2 cohorts.

    PubMed

    Mohanti, Bidhu K; Thakar, Alok; Kaur, Jaspreet; Bahadur, Sudhir; Malik, Monica; Gandhi, Ajeet K; Bhasker, Suman; Sharma, Atul

    2017-09-01

    This study compared 2 sequential cohorts to identify the postoperative radiotherapy (PORT) dose requirement for head and neck squamous cell carcinoma (HNSCC). Two distinct PORT dose regimens were prescribed over 11 years; group 1 received 56 Gy or less, and group 2 received 60 Gy or more. The 2D and 3D techniques were used. Two sequential cohorts consisted of 478 patients, with mean and median follow-up for group 1 and 2 as: 37.0 versus 28.5 months and 13.8 versus 13.1 months, respectively. Grades 3-4 mucosal toxicities (11.4% vs 28.3%), hospitalization (3.2% vs 17.4%), and nasogastric feeding (11.9% vs 29.7%) were higher in group 2. The 2-year disease-free survival (DFS) was higher with PORT >60 Gy for the following factors: age ≤ 50 years (P = .041); ≥ 4 positive nodes (P = .029); and overall treatment time (OTT) ≥ 100 days (P = .042). Except for the benefit of doses >60 Gy for limited parameters, a lower PORT dose did not compromise the results and can potentially reduce the morbidities and healthcare costs. © 2017 Wiley Periodicals, Inc.

  3. Relation between various soil phosphorus extraction methods and sorption parameters in calcareous soils with different texture.

    PubMed

    Jalali, Mohsen; Jalali, Mahdi

    2016-10-01

    The aim of this study was to investigate the influence of soil texture on phosphorus (P) extractability and sorption from a wide range of calcareous soils across Hamedan, western Iran. Fifty seven soil samples were selected and partitioned into five types on the basis of soil texture (clay, sandy, sandy clay loam, sandy loam and mixed loam) and the P extracted with calcium chloride (PCaCl2), citrate (Pcitrate), HCl (PHCl), Olsen (POls), and Mehlich-3 (PM3) solutions. On the average, the P extracted was in the order PHCl>PM3>Pcitrate>POls>PCaCl2. The P extracted by Pcitrate, PHCl, POls, and PM3 methods were significantly higher in sandy, sandy clay loam and sandy loam textures than clay and mixed loam textures, while soil phosphorus buffer capacity (PBC) was significantly higher in clay and mixed loam soil textures. The correlation analysis revealed a significant positive relationship between silt content Freundlich sorption coefficient (KF), maximum P sorption (Qmax), linear distribution coefficient (Kd), and PBC. All extractions were highly correlated with each other and among soil components with silt content. The principal component analysis (PCA) performed on data identified five principal components describing 74.5% of total variation. The results point to soil texture as an important factor and that silt was the crucial soil property associated with P sorption and its extractability in these calcareous soils. DPSM3-2 (PM3PM3+Qmax×100) and DPScitrate (PcitratePcitrate+Qmax×100) proved to be good indicators of soil's potential P release in these calcareous soils. Among the DPS, 21% of soils reported DPSM3-2, values higher than the environmental threshold, indicating build-up of P and P release. Most of the studied sandy clay loam soils had exceeded the environmentally unacceptable P concentration. Various management practices should be taken into account to reduce P losses from these soils. Further inorganic and organic P fertilizer inputs should be reduced

  4. Frame modal analysis

    NASA Technical Reports Server (NTRS)

    Guyan, R. J.; Heckenlaible, R. N.

    1971-01-01

    Computer model calculates natural frequencies and modal displacements of three-dimensional frame structures, and generates stiffness and mass matrices. Structures may be divided into several substructures prior to calculation of modal characteristics.

  5. Modalities and Hidden Handicaps.

    ERIC Educational Resources Information Center

    Keefee, Susan D.

    1985-01-01

    A teacher of learning handicapped students describes her modality perspective, noting characteristics of visual, auditory, and kinesthetic learners and considering the impact of deficiencies in more than one modality. (CL)

  6. Extraction of soil and vegetation parameters from high resolution bi-directional reflectance spectra

    NASA Technical Reports Server (NTRS)

    Huete, A. R.

    1992-01-01

    High spectral resolution reflectance spectra were collected over a semi-desert grassland at both dry and wet season periods. Spectral reflectance measurements were made from several viewing angles at both low and high solar zenith angles. A mixture model was used to separate and extract green vegetation from dry/dead vegetation and soil. The extracted vegetation signal varied greatly with view and sun angle variations such that off-nadir viewing and illuminating angles resulted in the highest vegetation loadings. These variations were normalized with cosine functions for both sun and view angle. These results offer a methodology for standardizing multi-temporal and multi-angular satellite measurements of vegetation activity.

  7. Optimization of Extraction Parameters for Enhanced Production of Ovotransferrin from Egg White for Antimicrobial Applications

    PubMed Central

    Alshammari, Eyad M. A.; Khan, Saif; Jawed, Arshad; Adnan, Mohd; Khan, Mahvish; Nabi, Gowher; Lohani, Mohtashim; Haque, Shafiul

    2015-01-01

    Ovotransferrin is the second most abundant protein (~12-13% of the total egg protein) in egg white after ovalbumin. Ovotransferrin is a potent natural antimicrobial agent as it possesses antibacterial, antifungal, and antiviral properties and is also the major metal binding protein found in egg, which makes it an industrially important protein. Ovotransferrin was extracted from egg white using its metal (iron) binding properties. In the present study, eggs from two different sources were used (fresh local eggs from domestic household source and poultry eggs from shops) to compare the results and Response Surface Methodology was used for the experiment design and data analysis. The following extraction conditions were optimized so as to maximize the yield of ovotransferrin from egg white: ethanol % (v/v) and pH and volume (mL) of 25 mM FeCl3/50 mL of egg white. A maximum yield of ~85 ± 2.5% was obtained near the optimum extraction conditions. The yield was calculated based on the theoretical value (934 mg) of ovotransferrin in 100 mL of 1.5x diluted egg white solution. Our results suggest that efficient downstream processing may reduce the cost of overall production process of this promising enzyme, making it a natural and cost-effective alternative to the existing chemically synthesized antimicrobial agents. PMID:26640801

  8. Extraction of anisotropic parameters of turbid media using hybrid model comprising differential- and decomposition-based Mueller matrices.

    PubMed

    Liao, Chia-Chi; Lo, Yu-Lung

    2013-07-15

    A hybrid model comprising the differential Mueller matrix formalism and the Mueller matrix decomposition method is proposed for extracting the linear birefringence (LB), linear dichroism (LD), circular birefringence (CB), circular dichroism (CD), and depolarization properties (Dep) of turbid optical samples. In contrast to the differential-based Mueller matrix method, the proposed hybrid model provides full-range measurements of all the anisotropic properties of the optical sample. Furthermore, compared to the decomposition-based Mueller matrix method, the proposed model is insensitive to the multiplication order of the constituent basis matrices. The validity of the proposed method is confirmed by extracting the anisotropic properties of a compound chitosan-glucose-microsphere sample with LB/CB/Dep properties and two ferrofluidic samples with CB/CD/Dep and LB/LD/Dep properties, respectively. It is shown that the proposed hybrid model not only yields full-range measurements of all the anisotropic parameters, but is also more accurate and more stable than the decomposition method. Moreover, compared to the decomposition method, the proposed model more accurately reflects the dependency of the phase retardation angle and linear dichroism angle on the direction of the external magnetic field for ferrofluidic samples. Overall, the results presented in this study confirm that the proposed model has significant potential for extracting the optical parameters of real-world samples characterized by either single or multiple anisotropic properties.

  9. Parameter extraction of an organic solar cell using asymptotic estimation and Lambert W function

    NASA Astrophysics Data System (ADS)

    Bǎrar, Ana; Mǎnǎilǎ-Maximean, Doina; Dǎnilǎ, Octavian; Vlǎdescu, Marian

    2016-12-01

    A theoretical characterization of an organic solar cell has been realized based on its equivalent model and an I-V curve corresponding to ITO/PEDOT/MEH-PPV:PCBM(1:4)/LiF/Al cell, taken from the literature. The parameters of the equivalent model have been determined using two methods: the approximation method and the Lambert W function. For the considered curve, the parameter values that have been obtained are similar to the results presented in literature. It has also been shown that the Lambert W function presents a considerably smaller error compared to the approximation method.

  10. Modal analysis of PATHFINDER unmanned air vehicle

    SciTech Connect

    Woehrle, T.G.; Costerus, B.W.; Lee, C.L.

    1994-10-19

    An experimental modal analysis was performed on PATHFINDER, a 450-lb, 100-ft wing span, flying-wing-design aircraft powered by solar/electric motors. The aircraft was softly suspended and then excited using random input from a long-stroke shaker. Modal data was taken from 92 measurement locations on the aircraft using newly designed, lightweight, tri-axial accelerometers. A conventional PC-based data acquisition system provided data handling. Modal parameters were calculated, and animated mode shapes were produced using SMS STARStruct{trademark} Modal Analysis System software. The modal parameters will be used for validation of finite element models, optimum placement of onboard accelerometers during flight testing, and vibration isolation design of sensor platforms.

  11. Identification of Historical Veziragasi Aqueduct Using the Operational Modal Analysis

    PubMed Central

    Ercan, E.; Nuhoglu, A.

    2014-01-01

    This paper describes the results of a model updating study conducted on a historical aqueduct, called Veziragasi, in Turkey. The output-only modal identification results obtained from ambient vibration measurements of the structure were used to update a finite element model of the structure. For the purposes of developing a solid model of the structure, the dimensions of the structure, defects, and material degradations in the structure were determined in detail by making a measurement survey. For evaluation of the material properties of the structure, nondestructive and destructive testing methods were applied. The modal analysis of the structure was calculated by FEM. Then, a nondestructive dynamic test as well as operational modal analysis was carried out and dynamic properties were extracted. The natural frequencies and corresponding mode shapes were determined from both theoretical and experimental modal analyses and compared with each other. A good harmony was attained between mode shapes, but there were some differences between natural frequencies. The sources of the differences were introduced and the FEM model was updated by changing material parameters and boundary conditions. Finally, the real analytical model of the aqueduct was put forward and the results were discussed. PMID:24511287

  12. Extracting order parameters from powder EPR lineshapes for spin-labelled lipids in membranes

    NASA Astrophysics Data System (ADS)

    Schorn, Karl; Marsh, Derek

    1997-10-01

    The corrections that must be made to the spectral separations of the hyperfine extrema in the pseudo-powder EPR lineshapes from lipid spin labels in randomly oriented membranes have been investigated by spectral simulations that include slow motional components. Using simulation parameters that are able to describe the corresponding experimental spectra rather well, it is found that any correction required to the outer hyperfine splitting, 2 Amax, is small, but that the correction to the inner splitting, 2 Amin, differs from that obtained previously from motional narrowing theory. Both Amax and Amin deduced from the simulated spectra are found to vary almost linearly with the molecular-frame order parameter, Szz. The corrections to Amin are used to obtain order parameters from the experimental line splittings. These are found to be in reasonable agreement with the order parameters derived from direct spectral simulation. The inclusion of slow motional components in the simulations represents an improvement over the correction to Amin that is routinely used for membrane systems and which is based on motional narrowing theory.

  13. A Poisson nonnegative matrix factorization method with parameter subspace clustering constraint for endmember extraction in hyperspectral imagery

    NASA Astrophysics Data System (ADS)

    Sun, Weiwei; Ma, Jun; Yang, Gang; Du, Bo; Zhang, Liangpei

    2017-06-01

    A new Bayesian method named Poisson Nonnegative Matrix Factorization with Parameter Subspace Clustering Constraint (PNMF-PSCC) has been presented to extract endmembers from Hyperspectral Imagery (HSI). First, the method integrates the liner spectral mixture model with the Bayesian framework and it formulates endmember extraction into a Bayesian inference problem. Second, the Parameter Subspace Clustering Constraint (PSCC) is incorporated into the statistical program to consider the clustering of all pixels in the parameter subspace. The PSCC could enlarge differences among ground objects and helps finding endmembers with smaller spectrum divergences. Meanwhile, the PNMF-PSCC method utilizes the Poisson distribution as the prior knowledge of spectral signals to better explain the quantum nature of light in imaging spectrometer. Third, the optimization problem of PNMF-PSCC is formulated into maximizing the joint density via the Maximum A Posterior (MAP) estimator. The program is finally solved by iteratively optimizing two sub-problems via the Alternating Direction Method of Multipliers (ADMM) framework and the FURTHESTSUM initialization scheme. Five state-of-the art methods are implemented to make comparisons with the performance of PNMF-PSCC on both the synthetic and real HSI datasets. Experimental results show that the PNMF-PSCC outperforms all the five methods in Spectral Angle Distance (SAD) and Root-Mean-Square-Error (RMSE), and especially it could identify good endmembers for ground objects with smaller spectrum divergences.

  14. Algebraic processing technique for extracting frequency-dependent shear-wave splitting parameters in an anisotropic medium

    NASA Astrophysics Data System (ADS)

    Han, Kai-Feng; Zeng, Xin-Wu

    2011-06-01

    Based on the dual source cumulative rotation technique in the time-domain proposed by Zeng and MacBeth (1993), a new algebraic processing technique for extracting shear-wave splitting parameters from multi-component VSP data in frequency-dependent medium has been developed. By using this dual source cumulative rotation technique in the frequency-domain (DCTF), anisotropic parameters, including polarization direction of the shear-waves and timedelay between the fast and slow shear-waves, can be estimated for each frequency component in the frequency domain. It avoids the possible error which comes from using a narrow-band filter in the current commonly used method. By using synthetic seismograms, the feasibility and validity of the technique was tested and a comparison with the currently used method was also given. The results demonstrate that the shear-wave splitting parameters frequency dependence can be extracted directly from four-component seismic data using the DCTF. In the presence of larger scale fractures, substantial frequency dependence would be found in the seismic frequency range, which implies that dispersion would occur at seismic frequencies. Our study shows that shear-wave anisotropy decreases as frequency increases.

  15. Effects of Arachis hypogaea nutshell extract on lipid metabolic enzymes and obesity parameters.

    PubMed

    Moreno, Diego A; Ilic, Nebojsa; Poulev, Alexander; Raskin, Ilya

    2006-05-08

    The aim of the present study was to assess the effects of peanut (Arachis hypogaea L.) shell extracts (PSE) on lipases and to evaluate its potential development for the treatment of obesity. The peanut shells were extracted in 95% ethanol, and the extracts were screened for inhibitory effects on pancreatic lipase (PL) and lipoprotein lipase (LPL) activities as well as on lipolysis of 3T3-L1 adipocytes. We also examined in vivo whether PSE could prevent the body weight gain induced by feeding a high-fat diet to male Wistar rats for 12 weeks. PSE inhibits a number of lipases, including PL, LPL and, possibly, hormone sensitive lipase (HSL). PSE-treated Wistar rats showed increased fecal lipid excretion respect to the control group. Body weight and body weight gain, and liver size, were significantly lower in rats fed the high-fat diet with 1% of PSE (w:w diet) than in those fed the high-fat diet alone. The rats treated with PSE showed reduced triacylglycerol content in the liver, as well as the serum glucose and insulin. The inhibitory activity of PSE on the lipid metabolic enzymes and the increase in fecal fat excretion suggests that PSE might be useful as a treatment to reduce the dietary fat absorption. The observed reduction in intracellular lipolytic activity of cultured 3T3-L1 adipocytes may reduce the levels of circulating free fatty acids. The observed effects are likely induced by more than one bioactive component of PSE. The PSE actions may, at least in part, be attributed to the inhibition of fat absorption in the digestive tract and the reduction of the adipocyte lipolysis.

  16. Extraction of cilium beat parameters by the combined application of photoelectric measurements and computer simulation.

    PubMed

    Gheber, L; Priel, Z

    1997-01-01

    Photoelectric signals were created and used to investigate the features of the signals as a function of the ciliary beat parameters. Moreover, correlation between the simulated and the measured signals permitted measurement of the cilium beat parameters. The simulations of the signals were based on generation of a series of time-frozen top-view frames of an active ciliary area and determination of the amount of light passing through an observation area in each of these frames. All the factors that might contribute to the shape of the signals, namely, partial ciliary transmittance of light, three-dimensional ciliary beat (composed of recovery, effective, and pause parts), phase distribution on the ciliary surface, and the large number of cilia that contribute to the photoelectric signal, were taken into account in generation of the signals. Changes in the ciliary parameters influenced the shape of the photoelectric signals, and the different phases of the beat could not be directly and unequivocally identified in the signals. The degree of temporal asymmetry of the beat and the portion of the cycle occupied by the pause significantly influenced the shapes of both the lower and the upper parts of the signal and the slopes of the signal. Increases in the angle of the arc swept by the cilium during the effective stroke smoothed the signals and increased the duration of the upper part of the signal. The angle of the arc projected by the cilium onto the cell surface during the recovery stroke had minor effects on the signal's shape. Characteristics of the metachronal wave also influenced the signal's shape markedly. Decreases in ciliary spacing smoothed the signals, whereas ciliary length had a minor influence on the simulated photoelectric signals. Comparison of the simulated and the measured signals showed that the beat parameters of the best-fitting simulated signals converged to values that agree well with the accepted range of beat parameters in mucociliary systems.

  17. Extraction of cilium beat parameters by the combined application of photoelectric measurements and computer simulation.

    PubMed Central

    Gheber, L; Priel, Z

    1997-01-01

    Photoelectric signals were created and used to investigate the features of the signals as a function of the ciliary beat parameters. Moreover, correlation between the simulated and the measured signals permitted measurement of the cilium beat parameters. The simulations of the signals were based on generation of a series of time-frozen top-view frames of an active ciliary area and determination of the amount of light passing through an observation area in each of these frames. All the factors that might contribute to the shape of the signals, namely, partial ciliary transmittance of light, three-dimensional ciliary beat (composed of recovery, effective, and pause parts), phase distribution on the ciliary surface, and the large number of cilia that contribute to the photoelectric signal, were taken into account in generation of the signals. Changes in the ciliary parameters influenced the shape of the photoelectric signals, and the different phases of the beat could not be directly and unequivocally identified in the signals. The degree of temporal asymmetry of the beat and the portion of the cycle occupied by the pause significantly influenced the shapes of both the lower and the upper parts of the signal and the slopes of the signal. Increases in the angle of the arc swept by the cilium during the effective stroke smoothed the signals and increased the duration of the upper part of the signal. The angle of the arc projected by the cilium onto the cell surface during the recovery stroke had minor effects on the signal's shape. Characteristics of the metachronal wave also influenced the signal's shape markedly. Decreases in ciliary spacing smoothed the signals, whereas ciliary length had a minor influence on the simulated photoelectric signals. Comparison of the simulated and the measured signals showed that the beat parameters of the best-fitting simulated signals converged to values that agree well with the accepted range of beat parameters in mucociliary systems

  18. Simulation methods for the online extraction of ECG parameters under Matlab/Simulink.

    PubMed

    von Wagner, G; Kunzmann, U; Schöchlin, J; Bolz, A

    2002-01-01

    The classification of cardiac pathologies in the human ECG greatly depends on the reliable extraction of characteristic features. This work presents a complete simulation environment for testing ECG classification algorithms under Matlab/Simulink. Evaluation of algorithm performance is undertaken in full compliance with the ANSI/AAMI standards EC38 and EC57, and ranges from beat-to-beat analysis to the comparison of episode markers (e.g., for VT/VF detection algorithms). For testing the quality of waveform boundary detection, our own testing methods have been implemented in compliance with existing literature.

  19. An Analysis Method for Superconducting Resonator Parameter Extraction with Complex Baseline Removal

    NASA Technical Reports Server (NTRS)

    Cataldo, Giuseppe

    2014-01-01

    A new semi-empirical model is proposed for extracting the quality (Q) factors of arrays of superconducting microwave kinetic inductance detectors (MKIDs). The determination of the total internal and coupling Q factors enables the computation of the loss in the superconducting transmission lines. The method used allows the simultaneous analysis of multiple interacting discrete resonators with the presence of a complex spectral baseline arising from reflections in the system. The baseline removal allows an unbiased estimate of the device response as measured in a cryogenic instrumentation setting.

  20. Extraction of Resonance Parameters and Role of the Final State Interactions

    NASA Astrophysics Data System (ADS)

    Strakovsky, Igor I.; Briscoe, William J.; Kudryavtsev, Alexander E.; Tarasov, Vladimir E.

    2014-01-01

    We present an overview of the SAID group effort to analyze new γn → π-p cross sections vs. the world database to get new multipoles and determine neutron electromagnetic couplings. The differential cross section for the processes γn → π-p was extracted from new measurements at CLAS and MAMI-B accounting for Fermi motion effects in the impulse approximation (IA) as well as NN- and πN-FSI effects beyond the IA. We evaluated results of several pion photoproduction analyses and compared πN PWA results as a constraint for analyses of pion photoproduction data (Watson's theorem).

  1. A compact model and direct parameters extraction techniques For amorphous gallium-indium-zinc-oxide thin film transistors

    NASA Astrophysics Data System (ADS)

    Moldovan, Oana; Castro-Carranza, Alejandra; Cerdeira, Antonio; Estrada, Magali; Barquinha, Pedro; Martins, Rodrigo; Fortunato, Elvira; Miljakovic, Slobodan; Iñiguez, Benjamin

    2016-12-01

    An advanced compact and analytical drain current model for the amorphous gallium indium zinc oxide (GIZO) thin film transistors (TFTs) is proposed. Its output saturation behavior is improved by introducing a new asymptotic function. All model parameters were extracted using an adapted version of the Universal Method and Extraction Procedure (UMEM) applied for the first time for GIZO devices in a simple and direct form. We demonstrate the correct behavior of the model for negative VDS, a necessity for a complete compact model. In this way we prove the symmetry of source and drain electrodes and extend the range of applications to both signs of VDS. The model, in Verilog-A code, is implemented in Electronic Design Automation (EDA) tools, such as Smart Spice, and compared with measurements of TFTs. It describes accurately the experimental characteristics in the whole range of GIZO TFTs operation, making the model suitable for the design of circuits using these types of devices.

  2. Extraction of frequency-dependent reflection, transmission, and scattering parameters for short metal reflectors from FEM-BEM simulations.

    PubMed

    Härmä, Sanna; Plessky, Victor P

    2008-04-01

    Reflectors comprised of only a single or a few electrodes provide controllable, weak reflectivity essential for surface acoustic wave (SAW) radi -frequency identification (RFID) tags. The reflection, transmission, and scattering parameters of such reflectors must be known as a function of frequency in order to be able to control the amplitudes of tag responses and to use phase-based encoding reliably. In this work, we present a method of extracting the main reflection, transmission, and scattering parameters for short metal reflectors as a function of frequency. We use test device S parameters obtained through finite- and boundaryelement method (FEM-BEM)-based simulations and, as an example, determine the reflection and transmission coefficients (their absolute values and phase angles) and the energy scattered into bulk for a few different single electrode reflectors. We compare these parameter values to earlier results. Although only used for simulated data in this work, the same method can be applied to measured data as well. Assuming the S parameters available, this method is very fast and does not require any heavy calculation or special software.

  3. Application of the L-curve in geophysical inverse problems: methodologies for the extraction of the optimal parameter

    NASA Astrophysics Data System (ADS)

    Bassrei, A.; Terra, F. A.; Santos, E. T.

    2007-12-01

    Inverse problems in Applied Geophysics are usually ill-posed. One way to reduce such deficiency is through derivative matrices, which are a particular case of a more general family that receive the name regularization. The regularization by derivative matrices has an input parameter called regularization parameter, which choice is already a problem. It was suggested in the 1970's a heuristic approach later called L-curve, with the purpose to provide the optimum regularization parameter. The L-curve is a parametric curve, where each point is associated to a λ parameter. In the horizontal axis one represents the error between the observed data and the calculated one and in the vertical axis one represents the product between the regularization matrix and the estimated model. The ideal point is the L-curve knee, where there is a balance between the quantities represented in the Cartesian axes. The L-curve has been applied to a variety of inverse problems, also in Geophysics. However, the visualization of the knee is not always an easy task, in special when the L-curve does not the L shape. In this work three methodologies are employed for the search and obtainment of the optimal regularization parameter from the L curve. The first criterion is the utilization of Hansen's tool box which extracts λ automatically. The second criterion consists in to extract visually the optimal parameter. By third criterion one understands the construction of the first derivative of the L-curve, and the posterior automatic extraction of the inflexion point. The utilization of the L-curve with the three above criteria were applied and validated in traveltime tomography and 2-D gravity inversion. After many simulations with synthetic data, noise- free as well as data corrupted with noise, with the regularization orders 0, 1, and 2, we verified that the three criteria are valid and provide satisfactory results. The third criterion presented the best performance, specially in cases where

  4. Neuromonitoring of cochlea and auditory nerve with multiple extracted parameters during induced hypoxia and nerve manipulation

    NASA Astrophysics Data System (ADS)

    Bohórquez, Jorge; Özdamar, Özcan; Morawski, Krzysztof; Telischi, Fred F.; Delgado, Rafael E.; Yavuz, Erdem

    2005-06-01

    A system capable of comprehensive and detailed monitoring of the cochlea and the auditory nerve during intraoperative surgery was developed. The cochlear blood flow (CBF) and the electrocochleogram (ECochGm) were recorded at the round window (RW) niche using a specially designed otic probe. The ECochGm was further processed to obtain cochlear microphonics (CM) and compound action potentials (CAP).The amplitude and phase of the CM were used to quantify the activity of outer hair cells (OHC); CAP amplitude and latency were used to describe the auditory nerve and the synaptic activity of the inner hair cells (IHC). In addition, concurrent monitoring with a second electrophysiological channel was achieved by recording compound nerve action potential (CNAP) obtained directly from the auditory nerve. Stimulation paradigms, instrumentation and signal processing methods were developed to extract and differentiate the activity of the OHC and the IHC in response to three different frequencies. Narrow band acoustical stimuli elicited CM signals indicating mainly nonlinear operation of the mechano-electrical transduction of the OHCs. Special envelope detectors were developed and applied to the ECochGm to extract the CM fundamental component and its harmonics in real time. The system was extensively validated in experimental animal surgeries by performing nerve compressions and manipulations.

  5. Concentration of Tea Extracts by Osmotic Evaporation: Optimisation of Process Parameters and Effect on Antioxidant Activity

    PubMed Central

    Marques, Marisa P.; Alves, Vítor D.; Coelhoso, Isabel M.

    2016-01-01

    In this work, the concentration process of three different tea extracts (medicinal Rosil No. 6, Black, and Forest Fruit teas) using the osmotic evaporation (OE) process, was studied. The effect of the OE process on the content of phenolic compounds and antioxidant activity was evaluated. The concentration process was carried out in a hollow-fibre membrane contactor with an effective surface area of 0.54 m2. The tea extract was circulated through the shell side of the contactor, while a concentrated osmotic solution (CaCl2 5 M) was circulated inside the fibres. The flux, the driving force, and the mass transfer coefficient were evaluated. A decrease of the water flux over time was observed and was attributed only to the decrease of the driving force, caused by the dilution of the osmotic solution. Using a surface area/feed volume ratio of 774 m2·m−3, it is possible to reach a tea concentration of 40% (w/w) in 5 h, with a constant water flux and without losing the phenolic content and antioxidant potential in most teas. PMID:28036043

  6. Extraction of vibration parameters from optical feedback interferometry signals using wavelets.

    PubMed

    Jha, Ajit; Azcona, Francisco J; Yañez, Carlos; Royo, Santiago

    2015-12-01

    This paper proposes the use of the wavelet transform as a technique that is suited for fringe detection and analysis of optical feedback interferometry (OFI) signals, thus allowing the retrieval of extremely small physical motion phenomena. A novel algorithm based on wavelet transform is used to process the OFI signal simultaneously in the time and frequency domains, enabling precise detection of signal fringes and, thus, the extraction of amplitude features of the vibrating target with error in the order of 0.1λ. Furthermore, using a complex Morlet wavelet as an analyzing wavelet enables us to extract important information from the time envelope of the OFI signal. Such an envelope can be useful in detecting fringes even in the presence of speckle reducing the error in a displacement reconstruction. Examples of OFI applications, including nanometric displacement sensing without direction ambiguity as well as the measurement of the frequency and velocity of vibrating targets and the detection in time of no periodic events, are also presented using this wavelet approach.

