Science.gov

Sample records for cross-spectrum experimental method

  1. Cross-spectrum measurement of thermal-noise limited oscillators.

    PubMed

    Hati, A; Nelson, C W; Howe, D A

    2016-03-01

    Cross-spectrum analysis is a commonly used technique for the detection of phase and amplitude noise of a signal in the presence of interfering uncorrelated noise. Recently, we demonstrated that the phase-inversion (anti-correlation) effect due to amplitude noise leakage can cause complete or partial collapse of the cross-spectral function. In this paper, we discuss the newly discovered effect of anti-correlated thermal noise that originates from the common-mode power divider (splitter), an essential component in a cross-spectrum noise measurement system. We studied this effect for different power splitters and discuss its influence on the measurement of thermal-noise limited oscillators. We provide theory, simulation and experimental results. In addition, we expand this study to reveal how the presence of ferrite-isolators and amplifiers at the output ports of the power splitters can affect the oscillator noise measurements. Finally, we discuss a possible solution to overcome this problem. PMID:27036804

  2. Measurement of the cross spectrum of HF electrostatic waves in an auroral plasma

    NASA Astrophysics Data System (ADS)

    Pottelette, R.; Illiano, J. M.

    1983-06-01

    A method for the metrology of space plasmas, based on the reception of electrostatic waves by a pair of small dipole antennas was tested in PORCUPINE project rocket experiments. Both dipoles received signals from the natural electrostatic microfield in the plasma; the cross spectrum of these random signals was measured. Data obtained during a weak auroral activity are presented. Natural electrostatic emissions were observed around the upper hybrid frequency and also around the three-halves harmonic of the electron gyrofrequency. A linear calculation shows that the amplitudes of these emissions are above the thermal noise level of the plasma. To explain the observations, it is necessary to take into account the presence of low-energy precipitating electrons (1 to 20 eV), which are highly anisotropic.

  3. A practical implementation of cross-spectrum in protein backbone resonance assignment.

    PubMed

    Chen, Kang; Delaglio, Frank; Tjandra, Nico

    2010-04-01

    The concept of cross-spectrum is applied in protein NMR spectroscopy to assist in the backbone sequential resonance assignment. Cross-spectrum analysis is used routinely to reveal correlations in frequency domains as a means to reveal common features contained in multiple time series. Here the cross-spectrum between related NMR spectra, for example HNCO and HN(CA)CO, can be calculated with point-by-point multiplications along their common C' carbon axis. In the resulting higher order cross-spectrum, an enhanced correlation signal occurs at every common i-1 carbon frequency allowing the amide proton H(N) (and nitrogen N) resonances from residues i and i-1 to be identified. The cross-spectrum approach is demonstrated using 2D spectra H(N)CO, H(NCA)CO, H(NCO)CACB, and H(N)CACB measured on a 15N/13C double-labeled Ubiquitin sample. These 2D spectra are used to calculate two pseudo-3D cross-spectra, H(i)-H(i)(-1)-C'(i)(-1) and H(i)-H(i)(-1)-CA(i)(-1)CB(i)(-1). We show using this approach, backbone resonances of H, C', CA, and CB can be fully assigned without ambiguity. The cross-spectrum principle is expected to offer an easy, practical, and more quantitative approach for heteronuclear backbone resonance assignment. PMID:20053573

  4. The cluster-galaxy cross spectrum. An additional probe of cosmological and halo parameters

    NASA Astrophysics Data System (ADS)

    Hütsi, G.; Lahav, O.

    2008-12-01

    Context: There are several wide field galaxy and cluster surveys planned for the near future, e.g. BOSS, WFMOS, ADEPT, Hetdex, SPT, eROSITA. In the simplest approach, one would analyze these independently, thus neglecting the extra information provided by the cluster-galaxy cross pairs. Aims: In this paper we have focused on the possible synergy between these surveys by investigating the amount of information encoded in the cross pairs. Methods: We present a model for the cluster-galaxy cross spectrum within the halo model framework. To assess the gain in performance due to inclusion of the cluster-galaxy cross pairs, we carry out a Fisher matrix analysis for a BOSS-like galaxy redshift survey targeting luminous red galaxies and a hypothetical mass-limited cluster redshift survey with a lower mass threshold of 1.7 × 1014 h-1 M⊙ over the same volume. Results: On small scales, a cluster-galaxy cross spectrum directly probes the density profile of the halos, instead of the density profile convolved with itself, as is the case for the galaxy power spectrum. Due to this different behavior, adding information from the cross pairs helps to tighten constraints on the halo occupation distribution (e.g. a factor of ~2 compression of the error ellipses on the m_glow-α plane) and offers an alternative mechanism compared with techniques that directly fit halo density profiles. By inclusion of the cross pairs, a factor of ~2 stronger constraints are obtained for σ_8, while the improvement for the dark energy figure-of-merit is somewhat weaker: an increase by a factor of 1.4. We have also written down the formalism for the case when only photometric redshifts are available for both the clusters and the galaxies. For the analysis of the photometric surveys the inclusion of the cluster-galaxy cross pairs might be very beneficial since the photo-z errors for the clusters are usually significantly smaller than for the typical galaxies.

  5. Experimental methods for identifying failure mechanisms

    NASA Technical Reports Server (NTRS)

    Daniel, I. M.

    1983-01-01

    Experimental methods for identifying failure mechanisms in fibrous composites are studied. Methods to identify failure in composite materials includes interferometry, holography, fractography and ultrasonics.

  6. Experimental study of the equivalent sound source center of the propeller rotating noise

    NASA Astrophysics Data System (ADS)

    Zhang, Qiang; Gu, Jiajin

    1992-06-01

    The theory and experimental technique for identifying the source of various propeller rotating noises using a cross-spectrum analysis method are discussed. The measurement of the equivalent source center of such noise on the light aircraft AD-200 is presented as an example. The efficiency of the method gives it excellent prospects for large-scale application.

  7. Gaseous Sulfate Solubility in Glass: Experimental Method

    SciTech Connect

    Bliss, Mary

    2013-11-30

    Sulfate solubility in glass is a key parameter in many commercial glasses and nuclear waste glasses. This report summarizes key publications specific to sulfate solubility experimental methods and the underlying physical chemistry calculations. The published methods and experimental data are used to verify the calculations in this report and are expanded to a range of current technical interest. The calculations and experimental methods described in this report will guide several experiments on sulfate solubility and saturation for the Hanford Waste Treatment Plant Enhanced Waste Glass Models effort. There are several tables of sulfate gas equilibrium values at high temperature to guide experimental gas mixing and to achieve desired SO3 levels. This report also describes the necessary equipment and best practices to perform sulfate saturation experiments for molten glasses. Results and findings will be published when experimental work is finished and this report is validated from the data obtained.

  8. Experimental design methods for bioengineering applications.

    PubMed

    Keskin Gündoğdu, Tuğba; Deniz, İrem; Çalışkan, Gülizar; Şahin, Erdem Sefa; Azbar, Nuri

    2016-01-01

    Experimental design is a form of process analysis in which certain factors are selected to obtain the desired responses of interest. It may also be used for the determination of the effects of various independent factors on a dependent factor. The bioengineering discipline includes many different areas of scientific interest, and each study area is affected and governed by many different factors. Briefly analyzing the important factors and selecting an experimental design for optimization are very effective tools for the design of any bioprocess under question. This review summarizes experimental design methods that can be used to investigate various factors relating to bioengineering processes. The experimental methods generally used in bioengineering are as follows: full factorial design, fractional factorial design, Plackett-Burman design, Taguchi design, Box-Behnken design and central composite design. These design methods are briefly introduced, and then the application of these design methods to study different bioengineering processes is analyzed.

  9. Time evolution of surface chlorophyll patterns from cross-spectrum analysis of satellite color images

    NASA Technical Reports Server (NTRS)

    Denman, Kenneth L.; Abbott, Mark R.

    1988-01-01

    The rate of decorrelation of surface chlorophyll patterns as a function of the time separation between pairs of images was determined from two sequences of CZCS images of the Pacific Ocean area adjacent to Vancouver Island, Canada; cloud-free subareas were selected that were common to several images separated in time by 1-17 days. Image pairs were subjected to two-dimensional autospectrum and cross-spectrum analysis in an array processor, and squared coherence estimates found for several wave bands were plotted against time separation, in analogy with a time-lagged cross correlation function. It was found that, for wavelengths of 50-150 km, significant coherence was lost after 7-10 days, while for wavelengths of 25-50 km, significant coherence was lost after only 5-7 days. In both cases, offshore regions maintained coherence longer than coastal regions.

  10. Using Experimental Methods in Higher Education Research

    ERIC Educational Resources Information Center

    Ross, Steven M.; Morrison, Gary R.; Lowther, Deborah L.

    2005-01-01

    Experimental methods have been used extensively for many years to conduct research in education and psychology. However, applications of experiments to investigate technology and other instructional innovations in higher education settings have been relatively limited. The present paper examines ways in which experiments can be used productively…

  11. A method for experimental modal separation

    NASA Technical Reports Server (NTRS)

    Hallauer, W. L., Jr.

    1977-01-01

    A method is described for the numerical simulation of multiple-shaker modal survey testing using simulated experimental data to optimize the shaker force-amplitude distribution for the purpose of isolating individual modes of vibration. Inertia, damping, stiffness, and model data are stored on magnetic disks, available by direct access to the interactive FORTRAN programs which perform all computations required by this relative force amplitude distribution method.

  12. Experimental test of airplane boarding methods

    SciTech Connect

    Steffen, Jason H.; Hotchkiss, Jon

    2011-10-26

    We report the results of an experimental comparison of different airplane boarding methods. This test was conducted in a mock 757 fuselage, located on a Southern California soundstage, with 12 rows of six seats and a single aisle. Five methods were tested using 72 passengers of various ages. We found a significant reduction in the boarding times of optimized methods over traditional methods. These improved methods, if properly implemented, could result in a significant savings to airline companies. The process of boarding an airplane is of interest to a variety of groups. The public is interested both as a curiosity, as it is something that they may regularly experience, and as a consumer, as their experiences good or bad can affect their loyalties. Airline companies and their employees also have a stake in an efficient boarding procedure as time saved in the boarding process may result is monetary savings, in the quality of interactions with passengers, and in the application of human resources to the general process of preparing an airplane for departure. A recent study (Nyquist and McFadden, 2008) indicates that the average cost to an airline company for each minute of time spent at the terminal is roughly $30. Thus, each minute saved in the turn-around time of a flight has the potential to generate over $16,000,000 in annual savings (assuming an average of 1500 flights per day). While the boarding process may not be the primary source of delay in returning an airplane to the skies, reducing the boarding time may effectively eliminate passenger boarding as a contributor in any meaningful measure. Consequently, subsequent efforts to streamline the other necessary tasks, such as refueling and maintenance, would be rewarded with a material reduction in time at the gate for each flight.

  13. Experimental test of airplane boarding methods

    DOE PAGES

    Steffen, Jason H.; Hotchkiss, Jon

    2011-10-26

    We report the results of an experimental comparison of different airplane boarding methods. This test was conducted in a mock 757 fuselage, located on a Southern California soundstage, with 12 rows of six seats and a single aisle. Five methods were tested using 72 passengers of various ages. We found a significant reduction in the boarding times of optimized methods over traditional methods. These improved methods, if properly implemented, could result in a significant savings to airline companies. The process of boarding an airplane is of interest to a variety of groups. The public is interested both as a curiosity,more » as it is something that they may regularly experience, and as a consumer, as their experiences good or bad can affect their loyalties. Airline companies and their employees also have a stake in an efficient boarding procedure as time saved in the boarding process may result is monetary savings, in the quality of interactions with passengers, and in the application of human resources to the general process of preparing an airplane for departure. A recent study (Nyquist and McFadden, 2008) indicates that the average cost to an airline company for each minute of time spent at the terminal is roughly $30. Thus, each minute saved in the turn-around time of a flight has the potential to generate over $16,000,000 in annual savings (assuming an average of 1500 flights per day). While the boarding process may not be the primary source of delay in returning an airplane to the skies, reducing the boarding time may effectively eliminate passenger boarding as a contributor in any meaningful measure. Consequently, subsequent efforts to streamline the other necessary tasks, such as refueling and maintenance, would be rewarded with a material reduction in time at the gate for each flight.« less

  14. CMB EB and TB cross-spectrum estimation via pseudospectrum techniques

    NASA Astrophysics Data System (ADS)

    Grain, J.; Tristram, M.; Stompor, R.

    2012-10-01

    We discuss methods for estimating EB and TB spectra of the cosmic microwave background anisotropy maps covering limited sky area. Such odd-parity correlations are expected to vanish whenever parity is not broken. As this is indeed the case in the standard cosmologies, any evidence to the contrary would have a profound impact on our theories of the early Universe. Such correlations could also become a sensitive diagnostic of some particularly insidious instrumental systematics. In this work we introduce three different unbiased estimators based on the so-called standard and pure pseudo-spectrum techniques and later assess their performance by means of extensive Monte Carlo simulations performed for different experimental configurations. We find that a hybrid approach combining a pure estimate of B-mode multipoles with a standard one for E-mode (or T) multipoles, leads to the smallest error bars for both EB (or TB respectively) spectra as well as for the three other polarization-related angular power spectra (i.e., EE, BB, and TE). However, if both E and B multipoles are estimated using the pure technique, the loss of precision for the EB spectrum is not larger than ˜30%. Moreover, for the experimental configurations considered here, the statistical uncertainties-due to sampling variance and instrumental noise-of the pseudo-spectrum estimates is at most a factor ˜1.4 for TT, EE, and TE spectra and a factor ˜2 for BB, TB, and EB spectra, higher than the most optimistic Fisher estimate of the variance.

  15. Experimental characterization of composites. [load test methods

    NASA Technical Reports Server (NTRS)

    Bert, C. W.

    1975-01-01

    The experimental characterization for composite materials is generally more complicated than for ordinary homogeneous, isotropic materials because composites behave in a much more complex fashion, due to macroscopic anisotropic effects and lamination effects. Problems concerning the static uniaxial tension test for composite materials are considered along with approaches for conducting static uniaxial compression tests and static uniaxial bending tests. Studies of static shear properties are discussed, taking into account in-plane shear, twisting shear, and thickness shear. Attention is given to static multiaxial loading, systematized experimental programs for the complete characterization of static properties, and dynamic properties.

  16. Experimental methods for geological remote sensing

    NASA Technical Reports Server (NTRS)

    Vincent, R. K.

    1972-01-01

    During the past year a two channel IR technique for discrimination among silicate rocks was tested for a second time, a three channel IR method was tested for the first time, and a new visible-reflective IR ratio method was hypothesized and qualitatively tested for iron oxide recognition. Both the two channel and three channel IR ratios methods were capable of discriminating felsic from mafic rock types. The three-channel ratio values measured by the scanner were found to agree, within reasonable limits, with the values of R calculated from laboratory data. The capability of the three channel method to obtain absolute ratios is accompanied by a costly processing routine. The two channel technique is superior for low thermal contrast scenes about which some ground truth is available because of its speed and economy.

  17. Experimental Mathemataics: Examples, Methods andImplications

    SciTech Connect

    Bailey, David H.; Borwein, Jonathan M.

    2005-01-31

    Recent years have seen the flowering of ''experimental'' mathematics, namely the utilization of modern computer technology as an active tool in mathematical research. This development is not limited to a handful of researchers, nor to a handful of universities, nor is it limited to one particular field of mathematics. Instead, it involves hundreds of individuals, at many different institutions, who have turned to the remarkable new computational tools now available to assist in their research, whether it be in number theory, algebra, analysis, geometry or even topology. These tools are being used to work out specific examples, generate plots, perform various algebraic and calculus manipulations, test conjectures, and explore routes to formal proof. Using computer tools to test conjectures is by itself a major time saver for mathematicians, as it permits them to quickly rule out false notions.

  18. Experimental and analysis methods in radiochemical experiments

    NASA Astrophysics Data System (ADS)

    Cattadori, C. M.; Pandola, L.

    2016-04-01

    Radiochemical experiments made the history of neutrino physics by achieving the first observation of solar neutrinos (Cl experiment) and the first detection of the fundamental pp solar neutrinos component (Ga experiments). They measured along decades the integral νe charged current interaction rate in the exposed target. The basic operation principle is the chemical separation of the few atoms of the new chemical species produced by the neutrino interactions from the rest of the target, and their individual counting in a low-background counter. The smallness of the expected interaction rate (1 event per day in a ˜ 100 ton target) poses severe experimental challenges on the chemical and on the counting procedures. The main aspects related to the analysis techniques employed in solar neutrino experiments are reviewed and described, with a special focus given to the event selection and the statistical data treatment.

  19. Experimental Tests of Subjective Bayesian Methods

    ERIC Educational Resources Information Center

    Li,Yuelin; Krantz, David H.

    2005-01-01

    We evaluated Samaniego and Reneau's 1994 novel weight method for eliciting subjective probability estimates. Experiment 1 replicated their experiment (subjects weighed their prior estimate against 10 new observations), with an additional weight judgment against 50 observations. In Experiment 2, subjects gave prior estimates to questions in a…

  20. An experimental unification of reservoir computing methods.

    PubMed

    Verstraeten, D; Schrauwen, B; D'Haene, M; Stroobandt, D

    2007-04-01

    Three different uses of a recurrent neural network (RNN) as a reservoir that is not trained but instead read out by a simple external classification layer have been described in the literature: Liquid State Machines (LSMs), Echo State Networks (ESNs) and the Backpropagation Decorrelation (BPDC) learning rule. Individual descriptions of these techniques exist, but a overview is still lacking. Here, we present a series of experimental results that compares all three implementations, and draw conclusions about the relation between a broad range of reservoir parameters and network dynamics, memory, node complexity and performance on a variety of benchmark tests with different characteristics. Next, we introduce a new measure for the reservoir dynamics based on Lyapunov exponents. Unlike previous measures in the literature, this measure is dependent on the dynamics of the reservoir in response to the inputs, and in the cases we tried, it indicates an optimal value for the global scaling of the weight matrix, irrespective of the standard measures. We also describe the Reservoir Computing Toolbox that was used for these experiments, which implements all the types of Reservoir Computing and allows the easy simulation of a wide range of reservoir topologies for a number of benchmarks.

  1. La Methode Experimentale en Pedagogie (The Experimental Method in Pedagogy)

    ERIC Educational Resources Information Center

    Rouquette, Michel-Louis

    1975-01-01

    The pedagogue is caught between the qualitative and quantitative or regularized aspects of his work, a situation not automatically conducive to scientific study. The article refreshes the instructor on the elementary principles of experimentation: observation, systematization, elaboration of hypothesis, and startegies of comparison. (Text is in…

  2. Acquisition of Psychomotor Skills in Dentistry: An Experimental Teaching Method.

    ERIC Educational Resources Information Center

    Vann, William F., Jr.; And Others

    1981-01-01

    A traditional method of teaching psychomotor skills in a preclinical restorative dentistry laboratory course was compared with an experimental method. The experimental group was taught using a guided systematic approach that relied on detailed checklists and exhaustive faculty feedback. (Author/MLW)

  3. Experimental Methodology in English Teaching and Learning: Method Features, Validity Issues, and Embedded Experimental Design

    ERIC Educational Resources Information Center

    Lee, Jang Ho

    2012-01-01

    Experimental methods have played a significant role in the growth of English teaching and learning studies. The paper presented here outlines basic features of experimental design, including the manipulation of independent variables, the role and practicality of randomised controlled trials (RCTs) in educational research, and alternative methods…

  4. Experimental implementation of the modified independent modal space control method

    NASA Technical Reports Server (NTRS)

    Baz, A.; Poh, S.

    1990-01-01

    An experimental realization of a modified independent modal space control (MIMSC) method to control the vibration of a flexible cantilevered beam is presented. In its operation the method relies on the use of one piezoelectric actuator to control several vibration modes through a time-sharing strategy. The effectiveness of the MIMSC method in damping out the beam vibration is demonstrated by comparing the results with those obtained by other modal control methods. Two methods are considered, the independent modal space control method and the pseudo-inverse method. The feasibility of the MIMSC method as a viable alternative for controlling large flexible structures with a very small number of actuators is emphasized.

  5. Experimental method for investigating helium effects in irradiated vanadium

    SciTech Connect

    Smith, D.L.; Matsui, H.; Greenwood, L.; Loomis, B.

    1987-10-01

    Analyses have been performed which indicate that an effective method for experimentally investigating helium effects in neutron irradiated vanadium base alloys can be developed. The experimental procedure involves only modest modifications to existing procedures currently used for irradiation testing of vanadium-base alloys in the FFTF reactor. Helium is generated in the vanadium alloy by decay of tritium which is either preinjected or generated within the test capsule. Calculations indicate that nearly constant He/dpa ratios of desired magnitude can be attained by proper selection of experimental parameters. The proposed method could have a major impact on the development of vanadium base alloys for fusion reactor applications. 8 refs., 4 figs.

  6. Taguchi method of experimental design in materials education

    NASA Technical Reports Server (NTRS)

    Weiser, Martin W.

    1993-01-01

    Some of the advantages and disadvantages of the Taguchi Method of experimental design as applied to Materials Science will be discussed. This is a fractional factorial method that employs the minimum number of experimental trials for the information obtained. The analysis is also very simple to use and teach, which is quite advantageous in the classroom. In addition, the Taguchi loss function can be easily incorporated to emphasize that improvements in reproducibility are often at least as important as optimization of the response. The disadvantages of the Taguchi Method include the fact that factor interactions are normally not accounted for, there are zero degrees of freedom if all of the possible factors are used, and randomization is normally not used to prevent environmental biasing. In spite of these disadvantages it is felt that the Taguchi Method is extremely useful for both teaching experimental design and as a research tool, as will be shown with a number of brief examples.

  7. Experimental methods for phase equilibria at high pressures.

    PubMed

    Dohrn, Ralf; Fonseca, José M S; Peper, Stephanie

    2012-01-01

    Knowledge of high-pressure phase equilibria is crucial in many fields, e.g., for the design and optimization of high-pressure chemical and separation processes, carbon capture and storage, hydrate formation, applications of ionic liquids, and geological processes. This review presents the variety of methods to measure phase equilibria at high pressures and, following a classification, discusses the measurement principles, advantages, challenges, and error sources. Examples of application areas are given. A detailed knowledge and understanding of the different methods is fundamental not only for choosing the most suitable method for a certain task but also for the evaluation of experimental data. The discrepancy between the (sometimes low) true accuracy of published experimental data and the (high) accuracy claimed by authors is addressed. Some essential requirements for the generation of valuable experimental results are summarized.

  8. Experimental comparison of empirical material decomposition methods for spectral CT.

    PubMed

    Zimmerman, Kevin C; Schmidt, Taly Gilat

    2015-04-21

    Material composition can be estimated from spectral information acquired using photon counting x-ray detectors with pulse height analysis. Non-ideal effects in photon counting x-ray detectors such as charge-sharing, k-escape, and pulse-pileup distort the detected spectrum, which can cause material decomposition errors. This work compared the performance of two empirical decomposition methods: a neural network estimator and a linearized maximum likelihood estimator with correction (A-table method). The two investigated methods differ in how they model the nonlinear relationship between the spectral measurements and material decomposition estimates. The bias and standard deviation of material decomposition estimates were compared for the two methods, using both simulations and experiments with a photon-counting x-ray detector. Both the neural network and A-table methods demonstrated a similar performance for the simulated data. The neural network had lower standard deviation for nearly all thicknesses of the test materials in the collimated (low scatter) and uncollimated (higher scatter) experimental data. In the experimental study of Teflon thicknesses, non-ideal detector effects demonstrated a potential bias of 11-28%, which was reduced to 0.1-11% using the proposed empirical methods. Overall, the results demonstrated preliminary experimental feasibility of empirical material decomposition for spectral CT using photon-counting detectors.

  9. Experimental comparison of empirical material decomposition methods for spectral CT

    NASA Astrophysics Data System (ADS)

    Zimmerman, Kevin C.; Gilat Schmidt, Taly

    2015-04-01

    Material composition can be estimated from spectral information acquired using photon counting x-ray detectors with pulse height analysis. Non-ideal effects in photon counting x-ray detectors such as charge-sharing, k-escape, and pulse-pileup distort the detected spectrum, which can cause material decomposition errors. This work compared the performance of two empirical decomposition methods: a neural network estimator and a linearized maximum likelihood estimator with correction (A-table method). The two investigated methods differ in how they model the nonlinear relationship between the spectral measurements and material decomposition estimates. The bias and standard deviation of material decomposition estimates were compared for the two methods, using both simulations and experiments with a photon-counting x-ray detector. Both the neural network and A-table methods demonstrated a similar performance for the simulated data. The neural network had lower standard deviation for nearly all thicknesses of the test materials in the collimated (low scatter) and uncollimated (higher scatter) experimental data. In the experimental study of Teflon thicknesses, non-ideal detector effects demonstrated a potential bias of 11-28%, which was reduced to 0.1-11% using the proposed empirical methods. Overall, the results demonstrated preliminary experimental feasibility of empirical material decomposition for spectral CT using photon-counting detectors.

  10. Experimental Comparison of Empirical Material Decomposition Methods for Spectral CT

    PubMed Central

    Zimmerman, Kevin C.; Schmidt, Taly Gilat

    2015-01-01

    Material composition can be estimated from spectral information acquired using photon counting x-ray detectors with pulse height analysis. Non-ideal effects in photon counting x-ray detectors such as charge-sharing, k-escape, and pulse-pileup distort the detected spectrum, which can cause material decomposition errors. This work compared the performance of two empirical decomposition methods: a neural network estimator and a linearized maximum likelihood estimator with correction (A-table method). The two investigated methods differ in how they model the nonlinear relationship between the spectral measurements and material decomposition estimates. The bias and standard deviation of material decomposition estimates were compared for the two methods, using both simulations and experiments with a photon-counting x-ray detector. Both the neural network and A-table methods demonstrated similar performance for the simulated data. The neural network had lower standard deviation for nearly all thicknesses of the test materials in the collimated (low scatter) and uncollimated (higher scatter) experimental data. In the experimental study of Teflon thicknesses, non-ideal detector effects demonstrated a potential bias of 11–28%, which was reduced to 0.1–11% using the proposed empirical methods. Overall, the results demonstrated preliminary experimental feasibility of empirical material decomposition for spectral CT using photon-counting detectors. PMID:25813054

  11. The contour method: a new approach in experimental mechanics

    SciTech Connect

    Prime, Michael B

    2009-01-01

    The recently developed contour method can measure complex residual-stress maps in situations where other measurement methods cannot. This talk first describes the principle of the contour method. A part is cut in two using a precise and low-stress cutting technique such as electric discharge machining. The contour of the resulting new surface, which will not be flat if residual stresses are relaxed by the cutting, is then measured. Finally, a conceptually simple finite element analysis determines the original residual stresses from the measured contour. Next, this talk gives several examples of applications. The method is validated by comparing with neutron diffraction measurements in an indented steel disk and in a friction stir weld between dissimilar aluminum alloys. Several applications are shown that demonstrate the power of the contour method: large aluminum forgings, railroad rails, and welds. Finally, this talk discusses why the contour method is significant departure from conventional experimental mechanics. Other relaxation method, for example hole-drilling, can only measure a 1-D profile of residual stresses, and yet they require a complicated inverse calculation to determine the stresses from the strain data. The contour method gives a 2-D stress map over a full cross-section, yet a direct calculation is all that is needed to reduce the data. The reason for these advantages lies in a subtle but fundamental departure from conventional experimental mechanics. Applying new technology to old methods like will not give similar advances, but the new approach also introduces new errors.

  12. An Experimental Method for Stereolithic Mandible Fabrication and Image Preparation

    PubMed Central

    Russett, Shawn; Major, Paul; Carey, Jason; Toogood, Roger; Boulanger, Pierre

    2007-01-01

    Reproduction of anatomical structures by rapid prototyping has proven to be a valid adjunct for craniofacial surgery, providing alternative methods to produce prostheses and development of surgical guides. The aim of this study was to introduce a methodology to fabricate asymmetric human mandibles by rapid prototyping to be used in future studies for evaluating mandibular symmetries. Stereolithic models of human mandibles were produced with varying amounts of asymmetry in the condylar neck, ramus and body of the mandible by means of rapid prototyping. A method for production of the synthetic mandibles was defined. Model preparation, landmark description and development of the experimental model were described. A series of synthetic mandibles ranging in asymmetry were accurately produced from a scanned human mandible. A method for creating the asymmetries, fabricating, coating and landmarking the synthetic mandibles was formulated. A description for designing a reproducible experimental model for image acquisition was also outlined. Production of synthetic mandibles by stereolithic modeling is a viable method for creating skeletal experimental models with known amounts of asymmetry. PMID:19662121

  13. [Experimental study on an auditory method for analyzing DNA segments].

    PubMed

    Xiao, Shouzhong; Fang, Xianglin

    2002-01-01

    To explore a new method for analyzing biological molecules that have already been sequenced, an experimental study on an auditory method was carried out. The auditory method for analyzing biological molecules includes audible representation of sequence data. Audible representation of sequence data was implemented by using a multimedia computer. Each mononucleotide in a DNA sequence was matched with a corresponding sound, i.e., a DNA sequence was "dubbed" in a sound sequence. When the sound sequence is played, a special cadence can be heard. In the audible representation experiment, special cadences of different exons can be clearly heard. The results show that audible representation of DNA sequence data can be implemented by using a multimedia technique. After a 5-time auditory training, subjects both in internal testing and external testing can obtain 93%-100% of judgment accuracy rate for the difference between two sound sequences of two different exons, thus providing an experimental basis for the practicability of this method. Auditory method for analyzing DNA segments might be beneficial for the research in comparative genomics and functional genomics. This new technology must be robust and be carefully evaluated and improved in a high-throughput environment before its implementation in an application setting. PMID:11951511

  14. A unique method of neutron flux determination from experimental data

    SciTech Connect

    Paxton, Frank A.

    1998-12-01

    A method is provided for determining the fission heat flux of a prime specimen inserted into a specimen of a test reactor. A pair of thermocouple test specimens are positioned at the same level in the holder and a determination is made of various experimental data including the temperature of the thermocouple test specimens, the temperature of bulk water channels located in the test holder, the gamma scan count ratios for the thermocouple test specimens and the prime specimen, and the thicknesses of the outer clads, the fuel fillers, and the backclad of the thermocouple test specimen. Using this experimental data, the absolute value of the fission heat flux for the thermocouple test specimens and prime specimen can be calculated.

  15. Nonlinear feedback method of robot control - A preliminary experimental study

    NASA Technical Reports Server (NTRS)

    Tarn, T. J.; Ganguly, S.; Li, Z.; Bejczy, A. K.

    1990-01-01

    The nonlinear feedback method of robot control has been experimentally implemented on two PUMA 560 robot arms. The feasibility of the proposed controller, which was shown viable through simulation results earlier, is stressed. The servomechanism operates in task space, and the nonlinear feedback takes care of the necessary transformations to compute the necessary joint currents. A discussion is presented of the implementation with details of the experiments performed. The performance of the controller is encouraging but was limited to 100-Hz sampling frequency and to derived velocity information at the time of the experimentation. The setup of the lab, the software aspects, results, and the control hardware architecture that has recently been implemented are discussed.

  16. Method of fission heat flux determination from experimental data

    DOEpatents

    Paxton, Frank A.

    1999-01-01

    A method is provided for determining the fission heat flux of a prime specimen inserted into a specimen of a test reactor. A pair of thermocouple test specimens are positioned at the same level in the holder and a determination is made of various experimental data including the temperature of the thermocouple test specimens, the temperature of bulk water channels located in the test holder, the gamma scan count ratios for the thermocouple test specimens and the prime specimen, and the thicknesses of the outer clads, the fuel fillers, and the backclad of the thermocouple test specimen. Using this experimental data, the absolute value of the fission heat flux for the thermocouple test specimens and prime specimen can be calculated.

  17. Experimental validation of an analytical method of calculating photon distributions

    SciTech Connect

    Wells, R.G.; Celler, A.; Harrop, R.

    1996-12-31

    We have developed a method for analytically calculating photon distributions in SPECT projections. This method models primary photon distributions as well as first and second order Compton scattering and Rayleigh scattering. It uses no free fitting parameters and so the projections produced are completely determined by the characteristics of the SPECT camera system, the energy of the isotope, an estimate of the source distribution and an attenuation map of the scattering object. The method was previously validated by comparison with Monte Carlo simulations and we are now verifying its accuracy with respect to phantom experiments. We have performed experiments using a Siemens MS3 SPECT camera system for a point source (2mm in diameter) within a homogeneous water bath and a small spherical source (1cm in diameter) within both a homogeneous water cylinder and a non-homogeneous medium consisting of air and water. Our technique reproduces well the distribution of photons in the experimentally acquired projections.

  18. Alternate Methods to Experimentally Investigate Shock Initiation Properties of Explosives

    NASA Astrophysics Data System (ADS)

    Svingala, Forrest; Lee, Richard; Sutherland, Gerrit; Samuels, Philip

    2015-06-01

    Reactive flow models are desired for many new explosives early in the formulation development stage. Traditionally, these models are parameterized by carefully-controlled 1-D shock experiments, including gas-gun testing with embedded gauges and wedge testing with explosive plane wave lenses (PWL). These experiments are easy to interpret, due to their 1-D nature, but are generally expensive to perform, and cannot be performed at all explosive test facilities. We investigate alternative methods to probe shock-initiation behavior of new explosives using widely-available pentolite gap test donors and simple time-of-arrival type diagnostics. These methods can be performed at a low cost at virtually any explosives testing facility, which allows experimental data to parameterize reactive flow models to be collected much earlier in the development of an explosive formulation. However, the fundamentally 2-D nature of these tests may increase the modeling burden in parameterizing these models, and reduce general applicability. Several variations of the so-called modified gap test were investigated and evaluated for suitability as an alternative to established 1-D gas gun and PWL techniques. At least partial agreement with 1-D test methods was observed for the explosives tested, and future work is planned to scope the applicability and limitations of these experimental techniques.

  19. The Assessment of Experimental Methods of Serial Number Restoration

    NASA Astrophysics Data System (ADS)

    Argo, Mackenzie

    Serial number restoration is a common and successful process of revealing obliterated serial numbers on firearms. In a crime laboratory setting, obliterated serial numbers are commonly processed in order to tie a person to a crime scene or provide an investigative lead for officers. Currently serial numbers are restored using a chemical etchant method that can eat away at the metal on the firearm even after the examination is complete. It can also take several hours to complete and only provide an examiner with a partial number. There are other nondestructive options however little to no literature is available. The purpose of this study is to discover new methods for nondestructive serial number restoration and to compare them to the traditional chemical method used. Metal bars of premeasured obliteration depths and different compositions were examined using three proposed experimental methods: near infrared imaging, cold frost, and scanning acoustic microscopy. Results did not indicate significant difference in the median number of visible digits recovered for each of the three proposed methods compared to the traditional chemical method. There were significant results in the median number of composition utilized and depth of obliteration. This indicates that different firearm compositions and depth of obliteration has an effect on serial number restoration.

  20. Experimental evaluation of the certification-trail method

    NASA Technical Reports Server (NTRS)

    Sullivan, Gregory F.; Wilson, Dwight S.; Masson, Gerald M.; Itoh, Mamoru; Smith, Warren W.; Kay, Jonathan S.

    1993-01-01

    Certification trails are a recently introduced and promising approach to fault-detection and fault-tolerance. A comprehensive attempt to assess experimentally the performance and overall value of the method is reported. The method is applied to algorithms for the following problems: huffman tree, shortest path, minimum spanning tree, sorting, and convex hull. Our results reveal many cases in which an approach using certification-trails allows for significantly faster overall program execution time than a basic time redundancy-approach. Algorithms for the answer-validation problem for abstract data types were also examined. This kind of problem provides a basis for applying the certification-trail method to wide classes of algorithms. Answer-validation solutions for two types of priority queues were implemented and analyzed. In both cases, the algorithm which performs answer-validation is substantially faster than the original algorithm for computing the answer. Next, a probabilistic model and analysis which enables comparison between the certification-trail method and the time-redundancy approach were presented. The analysis reveals some substantial and sometimes surprising advantages for ther certification-trail method. Finally, the work our group performed on the design and implementation of fault injection testbeds for experimental analysis of the certification trail technique is discussed. This work employs two distinct methodologies, software fault injection (modification of instruction, data, and stack segments of programs on a Sun Sparcstation ELC and on an IBM 386 PC) and hardware fault injection (control, address, and data lines of a Motorola MC68000-based target system pulsed at logical zero/one values). Our results indicate the viability of the certification trail technique. It is also believed that the tools developed provide a solid base for additional exploration.

  1. Experimental validation of boundary element methods for noise prediction

    NASA Technical Reports Server (NTRS)

    Seybert, A. F.; Oswald, Fred B.

    1992-01-01

    Experimental validation of methods to predict radiated noise is presented. A combined finite element and boundary element model was used to predict the vibration and noise of a rectangular box excited by a mechanical shaker. The predicted noise was compared to sound power measured by the acoustic intensity method. Inaccuracies in the finite element model shifted the resonance frequencies by about 5 percent. The predicted and measured sound power levels agree within about 2.5 dB. In a second experiment, measured vibration data was used with a boundary element model to predict noise radiation from the top of an operating gearbox. The predicted and measured sound power for the gearbox agree within about 3 dB.

  2. Theoretical and experimental physical methods of neutron-capture therapy

    NASA Astrophysics Data System (ADS)

    Borisov, G. I.

    2011-09-01

    This review is based to a substantial degree on our priority developments and research at the IR-8 reactor of the Russian Research Centre Kurchatov Institute. New theoretical and experimental methods of neutron-capture therapy are developed and applied in practice; these are: A general analytical and semi-empiric theory of neutron-capture therapy (NCT) based on classical neutron physics and its main sections (elementary theories of moderation, diffuse, reflection, and absorption of neutrons) rather than on methods of mathematical simulation. The theory is, first of all, intended for practical application by physicists, engineers, biologists, and physicians. This theory can be mastered by anyone with a higher education of almost any kind and minimal experience in operating a personal computer.

  3. Integrating Informative Priors from Experimental Research with Bayesian Methods

    PubMed Central

    Hamra, Ghassan; Richardson, David; MacLehose, Richard; Wing, Steve

    2013-01-01

    Informative priors can be a useful tool for epidemiologists to handle problems of sparse data in regression modeling. It is sometimes the case that an investigator is studying a population exposed to two agents, X and Y, where Y is the agent of primary interest. Previous research may suggest that the exposures have different effects on the health outcome of interest, one being more harmful than the other. Such information may be derived from epidemiologic analyses; however, in the case where such evidence is unavailable, knowledge can be drawn from toxicologic studies or other experimental research. Unfortunately, using toxicologic findings to develop informative priors in epidemiologic analyses requires strong assumptions, with no established method for its utilization. We present a method to help bridge the gap between animal and cellular studies and epidemiologic research by specification of an order-constrained prior. We illustrate this approach using an example from radiation epidemiology. PMID:23222512

  4. Experimental methods of molecular matter-wave optics.

    PubMed

    Juffmann, Thomas; Ulbricht, Hendrik; Arndt, Markus

    2013-08-01

    We describe the state of the art in preparing, manipulating and detecting coherent molecular matter. We focus on experimental methods for handling the quantum motion of compound systems from diatomic molecules to clusters or biomolecules.Molecular quantum optics offers many challenges and innovative prospects: already the combination of two atoms into one molecule takes several well-established methods from atomic physics, such as for instance laser cooling, to their limits. The enormous internal complexity that arises when hundreds or thousands of atoms are bound in a single organic molecule, cluster or nanocrystal provides a richness that can only be tackled by combining methods from atomic physics, chemistry, cluster physics, nanotechnology and the life sciences.We review various molecular beam sources and their suitability for matter-wave experiments. We discuss numerous molecular detection schemes and give an overview over diffraction and interference experiments that have already been performed with molecules or clusters.Applications of de Broglie studies with composite systems range from fundamental tests of physics up to quantum-enhanced metrology in physical chemistry, biophysics and the surface sciences.Nanoparticle quantum optics is a growing field, which will intrigue researchers still for many years to come. This review can, therefore, only be a snapshot of a very dynamical process.

  5. An experimental database for evaluating PIV uncertainty quantification methods

    NASA Astrophysics Data System (ADS)

    Warner, Scott; Neal, Douglas; Sciacchitano, Andrea

    2014-11-01

    Uncertainty quantification for particle image velocimetry (PIV) data has recently become a topic of great interest as shown by the publishing of several different methods within the past few years. A unique experiment has been designed to test the efficacy of PIV uncertainty methods, using a rectangular jet as the flow field. The novel aspect of the experimental setup consists of simultaneous measurements by means of two different time-resolved PIV systems and a hot-wire anemometer (HWA). The first PIV system, called the ``PIV-Measurement'' system, collects the data for which uncertainty is to be evaluated. It is based on a single camera and features a dynamic velocity range (DVR) representative of many PIV experiments. The second PIV system, called the ``PIV-HDR'' (high dynamic range) system, has a significantly higher DVR obtained with a higher digital imaging resolution. The hot-wire was placed in close proximity to the PIV measurement domain. All three of the measurement systems were carefully set to simultaneously collect time-resolved data on a point-by-point basis. The HWA validates the PIV-HDR system as the reference velocity so that it can be used to evaluate the instantaneous error in the PIV-measurement system.

  6. Theoretical and experimental investigation of multispectral photoacoustic osteoporosis detection method

    NASA Astrophysics Data System (ADS)

    Steinberg, Idan; Hershkovich, Hadas Sara; Gannot, Israel; Eyal, Avishay

    2014-03-01

    Osteoporosis is a widespread disorder, which has a catastrophic impact on patients lives and overwhelming related to healthcare costs. Recently, we proposed a multispectral photoacoustic technique for early detection of osteoporosis. Such technique has great advantages over pure ultrasonic or optical methods as it allows the deduction of both bone functionality from the bone absorption spectrum and bone resistance to fracture from the characteristics of the ultrasound propagation. We demonstrated the propagation of multiple acoustic modes in animal bones in-vitro. To further investigate the effects of multiple wavelength excitations and of induced osteoporosis on the PA signal a multispectral photoacoustic system is presented. The experimental investigation is based on measuring the interference of multiple acoustic modes. The performance of the system is evaluated and a simple two mode theoretical model is fitted to the measured phase signals. The results show that such PA technique is accurate and repeatable. Then a multiple wavelength excitation is tested. It is shown that the PA response due to different excitation wavelengths revels that absorption by the different bone constitutes has a profound effect on the mode generation. The PA response is measured in single wavelength before and after induced osteoporosis. Results show that induced osteoporosis alters the measured amplitude and phase in a consistent manner which allows the detection of the onset of osteoporosis. These results suggest that a complete characterization of the bone over a region of both acoustic and optical frequencies might be used as a powerful tool for in-vivo bone evaluation.

  7. Dendrite growth under forced convection: analysis methods and experimental tests

    NASA Astrophysics Data System (ADS)

    Alexandrov, D. V.; Galenko, P. K.

    2014-08-01

    An analysis is given of the nonisothermal growth of a dendrite crystal under forced fluid flow in a binary system. The theoretical model utilized employs a free moving crystal-liquid interface and makes use of the Oseen approximation for the equations of motion of the liquid. A criterion for the stable growth of two-dimensional and three-dimensional parabolic dendrites is derived under the assumption of an anisotropic surface tension at the crystal-liquid interface, which generalizes the previous known results for the stable growth of a dendrite with convection in a one-component fluid and for the growth of a dendrite in a two-component system at rest. The criterion obtained within the Oseen hydrodynamic approximation is extended to arbitrary Peclet numbers and dendrite growth with convection in a nonisothermal multicomponent system. Model predictions are compared with experimental data on crystal growth kinetics in droplets processed in electromagnetic and electrostatic levitation facilities. Theoretical and simulation methods currently being developed are applied to crystallization processes under earthly and reduced gravity conditions.

  8. Can We Study Intelligence Using the Experimental Method?

    ERIC Educational Resources Information Center

    Eysenck, Hans J.

    1995-01-01

    It is argued that the study of one important aspect of intelligence, creativity, can be furthered by the introduction of causal theories and their experimental study. Purely correlational investigations are a useful beginning, but psychology can only acquire true scientific stature by combining correlational and experimental approaches. (SLD)

  9. Assessing Methods for Generalizing Experimental Impact Estimates to Target Populations

    ERIC Educational Resources Information Center

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

    2016-01-01

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

  10. Leveraging the Experimental Method to Inform Solar Cell Design

    ERIC Educational Resources Information Center

    Rose, Mary Annette; Ribblett, Jason W.; Hershberger, Heather Nicole

    2010-01-01

    In this article, the underlying logic of experimentation is exemplified within the context of a photoelectrical experiment for students taking a high school engineering, technology, or chemistry class. Students assume the role of photochemists as they plan, fabricate, and experiment with a solar cell made of copper and an aqueous solution of…

  11. Quasi-Experimental Analysis: A Mixture of Methods and Judgment.

    ERIC Educational Resources Information Center

    Cordray, David S.

    1986-01-01

    The role of human judgment in the development and synthesis of evidence has not been adequately developed or acknowledged within quasi-experimental analysis. Corrective solutions need to confront the fact that causal analysis within complex environments will require a more active assessment that entails reasoning and statistical modeling.…

  12. Experimental methods of determining thermal properties of granite

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Determination of thermal properties of granite using the block method is discussed and compared with other methods. Problems that limit the accuracy of contact method in determining thermal properties of porous media are evaluated. Thermal properties of granite is determined in the laboratory with a...

  13. Sphericity measurements by the radial method: II. Experimental verification

    NASA Astrophysics Data System (ADS)

    Janecki, D.; Stępień, K.; Adamczak, S.

    2016-01-01

    The new concept of sphericity measurements enables accurate measurement of spherical elements. This concept assumes that measurements can be performed using a typical radial roundness measuring instrument equipped with a special mechanism for controlled positioning of a measured element. The concept requires solving numerous theoretical problems, and this was described in the previous companion paper. This second paper discusses the measuring equipment and the results of the experimental verification of the concept.

  14. Experimental method for the purification and reconditioning of ferrofluids

    NASA Astrophysics Data System (ADS)

    Cotae, Constantin

    1987-03-01

    The paper presents the theoretical aspects regarding the magnetogravimetric purification of ferrofluids both in the process of preparation and for their reconditioning from impurities. An experimental device used for magnetogravimetric purification is described together with experiments on some samples of oil-based ferrofluid that became impure with non-mixible solid, liquid, magnetic and nonmagnetic ingredients. The experiments resulted in a complete purification of the ferrofluid samples.

  15. Method for experimental determination of flutter speed by parameter identification

    NASA Technical Reports Server (NTRS)

    Nissim, E.; Gilyard, Glenn B.

    1989-01-01

    A method for flight flutter testing is proposed which enables one to determine the flutter dynamic pressure from flights flown far below the flutter dynamic pressure. The method is based on the identification of the coefficients of the equations of motion at low dynamic pressures, followed by the solution of these equations to compute the flutter dynamic pressure. The initial results of simulated data reported in the present work indicate that the method can accurately predict the flutter dynamic pressure, as described. If no insurmountable difficulties arise in the implementation of this method, it may significantly improve the procedures for flight flutter testing.

  16. Experimental Investigation of the Momentum Method for Determining Profile Drag

    NASA Technical Reports Server (NTRS)

    Goett, Harry J

    1939-01-01

    Report presents the results of an experimental investigation conducted in the full-scale tunnel to determine the accuracy of the Jones and the Betz equations for computing profile drag from total and static pressure surveys in the wake of wings. Surveys were made behind 6 by 8-foot airfoils of the NACA 0009, and 0018 sections at zero lift and behind the NACA 0012 at positive lifts. The surveys were made at various spanwise positions and at distances behind the airfoil ranging from 0.05c to 3.00c.

  17. Experimental verification of a recursive method to calculate evapotranspiration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recently, a recursive combination method (RCM) to calculate potential and crop evapotranspiration (ET) was given by Lascano and Van Bavel (Agron. J. 2007, 99:585–590). The RCM differs from the Penman-Monteith (PM) method, the main difference being that the assumptions made regarding the temperature ...

  18. Experimental Methods in Reduced-gravity Soldering Research

    NASA Technical Reports Server (NTRS)

    Pettegrew, Richard D.; Struk, Peter M.; Watson, John K.; Haylett, Daniel R.

    2002-01-01

    The National Center for Microgravity Research, NASA Glenn Research Center, and NASA Johnson Space Center are conducting an experimental program to explore the influence of reduced gravity environments on the soldering process. An improved understanding of the effects of the acceleration environment is important to application of soldering during current and future human space missions. Solder joint characteristics that are being considered include solder fillet geometry, porosity, and microstructural features. Both through-hole and surface mounted devices are being investigated. This paper focuses on the experimental methodology employed in this project and the results of macroscopic sample examination. The specific soldering process, sample configurations, materials, and equipment were selected to be consistent with those currently on-orbit. Other apparatus was incorporated to meet requirements imposed by operation onboard NASA's KC-135 research aircraft and instrumentation was provided to monitor both the atmospheric and acceleration environments. The contingent of test operators was selected to include both highly skilled technicians and less skilled individuals to provide a population cross-section that would be representative of the skill mix that might be encountered in space mission crews.

  19. Theoretical and Experimental Research of Error of Method of Thermocouple with Controlled Profile of Temperature Field

    NASA Astrophysics Data System (ADS)

    Jun, Su; Kochan, O.; Chunzhi, Wang; Kochan, R.

    2015-12-01

    The method of study and experimental researches of the error of method of the thermocouple with controlled profile of temperature field along the main thermocouple are considered in this paper. Experimentally determined values of error of method are compared to the theoretical estimations done using Newton's law of cooling. They converge well.

  20. The Keyword Method of Vocabulary Acquisition: An Experimental Evaluation.

    ERIC Educational Resources Information Center

    Griffith, Douglas

    The keyword method of vocabulary acquisition is a two-step mnemonic technique for learning vocabulary terms. The first step, the acoustic link, generates a keyword based on the sound of the foreign word. The second step, the imagery link, ties the keyword to the meaning of the item to be learned, via an interactive visual image or other…

  1. DETECTORS AND EXPERIMENTAL METHODS: BESIII track fitting algorithm

    NASA Astrophysics Data System (ADS)

    Wang, Ji-Ke; Mao, Ze-Pu; Bian, Jian-Ming; Cao, Guo-Fu; Cao, Xue-Xiang; Chen, Shen-Jian; Deng, Zi-Yan; Fu, Cheng-Dong; Gao, Yuan-Ning; He, Kang-Lin; He, Miao; Hua, Chun-Fei; Huang, Bin; Huang, Xing-Tao; Ji, Xiao-Bin; Li, Fei; Li, Bai-Bo; Li, Wei-Dong; Liang, Yu-Tie; Liu, Chun-Xiu; Liu, Huai-Min; Liu, Suo; Liu, Ying-Jie; Ma, Qiu-Mei; Ma, Xiang; Mao, Ya-Jun; Mo, Xiao-Hu; Pan, Ming-Hua; Pang, Cai-Ying; Ping, Rong-Gang; Qin, Ya-Hong; Qiu, Jin-Fa; Sun, Sheng-Sen; Sun, Yong-Zhao; Wang, Liang-Liang; Wen, Shuo-Pin; Wu, Ling-Hui; Xie, Yu-Guang; Xu, Min; Yan, Liang; You, Zheng-Yun; Yuan, Chang-Zheng; Yuan, Ye; Zhang, Bing-Yun; Zhang, Chang-Chun; Zhang, Jian-Yong; Zhang, Xue-Yao; Zhang, Yao; Zheng, Yang-Heng; Zhu, Ke-Jun; Zhu, Yong-Sheng; Zhu, Zhi-Li; Zou, Jia-Heng

    2009-10-01

    A track fitting algorithm based on the Kalman filter method has been developed for BESIII of BEPCII. The effects of multiple scattering and energy loss when the charged particles go through the detector, non-uniformity of magnetic field (NUMF) and wire sag, etc., have been carefully handled. This algorithm works well and the performance satisfies the physical requirements tested by the simulation data.

  2. An entrepreneurial physics method and its experimental test

    NASA Astrophysics Data System (ADS)

    Brown, Robert

    2012-02-01

    As faculty in a master's program for entrepreneurial physics and in an applied physics PhD program, I have advised upwards of 40 master and doctoral theses in industrial physics. I have been closely involved with four robust start-up manufacturing companies focused on physics high-technology and I have spent 30 years collaborating with industrial physicists on research and development. Thus I am in a position to reflect on many articles and advice columns centered on entrepreneurship. What about the goals, strategies, resources, skills, and the 10,000 hours needed to be an entrepreneur? What about business plans, partners, financing, patents, networking, salesmanship and regulatory affairs? What about learning new technology, how to solve problems and, in fact, learning innovation itself? At this point, I have my own method to propose to physicists in academia for incorporating entrepreneurship into their research lives. With this method, we do not start with a major invention or discovery, or even with a search for one. The method is based on the training we have, and the teaching we do (even quantum electrodynamics!), as physicists. It is based on the networking we build by 1) providing courses of continuing education for people working in industry and 2) through our undergraduate as well as graduate students who have gone on to work in industry. In fact, if we were to be limited to two words to describe the method, they are ``former students.'' Data from local and international medical imaging manufacturing industry are presented.

  3. Experimental analysis of methods for measuring small mammal populations

    USGS Publications Warehouse

    Stickel, L.F.

    1946-01-01

    SUMMARY: The Peromyscus leucopus on a 17-acre study area were live-trapped, marked, and released over a seven-day period. On the three following nights intensive snap-trapping was done on the central acre of the study plot. The animals caught by snap traps in the central acre represented the population of the central acre and several surrounding acres. By the currently accepted methods of interpreting snap-trap data, the population per acre would be considered to be 23 adults. The live-trap data show that the true population was between six and seven adults per acre. Modern methods of live-trapping are shown to be valid for population studies. Two methods are presented for the conversion of live-trap data into per acre figures. Errors involved in the current use of snap-trap data are discussed and snap-trap methods are shown to be invalid for determining actual population numbers. It should be practical to use a snap-trap quadrant technique to obtain a relative measure or index figure for small mammal populations.

  4. An Experimental Method for the Active Learning of Greedy Algorithms

    ERIC Educational Resources Information Center

    Velazquez-Iturbide, J. Angel

    2013-01-01

    Greedy algorithms constitute an apparently simple algorithm design technique, but its learning goals are not simple to achieve.We present a didacticmethod aimed at promoting active learning of greedy algorithms. The method is focused on the concept of selection function, and is based on explicit learning goals. It mainly consists of an…

  5. Interleaved Carbon Minibeams: An Experimental Radiosurgery Method With Clinical Potential

    SciTech Connect

    Dilmanian, F. Avraham; Rusek, Adam; Fois, Giovanna R.; Olschowka, John; Desnoyers, Nicolle R.; Park, Jane Y.; Dioszegi, Istvan; Dane, Bari; Wang Ruiliang; Tomasi, Dardo; Lee, Hedok; Hurley, Sean D.; Coyle, Patricia K.; Meek, Allen G.; O'Banion, M. Kerry

    2012-10-01

    Purpose: To evaluate the efficacy of 'interleaved carbon minibeams' for ablating a 6.5-mm target in a rabbit brain with little damage to the surrounding brain. The method is based on the well-established tissue-sparing effect of arrays of thin planes of radiation. Methods and Materials: Broad carbon beams from the National Aeronautics and Space Agency Space Radiation Facility at Brookhaven National Laboratory were segmented into arrays of parallel, horizontal, 0.3-mm-thick planar beams (minibeams). The minibeams' gradual broadening in tissues resulted in 0.525-mm beam thickness at the target's proximal side in the spread-out Bragg peak. Interleaving was therefore implemented by choosing a 1.05 mm beam spacing on-center. The anesthetized rabbit, positioned vertically on a stage capable of rotating about a vertical axis, was exposed to arrays from four 90 Degree-Sign angles, with the stage moving up by 0.525 mm in between. This produced a solid radiation field at the target while exposing the nontargeted tissues to single minibeam arrays. The target 'physical' absorbed dose was 40.2 Gy. Results: The rabbit behaved normally during the 6-month observation period. Contrast magnetic resonance imaging and hematoxylin and eosin histology at 6 months showed substantial focal target damage with little damage to the surrounding brain. Conclusion: We plan to evaluate the method's therapeutic efficacy by comparing it with broad-beam carbon therapy in animal models. The method's merits would combine those of carbon therapy (i.e., tight target dose because of the carbon's Bragg-peak, sharp dose falloff, and high relative biological effectiveness at the target), together with the method's low impact on the nontargeted tissues. The method's smaller impact on the nontargeted brain might allow carbon therapy at higher target doses and/or lower normal tissue impact, thus leading to a more effective treatment of radioresistant tumors. It should also make the method more amenable to

  6. Prediction of skin sensitizers using alternative methods to animal experimentation.

    PubMed

    Johansson, Henrik; Lindstedt, Malin

    2014-07-01

    Regulatory frameworks within the European Union demand that chemical substances are investigated for their ability to induce sensitization, an adverse health effect caused by the human immune system in response to chemical exposure. A recent ban on the use of animal tests within the cosmetics industry has led to an urgent need for alternative animal-free test methods that can be used for assessment of chemical sensitizers. To date, no such alternative assay has yet completed formal validation. However, a number of assays are in development and the understanding of the biological mechanisms of chemical sensitization has greatly increased during the last decade. In this MiniReview, we aim to summarize and give our view on the recent progress of method development for alternative assessment of chemical sensitizers. We propose that integrated testing strategies should comprise complementary assays, providing measurements of a wide range of mechanistic events, to perform well-educated risk assessments based on weight of evidence. PMID:24548737

  7. Prediction of skin sensitizers using alternative methods to animal experimentation.

    PubMed

    Johansson, Henrik; Lindstedt, Malin

    2014-07-01

    Regulatory frameworks within the European Union demand that chemical substances are investigated for their ability to induce sensitization, an adverse health effect caused by the human immune system in response to chemical exposure. A recent ban on the use of animal tests within the cosmetics industry has led to an urgent need for alternative animal-free test methods that can be used for assessment of chemical sensitizers. To date, no such alternative assay has yet completed formal validation. However, a number of assays are in development and the understanding of the biological mechanisms of chemical sensitization has greatly increased during the last decade. In this MiniReview, we aim to summarize and give our view on the recent progress of method development for alternative assessment of chemical sensitizers. We propose that integrated testing strategies should comprise complementary assays, providing measurements of a wide range of mechanistic events, to perform well-educated risk assessments based on weight of evidence.

  8. An experimental method for the assessment of color simulation tools.

    PubMed

    Lillo, Julio; Alvaro, Leticia; Moreira, Humberto

    2014-07-22

    The Simulcheck method for evaluating the accuracy of color simulation tools in relation to dichromats is described and used to test three color simulation tools: Variantor, Coblis, and Vischeck. A total of 10 dichromats (five protanopes, five deuteranopes) and 10 normal trichromats participated in the current study. Simulcheck includes two psychophysical tasks: the Pseudoachromatic Stimuli Identification task and the Minimum Achromatic Contrast task. The Pseudoachromatic Stimuli Identification task allows determination of the two chromatic angles (h(uv) values) that generate a minimum response in the yellow–blue opponent mechanism and, consequently, pseudoachromatic stimuli (greens or reds). The Minimum Achromatic Contrast task requires the selection of the gray background that produces minimum contrast (near zero change in the achromatic mechanism) for each pseudoachromatic stimulus selected in the previous task (L(R) values). Results showed important differences in the colorimetric transformations performed by the three evaluated simulation tools and their accuracy levels. Vischeck simulation accurately implemented the algorithm of Brettel, Viénot, and Mollon (1997). Only Vischeck appeared accurate (similarity in huv and L(R) values between real and simulated dichromats) and, consequently, could render reliable color selections. It is concluded that Simulcheck is a consistent method because it provided an equivalent pattern of results for huv and L(R) values irrespective of the stimulus set used to evaluate a simulation tool. Simulcheck was also considered valid because real dichromats provided expected huv and LR values when performing the two psychophysical tasks included in this method.

  9. Comparison of methods for evaluation of experimentally induced emphysema

    SciTech Connect

    Busch, R.H.; Buschbom, R.L.; Smith, L.G.

    1984-04-01

    Four methods to quantify induced emphysema, in a manner economically applicable to large numbers of animals, are compared by correlation analyses. Lung tissue used was from rats pretreated intratracheally with elastase or saline prior to exposure to air or (NH/sub 4/)/sub 2/SO/sub 4/ or NH/sub 4/NO/sub 3/ aerosols. The most sensitive quantitative evaluation was from mean chord length (MCL) measurements on scanning electron micrographs (SEM). Four-corner and parallel-line grids provided similar results, and reducing sample size to one selected field per lobe yielded a high degree of reliability for MCL measurements. Alveolar-pore perimeter and area (also measured on SEM photographs) were increased by induced emphysema, but were not reliable indicators for degree of pulmonary involvement. Both subjective score (grading the degree of emphysema) and percentage-area-affected determinations indicated the presence of emphysema, but with less sensitivity than MCL measurements. However, these two subgross methods (performed with a dissecting microscope) provided valuable information on the distribution of pulmonary lesions; emphysema was induced in a nonuniform but consistent and progressive pattern in the two lobes of the lung studied. 23 studied.

  10. Superconducting microstrip antennas: An experimental comparison of two feeding methods

    SciTech Connect

    Richard, M.A.; Claspy, P.C. ); Bhasin, K.B. . Lewis Research Center)

    1993-07-01

    The recent discovery of high-temperature superconductors (HTS's) has generated a substantial amount of interest in microstrip antenna applications. However, the high permittivity of substrates compatible with HTS causes difficulty in feeding such antennas because of the high patch edge impedance. In this paper, two methods for feeding HTS microstrip antennas at K and Ka-band are examined. Superconducting microstrip antennas that are directly coupled and gap-coupled to a microstrip transmission line have been designed and fabricated on lanthanum aluminate substrates using Y-Ba-Cu-O superconducting thin films. Measurements from these antennas, including input impedance, bandwidth, efficiency, and patterns, are presented and compared with published models. The measured results demonstrate that usable antennas can be constructed using either of these architectures, although the antennas suffer from narrow bandwidths. In each case, the HTS antenna shows a substantial improvement over an identical antenna made with normal metals.

  11. Superconducting microstrip antennas - An experimental comparison of two feeding methods

    NASA Technical Reports Server (NTRS)

    Richard, M. A.; Bhasin, Kul B.; Claspy, Paul C.

    1993-01-01

    The recent discovery of high-temperature superconductors (HTSs) has generated a substantial amount of interest in microstrip antenna applications. However, the high permittivity of substrates compatible with HTS causes difficulty in feeding such antennas because of the high patch edge impedance. Two methods for feeding HTS microstrip antennas at K- and Ka-band are examined. Superconducting microstrip antennas that are directly coupled and gap-coupled to a microstrip transmission line have been designed and fabricated on lanthanum aluminate substrates using Y-Ba-Cu-O superconducting thin films. Measurements from these antennas, including input impedance, bandwidth, efficiency, and patterns, are presented and compared with published models. The measured results demonstrate that usable antennas can be constructed using either of these architectures, although the antennas suffer from narrow bandwidths. In each case, the HTS antenna shows a substantial improvement over an identical antenna made with normal metals.

  12. Superconducting Microstrip Antennas: An Experimental Comparison of Two Feeding Methods

    NASA Technical Reports Server (NTRS)

    Richard, Mark A.; Claspy, Paul C.; Bhasin, Kul B.

    1993-01-01

    The recent discovery of high-temperature superconductors (HTSs) has generated a substantial amount of interest in microstrip antenna applications. However, the high permittivity of substrates compatible with HTS causes difficulty in feeding such antennas because of the high patch edge impedance. Two methods for feeding HTS microstrip antennas at K- and Ka-band are examined. Superconducting microstrip antennas that are directly coupled and gas-coupled to a microstrip transmission line have been designed and fabricated on lanthanum aluminate substrates using Y-Ba-Cu-O superconducting thin films. Measurements from these antennas, including input impedance, bandwidth, efficiency, and patterns, are presented and compared with published models. The measured results demonstrate that usable antennas can be constructed using either of these architectures, although the antennas suffer from narrow bandwidths. In each case, the HTS antenna shows a substantial improvement over an identical antenna made with normal metals

  13. Experimental Validation for Hot Stamping Process by Using Taguchi Method

    NASA Astrophysics Data System (ADS)

    Fawzi Zamri, Mohd; Lim, Syh Kai; Razlan Yusoff, Ahmad

    2016-02-01

    Due to the demand for reduction in gas emissions, energy saving and producing safer vehicles has driven the development of Ultra High Strength Steel (UHSS) material. To strengthen UHSS material such as boron steel, it needed to undergo a process of hot stamping for heating at certain temperature and time. In this paper, Taguchi method is applied to determine the appropriate parameter of thickness, heating temperature and heating time to achieve optimum strength of boron steel. The experiment is conducted by using flat square shape of hot stamping tool with tensile dog bone as a blank product. Then, the value of tensile strength and hardness is measured as response. The results showed that the lower thickness, higher heating temperature and heating time give the higher strength and hardness for the final product. In conclusion, boron steel blank are able to achieve up to 1200 MPa tensile strength and 650 HV of hardness.