  7. [Research on and application of hybrid optimization algorithm in Brillouin scattering spectrum parameter extraction problem].

    PubMed

    Zhang, Yan-jun; Zhang, Shu-guo; Fu, Guang-wei; Li, Da; Liu, Yin; Bi, Wei-hong

    2012-04-01

    This paper presents a novel algorithm which blends optimize particle swarm optimization (PSO) algorithm and Levenberg-Marquardt (LM) algorithm according to the probability. This novel algorithm can be used for Pseudo-Voigt type of Brillouin scattering spectrum to improve the degree of fitting and precision of shift extraction. This algorithm uses PSO algorithm as the main frame. First, PSO algorithm is used in global search, after a certain number of optimization every time there generates a random probability rand (0, 1). If rand (0, 1) is less than or equal to the predetermined probability P, the optimal solution obtained by PSO algorithm will be used as the initial value of LM algorithm. Then LM algorithm is used in local depth search and the solution of LM algorithm is used to replace the previous PSO algorithm for optimal solutions. Again the PSO algorithm is used for global search. If rand (0, 1) was greater than P, PSO algorithm is still used in search, waiting the next optimization to generate random probability rand (0, 1) to judge. Two kinds of algorithms are alternatively used to obtain ideal global optimal solution. Simulation analysis and experimental results show that the new algorithm overcomes the shortcomings of single algorithm and improves the degree of fitting and precision of frequency shift extraction in Brillouin scattering spectrum, and fully prove that the new method is practical and feasible.

  8. Extraction of circuital parameters of organic solar cells using the exact solution based on Lambert W-function

    NASA Astrophysics Data System (ADS)

    Del Pozo, G.; Romero, B.; Arredondo, B.

    2012-06-01

    The electrical behavior of organic solar cell (OSC) has been analyzed using a simple circuital model consisting on an ideal diode together with a series and parallel resistances (RS and RP respectively). Applying Kirchhoff's Laws to the circuit leads to a transcendental equation that can be solved numerically without approximations using the Lambert W function. Theoretical expression has been fitted to experimental current-voltage (I-V) curves under forward bias, obtaining fairly accurate values for the electrical parameters. This model has been validated comparing the extracted parameters for dark and illumination conditions of different devices. Results show good agreement for RS, and ideality factor (η). Electrical parameters obtained in this work are also compared to those ones extracted using an approximated method often employed by other authors 1. We conclude that approximated method leads to reasonable good values for RS, RP and η. However, in the case of Rp the voltage range chosen to fit the data with the exact method must be constrained to the fourth quadrant, where the role of parallel resistance is more critical. To validate the model, a bunch of organic solar cells with structure ITO/ poly(3,4-ethylenedioxythiophene)-poly (4-styrene sulfonate (PEDOT:PSS)/ poly(3-hexylthiophene) (P3HT): 1-(3-methoxycarbonyl)-propyl-1-1-phenyl-(6,6)C61 (PCBM)/Al has been fabricated in inert atmosphere. Different active layers were deposited varying the P3HT:PCBM ratio (1:0.64, 1:1, 1:1.55) and the active layer thickness (ranging from 100 to 280 nm). Devices are encapsulated inside the glove-box prior its characterization outside the glove-box. Electro optical characterization has been performed with a halogen lamp. Values extracted for RS range from 142 Ω to 273 Ω, values for RP range from 25 kΩ to 331 kΩ. Ideality factor ranges from 5 to 17.

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

    NASA Astrophysics Data System (ADS)

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

    2011-04-01

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

  10. Extracting dimensional geometric parameters from B-spline surface models of aircraft

    NASA Technical Reports Server (NTRS)

    Jayaram, U.; Myklebust, Arvid; Gelhausen, P.

    1992-01-01

    Research that creates techniques to automatically obtain dimensional geometric parameters from the nonuniform B-spline surface description of an object is presented. These techniques have been implemented successfully in the aircraft design software, ACSYNT, a computer-aided design system for conceptual aircraft design created at Virginia Tech and NASA Ames. The techniques created and implemented in this research are also of significance to general-purpose design.

  11. Poincare Plots and Symbolic Dynamics Patterns of Left Ventricular Function Parameters Extracted From Echocardiographic Acoustic Quantification

    DTIC Science & Technology

    2007-11-02

    N/A Dates Covered (from... to) - Title and Subtitle Poincare Plots and Symbolic Dynamics Patterns of Left Ventricular Function Parameters...IV. POINCARE ’ PLOTS ANALYSIS Poincarè plot analysis is a simple and robust graphical technique based on the analysis of the maps obtained by...Fortuin, et al. Ecocardiographic assessment of a normal adult aging population. Circulation 1977;56:273-278. [13] J.M. Gardin, W.L. Henry , D.D. Savage, J

  12. Back to the Future: Have Remotely Sensed Digital Elevation Models Improved Hydrological Parameter Extraction?

    NASA Astrophysics Data System (ADS)

    Jarihani, B.

    2015-12-01

    Digital Elevation Models (DEMs) that accurately replicate both landscape form and processes are critical to support modeling of environmental processes. Pre-processing analysis of DEMs and extracting characteristics of the watershed (e.g., stream networks, catchment delineation, surface and subsurface flow paths) is essential for hydrological and geomorphic analysis and sediment transport. This study investigates the status of the current remotely-sensed DEMs in providing advanced morphometric information of drainage basins particularly in data sparse regions. Here we assess the accuracy of three available DEMs: (i) hydrologically corrected "H-DEM" of Geoscience Australia derived from the Shuttle Radar Topography Mission (SRTM) data; (ii) the Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model (ASTER GDEM) version2 1-arc-second (~30 m) data; and (iii) the 9-arc-second national GEODATA DEM-9S ver3 from Geoscience Australia and the Australian National University. We used ESRI's geospatial data model, Arc Hydro and HEC-GeoHMS, designed for building hydrologic information systems to synthesize geospatial and temporal water resources data that support hydrologic modeling and analysis. A coastal catchment in northeast Australia was selected as the study site where very high resolution LiDAR data are available for parts of the area as reference data to assess the accuracy of other lower resolution datasets. This study provides morphometric information for drainage basins as part of the broad research on sediment flux from coastal basins to Great Barrier Reef, Australia. After applying geo-referencing and elevation corrections, stream and sub basins were delineated for each DEM. Then physical characteristics for streams (i.e., length, upstream and downstream elevation, and slope) and sub-basins (i.e., longest flow lengths, area, relief and slopes) were extracted and compared with reference datasets from LiDAR. Results showed that

  13. The effect of heracleum persicum (Golpar) oil and alcoholic extracts on sperm parameters and chromatin quality in mice

    PubMed Central

    Taghizabet, Neda; Mangoli, Esmat; Anbari, Fatemeh; Masoodi, Seyed Ali; Talebi, Ali Reza; Mazrooei, Malihe

    2016-01-01

    Background: Evaluating the significance and the effects of plant-derived drugs on laboratory animal’s fertility was recognized. There was antioxidant activity reported from Heracleum persicum (Golpar). Objective: Current study aims to study the antioxidant effect of Golpar extracts on sperm parameters and chromatin quality in mice. Materials and Methods: Eighteen adult male mice were divided to 3 groups (10 wk old, 35 gr weight): group1 received hydro alcoholic extract (1000 mg/kg, ip), group 2 received oil extract (200 mg/kg, ip) and group 3 serving as the sham control group that received sterile water. Finally, left cauda epididymis of each animal was dissected and sperm analysis was done accordingly. To asses sperm chromatin and DNA quality, we used aniline blue (AB), toluidine blue (TB), chromomycin A3 (CMA3) and acridine orange (AO) staining. Results: Progressive and non-progressive sperm motility were significantly increased in group 1 in comparison with group 3 (p=0.032). There was an increasing trend in progressive sperm motility and decreasing trend in non-progressive sperm motility in group 2 in comparison with group 3, but the differences were not significant (p=0.221 and p=0.144, respectively). According to the sperm chromatin quality, the results of TB and AO tests revealed significant differences (p=0.004, p=0.000, respectively) between those groups and showed that the extracts of Golpar cause DNA damage, but no differences can be observed between them in AB and CMA3 staining (p>0.05). Conclusion: The results showed that Heracleum persicum extracts may improve sperm motility. Also, it has harmful effects on sperm chromatin condensation and DNA integrity in mice. PMID:27525319

  14. Extracting full-field dynamic strain on a wind turbine rotor subjected to arbitrary excitations using 3D point tracking and a modal expansion technique

    NASA Astrophysics Data System (ADS)

    Baqersad, Javad; Niezrecki, Christopher; Avitabile, Peter

    2015-09-01

    Health monitoring of rotating structures such as wind turbines and helicopter rotors is generally performed using conventional sensors that provide a limited set of data at discrete locations near or on the hub. These sensors usually provide no data on the blades or inside them where failures might occur. Within this paper, an approach was used to extract the full-field dynamic strain on a wind turbine assembly subject to arbitrary loading conditions. A three-bladed wind turbine having 2.3-m long blades was placed in a semi-built-in boundary condition using a hub, a machining chuck, and a steel block. For three different test cases, the turbine was excited using (1) pluck testing, (2) random impacts on blades with three impact hammers, and (3) random excitation by a mechanical shaker. The response of the structure to the excitations was measured using three-dimensional point tracking. A pair of high-speed cameras was used to measure displacement of optical targets on the structure when the blades were vibrating. The measured displacements at discrete locations were expanded and applied to the finite element model of the structure to extract the full-field dynamic strain. The results of the paper show an excellent correlation between the strain predicted using the proposed approach and the strain measured with strain-gages for each of the three loading conditions. The approach used in this paper to predict the strain showed higher accuracy than the digital image correlation technique. The new expansion approach is able to extract dynamic strain all over the entire structure, even inside the structure beyond the line of sight of the measurement system. Because the method is based on a non-contacting measurement approach, it can be readily applied to a variety of structures having different boundary and operating conditions, including rotating blades.

  15. Use of solid-phase extraction in various of its modalities for sample preparation in the determination of estrogens and progestogens in sediment and water.

    PubMed

    Lópezde Alda, M J; Barceló, D

    2001-12-14

    The environmental analysis of estrogens and progestogens at physiologically active concentrations (low ng/l range) requires the use of very sensitive and selective methods, which, in most cases, make necessary an extraction/purification step. In this study, various procedures for the determination of several estrogens (estriol, estradiol, ethynyl estradiol, estrone, and diethylstilbestrol) and progestogens (progesterone, norethindrone, and levonorgestrel) in environmental matrices, including water and river sediment, are described. In all procedures, final analysis of the target compounds is performed by reversed-phase liquid chromatography-diode array detection-mass spectrometry, whereas sample preparation always includes a solid-phase extraction (SPE) step. For this SPE step. various types of sorbents, protocols, and devices have been used, and their respective advantages and disadvantages are discussed. For the off-line SPE of estrogens and progestogens from water samples, a syringe type cartridge LiChrolut RP-18 (500 mg) was selected out of two other sorbents--LiChrolut EN (200 mg) and Isolut ENV (500 mg)--for use with the automated sample preparation instrument ASPEC XL. For the on-line SPE and analysis of water samples the 10 mm x 2 mm I.D. HySphere-Resin-GP cartridge, was preferred to the C18 Baker, the PLRP-S, and the Oasis HLB. for use with the Prospekt system. A completely manual protocol based on the use of Sep-Pak C18 Plus cartridges was developed for purification of sediment extracts. All procedures were shown to be linear over a wide range of concentration, exhibited satisfactory repeatability and accuracy, and reached limits of detection usually in the low ng/l and ng/g range. Comparatively, the on-line method was shown to be advantageous in terms of automation and general method performance.

  16. An exploratory clustering approach for extracting stride parameters from tracking collars on free-ranging wild animals.

    PubMed

    Dewhirst, Oliver P; Roskilly, Kyle; Hubel, Tatjana Y; Jordan, Neil R; Golabek, Krystyna A; McNutt, J Weldon; Wilson, Alan M

    2017-02-01

    Changes in stride frequency and length with speed are key parameters in animal locomotion research. They are commonly measured in a laboratory on a treadmill or by filming trained captive animals. Here, we show that a clustering approach can be used to extract these variables from data collected by a tracking collar containing a GPS module and tri-axis accelerometers and gyroscopes. The method enables stride parameters to be measured during free-ranging locomotion in natural habitats. As it does not require labelled data, it is particularly suitable for use with difficult to observe animals. The method was tested on large data sets collected from collars on free-ranging lions and African wild dogs and validated using a domestic dog. © 2017. Published by The Company of Biologists Ltd.

  17. Note: Hybrid-π model and parameter extraction method for electrode-electrolyte interface characterization with superbly accurate reactance

    NASA Astrophysics Data System (ADS)

    Hong, Yan; Goh, Wang Ling; Wang, Yong

    2017-08-01

    This paper presents an equivalent circuit model for the electrode-electrolyte interface and aims at improving the modeling accuracy of the parasitic effects at frequencies up to 300 MHz. Different from the conventional model, the electrode inductances, body loss capacitances, and body loss resistances are all included in the proposed hybrid-π model. In addition, the S-parameters obtained by a vector network analyzer are innovatively used to extract the parameters of the electrode-electrolyte interface model for a frequency range from 10 Hz to 300 MHz. Since reactance is proportional to frequency, the proposed technique can precisely calculate the parasitic effects at higher frequencies. Verified by experiments, the hybrid-π model presents better accuracies when fitted to both the phases and magnitudes of S11 and S21. The superb modeling accuracy of this work is beneficial for biomedical applications that have an electrode-electrolyte interface.

  18. Adaptive Modal Identification for Flutter Suppression Control

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan T.; Drew, Michael; Swei, Sean S.

    2016-01-01

    In this paper, we will develop an adaptive modal identification method for identifying the frequencies and damping of a flutter mode based on model-reference adaptive control (MRAC) and least-squares methods. The least-squares parameter estimation will achieve parameter convergence in the presence of persistent excitation whereas the MRAC parameter estimation does not guarantee parameter convergence. Two adaptive flutter suppression control approaches are developed: one based on MRAC and the other based on the least-squares method. The MRAC flutter suppression control is designed as an integral part of the parameter estimation where the feedback signal is used to estimate the modal information. On the other hand, the separation principle of control and estimation is applied to the least-squares method. The least-squares modal identification is used to perform parameter estimation.

  19. A motion algorithm to extract physical and motion parameters of mobile targets from cone-beam computed tomographic images.

    PubMed

    Alsbou, Nesreen; Ahmad, Salahuddin; Ali, Imad

    2016-05-17

    A motion algorithm has been developed to extract length, CT number level and motion amplitude of a mobile target from cone-beam CT (CBCT) images. The algorithm uses three measurable parameters: Apparent length and blurred CT number distribution of a mobile target obtained from CBCT images to determine length, CT-number value of the stationary target, and motion amplitude. The predictions of this algorithm are tested with mobile targets having different well-known sizes that are made from tissue-equivalent gel which is inserted into a thorax phantom. The phantom moves sinusoidally in one-direction to simulate respiratory motion using eight amplitudes ranging 0-20 mm. Using this motion algorithm, three unknown parameters are extracted that include: Length of the target, CT number level, speed or motion amplitude for the mobile targets from CBCT images. The motion algorithm solves for the three unknown parameters using measured length, CT number level and gradient for a well-defined mobile target obtained from CBCT images. The motion model agrees with the measured lengths which are dependent on the target length and motion amplitude. The gradient of the CT number distribution of the mobile target is dependent on the stationary CT number level, the target length and motion amplitude. Motion frequency and phase do not affect the elongation and CT number distribution of the mobile target and could not be determined. A motion algorithm has been developed to extract three parameters that include length, CT number level and motion amplitude or speed of mobile targets directly from reconstructed CBCT images without prior knowledge of the stationary target parameters. This algorithm provides alternative to 4D-CBCT without requirement of motion tracking and sorting of the images into different breathing phases. The motion model developed here works well for tumors that have simple shapes, high contrast relative to surrounding tissues and move nearly in regular motion pattern

  20. Semi-modal active vibration control of plates using discrete piezoelectric modal filters

    NASA Astrophysics Data System (ADS)

    Trindade, Marcelo A.; Pagani, Carlos C.; Oliveira, Leopoldo P. R.

    2015-09-01

    Modal sensors and actuators working in closed loop enable to observe and control independently specific vibration modes, reducing the apparent dynamical complexity of the system and the necessary energy to control them. Modal sensors may be obtained by a properly designed weighted sum of the output signals of an array of sensors distributed on the host structure. Although some works found in the literature present techniques for designing and implementing modal filters based on a given array of sensors, the effect of the sensors' distribution on the modal filter performance has received little attention. Recent studies have shown that some parameters, such as size, shape and location of the sensors, are very important for the performance of the resulting modal filters. This work presents a methodology for the design of semi-modal active vibration control of a rectangular plate using modal filters based on arrays of piezoelectric sensors. The geometric distribution of the array of piezoelectric sensors bonded to a rectangular plate is numerically optimized to improve the effectiveness and frequency range of a set of modal filters. An experimental implementation of the modal filters is carried out in order to validate their performance. It is shown that proper setup of weighting coefficients is an important requirement. Then, two simple control laws, namely direct velocity feedback and positive position feedback, using the modal filter output are designed and implemented. It is shown that modal filtering allows to effectively control selected vibration modes with quite simple signal processing requirements.

  1. Rate-equation modelling and ensemble approach to extraction of parameters for viral infection-induced cell apoptosis and necrosis

    NASA Astrophysics Data System (ADS)

    Domanskyi, Sergii; Schilling, Joshua E.; Gorshkov, Vyacheslav; Libert, Sergiy; Privman, Vladimir

    2016-09-01

    We develop a theoretical approach that uses physiochemical kinetics modelling to describe cell population dynamics upon progression of viral infection in cell culture, which results in cell apoptosis (programmed cell death) and necrosis (direct cell death). Several model parameters necessary for computer simulation were determined by reviewing and analyzing available published experimental data. By comparing experimental data to computer modelling results, we identify the parameters that are the most sensitive to the measured system properties and allow for the best data fitting. Our model allows extraction of parameters from experimental data and also has predictive power. Using the model we describe interesting time-dependent quantities that were not directly measured in the experiment and identify correlations among the fitted parameter values. Numerical simulation of viral infection progression is done by a rate-equation approach resulting in a system of "stiff" equations, which are solved by using a novel variant of the stochastic ensemble modelling approach. The latter was originally developed for coupled chemical reactions.

  2. Rate-equation modelling and ensemble approach to extraction of parameters for viral infection-induced cell apoptosis and necrosis.

    PubMed

    Domanskyi, Sergii; Schilling, Joshua E; Gorshkov, Vyacheslav; Libert, Sergiy; Privman, Vladimir

    2016-09-07

    We develop a theoretical approach that uses physiochemical kinetics modelling to describe cell population dynamics upon progression of viral infection in cell culture, which results in cell apoptosis (programmed cell death) and necrosis (direct cell death). Several model parameters necessary for computer simulation were determined by reviewing and analyzing available published experimental data. By comparing experimental data to computer modelling results, we identify the parameters that are the most sensitive to the measured system properties and allow for the best data fitting. Our model allows extraction of parameters from experimental data and also has predictive power. Using the model we describe interesting time-dependent quantities that were not directly measured in the experiment and identify correlations among the fitted parameter values. Numerical simulation of viral infection progression is done by a rate-equation approach resulting in a system of "stiff" equations, which are solved by using a novel variant of the stochastic ensemble modelling approach. The latter was originally developed for coupled chemical reactions.

  3. Extracting Host Galaxy Dispersion Measure and Constraining Cosmological Parameters using Fast Radio Burst Data

    NASA Astrophysics Data System (ADS)

    Yang, Yuan-Pei; Zhang, Bing

    2016-10-01

    The excessive dispersion measures (DMs) and high Galactic latitudes of fast radio bursts (FRBs) hint toward a cosmological origin of these mysterious transients. Methods of using measured DM and redshift z to study cosmology have been proposed, but one needs to assume a certain amount of DM contribution from the host galaxy ({{DM}}{HG}) in order to apply those methods. We introduce a slope parameter β (z)\\equiv d{ln}< {{DM}}{{E}}> /d{ln}z (where {{DM}}{{E}} is the observed DM subtracting the Galactic contribution), which can be directly measured when a sample of FRBs have z measured. We show that < {{DM}}{HG}> can be roughly inferred from β and the mean values, \\overline{< {{DM}}{{E}}> } and \\bar{z}, of the sample. Through Monte Carlo simulations, we show that the mean value of local host galaxy DM, < {{DM}}{HG,{loc}}> , along with other cosmological parameters (mass density {{{Ω }}}m in the ΛCDM model, and the IGM portion of the baryon energy density {{{Ω }}}b{f}{IGM}), can be independently measured through Markov Chain Monte Carlo fitting to the data.

  4. Extracting intrinsic dynamic parameters of biomolecular folding from single-molecule force spectroscopy experiments.

    PubMed

    Nam, Gi-Moon; Makarov, Dmitrii E

    2016-01-01

    Single-molecule studies in which a mechanical force is transmitted to the molecule of interest and the molecular extension or position is monitored as a function of time are versatile tools for probing the dynamics of protein folding, stepping of molecular motors, and other biomolecular processes involving activated barrier crossing. One complication in interpreting such studies, however, is the fact that the typical size of a force probe (e.g., a dielectric bead in optical tweezers or the atomic force microscope tip/cantilever assembly) is much larger than the molecule itself, and so the observed molecular motion is affected by the hydrodynamic drag on the probe. This presents the experimenter with a nontrivial task of deconvolving the intrinsic molecular parameters, such as the intrinsic free energy barrier and the effective diffusion coefficient exhibited while crossing the barrier from the experimental signal. Here we focus on the dynamical aspect of this task and show how the intrinsic diffusion coefficient along the molecular reaction coordinate can be inferred from single-molecule measurements of the rates of biomolecular folding and unfolding. We show that the feasibility of accomplishing this task is strongly dependent on the relationship between the intrinsic molecular elasticity and that of the linker connecting the molecule to the force probe and identify the optimal range of instrumental parameters allowing determination of instrument-free molecular dynamics. © 2015 The Protein Society.

  5. Theoretical uncertainties in extracting cosmic-ray diffusion parameters: the boron-to-carbon ratio

    NASA Astrophysics Data System (ADS)

    Genolini, Yoann

    2016-05-01

    PAMELA and, more recently, AMS-02, are ushering us into a new era of greatly reduced statistical uncertainties in experimental measurements of cosmic ray fluxes. In particular, new determinations of traditional diagnostic tools such as the boron to carbon ratio (B/C) are expected to significantly reduce errors on cosmic-ray diffusion parameters, with important implications for astroparticle physics, ranging from inferring primary source spectra to indirect dark matter searches. It is timely to stress, however, that the conclusions inferred crucially depend on the framework in which the data are interpreted as well as on some nuclear input parameters. We aim at assessing the theoretical uncertainties affecting the outcome, with models as simple as possible while still retaining the key dependences. We compare different semi-analytical, two-zone model descriptions of cosmic ray transport in the Galaxy: infinite slab(lD), cylindrical symmetry (2D) with homogeneous sources, cylindrical symmetry (2D) with inhomogeneous source distribution. We tested for the effect of a primary source contamination in the boron flux by parametrically altering its flux. We also tested for nuclear cross-section uncertainties.

  6. Effective Glottal Instant Detection and Electroglottographic Parameter Extraction for Automated Voice Pathology Assessment.

    PubMed

    Deshpande, Pranav; Manikandan, M Sabarimalai

    2017-01-17

    Accurate determination of glottal instants and electroglottographic (EGG) parameters is most important in voice pathology analysis including multiple voice disorders: neurological, functional, and laryngeal diseases. In this paper, we present a new effective method for reliable detection of glottal instants and EGG parameters from an EGG signal composed of voiced and non-voice segments. In the first stage, we present an adaptive variational mode decomposition (aVMD) based algorithm for suppressing low-frequency artifacts and additive high-frequency noises. Based upon mode center frequency criterion, the proposed method first constructs a candidate EGG feature signal for determination of glottal closure and opening instants. In the second stage, the candidate glottal instants are determined by detecting the positive and negative zerocrossings in normalized candidate EGG feature signal, respectively. Finally, an autocorrelation features based postprocessing algorithm is presented to reject non-glottal instants from the non-speech production segments. The accuracy and robustness of the method is tested using noise-free and noisy EGG signals. Evaluation results show that the proposed method achieves an average overall accuracy (OA) of 95.06%, identification rate (IR) of 95.34%, missed rate (MR) of 3.60% and false alarm rate (FAR) of 0.06% with average absolute identification error of 0.71 0.66 ms for a SNR of 15 dB. Results demonstrate that the proposed method significantly outperforms the other existing methods under both noise-free and noisy EGG signals.

  7. Effects of Common Fig (Ficus carica) Leaf Extracts on Sperm Parameters and Testis of Mice Intoxicated with Formaldehyde

    PubMed Central

    Naghdi, Majid; Maghbool, Maryam; Seifalah-Zade, Morteza; Mahaldashtian, Maryam; Makoolati, Zohreh; Kouhpayeh, Seyed Amin; Ghasemi, Afsaneh; Fereydouni, Narges

    2016-01-01

    Formaldehyde (FA) is the leading cause of cellular injury and oxidative damage in testis that is one of the main infertility causes. There has been an increasing evidence of herbal remedies use in male infertility treatment. This assay examines the role of Ficus carica (Fc) leaf extracts in sperm parameters and testis of mice intoxicated with FA. Twenty-five adult male mice were randomly divided into control; sham; FA-treated (10 mg/kg twice per day); Fc-treated (200 mg/kg); and FA + Fc-treated groups. Cauda epididymal spermatozoa were analyzed for viability, count, and motility. Testes were weighed and gonadosomatic index (GSI) was calculated. Also, histoarchitecture of seminiferous tubules was assessed in the Haematoxylin and Eosin stained paraffin sections. The findings showed that FA significantly decreased GSI and increased percentage of immotile sperm compared with control group. Disorganized and vacuolated seminiferous epithelium, spermatogenic arrest, and lumen filled with immature germ cells were also observed in the testes. However, Fc leaf extracts improved sperm count, nonprogressive motility of spermatozoa, and GSI in FA-treated testes. Moreover, seminiferous tubule with spermatogenic arrest was rarely seen, indicating that Fc has the positive effects on testis and epididymal sperm parameters exposed with FA. PMID:26904140

  8. Effect of Aqueous Stem Bark Extract of Khaya senegalensis on Some Biochemical, Haematological, and Histopathological Parameters of Rats.

    PubMed

    Onu, A; Saidu, Y; Ladan, M J; Bilbis, L S; Aliero, A A; Sahabi, S M

    2013-01-01

    The subchronic effect of aqueous stem bark extract of Khaya senegalensis on some biochemical, haematological, and histopathological parameters of rats was investigated. The rats were divided into six groups of five rats per group. Groups I to VI were administered graded doses of 0, 400, 800, 1200, 1600, and 2000 mg/kg bw, respectively. The result of study revealed that administration of the Khaya senegalensis for twenty-eight days at the experimental dose resulted in significant (P < 0.05) increase in urea, electrolytes (Na(+), K(+)), and creatinine levels. The extract also significantly (P < 0.05) increased serum activity of ALT, AST, and ALP. The levels of protein, albumin, and bilirubin were significantly changed when compared to their control values, but they were not dose dependent. The hematological indices assayed in this study were not significantly affected at the experimental dose when compared to the control values. Histological studies of the liver showed cellular degeneration and necrosis and bile duct hyperplasia and fibrosis with lymphocytic infiltration of the hepatocyte, providing supportive evidence for discussing the biochemical findings, indicative of functional derangement. The histological architecture of the kidney and that of the heart were however preserved. The result of this study indicates that the aqueous stem bark extract of K. senegalensis may affect the cellular integrity of vital organs of the body.