  14. Translocations of amphibians: Proven management method or experimental technique

    USGS Publications Warehouse

    Seigel, Richard A.; Dodd, C. Kenneth

    2002-01-01

    In an otherwise excellent review of metapopulation dynamics in amphibians, Marsh and Trenham (2001) make the following provocative statements (emphasis added): If isolation effects occur primarily in highly disturbed habitats, species translocations may be necessary to promote local and regional population persistence. Because most amphibians lack parental care, they areprime candidates for egg and larval translocations. Indeed, translocations have already proven successful for several species of amphibians. Where populations are severely isolated, translocations into extinct subpopulations may be the best strategy to promote regional population persistence. We take issue with these statements for a number of reasons. First, the authors fail to cite much of the relevant literature on species translocations in general and for amphibians in particular. Second, to those unfamiliar with current research in amphibian conservation biology, these comments might suggest that translocations are a proven management method. This is not the case, at least in most instances where translocations have been evaluated for an appropriate period of time. Finally, the authors fail to point out some of the negative aspects of species translocation as a management method. We realize that Marsh and Trenham's paper was not concerned primarily with translocations. However, because Marsh and Trenham (2001) made specific recommendations for conservation planners and managers (many of whom are not herpetologists or may not be familiar with the pertinent literature on amphibians), we believe that it is essential to point out that not all amphibian biologists are as comfortable with translocations as these authors appear to be. We especially urge caution about advocating potentially unproven techniques without a thorough review of available options.

  15. Teaching Experimental Method Using the Feature-Present/Feature-Absent Effect

    ERIC Educational Resources Information Center

    Balch, William R.

    2010-01-01

    To determine whether a classroom experiment improved the learning of experimental method, at the start of the semester 2 introductory psychology classes took a 10-question multiple-choice pretest on experimental method. Two days later, before the instructor covered the relevant material in the course, 1 class took part in a classroom experiment on…

  16. Topics on Test Methods for Space Systems and Operations Safety: Applicability of Experimental Data

    NASA Technical Reports Server (NTRS)

    Hirsch, David B.

    2009-01-01

    This viewgraph presentation reviews topics on test methods for space systems and operations safety through experimentation and analysis. The contents include: 1) Perception of reality through experimentation and analysis; 2) Measurements, methods, and correlations with real life; and 3) Correlating laboratory aerospace materials flammability data with data in spacecraft environments.

  17. The agencies method for coalition formation in experimental games

    PubMed Central

    Nash, John F.; Nagel, Rosemarie; Ockenfels, Axel; Selten, Reinhard

    2012-01-01

    In society, power is often transferred to another person or group. A previous work studied the evolution of cooperation among robot players through a coalition formation game with a non-cooperative procedure of acceptance of an agency of another player. Motivated by this previous work, we conduct a laboratory experiment on finitely repeated three-person coalition formation games. Human players with different strength according to the coalition payoffs can accept a transfer of power to another player, the agent, who then distributes the coalition payoffs. We find that the agencies method for coalition formation is quite successful in promoting efficiency. However, the agent faces a tension between short-term incentives of not equally distributing the coalition payoff and the long-term concern to keep cooperation going. In a given round, the strong player in our experiment often resolves this tension approximately in line with the Shapley value and the nucleolus. Yet aggregated over all rounds, the payoff differences between players are rather small, and the equal division of payoffs predicts about 80% of all groups best. One reason is that the voting procedure appears to induce a balance of power, independent of the individual player's strength: Selfish subjects tend to be voted out of their agency and are further disciplined by reciprocal behaviors. PMID:23175792

  18. Experimental study of ? RF plasma jet by optical methods

    NASA Astrophysics Data System (ADS)

    DeBenedictis, S.; Dilecce, G.; Simek, M.; Vigliotti, M.

    1998-11-01

    An 0963-0252/7/4/013/img9 jet stream expanding from a radio-frequency discharge has been investigated by optical emission spectroscopy. The axial and lateral profiles of the expansion glow and the jet axial velocity have been measured by optical methods in order to infer the fluid-dynamic properties of the jet. The position of the shock wave is located at about 5 mm from the nozzle, and the stream velocity achieves a maximum of about 2 Mach in the supersonic region. Optical titration of N atoms and the analysis of emitting excited species 0963-0252/7/4/013/img10 and 0963-0252/7/4/013/img11) have been carried out to monitor the active species in the jet stream and their energy content. The titration of N atoms by NO, injected in the subsonic region, monitored by 0963-0252/7/4/013/img9 first positive 0963-0252/7/4/013/img13 band, 0963-0252/7/4/013/img14 NO 0963-0252/7/4/013/img15 and 0963-0252/7/4/013/img16 continuum emissions, has been examined. This latter emission has been found to give a reasonable estimation of the N density, which is in the range of about (0.1-0.2)% 0963-0252/7/4/013/img9 for a discharge power varying from 50 to 80 W. The 0963-0252/7/4/013/img9 first positive emission, NO 0963-0252/7/4/013/img15 and 0963-0252/7/4/013/img20 bands, instead, are largely affected by the presence of the 0963-0252/7/4/013/img21 metastable and by the high velocity of the N stream. The analysis of 0963-0252/7/4/013/img22 and 0963-0252/7/4/013/img11 vibrational distributions shows the presence of a significant density of the 0963-0252/7/4/013/img21 metastable as well as a non-negligible presence in the expansion of hot electrons. A quasi-one-dimensional fluid-dynamic model of the expansion gives a rough account of the measured location of the shock wave and of the velocity and temperature axial profiles.

  19. Scaffolded Instruction Improves Student Understanding of the Scientific Method & Experimental Design

    ERIC Educational Resources Information Center

    D'Costa, Allison R.; Schlueter, Mark A.

    2013-01-01

    Implementation of a guided-inquiry lab in introductory biology classes, along with scaffolded instruction, improved students' understanding of the scientific method, their ability to design an experiment, and their identification of experimental variables. Pre- and postassessments from experimental versus control sections over three semesters…

  20. Applying computational methods to interpret experimental results in tribology and enantioselective catalysis

    NASA Astrophysics Data System (ADS)

    Garvey, Michael T.

    Computational methods are rapidly becoming a mainstay in the field of chemistry. Advances in computational methods (both theory and implementation), increasing availability of computational resources and the advancement of parallel computing are some of the major forces driving this trend. It is now possible to perform density functional theory (DFT) calculations with chemical accuracy for model systems that can be interrogated experimentally. This allows computational methods to supplement or complement experimental methods. There are even cases where DFT calculations can give insight into processes and interactions that cannot be interrogated directly by current experimental methods. This work presents several examples of the application of computational methods to the interpretation and analysis of experimentally obtained results. First, triobological systems were investigated primarily with full-potential linearized augmented plane wave (FLAPW) method DFT calculations. Second, small organic molecules adsorbed on Pd(111) were studied using projector-augmented wave (PAW) method DFT calculations and scanning tunneling microscopy (STM) image simulations to investigate molecular interactions involved in enantioselective heterogeneous catalysis. A method for method for calculating pressure-dependent shear properties of model boundary-layer lubricants is demonstrated. The calculated values are compared with experimentally obtained results. For the case of methyl pyruvate adsorbed on Pd(111), DFT-calculated adsorption energies and structures are used along with STM simulations to identify species observed by STM imaging. A previously unobserved enol species is discovered to be present along with the expected keto species. The information about methyl pyruvate species on Pd(111) is combined with previously published studies of S-alpha-(1-naphthyl)-ethylamine (NEA) to understand the nature of their interaction upon coadsorption on Pd(111). DFT calculated structures and

  1. a Comparative Study of Vibrating Loaded Plates Between the Rayleigh-Ritz and Experimental Methods

    NASA Astrophysics Data System (ADS)

    Low, K. H.; Chai, G. B.; Tan, G. S.

    1997-01-01

    Natural frequencies of rectangular plates carrying a concentrated mass are obtained by employing a set of trigonometric beam functions in the Rayleigh-Ritz method. Two models of the energy method using one-term and 100-term model are used in the study. Results obtained from the analytical study using the energy method are compared with those measured experimentally. It is found that the 100-term analytical model can generally predict well the experimental frequencies of a plate carrying an arbitrarily placed concentrated mass, whereas the one-term analytical model is only good for estimating the first-mode frequency of a plate carrying a centrally placed mass.

  2. Experimental method research on transverse flexoelectric response of poly(vinylidene fluoride)

    NASA Astrophysics Data System (ADS)

    Zhang, Shuwen; Xu, Minglong; Ma, Guoliang; Liang, Xu; Shen, Shengping

    2016-07-01

    Flexoelectricity describes the strain-gradient-induced electric polarization existing in dielectric materials. The coefficient that exists between the strain-gradient and the induced electric polarization defines the flexoelectric coefficient tensor. It is necessary to analyze different experimental methods to evaluate the procedure of measuring the transverse flexoelectric coefficient tensor component. In this work, the transverse flexoelectric coefficient tensor component of poly(vinylidene fluoride) (PVDF) is studied using three different experimental methods and the effects of the mentioned methods are evaluated. The results presented in this work are helpful for the design of experiments of different dielectric materials, including ceramics and polymers on flexoelectricity.

  3. Experimental method for the examination of systematic distortions in lidar data.

    PubMed

    Kovalev, Vladimir A; Hao, Wei Min; Wold, Cyle; Adam, Mariana

    2007-09-20

    An experimental method for determining the presence and the level of systematic distortions in lidar data is considered. The method has been developed on the basis of two years of field experiments with the Fire Sciences Laboratory elastic scanning lidar. The influence of multiplicative and additive distortion components is considered using numerical experiments and is illustrated with experimental data. The examination method is most applicable for short wavelengths at which the atmospheric molecular component in clear atmospheres is large enough to stabilize the Kano-Hamilton multiangle solution, based on the assumption of horizontal atmospheric homogeneity. PMID:17882291

  4. Choices for Studying Choice: Assessing Charter School Effectiveness Using Two Quasi-Experimental Methods

    ERIC Educational Resources Information Center

    Davis, Devora H.; Raymond, Margaret E.

    2012-01-01

    Two quasi-experimental methods--fixed effects (FE) and virtual control records (VCR)--were used to measure charter schooling in 14 states and two districts. The new VCR method uses all available observable charter student characteristics and prior performance to create a composite comparison record. A head-to-head comparison of the FE and VCR…

  5. Limits and conditions of applicability of the experimental measurement methods of liquid flow rates through pipes

    NASA Astrophysics Data System (ADS)

    Botezatu, N. P.

    1980-04-01

    Various flow measurement methods and their applications are reviewed in order to establish the best methods for rationalization and optimization of water consumption in a large industrial system. The methods discussed include volumetric and gravimetric techniques, Pitot and Venturi tubes, electromagnetic and ultrasonic flowmeters, counters, rotameters, and anemometers, as well as the use of classical and radioactive tracers. A comparative analysis of various methods and experimental results indicate that the method of radioactive tracers is the only universal method of measurement of fluid flows through pipes and channels for fluids of any physicochemical properties under any conditions.

  6. Prediction of sonic boom from experimental near-field overpressure data. Volume 1: Method and results

    NASA Technical Reports Server (NTRS)

    Glatt, C. R.; Hague, D. S.; Reiners, S. J.

    1975-01-01

    A computerized procedure for predicting sonic boom from experimental near-field overpressure data has been developed. The procedure extrapolates near-field pressure signatures for a specified flight condition to the ground by the Thomas method. Near-field pressure signatures are interpolated from a data base of experimental pressure signatures. The program is an independently operated ODIN (Optimal Design Integration) program which obtains flight path information from other ODIN programs or from input.

  7. Experimental parameter estimation method for nonlinear viscoelastic composite material models: an application on arterial tissue.

    PubMed

    Sunbuloglu, Emin; Bozdag, Ergun; Toprak, Tuncer; Islak, Civan

    2013-01-01

    This study is aimed at setting a method of experimental parameter estimation for large-deforming nonlinear viscoelastic continuous fibre-reinforced composite material model. Specifically, arterial tissue was investigated during experimental research and parameter estimation studies, due to medical, scientific and socio-economic importance of soft tissue research. Using analytical formulations for specimens under combined inflation/extension/torsion on thick-walled cylindrical tubes, in vitro experiments were carried out with fresh sheep arterial segments, and parameter estimation procedures were carried out on experimental data. Model restrictions were pointed out using outcomes from parameter estimation. Needs for further studies that can be developed are discussed.

  8. A comparison of different experimental methods for general recombination correction for liquid ionization chambers.

    PubMed

    Andersson, Jonas; Kaiser, Franz-Joachim; Gómez, Faustino; Jäkel, Oliver; Pardo-Montero, Juan; Tölli, Heikki

    2012-11-01

    Radiation dosimetry of highly modulated dose distributions requires a detector with a high spatial resolution. Liquid filled ionization chambers (LICs) have the potential to become a valuable tool for the characterization of such radiation fields. However, the effect of an increased recombination of the charge carriers, as compared to using air as the sensitive medium has to be corrected for. Due to the presence of initial recombination in LICs, the correction for general recombination losses is more complicated than for air-filled ionization chambers. In the present work, recently published experimental methods for general recombination correction for LICs are compared and investigated for both pulsed and continuous beams. The experimental methods are all based on one of two approaches: either measurements at two different dose rates (two-dose-rate methods), or measurements at three different LIC polarizing voltages (three-voltage methods). In a comparison with the two-dose-rate methods, the three-voltage methods fail to achieve accurate corrections in several instances, predominantly at low polarizing voltages and dose rates. However, for continuous beams in the range of polarizing voltages recommended by the manufacturer of the LICs used, the agreement between the different methods is generally within the experimental uncertainties. For pulsed beams, the agreement between the methods is poor. The inaccuracies found in the results from the three-voltage methods are associated with numerical difficulties in solving the resulting equation systems, which also make these methods sensitive to small variations in the experimental data. These issues are more pronounced for the case of pulsed beams. Furthermore, the results suggest that the theoretical modelling of initial recombination used in the three-voltage methods may be a contributing factor to the deviating results observed.

  9. Comparison between experimental and computational methods for scattering anisotropy coefficient determination in dental-resin composites

    NASA Astrophysics Data System (ADS)

    Fernández-Oliveras, Alicia; Carrasco, Irene M.; Ghinea, Razvan; Pérez, María M.; Rubiño, Manuel

    2012-06-01

    Understanding the behaviour of light propagation in biological materials is essential for biomedical engineering and its applications. Among the key optical properties of biological media is the angular distribution of the scattered light, characterized by the average cosine of the scattering angle, called the scattering anisotropy coefficient (g). The value of g can be determined by experimentally irradiating the material with a laser beam and making angular-scattering measurements in a goniometer. In this work, an experimental technique was used to determine g by means of goniometric measurements of the laser light scattered off two different dental-resin composites (classified as nano and hybrid). To assess the accuracy of the experimental method, a Mie theory-based computational model was used. Independent measurements were used to determine some of the required input parameters for computation of the theoretical model. The g values estimated with the computational method (nano-filled: 0.9399; hybrid: 0.8975) and the values calculated with the experimental method presented (nano-filled: 0.98297 +/- 0.00021; hybrid: 0.95429 +/- 0.00014) agreed well for both dental resins, with slightly higher experimental values. The higher experimental values may indicate that the scattering particle causes more narrow-angle scattering than does a perfect sphere of equal volume, assuming that with more spherical scattering particles the scattering anisotropy coefficient increases. Since g represents the angular distribution of the scattered light, values provided by both the experimental and the computational methods show a strongly forward-directed scattering in the dental resins studied, more pronounced in the nano-filled composite than in the hybrid composite.

  10. Highly Efficient Design-of-Experiments Methods for Combining CFD Analysis and Experimental Data

    NASA Technical Reports Server (NTRS)

    Anderson, Bernhard H.; Haller, Harold S.

    2009-01-01

    It is the purpose of this study to examine the impact of "highly efficient" Design-of-Experiments (DOE) methods for combining sets of CFD generated analysis data with smaller sets of Experimental test data in order to accurately predict performance results where experimental test data were not obtained. The study examines the impact of micro-ramp flow control on the shock wave boundary layer (SWBL) interaction where a complete paired set of data exist from both CFD analysis and Experimental measurements By combining the complete set of CFD analysis data composed of fifteen (15) cases with a smaller subset of experimental test data containing four/five (4/5) cases, compound data sets (CFD/EXP) were generated which allows the prediction of the complete set of Experimental results No statistical difference were found to exist between the combined (CFD/EXP) generated data sets and the complete Experimental data set composed of fifteen (15) cases. The same optimal micro-ramp configuration was obtained using the (CFD/EXP) generated data as obtained with the complete set of Experimental data, and the DOE response surfaces generated by the two data sets were also not statistically different.

  11. Design and structural verification of locomotive bogies using combined analytical and experimental methods

    NASA Astrophysics Data System (ADS)

    Manea, I.; Popa, G.; Girnita, I.; Prenta, G.

    2015-11-01

    The paper presents a practical methodology for design and structural verification of the locomotive bogie frames using a modern software package for design, structural verification and validation through combined, analytical and experimental methods. In the initial stage, the bogie geometry is imported from a CAD program into a finite element analysis program, such as Ansys. The analytical model validation is done by experimental modal analysis carried out on a finished bogie frame. The bogie frame own frequencies and own modes by both experimental and analytic methods are determined and the correlation analysis of the two types of models is performed. If the results are unsatisfactory, the structural optimization should be performed. If the results are satisfactory, the qualification procedures follow by static and fatigue tests carried out in a laboratory with international accreditation in the field. This paper presents an application made on bogie frames for the LEMA electric locomotive of 6000 kW.

  12. Recent mouse and rat methods for the study of experimental oral candidiasis.

    PubMed

    Costa, Anna C B P; Pereira, Cristiane A; Junqueira, Juliana C; Jorge, Antonio O C

    2013-07-01

    The Candida genus expresses virulence factors that, when combined with immunosuppression and other risk factors, can cause different manifestations of oral candidiasis. The treatment of mucosal infections caused by Candida and the elucidation of the disease process have proven challenging. Therefore, the study of experimentally induced oral candidiasis in rats and mice is useful to clarify the etiopathology of this condition, improve diagnosis, and search for new therapeutic options because the disease process in these animals is similar to that of human candidiasis lesions. Here, we describe and discuss new studies involving rat and mouse models of oral candidiasis with respect to methods for inducing experimental infection, methods for evaluating the development of experimental candidiasis, and new treatment strategies for oral candidiasis.

  13. Experimental method for determination of bending and torsional rigidities of advanced composite laminates

    SciTech Connect

    Maeda, Takenori

    1995-11-01

    This paper presents an experimental method for the determination of the bending and torsional rigidities of advanced fiber composite laminates with the aid of laser holographic interferometry. The proposed method consists of a four-point bending test and a resonance test. The bending rigidity ratio (D{sub 12}/D{sub 22}) can be determined from the fringe patterns of the four-point bending test. The bending rigidities (D{sub 11} and D{sub 22}) and the torsional rigidity (D{sub 66}) are calculated from the natural frequencies of cantilever plates of the resonance test. The test specimens are carbon/epoxy cross-ply laminates. The adequacy of the experimental method is confirmed by comparing the measured rigidities with the theoretical values obtained from classical lamination theory (CLT) by using the measured tensile properties. The results show that the present method can be used to evaluate the rigidities of orthotropic laminates with reasonably good accuracy.

  14. The Use of Techniques of Sensory Evaluation as a Framework for Teaching Experimental Methods.

    ERIC Educational Resources Information Center

    Bennett, R.; Hamilton, M.

    1981-01-01

    Describes sensory assessment techniques and conditions for their satisfactory performance, including how they can provide open-ended exercises and advantages as relatively inexpensive and simple methods of teaching experimentation. Experiments described focus on diffusion of salt into potatoes after being cooked in boiled salted water. (Author/JN)

  15. [A method for choosing preparations that reduce the toxicity of cytostatics in experimental chemotherapy of tumors].

    PubMed

    Zueva, E P; Iaremenko, K V

    1989-01-01

    A special scale is proposed to evaluate the level of toxicity of drugs during experimental chemotherapy of tumours. The method allows to standardize somehow the choice of the drugs reducing the toxic action of cytostatics and also to compare different drugs to choose the most effective correctors of cytostatic therapy. PMID:2707428

  16. Estimation of the drift eliminator efficiency using numerical and experimental methods

    NASA Astrophysics Data System (ADS)

    Stodůlka, Jiří; Vitkovičová, Rut

    2016-03-01

    The purpose of the drift eliminators is to prevent water from escaping in significant amounts the cooling tower. They are designed to catch the droplets dragged by the tower draft and the efficiency given by the shape of the eliminator is the main evaluation criteria. The ability to eliminate the escaping water droplets is studied using CFD and using the experimental IPI method.

  17. Analysis of the water film behavior and its breakup on profile using experimental and numerical methods

    NASA Astrophysics Data System (ADS)

    Muzik, Tomas; Safarik, Pavel; Tucek, Antonín

    2014-08-01

    This paper deals with the description of water film behaviour on the airfoil NACA0012 using experimental and numerical methods. Properties of the water film on the profile and its breakup into droplets behind the profile are investigated in the aerodynamic tunnel and using CFD methods. The characteristic parameters of the water film, like its thickness and shape for different flow modes are described. Hereafter are described droplets drifted by the air, which water film is broken behind the profile.

  18. Theoretical-experimental method of determining the drag coefficient of a harmonically oscillating thin plate

    NASA Astrophysics Data System (ADS)

    Egorov, A. G.; Kamalutdinov, A. M.; Paimushin, V. N.; Firsov, V. A.

    2016-03-01

    A method for determining the drag coefficient of a thin plate harmonically oscillating in a viscous incompressible fluid is proposed. The method is based on measuring the amplitude of deflections of cantilever-fixed thin plates exhibiting damping flexural oscillations with a frequency corresponding to the first mode and on solving an inverse problem of calculating the drag coefficient on the basis of the experimentally found logarithmic decrement of beam oscillations.

  19. An experimental verification of the local circulation method for a horizontal axis wind turbine

    SciTech Connect

    Nasu, K.I.; Azuma, A.

    1983-08-01

    The Local Circulation Method (LCM) was developed by the authors as a useful method for the prediction of rotary wing unsteady aerodynamics. In order to examine empirically the validity of the LCM, an experimental test of horizontal axis wind turbine was conducted in a low speed wind tunnel. The results obtained were compared with the computational results predicted by the LCM. The coverage of this experiment is from static performances to time-varying airloading of the wing in yawed wind.

  20. Bidirectional Connected Control Method Applied to an Experimental Structural Model Split into Four Substructures

    NASA Astrophysics Data System (ADS)

    Watanabe, T.; Seto, K.; Toyoda, H.; Takano, T.

    2016-09-01

    Connected Control Method (CCM) is a well-known mechanism in the field of civil structural vibration control that utilizes mutual reaction forces between plural buildings connected by dampers as damping force. However, the fact that CCM requires at least two buildings to obtain reaction force prevents CCM from further development. In this paper, a novel idea to apply CCM onto a single building by splitting the building into four substructures is presented. An experimental model structure split into four is built and CCM is applied by using four magnetic dampers. Experimental analysis is carried out and basic performance and effectiveness of the presented idea is confirmed.

  1. Experimental Method for Characterizing Electrical Steel Sheets in the Normal Direction

    PubMed Central

    Hihat, Nabil; Lecointe, Jean Philippe; Duchesne, Stephane; Napieralska, Ewa; Belgrand, Thierry

    2010-01-01

    This paper proposes an experimental method to characterise magnetic laminations in the direction normal to the sheet plane. The principle, which is based on a static excitation to avoid planar eddy currents, is explained and specific test benches are proposed. Measurements of the flux density are made with a sensor moving in and out of an air-gap. A simple analytical model is derived in order to determine the permeability in the normal direction. The experimental results for grain oriented steel sheets are presented and a comparison is provided with values obtained from literature. PMID:22163394

  2. Design studies for the transmission simulator method of experimental dynamic substructuring.

    SciTech Connect

    Mayes, Randall Lee; Arviso, Michael

    2010-05-01

    In recent years, a successful method for generating experimental dynamic substructures has been developed using an instrumented fixture, the transmission simulator. The transmission simulator method solves many of the problems associated with experimental substructuring. These solutions effectively address: (1) rotation and moment estimation at connection points; (2) providing substructure Ritz vectors that adequately span the connection motion space; and (3) adequately addressing multiple and continuous attachment locations. However, the transmission simulator method may fail if the transmission simulator is poorly designed. Four areas of the design addressed here are: (1) designating response sensor locations; (2) designating force input locations; (3) physical design of the transmission simulator; and (4) modal test design. In addition to the transmission simulator design investigations, a review of the theory with an example problem is presented.

  3. Method for morphometric analysis of axons in experimental peripheral nerve reconstruction.

    PubMed

    Heijke, G C; Klopper, P J; Baljet, B; Van Doorn, I B; Dutrieux, R P

    2000-01-01

    A new method for morphometric analysis of axons in experimental peripheral nerve reconstruction is presented. Twelve adult female rabbits were used. In nine animals the saphenous nerve was transected and stitched epineurially. Three animals functioned as control. After 3, 6, and 12 months, the nerves were harvested, fixed in Kryofix and embedded in Histowax. Transverse sections of 6 microm were cut, immunohistochemically stained for NF 90, and counterstained by Sirius Red. Quantification of nerve fibers in cross sections was performed by using a confocal laser scanning microscope (CLSM), and the images were stored digitally. Data analyzing was performed by the Optimas program (5.2). Calculations were done with Microsoft Excel. The total number of axons, the mean axon diameter and the percentage axon area/fascicle area were evaluated statistically. This method for morphologic analysis provides automatically complete registration of axons and so different methods of experimental nerve reconstruction can be compared in a fast and reliable way.

  4. Experimental Validation of Methods for Prophylaxis against Deep Venous Thrombosis: A Review and Proposal

    PubMed Central

    Agutter, Paul S.; Malone, P. Colm; Silver, Ian A.

    2012-01-01

    The experimental procedure by which the valve cusp hypoxia (VCH) hypothesis of the etiology of deep venous thrombosis (DVT) was confirmed lends itself to testing of methods of prophylaxis. Similar animal experiments could end the present exclusive reliance on statistical analysis of data from large patient cohorts to evaluate prophylactic regimes. The reduction of need for such (usually retrospective) analyses could enable rationally-based clinical trials of prophylactic methods to be conducted more rapidly, and the success of such trials would lead to decreased incidences of DVT-related mortality and morbidity. This paper reviews the VCH hypothesis (“VCH thesis”, following its corroboration) and its implications for understanding DVT and its sequelae, and outlines the experimental protocol for testing prophylactic methods. The advantages and limitations of the protocol are briefly discussed. PMID:22567254

  5. Experimental Validation of Methods for Prophylaxis against Deep Venous Thrombosis: A Review and Proposal.

    PubMed

    Agutter, Paul S; Malone, P Colm; Silver, Ian A

    2012-01-01

    The experimental procedure by which the valve cusp hypoxia (VCH) hypothesis of the etiology of deep venous thrombosis (DVT) was confirmed lends itself to testing of methods of prophylaxis. Similar animal experiments could end the present exclusive reliance on statistical analysis of data from large patient cohorts to evaluate prophylactic regimes. The reduction of need for such (usually retrospective) analyses could enable rationally-based clinical trials of prophylactic methods to be conducted more rapidly, and the success of such trials would lead to decreased incidences of DVT-related mortality and morbidity. This paper reviews the VCH hypothesis ("VCH thesis", following its corroboration) and its implications for understanding DVT and its sequelae, and outlines the experimental protocol for testing prophylactic methods. The advantages and limitations of the protocol are briefly discussed.

  6. Clinical experimentation with aerosol antibiotics: current and future methods of administration

    PubMed Central

    Zarogoulidis, Paul; Kioumis, Ioannis; Porpodis, Konstantinos; Spyratos, Dionysios; Tsakiridis, Kosmas; Huang, Haidong; Li, Qiang; Turner, J Francis; Browning, Robert; Hohenforst-Schmidt, Wolfgang; Zarogoulidis, Konstantinos

    2013-01-01

    Currently almost all antibiotics are administered by the intravenous route. Since several systems and situations require more efficient methods of administration, investigation and experimentation in drug design has produced local treatment modalities. Administration of antibiotics in aerosol form is one of the treatment methods of increasing interest. As the field of drug nanotechnology grows, new molecules have been produced and combined with aerosol production systems. In the current review, we discuss the efficiency of aerosol antibiotic studies along with aerosol production systems. The different parts of the aerosol antibiotic methodology are presented. Additionally, information regarding the drug molecules used is presented and future applications of this method are discussed. PMID:24115836

  7. Experimental comparison and validation of hot-ball method with guarded hot plate method on polyurethane foams

    NASA Astrophysics Data System (ADS)

    Hudec, Ján; Glorieux, Christ; Dieška, Peter; Kubičár, Ľudovít

    2016-07-01

    The Hot-ball method is an innovative transient method for measuring thermophysical properties. The principle is based on heating of a small ball, incorporated in measured medium, by constant heating power and simultaneous measuring of the ball's temperature response since the heating was initiated. The shape of the temperature response depends on thermophysical properties of the medium, where the sensor is placed. This method is patented by Institute of Physics, SAS, where the method and sensors based on this method are being developed. At the beginning of the development of sensors for this method we were oriented on monitoring applications, where relative precision is much more important than accuracy. Meanwhile, the quality of sensors was improved good enough to be used for a new application - absolute measuring of thermophysical parameters of low thermally conductive materials. This paper describes experimental verification and validation of measurement by hot-ball method. Thanks to cooperation with Laboratory of Soft Matter and Biophysics of Catholic University of Leuven in Belgium, established Guarded Hot Plate method was used as a reference. Details about measuring setups, description of the experiments and results of the comparison are presented.

  8. Impacts of children with troubles on working poor families: mixed-method and experimental evidence.

    PubMed

    Bernheimer, Lucinda P; Weisner, Thomas S; Lowe, Edward D

    2003-12-01

    Mixed-method and experimental data on working poor families and children with troubles participating in the New Hope anti-poverty experimental initiative in Milwaukee are described. Sixty percent of these families had at least one child who had significant problems (learning, school achievement and/or behavior, home behavior, retardation, other disabilities). Control group families with children who had troubles had more difficulties in sustaining their family routine than did New Hope experimental families. In the context of the many other challenges these parents face, adaptation to children with troubles does not stand out as sharply compared to middle-class European American families. There is less family adaptation specifically due to, or in response to, the troubled child, and more adaptation to the struggles of making ends meet.

  9. Experimental validation of normalized uniform load surface curvature method for damage localization.

    PubMed

    Jung, Ho-Yeon; Sung, Seung-Hoon; Jung, Hyung-Jo

    2015-10-16

    In this study, we experimentally validated the normalized uniform load surface (NULS) curvature method, which has been developed recently to assess damage localization in beam-type structures. The normalization technique allows for the accurate assessment of damage localization with greater sensitivity irrespective of the damage location. In this study, damage to a simply supported beam was numerically and experimentally investigated on the basis of the changes in the NULS curvatures, which were estimated from the modal flexibility matrices obtained from the acceleration responses under an ambient excitation. Two damage scenarios were considered for the single damage case as well as the multiple damages case by reducing the bending stiffness (EI) of the affected element(s). Numerical simulations were performed using MATLAB as a preliminary step. During the validation experiments, a series of tests were performed. It was found that the damage locations could be identified successfully without any false-positive or false-negative detections using the proposed method. For comparison, the damage detection performances were compared with those of two other well-known methods based on the modal flexibility matrix, namely, the uniform load surface (ULS) method and the ULS curvature method. It was confirmed that the proposed method is more effective for investigating the damage locations of simply supported beams than the two conventional methods in terms of sensitivity to damage under measurement noise.

  10. An Experimental Comparison of Two Methods on Photosynthesis Driving Soil Respiration: Girdling and Defoliation

    PubMed Central

    Jing, Yanli; Guan, Dexin; Wu, Jiabing; Wang, Anzhi; Jin, Changjie; Yuan, Fenghui

    2015-01-01

    Previous studies with different experimental methods have demonstrated that photosynthesis significantly influences soil respiration (RS). To compare the experimental results of different methods, RS after girdling and defoliation was measured in five-year-old seedlings of Fraxinus mandshurica from June to September. Girdling and defoliation significantly reduced RS by 33% and 25% within 4 days, and 40% and 32% within the entire treatment period, respectively. The differential response of RS to girdling and defoliation was a result of the over-compensation for RS after girdling and redistribution of stored carbon after defoliation. No significant effect on RS was observed between girdling and defoliation treatment, while the soluble sugar content in fine roots was higher in defoliation than in girdling treatment, indicating that defoliation had less compensation effect for RS after interrupting photosynthates supply. We confirm the close coupling of RS with photosynthesis and recommend defoliation for further studies to estimate the effect of photosynthesis on RS. PMID:26177498

  11. DETECTORS AND EXPERIMENTAL METHODS: Decay vertex reconstruction and 3-dimensional lifetime determination at BESIII

    NASA Astrophysics Data System (ADS)

    Xu, Min; He, Kang-Lin; Zhang, Zi-Ping; Wang, Yi-Fang; Bian, Jian-Ming; Cao, Guo-Fu; Cao, Xue-Xiang; Chen, Shen-Jian; Deng, Zi-Yan; Fu, Cheng-Dong; Gao, Yuan-Ning; Han, Lei; Han, Shao-Qing; He, Miao; Hu, Ji-Feng; Hu, Xiao-Wei; Huang, Bin; Huang, Xing-Tao; Jia, Lu-Kui; Ji, Xiao-Bin; Li, Hai-Bo; Li, Wei-Dong; Liang, Yu-Tie; Liu, Chun-Xiu; Liu, Huai-Min; Liu, Ying; Liu, Yong; Luo, Tao; Lü, Qi-Wen; Ma, Qiu-Mei; Ma, Xiang; Mao, Ya-Jun; Mao, Ze-Pu; Mo, Xiao-Hu; Ning, Fei-Peng; Ping, Rong-Gang; Qiu, Jin-Fa; Song, Wen-Bo; Sun, Sheng-Sen; Sun, Xiao-Dong; Sun, Yong-Zhao; Tian, Hao-Lai; Wang, Ji-Ke; Wang, Liang-Liang; Wen, Shuo-Pin; Wu, Ling-Hui; Wu, Zhi; Xie, Yu-Guang; Yan, Jie; Yan, Liang; Yao, Jian; Yuan, Chang-Zheng; Yuan, Ye; Zhang, Chang-Chun; Zhang, Jian-Yong; Zhang, Lei; Zhang, Xue-Yao; Zhang, Yao; Zheng, Yang-Heng; Zhu, Yong-Sheng; Zou, Jia-Heng

    2009-06-01

    This paper focuses mainly on the vertex reconstruction of resonance particles with a relatively long lifetime such as K0S, Λ, as well as on lifetime measurements using a 3-dimensional fit. The kinematic constraints between the production and decay vertices and the decay vertex fitting algorithm based on the least squares method are both presented. Reconstruction efficiencies including experimental resolutions are discussed. The results and systematic errors are calculated based on a Monte Carlo simulation.

  12. Experimental validation of finite element and boundary element methods for predicting structural vibration and radiated noise

    NASA Technical Reports Server (NTRS)

    Seybert, A. F.; Wu, T. W.; Wu, X. F.

    1994-01-01

    This research report is presented in three parts. In the first part, acoustical analyses were performed on modes of vibration of the housing of a transmission of a gear test rig developed by NASA. The modes of vibration of the transmission housing were measured using experimental modal analysis. The boundary element method (BEM) was used to calculate the sound pressure and sound intensity on the surface of the housing and the radiation efficiency of each mode. The radiation efficiency of each of the transmission housing modes was then compared to theoretical results for a finite baffled plate. In the second part, analytical and experimental validation of methods to predict structural vibration and radiated noise are presented. A rectangular box excited by a mechanical shaker was used as a vibrating structure. Combined finite element method (FEM) and boundary element method (BEM) models of the apparatus were used to predict the noise level radiated from the box. The FEM was used to predict the vibration, while the BEM was used to predict the sound intensity and total radiated sound power using surface vibration as the input data. Vibration predicted by the FEM model was validated by experimental modal analysis; noise predicted by the BEM was validated by measurements of sound intensity. Three types of results are presented for the total radiated sound power: sound power predicted by the BEM model using vibration data measured on the surface of the box; sound power predicted by the FEM/BEM model; and sound power measured by an acoustic intensity scan. In the third part, the structure used in part two was modified. A rib was attached to the top plate of the structure. The FEM and BEM were then used to predict structural vibration and radiated noise respectively. The predicted vibration and radiated noise were then validated through experimentation.

  13. Experimental study to explore the 8Be-induced nuclear reaction via the Trojan horse method

    NASA Astrophysics Data System (ADS)

    Wen, Qun-Gang; Li, Cheng-Bo; Zhou, Shu-Hua; Irgaziev, Bakhadir; Fu, Yuan-Yong; Spitaleri, Claudio; La Cognata, Marco; Zhou, Jing; Meng, Qiu-Ying; Lamia, Livio; Lattuada, Marcello

    2016-03-01

    To explore a possible indirect method for 8Be induced astrophysical reactions, the 8Be=(8Be+n ) cluster structure has been studied via the Trojan horse method. For the first time a 8Be nucleus having an ultrashort lifetime is studied by the Trojan horse method and a 9Be nucleus in the ground state is used for this purpose. The 9Be nucleus is assumed to have a (8Be+n ) cluster structure and used as a Trojan horse nucleus. The 8Be nucleus acts as a participant, while the neutron is a spectator to the virtual 8Be+d →α +6Li reaction via the 3-body reaction 8Be+d →α +6Li+n . The experimental neutron momentum distribution inside 9Be has been reconstructed. The agreement between the experimental momentum distribution and the theoretical one indicates that a (8Be+n ) cluster structure inside 9Be is very likely. Therefore, the experimental study of 8Be induced reactions, for example, the measurement of the 8Be+α →12C reaction proceeding through the Hoyle state, is possible.

  14. Control rod heterogeneity effects in liquid-metal fast breeder reactors: Method developments and experimental validation

    SciTech Connect

    Carta, M.; Granget, G.; Palmiotti, G.; Salvatores, M.; Soule, R.

    1988-11-01

    The control rod worth assessment in a large liquid-metal fast breeder reactor is strongly dependent on the actual arrangement of the absorber pins inside the control rod subassemblies. The so-called heterogeneity effects (i.e., the effects on the rod reactivity of the actual rod internal geometry versus homogenization of the absorber atoms over all the subassembly volume) have been evaluated, using explicit and variational methods to derive appropriate cross sections. An experimental program performed at the MASURCA facility has been used to validate these methods.

  15. Experimental investigation of the systematic error on photomechanic methods induced by camera self-heating.

    PubMed

    Ma, Qinwei; Ma, Shaopeng

    2013-03-25

    The systematic error for photomechanic methods caused by self-heating induced image expansion when using a digital camera was systematically studied, and a new physical model to explain the mechanism has been proposed and verified. The experimental results showed that the thermal expansion of the camera outer case and lens mount, instead of mechanical components within the camera, were the main reason for image expansion. The corresponding systematic error for both image analysis and fringe analysis based photomechanic methods were analyzed and measured, then error compensation techniques were proposed and verified.

  16. Experimental Design Optimization of a Sequential Injection Method for Promazine Assay in Bulk and Pharmaceutical Formulations

    PubMed Central

    Idris, Abubakr M.; Assubaie, Fahad N.; Sultan, Salah M.

    2007-01-01

    Experimental design optimization approach was utilized to develop a sequential injection analysis (SIA) method for promazine assay in bulk and pharmaceutical formulations. The method was based on the oxidation of promazine by Ce(IV) in sulfuric acidic media resulting in a spectrophotometrically detectable species at 512 nm. A 33 full factorial design and response surface methods were applied to optimize experimental conditions potentially controlling the analysis. The optimum conditions obtained were 1.0 × 10−4 M sulphuric acid, 0.01 M Ce(IV), and 10 μL/s flow rate. Good analytical parameters were obtained including range of linearity 1–150 μg/mL, linearity with correlation coefficient 0.9997, accuracy with mean recovery 98.2%, repeatability with RSD 1.4% (n = 7 consequent injections), intermediate precision with RSD 2.1% (n = 5 runs over a week), limits of detection 0.34 μg/mL, limits of quantification 0.93 μg/mL, and sampling frequency 23 samples/h. The obtained results were realized by the British Pharmacopoeia method and comparable results were obtained. The provided SIA method enjoys the advantages of the technique with respect to rapidity, reagent/sample saving, and safety in solution handling and to the environment. PMID:18350124

  17. An experimental method for quantitatively evaluating the elemental processes of indoor radioactive aerosol behavior.

    PubMed

    Yamazawa, H; Yamada, S; Xu, Y; Hirao, S; Moriizumi, J

    2015-11-01

    An experimental method for quantitatively evaluating the elemental processes governing the indoor behaviour of naturally occurring radioactive aerosols was proposed. This method utilises transient response of aerosol concentrations to an artificial change in aerosol removal rate by turning on and off an air purifier. It was shown that the indoor-outdoor exchange rate and the indoor deposition rate could be estimated by a continuous measurement of outdoor and indoor aerosol number concentration measurements and by the method proposed in this study. Although the scatter of the estimated parameters is relatively large, both the methods gave consistent results. It was also found that the size distribution of radioactive aerosol particles and hence activity median aerodynamic diameter remained not largely affected by the operation of the air purifier, implying the predominance of the exchange and deposition processes over other processes causing change in the size distribution such as the size growth by coagulation and the size dependence of deposition.

  18. New experimental method for lidar overlap factor using a CCD side-scatter technique.

    PubMed

    Wang, Zhenzhu; Tao, Zongming; Liu, Dong; Wu, Decheng; Xie, Chenbo; Wang, Yingjian

    2015-04-15

    In theory, lidar overlap factor can be derived from the difference between the particle backscatter coefficient retrieved from lidar elastic signal without overlap correction and the actual particle backscatter coefficient, which can be obtained by other measured techniques. The side-scatter technique using a CCD camera is testified to be a powerful tool to detect the particle backscatter coefficient in near ground layer during night time. A new experiment approach to determine the overlap factor for vertically pointing lidar is presented in this study, which can be applied to Mie lidars. The effect of overlap factor on Mie lidar is corrected by an iteration algorithm combining the retrieved particle backscatter coefficient using CCD side-scatter method and Fernald method. This method has been successfully applied to Mie lidar measurements during a routine campaign, and the comparison of experimental results in different atmosphere conditions demonstrated that this method is available in practice.

  19. Experimental validation of the orthogonalised reverse path method using a nonlinear beam

    NASA Astrophysics Data System (ADS)

    Muhamed, P.; Worden, K.; Sims, N. D.

    2012-08-01

    The Orthogonalised Reverse Path (ORP) method is a new algorithm of the 'reverse path' class but developed in the time-domain. Like the Conditioned Reverse Path (CRP) method, the ORP approach is capable of identifying the underlying linear FRF of a system or structure in the presence of nonlinearities and may well also lead to simplifications in the estimation of coefficients of nonlinear terms. The method has shown itself to be numerically robust not only for simple simulated SDOF systems but also for simulated MDOF systems. The aim of this paper is to discuss an application of the ORP method to an experimental test set-up based on a nonlinear beam rig.

  20. DETECTORS AND EXPERIMENTAL METHODS: A method for interpolating asymmetric peak shapes in multiplet γ-ray spectra

    NASA Astrophysics Data System (ADS)

    Wang, Si-Guang; Mao, Ya-Jun; Tang, Pei-Jia; Zhu, Bo; Liang, Yu-Tie

    2009-05-01

    The peak shapes of γ-rays at various energies must be known before unfolding the multiplet spectra obtained by using semiconductor or scintillation detectors. Traditional methods describe isolated peaks with multi-parameter fitting functions, and assume that most of these parameters do not vary with energy because it is rare to find a spectrum with enough isolated peaks to constrain their dependence. We present an algorithm for interpolating the γ-ray profile at any intermediate energy given a pair of isolated γ-ray peaks from the spectrum under consideration. The algorithm is tested on experimental data and leads to a good agreement between the interpolated profile and the fitting function. This method is more accurate than the traditional approach, since all aspects of the peak shape are allowed to vary with energy. New definitions of Left-Half Width at Half Maximum, and Right-Half Width at Half Maximum for peak shape description are introduced in this paper.

  1. A validated spectrofluorimetric method for the determination of nifuroxazide through coumarin formation using experimental design

    PubMed Central

    2013-01-01

    Background Nifuroxazide (NF) is an oral nitrofuran antibiotic, having a wide range of bactericidal activity against gram positive and gram negative enteropathogenic organisms. It is formulated either in single form, as intestinal antiseptic or in combination with drotaverine (DV) for the treatment of gastroenteritis accompanied with gastrointestinal spasm. Spectrofluorimetry is a convenient and sensitive technique for pharmaceutical quality control. The new proposed spectrofluorimetric method allows its determination either in single form or in binary mixture with DV. Furthermore, experimental conditions were optimized using the new approach: Experimental design, which has many advantages over the old one, one variable at a time (OVAT approach). Results A novel and sensitive spectrofluorimetric method was designed and validated for the determination of NF in pharmaceutical formulation. The method was based upon the formation of a highly fluorescent coumarin compound by the reaction between NF and ethylacetoacetate (EAA) using sulfuric acid as catalyst. The fluorescence was measured at 390 nm upon excitation at 340 nm. Experimental design was used to optimize experimental conditions. Volumes of EAA and sulfuric acid, temperature and heating time were considered the critical factors to be studied in order to establish an optimum fluorescence. Each two factors were co-tried at three levels. Regression analysis revealed good correlation between fluorescence intensity and concentration over the range 20–400 ng ml-1. The suggested method was successfully applied for the determination of NF in pure and capsule forms. The procedure was validated in terms of linearity, accuracy, precision, limit of detection and limit of quantification. The selectivity of the method was investigated by analysis of NF in presence of the co-mixed drug DV where no interference was observed. The reaction pathway was suggested and the structure of the fluorescent product was proposed

  2. Automated method for modeling seven-helix transmembrane receptors from experimental data.

    PubMed Central

    Herzyk, P; Hubbard, R E

    1995-01-01

    A rule-based automated method is presented for modeling the structures of the seven transmembrane helices of G-protein-coupled receptors. The structures are generated by using a simulated annealing Monte Carlo procedure that positions and orients rigid helices to satisfy structural restraints. The restraints are derived from analysis of experimental information from biophysical studies on native and mutant proteins, from analysis of the sequences of related proteins, and from theoretical considerations of protein structure. Calculations are presented for two systems. The method was validated through calculations using appropriate experimental information for bacteriorhodopsin, which produced a model structure with a root mean square (rms) deviation of 1.87 A from the structure determined by electron microscopy. Calculations are also presented using experimental and theoretical information available for bovine rhodopsin to assign the helices to a projection density map and to produce a model of bovine rhodopsin that can be used as a template for modeling other G-protein-coupled receptors. Images FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 8 FIGURE 11 PMID:8599649

  3. Validation of experimental whole-body SAR assessment method in a complex indoor environment.

    PubMed

    Bamba, Aliou; Joseph, Wout; Vermeeren, Gunter; Tanghe, Emmeric; Gaillot, Davy Paul; Andersen, Jørgen B; Nielsen, Jesper Ødum; Lienard, Martine; Martens, Luc

    2013-02-01

    Experimentally assessing the whole-body specific absorption rate (SAR(wb) ) in a complex indoor environment is very challenging. An experimental method based on room electromagnetics theory (accounting only the line-of-sight as specular path) is validated using numerical simulations with the finite-difference time-domain method. Furthermore, the method accounts for diffuse multipath components (DMC) in the total absorption rate by considering the reverberation time of the investigated room, which describes all the losses in a complex indoor environment. The advantage of the proposed method is that it allows discarding the computational burden because it does not use any discretizations. Results show good agreement between measurement and computation at 2.8 GHz, as long as the plane wave assumption is valid, that is, at large distances from the transmitter. Relative deviations of 0.71% and 4% have been obtained for far-field scenarios, and 77.5% for the near field-scenario. The contribution of the DMC in the total absorption rate is also quantified here, which has never been investigated before. It is found that the DMC may represent an important part of the total absorption rate; its contribution may reach up to 90% for certain scenarios in an indoor environment.

  4. Experimental testing of focusing properties of subwavelength photon sieves using exposure method

    NASA Astrophysics Data System (ADS)

    Jiang, Wenbo; Zhang, Xiaohua

    2016-04-01

    An exposure method is proposed to test the focusing properties of subwavelength photon sieves. To solve the problems caused by the subwavelength photon sieves (such as short focal length and small focal spot size), a grating moiré fringe phase detection technique and a microcontact sensor with lead zirconium titanate (PZT) stepping hybrid technique are used in the experimental setup. The focusing properties of the subwavelength photon sieves are tested by this setup. The results show that the focal length and the focal spot size are close to the designed value. Finally, the intensity distribution of the focal spot is proposed. This research result will be beneficial for understanding the focusing properties of subwavelength photon sieves, will help us to improve the imaging quality, and will provide a good experimental basis for practical applications in the nanolithography field.

  5. Direction and Integration of Experimental Ground Test Capabilities and Computational Methods

    NASA Technical Reports Server (NTRS)

    Dunn, Steven C.

    2016-01-01

    This paper groups and summarizes the salient points and findings from two AIAA conference panels targeted at defining the direction, with associated key issues and recommendations, for the integration of experimental ground testing and computational methods. Each panel session utilized rapporteurs to capture comments from both the panel members and the audience. Additionally, a virtual panel of several experts were consulted between the two sessions and their comments were also captured. The information is organized into three time-based groupings, as well as by subject area. These panel sessions were designed to provide guidance to both researchers/developers and experimental/computational service providers in defining the future of ground testing, which will be inextricably integrated with the advancement of computational tools.

  6. Evaluation of a Consistent LES/PDF Method Using a Series of Experimental Spray Flames

    NASA Astrophysics Data System (ADS)

    Heye, Colin; Raman, Venkat

    2012-11-01

    A consistent method for the evolution of the joint-scalar probability density function (PDF) transport equation is proposed for application to large eddy simulation (LES) of turbulent reacting flows containing evaporating spray droplets. PDF transport equations provide the benefit of including the chemical source term in closed form, however, additional terms describing LES subfilter mixing must be modeled. The recent availability of detailed experimental measurements provide model validation data for a wide range of evaporation rates and combustion regimes, as is well-known to occur in spray flames. In this work, the experimental data will used to investigate the impact of droplet mass loading and evaporation rates on the subfilter scalar PDF shape in comparison with conventional flamelet models. In addition, existing model term closures in the PDF transport equations are evaluated with a focus on their validity in the presence of regime changes.

  7. Synergy between experimental and theoretical methods in the exploration of homogeneous transition metal catalysis.

    PubMed

    Lupp, D; Christensen, N J; Fristrup, P

    2014-08-01

    In this Perspective, we will focus on the use of both experimental and theoretical methods in the exploration of reaction mechanisms in homogeneous transition metal catalysis. We briefly introduce the use of Hammett studies and kinetic isotope effects (KIE). Both of these techniques can be complemented by computational chemistry - in particular in cases where interpretation of the experimental results is not straightforward. The good correspondence between experiment and theory is only possible due to recent advances within the applied theoretical framework. We therefore also highlight the innovations made in the last decades with emphasis on dispersion-corrected DFT and solvation models. The current state-of-the-art is highlighted using examples from the literature with particular focus on the synergy between experiment and theory.

  8. A simple method of catalase purification for the undergraduate experimental course.

    PubMed

    Chen, Qian; Cheng, Meng; Wang, Yinnan; Yao, Ming; Chen, Yongchun; Gao, Yuan; Ding, Wenyuan

    2015-02-01

    Catalase is a characteristic enzyme of peroxisomes, of which it is the most abundant protein. This enzyme serves as a typical example of a peroxisomal enzyme and is important in the teaching of biochemistry and molecular biology. Although there is substantial information regarding catalase purification, purifying catalase for the junior‑grade undergraduate experimental course face challenges in obtaining materials and increasingly expensive purification equipment. This study presents a simple method for the purification of mouse liver catalase using ethanol‑chloroform treatment, sodium sulfate fractionation, dialysis and Sephadex G‑200 gel filtration chromatography. Catalase was purified 31.8‑fold with an 18.3% yield. The advantages of this method were its low operating environment requirements, simple procedure and reduced cost. Furthermore, the method was designed to improve students' comprehensive ability and manipulative ability and to introduce a sense of innovation in the fields of biochemistry and molecular biology during their junior year.

  9. Experimental Scatter Correction Methods in Industrial X-Ray Cone-Beam CT

    NASA Astrophysics Data System (ADS)

    Schörner, K.; Goldammer, M.; Stephan, J.

    2011-06-01

    Scattered radiation presents a major source of image degradation in industrial cone-beam computed tomography systems. Scatter artifacts introduce streaks, cupping and a loss of contrast in the reconstructed CT-volumes. In order to overcome scatter artifacts, we present two complementary experimental correction methods: the beam-stop array (BSA) and an inverse technique we call beam-hole array (BHA). Both correction methods are examined in comparative measurements where it is shown that the aperture-based BHA technique has practical and scatter-reducing advantages over the BSA. The proposed BHA correction method is successfully applied to a large-scale industrial specimen whereby scatter artifacts are reduced and contrast is enhanced significantly.

  10. Digital analysis of experimental human bitemarks: application of two new methods.

    PubMed

    Al-Talabani, Nazar; Al-Moussawy, Noori D; Baker, Faik A; Mohammed, Haitham Abdullah

    2006-11-01

    Bitemark determination in forensic odontology is commonly performed by comparing the morphology of the dentition of the suspect with life-sized photographs of injury on the victim's skin using transparent overlays or computers. The purpose of this study is to investigate the suitability of two new different methods for identification of bitemarks by digital analysis. A sample of 50 volunteers was asked to make experimental bitemarks on the arms of each other. Stone study casts were prepared from upper and lower dental arches of each volunteer. The bitemarks and the study casts were photographed; the photos were entered into the computer and Adobe Photoshop software program was applied to analyze the results. Two methods (2D polyline and Painting) of identification were used. In the 2D polyline method, fixed points were chosen on the tips of the canines and a straight line was drawn between the two fixed points in the arch (intercanine line). Straight lines passing between the incisal edges of the incisors were drawn vertically on the intercanine line; the lines and angles created were calculated. In the painting method, identification was based on canine-to-canine distance, tooth width and the thickness, and rotational value of each tooth. The results showed that both methods were applicable. However, the 2D polyline method was more convenient to use and gave prompt computer-read results, whereas the painting method depended on the visual reading of the operator. PMID:17199623

  11. Method of computer generation and projection recording of microholograms for holographic memory systems: mathematical modelling and experimental implementation

    SciTech Connect

    Betin, A Yu; Bobrinev, V I; Evtikhiev, N N; Zherdev, A Yu; Zlokazov, E Yu; Lushnikov, D S; Markin, V V; Odinokov, S B; Starikov, S N; Starikov, R S

    2013-01-31

    A method of computer generation and projection recording of microholograms for holographic memory systems is presented; the results of mathematical modelling and experimental implementation of the method are demonstrated. (holographic memory)

  12. The experimental determination of the moments of inertia of airplanes by a simplified compound-pendulum method

    NASA Technical Reports Server (NTRS)

    Gracey, William

    1948-01-01

    A simplified compound-pendulum method for the experimental determination of the moments of inertia of airplanes about the x and y axes is described. The method is developed as a modification of the standard pendulum method reported previously in NACA report, NACA-467. A brief review of the older method is included to form a basis for discussion of the simplified method. (author)

  13. Experimental method for characterizing CVOC removal from fractured clays during boiling.

    PubMed

    Liu, Xiaoling; Tan, Tianwu; Falta, Ronald W; Murdoch, Lawrence C

    2013-09-01

    Conventional remediation methods that rely on contact with contaminants can be ineffective in fractured media, but thermal methods of remediation involving CVOC stripping at boiling temperature show promise. However, limited experimental data are available to characterize thermal remediation because of challenges associated with high temperature. This research reports an experimental method using uniformly contaminated clay packed into two types of experimental cells, a rigid-wall stainless steel tube and a flexible-wall Teflon tube in a pressurized chamber. Both tubes are 5 cm in diameter and approximately 25 cm long. This laboratory apparatus was developed as a 1D physical model for contaminant transport in a cylindrical matrix towards a fracture, which is represented by one end of the cylinder and serves as the outlet of vapor and contaminant. The clay was contaminated with dissolved 1,2-dichloroethane (DCA) and bromide, and the columns were heated to more than 100 °C and then the top end was depressurized to atmospheric pressure to induce boiling. The outflow was condensed and analyzed for contaminant mass. The flexible-wall cell was confined to 100 kPa (gage), allowing equilibrium boiling temperatures of approximately 120 °C to be maintained. The clay was sampled before and after heating and extracted to determine the DCA distribution along the length of the column. During a typical test in the rigid-wall cell, internal temperatures and pressures along the column during heating reached the saturated vapor pressure curve. DCA concentrations in the recovered condensate were up to 12 times of the initial pore concentration in the clay. Less than 5% of non-volatile bromide was recovered. Significant removal of DCA and water occurred along the entire length of the clay column. This suggests that boiling was occurring in the clay matrix. PMID:23872027

  14. Experimental method for characterizing CVOC removal from fractured clays during boiling.

    PubMed

    Liu, Xiaoling; Tan, Tianwu; Falta, Ronald W; Murdoch, Lawrence C

    2013-09-01

    Conventional remediation methods that rely on contact with contaminants can be ineffective in fractured media, but thermal methods of remediation involving CVOC stripping at boiling temperature show promise. However, limited experimental data are available to characterize thermal remediation because of challenges associated with high temperature. This research reports an experimental method using uniformly contaminated clay packed into two types of experimental cells, a rigid-wall stainless steel tube and a flexible-wall Teflon tube in a pressurized chamber. Both tubes are 5 cm in diameter and approximately 25 cm long. This laboratory apparatus was developed as a 1D physical model for contaminant transport in a cylindrical matrix towards a fracture, which is represented by one end of the cylinder and serves as the outlet of vapor and contaminant. The clay was contaminated with dissolved 1,2-dichloroethane (DCA) and bromide, and the columns were heated to more than 100 °C and then the top end was depressurized to atmospheric pressure to induce boiling. The outflow was condensed and analyzed for contaminant mass. The flexible-wall cell was confined to 100 kPa (gage), allowing equilibrium boiling temperatures of approximately 120 °C to be maintained. The clay was sampled before and after heating and extracted to determine the DCA distribution along the length of the column. During a typical test in the rigid-wall cell, internal temperatures and pressures along the column during heating reached the saturated vapor pressure curve. DCA concentrations in the recovered condensate were up to 12 times of the initial pore concentration in the clay. Less than 5% of non-volatile bromide was recovered. Significant removal of DCA and water occurred along the entire length of the clay column. This suggests that boiling was occurring in the clay matrix.

  15. Effect Sizes as Result Interpretation Aids in Single-Subject Experimental Research: Description and Application of Four Nonoverlap Methods

    ERIC Educational Resources Information Center

    Rakap, Salih

    2015-01-01

    Single-subject experimental research (SSER), one of the most commonly used research methods in special education and applied behaviour analysis, is a scientific, rigorous and valid method to evaluate the effectiveness of behavioural, educational and psychological treatments. However, studies using single-subject experimental research designs are…

  16. Experimental methods in the study of neutron scattering at small angles

    SciTech Connect

    Dragolici, Cristian A.

    2014-11-24

    Small angle scattering (SAS) is the collective name given to the techniques of small angle neutron (SANS) and X-ray (SAXS) scattering. They offer the possibility to analyze particles without disturbing their natural environment. In each of these techniques radiation is elastically scattered by a sample and the resulting scattering pattern is analyzed to provide information about the size, shape and orientation of some component of the sample. Accordingly, a large number of methods and experimental patterns have been developed to ease the investigation of condensed matter by use of these techniques. Some of them are the discussed in this paper.

  17. Highly porous thermal protection materials: Modelling and prediction of the methodical experimental errors

    NASA Astrophysics Data System (ADS)

    Cherepanov, Valery V.; Alifanov, Oleg M.; Morzhukhina, Alena V.; Budnik, Sergey A.

    2016-11-01

    The formation mechanisms and the main factors affecting the systematic error of thermocouples were investigated. According to the results of experimental studies and mathematical modelling it was established that in highly porous heat resistant materials for aerospace application the thermocouple errors are determined by two competing mechanisms provided correlation between the errors and the difference between radiation and conduction heat fluxes. The comparative analysis was carried out and some features of the methodical error formation related to the distances from the heated surface were established.

  18. TiO2 synthesized by microwave assisted solvothermal method: Experimental and theoretical evaluation

    NASA Astrophysics Data System (ADS)

    Moura, K. F.; Maul, J.; Albuquerque, A. R.; Casali, G. P.; Longo, E.; Keyson, D.; Souza, A. G.; Sambrano, J. R.; Santos, I. M. G.

    2014-02-01

    In this study, a microwave assisted solvothermal method was used to synthesize TiO2 with anatase structure. The synthesis was done using Ti (IV) isopropoxide and ethanol without templates or alkalinizing agents. Changes in structural features were observed with increasing time of synthesis and evaluated using periodic quantum chemical calculations. The anatase phase was obtained after only 1 min of reaction besides a small amount of brookite phase. Experimental Raman spectra are in accordance with the theoretical one. Micrometric spheres constituted by nanometric particles were obtained for synthesis from 1 to 30 min, while spheres and sticks were observed after 60 min.

  19. Synthesis mechanism of lithium nickel oxide using hydrothermal electrochemical method: Thermodynamic modelling and experimental verification

    NASA Astrophysics Data System (ADS)

    Tao, Ying; Chen, Zhenhua; Zhu, Baojun

    2005-05-01

    Potential-pOH diagrams of nickel are drawn at various temperatures to predict the reaction of nickel in a 4 M lithium hydroxide solution. Based on these diagrams, the thermodynamic stability of each constituent of nickel in 4 M LiOH solution at various temperatures is evaluated. The oxidation mechanism is studied based on the thermodynamic analysis and the oxidation proceeds in the following order: Ni, Ni(OH) 2 or HNiO 2-, NiOOH rad H 2O, NiOOH, LiNiO 2. The thermodynamic model is validated experimentally by the cyclic voltammogram method.

  20. An experimental evaluation method for the performance of a laser line scanning system with multiple sensors

    NASA Astrophysics Data System (ADS)

    Tian, Qingguo; Yang, Yujie; Zhang, Xiangyu; Ge, Baozhen

    2014-01-01

    Laser line scanning 3D digitising systems have a wide range of applications. Their working performance is mainly determined by the system calibration procedure and is also affected by the working conditions, CCD camera imperfections, and object surface optical characteristics. Therefore, a comprehensive evaluation of working performance is necessary before and during use. This study proposes an experimental method for the performance evaluation of a laser line scanner (LLS) with 8 scanning sensors developed in our laboratory. This method first obtains the dense point clouds of standard parts composed of disks, cylinders, and squares. Next, the single-layer point clouds located in horizontal planes of different heights are fitted using the least squares method to obtain the enclosed contours S. Three parameters, namely, the standard deviation of the distance distribution between points and S, the mean distance of the distance distribution, and the shape feature sizes, are used to evaluate the performance. The proposed method evaluates both the scanner as a whole and each scanning sensor. Using this method, more comprehensive information can be acquired to evaluate the scanner performance. The experimental results show that the absolute dimension size error and relative error are less than 5 mm and 3%, respectively, and the relative shape error is less than 2%; therefore, the evaluated LLS system can meet the requirements for human anthropometry applications. Although each scanning sensor has different random and systematic error, these errors are the function of measurement depth. These conclusions are helpful for the further use of this scanner system and can be utilised to optimise this LLS system further.

  1. An inverse finite element method for beam shape sensing: theoretical framework and experimental validation

    NASA Astrophysics Data System (ADS)

    Gherlone, Marco; Cerracchio, Priscilla; Mattone, Massimiliano; Di Sciuva, Marco; Tessler, Alexander

    2014-04-01

    Shape sensing, i.e., reconstruction of the displacement field of a structure from surface-measured strains, has relevant implications for the monitoring, control and actuation of smart structures. The inverse finite element method (iFEM) is a shape-sensing methodology shown to be fast, accurate and robust. This paper aims to demonstrate that the recently presented iFEM for beam and frame structures is reliable when experimentally measured strains are used as input data. The theoretical framework of the methodology is first reviewed. Timoshenko beam theory is adopted, including stretching, bending, transverse shear and torsion deformation modes. The variational statement and its discretization with C0-continuous inverse elements are briefly recalled. The three-dimensional displacement field of the beam structure is reconstructed under the condition that least-squares compatibility is guaranteed between the measured strains and those interpolated within the inverse elements. The experimental setup is then described. A thin-walled cantilevered beam is subjected to different static and dynamic loads. Measured surface strains are used as input data for shape sensing at first with a single inverse element. For the same test cases, convergence is also investigated using an increasing number of inverse elements. The iFEM-recovered deflections and twist rotations are then compared with those measured experimentally. The accuracy, convergence and robustness of the iFEM with respect to unavoidable measurement errors, due to strain sensor locations, measurement systems and geometry imperfections, are demonstrated for both static and dynamic loadings.