  9. Effect of Aqueous Stem Bark Extract of Khaya senegalensis on Some Biochemical, Haematological, and Histopathological Parameters of Rats

    PubMed Central

    Onu, A.; Saidu, Y.; Ladan, M. J.; Bilbis, L. S.; Aliero, A. A.; Sahabi, S. M.

    2013-01-01

    The subchronic effect of aqueous stem bark extract of Khaya senegalensis on some biochemical, haematological, and histopathological parameters of rats was investigated. The rats were divided into six groups of five rats per group. Groups I to VI were administered graded doses of 0, 400, 800, 1200, 1600, and 2000 mg/kg bw, respectively. The result of study revealed that administration of the Khaya senegalensis for twenty-eight days at the experimental dose resulted in significant (P < 0.05) increase in urea, electrolytes (Na+, K+), and creatinine levels. The extract also significantly (P < 0.05) increased serum activity of ALT, AST, and ALP. The levels of protein, albumin, and bilirubin were significantly changed when compared to their control values, but they were not dose dependent. The hematological indices assayed in this study were not significantly affected at the experimental dose when compared to the control values. Histological studies of the liver showed cellular degeneration and necrosis and bile duct hyperplasia and fibrosis with lymphocytic infiltration of the hepatocyte, providing supportive evidence for discussing the biochemical findings, indicative of functional derangement. The histological architecture of the kidney and that of the heart were however preserved. The result of this study indicates that the aqueous stem bark extract of K. senegalensis may affect the cellular integrity of vital organs of the body. PMID:24348549

  10. The effect of Ipomoea reptans poir ethanolic extract on the histopathological parameters of pancreas in streptozotocin-induced diabetic rats

    NASA Astrophysics Data System (ADS)

    Hayati, Farida; Widyarini, Sitarina; Lanova, Lulung; Wijayanti, Marsih

    2017-03-01

    The aim of this study was to investigate the effect of ethanolic extract of Ipomoea reptans Poir in male Wistar rats on the histopathological parameters of the pancreas. The rats (N=30) were divided into six groups, each consisting of five rats. The treatment groups were divided into: group I as the normal group fed ad libitum during the research, group II as the positive control administered glibenclamide 0.09 mg/200g BW, group III as the negative control given aquadest, and group IV to VI given ethanolic extract of Ipomoea reptans Poir as much as 200 mg/KgBW, 400 mg/KgBW and 600 mg/KgBW respectively. The study of antidiabetic effect was undertaken by oral administration for 21 days. On the 21st day, all the rats were dissected to prepare histopathological preparates through Gomori's chrome alum hematoxylin-phloxine staining method. The histopathological study showed that the ethanol extract of Ipomoea reptans Poir at a dose of 200 mg/KgBW and 400mg/KgBW had an antidiabetic activity through protection of pancreatic β-cell from damage in male Wistar rats induced by streptozotocin.

  11. Effect of dietary supplementation with propolis and Aloe barbadensis extracts on hematological parameters and parasitism in Nile tilapia.

    PubMed

    Dotta, Geovana; Brum, Aline; Jeronimo, Gabriela Tomas; Maraschin, Marcelo; Martins, Maurício Laterça

    2015-01-01

    This study evaluated the influence of diet supplementation with propolis and Aloe barbadensis on hematological parameters and parasitism in tilapia. One hundred and eighty fish were distributed among 12 water tanks forming four treatments: fish supplemented with a 1:1 mixture of 0%, 0.5%, 1% and 2% propolis and aloe extracts. After the fish had been fed on the experimental diets for 15 and 21 days, blood samples were taken and parasites collected. The monogeneans Cichlidogyrus sclerosus, C. halli, C. thurstonae and Scutogyrus longicornis were identified in the gills. Between the sampling times, there were increases in the numbers of erythrocytes, leukocytes, thrombocytes and lymphocytes, as observed after 21 days, possibly due to the stress level over the course of the assay and/or accumulation of substances in the organism. Supplementation with the mixture of propolis and aloe for 15 days showed the highest efficacy against the parasites. This was possibly due to the association between the two compounds. The results demonstrated that supplementation with mixtures of extracts did not produce hematological alterations and also favored a significant reduction in the number of gill parasites. The best results were achieved after 15 days of feeding with a diet with 0.5% and 1% supplementation with the extract mixture, which increased efficiency by 83 and 85% respectively.

  12. Comparison of automatic denoising methods for phonocardiograms with extraction of signal parameters via the Hilbert Transform

    NASA Astrophysics Data System (ADS)

    Messer, Sheila R.; Agzarian, John; Abbott, Derek

    2001-05-01

    Phonocardiograms (PCGs) have many advantages over traditional auscultation (listening to the heart) because they may be replayed, may be analyzed for spectral and frequency content, and frequencies inaudible to the human ear may be recorded. However, various sources of noise may pollute a PCG including lung sounds, environmental noise and noise generated from contact between the recording device and the skin. Because PCG signals are known to be nonlinear and it is often not possible to determine their noise content, traditional de-noising methods may not be effectively applied. However, other methods including wavelet de-noising, wavelet packet de-noising and averaging can be employed to de-noise the PCG. This study examines and compares these de-noising methods. This study answers such questions as to which de-noising method gives a better SNR, the magnitude of signal information that is lost as a result of the de-noising process, the appropriate uses of the different methods down to such specifics as to which wavelets and decomposition levels give best results in wavelet and wavelet packet de-noising. In general, the wavelet and wavelet packet de-noising performed roughly equally with optimal de-noising occurring at 3-5 levels of decomposition. Averaging also proved a highly useful de- noising technique; however, in some cases averaging is not appropriate. The Hilbert Transform is used to illustrate the results of the de-noising process and to extract instantaneous features including instantaneous amplitude, frequency, and phase.

  13. Basic Test Framework for the Evaluation of Text Line Segmentation and Text Parameter Extraction

    PubMed Central

    Brodić, Darko; Milivojević, Dragan R.; Milivojević, Zoran

    2010-01-01

    Text line segmentation is an essential stage in off-line optical character recognition (OCR) systems. It is a key because inaccurately segmented text lines will lead to OCR failure. Text line segmentation of handwritten documents is a complex and diverse problem, complicated by the nature of handwriting. Hence, text line segmentation is a leading challenge in handwritten document image processing. Due to inconsistencies in measurement and evaluation of text segmentation algorithm quality, some basic set of measurement methods is required. Currently, there is no commonly accepted one and all algorithm evaluation is custom oriented. In this paper, a basic test framework for the evaluation of text feature extraction algorithms is proposed. This test framework consists of a few experiments primarily linked to text line segmentation, skew rate and reference text line evaluation. Although they are mutually independent, the results obtained are strongly cross linked. In the end, its suitability for different types of letters and languages as well as its adaptability are its main advantages. Thus, the paper presents an efficient evaluation method for text analysis algorithms. PMID:22399932

  14. Range image segmentation and surface parameter extraction for a mobile robot

    SciTech Connect

    Goldstein, M.; Pin, F.G.; Weisbin, C.R.

    1987-01-01

    This paper presents a methodology for a concise representation of the 3-D world model for a mobile robot, using range data. The process starts with the segmentation of the scene into ''objects'' that are given a unique label, based on principles of range continuity. Then the external surface of each object is partitioned into homogeneous surface patches. Contours of surface patches in 3-D space are identified by estimating the normal and curvature associated with each pixel. The resulting surface patches are then classified as planar, convex or concave. Since the world model uses a volumetric representation for the 3-D environment, planar surfaces are represented by thin volumetric polyhedra. Spherical and clindrical surfaces are extracted and represented by appropriate volumetric primitives. All other surfaces are represented using the boolean union of spherical volumes (as described in a separate paper by the same authors). The result is a general, concise representation of the external 3-D world, which allows for efficient and robust 3-D object recognition. 20 refs., 14 figs.

  15. Surface functionalization of nanofibrillated cellulose extracted from wheat straw: Effect of process parameters.

    PubMed

    Singh, Mandeep; Kaushik, Anupama; Ahuja, Dheeraj

    2016-10-05

    Aggregates of microfibrillated cellulose isolated from wheat straw fibers were subjected to propionylation under different processing conditions of time, temperature and concentration. The treated fibers were then homogenized to obtain surface modified nanofibrillated cellulose. For varying parameters, progress of propionylation and its effects on various characteristics was investigated by FTIR, degree of substitution, elemental analysis, SEM, EDX, TEM, X-ray diffraction, static and dynamic contact angle measurements. Thermal stability of the nanofibrils was also investigated using thermogravimetric technique. FTIR analysis confirmed the propionylation of the hydroxyl groups of the cellulose fibers. The variations in reaction conditions such as time and temperature had shown considerable effect on degree of substitution (DS) and surface contact angle (CA). These characterization results represent the optimizing conditions under which cellulose nanofibrils with hydrophobic characteristics up to contact angle of 120° can be obtained.

  16. Quantification of pulmonary arterial wall distensibility using parameters extracted from volumetric micro-CT images

    NASA Astrophysics Data System (ADS)

    Johnson, Roger H.; Karau, Kelly L.; Molthen, Robert C.; Dawson, Christopher A.

    1999-09-01

    Stiffening, or loss of distensibility, of arterial vessel walls is among the manifestations of a number of vascular diseases including pulmonary arterial hypertension. We are attempting to quantify the mechanical properties of vessel walls of the pulmonary arterial tree using parameters derived from high-resolution volumetric x-ray CT images of rat lungs. The pulmonary arterial trees of the excised lungs are filled with a contrast agent. The lungs are imaged with arterial pressures spanning the physiological range. Vessel segment diameters are measured from the inlet to the periphery, and distensibilities calculated from diameters as a function of pressure. The method shows promise as an adjunct to other morphometric techniques such as histology and corrosion casting. It possesses the advantages of being nondestructive, characterizing the vascular structures while the lungs are imaged rapidly and in a near-physiological state, and providing the ability to associate mechanical properties with vessel location in the intact tree hierarchy.

  17. Extracting lunar dust parameters from image charge signals produced by the Lunar Dust Experiment

    NASA Astrophysics Data System (ADS)

    Stanley, J.; Kempf, S.; Horanyi, M.; Szalay, J.

    2015-12-01

    The Lunar Dust Experiment (LDEX) onboard the Lunar Atmosphere and Dust Environment Explorer (LADEE) is an impact ionization dust detector used to characterize the lunar dust exosphere generated by the impacts of large interplanetary particles and meteor streams (Horanyi et al., 2015). In addition to the mass and speed of these lofted particles, LDEX is sensitive to their charge. The resulting signatures of impact events therefore provide valuable information about not only the ambient plasma environment, but also the speed vectors of these dust grains. Here, impact events produced from LDEX's calibration at the Dust Accelerator Laboratory are analyzed using an image charge model derived from the electrostatic simulation program, Coulomb. We show that parameters such as dust grain speed, size, charge, and position of entry into LDEX can be recovered and applied to data collected during LADEE's seven-month mission.

  18. Phytochemical properties and pharmacological effects of Quercus ilex L. aqueous extract on gastrointestinal physiological parameters in vitro and in vivo.

    PubMed

    Rtibi, Kaïs; Hammami, Imen; Selmi, Slimen; Grami, Dhekra; Sebai, Hichem; Amri, Mohamed; Marzouki, Lamjed

    2017-08-09

    Several research studies have reported on the pharmacological relevance of the medicinal plants used for treating various gastrointestinal disorders and controlling the dietary glucose uptake in the intestinal tract. Male rats were used to investigate the pharmacological effects of green oak acorn aqueous extract (GOAE) on gastrointestinal physiological parameters in vivo and in vitro. In this respect, the gastro-intestinal motility and hypersecretion essays were evaluated using a simple test meal (10% charcoal in 5% gum arabic) and castor oil induced diarrhea. However, the effect of GOAE on glucose absorption and homeostasis was assessed by the Ussing chamber system and oral glucose tolerance test (OGTT) measures. Various doses of the Quercus ilex aqueous extract (125, 250 and 500mgkg(-1)) administered orally produced a significantly dose-related inhibition of gut meal travel distance in normal rat. The highest intestinal transit reduction of 49.34% was obtained with 500mgkg(-1) compared to 58.33% caused by reference drug (clonidine, 1mgkg(-1)). In castor oil induced diarrhea in rat, Q. ilex extract reduced the frequency of defecation, fluid accumulation and electrolyte transport. These effects were associated with decreased histopathological damage and regulation of intracellular mediators disturbance in the intestinal mucosa. In addition, GOAE treatment improved glucose tolerance and significantly and dose-dependently reduced (>50%) the glucose absorption via intestinal epithelium. Phytochemical screening revealed the presence of many bioactive natural compounds. These results suggest that the extract was effective towards reducing diarrhea, fluid accumulation, electrolyte transport and glucose absorption, and no toxic effects of the GOAE presented on this study. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  19. Modal testing the EOLE

    SciTech Connect

    Carne, T.G.; Lauffer, J.P.; Gomez, A.J.; Benjannet, H.

    1988-04-01

    This report presents the results of the modal test of the 110-m-tall EOLE wind turbine. Modal testing an immense and flexible wind turbine poses a number of problems. It requires innovative excitation techniques since the modal frequencies of this type of structure are quite low /emdash/ some below 1.0 Hz. Also, substantial energy must be input to the structure to obtain reasonable levels of response. Step-relaxation and wind were used to excite the structure.

  20. Multishaker modal testing

    NASA Technical Reports Server (NTRS)

    Craig, R. R., Jr.

    1983-01-01

    Procedures for improving the modal modeling of structures using test data and to determine appropriate analytical models based on substructure experimental data were explored. Two related research topics were considered in modal modeling: using several independently acquired columns of frequency response data, and modal modeling using simultaneous multi-point excitation. In component mode synthesis modeling, the emphasis is on determining the best way to employ complex modes and residuals.

  1. Modal testing the EOLE

    SciTech Connect

    Carne, T.G.; Lauffer, J.P.; Gomez, A.J.

    1987-01-01

    Modal testing an immense and flexible wind turbine poses a number of problems. It requires innovative excitation techniques since the modal frequencies of this type of structure are quite low. Also, substantial energy must be input to the structure to obtain reasonable levels of response. In this paper, the results of the modal test of the 110 m tall EOLE wind turbine are presented which had a number of modal frequencies below 1.0 Hz. Step-relaxation and wind were used to excite the structure. 5 refs., 14 figs., 2 tabs.

  2. Automated extraction of oscillation parameters for Kepler observations of solar-type stars

    NASA Astrophysics Data System (ADS)

    Huber, D.; Stello, D.; Bedding, T. R.; Chaplin, W. J.; Arentoft, T.; Quirion, P.-O.; Kjeldsen, H.

    2009-10-01

    The recent launch of the Kepler space telescope brings the opportunity to study oscillations systematically in large numbers of solar-like stars. In the framework of the asteroFLAG project, we have developed an automated pipeline to estimate global oscillation parameters, such as the frequency of maximum power (νmax ) and the large frequency spacing (Δν), for a large number of time series. We present an effective method based on the autocorrelation function to find excess power and use a scaling relation to estimate granulation timescales as initial conditions for background modelling. We derive reliable uncertainties for νmax and Δν through extensive simulations. We have tested the pipeline on about 2000 simulated Kepler stars with magnitudes of V ˜ 7-12 and were able to correctly determine νmax and Δν for about half of the sample. For about 20%, the returned large frequency spacing is accurate enough to determine stellar radii to a 1% precision. We conclude that the methods presented here are a promising approach to process the large amount of data expected from Kepler.

  3. Extraction of accurate biomolecular parameters from single-molecule force spectroscopy experiments.

    PubMed

    Farrance, Oliver E; Paci, Emanuele; Radford, Sheena E; Brockwell, David J

    2015-02-24

    The atomic force microscope (AFM) is able to manipulate biomolecules and their complexes with exquisite force sensitivity and distance resolution. This capability, complemented by theoretical models, has greatly improved our understanding of the determinants of mechanical strength in proteins and revealed the diverse effects of directional forces on the energy landscape of biomolecules. In unbinding experiments, the interacting partners are usually immobilized on their respective substrates via extensible linkers. These linkers affect both the force and contour length (Lc) of the complex at rupture. Surprisingly, while the former effect is well understood, the latter is largely neglected, leading to incorrect estimations of Lc, a parameter that is often used as evidence for the detection of specific interactions and remodeling events and for the inference of interaction regions. To address this problem, a model that predicts contour length measurements from single-molecule forced-dissociation experiments is presented that considers attachment position on the AFM tip, geometric effects, and polymer dynamics of the linkers. Modeled data are compared with measured contour length distributions from several different experimental systems, revealing that current methods underestimate contour lengths. The model enables nonspecific interactions to be identified unequivocally, allows accurate determination of Lc, and, by comparing experimental and modeled distributions, enables partial unfolding events before rupture to be identified unequivocally.

  4. Effects of Sterculia setigera Del. Stem Bark Extract on Hematological and Biochemical Parameters of Wistar Rats

    PubMed Central

    Zaruwa, Moses Z.; Ibok, Nne. I.; Ibok, Ibokabasi U.; Onyenonachi, Emmanuel C.; Danchal, C.; Ahmed, Aisha G.; Ahmed, Maryam U.; Sudi, Ismaila Y.

    2016-01-01

    Africa is rich in a wide range of flora that are exploited as herbal medicines and remedies. Several diseases such as diabetes, diarrhea, dysentery and jaundice have been successfully managed using herbal medicines. Herbal decoctions or concoctions have been used as pain killers, antibiotics, and hematinics. This study evaluated the hematopoietic and biochemical properties of the stem bark of Sterculia setigera Del. in Wistar rats. Results showed that S. setigera decoction has copiously high tannin and cardiac glycoside levels. Ingestion of the decoction by rats over a 16-day period significantly (P < 0.05) increased the body weights of rats by 22.4% in the S. setigera-treated group. Hematological profiles showed raised levels of red blood cells, hemoglobin, packed cell volume, mean corpuscular volume, mean cell hemoglobin, mean cell hemoglobin concentration, and platelets, while biochemical parameters showed lower levels of alanine aminotransferase and aspartate aminotransferase, and slight increase in albumin and TP levels. We posit that the results justify the use of the stem bark of S. setigera as a hematinic by traditional medical practitioners and show its relative safety. Further experiments are needed to evaluate its safety. PMID:27980418

  5. Extracting physical parameters from marine seismic data: New methods in seismic oceanography and velocity inversion

    NASA Astrophysics Data System (ADS)

    Fortin, Will F. J.

    The utility and meaning of a geophysical dataset is dependent on good interpretation informed by high-quality data, processing, and attribute examination via technical methodologies. Active source marine seismic reflection data contains a great deal of information in the location, phase, and amplitude of both pre- and post-stack seismic reflections. Using pre- and post-stack data, this work has extracted useful information from marine reflection seismic data in novel ways in both the oceanic water column and the sub-seafloor geology. In chapter 1 we develop a new method for estimating oceanic turbulence from a seismic image. This method is tested on synthetic seismic data to show the method's ability to accurately recover both distribution and levels of turbulent diffusivity. Then we apply the method to real data offshore Costa Rica where we observe lee waves. Our results find elevated diffusivities near the seafloor as well as above the lee waves five times greater than surrounding waters and 50 times greater than open ocean diffusivities. Chapter 2 investigates subsurface geology in the Cascadia Subduction Zone and outlines a workflow for using pre-stack waveform inversion to produce highly detailed velocity models and seismic images. Using a newly developed inversion code, we achieve better imaging results as compared to the product of a standard, user-intensive method for building a velocity model. Our results image the subduction interface ~30 km farther landward than previous work and better images faults and sedimentary structures above the oceanic plate as well as in the accretionary prism. The resultant velocity model is highly detailed, inverted every 6.25 m with ~20 m vertical resolution, and will be used to examine the role of fluids in the subduction system. These results help us to better understand the natural hazards risks associated with the Cascadia Subduction Zone. Chapter 3 returns to seismic oceanography and examines the dynamics of nonlinear

  6. White Shrimp Litopenaeus vannamei That Have Received Gracilaria tenuistipitata Extract Show Early Recovery of Immune Parameters after Ammonia Stressing

    PubMed Central

    Chen, Yu-Yuan; Chen, Jiann-Chu; Lin, Yong-Chin; Yeh, Su-Tuen; Huang, Chien-Lun

    2015-01-01

    White shrimp Litopenaeus vannamei immersed in seawater (35‰) containing Gracilaria tenuistipitata extract (GTE) at 0 (control), 400, and 600 mg/L for 3 h were exposed to 5 mg/L ammonia-N (ammonia as nitrogen), and immune parameters including hyaline cells (HCs), granular cells (GCs, including semi-granular cells), total hemocyte count (THC), phenoloxidase (PO) activity, respiratory bursts (RBs), superoxide dismutase (SOD) activity, lysozyme activity, and hemolymph protein level were examined 24~120 h post-stress. The immune parameters of shrimp immersed in 600 mg/L GTE returned to original values earlier, at 96~120 h post-stress, whereas in control shrimp they did not. In another experiment, shrimp were immersed in seawater containing GTE at 0 and 600 mg/L for 3 h and examined for transcript levels of immune-related genes at 24 h post-stress. Transcript levels of lipopolysaccharide and β-1,3-glucan binding protein (LGBP), peroxinectin (PX), cytMnSOD, mtMnSOD, and HSP70 were up-regulated at 24 h post-stress in GTE receiving shrimp. We concluded that white shrimp immersed in seawater containing GTE exhibited a capability for maintaining homeostasis by regulating cellular and humoral immunity against ammonia stress as evidenced by up-regulated gene expression and earlier recovery of immune parameters. PMID:26058012

  7. White Shrimp Litopenaeus vannamei That Have Received Gracilaria tenuistipitata Extract Show Early Recovery of Immune Parameters after Ammonia Stressing.

    PubMed

    Chen, Yu-Yuan; Chen, Jiann-Chu; Lin, Yong-Chin; Yeh, Su-Tuen; Huang, Chien-Lun

    2015-06-05

    White shrimp Litopenaeus vannamei immersed in seawater (35‰) containing Gracilaria tenuistipitata extract (GTE) at 0 (control), 400, and 600 mg/L for 3 h were exposed to 5 mg/L ammonia-N (ammonia as nitrogen), and immune parameters including hyaline cells (HCs), granular cells (GCs, including semi-granular cells), total hemocyte count (THC), phenoloxidase (PO) activity, respiratory bursts (RBs), superoxide dismutase (SOD) activity, lysozyme activity, and hemolymph protein level were examined 24~120 h post-stress. The immune parameters of shrimp immersed in 600 mg/L GTE returned to original values earlier, at 96~120 h post-stress, whereas in control shrimp they did not. In another experiment, shrimp were immersed in seawater containing GTE at 0 and 600 mg/L for 3 h and examined for transcript levels of immune-related genes at 24 h post-stress. Transcript levels of lipopolysaccharide and β-1,3-glucan binding protein (LGBP), peroxinectin (PX), cytMnSOD, mtMnSOD, and HSP70 were up-regulated at 24 h post-stress in GTE receiving shrimp. We concluded that white shrimp immersed in seawater containing GTE exhibited a capability for maintaining homeostasis by regulating cellular and humoral immunity against ammonia stress as evidenced by up-regulated gene expression and earlier recovery of immune parameters.

  8. Production of melanin by soil microbial isolate on fruit waste extract: two step optimization of key parameters.

    PubMed

    Tarangini, Korumilli; Mishra, Susmita

    2014-12-01

    In this study, optimization of production parameters influencing melanin production in an economical fruit waste extract was attempted using a garden soil isolate (Bacillus safensis). Taguchi approach was adopted for screening of critical parameters and further optimization was done using a central composite design of response surface methodology (RSM). At optimum conditions (pH 6.84 and Temp 30.7 °C), a significant yield of ∼6.96 mg/mL was observed. Statistical analysis revealed that the experimental results fitted well to the statistical model with model R(2) value 0.982. The optimization of process parameters using RSM reported a 15% increase in the pigment yield than average yield obtained from the studied model. The melanin produced was confirmed by UV-visible spectroscopy, FTIR and XRD analysis. Moreover melanin obtained has significant photoprotective, radical scavenging and metal chelating activity. Thus, B. safensis has the potential to be a new source for the production of melanin, which is of industrial interest.

  9. Determination of optimal wavelet denoising parameters for red edge feature extraction from hyperspectral data

    NASA Astrophysics Data System (ADS)

    Shafri, Helmi Z. M.; Yusof, Mohd R. M.

    2009-05-01

    A study of wavelet denoising on hyperspectral reflectance data, specifically the red edge position (REP) and its first derivative is presented in this paper. A synthetic data set was created using a sigmoid to simulate the red edge feature for this study. The sigmoid is injected with Gaussian white noise to simulate noisy reflectance data from handheld spectroradiometers. The use of synthetic data enables better quantification and statistical study of the effects of wavelet denoising on the features of hyperspectral data, specifically the REP. The simulation study will help to identify the most suitable wavelet parameters for denoising and represents the applicability of the wavelet-based denoising procedure in hyperspectral sensing for vegetation. The suitability of the thresholding rules and mother wavelets used in wavelet denoising is evaluated by comparing the denoised sigmoid function with the clean sigmoid, in terms of the shift in the inflection point meant to represent the REP, and also the overall change in the denoised signal compared with the clean one. The VisuShrink soft threshold was used with rescaling based on the noise estimate, in conjunction with wavelets of the Daubechies, Symlet and Coiflet families. It was found that for the VisuShrink threshold with single level noise estimate rescaling, the Daubechies 9 and Symlet 8 wavelets produced the least distortion in the location of sigmoid inflection point and the overall curve. The selected mother wavelets were used to denoise oil palm reflectance data to enable determination of the red edge position by locating the peak of the first derivative.

  10. Hydro-Methanolic Extract of Cornus Mas L. and Blood Glucose, Lipid Profile and Hematological Parameters of Male Rats

    PubMed Central

    Abdollahi, Bita; Mesgari Abbasi, Mehran; Zakeri Milani, Parvin; Nourdadgar, Ashraf Sadat; Banan Khojasteh, Seyyed Mehdi; Nejati, Vahid

    2014-01-01

    Background: Cornus mas L, an olive-shaped red-colored single-seeded fruit, is used in traditional medicine in different parts of Europe and Asia. Objectives: In the present study, 40 male Wistar rats were randomly divided into five groups, and the effects of 21 days of intraperitoneally (IP) administration of 50, 200 and 400 mg/kg body weight of C. mas hydro-methanolic extract on the rats hematological and biochemical parameters were investigated. The experimental study was carried out in Tabriz, Iran. Materials and Methods: The hematology and biochemical tests were performed by the Technicon H1 Hematology Analyzer and enzymatic methods, respectively. Results: The results indicated that all doses of the extract caused significant (P < 0.05) decreases in the hemoglobin distribution width (HDW) (2.3 ± 0.2 vs. 2.5 ± 0.2, P = 0.049) and platelet distribution width (PDW) (56.5 ± 1.8 vs. 63.9 ± 3.6, P = 0.001) of the treated groups vs. control group, whereas only high doses caused significant elevation in the mean corpuscular hemoglobin concentration (MCHC) (30.3 ± 0.8 vs. 28.6 ± 0.6, P = 0.047), mean platelet volume (MPV) (5.0 ± 0.6 vs. 4.1 ± 0.3, P = 0.002), total platelet mass (PCT) (0.33 ± 0.07 vs. 0.26 ± 0.01, P = 0.050), and significant decrease in the red cell distribution width (RDW) (13.8 ± 0.4 vs. 14.7 ± 1.3, P = 0.048) of the treated groups vs. control group. Conclusions: Decreasing effect of the extract on platelet activity might classify it as an alternative for antiplatelet therapy in cardiovascular diseases (CVD). The results of this study suggested that further investigations with higher doses of C. mas fruit extract are necessary to obtain significant protective and nonprotective changes in hematological and biochemical parameters. PMID:25031858

  11. Modal analysis using a Fourier analyzer, curve-fitting, and modal tuning

    NASA Technical Reports Server (NTRS)

    Craig, R. R., Jr.; Chung, Y. T.