  2. Measuring effective radium concentration with large numbers of samples. Part I--experimental method and uncertainties.

    PubMed

    Girault, Frédéric; Perrier, Frédéric

    2012-11-01

    Effective radium concentration EC(Ra), product of radium concentration and radon emanation, is the source term for radon release into the pore space of rocks and the environment. To measure EC(Ra), we have conducted, over a period of three years, more than 5500 radon-222 accumulation experiments in the laboratory with scintillation flasks, and about 700 with integrating solid state nuclear track detectors, leading to experimental values of EC(Ra) for more than 1570 rock and soil samples. Through detailed systematic checks and intercomparison between various repeated experiments, the experimental uncertainty has been assessed, and ranges from 30% (1 σ) for EC(Ra) values smaller than 0.2 Bq kg(-1) to about 8-10% for EC(Ra) values larger than 50 Bq kg(-1). The detection limit, defined as the 90% probability for obtaining a non-zero experimental EC(Ra) value at 68% confidence level, depends on the mass of the sample with respect to the volume of the accumulation volume, and typically varies between 0.04 and 0.09 Bq kg(-1). To measure EC(Ra) from large numbers of samples with sufficient accuracy and uncertainty for our purpose, i.e. for the most natural objects encountered in the environment, the accumulation method with scintillation flask emerged as particularly useful and robust. Properties of EC(Ra) and interpretations inferred from this large data set are presented in the companion paper.

  3. Analysis Method and Experimental Conditions Affect Computed Circadian Phase from Melatonin Data

    PubMed Central

    Klerman, Hadassa; St. Hilaire, Melissa A.; Kronauer, Richard E.; Gooley, Joshua J.; Gronfier, Claude; Hull, Joseph T.; Lockley, Steven W.; Santhi, Nayantara; Wang, Wei; Klerman, Elizabeth B.

    2012-01-01

    Accurate determination of circadian phase is necessary for research and clinical purposes because of the influence of the master circadian pacemaker on multiple physiologic functions. Melatonin is presently the most accurate marker of the activity of the human circadian pacemaker. Current methods of analyzing the plasma melatonin rhythm can be grouped into three categories: curve-fitting, threshold-based and physiologically-based linear differential equations. To determine which method provides the most accurate assessment of circadian phase, we compared the ability to fit the data and the variability of phase estimates for seventeen different markers of melatonin phase derived from these methodological categories. We used data from three experimental conditions under which circadian rhythms - and therefore calculated melatonin phase - were expected to remain constant or progress uniformly. Melatonin profiles from older subjects and subjects with lower melatonin amplitude were less likely to be fit by all analysis methods. When circadian drift over multiple study days was algebraically removed, there were no significant differences between analysis methods of melatonin onsets (P = 0.57), but there were significant differences between those of melatonin offsets (P<0.0001). For a subset of phase assessment methods, we also examined the effects of data loss on variability of phase estimates by systematically removing data in 2-hour segments. Data loss near onset of melatonin secretion differentially affected phase estimates from the methods, with some methods incorrectly assigning phases too early while other methods assigning phases too late; missing data at other times did not affect analyses of the melatonin profile. We conclude that melatonin data set characteristics, including amplitude and completeness of data collection, differentially affect the results depending on the melatonin analysis method used. PMID:22511928

  4. Extensions Of The Method Of Moments For Deconvolution Of Experimental Data

    NASA Astrophysics Data System (ADS)

    Small, Enoch W.; Libertini, Louis J.; Brown, David W.; Small, Jeanne R.

    1989-05-01

    The Method of Moments is one of a series of closely related transform methods which have been developed primarily for the deconvolution and analysis of fluorescence decay data. The main distinguishing feature of the Method of Moments is that it has been designed to be robust with respect to several important nonrandom errors of instrumental origin. The historical development of the method is reviewed here. Several new extensions are also described, including a statistical theory, an improved global analysis, and a method for analyzing continuous distributions of lifetimes. The new statistical theory is the first to incorporate a combined treatment of exponential depression and moment index displacement, both necessary components of the Method of Moments. In comparisons with the more commonly used least squares iterative reconvolution (LSIR) approach, it is shown that, in analyses of ideal synthetic data with random noise, the Method of Moments gives deviations in recovered parameters which are slightly greater but essentially comparable to those found by the data fitting method. Real experimental data also contain nonrandom errors. In the presence of certain such errors, decay parameters recovered by the Method of Moments will be unaffected, whereas the least squares method may yield incorrect results, unless care is taken to fit all of the data errors. An example of the improved global analysis application of the Method of Moments is shown in which two rhodamine dyes with very close lifetimes are distinguished based on spectral data. Also, the use of the distribution analysis method is illustrated with the binding of the intercalating dye ethidium bromide to DNA and nucleosome core particles. At very low ionic strength the width and location of the lifetime distribution shows a time dependence, indicating time-dependent changes in the environment of the probe. Finally, examples of Method of Moments analyses are shown for a totally different kind of data

  5. Consistent View of Polypeptide Chain Expansion in Chemical Denaturants from Multiple Experimental Methods.

    PubMed

    Borgia, Alessandro; Zheng, Wenwei; Buholzer, Karin; Borgia, Madeleine B; Schüler, Anja; Hofmann, Hagen; Soranno, Andrea; Nettels, Daniel; Gast, Klaus; Grishaev, Alexander; Best, Robert B; Schuler, Benjamin

    2016-09-14

    There has been a long-standing controversy regarding the effect of chemical denaturants on the dimensions of unfolded and intrinsically disordered proteins: A wide range of experimental techniques suggest that polypeptide chains expand with increasing denaturant concentration, but several studies using small-angle X-ray scattering (SAXS) have reported no such increase of the radius of gyration (Rg). This inconsistency challenges our current understanding of the mechanism of chemical denaturants, which are widely employed to investigate protein folding and stability. Here, we use a combination of single-molecule Förster resonance energy transfer (FRET), SAXS, dynamic light scattering (DLS), and two-focus fluorescence correlation spectroscopy (2f-FCS) to characterize the denaturant dependence of the unfolded state of the spectrin domain R17 and the intrinsically disordered protein ACTR in two different denaturants. Standard analysis of the primary data clearly indicates an expansion of the unfolded state with increasing denaturant concentration irrespective of the protein, denaturant, or experimental method used. This is the first case in which SAXS and FRET have yielded even qualitatively consistent results regarding expansion in denaturant when applied to the same proteins. To more directly illustrate this self-consistency, we used both SAXS and FRET data in a Bayesian procedure to refine structural ensembles representative of the observed unfolded state. This analysis demonstrates that both of these experimental probes are compatible with a common ensemble of protein configurations for each denaturant concentration. Furthermore, the resulting ensembles reproduce the trend of increasing hydrodynamic radius with denaturant concentration obtained by 2f-FCS and DLS. We were thus able to reconcile the results from all four experimental techniques quantitatively, to obtain a comprehensive structural picture of denaturant-induced unfolded state expansion, and to

  6. Development of advanced methods for analysis of experimental data in diffusion

    NASA Astrophysics Data System (ADS)

    Jaques, Alonso V.

    There are numerous experimental configurations and data analysis techniques for the characterization of diffusion phenomena. However, the mathematical methods for estimating diffusivities traditionally do not take into account the effects of experimental errors in the data, and often require smooth, noiseless data sets to perform the necessary analysis steps. The current methods used for data smoothing require strong assumptions which can introduce numerical "artifacts" into the data, affecting confidence in the estimated parameters. The Boltzmann-Matano method is used extensively in the determination of concentration - dependent diffusivities, D(C), in alloys. In the course of analyzing experimental data, numerical integrations and differentiations of the concentration profile are performed. These methods require smoothing of the data prior to analysis. We present here an approach to the Boltzmann-Matano method that is based on a regularization method to estimate a differentiation operation on the data, i.e., estimate the concentration gradient term, which is important in the analysis process for determining the diffusivity. This approach, therefore, has the potential to be less subjective, and in numerical simulations shows an increased accuracy in the estimated diffusion coefficients. We present a regression approach to estimate linear multicomponent diffusion coefficients that eliminates the need pre-treat or pre-condition the concentration profile. This approach fits the data to a functional form of the mathematical expression for the concentration profile, and allows us to determine the diffusivity matrix directly from the fitted parameters. Reformulation of the equation for the analytical solution is done in order to reduce the size of the problem and accelerate the convergence. The objective function for the regression can incorporate point estimations for error in the concentration, improving the statistical confidence in the estimated diffusivity matrix

  7. Structural, vibrational and nuclear magnetic resonance investigations of 4-bromoisoquinoline by experimental and theoretical DFT methods

    NASA Astrophysics Data System (ADS)

    Arjunan, V.; Thillai Govindaraja, S.; Jayapraksh, A.; Mohan, S.

    2013-04-01

    Quantum chemical calculations of energy, structural parameters and vibrational wavenumbers of 4-bromoisoquinoline (4BIQ) were carried out by using B3LYP method using 6-311++G**, cc-pVTZ and LANL2DZ basis sets. The optimised geometrical parameters obtained by DFT calculations are in good agreement with electron diffraction data. Interpretations of the experimental FTIR and FT-Raman spectra have been reported with the aid of the theoretical wavenumbers. The differences between the observed and scaled wavenumber values of most of the fundamentals are very small. The thermodynamic parameters have also been computed. Electronic properties of the molecule were discussed through the molecular electrostatic potential surface, HOMO-LUMO energy gap and NBO analysis. To provide precise assignments of 1H and 13C NMR spectra, isotropic shielding and chemical shifts were calculated with the Gauge-Invariant Atomic Orbital (GIAO) method.

  8. Calculation of low bandgap homopolymers: Comparison of TD-DFT methods with experimental oligomer series

    NASA Astrophysics Data System (ADS)

    Oliveira, Eliezer Fernando; Roldao, Juan Carlos; Milián-Medina, Begoña; Lavarda, Francisco Carlos; Gierschner, Johannes

    2016-02-01

    The performance of different DFT functionals (B3LYP, BHLYP, CAM-B3LYP, M06HF) on the prediction of vertical transition energies Evert of low bandgap homopolymers is tested against the experimentally available oligomer series (thienopyrazines and thienothiophenes). This allows for a detailed and accurate comparison on the consistency of DFT methods for chainlength evolution and polymer limit prediction, and for an understanding of geometry and time-dependent contributions to Evert by combinatorial analysis. Together with former studies on wide/medium bandgap polymers and low bandgap co-polymers, our results on low bandgap homopolymers suggest offset-corrected M06HF as the most viable method for time inexpensive and reliable prediction of semiconducting polymers at the moment.

  9. Maximum-likelihood methods in cryo-EM. Part II: application to experimental data

    PubMed Central

    Scheres, Sjors H.W.

    2010-01-01

    With the advent of computationally feasible approaches to maximum likelihood image processing for cryo-electron microscopy, these methods have proven particularly useful in the classification of structurally heterogeneous single-particle data. A growing number of experimental studies have applied these algorithms to study macromolecular complexes with a wide range of structural variability, including non-stoichiometric complex formation, large conformational changes and combinations of both. This chapter aims to share the practical experience that has been gained from the application of these novel approaches. Current insights on how to prepare the data and how to perform two- or three-dimensional classifications are discussed together with aspects related to high-performance computing. Thereby, this chapter will hopefully be of practical use for those microscopists wanting to apply maximum likelihood methods in their own investigations. PMID:20888966

  10. Experimental demonstration of novel end-pumping method for double-clad fiber devices.

    PubMed

    Peterka, Pavel; Kasík, Ivan; Mat Jec, Vlastimil; Kube Ek, Václav; Dvo A Ek, Pavel

    2006-11-15

    We present experimental demonstration of an end-pumping scheme based on splicing the multimode pump and single-mode signal fibers directly to a double-clad fiber with a tailored cross section. The method is used to pump a double-clad, erbium- and ytterbium-doped, fiber ring laser. The efficiency of the end-pumping method is tested by determining the slope efficiencies of the fiber ring laser and the fiber laser in a Fabry-Perot configuration. Comparable slope efficiencies are found when both laser configurations have similar output coupler ratios. The developed pumping scheme and double-clad fiber can find applications in cost-effective power fiber amplifiers and lasers. PMID:17072383

  11. An experimental method for measuring stress intensity factor distributions in three-dimensional problems

    SciTech Connect

    Smith, C.W.

    2000-04-01

    In this paper, an attempt has been made to briefly chart the progress over a period of some 30 years during which the writer and his associates have tried to effect a marriage between the well known, frozen stress method (augmented with the methods of Tardy and Post for refining the near tip fringe analysis), with the principles of fracture mechanics, using an extension of an idea proposed by Irwin. Although a conscious effort was made by the writer to keep the elements of the method as simple as possible so as to allow the application to as broad a range of practical problems as possible while maintaining reasonable engineering accuracy, there were occasional diversions into supporting developments such as the singularity change when a crack intersects a free boundary and the combined use of the stress freezing method with moire. In general, the guidelines employed by the writer included: Use of well established experimental methods; simple algorithms where singularity dominated data zones were revealed by the data itself; applicability to any crack shapes even when unknown apriori; and engineering accuracy of {+-}5% in K{sub 1} in Mode 1 dominated problems.

  12. Experimental Methods for Investigation of Shape Memory Based Elastocaloric Cooling Processes and Model Validation.

    PubMed

    Schmidt, Marvin; Ullrich, Johannes; Wieczorek, André; Frenzel, Jan; Eggeler, Gunther; Schütze, Andreas; Seelecke, Stefan

    2016-01-01

    Shape Memory Alloys (SMA) using elastocaloric cooling processes have the potential to be an environmentally friendly alternative to the conventional vapor compression based cooling process. Nickel-Titanium (Ni-Ti) based alloy systems, especially, show large elastocaloric effects. Furthermore, exhibit large latent heats which is a necessary material property for the development of an efficient solid-state based cooling process. A scientific test rig has been designed to investigate these processes and the elastocaloric effects in SMAs. The realized test rig enables independent control of an SMA's mechanical loading and unloading cycles, as well as conductive heat transfer between SMA cooling elements and a heat source/sink. The test rig is equipped with a comprehensive monitoring system capable of synchronized measurements of mechanical and thermal parameters. In addition to determining the process-dependent mechanical work, the system also enables measurement of thermal caloric aspects of the elastocaloric cooling effect through use of a high-performance infrared camera. This combination is of particular interest, because it allows illustrations of localization and rate effects - both important for efficient heat transfer from the medium to be cooled. The work presented describes an experimental method to identify elastocaloric material properties in different materials and sample geometries. Furthermore, the test rig is used to investigate different cooling process variations. The introduced analysis methods enable a differentiated consideration of material, process and related boundary condition influences on the process efficiency. The comparison of the experimental data with the simulation results (of a thermomechanically coupled finite element model) allows for better understanding of the underlying physics of the elastocaloric effect. In addition, the experimental results, as well as the findings based on the simulation results, are used to improve the

  13. A novel full-field experimental method to measure the local compressibility of gas diffusion media

    NASA Astrophysics Data System (ADS)

    Lai, Yeh-Hung; Li, Yongqiang; Rock, Jeffrey A.

    The gas diffusion medium (GDM) in a proton exchange membrane (PEM) fuel cell needs to simultaneously satisfy the requirements of transporting reactant gases, removing product water, conducting electrons and heat, and providing mechanical support to the membrane electrode assembly (MEA). Concerning the localized over-compression which may force carbon fibers and other conductive debris into the membrane to cause fuel cell failure by electronically shorting through the membrane, we have developed a novel full-field experimental method to measure the local thickness and compressibility of GDM. Applying a uniform air pressure upon a thin polyimide film bonded on the top surface of the GDM with support from the bottom by a flat metal substrate and measuring the thickness change using the 3-D digital image correlation technique with an out-of-plane displacement resolution less than 0.5 μm, we have determined the local thickness and compressive stress/strain behavior in the GDM. Using the local thickness and compressibility data over an area of 11.2 mm × 11.2 mm, we numerically construct the nominal compressive response of a commercial Toray™ TGP-H-060 based GDM subjected to compression by flat platens. Good agreement in the nominal stress/strain curves from the numerical construction and direct experimental flat-platen measurement confirms the validity of the methodology proposed in this article. The result shows that a nominal pressure of 1.4 MPa compressed between two flat platens can introduce localized compressive stress concentration of more than 3 MPa in up to 1% of the total area at various locations from several hundred micrometers to 1 mm in diameter. We believe that this full-field experimental method can be useful in GDM material and process development to reduce the local hard spots and help to mitigate the membrane shorting failure in PEM fuel cells.

  14. Experimental Methods for Investigation of Shape Memory Based Elastocaloric Cooling Processes and Model Validation.

    PubMed

    Schmidt, Marvin; Ullrich, Johannes; Wieczorek, André; Frenzel, Jan; Eggeler, Gunther; Schütze, Andreas; Seelecke, Stefan

    2016-01-01

    Shape Memory Alloys (SMA) using elastocaloric cooling processes have the potential to be an environmentally friendly alternative to the conventional vapor compression based cooling process. Nickel-Titanium (Ni-Ti) based alloy systems, especially, show large elastocaloric effects. Furthermore, exhibit large latent heats which is a necessary material property for the development of an efficient solid-state based cooling process. A scientific test rig has been designed to investigate these processes and the elastocaloric effects in SMAs. The realized test rig enables independent control of an SMA's mechanical loading and unloading cycles, as well as conductive heat transfer between SMA cooling elements and a heat source/sink. The test rig is equipped with a comprehensive monitoring system capable of synchronized measurements of mechanical and thermal parameters. In addition to determining the process-dependent mechanical work, the system also enables measurement of thermal caloric aspects of the elastocaloric cooling effect through use of a high-performance infrared camera. This combination is of particular interest, because it allows illustrations of localization and rate effects - both important for efficient heat transfer from the medium to be cooled. The work presented describes an experimental method to identify elastocaloric material properties in different materials and sample geometries. Furthermore, the test rig is used to investigate different cooling process variations. The introduced analysis methods enable a differentiated consideration of material, process and related boundary condition influences on the process efficiency. The comparison of the experimental data with the simulation results (of a thermomechanically coupled finite element model) allows for better understanding of the underlying physics of the elastocaloric effect. In addition, the experimental results, as well as the findings based on the simulation results, are used to improve the

  15. A Wavelet-Based ECG Delineation Method: Adaptation to an Experimental Electrograms with Manifested Global Ischemia.

    PubMed

    Hejč, Jakub; Vítek, Martin; Ronzhina, Marina; Nováková, Marie; Kolářová, Jana

    2015-09-01

    We present a novel wavelet-based ECG delineation method with robust classification of P wave and T wave. The work is aimed on an adaptation of the method to long-term experimental electrograms (EGs) measured on isolated rabbit heart and to evaluate the effect of global ischemia in experimental EGs on delineation performance. The algorithm was tested on a set of 263 rabbit EGs with established reference points and on human signals using standard Common Standards for Quantitative Electrocardiography Standard Database (CSEDB). On CSEDB, standard deviation (SD) of measured errors satisfies given criterions in each point and the results are comparable to other published works. In rabbit signals, our QRS detector reached sensitivity of 99.87% and positive predictivity of 99.89% despite an overlay of spectral components of QRS complex, P wave and power line noise. The algorithm shows great performance in suppressing J-point elevation and reached low overall error in both, QRS onset (SD = 2.8 ms) and QRS offset (SD = 4.3 ms) delineation. T wave offset is detected with acceptable error (SD = 12.9 ms) and sensitivity nearly 99%. Variance of the errors during global ischemia remains relatively stable, however more failures in detection of T wave and P wave occur. Due to differences in spectral and timing characteristics parameters of rabbit based algorithm have to be highly adaptable and set more precisely than in human ECG signals to reach acceptable performance. PMID:26577367

  16. Reliability of an experimental method to analyse the impact point on a golf ball during putting.

    PubMed

    Richardson, Ashley K; Mitchell, Andrew C S; Hughes, Gerwyn

    2015-06-01

    This study aimed to examine the reliability of an experimental method identifying the location of the impact point on a golf ball during putting. Forty trials were completed using a mechanical putting robot set to reproduce a putt of 3.2 m, with four different putter-ball combinations. After locating the centre of the dimple pattern (centroid) the following variables were tested; distance of the impact point from the centroid, angle of the impact point from the centroid and distance of the impact point from the centroid derived from the X, Y coordinates. Good to excellent reliability was demonstrated in all impact variables reflected in very strong relative (ICC = 0.98-1.00) and absolute reliability (SEM% = 0.9-4.3%). The highest SEM% observed was 7% for the angle of the impact point from the centroid. In conclusion, the experimental method was shown to be reliable at locating the centroid location of a golf ball, therefore allowing for the identification of the point of impact with the putter head and is suitable for use in subsequent studies.

  17. An Experimental Method for Measuring Water Droplet Impingement Efficiency on Two- and Three-dimensional Bodies

    NASA Technical Reports Server (NTRS)

    Papadakis, M.; Zumwalt, G. W.; Elangonan, R.; Freund, G. A., Jr.; Breer, M.; Whitmer, L.

    1989-01-01

    An experimental method was developed to determine the droplet impingement characteristics on 2-D and 3-D bodies. The experimental results provide the essential droplet impingement data required to validate water droplet trajectory codes, which are used in the analysis of aircraft icing. A body, whose water droplet impingement characteristics are required, is covered at strategic locations by thin strips of moisture absorbing (blotter) paper, and is exposed to an air stream containing a water dye solution spray cloud. Water droplet impingement data are extracted from the dyed blotter strips by measuring the optical reflectance of the dye deposit on the strips, using an automated reflectometer. Models tested include a 4-inch diameter cylinder, a NACA 652015 airfoil section, a MS(1)-0317 supercritical airfoil section, three simulated ice shapes, an axisymmetric inlet and a Boeing 737-300 inlet model. Detailed descriptions of the dye tracer technique, instrumentation, data reduction method and the results obtained are presented. Analytical predictions of collection efficiency characteristics for most test configurations are included for comparison.

  18. Performance of Higher Order Campbell methods, Part II: calibration and experimental application

    NASA Astrophysics Data System (ADS)

    Elter, Zs.; de Izarra, G.; Filliatre, P.; Jammes, C.; Pázsit, I.

    2016-11-01

    Applying Higher Order Campbelling methods in neutron flux monitoring with fission chambers is advantageous due to their capabilities to suppress the impact of unwanted noises and signal contributions (such as gamma radiation). This work aims to verify through experimental results that the basic assumptions behind the Higher Order Campelling methods are valid in critical reactors. The experiments, reported in this work, were performed at the MINERVE reactor in Cadarache. It is shown that the calibration of a fission chamber and the associated electronic system is possible in higher order mode. With the use of unbiased cumulant estimators and with digital processing, it is shown that over a wide count rate range, accurate count rate estimation can be achieved based on signal samples of a few ms, which is a significant progress compared to similar experimental results in the literature. The difference between the count rate estimated by pulse counting and by the Higher Order Campelling is less than 4%. The work also investigates the possibility of monitoring transient events. For this purpose, a control rod drop event was followed in Higher Order Campbelling mode.

  19. Designing specific protein–protein interactions using computation, experimental library screening, or integrated methods

    PubMed Central

    Chen, T Scott; Keating, Amy E

    2012-01-01

    Given the importance of protein–protein interactions for nearly all biological processes, the design of protein affinity reagents for use in research, diagnosis or therapy is an important endeavor. Engineered proteins would ideally have high specificities for their intended targets, but achieving interaction specificity by design can be challenging. There are two major approaches to protein design or redesign. Most commonly, proteins and peptides are engineered using experimental library screening and/or in vitro evolution. An alternative approach involves using protein structure and computational modeling to rationally choose sequences predicted to have desirable properties. Computational design has successfully produced novel proteins with enhanced stability, desired interactions and enzymatic function. Here we review the strengths and limitations of experimental library screening and computational structure-based design, giving examples where these methods have been applied to designing protein interaction specificity. We highlight recent studies that demonstrate strategies for combining computational modeling with library screening. The computational methods provide focused libraries predicted to be enriched in sequences with the properties of interest. Such integrated approaches represent a promising way to increase the efficiency of protein design and to engineer complex functionality such as interaction specificity. PMID:22593041

  20. Experimental methods of indoor millimeter-wave radiometric imaging for personnel concealed contraband detection

    NASA Astrophysics Data System (ADS)

    Hu, Taiyang; Xiao, Zelong; Li, Hao; Lv, Rongchuan; Lu, Xuan

    2014-11-01

    The increasingly emerging terrorism attacks and violence crimes around the world have posed severe threats to public security, so carrying out relevant research on advanced experimental methods of personnel concealed contraband detection is crucial and meaningful. All of the advantages of imaging covertly, avoidance of interference with other systems, intrinsic property of being safe to persons under screening , and the superior ability of imaging through natural or manmade obscurants, have significantly combined to enable millimeter-wave (MMW) radiometric imaging to offer great potential in personnel concealed contraband detection. Based upon the current research status of MMW radiometric imaging and urgent demands of personnel security screening, this paper mainly focuses on the experimental methods of indoor MMW radiometric imaging. The reverse radiation noise resulting from super-heterodyne receivers seriously affects the image experiments carried out at short range, so both the generation mechanism and reducing methods of this noise are investigated. Then, the benefit of sky illumination no longer exists for the indoor radiometric imaging, and this leads to the decrease in radiometric temperature contrast between target and background. In order to enhance the radiometric temperature contrast for improving indoor imaging performance, the noise illumination technique is adopted in the indoor imaging scenario. In addition, the speed and accuracy of concealed contraband detection from acquired MMW radiometric images are usually restricted to the deficiencies in traditional artificial interpretation by security inspectors, thus an automatic recognition and location algorithm by integrating improved Fuzzy C-means clustering with moment invariants is put forward. A series of original results are also presented to demonstrate the significance and validity of these methods.

  1. Landmarks in nature to support wayfinding: the effects of seasons and experimental methods.

    PubMed

    Kettunen, Pyry; Irvankoski, Katja; Krause, Christina M; Sarjakoski, L Tiina

    2013-08-01

    Landmarks constitute an essential basis for a structural understanding of the spatial environment. Therefore, they are crucial factors in external spatial representations such as maps and verbal route descriptions, which are used to support wayfinding. However, selecting landmarks for these representations is a difficult task, for which an understanding of how people perceive and remember landmarks in the environment is needed. We investigated the ways in which people perceive and remember landmarks in nature using the thinking aloud and sketch map methods during both the summer and the winter seasons. We examined the differences between methods to identify those landmarks that should be selected for external spatial representations, such as maps or route descriptions, in varying conditions. We found differences in the use of landmarks both in terms of the methods and also between the different seasons. In particular, the participants used passage and tree-related landmarks at significantly different frequencies with the thinking aloud and sketch map methods. The results are likely to reflect the different roles of the landmark groups when using the two methods, but also the differences in counting landmarks when using both methods. Seasonal differences in the use of landmarks occurred only with the thinking aloud method. Sketch maps were drawn similarly in summertime and wintertime; the participants remembered and selected landmarks similarly independent of the differences in their perceptions of the environment due to the season. The achieved results may guide the planning of external spatial representations within the context of wayfinding as well as when planning further experimental studies. PMID:23392783

  2. Landmarks in nature to support wayfinding: the effects of seasons and experimental methods.

    PubMed

    Kettunen, Pyry; Irvankoski, Katja; Krause, Christina M; Sarjakoski, L Tiina

    2013-08-01

    Landmarks constitute an essential basis for a structural understanding of the spatial environment. Therefore, they are crucial factors in external spatial representations such as maps and verbal route descriptions, which are used to support wayfinding. However, selecting landmarks for these representations is a difficult task, for which an understanding of how people perceive and remember landmarks in the environment is needed. We investigated the ways in which people perceive and remember landmarks in nature using the thinking aloud and sketch map methods during both the summer and the winter seasons. We examined the differences between methods to identify those landmarks that should be selected for external spatial representations, such as maps or route descriptions, in varying conditions. We found differences in the use of landmarks both in terms of the methods and also between the different seasons. In particular, the participants used passage and tree-related landmarks at significantly different frequencies with the thinking aloud and sketch map methods. The results are likely to reflect the different roles of the landmark groups when using the two methods, but also the differences in counting landmarks when using both methods. Seasonal differences in the use of landmarks occurred only with the thinking aloud method. Sketch maps were drawn similarly in summertime and wintertime; the participants remembered and selected landmarks similarly independent of the differences in their perceptions of the environment due to the season. The achieved results may guide the planning of external spatial representations within the context of wayfinding as well as when planning further experimental studies.

  3. An experimental study of the accuracy in measurement of modulation transfer function using an edge method

    NASA Astrophysics Data System (ADS)

    Lee, Dong-Hoon; Kim, Ye-seul; Park, Hye-Suk; Lee, Young-Jin; Kim, Hee-Joung

    2015-03-01

    Image evaluation is necessary in digital radiography (DR) which is widely used in medical imaging. Among parameters of image evaluation, modulation transfer function (MTF) is the important factor in the field of medical imaging and necessary to obtain detective quantum efficiency (DQE) which represents overall performance of the detector signal-to-noise ratio. However, the accurate measurement of MTF is still not easy because of geometric effect, electric noise, quantum noise, and truncation error. Therefore, in order to improve accuracy of MTF, four experimental methods were tested in this study such as changing the tube current, applying smoothing method in edge spread function (ESF), adjusting line spread function (LSF) range, and changing tube angle. Our results showed that MTF's fluctuation was decreased by high tube current and smoothing method. However, tube current should not exceed detector saturation and smoothing in ESF causes a distortion in ESF and MTF. In addition, decreasing LSF range diminished fluctuation and the number of sampling in MTF and high tube angle generates degradation in MTF. Based on these results, excessively low tube current and the smoothing method should be avoided. Also, optimal range of LSF considering reduction of fluctuation and the number of sampling in MTF was necessary and precise tube angle is essential to obtain an accurate MTF. In conclusion, our results demonstrated that accurate MTF can be acquired.

  4. REVIEW: A review of in vivo experimental methods to determine the composition of the human body

    NASA Astrophysics Data System (ADS)

    Sutcliffe, J. F.

    1996-05-01

    This review of experimental methods employed in the measurement of the composition of the human body covers the developments that have occurred over the past 30 years. Early methods such as hydrodensitometry and skinfold anthropometry have been superseded by dual-energy x-ray absorptiometry and bioelectrical impedance spectroscopy. The measurement of the whole-body abundance of certain elements by isotopic dilution, neutron activation analysis and x-ray fluorescence can give important information of clinical significance, but neutron activation facilities remain available in only a few centres worldwide. The relatively simple, rapid and risk-free electrical methods such as multifrequency bioelectrical impedance analysis, which can be employed at the bedside, have been found to be more complicated in their interpretation. Electromagnetic methods may only measure the composition of the human body at its surface. X-ray computed tomography and magnetic resonance imaging have not yet been employed much in body composition measurements. Some models for the composition of the human body are reviewed.

  5. Experimental and theoretical analysis of a method to predict thermal runaway in Li-ion cells

    NASA Astrophysics Data System (ADS)

    Shah, Krishna; Chalise, Divya; Jain, Ankur

    2016-10-01

    Thermal runaway is a well-known safety concern in Li-ion cells. Methods to predict and prevent thermal runaway are critically needed for enhanced safety and performance. While much work has been done on understanding the kinetics of various heat generation processes during thermal runaway, relatively lesser work exists on understanding how heat removal from the cell influences thermal runaway. Through a unified analysis of heat generation and heat removal, this paper derives and experimentally validates a non-dimensional parameter whose value governs whether or not thermal runaway will occur in a Li-ion cell. This parameter is named the Thermal Runaway Number (TRN), and comprises contributions from thermal transport within and outside the cell, as well as the temperature dependence of heat generation rate. Experimental data using a 26650 thermal test cell are in good agreement with the model, and demonstrate the dependence of thermal runaway on various thermal transport and heat generation parameters. This parameter is used to predict the thermal design space in which the cell will or will not experience thermal runaway. By combining all thermal processes contributing to thermal runaway in a single parameter, this work contributes towards a unified understanding of thermal runaway, and provides the fundamental basis for design tools for safe, high-performance Li-ion batteries.

  6. DETECTORS AND EXPERIMENTAL METHODS: An artificial neural network for proton identification in HERMES data

    NASA Astrophysics Data System (ADS)

    Wang, Si-Guang; Mao, Ya-Jun; Ye, Hong-Xue

    2009-03-01

    The HERMES time-of-flight (TOF) system is used for proton identification, but must be carefully calibrated for systematic biases in the equipment. This paper presents an artificial neural network (ANN) trained to recognize protons from Λ° decay using only raw event data such as time delay, momentum, and trajectory. To avoid the systematic errors associated with Monte Carlo models, we collect a sample of raw experimental data from the year 2000. We presume that when for a positive hadron (assigned one proton mass) and a negative hadron (assigned one π- mass) the reconstructed invariant mass lies within the Λ° resonance, the positive hadron is more likely to be a proton. Such events are assigned an output value of one during the training process; all others were assigned the output value zero. The trained ANN is capable of identifying protons in independent experimental data, with an efficiency equivalent to the traditional TOF calibration. By modifying the threshold for proton identification, a researcher can trade off between selection efficiency and background rejection power. This simple and convenient method is applicable to similar detection problems in other experiments.

  7. Integration of experimental and computational methods for identifying geometric, thermal and diffusive properties of biomaterials

    NASA Astrophysics Data System (ADS)

    Weres, Jerzy; Kujawa, Sebastian; Olek, Wiesław; Czajkowski, Łukasz

    2016-04-01

    Knowledge of physical properties of biomaterials is important in understanding and designing agri-food and wood processing industries. In the study presented in this paper computational methods were developed and combined with experiments to enhance identification of agri-food and forest product properties, and to predict heat and water transport in such products. They were based on the finite element model of heat and water transport and supplemented with experimental data. Algorithms were proposed for image processing, geometry meshing, and inverse/direct finite element modelling. The resulting software system was composed of integrated subsystems for 3D geometry data acquisition and mesh generation, for 3D geometry modelling and visualization, and for inverse/direct problem computations for the heat and water transport processes. Auxiliary packages were developed to assess performance, accuracy and unification of data access. The software was validated by identifying selected properties and using the estimated values to predict the examined processes, and then comparing predictions to experimental data. The geometry, thermal conductivity, specific heat, coefficient of water diffusion, equilibrium water content and convective heat and water transfer coefficients in the boundary layer were analysed. The estimated values, used as an input for simulation of the examined processes, enabled reduction in the uncertainty associated with predictions.

  8. Microbiota of Soil-Like Substrate Depending on Wheat Straw Processing Method in Experimental LSS Model

    NASA Astrophysics Data System (ADS)

    Tirranen, Lyalya; Sysoeva, Olga

    In previous experiments conducted in the closed environmental system BIOS-3 plant waste and test persons' exometabolites were carried away from the life-support system (LSS). It is possible to create a new-generation LSS with a higher degree of matter cycle closure by adding to the soil-like substrate inedible plant waste used for cultivation of plants in the experimental LSS model. Using single-factor analysis of variance, we estimated the effect of the introduced inedible plant waste on the microbiota of the soil-like substrate (SLS). The plant waste was used: to increase the degree of matter cycle closure in the system; to replace the volume of soil-like substrate in the system; as a fertilizer for growing higher plants in the experimental LSS model. A statistically significant effect of wheat straw processing method on the number of all microorganism groups was observed in different variants of the experiment. The obtained results can be used in planning and carrying out of subsequent experiments with higher plants cultivated on SLS with waste in a closed environmental system including humans.

  9. Spatial memory: Theoretical basis and comparative review on experimental methods in rodents.

    PubMed

    Paul, Carrillo-Mora; Magda, Giordano; Abel, Santamaría

    2009-11-01

    The assessment of learning and memory in animal models has been widely employed in scientific research for a long time. Among these models, those representing diseases with primary processes of affected memory - such as amnesia, dementia, brain aging, etc. - studies dealing with the toxic effects of specific drugs, and other exploring neurodevelopment, trauma, epilepsy and neuropsychiatric disorders, are often called on to employ these tools. There is a diversity of experimental methods assessing animal learning and memory skills. Overall, mazes are the devices mostly used today to test memory in rodents; there are several types of them, but their real usefulness, advantages and applications remain to be fully established and depend on the particular variant selected by the experimenter. The aims of the present article are first, to briefly review the accumulated knowledge in regard to spatial memory tasks; second, to bring the reader information on the different types of rodent mazes available to test spatial memory; and third, to elucidate the usefulness and limitations of each of these devices.

  10. Might the Masson trichrome stain be considered a useful method for categorizing experimental tendon lesions?

    PubMed

    Martinello, Tiziana; Pascoli, Francesco; Caporale, Giovanni; Perazzi, Anna; Iacopetti, Ilaria; Patruno, Marco

    2015-08-01

    Strain injuries of tendons are the most common orthopedic injuries in athletic subjects, be they equine or human. When the tendon is suddenly damaged, an acute inflammatory phase occurs whereas its repetitive overloading may cause chronic injuries. Currently the criteria used for grading injuries are general and subjective, and therefore a reliable grading method would be an improvement. The main purpose of this study was to assess qualitatively the histological pattern of Masson trichrome stain in healthy and injured tendons; indeed, the known "paradox" of Masson staining was used to create an evaluation for the matrix of tendons, following experimental lesions and natural repair processes. A statistically significant difference of aniline-staining between healthy and lesioned tendons was observed. Overall, we think that the Masson staining might be regarded as an informative tool in discerning the collagen spatial arrangement and therefore the histological characteristics of tendons. PMID:25733060

  11. Might the Masson trichrome stain be considered a useful method for categorizing experimental tendon lesions?

    PubMed

    Martinello, Tiziana; Pascoli, Francesco; Caporale, Giovanni; Perazzi, Anna; Iacopetti, Ilaria; Patruno, Marco

    2015-08-01

    Strain injuries of tendons are the most common orthopedic injuries in athletic subjects, be they equine or human. When the tendon is suddenly damaged, an acute inflammatory phase occurs whereas its repetitive overloading may cause chronic injuries. Currently the criteria used for grading injuries are general and subjective, and therefore a reliable grading method would be an improvement. The main purpose of this study was to assess qualitatively the histological pattern of Masson trichrome stain in healthy and injured tendons; indeed, the known "paradox" of Masson staining was used to create an evaluation for the matrix of tendons, following experimental lesions and natural repair processes. A statistically significant difference of aniline-staining between healthy and lesioned tendons was observed. Overall, we think that the Masson staining might be regarded as an informative tool in discerning the collagen spatial arrangement and therefore the histological characteristics of tendons.

  12. Marine Mammal Train Oil Production Methods: Experimental Reconstructions of Norwegian Iron Age Slab-Lined Pits

    NASA Astrophysics Data System (ADS)

    Nilsen, Gørill

    2016-08-01

    Seal hunting and whaling have played an important part of people's livelihoods throughout prehistory as evidenced by rock carvings, remains of bones, artifacts from aquatic animals and hunting tools. This paper focuses on one of the more elusive resources relating to such activities: marine mammal blubber. Although marine blubber easily decomposes, the organic material has been documented from the Mesolithic Period onwards. Of particular interest in this article are the many structures in Northern Norway from the Iron Age and in Finland on Kökar, Åland, from both the Bronze and Early Iron Ages in which these periods exhibited traits interpreted as being related to oil rendering from marine mammal blubber. The article discusses methods used in this oil production activity based on historical sources, archaeological investigations and experimental reconstruction of Iron Age slab-lined pits from Northern Norway.

  13. Contaminated water delivery as a simple and effective method of experimental Salmonella infection

    PubMed Central

    O’Donnell, Hope; Pham, Oanh H.; Benoun, Joseph M.; Ravesloot-Chávez, Marietta M.; McSorley, Stephen J.

    2016-01-01

    Aims In most infectious disease models, it is assumed that gavage needle infection is the most reliable means of pathogen delivery to the gastrointestinal tract. However, this methodology can cause esophageal tearing and induces stress in experimental animals, both of which have the potential to impact early infection and the subsequent immune response. Materials and Methods C57BL/6 mice were orally infected with virulent Salmonella Typhimurium SL1344 either by intragastric gavage preceded by sodium bicarbonate, or by contamination of drinking water. Results We demonstrate that water contamination delivery of Salmonella is equivalent to gavage inoculation in providing a consistent model of infection. Furthermore, exposure of mice to contaminated drinking water for as little as 4 hours allowed maximal mucosal and systemic infection, suggesting an abbreviated window exists for natural intestinal entry. Conclusions Together, these data question the need for gavage delivery for infection with oral pathogens. PMID:26439708

  14. Online signal filtering based on the algebraic method and its experimental validation

    NASA Astrophysics Data System (ADS)

    Morales, R.; Segura, E.; Somolinos, J. A.; Núñez, L. R.; Sira-Ramírez, H.

    2016-01-01

    An on-line algebraic filtering scheme, based on the recently introduced algebraic approach to parameter and state estimation, is presented along with successful experimental results. The proposed filtering algorithm is based on the connections between a time derivative estimator and an algebraically based signal filtering option. The main advantages of the proposed approach are: (i) there are no appreciable delays in the filtered signal; (ii) the method does not require any statistical assessment of the noises corrupting the signal; (iii) high attenuation of the noise effects is achieved; (iv) the on-line computations are carried out in real time; and (v) high versatility and ease of implementation. Several experiments related to real depth measurements were conducted to show the effectiveness of the proposed algorithm. Comparisons are performed with different filtering alternatives.

  15. Simple experimental method for alpha particle range determination in lead iodide films

    SciTech Connect

    Dmitriev, Yuri; Bennett, Paul R.; Cirignano, Leonard J.; Klugerman, Mikhail; Shah, Kanai S.

    2007-05-15

    An experimental method for determining the range of alpha particles in films based on I-V{sub s} analysis has been suggested. The range of 5.5 MeV alpha particles in PbI{sub 2} films determined by this technique is 30{+-}5 {mu}m, and this value is in agreement with the value calculated by SRIM (the stopping and range of ions in matter), r=24 {mu}m in PbI{sub 2}. More than 100 I-V{sub s} of PbI{sub 2} films with different thicknesses and quality have been analyzed, and the influence of alpha particle radiation on PbI{sub 2} I-V{sub s} curves has been studied. Developed analytical methods (dependence of current density on electric field and conception of surface defects) were used, and the method limitations are discussed. It was shown that I-V{sub s} demonstrate the tendency to obey Ohm's law under alpha radiation. On the other hand, dark conductivity of the lead iodide films shows a typical impure character that can lead to an overestimation of the alpha particles' range in PbI{sub 2} films. After films were exposed to alpha radiation, the dark resistivity and I-V shape of some films improved. Also, a weak decrease of the charge carrier concentration, due to a decrease of the ''surface defect'' concentration (''surface refining''), was registered after successive measurements of I-V{sub s}.

  16. Experimental comparison of micro-PIXE with other methods utilized for biomineralization studies

    NASA Astrophysics Data System (ADS)

    Cichocki, T.; Heck, D.; Jarczyk, L.; Rokita, E.; Strzalkowski, A.; Sych, M.

    1988-05-01

    The present study deals with the investigation of arterial wall mineralization i.e. of inorganic compound development within artery wall under normal or pathologic conditions. Autopsy samples of human aorta as well as fragments of aorta obtained from hypercholesterolemic rabbits were used for the experiments. The samples were investigated using micro-PIXE, PIXE and PIGE techniques, infrared and Raman spectroscopy, X-ray powder diffraction and a variety of histochemical methods in order to compare the techniques based on a proton microprobe with the other methods which aimed at the investigation of inorganic deposits. Proton microprobe measurements confirm the different composition of mineral deposits found in rabbit and human aorta samples. In the case of animal aorta the apatite crystals constitute the mineral form of deposits while for human samples we deal with a mixture of different compounds. Moreover, for rabbit aorta samples the deposits were found always in the atheromas, while in human aorta sections the mineral deposits were localized in the media of the aortic wall. The proton microprobe can be considered to be a valuable addition to the experimental methods that have been applied in the study of the biomineralization process. It permits a qualitative determination of mineral deposits in situ while infrared and Raman spectroscopy as well as X-ray powder diffraction measurements may be performed only for ashed aorta samples. The possibility of in situ measurements and high detection sensitivity seem to be the most significant advantages of a proton microprobe in the study of artery wall mineralization.

  17. Use of experimental data in testing methods for design against uncertainty

    NASA Astrophysics Data System (ADS)

    Rosca, Raluca Ioana

    Modern methods of design take into consideration the fact that uncertainty is present in everyday life, whether in the form of variable loads (the strongest wind that would affect a building), material properties of an alloy, or future demand for the product or cost of labor. Moreover, the Japanese example showed that it may be more cost-effective to design taking into account the existence of the uncertainty rather than to plan to eliminate or greatly reduce it. The dissertation starts by comparing the theoretical basis of two methods for design against uncertainty, namely probability theory and possibility theory. A two-variable design problem is then used to show the differences. It is concluded that for design problems with two or more cases of failure of very different magnitude (as the stop of a car due to lack of gas or motor failure), probability theory divides existent resources in a more intuitive way than possibility theory. The dissertation continues with the description of simple experiments (building towers of dominoes) and then it presents the methodology to increase the amount of information that can be drawn from a given data set. The methodology is shown on the Bidder-Challenger problem, a simulation of a problem of a company that makes microchips to set a target speed for its next microchip. The simulations use the domino experimental data. It is demonstrated that important insights into methods of probability and possibility based design can be gained from experiments.

  18. On the reliability of HELIOSAT method: A comparison with experimental data

    SciTech Connect

    Guemene Dountio, E.; Njomo, D.; Fouda, Efa; Simo, A.

    2010-06-15

    This study deals with comparison of Cameroonian ground based measurements with estimations done using satellite images, by applying the second version of the HELIOSAT method, as computed by the web tool HELIOCLIM of the SoDa project. Measurements and satellite resources were chosen for the same period of the year 1985, on ten Cameroonian locations, distributed with mean spatial resolution of 200 km between two neighbouring stations. Correlations curves are constructed between daily irradiation estimates from satellite data and from measurements. The consequent regression equations are established, using the least square method. Finally, a brief discussion is carried out on the spatial distribution of errors observed on results. Similarly to previous studies this study confirmed the capability of the method to produce good results for the Garoua location, and established its extension on other sahelian sites, comparatively to the poor agreement observed on southern sites. Furthermore, even if the study was not done on a long period, it brought out the necessity to correct the HELIOSAT results for many Cameroonian locations, to march the experimental results. (author)

  19. Inferring Regulatory Networks from Experimental Morphological Phenotypes: A Computational Method Reverse-Engineers Planarian Regeneration

    PubMed Central

    Lobo, Daniel; Levin, Michael

    2015-01-01

    Transformative applications in biomedicine require the discovery of complex regulatory networks that explain the development and regeneration of anatomical structures, and reveal what external signals will trigger desired changes of large-scale pattern. Despite recent advances in bioinformatics, extracting mechanistic pathway models from experimental morphological data is a key open challenge that has resisted automation. The fundamental difficulty of manually predicting emergent behavior of even simple networks has limited the models invented by human scientists to pathway diagrams that show necessary subunit interactions but do not reveal the dynamics that are sufficient for complex, self-regulating pattern to emerge. To finally bridge the gap between high-resolution genetic data and the ability to understand and control patterning, it is critical to develop computational tools to efficiently extract regulatory pathways from the resultant experimental shape phenotypes. For example, planarian regeneration has been studied for over a century, but despite increasing insight into the pathways that control its stem cells, no constructive, mechanistic model has yet been found by human scientists that explains more than one or two key features of its remarkable ability to regenerate its correct anatomical pattern after drastic perturbations. We present a method to infer the molecular products, topology, and spatial and temporal non-linear dynamics of regulatory networks recapitulating in silico the rich dataset of morphological phenotypes resulting from genetic, surgical, and pharmacological experiments. We demonstrated our approach by inferring complete regulatory networks explaining the outcomes of the main functional regeneration experiments in the planarian literature; By analyzing all the datasets together, our system inferred the first systems-biology comprehensive dynamical model explaining patterning in planarian regeneration. This method provides an automated

  20. An experimental study of rill sediment delivery in purple soil, using the volume-replacement method

    PubMed Central

    Huang, Yuhan; Luo, Banglin; Ding, Linqiao; Gong, Chunming

    2015-01-01

    Experimental studies provide a basis for understanding the mechanisms of rill erosion and can provide estimates for parameter values in physical models simulating the erosion process. In this study, we investigated sediment delivery during rill erosion in purple soil. We used the volume-replacement method to measure the volume of eroded soil and hence estimate the mass of eroded soil. A 12 m artificial rill was divided into the following sections: 0–0.5 m, 0.5–1 m, 1–2 m, 2–3 m, 3–4 m, 4–5 m, 5–6 m, 6–7 m, 7–8 m, 8–10 m, and 10–12 m. Erosion trials were conducted with three flow rates (2 L/min, 4 L/min, and 8 L/min) and five slope gradients (5°, 10°, 15°, 20°, and 25°). The eroded rill sections were refilled with water to measure the eroded volume in each section and subsequently calculate the eroded sediment mass. The cumulative sediment mass was used to compute the sediment concentration along the length of the rill. The results show that purple soil sediment concentration increases with rill length before eventually reaching a maximal value; that is, the rate of increase in sediment concentration is greatest at the rill inlet and then gradually slows. Steeper slopes and higher flow rates result in sediment concentration increasing more rapidly along the rill length and the maximum sediment concentration being reached at an earlier location in the rill. Slope gradient and flow rate both result in an increase in maximal sediment concentration and accumulated eroded amount. However, slope gradient has a greater influence on rill erosion than flow rate. The results and experimental method in this study may provide a reference for future rill-erosion experiments. PMID:26734498

  1. Experimental study and finite element analysis based on equivalent load method for laser ultrasonic measurement of elastic constants.

    PubMed

    Zhan, Yu; Liu, Changsheng; Zhang, Fengpeng; Qiu, Zhaoguo

    2016-07-01

    The laser ultrasonic generation of Rayleigh surface wave and longitudinal wave in an elastic plate is studied by experiment and finite element method. In order to eliminate the measurement error and the time delay of the experimental system, the linear fitting method of experimental data is applied. The finite element analysis software ABAQUS is used to simulate the propagation of Rayleigh surface wave and longitudinal wave caused by laser excitation on a sheet metal sample surface. The equivalent load method is proposed and applied. The pulsed laser is equivalent to the surface load in time and space domain to meet the Gaussian profile. The relationship between the physical parameters of the laser and the load is established by the correction factor. The numerical solution is in good agreement with the experimental result. The simple and effective numerical and experimental methods for laser ultrasonic measurement of the elastic constants are demonstrated. PMID:27079489

  2. Experimental study and finite element analysis based on equivalent load method for laser ultrasonic measurement of elastic constants.

    PubMed

    Zhan, Yu; Liu, Changsheng; Zhang, Fengpeng; Qiu, Zhaoguo

    2016-07-01

    The laser ultrasonic generation of Rayleigh surface wave and longitudinal wave in an elastic plate is studied by experiment and finite element method. In order to eliminate the measurement error and the time delay of the experimental system, the linear fitting method of experimental data is applied. The finite element analysis software ABAQUS is used to simulate the propagation of Rayleigh surface wave and longitudinal wave caused by laser excitation on a sheet metal sample surface. The equivalent load method is proposed and applied. The pulsed laser is equivalent to the surface load in time and space domain to meet the Gaussian profile. The relationship between the physical parameters of the laser and the load is established by the correction factor. The numerical solution is in good agreement with the experimental result. The simple and effective numerical and experimental methods for laser ultrasonic measurement of the elastic constants are demonstrated.

  3. TiO{sub 2} synthesized by microwave assisted solvothermal method: Experimental and theoretical evaluation

    SciTech Connect

    Moura, K.F.; Maul, J.; Albuquerque, A.R.; Casali, G.P.

    2014-02-15

    In this study, a microwave assisted solvothermal method was used to synthesize TiO{sub 2} with anatase structure. The synthesis was done using Ti (IV) isopropoxide and ethanol without templates or alkalinizing agents. Changes in structural features were observed with increasing time of synthesis and evaluated using periodic quantum chemical calculations. The anatase phase was obtained after only 1 min of reaction besides a small amount of brookite phase. Experimental Raman spectra are in accordance with the theoretical one. Micrometric spheres constituted by nanometric particles were obtained for synthesis from 1 to 30 min, while spheres and sticks were observed after 60 min. - Graphical abstract: FE-SEM images of anatase obtained with different periods of synthesis associated with the order–disorder degree. Display Omitted - Highlights: • Anatase microspheres were obtained by the microwave assisted hydrothermal method. • Only ethanol and titanium isopropoxide were used as precursors during the synthesis. • Raman spectra and XRD patterns were compared with quantum chemical calculations. • Time of synthesis increased the short-range disorder in one direction and decreased in another.

  4. An investigation on characterizing dense coal-water slurry with ultrasound: theoretical and experimental method

    SciTech Connect

    Xue, M.H.; Su, M.X.; Dong, L.L.; Shang, Z.T.; Cai, X.S.

    2010-07-01

    Particle size distribution and concentration in particulate two-phase flow are important parameters in a wide variety of industrial areas. For the purpose of online characterization in dense coal-water slurries, ultrasonic methods have many advantages such as avoiding dilution, the capability for being used in real time, and noninvasive testing, while light-based techniques are not capable of providing information because optical methods often require the slurry to be diluted. In this article, the modified Urick equation including temperature modification, which can be used to determine the concentration by means of the measurement of ultrasonic velocity in a coal-water slurry, is evaluated on the basis of theoretical analysis and experimental study. A combination of the coupled-phase model and the Bouguer-Lambert-Beer law is employed in this work, and the attenuation spectrum is measured within the frequency region from 3 to 12 MHz. Particle size distributions of the coal-water slurry at different volume fractions are obtained with the optimum regularization technique. Therefore, the ultrasonic technique presented in this work brings the possibility of using ultrasound for online measurements of dense slurries.

  5. A framework program for the teaching of alternative methods (replacement, reduction, refinement) to animal experimentation.

    PubMed

    Daneshian, Mardas; Akbarsha, Mohammad A; Blaauboer, Bas; Caloni, Francesca; Cosson, Pierre; Curren, Rodger; Goldberg, Alan; Gruber, Franz; Ohl, Frauke; Pfaller, Walter; van der Valk, Jan; Vinardell, Pilar; Zurlo, Joanne; Hartung, Thomas; Leist, Marcel

    2011-01-01

    Development of improved communication and education strategies is important to make alternatives to the use of animals, and the broad range of applications of the 3Rs concept better known and understood by different audiences. For this purpose, the Center for Alternatives to Animal Testing in Europe (CAAT-Europe) together with the Transatlantic Think Tank for Toxicology (t(4)) hosted a three-day workshop on "Teaching Alternative Methods to Animal Experimentation". A compilation of the recommendations by a group of international specialists in the field is summarized in this report. Initially, the workshop participants identified the different audience groups to be addressed and also the communication media that may be used. The main outcome of the workshop was a framework for a comprehensive educational program. The modular structure of the teaching program presented here allows adaptation to different audiences with their specific needs; different time schedules can be easily accommodated on this basis. The topics cover the 3Rs principle, basic research, toxicological applications, method development and validation, regulatory aspects, case studies and ethical aspects of 3Rs approaches. This expert consortium agreed to generating teaching materials covering all modules and providing them in an open access online repository.

  6. Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials.

    PubMed

    Hagmann, Joseph A; Le, Son T; Richter, Curt A; Seiler, David G

    2016-01-21

    Novel electronic materials are often produced for the first time by synthesis processes that yield bulk crystals (in contrast to single crystal thin film synthesis) for the purpose of exploratory materials research. Certain materials pose a challenge wherein the traditional bulk Hall bar device fabrication method is insufficient to produce a measureable device for sample transport measurement, principally because the single crystal size is too small to attach wire leads to the sample in a Hall bar configuration. This can be, for example, because the first batch of a new material synthesized yields very small single crystals or because flakes of samples of one to very few monolayers are desired. In order to enable rapid characterization of materials that may be carried out in parallel with improvements to their growth methodology, a method of device fabrication for very small samples has been devised to permit the characterization of novel materials as soon as a preliminary batch has been produced. A slight variation of this methodology is applicable to producing devices using exfoliated samples of two-dimensional materials such as graphene, hexagonal boron nitride (hBN), and transition metal dichalcogenides (TMDs), as well as multilayer heterostructures of such materials. Here we present detailed protocols for the experimental device fabrication of fragments and flakes of novel materials with micron-sized dimensions onto substrate and subsequent measurement in a commercial superconducting magnet, dry helium close-cycle cryostat magnetotransport system at temperatures down to 0.300 K and magnetic fields up to 12 T.

  7. Vibrational studies on (E)-1-((pyridine-2-yl)methylene)semicarbazide using experimental and theoretical method

    NASA Astrophysics Data System (ADS)

    Subashchandrabose, S.; Ramesh Babu, N.; Saleem, H.; Syed Ali Padusha, M.

    2015-08-01

    The (E)-1-((pyridine-2-yl)methylene)semicarbazide (PMSC) was synthesized. The experimental and theoretical study on molecular structure and vibrational spectra were carried out. The FT-IR (400-4000 cm-1), FT-Raman (50-3500 cm-1) and UV-Vis (200-500 nm) spectra of PMSC were recorded. The geometric structure, conformational analysis, vibrational wavenumbers of PMSC in the ground state have been calculated using B3LYP method of 6-311++G(d,p) basis set. The complete vibrational assignments were made on the basis of TED, calculated by SQM method. The Non-linear optical activity was measured by means of first order hyperpolarizability calculation and π-electrons of conjugative bond in the molecule. The intra-molecular charge transfer, mode hyperconjugative interaction and molecular stabilization energies were calculated. The band gap energies between occupied and unoccupied molecular orbitals were analyzed; it proposes lesser band gap with more reactivity. To understand the electronic properties of this molecule the Mulliken charges were also calculated.

  8. Experimental Sentinel-2 LAI estimation using parametric, non-parametric and physical retrieval methods - A comparison

    NASA Astrophysics Data System (ADS)

    Verrelst, Jochem; Rivera, Juan Pablo; Veroustraete, Frank; Muñoz-Marí, Jordi; Clevers, Jan G. P. W.; Camps-Valls, Gustau; Moreno, José

    2015-10-01

    Given the forthcoming availability of Sentinel-2 (S2) images, this paper provides a systematic comparison of retrieval accuracy and processing speed of a multitude of parametric, non-parametric and physically-based retrieval methods using simulated S2 data. An experimental field dataset (SPARC), collected at the agricultural site of Barrax (Spain), was used to evaluate different retrieval methods on their ability to estimate leaf area index (LAI). With regard to parametric methods, all possible band combinations for several two-band and three-band index formulations and a linear regression fitting function have been evaluated. From a set of over ten thousand indices evaluated, the best performing one was an optimized three-band combination according to (ρ560 -ρ1610 -ρ2190) / (ρ560 +ρ1610 +ρ2190) with a 10-fold cross-validation RCV2 of 0.82 (RMSECV : 0.62). This family of methods excel for their fast processing speed, e.g., 0.05 s to calibrate and validate the regression function, and 3.8 s to map a simulated S2 image. With regard to non-parametric methods, 11 machine learning regression algorithms (MLRAs) have been evaluated. This methodological family has the advantage of making use of the full optical spectrum as well as flexible, nonlinear fitting. Particularly kernel-based MLRAs lead to excellent results, with variational heteroscedastic (VH) Gaussian Processes regression (GPR) as the best performing method, with a RCV2 of 0.90 (RMSECV : 0.44). Additionally, the model is trained and validated relatively fast (1.70 s) and the processed image (taking 73.88 s) includes associated uncertainty estimates. More challenging is the inversion of a PROSAIL based radiative transfer model (RTM). After the generation of a look-up table (LUT), a multitude of cost functions and regularization options were evaluated. The best performing cost function is Pearson's χ -square. It led to a R2 of 0.74 (RMSE: 0.80) against the validation dataset. While its validation went fast

  9. Experimental evaluation of rodent exclusion methods to reduce hantavirus transmission to humans in rural housing.

    PubMed

    Glass, G E; Johnson, J S; Hodenbach, G A; Disalvo, C L; Peters, C J; Childs, J E; Mills, J N

    1997-04-01

    An experimental assessment of methods to reduce rodent infestations in rural housing was conducted in Yosemite National Park, California, Sequoia/Kings Canyon National Parks, California, and Shenandoah National Park, Virginia. During pretreatment surveys, nearly all (63 of 68) selected units had past or ongoing rodent activity inside. Active infestations were found in 58.8% of the units. Peromyscus spp. represented 91.2% of all animals caught inside housing units. Despite little harborage, rodent activity was common near housing (290 animals/2,254 trap nights). The most common species present was Peromyscus maniculatus (43-50% of all captures). This species was especially frequent (49-87% of Peromyscus captures) around the foundations of housing units. Habitat had little effect on captures. There were 1.8 Peromyscus caught per unit along the foundations of housing in modified rural settings with grass lawns compared with 1.2 Peromyscus caught per unit in sites located in mature woodlands. During autumn of 1994, randomly selected housing units were rodent proofed by sealing openings associated with chases, roof eaves, and attics with insulation and wire mesh. Housing was examined and the fauna was resampled in the spring-summer of 1995. Rodent-proofed houses were infested significantly less often (3 of 28) than control houses (13 of 36) (P = 0.02) and the intensity of infestation was lower in experimental houses (6 versus 23 mice/treatment). More than 25% of the mice trapped inside the houses had been marked outside the houses during the three-day surveys, demonstrating movement of mice adjacent to the buildings into not rodent-proofed housing. As in the previous autumn, most of the animals captured in (98.9%) and along the foundations of the houses (77.5%) were Peromyscus spp. These results demonstrate that Peromyscus frequently invade rural housing but rodent-proofing effectively eliminates or substantially reduces rodent activity.

  10. The dynamics of a cantilevered pipe aspirating fluid studied by experimental, numerical and analytical methods

    NASA Astrophysics Data System (ADS)

    Giacobbi, Dana B.; Rinaldi, Stephanie; Semler, Christian; Païdoussis, Michael P.

    2012-04-01

    This paper investigates the dynamics of a slender, flexible, aspirating cantilevered pipe, ingesting fluid at its free end and conveying it towards its clamped end. The problem is interesting not only from a fundamental perspective, but also because applications exist, notably in ocean mining. First, the need for the present work is demonstrated through a review of previous research into the topic - spanning many years and yielding often contradictory results - most recently suggesting that the system loses stability by flutter at relatively low flow velocities. In the present paper, that conclusion is refined and expanded upon by exploring the problem in three ways: experimentally, numerically and analytically. First, air-flow experiments were conducted using different elastomer pipes and intake shapes, in which the flow velocity of the fluid was varied and the frequency and amplitude of oscillation of the pipe were measured. Second, a fully coupled Computational Fluid Dynamics (CFD) and Computational Structural Mechanics (CSM) model was developed in ANSYS™ in order to simulate experiments and corroborate experimental results. Finally, using a Newtonian analytical approach, a new linear equation of motion describing the system was derived, and then solved via the Galerkin method in order to determine its stability characteristics. Heavily influenced by the CFD analysis, the proposed analytical model is different from previous ones, most notably because of the inclusion of a two-part fluid depressurisation at the intake. In general, both the actual and numerical experiments suggest a first-mode loss of stability by flutter at flow velocities comparable to those for the discharging case, which agrees with the results from the new analytical model.

  11. Experimental evaluation of rodent exclusion methods to reduce hantavirus transmission to humans in rural housing.

    PubMed

    Glass, G E; Johnson, J S; Hodenbach, G A; Disalvo, C L; Peters, C J; Childs, J E; Mills, J N

    1997-04-01

    An experimental assessment of methods to reduce rodent infestations in rural housing was conducted in Yosemite National Park, California, Sequoia/Kings Canyon National Parks, California, and Shenandoah National Park, Virginia. During pretreatment surveys, nearly all (63 of 68) selected units had past or ongoing rodent activity inside. Active infestations were found in 58.8% of the units. Peromyscus spp. represented 91.2% of all animals caught inside housing units. Despite little harborage, rodent activity was common near housing (290 animals/2,254 trap nights). The most common species present was Peromyscus maniculatus (43-50% of all captures). This species was especially frequent (49-87% of Peromyscus captures) around the foundations of housing units. Habitat had little effect on captures. There were 1.8 Peromyscus caught per unit along the foundations of housing in modified rural settings with grass lawns compared with 1.2 Peromyscus caught per unit in sites located in mature woodlands. During autumn of 1994, randomly selected housing units were rodent proofed by sealing openings associated with chases, roof eaves, and attics with insulation and wire mesh. Housing was examined and the fauna was resampled in the spring-summer of 1995. Rodent-proofed houses were infested significantly less often (3 of 28) than control houses (13 of 36) (P = 0.02) and the intensity of infestation was lower in experimental houses (6 versus 23 mice/treatment). More than 25% of the mice trapped inside the houses had been marked outside the houses during the three-day surveys, demonstrating movement of mice adjacent to the buildings into not rodent-proofed housing. As in the previous autumn, most of the animals captured in (98.9%) and along the foundations of the houses (77.5%) were Peromyscus spp. These results demonstrate that Peromyscus frequently invade rural housing but rodent-proofing effectively eliminates or substantially reduces rodent activity. PMID:9158040

  12. On the Use of Experimental Methods to Improve Confidence in Educed Impedance

    NASA Technical Reports Server (NTRS)

    Jones, Michael G.; Watson, Willie R.