    1981-01-01

    The proposed modal test program differs from single-input methods in that preliminary data may be acquired using multiple inputs, and modal tuning procedures may be employed to define closely spaced frquency modes more accurately or to make use of frequency response functions (FRF's) which are based on several input locations. In some respects the proposed modal test proram resembles earlier sine-sweep and sine-dwell testing in that broadband FRF's are acquired using several input locations, and tuning is employed to refine the modal parameter estimates. The major tasks performed in the proposed modal test program are outlined. Data acquisition and FFT processing, curve fitting, and modal tuning phases are described and examples are given to illustrate and evaluate them.

  12. Development of response surface methodology for optimization of extraction parameters and quantitative estimation of embelin from Embelia ribes Burm by high performance liquid chromatography

    PubMed Central

    Alam, Md. Shamsir; Damanhouri, Zoheir A.; Ahmad, Aftab; Abidin, Lubna; Amir, Mohd; Aqil, Mohd; Khan, Shah Alam; Mujeeb, Mohd

    2015-01-01

    Background: Embelia ribes Burm is widely used medicinal plant for the treatment of different types of disorders in the Indian traditional systems of medicine. Objective: The present work was aimed to optimize the extraction parameters of embelin from E. ribes fruits and also to quantify embelin content in different extracts of the plant. Materials and Methods: Optimization of extraction parameters such as solvent: drug ratio, temperature and time were carried out by response surface methodology (RSM). Quantitative estimation of embelin in different extracts of E. ribes fruits was done through high performance liquid chromatography. Results: The optimal conditions determined for extraction of embelin through RSM were; extraction time (27.50 min), extraction temperature 45°C and solvent: drug ratio (8:1). Under the optimized conditions, the embelin yield (32.71%) was equitable to the expected yield (31.07%, P > 0.05). These results showed that the developed model is satisfactory and suitable for the extraction process of embelin. The analysis of variance showed a high goodness of model fit and the accomplishment of the RSM method for improving embelin extraction from the fruits of E. ribes. Conclusion: It is concluded that this may be a useful method for the extraction and quantitative estimation of embelin from the fruits of E. ribes. PMID:26109763

  13. Roots of Modality

    ERIC Educational Resources Information Center

    Rubinstein, Aynat

    2012-01-01

    This dissertation explores the interplay of grammar and context in the interpretation of modal words like "ought," "necessary," and "need." The empirical foci of the discussion are patterns in the use of strong and weak necessity modals in conversation, and the interpretation of syntactically and semantically…

  14. Video: Modalities and Methodologies

    ERIC Educational Resources Information Center

    Hadfield, Mark; Haw, Kaye

    2012-01-01

    In this article, we set out to explore what we describe as the use of video in various modalities. For us, modality is a synthesizing construct that draws together and differentiates between the notion of "video" both as a method and as a methodology. It encompasses the use of the term video as both product and process, and as a data…

  15. Modals of Strong Obligation

    ERIC Educational Resources Information Center

    Matthews-Bresky, R. J. H.

    1977-01-01

    Discusses regularities and peculiarities in the use of the modal verbs of obligation "must,""need" and "should," also of the non-modals "have (got) to" and "need to." Agreements and differences in the use of the verbs are shown, with examples. Use of the various tense-forms is discussed. (IFS/WGA)

  16. Modal control of structural systems

    NASA Astrophysics Data System (ADS)

    Miller, D. F.; Wells, W. R.

    1984-11-01

    There is much interest in the practical control of large space structures such as space transportation systems and large communication satellites. The control task is normally thought of in terms of maintaining specified shape configurations, orientation and alignment, vibration suppression and pointing accuracy, etc. Because of their inherent flexibility, they are generally analyzed as distributed parameter systems which creates difficulties in the design and analysis of controllers for them. Modal control techniques have been developed to bypass problems associated with distributed parameter theory. Modal control is built upon the notion that certain specified system modes can be controlled by appropriate design of the associated closed-loop eigenvalues. This reduces the number of sensors and actuators needed to effect the control of the structure. An undesirable phenomenon, referred to as observation and control spillover, can occur if the number of sensors and actuators used is small. Spillover refers to the phenomenon in which energy intended to go solely into the controlled modes leaks into the uncontrolled modes. This report discusses the control of flexible systems described by a generalized one-dimensional wave equation which relates the structure displacement to the force distribution acting on the structure. Optimal control involving the minimization of a quadratic performance index representing control and modal energy content is considered. Typically this control formulation leads to a state feedback algorithm.

  17. [Study on the characteristic UV absorption parameters of dissolved organic matter extracted from chicken manure during composting].

    PubMed

    Li, Ming-xiao; He, Xiao-song; Liu, Jun; Xi, Bei-dou; Zhao, Yue; Wei, Zi-min; Jiang, Yong-hai; Su, Jing; Hu, Chun-ming

    2010-11-01

    The characteristic parameters obtained from UV-Visible spectra of dissolved organic matter (DOM) during composting were studied in the present paper. The results showed that, during composting progress, the non-humic substances were translated into humus substances, and the aromatization, humification degree and molecular weight of the humus substances increased, while the fatty chains linked with the benzene ring structure were cleavaged into carbonyl, carboxyl and other functional groups. The correlation analysis showed that, when DOM concentration (DOC) from all samples was the same, the specific ultraviolet absorbance values at 254 and 280 nm (SUVA254 and SUVA280, respectively), and the area of a spectrum obtained from 226 to 400 nm (A(226-400)) showed significant positive correlation, furthermore, they were all significantly negatively correlated with the concentration of DOM (DOC), but the correlation between A(226-400) and DOC was the best; The ratio between the absorbance value at 253 nm and that at 203 nm (E253/E203) was significantly correlative with SUVA254, SUVA280 and A 226-400, though the correlation between E253/E203 and DOC was not as good as the other three characteristic parameters; The ratio between the absorbance value at 250 nm and that at 365 nm (E250/E365) and the ratio between the absorbance value at 465 nm and that at 665 nm(E250/E365) were not correlated with the other parameters. The results showed that, the stability of DOM extracted from chicken manure increased during composting, and the complex ability between DOM and heavy metals enhanced as well; A(226-400) reflects the changes of compost maturity best in all UV-Visible spectral absorption parameters studied in this paper.

  18. Experimental Study of Three-body Cabibbo-suppressed D0 Decays and Extraction of Cp Violation Parameters

    SciTech Connect

    Mishra, Kalanand; /Nehru U.

    2008-02-22

    The authors present measurements of the relative branching ratios, Dalitz plot structures and CP-asymmetry values in the three-body singly Cabibbo-suppressed decays D{sup 0} {yields} {pi}{sup -}{pi}{sup +}{pi}{sup 0} and D{sup 0} {yields} K{sup -}K{sup +}{pi}{sup 0} using data collected by the BABAR detector at the PEP-II asymmetric-energy ring at SLAC. The author applies the results of the D{sup 0} {yields} {pi}{sup -}{pi}{sup +}{pi}{sup 0} analysis to extracting CP-violation parameters related to the CKM angle {gamma} (or {phi}{sub 3}) using the decay B{sup -} {yields} D{sub {pi}{sup +}{pi}{sup -}{pi}{sup 0}} K{sup -}.

  19. Selection of Atmospheric Environmental Monitoring Sites based on Geographic Parameters Extraction of GIS and Fuzzy Matter-Element Analysis

    PubMed Central

    Wu, Jianfa; Peng, Dahao; Ma, Jianhao; Zhao, Li; Sun, Ce; Ling, Huanzhang

    2015-01-01

    To effectively monitor the atmospheric quality of small-scale areas, it is necessary to optimize the locations of the monitoring sites. This study combined geographic parameters extraction by GIS with fuzzy matter-element analysis. Geographic coordinates were extracted by GIS and transformed into rectangular coordinates. These coordinates were input into the Gaussian plume model to calculate the pollutant concentration at each site. Fuzzy matter-element analysis, which is used to solve incompatible problems, was used to select the locations of sites. The matter element matrices were established according to the concentration parameters. The comprehensive correlation functions KA (xj) and KB (xj), which reflect the degree of correlation among monitoring indices, were solved for each site, and a scatter diagram of the sites was drawn to determine the final positions of the sites based on the functions. The sites could be classified and ultimately selected by the scatter diagram. An actual case was tested, and the results showed that 5 positions can be used for monitoring, and the locations conformed to the technical standard. In the results of this paper, the hierarchical clustering method was used to improve the methods. The sites were classified into 5 types, and 7 locations were selected. Five of the 7 locations were completely identical to the sites determined by fuzzy matter-element analysis. The selections according to these two methods are similar, and these methods can be used in combination. In contrast to traditional methods, this study monitors the isolated point pollutant source within a small range, which can reduce the cost of monitoring. PMID:25923911

  20. Effects of chamomile extract on biochemical and clinical parameters in a rat model of polycystic ovary syndrome.

    PubMed

    Farideh, Zafari Zangeneh; Bagher, Minaee; Ashraf, Amirzargar; Akram, Ahangarpour; Kazem, Mousavizadeh

    2010-10-01

    Polycystic ovary syndrome (PCOS) is a complex endocrine and metabolic disorder associated with ovulatory dysfunction. Presently, little is known about the primary factors that initiate PCOS. Chamomile flowers are used in alternative medicine for its anti-spasmolytic and anti-inflammatory effects. Antispasmodic properties of chamomile ease menstrual cramps and lessen the possibility of premature labor. This medicinal herb also stimulates menstruation. In this study, we evaluated the effects of Chamomile alcoholic-extract on the biochemical and clinical parameters in a rat model of PCOS. Estrous cyclicity of 30 virgin adult cycling rats was monitored by vaginal smears obtained between 0800 and 1200 hours. After about 4 days, each rat received an i.m. injection of Estradiol Valerate (Aburaihan Co., Iran), 2 mg in 0.2 ml of corn oil, to induce PCO. Corn oil was injected to the rats in the control group. All the rats in the experimental group were evaluated for follicular cysts 60 days after the injection. Rats with PCOS were treated by multiple doses (25, 50, 75 mg/kg) of intraperitoneal injections of Chamomile alcoholic-extract for ten days. The data were statistically analyzed at a significance level of p<0.05 by ANOVA, followed by the Student Newman-Keuls post hoc test. The histological and hormonal results showed that Chamomile can decrease the signs of PCOS in the ovarian tissue and help LH secretion in rats (p<0.05). The alcoholic-extract of dried Matricaria chamomilla L. flowers can not only induce recovery from a PCO induced state in rats, but also increase dominant follicles. Additionally better endometrial tissue arrangements can be regarded as another therapeutic effect of Chamomile.

  1. Effects of Chamomile Extract on Biochemical and Clinical Parameters in a Rat Model of Polycystic Ovary Syndrome

    PubMed Central

    Zafari Zangeneh, Farideh; Minaee, Bagher; Amirzargar, Ashraf; Ahangarpour, Akram; Mousavizadeh, Kazem

    2010-01-01

    Introduction Polycystic ovary syndrome (PCOS) is a complex endocrine and metabolic disorder associated with ovulatory dysfunction. Presently, little is known about the primary factors that initiate PCOS. Chamomile flowers are used in alternative medicine for its anti-spasmolytic and anti-inflammatory effects. Antispasmodic properties of chamomile ease menstrual cramps and lessen the possibility of premature labor. This medicinal herb also stimulates menstruation. In this study, we evaluated the effects of Chamomile alcoholic-extract on the biochemical and clinical parameters in a rat model of PCOS. Materials and Methods Estrous cyclicity of 30 virgin adult cycling rats was monitored by vaginal smears obtained between 0800 and 1200 hours. After about 4 days, each rat received an i.m. injection of Estradiol Valerate (Aburaihan Co., Iran), 2 mg in 0.2 ml of corn oil, to induce PCO. Corn oil was injected to the rats in the control group. All the rats in the experimental group were evaluated for follicular cysts 60 days after the injection. Rats with PCOS were treated by multiple doses (25, 50, 75 mg/kg) of intraperitoneal injections of Chamomile alcoholic-extract for ten days. The data were statistically analyzed at a significance level of p<0.05 by ANOVA, followed by the Student Newman-Keuls post hoc test. Results The histological and hormonal results showed that Chamomile can decrease the signs of PCOS in the ovarian tissue and help LH secretion in rats (p<0.05). Conclusion The alcoholic-extract of dried Matricaria chamomilla L. flowers can not only induce recovery from a PCO induced state in rats, but also increase dominant follicles. Additionally better endometrial tissue arrangements can be regarded as another therapeutic effect of Chamomile. PMID:23926485

  2. Comparison of two dissimilar modal identification techniques

    NASA Technical Reports Server (NTRS)

    Pappa, Richard S.; Schenk, Axel; Niedbal, Norbert; Klusowski, Erhard

    1992-01-01

    Recent laboratory results using a refined phase resonance method and the eigensystem realization algorithm on the same test structure are reported. These methods are dissimilar modal identification techniques suitable for future large spacecraft. The theory, application approach, and results obtained for each technique are summarized and compared. Although both methods worked well in this investigation, significant differences occurred in some identified mode shapes. Comparison of independently derived modal parameters provides the means for disclosing such discrepancies in flight projects.

  3. Modal-Power-Based Haptic Motion Recognition

    NASA Astrophysics Data System (ADS)

    Kasahara, Yusuke; Shimono, Tomoyuki; Kuwahara, Hiroaki; Sato, Masataka; Ohnishi, Kouhei

    Motion recognition based on sensory information is important for providing assistance to human using robots. Several studies have been carried out on motion recognition based on image information. However, in the motion of humans contact with an object can not be evaluated precisely by image-based recognition. This is because the considering force information is very important for describing contact motion. In this paper, a modal-power-based haptic motion recognition is proposed; modal power is considered to reveal information on both position and force. Modal power is considered to be one of the defining features of human motion. A motion recognition algorithm based on linear discriminant analysis is proposed to distinguish between similar motions. Haptic information is extracted using a bilateral master-slave system. Then, the observed motion is decomposed in terms of primitive functions in a modal space. The experimental results show the effectiveness of the proposed method.

  4. A method for extracting temporal parameters based on hidden Markov models in body sensor networks with inertial sensors.

    PubMed

    Guenterberg, Eric; Yang, Allen Y; Ghasemzadeh, Hassan; Jafari, Roozbeh; Bajcsy, Ruzena; Sastry, S Shankar

    2009-11-01

    Human movement models often divide movements into parts. In walking, the stride can be segmented into four different parts, and in golf and other sports, the swing is divided into sections based on the primary direction of motion. These parts are often divided based on key events, also called temporal parameters. When analyzing a movement, it is important to correctly locate these key events, and so automated techniques are needed. There exist many methods for dividing specific actions using data from specific sensors, but for new sensors or sensing positions, new techniques must be developed. We introduce a generic method for temporal parameter extraction called the hidden Markov event model based on hidden Markov models. Our method constrains the state structure to facilitate precise location of key events. This method can be quickly adapted to new movements and new sensors/sensor placements. Furthermore, it generalizes well to subjects not used for training. A multiobjective optimization technique using genetic algorithms is applied to decrease error and increase cross-subject generalizability. Further, collaborative techniques are explored. We validate this method on a walking dataset by using inertial sensors placed on various locations on a human body. Our technique is designed to be computationally complex for training, but computationally simple at runtime to allow deployment on resource-constrained sensor nodes.

  5. Comparison of adaptive neuro-fuzzy inference system and artificial neural networks for estimation of oxidation parameters of sunflower oil added with some natural byproduct extracts.

    PubMed

    Karaman, Safa; Ozturk, Ismet; Yalcin, Hasan; Kayacier, Ahmed; Sagdic, Osman

    2012-01-15

    Apple pomace, orange peel and potato peel, which have important antioxidative compounds in their structures, are byproducts obtained from fruit or vegetable processing. Use of vegetable extracts is popular and a common technique in the preservation of vegetable oils. Utilization of apple pomace, orange peel and potato peel extracts as natural antioxidant agents in refined sunflower oil during storage in order to reduce or retard oxidation was investigated. All byproduct extracts were added at 3000 ppm to sunflower oil and different nonlinear models were constructed for the estimation of oxidation parameters. Peroxide values of sunflower oil samples containing different natural extracts were found to be lower compared to control sample. Adaptive neuro-fuzzy inference system (ANFIS) and artificial neural networks (ANN) were used for the construction of models that could predict the oxidation parameters and were compared to multiple linear regression (MLR) for the determination of the best model with high accuracy. It was shown that the ANFIS model with high coefficient of determination (R(2) = 0.999) performed better compared to ANN (R(2) = 0.899) and MLR (R(2) = 0.636) for the prediction of oxidation parameters Incorporation of different natural byproduct extracts into sunflower oil provided an important retardation in oxidation during storage. Effective predictive models were constructed for the estimation of oxidation parameters using ANFIS and ANN modeling techniques. These models can be used to predict oxidative parameter values. Copyright © 2011 Society of Chemical Industry.

  6. Whole body vibration exercise combined with an extract of Coriandrum sativum modify some biochemical/physiological parameters in rats

    PubMed Central

    Cardoso, André L.B.D.; Guimarães, Carlos A.S.; Almeida, Lívia P.; Neves, Rosane F.; Sá-Caputo, Danúbia C.; Moreira-Marconi, Eloá; Dionello, Carla F.; Morel, Danielle S.; Paineiras-Domingos, Laisa L.; Costa-Cavalcanti, Rebeca G.; Sousa-Gonçalves, Cintia R.; Arnóbio, Adriano; Asad, Nasser R.; Bernardo-Filho, Mario

    2017-01-01

    The aim of the present study was to evaluate the effect of the association of whole body vibration (WBV) exercise with an aqueous extract of coriander on the biodistribution of the radiopharmaceutical sodium pertechnetate, on the concentration of some plasma biomarker, on the feed intake, on the body mass, and on the stool consistency in rats. Rats were divided in four groups and submitted to different treatments for 40 days. The control group (CON) received deionized water. The group treated with coriander (COR) received the extract of coriander. The rats that were exposed to WBV exercises (WBV-E) also received deionized water. A group of animals received coriander and was exposed to WBV (COR + WBV-E). We found in testis a decrease (0.13 ± 0.01 to 0.06 ± 0.03) of the percentages of injected radioactivity per gram (%ATI/g) in the WBV-E in comparison with the COR. There is no significant alteration on the concentrations of the plasma biomarkers. The feed intake showed a statistically significant increase in WBV-E. No significant difference on the body mass was found. The stool analysis showed a statistical difference on the consistency between COR (hard and dry, darker) and all the other groups (normal). In conclusion, it was verified that possible modifications in some biochemical/physiological parameters of the rats submitted to WBV exercise would be capable to increase the feed intake without changing the body mass, and normalizing the stool consistency altered by the coriander supplementation. Further studies are needed to try to understand better the biological effects involving the association of WBV exercise and coriander. PMID:28507199

  7. Whole body vibration exercise combined with an extract of Coriandrum sativum modify some biochemical/physiological parameters in rats.

    PubMed

    Frederico, Éric H F F; Cardoso, André L B D; Guimarães, Carlos A S; Almeida, Lívia P; Neves, Rosane F; Sá-Caputo, Danúbia C; Moreira-Marconi, Eloá; Dionello, Carla F; Morel, Danielle S; Paineiras-Domingos, Laisa L; Costa-Cavalcanti, Rebeca G; Sousa-Gonçalves, Cintia R; Arnóbio, Adriano; Asad, Nasser R; Bernardo-Filho, Mario

    2017-06-30

    The aim of the present study was to evaluate the effect of the association of whole body vibration (WBV) exercise with an aqueous extract of coriander on the biodistribution of the radiopharmaceutical sodium pertechnetate, on the concentration of some plasma biomarker, on the feed intake, on the body mass, and on the stool consistency in rats. Rats were divided in four groups and submitted to different treatments for 40 days. The control group (CON) received deionized water. The group treated with coriander (COR) received the extract of coriander. The rats that were exposed to WBV exercises (WBV-E) also received deionized water. A group of animals received coriander and was exposed to WBV (COR + WBV-E). We found in testis a decrease (0.13 ± 0.01 to 0.06 ± 0.03) of the percentages of injected radioactivity per gram (%ATI/g) in the WBV-E in comparison with the COR. There is no significant alteration on the concentrations of the plasma biomarkers. The feed intake showed a statistically significant increase in WBV-E. No significant difference on the body mass was found. The stool analysis showed a statistical difference on the consistency between COR (hard and dry, darker) and all the other groups (normal). In conclusion, it was verified that possible modifications in some biochemical/physiological parameters of the rats submitted to WBV exercise would be capable to increase the feed intake without changing the body mass, and normalizing the stool consistency altered by the coriander supplementation. Further studies are needed to try to understand better the biological effects involving the association of WBV exercise and coriander. © 2017 The Author(s).

  8. Impedometric monitoring of the behavior of the supported liquid membrane in electromembrane extraction systems: An insight into the origin of optimized experimental parameters.

    PubMed

    Mohammadi, Jamil; Davarani, Saied Saeed Hosseiny; Moazami, Hamid Reza

    2016-08-31

    Electromembrane extraction (EME) was carried out using a novel instrumentation capable of impedometric monitoring of the system during the extraction. This instrumentation involves a classical two-electrode assembly fed by two time-resolved potential functions, the first for the extraction of analyte and the second for obtaining the impedance information. The impedometric analysis of the system was achieved by Laplace transformation of the current recorded during the extraction. It has been shown that the obtained impedance information can be converted to very useful knowledge about time dependence of double layer capacitance, kinetics of analyte depletion, total permeability of the SLM and the effect of experimental parameters on system behavior. It has also been shown that the impedance analysis is a powerful tool for the estimation of optimum experimental parameters without determination of analyte in the acceptor phase.

  9. Auto-OBSD: Automatic parameter selection for reliable Oscillatory Behavior-based Signal Decomposition with an application to bearing fault signature extraction

    NASA Astrophysics Data System (ADS)

    Huang, Huan; Baddour, Natalie; Liang, Ming

    2017-03-01

    Bearing signals are often contaminated by in-band interferences and random noise. Oscillatory Behavior-based Signal Decomposition (OBSD) is a new technique which decomposes a signal according to its oscillatory behavior, rather than frequency or scale. Due to the low oscillatory transients of bearing fault-induced signals, the OBSD can be used to effectively extract bearing fault signatures from a blurred signal. However, the quality of the result highly relies on the selection of method-related parameters. Such parameters are often subjectively selected and a systematic approach has not been reported in the literature. As such, this paper proposes a systematic approach to automatic selection of OBSD parameters for reliable extraction of bearing fault signatures. The OBSD utilizes the idea of Morphological Component Analysis (MCA) that optimally projects the original signal to low oscillatory wavelets and high oscillatory wavelets established via the Tunable Q-factor Wavelet Transform (TQWT). In this paper, the effects of the selection of each parameter on the performance of the OBSD for bearing fault signature extraction are investigated. It is found that some method-related parameters can be fixed at certain values due to the nature of bearing fault-induced impulses. To adaptively tune the remaining parameters, index-guided parameter selection algorithms are proposed. A Convergence Index (CI) is proposed and a CI-guided self-tuning algorithm is developed to tune the convergence-related parameters, namely, penalty factor and number of iterations. Furthermore, a Smoothness Index (SI) is employed to measure the effectiveness of the extracted low oscillatory component (i.e. bearing fault signature). It is shown that a minimum SI implies an optimal result with respect to the adjustment of relevant parameters. Thus, two SI-guided automatic parameter selection algorithms are also developed to specify two other parameters, i.e., Q-factor of high-oscillatory wavelets and

  10. Theoretical optimization by genetic algorithm of delayed extraction parameters for a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer.

    PubMed

    Tauro, S; Razvi, M A N

    2005-01-01

    This paper presents the application of a genetic algorithm (GA) to optimize the operating parameters, namely pulse voltage and extraction delay time, when using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOFMS). Simulations predict the presence of several combinations of these parameters that give a local maximum. The aim is to locate the optimal combination (a global maximum) of pulse voltage and extraction time delay in order to focus the ions of a particular m/z value to achieve the best resolution in a given instrumental geometry. The GA locates the global maximum quickly. The results indicate that it may be possible to achieve very high resolving power by using delayed extraction (DE)-MALDI-TOFMS with parameters obtained from the GA.

  11. DC parameter extraction of equivalent circuit model in InGaAsSb heterojunction bipolar transistors including non-ideal effects in the base region

    NASA Astrophysics Data System (ADS)

    Chang, Yang-Hua; Cheng, Zong-Tai

    2011-07-01

    This paper presents the DC parameter extraction of the equivalent circuit model in an InP-InGaAsSb double heterojunction bipolar transistor (HBT). The non-ideal collector current is modeled by a non-ideal doping distribution in the base region. Then several consequent non-ideal effects, which have always been neglected in typical HBTs, are studied using Medici device simulator. Moreover, the associated DC parameters of VBIC model are extracted accordingly. The equivalent circuit model is in good agreement with the measured data in I C- V CE characteristics.

  12. Extraction of Precise Gamow-Teller Quenching Value Q, Landau-Migdal Parameter g'{{NΔ }} and Pion Condensation

    NASA Astrophysics Data System (ADS)

    Sakai, Hideyuki

    2003-12-01

    Measurements on 90Zr(p, n) and 90Zr(n, p) reactions at 300 MeV were made and reliable Sβ- and Sβ+ values are successfully extracted. A Gamow-Teller quenching factor (Q) in terms of the spin sum rule of Sβ- - Sβ+ = 3(N - Z) is derived as Q = 0.89 ± 0.04(MDA) ± 0.04(IVSM) apart from the systematic uncertainty of Δ / σ GT <= 15% . The Landau-Migdal (LM) parameters representing a short-range correlation in an isospin-spin channel are deduced to be g'{NN} = 0.60 ± 0.02 and g'{NΔ } = 0.24 ± 0.10 with the Chew-Low coupling constant fΔ/fπ = 2. The critical density of the pion condensation is estimated to be ρc 2ρ0 which can be easily realized in the neutron stars. Recent observation of the surface temperature of the neutron star 3C58 supports the pionic cooling mechanism and consequently manifestation of the pion condensation in neutron stars.

  13. Grape Seed Proanthocyanidin Extract Improved some of Biochemical Parameters and Antioxidant Disturbances of Red Blood Cells in Diabetic Rats

    PubMed Central

    Mansouri, Esrafil; Khorsandi, Layasadat; Zare Moaiedi, Maasoumeh

    2015-01-01

    Grape seed proanthocyanidin extract (GSPE) has a broad spectrum of biologic properties against oxidative stress. This study aimed to investigate the effects of GSPE on biochemical factors and antioxidant enzymes of erythrocyte in diabetic rats. Diabetes was induced through single injection of streptozotocin (50 mg.Kg-1, i.p). Forty Male Sprague-Dawley rats were divided into four Groups: Group 1, healthy control group; Group 2, healthy group treated with GSPE (200 mg.Kg-1); Group 3, diabetic control group; Group 4, diabetic group treated with GSPE (200 mg.Kg-1) for 4 weeks. At the end, the experimental animals were sacrificed and blood samples were collected and plasma parameters and erythrocytes antioxidant status were evaluated. The results show, treatment with GSPE significantly reduced (P<0.001) urine volume, proteinuria and biochemical factors such as blood urea nitrogen, creatinine, triglyceride, total cholesterol, low density lipoprotein and very low density lipoprotein as well as malondialdehyde. Also GSPE treatment significantly (P<0.005) increased high density lipoprotein, total protein and albumin. Moreover GSPE significantly increased antioxidant enzymes activity such as: superoxide dismutase, glutathione peroxidase and catalase. These results suggest that GSPE can ameliorate biochemical abnormalities and antioxidant system status in streptozotocin- induced diabetic rats probably by its potent antioxidant features. PMID:25561939

  14. Seasonal parameter extraction of paddy rice fields in West Java using multi-temporal MODIS imagery datasets

    NASA Astrophysics Data System (ADS)

    Sianturi, Riswan S.; Nieuwenhuis, Willem; Jetten, V. G.