    2011-01-01

    Results from impedance eduction methods developed by NASA Langley Research Center are used throughout the acoustic liner community. In spite of recent enhancements, occasional anomalies persist with these methods, generally at frequencies where the liner produces minimal attenuation. This investigation demonstrates an experimental approach to educe impedance with increased confidence over a desired frequency range, by combining results from successive tests with different cavity depths. A series of tests is conducted with three wire-mesh facesheets, for which the results should be weakly dependent on source sound pressure level and mean grazing flow speed. First, a raylometer is used to measure the DC flow resistance of each facesheet. These facesheets are then mounted onto a frame and a normal incidence tube is used to determine their respective acoustic impedance spectra. A comparison of the acoustic resistance component with the DC flow resistance for each facesheet is used to validate the measurement process. Next, each facesheet is successively mounted onto three frames with different cavity depths, and a grazing flow impedance tube is used to educe their respective acoustic impedance spectra with and without mean flow. The no-flow results are compared with those measured in the normal incidence tube to validate the impedance eduction method. Since the anti-resonance frequency varies with cavity depth, each sample provides robust results over a different frequency range. Hence, a combination of results can be used to determine the facesheet acoustic resistance. When combined with the acoustic reactance, observed to be weakly dependent on the source sound pressure level and grazing flow Mach number, the acoustic impedance can be educed with increased confidence. Representative results of these tests are discussed, and the complete database is available in electronic format upon request.

  13. Linking experimental results, biological networks and sequence analysis methods using Ontologies and Generalised Data Structures.

    PubMed

    Koehler, Jacob; Rawlings, Chris; Verrier, Paul; Mitchell, Rowan; Skusa, Andre; Ruegg, Alexander; Philippi, Stephan

    2005-01-01

    The structure of a closely integrated data warehouse is described that is designed to link different types and varying numbers of biological networks, sequence analysis methods and experimental results such as those coming from microarrays. The data schema is inspired by a combination of graph based methods and generalised data structures and makes use of ontologies and meta-data. The core idea is to consider and store biological networks as graphs, and to use generalised data structures (GDS) for the storage of further relevant information. This is possible because many biological networks can be stored as graphs: protein interactions, signal transduction networks, metabolic pathways, gene regulatory networks etc. Nodes in biological graphs represent entities such as promoters, proteins, genes and transcripts whereas the edges of such graphs specify how the nodes are related. The semantics of the nodes and edges are defined using ontologies of node and relation types. Besides generic attributes that most biological entities possess (name, attribute description), further information is stored using generalised data structures. By directly linking to underlying sequences (exons, introns, promoters, amino acid sequences) in a systematic way, close interoperability to sequence analysis methods can be achieved. This approach allows us to store, query and update a wide variety of biological information in a way that is semantically compact without requiring changes at the database schema level when new kinds of biological information is added. We describe how this datawarehouse is being implemented by extending the text-mining framework ONDEX to link, support and complement different bioinformatics applications and research activities such as microarray analysis, sequence analysis and modelling/simulation of biological systems. The system is developed under the GPL license and can be downloaded from http://sourceforge.net/projects/ondex/

  14. Assessment of experimental bond dissociation energies using composite ab initio methods and evaluation of the performances of density functional methods in the calculation of bond dissociation energies.

    PubMed

    Feng, Yong; Liu, Lei; Wang, Jin-Ti; Huang, Hao; Guo, Qing-Xiang

    2003-01-01

    Composite ab initio CBS-Q and G3 methods were used to calculate the bond dissociation energies (BDEs) of over 200 compounds listed in CRC Handbook of Chemistry and Physics (2002 ed.). It was found that these two methods agree with each other excellently in the calculation of BDEs, and they can predict BDEs within 10 kJ/mol of the experimental values. Using these two methods, it was found that among the examined compounds 161 experimental BDEs are valid because the standard deviation between the experimental and theoretical values for them is only 8.6 kJ/mol. Nevertheless, 40 BDEs listed in the Handbook may be highly inaccurate as the experimental and theoretical values for them differ by over 20 kJ/mol. Furthermore, 11 BDEs listed in the Handbook may be seriously flawed as the experimental and theoretical values for them differ by over 40 kJ/mol. Using the 161 cautiously validated experimental BDEs, we then assessed the performances of the standard density functional (DFT) methods including B3LYP, B3P86, B3PW91, and BH&HLYP in the calculation of BDEs. It was found that the BH&HLYP method performed poorly for the BDE calculations. B3LYP, B3P86, and B3PW91, however, performed reasonably well for the calculation of BDEs with standard deviations of about 12.1-18.0 kJ/mol. Nonetheless, all the DFT methods underestimated the BDEs by 4-17 kJ/mol in average. Sometimes, the underestimation by the DFT methods could be as high as 40-60 kJ/mol. Therefore, the DFT methods were more reliable for relative BDE calculations than for absolute BDE calculations. Finally, it was observed that the basis set effects on the BDEs calculated by the DFT methods were usually small except for the heteroatom-hydrogen BDEs. PMID:14632451

  15. Assessment of experimental bond dissociation energies using composite ab initio methods and evaluation of the performances of density functional methods in the calculation of bond dissociation energies.

    PubMed

    Feng, Yong; Liu, Lei; Wang, Jin-Ti; Huang, Hao; Guo, Qing-Xiang

    2003-01-01

    Composite ab initio CBS-Q and G3 methods were used to calculate the bond dissociation energies (BDEs) of over 200 compounds listed in CRC Handbook of Chemistry and Physics (2002 ed.). It was found that these two methods agree with each other excellently in the calculation of BDEs, and they can predict BDEs within 10 kJ/mol of the experimental values. Using these two methods, it was found that among the examined compounds 161 experimental BDEs are valid because the standard deviation between the experimental and theoretical values for them is only 8.6 kJ/mol. Nevertheless, 40 BDEs listed in the Handbook may be highly inaccurate as the experimental and theoretical values for them differ by over 20 kJ/mol. Furthermore, 11 BDEs listed in the Handbook may be seriously flawed as the experimental and theoretical values for them differ by over 40 kJ/mol. Using the 161 cautiously validated experimental BDEs, we then assessed the performances of the standard density functional (DFT) methods including B3LYP, B3P86, B3PW91, and BH&HLYP in the calculation of BDEs. It was found that the BH&HLYP method performed poorly for the BDE calculations. B3LYP, B3P86, and B3PW91, however, performed reasonably well for the calculation of BDEs with standard deviations of about 12.1-18.0 kJ/mol. Nonetheless, all the DFT methods underestimated the BDEs by 4-17 kJ/mol in average. Sometimes, the underestimation by the DFT methods could be as high as 40-60 kJ/mol. Therefore, the DFT methods were more reliable for relative BDE calculations than for absolute BDE calculations. Finally, it was observed that the basis set effects on the BDEs calculated by the DFT methods were usually small except for the heteroatom-hydrogen BDEs.

  16. A review of experimental methods for solid solubility determination in cryogenic systems

    NASA Astrophysics Data System (ADS)

    De Stefani, V.; Baba-Ahmed, A.; Richon, D.

    2004-09-01

    Over the past years, there have been a number of serious explosions in air industry, which have resulted in workers injuries and fatalities. At the same time, there has been an increase in the use of air separation products for industrial activities. The quality of air entering an air separation plant is of crucial importance for its safe and reliable operation and the interest in the solubility data of solids in cryogenic liquid solvents is closely connected to the problem of impurities accumulation in the process plant and storage tanks. Such accumulations, especially in liquid oxygen, may cause fouling and blockage in heat exchangers and pipelines and they may eventually cause serious explosions. For this reason the air contaminants composition in liquid oxygen must be determined with great precision. This paper aims at reviewing experimental methods for determining the solubility of solid compounds that may be present in the cryogenic liquefaction processing of air distillation. A review of the literature data on solubility of solids in liquid oxygen and nitrogen is included as well. Emphasis is given to the difficulties in setting-up measuring apparatuses working at extreme conditions, i.e. low compositions and low temperatures.

  17. Experimental Evaluation of a Method for Turbocharging Four-Stroke, Single Cylinder, Internal Combustion Engines

    NASA Astrophysics Data System (ADS)

    Buchman, Michael; Winter, Amos

    2015-11-01

    Turbocharging an engine increases specific power, improves fuel economy, reduces emissions, and lowers cost compared to a naturally aspirated engine of the same power output. These advantages make turbocharging commonplace for multi-cylinder engines. Single cylinder engineers are not commonly turbocharged due to the phase lag between the exhaust stroke, which powers the turbocharger, and the intake stroke, when air is pumped into the engine. Our proposed method of turbocharging single cylinder engines is to add an ``air capacitor'' to the intake manifold, an additional volume that acts as a buffer to store compressed air between the exhaust and intake strokes, and smooth out the pressure pulses from the turbocharger. This talk presents experimental results from a single cylinder, turbocharged diesel engine fit with various sized air capacitors. Power output from the engine was measured using a dynamometer made from a generator, with the electrical power dissipated with resistive heating elements. We found that intake air density increases with capacitor size as theoretically predicted, ranging from 40 to 60 percent depending on heat transfer. Our experiment was able to produce 29 percent more power compared to using natural aspiration. These results validated that an air capacitor and turbocharger may be a simple, cost effective means of increasing the power density of single cylinder engines.

  18. Nanostructure Characterization of Bismuth Telluride-Based Powders and Extruded Alloys by Various Experimental Methods

    NASA Astrophysics Data System (ADS)

    Vasilevskiy, D.; Bourbia, O.; Gosselin, S.; Turenne, S.; Masut, R. A.

    2011-05-01

    High-resolution transmission electron microscopy (HRTEM) observations of mechanically alloyed powders and bulk extruded alloys give experimental evidence of nanosized grains in bismuth telluride-based materials. In this study we combine HRTEM observations and x-ray diffraction (XRD) measurements, of both mechanically alloyed powders and extruded samples, with mechanical spectroscopy (MS) of extruded rods. Both HRTEM and XRD show that nanostructures with an average grain size near 25 nm can be achieved within 2 h of mechanical alloying from pure elements in an attritor-type milling machine. Residual strain orthogonal to the c-axis of powder nanoparticles has been evaluated at about 1.2% by XRD peak broadening. In contrast, XRD has been found unreliable for evaluation of grain size in highly textured extruded materials for which diffraction conditions are similar to those of single crystals, while MS appears promising for study of bulk extruded samples. Nanostructured extruded alloys at room temperature exhibit an internal friction (IF) background that is one order of magnitude higher than that of conventional zone-melted material with a grain size of several millimeters. IF as a function of sample temperature gives activation energies that are also different between bulk materials having nano- and millimeter-size grains, a result that is attributed to different creep mechanisms. Nanograin size, as well as orientation and volumetric proportion, provide valuable information for optimization of technological parameters of thermoelectric alloys and should be carefully cross-examined by various independent methods.

  19. The 'triple contrast' method in experimental wound ballistics and backspatter analysis.

    PubMed

    Schyma, Christian; Lux, Constantin; Madea, Burkhard; Courts, Cornelius

    2015-09-01

    In practical forensic casework, backspatter recovered from shooters' hands can be an indicator of self-inflicted gunshot wounds to the head. In such cases, backspatter retrieved from inside the barrel indicates that the weapon found at the death scene was involved in causing the injury to the head. However, systematic research on the aspects conditioning presence, amount and specific patterns of backspatter is lacking so far. Herein, a new concept of backspatter investigation is presented, comprising staining technique, weapon and target medium: the 'triple contrast method' was developed, tested and is introduced for experimental backspatter analysis. First, mixtures of various proportions of acrylic paint for optical detection, barium sulphate for radiocontrast imaging in computed tomography and fresh human blood for PCR-based DNA profiling were generated (triple mixture) and tested for DNA quantification and short tandem repeat (STR) typing success. All tested mixtures yielded sufficient DNA that produced full STR profiles suitable for forensic identification. Then, for backspatter analysis, sealed foil bags containing the triple mixture were attached to plastic bottles filled with 10% ballistic gelatine and covered by a 2-3-mm layer of silicone. To simulate backspatter, close contact shots were fired at these models. Endoscopy of the barrel inside revealed coloured backspatter containing typable DNA and radiographic imaging showed a contrasted bullet path in the gelatine. Cross sections of the gelatine core exhibited cracks and fissures stained by the acrylic paint facilitating wound ballistic analysis.

  20. Theoretical and experimental methods for in situ infrared spectroelectrochemistry of organic monomolecular films

    SciTech Connect

    Popenoe, D.D.

    1992-09-09

    This work describes the theoretical analysis, experimental development, and application of an in situ spectroelectrochemical cell for measuring infrared reflection-absorption spectra (IRRAS) of monolayer-coated Au surfaces beneath a thin aqueous overlayer. The cell allows the interchange of sample and reference substrates, thereby facilitating IRRAS of long-chain alkanethiolates in the C-H stretching region without electrochemical or polarization-modulation methods. The same in situ cell is combined with electrochemical modulation to study monolayers self-assembled from 11-mercaptoundecyl ferrocenecarboxylate (FcCOOC{sub 11}SH) at gold and to correlate the monolayer structure and composition with the ferrocenyl redox chemistry. An electrochemically active monolayer of an alkanethiolate derivatized with a flavin, formed by self-assembly from ethanolic solutions of 11,11`-dithiobisundecanoic acid, bis[2-(7,8-dimethyl-10-isoalloxazino)ethyl] ester, is described. IRRAS of the film, which is a candidate for future in situ spectroscopic studies, are presented and compared with transmission spectra of bulk analogs.

  1. Theoretical and experimental methods for in situ infrared spectroelectrochemistry of organic monomolecular films

    SciTech Connect

    Popenoe, D.D.

    1992-09-09

    This work describes the theoretical analysis, experimental development, and application of an in situ spectroelectrochemical cell for measuring infrared reflection-absorption spectra (IRRAS) of monolayer-coated Au surfaces beneath a thin aqueous overlayer. The cell allows the interchange of sample and reference substrates, thereby facilitating IRRAS of long-chain alkanethiolates in the C-H stretching region without electrochemical or polarization-modulation methods. The same in situ cell is combined with electrochemical modulation to study monolayers self-assembled from 11-mercaptoundecyl ferrocenecarboxylate (FcCOOC{sub 11}SH) at gold and to correlate the monolayer structure and composition with the ferrocenyl redox chemistry. An electrochemically active monolayer of an alkanethiolate derivatized with a flavin, formed by self-assembly from ethanolic solutions of 11,11'-dithiobisundecanoic acid, bis(2-(7,8-dimethyl-10-isoalloxazino)ethyl) ester, is described. IRRAS of the film, which is a candidate for future in situ spectroscopic studies, are presented and compared with transmission spectra of bulk analogs.

  2. The 'triple contrast' method in experimental wound ballistics and backspatter analysis.

    PubMed

    Schyma, Christian; Lux, Constantin; Madea, Burkhard; Courts, Cornelius

    2015-09-01

    In practical forensic casework, backspatter recovered from shooters' hands can be an indicator of self-inflicted gunshot wounds to the head. In such cases, backspatter retrieved from inside the barrel indicates that the weapon found at the death scene was involved in causing the injury to the head. However, systematic research on the aspects conditioning presence, amount and specific patterns of backspatter is lacking so far. Herein, a new concept of backspatter investigation is presented, comprising staining technique, weapon and target medium: the 'triple contrast method' was developed, tested and is introduced for experimental backspatter analysis. First, mixtures of various proportions of acrylic paint for optical detection, barium sulphate for radiocontrast imaging in computed tomography and fresh human blood for PCR-based DNA profiling were generated (triple mixture) and tested for DNA quantification and short tandem repeat (STR) typing success. All tested mixtures yielded sufficient DNA that produced full STR profiles suitable for forensic identification. Then, for backspatter analysis, sealed foil bags containing the triple mixture were attached to plastic bottles filled with 10% ballistic gelatine and covered by a 2-3-mm layer of silicone. To simulate backspatter, close contact shots were fired at these models. Endoscopy of the barrel inside revealed coloured backspatter containing typable DNA and radiographic imaging showed a contrasted bullet path in the gelatine. Cross sections of the gelatine core exhibited cracks and fissures stained by the acrylic paint facilitating wound ballistic analysis. PMID:25616629

  3. Detecting method of subjects' 3D positions and experimental advanced camera control system

    NASA Astrophysics Data System (ADS)

    Kato, Daiichiro; Abe, Kazuo; Ishikawa, Akio; Yamada, Mitsuho; Suzuki, Takahito; Kuwashima, Shigesumi

    1997-04-01

    Steady progress is being made in the development of an intelligent robot camera capable of automatically shooting pictures with a powerful sense of reality or tracking objects whose shooting requires advanced techniques. Currently, only experienced broadcasting cameramen can provide these pictures.TO develop an intelligent robot camera with these abilities, we need to clearly understand how a broadcasting cameraman assesses his shooting situation and how his camera is moved during shooting. We use a real- time analyzer to study a cameraman's work and his gaze movements at studios and during sports broadcasts. This time, we have developed a detecting method of subjects' 3D positions and an experimental camera control system to help us further understand the movements required for an intelligent robot camera. The features are as follows: (1) Two sensor cameras shoot a moving subject and detect colors, producing its 3D coordinates. (2) Capable of driving a camera based on camera movement data obtained by a real-time analyzer. 'Moving shoot' is the name we have given to the object position detection technology on which this system is based. We used it in a soccer game, producing computer graphics showing how players moved. These results will also be reported.

  4. Which electrode? A comparison of four endoscopic methods of electrocoagulation in experimental bleeding ulcers.

    PubMed Central

    Swain, C P; Mills, T N; Shemesh, E; Dark, J M; Lewin, M R; Clifton, J S; Northfield, T C; Cotton, P B; Salmon, P R

    1984-01-01

    Several inexpensive endoscopic methods of electrocoagulation have been advocated for treatment of gastrointestinal haemorrhage. We compared four types of electrode: dry monopolar - Cameron Miller (M), liquid monopolar - Storz (L), bipolar - Bicap ACMI (B), and heater probe - Seattle (H). The electrical and thermal properties of these probes were studied using computerised monitoring of energy deposition and their efficacy and safety was tested in a randomised study in 140 experimental canine gastric ulcers. At optimal pulse settings 20J (M), 70J (L), 17J (B), 15J (H), effective haemostasis was achieved in all ulcers, the mean number of pulses being M5, L6, H6 and B11, the first three requiring significantly (p less than 0.01) less pulse than B. Relative safety of the electrodes was assessed by comparing the incidence of full thickness damage at histology: B24%, H20%, L58% and M69%; B and H proving significantly (p less than 0.01) safer than L and M. Sticking was assessed as H greater than B greater than M much greater than L. Insensitivity to extreme angulation and force of application was assessed as L greater than B greater than M (H is preset). Of the two safer electrodes the heater probe was more effective than the bipolar probe. Despite its greater tendency to stick than the other devices, the heater probe appeared the most promising of the endoscopic electrodes tested. Images Fig. 1 Fig. 2 PMID:6510772

  5. Numerical and Experimental Methods for Wake Flow Analysis in Complex Terrain

    NASA Astrophysics Data System (ADS)

    Castellani, Francesco; Astolfi, Davide; Piccioni, Emanuele; Terzi, Ludovico

    2015-06-01

    Assessment and interpretation of the quality of wind farms power output is a non-trivial task, which poses at least three main challenges: reliable comprehension of free wind flow, which is stretched to the limit on very complex terrains, realistic model of how wake interactions resemble on the wind flow, awareness of the consequences on turbine control systems, including alignment patterns to the wind and, consequently, power output. The present work deals with an onshore wind farm in southern Italy, which has been a test case of IEA- Task 31 Wakebench project: 17 turbines, with 2.3 MW of rated power each, are sited on a very complex terrain. A cluster of machines is investigated through numerical and experimental methods: CFD is employed for simulating wind fields and power extraction, as well as wakes, are estimated through the Actuator Disc model. SCADA data mining techniques are employed for comparison between models and actual performances. The simulations are performed both on the real terrain and on flat terrain, in order to disentangle the effects of complex flow and wake effects. Attention is devoted to comparison between actual alignment patterns of the cluster of turbines and predicted flow deviation.

  6. [Claude Bernard, the experimental method, and the Société de Biologie].

    PubMed

    Bange, Christian

    2009-01-01

    Claude Bernard was one of the founder of the Société de Biologie created in 1849. He actively took part to it from its very beginning by presenting various communications and several important memoirs. Epistemological thoughts found in these memoirs lead to the methodological chapters introducing the volumes of his edited lessons given at the Collège de France. In 1865, these texts formed the basis to his Introduction à l'étude de la Médecine expérimentale, in which Bernard claims the experimental method should rely on the principle of determinism of the phenomena of Life. He was a dutiful President of the Société from 1867 until his death. He nevertheless was not often involved in debates, but agreed on the defense of the scientific principles he had claimed. He remained influential until his death, as noted in 1899 by the report Engène Gley wrote on the Société de Biologie during its fifty first years. Gley points regularly to Bernard's axioms which remained the true scientific credo of French biologists.

  7. Convergent methods assessing bone growth in an experimental model at dental implants in the minipig.

    PubMed

    Friedmann, Anton; Friedmann, Asisa; Grize, Leticia; Obrecht, Marcel; Dard, Michel

    2014-05-01

    Implant dentistry demonstrated its reliability in treating successfully an increased amount of patients with dental implants exhibiting hydrophilic (modSLA) or non-hydrophilic (SLA) surfaces. Objectives of this minipig study consisted in assessing bone regeneration at both types of dental implants in a new experimental model (lateral bone defects) by implementing a convergent analysis approach combining histology and contact radiography. In six adult female minipigs standardized acute alveolar defects were created, then receiving two implants in the mandibles bilaterally (modSLA and SLA, one of each combined with Guided Bone Regeneration). Animals were sacrificed after 28 days of healing. Mid-crestal specimen were analyzed assessing missing BIC to implant shoulder (fBIC); vertical bone growth upon implant surface, bone:tissue ratio and grafting material area occupied by material remnants for GBR sites. Values obtained from both analyses were compared and statistical correlations scrutinized. Although dimensions of mean differences and adjusted means given by radiographic method were lower than histological ones, comparison of different implants yielded similar results. Statistical analyses of correlation and concordance coefficients used to evaluate radiological method of measurement showed high level of concordance (concordance coefficient=0.912 and correlation coefficient=0.939) for fBIC. Similar results were observed for vertical new bone and for remnants of graft. Discrepancies for new bone and for mineralized tissue resulted in concordance coefficient of 0.182 and 0.054. The results indicate that contact X-rays can be used for morphometric assessments regarding defect fill; however, histological staining remains beneficial if greater resolution for distinguishing qualitative differences in the tissues is required. PMID:24656913

  8. Experimental Investigation of Pressure-volume-Temperature Mass Gauging Method Under Microgravity Condition by Parabolic Flight

    NASA Astrophysics Data System (ADS)

    Seo, Mansu; Park, Hana; Yoo, DonGyu; Jung, Youngsuk; Jeong, Sangkwon

    Gauging the volume or mass of liquid propellant of a rocket vehicle in space is an important issue for its economic feasibility and optimized design of loading mass. Pressure-volume-temperature (PVT) gauging method is one of the most suitable measuring techniques in space due to its simplicity and reliability. This paper presents unique experimental results and analyses of PVT gauging method using liquid nitrogen under microgravity condition by parabolic flight. A vacuum-insulated and cylindrical-shaped liquid nitrogen storage tank with 9.2 L volume is manufactured by observing regulation of parabolic flight. PVT gauging experiments are conducted under low liquid fraction condition from 26% to 32%. Pressure, temperature, and the injected helium mass into the storage tank are measured to obtain the ullage volume by gas state equation. Liquid volume is finally derived by the measured ullage volume and the known total tank volume. Two sets of parabolic flights are conducted and each set is composed of approximately 10 parabolic flights. In the first set of flights, the short initial waiting time (3 ∼ 5 seconds) cannot achieve sufficient thermal equilibrium condition at the beginning. It causes inaccurate gauging results due to insufficient information of the initial helium partial pressure in the tank. The helium injection after 12 second waiting time at microgravity condition with high mass flow rate in the second set of flights achieves successful initial thermal equilibrium states and accurate measurement results of initial helium partial pressure. Liquid volume measurement errors in the second set are within 11%.

  9. Experimental validation of an ambient vibration-based multiple damage identification method using statistical modal filtering

    NASA Astrophysics Data System (ADS)

    El-Ouafi Bahlous, S.; Smaoui, H.; El-Borgi, S.

    2009-08-01

    For civil engineering structures, ambient vibration tests are preferred over forced vibration ones because the artificially excitation of large structures having low natural frequencies is quite difficult and expensive. In the ambient vibration tests, operation disturbances can be avoided and the measured response is representative of the actual operating conditions of the structures which vibrate due to natural excitation. The proposed damage identification method is intended for moderate degrees of damage and requires vibration data relative to the current and reference states of the structure as well as a parametric finite element model. It is based on a residual generated from a modal filtering approach by the calculation of the error between the measurements at the current state and their projections onto the incomplete modal basis of the structure as identified at reference state. To detect and locate damage, the residual is evaluated by means of global, sensitivity and rejection tests, modified to allow only physically feasible simple and multiple damage scenarios. The mean of the residual, which turns out to be normally distributed, is used in the final phase of damage quantification. The proposed damage diagnosis method is validated experimentally via ambient vibration tests conducted on full-scale reinforced concrete beams and slabs which contain various simple and multiple damage configurations. With damage expressed in terms of loss of flexural stiffness, the damage detection, localization and quantification are found to be successful for degrees of damage less than about 28% of the initial flexural stiffness of the tested specimens. The exception is that, for multiple damage scenarios, the relative quantification errors may be unacceptable in locations where poor accuracy is expected.

  10. Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials.

    PubMed

    Hagmann, Joseph A; Le, Son T; Richter, Curt A; Seiler, David G

    2016-01-01

    Novel electronic materials are often produced for the first time by synthesis processes that yield bulk crystals (in contrast to single crystal thin film synthesis) for the purpose of exploratory materials research. Certain materials pose a challenge wherein the traditional bulk Hall bar device fabrication method is insufficient to produce a measureable device for sample transport measurement, principally because the single crystal size is too small to attach wire leads to the sample in a Hall bar configuration. This can be, for example, because the first batch of a new material synthesized yields very small single crystals or because flakes of samples of one to very few monolayers are desired. In order to enable rapid characterization of materials that may be carried out in parallel with improvements to their growth methodology, a method of device fabrication for very small samples has been devised to permit the characterization of novel materials as soon as a preliminary batch has been produced. A slight variation of this methodology is applicable to producing devices using exfoliated samples of two-dimensional materials such as graphene, hexagonal boron nitride (hBN), and transition metal dichalcogenides (TMDs), as well as multilayer heterostructures of such materials. Here we present detailed protocols for the experimental device fabrication of fragments and flakes of novel materials with micron-sized dimensions onto substrate and subsequent measurement in a commercial superconducting magnet, dry helium close-cycle cryostat magnetotransport system at temperatures down to 0.300 K and magnetic fields up to 12 T. PMID:26863449

  11. An Experimental Comparison of Two Methods Of Teaching Numerical Control Manual Programming Concepts; Visual Media Versus Hands-On Equipment.

    ERIC Educational Resources Information Center

    Biekert, Russell

    Accompanying the rapid changes in technology has been a greater dependence on automation and numerical control, which has resulted in the need to find ways of preparing programers for industrial machines using numerical control. To compare the hands-on equipment method and a visual media method of teaching numerical control, an experimental and a…

  12. Correction of steel casing effect for density log using numerical and experimental methods in the slim borehole

    SciTech Connect

    Hwang, Seho; Shin, Jehyun; Kim, Jongman; Won, Byeongho

    2015-03-10

    Density log is widely applied for a variety of fields such as the petroleum exploration, mineral exploration, and geotechnical survey. The logging condition of density log is normally open holes but there are frequently cased boreholes. The primary calibration curve by slim hole logging manufacturer is normally the calibration curves for the variation of borehole diameter. In this study, we have performed the correction of steel casing effects using numerical and experimental methods. We have performed numerical modeling using the Monte Carlo N-Particle (MCNP) code based on Monte Carlo method, and field experimental method from open and cased hole log. In this study, we used the FDGS (Formation Density Gamma Sonde) for slim borehole with a 100 mCi 137Cs source, three inch borehole and steel casing. The casing effect between numerical and experimental method is well matched.

  13. Experimental monitoring of the hydro-mechanical state of a discontinuity using controlled source seismic method

    NASA Astrophysics Data System (ADS)

    Place, Joachim; Blake, Oshaine; Rietbrock, Andreas; Faulkner, Dan

    2013-04-01

    Great earthquakes often occur in crystalline rocks, and basement rocks can host geothermal and hydrocarbon resources. In such rocks, the fluid storage and transfer properties depend mainly on the natural fault and fracture networks. Therefore, it is of primary importance to characterise the physical properties of the fault zones in order to better understand the seismogenic processes and how the resources can be exploited. Seismic waves are known to be sensitive to many parameters which evolve depending on the fault response to stresses and fluid type. Therefore seismic methods show a great potential to monitor the hydro-mechanical state of structures remotely, with no need for drilling through the structures. We developed a basic experimental approach at sample scale to monitor the mechanical coupling through a discontinuity between a granite sample in contact with a piece of steel, when the effective pressure (Peff) and the nature of the filling fluid vary. Piezoceramics utilised both as sources and sensors are located on the steel (in which the attenuation is assumed to be zero) and both generate and record the P and S wave fields reflected off the discontinuity at normal incidence. This permits the normal (Bn) and tangential (Bt) fracture compliances to be calculated after Schoenberg's linear slip theory from the measurement of P-P and S-S reflection coefficients. The roughness of the sample surface, as well as the effect of fluid type (air or water) and Peff were studied. Under dry conditions, it is observed that the poorer the contact area, the higher Bn and Bt, meaning that the seismic energy of P and S waves is less transmitted. Increasing the effective pressure decreases the compliances, which is interpreted as the effect of the closure of the voids at the interface; this permits more seismic energy to be transmitted through the interface. It is also observed that Bn is significantly higher than Bt at low Peff (<60 MPa). Under water saturated conditions

  14. Improvement of mechanical properties of polymeric composites: Experimental methods and new systems

    NASA Astrophysics Data System (ADS)

    Nguyen, Felix Nhanchau

    Filler- (e.g., particulate or fiber) reinforced structural polymers or polymeric composites have changed the way things are made. Today, they are found, for example, in air/ground transportation vehicles, sporting goods, ballistic barrier applications and weapons, electronic packaging, musical instruments, fashion items, and more. As the demand increases, so does the desire to have not only well balanced mechanical properties, but also light weight and low cost. This leads to a constant search for novel constituents and additives, new fabrication methods and analytical techniques. To achieve new or improved composite materials requires more than the identification of the right reinforcements to be used with the right polymer matrix at the right loading. Also, an optimized adhesion between the two phases and a toughened matrix system are needed. This calls for new methods to predict, modify and assess the level of adhesion, and new developments in matrix tougheners to minimize compromises in other mechanical/thermal properties. Furthermore, structural optimization, associated with fabrication (e.g., avoidance of fiber-fiber touching or particle aggregation), and sometimes special properties, such as electrical conductivity or magnetic susceptibility are necessary. Finally, the composite system's durability, often under hostile conditions, is generally mandatory. The present study researches new predictive and experimental methods for optimizing and characterizing filler-matrix adhesion and develops a new type of epoxy tougheners. Specifically, (1) a simple thermodynamic parameter evaluated by UNIFAC is applied successfully to screen out candidate adhesion promoters, which is necessary for optimization of the physio-chemical interactions between the two phases; (2) an optical-acoustical mechanical test assisted with an acoustic emission technique is developed to de-convolute filler debonding/delamination among many other micro failure events, and (3) novel core

  15. Development of Experimental Methods in Electroseismic Research, with Application to Aquifer Characterization

    NASA Astrophysics Data System (ADS)

    Haines, S. S.; Pride, S. R.; Klemperer, S. L.

    2001-12-01

    data show the interface response as a distinct arrival with essentially zero moveout and (depending on electrode geometry) reversed polarity on opposite sides of the shot point. This experimental design permits us to test different acquisition strategies (electrode configurations including measurements relative to a common reference electrode, various seismic sources, etc) in order to maximize the recorded interface response. It provides data with which we can design processing algorithms to remove the coseismic energy from records, a step that is vital for the interpretation of the interface response from subsurface layers. By developing a repeatable reliable protocol for data collection, processing, and interpretation, we will provide the basis for the application of the electroseismic method to site characterization problems.

  16. Cone penetration and bevameter geotechnical tests in lunar regolith simulants: discrete element method analysis and experimentation

    NASA Astrophysics Data System (ADS)

    Kulchitsky, A. V.; Johnson, J.; Duvoy, P.; Wilkinson, A.; Creager, C. M.

    2012-12-01

    For in situ resource utilization on the Moon, asteroids, Mars, or other space body it is necessary to be able to simulate the interaction of mobile platforms and excavation machines with the regolith for engineering design, planning, and operations. For accurate simulations, tools designed to measure regolith properties will need to be deployed and interpreted. Two such tools are the penetrometer, used to measure a soil strength index as a function of depth, and the bevameter, used to characterize regolith surface properties of strength, friction and sinkage. The penetrometer interrogates regolith properties from the surface to a depth limited only by the capabilities of the instrument to penetrate the regolith while a bevameter interrogates only the upper few centimeters needed to describe a mobility platform's traction and sinkage. Interpretation of penetrometer and bevameter data can be difficult, especially on low gravity objects. We use the discrete element method (DEM) model to simulate the large regolith deformations and failures associated with the tests to determine regolith properties. The DEM simulates granular material behavior using large aggregates of distinct particles. Realistic physics of particle-particle interaction introduces many granular specific phenomena such as interlocking and force chain formation that cannot be represented using continuum methods. In this work, experiments using a cone penetrometer test (CPT) and bevameter on lunar simulants JSC-1A and GRC-1 were performed at NASA Glenn Research Center. These tests were used to validate the physics in the COUPi DEM model. COUPi is a general physical DEM code being developed to model machine/regolith interactions as part of a NASA Lunar Science Institute sponsored project on excavation and mobility modeling. The experimental results were used in this work to build an accurate model to simulate the lunar regolith. The CPT consists of driving an instrumented cone with opening angle of 60

  17. An experimental investigation by optical methods of the physics and chemistry of transient plasma ignition

    NASA Astrophysics Data System (ADS)

    Pendleton, Scott James

    The use of nonequilibrium plasma generated by nanosecond discharges to ignite fuel/air mixtures, known as transient plasma ignition (TPI), has been shown to effectively reduce ignition delay and improve engine performance relative to spark ignition for combustion engines. While this method is potentially useful for many engine applications, at present the underlying physics are poorly understood. This work provides a review of previous engine implementation work as well as previous experimental work seeking to provide an understanding of the physical and chemical mechanisms of TPI. Work on producing the pulses needed for TPI, both engine testing and optical diagnostic is presented. The emission of TPI is analyzed in order to determine the spectral, spatial, and temporal behavior of the discharge. Temperature mesurements of TPI using optical emission spectroscopy (OES) show that the temperature in streamer discharge and afterglow increases, though it is difficult to quantify the increase with this method. The results of coherent anti-Stokes Raman spectroscopy temperature measurements are reported and discussed, with temperature increases up to 1500 K above ambient observed in the discharge afterglow in fuel/air mixtures. The impact of this temperature increase on TPI and the possibility of thermal ignition is considered. In addition, CARS measurements show that generation of vibrationally excited states of nitrogen is inefficient during the discharge in air but that generation occurs at a high rate roughly 5 micros following the discharge; with the addition of fuels vibrationally excited states are observed during the discharge but an increase in population is still seen at 5 micros. Possible mechanisms for this behavior are discussed. Additionally, this work uses two-photon absorption laser induced fluorescence to measure oxygen atom concentrations in streamer discharge afterglow in a variety of fuel/air mixtures in order to account for the oxygen pathways in

  18. Parameter estimation and uncertainty quantification in a biogeochemical model using optimal experimental design methods

    NASA Astrophysics Data System (ADS)

    Reimer, Joscha; Piwonski, Jaroslaw; Slawig, Thomas

    2016-04-01

    The statistical significance of any model-data comparison strongly depends on the quality of the used data and the criterion used to measure the model-to-data misfit. The statistical properties (such as mean values, variances and covariances) of the data should be taken into account by choosing a criterion as, e.g., ordinary, weighted or generalized least squares. Moreover, the criterion can be restricted onto regions or model quantities which are of special interest. This choice influences the quality of the model output (also for not measured quantities) and the results of a parameter estimation or optimization process. We have estimated the parameters of a three-dimensional and time-dependent marine biogeochemical model describing the phosphorus cycle in the ocean. For this purpose, we have developed a statistical model for measurements of phosphate and dissolved organic phosphorus. This statistical model includes variances and correlations varying with time and location of the measurements. We compared the obtained estimations of model output and parameters for different criteria. Another question is if (and which) further measurements would increase the model's quality at all. Using experimental design criteria, the information content of measurements can be quantified. This may refer to the uncertainty in unknown model parameters as well as the uncertainty regarding which model is closer to reality. By (another) optimization, optimal measurement properties such as locations, time instants and quantities to be measured can be identified. We have optimized such properties for additional measurement for the parameter estimation of the marine biogeochemical model. For this purpose, we have quantified the uncertainty in the optimal model parameters and the model output itself regarding the uncertainty in the measurement data using the (Fisher) information matrix. Furthermore, we have calculated the uncertainty reduction by additional measurements depending on time

  19. INVESTIGATION ON THE OSCILLATING GAS FLOW ALONG AN INERTANCE TUBE BY EXPERIMENTAL AND CFD METHODS

    SciTech Connect

    Chen Houlei; Zhao Miguang; Yang Luwei; Cai Jinghui; Hong Guotong; Liang Jingtao

    2010-04-09

    To investigate the oscillating gas flow along an inertance tube used in pulse tube coolers, a CFD model is set up for FLUENT and an experimental measuring cell is designed and optimized by CFD results. Some characteristics of oscillating flow are demonstrated and discussed. Then, the flow status along an inertance tube is measured by the optimized measuring cell. The experimental results validate the simulating results.

  20. Measuring the subjective value of risky and ambiguous options using experimental economics and functional MRI methods.

    PubMed

    Levy, Ifat; Rosenberg Belmaker, Lior; Manson, Kirk; Tymula, Agnieszka; Glimcher, Paul W

    2012-09-19

    Most of the choices we make have uncertain consequences. In some cases the probabilities for different possible outcomes are precisely known, a condition termed "risky". In other cases when probabilities cannot be estimated, this is a condition described as "ambiguous". While most people are averse to both risk and ambiguity(1,2), the degree of those aversions vary substantially across individuals, such that the subjective value of the same risky or ambiguous option can be very different for different individuals. We combine functional MRI (fMRI) with an experimental economics-based method(3 )to assess the neural representation of the subjective values of risky and ambiguous options(4). This technique can be now used to study these neural representations in different populations, such as different age groups and different patient populations. In our experiment, subjects make consequential choices between two alternatives while their neural activation is tracked using fMRI. On each trial subjects choose between lotteries that vary in their monetary amount and in either the probability of winning that amount or the ambiguity level associated with winning. Our parametric design allows us to use each individual's choice behavior to estimate their attitudes towards risk and ambiguity, and thus to estimate the subjective values that each option held for them. Another important feature of the design is that the outcome of the chosen lottery is not revealed during the experiment, so that no learning can take place, and thus the ambiguous options remain ambiguous and risk attitudes are stable. Instead, at the end of the scanning session one or few trials are randomly selected and played for real money. Since subjects do not know beforehand which trials will be selected, they must treat each and every trial as if it and it alone was the one trial on which they will be paid. This design ensures that we can estimate the true subjective value of each option to each subject. We

  1. Application of a panel method to wake-vortex/wing interaction and comparison with experimental data

    NASA Technical Reports Server (NTRS)

    Smith, Brian E.; Ross, James C.

    1987-01-01

    The ability of the Vortex Separation AEROdynamics (VSAERO) program to calculate aerodynamic loads on wings due to interaction with free vortices was studied. The loads were calculated for various positions of a downstream following wing relative to an upstream vortex-generating wing. Calculated vortex-induced span loads, rolling-moment coefficients, and lift coefficients on the following wing were compared with experimental results of McMillan et al. and El-Ramly et al. Comparisons of calculated and experimental vortex tangential velocities were also made.

  2. Experimental Method Development for Estimating Solid-phase Diffusion Coefficients and Material/Air Partition Coefficients of SVOCs

    EPA Science Inventory

    The solid-phase diffusion coefficient (Dm) and material-air partition coefficient (Kma) are key parameters for characterizing the sources and transport of semivolatile organic compounds (SVOCs) in the indoor environment. In this work, a new experimental method was developed to es...

  3. Evaluating Propensity Score Methods in a Quasi-Experimental Study of the Impact of Menu-Labeling

    PubMed Central

    Mayne, Stephanie L.; Lee, Brian K.; Auchincloss, Amy H.

    2015-01-01

    Background Quasi-experimental studies of menu labeling have found mixed results for improving diet. Differences between experimental groups can hinder interpretation. Propensity scores are an increasingly common method to improve covariate balance, but multiple methods exist and the improvements associated with each method have rarely been compared. In this re-analysis of the impact of menu labeling, we compare multiple propensity score methods to determine which methods optimize balance between experimental groups. Methods Study participants included adult customers who visited full-service restaurants with menu labeling (treatment) and without (control). We compared the balance between treatment groups obtained by four propensity score methods: 1) 1:1 nearest neighbor matching (NN), 2) augmented 1:1 NN (using caliper of 0.2 and an exact match on an imbalanced covariate), 3) full matching, and 4) inverse probability weighting (IPW). We then evaluated the treatment effect on differences in nutrients purchased across the different methods. Results 1:1 NN resulted in worse balance than the original unmatched sample (average standardized absolute mean distance [ASAM]: 0.185 compared to 0.171). Augmented 1:1 NN improved balance (ASAM: 0.038) but resulted in a large reduction in sample size. Full matching and IPW improved balance over the unmatched sample without a reduction in sample size (ASAM: 0.049 and 0.031, respectively). Menu labeling was associated with decreased calories, fat, sodium and carbohydrates in the unmatched analysis. Results were qualitatively similar in the propensity score matched/weighted models. Conclusions While propensity scores offer an increasingly popular tool to improve causal inference, choosing the correct method can be challenging. Our results emphasize the benefit of examining multiple methods to ensure results are consistent, and considering approaches beyond the most popular method of 1:1 NN matching. PMID:26677849

  4. Guided-Inquiry Labs Using Bean Beetles for Teaching the Scientific Method & Experimental Design

    ERIC Educational Resources Information Center

    Schlueter, Mark A.; D'Costa, Allison R.

    2013-01-01

    Guided-inquiry lab activities with bean beetles ("Callosobruchus maculatus") teach students how to develop hypotheses, design experiments, identify experimental variables, collect and interpret data, and formulate conclusions. These activities provide students with real hands-on experiences and skills that reinforce their understanding of the…

  5. Andragogical and Pedagogical Methods Compared: A Review of the Experimental Literature.

    ERIC Educational Resources Information Center

    Rachal, John R.

    Although andragogy became an article of faith among many adult educators in the 25 years since Knowles first popularized the concept, relatively few studies have attempted to compare andragogy and pedagogy experimentally. Eighteen studies that attempted to do so included 15 dissertations and 3 journal articles. The studies were organized by…

  6. Return to Our Roots: Raising Radishes to Teach Experimental Design. Methods and Techniques.

    ERIC Educational Resources Information Center

    Stallings, William M.

    1993-01-01

    Reviews research in teaching applied statistics. Concludes that students should analyze data from studies they have designed and conducted. Describes an activity in which students study germination and growth of radish seeds. Includes a table providing student instructions for both the experimental procedure and data analysis. (CFR)

  7. An Experimental Evaluation of the Effectiveness of an Audio-Tutorial Method in Teaching Vocational Agriculture.

    ERIC Educational Resources Information Center

    McVey, Gary C.

    To determine the effectiveness of an audio-tutorial technique in vocational agriculture, six treatment schools and six control schools were randomly selected from 48 Iowa high schools qualifying for participation in the study. While each school was provided the same reference material and teaching outline for the 14-day experimental period, the…

  8. Comparison of Breast Health Teaching Methods for Adolescent Females: Results of a Quasi-Experimental Study

    ERIC Educational Resources Information Center

    Evans, Retta R.; Horton, Jacqueline A.; Ahmad, Wajih A.; Davies, Susan L.; Snyder, Scott W.; Macrina, David M.

    2013-01-01

    Purpose: A breast health educational program was administered in two public high school settings in north Alabama to subjects enrolled in health related courses. The purpose of this quasi-experimental study was to determine if teaching breast health with or without interactive learning would affect the breast health knowledge and beliefs of…

  9. Adsorption of benzaldehyde at the surface of ice, studied by experimental method and computer simulation.

    PubMed

    Petitjean, Mélanie; Hantal, György; Chauvin, Coline; Mirabel, Philippe; Le Calvé, Stéphane; Hoang, Paul N M; Picaud, Sylvain; Jedlovszky, Pál

    2010-06-15

    Adsorption study of benzaldehyde on ice surfaces is performed by combining experimental and theoretical approaches. The experiments are conducted over the temperature range 233-253 K using a coated wall flow tube coupled to a mass spectrometric detector. Besides the experimental way, the adsorption isotherm is also determined by performing a set of grand canonical Monte Carlo simulations at 233 K. The experimental and calculated adsorption isotherms show a very good agreement within the corresponding errors. Besides, both experimental and theoretical studies permit us to derive the enthalpy of adsorption of benzaldehyde on ice surfaces DeltaH(ads), which are in excellent agreement: DeltaH(ads) = -61.4 +/- 9.7 kJ/mol (experimental) and DeltaH(ads) = -59.4 +/- 5.1 kJ/mol (simulation). The obtained results indicate a much stronger ability of benzaldehyde of being adsorbed at the surface of ice than that of small aliphatic aldehydes, such as formaldehyde or acetaldehyde. At low surface coverages the adsorbed molecules exclusively lie parallel with the ice surface. With increasing surface coverage, however, the increasing competition of the adsorbed molecules for the surface area to be occupied leads to the appearance of two different perpendicular orientations relative to the surface. In the first orientation, the benzaldehyde molecule turns its aldehyde group toward the ice phase, and, similarly to the molecules in the lying orientation, forms a hydrogen bond with a surface water molecule. In the other perpendicular orientation the aldehyde group turns to the vapor phase, and its O atom interacts with the delocalized pi system of the benzene ring of a nearby lying benzaldehyde molecule of the second molecular layer. In accordance with this observed scenario, the saturated adsorption layer, being stable in a roughly 1 kJ/mol broad range of chemical potentials, contains, besides the first molecular layer, also traces of the second molecular layer of adsorbed

  10. Graphite furnace atomic absorption spectrophotometry--a novel method to quantify blood volume in experimental models of intracerebral hemorrhage.

    PubMed

    Kashefiolasl, Sepide; Foerch, Christian; Pfeilschifter, Waltraud

    2013-02-15

    Intracerebral hemorrhage (ICH) accounts for 10% of all strokes and has a significantly higher mortality than cerebral ischemia. For decades, ICH has been neglected by experimental stroke researchers. Recently, however, clinical trials on acute blood pressure lowering or hyperacute supplementation of coagulation factors in ICH have spurred an interest to also design and improve translational animal models of spontaneous and anticoagulant-associated ICH. Hematoma volume is a substantial outcome parameter of most experimental ICH studies. We present graphite furnace atomic absorption spectrophotometric analysis (AAS) as a suitable method to precisely quantify hematoma volumes in rodent models of ICH.

  11. A simple method of calculating power-law velocity profile exponents from experimental data. [for boundary layer shape factor

    NASA Technical Reports Server (NTRS)

    Allen, J. M.

    1974-01-01

    Analytical expressions for the effects of compressibility and heat transfer on laminar and turbulent shape factors H have been developed. Solving the turbulent equation for the power law velocity profile exponent N has resulted in a simple technique by which the N values of experimental turbulent profiles can be calculated directly from the integral parameters. Thus the data plotting, curve fitting, and slope measuring, which is the normal technique of obtaining experimental N values, is eliminated. The N values obtained by this method should be within the accuracy with which they could be measured.

  12. Thermal accommodation of gases on solid surfaces - Description of experimental methods and of some recently completed investigations

    NASA Astrophysics Data System (ADS)

    Thomas, L. B.

    An inventory is presented of state-of-the-art experimental methods for clean surface accommodation coefficients (ACs). It is noted that special procedures are needed to maintain metal surfaces, once cleaned, in that condition for extended periods which will allow AC measurements to be conducted. Attention is given to the Pyrex glass-based vacuum systems, McLeod gauges, and getter-employing experimental tubes used in AC measurements, as well as to sample results from AC investigations, conducted in 1980-1982, which dealt with inert gases on alkali metals, heats of sublimation, and the transition regime.

  13. A proposed experimental method for interpreting Doppler effect measurements and determining their precision

    NASA Technical Reports Server (NTRS)

    Klann, P. G.

    1973-01-01

    The principal problem in the measurement of the Doppler reactivity effect is separating it from the thermal reactivity effects of the expansion of the heated sample. It is shown in this proposal that the thermal effects of sample expansion can be experimentally determined by making additional measurements with porous samples having the same mass and/or volume as the primary sample. By combining these results with independent measurements of the linear temperature coefficient and the computed temperature dependence of the Doppler coefficient the magnitude of the Doppler coefficient may be extracted from the data. These addiational measurements are also useful to experimentally determine the precision of the reactivity oscillator technique used to measure the reactivity effects of the heated sample.

  14. Swept shock/boundary-layer interactions: Scaling laws, flowfield structure, and experimental methods

    NASA Technical Reports Server (NTRS)

    Settles, Gary S.

    1993-01-01

    A general review is given of several decades of research on the scaling laws and flowfield structures of swept shock wave/turbulent boundary layer interactions. Attention is further restricted to the experimental study and physical understanding of the steady-state aspects of these flows. The interaction produced by a sharp, upright fin mounted on a flat plate is taken as an archetype. An overall framework of quasiconical symmetry describing such interactions is first developed. Boundary-layer separation, the interaction footprint, Mach number scaling, and Reynolds number scaling are then considered, followed by a discussion of the quasiconical similarity of interactions produced by geometrically-dissimilar shock generators. The detailed structure of these interaction flowfields is next reviewed, and is illustrated by both qualitative visualizations and quantitative flow images in the quasiconical framework. Finally, the experimental techniques used to investigate such flows are reviewed, with emphasis on modern non-intrusive optical flow diagnostics.

  15. DETECTORS AND EXPERIMENTAL METHODS: Software alignment of the BESIII main drift chamber using the Kalman Filter method

    NASA Astrophysics Data System (ADS)

    Wang, Ji-Ke; Mao, Ze-Pu; Bian, Jian-Ming; Cao, Guo-Fu; Cao, Xue-Xiang; Chen, Shen-Jian; Deng, Zi-Yan; Fu, Cheng-Dong; Gao, Yuan-Ning; He, Kang-Lin; He, Miao; Hua, Chun-Fei; Huang, Bin; Huang, Xing-Tao; Ji, Xiao-Bin; Li, Fei; Li, Hai-Bo; Li, Wei-Dong; Liang, Yu-Tie; Liu, Chun-Xiu; Liu, Huai-Min; Liu, Suo; Liu, Ying-Jie; Ma, Qiu-Mei; Ma, Xiang; Mao, Ya-Jun; Mo, Xiao-Hu; Pan, Ming-Hua; Pang, Cai-Ying; Ping, Rong-Gang; Qin, Ya-Hong; Qiu, Jin-Fa; Sun, Sheng-Sen; Sun, Yong-Zhao; Wang, Liang-Liang; Wen, Shuo-Pin; Wu, Ling-Hui; Xie, Yu-Guang; Xu, Min; Yan, Liang; You, Zheng-Yun; Yuan, Chang-Zheng; Yuan, Ye; Zhang, Bing-Yun; Zhang, Chang-Chun; Zhang, Jian-Yong; Zhang, Xue-Yao; Zhang, Yao; Zheng, Yang-Heng; Zhu, Ke-Jun; Zhu, Yong-Sheng; Zhu, Zhi-Li; Zou, Jia-Heng

    2009-03-01

    Software alignment is quite important for a tracking detector to reach its ultimate position accuracy and momentum resolution. We developed a new alignment algorithm for the BESIII Main Drift Chamber using the Kalman Filter method. Two different types of data which are helix tracks and straight tracks are used to test this algorithm, and the results show that the design and implementation is successful.

  16. Experimental Plan for the Cold Demonstration (Scoping Tests) of Glass Removal Methods from a DWPF Melter

    SciTech Connect

    Smith, M.E.

    2001-09-21

    SRS and WVDP currently do not have the capability to size reduce, decontaminate, classify, and dispose of large, failed, highly contaminated equipment. Tanks Focus Area Task 777 was developed to address this problem. The first activity for Task 777 is to develop and demonstrate techniques suitable for removing the solid HLW glass from HLW melters. This experimental plan describes the work that will be performed for this glass removal demonstration.

  17. Human experimental pain models: A review of standardized methods in drug development

    PubMed Central

    Reddy, K. Sunil kumar; Naidu, M. U. R.; Rani, P. Usha; Rao, T. Ramesh Kumar

    2012-01-01

    Human experimental pain models are essential in understanding the pain mechanisms and appear to be ideally suited to test analgesic compounds. The challenge that confronts both the clinician and the scientist is to match specific treatments to different pain-generating mechanisms and hence reach a pain treatment tailored to each individual patient. Experimental pain models offer the possibility to explore the pain system under controlled settings. Standardized stimuli of different modalities (i.e., mechanical, thermal, electrical, or chemical) can be applied to the skin, muscles, and viscera for a differentiated and comprehensive assessment of various pain pathways and mechanisms. Using a multimodel-multistructure testing, the nociception arising from different body structures can be explored and modulation of specific biomarkers by new and existing analgesic drugs can be profiled. The value of human experimental pain models is to link animal and clinical pain studies, providing new possibilities for designing successful clinical trials. Spontaneous pain, the main compliant of the neuropathic patients, but currently there is no human model available that would mimic chronic pain. Therefore, current human pain models cannot replace patient studies for studying efficacy of analgesic compounds, although being helpful for proof-of-concept studies and dose finding. PMID:23626642

  18. Comparison of the Experimental Performance of Ferroelectric CPW Circuits with Method of Moment Simulations and Conformal Mapping

    NASA Technical Reports Server (NTRS)

    VanKeuls, Fred W.; Chevalier, Chris T.; Miranda, Felix A.; Carlson, C. M.; Rivkin, T. V.; Parilla, P. A.; Perkins, J. D.; Ginley, D. S.

    2001-01-01

    Experimental measurements of coplanar waveguide (CPW) circuits atop thin films of ferroelectric Ba(x)Sr(1-x)TiO3 (BST) were made as a function bias from 0 to 200 V and frequency from 0.045 to 20 GHz. The resulting phase shifts are compared with method of moments electromagnetic simulations and a conformal mapping analysis to determine the dielectric constant of the BST films. Based on the correlation between the experimental and the modeled data, an analysis of the extent to which the electromagnetic simulators provide reliable values for the dielectric constant of the ferroelectric in these structures has been performed. In addition, to determine how well the modeled data compare with experimental data, the dielectric constant values were also compared to low frequency measurements of interdigitated capacitor circuits on the same films. Results of these comparisons will be presented.

  19. Experimental Null Method to Guide the Development of Technical Procedures and to Control False-Positive Discovery in Quantitative Proteomics.

    PubMed

    Shen, Xiaomeng; Hu, Qiang; Li, Jun; Wang, Jianmin; Qu, Jun

    2015-10-01

    Comprehensive and accurate evaluation of data quality and false-positive biomarker discovery is critical to direct the method development/optimization for quantitative proteomics, which nonetheless remains challenging largely due to the high complexity and unique features of proteomic data. Here we describe an experimental null (EN) method to address this need. Because the method experimentally measures the null distribution (either technical or biological replicates) using the same proteomic samples, the same procedures and the same batch as the case-vs-contol experiment, it correctly reflects the collective effects of technical variability (e.g., variation/bias in sample preparation, LC-MS analysis, and data processing) and project-specific features (e.g., characteristics of the proteome and biological variation) on the performances of quantitative analysis. To show a proof of concept, we employed the EN method to assess the quantitative accuracy and precision and the ability to quantify subtle ratio changes between groups using different experimental and data-processing approaches and in various cellular and tissue proteomes. It was found that choices of quantitative features, sample size, experimental design, data-processing strategies, and quality of chromatographic separation can profoundly affect quantitative precision and accuracy of label-free quantification. The EN method was also demonstrated as a practical tool to determine the optimal experimental parameters and rational ratio cutoff for reliable protein quantification in specific proteomic experiments, for example, to identify the necessary number of technical/biological replicates per group that affords sufficient power for discovery. Furthermore, we assessed the ability of EN method to estimate levels of false-positives in the discovery of altered proteins, using two concocted sample sets mimicking proteomic profiling using technical and biological replicates, respectively, where the true

  20. Experimental Null Method to Guide the Development of Technical Procedures and to Control False-Positive Discovery in Quantitative Proteomics.

    PubMed

    Shen, Xiaomeng; Hu, Qiang; Li, Jun; Wang, Jianmin; Qu, Jun

    2015-10-01

    Comprehensive and accurate evaluation of data quality and false-positive biomarker discovery is critical to direct the method development/optimization for quantitative proteomics, which nonetheless remains challenging largely due to the high complexity and unique features of proteomic data. Here we describe an experimental null (EN) method to address this need. Because the method experimentally measures the null distribution (either technical or biological replicates) using the same proteomic samples, the same procedures and the same batch as the case-vs-contol experiment, it correctly reflects the collective effects of technical variability (e.g., variation/bias in sample preparation, LC-MS analysis, and data processing) and project-specific features (e.g., characteristics of the proteome and biological variation) on the performances of quantitative analysis. To show a proof of concept, we employed the EN method to assess the quantitative accuracy and precision and the ability to quantify subtle ratio changes between groups using different experimental and data-processing approaches and in various cellular and tissue proteomes. It was found that choices of quantitative features, sample size, experimental design, data-processing strategies, and quality of chromatographic separation can profoundly affect quantitative precision and accuracy of label-free quantification. The EN method was also demonstrated as a practical tool to determine the optimal experimental parameters and rational ratio cutoff for reliable protein quantification in specific proteomic experiments, for example, to identify the necessary number of technical/biological replicates per group that affords sufficient power for discovery. Furthermore, we assessed the ability of EN method to estimate levels of false-positives in the discovery of altered proteins, using two concocted sample sets mimicking proteomic profiling using technical and biological replicates, respectively, where the true

  1. Temperature mapping in bread dough using SE and GE two-point MRI methods: experimental and theoretical estimation of uncertainty.

    PubMed

    Lucas, Tiphaine; Musse, Maja; Bornert, Mélanie; Davenel, Armel; Quellec, Stéphane

    2012-04-01

    Two-dimensional (2D)-SE, 2D-GE and tri-dimensional (3D)-GE two-point T(1)-weighted MRI methods were evaluated in this study in order to maximize the accuracy of temperature mapping of bread dough during thermal processing. Uncertainties were propagated throughout each protocol of measurement, and comparisons demonstrated that all the methods with comparable acquisition times minimized the temperature uncertainty to similar extent. The experimental uncertainties obtained with low-field MRI were also compared to the theoretical estimations. Some discrepancies were reported between experimental and theoretical values of uncertainties of temperature; however, experimental and theoretical trends with varying parameters agreed to a large extent for both SE and GE methods. The 2D-SE method was chosen for further applications on prefermented dough because of its lower sensitivity to susceptibility differences in porous media. It was applied for temperature mapping in prefermented dough during chilling prior to freezing and compared locally to optical fiber measurements.

  2. Temperature mapping in bread dough using SE and GE two-point MRI methods: experimental and theoretical estimation of uncertainty.

    PubMed

    Lucas, Tiphaine; Musse, Maja; Bornert, Mélanie; Davenel, Armel; Quellec, Stéphane

    2012-04-01

    Two-dimensional (2D)-SE, 2D-GE and tri-dimensional (3D)-GE two-point T(1)-weighted MRI methods were evaluated in this study in order to maximize the accuracy of temperature mapping of bread dough during thermal processing. Uncertainties were propagated throughout each protocol of measurement, and comparisons demonstrated that all the methods with comparable acquisition times minimized the temperature uncertainty to similar extent. The experimental uncertainties obtained with low-field MRI were also compared to the theoretical estimations. Some discrepancies were reported between experimental and theoretical values of uncertainties of temperature; however, experimental and theoretical trends with varying parameters agreed to a large extent for both SE and GE methods. The 2D-SE method was chosen for further applications on prefermented dough because of its lower sensitivity to susceptibility differences in porous media. It was applied for temperature mapping in prefermented dough during chilling prior to freezing and compared locally to optical fiber measurements. PMID:22227351

  3. DETECTORS AND EXPERIMENTAL METHODS: Study of BESIII MUC offline software with cosmic-ray data

    NASA Astrophysics Data System (ADS)

    Liang, Yu-Tie; Mao, Ya-Jun; You, Zheng-Yun; Li, Wei-Dong; Bian, Jian-Ming; Cao, Guo-Fu; Cao, Xue-Xiang; Chen, Shen-Jian; Deng, Zi-Yan; Fu, Cheng-Dong; Gao, Yuan-Ning; Han, Lei; Han, Shao-Qing; He, Kang-Lin; He, Miao; Hu, Ji-Feng; Hu, Xiao-Wei; Huang, Bin; Huang, Xing-Tao; Jia, Lu-Kui; Ji, Xiao-Bin; Li, Hai-Bo; Liu, Bei-Jiang; Liu, Chun-Xiu; Liu, Huai-Min; Liu, Ying; Liu, Yong; Luo, Tao; Lu, Qi-Wen; Ma, Qiu-Mei; Ma, Xiang; Mao, Ze-Pu; Mo, Xiao-Hu; Ning, Fei-Peng; Ping, Rong-Gang; Qiu, Jin-Fa; Song, Wen-Bo; Sun, Sheng-Sen; Sun, Xiao-Dong; Sun, Yong-Zhao; Tian, Hao-Lai; Wang, Ji-Ke; Wang, Liang-Liang; Wen, Shuo-Pin; Wu, Ling-Hui; Wu, Zhi; Xie, Yu-Guang; Xu, Min; Yan, Jie; Yan, Liang; Yao, Jian; Yuan, Chang-Zheng; Yuan, Ye; Zhang, Chang-Chun; Zhang, Jian-Yong; Zhang, Lei; Zhang, Xue-Yao; Zhang, Yao; Zheng, Yang-Heng; Zhu, Yong-Sheng; Zou, Jia-Heng

    2009-07-01

    Cosmic-ray data of 90 M events have been collected and used for calibration, alignment as well as detector tuning. A special tracking algorithm for the BESIII muon counter is developed and verified with Monte-Carlo simulation and then further confirmed with the cosmic-ray data. The obtained strip resolutions are in good agreement with the design values. A new alignment approach for the BESIII muon counter is confirmed with the cosmic-ray data and proposed to be used in future analysis of experimental data.

  4. DETECTORS AND EXPERIMENTAL METHODS: ELDRS and dose-rate dependence of vertical NPN transistor

    NASA Astrophysics Data System (ADS)

    Zheng, Yu-Zhan; Lu, Wu; Ren, Di-Yuan; Wang, Gai-Li; Yu, Xue-Feng; Guo, Qi

    2009-01-01

    The enhanced low-dose-rate sensitivity (ELDRS) and dose-rate dependence of vertical NPN transistors are investigated in this article. The results show that the vertical NPN transistors exhibit more degradation at low dose rate, and that this degradation is attributed to the increase on base current. The oxide trapped positive charge near the SiO2-Si interface and interface traps at the interface can contribute to the increase on base current and the two-stage hydrogen mechanism associated with space charge effect can well explain the experimental results.

  5. Theoretical and experimental comparative analysis of beamforming methods for loudspeaker arrays under given performance constraints

    NASA Astrophysics Data System (ADS)

    Olivieri, Ferdinando; Fazi, Filippo Maria; Nelson, Philip A.; Shin, Mincheol; Fontana, Simone; Yue, Lang

    2016-07-01

    Methods for beamforming are available that provide the signals used to drive an array of sources for the implementation of systems for the so-called personal audio. In this work, performance of the delay-and-sum (DAS) method and of three widely used methods for optimal beamforming are compared by means of computer simulations and experiments in an anechoic environment using a linear array of sources with given constraints on quality of the reproduced field at the listener's position and limit to input energy to the array. Using the DAS method as a benchmark for performance, the frequency domain responses of the loudspeaker filters can be characterized in three regions. In the first region, at low frequencies, input signals designed with the optimal methods are identical and provide higher directivity performance than that of the DAS. In the second region, performance of the optimal methods are similar to the DAS method. The third region starts above the limit due to spatial aliasing. A method is presented to estimate the boundaries of these regions.