    2015-10-01

    Continuous monitoring on farming practices is urgently needed provided the challenges faced by rice fields. Information of seasonal parameters supplies crucial inputs for monitoring rice fields as well as improving other applications, such as biomass monitoring, yield estimation, integrated pest management, irrigation water management, and precision farming. We extracted the heading stages using multi-temporal MODerate resolution Imaging Spectroradiometer (MODIS) imageries in rice fields in northern districts of West Java, Indonesia. The spatial distribution of the heading stages in the whole year suggests complex cropping pattern of rice fields in West Java. The monthly average of EVI shows that green waves move northward as the results of stipulated cropping calendar. The Root Mean Square Error (RMSE) for the heading stages is 12.77 days. The heading stages periods of most rice fields are from the middle of February to the middle of March and from the middle of June to the middle of July for rendeng and gadu, consecutively. The findings provide timely and cost effective information for monitoring rice fields.

  15. Harmonics elimination algorithm for operational modal analysis using random decrement technique

    NASA Astrophysics Data System (ADS)

    Modak, S. V.; Rawal, Chetan; Kundra, T. K.

    2010-05-01

    Operational modal analysis (OMA) extracts modal parameters of a structure using their output response, during operation in general. OMA, when applied to mechanical engineering structures is often faced with the problem of harmonics present in the output response, and can cause erroneous modal extraction. This paper demonstrates for the first time that the random decrement (RD) method can be efficiently employed to eliminate the harmonics from the randomdec signatures. Further, the research work shows effective elimination of large amplitude harmonics also by proposing inclusion of additional random excitation. This obviously need not be recorded for analysis, as is the case with any other OMA method. The free decays obtained from RD have been used for system modal identification using eigen-system realization algorithm (ERA). The proposed harmonic elimination method has an advantage over previous methods in that it does not require the harmonic frequencies to be known and can be used for multiple harmonics, including periodic signals. The theory behind harmonic elimination is first developed and validated. The effectiveness of the method is demonstrated through a simulated study and then by experimental studies on a beam and a more complex F-shape structure, which resembles in shape to the skeleton of a drilling or milling machine tool. Cases with presence of single and multiple harmonics in the response are considered.

  16. Toxicological study of the butanol fractionated root extract of Asparagus africanus Lam., on some blood parameter and histopathology of liver and kidney in mice.

    PubMed

    Kebede, Sintayehu; Afework, Mekbeb; Debella, Asfaw; Ergete, Wondwossen; Makonnen, Eyasu

    2016-01-27

    The butanol fractionated root extract of Asparagus africanus Lam., a traditional herb widely used to treat various ailments were analyzed for the presence of potential toxicity after single (acute) and repeated (subchronic) dose oral administration in adult swiss albino mice using gavages. For the acute study, butanol fractionated extract of the plant was administered in single doses of 1000, 3000 and 5000 mg/kg body weight. In the sub-chronic dose study, the extract was administered at doses of 300 and 600 mg/kg body weight/day for 42 days. Selected hematological and biochemical parameters of the blood followed by histopathological analysis were investigated after 42 days of daily administrations. The results were expressed as M ± SE, and differences at P < 0.05 was considered significant. One way analysis of variance (ANOVA) and least significant difference tests were employed to check the significant differences between the various parameters of the experimental groups. In the acute study, the extract did not caused dose-dependent general behavioral adverse effects, body weight change and mortality. The single dose toxicity studies therefore showed that the butanol fraction of the extract has high safety profile when given orally. After 42 days of daily dosing, in the sub-chronic study, no clinically significant changes were observed for hematological and biochemical parameters. Except an occasional small number of focal mononuclear lymphocytic cells infiltrations around the central and portal triad of the liver of a few mice, the histopathological parameters do not show significant change. It is concluded that, the butanol fractionated extract from A. africanus at the given dose does not show significant toxicity. The presence of focal inflammation on the liver of a few mice may be associated to the presence of flavonoid glycoside in the butanol fractionated extract.

  17. Protective effect of combined pumpkin seed and ginger extracts on sperm characteristics, biochemical parameters and epididymal histology in adult male rats treated with cyclophosphamide.

    PubMed

    Aghaie, Somaieh; Nikzad, Hossein; Mahabadi, Javad Amini; Taghizadeh, Mohsen; Azami-Tameh, Abolfazl; Taherian, Aliakbar; Sajjadian, Seyyed Mohammad Sajjad; Kamani, Mehran

    2016-09-01

    Reproductive toxicity is one of the side effects of cyclophosphamide (CP) in cancer treatment. Pumpkin seeds and Zingiber officinale are natural sources of antioxidants. We investigated the possible protective effect of combined pumpkin seed and Zingiber officinale extracts on sperm characteristics, epididymal histology and biochemical parameters of CP-treated rats. Male adult Wistar rats were divided randomly into six groups. Group 1, as a control, received an isotonic saline solution injection intraperitoneally (IP). Group 2 were injected IP with a single dose of CP (100 mg/kg) once. Groups 3 and 4 received CP plus 300 and 600 mg/kg combined pumpkin seed and Zingiber officinale extract (50:50). Groups 5 and 6 received only 300 and 600 mg/kg combined pumpkin seed and Zingiber officinale extract. Six weeks after treatment, sperm characteristics, histopathological changes and biochemical parameters were assessed. In CP-treated rats, motile spermatozoa were decreased, and abnormal or dead spermatozoa increased significantly (P < 0.001) but administration of the mixed extract improved sperm parameters. Epididymal epithelium and fibromascular thickness were also improved in extract-treated rats compared to control or CP groups. Biochemical analysis showed that the administration of combined extracts could increase the total antioxidant capacity (TAC) level significantly in groups 3, 4, 5 and 6. Interestingly, the mixed extract could decrease most of the side effects of CP such as vacuolization and separation of epididymal tissue. Our findings indicated that the combined extracts might be used as a protective agent against CP-induced reproductive toxicity.

  18. Effect of celery (Apium graveolens) extracts on some biochemical parameters of oxidative stress in mice treated with carbon tetrachloride.

    PubMed

    Popović, Mira; Kaurinović, Biljana; Trivić, Svetlana; Mimica-Dukić, Neda; Bursać, Marija

    2006-07-01

    Extracts of celery leaves and roots in ether, chloroform, ethyl acetate, n-butanol and water were evaporated to dryness and dissolved in 50% ethanol to make 10% (w[sol ]v) solutions. The potential protective action of the extracts was assessed by the corresponding in vitro and in vivo tests. In the in vitro experiments crude methanol extracts were tested as potential scavengers of free OH* and DPPH* radicals, as well as inhibitors of liposomal peroxidation (LPx). Analogous experiments were also carried out with the extracts of celery root, for comparison. The results obtained show that both the extracts of root and leaves are good scavengers of OH* and DPPH* radicals and reduce LPx intensity in liposomes, which points to their protective (antioxidant) activity. In vivo experiments were concerned with antioxidant systems (activities of GSHPx, GSHR, Px, CAT, XOD, GSH content and intensity of LPx) in liver homogenate and blood of mice after their treatment with extracts of celery leaves, or in combination with CCl4. On the basis of the results obtained it can be concluded that the examined extracts showed a certain protective effect. Of all the extracts the n-butanol extract showed the highest protective effect. Combined treatments with CCl4 and extracts showed both positive and negative synergism - inducing or suppressing the impact of CCl4 alone. The differences observed in the action of particular extracts are probably due to the different contents of flavonoids and some other antioxidant compounds.

  19. Dominant modal decomposition method

    NASA Astrophysics Data System (ADS)

    Dombovari, Zoltan

    2017-03-01

    The paper deals with the automatic decomposition of experimental frequency response functions (FRF's) of mechanical structures. The decomposition of FRF's is based on the Green function representation of free vibratory systems. After the determination of the impulse dynamic subspace, the system matrix is formulated and the poles are calculated directly. By means of the corresponding eigenvectors, the contribution of each element of the impulse dynamic subspace is determined and the sufficient decomposition of the corresponding FRF is carried out. With the presented dominant modal decomposition (DMD) method, the mode shapes, the modal participation vectors and the modal scaling factors are identified using the decomposed FRF's. Analytical example is presented along with experimental case studies taken from machine tool industry.

  20. Fully Automated Operational Modal Analysis using multi-stage clustering

    NASA Astrophysics Data System (ADS)

    Neu, Eugen; Janser, Frank; Khatibi, Akbar A.; Orifici, Adrian C.

    2017-02-01

    The interest for robust automatic modal parameter extraction techniques has increased significantly over the last years, together with the rising demand for continuous health monitoring of critical infrastructure like bridges, buildings and wind turbine blades. In this study a novel, multi-stage clustering approach for Automated Operational Modal Analysis (AOMA) is introduced. In contrast to existing approaches, the procedure works without any user-provided thresholds, is applicable within large system order ranges, can be used with very small sensor numbers and does not place any limitations on the damping ratio or the complexity of the system under investigation. The approach works with any parametric system identification algorithm that uses the system order n as sole parameter. Here a data-driven Stochastic Subspace Identification (SSI) method is used. Measurements from a wind tunnel investigation with a composite cantilever equipped with Fiber Bragg Grating Sensors (FBGSs) and piezoelectric sensors are used to assess the performance of the algorithm with a highly damped structure and low signal to noise ratio conditions. The proposed method was able to identify all physical system modes in the investigated frequency range from over 1000 individual datasets using FBGSs under challenging signal to noise ratio conditions and under better signal conditions but from only two sensors.

  1. Protective effect of pumpkin seed extract on sperm characteristics, biochemical parameters and epididymal histology in adult male rats treated with cyclophosphamide.

    PubMed

    Aghaei, S; Nikzad, H; Taghizadeh, M; Tameh, A A; Taherian, A; Moravveji, A

    2014-10-01

    Cancer treatment with cyclophosphamide (CP) may result in reproductive toxicity as one of its side effects. The pumpkin seed is a rich natural source of antioxidant. We have assessed the possible protective efficacy of pumpkin seed extract on sperm characteristics, biochemical parameters and epididymal histology of CP-treated rats. Male adult Wistar rats were categorised into four groups. Group 1 served as control and received intraperitoneal (IP) injection of isotonic saline solution. Group 2 rats were treated with CP by IP injection in a single dose of 100 mg/kg body weight, only once. Group 3 and 4 received CP plus 300 and 600 mg/kg pumpkin seed extract respectively. Six weeks after treatment, sperm characteristics, biochemical parameters and histopathological changes were examined. Results showed that, sperm characteristics in CP-treated rats were significantly decreased. Biochemical analysis results showed that the co-administration of 300 mg pumpkin seed extract could increase the total antioxidant capacity (TAC) level significantly. In CP-treated rats, histopathological changes such as vacuolisation, disorganisation and separation of epididymal epithelium were observed as well. Interestingly, pumpkin seed extract could improve the above-mentioned parameters remarkably in CP-treated rats. Our findings indicated that pumpkin seed extract might be used as protective agent against CP-induced reproductive toxicity. © 2013 Blackwell Verlag GmbH.

  2. Effect of extraction parameters on the chemical structure and gel properties of kappa/iota-hybrid carrageenans obtained from Mastocarpus stellatus.

    PubMed

    Hilliou, L; Larotonda, F D S; Abreu, P; Ramos, A M; Sereno, A M; Gonçalves, M P

    2006-09-01

    Extraction parameters (temperature, pH, duration) and alkaline pre-treatment duration have been systematically varied in the aim of exploring their impact on both chemical structure and gelling properties of carrageenan biopolymers obtained from Mastocarpus stellatus seaweeds, collected on the Northern coast of Portugal. Increasing the alkaline pre-treatment duration PT leads to kappa/iota-hybrid carrageenans containing less sulphate groups and biological precursor monomers. As a result, gel properties in the presence of KCl are improved as demonstrated by the increase in the Young's modulus with parameter PT. Increasing the extraction duration t ameliorates the biopolymer yield with no significant change in the complex kappa/iota-hybrid carrageenan chemical structure. However, smaller molecular weights are obtained and gel properties are seen to be negatively affected. Extraction temperature and pH have dramatic effects on the biopolymer gel strength, and a set of extraction parameters optimized with respect to extraction yield and gel properties is reported. In addition, kappa/iota-hybrid carrageenans obtained throughout this study exhibit a wide range of gel strengths in KCl, and allow us to present correlations between gel thermal properties and the kappa/iota-hybrid carrageenans chemical structure.

  3. Modal vector estimation for closely spaced frequency modes

    NASA Technical Reports Server (NTRS)

    Craig, R. R., Jr.; Chung, Y. T.; Blair, M.

    1982-01-01

    Techniques for obtaining improved modal vector estimates for systems with closely spaced frequency modes are discussed. In describing the dynamical behavior of a complex structure modal parameters are often analyzed: undamped natural frequency, mode shape, modal mass, modal stiffness and modal damping. From both an analytical standpoint and an experimental standpoint, identification of modal parameters is more difficult if the system has repeated frequencies or even closely spaced frequencies. The more complex the structure, the more likely it is to have closely spaced frequencies. This makes it difficult to determine valid mode shapes using single shaker test methods. By employing band selectable analysis (zoom) techniques and by employing Kennedy-Pancu circle fitting or some multiple degree of freedom (MDOF) curve fit procedure, the usefulness of the single shaker approach can be extended.

  4. An investigation into NVC characteristics of vehicle behaviour using modal analysis

    NASA Astrophysics Data System (ADS)

    Hanouf, Zahir; Faris, Waleed F.; Ahmad, Kartini

    2017-03-01

    NVC characterizations of vehicle behavior is one essential part of the development targets in automotive industries. Therefore understanding dynamic behavior of each structural part of the vehicle is a major requirement in improving the NVC characteristics of a vehicle. The main focus of this research is to investigate structural dynamic behavior of a passenger car using modal analysis part by part technique and apply this method to derive the interior noise sources. In the first part of this work computational modal analysis part by part tests were carried out to identify the dynamic parameters of the passenger car. Finite elements models of the different parts of the car are constructed using VPG 3.2 software. Ls-Dyna pre and post processing was used to identify and analyze the dynamic behavior of each car components panels. These tests had successfully produced natural frequencies and their associated mode shapes of such panels like trunk, hood, roof and door panels. In the second part of this research, experimental modal analysis part by part is performed on the selected car panels to extract modal parameters namely frequencies and mode shapes. The study establishes the step-by-step procedures to carry out experimental modal analysis on the car structures, using single input excitation and multi-output responses (SIMO) technique. To ensure the validity of the results obtained by the previous method an inverse method was done by fixing the response and moving the excitation and the results found were absolutely the same. Finally, comparison between results obtained from both analyses showed good similarity in both frequencies and mode shapes. Conclusion drawn from this part of study was that modal analysis part-by-part can be strongly used to establish the dynamic characteristics of the whole car. Furthermore, the developed method is also can be used to show the relationship between structural vibration of the car panels and the passengers’ noise comfort

  5. Extraction of physical Schottky parameters using the Lambert function in Ni/AlGaN/GaN HEMT devices with defined conduction phenomena

    NASA Astrophysics Data System (ADS)

    Latry, O.; Divay, A.; Fadil, D.; Dherbécourt, P.

    2017-01-01

    Electrical characterization analyses are proposed in this work using the Lambert function on Schottky junctions in GaN wide band gap semiconductor devices for extraction of physical parameters. The Lambert function is used to give an explicit expression of the current in the Schottky junction. This function is applied with defined conduction phenomena, whereas other work presented arbitrary (or undefined) conduction mechanisms in such parameters’ extractions. Based upon AlGaN/GaN HEMT structures, extractions of parameters are undergone in order to provide physical characteristics. This work highlights a new expression of current with defined conduction phenomena in order to quantify the physical properties of Schottky contacts in AlGaN/GaN HEMT transistors. Project supported by the French Department of Defense (DGA).

  6. Modal testing in the design evaluation of wind turbines

    SciTech Connect

    Lauffer, J.P.; Carne, T.G.; Ashwill, T.D.

    1988-04-01

    This report reviews several techniques of low-frequency excitation used successfully to measure modal parameters for wind turbines, including impact, wind, step-relaxation, and human input. As one application of these techniques, a prototype turbine was tested and two modal frequencies were found to be close to integral multiples of the operating speed, which caused a resonant condition. The design was modified to shift these frequencies, and the turbine was retested to confirm expected changes in modal frequencies.

  7. Teaching German Modal Particles.

    ERIC Educational Resources Information Center

    Rosler, Dietmar

    1982-01-01

    Believes modern linguistics has done little to explore German modal particles because by focusing on sentences as the basic category for linguistic thinking these words did not seem to matter. Describes model which gives students experience with these particles in meaningful communication. (Author/BK)

  8. Teaching German Modal Particles.

    ERIC Educational Resources Information Center

    Rosler, Dietmar

    1982-01-01

    Believes modern linguistics has done little to explore German modal particles because by focusing on sentences as the basic category for linguistic thinking these words did not seem to matter. Describes model which gives students experience with these particles in meaningful communication. (Author/BK)

  9. Determination of Parameters for the Supercritical Extraction of Antioxidant Compounds from Green Propolis Using Carbon Dioxide and Ethanol as Co-Solvent

    PubMed Central

    Barreto, Gabriele de Abreu; Costa, Samantha Serra; Silva, Rejane Pina Dantas; da Silva, Danielle Figuerêdo; Brandão, Hugo Neves; da Rocha, José Luiz Carneiro; Nunes, Silmar Baptista; Umsza-Guez, Marcelo Andres

    2015-01-01

    The aim of this study was to determine the best processing conditions to extract Brazilian green propolis using a supercritical extraction technology. For this purpose, the influence of different parameters was evaluated such as S/F (solvent mass in relation to solute mass), percentage of co-solvent (1 and 2% ethanol), temperature (40 and 50°C) and pressure (250, 350 and 400 bar) using supercritical carbon dioxide. The Global Yield Isotherms (GYIs) were obtained through the evaluation of the yield, and the chemical composition of the extracts was also obtained in relation to the total phenolic compounds, flavonoids, antioxidant activity and 3,5-diprenyl-4-hydroxicinnamic acid (Artepillin C) and acid 4-hydroxycinnamic (p-coumaric acid). The best results were identified at 50°C, 350 bar, 1% ethanol (co-solvent) and S/F of 110. These conditions, a content of 8.93±0.01 and 0.40±0.05 g/100 g of Artepillin C and p-coumaric acid, respectively, were identified indicating the efficiency of the extraction process. Despite of low yield of the process, the extracts obtained had high contents of relevant compounds, proving the viability of the process to obtain green propolis extracts with important biological applications due to the extracts composition. PMID:26252491

  10. Determination of Parameters for the Supercritical Extraction of Antioxidant Compounds from Green Propolis Using Carbon Dioxide and Ethanol as Co-Solvent.

    PubMed

    Machado, Bruna Aparecida Souza; Barreto, Gabriele de Abreu; Costa, Aline Silva; Costa, Samantha Serra; Silva, Rejane Pina Dantas; da Silva, Danielle Figuerêdo; Brandão, Hugo Neves; da Rocha, José Luiz Carneiro; Nunes, Silmar Baptista; Umsza-Guez, Marcelo Andres; Padilha, Francine Ferreira

    2015-01-01

    The aim of this study was to determine the best processing conditions to extract Brazilian green propolis using a supercritical extraction technology. For this purpose, the influence of different parameters was evaluated such as S/F (solvent mass in relation to solute mass), percentage of co-solvent (1 and 2% ethanol), temperature (40 and 50°C) and pressure (250, 350 and 400 bar) using supercritical carbon dioxide. The Global Yield Isotherms (GYIs) were obtained through the evaluation of the yield, and the chemical composition of the extracts was also obtained in relation to the total phenolic compounds, flavonoids, antioxidant activity and 3,5-diprenyl-4-hydroxicinnamic acid (Artepillin C) and acid 4-hydroxycinnamic (p-coumaric acid). The best results were identified at 50°C, 350 bar, 1% ethanol (co-solvent) and S/F of 110. These conditions, a content of 8.93±0.01 and 0.40±0.05 g/100 g of Artepillin C and p-coumaric acid, respectively, were identified indicating the efficiency of the extraction process. Despite of low yield of the process, the extracts obtained had high contents of relevant compounds, proving the viability of the process to obtain green propolis extracts with important biological applications due to the extracts composition.

  11. Bacterial clearance, heterophil function, and hematological parameters of transport stressed turkey poults supplemented with dietary yeast extract

    USDA-ARS?s Scientific Manuscript database

    Yeast extracts contain biological response modifiers that may be useful as alternatives to antibiotics for controlling pathogens in poultry production and mitigating the deleterious effects of production stressors. A standardized yeast extract feed supplement, Alphamune™ (YE), was added to turkey po...

  12. Modal Mineralogy of Lunar Soils

    NASA Astrophysics Data System (ADS)

    Taylor, J.; Martel, L.; Lucey, P. G.; Crites, S. T.; Blake, D. F.

    2012-12-01

    Modal mineralogy of the lunar regolith is fundamentally important. It varies with the composition of underlying bedrock, extent of addition of materials excavated by impact both local and distant, and small-scale reworking by micrometeorite bombardment, so it contains information about local geological history. Determining modal mineralogy of soils provides vital ground truth to remote sensing studies. Mineralogy can be determined by a variety of techniques that provide complementary information: X-Ray Diffraction (XRD), optical point counting, element mapping by scanning electron microscopy (SEM) or electron microprobe (EMP), and normative calculation from a bulk chemical analysis. SEM and EMP element mapping can be converted into mineral modal abundances in a variety of ways, including defining compositional windows for specific minerals and using image processing techniques. XRD provides direct determination of the phases present, but gives little information about the chemical composition of those phases. We have launched a project to determine the modal mineralogy of over 100 lunar soils from all Apollo sites. The goal is to use this quantitative mineralogy and laboratory and remote reflectance spectra of the same soils to improve our ability to extract quantitative mineralogy from remote sensing data. Samples (< 1mm bulk soils) were dry-sieved and the <150 micron fractions analyzed in a Terra XRD instrument (InXitu, Inc.) using sample sizes of ~35 mg. We reduced the data using Reitveld refinement as implemented by the Jade program (Materials Data, Inc.). Glass abundances were determined by choosing a linear background and fitting a broad Gaussian to the scattering hump above background. Quantitative XRD is well established, but usually requires some calibration, in spite of the sophisticated Reitveld refinement and whole-pattern fitting. We calibrated the instrument by using mixtures of terrestrial minerals and results from the Lunar Sample Characterization

  13. Determining material damping type by comparing modal frequency estimators.

    PubMed

    Anthony, D K; Simón, F; Juan, Jesús

    2009-09-01

    The accuracy of modal frequency and damping estimators for non-lightly damped single degree of freedom systems depend on the response parameter used as well as the damping mechanism. Therefore, in order to make accurate modal parameter measurements, the damping mechanism at play must be known to be either viscous or hysteretic a priori. Here, comparisons between the evaluated frequency values are used to glean this information. The damping mechanism of an experimental system (consisting of resilient layer and mass plate) is then determined using two simple modal parameter estimators and applying statistical methods.

  14. The effects of the leaf water extract of Struchium sparganophora (Linn.) Ktze asteraceae on the hematopoietic parameters and the organ system of rats.

    PubMed

    Saka, Kasim Lateef; Kudirat, Okunowo; James, Olaitan Olatunde; Olugbenga, Fajemirokun Timothy

    2013-11-01

    Struchium sparganophora, (Linn.) Asteraceae is a culinary herb consumed in the western part of Nigeria and it is known to have a nutritive value. This study was carried out to assess its' effects on the hematopoietic parameters and its toxicity on the organ system of Wistar rats. The animals were randomly divided to five (5) groups. The group 1 (control) received distilled water equivalent to the volume of extract administered while groups, 2, 3, 4 and 5 received the aqueous extract of 0.2g, 0.4g, 0.8g and 1.6g/kg body weight orally respectively for 4 weeks. The rats were anaesthesized with chloroform vapors 24 hours after the last day of extract administration and blood and organ tissues were collected through dissection for hematopoietic as well as histological examinations. Hematological parameters like hemoglobin (Hb) concentration, packed cell volume (PCV), white blood count (WBC) and platelet count were examined. The hematological parameters observed were not significantly different (P > 0.05) from that of the control except platelet counts that showed significant difference (P < 0.05). Histological assessment of cerebellum, kidney and trapezoid nuclei of the brain in all groups showed normal cytoarchitecture. However neuropathological damage such as lesions, chromatolysis and necrosis were observed to progress in the liver as the concentration of extract increases. This study shows that the extract at low doses did not cause significant (P > 0.05) necrohistopathological effects on the brain and the kidney indicating that the plant is safe at low doses but at a high dose of 1.6g/kg and above significant (P < 0.05) suppression of the platelet level was observed suggesting disturbances of hematopoiesis as even reflected by the necrohistopatholo-gical effects on the liver. Thus, the result revealed that the aqueous extract did not possess blood boosting ability and could cause liver damage if consumed at high concentrations.

  15. Computer animation of modal and transient vibrations

    NASA Technical Reports Server (NTRS)

    Lipman, Robert R.

    1987-01-01

    An interactive computer graphics processor is described that is capable of generating input to animate modal and transient vibrations of finite element models on an interactive graphics system. The results from NASTRAN can be postprocessed such that a three dimensional wire-frame picture, in perspective, of the finite element mesh is drawn on the graphics display. Modal vibrations of any mode shape or transient motions over any range of steps can be animated. The finite element mesh can be color-coded by any component of displacement. Viewing parameters and the rate of vibration of the finite element model can be interactively updated while the structure is vibrating.

  16. Das modale Hilfsverb "will" (The Modal Auxiliary Verb "Will")

    ERIC Educational Resources Information Center

    Kunsmann, Peter W.

    1975-01-01

    That "will" and "shall" are modal, not temporal, verbs is shown by their syntactic similarity to the modals and by the fact that they follow the same transformational rules as the modals. This example demonstrates the usefulness of transformational grammar in explaining grammatical relationships to students. (Text is in…

  17. Parameters optimization of supercritical fluid-CO2 extracts of frankincense using response surface methodology and its pharmacodynamics effects.

    PubMed

    Zhou, Jing; Ma, Xing-miao; Qiu, Bi-Han; Chen, Jun-xia; Bian, Lin; Pan, Lin-mei

    2013-01-01

    The volatile oil parts of frankincense (Boswellia carterii Birdw.) were extracted with supercritical carbon dioxide under constant pressure (15, 20, or 25 MPa) and fixed temperature (40, 50, or 60°C), given time (60, 90, or 120 min) aiming at the acquisition of enriched fractions containing octyl acetate, compounds of pharmaceutical interest. A mathematical model was created by Box-Behnken design, a popular template for response surface methodology, for the extraction process. The response value was characterized by synthetical score, which comprised yields accounting for 20% and content of octyl acetate for 80%. The content of octyl acetate was determined by GC. The supercritical fluid extraction showed higher selectivity than conventional steam distillation. Supercritical fluid-CO(2) for extracting frankincense under optimum condition was of great validity, which was also successfully verified by the pharmacological experiments. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Optimisation of biological and physical parameters for lycopene supercritical CO2 extraction from ordinary and high-pigment tomato cultivars.

    PubMed

    Lenucci, Marcello S; Caccioppola, Alessandro; Durante, Miriana; Serrone, Lucia; Leonardo, Rescio; Piro, Gabriella; Dalessandro, Giuseppe

    2010-08-15

    Lycopene is used for several industrial applications. Supercritical CO(2) (SC-CO(2)) extraction from red-ripe tomato fruits is an excellent technique to replace the use of harmful solvents. In this study, starting from red-ripe tomatoes of ordinary and high-lycopene cultivars, the effect of different agronomical and technical aspects on lycopene content, stability and yield was evaluated throughout the production process from fresh tomatoes to the final SC-CO(2)-extracted oleoresin containing lycopene. Red-ripe tomato cultivars differed in their lycopene content. Irrigation excess or deficit caused an increase in the amount of lycopene in the fruits. Fresh tomatoes were processed into a lyophilised matrix suitable for SC-CO(2) extraction, which could be stored for more than 6 months at -20 degrees C without lycopene loss. Under the optimal extraction conditions, efficiencies of up to 80% were achieved, but the recovery of lycopene in the extracted oleoresin was very low (approximately 24%). Co-extraction of the tomato matrix mixed with a lipid co-matrix allowed the recovery of approximately 90% of lycopene in the oleoresin. Using the high-lycopene cultivars, the yield of total extracted lycopene increased by approximately 60% with respect to the ordinary cultivars. Lipids and other biologically active molecules were present in the oleoresin. A method for extracting, from a tomato matrix, a natural and solvent-free oleoresin containing lycopene dissolved in a highly unsaturated vegetable oil has been described. The oleoresin represents an excellent product for testing on cancer and cardiovascular disease prevention. Copyright (c) 2010 Society of Chemical Industry.

  19. The modal projector.

    PubMed

    Butler, John L; Butler, Alexander L; Butler, Stephen C

    2011-04-01

    The superposition of acoustical modes radiated from a transducer can provide directionality from a compact projector. This paper presents the foundation, as well as examples, of piezoelectric ceramic, piezoelectric single crystal, and magnetostrictive versions of this "modal projector." Measured and analytical, as well as finite element analysis modeled, results show good agreement and establish this transducer as a viable source of intensity with the advantages of an improved directivity index, reducing the power needed from a compact source.

  20. Energy-based modalities.

    PubMed

    Engebretson, Joan; Wardell, Diane Wind

    2007-06-01

    Research on touch therapies is still in the early stages of development. Studies of Therapeutic Touch, Healing Touch, and Reiki are quite promising; however, at this point, they can only suggest that these healing modalities have efficacy in reducing anxiety; improving muscle relaxation; aiding in stress reduction, relaxation, and sense of well-being; promoting wound healing; and reducing pain. The multidimensional aspects of healing inherent in patient care continue to be expanded and facilitated by our understanding and application of energy therapies.

  1. Digital multishaker modal testing

    NASA Technical Reports Server (NTRS)

    Blair, M.; Craig, R. R., Jr.

    1983-01-01

    A review of several modal testing techniques is made, along with brief discussions of their advantages and limitations. A new technique is presented which overcomes many of the previous limitations. Several simulated experiments are included to verify the validity and accuracy of the new method. Conclusions are drawn from the simulation studies and recommendations for further work are presented. The complete computer code configured for the simulation study is presented.

  2. Optimization of extraction parameters by using response surface methodology, purification, and identification of anthocyanin pigments in Melastoma malabathricum fruit.

    PubMed

    Anuar, Nordiyanah; Mohd Adnan, Ahmad Faris; Saat, Naziz; Aziz, Norkasmani; Mat Taha, Rosna

    2013-01-01

    Anthocyanins not just have various benefits in food industry but also have been used as natural colourants in cosmetic, coating products and as potential natural photosensitizers in solar cell. Thus, the main purpose of this study was to obtain information on the maximum yield of anthocyanin that can be recovered from Melastoma malabathricum fruit. Factors such as extraction temperature, extraction time, and solid to liquid ratio were identified to be significantly affecting anthocyanin extraction efficiency. By using three-level three-factor Box-Behnken design, the optimized conditions for anthocyanin extraction by acidified methanol (R (2) = 0.972) were temperature of 60°C, time of 86.82 min, and 0.5 : 35 (g/mL) solid to liquid ratio while the optimum extraction conditions by acidified ethanol (R (2) = 0.954) were temperature of 60°C, time of 120 min, and 0.5 : 23.06 (g/mL) solid to liquid ratio. The crude anthocyanin extract was further purified by using Amberlite XAD-7 and Sephadex LH-20 column chromatography. Identification of anthocyanins revealed the presence of cyanidin dihexoside, cyanidin hexoside, and delphinidin hexoside as the main anthocyanins in M. malabathricum fruit.

  3. Changbai Mountain Ginseng (Panax ginseng C.A. Mey) Extract Supplementation Improves Exercise Performance and Energy Utilization and Decreases Fatigue-Associated Parameters in Mice.

    PubMed

    Ma, Guo-Dong; Chiu, Chun-Hui; Hsu, Yi-Ju; Hou, Chien-Wen; Chen, Yi-Ming; Huang, Chi-Chang

    2017-02-05

    Changbai Mountain Ginseng (CMG, Panax ginseng C.A. Mey) is a traditional medicine commonly found in Northeast China and grows at elevations of 2000 m or higher in the Changbai Mountain Range. CMG, considered to be a "buried treasure medicine", is priced higher than other types of ginseng. However, few studies have demonstrated the effects of CMG supplementation on exercise performance, physical fatigue, and the biochemical profile. The major compound of CMG extract was characterized by electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). Male ICR mice were divided into 3 groups, the vehicle, CMG-1X and CMG-5X groups (n = 8 per group), and respectively administered 0, 5, or 25 mg/kg/day of CMG extract orally for four weeks. HPLC-ESI-MS/MS results showed that the major compound in CMG extract is ginsenoside Ro. CMG extract significantly increased muscle weight and relative muscle weight (%). CMG extract supplementation dose-dependently increased grip strength (p < 0.0001) and endurance swimming time, decreased levels of serum lactate (p < 0.0001), ammonia (p < 0.0001), creatine kinase (CK, p = 0.0002), and blood urea nitrogen (p < 0.0001), and economized glucose levels (p < 0.0001) after acute exercise challenge. The glycogen in the gastrocnemius muscle was significantly increased with CMG extract treatment. Biochemical profile results showed that creatinine and triacylglycerol significantly decreased and total protein and glucose increased with CMG treatment. This is the first report that CMG extract supplementation increases muscle mass, improves exercise performance and energy utilization, and decreases fatigue-associated parameters in vivo. The major component of CMG extract is ginsenoside Ro, which could be a potential bioactive compound for use as an ergogenic aid ingredient by the food industry.

  4. Effect of the dietary polyphenolic fraction of chicory root, peel, seed and leaf extracts on caecal fermentation and blood parameters in rats fed diets containing prebiotic fructans.

    PubMed

    Juśkiewicz, Jerzy; Zduńczyk, Zenon; Zary-Sikorska, Ewa; Król, Bogusław; Milala, Joanna; Jurgoński, Adam

    2011-03-01

    The aim of this 28 d experiment was to examine the physiological response of growing rats to a dietary combination of prebiotic chicory fructans, with polyphenols originating from different parts of the chicory plant, i.e. roots, root peels, seeds and leaves. A total of forty rats were assigned to groups fed the following diets characterised by a similar content of oligofructose and inulin: control, with 10 % of a root extract (a low level of dietary polyphenols, 0·05 %), with 6·5 % of a root peel extract (a medium level of dietary polyphenols, 0·107 %), with a combination of 8 % of a peel extract and 0·8 % of a seed extract (a high level of dietary polyphenols, 0·208 %) and with 2·5 % of a leaf extract (a medium level of dietary polyphenols, 0·106 %, with chicoric acid constituting half of them). Chicory seeds are the richest source of polyphenols, especially abundant in dicaffeoylquinic acids. When applied as a dietary supplement, the mixture of monocaffeoylquinic and dicaffeoylquinic acids, from the extracts made of roots, root peels and seeds, elicited more favourable changes in parameters of the antioxidative status of the body and in the activity of bacterial β-glucuronidase in the faeces and caecal digesta. In turn, the extract from chicory leaves, containing considerable quantities of chicoric acid and polyphenolic glycosides, apart from chlorogenic acids, also triggered desirable changes in the lipid profile of the blood serum. The high concentration of polyphenols in the extracts examined enables their application as dietary supplements to be administered in low doses.

  5. Asymptotic modal analysis and statistical energy analysis

    NASA Technical Reports Server (NTRS)

    Dowell, Earl H.

    1992-01-01

    Asymptotic Modal Analysis (AMA) is a method which is used to model linear dynamical systems with many participating modes. The AMA method was originally developed to show the relationship between statistical energy analysis (SEA) and classical modal analysis (CMA). In the limit of a large number of modes of a vibrating system, the classical modal analysis result can be shown to be equivalent to the statistical energy analysis result. As the CMA result evolves into the SEA result, a number of systematic assumptions are made. Most of these assumptions are based upon the supposition that the number of modes approaches infinity. It is for this reason that the term 'asymptotic' is used. AMA is the asymptotic result of taking the limit of CMA as the number of modes approaches infinity. AMA refers to any of the intermediate results between CMA and SEA, as well as the SEA result which is derived from CMA. The main advantage of the AMA method is that individual modal characteristics are not required in the model or computations. By contrast, CMA requires that each modal parameter be evaluated at each frequency. In the latter, contributions from each mode are computed and the final answer is obtained by summing over all the modes in the particular band of interest. AMA evaluates modal parameters only at their center frequency and does not sum the individual contributions from each mode in order to obtain a final result. The method is similar to SEA in this respect. However, SEA is only capable of obtaining spatial averages or means, as it is a statistical method. Since AMA is systematically derived from CMA, it can obtain local spatial information as well.

  6. Modal confidence factor in vibration testing

    NASA Technical Reports Server (NTRS)

    Ibrahim, S. R.

    1978-01-01

    The theory and applications of a time domain modal test technique are presented. The method uses free decay of random responses from a structure under test to identify its modal characteristics namely, natural frequencies, damping factors, and mode shapes. The method can identify multimodal (highly coupled) systems and modes that have very small contribution in the responses. A method is presented to decrease the effects of high levels of noise in the data and thus improve the accuracy of identified parameters. This is accomplished using an oversized mathematical model. The concept of modal confidence factor (MCF) is developed. The MCF is a number calculated for every identified mode for a structure under test. The MCF varies from 0.000 for a distorted, nonlinear, or noise mode to 100.0 for a pure structural mode. The theory of the MCF is based on the correlation that exits between the modal deflection at a certain station and the modal deflection at the same station delayed in time. The theory and application of the MCF is illustrated by two experiments. The first experiment deals with simulated responses from a two degree of freedom system with 20 percent, 40 percent, and 100 percent noise added. The second experiment was run on a generalized payload model. The free decay response from the payload model contained about 22 percent noise.

  7. Semantic Structure of English Modals

    ERIC Educational Resources Information Center

    Cook, Walter A.

    1978-01-01

    English modal verbs constitute a problem for the student of English as a foreign language. This study presents a methodology for a systematic presentation of the meaning of modal verbs. The modals "can,""may,""must," and "have to" are studied. (SW)

  8. Modal shape identification of large structure exposed to wind excitation by operational modal analysis technique

    NASA Astrophysics Data System (ADS)

    De Vivo, A.; Brutti, C.; Leofanti, J. L.

    2013-08-01

    Research efforts during recent decades qualify Operational Modal Analysis (OMA) as an interesting tool that is able to identify the modal characteristic parameters of structures excited randomly by environmental loads, eliminating the problem of measuring the external exciting forces. In this paper, an existing OMA technique, the Natural Excitation Technique (NExT) was studied and implemented in order to achieve, from the wind force, the modal parameters of Vega Launcher, the new European launcher vehicle for small and medium satellites. Following a brief summary of the fundamental equations of the method, the modal parameters of Vega are calculated using the OMA technique; the results are then compared with those achieved using a traditional Experimental Modal Analysis under excitation induced by shakers. The comparison shows there is a very good agreement between the results obtained by the two different methods, OMA and the traditional experimental analysis, proving that OMA is a reliable tool to analyse the dynamic behaviour of large structures. Finally, this approach can be used for any type of large structure in civil and mechanical fields and the technique appears to be very promising for further applications.

  9. Impact of quality parameters on the recovery of putrescine and cadaverine in fish using methanol-hydrochloric acid solvent extraction.

    PubMed

    Richard, Nicole L; Pivarnik, Lori F; Ellis, P Christopher; Lee, Chong M

    2011-01-01

    Methanol (MeOH) extraction by AOAC Official Method 996.07 has resulted in low amine recoveries in fresh fish tissue. Addition of 25% 0.4 M HCl to the 75% methanol-water extraction solvent resulted in higher recoveries of putrescine and cadaverine. Average putrescine recovery increased from 55 to 92% in flounder, scup, bluefish, and salmon; from 92 to 98% in mackerel; and from 83 to 107% in processed mackerel. Average cadaverine recovery increased from 57 to 95% in flounder, scup, bluefish, and salmon; from 91 to 97% in mackerel; and from 92 to 108% in processed mackerel. Fish stored on ice for 12 days also showed differences between background concentrations determined with the two solvents. However, the values decreased with storage time, indicating that degradation of the protein matrix may cause more comparable measurements between the two solvents. However, consistently higher putrescine and cadaverine measurements were determined using MeOH-HCl. Although significant differences in the extraction of amines from the high-fat fish tissue were not seen between MeOH and MeOH-HCl, it would be ideal to have one solvent for biogenic amine extraction. This study confirms that MeOH-HCl is a better solvent for complete extraction and recovery of putrescine and cadaverine in fresh and processed fish tissues.

  10. Optimization of processing parameters for extraction of amylase enzyme from dragon (Hylocereus polyrhizus) peel using response surface methodology.

    PubMed

    Amid, Mehrnoush; Manap, Mohd Yazid Abdul; Zohdi, Norkhanani

    2014-01-01

    The main goal of this study was to investigate the effect of extraction conditions on the enzymatic properties of thermoacidic amylase enzyme derived from dragon peel. The studied extraction variables were the buffer-to-sample (B/S) ratio (1:2 to 1:6, w/w), temperature (-18°C to 25°), mixing time (60 to 180 seconds), and the pH of the buffer (2.0 to 8.0). The results indicate that the enzyme extraction conditions exhibited the least significant (P < 0.05) effect on temperature stability. Conversely, the extraction conditions had the most significant (P < 0.05) effect on the specific activity and pH stability. The results also reveal that the main effect of the B/S ratio, followed by its interaction with the pH of the buffer, was significant (P < 0.05) among most of the response variables studied. The optimum extraction condition caused the amylase to achieve high enzyme activity (648.4 U), specific activity (14.2 U/mg), temperature stability (88.4%), pH stability (85.2%), surfactant agent stability (87.2%), and storage stability (90.3%).

  11. Optimization of Processing Parameters for Extraction of Amylase Enzyme from Dragon (Hylocereus polyrhizus) Peel Using Response Surface Methodology

    PubMed Central

    Abdul Manap, Mohd Yazid; Zohdi, Norkhanani

    2014-01-01

    The main goal of this study was to investigate the effect of extraction conditions on the enzymatic properties of thermoacidic amylase enzyme derived from dragon peel. The studied extraction variables were the buffer-to-sample (B/S) ratio (1 : 2 to 1 : 6, w/w), temperature (−18°C to 25°), mixing time (60 to 180 seconds), and the pH of the buffer (2.0 to 8.0). The results indicate that the enzyme extraction conditions exhibited the least significant (P < 0.05) effect on temperature stability. Conversely, the extraction conditions had the most significant (P < 0.05) effect on the specific activity and pH stability. The results also reveal that the main effect of the B/S ratio, followed by its interaction with the pH of the buffer, was significant (P < 0.05) among most of the response variables studied. The optimum extraction condition caused the amylase to achieve high enzyme activity (648.4 U), specific activity (14.2 U/mg), temperature stability (88.4%), pH stability (85.2%), surfactant agent stability (87.2%), and storage stability (90.3%). PMID:25050403

  12. [Effect of Rhaponticum carthamoides extract in combination with dosed physical load on hemorheological parameters of rats with myocardial infarction].

    PubMed

    Plotnikov, M B; Vasil'ev, A S; Aliev, O I; Anishchenko, A M; Krasnov, E A

    2011-01-01

    The administration of the extract from Rhaponticum carthamoides (150 mg/kg, p.o., for 10 days) in combination with dosed low-power exercise in rats with experimental myocardial infarction led to an improvement of hemorheological indices, which was manifested by a decrease in the whole blood viscosity, aggregation of erythrocytes, and increase in erythrocyte deformability. In particular, the extract from R. carthamoides contributed to an increase in the hematocrit/blood viscosity, which was indicative of an improvement of the blood overall oxygen transport capacity. In addition, administration of the extract in combination with dosed exercise favored normalization of the lactate and pyruvate concentrations in blood of rats with myocardial infarction.

  13. Robust vibration isolation via frequency-shaped sliding control and modal decomposition

    NASA Astrophysics Data System (ADS)

    Zuo, Lei; Slotine, Jean-Jacques E.

    2005-08-01

    A robust controller design is proposed for multi-degree-of-freedom active vibration isolation, which accounts for plant uncertainties and payload disturbances using frequency-shaped sliding control. First, modal decomposition is employed to rewrite the MIMO vibration control problem as a combination of individual SISO control problems in modal coordinates. The modal parameters for decomposition and modelling can be extracted from theoretical or experimental modal analysis. Next, the target frequency-domain performance of isolation, in this case a skyhook model, is recast as a frequency-shaped sliding surface. The practical effects of boundary layer approximation in the resulting controller design are examined. Simulations illustrate that the ideal skyhook effect can indeed be robustly achieved. The frequency-shaped manifold is also extended to adaptive vibration isolation without using model reference. This algorithm has been recently verified by experiments (IEEE Transactions on Control Systems Technology (2005), in press), and has been demonstrated very effective for vibration isolation. The paper also shows, more generally, that the design of a frequency-shaped sliding surface is formally equivalent to a feedback-feedforward compensation problem. Nonlinear target dynamics of the same order as the nominal plant can also be attained.

  14. Effect of the icing with thyme, oregano and clove extracts on quality parameters of gutted and beheaded anchovy (Engraulis encrasicholus) during chilled storage.

    PubMed

    Bensid, Abdelkader; Ucar, Yilmaz; Bendeddouche, Badis; Özogul, Fatih

    2014-02-15

    The effect of ice containing thyme (0.04% w/v), oregano (0.03% w/v) and clove (0.02% w/v) extracts on the quality parameters of anchovy (Engraulis encrasicholus) was assessed through the chemical, sensory and microbiological methods. According to sensory analyses, anchovy stored in ice prepared with each plant extracts had a shelf life of 12 days, while batch stored in traditional ice had a shelf life of 9 days. pH were not significantly affected by the presence of plant extracts in the ice. However, a marked antioxidant effect (P<0.05) could be detected with fish kept under plant extract icing systems, according to peroxide (PV) and thiobarbituric acid (TBA) values. Moreover, the employment of such icing systems led to lower (P<0.05) total volatile base-nitrogen (TVB-N) value and free fatty acid (FFA) formation. Thus, TVB-N proved to be a suitable index for the spoilage of anchovies during chilled storage. The employment of such icing systems also led to significantly lower counts of aerobic mesophiles and psychrotrophic bacteria in anchovy muscle with skin, as compared with the traditional ice batch. This work demonstrates that the use of ice with plant extracts for the storage of gutted and beheaded anchovy can be recommended to improve the quality and extend the shelf life. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Optimization of process parameters of extraction of amentoflavone, quercetin and ginkgetin from Taxus chinensis using supercritical CO2 plus co-solvent.

    PubMed

    Ruan, Xiao; Yan, Liu-Ye; Li, Xian-Xian; Liu, Ben; Zhang, Huan; Wang, Qiang

    2014-10-31

    The effects of extraction time, temperature, pressure and different concentration of ethanol and their interactions on the yields of amentoflavone, quercetin and ginkgetin extracted from Taxus chinensis by supercritical CO2 were investigated by using a central composite design (CCD). An CCD experimental design with four factors and five levels was used to optimize the extraction parameters. Ultra performance liquid chromatography (UPLC) was used to analyze the content of the tree components in the extracts. Experimental results show that the main effects of factors and their interactions are significant on the yields (p < 0.05). The optimal extraction conditions were established for the three compounds: yield of 4.47 mg/g for amentoflavone at 48 °C, 25 MPa, 2.02 h and 78.5% ethanol, 3.73 mg/g for quercetin at 46 °C, 24 MPa, 2.3 h, 82% ethanol and 3.47 mg/g for ginkgetin at 48 °C, 20 MPa, 2.38 h, 82% ethanol, respectively.

  16. Effect of plant extracts and a disinfectant on biological parameters and pathogenicity of the fungus Beauveria bassiana (Bals.) Vuill. (Ascomycota: Cordycipitaceae).

    PubMed

    Martins, C C; Alves, L F A; Mamprim, A P

    2016-06-01

    The fungus Beauveria bassiana is naturally found in poultry houses and causes high rates of mortality in Alphitobius diaperinus. Laboratory and field experiments have shown the potential of this fungus as an insect control agent. However, in poultry houses, bacteria as Salmonella, can be found and have been studied alternative control methods for this pathogen. Thus, this study aimed to evaluate the effect of plant extracts and a disinfectant on the fungus Beauveria bassiana (strain Unioeste 4). Conidial viability, colony-forming unit (CFU) counts, vegetative growth, conidia production, insecticidal activity of the fungus and compatibility were used as parameters in the evaluation of the effect of these products on the fungus. Alcoholic and aqueous extracts of jabuticaba (Myrciaria cauliflora (Mart.), guava (Psidium guajava (L.)), and jambolan (Syzygium cumini (L.), at concentrations of 10% as well as the commercial disinfectant, Peroxitane® 1512 AL, were evaluated at the recommended concentrations (RC), 1:200 (RC), 0.5 RC and 2 RC. There was a negative influence of alcoholic and aqueous extracts of jabuticaba, guava and three dilutions of Peroxitane on the viability of conidia. The CFUs and vegetative growth of the fungus were affected only by the Peroxitane (all dilutions). For conidial production, the aqueous extract of guava had a positive effect, increasing production, while the Peroxitane at the R and RC concentrations resulted in a negative influence. The mortality of A. diaperinus, caused by the fungus after exposure to these products, was 60% for the peracetic acid at 0.5 RC, and above 80% for the extracts. Thus, the results showed that all the extracts and Peroxitane at RC 0.5 are compatible with the fungus B. bassiana Unioeste 4, however only the extracts had a low impact on inoculum potential.

  17. Modal Interfaces in Hawaii

    NASA Technical Reports Server (NTRS)

    Wright, E. Alvey

    1974-01-01

    Hawaii, an archipelago where transportation distances are short but the interfaces are many, seeks elimination of modal changes by totally-submerged hydrofoil craft operating at the water surface directly between tourist resort destinations, by dual mode rapid transit vehicles operating directly between the deplaning bridges at Honolulu International Airport and hotel porte-cochere at Waikiki, by demand responsive vehicles for collection and distribution operating on fixed guideways for line haul, and by roll-on/roll-off inter-island ferries for all models of manually operated ground vehicles. The paper also describes facilitation of unavoidable interfaces by innovative sub-systems.

  18. RF Modal Quantity Gaging

    NASA Technical Reports Server (NTRS)

    Vanleuven, K.

    1989-01-01

    The primary objective is to provide a concept of a radio frequency (RF) modal resonance technique which is being investigated as a method for gaging the quantities of subcritical cryogenic propellants in metallic tanks. Of special interest are the potential applications of the technique to microgravity propellant gaging situations. The results of concept testing using cryogenic oxygen, hydrogen, and nitrogen, as well as paraffin simulations of microgravity fluid orientations, are reported. These test results were positive and showed that the gaging concept was viable.

  19. Modal phase measuring deflectometry

    SciTech Connect

    Huang, Lei; Xue, Junpeng; Gao, Bo; McPherson, Chris; Beverage, Jacob; Idir, Mourad

    2016-10-14

    Here in this work, a model based method is applied to phase measuring deflectometry, which is named as modal phase measuring deflectometry. The height and slopes of the surface under test are represented by mathematical models and updated by optimizing the model coefficients to minimize the discrepancy between the reprojection in ray tracing and the actual measurement. The pose of the screen relative to the camera is pre-calibrated and further optimized together with the shape coefficients of the surface under test. Simulations and experiments are conducted to demonstrate the feasibility of the proposed approach.

  20. Modal Interfaces in Hawaii

    NASA Technical Reports Server (NTRS)

    Wright, E. Alvey

    1974-01-01

    Hawaii, an archipelago where transportation distances are short but the interfaces are many, seeks elimination of modal changes by totally-submerged hydrofoil craft operating at the water surface directly between tourist resort destinations, by dual mode rapid transit vehicles operating directly between the deplaning bridges at Honolulu International Airport and hotel porte-cochere at Waikiki, by demand responsive vehicles for collection and distribution operating on fixed guideways for line haul, and by roll-on/roll-off inter-island ferries for all models of manually operated ground vehicles. The paper also describes facilitation of unavoidable interfaces by innovative sub-systems.

  1. Modal identification experiment

    NASA Technical Reports Server (NTRS)

    Kvaternik, Raymond G.

    1992-01-01

    The Modal Identification Experiment (MIE) is a proposed on-orbit experiment being developed by NASA's Office of Aeronautics and Space Technology wherein a series of vibration measurements would be made on various configurations of Space Station Freedom (SSF) during its on-orbit assembly phase. The experiment is to be conducted in conjunction with station reboost operations and consists of measuring the dynamic responses of the spacecraft produced by station-based attitude control system and reboost thrusters, recording and transmitting the data, and processing the data on the ground to identify the natural frequencies, damping factors, and shapes of significant vibratory modes. The experiment would likely be a part of the Space Station on-orbit verification. Basic research objectives of MIE are to evaluate and improve methods for analytically modeling large space structures, to develop techniques for performing in-space modal testing, and to validate candidate techniques for in-space modal identification. From an engineering point of view, MIE will provide the first opportunity to obtain vibration data for the fully-assembled structure because SSF is too large and too flexible to be tested as a single unit on the ground. Such full-system data is essential for validating the analytical model of SSF which would be used in any engineering efforts associated with structural or control system changes that might be made to the station as missions evolve over time. Extensive analytical simulations of on-orbit tests, as well exploratory laboratory simulations using small-scale models, have been conducted in-house and under contract to develop a measurement plan and evaluate its potential performance. In particular, performance trade and parametric studies conducted as part of these simulations were used to resolve issues related to the number and location of the measurements, the type of excitation, data acquisition and data processing, effects of noise and nonlinearities

  2. Multi-modal image registration using structural features.

    PubMed

    Kasiri, Keyvan; Clausi, David A; Fieguth, Paul

    2014-01-01

    Multi-modal image registration has been a challenging task in medical images because of the complex intensity relationship between images to be aligned. Registration methods often rely on the statistical intensity relationship between the images which suffers from problems such as statistical insufficiency. The proposed registration method works based on extracting structural features by utilizing the complex phase and gradient-based information. By employing structural relationships between different modalities instead of complex similarity measures, the multi-modal registration problem is converted into a mono-modal one. Therefore, conventional mono-modal similarity measures can be utilized to evaluate the registration results. This new registration paradigm has been tested on magnetic resonance (MR) brain images of different modes. The method has been evaluated based on target registration error (TRE) to determine alignment accuracy. Quantitative results demonstrate that the proposed method is capable of achieving comparable registration accuracy compared to the conventional mutual information.

  3. Effects of a triplex mixture of Peganum harmala, Rhus coriaria, and Urtica dioica aqueous extracts on metabolic and histological parameters in diabetic rats.