  6. Analyzing Empirical Evaluations of Non-Experimental Methods in Field Settings

    ERIC Educational Resources Information Center

    Steiner, Peter M.; Wong, Vivian

    2016-01-01

    Despite recent emphasis on the use of randomized control trials (RCTs) for evaluating education interventions, in most areas of education research, observational methods remain the dominant approach for assessing program effects. Over the last three decades, the within-study comparison (WSC) design has emerged as a method for evaluating the…

  7. Design of a laboratory method for rapid evaluation of experimental flocculants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reports of novel organic polymeric flocculants have become commonplace. The method used to test the effectiveness of these flocculants is most often the flocculation of a kaolin suspension in a jar test. The widely varying versions of this method that appear in the literature suffer from a range o...

  8. Comparison of Three Methods for Teaching and Evaluating Writing: A Quasi-Experimental Study

    ERIC Educational Resources Information Center

    Plutsky, Susan; Wilson, Barbara A.

    2004-01-01

    This study was undertaken to determine whether significant differences exist in the performance of students based on three methods for teaching and evaluating writing: faculty review, group review, and Calibrated Peer Review (CPR), an Internet software program designed to teach writing. Classes were randomly assigned a method; 148 students were…

  9. Shear Lag in Box Beams Methods of Analysis and Experimental Investigations

    NASA Technical Reports Server (NTRS)

    Kuhn, Paul; Chiarito, Patrick T

    1942-01-01

    The bending stresses in the covers of box beams or wide-flange beams differ appreciably from the stresses predicted by the ordinary bending theory on account of shear deformation of the flanges. The problem of predicting these differences has become known as the shear-lag problem. The first part of this paper deals with methods of shear-lag analysis suitable for practical use. The second part of the paper describes strain-gage tests made by the NACA to verify the theory. Three tests published by other investigators are also analyzed by the proposed method. The third part of the paper gives numerical examples illustrating the methods of analysis. An appendix gives comparisons with other methods, particularly with the method of Ebner and Koller.

  10. Novel Approaches in Astrocyte Protection: from Experimental Methods to Computational Approaches.

    PubMed

    Garzón, Daniel; Cabezas, Ricardo; Vega, Nelson; Ávila-Rodriguez, Marcos; Gonzalez, Janneth; Gómez, Rosa Margarita; Echeverria, Valentina; Aliev, Gjumrakch; Barreto, George E

    2016-04-01

    Astrocytes are important for normal brain functioning. Astrocytes are metabolic regulators of the brain that exert many functions such as the preservation of blood-brain barrier (BBB) function, clearance of toxic substances, and generation of antioxidant molecules and growth factors. These functions are fundamental to sustain the function and survival of neurons and other brain cells. For these reasons, the protection of astrocytes has become relevant for the prevention of neuronal death during brain pathologies such as Parkinson's disease, Alzheimer's disease, stroke, and other neurodegenerative conditions. Currently, different strategies are being used to protect the main astrocytic functions during neurological diseases, including the use of growth factors, steroid derivatives, mesenchymal stem cell paracrine factors, nicotine derivatives, and computational biology tools. Moreover, the combined use of experimental approaches with bioinformatics tools such as the ones obtained through system biology has allowed a broader knowledge in astrocytic protection both in normal and pathological conditions. In the present review, we highlight some of these recent paradigms in assessing astrocyte protection using experimental and computational approaches and discuss how they could be used for the study of restorative therapies for the brain in pathological conditions.

  11. Optimization of single-walled carbon nanotube solubility by noncovalent PEGylation using experimental design methods.

    PubMed

    Hadidi, Naghmeh; Kobarfard, Farzad; Nafissi-Varcheh, Nastaran; Aboofazeli, Reza

    2011-01-01

    In this study, noncovalent functionalization of single-walled carbon nanotubes (SWCNTs) with phospholipid-polyethylene glycols (Pl-PEGs) was performed to improve the solubility of SWCNTs in aqueous solution. Two kinds of PEG derivatives, ie, Pl-PEG 2000 and Pl-PEG 5000, were used for the PEGylation process. An experimental design technique (D-optimal design and second-order polynomial equations) was applied to investigate the effect of variables on PEGylation and the solubility of SWCNTs. The type of PEG derivative was selected as a qualitative parameter, and the PEG/SWCNT weight ratio and sonication time were applied as quantitative variables for the experimental design. Optimization was performed for two responses, aqueous solubility and loading efficiency. The grafting of PEG to the carbon nanostructure was determined by thermogravimetric analysis, Raman spectroscopy, and scanning electron microscopy. Aqueous solubility and loading efficiency were determined by ultraviolet-visible spectrophotometry and measurement of free amine groups, respectively. Results showed that Pl-PEGs were grafted onto SWCNTs. Aqueous solubility of 0.84 mg/mL and loading efficiency of nearly 98% were achieved for the prepared Pl-PEG 5000-SWCNT conjugates. Evaluation of functionalized SWCNTs showed that our noncovalent functionalization protocol could considerably increase aqueous solubility, which is an essential criterion in the design of a carbon nanotube-based drug delivery system and its biodistribution.

  12. The spectroscopic and the QTAIM properties of pyridine and phenanthroline derivatives using experimental and computational methods.

    PubMed

    Adeniyi, Adebayo A; Ajibade, Peter A

    2014-07-15

    The experimental and theoretical properties of ligands consisting of pyridine and phenanthroline derivatives have been studied. The results show a very high correlation between the experimental and theoretical spectroscopic properties of the ligands such as the IR, NMR chemical shift and UV. The carboxylic units in the ligands lead to increase in the dipole and anisotropic properties of the molecules while the methyl group lead to increase in the isotropic shielding tensor of the molecules. Most of the observed UV λmax in the ligands are predominantly excitation of electrons from the HOMO-2 or HOMO-1 or HOMO to the LUMO of the ligands. The ligand 2,2-dicarboxylphenanthroline (dcphn) is predicted to be the best starting material for non-linear optical (NLO) application due to its far higher first static hyperpolarizability tensor compare to other ligands and its lowest band gap. The same ligand can also be best for DNA binding because it has the lowest value of LUMO. The atomic charge of the nitrogen is found to be highly correlated with molecular HOMO, LUMO and non-Lewis orbital. The (15)N NMR chemical shift is found to be highly correlated atomic anisotropy, energy and intra-atomic isotropic shielding tensor. PMID:24691368

  13. The spectroscopic and the QTAIM properties of pyridine and phenanthroline derivatives using experimental and computational methods

    NASA Astrophysics Data System (ADS)

    Adeniyi, Adebayo A.; Ajibade, Peter A.

    2014-07-01

    The experimental and theoretical properties of ligands consisting of pyridine and phenanthroline derivatives have been studied. The results show a very high correlation between the experimental and theoretical spectroscopic properties of the ligands such as the IR, NMR chemical shift and UV. The carboxylic units in the ligands lead to increase in the dipole and anisotropic properties of the molecules while the methyl group lead to increase in the isotropic shielding tensor of the molecules. Most of the observed UV λmax in the ligands are predominantly excitation of electrons from the HOMO-2 or HOMO-1 or HOMO to the LUMO of the ligands. The ligand 2,2-dicarboxylphenanthroline (dcphn) is predicted to be the best starting material for non-linear optical (NLO) application due to its far higher first static hyperpolarizability tensor compare to other ligands and its lowest band gap. The same ligand can also be best for DNA binding because it has the lowest value of LUMO. The atomic charge of the nitrogen is found to be highly correlated with molecular HOMO, LUMO and non-Lewis orbital. The 15N NMR chemical shift is found to be highly correlated atomic anisotropy, energy and intra-atomic isotropic shielding tensor.

  14. Characterisation of blast loading in complex, confined geometries using quarter symmetry experimental methods

    NASA Astrophysics Data System (ADS)

    Anthistle, T.; Fletcher, D. I.; Tyas, A.

    2016-03-01

    Explosions in confined spaces lead to complicated patterns of shock wave reflection and interactions which are best investigated by use of experimental tests or numerical simulations. This paper describes the design and outcome of a series of experiments using a test cell to measure the pressures experienced when structures were placed inside to alter the propagation of shock waves, utilising quarter symmetry to reduce the size of the required test cell and charge. An 80 g charge of PE4 (a conventional RDX-based plastic explosive) was placed at half height in one corner of the test cell, which represents the centre of a rectangular enclosure when symmetry is taken into consideration. Steel cylinders and rectangular baffles were placed within the test cell at various locations. Good reproducibility was found between repeated tests in three different arrangements, in terms of both the recorded pressure data and the calculated cumulative impulse. The presence of baffles within the test cell made a small difference to the pressures and cumulative impulse experienced compared to tests with no baffles present; however, the number and spacing of baffles was seen to make minimal difference to the experienced pressures and no noticeable difference to the cumulative impulse history. The paper presents useful experimental data that may be used for three-dimensional code validation.

  15. A comparative experimental evaluation of uncertainty estimation methods for two-component PIV

    NASA Astrophysics Data System (ADS)

    Boomsma, Aaron; Bhattacharya, Sayantan; Troolin, Dan; Pothos, Stamatios; Vlachos, Pavlos

    2016-09-01

    Uncertainty quantification in planar particle image velocimetry (PIV) measurement is critical for proper assessment of the quality and significance of reported results. New uncertainty estimation methods have been recently introduced generating interest about their applicability and utility. The present study compares and contrasts current methods, across two separate experiments and three software packages in order to provide a diversified assessment of the methods. We evaluated the performance of four uncertainty estimation methods, primary peak ratio (PPR), mutual information (MI), image matching (IM) and correlation statistics (CS). The PPR method was implemented and tested in two processing codes, using in-house open source PIV processing software (PRANA, Purdue University) and Insight4G (TSI, Inc.). The MI method was evaluated in PRANA, as was the IM method. The CS method was evaluated using DaVis (LaVision, GmbH). Utilizing two PIV systems for high and low-resolution measurements and a laser doppler velocimetry (LDV) system, data were acquired in a total of three cases: a jet flow and a cylinder in cross flow at two Reynolds numbers. LDV measurements were used to establish a point validation against which the high-resolution PIV measurements were validated. Subsequently, the high-resolution PIV measurements were used as a reference against which the low-resolution PIV data were assessed for error and uncertainty. We compared error and uncertainty distributions, spatially varying RMS error and RMS uncertainty, and standard uncertainty coverages. We observed that qualitatively, each method responded to spatially varying error (i.e. higher error regions resulted in higher uncertainty predictions in that region). However, the PPR and MI methods demonstrated reduced uncertainty dynamic range response. In contrast, the IM and CS methods showed better response, but under-predicted the uncertainty ranges. The standard coverages (68% confidence interval) ranged from

  16. A comparative experimental evaluation of uncertainty estimation methods for two-component PIV

    NASA Astrophysics Data System (ADS)

    Boomsma, Aaron; Bhattacharya, Sayantan; Troolin, Dan; Pothos, Stamatios; Vlachos, Pavlos

    2016-09-01

    Uncertainty quantification in planar particle image velocimetry (PIV) measurement is critical for proper assessment of the quality and significance of reported results. New uncertainty estimation methods have been recently introduced generating interest about their applicability and utility. The present study compares and contrasts current methods, across two separate experiments and three software packages in order to provide a diversified assessment of the methods. We evaluated the performance of four uncertainty estimation methods, primary peak ratio (PPR), mutual information (MI), image matching (IM) and correlation statistics (CS). The PPR method was implemented and tested in two processing codes, using in-house open source PIV processing software (PRANA, Purdue University) and Insight4G (TSI, Inc.). The MI method was evaluated in PRANA, as was the IM method. The CS method was evaluated using DaVis (LaVision, GmbH). Utilizing two PIV systems for high and low-resolution measurements and a laser doppler velocimetry (LDV) system, data were acquired in a total of three cases: a jet flow and a cylinder in cross flow at two Reynolds numbers. LDV measurements were used to establish a point validation against which the high-resolution PIV measurements were validated. Subsequently, the high-resolution PIV measurements were used as a reference against which the low-resolution PIV data were assessed for error and uncertainty. We compared error and uncertainty distributions, spatially varying RMS error and RMS uncertainty, and standard uncertainty coverages. We observed that qualitatively, each method responded to spatially varying error (i.e. higher error regions resulted in higher uncertainty predictions in that region). However, the PPR and MI methods demonstrated reduced uncertainty dynamic range response. In contrast, the IM and CS methods showed better response, but under-predicted the uncertainty ranges. The standard coverages (68% confidence interval) ranged from

  17. DETECTORS AND EXPERIMENTAL METHODS Study of low momentum track reconstruction for the BESIII main drift chamber

    NASA Astrophysics Data System (ADS)

    Jia, Lu-Kui; Mao, Ze-Pu; Li, Wei-Dong; Cao, Guo-Fu; Cao, Xue-Xiang; Deng, Zi-Yan; He, Kang-Lin; Liu, Chun-Yan; Liu, Huai-Min; Liu, Qiu-Guang; Ma, Qiu-Mei; Ma, Xiang; Qiu, Jin-Fa; Tian, Hao-Lai; Wang, Ji-Ke; Wu, Ling-Hui; Yuan, Ye; Zang, Shi-Lei; Zhang, Chang-Chun; Zhang, Lei; Zhang, Yao; Zhu, Kai; Zou, Jia-Heng

    2010-12-01

    In order to overcome the difficulty brought by the circling charged tracks with transverse momentum less than 120 MeV in the BESIII Main Drift Chamber (MDC), a specialized method called TCurlFinder was developed. This tracking method focuses on the charged track reconstruction under 120 MeV and possesses a special mechanism to reject background noise hits. The performance of the package has been carefully checked and tuned by both Monte Carlo data and real data. The study shows that this tracking method could obviously enhance the reconstruction efficiency in the low transverse momentum region, providing physics analysis with more and reliable data.

  18. Coulometric method of the chloride ion concentration measurement: mathematical model of the measuring transducer and its experimental verification

    NASA Astrophysics Data System (ADS)

    Holiczer, Witold

    2001-08-01

    The present paper deals with theoretical basis of coulometric method used for measurement of chloride ions concentration in water solutions. Static transfer equations were derivated for generator electrodes circuit, as well as for equation describing the kinetics of phenomena taking place in detector electrodes circuit. Basing on assumptions resulting from mathematical models, chloride ions concentration meter was designed and built. This model was used for experimental verification of derivated transfer equations. Results of performed measurements and their analysis confirmed presented theoretical considerations.

  19. Experimental Reading with Invented Spelling (ERIS): A Preschool and Kindergarten Method.

    ERIC Educational Resources Information Center

    Richgels, Donald J.

    1987-01-01

    Describes a program that associates phonics instruction with children's earliest reading and writing, using the ERIS method to teach sound/letter correspondences and to provide opportunities for writing and reading. (NKA)

  20. Influence of synthesis experimental parameters on the formation of magnetite nanoparticles prepared by polyol method

    NASA Astrophysics Data System (ADS)

    Vega-Chacón, Jaime; Picasso, Gino; Avilés-Félix, Luis; Jafelicci, Miguel, Jr.

    2016-03-01

    In this paper we present a modified polyol method for synthesizing magnetite nanoparticles using iron (III) nitrate, a low toxic and cheap precursor salt. The influence of the precursor salt nature and initial ferric concentration in the average particle size and magnetic properties of the obtained nanoparticles were investigated. Magnetite nanoparticles have received much attention due to the multiple uses in the biomedical field; for these purposes nanoparticles with monodisperse size distribution, superparamagnetic behavior and a combination between small average size and high saturation magnetization are required. The polyol conventional method allows synthesizing water-dispersible magnetite nanoparticles with these features employing iron (III) acetylacetonate as precursor salt. Although the particle sizes of samples synthesized from the conventional polyol method (denoted CM) are larger than those of samples synthesized from the modified method (denoted MM), they display similar saturation magnetization. The differences in the nanoparticles average sizes of samples CM and samples MM were explained though the known nanoparticle formation mechanism.

  1. Experimental and theoretical studies of iterative methods for nonlinear, nonsymmetric systems arising in combustion

    SciTech Connect

    Hagstrom, T.; Radhakrishnan, K.

    1994-12-31

    The authors report on some iterative methods which they have tested for use in combustion simulations. In particular, they have developed a code to solve zero Mach number reacting flow equations with complex reaction and diffusion physics. These equations have the form of a nonlinear parabolic system coupled with constraints. In semi-discrete form, one obtains DAE`s of index two or three depending on the number of spatial dimensions. The authors have implemented a fourth order (fully implicit) BDF method in time, coupled with a suite of fourth order explicit and implicit spatial difference approximations. Most codes they know of for simulating reacting flows use a splitting strategy to march in time. This results in a sequence of nonlinear systems to solve, each of which has a simpler structure than the one they are faced with. The rapid and robust solution of the coupled system is the essential requirement for the success of their approach. They have implemented and analyzed nonlinear generalizations of conjugate gradient-like methods for nonsymmetric systems, including CGS and the quasi-Newton based method of Eirola and Nevanlinna. They develop a general framework for the nonlinearization of linear methods in terms of the acceleration of fixed-point iterations, where the latter is assumed to include the {open_quote}preconditioning{open_quote}. Their preconditioning is a single step of a split method, using lower order spatial difference approximations as well as simplified (Fickian) approximations of the diffusion physics.

  2. Comparison of experimental methods for determination of the volumetric mass transfer coefficient in fermentation processes

    NASA Astrophysics Data System (ADS)

    Tobajas, M.; García-Calvo, E.

    Mass transfer in bioreactors has been examined. In the present work, dynamic methods are used for the determination of KLa values for water, model media and a fermentation broth (Candida utilis) in an airlift reactor. The conventional dynamic method is applied at the end of the microbial process in order to avoid an alteration in the metabolism of the microorganisms. New dynamic methods are used to determine KLa in an airlift reactor during the microbial growth of Candida utilis on glucose. One of the methods is based on the continuous measurement of carbon dioxide production while the other method is based on the relationship between the oxygen transfer and biomass growth rates. These methods of determining KLa does not interfere with the microorganisms action. A theoretical mass transfer model has been used for KLa estimation for the systems described above. Some differences between calculated and measured values are found for fermentation processes due to the model is developed for two-phase air-water systems. Nevertheless, the average deviation between the predicted values and those obtained from the relationship between oxygen transfer and biomass production rates are lower than 25% in any case.

  3. Experimental validation of theoretical methods to estimate the energy radiated by elastic waves during an impact

    NASA Astrophysics Data System (ADS)

    Farin, Maxime; Mangeney, Anne; Rosny, Julien de; Toussaint, Renaud; Sainte-Marie, Jacques; Shapiro, Nikolaï M.

    2016-02-01

    Estimating the energy lost in elastic waves during an impact is an important problem in seismology and in industry. We propose three complementary methods to estimate the elastic energy radiated by bead impacts on thin plates and thick blocks from the generated vibration. The first two methods are based on the direct wave front and are shown to be equivalent. The third method makes use of the diffuse regime. These methods are tested for laboratory experiments of impacts and are shown to give the same results, with error bars of 40 percent and 300 percent for impacts on a smooth plate and on a rough block, respectively. We show that these methods are relevant to establish the energy budget of an impact. On plates of glass and PMMA, the radiated elastic energy increases from 2 percent to almost 100 percent of the total energy lost as the bead diameter approaches the plate thickness. The rest of the lost energy is dissipated by viscoelasticity. For beads larger than the plate thickness, plastic deformation occurs and reduces the amount of energy radiated in the form of elastic waves. On a concrete block, the energy dissipation during the impact is principally inelastic because only 0.2-2 percent of the energy lost by the bead is transported by elastic waves. The radiated elastic energy estimated with the presented methods is quantitatively validated by Hertz's model of elastic impact.

  4. An Experimental Study of DLV Method in Damage Detection of Frame Structures

    NASA Astrophysics Data System (ADS)

    Wang, Yen-Po; Chen, Yi-Hsuan; Lee, Chien-Liang

    2010-05-01

    A structural damage detection method integrating the damage locating vector (DLV) method and ARX model for system identification of frame structures from seismic acceleration responses has been explored in this paper. The concept of the DLV method is to identify the members with zero stress under some specific loading patterns derived from the changes in flexibility matrix of the structure before and after the damage state. Success of the DLV method requires clear identification of the flexibility matrix for at least the first few dominant modes. In this study, a five-storey steel frame with diagonal bracings is considered as the objective building. The damage condition of the structure is simulated by partially removing some of the diagonals. With the flexibility matrices of both the intact and damaged structure identified from seismic structural responses via shaking table tests, results indicate that the damaged locations can be successfully identified by the DLV method if sufficient modes of vibration are taken into account in the realization of the flexibility matrices. The feasibility of using DLV method for damage detection of frame structures using seismic response data is confirmed.

  5. Experimental methods for the characterization of the frequency-dependent viscoelastic properties of soft materials

    PubMed Central

    Kazemirad, Siavash; K. Heris, Hossein; Mongeau, Luc

    2013-01-01

    A characterization method based on Rayleigh wave propagation was developed for the quantification of the frequency-dependent viscoelastic properties of soft materials at high frequencies; i.e., up to 4 kHz. Planar harmonic surface waves were produced on the surface of silicone rubber samples. The phase and amplitude of the propagating waves were measured at different locations along the propagation direction, which allowed the calculation of the complex Rayleigh wavenumbers at each excitation frequency using a transfer function method. An inverse wave propagation problem was then solved to obtain the complex shear/elastic moduli from the measured wavenumbers. In a separate, related investigation, dynamic indentation tests using atomic force microscopy (AFM) were performed at frequencies up to 300 Hz. No systematic verification study is available for the AFM-based method, which can be used when the dimensions of the test samples are too small for other existing testing methods. The results obtained from the Rayleigh wave propagation and AFM-based indentation methods were compared with those from a well-established method, which involves the generation of standing longitudinal compression waves in rod-shaped test specimens. The results were cross validated and qualitatively confirmed theoretical expectations presented in the literature for the frequency-dependence of polymers. PMID:23654420

  6. DETECTORS AND EXPERIMENTAL METHODS: Equivalent properties of single event burnout induced by different sources

    NASA Astrophysics Data System (ADS)

    Yang, Shi-Yu; Cao, Zhou; Da, Dao-An; Xue, Yu-Xiong

    2009-05-01

    The experimental results of single event burnout induced by heavy ions and 252Cf fission fragments in power MOSFET devices have been investigated. It is concluded that the characteristics of single event burnout induced by 252Cf fission fragments is consistent to that in heavy ions. The power MOSFET in the “turn-off" state is more susceptible to single event burnout than it is in the “turn-on" state. The thresholds of the drain-source voltage for single event burnout induced by 173 MeV bromine ions and 252Cf fission fragments are close to each other, and the burnout cross section is sensitive to variation of the drain-source voltage above the threshold of single event burnout. In addition, the current waveforms of single event burnouts induced by different sources are similar. Different power MOSFET devices may have different probabilities for the occurrence of single event burnout.

  7. Experimental Method to Determine the Detonation Characteristics of Very Non-Ideal High Explosives

    NASA Astrophysics Data System (ADS)

    Baudin, Gerard

    2005-07-01

    Common experimental configurations used to determine HE detonation velocity-curvature are right circular cylinders detonated in air. The steadily propagating detonation front is curved and its velocity depends upon the diameter of the cylinder. This configuration requires several experiments with different diameters and sufficiently long cylinders to assume a steadily propagating detonation front. This last hypothesis is practically not achieved for non-ideal HE using reasonably long cylinders. To elude this problem, a special explosive device called ``logosphere,'' developed by CEA, has been adapted to non ideal HE. It provides a well define spherically diverging detonation wave and allows measurements of the detonation velocity-curvature relationship by means of piezoelectric pins without any perturbation. VISAR and DLI diagnostics record the material velocities at the rear surface of HE through transparent windows. The particle velocity values are used to determine the curved detonation states using the detonation velocity-acceleration-curvature model of Louis Brun.

  8. Experimental Method to Determine the Detonation Characteristics of a Very Non-Ideal High Explosive

    NASA Astrophysics Data System (ADS)

    Baudin, G.; Le Gallic, C.; Davoine, F.; Bouinot, P.

    2006-07-01

    Common experimental configurations used to determine HE detonation velocity-curvature are right circular cylinders detonated in air. The steadily propagating detonation front is curved and its velocity depends upon the diameter of the cylinder. This configuration requires several experiments with different diameters and sufficiently long cylinders to assume a steadily propagating detonation front. This last hypothesis is practically not achieved for non-ideal HE using reasonably long cylinders. To elude this problem, a special explosive device called "logosphere", developed by CEA, has been adapted to non ideal HE. It provides a well define spherically diverging detonation wave and allows measurements of the detonation velocity-curvature relationship by means of piezoelectric pins without any perturbation. VISAR and IDL diagnostics record the material velocities at the rear surface of the explosive through transparent windows. The particle velocity values are used to determine the curved detonation states using the detonation velocity-acceleration-curvature model of Louis Brun.

  9. A dynamic method to forecast the wheel slip for antilock braking system and its experimental evaluation.

    PubMed

    Oniz, Yesim; Kayacan, Erdal; Kaynak, Okyay

    2009-04-01

    The control of an antilock braking system (ABS) is a difficult problem due to its strongly nonlinear and uncertain characteristics. To overcome this difficulty, the integration of gray-system theory and sliding-mode control is proposed in this paper. This way, the prediction capabilities of the former and the robustness of the latter are combined to regulate optimal wheel slip depending on the vehicle forward velocity. The design approach described is novel, considering that a point, rather than a line, is used as the sliding control surface. The control algorithm is derived and subsequently tested on a quarter vehicle model. Encouraged by the simulation results indicating the ability to overcome the stated difficulties with fast convergence, experimental results are carried out on a laboratory setup. The results presented indicate the potential of the approach in handling difficult real-time control problems. PMID:19095541

  10. Network topology and parameter estimation: from experimental design methods to gene regulatory network kinetics using a community based approach

    PubMed Central

    2014-01-01

    Background Accurate estimation of parameters of biochemical models is required to characterize the dynamics of molecular processes. This problem is intimately linked to identifying the most informative experiments for accomplishing such tasks. While significant progress has been made, effective experimental strategies for parameter identification and for distinguishing among alternative network topologies remain unclear. We approached these questions in an unbiased manner using a unique community-based approach in the context of the DREAM initiative (Dialogue for Reverse Engineering Assessment of Methods). We created an in silico test framework under which participants could probe a network with hidden parameters by requesting a range of experimental assays; results of these experiments were simulated according to a model of network dynamics only partially revealed to participants. Results We proposed two challenges; in the first, participants were given the topology and underlying biochemical structure of a 9-gene regulatory network and were asked to determine its parameter values. In the second challenge, participants were given an incomplete topology with 11 genes and asked to find three missing links in the model. In both challenges, a budget was provided to buy experimental data generated in silico with the model and mimicking the features of different common experimental techniques, such as microarrays and fluorescence microscopy. Data could be bought at any stage, allowing participants to implement an iterative loop of experiments and computation. Conclusions A total of 19 teams participated in this competition. The results suggest that the combination of state-of-the-art parameter estimation and a varied set of experimental methods using a few datasets, mostly fluorescence imaging data, can accurately determine parameters of biochemical models of gene regulation. However, the task is considerably more difficult if the gene network topology is not completely

  11. Experimental Pi.

    ERIC Educational Resources Information Center

    Corris, G.

    1990-01-01

    Discusses the calculation of pi by means of experimental methods. Polygon circle ratios, Archimedes' method, Buffon's needles, a Monte Carlo method, and prime number approaches are used. Presents three BASIC programs for the calculations. (YP)

  12. Improved dispersion method of multi-wall carbon nanotube for inhalation toxicity studies of experimental animals.

    PubMed

    Taquahashi, Yuhji; Ogawa, Yukio; Takagi, Atsuya; Tsuji, Masaki; Morita, Koichi; Kanno, Jun

    2013-01-01

    A multi-wall carbon nanotube (MWCNT) product Mitsui MWNT-7 is a mixture of dispersed single fibers and their agglomerates/aggregates. In rodents, installation of such mixture induces inflammatory lesions triggered predominantly by the aggregates/agglomerates at the level of terminal bronchiole of the lungs. In human, however, pulmonary toxicity induced by dispersed single fibers that reached the lung alveoli is most important to assess. Therefore, a method to generate aerosol predominantly consisting of dispersed single fibers without changing their length and width is needed for inhalation studies. Here, we report a method (designated as Taquann method) to effectively remove the aggregate/agglomerates and enrich the well-dispersed singler fibers in dry state without dispersant and without changing the length and width distribution of the single fibers. This method is base on two major concept; liquid-phase fine filtration and critical point drying to avoid re-aggregation by surface tension. MWNT-7 was suspended in Tert-butyl alcohol, freeze-and-thawed, filtered by a vibrating 25 µm mesh Metallic Sieve, snap-frozen by liquid nitrogen, and vacuum-sublimated (an alternative method to carbon dioxide critical point drying). A newly designed direct injection system generated well-dispersed aerosol in an inhalation chamber. The lung of mice exposed to the aerosol contained single fibers with a length distribution similar to the original and the Taquann-treated sample. Taquann method utilizes inexpensive materials and equipments mostly found in common biological laboratories, and prepares dry powder ready to make well-dispersed aerosol. This method and the chamber with direct injection system would facilitate the inhalation toxicity studies more relevant to human exposure.

  13. A combined experimental-modelling method for the detection and analysis of pollution in coastal zones

    NASA Astrophysics Data System (ADS)

    Limić, Nedzad; Valković, Vladivoj

    1996-04-01

    Pollution of coastal seas with toxic substances can be efficiently detected by examining toxic materials in sediment samples. These samples contain information on the overall pollution from surrounding sources such as yacht anchorages, nearby industries, sewage systems, etc. In an efficient analysis of pollution one must determine the contribution from each individual source. In this work it is demonstrated that a modelling method can be utilized for solving this latter problem. The modelling method is based on a unique interpretation of concentrations in sediments from all sampling stations. The proposed method is a synthesis consisting of the utilization of PIXE as an efficient method of pollution concentration determination and the code ANCOPOL (N. Limic and R. Benis, The computer code ANCOPOL, SimTel/msdos/geology, 1994 [1]) for the calculation of contributions from the main polluters. The efficiency and limits of the proposed method are demonstrated by discussing trace element concentrations in sediments of Punat Bay on the island of Krk in Croatia.

  14. Modern methods of experimental construction of texture complete direct pole figures by using X-ray data

    NASA Astrophysics Data System (ADS)

    Isaenkova, M.; Perlovich, Yu; Fesenko, V.

    2016-04-01

    Currently used methods for constructing texture complete direct pole figure (CDPF) based on the results of X-ray diffractometric measurements were considered with respect to the products of Zr-based alloys and, in particular, used in a nuclear reactor cladding tubes, for which the accuracy of determination of integral texture parameters is of the especial importance. The main attention was devoted to technical issues which are solved by means of computer processing of large arrays of obtained experimental data. Among considered questions there are amendments of the defocusing, techniques for constructing of complete direct pole figures and determination of integral textural parameters. The methods of reconstruction of complete direct pole figures by partial direct pole figures recorded up to tilt angles of sample ψ=70-80°: the method of extrapolation of data to an uninvestigated region of the stereographic projection, and the method of "sewing" of partial pole figures measured for three mutually perpendicular plane sections of the product. The limits of applicability of these methods, depending on the shape of the test product and the degree of inhomogeneity of the layer-by-layer texture, were revealed. On the basis of a large number of experimental data, the accuracy of the integral parameters used for calculation of the physical and mechanical properties of metals with a hexagonal crystal structure was found to be equal to 0.02, when taking into account the texture heterogeneity of regular products from Zr-based alloys.

  15. A Comparison of 1D and 2D (Unbiased) Experimental Methods for Measuring CSAsolarDD Cross-Correlated Relaxation

    NASA Astrophysics Data System (ADS)

    Batta, Gy.; Kövér, K. E.; Kowalewski, J.

    1999-01-01

    Conventional and enhanced 1D experiments and different NOESY experiments (the 2D unbiased method) were performed for measuring CSA/DD cross-correlated relaxation on trehalose, a compound which could be approximated as a spherical top, and on simple model compounds comprisingC3vsymmetry (CHCl3, triphenylsilane (TPSi)). The comparison gives experimental evidence for the equivalence of the methods within the limits of the two-spin approach. 1D data are evaluated with both the simple initial rate and the Redfield relaxation matrix approach. The 2D data are obtained from the so-called transfer matrix using the Perrin-Gipe eigenvalue/eigenvector method. For the improved performance of the 2D method, anX-filtered (HHH) NOESY is suggested at the natural abundance of13C (or other dilute, low γ species). Also, experimental parameters crucial for reliable CSA data are tested (e.g., the impact of insufficient relaxation delay). Error estimation is carried out for fair comparison of methods. Revised liquid state1H and13C (29Si) CSA data are presented for chloroform and TPSi.

  16. Optimization and Experimentation of Dual-Mass MEMS Gyroscope Quadrature Error Correction Methods.

    PubMed

    Cao, Huiliang; Li, Hongsheng; Kou, Zhiwei; Shi, Yunbo; Tang, Jun; Ma, Zongmin; Shen, Chong; Liu, Jun

    2016-01-01

    This paper focuses on an optimal quadrature error correction method for the dual-mass MEMS gyroscope, in order to reduce the long term bias drift. It is known that the coupling stiffness and demodulation error are important elements causing bias drift. The coupling stiffness in dual-mass structures is analyzed. The experiment proves that the left and right masses' quadrature errors are different, and the quadrature correction system should be arranged independently. The process leading to quadrature error is proposed, and the Charge Injecting Correction (CIC), Quadrature Force Correction (QFC) and Coupling Stiffness Correction (CSC) methods are introduced. The correction objects of these three methods are the quadrature error signal, force and the coupling stiffness, respectively. The three methods are investigated through control theory analysis, model simulation and circuit experiments, and the results support the theoretical analysis. The bias stability results based on CIC, QFC and CSC are 48 °/h, 9.9 °/h and 3.7 °/h, respectively, and this value is 38 °/h before quadrature error correction. The CSC method is proved to be the better method for quadrature correction, and it improves the Angle Random Walking (ARW) value, increasing it from 0.66 °/√h to 0.21 °/√h. The CSC system general test results show that it works well across the full temperature range, and the bias stabilities of the six groups' output data are 3.8 °/h, 3.6 °/h, 3.4 °/h, 3.1 °/h, 3.0 °/h and 4.2 °/h, respectively, which proves the system has excellent repeatability. PMID:26751455

  17. Optimization and Experimentation of Dual-Mass MEMS Gyroscope Quadrature Error Correction Methods.

    PubMed

    Cao, Huiliang; Li, Hongsheng; Kou, Zhiwei; Shi, Yunbo; Tang, Jun; Ma, Zongmin; Shen, Chong; Liu, Jun

    2016-01-07

    This paper focuses on an optimal quadrature error correction method for the dual-mass MEMS gyroscope, in order to reduce the long term bias drift. It is known that the coupling stiffness and demodulation error are important elements causing bias drift. The coupling stiffness in dual-mass structures is analyzed. The experiment proves that the left and right masses' quadrature errors are different, and the quadrature correction system should be arranged independently. The process leading to quadrature error is proposed, and the Charge Injecting Correction (CIC), Quadrature Force Correction (QFC) and Coupling Stiffness Correction (CSC) methods are introduced. The correction objects of these three methods are the quadrature error signal, force and the coupling stiffness, respectively. The three methods are investigated through control theory analysis, model simulation and circuit experiments, and the results support the theoretical analysis. The bias stability results based on CIC, QFC and CSC are 48 °/h, 9.9 °/h and 3.7 °/h, respectively, and this value is 38 °/h before quadrature error correction. The CSC method is proved to be the better method for quadrature correction, and it improves the Angle Random Walking (ARW) value, increasing it from 0.66 °/√h to 0.21 °/√h. The CSC system general test results show that it works well across the full temperature range, and the bias stabilities of the six groups' output data are 3.8 °/h, 3.6 °/h, 3.4 °/h, 3.1 °/h, 3.0 °/h and 4.2 °/h, respectively, which proves the system has excellent repeatability.

  18. Optimization and Experimentation of Dual-Mass MEMS Gyroscope Quadrature Error Correction Methods

    PubMed Central

    Cao, Huiliang; Li, Hongsheng; Kou, Zhiwei; Shi, Yunbo; Tang, Jun; Ma, Zongmin; Shen, Chong; Liu, Jun

    2016-01-01

    This paper focuses on an optimal quadrature error correction method for the dual-mass MEMS gyroscope, in order to reduce the long term bias drift. It is known that the coupling stiffness and demodulation error are important elements causing bias drift. The coupling stiffness in dual-mass structures is analyzed. The experiment proves that the left and right masses’ quadrature errors are different, and the quadrature correction system should be arranged independently. The process leading to quadrature error is proposed, and the Charge Injecting Correction (CIC), Quadrature Force Correction (QFC) and Coupling Stiffness Correction (CSC) methods are introduced. The correction objects of these three methods are the quadrature error signal, force and the coupling stiffness, respectively. The three methods are investigated through control theory analysis, model simulation and circuit experiments, and the results support the theoretical analysis. The bias stability results based on CIC, QFC and CSC are 48 °/h, 9.9 °/h and 3.7 °/h, respectively, and this value is 38 °/h before quadrature error correction. The CSC method is proved to be the better method for quadrature correction, and it improves the Angle Random Walking (ARW) value, increasing it from 0.66 °/√h to 0.21 °/√h. The CSC system general test results show that it works well across the full temperature range, and the bias stabilities of the six groups’ output data are 3.8 °/h, 3.6 °/h, 3.4 °/h, 3.1 °/h, 3.0 °/h and 4.2 °/h, respectively, which proves the system has excellent repeatability. PMID:26751455

  19. Theoretical and experimental dynamic analysis aimed at the improvement of an acoustic method for fresco detachment diagnosis

    NASA Astrophysics Data System (ADS)

    Del Vescovo, Dionisio; Fregolent, Annalisa

    2009-10-01

    An acoustic non-invasive method for the diagnosis of detachment in frescos was previously proposed by the authors. This method is based on the indirect evaluation of the vibrations due to detachments, by means of a surface inspection. In this paper the relations between the dynamics of the structure to be inspected and the operational principles of the acoustic method of diagnosis are presented. The dynamic analysis is carried out using experimental investigations and analytical and numerical models. It shows that the quality of the diagnosis depends on the capability of the acoustic device to excite the structural resonances related to the detachments. These results are useful for future improvements, in particular to enhance the sensitivity of the proposed method.

  20. Validation of a LC method for the analysis of oxaliplatin in a pharmaceutical formulation using an experimental design.

    PubMed

    Ficarra, R; Calabrò, M L; Cutroneo, P; Tommasini, S; Melardi, S; Semreen, M; Furlanetto, S; Ficarra, P; Altavilla, G

    2002-08-01

    A rapid and sensitive RP-HPLC method with UV detection for routine control of oxaliplatin in a pharmaceutical formulation (Eloxatin) was developed. Quantitation was accomplished with the internal standard method. The procedure was validated by linearity (correlation coefficient=0.999948), accuracy, robustness and intermediate precision. Experimental design was used during validation to calculate method robustness and intermediate precision. For robustness test three factors were considered: percentage v/v of acetonitrile, flow rate and temperature; an increase in the flow rate results in a decrease of the drug found concentration, while the percentage of organic modifier and temperature have no important effect on the response. For intermediate precision measure the considered variables were: analyst, equipment and days. The RSD value (2.27%, n=24) indicated a good precision of the analytical method.

  1. The Parallel Asynchronous Differential Evolution Method as a Tool to Analyze Synchrotron Scattering Experimental Data from Vesicular Systems

    NASA Astrophysics Data System (ADS)

    Zhabitskaya, Evgeniya; Zemlyanaya, Elena; Kiselev, Mikhail; Gruzinov, Andrey

    2016-02-01

    In this work we use an Asynchronous Differential Evolution (ADE) method to estimate parameters of the Separated Form Factor (SFF) model which is used to investigate a structure of drug delivery Phospholipid Transport Nano System (PTNS) unilamellar vesicles by experimental small angle synchrotron X-ray scattering spectra (SAXS). We compare the efficiency of different optimizing procedures (OP) for the search for the SFF-model parameters. It is shown that the probability to find the global solution of this problem by ADE-methods is significantly higher than that by either Nelder-Mead method or a Quasi-Newton method with Davidon-Fletcher-Powell formula. The parallel realization of ADE accelerates the calculations significantly. The speed-up obtained by the parallel realization of ADE and results of the model are presented. The work has been performed under the grant of Russian Scientific Foundation (project No 14-12-00516)

  2. Developing an Experimental Simulation Method for Rock Avalanches: Fragmentation Behavior of Brittle Analogue Material

    NASA Astrophysics Data System (ADS)

    Thordén Haug, Øystein; Rosenau, Matthias; Leever, Karen; Oncken, Onno

    2013-04-01

    Gravitational mass movement on earth and other planets show a scale dependent behavior, of which the physics is not fully understood. In particular, the runout distance for small to medium sized landslides (volume < 106m3) can be predicted by a simple Coulomb friction law consistent with a constant kinetic coefficient of friction at the landslide base. This implies that the runout can be considered independent of volume. Large volume landslides (rock avalanches), however, show a dependence of runout on volume. This break in scaling behavior suggests that different dynamics control small and large landslides/rock avalanches. Several mechanisms have been proposed to explain this scale dependent behavior, but no consensus has been reached. Experimental simulations of rock avalanches usually involve transport of loose granular material down a chute. Though such granular avalanche models provide important insights into avalanche dynamics, they imply that the material fully disintegrate instantaneously. Observations from nature, however, suggests that a transition from solid to "liquid" occurs over some finite distance downhill, critically controlling the mobility and energy budget of the avalanche. Few experimental studies simulated more realistically the material failing during sliding and those were realized in a labscale centrifuge, where the range of volumes/scales is limited. To develop a new modeling technique to study the scale dependent runout behavior of rock avalanches, we designed, tested and verified several brittle materials allowing fragmentation to occur under normal gravity conditions. According to the model similarity theory, the analogue material must behave dynamically similar to the rocks in natural rock avalanches. Ideally, the material should therefore deform in a brittle manner with limited elastic and ductile strains up to a certain critical stress, beyond which the material breaks and deforms irreversibly. According to scaling relations derived

  3. Experimental research of methods for clustering and selecting image fragments using spatial invariant equivalent models

    NASA Astrophysics Data System (ADS)

    Krasilenko, Vladimir G.; Lazarev, Alexander A.; Nikitovich, Diana V.

    2014-08-01

    In the paper, we show that the nonlinear spatial non-linear equivalency functions on the basis of continuous logic equivalence (nonequivalence) operations have better discriminatory properties for comparing images. Further, using the equivalent model of multiport neural networks and associative memory, (including matrix-matrix and matrix-tensor with adaptive-weighted correlation, multi-port neural-net auto-associative and hetero-associative memory (MP NN AAM and HAM ) and the proposed architecture based on them, we show how we can modify these models and architectures for space-invariant associative recognition and clustering (high performance parallel clustering processing) images. We consider possible implementations of 2D image classifiers, devices for partitioning image fragments into clusters and their architectures. The main base unit of such architectures is a matrix-matrix or matrix-tensor equivalentor, which can be implemented on the basis of two traditional correlators. We show that the classifiers based on the equivalency paradigm and optoelectronic architectures with space-time integration and parallel-serial 2D images processing have advantages such as increased memory capacity (more than ten times of the number of neurons!), High performance in different modes . We present the results of associative significant dimension (128x128, 610x340) image recognition - renewal modeling. It will be shown that these models are capable to recognize images with a significant percentage (20- 30%) damaged pixels. The experimental results show that such models can be successfully used for auto-and heteroassociative pattern recognition. We show simulation results of using these modifications for clustering and learning models and algorithms for cluster analysis of specific images and divide them into categories of the array. Show example of a cluster division of image fragments, letters and graphics for clusters with simultaneous formation of the outputweighted spatial

  4. Aligning Experimental and Theoretical Anisotropic B-Factors: Water Models, Normal-Mode Analysis Methods, and Metrics

    PubMed Central

    2014-01-01

    The strength of X-ray crystallography in providing the information for protein dynamics has been under appreciated. The anisotropic B-factors (ADPs) from high-resolution structures are invaluable in studying the relationship among structure, dynamics, and function. Here, starting from an in-depth evaluation of the metrics used for comparing the overlap between two ellipsoids, we applied normal-mode analysis (NMA) to predict the theoretical ADPs and then align them with experimental results. Adding an extra layer of explicitly treated water on protein surface significantly improved the energy minimization results and better reproduced the anisotropy of experimental ADPs. In comparing experimental and theoretical ADPs, we focused on the overlap in shape, the alignment of dominant directions, and the similarity in magnitude. The choices of water molecules, NMA methods, and the metrics for evaluating the overlap of ADPs determined final results. This study provides useful information for exploring the physical basis and the application potential of experimental ADPs. PMID:24673391

  5. The Editor's Manipulation of Photographs: An Experimental Study of the Effect of Varying Reproduction Methods.

    ERIC Educational Resources Information Center

    Fosdick, James A.; Shoemaker, Pamela J.

    A study was conducted to determine the effect on perceived meaning of the way a photograph is reproduced and to discover whether there would be an interaction between the complexity of photographic subject matter and the complexity of reproduction method. Each of 160 college students in a sophomore-level American history course was given a packet…

  6. Interactive Computing With a Programmable Calculator; Student Experimentations in Numerical Methods.

    ERIC Educational Resources Information Center

    Gerald, Curtis F.

    Programable desk calculators can provide students with personal experience in the use of numerical methods. Courses at California Polytechnic State University at San Luis Obispo use the Compucorp Model 025 Educator Experiences with it as a teaching device for solving non-linear equations and differential equations show that students can by-pass…

  7. Modeling and Experimental Methods to Probe the Link between Global Transcription and Spatial Organization of Chromosomes

    PubMed Central

    Gupta, Soumya; Libchaber, Albert; Tlusty, Tsvi; Shivashankar, G. V.

    2012-01-01

    Genomes are spatially assembled into chromosome territories (CT) within the nucleus of living cells. Recent evidences have suggested associations between three-dimensional organization of CTs and the active gene clusters within neighboring CTs. These gene clusters are part of signaling networks sharing similar transcription factor or other downstream transcription machineries. Hence, presence of such gene clusters of active signaling networks in a cell type may regulate the spatial organization of chromosomes in the nucleus. However, given the probabilistic nature of chromosome positions and complex transcription factor networks (TFNs), quantitative methods to establish their correlation is lacking. In this paper, we use chromosome positions and gene expression profiles in interphase fibroblasts and describe methods to capture the correspondence between their spatial position and expression. In addition, numerical simulations designed to incorporate the interacting TFNs, reveal that the chromosome positions are also optimized for the activity of these networks. These methods were validated for specific chromosome pairs mapped in two distinct transcriptional states of T-Cells (naïve and activated). Taken together, our methods highlight the functional coupling between topology of chromosomes and their respective gene expression patterns. PMID:23049710

  8. Does mode mixing matter in EMD-based highlight volume methods for hydrocarbon detection? Experimental evidence

    NASA Astrophysics Data System (ADS)

    Xue, Ya-juan; Cao, Jun-xing; Du, Hao-kun; Zhang, Gu-lan; Yao, Yao

    2016-09-01

    Empirical mode decomposition (EMD)-based spectral decomposition methods have been successfully used for hydrocarbon detection. However, mode mixing that occurs during the sifting process of EMD causes the 'true' intrinsic mode function (IMF) to be extracted incorrectly and blurs the physical meaning of the IMF. We address the issue of how the mode mixing influences the EMD-based methods for hydrocarbon detection by introducing mode-mixing elimination methods, specifically ensemble EMD (EEMD) and complete ensemble EMD (CEEMD)-based highlight volumes, as feasible tools that can identify the peak amplitude above average volume and the peak frequency volume. Three schemes, that is, using all IMFs, selected IMFs or weighted IMFs, are employed in the EMD-, EEMD- and CEEMD-based highlight volume methods. When these methods were applied to seismic data from a tight sandstone gas field in Central Sichuan, China, the results demonstrated that the amplitude anomaly in the peak amplitude above average volume captured by EMD, EEMD and CEEMD combined with Hilbert transforms, whether using all IMFs, selected IMFs or weighted IMFs, are almost identical to each other. However, clear distinctions can be found in the peak frequency volume when comparing results generated using all IMFs, selected IMFs, or weighted IMFs. If all IMFs are used, the influence of mode mixing on the peak frequency volume is not readily discernable. However, using selected IMFs or a weighted IMFs' scheme affects the peak frequency in relation to the reservoir thickness in the EMD-based method. Significant improvement in the peak frequency volume can be achieved in EEMD-based highlight volumes using selected IMFs. However, if the weighted IMFs' scheme is adopted (i.e., if the undesired IMFs are included with reduced weights rather than excluded from the analysis entirely), the CEEMD-based peak frequency volume provides a more accurate reservoir thickness estimate compared with the other two methods. This

  9. Reducing the effects of acoustic heterogeneity with an iterative reconstruction method from experimental data in microwave induced thermoacoustic tomography

    SciTech Connect

    Wang, Jinguo; Zhao, Zhiqin Song, Jian; Chen, Guoping; Nie, Zaiping; Liu, Qing-Huo

    2015-05-15

    Purpose: An iterative reconstruction method has been previously reported by the authors of this paper. However, the iterative reconstruction method was demonstrated by solely using the numerical simulations. It is essential to apply the iterative reconstruction method to practice conditions. The objective of this work is to validate the capability of the iterative reconstruction method for reducing the effects of acoustic heterogeneity with the experimental data in microwave induced thermoacoustic tomography. Methods: Most existing reconstruction methods need to combine the ultrasonic measurement technology to quantitatively measure the velocity distribution of heterogeneity, which increases the system complexity. Different to existing reconstruction methods, the iterative reconstruction method combines time reversal mirror technique, fast marching method, and simultaneous algebraic reconstruction technique to iteratively estimate the velocity distribution of heterogeneous tissue by solely using the measured data. Then, the estimated velocity distribution is used subsequently to reconstruct the highly accurate image of microwave absorption distribution. Experiments that a target placed in an acoustic heterogeneous environment are performed to validate the iterative reconstruction method. Results: By using the estimated velocity distribution, the target in an acoustic heterogeneous environment can be reconstructed with better shape and higher image contrast than targets that are reconstructed with a homogeneous velocity distribution. Conclusions: The distortions caused by the acoustic heterogeneity can be efficiently corrected by utilizing the velocity distribution estimated by the iterative reconstruction method. The advantage of the iterative reconstruction method over the existing correction methods is that it is successful in improving the quality of the image of microwave absorption distribution without increasing the system complexity.

  10. A comparative experimental study of gross alpha methods in natural waters.

    PubMed

    Montaña, M; Fons, J; Corbacho, J A; Camacho, A; Zapata-García, D; Guillén, J; Serrano, I; Tent, J; Baeza, A; Llauradó, M; Vallés, I

    2013-04-01

    The aim of the present work was to compare the results obtained with gross alpha methods such as evaporation, co-precipitation and total evaporation by liquid scintillation counting and to check whether these results are representative of the real total alpha activity concentration on the sample. The study was carried out on eight natural waters with very different radioactive characteristics. For all the samples uranium ((238)U, (235)U, and (234)U), radium ((226)Ra and (224)Ra), (210)Po, and (232)Th isotopes were also assayed by using radiochemical separation and alpha spectrometry in order to determine the sum of the activities of these alpha emitters. Precision (expressed as relative standard deviation) was below 28% for evaporation and below 18% for co-precipitation. In the case of total by liquid scintillation counting it was below 10% for samples with Total Alpha activity above 0.1 Bq/L (this value is about three times the MDA). Furthermore, for most of the studied waters, the Total Alpha activity and the gross alpha activity determined by the three methods were comparable. The obtained bias by the evaporation, co-precipitation, and total evaporation by liquid scintillation counting methods was lower than 40%, 25% and 20%, respectively. The ANOVA test was applied to find out if there was significant variability among the methods. For the samples with the most common radiochemical characteristics there were no significant differences among the three studied methods. However differences were detected for samples with a high saline content or with a very low activity level. PMID:23220539

  11. Friction Factor Evaluation Using Experimental and Finite Element Methods for Al-4%Cu Preforms

    NASA Astrophysics Data System (ADS)

    Desalegn, Wogaso; Davidson, M. J.; Khanra, A. K.

    2014-08-01

    In this study, ring compression tests and finite element (FE) simulations have been utilized to evaluate the friction factor, m, under different lubricating conditions for powder metallurgical (P/M) Al-4%Cu preforms. A series of ring compression tests were carried out to obtain friction factor ( m) for a number of lubricating conditions, including zinc stearate, graphite, molybdenum disulfide powder, and unlubricated condition. FE simulations were used to analyze materials deformation, densification, and geometric changes, and to derive the friction calibration curves. The friction factor has been determined for various initial relative densities and different lubricating conditions, and a proper lubricant for cold forging of P/M Al-4%Cu preforms is found. Studies show that the use of lubricants has reduced the friction. However, increase in the number of pores in the preforms leads to excessive friction. The FE simulation results demonstrate a shift in the neutral plane distance from the axis of ring specimen, which occurred due to variations in the frictional conditions and initial relative densities. The load requirement for deformation, effective stress, and effective strain induced, and bulging phenomena obtained by FE simulations have a good agreement with the experimental data.

  12. A new method for studying microaerobic fermentations; 2: An experimental investigation of xylose fermentation

    SciTech Connect

    Franzen, C.J.; Liden, G.; Niklasson, C. . Dept. of Chemical Reaction)

    1994-08-05

    A new experimental technique, called oxygen programmed fermentation (OPF), was used to study microbial cultures of the yeasts Pichia stipitis and Candida utilis growing on xylose as carbon and energy source. In the oxygen programmed fermentation, the inlet oxygen mole fraction was continuously changed to scan through a wide range of oxygen uptake rates in a continuous culture. The largest ethanol yields and productivities for P. stipitis were found at oxygen transfer rates below 1.5 mmol L[sup [minus]1] h[sup [minus]1]. It was found that the ratio between the culture fluorescence and near-IR absorbance increased at oxygen transfer rates lower than 1.5 mmol L[sup [minus]1] h[sup [minus]1]. Small amounts of ethanol were produced also by C. utilis when the oxygen transfer rate was between 0 and 3 mmol L[sup [minus]1] h[sup [minus]1]. It is suggested that OPF will form a nice complement to ordinary, microaerobic chemostat experiments, by making the identification of interesting regions of oxygen transfer rates possible in an efficient and time-saving initial experiment.

  13. Confined-pyrolysis as an experimental method for hydrothermal organic synthesis.

    PubMed

    Leif, R N; Simoneit, B R

    1995-10-01

    A closed pyrolysis system has been developed as a tool for studying the reactions of organic compounds under extreme hydrothermal conditions. Small high pressure stainless steel vessels in which the ratio of sediment or sample to water has been adjusted to eliminate the headspace at peak experimental conditions confines the organic components to the bulk solid matrix and eliminates the partitioning of the organic compounds away from the inorganic components during the experiment. Confined pyrolysis experiments were performed to simulate thermally driven catagenetic changes in sedimentary organic matter using a solids to water ratio of 3.4 to 1. The extent of alteration was measured by monitoring the steroid and triterpenoid biomarkers and polycyclic aromatic hydrocarbon distributions. These pyrolysis experiments duplicated the hydrothermal transformations observed in nature. Molecular probe experiments using alkadienes, alkenes and alkanes in H2O and D2O elucidated the isomerization and hydrogenation reactions of aliphatic compounds and competing oxidative reactions occurring under hydrothermal conditions. This confined pyrolysis technique is being applied to test experiments on organic synthesis of relevance to chemical evolution for the origin of life.

  14. Experimental methods in RIB target/ion source development and characterization

    SciTech Connect

    Welton, R.F.; Alton, G.D.; Murray, S.N.; Cui, B.

    1997-11-01

    We have developed off-line experimental techniques and apparatuses that permit direct measurement of effusive-flow delay-times and ionization efficiencies for nearly any chemically reactive element in high-temperature target/ion sources (TISs) commonly used for on-line radioactive ion beam (RIB) generation. The apparatuses include a hot Ta valve for effusive-flow delay-time measurements, a cooled molecular-injection system for determination of ionization efficiencies and a gas-flow measurement/control system for introducing very low, well-defined molecular flows into the TIS. Measurements are performed on a test-stand using molecular feed compounds containing stable complements of the radioactive nuclei of interest delivered to the TIS at flow-rates commensurate with on-line RIB generation. In this report, the general techniques are described and effusive-flow delay-times and ionization efficiency measurements are reported for fluorine in an electron-beam-plasma target/ion source (EBPTIS) developed for RIB generation and operated in both positive and negative ion extraction modes.

  15. Confined-Pyrolysis as an Experimental Method for Hydrothermal Organic Synthesis

    NASA Technical Reports Server (NTRS)

    Leif, Roald N.; Simoneit, Bernd R. T.

    1995-01-01

    A closed pyrolysis system has been developed as a tool for studying the reactions of organic compounds under extreme hydrothermal conditions. Small high pressure stainless steel vessels in which the ratio of sediment or sample to water has been adjusted to eliminate the headspace at peak experimental conditions confines the organic components to the bulk solid matrix and eliminates the partitioning of the organic compounds away from the inorganic components during the experiment. Confined pyrolysis experiments were performed to simulate thermally driven catagenetic changes in sedimentary organic matter using a solids to water ratio of 3.4 to 1. The extent of alteration was measured by monitoring the steroid and triterpenoid biomarkers and polycyclic aromatic hydrocarbon distributions. These pyrolysis experiments duplicated the hydrothermal transformations observed in nature. Molecular probe experiments using alkadienes, alkenes and alkanes in H2O and D2O elucidated the isomerization and hydrogenation reactions of aliphatic and the competing oxidative reactions occurring under hydrothermal conditions. This confined pyrolysis technique is being applied to test experiments on organic synthesis of relevance to chemical evolution for the origin of life.

  16. Analytical methods to determine electrochemical factors in electrotaxis setups and their implications for experimental design.

    PubMed

    Schopf, Anika; Boehler, Christian; Asplund, Maria

    2016-06-01

    Direct current (DC) stimulation can be used to influence the orientation and migratory behavior of cells and results in cellular electrotaxis. Experimental work on such phenomena commonly relies on electrochemical dissolution of silver:silver-chloride (Ag:AgCl) electrodes to provide the stimulation via salt bridges. The strong ionic flow can be expected to influence the cell culture environment. In order to shed more light on which effects that must be considered, and possibly counter balanced, we here characterize a typical DC stimulation system. Silver migration speed was determined by stripping voltammetry. pH variability with stimulation was measured by ratiometric image analysis and conductivity alterations were quantified via two electrode impedance spectroscopy. It could be concluded that pH shifts towards more acidic values, in a linear manner with applied charge, after the buffering capability of the culture medium is exceeded. In contrast, the influence on conductivity was of negligible magnitude. Silver ions could enter the culture chamber at low concentrations long before a clear effect on the viability of the cultured cells could be observed. A design rule of 1cm salt bridge per C of stimulation charge transferred was however sufficient to ensure separation between cells and silver at all times. PMID:26775205

  17. Three-dimensional stress analysis of O-ring under uniform squeeze and internal pressure by photoelastic experimental hybrid method

    NASA Astrophysics Data System (ADS)

    Hawong, J. S.; Nam, J. H.; Liu, Y.; Shin, D. C.

    2010-03-01

    Until now, it is known that stresses on the plane (y-z plane) perpendicular to the circumferential direction (x axis) of Oring exist and stresses on the plane (x-y plane and x-z plane) parallel to the circumferential direction of O-ring does not exist when O-ring is under uniform squeeze rate and internal pressure. But it was known that stresses of x-y plane and xz plane of O-ring under uniform squeeze and internal pressure were existed by this research. To analyze 3 dimensional stress distributions of O-ring under those loadings, stress distributions of every plane should be analyzed. Therefore, photoelastic experimental hybrid method for 3 dimensional stress distributions of O-ring under uniform squeeze and internal pressure were developed in this research. Photoelastic experimental procedures for 3 dimensional stress distributions of O-ring under those loadings were introduced. Stress distributions of O-ring under those loadings were analyzed by photoelastic experimental hybrid method developed in this research. Von Mises equivalent stresses at arbitrary point of O-ring under those loadings were analyzed.

  18. Three-dimensional stress analysis of O-ring under uniform squeeze and internal pressure by photoelastic experimental hybrid method

    NASA Astrophysics Data System (ADS)

    Hawong, J. S.; Nam, J. H.; Liu, Y.; Shin, D. C.

    2009-12-01

    Until now, it is known that stresses on the plane (y-z plane) perpendicular to the circumferential direction (x axis) of Oring exist and stresses on the plane (x-y plane and x-z plane) parallel to the circumferential direction of O-ring does not exist when O-ring is under uniform squeeze rate and internal pressure. But it was known that stresses of x-y plane and xz plane of O-ring under uniform squeeze and internal pressure were existed by this research. To analyze 3 dimensional stress distributions of O-ring under those loadings, stress distributions of every plane should be analyzed. Therefore, photoelastic experimental hybrid method for 3 dimensional stress distributions of O-ring under uniform squeeze and internal pressure were developed in this research. Photoelastic experimental procedures for 3 dimensional stress distributions of O-ring under those loadings were introduced. Stress distributions of O-ring under those loadings were analyzed by photoelastic experimental hybrid method developed in this research. Von Mises equivalent stresses at arbitrary point of O-ring under those loadings were analyzed.

  19. Experimental design and multiple response optimization. Using the desirability function in analytical methods development.

    PubMed

    Candioti, Luciana Vera; De Zan, María M; Cámara, María S; Goicoechea, Héctor C

    2014-06-01

    A review about the application of response surface methodology (RSM) when several responses have to be simultaneously optimized in the field of analytical methods development is presented. Several critical issues like response transformation, multiple response optimization and modeling with least squares and artificial neural networks are discussed. Most recent analytical applications are presented in the context of analytLaboratorio de Control de Calidad de Medicamentos (LCCM), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, C.C. 242, S3000ZAA Santa Fe, ArgentinaLaboratorio de Control de Calidad de Medicamentos (LCCM), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, C.C. 242, S3000ZAA Santa Fe, Argentinaical methods development, especially in multiple response optimization procedures using the desirability function.

  20. Methods of Experimental Investigation of Cavitation in a Convergent - Divergent Nozzle of Rectangular Cross Section

    NASA Astrophysics Data System (ADS)

    Jana, Jablonská; Milada, Kozubková; Daniel, Himr; Michal, Weisz

    2016-08-01

    Cavitation is a phenomenon with both positive and negative effects and with dynamic manifestations in hydraulic, food, chemical and other machinery. This article deals with the detection and dynamic behavior of cavitation clouds in water flows through a rectangular cross-section convergent-divergent nozzle. Cavitation was measured by methods applicable in engineering practice. Pressure, flow rate, noise, vibration, and amount of air dissolved in the liquid were measured and cavitation region was recorded with a high-speed camera. Evaluation of acquired images in connection with measured pressure pulsations and mechanical vibrations was performed with the use of the FFT method. In certain cases, dimensionless parameters were used to generalize the measurements. The results will be used to specify multiphase mathematical cavitation model parameters.

  1. Thermochemistry of dihalogen-substituted benzenes: data evaluation using experimental and quantum chemical methods.

    PubMed

    Verevkin, Sergey P; Emel'yanenko, Vladimir N; Varfolomeev, Mikhail A; Solomonov, Boris N; Zherikova, Kseniya V; Melkhanova, Svetlana V

    2014-12-11

    Temperature dependence of vapor pressures for 12 dihalogen-substituted benzenes (halogen = F, Cl, Br, I) was studied by the transpiration method, and molar vaporization or sublimation enthalpies were derived. These data together with results available in the literature were collected and checked for internal consistency using structure-property correlations. Gas-phase enthalpies of formation of dihalogen-substituted benzenes were calculated by using quantum-chemical methods. Evaluated vaporization enthalpies in combination with gas-phase enthalpies of formation were used for estimation liquid-phase enthalpies of formation of dihalogen-substituted benzenes. Pairwise interactions of halogens on the benzene ring were derived and used for development of simple group additivity procedures for estimation of vaporization enthalpies, gas-phase, and liquid-phase enthalpies of formation of dihalogen-substituted benzenes.

  2. Advanced experimental applications for x-ray transmission gratings spectroscopy using a novel grating fabrication method

    SciTech Connect

    Hurvitz, G.; Ehrlich, Y.; Shpilman, Z.; Levy, I.; Fraenkel, M.; Strum, G.

    2012-08-15

    A novel fabrication method for soft x-ray transmission grating and other optical elements is presented. The method uses focused-ion-beam technology to fabricate high-quality free standing grating bars on transmission electron microscopy grids. High quality transmission gratings are obtained with superb accuracy and versatility. Using these gratings and back-illuminated CCD camera, absolutely calibrated x-ray spectra can be acquired for soft x-ray source diagnostics in the 100-3000 eV spectral range. Double grating combinations of identical or different parameters are easily fabricated, allowing advanced one-shot application of transmission grating spectroscopy. These applications include spectroscopy with different spectral resolutions, bandwidths, dynamic ranges, and may serve for identification of high-order contribution, and spectral calibrations of various x-ray optical elements.