    PubMed

    Abedi Gaballu, Fereydoon; Abedi Gaballu, Yousef; Moazenzade Khyavy, Omid; Mardomi, Alireza; Ghahremanzadeh, Kazem; Shokouhi, Behrooz; Mamandy, Himan

    2015-08-01

    Several therapeutic effects such as antioxidant and blood glucose-lowering activities have been reported for Peganum harmala L (Zygophyllaceae) (PH) seeds, Rhus coriaria L (Anacardiaceae) (RC) fruits, and Urtica dioica L (Urticaceae) (UD) leaves. This study investigates the effects of a triplex mixture (1:1:1) of these medicinal plants on metabolic and histological parameters in diabetic rats. Aqueous extracts of PH, RC and UD were administered as either monotherapy or in combination at a final dose of 200 mg/kg to alloxan-induced diabetic rats by daily gavage. Biochemical parameters including blood glucose, liver function-related enzymes, lipid profile, and creatinine were estimated by spectrophotometric methods. Tissues from the liver and kidney stained with hematoxylin/eosin were histologically examined. The results obtained from the exposure groups were compared to either healthy or diabetic control groups. Compared with the diabetic control rats, all aqueous extracts (ED50 = 11.5 ± 2.57 mg/ml) led to significant decreases in the levels of ALP (1.39-2.23-fold, p < 0.05), low-density lipoprotein cholesterol (LDL-C) (1.79-3.26-fold, p < 0.05), and blood glucose (1.27-4.16-fold, p < 0.05). The serum concentrations of TG was decreased only by treatment with UD and triplex mixture (1.25- and 1.20-fold, respectively, p < 0.05). Among the studied parameters, alanine aminotransferase (ALT), LDL-C, TG, and creatinine recovered to healthy control levels after 4 weeks of treatment with the extract mixture. This study showed that PH, RC, and UD extracts, especially their combination, had significant antidiabetic, hypolipidemic, and liver and renal damage recovering effects.

  4. SU-F-R-32: Evaluation of MRI Acquisition Parameter Variations On Texture Feature Extraction Using ACR Phantom

    SciTech Connect

    Xie, Y; Wang, J; Wang, C; Chang, Z

    2016-06-15

    Purpose: To investigate the sensitivity of classic texture features to variations of MRI acquisition parameters. Methods: This study was performed on American College of Radiology (ACR) MRI Accreditation Program Phantom. MR imaging was acquired on a GE 750 3T scanner with XRM explain gradient, employing a T1-weighted images (TR/TE=500/20ms) with the following parameters as the reference standard: number of signal average (NEX) = 1, matrix size = 256×256, flip angle = 90°, slice thickness = 5mm. The effect of the acquisition parameters on texture features with and without non-uniformity correction were investigated respectively, while all the other parameters were kept as reference standard. Protocol parameters were set as follows: (a). NEX = 0.5, 2 and 4; (b).Phase encoding steps = 128, 160 and 192; (c). Matrix size = 128×128, 192×192 and 512×512. 32 classic texture features were generated using the classic gray level run length matrix (GLRLM) and gray level co-occurrence matrix (GLCOM) from each image data set. Normalized range ((maximum-minimum)/mean) was calculated to determine variation among the scans with different protocol parameters. Results: For different NEX, 31 out of 32 texture features’ range are within 10%. For different phase encoding steps, 31 out of 32 texture features’ range are within 10%. For different acquisition matrix size without non-uniformity correction, 14 out of 32 texture features’ range are within 10%; for different acquisition matrix size with non-uniformity correction, 16 out of 32 texture features’ range are within 10%. Conclusion: Initial results indicated that those texture features that range within 10% are less sensitive to variations in T1-weighted MRI acquisition parameters. This might suggest that certain texture features might be more reliable to be used as potential biomarkers in MR quantitative image analysis.

  5. Halo and Core Parameters Extracted from a Data on Reaction Cross-section in the Glauber Model

    NASA Astrophysics Data System (ADS)

    Novikov, Ivan; Rueter, Keiti; Shabelski, Yuli

    2017-01-01

    Core and halo radii for various exotic nuclei were extracted from the experimental data on the interaction cross-section using exact expressions obtained in the Glauber theory using Markov Chain Monte Carlo approach. Here, the difference between reaction and interaction cross-sections were taken into account The results of the experimental data analyzes on interaction cross-section of 11Li, 16C, 31Ne and 37Mg nuclei on 12C target are presented.

  6. Extraction of Respiratory Signal Based on Image Clustering and Intensity Parameters at Radiotherapy with External Beam: A Comparative Study

    PubMed Central

    Samadi Miandoab, P.; Esmaili Torshabi, A.; Nankali, S.

    2016-01-01

    Background: Since tumors located in thorax region of body mainly move due to respiration, in the modern radiotherapy, there have been many attempts such as; external markers, strain gage and spirometer represent for monitoring patients’ breathing signal. With the advent of fluoroscopy technique, indirect methods were proposed as an alternative approach to extract patients’ breathing signals. Materials and Methods: The purpose of this study is to extract respiratory signals using two available methods based on clustering and intensity strategies on medical image dataset of XCAT phantom. Results: For testing and evaluation methods, correlation coefficient, standard division, amplitude ratio and different phases are utilized. Phantom study showed excellent match between correlation coefficient, standard division, amplitude ratio and different phase. Both techniques segmenting medical images are robust due to their inherent mathematical properties. Using clustering strategy, lung region borders are remarkably extracted regarding intensity-based method. This may also affect the amount of amplitude signal. Conclusion: To evaluate the performance of these methods, results are compared with slice body volume (SBV) method. Moreover, all methods have shown the same correlation coefficient of 99%, but at different amplitude ratio and different phase. In SBV method, standard division and different phase are better than clustering and intensity methods with SDR=4.71 mm, and SDL=4.12 mm and average different phase 1.47 %, but amplitude ration of clustering method is significantly more remarkable than SBV and intensity methods. PMID:28144595

  7. [Research on quality parameters of scutellariae radix (formula particles) using on-line NIR in pilot with different extraction process].

    PubMed

    Li, Yang; Wu, Zhi-Sheng; Shi, Xin-Yuan; Pan, Xiao-Ning; Zhang, Qiao; Qiao, Yan-Jiang

    2014-10-01

    The on-line monitor for the changes in the content of baicalin in Scutellariae Radix formula particles during the extraction process was conducted by using near infrared spectroscopy (NIR). High performance liquid chromatography (HPLC) was used as a reference method. Kennard-Stone (KS) was used to divide sample sets, so as to compare different pretreatment methods. The synergy interval partial least squares (SiPLS) was used to screen out modeling wave band to establish partial least-squares models. The relative error method was applied to predict forecast set samples of Scutellariae Radix in three extraction phases. The results showed that the model established by Savitzky-Golay smoothing with 11 points (SG11 points) was the best, with the root mean square with cross validation (RMSECV), root mean square error of correction (RMSEC) and root mean square error of prediction (RMSEP) of baicalin of 0.092 7, 0.134 4 and 0.114 8, respectively, the determination coefficient R2 of greater than 0.99, and the relative error of baicalin content of less than 5%. This indicates that the on-line near infrared reflectance spectroscopy could be applied in on-line monitor and quality control of the extraction process of Scutellariae Radix formula particles.

  8. Fine structure of modal focusing effect in a three dimensional plasma-sheath-lens formed by disk electrodes

    SciTech Connect

    Stamate, Eugen; Yamaguchi, Masahito

    2015-08-31

    Modal and discrete focusing effects associated with three-dimensional plasma-sheath-lenses show promising potential for applications in ion beam extraction, mass spectrometry, plasma diagnostics and for basic studies of plasma sheath. The ion focusing properties can be adjusted by controlling the geometrical structure of the plasma-sheath-lens and plasma parameters. The positive and negative ion kinetics within the plasma-sheath-lens are investigated both experimentally and theoretically and a modal focusing ring is identified on the surface of disk electrodes. The focusing ring is very sensitive to the sheath thickness and can be used to monitor very small changes in plasma parameters. Three dimensional simulations are found to be in very good agreement with experiments.

  9. Approaches to adaptive digital control focusing on the second order modal descriptions of large, flexible spacecraft dynamics

    NASA Technical Reports Server (NTRS)

    Johnson, C. R., Jr.

    1979-01-01

    The widespread modal analysis of flexible spacecraft and recognition of the poor a priori parameterization possible of the modal descriptions of individual structures have prompted the consideration of adaptive modal control strategies for distributed parameter systems. The current major approaches to computationally efficient adaptive digital control useful in these endeavors are explained in an original, lucid manner using modal second order structure dynamics for algorithm explication. Difficulties in extending these lumped-parameter techniques to distributed-parameter system expansion control are cited.

  10. Evaluation of a nonlinear parameter extraction mathematical model including the term C(subm(sub delta e squared))

    NASA Technical Reports Server (NTRS)

    Suit, W. T.

    1986-01-01

    Shuttle flight test data were used to determine values for the short-period parameters. The best identified, as judged by its estimated standard deviation, was the elevon effectiveness parameter C (sub m (sub sigma e squared)). However, the scatter about the preflight prediction of C (sub m (sub sigma e squared)) was large. Other investigators have suggested that adding nonlinear terms to the mathematical model used to identify C (sub m (sub sigma e)) could reduce the scatter. The results of this investigation show that C (sub m (sub sigma e squared)) is the only identifiable nonlinear parameter applicable and that the changes in C (sub m (sub sigma e)) values when C (sub m (sub sigma e squared)) is included are in the order of ten percent for the data estimated.

  11. Spacecraft structural system identification by modal test

    NASA Technical Reports Server (NTRS)

    Chen, J.-C.; Peretti, L. F.; Garba, J. A.

    1984-01-01

    A structural parameter estimation procedure using the measured natural frequencies and kinetic energy distribution as observers is proposed. The theoretical derivation of the estimation procedure is described and its constraints and limitations are explained. This procedure is applied to a large complex spacecraft structural system to identify the inertia matrix using modal test results. The inertia matrix is chosen after the stiffness matrix has been updated by the static test results.

  12. Parameters optimization using experimental design for headspace solid phase micro-extraction analysis of short-chain chlorinated paraffins in waters under the European water framework directive.

    PubMed

    Gandolfi, F; Malleret, L; Sergent, M; Doumenq, P

    2015-08-07

    The water framework directives (WFD 2000/60/EC and 2013/39/EU) force European countries to monitor the quality of their aquatic environment. Among the priority hazardous substances targeted by the WFD, short chain chlorinated paraffins C10-C13 (SCCPs), still represent an analytical challenge, because few laboratories are nowadays able to analyze them. Moreover, an annual average quality standards as low as 0.4μgL(-1) was set for SCCPs in surface water. Therefore, to test for compliance, the implementation of sensitive and reliable analysis method of SCCPs in water are required. The aim of this work was to address this issue by evaluating automated solid phase micro-extraction (SPME) combined on line with gas chromatography-electron capture negative ionization mass spectrometry (GC/ECNI-MS). Fiber polymer, extraction mode, ionic strength, extraction temperature and time were the most significant thermodynamic and kinetic parameters studied. To determine the suitable factors working ranges, the study of the extraction conditions was first carried out by using a classical one factor-at-a-time approach. Then a mixed level factorial 3×2(3) design was performed, in order to give rise to the most influent parameters and to estimate potential interactions effects between them. The most influent factors, i.e. extraction temperature and duration, were optimized by using a second experimental design, in order to maximize the chromatographic response. At the close of the study, a method involving headspace SPME (HS-SPME) coupled to GC/ECNI-MS is proposed. The optimum extraction conditions were sample temperature 90°C, extraction time 80min, with the PDMS 100μm fiber and desorption at 250°C during 2min. Linear response from 0.2ngmL(-1) to 10ngmL(-1) with r(2)=0.99 and limits of detection and quantification, respectively of 4pgmL(-1) and 120pgmL(-1) in MilliQ water, were achieved. The method proved to be applicable in different types of waters and show key advantages, such

  13. Separation of structural modes and harmonic frequencies in Operational Modal Analysis using random decrement

    NASA Astrophysics Data System (ADS)

    Modak, S. V.

    2013-12-01

    Operational Modal Analysis (OMA) is used to extract modal parameters of a structure on the basis of their output response measured during operation. OMA, when applied to mechanical engineering structures is often faced with the problem of harmonics present in the output response. A complex structure may have many dominant frequency components in its response frequency spectrum. These may contain frequency components associated with resonant frequencies of the structure, which and the associated mode shapes and the damping factors represent the data of interest, but may also contain frequencies or harmonics associated with the excitation sources. Since in OMA the characteristics of the excitation sources are not known, one of the problems lies in separating the resonant frequencies from the harmonic excitation frequencies. Any error in this regard may lead to an error in modal identification with the consequence that a harmonic may be construed as a structural mode and vice versa. This issue is addressed in this paper and a method is presented for separating resonant frequencies from harmonic excitation frequencies using random decrement of the response. The principle of the method is presented using an analytical study on a single degree of freedom system. The effectiveness of the method is then demonstrated through numerical studies on a lumped parameter multi-degree of freedom system and a simulated plate structure. Detection of single and multiple harmonics in the response that are well separated as well as close to resonant frequencies are considered.

  14. Extracting survival parameters from isothermal, isobaric, and "iso-concentration" inactivation experiments by the "3 end points method".

    PubMed

    Corradini, M G; Normand, M D; Newcomer, C; Schaffner, D W; Peleg, M

    2009-01-01

    Theoretically, if an organism's resistance can be characterized by 3 survival parameters, they can be found by solving 3 simultaneous equations that relate the final survival ratio to the lethal agent's intensity. (For 2 resistance parameters, 2 equations will suffice.) In practice, the inevitable experimental scatter would distort the results of such a calculation or render the method unworkable. Averaging the results obtained with more than 3 final survival ratio triplet combinations, determined in four or more treatments, can remove this impediment. This can be confirmed by the ability of a kinetic inactivation model derived from the averaged parameters to predict survival patterns under conditions not employed in their determination, as demonstrated with published isothermal survival data of Clostridium botulinum spores, isobaric data of Escherichia coli under HPP, and Pseudomonas exposed to hydrogen peroxide. Both the method and the underlying assumption that the inactivation followed a Weibull-Log logistic (WeLL) kinetics were confirmed in this way, indicating that when an appropriate survival model is available, it is possible to predict the entire inactivation curves from several experimental final survival ratios alone. Where applicable, the method could simplify the experimental procedure and lower the cost of microbial resistance determinations. In principle, the methodology can be extended to deteriorative chemical reactions if they too can be characterized by 2 or 3 kinetic parameters.

  15. Analysis of structural response data using discrete modal filters. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Freudinger, Lawrence C.

    1991-01-01

    The application of reciprocal modal vectors to the analysis of structural response data is described. Reciprocal modal vectors are constructed using an existing experimental modal model and an existing frequency response matrix of a structure, and can be assembled into a matrix that effectively transforms the data from the physical space to a modal space within a particular frequency range. In other words, the weighting matrix necessary for modal vector orthogonality (typically the mass matrix) is contained within the reciprocal model matrix. The underlying goal of this work is mostly directed toward observing the modal state responses in the presence of unknown, possibly closed loop forcing functions, thus having an impact on both operating data analysis techniques and independent modal space control techniques. This study investigates the behavior of reciprocol modal vectors as modal filters with respect to certain calculation parameters and their performance with perturbed system frequency response data.

  16. The effects of different levels of peppermint alcoholic extract on body-weight gain and blood biochemical parameters of adult male Wistar rats

    PubMed Central

    Mesbahzadeh, Behzad; Akbari, Mohsen; kor, Nasroallah Moradi; Zadeh, Jalal Bayati

    2015-01-01

    Introduction Peppermint is an efficient medicinal plant for the treatment of diseases, and it also can be used to produce raw materials in the pharmaceutical industry. The purpose of the current study was to evaluate the effects of various levels of peppermint alcoholic extract on body-weight gain and blood biochemical parameters in adult male Wistar rats. Methods This experiment was conducted using a completely randomized design (CRD). Fifty adult, healthy, male Wistar rats (ages of 2.5–3 months; weights of 190–210 g) were allocated randomly into five groups. T1 was the control group in which the rats received 0.3 ml of distilled water). Groups T2, T3, T4, and T5 received 75, 150, 300, and 600 mg/kg of peppermint extract, respectively. The rats received daily pretreatment by oral gavages for 21 days. We recorded body weights at the beginning and at the end of the study to determine the changes in the body weights. Blood samples were collected for the measurement of glucose, cholesterol, triglycerides, HDL, LDL, albumin, globulin, and total protein. Statistical analysis of the data was done by SAS software. The data statistically analyzed using one-way analysis of variance (ANOVA), which was conducted through Dennett’s multiple comparison post-test. Results The results indicated that the rats treated with peppermint gained more weight (p < 0.05) and also decreased the serum concentrations of triglycerides, total cholesterol, LDL, and glucose in T3, T4 and T5 than the other groups (p < 0.05). Conclusion Peppermint extract had a positive effect on body-weight gain and some blood parameters in adult male Wistar rats. The findings showed that peppermint is a crucial substance at high temperature, and future research should be focused on determining the details of the mechanisms involved in producing the observed effects of peppermint extract. PMID:26516445

  17. The effect of parameters of equilibrium-based 3-D biomechanical models on extracted muscle synergies during isometric lumbar exertion.

    PubMed

    Eskandari, A H; Sedaghat-Nejad, E; Rashedi, E; Sedighi, A; Arjmand, N; Parnianpour, M

    2016-04-11

    A hallmark of more advanced models is their higher details of trunk muscles represented by a larger number of muscles. The question is if in reality we control these muscles individually as independent agents or we control groups of them called "synergy". To address this, we employed a 3-D biomechanical model of the spine with 18 trunk muscles that satisfied equilibrium conditions at L4/5, with different cost functions. The solutions of several 2-D and 3-D tasks were arranged in a data matrix and the synergies were computed by using non-negative matrix factorization (NMF) algorithms. Variance accounted for (VAF) was used to evaluate the number of synergies that emerged by the analysis, which were used to reconstruct the original muscle activations. It was showed that four and six muscle synergies were adequate to reconstruct the input data of 2-D and 3-D torque space analysis. The synergies were different by choosing alternative cost functions as expected. The constraints affected the extracted muscle synergies, particularly muscles that participated in more than one functional tasks were influenced substantially. The compositions of extracted muscle synergies were in agreement with experimental studies on healthy participants. The following computational methods show that the synergies can reduce the complexity of load distributions and allow reduced dimensional space to be used in clinical settings.

  18. Olive oil pilot-production assisted by pulsed electric field: impact on extraction yield, chemical parameters and sensory properties.

    PubMed

    Puértolas, Eduardo; Martínez de Marañón, Iñigo

    2015-01-15

    The impact of the use of pulsed electric field (PEF) technology on Arroniz olive oil production in terms of extraction yield and chemical and sensory quality has been studied at pilot scale in an industrial oil mill. The application of a PEF treatment (2 kV/cm; 11.25 kJ/kg) to the olive paste significantly increased the extraction yield by 13.3%, with respect to a control. Furthermore, olive oil obtained by PEF showed total phenolic content, total phytosterols and total tocopherols significantly higher than control (11.5%, 9.9% and 15.0%, respectively). The use of PEF had no negative effects on general chemical and sensory characteristics of the olive oil, maintaining the highest quality according to EU legal standards (EVOO; extra virgin olive oil). Therefore, PEF could be an appropriate technology to improve olive oil yield and produce EVOO enriched in human-health-related compounds, such as polyphenols, phytosterols and tocopherols. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Kinetic and thermodynamic parameters, and partial characterization of the crude extract of tannase produced by Saccharomyces cerevisiae CCMB 520.

    PubMed

    Lopes, Lúzia Morgana de Melo; Costa Batista, Larissa Hayannyelly; Gouveia, Marcos Juliano; Leite, Tonny Cley Campos; de Mello, Marcelo Rodrigues Figueira; de Assis, Sandra Aparecida; de Sena, Amanda Reges

    2017-09-20

    Tannase can be used in different industrial sectors such as in food (juices and wine) and pharmaceutical production (trimethoprim) because it catalyses the hydrolysis of hydrolysable tannins. The aim of the current study is to assess the tannase found in the crude extract of Saccharomyces cerevisiae CCMB 520, and to set its catalytic and thermodynamic properties. The enzyme was optimally active at pH 6.0 and temperature 30 °C. Tannase was activated by Na(+), Ca(2+), K(+) at 5 × 10(-3) mol/L. The half-life at 30 °C was 3465.7 min. The activation energy was 40.32 kJ/mol. The Gibbs free energy, enthalpy and entropy at 30 °C were 85.40, 48.10 and -0.12 kJ/mol K, respectively. Our results suggest that the tannase found in the crude extract of S. cerevisiae is an attractive enzyme for industrial applications, such as for beverage manufacturing and gallic acid production, due its catalytic and thermodynamic properties (heat-stable and resistant to metal ions).

  20. Constituents, biological activities and quality control parameters of the crude extract and essential oil from Arracacia tolucensis var. multifida.

    PubMed

    Figueroa, Mario; Rivero-Cruz, Isabel; Rivero-Cruz, Blanca; Bye, Robert; Navarrete, Andrés; Mata, Rachel

    2007-08-15

    Bioassay guided fractionation of an antimycobacterial extract of Arracacia tolucensis var. multifida (Umbelliferae) led to the isolation of isoimperatorin (1), osthol (2), suberosin (3), 8-methoxypsoralen (8-MOP) (4), herniarin (5), scoparone (6), umbelliferone (7), dihydroxypeucedanin (8), 5-methoxypsoralen (5-MOP) (9), isoscopoletin (10) and scopoletin (11). The isolates were tested against Mycobacterium tuberculosis and only 1-4 showed significant activity with MIC values of 64, 32, 16 and 128 microg/mL, respectively. The essential oil showed moderate in vitro antibacterial activity against representative Gram-positive and Gram-negative bacteria. The volatile oil of Arracacia tolucensis var. multifida was analyzed by GC-MS and found to be composed mainly by 2 and 3. The essential oil (IC(50)=116.4+/-23.2 microg/mL) and the extract (IC(50)=1153.1+/-53.2 microg/mL) of the plant provoked concentration dependent inhibition of the tone and amplitude of the guinea-pig ileum spontaneous contractions; the latter activity was related with the high coumarin content of this species. A suitable (novel and rapid) HPLC method to quantify the major active coumarins of the plant was developed. The method provides also a reproducible fingerprint useful for identity tests of this plant.

  1. Hahn Sequence Space of Modals

    PubMed Central

    Balasubramanian, T.; Zion Chella Ruth, S.

    2014-01-01

    The history of modal intervals goes back to the very first publications on the topic of interval calculus. The modal interval analysis is used in Computer graphics and Computer Aided Design (CAD), namely, the computation of narrow bounds on Bezier and B-Spline curves. Since modal intervals are used in many fields, we introduce a new sequence space h(gI) called the Hahn sequence space of modal intervals. We have given some new definitions and theorems. Some inclusion relation and some topological properties of this space are investigated. Also dual spaces of this space are computed. PMID:27382628

  2. Non-controlled CO2 and CH4 emission from landfills: a useful parameter to evaluate landfill gas extraction efficiency

    NASA Astrophysics Data System (ADS)

    Nolasco, D.; Mora Fernández, N.; de Paz Carmona, H.; Padilla, G.; Melian, G.; Hernandez Perez, P. A.; Perez, N.

    2009-12-01

    Landfills are important sources of greenhouse gases to the environment like CO2 and CH4 as well as other trace gas components. In order to control the emissions of these contaminant gases, installation of gas extraction systems at landfills is required. However, in spite of the technical efforts to minimize landfill gas emissions, a significant amount of non-controlled emissions are released into the atmosphere in the form of non-controlled emissions through landfill surfaces. The evaluation of non-controlled CO2 and CH4 emissions to the atmosphere by landfills has important technical and environmental implications. It will provide a better estimation of the landfill gas emissions to the atmosphere and to evaluate the efficiency of the landfill gas extraction systems by comparison of non-controlled vs controlled emissions. To understand the dynamics of non-controlled emissions of biogas from landfills, several soil gas surveys were performed at landfill of Arico in Tenerife, Canary Islands. The aim of this study was to evaluate the efficiency of the gas extraction system at landfill of Arico. A non-controlled CO2 and CH4 emission surveys of 355 and 305 sampling sites were carried out during summers of 2007 and 2008, respectively. Surface CO2 and CH4 efflux measurements were performed by means of a double efflux portable NDIR spectrometer and according to the accumulation chamber method. Surface CO2 and CH4 efflux values ranged from negligible to 6413 gm-2d-1 and 175.9 gm-2d-1, respectively. Controlled emission rates of CO2 and CH4 were estimated by the operating company of the landfill. The spatial distributions of CO2 and CH4 effluxes at landfill of Arico showed a different distribution pattern for each component and a relationship with the present use of the landfill. Taking into consideration the spatial distribution of the CO2 and CH4 efflux values as well as the extension of the landfill, the non-controlled emission of CO2 and CH4 to the atmosphere during the

  3. Effects of symmetry, shape, and structural parameters of two-dimensional SiNx photonic crystal on the extracted light from Y2O3:Eu3+ film

    NASA Astrophysics Data System (ADS)

    Oh, Jeong Rok; Lee, Young Kwang; Park, Hoo Keun; Do, Young Rag

    2009-02-01

    This study examined the effects of the triangular- and square-lattice symmetries as well as the nanorod and airhole shapes of two-dimensional (2D) SiNx photonic crystal layers (PCLs) on the light extraction efficiency of thin-film phosphors (TFPs) in an attempt to improve the light extraction efficiency from the phosphor side of an Y2O3:Eu3+ thin film. Triangular-lattice and square-lattice 2D SiNx nanorods/airholes were fabricated as PCLs on sol-gel derived Y2O3:Eu3+ TFPs using different combinations of the following processes: nanosphere lithography or laser interfering lithography, mask fabrication, and reactive ion etching. The integrated light efficiency of the triangular lattice was approximately 1.33 and 1.64 times as high as that of the square lattice for the nanorods and airholes. The greatest improvement in the phosphor-side extraction efficiency of the Y2O3:Eu3+ TFPs was obtained by adding triangular-lattice 2D SiNx airhole PCL arrays. The angular distribution of the light emitted from the various types of 2D SiNx PCL-coated Y2O3:Eu3+ TFPs was also investigated to better understand the effects of the symmetry and shape of the 2D PCLs on the viewing angle of the light emitted from the Y2O3:Eu3+ thin films. Moreover, the effects of structural parameters, including the dielectric-areal fill factor and lattice parameter (below cutoff size and above 1.0 μm size, as well as the optimum size of triangular lattice) of the 2D SiNx PC arrays, on the extraction efficiency of the Y2O3:Eu3+ TFPs were investigated to improve the scattering capability of the leaky modes as a function of the structural parameters. This enhanced extraction efficiency was attributed to the scattering of the forward emission excited directly by inward UV and the scattering of re-excited forward emission by backscattered UV through the leaky and/or Bragg scattering produced by the 2D periodic array.

  4. Learning across senses: cross-modal effects in multisensory statistical learning.

    PubMed

    Mitchel, Aaron D; Weiss, Daniel J

    2011-09-01

    It is currently unknown whether statistical learning is supported by modality-general or modality-specific mechanisms. One issue within this debate concerns the independence of learning in one modality from learning in other modalities. In the present study, the authors examined the extent to which statistical learning across modalities is independent by simultaneously presenting learners with auditory and visual streams. After establishing baseline rates of learning for each stream independently, they systematically varied the amount of audiovisual correspondence across 3 experiments. They found that learners were able to segment both streams successfully only when the boundaries of the audio and visual triplets were in alignment. This pattern of results suggests that learners are able to extract multiple statistical regularities across modalities provided that there is some degree of cross-modal coherence. They discuss the implications of their results in light of recent claims that multisensory statistical learning is guided by modality-independent mechanisms. (c) 2011 APA, all rights reserved.

  5. Assessment of extraction parameters on antioxidant capacity, polyphenol content, epigallocatechin gallate (EGCG), epicatechin gallate (ECG) and iriflophenone 3-C-β-glucoside of agarwood (Aquilaria crassna) young leaves.

    PubMed

    Tay, Pei Yin; Tan, Chin Ping; Abas, Faridah; Yim, Hip Seng; Ho, Chun Wai

    2014-08-14

    The effects of ethanol concentration (0%-100%, v/v), solid-to-solvent ratio (1:10-1:60, w/v) and extraction time (30-180 min) on the extraction of polyphenols from agarwood (Aquilaria crassna) were examined. Total phenolic content (TPC), total flavonoid content (TFC) and total flavanol (TF) assays and HPLC-DAD were used for the determination and quantification of polyphenols, flavanol gallates (epigallocatechin gallate--EGCG and epicatechin gallate--ECG) and a benzophenone (iriflophenone 3-C-β-glucoside) from the crude polyphenol extract (CPE) of A. crassna. 2,2'-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was used to evaluate the antioxidant capacity of the CPE. Experimental results concluded that ethanol concentration and solid-to-solvent ratio had significant effects (p<0.05) on the yields of polyphenol and antioxidant capacity. Extraction time had an insignificant influence on the recovery of EGCG, ECG and iriflophenone 3-C-β-glucoside, as well as radical scavenging capacity from the CPE. The extraction parameters that exhibited maximum yields were 40% (v/v) ethanol, 1:60 (w/v) for 30 min where the TPC, TFC, TF, DPPH, EGCG, ECG and iriflophenone 3-C-β-glucoside levels achieved were 183.5 mg GAE/g DW, 249.0 mg QE/g DW, 4.9 mg CE/g DW, 93.7%, 29.1 mg EGCG/g DW, 44.3 mg ECG/g DW and 39.9 mg iriflophenone 3-C-β-glucoside/g DW respectively. The IC50 of the CPE was 24.6 mg/L.

  6. Parasitological and biochemical parameters in Schistosoma mansoni-infected mice treated with methanol extract from the plants Chenopodium ambrosioides, Conyza dioscorides and Sesbania sesban.

    PubMed

    Kamel, E G; El-Emam, M A; Mahmoud, S S M; Fouda, F M; Bayaumy, F E

    2011-12-01

    This study aims to detect the antischistosomal properties of the plants' Chenopodium ambrosioides, Conyza dioscorides and Sesbania sesban methanol extract against Schistosoma mansoni in infected mice, including determination of total protein and albumin levels and the activities of alanine and aspartate transaminases (AlT, AsT) and acid and alkaline phosphatases (AcP and AkP) enzymes in the serum of infected treated mice. Male Swiss albino mice were infected with S. mansoni and orally treated with methanol extract of the plants C. ambrosioides (1250 mg/kg/day), C. dioscorides and S. sesban (1000 mg/kg/day from each) for 2 consecutive days 7 weeks post infection (PI). In addition, treatment of mice with the tested dose of each plant extract was successively done (i.e. the 1st extract followed by the 2nd and 3rd one with an hour interval). Parasitological and biochemical parameters were assessed. Nine weeks PI, the reduction rates of worm load/mouse treated with either C. dioscorides (1000 mg/kg), C. ambrosioides (1250 mg/kg) or S. sesban (1000 mg/kg) were 40.9%, 53.7% and 54.4%, respectively. Successive treatment raised the reduction rates of worm load/mouse to 66.3% and the ova/g tissue in liver to 76.9%. Moreover, serum total protein and albumin levels and activities of AlT, Ast, AcP and AkP enzymes of infected treated mice were improved in comparison with those of infected untreated ones. It is concluded that administration of C. dioscorides, C. ambrosioides and S. sesban methanol extract to infected mice exhibited a moderate antischistosomal effect. Successive treatment improved the antischistosomal properties of these plant species, hence ameliorated the liver functions of treated mice that may suggest degenerations of liver granulomas and regenerative changes.

  7. Extracting Material Constitutive Parameters from Scattering Parameters

    DTIC Science & Technology

    2006-09-01

    Zhou, Jiangfeng, Zang , Lei , Tuttle, Gary, Koschny, Thomas, & Soukoulis, Costas M., “Negative index materials using simple short wire pairs,” Phys...Rev. B., 73, 041101, (2006). 22. Zhou, Jiangfeng, Koschny, Thomas, Zhang, Lei , Tuttle, Gary, & Soukoulis, Costas M., “Experimental demonstration of

  8. The effect of Prosopis farcta beans extract on blood biochemical parameters in streptozotocin-induced diabetic male rats

    PubMed Central

    Dashtban, Mohsen; Sarir, Hadi; Omidi, Arash

    2016-01-01

    Background: The use of herbals in the treatment of diabetes mellitus is a well-established practice in traditional medicine. The medicinal plant Prosopis farcta has some antioxidant activity, which may be useful in diabetic patients. Since, there is no report on the antidiabetic effect of the P. farcta, this study evaluated antidiabetic activity of P. farcta bean extract (PFE) in streptozotocin (STZ)-induced diabetic rats. Materials and Methods: Hyperglycemia was induced in male albino Wistar rats by intraperitoneal injection of STZ (55 mg/kg body weight [BW]), after which, the animals were randomly allocated into six experimental groups as follows: Group 1: Normal rats (received normal saline), Groups 2 and 3: Normal rats received PFE; (50 and 75 mg/kg BW), Group 4: Diabetic control rats, Group 5: Diabetic rats received PFE (50 mg/kg BW), Group 6: Diabetic rats received PFE (75 mg/kg BW). Three days after induction of diabetes, rats were received an extract of PFE orally for 12 days. Blood samples were collected by cardiac puncture to determine liver enzymes; aspartate aminotransferase and alanine aminotransferase (AST and ALT), cholesterol, triglyceride (TG), high and low density lipoproteins (HDL and LDL). Results: The administration of PFE (50 and 75 mg/kg) in STZ-induced diabetic rats significantly reduced the blood glucose levels when compared with the STZ-control group (227.2 ± 12.00 and 259.6 ± 7.03 vs. 454.6 ± 12.66, P < 0.001). PFE in diabetic groups had no significant effect on the levels of cholesterol, TG, HDL, LDL, AST, and ALT compare to the STZ-control group. Conclusion: P. farcta could reduce blood glucose in diabetic rats. PMID:27512685

  9. The effect of Prosopis farcta beans extract on blood biochemical parameters in streptozotocin-induced diabetic male rats.

    PubMed

    Dashtban, Mohsen; Sarir, Hadi; Omidi, Arash

    2016-01-01

    The use of herbals in the treatment of diabetes mellitus is a well-established practice in traditional medicine. The medicinal plant Prosopis farcta has some antioxidant activity, which may be useful in diabetic patients. Since, there is no report on the antidiabetic effect of the P. farcta, this study evaluated antidiabetic activity of P. farcta bean extract (PFE) in streptozotocin (STZ)-induced diabetic rats. Hyperglycemia was induced in male albino Wistar rats by intraperitoneal injection of STZ (55 mg/kg body weight [BW]), after which, the animals were randomly allocated into six experimental groups as follows: Group 1: Normal rats (received normal saline), Groups 2 and 3: Normal rats received PFE; (50 and 75 mg/kg BW), Group 4: Diabetic control rats, Group 5: Diabetic rats received PFE (50 mg/kg BW), Group 6: Diabetic rats received PFE (75 mg/kg BW). Three days after induction of diabetes, rats were received an extract of PFE orally for 12 days. Blood samples were collected by cardiac puncture to determine liver enzymes; aspartate aminotransferase and alanine aminotransferase (AST and ALT), cholesterol, triglyceride (TG), high and low density lipoproteins (HDL and LDL). The administration of PFE (50 and 75 mg/kg) in STZ-induced diabetic rats significantly reduced the blood glucose levels when compared with the STZ-control group (227.2 ± 12.00 and 259.6 ± 7.03 vs. 454.6 ± 12.66, P < 0.001). PFE in diabetic groups had no significant effect on the levels of cholesterol, TG, HDL, LDL, AST, and ALT compare to the STZ-control group. P. farcta could reduce blood glucose in diabetic rats.

  10. Extracting Roof Parameters and Heat Bridges Over the City of Oldenburg from Hyperspectral, Thermal, and Airborne Laser Scanning Data

    NASA Astrophysics Data System (ADS)

    Bannehr, L.; Luhmann, Th.; Piechel, J.; Roelfs, T.; Schmidt, An.

    2011-09-01

    Remote sensing methods are used to obtain different kinds of information about the state of the environment. Within the cooperative research project HiReSens, funded by the German BMBF, a hyperspectral scanner, an airborne laser scanner, a thermal camera, and a RGB-camera are employed on a small aircraft to determine roof material parameters and heat bridges of house tops over the city Oldenburg, Lower Saxony. HiReSens aims to combine various geometrical highly resolved data in order to achieve relevant evidence about the state of the city buildings. Thermal data are used to obtain the energy distribution of single buildings. The use of hyperspectral data yields information about material consistence of roofs. From airborne laser scanning data (ALS) digital surface models are inferred. They build the basis to locate the best orientations for solar panels of the city buildings. The combination of the different data sets offers the opportunity to capitalize synergies between differently working systems. Central goals are the development of tools for the collection of heat bridges by means of thermal data, spectral collection of roofs parameters on basis of hyperspectral data as well as 3D-capture of buildings from airborne lasers scanner data. Collecting, analyzing and merging of the data are not trivial especially not when the resolution and accuracy is aimed in the domain of a few decimetre. The results achieved need to be regarded as preliminary. Further investigations are still required to prove the accuracy in detail.

  11. Re-typograph phase I: a proof-of-concept for typeface parameter extraction from historical documents

    NASA Astrophysics Data System (ADS)

    Lamiroy, Bart; Bouville, Thomas; Blégean, Julien; Cao, Hongliu; Ghamizi, Salah; Houpin, Romain; Lloyd, Matthias

    2015-01-01

    This paper reports on the first phase of an attempt to create a full retro-engineering pipeline that aims to construct a complete set of coherent typographic parameters defining the typefaces used in a printed homogenous text. It should be stressed that this process cannot reasonably be expected to be fully automatic and that it is designed to include human interaction. Although font design is governed by a set of quite robust and formal geometric rulesets, it still heavily relies on subjective human interpretation. Furthermore, different parameters, applied to the generic rulesets may actually result in quite similar and visually difficult to distinguish typefaces, making the retro-engineering an inverse problem that is ill conditioned once shape distortions (related to the printing and/or scanning process) come into play. This work is the first phase of a long iterative process, in which we will progressively study and assess the techniques from the state-of-the-art that are most suited to our problem and investigate new directions when they prove to not quite adequate. As a first step, this is more of a feasibility proof-of-concept, that will allow us to clearly pinpoint the items that will require more in-depth research over the next iterations.

  12. Mimicry for all modalities.

    PubMed

    Dalziell, Anastasia H; Welbergen, Justin A

    2016-06-01

    Mimicry is a canonical example of adaptive signal design. In principle, what constitutes mimicry is independent of the taxonomic identity of the mimic, the ecological context in which it operates, and the sensory modality through which it is expressed. However, in practice the study of mimicry is inconsistent across research fields, with theoretical and empirical advances often failing to cross taxonomic and sensory divides. We propose a novel conceptual framework whereby mimicry evolves if a receiver perceives the similarity between a mimic and a model and as a result confers a selective benefit onto the mimic. Here, misidentification and/or deception are no longer formal requirements, and mimicry can evolve irrespective of the underlying proximate mechanisms. The centrality of receiver perception in this framework enables us to formally distinguish mimicry from perceptual exploitation and integrate mimicry and multicomponent signalling theory for the first time. In addition, it resolves inconsistencies in our understanding of the role of learning in mimicry evolution, and shows that imperfect mimicry is expected to be the norm. Mimicry remains a key model for understanding signal evolution and cognition, and we recommend the adoption of a unified approach to stimulate future interdisciplinary developments in this fascinating area of research.

  13. State-space formulation of multi-shaker modal analysis

    NASA Technical Reports Server (NTRS)

    Craig, Roy R., Jr.; Kurdila, Andrew J.; Kim, Hyoung M.

    1987-01-01

    As modal testing techniques have improved in recent years, the demands placed on the accuracy of modal test results have increased. This paper describes a new multi-input, multi-output modal parameter estimation algorithm suitable for the identification of reduced-order models of structures. The method described is a frequency-domain method based on excitation and response spectra. The principal features of the algorithm are: (1) applicability to general linear, time-invariant systems, (2) direct use of multiple input and multiple response data, (3) identification of reduced-order models with minimum user interaction through the use of two automatic model-reduction techniques, (4) identification of a consistent set of modal parameters through the use of numerically stable least-squares techniques, and (5) complete user documentation.

  14. State-space formulation of multi-shaker modal analysis

    NASA Technical Reports Server (NTRS)

    Craig, Roy R., Jr.; Kurdila, Andrew J.; Kim, Hyoung M.

    1987-01-01

    As modal testing techniques have improved in recent years, the demands placed on the accuracy of modal test results have increased. This paper describes a new multi-input, multi-output modal parameter estimation algorithm suitable for the identification of reduced-order models of structures. The method described is a frequency-domain method based on excitation and response spectra. The principal features of the algorithm are: (1) applicability to general linear, time-invariant systems, (2) direct use of multiple input and multiple response data, (3) identification of reduced-order models with minimum user interaction through the use of two automatic model-reduction techniques, (4) identification of a consistent set of modal parameters through the use of numerically stable least-squares techniques, and (5) complete user documentation.

  15. Long-term effects of chromium, grape seed extract, and zinc on various metabolic parameters of rats.

    PubMed

    Preuss, H G; Montamarry, S; Echard, B; Scheckenbach, R; Bagchi, D

    2001-07-01

    Progressive insulin resistance may contribute to both enhanced glycosylation of proteins and nucleic acids and augmented free radical damage commonly associated with aging. Accordingly, ingestion of chromium and antioxidants which improve insulin sensitivity and/or lessen free radical formation could theoretically ameliorate these basic disorders and lessen signs and symptoms of chronic age-related disorders. However, this supposition is based primarily upon acute rather than chronic data. Therefore, we divided 104 F344/BN rats into 2 groups: a control group receiving a basic diet and a test group receiving the same diet with added chromium polynicotinate (5 ppm), zinc monomethionine (18 ppm elemental zinc), and a grape seed extract high in flavonoids (250 ppm). Initial mean systolic blood pressures (SBP) of both control and test groups were 122 mm Hg. Over the first 7 months, the SBP of the control animals steadily increased to 140 mm Hg and remained at this level for the next 7-8 months. In contrast, the SBP of the test animals initially decreased over the first 4 months to as low as 110-114 mm Hg. The SBP then increased over the following months, essentially reaching the starting value of 120 mm Hg. This was still significantly lower than control (p < 0.001). In 12 control and 12 test rats, hepatic TBARS formation, an estimate of lipid peroxidation/free radical formation, was significantly lower after 1 year ingesting the test diet (p < 0.04); and HbA1C was also statistically significantly lower in the test group (5.4 vs. 4.8%, p < 0.003). Circulating levels of cholesterol, HDL, and triglycerides were similar between the two groups. Body, kidney, and liver weights were not different after 1 year ingesting the different diets; but epididymal fat pad weight was less in the group receiving supplements. We conclude that after prolonged supplementation a combination of agents known to sensitize insulin response and act as antioxidants (chromium polynicotinate, grape

  16. Syzygium cumini seed extract ameliorates adenosine deaminase activity and biochemical parameters but does not alter insulin sensitivity and pancreas architecture in a short-term model of diabetes.

    PubMed

    Bitencourt, Paula Eliete Rodrigues; Bona, Karine Santos De; Cargnelutti, Lariane Oliveira; Bonfanti, Gabriela; Pigatto, Aline; Boligon, Aline; Athayde, Margareth L; Pierezan, Felipe; Zanette, Régis Adriel; Moretto, Maria Beatriz

    2015-09-01

    The effects of the aqueous seed extract of Syzygium cumini (ASc) in a short-term model of diabetes in rats are little explored. The present study was designed to evaluate the effect of the ASc on adenosine deaminase (ADA) activity and on biochemical and histopathological parameters in diabetic rats. ASc (100 mg/kg) was administered for 21 days in control and streptozotocin (STZ)-induced (60 mg/kg) diabetic rats. ADA activity, lipoperoxidation (cerebral cortex, kidney, liver and pancreas) and biochemical (serum) and histopathological (pancreas) parameters were evaluated. The main findings in this short-term model of Diabetes mellitus (DM) were that the ASc (i) significantly reverted the increase of ADA activity in serum and kidney; (ii) ameliorated the lipoperoxidation in the cerebral cortex and pancreas of the diabetic group; (iii) demonstrated hypolipidemic and hypoglycemic properties and recovered the liver glycogen; and iv) prevented the HOMA-IR index increase in the diabetic group. Therefore, the ASc can be a positive factor for increasing the availability of substrates with significant protective actions, such as adenosine. Moreover, by maintaining glycogen and HOMA-IR levels, the extract could modulate the hyperglycemic state through the direct peripheral glucose uptake. Our data revealed that the short-term treatment with ASc has an important protective role under pathophysiological conditions caused by the early stage of DM. These results enhance our understanding of the effect of the ASc on the purinergic system in DM.

  17. Effects of Different Levels of Coriander (Coriandrum sativum) Seed Powder and Extract on Serum Biochemical Parameters, Microbiota, and Immunity in Broiler Chicks

    PubMed Central

    Hosseinzadeh, Hesam; Alaw Qotbi, Ali Ahmad; Seidavi, Alireza; Norris, David; Brown, David

    2014-01-01

    The use of herbs and spices has gained increasing interest as feed additives and possible alternative to antibiotics in poultry production. The effects of using different levels of coriander seed powder or extract on selected blood parameters, intestinal microflora, and immune response of broiler chickens were investigated in this study. A total of 420-day-old broiler chicks were randomly assigned to 7 treatments with 4 replicates and fed for 42 days. Results showed that inclusion of 2.0% coriander powder in broiler diets lowered total cholesterol while blood urea was significantly higher in birds on T4 compared to T1 and T2. Furthermore, there were no treatment effects on Lactobacillus bacteria; however, the population of E. coli was significantly higher in the ileum of chickens fed T0. Noticeable significant improvements of antibody titer against Newcastle, infectious bronchitis, and infectious bursal disease were observed in birds receiving coriander extract in water. Immunoglobulin G antibody against sheep red blood cells showed significant improvement in birds fed T3; likewise, immunoglobulin M was significantly higher in birds on T2 and T3 at 28 d of age. These results revealed that coriander extract or powder can be used as antibiotic alternative in broiler feeds. PMID:25614892

  18. Effects of different levels of coriander (Coriandrum sativum) seed powder and extract on serum biochemical parameters, microbiota, and immunity in broiler chicks.

    PubMed

    Hosseinzadeh, Hesam; Alaw Qotbi, Ali Ahmad; Seidavi, Alireza; Norris, David; Brown, David

    2014-01-01

    The use of herbs and spices has gained increasing interest as feed additives and possible alternative to antibiotics in poultry production. The effects of using different levels of coriander seed powder or extract on selected blood parameters, intestinal microflora, and immune response of broiler chickens were investigated in this study. A total of 420-day-old broiler chicks were randomly assigned to 7 treatments with 4 replicates and fed for 42 days. Results showed that inclusion of 2.0% coriander powder in broiler diets lowered total cholesterol while blood urea was significantly higher in birds on T4 compared to T1 and T2. Furthermore, there were no treatment effects on Lactobacillus bacteria; however, the population of E. coli was significantly higher in the ileum of chickens fed T0. Noticeable significant improvements of antibody titer against Newcastle, infectious bronchitis, and infectious bursal disease were observed in birds receiving coriander extract in water. Immunoglobulin G antibody against sheep red blood cells showed significant improvement in birds fed T3; likewise, immunoglobulin M was significantly higher in birds on T2 and T3 at 28 d of age. These results revealed that coriander extract or powder can be used as antibiotic alternative in broiler feeds.

  19. On adaptive modal control of large flexible spacecraft

    NASA Technical Reports Server (NTRS)

    Johnson, C. R., Jr.

    1979-01-01

    A recently developed strategy for adaptive sampled-data control of distributed parameter systems based on a plant modal expansion description and modal simultaneous identification and regulation algorithms is presented with frequent reference to the annular momentum control device (AMCD) test example. The requirements of observation spillover reduction and modal eigenvector shape prespecification, which are especially crucial to the proposed adaptive control strategy, are addressed. Individual low pass time filtering of sensed AMCD particle displacements is proposed for observation spillover reduction. A layered scheme incorporating 'eigenvector' shape improvement is outlined to combat the expansion basis prespecification requirement.

  20. Compensation of skeletal Class III malocclusion by isolated extraction of mandibular teeth: Part 2: Skeletal, dentoalveolar and soft tissue parameters in comparison with nonextraction Class III therapies.

    PubMed

    Zimmer, Bernd; Gaida, Sarah; Dathe, Henning

    2016-03-01

    To retrospectively compare two compensatory approaches taken in skeletal Class III patients during the main treatment stage, including a study group of multiband treatment plus isolated extraction of mandibular teeth and a control group of multiband treatment without extraction of teeth. The extraction group included 22 (12 female, 10 male) patients receiving compensatory multiband treatment for a mean of 3.47 ± 1.14 years and 16.22 ± 1.92 years old at debonding. The nonextraction group included 24 (14 female, 10 male) patients undergoing multiband treatment for 2.76 ± 1.28 years and 15.38 ± 1.46 years old at debonding. Lateral cephalograms obtained at baseline and upon completion of active treatment were traced for skeletal, dentoalveolar, and soft tissue parameters. Welch and Wilcoxon tests were used to analyze intergroup differences (initial values, final values, initial-to-final changes) and within-group differences (p < 0.05). Upon completion of active treatment, the only significant intergroup differences were noted for U1NA and L1ML. Significant within-group changes over the courses of treatment were seen for SNB, MLNL, U1NA, U1NL, L1NB, L1ML, H-angle, ULipEL, and LLipEL (extraction group) or for SNB, ANB, individual ANB, Wits appraisal, U1NA, U1NL, H-angle, Naslab-a, ULipEL, and LLipEL (nonextraction group). Parameters that changed by significantly different amounts in both groups included Wits appraisal, L1NB, L1ML, and LLipEL. The added value of isolated extraction therapy basically lies in increasing the potential for retruding the lower incisor inclinations, so that compensatory treatment becomes an option even in selected patients presenting with adverse occlusal situations that would otherwise require orthognathic surgery. Given the successful outcomes in both groups, which had been established by Peer Assessment Rating (PAR) scores, it was possible to define the skeletal, dentoalveolar, and soft tissue characteristics of successful treatment more

  1. Extraction of convective cloud parameters from Doppler Weather Radar MAX(Z) product using Image Processing Technique

    NASA Astrophysics Data System (ADS)

    Arunachalam, M. S.; Puli, Anil; Anuradha, B.

    2016-07-01

    In the present work continuous extraction of convective cloud optical information and reflectivity (MAX(Z) in dBZ) using online retrieval technique for time series data production from Doppler Weather Radar (DWR) located at Indian Meteorological Department, Chennai has been developed in MATLAB. Reflectivity measurements for different locations within the DWR range of 250 Km radii of circular disc area can be retrieved using this technique. It gives both time series reflectivity of point location and also Range Time Intensity (RTI) maps of reflectivity for the corresponding location. The Graphical User Interface (GUI) developed for the cloud reflectivity is user friendly; it also provides the convective cloud optical information such as cloud base height (CBH), cloud top height (CTH) and cloud optical depth (COD). This technique is also applicable for retrieving other DWR products such as Plan Position Indicator (Z, in dBZ), Plan Position Indicator (Z, in dBZ)-Close Range, Volume Velocity Processing (V, in knots), Plan Position Indicator (V, in m/s), Surface Rainfall Intensity (SRI, mm/hr), Precipitation Accumulation (PAC) 24 hrs at 0300UTC. Keywords: Reflectivity, cloud top height, cloud base, cloud optical depth

  2. Stevia rebaudiana Bertoni as a natural antioxidant/antimicrobial for high pressure processed fruit extract: processing parameter optimization.

    PubMed

    Barba, Francisco José; Criado, María Nieves; Belda-Galbis, Clara Miracle; Esteve, María José; Rodrigo, Dolores

    2014-04-01

    Response surface methodology was used to evaluate the optimal high pressure processing treatment (300-500 MPa, 5-15 min) combined with Stevia rebaudiana (Stevia) addition (0-2.5% (w/v)) to guarantee food safety while maintaining maximum retention of nutritional properties. A fruit extract matrix was selected and Listeria monocytogenes inactivation was followed from the food safety point of view while polyphenoloxidase (PPO) and peroxidase (POD) activities, total phenolic content (TPC) and antioxidant capacity (TEAC and ORAC) were studied from the food quality point of view. A combination of treatments achieved higher levels of inactivation of L. monocytogenes and of the oxidative enzymes, succeeding in completely inactivating POD and also increasing the levels of TPC, TEAC and ORAC. A treatment of 453 MPa for 5 min with a 2.5% (w/v) of Stevia succeeded in inactivating over 5 log cycles of L. monocytogenes and maximizing inactivation of PPO and POD, with the greatest retention of bioactive components. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. A Genetic Algorithm Approach to InGaP/GaAs HBT Parameter Extraction and RF Characterization

    NASA Astrophysics Data System (ADS)

    Li, Yiming; Cho, Yen-Yu; Wang, Chuan-Sheng; Huang, Kuen-Yu

    2003-04-01

    In this paper, a computational intelligence technique is applied to extract and simulate the stationary and high-frequency properties of heterojunction bipolar transistors (HBTs). A set of HBT circuit equations formulated with the Gummel-Poon model in time domain is solved with (1) the waveform relaxation (WR), (2) monotone iterative (MI) method, and (3) genetic algorithm (GA) with floating-point operators. The coupled nonlinear equations are decoupled and solved with the WR and MI methods in time domain, and the results obtained are used for the optimization of the characteristics with the GA method. The iteration can be terminated when the final convergent global solution is obtained. The time domain result is used in analyzing the property of the output third-order intercept point (OIP3) with the fast Fourier transform (FFT). Compared with the SPICE result, our simulation results demonstrate that this method is accurate and stable in high frequency simulation. This approach has practical applications in HBT characterization and radio frequency (RF) circuit optimal design.

  4. Accurate extraction of WSe2 FETs parameters by using pulsed I-V method at various temperatures

    NASA Astrophysics Data System (ADS)

    Lee, Sung Tae; Cho, In Tak; Kang, Won Mook; Park, Byung Gook; Lee, Jong-Ho

    2016-11-01

    This work investigates the intrinsic characteristics of multilayer WSe2 field effect transistors (FETs) by analysing Pulsed I- V (PIV) and DC characteristics measured at various temperatures. In DC measurement, unwanted charge trapping due to the gate bias stress results in I- V curves different from the intrinsic characteristic. However, PIV reduces the effect of gate bias stress so that intrinsic characteristic of WSe2 FETs is obtained. The parameters such as hysteresis, field effect mobility (μeff), subthreshold slope ( SS), and threshold voltage ( V th) measured by PIV are significantly different from those obtained by DC measurement. In PIV results, the hysteresis is considerably reduced compared with DC measurement, because the charge trapping effect is significantly reduced. With increasing temperature, the field effect mobility (μeff) and subthreshold swing ( SS) are deteriorated, and threshold voltage ( V th) decreases.

  5. Extracting the QCD ΛMS¯ parameter in Drell-Yan process using Collins-Soper-Sterman approach

    NASA Astrophysics Data System (ADS)

    Taghavi, R.; Mirjalili, A.

    <