  3. Experimental Methods to Evaluate Science Utility Relative to the Decadal Survey

    NASA Technical Reports Server (NTRS)

    Widergren, Cynthia

    2012-01-01

    The driving factor for competed missions is the science that it plans on performing once it has reached its target body. These science goals are derived from the science recommended by the most current Decadal Survey. This work focuses on science goals in previous Venus mission proposals with respect to the 2013 Decadal Survey. By looking at how the goals compare to the survey and how much confidence NASA has in the mission's ability to accomplish these goals, a method was created to assess the science return utility of each mission. This method can be used as a tool for future Venus mission formulation and serves as a starting point for future development of create science utility assessment tools.

  4. Advanced experimental applications for x-ray transmission gratings spectroscopy using a novel grating fabrication method.

    PubMed

    Hurvitz, G; Ehrlich, Y; Strum, G; Shpilman, Z; Levy, I; Fraenkel, M

    2012-08-01

    A novel fabrication method for soft x-ray transmission grating and other optical elements is presented. The method uses focused-ion-beam technology to fabricate high-quality free standing grating bars on transmission electron microscopy grids. High quality transmission gratings are obtained with superb accuracy and versatility. Using these gratings and back-illuminated CCD camera, absolutely calibrated x-ray spectra can be acquired for soft x-ray source diagnostics in the 100-3000 eV spectral range. Double grating combinations of identical or different parameters are easily fabricated, allowing advanced one-shot application of transmission grating spectroscopy. These applications include spectroscopy with different spectral resolutions, bandwidths, dynamic ranges, and may serve for identification of high-order contribution, and spectral calibrations of various x-ray optical elements.

  5. A new experimental method for the determination of the effective orifice area based on the acoustical source term

    NASA Astrophysics Data System (ADS)

    Kadem, L.; Knapp, Y.; Pibarot, P.; Bertrand, E.; Garcia, D.; Durand, L. G.; Rieu, R.

    2005-12-01

    The effective orifice area (EOA) is the most commonly used parameter to assess the severity of aortic valve stenosis as well as the performance of valve substitutes. Particle image velocimetry (PIV) may be used for in vitro estimation of valve EOA. In the present study, we propose a new and simple method based on Howe’s developments of Lighthill’s aero-acoustic theory. This method is based on an acoustical source term (AST) to estimate the EOA from the transvalvular flow velocity measurements obtained by PIV. The EOAs measured by the AST method downstream of three sharp-edged orifices were in excellent agreement with the EOAs predicted from the potential flow theory used as the reference method in this study. Moreover, the AST method was more accurate than other conventional PIV methods based on streamlines, inflexion point or vorticity to predict the theoretical EOAs. The superiority of the AST method is likely due to the nonlinear form of the AST. There was also an excellent agreement between the EOAs measured by the AST method downstream of the three sharp-edged orifices as well as downstream of a bioprosthetic valve with those obtained by the conventional clinical method based on Doppler-echocardiographic measurements of transvalvular velocity. The results of this study suggest that this new simple PIV method provides an accurate estimation of the aortic valve flow EOA. This new method may thus be used as a reference method to estimate the EOA in experimental investigation of the performance of valve substitutes and to validate Doppler-echocardiographic measurements under various physiologic and pathologic flow conditions.

  6. PEM fuel cell fault detection and identification using differential method: simulation and experimental validation

    NASA Astrophysics Data System (ADS)

    Frappé, E.; de Bernardinis, A.; Bethoux, O.; Candusso, D.; Harel, F.; Marchand, C.; Coquery, G.

    2011-05-01

    PEM fuel cell performance and lifetime strongly depend on the polymer membrane and MEA hydration. As the internal moisture is very sensitive to the operating conditions (temperature, stoichiometry, load current, water management…), keeping the optimal working point is complex and requires real-time monitoring. This article focuses on PEM fuel cell stack health diagnosis and more precisely on stack fault detection monitoring. This paper intends to define new, simple and effective methods to get relevant information on usual faults or malfunctions occurring in the fuel cell stack. For this purpose, the authors present a fault detection method using simple and non-intrusive on-line technique based on the space signature of the cell voltages. The authors have the objective to minimize the number of embedded sensors and instrumentation in order to get a precise, reliable and economic solution in a mass market application. A very low number of sensors are indeed needed for this monitoring and the associated algorithm can be implemented on-line. This technique is validated on a 20-cell PEMFC stack. It demonstrates that the developed method is particularly efficient in flooding case. As a matter of fact, it uses directly the stack as a sensor which enables to get a quick feedback on its state of health.

  7. Simultaneous HPLC determination of 22 components of essential oils; method robustness with experimental design.

    PubMed

    Porel, A; Sanyal, Y; Kundu, A

    2014-01-01

    The aim of the present study was the development and validation of a simple, precise and specific reversed phase HPLC method for the simultaneous determination of 22 components present in different essential oils namely cinnamon bark oil, caraway oil and cardamom fruit oil. The chromatographic separation of all the components was achieved on Wakosil-II C18 column with mixture of 30 mM ammonium acetate buffer (pH 4.7), methanol and acetonitrile in different ratio as mobile phase in a ternary linear gradient mode. The calibration graphs plotted with five different concentrations of each component were linear with a regression coefficient R(2) >0.999. The limit of detection and limit of quantitation were estimated for all the components. Effect on analytical responses by small and deliberate variation of critical factors was examined by robustness testing with Design of Experiment employing Central Composite Design and established that this method was robust. The method was then validated for linearity, precision, accuracy, specificity and demonstrated to be applicable to the determination of the ingredients in commercial sample of essential oil.

  8. Methods of preventing vinorelbine-induced phlebitis: an experimental study in rabbits

    PubMed Central

    Kohno, Emiko; Murase, Saori; Nishikata, Mayumi; Okamura, Noboru; Matzno, Sumio; Kuwahara, Takashi; Matsuyama, Kenji

    2008-01-01

    Purpose: In order to identify methods for preventing phlebitis caused by intravenous administration of vinorelbine (VNR), we established a procedure for estimating the severity of phlebitis in an animal model. Methods: Four different factors (administration rate, dilution, flushing, and infusion of fat emulsion) were evaluated for alleviation of phlebitis caused by VNR infusion. VNR was diluted with normal saline to prepare test solutions with concentrations of 0.6 mg/mL or 0.3 mg/mL for infusion into the auricular veins of rabbits. Two days after VNR infusion, the veins were subjected to histopathological examination. Results: VNR did not cause obvious loss of venous endothelial cells, the most sensitive and common feature of phlebitis, but VNR infusion led to inflammatory cell infiltration, edema, and epidermal degeneration. Tissue damage was significantly decreased by shortening the administration time and by diluting the VNR solution for infusion from 0.6 mg/mL to 0.3 mg/mL. However, there was no effect of flushing with normal saline after VNR infusion, while treatment with fat emulsion before and after VNR infusion only had a minimal effect. Conclusion: Rapid infusion and dilution are effective methods of reducing phlebitis caused by the infusion of VNR, but the efficacy of flushing with normal saline or infusion of fat emulsion was not confirmed. PMID:18695742

  9. Simultaneous HPLC Determination of 22 Components of Essential Oils; Method Robustness with Experimental Design

    PubMed Central

    Porel, A.; Sanyal, Y.; Kundu, A.

    2014-01-01

    The aim of the present study was the development and validation of a simple, precise and specific reversed phase HPLC method for the simultaneous determination of 22 components present in different essential oils namely cinnamon bark oil, caraway oil and cardamom fruit oil. The chromatographic separation of all the components was achieved on Wakosil–II C18 column with mixture of 30 mM ammonium acetate buffer (pH 4.7), methanol and acetonitrile in different ratio as mobile phase in a ternary linear gradient mode. The calibration graphs plotted with five different concentrations of each component were linear with a regression coefficient R2 >0.999. The limit of detection and limit of quantitation were estimated for all the components. Effect on analytical responses by small and deliberate variation of critical factors was examined by robustness testing with Design of Experiment employing Central Composite Design and established that this method was robust. The method was then validated for linearity, precision, accuracy, specificity and demonstrated to be applicable to the determination of the ingredients in commercial sample of essential oil. PMID:24799735

  10. Simultaneous HPLC determination of 22 components of essential oils; method robustness with experimental design.

    PubMed

    Porel, A; Sanyal, Y; Kundu, A

    2014-01-01

    The aim of the present study was the development and validation of a simple, precise and specific reversed phase HPLC method for the simultaneous determination of 22 components present in different essential oils namely cinnamon bark oil, caraway oil and cardamom fruit oil. The chromatographic separation of all the components was achieved on Wakosil-II C18 column with mixture of 30 mM ammonium acetate buffer (pH 4.7), methanol and acetonitrile in different ratio as mobile phase in a ternary linear gradient mode. The calibration graphs plotted with five different concentrations of each component were linear with a regression coefficient R(2) >0.999. The limit of detection and limit of quantitation were estimated for all the components. Effect on analytical responses by small and deliberate variation of critical factors was examined by robustness testing with Design of Experiment employing Central Composite Design and established that this method was robust. The method was then validated for linearity, precision, accuracy, specificity and demonstrated to be applicable to the determination of the ingredients in commercial sample of essential oil. PMID:24799735

  11. A Quantitative MRI Method for Imaging Blood-Brain Barrier Leakage in Experimental Traumatic Brain Injury

    PubMed Central

    Watts, Lora Talley; Jiang, Zhao; Shen, Qiang; Li, Yunxia; Duong, Timothy Q.

    2014-01-01

    Blood-brain barrier (BBB) disruption is common following traumatic brain injury (TBI). Dynamic contrast enhanced (DCE) MRI can longitudinally measure the transport coefficient Ktrans which reflects BBB permeability. Ktrans measurements however are not widely used in TBI research because it is generally considered to be noisy and possesses low spatial resolution. We improved spatiotemporal resolution and signal sensitivity of Ktrans MRI in rats by using a high-sensitivity surface transceiver coil. To overcome the signal drop off profile of the surface coil, a pre-scan module was used to map the flip angle (B1 field) and magnetization (M0) distributions. A series of T1-weighted gradient echo images were acquired and fitted to the extended Kety model with reversible or irreversible leakage, and the best model was selected using F-statistics. We applied this method to study the rat brain one hour following controlled cortical impact (mild to moderate TBI), and observed clear depiction of the BBB damage around the impact regions, which matched that outlined by Evans Blue extravasation. Unlike the relatively uniform T2 contrast showing cerebral edema, Ktrans shows a pronounced heterogeneous spatial profile in and around the impact regions, displaying a nonlinear relationship with T2. This improved Ktrans MRI method is also compatible with the use of high-sensitivity surface coil and the high-contrast two-coil arterial spin-labeling method for cerebral blood flow measurement, enabling more comprehensive investigation of the pathophysiology in TBI. PMID:25478693

  12. Wedge MUSIC: a novel approach to examine experimental differences of brain source connectivity patterns from EEG/MEG data.

    PubMed

    Ewald, Arne; Avarvand, Forooz Shahbazi; Nolte, Guido

    2014-11-01

    We introduce a novel method to estimate bivariate synchronization, i.e. interacting brain sources at a specific frequency or band, from MEG or EEG data robust to artifacts of volume conduction. The data driven calculation is solely based on the imaginary part of the cross-spectrum as opposed to the imaginary part of coherency. In principle, the method quantifies how strong a synchronization between a distinct pair of brain sources is present in the data. As an input of the method all pairs of pre-defined locations inside the brain can be used which is computationally exhaustive. In contrast to that, reference sources can be used that have been identified by any source reconstruction technique in a prior analysis step. We introduce different variants of the method and evaluate the performance in simulations. As a particular advantage of the proposed methodology, we demonstrate that the novel approach is capable of investigating differences in brain source interactions between experimental conditions or with respect to a certain baseline. For measured data, we first show the application on resting state MEG data where we find locally synchronized sources in the motor-cortex based on the sensorimotor idle rhythms. Finally, we show an example on EEG motor imagery data where we contrast hand and foot movements. Here, we also find local interactions in the expected brain areas.

  13. Experimental study of limit lean methane/air flame in a standard flammability tube using particle image velocimetry method

    SciTech Connect

    Shoshin, Yuriy; Gorecki, Grzegorz; Jarosinski, Jozef; Fodemski, Tadeusz

    2010-05-15

    Lean limit methane/air flame propagating upward in a standard 50 mm diameter and 1.8 m length tube was studied experimentally using particle image velocimetry method. Local stretch rate along the flame front was determined by measured gas velocity distributions. It was found that local stretch rate is maximum at the flame leading point, which is in agreement with earlier theoretical results. Similar to earlier observations, extinction of upward propagating limit flame was observed to start from the flame top. It is stated that the observed behavior of the extinction of the lean limit methane/air flame can not be explained in terms of the coupled effect of flame stretch and preferential diffusion. To qualitatively explain the observed extinction behavior, it is suggested that the positive strain-induced flame stretch increases local radiation heat losses from the flame front. An experimental methodology for PIV measurements in a round tube is described. (author)

  14. Experimental Validation of the Constant Level Method for Identification of Non-Linear Multi-Degree Systems

    NASA Astrophysics Data System (ADS)

    Dimitriadis, G.

    2002-12-01

    System identification for non-linear dynamical systems could find use in many applications such as condition monitoring, finite element model validation and determination of stability. The effectiveness of existing non-linear system identification techniques is limited by various factors such as the complexity of the system under investigation and the type of non-linearities present. In this work, the constant level identification approach, which can identify multi-degree-of-freedom systems featuring any type of non-linear function, including discontinuous functions, is validated experimentally. The method is shown to identify accurately an experimental dynamical system featuring two types of stiffness non-linearity. The full equations of motion are also extracted accurately, even in the presence of a discontinuous non-linearity.

  15. Electrode kinetics of oxygen reduction - A theoretical and experimental analysis of the rotating ring-disc electrode method

    NASA Technical Reports Server (NTRS)

    Hsueh, K.-L.; Chin, D.-T.; Srinivasan, S.

    1983-01-01

    In order to calculate most of the rate constants for the intermediate formation of H2O2 in the electroreduction of O2 to H2O, the theoretical treatments of the rotating ring-disc electrode method by Damjanovic et al. (1966, 1967), Bagotskii et al. (1968, 1969), and Wroblowa et al. (1976) are modified. Rotating ring-disc electrode experimental data obtained for O2 reduction in Pt in 0.55 M H2SO4 are used to illustrate the calculations of rate constants according to the above theoretical treatments. A simple reaction model as proposed by the first author is consistent with the experimental data. The results indicate that O2 (97 percent) reduces to H2O in a direct four-electron transfer reaction. The adsorption of O2 is probably the rate-determining step in the potential region more negative than 0.5 V vs. reversible hydrogen electrode.

  16. Comparison of experimental and bioelectrical impedance analysis methods in calculation of dry weight in peritoneal dialysis patients

    PubMed Central

    Naini, A Emami; Savoj, J; Atapoor, A; Mortazavi, M; Taheri, Sh

    2012-01-01

    Background: To optimize dialysis prescription and fluid balance of the peritoneal dialysis (PD) patients, it is important to assess their dry weight accurately. The experimental evaluation is the method which is widely used in PD centers which needs continuous and controlled reduction of the postdialysis weight down to the point where patient does not show any signs of hypotension and volume overload. This study intends to indicate that the bioelectrical impedance analysis (BIA) method can be used as an alternative method to evaluate the dry weight. Materials and Methods: The demographic data of 101 continuous ambulatory peritoneal dialysis (CAPD) patients of Alzahra and Noor hospitals of Isfahan University (50 males and 51 females) who had been referred for periodical examinations from April 2009 to April 2010 were extracted from their files. The normal body volume was selected as the inclusion criteria and identified by an examiner group (a nephrologist, a general practitioner and a PD nurse). The patients’ dry weights were calculated based on both methods. The bioelectrical impedance analysis method was done by the Maltron Bioscan ver916 and data were analyzed by SPSS program ver18. Results: There were 49.5% males and 50.5% females with the mean age of 54.6±17 years. The mean dry weight in the experimental method was 63.4±13.3 kg in comparison to the other (61.5± 13.7 kg). There was a significant difference between the results (P value <0.001) depended on the gender t-test, but there was a 98% correlation between the results by two methods. No correlation observed between the patient's age, body mass index, blood pressure, previous hemodialysis history, PD duration time, and underlying disease. Conclusion: The study showed that there is significant difference between the two methods. However, there was 98% direct correlation between them. It is concluded that bioelectrical impedance analysis could be a better alternative for accurate evaluation of dry

  17. Experimental validation of an optimized signal processing method to handle non-linearity in swept-source optical coherence tomography.

    PubMed

    Vergnole, Sébastien; Lévesque, Daniel; Lamouche, Guy

    2010-05-10

    We evaluate various signal processing methods to handle the non-linearity in wavenumber space exhibited by most laser sources for swept-source optical coherence tomography. The following methods are compared for the same set of experimental data: non-uniform discrete Fourier transforms with Vandermonde matrix or with Lomb periodogram, resampling with linear interpolation or spline interpolation prior to fast-Fourier transform (FFT), and resampling with convolution prior to FFT. By selecting an optimized Kaiser-Bessel window to perform the convolution, we show that convolution followed by FFT is the most efficient method. It allows small fractional oversampling factor between 1 and 2, thus a minimal computational time, while retaining an excellent image quality. PMID:20588899

  18. Methods for determining the CO2 sorption capacity of coal: Experimental and theoretical high pressure isotherms

    NASA Astrophysics Data System (ADS)

    Weishauptová, Zuzana; Přibyl, Oldřich

    2016-04-01

    volumetric sorption apparatus working within the temperature range of 30°C to 65°C at a pressure of 15 MPa was used for measuring the CO2 high pressure isotherms. The data for constructing the theoretical high pressure isotherm were obtained from a gravimetric sorption apparatus and a mercury porosimeter. The Dubinin, Langmuir, and Gibbs equations were used for evaluating the data. The measured experimental high pressure isotherms were compared with the theoretical isotherms using linearized Langmuir isotherms. The Langmuir parameters confirmed a reasonable correspondence between the sorption capacities derived using the two approaches applied here.

  19. Simple Experimental Methods for Determining the Apparent Focal Shift in a Microscope System

    PubMed Central

    Bratton, Benjamin P.; Shaevitz, Joshua W.

    2015-01-01

    Three-dimensional optical microscopy is often complicated by a refractive index mismatch between the sample and objective lens. This mismatch causes focal shift, a difference between sample motion and focal-plane motion, that hinders the accuracy of 3D reconstructions. We present two methods for measuring focal shift using fluorescent beads of different sizes and ring-stained fluorescent beads. These simple methods are applicable to most situations, including total internal reflection objectives and samples very close to the interface. For distances 0–1.5 μm into an aqueous environment, our 1.49-NA objective has a relative focal shift of 0.57 ± 0.02, significantly smaller than the simple n2/n1 approximation of 0.88. We also expand on a previous sub-critical angle theory by means of a simple polynomial extrapolation. We test the validity of this extrapolation by measuring the apparent focal shift in samples where the refractive index is between 1.33 and 1.45 and with objectives with numerical apertures between 1.25 and 1.49. PMID:26270960

  20. Experimental methods to preserve male fertility and treat male factor infertility.

    PubMed

    Gassei, Kathrin; Orwig, Kyle E

    2016-02-01

    Infertility is a prevalent condition that has insidious impacts on the infertile individuals, their families, and society, which extend far beyond the inability to have a biological child. Lifestyle changes, fertility treatments, and assisted reproductive technology (ART) are available to help many infertile couples achieve their reproductive goals. All of these technologies require that the infertile individual is able to produce at least a small number of functional gametes (eggs or sperm). It is not possible for a person who does not produce gametes to have a biological child. This review focuses on the infertile man and describes several stem cell-based methods and gene therapy approaches that are in the research pipeline and may lead to new fertility treatment options for men with azoospermia.

  1. Methods employed for induction and analysis of experimental myocardial infarction in mice.

    PubMed

    Borst, Oliver; Ochmann, Carmen; Schönberger, Tanja; Jacoby, Christoph; Stellos, Konstantinos; Seizer, Peter; Flögel, Ulrich; Lang, Florian; Gawaz, Meinrad

    2011-01-01

    Myocardial ischemia und subsequent reperfusion is followed by a complex sequence of pathophysiological responses involving inflammatory cell infiltration and cytokine release as well as postinfarction wound healing and myocardial tissue remodeling. With the development of gene targeted mice the contribution of individual gene products to the pathophysiology of myocardial ischemia and reperfusion can be defined leading to an increasing interest in the widely-used mouse model of myocardial infarction. This methological paper describes in detail the required equipment, surgical instruments, drugs and additional material, the methods of anesthesia and analgesia, the procedures involved in preparation of the animal, tracheotomy, intubation, thoracotomy, occlusion of the left descending artery, removal of the heart, determination of infarct size, analysis of cardiac functional parameters with echocardiography and magnetic resonance imaging (MRI) as well as determination of the morphological consequences utilizing gelatin zymography, histology and immunohistochemistry. PMID:21865843

  2. Understanding the nanoparticle-protein corona complexes using computational and experimental methods.

    PubMed

    Kharazian, B; Hadipour, N L; Ejtehadi, M R

    2016-06-01

    Nanoparticles (NP) have capability to adsorb proteins from biological fluids and form protein layer, which is called protein corona. As the cell sees corona coated NPs, the protein corona can dictate biological response to NPs. The composition of protein corona is varied by physicochemical properties of NPs including size, shape, surface chemistry. Processing of protein adsorption is dynamic phenomena; to that end, a protein may desorb or leave a surface vacancy that is rapidly filled by another protein and cause changes in the corona composition mainly by the Vroman effect. In this review, we discuss the interaction between NP and proteins and the available techniques for identification of NP-bound proteins. Also we review current developed computational methods for understanding the NP-protein complex interactions.

  3. Simulation and optimization of an experimental membrane wastewater treatment plant using computational intelligence methods.

    PubMed

    Ludwig, T; Kern, P; Bongards, M; Wolf, C

    2011-01-01

    The optimization of relaxation and filtration times of submerged microfiltration flat modules in membrane bioreactors used for municipal wastewater treatment is essential for efficient plant operation. However, the optimization and control of such plants and their filtration processes is a challenging problem due to the underlying highly nonlinear and complex processes. This paper presents the use of genetic algorithms for this optimization problem in conjunction with a fully calibrated simulation model, as computational intelligence methods are perfectly suited to the nonconvex multi-objective nature of the optimization problems posed by these complex systems. The simulation model is developed and calibrated using membrane modules from the wastewater simulation software GPS-X based on the Activated Sludge Model No.1 (ASM1). Simulation results have been validated at a technical reference plant. They clearly show that filtration process costs for cleaning and energy can be reduced significantly by intelligent process optimization.

  4. Light pipe design method and stepper experimentation for interference effects reduction in laser illumination

    NASA Astrophysics Data System (ADS)

    Poyet, Jean-Michel; Lutz, Yves

    2016-07-01

    The use of light pipes is an efficient and low-cost technique to get a homogeneous illumination for laser-gated viewing systems. However, this technique suffers from drawbacks when used with coherent sources like solid-state lasers. Compacting light pipe-based laser illuminators involves working with small light pipe sections, and experiments show that interference fringes appear on the laser illumination profiles. The principle of light pipe homogenization has been reviewed using geometrical optics to understand the phenomenon better, and a pragmatic light pipe design method, based on laser-gated viewing system parameters, is proposed. Another original solution based on optical stepper is studied to reduce both interference fringes and speckle noise to increase the homogeneity of laser illumination profiles.

  5. Methods employed for induction and analysis of experimental myocardial infarction in mice.

    PubMed

    Borst, Oliver; Ochmann, Carmen; Schönberger, Tanja; Jacoby, Christoph; Stellos, Konstantinos; Seizer, Peter; Flögel, Ulrich; Lang, Florian; Gawaz, Meinrad

    2011-01-01

    Myocardial ischemia und subsequent reperfusion is followed by a complex sequence of pathophysiological responses involving inflammatory cell infiltration and cytokine release as well as postinfarction wound healing and myocardial tissue remodeling. With the development of gene targeted mice the contribution of individual gene products to the pathophysiology of myocardial ischemia and reperfusion can be defined leading to an increasing interest in the widely-used mouse model of myocardial infarction. This methological paper describes in detail the required equipment, surgical instruments, drugs and additional material, the methods of anesthesia and analgesia, the procedures involved in preparation of the animal, tracheotomy, intubation, thoracotomy, occlusion of the left descending artery, removal of the heart, determination of infarct size, analysis of cardiac functional parameters with echocardiography and magnetic resonance imaging (MRI) as well as determination of the morphological consequences utilizing gelatin zymography, histology and immunohistochemistry.

  6. A comparison of methods to estimate nutritional requirements from experimental data.

    PubMed

    Pesti, G M; Vedenov, D; Cason, J A; Billard, L

    2009-01-01

    1. Research papers use a variety of methods for evaluating experiments designed to determine nutritional requirements of poultry. Growth trials result in a set of ordered pairs of data. Often, point-by-point comparisons are made between treatments using analysis of variance. This approach ignores that response variables (body weight, feed efficiency, bone ash, etc.) are continuous rather than discrete. Point-by-point analyses harvest much less than the total amount of information from the data. Regression models are more effective at gleaning information from data, but the concept of "requirements" is poorly defined by many regression models. 2. Response data from a study of the lysine requirements of young broilers was used to compare methods of determining requirements. In this study, multiple range tests were compared with quadratic polynomials (QP), broken line models with linear (BLL) or quadratic (BLQ) ascending portions, the saturation kinetics model (SK) a logistic model (LM) and a compartmental (CM) model. 3. The sum of total residuals squared was used to compare the models. The SK and LM were the best fit models, followed by the CM, BLL, BLQ, and QP models. A plot of the residuals versus nutrient intake showed clearly that the BLQ and SK models fitted the data best in the important region where the ascending portion meets the plateau. 4. The BLQ model clearly defines the technical concept of nutritional requirements as typically defined by nutritionists. However, the SK, LM and CM models better depict the relationship typically defined by economists as the "law of diminishing marginal productivity". The SK model was used to demonstrate how the law of diminishing marginal productivity can be applied to poultry nutrition, and how the "most economical feeding level" may replace the concept of "requirements". PMID:19234926

  7. Experimental test results from an environmental protection agency test method for determination of vapor suppressant effectiveness

    NASA Astrophysics Data System (ADS)

    Tock, Richard W.; Ahern, Daniel W.

    2005-04-01

    The results obtained from laboratory experiments conducted using Environmental Protection Agency (EPA) subpart WWWW of 40 Code of Federal Regulations (CFR) part 63 (1)-test method are discussed in this article. The original test method was developed to measure the effectiveness of wax suppressants used to reduce hazardous air pollutant (HAP) emissions from unsaturated polyester (UP)/vinyl ester resins. Wax additions of ˜1.5% by weight to commercial UP resins suppress HAP emissions through the formation of surface barrier films. However, the tests performed in this study included the use of limestone and an adjunct, organic fiber reinforcement, rather than the wax. The addition of either commercial product to the UP formulations tested in this study was also shown to reduce HAP emissions. Suppression was a combination of absorption and an increased diffusion path barrier for the volatile organic carbon (VOC) components. Based on the limited data obtained, it was shown that the oil absorption characteristics of the two adjunct products could be used to estimate the expected level of vapor suppression for a specific resin formulation. Values reported in the literature for the oil adsorption characteristics of the adjunct limestone and the commercial biomass fiber were used in the laboratory tests. Although the oil adsorption characteristic of any ingredient added to a base resin formulation is indicative of its potential for emissions reduction, the EPA test protocol is still required to be performed for validation. Such screening tests will always be needed due to the variability associated with commercial UP resins and the evolution of customized UP/fiberglass composite formulations developed by custom molding shops.

  8. Experimental validation of a method characterizing bow tie filters in CT scanners using a real-time dose probe

    SciTech Connect

    McKenney, Sarah E.; Nosratieh, Anita; Gelskey, Dale; Yang Kai; Huang Shinying; Chen Lin; Boone, John M.

    2011-03-15

    Purpose: Beam-shaping or ''bow tie'' (BT) filters are used to spatially modulate the x-ray beam in a CT scanner, but the conventional method of step-and-shoot measurement to characterize a beam's profile is tedious and time-consuming. The theory for characterization of bow tie relative attenuation (COBRA) method, which relies on a real-time dosimeter to address the issues of conventional measurement techniques, was previously demonstrated using computer simulations. In this study, the feasibility of the COBRA theory is further validated experimentally through the employment of a prototype real-time radiation meter and a known BT filter. Methods: The COBRA method consisted of four basic steps: (1) The probe was placed at the edge of a scanner's field of view; (2) a real-time signal train was collected as the scanner's gantry rotated with the x-ray beam on; (3) the signal train, without a BT filter, was modeled using peak values measured in the signal train of step 2; and (4) the relative attenuation of the BT filter was estimated from filtered and unfiltered data sets. The prototype probe was first verified to have an isotropic and linear response to incident x-rays. The COBRA method was then tested on a dedicated breast CT scanner with a custom-designed BT filter and compared to the conventional step-and-shoot characterization of the BT filter. Using basis decomposition of dual energy signal data, the thickness of the filter was estimated and compared to the BT filter's manufacturing specifications. The COBRA method was also demonstrated with a clinical whole body CT scanner using the body BT filter. The relative attenuation was calculated at four discrete x-ray tube potentials and used to estimate the thickness of the BT filter. Results: The prototype probe was found to have a linear and isotropic response to x-rays. The relative attenuation produced from the COBRA method fell within the error of the relative attenuation measured with the step-and-shoot method

  9. Structural characterization of N-methylcarbamate: β-Cyclodextrin complexes by experimental methods and molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Pacioni, Natalia L.; Pierini, Adriana B.; Veglia, Alicia V.

    2013-02-01

    Detailed insights regarding the inclusion process between β-cyclodextrin and the N-methylcarbamates insecticides like Bendiocarb, Carbaryl, Carbofuran and Promecarb, are proposed in bases of experimental and computational methods. The results from Fourier transform infrared spectroscopy, differential scanning calorimetry, induced circular dichroism and molecular dynamics indicate that only in the case of Promecarb the interaction with the macrocycle is produced by the alkyl rest of the molecule. In all other cases the aromatic moiety is the part of the insecticide that is partially included in the cavity of β-cyclodextrin.

  10. Experimental research of the possible use of photodynamic methods in the treatment of melanoma of the iris

    NASA Astrophysics Data System (ADS)

    Kecik, Tadeusz; Switka-Wieclawska, Iwona; Kasprzak, Jan; Graczyk, Alfreda; Pratnicki, Antoni

    1995-03-01

    In our experimental work we present the use of hematoporphyrin derivative photodynamic therapy (HpD-PDT) in the treatment of melanoma. Eighteen eyes of rabbits were incubated intracamerally with amelanotic Greene melanoma tissue. The technique involves the administration of HpD and photoactivation of tumor with red light (630 nm) to achieve selective destruction of cancer cells. After photoradiation the tumor showed blanching and shrinkage, we could also observe the tumor vasculature damaged. Successfully treated tumors had large areas of necrosis with severely damaged blood vessels in histopathological examination. Results indicate that HpD-PDT is a very promising modern modality offering a new method of melanoma treatment.

  11. Experimental Research of High-Energy Capabilities of Material Recognition by Dual-Energy Method for the Low- Dose Radiation

    NASA Astrophysics Data System (ADS)

    Abashkin, A.; Osipov, S.; Chakhlov, S.; Shteyn, A.

    2016-06-01

    The algorithm to produce primary radiographs, its transformation by dual energy method and recognition of the object materials were enhanced based on the analysis of experimental results. The experiments were carried out at the inspection complex with high X- ray source - betatron MIB 4/9 in Tomsk Polytechnic University. For the reduced X -ray dose rate, the possibility of recognition of the object materials with thickness from 20 to 120 g/cm2 was proved under the condition that as the dose rate is reduced by the defined number of times, the segment of the image fragment with the reliably identified material will increase by the same number of times.

  12. Utility of the microculture method in non-invasive samples obtained from an experimental murine model with asymptomatic leishmaniasis.

    PubMed

    Allahverdiyev, Adil M; Bagirova, Malahat; Cakir-Koc, Rabia; Elcicek, Serhat; Oztel, Olga Nehir; Canim-Ates, Sezen; Abamor, Emrah Sefik; Yesilkir-Baydar, Serap

    2012-07-01

    The sensitivity of diagnostic methods for visceral leishmaniasis (VL) decreases because of the low number of parasites and antibody amounts in asymptomatic healthy donors who are not suitable for invasive sample acquisition procedures. Therefore, new studies are urgently needed to improve the sensitivity and specificity of the diagnostic approaches in non-invasive samples. In this study, the sensitivity of the microculture method (MCM) was compared with polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA), and immunofluorescent antibody test (IFAT) methods in an experimental murine model with asymptomatic leishmaniasis. Results showed that the percent of positive samples in ELISA, IFAT, and peripheral blood (PB) -PCR tests were 17.64%, 8.82%, and 5.88%, respectively, whereas 100% positive results were obtained with MCM and MCM-PCR methods. Thus, this study, for the first time, showed that MCM is more sensitive, specific, and economic than other methods, and the sensitivity of PCR that was performed to samples obtained from MCM was higher than sensitivity of the PCR method sampled by PB. PMID:22764296

  13. Localized 2D COSY sequences: Method and experimental evaluation for a whole metabolite quantification approach

    NASA Astrophysics Data System (ADS)

    Martel, Dimitri; Tse Ve Koon, K.; Le Fur, Yann; Ratiney, Hélène

    2015-11-01

    Two-dimensional spectroscopy offers the possibility to unambiguously distinguish metabolites by spreading out the multiplet structure of J-coupled spin systems into a second dimension. Quantification methods that perform parametric fitting of the 2D MRS signal have recently been proposed for resolved PRESS (JPRESS) but not explicitly for Localized Correlation Spectroscopy (LCOSY). Here, through a whole metabolite quantification approach, correlation spectroscopy quantification performances are studied. The ability to quantify metabolite relaxation constant times is studied for three localized 2D MRS sequences (LCOSY, LCTCOSY and the JPRESS) in vitro on preclinical MR systems. The issues encountered during implementation and quantification strategies are discussed with the help of the Fisher matrix formalism. The described parameterized models enable the computation of the lower bound for error variance - generally known as the Cramér Rao bounds (CRBs), a standard of precision - on the parameters estimated from these 2D MRS signal fittings. LCOSY has a theoretical net signal loss of two per unit of acquisition time compared to JPRESS. A rapid analysis could point that the relative CRBs of LCOSY compared to JPRESS (expressed as a percentage of the concentration values) should be doubled but we show that this is not necessarily true. Finally, the LCOSY quantification procedure has been applied on data acquired in vivo on a mouse brain.

  14. A New Method of Selective, Rapid Cooling of the Brain: An Experimental Study

    SciTech Connect

    Allers, Mats; Boris-Moeller, Fredrik; Lunderquist, Anders; Wieloch, Tadeusz

    2006-04-15

    Purpose. To determine whether retrograde perfusion of cooled blood into one internal jugular vein (IJV) in the pig can selectively reduce the brain temperature without affecting the core body temperature (CBT). Methods. In 7 domestic pigs, the left IJV was catheterized on one side and a catheter placed with the tip immediately below the rete mirabile. Thermistors were placed in both brain hemispheres and the brain temperature continuously registered. Thermistors placed in the rectum registered the CBT. From a catheter in the right femoral vein blood was aspirated with the aid of a roller pump, passed through a cooling device, and infused into the catheter in the left IJV at an initial rate of 200 ml/min. Results. Immediately after the start of the infusion of cooled blood (13.8 deg. C) into the IJV, the right brain temperature started to drop from its initial 37.9 deg. C and reached 32 deg. C within 5 min. By increasing the temperature of the perfusate a further drop in the brain temperature was avoided and the brain temperature could be kept around 32 deg. C during the experiment. In 4 of the animals a heating blanket was sufficient to compensate for the slight drop in CBT during the cooling period. Conclusions. We conclude that brain temperature can be reduced in the pig by retrograde perfusion of the internal jugular vein with cooled blood and that the core body temperature can be maintained with the aid of a heating blanket.

  15. Mechanical Stress Simulation of Scored Tablets Based on the Finite Element Method and Experimental Verification.

    PubMed

    Okada, Nobuto; Hayashi, Yoshihiro; Onuki, Yoshinori; Miura, Takahiro; Obata, Yasuko; Takayama, Kozo

    2016-01-01

    Scored tablets can be divided into equal halves for individual treatment of patients. However, the relationships between scored shapes and tablet characteristics such as the dividing strength, halving equality, and breaking strength are poorly understood. The purpose of this study was to simulate the mechanical stress distribution of scored tablets by using the finite element method (FEM). A runnel of triangle pole on the top surface of flat tablets was fabricated as the score shape. The depth and angle of the scores were selected as design variables. Elastic parameters such as a Young's modulus and a Poisson ratio for the model powder bed were measured. FEM simulation was then applied to the scored tablets, represented as a continuum elastic model. Stress distributions in the inner structure of the tablets were simulated after applying external force. The adequacy of the simulation was evaluated in experiments using scored tablets. As a result, we observed a relatively good agreement between the FEM simulation and the experiments, suggesting that FEM simulation is advantageous for designing scored tablets. PMID:27477653

  16. Experimental methods to validate measures of emotional state and readiness for duty in critical operations.

    SciTech Connect

    Weston, Louise Marie

    2007-09-01

    A recent report on criticality accidents in nuclear facilities indicates that human error played a major role in a significant number of incidents with serious consequences and that some of these human errors may be related to the emotional state of the individual. A pre-shift test to detect a deleterious emotional state could reduce the occurrence of such errors in critical operations. The effectiveness of pre-shift testing is a challenge because of the need to gather predictive data in a relatively short test period and the potential occurrence of learning effects due to a requirement for frequent testing. This report reviews the different types of reliability and validity methods and testing and statistical analysis procedures to validate measures of emotional state. The ultimate value of a validation study depends upon the percentage of human errors in critical operations that are due to the emotional state of the individual. A review of the literature to identify the most promising predictors of emotional state for this application is highly recommended.

  17. An experimental study of concurrent methods for adaptively controlling vertical tail buffet in high performance aircraft

    NASA Astrophysics Data System (ADS)

    Roberts, Patrick J.

    High performance twin-tail aircraft, like the F-15 and F/A-18, encounter a condition known as tail buffet. At high angles of attack, vortices are generated at the wing fuselage interface (shoulder) or other leading edge extensions. These vortices are directed toward the twin vertical tails. When the flow interacts with the vertical tail it creates pressure variations that can oscillate the vertical tail assembly. This results in fatigue cracks in the vertical tail assembly that can decrease the fatigue life and increase maintenance costs. Recently, an offset piezoceramic stack actuator was used on an F-15 wind tunnel model to control buffet induced vibrations at high angles of attack. The controller was based on the acceleration feedback control methods, In this thesis a procedure for designing the offset piezoceramic stack actuators is developed. This design procedure includes determining the quantity and type of piezoceramic stacks used in these actuators. The changes of stresses, in the vertical tail caused by these actuators during an active control, are investigated. In many cases, linear controllers are very effective in reducing vibrations. However, during flight, the natural frequencies of the vertical tail structural system changes as the airspeed increases. This in turn, reduces the effectiveness of a linear controller. Other causes such as the unmodeled dynamics and nonlinear effects due to debonds also reduce the effectiveness of linear controllers. In this thesis, an adaptive neural network is used to augment the linear controller to correct these effects.

  18. Monte Carlo modeling of proton therapy installations: a global experimental method to validate secondary neutron dose calculations.

    PubMed

    Farah, J; Martinetti, F; Sayah, R; Lacoste, V; Donadille, L; Trompier, F; Nauraye, C; De Marzi, L; Vabre, I; Delacroix, S; Hérault, J; Clairand, I

    2014-06-01

    Monte Carlo calculations are increasingly used to assess stray radiation dose to healthy organs of proton therapy patients and estimate the risk of secondary cancer. Among the secondary particles, neutrons are of primary concern due to their high relative biological effectiveness. The validation of Monte Carlo simulations for out-of-field neutron doses remains however a major challenge to the community. Therefore this work focused on developing a global experimental approach to test the reliability of the MCNPX models of two proton therapy installations operating at 75 and 178 MeV for ocular and intracranial tumor treatments, respectively. The method consists of comparing Monte Carlo calculations against experimental measurements of: (a) neutron spectrometry inside the treatment room, (b) neutron ambient dose equivalent at several points within the treatment room, (c) secondary organ-specific neutron doses inside the Rando-Alderson anthropomorphic phantom. Results have proven that Monte Carlo models correctly reproduce secondary neutrons within the two proton therapy treatment rooms. Sensitive differences between experimental measurements and simulations were nonetheless observed especially with the highest beam energy. The study demonstrated the need for improved measurement tools, especially at the high neutron energy range, and more accurate physical models and cross sections within the Monte Carlo code to correctly assess secondary neutron doses in proton therapy applications.

  19. Experimental method development for estimating solid-phase diffusion coefficients and material/air partition coefficients of SVOCs

    NASA Astrophysics Data System (ADS)

    Liu, Xiaoyu; Guo, Zhishi; Roache, Nancy F.

    2014-06-01

    The solid-phase diffusion coefficient (Dm) and material/air partition coefficient (Kma) are key parameters for characterizing the sources and transport of semivolatile organic compounds (SVOCs) in the indoor environment. In this work, a new experimental method was developed to estimate parameters Dm and Kma. The SVOCs chosen for study were polychlorinated biphenyl (PCB) congeners, including PCB-52, PCB-66, PCB-101, PCB-110, and PCB-118. The test materials included polypropylene, high density polyethylene, low density polyethylene, polytetrafluoroethylene, polyether ether ketone, glass, stainless steel and concrete. Two 53-L environmental chambers were connected in series, with the relatively stable SVOCs source in the source chamber and the test materials, made as small “buttons”, in the test chamber. Prior to loading the test chamber with the test materials, the test chamber had been dosed with SVOCs for 12 days to “coat” the chamber walls. During the tests, the material buttons were removed from the test chamber at different exposure times to determine the amount of SVOC absorbed by the buttons. SVOC concentrations at the inlet and outlet of the test chamber were also monitored. The data were used to estimate the partition and diffusion coefficients by fitting a sink model to the experimental data. The parameters obtained were employed to predict the accumulation of SVOCs in the sink materials using an existing mass transfer model. The model prediction agreed reasonably well with the experimental data.

  20. A hybrid approach for simulating fluid loading effects on structures using experimental modal analysis and the boundary element method.

    PubMed

    Shepherd, Micah R; Fahnline, John B; Dare, Tyler P; Hambric, Stephen A; Campbell, Robert L

    2015-11-01

    Many structural acoustics problems involve a vibrating structure in a heavy fluid. However, obtaining fluid-loaded natural frequencies and damping experimentally can be difficult and expensive. This paper presents a hybrid experimental-numerical approach to determine the heavy-fluid-loaded resonance frequencies and damping of a structure from in-air measurements. The approach combines in-air experimentally obtained mode shapes with simulated in-water acoustic resistance and reactance matrices computed using boundary element (BE) analysis. The procedure relies on accurate estimates of the mass-normalized, in vacuo mode shapes using singular value decomposition and rational fraction polynomial fitting, which are then used as basis modes for the in-water BE analysis. The method is validated on a 4.445 cm (1.75 in.) thick nickel-aluminum-bronze rectangular plate by comparing natural frequencies and damping obtained using the hybrid approach to equivalent data obtained from actual in-water measurements. Good agreement is shown for the fluid-loaded natural frequencies and one-third octave loss factors. Finally, the limitations of the hybrid approach are examined.

  1. A hybrid approach for simulating fluid loading effects on structures using experimental modal analysis and the boundary element method.

    PubMed

    Shepherd, Micah R; Fahnline, John B; Dare, Tyler P; Hambric, Stephen A; Campbell, Robert L

    2015-11-01

    Many structural acoustics problems involve a vibrating structure in a heavy fluid. However, obtaining fluid-loaded natural frequencies and damping experimentally can be difficult and expensive. This paper presents a hybrid experimental-numerical approach to determine the heavy-fluid-loaded resonance frequencies and damping of a structure from in-air measurements. The approach combines in-air experimentally obtained mode shapes with simulated in-water acoustic resistance and reactance matrices computed using boundary element (BE) analysis. The procedure relies on accurate estimates of the mass-normalized, in vacuo mode shapes using singular value decomposition and rational fraction polynomial fitting, which are then used as basis modes for the in-water BE analysis. The method is validated on a 4.445 cm (1.75 in.) thick nickel-aluminum-bronze rectangular plate by comparing natural frequencies and damping obtained using the hybrid approach to equivalent data obtained from actual in-water measurements. Good agreement is shown for the fluid-loaded natural frequencies and one-third octave loss factors. Finally, the limitations of the hybrid approach are examined. PMID:26627781

  2. Reliability of bond dissociation enthalpy calculated by the PM6 method and experimental TEAC values in antiradical QSAR of flavonoids.

    PubMed

    Amić, Dragan; Lucić, Bono

    2010-01-01

    The applicability of the newly developed RM1 and PM6 methods implemented in the semiempirical quantum chemistry mopac2009 software package in modeling free radical scavenging activity of flavonoids was examined. Bond dissociation enthalpy (BDE) of OH groups could be calculated much faster than with DFT method but with similar quality. Despite the known shortcomings of the Trolox equivalent antioxidant capacity (TEAC) assay, we show that taking into account the hydrogen atom transfer (HAT) mechanism of free radical scavenging of flavonoids encoded by minimal BDE values (BDE(min)) and the number of OH groups (nOH), as well as experimental data, reasonable QSAR models could be developed. For TEAC values of 38 flavonoids measured by the ABTS free radical, a model based on BDE(min) and nOH was developed, having very good statistical parameters (r=0.983, r(cv)=0.976). The applicability of this model to three different data sets of flavonoids and reliability of TEAC values measured in distinct laboratories were discussed. Finally, a reasonably good model of experimental vitamin C equivalent antioxidant capacity (VCEAC) of 36 flavonoids was obtained (r=0.954, r(cv)=0.947), involving BDE(min) and nOH as descriptors. Additionally, all presented models have comparable fit and cross-validated statistical parameters, as well as significant regression coefficients.

  3. A Method for Combining Experimentation and Molecular Dynamics Simulation to Improve Cohesive Zone Models for Metallic Microstructures

    NASA Technical Reports Server (NTRS)

    Hochhalter, J. D.; Glaessgen, E. H.; Ingraffea, A. R.; Aquino, W. A.

    2009-01-01

    Fracture processes within a material begin at the nanometer length scale at which the formation, propagation, and interaction of fundamental damage mechanisms occur. Physics-based modeling of these atomic processes quickly becomes computationally intractable as the system size increases. Thus, a multiscale modeling method, based on the aggregation of fundamental damage processes occurring at the nanoscale within a cohesive zone model, is under development and will enable computationally feasible and physically meaningful microscale fracture simulation in polycrystalline metals. This method employs atomistic simulation to provide an optimization loop with an initial prediction of a cohesive zone model (CZM). This initial CZM is then applied at the crack front region within a finite element model. The optimization procedure iterates upon the CZM until the finite element model acceptably reproduces the near-crack-front displacement fields obtained from experimental observation. With this approach, a comparison can be made between the original CZM predicted by atomistic simulation and the converged CZM that is based on experimental observation. Comparison of the two CZMs gives insight into how atomistic simulation scales.

  4. Statistical experimental design for bioprocess modeling and optimization analysis: repeated-measures method for dynamic biotechnology process.

    PubMed

    Lee, Kwang-Min; Gilmore, David F

    2006-11-01

    The statistical design of experiments (DOE) is a collection of predetermined settings of the process variables of interest, which provides an efficient procedure for planning experiments. Experiments on biological processes typically produce long sequences of successive observations on each experimental unit (plant, animal, bioreactor, fermenter, or flask) in response to several treatments (combination of factors). Cell culture and other biotech-related experiments used to be performed by repeated-measures method of experimental design coupled with different levels of several process factors to investigate dynamic biological process. Data collected from this design can be analyzed by several kinds of general linear model (GLM) statistical methods such as multivariate analysis of variance (MANOVA), univariate ANOVA (time split-plot analysis with randomization restriction), and analysis of orthogonal polynomial contrasts of repeated factor (linear coefficient analysis). Last, regression model was introduced to describe responses over time to the different treatments along with model residual analysis. Statistical analysis of biprocess with repeated measurements can help investigate environmental factors and effects affecting physiological and bioprocesses in analyzing and optimizing biotechnology production. PMID:17159235

  5. Experimental determination of field factors ([Formula: see text]) for small radiotherapy beams using the daisy chain correction method.

    PubMed

    Lárraga-Gutiérrez, José Manuel

    2015-08-01

    Recently, Alfonso et al proposed a new formalism for the dosimetry of small and non-standard fields. The proposed new formalism is strongly based on the calculation of detector-specific beam correction factors by Monte Carlo simulation methods, which accounts for the difference in the response of the detector between the small and the machine specific reference field. The correct calculation of the detector-specific beam correction factors demands an accurate knowledge of the linear accelerator, detector geometry and composition materials. The present work shows that the field factors in water may be determined experimentally using the daisy chain correction method down to a field size of 1 cm × 1 cm for a specific set of detectors. The detectors studied were: three mini-ionization chambers (PTW-31014, PTW-31006, IBA-CC01), three silicon-based diodes (PTW-60018, IBA-SFD and IBA-PFD) and one synthetic diamond detector (PTW-60019). Monte Carlo simulations and experimental measurements were performed for a 6 MV photon beam at 10 cm depth in water with a source-to-axis distance of 100 cm. The results show that the differences between the experimental and Monte Carlo calculated field factors are less than 0.5%-with the exception of the IBA-PFD-for field sizes between 1.5 cm × 1.5 cm and 5 cm × 5 cm. For the 1 cm × 1 cm field size, the differences are within 2%. By using the daisy chain correction method, it is possible to determine measured field factors in water. The results suggest that the daisy chain correction method is not suitable for measurements performed with the IBA-PFD detector. The latter is due to the presence of tungsten powder in the detector encapsulation material. The use of Monte Carlo calculated [Formula: see text] is encouraged for field sizes less than or equal to 1 cm × 1 cm for the dosimeters used in this work. PMID:26161448

  6. Potential of 99mTc-LDLs labeled by two different methods for scintigraphic detection of experimental atherosclerosis in rabbits.

    PubMed

    Atsma, D E; Feitsma, R I; Camps, J; van't Hooft, F M; van der Wall, E E; Nieuwenhuizen, W; Pauwels, E K

    1993-01-01

    In this study we evaluated two different 99mTc-labeling techniques to produce 99mTc-low density lipoprotein (99mTc-LDL) suitable for the scintigraphic delineation of experimental atherosclerotic lesions. The two methods are 1) a procedure that uses stannous chloride and sodium borohydride (borohydride method) and 2) a procedure that uses sodium dithionite as a reducing agent and that has been successfully applied in previous scintigraphic atherosclerosis detection (dithionite method). 99mTc-LDL produced by either method was injected into New Zealand White rabbits with diet-induced atherosclerotic plaques and in control rabbits. Scintigraphic images were taken 10 minutes (t = 0) and 1, 4, 8, 16, and 24 hours after injection. Clearance of plasma radioactivity was also studied. Stability of the 99mTc-LDL complex in the circulation was examined by size exclusion chromatography of plasma samples. After scintigraphy, the animals were killed, and the biodistribution of radioactivity was determined. The thoracic and abdominal aortas appeared in scintigraphic images to accumulate 99mTc over their entire length with either 99mTc-LDL preparation. The sparse imaging of focal atherosclerosis was found to be due to the fact that the aortas were covered with confluent atherosclerotic lesions. Scintigraphic image analysis showed that 24 hours after injection, the accumulated radioactivity in the abdominal aorta of the atherosclerotic rabbits was 57% and 54%, respectively, of the accumulated radioactivity in the abdominal aorta at t = 0 when the borohydride versus the dithionite method was used. In the control animals this value was 25% for the dithionite method, whereas in the borohydride method the aortas could not be detected in the images at t = 24 hours.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8422342

  7. Experimental validation of the intrinsic spatial efficiency method over a wide range of sizes for cylindrical sources

    NASA Astrophysics Data System (ADS)

    Ortiz-Ramírez, Pablo; Camilla, S.; Larroquette, Philippe

    2016-07-01

    The intrinsic spatial efficiency method is a new absolute method to determine the efficiency of a gamma spectroscopy system for any extended source. In the original work the method was experimentally demonstrated and validated for homogeneous cylindrical sources containing 137Cs, whose sizes varied over a small range (29.5 mm radius and 15.0 to 25.9 mm height). In this work we present an extension of the validation over a wide range of sizes. The dimensions of the cylindrical sources vary between 10 to 40 mm height and 8 to 30 mm radius. The cylindrical sources were prepared using the reference material IAEA-372, which had a specific activity of 11320 Bq/kg at july 2006. The obtained results were better for the sources with 29 mm radius showing relative bias lesser than 5% and for the sources with 10 mm height showing relative bias lesser than 6%. In comparison with the obtained results in the work where we present the method, the majority of these results show an excellent agreement.

  8. Determination of surface dose rate of indigenous (32)P patch brachytherapy source by experimental and Monte Carlo methods.

    PubMed

    Kumar, Sudhir; Srinivasan, P; Sharma, S D; Saxena, Sanjay Kumar; Bakshi, A K; Dash, Ashutosh; Babu, D A R; Sharma, D N

    2015-09-01

    Isotope production and Application Division of Bhabha Atomic Research Center developed (32)P patch sources for treatment of superficial tumors. Surface dose rate of a newly developed (32)P patch source of nominal diameter 25 mm was measured experimentally using standard extrapolation ionization chamber and Gafchromic EBT film. Monte Carlo model of the (32)P patch source along with the extrapolation chamber was also developed to estimate the surface dose rates from these sources. The surface dose rates to tissue (cGy/min) measured using extrapolation chamber and radiochromic films are 82.03±4.18 (k=2) and 79.13±2.53 (k=2) respectively. The two values of the surface dose rates measured using the two independent experimental methods are in good agreement to each other within a variation of 3.5%. The surface dose rate to tissue (cGy/min) estimated using the MCNP Monte Carlo code works out to be 77.78±1.16 (k=2). The maximum deviation between the surface dose rates to tissue obtained by Monte Carlo and the extrapolation chamber method is 5.2% whereas the difference between the surface dose rates obtained by radiochromic film measurement and the Monte Carlo simulation is 1.7%. The three values of the surface dose rates of the (32)P patch source obtained by three independent methods are in good agreement to one another within the uncertainties associated with their measurements and calculation. This work has demonstrated that MCNP based electron transport simulations are accurate enough for determining the dosimetry parameters of the indigenously developed (32)P patch sources for contact brachytherapy applications.

  9. Experimental phasing for structure determination using membrane-protein crystals grown by the lipid cubic phase method

    SciTech Connect

    Li, Dianfan; Pye, Valerie E.; Caffrey, Martin

    2015-01-01

    Very little information is available in the literature concerning the experimental heavy-atom phasing of membrane-protein structures where the crystals have been grown using the lipid cubic phase (in meso) method. In this paper, pre-labelling, co-crystallization, soaking, site-specific mercury binding to genetically engineered single-cysteine mutants and selenomethionine labelling as applied to an integral membrane kinase crystallized in meso are described. An assay to assess cysteine accessibility for mercury labelling of membrane proteins is introduced. Despite the marked increase in the number of membrane-protein structures solved using crystals grown by the lipid cubic phase or in meso method, only ten have been determined by SAD/MAD. This is likely to be a consequence of the technical difficulties associated with handling proteins and crystals in the sticky and viscous hosting mesophase that is usually incubated in glass sandwich plates for the purposes of crystallization. Here, a four-year campaign aimed at phasing the in meso structure of the integral membrane diacylglycerol kinase (DgkA) from Escherichia coli is reported. Heavy-atom labelling of this small hydrophobic enzyme was attempted by pre-labelling, co-crystallization, soaking, site-specific mercury binding to genetically engineered single-cysteine mutants and selenomethionine incorporation. Strategies and techniques for special handling are reported, as well as the typical results and the lessons learned for each of these approaches. In addition, an assay to assess the accessibility of cysteine residues in membrane proteins for mercury labelling is introduced. The various techniques and strategies described will provide a valuable reference for future experimental phasing of membrane proteins where crystals are grown by the lipid cubic phase method.

  10. Studies on the dissolution of polycyclic aromatic hydrocarbons from contaminated materials using a novel dialysis tubing experimental method

    SciTech Connect

    Woolgar, P.J. Scottish Environment Protection Agency, Stirling ); Jones, K.C. )

    1999-06-15

    Assessment of risk and remediation strategies at contaminated sites requires that both the amounts of contaminants present and their potential for release from materials and soils be evaluated. The release, or dissolution, of polycyclic aromatic hydrocarbons (PAHs) from contaminated materials to water was therefore investigated. To facilitate investigations of PAH dissolution from physically disparate materials such as solid coal tars, creosote, oil, and spent oxide, an experimental method for measuring dissolved PAHs was developed employing dialysis tubing in batch-type system. This was validated and compared to aqueous-phase PAH concentrations measured using more traditional techniques and also predicted using Raoult's law. The experimental procedure was successfully used to determine near equilibrium aqueous concentrations of PAHs, but it could only be used to determine relative rates of approach to equilibrium as the dialysis tubing effected the rate constants. It was found that the contaminant materials influenced dissolution, in particular the close to equilibrium concentrations. For materials chemically similar to PAHs, such as nonaqueous-phase liquids (NAPLs), the concentrations could be predicted using Raoult's law. For materials that were chemically dissimilar to PAHs, such as spent oxide, release was more thermodynamically favorable than for NAPLs.

  11. Comparison of Experimentally Measured Temperature Gradient and Finite-Element-Method Simulations for Two Continuously Cast Bloom Heating Strategies

    NASA Astrophysics Data System (ADS)

    Kvíčala, M.; Frydrýšek, K.; Štamborská, M.

    2015-03-01

    This paper deals with the comparison of experimentally measured temperature gradients and finite-element-method (FEM) simulations of two heating strategies that were used for continuously cast bloom soaking. The temperature gradient between the bloom surface and center was measured by two thermocouples incorporated directly into the bloom. Scanning electron microscopy equipped by energy dispersive X-ray spectroscopy analysis, hot tensile tests, and interdendritic solidification software was used for modeling of steel thermophysical properties with respect to the alloying-elements macrosegregation. The model of the bloom was programmed in the Fortran language. The FEM software MARC/MENTAT 2012 was used for simulation of two heating strategies (plane strain formulation). The first heating model was fitted to the commonly used heating strategy when internal defects grew above the critical limit. The second heating model was a newly proposed strategy that consisted of slower heating up to 1073 K when the first warming-through period occurred. The FEM simulations included determinations of the temperature gradient, the equivalent of stress, the equivalent of elastic strain, the equivalent of plastic strain, and the equivalent of total strain. The simulation results were in good agreement with experimental observations. The new heating strategy based on the FEM simulations led to significantly lower occurrence of internal defects in hot-rolled billets that are used for cylinder production.

  12. An experimental and analytical investigation of the rail shear-test method as applied to composite materials

    NASA Technical Reports Server (NTRS)

    Garcia, R.; Mcwithey, R. R.; Weisshaar, T. A.

    1979-01-01

    This report presents the results from an experimental and analytical investigation of the stress distributions occurring in a rail shear test. The effects of non-uniform stresses induced by differential thermal expansion, rail flexibility and specimen aspect ratio on measured shear modulus and ultimate strength of composite laminates are shown. A two-dimensional linearly elastic finite element model was used to analytically determine how various geometric parameters influenced the magnitude and distribution of inplane normal and shear stresses in a tensile rail shear specimen. Rail shear tests were conducted at room temperature and 589 K (600 F) on selected graphite-polyimide composite laminates using two titanium rail configurations. The analysis and test methods are discussed, and the results of the effects of the various parameters on shear modulus and ultimate strength are presented.

  13. Autogenic-Feedback Training (AFT) as a preventive method for space motion sickness: Background and experimental design

    NASA Technical Reports Server (NTRS)

    Cowings, Patricia S.; Toscano, William B.

    1993-01-01

    Finding an effective treatment for the motion sickness-like symptoms that occur in space has become a high priority for NASA. The background research is reviewed and the experimental design of a formal life sciences shuttle flight experiment designed to prevent space motion sickness in shuttle crew members is presented. This experiment utilizes a behavioral medicine approach to solving this problem. This method, Autogenic-Feedback Training (AFT), involves training subjects to voluntarily control several of their own physiological responses to environmental stressors. AFT has been used reliably to increase tolerance to motion sickness during ground-based tests in over 200 men and women under a variety of conditions that induce motion sickness, and preliminary evidence from space suggests that AFT may be an effective treatment for space motion sickness as well. Proposed changes to this experiment for future manifests are included.

  14. A finite volume method and experimental study of a stator of a piezoelectric traveling wave rotary ultrasonic motor.

    PubMed

    Bolborici, V; Dawson, F P; Pugh, M C

    2014-03-01

    Piezoelectric traveling wave rotary ultrasonic motors are motors that generate torque by using the friction force between a piezoelectric composite ring (or disk-shaped stator) and a metallic ring (or disk-shaped rotor) when a traveling wave is excited in the stator. The motor speed is proportional to the amplitude of the traveling wave and, in order to obtain large amplitudes, the stator is excited at frequencies close to its resonance frequency. This paper presents a non-empirical partial differential equations model for the stator, which is discretized using the finite volume method. The fundamental frequency of the discretized model is computed and compared to the experimentally-measured operating frequency of the stator of Shinsei USR60 piezoelectric motor.

  15. Experimental studies on the role of planktivorous fishes in the elimination of Microcystis bloom from Donghu Lake using enclosure method

    NASA Astrophysics Data System (ADS)

    Xie, Ping

    1996-09-01

    The hypertrophic subtropic Donghu Lake's dense water bloom (of mainly Microcystis, Anabaena and Oscillatoria) that occurred annually from the beginning of the 1970s, has disappeared since 1985. The influence of planktivorous fishes (silver and bighead carps) on the water bloom was studied for three years using the enclosure method. The enclosures stocked densely with bighead and/or silver carp were free of water bloom during the experimental period. The water bloom that appeared in the fish-free enclosures was completely eliminated in 10 20 days by introduction of silver and/or bighead carp(grass carp was not effective in controlling water bloom). This study showed clearly that grazing pressure by planktivorous fishes is a key factor in eliminating water bloom from the lake.

  16. a Proposal for a General Method for Determining Semi-Experimental Equilibrium Structures of Carbon Atom Backbones

    NASA Astrophysics Data System (ADS)

    Craig, Norman C.

    2010-06-01

    Semi-experimental equilibrium structures are determined from ground state rotational constants derived from the analysis of rotational transitions in high-resolution spectra and from the quantum chemical calculation of spectroscopic alphas. In the full application of this method, spectra of numerous isotopic species must be investigated. Most of these isotopic species require specialized synthesis. We now propose focusing on the carbon atoms, for which microwave spectroscopy routinely yields spectra for polar molecules with 13C substitution in natural abundance. Needed spectroscopic alphas can be computed with Gaussian software. Application of the Kraitchman substitution relationships gives Cartesian coordinates for the carbon atoms and thence bond parameters for the carbon backbone. This method will be evaluated with ethylene, 1,1-difluoroethylene, 1,1-difluorocyclopropane, propene, and butadiene. The method will then be applied to cis-hexatriene and the two conformers of glycidol. R. D. Suenram, B. H. Pate, A. Lessari, J. L. Neill, S. Shipman, R. A. Holmes, M. C. Leyden, and N. C. Craig, J. Phys. Chem. A 113, 1864-1868 (2009). A. R. Conrad, N. H. Teumelsan, P. E. Wang, and M. J. Tubergen, J. Phys. Chem. A 114, 336-342 (2010).

  17. Tracking evolution of myoglobin stability in cetaceans using experimentally calibrated computational methods that account for generic protein relaxation.

    PubMed

    Holm, Jeppe; Dasmeh, Pouria; Kepp, Kasper P

    2016-07-01

    The evolution of cetaceans (whales, dolphins, and porpoises) from land to water is one of the most spectacular events in mammal evolution. It has been suggested that selection for higher myoglobin stability (∆G of folding) allowed whales to conquer the deep-diving niche. The stability of multi-site protein variants, including ancient proteins, is however hard to describe theoretically. From a compilation of experimental ∆∆G vs. ∆G we first find that protein substitutions are subject to large generic protein relaxation effects. Using this discovery, we develop a simple two-parameter model that predicts multi-site ∆∆G as accurately as standard methods do for single-site mutations and reproduces trends in contemporary myoglobin stabilities. We then apply this new method to the study of the evolution of Mb stability in cetaceans: With both methods the main change in stability (about 1kcal/mol) occurred very early, and stability was later relaxed in dolphins and porpoises, but was further increased in the sperm whales. This suggests that single proteins can affect whole organism evolution and indicates a role of Mb stability in the evolution of cetaceans. Transition to the deep-diving niche probably occurred already in the ancestor of contemporary baleen and toothed whales. In summary, we have discovered generic stability relaxation effects in proteins that, when incorporated into a simple model, improves the description of multi-site protein variants. PMID:27068539

  18. Experimental measurements of a prototype high-concentration Fresnel lens and sun-tracking method for photovoltaic panel's efficiency enhancement

    NASA Astrophysics Data System (ADS)

    Rajaee, Meraj; Ghorashi, Seyed Mohamad Bagher

    2015-08-01

    Concentrator photovoltaic modules are a promising technology for highly efficient solar energy conversion. This system presents several advantages due to additional degrees of freedom that has been provided by the spectral separation such as cost and mass reduction, increase in the incident solar flux on PV cells and performances. This paper has proposed a unique photovoltaic solar cell system that consists of semi-Fresnel lens convergent structure and a novel two axis sun tracking module to enhance the efficiency of solar cell by using less cell area and energy losses. The grooves of this lens are calculated according to the refraction and convergent angles of the light easy for perpendicular incidence angle. The update time interval during tracking causes misalignment of the lens' optical axis versus the sunrays. Then an inventive sun-tracking method is introduced to adjust the module so that the incident rays are always perpendicular to the module's surface. As a result, all rays will be refracted with the predetermined angles. This way the focus area is reduced and smaller cells can be used. We also mentioned different module connections in order to provide compensation method during losses, for networks and power systems. Experimental results show that using semi-Fresnel lens, along with the sun-tracking method increases the efficiency of PV panel.

  19. Experimental study of flow separation control on a low- Re airfoil using leading-edge protuberance method

    NASA Astrophysics Data System (ADS)

    Zhang, M. M.; Wang, G. F.; Xu, J. Z.

    2014-04-01

    An experimental study of flow separation control on a low- Re c airfoil was presently investigated using a newly developed leading-edge protuberance method, motivated by the improvement in the hydrodynamics of the giant humpback whale through its pectoral flippers. Deploying this method, the control effectiveness of the airfoil aerodynamics was fully evaluated using a three-component force balance, leading to an effectively impaired stall phenomenon and great improvement in the performances within the wide post-stall angle range (22°-80°). To understand the flow physics behind, the vorticity field, velocity field and boundary layer flow field over the airfoil suction side were examined using a particle image velocimetry and an oil-flow surface visualization system. It was found that the leading-edge protuberance method, more like low-profile vortex generator, effectively modified the flow pattern of the airfoil boundary layer through the chordwise and spanwise evolutions of the interacting streamwise vortices generated by protuberances, where the separation of the turbulent boundary layer dominated within the stall region and the rather strong attachment of the laminar boundary layer still existed within the post-stall region. The characteristics to manipulate the flow separation mode of the original airfoil indicated the possibility to further optimize the control performance by reasonably designing the layout of the protuberances.

  20. Tracking evolution of myoglobin stability in cetaceans using experimentally calibrated computational methods that account for generic protein relaxation.

    PubMed

    Holm, Jeppe; Dasmeh, Pouria; Kepp, Kasper P

    2016-07-01

    The evolution of cetaceans (whales, dolphins, and porpoises) from land to water is one of the most spectacular events in mammal evolution. It has been suggested that selection for higher myoglobin stability (∆G of folding) allowed whales to conquer the deep-diving niche. The stability of multi-site protein variants, including ancient proteins, is however hard to describe theoretically. From a compilation of experimental ∆∆G vs. ∆G we first find that protein substitutions are subject to large generic protein relaxation effects. Using this discovery, we develop a simple two-parameter model that predicts multi-site ∆∆G as accurately as standard methods do for single-site mutations and reproduces trends in contemporary myoglobin stabilities. We then apply this new method to the study of the evolution of Mb stability in cetaceans: With both methods the main change in stability (about 1kcal/mol) occurred very early, and stability was later relaxed in dolphins and porpoises, but was further increased in the sperm whales. This suggests that single proteins can affect whole organism evolution and indicates a role of Mb stability in the evolution of cetaceans. Transition to the deep-diving niche probably occurred already in the ancestor of contemporary baleen and toothed whales. In summary, we have discovered generic stability relaxation effects in proteins that, when incorporated into a simple model, improves the description of multi-site protein variants.

  1. Experimental validation of a modal flexibility-based damage detection method for a cyber-physical system

    NASA Astrophysics Data System (ADS)

    Martinez-Castro, Rosana E.; Eskew, Edward L.; Jang, Shinae

    2014-03-01

    The detection and localization of damage in a timely manner is critical in order to avoid the failure of structures. When a structure is subjected to an unscheduled impulsive force, the resulting damage can lead to failure in a very short period of time. As such, a monitoring strategy that can adapt to variability in the environment and that anticipates changes in physical processes has the potential of detecting, locating and mitigating damage. These requirements can be met by a cyber-physical system (CPS) equipped with Wireless Smart Sensor Network (WSSN) systems that is capable of measuring and analyzing dynamic responses in real time using on-board in network processing. The Eigenparameter Decomposition of Structural Flexibility Change (ED) Method is validated with real data and considered to be used in the computational core of this CPS. The condition screening is implemented on a damaged structure and compared to an original baseline calculation, hence providing a supervised learning environment. An experimental laboratory study on a 5-story shear building with three damage conditions subjected to an impulsive force has been chosen to validate the effectiveness of the method proposed to locate and quantify the extent of damage. A numerical simulation of the same building subject to band-limited white noise has also been developed with this purpose. The effectiveness of the ED Method to locate damage is compared to that of the Damage Index Method. With some modifications, the ED Method is capable of locating and quantifying damage satisfactorily in a shear building subject to a lower frequency content predominant excitation.

  2. An experimental evaluation of the instrumented flux synthesis method for the real-time estimation of reactivity. Final report

    SciTech Connect

    Hughes, J.C.; Henry, A.F.; Lanning, D.D.; Bernard, J.A.

    1996-01-01

    One method of determining the flux density is flux synthesis which approximates the flux in the core by linear combinations of precomputed shape functions. In traditional flux synthesis, the unknown mixing coefficients are determined using a weighted residual method of solving the diffusion equation. In the instrumented synthesis method, the mixing coefficients are determined using count rates from neutron detectors in the core. In this way the mixing coefficients are linked to conditions in the reactor. Using the synthesized flux, kinetics parameters, notably reactivity, can be calculated in real time. An experimental evaluation has been performed in the Massachusetts Institute of Technology Reactor, MITR-II. Detector measurements have been collected using fission chambers placed at the periphery of the core. The reactor was put into a number of various conditions, both static and transient, and data were collected using a digital acquisition system for later combination with shape functions. Transients included increasing power, decreasing power, and a reactor scram. The shape functions were generated using Version 3.0 of the QUARTZ code, a quadratic nodal diffusion theory code in triangular-Z geometry. Supernodal analysis algorithms have been added to the original program, along with subroutines to guarantee diagonal dominance of the leakage matrix in the finite difference or quadratic current approximations in the coarse mesh. The agreement between coarse mesh and fine mesh in all cases is excellent, with finite difference coarse mesh solutions generally slightly better. The synthesis method has been shown to accurately reflect the changes from an initial condition by combining representative flux shapes. It can be concluded that, with proper calibration of the measurement system and inclusion of representative flux shapes, the instrumented synthesis method will properly predict the flux in the core under a number of conditions.

  3. Experimental and Finite Element Modeling of Near-Threshold Fatigue Crack Growth for the K-Decreasing Test Method

    NASA Technical Reports Server (NTRS)

    Smith, Stephen W.; Seshadri, Banavara R.; Newman, John A.

    2015-01-01

    The experimental methods to determine near-threshold fatigue crack growth rate data are prescribed in ASTM standard E647. To produce near-threshold data at a constant stress ratio (R), the applied stress-intensity factor (K) is decreased as the crack grows based on a specified K-gradient. Consequently, as the fatigue crack growth rate threshold is approached and the crack tip opening displacement decreases, remote crack wake contact may occur due to the plastically deformed crack wake surfaces and shield the growing crack tip resulting in a reduced crack tip driving force and non-representative crack growth rate data. If such data are used to life a component, the evaluation could yield highly non-conservative predictions. Although this anomalous behavior has been shown to be affected by K-gradient, starting K level, residual stresses, environmental assisted cracking, specimen geometry, and material type, the specifications within the standard to avoid this effect are limited to a maximum fatigue crack growth rate and a suggestion for the K-gradient value. This paper provides parallel experimental and computational simulations for the K-decreasing method for two materials (an aluminum alloy, AA 2024-T3 and a titanium alloy, Ti 6-2-2-2-2) to aid in establishing clear understanding of appropriate testing requirements. These simulations investigate the effect of K-gradient, the maximum value of stress-intensity factor applied, and material type. A material independent term is developed to guide in the selection of appropriate test conditions for most engineering alloys. With the use of such a term, near-threshold fatigue crack growth rate tests can be performed at accelerated rates, near-threshold data can be acquired in days instead of weeks without having to establish testing criteria through trial and error, and these data can be acquired for most engineering materials, even those that are produced in relatively small product forms.

  4. A Comparison of School Psychologists' Acceptability, Training, and Use of Norm-Referenced, Curriculum-Based, and Brief Experimental Analysis Methods to Assess Reading

    ERIC Educational Resources Information Center

    Chafouleas, Sandra M.; Riley-Tillman, T. Chris; Eckert, Tanya L.

    2003-01-01

    This investigation compared the acceptability of three methods for assessing reading (i.e., norm-referenced assessment, curriculum-based assessment, brief experimental analysis), and explored how a new assessment methodology can gain acceptance as a useful and appropriate approach. Given that brief experimental analysis is a relatively new…

  5. Experimental phasing for structure determination using membrane-protein crystals grown by the lipid cubic phase method.

    PubMed

    Li, Dianfan; Pye, Valerie E; Caffrey, Martin

    2015-01-01

    Despite the marked increase in the number of membrane-protein structures solved using crystals grown by the lipid cubic phase or in meso method, only ten have been determined by SAD/MAD. This is likely to be a consequence of the technical difficulties associated with handling proteins and crystals in the sticky and viscous hosting mesophase that is usually incubated in glass sandwich plates for the purposes of crystallization. Here, a four-year campaign aimed at phasing the in meso structure of the integral membrane diacylglycerol kinase (DgkA) from Escherichia coli is reported. Heavy-atom labelling of this small hydrophobic enzyme was attempted by pre-labelling, co-crystallization, soaking, site-specific mercury binding to genetically engineered single-cysteine mutants and selenomethionine incorporation. Strategies and techniques for special handling are reported, as well as the typical results and the lessons learned for each of these approaches. In addition, an assay to assess the accessibility of cysteine residues in membrane proteins for mercury labelling is introduced. The various techniques and strategies described will provide a valuable reference for future experimental phasing of membrane proteins where crystals are grown by the lipid cubic phase method.

  6. Experimental phasing for structure determination using membrane-protein crystals grown by the lipid cubic phase method

    PubMed Central

    Li, Dianfan; Pye, Valerie E.; Caffrey, Martin

    2015-01-01

    Despite the marked increase in the number of membrane-protein structures solved using crystals grown by the lipid cubic phase or in meso method, only ten have been determined by SAD/MAD. This is likely to be a consequence of the technical difficulties associated with handling proteins and crystals in the sticky and viscous hosting mesophase that is usually incubated in glass sandwich plates for the purposes of crystallization. Here, a four-year campaign aimed at phasing the in meso structure of the integral membrane diacylglycerol kinase (DgkA) from Escherichia coli is reported. Heavy-atom labelling of this small hydrophobic enzyme was attempted by pre-labelling, co-crystallization, soaking, site-specific mercury binding to genetically engineered single-cysteine mutants and selenomethionine incorporation. Strategies and techniques for special handling are reported, as well as the typical results and the lessons learned for each of these approaches. In addition, an assay to assess the accessibility of cysteine residues in membrane proteins for mercury labelling is introduced. The various techniques and strategies described will provide a valuable reference for future experimental phasing of membrane proteins where crystals are grown by the lipid cubic phase method. PMID:25615865

  7. A fast experimental beam hardening correction method for accurate bone mineral measurements in 3D μCT imaging system.

    PubMed

    Koubar, Khodor; Bekaert, Virgile; Brasse, David; Laquerriere, Patrice

    2015-06-01

    Bone mineral density plays an important role in the determination of bone strength and fracture risks. Consequently, it is very important to obtain accurate bone mineral density measurements. The microcomputerized tomography system provides 3D information about the architectural properties of bone. Quantitative analysis accuracy is decreased by the presence of artefacts in the reconstructed images, mainly due to beam hardening artefacts (such as cupping artefacts). In this paper, we introduced a new beam hardening correction method based on a postreconstruction technique performed with the use of off-line water and bone linearization curves experimentally calculated aiming to take into account the nonhomogeneity in the scanned animal. In order to evaluate the mass correction rate, calibration line has been carried out to convert the reconstructed linear attenuation coefficient into bone masses. The presented correction method was then applied on a multimaterial cylindrical phantom and on mouse skeleton images. Mass correction rate up to 18% between uncorrected and corrected images were obtained as well as a remarkable improvement of a calculated mouse femur mass has been noticed. Results were also compared to those obtained when using the simple water linearization technique which does not take into account the nonhomogeneity in the object.

  8. Numerical simulation and experimental validation of biofilm in a multi-physics framework using an SPH based method

    NASA Astrophysics Data System (ADS)

    Soleimani, Meisam; Wriggers, Peter; Rath, Henryke; Stiesch, Meike

    2016-10-01

    In this paper, a 3D computational model has been developed to investigate biofilms in a multi-physics framework using smoothed particle hydrodynamics (SPH) based on a continuum approach. Biofilm formation is a complex process in the sense that several physical phenomena are coupled and consequently different time-scales are involved. On one hand, biofilm growth is driven by biological reaction and nutrient diffusion and on the other hand, it is influenced by fluid flow causing biofilm deformation and interface erosion in the context of fluid and deformable solid interaction. The geometrical and numerical complexity arising from these phenomena poses serious complications and challenges in grid-based techniques such as finite element. Here the solution is based on SPH as one of the powerful meshless methods. SPH based computational modeling is quite new in the biological community and the method is uniquely robust in capturing the interface-related processes of biofilm formation such as erosion. The obtained results show a good agreement with experimental and published data which demonstrates that the model is capable of simulating and predicting overall spatial and temporal evolution of biofilm.

  9. Experimental investigation for an isolation technique on conducting the electromechanical impedance method in high-temperature pipeline facilities

    NASA Astrophysics Data System (ADS)

    Na, Wongi S.; Lee, Hyeonseok

    2016-11-01

    In general, the pipelines within a nuclear power plant facility may experience high temperatures up to several hundred degrees. Thus it is absolutely vital to monitor these pipes to prevent leakage of radioactive substances which may lead to a catastrophic outcome of the surrounding environment. Over the years, one of the structural health monitoring technique known as the electromechanical impedance (EMI) technique has been of great interests in various fields including civil infrastructures, mechanical and aerospace structures. Although it has one of the best advantages to be able for a single piezoelectric transducer to act as a sensor and an actuator, simultaneously, its low curie temperature makes it difficult for the EMI technique to be conducted at high temperature environment. To overcome this problem, this study shows a method to avoid attaching the piezoelectric transducer directly onto the target structure using a metal wire for damage detection at high temperature. By shifting the frequency to compensate the signature changes subjected to the variations in temperature, the experimental results indicate that damage identification is more successful above 200 oC, making the metal wire method suitable for the EMI technique at high temperature environment.

  10. Numerical simulation and experimental validation of biofilm in a multi-physics framework using an SPH based method

    NASA Astrophysics Data System (ADS)

    Soleimani, Meisam; Wriggers, Peter; Rath, Henryke; Stiesch, Meike

    2016-06-01

    In this paper, a 3D computational model has been developed to investigate biofilms in a multi-physics framework using smoothed particle hydrodynamics (SPH) based on a continuum approach. Biofilm formation is a complex process in the sense that several physical phenomena are coupled and consequently different time-scales are involved. On one hand, biofilm growth is driven by biological reaction and nutrient diffusion and on the other hand, it is influenced by fluid flow causing biofilm deformation and interface erosion in the context of fluid and deformable solid interaction. The geometrical and numerical complexity arising from these phenomena poses serious complications and challenges in grid-based techniques such as finite element. Here the solution is based on SPH as one of the powerful meshless methods. SPH based computational modeling is quite new in the biological community and the method is uniquely robust in capturing the interface-related processes of biofilm formation such as erosion. The obtained results show a good agreement with experimental and published data which demonstrates that the model is capable of simulating and predicting overall spatial and temporal evolution of biofilm.

  11. A method for histopathological study of the multifocal nature of spinal cord lesions in murine experimental autoimmune encephalomyelitis.

    PubMed

    Gibson-Corley, Katherine N; Boyden, Alexander W; Leidinger, Mariah R; Lambertz, Allyn M; Ofori-Amanfo, Georgina; Naumann, Paul W; Goeken, J Adam; Karandikar, Nitin J

    2016-01-01

    Experimental autoimmune encephalomyelitis (EAE) is a well-established mouse model for multiple sclerosis and is characterized by infiltration of mononuclear cells and demyelination within the central nervous system along with the clinical symptoms of paralysis. EAE is a multifocal and random disease, which sometimes makes histopathologic analysis of lesions difficult as it may not be possible to predict where lesions will occur, especially when evaluating cross sections of spinal cord. Consequently, lesions may be easily missed due to limited sampling in traditional approaches. To evaluate the entire length of the spinal cord while maintaining anatomic integrity, we have developed a method to section the cord within the decalcified spinal column, which allows for the study of the multifocal nature of this disease and also minimizes handling artifact. HE and Luxol fast blue staining of these spinal cord sections revealed a paucity of lesions in some areas, while others showed marked inflammation and demyelination. The percentage of spinal cord affected by EAE was evaluated at four separate areas of longitudinally sectioned cord and it varied greatly within each animal. Immunohistochemical staining of in situ spinal cords which had undergone decalcification was successful for key immuno-markers used in EAE research including CD3 for T cells, B220 for B cells and F4/80 for murine macrophages. This method will allow investigators to look at the entire spinal cord on a single slide and evaluate the spinal cord with and without classic EAE lesions. PMID:26855861

  12. Excised porcine skin experimental systems to validate quantitative microdialysis methods for determination of drugs in skin after topical application.

    PubMed

    Seki, Toshinobu; Wang, Aiping; Yuan, Dan; Saso, Yuko; Hosoya, Osamu; Chono, Sumio; Morimoto, Kazuhiro

    2004-11-24

    Microdialysis is useful as a method to evaluate the disposition of drugs in the skin to design improved transdermal delivery systems (TDDSs). In this study, quantitative microdialysis methods were validated in excised porcine skin experimental systems in vitro. Flurbiprofen (FP), used as a model drug, showed high affinity for the skin tissues in equilibrium states between the medium and skin. The membrane clearances of FP for permeation through the membrane of a dialysis fiber placed in the skin (CL(m in S)) were lower than that in the medium. The adsorption of components in the skin to the membrane surface of the dialysis fiber and accumulation of FP near the dialysis fiber are the most likely reasons for this. When CL(m in S) was used to predict the extracellular FP concentration in skin (C(T)), the value obtained was lower than that expected from the FP concentration in the medium on the dermis side, which should be equal to C(T) at equilibrium. In the zero net flux (ZNF) method, in which the concentration difference of perfusate (DeltaC) between the inflow and outflow were used to obtain C(T), the predicted C(T) was similar to the expected value. In an in vitro skin permeation experiment, the ZNF method was used for the prediction of C(T) near the dialysis fiber. The predicted C(T) was over 10 times higher than the FP concentration in the medium on the dermis side, suggesting a concentration gradient in the dermis. Although the ZNF method is good for predicting the C(T) in skin, the mass balance has to be considered for the quantitative evaluation of the skin permeation of drugs. In this study, the effect of the mass transfer of FP from the perfusate to the skin on the cumulative amount of FP passing through the skin was relatively low because of the use of suitable solutions as perfusate. The perfusion conditions and schedules should be designed carefully for quantitative evaluations using the ZNF method. These results provide useful information for the in

  13. Structural and spectroscopic properties of an aliphatic boronic acid studied by combination of experimental and theoretical methods

    NASA Astrophysics Data System (ADS)

    Cyrański, Michał K.; Jezierska, Aneta; Klimentowska, Paulina; Panek, Jarosław J.; Żukowska, GraŻyna Z.; Sporzyński, Andrzej

    2008-03-01

    Boronic acids have emerged as one of the most useful class of organoboron molecules, with application in synthesis, catalysis, analytical chemistry, supramolecular chemistry, biology, and medicine. In this study, the structural and spectroscopic properties of n-butylboronic acid were investigated using experimental and theoretical approaches. X-ray crystallography method provided structural information on the studied compound in the solid state. Infrared and Raman spectroscopy served as tools for the data collection on vibrational modes of the analyzed system. Car-Parrinello molecular dynamics simulations in solid state were carried out at 100 and 293K to investigate an environmental and temperature influence on molecular properties of the n-butylboronic acid. Analysis of interatomic distances of atoms involved in the intermolecular hydrogen bond was performed to study the proton motion in the crystal. Subsequently, Fourier transform of autocorrelation functions of atomic velocities and dipole moment was applied to study the vibrational properties of the compound. In addition, the inclusion of quantum nature of proton motion was performed for O-H stretching vibrational mode by application of the envelope method for intermolecular hydrogen-bonded system. The second part of the computational study consists of simulations performed in vacuo. Monomeric and dimeric forms of the n-butylboronic acid were investigated using density functional theory and Møller-Plesset second-order perturbation method. The basis set superposition error was estimated. Finally, atoms in molecules (AIM) theory was applied to study electron density topology and properties of the intermolecular hydrogen bond. Successful reproduction of the molecular properties of the n-butylboronic acid by computational methodologies, presented in the manuscript, indicates the way for future studies of large boron-containing organic systems of importance in biology or materials science.

  14. Structural and spectroscopic properties of an aliphatic boronic acid studied by combination of experimental and theoretical methods.

    PubMed

    Cyrański, Michał K; Jezierska, Aneta; Klimentowska, Paulina; Panek, Jarosław J; Zukowska, Grazyna Z; Sporzyński, Andrzej

    2008-03-28

    Boronic acids have emerged as one of the most useful class of organoboron molecules, with application in synthesis, catalysis, analytical chemistry, supramolecular chemistry, biology, and medicine. In this study, the structural and spectroscopic properties of n-butylboronic acid were investigated using experimental and theoretical approaches. X-ray crystallography method provided structural information on the studied compound in the solid state. Infrared and Raman spectroscopy served as tools for the data collection on vibrational modes of the analyzed system. Car-Parrinello molecular dynamics simulations in solid state were carried out at 100 and 293 K to investigate an environmental and temperature influence on molecular properties of the n-butylboronic acid. Analysis of interatomic distances of atoms involved in the intermolecular hydrogen bond was performed to study the proton motion in the crystal. Subsequently, Fourier transform of autocorrelation functions of atomic velocities and dipole moment was applied to study the vibrational properties of the compound. In addition, the inclusion of quantum nature of proton motion was performed for O-H stretching vibrational mode by application of the envelope method for intermolecular hydrogen-bonded system. The second part of the computational study consists of simulations performed in vacuo. Monomeric and dimeric forms of the n-butylboronic acid were investigated using density functional theory and Moller-Plesset second-order perturbation method. The basis set superposition error was estimated. Finally, atoms in molecules (AIM) theory was applied to study electron density topology and properties of the intermolecular hydrogen bond. Successful reproduction of the molecular properties of the n-butylboronic acid by computational methodologies, presented in the manuscript, indicates the way for future studies of large boron-containing organic systems of importance in biology or materials science. PMID:18376948

  15. Experimental infection of Holstein cows and calves with EHDV‑7 and preliminary evaluation of different inoculation methods.

    PubMed

    Ruder, Mark G; Mead, Daniel G; Stallknecht, David E; Kedmi, Maor; Klement, Eyal; Brown, Justin D; Carter, Deborah L; Howerth, Elizabeth W

    2015-01-01

    Infection of cattle with epizootic haemorrhagic disease (EHD) virus (EHDV) is frequently subclinical, yet reports of disease have increased in recent years. In 2006, a widespread EHDV‑7 epidemic caused disease and economic loss in the Israeli dairy industry. In this study, the main objective was to infect cattle with EHDV‑7 and replicate disease observed in Israel during 2006. Two infection studies were performed. Experiment 1, 4 cows inoculated with intradermal (ID) and subcutaneous (SC) injections with an EHDV‑7 blood inoculum. Experiment 2, 6 calves inoculated using 1 of the following 3 methods (2 calves/method): (1) mammalian cell culture supernatant by ID and SC injection; (2) culture supernatant by ID, SC, and intravenous injection; and (3) bite transmission from Culicoides sonorensis. Further, during experiment 2, C. sonorensis were fed on 4 infected calves (18 days post-inoculation) and processed for virus isolation 10 days later in order to evaluate infectivity of low‑titer viraemia. Three cows had detectable viraemia and all 4 seroconverted. No clinical signs were observed. All 6 calves developed viraemia, peaking 7‑10 dpi and all calves seroconverted. No differences in virus kinetics were observed between the inoculation groups. Calves in group 2 had transiently elevated rectal temperatures but no other clinical abnormalities were observed. The 124 midge pools processed after feeding on calves with low‑titer viraemia were virus isolation negative. Detectable viraemia was more consistent in calves than adult cows. This study demonstrates US‑origin cattle are susceptible to EHDV‑7 infection by multiple inoculation methods; however, as reported in other studies, the disease was not replicated experimentally. PMID:26741239

  16. Hygroscopic growth of urban aerosol particles in Beijing (China) during wintertime: a comparison of three experimental methods

    NASA Astrophysics Data System (ADS)

    Meier, J.; Wehner, B.; Massling, A.; Birmili, W.; Nowak, A.; Gnauk, T.; Brüggemann, E.; Herrmann, H.; Min, H.; Wiedensohler, A.

    2009-09-01

    0.1) the values measured by the other two methods. In the case of aerosol dominated by organics, the reverse was true, with an overestimation of up to 0.2. The results shed light on the experimental and methodological uncertainties that are still connected with the determination of hygroscopic growth factors.

  17. DETECTORS AND EXPERIMENTAL METHODS: Heuristic approach for peak regions estimation in gamma-ray spectra measured by a NaI detector

    NASA Astrophysics Data System (ADS)

    Zhu, Meng-Hua; Liu, Liang-Gang; You, Zhong; Xu, Ao-Ao

    2009-03-01

    In this paper, a heuristic approach based on Slavic's peak searching method has been employed to estimate the width of peak regions for background removing. Synthetic and experimental data are used to test this method. With the estimated peak regions using the proposed method in the whole spectrum, we find it is simple and effective enough to be used together with the Statistics-sensitive Nonlinear Iterative Peak-Clipping method.

  18. Screening Method for calculating Global Warming Potential through computational and experimental investigations of radiative forcing and atmospheric lifetime

    NASA Astrophysics Data System (ADS)

    Bevington, C. B.; Betowski, D.; Ottinger, D.; Sheppard, M.; Elrod, M. J.; Offenberg, J.; Hetfield, C.; Libelo, E. L.

    2011-12-01

    The universe of chemical substances in commerce that may have significant atmospheric impacts such as global warming potential, ozone depletion potential, and ozone creation potential is not well defined. Staff from the U.S. E.P.A. have developed a screening method and evaluated chemicals using criteria indicative of potential atmospheric impact. Screening criteria included physical chemical properties such as boiling point and vapor pressure as well as structural characteristics such as molecular weight and number of halogen atoms. Preliminary results show that there are over 1,000 chemicals with a 100-year time horizon Global Warming Potential (GWP) of greater than 1 and over 700 chemicals with a GWP of greater than 10, relative to a value of 1 for CO2. The primary goal of this scoping project is to calculate the GWP for each of these chemicals. GWP is calculated using three primary inputs: molecular weight, atmospheric lifetime, and radiative forcing. Where available, experimentally derived radiative forcing and atmospheric lifetime values have been identified and are utilized. Surprisingly, measured values were only available for approximately 20% of chemicals. Where measured data were not available, values were estimated in various ways. Besides calculating these values, characterizing the accuracy and efficacy of these various estimation methods, is also of interest. Radiative efficiency was calculated using quantum mechanical ab initio methods, utilizing Gaussian software. In addition, a preliminary Quantitative Structure Activity Relationship (QSAR) building on the work of Bera et al's "Design strategies to minimize the radiative efficiency of global warming molecules" (2010) was used to estimate radiative forcing for over 800 fluorinated chemicals. For atmospheric lifetime, QSARs were used to estimate OH rate constants and atmospheric lifetime values. Recognizing the limitations and uncertainty introduced by using QSARs for atmospheric lifetime estimation

  19. Development and experimental verification of a finite element method for accurate analysis of a surface acoustic wave device

    NASA Astrophysics Data System (ADS)

    Mohibul Kabir, K. M.; Matthews, Glenn I.; Sabri, Ylias M.; Russo, Salvy P.; Ippolito, Samuel J.; Bhargava, Suresh K.

    2016-03-01

    Accurate analysis of surface acoustic wave (SAW) devices is highly important due to their use in ever-growing applications in electronics, telecommunication and chemical sensing. In this study, a novel approach for analyzing the SAW devices was developed based on a series of two-dimensional finite element method (FEM) simulations, which has been experimentally verified. It was found that the frequency response of the two SAW device structures, each having slightly different bandwidth and center lobe characteristics, can be successfully obtained utilizing the current density of the electrodes via FEM simulations. The two SAW structures were based on XY Lithium Niobate (LiNbO3) substrates and had two and four electrode finger pairs in both of their interdigital transducers, respectively. Later, SAW devices were fabricated in accordance with the simulated models and their measured frequency responses were found to correlate well with the obtained simulations results. The results indicated that better match between calculated and measured frequency response can be obtained when one of the input electrode finger pairs was set at zero volts and all the current density components were taken into account when calculating the frequency response of the simulated SAW device structures.

  20. Microwave selective thermal development of latent fingerprints on porous surfaces: potentialities of the method and preliminary experimental results.

    PubMed

    Rosa, Roberto; Veronesi, Paolo; Leonelli, Cristina

    2013-09-01

    The thermal development of latent fingerprints on paper surfaces is a simple, safe, and chemicals-free method, based on the faster heating of the substrate underlying the print residue. Microwave heating is proposed for the first time for the development of latent fingerprints on cellulose-based substrate, in order to add to the thermal development mechanism the further characteristic of being able to heat the fingerprint residues to a different extent with respect to the substrate, due to the intrinsic difference in their dielectric properties. Numerical simulation was performed to confirm and highlight the selectivity of microwaves, and preliminary experimental results point out the great potentialities of this technique, which allowed developing both latent sebaceous-rich and latent eccrine-rich fingerprints on different porous surfaces, in less than 30 sec time with an applied output power of 500 W. Microwaves demonstrated more effectiveness in the development of eccrine-rich residues, aged up to 12 weeks.

  1. Experimental modal analysis of an aluminum rectangular plate by use of the slope-assisted BOTDA method

    NASA Astrophysics Data System (ADS)

    Minardo, A.; Coscetta, A.; Pirozzi, S.; Bernini, R.; Zeni, L.

    2013-12-01

    We report an experimental modal analysis of an aluminum rectangular plate (50 cm×30 cm×0.3 cm), carried out by use of a Brillouin optical time-domain analysis (BOTDA) sensor operating in the slope-assisted configuration, i.e. at a fixed pump-probe frequency shift. Strain measurements were acquired along an optical fiber attached to the structure, at a maximum acquisition rate of 250 Hz, a spatial resolution of 30 cm and a sampling distance of 5 cm in both x- and y-directions. A sequence of dynamic tests, aimed to evaluate the resonant frequencies and strain modal shapes of the structure, were performed on the plate for various boundary conditions (plate clamped with four, three or two bolts). Comparison with finite element method (FEM) analysis and dynamic strain measurements with strain gauges shows that Brillouin based distributed sensors can be usefully employed to perform the modal analysis of a vibrating structure, even if the spatial resolution is comparable with the plate dimensions.

  2. Evaluation of different methods for the experimental infection of the land snail Helix aspersa with Aelurostrongylus abstrusus lungworm.

    PubMed

    Napoli, Ettore; Falsone, Luigi; Gaglio, Gabriella; Colella, Vito; Otranto, Domenico; Giannetto, Salvatore; Brianti, Emanuele

    2016-07-30

    The laboratory maintenance of parasitic life cycles is crucial to support research in many fields of parasitology. The land snail Helix aspersa (syn. Cornu aspersum), an intermediate host of feline lungworms Aelurostrongylus abstrusus and Troglostrongylus brevior, is adopted to produce infective stages of those nematodes in laboratory condition. The aim of this study was to compare the most common methods of experimental infection of H. aspersa with first stage larvae (L1) of A. abstrusus (i.e., contact of the snail foot with the L1) with the injection of these larvae in the foot of the snail, instrumental to reduce the infection time and to maximize the output of third-stage larvae (L3). Three groups (i.e., A, B, C) of 15 H. aspersa snails were infected with L1 of A. abstrusus (n=250 for each snail), whereas a fourth group (group D) was not infected (control). Snails were individually placed for 48h on a microfilm containing L1 (group A), on a potato slice previously irrigated with a suspension of L1 (group B), or they were inoculated by injection of L1 in the posterior-ventral portion of the foot (group C). Eighteen days after the infection all snails were analyzed and tissues were digested to recover L3. No difference in mortality rate was recorded among snail groups and the mean number of retrieved L3 was significantly larger in group C (71.5±52.9) compared to group B (38.2±44.9; p=0.0161) and group A (19±23.3; p<0.0001). The injection of A. abstrusus L1 in the foot of H. aspersa proved to be a fast, easy to apply and effective method, resulting in the largest number of infective larvae retrieved. PMID:27369568

  3. Monte Carlo Simulations Of The Dose Distributions From Carbon Microbeams Used In An Experimental Radiation Therapy Method

    SciTech Connect

    Dioszegi, I.; Rusek, A.; Chiang, I. H.; Dane, B. R.; Meek, A. G.; Dilmanian, F. A.

    2011-06-01

    Recent upgrades of the MCNPX Monte Carlo code include transport of heavy ions. We employed the new code to simulate the energy and dose distributions produced by carbon beams in rabbit's head in and around a brain tumor. The work was within our experimental technique of interlaced carbon microbeams, which uses two 90 deg. arrays of parallel, thin planes of carbon beams (microbeams) interlacing to produce a solid beam at the target. A similar version of the method was earlier developed with synchrotron-generated x-ray microbeams. We first simulated the Bragg peak in high density polyethylene and other materials, where we could compare the calculated carbon energy deposition to the measured data produced at the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory (BNL). The results showed that new MCNPX code gives a reasonable account of the carbon beam's dose up to {approx}200 MeV/nucleon beam energy. At higher energies, which were not relevant to our project, the model failed to reproduce the Bragg-peak's extent of increasing nuclear breakup tail. In our model calculations we determined the dose distribution along the beam path, including the angular straggling of the microbeams, and used the data for determining the optimal values of beam spacing in the array for producing adequate beam interlacing at the target. We also determined, for the purpose of Bragg-peak spreading at the target, the relative beam intensities of the consecutive exposures with stepwise lower beam energies, and simulated the resulting dose distribution in the spread out Bragg-peak. The details of the simulation methods used and the results obtained are presented.

  4. Comparison of the various methods for the direct calculation of the transmission functions of the 15-micron CO2 band with experimental data

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Various methods for calculating the transmission functions of the 15 micron CO2 band are described. The results of these methods are compared with laboratory measurements. It is found that program P4 provides the best agreement with experimental results on the average.

  5. A new method for the experimental heating of intact soil profiles for application to climate change experiments

    SciTech Connect

    Hanson, Paul J; Childs, Kenneth W; Wullschleger, Stan D; Riggs, Jeffery S; Thomas, Warren Kyle; Todd Jr, Donald E; Warren, Jeffrey

    2011-01-01

    Advanced facilities are needed to evaluate the response of complex ecosystems to projected unique climate conditions not observable in the context of current natural variation or through the use of climate gradients. A next-generation, experimental system for simulating future belowground temperature increases was conceived, simulated, constructed and tested in a temperate deciduous forest in Oak Ridge, Tennessee, USA. The new system uses low-wattage, 3-m deep, circumferentially-installed heaters surrounding a defined soil volume to both add the necessary energy to support a set-point soil temperature differential within the treatment area and to add exterior energy inputs equal to that which might be lost from lateral heat conduction. This approach, which is designed to work in conjunction with aboveground heated chambers, requires only two control positions, (1) aboveground air temperatures at 1 m and (2) belowground temperatures at 0.8 m. The approach is capable of achieving in situ target temperature differentials in the tested range of +4.0 0.5 C for soils to a measured depth of -2 m located within the aboveground boundary for air heating. These differentials were sustained throughout 2009, and both diurnal and seasonal cycles at all soil depths were retained using this simple heating approach. Measured mean energy inputs required to sustain the target heating level of +4 C over the 7.1 m2 target area were substantial: 21.1 kW h d-1 m-2 for aboveground heating but 16 times lower for belowground heaters at 1.3 kW h d-1 m-2. Observations of soil CO2 efflux from the surface of the target soil volumes showed CO2 losses throughout 2009 that were elevated above the temperature response curve for control CO2 losses at levels greater than have been reported in previous soil warming studies. Stimulation of biological activity of previously undisturbed deep-soil carbon stocks is the expected source. Long-term research programs may be able to apply similar experimental

  6. Standardization of the experimental autoimmune myasthenia gravis (EAMG) model by immunization of rats with Torpedo californica acetylcholine receptors--Recommendations for methods and experimental designs.

    PubMed

    Losen, Mario; Martinez-Martinez, Pilar; Molenaar, Peter C; Lazaridis, Konstantinos; Tzartos, Socrates; Brenner, Talma; Duan, Rui-Sheng; Luo, Jie; Lindstrom, Jon; Kusner, Linda

    2015-08-01

    Myasthenia gravis (MG) with antibodies against the acetylcholine receptor (AChR) is characterized by a chronic, fatigable weakness of voluntary muscles. The production of autoantibodies involves the dysregulation of T cells which provide the environment for the development of autoreactive B cells. The symptoms are caused by destruction of the postsynaptic membrane and degradation of the AChR by IgG autoantibodies, predominantly of the G1 and G3 subclasses. Active immunization of animals with AChR from mammalian muscles, AChR from Torpedo or Electrophorus electric organs, and recombinant or synthetic AChR fragments generates a chronic model of MG, termed experimental autoimmune myasthenia gravis (EAMG). This model covers cellular mechanisms involved in the immune response against the AChR, e.g. antigen presentation, T cell-help and regulation, B cell selection and differentiation into plasma cells. Our aim is to define standard operation procedures and recommendations for the rat EAMG model using purified AChR from the Torpedo californica electric organ, in order to facilitate more rapid translation of preclinical proof of concept or efficacy studies into clinical trials and, ultimately, clinical practice. PMID:25796590

  7. Integrating experimental and numerical methods for a scenario-based quantitative assessment of subsurface energy storage options

    NASA Astrophysics Data System (ADS)

    Kabuth, Alina; Dahmke, Andreas; Hagrey, Said Attia al; Berta, Márton; Dörr, Cordula; Koproch, Nicolas; Köber, Ralf; Köhn, Daniel; Nolde, Michael; Tilmann Pfeiffer, Wolf; Popp, Steffi; Schwanebeck, Malte; Bauer, Sebastian

    2016-04-01

    Within the framework of the transition to renewable energy sources ("Energiewende"), the German government defined the target of producing 60 % of the final energy consumption from renewable energy sources by the year 2050. However, renewable energies are subject to natural fluctuations. Energy storage can help to buffer the resulting time shifts between production and demand. Subsurface geological structures provide large potential capacities for energy stored in the form of heat or gas on daily to seasonal time scales. In order to explore this potential sustainably, the possible induced effects of energy storage operations have to be quantified for both specified normal operation and events of failure. The ANGUS+ project therefore integrates experimental laboratory studies with numerical approaches to assess subsurface energy storage scenarios and monitoring methods. Subsurface storage options for gas, i.e. hydrogen, synthetic methane and compressed air in salt caverns or porous structures, as well as subsurface heat storage are investigated with respect to site prerequisites, storage dimensions, induced effects, monitoring methods and integration into spatial planning schemes. The conceptual interdisciplinary approach of the ANGUS+ project towards the integration of subsurface energy storage into a sustainable subsurface planning scheme is presented here, and this approach is then demonstrated using the examples of two selected energy storage options: Firstly, the option of seasonal heat storage in a shallow aquifer is presented. Coupled thermal and hydraulic processes induced by periodic heat injection and extraction were simulated in the open-source numerical modelling package OpenGeoSys. Situations of specified normal operation as well as cases of failure in operational storage with leaking heat transfer fluid are considered. Bench-scale experiments provided parameterisations of temperature dependent changes in shallow groundwater hydrogeochemistry. As a

  8. An investigation into the effects of quality improvement method on patients' satisfaction: a semi experimental research in Iran.

    PubMed

    Navipour, Hasan; Nayeri, Nahid Dehghan; Hooshmand, Abbas; Zargar, Marjaneh Taghavi

    2011-01-01

    Today, to increase effectiveness is a Strategy for success of organizations and their viability. In health care organization not only service cost- effectiveness is a major problem for productivity and organizational management but also customer-centred is in first priority. Because of these reasons, most of health organization trend to patient satisfaction for their viability. If complex process implemented for viability without attention to patient satisfaction, this is no success result. The FOCUS PDCA process is a new strategy for effectiveness of service quality. To this reason, the recent research done and its objective is to assess effect of FOCUS PDCA process strategy on patient satisfaction in surgery units of hospitals affiliated to Tehran Medical University. This research is a semi experimental with non- equivalent design. The sample was all of patients who hospitalized in two selected surgery units. Self-report was method of data gathering. Patient satisfaction assessed with questionnaire in pre and posttest. Then manipulation implemented as post-operation care process selected. Modelling and opportunity statement Diagrams prepared and improvement team organized. Flow process, convergences and cause- effect charts used to prepare list of items to be improved. Executive program was written. This include personnel training, standard implementation, election and training of quality control nurses (Q.C Ns), daily QC of caring and providing appropriate feed back to personnel, forming group session for determining corrective actions. Then after 1 month patient satisfaction was assessed. Statistical analysis shows this process increase patient satisfaction and it leads to care effectiveness. The findings of the pre-intervention phase indicated that the satisfaction level had been low in both groups and it is not significantly different in the two groups (P> 0.05). There was a significant difference before and after following intervention in the case study

  9. Method for Making Measurements of the Post-Combustion Residence Time in a Gas Turbine Engine

    NASA Technical Reports Server (NTRS)

    Miles, Jeffrey H (Inventor)

    2015-01-01

    A system and method of measuring a residence time in a gas-turbine engine is provided, whereby the method includes placing pressure sensors at a combustor entrance and at a turbine exit of the gas-turbine engine and measuring a combustor pressure at the combustor entrance and a turbine exit pressure at the turbine exit. The method further includes computing cross-spectrum functions between a combustor pressure sensor signal from the measured combustor pressure and a turbine exit pressure sensor signal from the measured turbine exit pressure, applying a linear curve fit to the cross-spectrum functions, and computing a post-combustion residence time from the linear curve fit.

  10. A study of the polymer-cnt interactions in polymer/cnt composites using experimental and computational methods

    NASA Astrophysics Data System (ADS)

    Meng, Jiangsha

    This dissertation work focuses on research related to understanding and controlling the polymer-carbon nanotube (CNT) interactions during composite fiber processing using both experimental and computational means, in order to achieve consistent formation of the interphase regions for various polymers in the vicinity of CNT. The development of the polymer crystalline interphase is important, since it has been shown to have a significant and positive impact on the mechanical performance of polymer/CNT composites. This is achieved by the improvement of stress transfer mechanisms between the polymer matrix and CNT. The preliminary results (i.e., both experimental and computational) provide insight toward understanding the fundamental mechanisms of polymer-CNT interactions under various processing conditions, as well as the resultant polymer or CNT behaviors and composite fibers performance governed by them. In this thesis work, the initialization and the development of the interphase region in fibers throughout all processing steps are investigated using full-atomistic molecular dynamics (MD) approach as well as experimental means. SWNT dispersion quality with and without polymers present during sonication process is also investigated experimentally, where the polymer-SWNT interactions are impacted by SWNT dispersion qualities. The resultant morphologies and composite fibers properties are also analyzed. The effect of laminar-flow rates (used during spinning) on the polymer/SWNT composite fiber properties as well as on the fundamental polymer-SWNT interactions and the resultant chain morphologies near the SWNT surface are studied in detail. Full-atomistic MD simulations are conducted to study the influence of various laminar-flow rates on the chain morphologies in the vicinity of SWNT. By combining results from both experimentation and computation, a better understanding of the spinning parameters on the microscopic fiber properties as well as on the microscopic

  11. On Overfitting in Analysis of Symmetrically Predicted Endogenous Subgroups from Randomized Experimental Samples: Part Three of a Method Note in Three Parts

    ERIC Educational Resources Information Center

    Harvill, Eleanor L.; Peck, Laura R.; Bell, Stephen H.

    2013-01-01

    Using exogenous characteristics to identify endogenous subgroups, the approach discussed in this method note creates symmetric subsets within treatment and control groups, allowing the analysis to take advantage of an experimental design. In order to maintain treatment--control symmetry, however, prior work has posited that it is necessary to use…

  12. Evaluation of four subcritical response methods for on-line prediction of flutter onset in wind-tunnel tests

    NASA Technical Reports Server (NTRS)

    Ruhlin, C. L.; Watson, J. J.; Ricketts, R. H.; Doggett, R. V., Jr.

    1982-01-01

    Four subcritical response methods were evaluated for on-line use in transonic wind-tunnel tests where the flutter model is excited solely by airstream turbulence. The methods were: randomdec, power-spectral-density, peak-hold, and cross-spectrum. Subcritical response data were obtained during tests in the Langley Transonic Dynamics Tunnel of a cantilevered flutter model wing. The test procedure was to maintain a constant Mach number and increase the dynamic pressure (q) in incremental steps. The four methods provided damping trends by which the flutter mode could be tracked and extrapolated to a flutter-onset q. A hard flutter point was obtained at M = 0.82. The peak-mold and cross-spectrum methods gave reliable results and could be most readily used for on-line testing.

  13. The plaque-antiserum method: an assay of virus infectivity and an experimental model of virus infection.

    PubMed

    De Flora, S

    1974-05-01

    Areas of cytopathic effect can be circumscribed in cell monolayers by adding antiserum to the liquid nutrient medium after adsorption of virus. This procedure represents a simple and reliable tool for the titration of virus infectivity and provides an experimental model for studying some aspects of virus infection.

  14. A method to integrate descriptive and experimental field studies at the level of data and empirical concepts1

    PubMed Central

    Bijou, Sidney W.; Peterson, Robert F.; Ault, Marion H.

    1968-01-01

    It is the thesis of this paper that data from descriptive and experimental field studies can be interrelated at the level of data and empirical concepts if both sets are derived from frequency-of-occurrence measures. The methodology proposed for a descriptive field study is predicated on three assumptions: (1) The primary data of psychology are the observable interactions of a biological organism and environmental events, past and present. (2) Theoretical concepts and laws are derived from empirical concepts and laws, which in turn are derived from the raw data. (3) Descriptive field studies describe interactions between behavioral and environmental events; experimental field studies provide information on their functional relationships. The ingredients of a descriptive field investigation using frequency measures consist of: (1) specifying in objective terms the situation in which the study is conducted, (2) defining and recording behavioral and environmental events in observable terms, and (3) measuring observer reliability. Field descriptive studies following the procedures suggested here would reveal interesting new relationships in the usual ecological settings and would also provide provocative cues for experimental studies. On the other hand, field-experimental studies using frequency measures would probably yield findings that would suggest the need for describing new interactions in specific natural situations. PMID:16795175

  15. Smartphones as Experimental Tools: Different Methods to Determine the Gravitational Acceleration in Classroom Physics by Using Everyday Devices

    ERIC Educational Resources Information Center

    Kuhn, Jochen; Vogt, Patrik

    2013-01-01

    New media technology becomes more and more important for our daily life as well as for teaching physics. Within the scope of our N.E.T. research project we develop experiments using New Media Experimental Tools (N.E.T.) in physics education and study their influence on students learning abilities. We want to present the possibilities e.g. of…

  16. 75 FR 71155 - Market Test of Experimental Product: “Alternative Postage Payment Method for Greeting Cards”

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-22

    ... From the Federal Register Online via the Government Publishing Office POSTAL SERVICE Market Test... Service TM . ACTION: Notice. SUMMARY: The Postal Service gives notice of a market test of an experimental... CONTACT: David H. Rubin, 202-268-2986. SUPPLEMENTARY INFORMATION: The United States Postal Service...

  17. Biaxial tension of fibrous tissue: using finite element methods to address experimental challenges arising from boundary conditions and anisotropy.

    PubMed

    Jacobs, Nathan T; Cortes, Daniel H; Vresilovic, Edward J; Elliott, Dawn M

    2013-02-01

    Planar biaxial tension remains a critical loading modality for fibrous soft tissue and is widely used to characterize tissue mechanical response, evaluate treatments, develop constitutive formulas, and obtain material properties for use in finite element studies. Although the application of tension on all edges of the test specimen represents the in situ environment, there remains a need to address the interpretation of experimental results. Unlike uniaxial tension, in biaxial tension the applied forces at the loading clamps do not transmit fully to the region of interest (ROI), which may lead to improper material characterization if not accounted for. In this study, we reviewed the tensile biaxial literature over the last ten years, noting experimental and analysis challenges. In response to these challenges, we used finite element simulations to quantify load transmission from the clamps to the ROI in biaxial tension and to formulate a correction factor that can be used to determine ROI stresses. Additionally, the impact of sample geometry, material anisotropy, and tissue orientation on the correction factor were determined. Large stress concentrations were evident in both square and cruciform geometries and for all levels of anisotropy. In general, stress concentrations were greater for the square geometry than the cruciform geometry. For both square and cruciform geometries, materials with fibers aligned parallel to the loading axes reduced stress concentrations compared to the isotropic tissue, resulting in more of the applied load being transferred to the ROI. In contrast, fiber-reinforced specimens oriented such that the fibers aligned at an angle to the loading axes produced very large stress concentrations across the clamps and shielding in the ROI. A correction factor technique was introduced that can be used to calculate the stresses in the ROI from the measured experimental loads at the clamps. Application of a correction factor to experimental biaxial

  18. A simple cage-autonomous method for the maintenance of the barrier status of germ-free mice during experimentation.

    PubMed

    Hecht, G; Bar-Nathan, C; Milite, G; Alon, I; Moshe, Y; Greenfeld, L; Dotsenko, N; Suez, J; Levy, M; Thaiss, C A; Dafni, H; Elinav, E; Harmelin, A

    2014-10-01

    The use of germ-free (GF) isolators for microbiome-related research is exponentially increasing, yet limited by its cost, isolator size and potential for trans-contamination. As such, current isolator technology is highly limiting to researchers engaged in short period experiments involving multiple mouse strains and employing a variety of mono-inoculated microorganisms. In this study, we evaluate the use of positive pressure Isocages as a solution for short period studies (days to 2-3 weeks) of experimentation with GF mice at multiple simultaneous conditions. We demonstrate that this new Isocage technology is cost-effective and room-sparing, and enables maintenance of multiple simultaneous groups of GF mice. Using this technology, transferring GF mice from isolators to Isocage racks for experimentation, where they are kept under fully germ-free conditions, enables parallel inoculation with different bacterial strains and simultaneous experimentation with multiple research conditions. Altogether, the new GF Isocage technology enables the expansion of GF capabilities in a safe and cost-effective manner that can facilitate the growth, elaboration and flexibility of microbiome research.

  19. Experimental Validation of the Dynamic Inertia Measurement Method to Find the Mass Properties of an Iron Bird Test Article

    NASA Technical Reports Server (NTRS)

    Chin, Alexander W.; Herrera, Claudia Y.; Spivey, Natalie D.; Fladung, William A.; Cloutier, David

    2015-01-01

    The mass properties of an aerospace vehicle are required by multiple disciplines in the analysis and prediction of flight behavior. Pendulum oscillation methods have been developed and employed for almost a century as a means to measure mass properties. However, these oscillation methods are costly, time consuming, and risky. The NASA Armstrong Flight Research Center has been investigating the Dynamic Inertia Measurement, or DIM method as a possible alternative to oscillation methods. The DIM method uses ground test techniques that are already applied to aerospace vehicles when conducting modal surveys. Ground vibration tests would require minimal additional instrumentation and time to apply the DIM method. The DIM method has been validated on smaller test articles, but has not yet been fully proven on large aerospace vehicles.

  20. Development of marker-based tracking methods for augmented reality applied to NPP maintenance work support and its experimental evaluation

    SciTech Connect

    Ishii, H.; Fujino, H.; Bian, Z.; Sekiyama, T.; Shimoda, H.; Yoshikawa, H.

    2006-07-01

    In this study, two types of marker-based tracking methods for Augmented Reality have been developed. One is a method which employs line-shaped markers and the other is a method which employs circular-shaped markers. These two methods recognize the markers by means of image processing and calculate the relative position and orientation between the markers and the camera in real time. The line-shaped markers are suitable to be pasted in the buildings such as NPPs where many pipes and tanks exist. The circular-shaped markers are suitable for the case that there are many obstacles and it is difficult to use line-shaped markers because the obstacles hide the part of the line-shaped markers. Both methods can extend the maximum distance between the markers and the camera compared to the legacy marker-based tracking methods. (authors)

  1. Use of experimental design and effective mobility calculations to develop a method for the determination of antimicrobials by capillary electrophoresis.

    PubMed

    Mamani, Mónica Cecília Vargas; Amaya-Farfan, Jaime; Reyes, Felix Guillermo Reyes; Silva, José Alberto Fracassi da; Rath, Susanne

    2008-09-15

    A capillary zone electrophoresis (CZE) method for the determination of chloramphenicol (CLP), danofloxacin (DANO), ciprofloxacin (CIPRO), enrofloxacin (ENRO), sulfamethazine (SMZ), sulfaquinoxaline (SQX) and sulfamethoxazole (SMX) is described. For the development, the effective mobilities were estimated and a central composite design was performed. The method was in-house validated for CLP, CIPRO, ENRO and SMX determination in pharmaceuticals. In comparison with the HPLC method recommended by the United States Pharmacopoeia, this CZE method exhibited the same performance, with the advantage that seven different antimicrobials in pharmaceutical formulations could be simultaneously determined. PMID:18761147

  2. Experimental exposure of young pigs using a pathogenic strain of Streptococcus suis serotype 2 and evaluation of this method for disease prevention.

    PubMed Central

    Torremorell, M; Pijoan, C; Dee, S

    1999-01-01

    Control of Streptococcus suis infections and associated disease have proven to be a difficult challenge under most farm conditions. The objective of this study was to experimentally expose young pigs with a pathogenic strain of S. suis serotype 2 as a means of controlling the disease in a commercial swine farm. Prior to the start of the study, the pathogenic S. suis strain responsible for mortality in the farm was identified and used to experimentally inoculate baby piglets. Over a 3-week period, groups of pigs were selected (100 pigs/wk) and divided into 2 groups: control (50 pigs/week) and experimentally exposed (50 pigs/week). Pigs in the experimentally exposed group were inoculated at 5 d old by tonsillar swabbing with the pathogenic S. suis farm isolate. The effect of exposure with this pathogenic strain was evaluated during the nursery and finishing stages and was based on: morbidity (pigs with central nervous signs (CNS) and/or lameness), mortality and number of treatments required by pigs that had either CNS or lameness. The relative risk (RR) of acquiring disease due to S. suis infection was also calculated. Results showed that morbidity in the experimentally exposed groups was lower than in the control group and these results were statistically different (P = 0.006). Experimentally exposed pigs also showed a statistically significant reduction in lameness problems (P = 0.012), but not in CNS (P = 0.20) or mortality (P = 0.59). Pigs in the control group had an increased RR of 4.76, 8.77 and 2.7 for morbidity, to have lameness or to have CNS signs, respectively. In conclusion, experimental exposure of young pigs with the farm's pathogenic S. suis strain at a young age, had a positive effect in reducing clinical signs characteristics of S. suis infection. This method constitutes a novel approach to the control of S. suis infections in swine farms. Images Figure 1. PMID:10534006

  3. Application of charge density methods to a protein model compound: Calculation of Coulombic intermolecular interaction energies from the experimental charge density

    PubMed Central

    Li, Xue; Wu, Guang; Abramov, Yuriy A.; Volkov, Anatoliy V.; Coppens, Philip

    2002-01-01

    A combined experimental and theoretical charge density study of the pentapeptide Boc-Gln-d-Iva-Hyp-Ala-Phol (Boc, butoxycarbonyl; Gln, glutamine; Iva, isovaline; Hyp, hydroxyproline; Ala, ethylalanine; Phol, phenylalaninol) is described. The experimental analysis, based on synchrotron x-ray data collected at 20 K, is combined with ab initio theoretical calculations. The topologies of the experimental and theoretical densities are analyzed in terms of the atoms in molecules quantum theory. Topological parameters, including atomic charges and higher moments integrated over the atomic basins, have been evaluated with the program topxd and are used to calculate the electrostatic interactions between the molecules in the crystal. The interaction energies obtained after adding dispersive and repulsive van der Waals contributions agree quite well with those based on M-B3LYP/6–31G** dimer calculations for two of the three dimers in the crystal, whereas for the third a larger stabilization is obtained than predicted by the calculation. The agreement with theory is significantly better than that obtained with multipole moments derived directly from the aspherical atom refinement. The convergence of the interaction as a function of addition of successively higher moments up to and including hexadecapoles (l = 4) is found to be within 2–3 kJ/mol. Although shortcomings of both the theoretical and experimental procedures are pointed out, the agreement obtained supports the potential of the experimental method for the evaluation of interactions in larger biologically relevant molecules. PMID:12221293

  4. Application of charge density methods to a protein model compound: calculation of Coulombic intermolecular interaction energies from the experimental charge density.

    PubMed

    Li, Xue; Wu, Guang; Abramov, Yuriy A; Volkov, Anatoliy V; Coppens, Philip

    2002-09-17

    A combined experimental and theoretical charge density study of the pentapeptide Boc-Gln-d-Iva-Hyp-Ala-Phol (Boc, butoxycarbonyl; Gln, glutamine; Iva, isovaline; Hyp, hydroxyproline; Ala, ethylalanine; Phol, phenylalaninol) is described. The experimental analysis, based on synchrotron x-ray data collected at 20 K, is combined with ab initio theoretical calculations. The topologies of the experimental and theoretical densities are analyzed in terms of the atoms in molecules quantum theory. Topological parameters, including atomic charges and higher moments integrated over the atomic basins, have been evaluated with the program topxd and are used to calculate the electrostatic interactions between the molecules in the crystal. The interaction energies obtained after adding dispersive and repulsive van der Waals contributions agree quite well with those based on M-B3LYP/6-31G** dimer calculations for two of the three dimers in the crystal, whereas for the third a larger stabilization is obtained than predicted by the calculation. The agreement with theory is significantly better than that obtained with multipole moments derived directly from the aspherical atom refinement. The convergence of the interaction as a function of addition of successively higher moments up to and including hexadecapoles (l = 4) is found to be within 2-3 kJ/mol. Although shortcomings of both the theoretical and experimental procedures are pointed out, the agreement obtained supports the potential of the experimental method for the evaluation of interactions in larger biologically relevant molecules. PMID:12221293

  5. Evaluation of the chronic inhalation toxicity of a manganese oxide aerosol--I. Introduction, experimental design, and aerosol generation methods.

    PubMed

    Ulrich, C E; Rinehart, W; Busey, W

    1979-03-01

    A brief literature review on manganese toxicity is presented; as related to designing a chronic inhalation study for evaluating methylcyclopentadienyl manganese tricarbonyl when utilized as a motor fuel additive. The experimental design of this study is described. The generation system utilized to simulate the manganese aerosol produced by an internal combustion engine is described in detail. This generation system operated twenty-four hours per day, seven days per week producing aerosols at 11.6, 112.5, and 1152 micrograms Mn/m3 with an aerodynamic diameter of approximately 0.11 micron.

  6. DETECTORS AND EXPERIMENTAL METHODS: Monte Carlo studies of micromegas as a neutron detector and its track reconstruction

    NASA Astrophysics Data System (ADS)

    Zhang, Yi; Zhang, Xiao-Dong; Wang, Wen-Xin; Yang, He-Run; Yang, Zheng-Cai; Hu, Bi-Tao

    2009-01-01

    In this paper a two dimensional readout micromegas detector with a polyethylene foil as converter was simulated on GEANT4 toolkit and GARFIELD for fast neutron detection. A new track reconstruction method based on time coincidence technology was developed in the simulation to obtain the incident neutron position. The results showed that with this reconstruction method higher spatial resolution was achieved.

  7. Prenotification, Incentives, and Survey Modality: An Experimental Test of Methods to Increase Survey Response Rates of School Principals

    ERIC Educational Resources Information Center

    Jacob, Robin Tepper; Jacob, Brian

    2012-01-01

    Teacher and principal surveys are among the most common data collection techniques employed in education research. Yet there is remarkably little research on survey methods in education, or about the most cost-effective way to raise response rates among teachers and principals. In an effort to explore various methods for increasing survey response…

  8. OTSEGO COUNTY EXPERIMENTAL PROGRAM FOR TESTING METHODS OF FORMING FARM MANAGEMENT STUDY GROUPS, A PROGRESS REPORT. EXTENSION STUDY, NUMBER 8.

    ERIC Educational Resources Information Center

    LONGEST, JAMES W.; GENGENBACK, WILLIAM H.

    THE MOST FREQUENT METHOD OF GROUP FORMATION FOR INTENSIVE FARM MANAGEMENT PROGRAMS IN NEW YORK STATE HAS BEEN TO COMBINE ALL INTERESTED FARMERS IN LARGE GROUPS AT THE COUNTY EXTENSION HEADQUARTERS. THIS EXPERIMENT WAS SET UP TO STUDY THE EFFECTIVENESS OF TWO METHODS OF FORMING SMALL GROUPS--BY SOCIOMETRIC CHOICE OR SIMILAR CHARACTERISTICS. ALL…

  9. Experimental Validation of the Dynamic Inertia Measurement Method to Find the Mass Properties of an Iron Bird Test Article

    NASA Technical Reports Server (NTRS)

    Chin, Alexander; Herrera, Claudia; Spivey, Natalie; Fladung, William; Cloutier, David

    2015-01-01

    This presentation describes the DIM method and how it measures the inertia properties of an object by analyzing the frequency response functions measured during a ground vibration test (GVT). The DIM method has been in development at the University of Cincinnati and has shown success on a variety of small scale test articles. The NASA AFRC version was modified for larger applications.

  10. Virtual prototype and experimental research on gear multi-fault diagnosis using wavelet-autoregressive model and principal component analysis method

    NASA Astrophysics Data System (ADS)

    Li, Zhixiong; Yan, Xinping; Yuan, Chengqing; Peng, Zhongxiao; Li, Li

    2011-10-01

    Gear systems are an essential element widely used in a variety of industrial applications. Since approximately 80% of the breakdowns in transmission machinery are caused by gear failure, the efficiency of early fault detection and accurate fault diagnosis are therefore critical to normal machinery operations. Reviewed literature indicates that only limited research has considered the gear multi-fault diagnosis, especially for single, coupled distributed and localized faults. Through virtual prototype simulation analysis and experimental study, a novel method for gear multi-fault diagnosis has been presented in this paper. This new method was developed based on the integration of Wavelet transform (WT) technique, Autoregressive (AR) model and Principal Component Analysis (PCA) for fault detection. The WT method was used in the study as the de-noising technique for processing raw vibration signals. Compared with the noise removing method based on the time synchronous average (TSA), the WT technique can be performed directly on the raw vibration signals without the need to calculate any ensemble average of the tested gear vibration signals. More importantly, the WT can deal with coupled faults of a gear pair in one operation while the TSA must be carried out several times for multiple fault detection. The analysis results of the virtual prototype simulation prove that the proposed method is a more time efficient and effective way to detect coupled fault than TSA, and the fault classification rate is superior to the TSA based approaches. In the experimental tests, the proposed method was compared with the Mahalanobis distance approach. However, the latter turns out to be inefficient for the gear multi-fault diagnosis. Its defect detection rate is below 60%, which is much less than that of the proposed method. Furthermore, the ability of the AR model to cope with localized as well as distributed gear faults is verified by both the virtual prototype simulation and

  11. Advances in experimental methods for the elucidation of Pseudomonas syringae effector function with a focus on AvrPtoB

    PubMed Central

    Munkvold, Kathy R.; Martin, Gregory B.

    2010-01-01

    SUMMARY Pseudomonas syringae infects a wide range of plant species through the use of a type III secretion system. The effector proteins injected into the plant cell through this molecular syringe serve as promoters of disease by subverting the plant immune response to the benefit of the bacteria in the intercellular space. The targets and activities of a subset of effectors have been elucidated recently. In this article, we focus on the experimental approaches that have proved most successful in probing the molecular basis of effectors, ranging from loss-of-function to gain-of-function analyses utilizing several techniques for effector delivery into plants. In particular, we highlight how these diverse approaches have been applied to the study of one effector—AvrPtoB—a multifunctional protein with the ability to suppress both effector-triggered immunity and pathogen (or microbe)-associated molecular pattern-triggered immunity. Taken together, advances in this field illustrate the need for multiple experimental approaches when elucidating the function of a single effector. PMID:19849784

  12. Effect of solid distribution on elastic properties of open-cell cellular solids using numerical and experimental methods.

    PubMed

    Zargarian, A; Esfahanian, M; Kadkhodapour, J; Ziaei-Rad, S

    2014-09-01

    Effect of solid distribution between edges and vertices of three-dimensional cellular solid with an open-cell structure was investigated both numerically and experimentally. Finite element analysis (FEA) with continuum elements and appropriate periodic boundary condition was employed to calculate the elastic properties of cellular solids using tetrakaidecahedral (Kelvin) unit cell. Relative densities between 0.01 and 0.1 and various values of solid fractions were considered. In order to validate the numerical model, three scaffolds with the relative density of 0.08, but different amounts of solid in vertices, were fabricated via 3-D printing technique. Good agreement was observed between numerical simulation and experimental results. Results of numerical simulation showed that, at low relative densities (<0.03), Young׳s modulus increased by shifting materials away from edges to vertices at first and then decreased after reaching a critical point. However, for the high values of relative density, Young׳s modulus increased monotonically. Mechanisms of such a behavior were discussed in detail. Results also indicated that Poisson׳s ratio decreased by increasing relative density and solid fraction in vertices. By fitting a curve to the data obtained from the numerical simulation and considering the relative density and solid fraction in vertices, empirical relations were derived for Young׳s modulus and Poisson׳s ratio. PMID:24956160

  13. A Dye-Tracer Technique for Experimentally Obtaining Impingement Characteristics of Arbitrary Bodies and a Method for Determining Droplet Size Distribution

    NASA Technical Reports Server (NTRS)

    VonGlahn, Uwe H.; Gelder, Thomas F.; Smyers, William H., Jr.

    1955-01-01

    A dye-tracer technique has been developed whereby the quantity of dyed water collected on a blotter-wrapped body exposed to an air stream containing a dyed-water spray cloud can be colorimetrically determined in order to obtain local collection efficiencies, total collection efficiency, and rearward extent of impingement on the body. In addition, a method has been developed whereby the impingement characteristics obtained experimentally for a body can be related to theoretical impingement data for the same body in order to determine the droplet size distribution of the impinging cloud. Several cylinders, a ribbon, and an aspirating device to measure cloud liquid-water content were used in the studies presented herein for the purpose of evaluating the dye-tracer technique. Although the experimental techniques used in the dye-tracer technique require careful control, the methods presented herein should be applicable for any wind tunnel provided the humidity of the air stream can be maintained near saturation.

  14. Comparison of cell counting methods in rodent pulmonary toxicity studies: automated and manual protocols and considerations for experimental design.

    PubMed

    Zeidler-Erdely, Patti C; Antonini, James M; Meighan, Terence G; Young, Shih-Houng; Eye, Tracy J; Hammer, Mary Ann; Erdely, Aaron

    2016-08-01

    Pulmonary toxicity studies often use bronchoalveolar lavage (BAL) to investigate potential adverse lung responses to a particulate exposure. The BAL cellular fraction is counted, using automated (i.e. Coulter Counter®), flow cytometry or manual (i.e. hemocytometer) methods, to determine inflammatory cell influx. The goal of the study was to compare the different counting methods to determine which is optimal for examining BAL cell influx after exposure by inhalation or intratracheal instillation (ITI) to different particles with varying inherent pulmonary toxicities in both rat and mouse models. General findings indicate that total BAL cell counts using the automated and manual methods tended to agree after inhalation or ITI exposure to particle samples that are relatively nontoxic or at later time points after exposure to a pneumotoxic particle when the response resolves. However, when the initial lung inflammation and cytotoxicity was high after exposure to a pneumotoxic particle, significant differences were observed when comparing cell counts from the automated, flow cytometry and manual methods. When using total BAL cell count for differential calculations from the automated method, depending on the cell diameter size range cutoff, the data suggest that the number of lung polymorphonuclear leukocytes (PMN) varies. Importantly, the automated counts, regardless of the size cutoff, still indicated a greater number of total lung PMN when compared with the manual method, which agreed more closely with flow cytometry. The results suggest that either the manual method or flow cytometry would be better suited for BAL studies where cytotoxicity is an unknown variable.

  15. Accelerated screening methods for determining chemical and thermal stability of refreigerant-lubricant mixtures. Part II: Experimental comparison and verification of methods. Final report, volume I

    SciTech Connect

    Kauffman, R.

    1995-09-01

    The research reported herein was performed to develop an accelerated screening method for determining the chemical and thermal stabilities of refrigerant/lubricant mixtures. The developed screening method was designed to be safe and to produce accelerated stability rankings that are in agreement with the rankings determined by the current test, Sealed Glass Tube Method to Test the Chemical Stability of Material for Use Within Refrigerant Systems, ANSI/ASHRAE Method 97-1989. The accelerated screening test developed was designed to be independent of refrigerant and lubricant compositions and to be used with a wide variety of construction materials. The studied refrigerants included CFC-11, CFC-12, HCFC-22, HFC-134a, and HFC-32/HFC-134a (zeotrope 30:70 by weight). The studied lubricants were selected from the chemical classes of mineral oil, alkylbenzene oil, polyglycols, and polyolesters. The work reported herein was performed in three phases. In the first phase, previously identified thermal analytical techniques were evaluated for development into an accelerated screening method for refrigerant/lubricant mixtures. The identified thermal analytical techniques used in situ measurements of color, temperature, or conductivity to monitor the degradation of the heated refrigerant/lubricant mixtures. The identified thermal analytical techniques also used catalysts such as ferric fluoride to accelerate the degradation of the heated refrigerant/lubricant mixtures. The thermal analytical technique employing in situ conductivity measurements was determined to be the most suitable for development into an accelerated screening method.

  16. A new calculation method adapted to the experimental conditions for determining samples γ-activities induced by 14 MeV neutrons

    NASA Astrophysics Data System (ADS)

    Rzama, A.; Erramli, H.; Misdaq, M. A.

    1994-09-01

    Induced gamma-activities of different disk shaped irradiated samples and standards with 14 MeV neutrons have been determined by using a Monte Carlo calculation method adapted to the experimental conditions. The self-absorption of the multienergetic emitted gamma rays has been taken into account in the final samples activities. The influence of the different activation parameters has been studied. Na, K, Cl and P contents in biological (red beet) samples have been determined.

  17. EXPERIMENTAL STUDY OF THE NEW BIOCATALYST METHOD FOR BIODIESEL-FUEL BASED ON THE LIPASE PRODUCTION FUNGUS

    NASA Astrophysics Data System (ADS)

    Hata, Toshiro; Shimada, Miki; Toida, Jinichi

    This paper describes how to develop and evaluate a new biocatalyst method for biodiesel fuel based on the lipase production fungus. This method can convert waste vegetable oil into biodiesel fuel without alkaline waste fluid and byproducts (gly cerine). The main outcomes of this research were: (1) The biodiesel fuel can be manufactured from lipase production fungus (Rhizupus oryzae NBRC 9364). (2) The lipase activity can be enhanced by adding glucose and oil. (3) Phased addition of the methanol enhances the conversion rate of the biodiesel fuel (Maximum conversion rate is 85%). (4) The proposed method can improve vehicle exhaust emission and reduce byproducts (glycerine). We concluded that our proposed methods are effective for the production of biodiesel fuel from waste vegetable oil.

  18. Experimental methods to determine inhalability and personal sampler performance for aerosols in ultra-low windspeed environments.

    PubMed

    Schmees, Darrah K; Wu, Yi-Hsuan; Vincent, James H

    2008-12-01

    Most previous experiments of aerosol inhalability as it relates to particle aerodynamic diameter were conducted in wind tunnels for windspeeds greater than 0.5 m s(-1). While that body of work was used to establish an inhalable aerosol convention, results from studies in calm air chambers (for essentially zero windspeed) are being discussed as the basis of a modified criterion. Meanwhile, however, information is lacking for windspeeds in the intermediate range, which--it so happens--pertain to most actual workplaces. With this in mind, we have developed a new experimental system to assess inhalability and personal sampler performance for aerosols with particle aerodynamic diameter within the range from 6 to 90 microm for ultra-low windspeed environments from about 0.1 to 0.5 m s(-1). In this range of conditions for particle size and windspeed, controlled aerosol experiments are very difficult to perform, most notably with respect to the problem of achieving uniform spatial distributions of both test aerosols and air velocity. In the work reported in this paper, we have addressed these difficulties in a new, custom-designed experimental facility. It is a novel wind tunnel design that provides stable and controllable low-turbulence air movement, and allows for the delivery of test aerosol to the working section both from upstream (as in conventional wind tunnel experiments) and from above (as in calm air studies). In this system, losses by elutriation of particles that are being convected in the horizontal aerosol flow are compensated by particles entering from above by gravitational settling. An important feature of the new facility is the life-size, breathing mannequin that contains physical means to achieve any combination of mouth and nasal inspiration and expiration, and allows any desired relevant breathing flowrate and pattern by means of an external computer-controlled breathing simulator. Special steps were taken in the detailed design to ensure that

  19. An experimental and theoretical method for determination of standard electrode potential for the redox couple diphenyl sulfone/diphenyl sulfide

    NASA Astrophysics Data System (ADS)

    Song, Y. Z.; Wei, K. X.; Lv, J. S.

    2013-12-01

    DFT calculations were performed for diphenyl sulfide and diphenyl sulfone. The electrochemistry of diphenyl sulfide on the gold electrode was investigated by cyclic voltammety and the results show that standard electrode potential for redox couple diphenyl sulfone/diphenyl sulfide is 1.058 V, which is consistent with that of 1.057 calculated at B3LYP/6-31++G( d, p)-IEFPCM level. The front orbit theory and Mulliken charges of molecular explain well on the oxidation of diphenyl sulfide in oxidative desulfurization. According to equilibrium theory the experimental equilibrium constant in the oxidative desulfurization of H2O2, is 1.17 × 1048, which is consistent with the theoretical equilibrium constant is 2.18 × 1048 at B3LYP/6-31++G( d, p)-IEFPCM level.

  20. DETECTORS AND EXPERIMENTAL METHODS Characteristics of the magnetic analysis system for a compact MPR-type spectrometer

    NASA Astrophysics Data System (ADS)

    Qi, Jian-Min; Zhou, Lin; Jiang, Shi-Lun; Peng, Tai-Ping

    2010-12-01

    The magnetic proton recoil (MPR) spectrometer is a novel diagnostic instrument with high performance for measurements of neutron spectra in inertial confinement fusion (ICF) experiments and high power fusion devices. A compact MPR-type spectrometer dedicated to the research of pulsed deuterium-tritium (DT) neutron spectroscopy of special experimental conditions is currently under design. Analyses of the main parameters and performance of the magnetic analysis system through 3-D particle transport calculations and MonteCarlo simulations and calibration of the system performance as a test using CR-39 solid track detector and α particle from 239Pu and 226Ra radioactive sources are presented in this paper. The results indicate that the magnetic analysis system will achieve a detection efficiency level of 10-5 -10-4 at an energy resolution of 1.5%-2.1%, and fulfills the design goals of the spectrometer.

  1. Experimental testing of integral truncation algorithms for the calculation of beam widths by proposed ISO standard methods

    NASA Astrophysics Data System (ADS)

    Apte, Paul; Gower, Malcolm C.; Ward, Brooke A.

    1995-04-01

    The experimental testing of baseline clipping algorithms was carried out on a purposely constructed test bench. Three different lasers were used for the tests including HeNe and collimated laserdiode. The beam profile intensity distribution was measured using a CCD camera at various distances from a reference lens. Results were analyzed on an 486 PC running custom developed software written in Turbo Pascal. This allows very fast evaluation of the algorithms to be performed at rates of several times per second depending upon computational load. Tables of beam width data were created and then analyzed using Mathematica to see if the data confirmed ABCD propagation laws. Values for the beam waist location, size, and propagation constant were calculated.

  2. Atomic structure of the (310) symmetrical tilt grain boundary in strontium titanate - a comparison among experimental methods and atomistic simulations

    SciTech Connect

    Ravikumar, V.; Dravid, V.P.; Wolf, D.

    1996-12-31

    Strontium Titanate is a prototypical perovskite oxide whose macroscopic electroceramic properties, like varistor and grain boundary barrier layer capacitor (GBBLC) behavior, are controlled by grain boundary (GB) phenomena. In this paper, we present a comparative analysis of the results of both experimental and theoretical investigations of the atomic structure of a (310) symmetrical tilt GB (a) {Sigma}=5 (310) [001] GB in the CSL notation in SrTiO{sub 3}. Bicrystals of SrTiO{sub 3} were procured from diffraction studies confirm that the GB conforms to the {Sigma} =5 misorientation. The atomic structure of this GB has been investigated using high resolution transmission electron microscopy (HRTEM) and associated image simulations, as well as by atomistic simulations using static iterative energy minimization schemes ({open_quotes}lattice-statics{close_quotes}).

  3. Comparison of cell counting methods in rodent pulmonary toxicity studies: automated and manual protocols and considerations for experimental design

    PubMed Central

    Zeidler-Erdely, Patti C.; Antonini, James M.; Meighan, Terence G.; Young, Shih-Houng; Eye, Tracy J.; Hammer, Mary Ann; Erdely, Aaron

    2016-01-01

    Pulmonary toxicity studies often use bronchoalveolar lavage (BAL) to investigate potential adverse lung responses to a particulate exposure. The BAL cellular fraction is counted, using automated (i.e. Coulter Counter®), flow cytometry or manual (i.e. hemocytometer) methods, to determine inflammatory cell influx. The goal of the study was to compare the different counting methods to determine which is optimal for examining BAL cell influx after exposure by inhalation or intratracheal instillation (ITI) to different particles with varying inherent pulmonary toxicities in both rat and mouse models. General findings indicate that total BAL cell counts using the automated and manual methods tended to agree after inhalation or ITI exposure to particle samples that are relatively nontoxic or at later time points after exposure to a pneumotoxic particle when the response resolves. However, when the initial lung inflammation and cytotoxicity was high after exposure to a pneumotoxic particle, significant differences were observed when comparing cell counts from the automated, flow cytometry and manual methods. When using total BAL cell count for differential calculations from the automated method, depending on the cell diameter size range cutoff, the data suggest that the number of lung polymorphonuclear leukocytes (PMN) varies. Importantly, the automated counts, regardless of the size cutoff, still indicated a greater number of total lung PMN when compared with the manual method, which agreed more closely with flow cytometry. The results suggest that either the manual method or flow cytometry would be better suited for BAL studies where cytotoxicity is an unknown variable. PMID:27251196

  4. Comparison of cell counting methods in rodent pulmonary toxicity studies: automated and manual protocols and considerations for experimental design.

    PubMed

    Zeidler-Erdely, Patti C; Antonini, James M; Meighan, Terence G; Young, Shih-Houng; Eye, Tracy J; Hammer, Mary Ann; Erdely, Aaron

    2016-08-01

    Pulmonary toxicity studies often use bronchoalveolar lavage (BAL) to investigate potential adverse lung responses to a particulate exposure. The BAL cellular fraction is counted, using automated (i.e. Coulter Counter®), flow cytometry or manual (i.e. hemocytometer) methods, to determine inflammatory cell influx. The goal of the study was to compare the different counting methods to determine which is optimal for examining BAL cell influx after exposure by inhalation or intratracheal instillation (ITI) to different particles with varying inherent pulmonary toxicities in both rat and mouse models. General findings indicate that total BAL cell counts using the automated and manual methods tended to agree after inhalation or ITI exposure to particle samples that are relatively nontoxic or at later time points after exposure to a pneumotoxic particle when the response resolves. However, when the initial lung inflammation and cytotoxicity was high after exposure to a pneumotoxic particle, significant differences were observed when comparing cell counts from the automated, flow cytometry and manual methods. When using total BAL cell count for differential calculations from the automated method, depending on the cell diameter size range cutoff, the data suggest that the number of lung polymorphonuclear leukocytes (PMN) varies. Importantly, the automated counts, regardless of the size cutoff, still indicated a greater number of total lung PMN when compared with the manual method, which agreed more closely with flow cytometry. The results suggest that either the manual method or flow cytometry would be better suited for BAL studies where cytotoxicity is an unknown variable. PMID:27251196

  5. Fast quantification of ethanol in whole blood specimens by the enzymatic alcohol dehydrogenase method. Optimization by experimental design.

    PubMed

    Kristoffersen, Lena; Skuterud, Bjørn; Larssen, Bente R; Skurtveit, Svetlana; Smith-Kielland, Anne

    2005-01-01

    A sensitive, fast, simple, and high-throughput enzymatic method for the quantification of ethanol in whole blood (blood) on Hitachi 917 is presented. Alcohol dehydrogenase (ADH) oxidizes ethanol to acetaldehyde using the coenzyme nicotinamide adenine dinucleotide (NAD), which is concurrently reduced to form NADH. Method development was performed with the aid of factorial design, varying pH, and concentrations of NAD+ and ADH. The linear range increased and reaction end point decreased with increasing NAD+ concentration and pH. The method was linear in the concentration range 0.0024-0.4220 g/dL. The limits of detection and quantification were 0.0007 g/dL and 0.0024 g/dL, respectively. Relative standard deviations for the repeatability and within-laboratory reproducibility were in the ranges 0.7-5.7% and 1.6-8.9%, respectively. The correlation coefficient when compared with headspace gas chromatography-flame ionization detection methods was 0.9903. Analysis of authentic positive blood specimens gave results that were slightly lower than those of the reference method.

  6. Experimental comparison of methods for simultaneous selection of two correlated traits in Tribolium : 1. Empirical and theoretical selection indexes.

    PubMed

    Campo, J L; Rodriguez, M C

    1985-11-01

    Two lines of Tribolium castaneum were selected in each of three replicates for egg laying between 7 and 11 days after adult emergency and for adult weight at 12 days, using theoretical (IT) and empirical (IP) index selection methods. Index coefficients were given empirically in the IP line and they were adjusted in the successive generations of selection according to the results obtained in the previous ones. Highly repeatable selection responses in all replicates occurred in both lines for the aggregate genotype (egg laying plus adult weight) and for each individual trait. The IP line tended to increase slightly more than the IT line for aggregate genotype and egg laying, while the highest response in adult weight was obtained with the IT method. The two methods gave consistently different responses in each replicate. The expected results were that IT selection should not exceed IP selection for the aggregate genotype and egg laying while theoretically the IT method should have been superior for increase adult weight. Theoretical expectations for adult weight have been fulfilled in practice. The IP method would be preferred in a practical sense because of its simplicity and freedom from need of parameter estimation. PMID:24247344

  7. Experimental colitis.

    PubMed

    MacPherson, B; Pfeiffer, C J

    1976-01-01

    Ulcerative colitis and Crohn's disease are complex, problematic diseases of unknown etiology in man, and appropriate experimental models would be useful in elucidating their pathogenesis and treatment. Although there have been numerous attempts to produce inflammatory ulcerative colonic disease in laboratory animals resembling those human disease forms, none has been entirely successful. Investigators have conducted experiments involving almost every etiological factor suggested for initiation of these diseases. The methods reviewed in this paper include production of experimental colitis by vascular impairment, and immunological methods such as bacterial infection, allergic reactions, direct and indirect hypersensitivity reactions, as well as autoimmune mechanisms. The results of carrageenan-induced colitis, irradiation, dietary, and drug-induced techniques are also discussed and the frequency and nature of spontaneous colonic lesions in animals is summarized.

  8. Total Quality Management: Statistics and Graphics III - Experimental Design and Taguchi Methods. AIR 1993 Annual Forum Paper.

    ERIC Educational Resources Information Center

    Schwabe, Robert A.

    Interest in Total Quality Management (TQM) at institutions of higher education has been stressed in recent years as an important area of activity for institutional researchers. Two previous AIR Forum papers have presented some of the statistical and graphical methods used for TQM. This paper, the third in the series, first discusses some of the…

  9. A method for estimating soil water diffusivity from moisture profiles and its application across an experimental catchment

    NASA Astrophysics Data System (ADS)

    Espejo, A.; Giráldez, J. V.; Vanderlinden, K.; Taguas, E. V.; Pedrera, A.

    2014-08-01

    Despite the well-accepted value of soil hydraulic properties for describing and modeling matter and energy fluxes in the unsaturated zone, their accurate measurement across scales is still a daunting task. The increasing availability of continuous soil water content measurements at discrete points in space, as provided by sensor networks, offers still unexplored possibilities for evaluating soil physical properties across landscapes. In this study, we propose a new method, based on the Bruce and Klute equation, to estimate effective soil water diffusivity from soil water profile data observed during continuous desiccation periods. An analytical expression is proposed for the diffusion-soil water relationship, assuming an exponential relationship between soil water content and the Boltzmann variable. The method has been evaluated using soil water profile data observed at inter-row and under canopy locations across a rainfed olive orchard in SW Spain. The spatial variability of the effective soil water diffusivity across the orchard was estimated. Different soil conditions under the tree canopies as compared to inter-row areas resulted in significantly different effective diffusivity relationships, reflecting the effect of trees on soil physical properties and water dynamics across olive orchards. The proposed method offers a suitable alternative to traditional laboratory methods and can be easily extended to estimate soil hydraulic conductivity and water retention curves.

  10. Experimental Demonstration of the Molten Oxide Electrolysis Method for Oxygen and Iron Production from Simulated Lunar Materials

    NASA Technical Reports Server (NTRS)

    Curreri, P. A.; Ethridge, E.; Hudson, S.; Sen, S.

    2006-01-01

    This paper presents the results of a Marshall Space Flight Center funded effort to conduct an experimental demonstration of the processing of simulated lunar resources by the molten oxide electrolysis (MOE) process to produce oxygen and metal from lunar resources to support human exploration of space. Oxygen extracted from lunar materials can be used for life support and propellant, and silicon and metallic elements produced can be used for in situ fabrication of thin-film solar cells for power production. The Moon is rich in mineral resources, but it is almost devoid of chemical reducing agents, therefore, molten oxide electrolysis, MOE, is chosen for extraction, since the electron is the most practical reducing agent. MOE was also chosen for following reasons. First, electrolytic processing offers uncommon versatility in its insensitivity to feedstock composition. Secondly, oxide melts boast the twin key attributes of highest solubilizing capacity for regolith and lowest volatility of any candidate electrolytes. The former is critical in ensuring high productivity since cell current is limited by reactant solubility, while the latter simplifies cell design by obviating the need for a gas-tight reactor to contain evaporation losses as would be the case with a gas or liquid phase fluoride reagent operating at such high temperatures. In the experiments reported here, melts containing iron oxide were electrolyzed in a low temperature supporting oxide electrolyte (developed by D. Sadoway, MIT).

  11. A comparison of diagnostic methods for the detection of bovine respiratory syncytial virus in experimental clinical specimens.

    PubMed Central

    West, K; Bogdan, J; Hamel, A; Nayar, G; Morley, P S; Haines, D M; Ellis, J A

    1998-01-01

    Virus shedding was monitored in nasal secretions of 12 calves experimentally infected with bovine respiratory syncytial virus (BRSV) using an antigen capture enzyme-linked immunosorbent assay (ELISA) detecting the nucleoprotein (NP) antigen of BRSV, by a polymerase chain reaction (PCR) amplifying the fusion protein of BRSV, and by a microisolation assay combined with immunoperoxidase staining for the F protein of BRSV. Under the conditions of this study, similar limits of detection and quantitative results were obtained from all three assays. BRSV was detected in nasal secretions of all calves for a minimum of 4 d. Virus shedding began on Day 2 after infection, peaked on Days 3-5, and was cleared in most calves by Day 8. The PCR, and to a lesser extent the ELISA, may detect virus shedding for a longer period after infection than virus isolation, possibly due to neutralization of the virus by rising mucosal antibody. Simulated environmental conditions likely to be experienced during transport of clinical field specimens markedly reduced the sensitivity of virus isolation but had a minimal effect on the results of the NP ELISA. Actual field transport conditions (overnight on ice) had minimal apparent effect on the results of the PCR assay. The less stringent specimen handling requirements, combined with low limits of detection, of both the nucleoprotein ELISA and PCR, indicate either of these assays are more suitable for diagnostic applications than virus isolation. PMID:9798088

  12. Energy dispersive X-ray microanalysis of biological bulk specimens: a review of the method and its application to experimental gerontology and cancer research

    SciTech Connect

    Nagy, I.

    1983-01-01

    Biological bulk specimens can be prepared by the freeze-fracture freeze-drying method, which is suitable for quantitative X-ray microanalysis of intracellular components. Although the spatial resolution of this analytic technique does not allow us to analyze smaller cellular compartments than the nucleus and cytoplasm it may deliver useful results for answering questions of experimental biology. Bulk specimens are also suitable for determination of intracellular water and dry mass contents under certain conditions. Applications of the bulk specimen X-ray microanalysis for experimental gerontology revealed an age dependent increase of the intracellular potassium content of the postmitotic cells, a diminution of intracellular water content during aging and delivered indirect proof for the decrease of the passive potassium permeability of the cell membrane in old hepatocytes and giant neurons. The bulk specimen method of X-ray microanalysis has been applied also in cancer research: it proved to be helpful in the determination of intracellular Na+-contents and Na+/K+ ratios in various human and experimental animal tumors as well as in other models of cell proliferation. These data gain a certain weight in light of the recent developments on the regulation of mitogenesis.

  13. Paraffin-embedded tissue blot as a sensitive method for discrimination between classical scrapie and experimental bovine spongiform encephalopathy in sheep.

    PubMed

    Webb, Paul R; Denyer, Margaret; Gough, Julie; Spiropoulos, John; Simmons, Marion M; Spencer, Yvonne I

    2011-05-01

    The paraffin-embedded tissue (PET) blot was modified for use as a tool to differentiate between classical scrapie and experimental bovine spongiform encephalopathy (BSE) in sheep. Medulla (obex) from 21 cases of classical scrapie and 6 cases of experimental ovine BSE were used to develop the method such that it can be used as a tool to differentiate between BSE and scrapie in the same way that differential immunohistochemistry (IHC) has been used previously. The differential PET blot successfully differentiated between all of the scrapie and ovine BSE cases. Differentiation was permitted more easily with PET blot than by differential IHC, with accurate observations possible at the macroscopic level. At the microscopic level, sensitivity was such that discrimination by the differential PET blot could be made with more confidence than with differential IHC in cases where the immunohistochemical differences were subtle. The differential PET blot makes use of harsh epitope demasking conditions, and, because of the differences in the way prion protein is processed in different prion diseases, it can serve as a new, highly sensitive method to discriminate between classical scrapie and experimental BSE in sheep.

  14. An experimental and analytical method for approximate determination of the tilt rotor research aircraft rotor/wing download

    NASA Technical Reports Server (NTRS)

    Jordon, D. E.; Patterson, W.; Sandlin, D. R.

    1985-01-01

    The XV-15 Tilt Rotor Research Aircraft download phenomenon was analyzed. This phenomenon is a direct result of the two rotor wakes impinging on the wing upper surface when the aircraft is in the hover configuration. For this study the analysis proceeded along tow lines. First was a method whereby results from actual hover tests of the XV-15 aircraft were combined with drag coefficient results from wind tunnel tests of a wing that was representative of the aircraft wing. Second, an analytical method was used that modeled that airflow caused gy the two rotors. Formulas were developed in such a way that acomputer program could be used to calculate the axial velocities were then used in conjunction with the aforementioned wind tunnel drag coefficinet results to produce download values. An attempt was made to validate the analytical results by modeling a model rotor system for which direct download values were determinrd..

  15. Research on theoretical optimization and experimental verification of minimum resistance hull form based on Rankine source method

    NASA Astrophysics Data System (ADS)

    Zhang, Bao-Ji; Zhang, Zhu-Xin

    2015-09-01

    To obtain low resistance and high efficiency energy-saving ship, minimum total resistance hull form design method is studied based on potential flow theory of wave-making resistance and considering the effects of tail viscous separation. With the sum of wave resistance and viscous resistance as objective functions and the parameters of B-Spline function as design variables, mathematical models are built using Nonlinear Programming Method (NLP) ensuring the basic limit of displacement and considering rear viscous separation. We develop ship lines optimization procedures with intellectual property rights. Series60 is used as parent ship in optimization design to obtain improved ship (Series60-1) theoretically. Then drag tests for the improved ship (Series60-1) is made to get the actual minimum total resistance hull form.

  16. Theoretical and experimental studies on zone-interference chromatography as a new method for determining macromolecular kinetic constants.

    PubMed

    Endo, S; Wada, A

    1983-11-01

    Zone-interference chromatography is a new method for studying macromolecular interactions (S. Endo and A. Wada, Anal. Biochem. 124 (1982) 372). This method is a new style of affinity chromatography which requires no preparation of affinity-column materials but utilizes the velocity difference in a column between interacting molecular species. Using the stochastic theory on the behavior of solute molecules, both the association and the dissociation rate constants can be analytically obtained from the degree of deformation of elution patterns, i.e., the change of the first and second moments. In order to verify the present theory, computer simulation of elution profiles by the extended plate theory and a binding experiment between glutamate dehydrogenase and ADP have been carried out. PMID:6661497

  17. [Experimental and clinical study of adoptive immunotherapy combined with preadministration of OK-432: a method to augment the therapeutic effect].

    PubMed

    Kan, N; Okino, T; Nakanishi, M; Sato, K; Mise, K; Teramura, Y; Yamasaki, S; Hori, T; Ohgaki, K; Tobe, T

    1989-04-01

    Our previous method of adoptive immunotherapy using IL2-cultured autologous lymphocytes consists of (1) in vitro sensitization by sonicated autologous tumor extract, (2) the induction and proliferation of active CTL by crude IL2, and (3) the preadministration of OK-432 for the augmentation of the therapeutic effect. Here we describe a new method to augment the therapeutic effect of OK432-combined AIT. In BALB/c mice with advanced malignant ascites (MOPC 104E), serial therapy with OK-432, cyclophosphamide and AIT significantly prolonged the survival compared with other therapeutic schedules through synergism between host's effector cells induced by immuno-chemotherapy and transferred killer cells. Many patients with advanced malignancies, for example, unresectable gastrointestinal cancer, locally advanced breast cancer or lung metastases of breast cancer, respond to such immuno-chemo-lymphocytotherapy, while previous OK432-combined AIT was effective only in malignant pleural effusion or metastatic liver tumor from breast cancer or peritoneal dissemination of gastric cancer.

  18. Assessment of real-time method to detect liver parasite burden under different experimental conditions in mice infected with Plasmodium yoelii sporozoites.

    PubMed

    Siddiqui, Arif Jamal; Bhardwaj, Jyoti; Goyal, Manish; Prakash, Kirtika; Soni, Awakash; Tiwari, Vishvanath; Puri, Sunil K

    2015-12-01

    Use of highly specific, sensitive and quantitative Real-Time PCR (qRT-PCR) based methods greatly facilitate the monitoring of experimental drug intervention and vaccination efficacy targeting liver stage malaria parasite. Here, in this study we have used qRT-PCR to detect the growing liver stage parasites following inoculation of Plasmodium yoelii sporozoite. Route of sporozoite administration and size of the sporozoite inoculums are two major determinants that affect the liver stage parasite load and therefore its detection and quantification. Thus, these factors need to be addressed to determine the accuracy of detection and quantification of Real-Time PCR method. Furthermore, applicability of quantitative RT-PCR system needs to be confirmed by analyzing the effect of different antimalarials on liver stage parasite burden. We have observed that parasite burden in mice infected via intravenous route was higher compared to that in subcutaneous, intradermal and intraperitoneal route infected mice. Moreover, this method detected liver stage parasite load with as low as 50 sporozoites. The inhibition studies with primaquine and atovaquone revealed inhibition of liver stage parasite and well correlated with patency and course of blood stage infection. This study characterized the simplicity, accuracy, and quantitative analysis of liver stage parasite development by real time PCR under different experimental conditions. Use of real time PCR method greatly improves the reproducibility and applicability to estimate the efficacy and potency of vaccine or drug candidates targeting liver stage parasite.

  19. A new method to detect systemic inflammatory response syndrome by continuous monitoring system: an experimental study in rats.

    PubMed

    Matsui, T; Ishizuka, T; Ishihara, M; Suzuki, M; Kurita, A; Kikuchi, M

    2005-01-01

    A continuous monitoring system was designed for detection of systemic inflammatory response syndrome (SIRS) using spectrum analyser and local temperature mapping system with deep body thermometer. This method demonstrated significant increases of heart and respiratory rates and deep body temperature from normal levels within 120 minutes after lipopolysaccharide administration in rats. Our monitoring system appears promising for clinical detection of SIRS in the early stages to prevent multiple organ failure. PMID:15764377

  20. Convenience experimentation.

    PubMed

    Krohs, Ulrich

    2012-03-01

    Systems biology aims at explaining life processes by means of detailed models of molecular networks, mainly on the whole-cell scale. The whole cell perspective distinguishes the new field of systems biology from earlier approaches within molecular cell biology. The shift was made possible by the high throughput methods that were developed for gathering 'omic' (genomic, proteomic, etc.) data. These new techniques are made commercially available as semi-automatic analytic equipment, ready-made analytic kits and probe arrays. There is a whole industry of supplies for what may be called convenience experimentation. My paper inquires some epistemic consequences of strong reliance on convenience experimentation in systems biology. In times when experimentation was automated to a lesser degree, modeling and in part even experimentation could be understood fairly well as either being driven by hypotheses, and thus proceed by the testing of hypothesis, or as being performed in an exploratory mode, intended to sharpen concepts or initially vague phenomena. In systems biology, the situation is dramatically different. Data collection became so easy (though not cheap) that experimentation is, to a high degree, driven by convenience equipment, and model building is driven by the vast amount of data that is produced by convenience experimentation. This results in a shift in the mode of science. The paper shows that convenience driven science is not primarily hypothesis-testing, nor is it in an exploratory mode. It rather proceeds in a gathering mode. This shift demands another shift in the mode of evaluation, which now becomes an exploratory endeavor, in response to the superabundance of gathered data.

  1. Experimental method of in-vivo dosimetry without build-up device on the skin for external beam radiotherapy

    NASA Astrophysics Data System (ADS)

    Jeon, Hosang; Nam, Jiho; Lee, Jayoung; Park, Dahl; Baek, Cheol-Ha; Kim, Wontaek; Ki, Yongkan; Kim, Dongwon

    2015-06-01

    Accurate dose delivery is crucial to the success of modern radiotherapy. To evaluate the dose actually delivered to patients, in-vivo dosimetry (IVD) is generally performed during radiotherapy to measure the entrance doses. In IVD, a build-up device should be placed on top of an in-vivo dosimeter to satisfy the electron equilibrium condition. However, a build-up device made of tissue-equivalent material or metal may perturb dose delivery to a patient, and requires an additional laborious and time-consuming process. We developed a novel IVD method using a look-up table of conversion ratios instead of a build-up device. We validated this method through a monte-carlo simulation and 31 clinical trials. The mean error of clinical IVD is 3.17% (standard deviation: 2.58%), which is comparable to that of conventional IVD methods. Moreover, the required time was greatly reduced so that the efficiency of IVD could be improved for both patients and therapists.

  2. Development and validation of a capillary electrophoresis method for the enantiomeric purity determination of RS86017 using experimental design.

    PubMed

    Liu, Meixia; Zheng, Yan; Ji, Yibing; Zhang, Can

    2011-04-28

    A selective capillary electrophoresis method for determination of enantiomeric purity of RS86017, a new antiarrhythmic agent with two chiral centers, was developed and validated using sulfobutyl ether-β-cyclodextrin as chiral selector. The concentration of the chiral selector and organic modifier, pH of background electrolyte (BGE), capillary temperature, and applied voltage were systematically optimized by using orthogonal design and concentration of chiral selector was further optimized. The optimal conditions included 25mM phosphate buffer at pH 8.0, containing 28mg/mL sulfobutyl ether-β-cyclodextrin and 20% acetonitrile as running buffer, an applied voltage of 22kV, and a temperature of 20°C. The detection wavelength was 206nm. The obtained method was capable of separating RS86017 from its potential chiral impurities, the S,R-enantiomer, the R,R-diastereomer and the S,S-diastereomer with a short analysis time of 10min. The separation was validated with respect to its selectivity, repeatability, linearity, precision, accuracy, limits of detection (LOD), limits of quantitation (LOQ) and robustness testing. The LODs and LOQs were 0.8μg/mL and 2.5μg/mL for all isomers of RS86017, respectively. Finally, the method was used to investigate the chiral purity of RS86017 in bulk samples.

  3. Conducting experimental research in marginalised populations: clinical and methodological implications from a mixed-methods randomised controlled trial in Kenya

    PubMed Central

    Lowther, Keira; Harding, Richard; Ahmed, Aabid; Gikaara, Nancy; Ali, Zippy; Kariuki, Hellen; Sherr, Lorraine; Simms, Victoria; Selman, Lucy

    2016-01-01

    ABSTRACT Experimental studies to test interventions for people living with HIV in low- and middle-income countries are essential to ensure appropriate and effective clinical care. The implications of study participation on outcome data in such populations have been discussed theoretically, but rarely empirically examined. We aimed to explore the effects of participating in a randomised controlled trial conducted in an HIV clinic in Mombasa, Kenya. We report qualitative data from the Treatment Outcomes in Palliative Care trial, which evaluated the impact of a nurse-led palliative care intervention for HIV positive adults on antiretroviral therapy compared to standard care. Participants in both arms attended five monthly quantitative data collection appointments. Post-trial exit, 10 control and 20 intervention patients participated in semi-structured qualitative interviews, analysed using thematic analysis. We found benefit attributed to the compassion of the research team, social support, communication, completion of patient reported outcome measures (PROMs) and material support (transport reimbursement). Being treated with compassion and receiving social support enabled participants to build positive relationships with the research team, which improved mental health and well-being. Open and non-judgmental communication made participants feel accepted. Participants described how repeated completion of the PROMs was a prompt for reflection, through which they began to help themselves and self-care. Participant reimbursements relieved financial hardship and enabled them to fulfil their social responsibilities, enhancing self-worth. These findings emphasise the importance of compassion, support and effective communication in the clinical encounter, particularly in stigmatised and isolated populations, and the potential of the integration of simple PROMs to improve patient outcomes. Participation in research has unexpected positive benefits for participants, which

  4. Metal-silicate Partitioning at High Pressure and Temperature: Experimental Methods and a Protocol to Suppress Highly Siderophile Element Inclusions.

    PubMed

    Bennett, Neil R; Brenan, James M; Fei, Yingwei

    2015-01-01

    Estimates of the primitive upper mantle (PUM) composition reveal a depletion in many of the siderophile (iron-loving) elements, thought to result from their extraction to the core during terrestrial accretion. Experiments to investigate the partitioning of these elements between metal and silicate melts suggest that the PUM composition is best matched if metal-silicate equilibrium occurred at high pressures and temperatures, in a deep magma ocean environment. The behavior of the most highly siderophile elements (HSEs) during this process however, has remained enigmatic. Silicate run-products from HSE solubility experiments are commonly contaminated by dispersed metal inclusions that hinder the measurement of element concentrations in the melt. The resulting uncertainty over the true solubility and metal-silicate partitioning of these elements has made it difficult to predict their expected depletion in PUM. Recently, several studies have employed changes to the experimental design used for high pressure and temperature solubility experiments in order to suppress the formation of metal inclusions. The addition of Au (Re, Os, Ir, Ru experiments) or elemental Si (Pt experiments) to the sample acts to alter either the geometry or rate of sample reduction respectively, in order to avoid transient metal oversaturation of the silicate melt. This contribution outlines procedures for using the piston-cylinder and multi-anvil apparatus to conduct solubility and metal-silicate partitioning experiments respectively. A protocol is also described for the synthesis of uncontaminated run-products from HSE solubility experiments in which the oxygen fugacity is similar to that during terrestrial core-formation. Time-resolved LA-ICP-MS spectra are presented as evidence for the absence of metal-inclusions in run-products from earlier studies, and also confirm that the technique may be extended to investigate Ru. Examples are also given of how these data may be applied. PMID:26132380

  5. Ability of laboratory methods to predict in-use efficacy of antimicrobial preservatives in an experimental cosmetic.

    PubMed Central

    Farrington, J K; Martz, E L; Wells, S J; Ennis, C C; Holder, J; Levchuk, J W; Avis, K E; Hoffman, P S; Hitchins, A D; Madden, J M

    1994-01-01

    The abilities of nine antimicrobial systems to preserve an experimental water-based cosmetic formulation were evaluated by six microbiological challenge tests: the U.S. Pharmacopeia test; the British Pharmacopeia test; the Cosmetic, Toiletry, and Fragrance Association test; the rapid screen test; the sequential challenge test; and the post-use test. The antimicrobial systems contained various combinations and amounts of two parabens and a quaternary compound in order to provide a broad range of preservation. The results obtained were compared with the abilities of the formulations to support maintenance and growth of microorganisms in microfloras obtained from human axilla areas and finger skin during an 8-week simulated in-use test. Without statistical analysis all of the tests predicted the results obtained with well-preserved or poorly preserved formulations. The rapid screen test was the best test for predicting differences at intermediate levels of preservation. Statistically, all of the tests were equivalent predictors of preservation efficacy in the in-use test (P = 0.05). At the P = 0.10 level, only the U.S. Pharmacopeia, British Pharmacopeia, rapid screen, Cosmetic, Toiletry, and Fragrance Association tests were significantly predictive. The results of prediction by a test, based on the preservative levels used, agreed well with the in-use test results (P = 0.01). A total of 20% of the formulations that contained excessive microbial levels contained human axilla microorganisms. The levels of preservation in failed products were similar to the levels of preservation in unused controls. PMID:7811091

  6. Investigating internal architecture effect in plastic deformation and failure for TPMS-based scaffolds using simulation methods and experimental procedure.

    PubMed

    Kadkhodapour, J; Montazerian, H; Raeisi, S

    2014-10-01

    Rapid prototyping (RP) has been a promising technique for producing tissue engineering scaffolds which mimic the behavior of host tissue as properly as possible. Biodegradability, agreeable feasibility of cell growth, and migration parallel to mechanical properties, such as strength and energy absorption, have to be considered in design procedure. In order to study the effect of internal architecture on the plastic deformation and failure pattern, the architecture of triply periodic minimal surfaces which have been observed in nature were used. P and D surfaces at 30% and 60% of volume fractions were modeled with 3∗3∗ 3 unit cells and imported to Objet EDEN 260 3-D printer. Models were printed by VeroBlue FullCure 840 photopolymer resin. Mechanical compression test was performed to investigate the compressive behavior of scaffolds. Deformation procedure and stress-strain curves were simulated by FEA and exhibited good agreement with the experimental observation. Current approaches for predicting dominant deformation mode under compression containing Maxwell's criteria and scaling laws were also investigated to achieve an understanding of the relationships between deformation pattern and mechanical properties of porous structures. It was observed that effect of stress concentration in TPMS-based scaffolds resultant by heterogeneous mass distribution, particularly at lower volume fractions, led to a different behavior from that of typical cellular materials. As a result, although more parameters are considered for determining dominant deformation in scaling laws, two mentioned approaches could not exclusively be used to compare the mechanical response of cellular materials at the same volume fraction. PMID:25175253

  7. Experimental methods for extracting seawater thorium isotopes from sediments as a proxy for dissolved dust inputs to the ocean.

    NASA Astrophysics Data System (ADS)

    Noble, T. L.; Robinson, L. F.; McManus, J. F.

    2006-12-01

    Dust fertilisation of the ocean could have a significant impact on atmospheric CO2, primarily by stimulating productivity. But this mechanism is hard to test due to the challenges associated with reconstructing the dissolved fraction of dust to the ocean in the past. We have developed a method that uses thorium adsorbed from seawater onto the surface of settling marine particles to record these dissolved detrital inputs and applied it to a suite of core top sediments samples from a diverse range of oceanographic and sedimentary settings. All U and Th isotopes were analyzed by ICP mass spectrometry. Dissolved 232Th in seawater is derived exclusively from continental material. By contrast 230Th is produced in situ from the radiogenic decay of 234U in the water column so it can be used to account for sedimentary processes that would otherwise bias the 232Th record. We tested eight methods for isolating scavenged (seawater) thorium. These methods included acid leaches and complexing agents. Progressively stronger acid leaches gave higher 232Th yields, but with no significant change in the 232Th/230Th ratio for nine out of ten sites. In addition there is no relationship between the percent dissolution of the sediment and the amount of 232Th recovery. A red clay sample from the deep Atlantic presented the greatest difficulty in isolating the adsorbed from lattice-bound Th signal. There was only one case where the ratio was significantly higher when treated with the strongest acid, presumably indicative of some detrital dissolution during the procedure. Our results demonstrate that six methods are successful at isolating scavenged from lattice bound Th. The ten core top sediments, from the Pacific, Indian, Atlantic, and Southern Oceans have 232Th/230Th ratios that range from 2000 to 16000, and are close to the values predicted by modern water column measurements and present day dust loading. For example, a north south transect across the Southern Ocean shows a progressive

  8. A benchmark study of molecular structure by experimental and theoretical methods: Equilibrium structure of thymine from microwave rotational constants and coupled-cluster computations

    NASA Astrophysics Data System (ADS)

    Vogt, Natalja; Demaison, Jean; Ksenafontov, Denis N.; Rudolph, Heinz Dieter

    2014-11-01

    Accurate equilibrium, re, structures of thymine have been determined using two different, and to some extent complementary techniques. The composite ab initio Born-Oppenheimer, re(best ab initio), structural parameters are obtained from the all-electron CCSD(T) and MP2 geometry optimizations using Gaussian basis sets up to quadruple-zeta quality. The semi-experimental mixed estimation method, where internal coordinates are fitted concurrently to equilibrium rotational constants and geometry parameters obtained from a high level of electronic structure theory. The equilibrium rotational constants are derived from experimental effective ground-state rotational constants and rovibrational corrections based on a quantum-chemical cubic force field. Equilibrium molecular structures accurate to 0.002 Å and 0.2° have been determined. This work is one of a few accurate equilibrium structure determinations for large molecules. The poor behavior of Kraitchman's equations is discussed.

  9. In Vivo Distribution of Helicobacter felis in the Gastric Mucus of the Mouse: Experimental Method and Results

    PubMed Central

    Schreiber, Sören; Stüben, Manuela; Josenhans, Christine; Scheid, Peter; Suerbaum, Sebastian

    1999-01-01

    We describe a method that permits the collection of very small samples (2 nl) from precisely defined positions within the gastric mucus of anesthetized mice. This method was used to study the in vivo local distribution of bacteria within the mucus of Helicobacter felis-infected mice. A total of 200 samples from 40 mice were analyzed. Each sample was microscopically analyzed, within less than 1 min, as a native preparation. To avoid changes in bacterial location within the mucus after collection and to improve the counting accuracy, bacterial motility was blocked by adjusting the pH inside the collecting pipette to 4.5. The mucus in a collected sample was subdivided into three layers, an epithelial layer (the first 25 μm of mucus from the tissue-mucus interface), a luminal layer (the last 25 μm to the mucus-lumen interface), and the remaining central mucus layer. The volume of the analyzed segments in the sample was between 4 and 9 pl. The concentration of bacteria inside the epithelial mucus layer was 3,400 per nl, but it was only 50 per nl inside the central mucus layer. The mean distance of H. felis to the epithelial surface was 16 μm. A total of 75% of all H. felis bacteria resided in the mucus zone between 5 and 20 μm from the tissue surface, with no bacteria closer than 5 μm to the epithelial surface. This method permits the study of factors determining the density of colonization and distribution of bacteria along chemical gradients with a high precision. PMID:10496889

  10. Noninvasive quantification of left ventricular mass by cardiac magnetic resonance imaging: Development of the method and experimental validation

    SciTech Connect

    Maddahi, J.; Crues, J.; Berman, D.S.; Mericle, J.; Garcia, E.V.; Becerra, A.M.; Henderson, R.; Bradley, W.

    1985-05-01

    Determination of left ventricular myocardial (LV) mass may aid evaluation of hypertrophic cardiomyopathies as well as percent viable myocardium in ischemic heart disease. The validity of cardiac NMR for determination of LV mass was evaluated in 9 dogs using a superconducting magnet operating at 0.35 Tesla. In-vivo gated spin echo pulsing sequences were used obtaining 0.7 cm thick slices of the heart, spaced by 1 cm, in three orthogonal planes. After sacrifice, the nonbeating hearts were imaged in-situ without gating. On each NMR slice, the LV surface area was planimetered and multiplied by slice spacing (1) and myocardial specific gravity (1.05) to obtain slice mass. For total LV mass, slice masses were added on coronal (Method (Meth) 1), transaxial (Meth 2), and sagittal (Meth 3) planes. Mass of the LV portions subject to partial volume effect were derived from an orthogonal plane. Excised LV weight ranged from 27 to 134 grams. The intra- and inter-observer agreement for planimetry of the NMR slices was high (r=.99 and r=.97, respectively). For in-situ imaging, r values of all methods were high (r=.99, .99, and .98); however, the slope and intercept of the regression line were closes to the line of identity with Meth 1 (y=0.94x+0.52). For in-vivo beating heart images, Meth 1 also had the best results (r=.99, y= 0.99x+8.3). Failure to correct for partial volume effect resulted in underestimation of in-situ and in-vivo LV masses as indicated by slope of <1 (r=,.98, y=0.77x+3.9; r=.98, y= 0.88x+0.98, respectively, Meth 1). Thus, cardiac NMR is a reproducible and accurate method for noninvasive determination of LV myocardial mass.

  11. Computational simulation of temperature elevations in tumors using Monte Carlo method and comparison to experimental measurements in laser photothermal therapy.

    PubMed

    Manuchehrabadi, Navid; Chen, Yonghui; Lebrun, Alexander; Ma, Ronghui; Zhu, Liang

    2013-12-01

    Accurate simulation of temperature distribution in tumors induced by gold nanorods during laser photothermal therapy relies on precise measurements of thermal, optical, and physiological properties of the tumor with or without nanorods present. In this study, a computational Monte Carlo simulation algorithm is developed to simulate photon propagation in a spherical tumor to calculate laser energy absorption in the tumor and examine the effects of the absorption (μ(a)) and scattering (μ(s)) coefficients of tumors on the generated heating pattern in the tumor. The laser-generated energy deposition distribution is then incorporated into a 3D finite-element model of prostatic tumors embedded in a mouse body to simulate temperature elevations during laser photothermal therapy using gold nanorods. The simulated temperature elevations are compared with measured temperatures in PC3 prostatic tumors in our previous in vivo experimental studies to extract the optical properties of PC3 tumors containing different concentrations of gold nanorods. It has been shown that the total laser energy deposited in the tumor is dominated by μ(a), while both μ(a) and μ(s) shift the distribution of the energy deposition in the tumor. Three sets of μ(a) and μ(s) are extracted, representing the corresponding optical properties of PC3 tumors containing different concentrations of nanorods to laser irradiance at 808 nm wavelength. With the injection of 0.1 cc of a 250 optical density (OD) nanorod solution, the total laser energy absorption rate is increased by 30% from the case of injecting 0.1 cc of a 50 OD nanorod solution, and by 125% from the control case without nanorod injection. Based on the simulated temperature elevations in the tumor, it is likely that after heating for 15 min, permanent thermal damage occurs in the tumor injected with the 250 OD nanorod solution, while thermal damage to the control tumor and the one injected with the 50 OD nanorod solution may be

  12. Experimental and Numerical Study on the Cracked Chevron Notched Semi-Circular Bend Method for Characterizing the Mode I Fracture Toughness of Rocks

    NASA Astrophysics Data System (ADS)

    Wei, Ming-Dong; Dai, Feng; Xu, Nu-Wen; Liu, Jian-Feng; Xu, Yuan

    2016-05-01

    The cracked chevron notched semi-circular bending (CCNSCB) method for measuring the mode I fracture toughness of rocks combines the merits (e.g., avoidance of tedious pre-cracking of notch tips, ease of sample preparation and loading accommodation) of both methods suggested by the International Society for Rock Mechanics, which are the cracked chevron notched Brazilian disc (CCNBD) method and the notched semi-circular bend (NSCB) method. However, the limited availability of the critical dimensionless stress intensity factor (SIF) values severely hinders the widespread usage of the CCNSCB method. In this study, the critical SIFs are determined for a wide range of CCNSCB specimen geometries via three-dimensional finite element analysis. A relatively large support span in the three point bending configuration was considered because the fracture of the CCNSCB specimen in that situation is finely restricted in the notch ligament, which has been commonly assumed for mode I fracture toughness measurements using chevron notched rock specimens. Both CCNSCB and NSCB tests were conducted to measure the fracture toughness of two different rock types; for each rock type, the two methods produce similar toughness values. Given the reported experimental results, the CCNSCB method can be reliable for characterizing the mode I fracture toughness of rocks.

  13. Absolute optical oscillator strengths for the electronic excitation of atoms at high resolution: Experimental methods and measurements for helium

    SciTech Connect

    Chan, W.F.; Cooper, G.; Brion, C.E. )

    1991-07-01

    An alternative method is described for the measurement of absolute optical oscillator strengths (cross sections) for electronic excitation of free atoms and molecules throughout the discrete region of the valence-shell spectrum at high energy resolution (full width at half maximum of 0.048 eV). The technique, utilizing the virtual-photon field of a fast electron inelastically scattered at negligible momentum transfer, avoids many of the difficulties associated with the various direct optical techniques that have traditionally been used for absolute optical oscillator strength measurements. The method is also free of the bandwidth (line saturation) effects that can seriously limit the accuracy of photoabsorption cross-section measurements for discrete transitions of narrow linewidth obtained using the Beer-Lambert law ({ital I}{sub 0}/{ital I}=exp({ital nl}{sigma}{sub {ital p}})). Since the line-saturation effects are not widely appreciated and are only usually considered in the context of peak heights, a detailed analysis of this problem is presented, with consideration of the integrated cross section (oscillator strength) over the profile of each discrete peak.

  14. Comparison of a simulated behavior of atomic oxygen using the NC-DSMC method and experimental irradiation results

    NASA Astrophysics Data System (ADS)

    Kimoto, Yugo

    2016-07-01

    Atomic oxygen (AO) is one of the main contributing factors in the deterioration of space materials in low earth orbit. Material degradation because of AO has been evaluated by JAXA using a laser detonation type AO irradiation facility on the ground. Meanwhile, the AO effect on spacecraft was studied not only in terms of the material surface in the ram direction but also on the side or rear of the material, reflecting the complexity of spacecraft shapes and the non-uniform configuration of spacecraft operation. Here a numerical simulation technique, the null-collision direct simulation Monte-Carlo (NC-DSMC) method, was used to understand the AO behavior on orbit. The DSMC method is a rarefied gas flow simulation technique used to chase the motion and collision of individual molecules using a random number stochastically. According to the virtual-collision concept, the molecular speed after the collision of molecules remains unchanged; namely, the NC concept is applied, which means that intermolecular collisions can be simulated precisely and effectively. Accordingly, we confirmed the reflection model by conducting experiments involving an irradiation test in the Combined Space Effects Test Facility. AO was produced by laser detonation, and AO monitor material and reflector were positioned in vacuum, where irradiation tests were performed. The details of the comparison results based on these experiments will be presented and discussed in the final paper.

  15. Tools and methods for experimental in-vivo measurement and biomechanical characterization of an Octopus vulgaris arm.

    PubMed

    Margheri, Laura; Mazzolai, Barbara; Cianchetti, Matteo; Dario, Paolo; Laschi, Cecilia

    2009-01-01

    This work illustrates new tools and methods for an in vivo and direct, but non-invasive, measurement of an octopus arm mechanical properties. The active elongation (longitudinal stretch) and the pulling force capability are measured on a specimen of Octopus vulgaris in order to quantitatively characterize the parameters describing the arm mechanics, for biomimetic design purposes. The novel approach consists of observing and measuring a living octopus with minimally invasive methods, which allow the animal to move with its complete ability. All tools are conceived in order to create a collaborative interaction with the animal for the acquisition of active measures. The data analysis is executed taking into account the presence of an intrinsic error due to the mobility of the subject and the aquatic environment. Using a system of two synchronized high-speed high-resolution cameras and purpose-made instruments, the maximum elongation of an arm and its rest length (when all muscles fibres are relaxed during propulsion movement) are measured and compared to define the longitudinal stretch, with the impressive average result of 194%. With a similar setup integrated with a force sensor, the pulling force capability is measured as a function of grasp point position along the arm. The measured parameters are used as real specifications for the design of an octopus-like arm with a biomimetic approach. PMID:19965276

  16. A Computational Method for Optimizing Experimental Environments for Phellinus igniarius via Genetic Algorithm and BP Neural Network

    PubMed Central

    Li, Zhongwei; Sun, Beibei; Xin, Yuezhen; Wang, Xun

    2016-01-01

    Flavones, the secondary metabolites of Phellinus igniarius fungus, have the properties of antioxidation and anticancer. Because of the great medicinal value, there are large demands on flavones for medical use and research. Flavones abstracted from natural Phellinus can not meet the medical and research need, since Phellinus in the natural environment is very rare and is hard to be cultivated artificially. The production of flavones is mainly related to the fermentation culture of Phellinus, which made the optimization of culture conditions an important problem. Some researches were made to optimize the fermentation culture conditions, such as the method of response surface methodology, which claimed the optimal flavones production was 1532.83 μg/mL. In order to further optimize the fermentation culture conditions for flavones, in this work a hybrid intelligent algorithm with genetic algorithm and BP neural network is proposed. Our method has the intelligent learning ability and can overcome the limitation of large-scale biotic experiments. Through simulations, the optimal culture conditions are obtained and the flavones production is increased to 2200 μg/mL.

  17. A Computational Method for Optimizing Experimental Environments for Phellinus igniarius via Genetic Algorithm and BP Neural Network.

    PubMed

    Li, Zhongwei; Sun, Beibei; Xin, Yuezhen; Wang, Xun; Zhu, Hu

    2016-01-01

    Flavones, the secondary metabolites of Phellinus igniarius fungus, have the properties of antioxidation and anticancer. Because of the great medicinal value, there are large demands on flavones for medical use and research. Flavones abstracted from natural Phellinus can not meet the medical and research need, since Phellinus in the natural environment is very rare and is hard to be cultivated artificially. The production of flavones is mainly related to the fermentation culture of Phellinus, which made the optimization of culture conditions an important problem. Some researches were made to optimize the fermentation culture conditions, such as the method of response surface methodology, which claimed the optimal flavones production was 1532.83 μg/mL. In order to further optimize the fermentation culture conditions for flavones, in this work a hybrid intelligent algorithm with genetic algorithm and BP neural network is proposed. Our method has the intelligent learning ability and can overcome the limitation of large-scale biotic experiments. Through simulations, the optimal culture conditions are obtained and the flavones production is increased to 2200 μg/mL. PMID:27595102

  18. A Computational Method for Optimizing Experimental Environments for Phellinus igniarius via Genetic Algorithm and BP Neural Network

    PubMed Central

    Li, Zhongwei; Sun, Beibei; Xin, Yuezhen; Wang, Xun

    2016-01-01

    Flavones, the secondary metabolites of Phellinus igniarius fungus, have the properties of antioxidation and anticancer. Because of the great medicinal value, there are large demands on flavones for medical use and research. Flavones abstracted from natural Phellinus can not meet the medical and research need, since Phellinus in the natural environment is very rare and is hard to be cultivated artificially. The production of flavones is mainly related to the fermentation culture of Phellinus, which made the optimization of culture conditions an important problem. Some researches were made to optimize the fermentation culture conditions, such as the method of response surface methodology, which claimed the optimal flavones production was 1532.83 μg/mL. In order to further optimize the fermentation culture conditions for flavones, in this work a hybrid intelligent algorithm with genetic algorithm and BP neural network is proposed. Our method has the intelligent learning ability and can overcome the limitation of large-scale biotic experiments. Through simulations, the optimal culture conditions are obtained and the flavones production is increased to 2200 μg/mL. PMID:27595102

  19. Experimental and Finite-Element Method Study of Zn-22Al Alloy Pipe Hot Extrusion Using a Porthole Die

    NASA Astrophysics Data System (ADS)

    Zhang, X. P.; Dong, X. H.; Feng, S. F.; Hong, X. T.; Tang, W.; Xiang, Z. B.; Wang, J. T.

    2013-11-01

    To reduce the pollution caused by lead alloys, environmentally friendly alloys are selected to fabricate metal tubes for delay detonators. Zn-22Al alloy was selected in this study as the tube metal because of its high environmental friendliness and low cost. The first step in metal tube production is to prepare a pipe. In this study, the Zn-22Al alloy was hot extruded using a porthole die. A finite-element method (FEM) was used to optimize the porthole-die extrusion of the Zn-22Al alloy pipes. The flow stress data for the alloy in the temperature range of 200-350 °C and strain rate range of 0.1-10 s-1 were measured. The FEM results showed that two stages existed for any random position of the interface during porthole die extrusion, viz., the bonded interface-forming period, and the post-bonded period. The dead-metal zones existed at the corners between the container and die face and between the bottom and sidewall of the welding chamber. The effects of the extrusion temperature and the chamber height of the die on the welding quality index were studied. Pipes with an outer diameter of 18 mm and an inner diameter of 10 mm were fabricated successfully by the hot-extrusion method at 200 °C using a porthole die with a chamber height of 15 mm.

  20. An experimental method to determine the resistance of a vertically aligned carbon nanotube forest in contact with a conductive layer

    NASA Astrophysics Data System (ADS)

    Vo, T. T.; Poulain, C.; Dijon, J.; Fournier, A.; Chevalier, N.; Mariolle, D.

    2012-08-01

    High density vertically aligned carbon nanotube (VACNT) forests are considered as a promising conductive material for many applications (interconnects in microelectronics or contact material layer in sliding contact applications). It is thus crucial to characterize the electrical resistance of these forests, especially in contact with the inherent top/bottom conductive substrates. This paper aims to develop an original method to determine the contribution of the different terms in this electrical resistance, which is measured with a tipless atomic force microscope used in high accuracy "force mode." VACNT stacks with different heights on AlCu substrate with or without Au/Pd top coating are studied. The electrical contact area between the probe tip and the forest is considered to be equivalent to the classical electrical contact area between a tip and a rough surface. With this assumption, the scattering resistance of a mono-wall CNT is 14.6 kΩ μm-1, the top/bottom contact resistance is, respectively, 265 kΩ/385 kΩ. The bottom resistance divided in half is obtained by an interface substrate/CNT catalyst treatment. The same assumption leads to an effective compressive modulus of 175 MPa. These results are consistent with the values published by other authors. The proposed method is effective to optimise the CNT interface contact resistance before integration in a more complex functional structure.

  1. Method of hyperthermia and tumor size influence effectiveness of doxorubicin release from thermosensitive liposomes in experimental tumors.

    PubMed

    Willerding, Linus; Limmer, Simone; Hossann, Martin; Zengerle, Anja; Wachholz, Kirsten; Ten Hagen, Timo L M; Koning, Gerben A; Sroka, Ronald; Lindner, Lars H; Peller, Michael

    2016-01-28

    Systemic chemotherapy of solid tumors could be enhanced by local hyperthermia (HT) in combination with thermosensitive liposomes (TSL) as drug carriers. In such an approach, effective HT of the tumor is considered essential for successful triggering local drug release and targeting of the drug to the tumor. To investigate the effect of HT method on the effectiveness of drug delivery, a novel laser-based HT device designed for the use in magnetic resonance imaging (MRI) was compared systematically with the frequently used cold light lamp and water bath HT. Long circulating phosphatidyldiglycerol-based TSL (DPPG2-TSL) with encapsulated doxorubicin (DOX) were used as drug carrier enabling intravascular drug release. Experiments were performed in male Brown Norway rats with a syngeneic soft tissue sarcoma (BN 175) located on both hind legs. One tumor was heated while the second tumor remained unheated as a reference. Six animals were investigated per HT method. DPPG2-TSL were injected i.v. at a stable tumor temperature above 40°C. Thereafter, temperature was maintained for 60min. Total DOX concentration in plasma, tumor tissue and muscle was determined post therapy by HPLC. Finally, the new laser-based device was tested in a MRI environment at 3T using DPPG2-TSL with encapsulated Gd-based contrast agent. All methods showed effective DOX delivery by TSL with 4.5-23.1ng/mg found in the heated tumors. In contrast, DOX concentration in the non-heated tumors was 0.5±0.1ng/mg. Independent of used HT methods, higher DOX levels were found in the smaller tumors. In comparison water bath induced lowest DOX delivery but still showing fourfold higher DOX concentrations compared to the non-heated tumors. With the laser-based applicator, a 13 fold higher DOX deposition was possible for large tumors and a 15 fold higher for the small tumors, respectively. Temperature gradients in the tumor tissue were higher with the laser and cold light lamp (-0.3°C/mm to -0.5°C/mm) compared to

  2. Optimization of experimental parameters based on the Taguchi robust design for the formation of zinc oxide nanocrystals by solvothermal method

    SciTech Connect

    Yiamsawas, Doungporn; Boonpavanitchakul, Kanittha; Kangwansupamonkon, Wiyong

    2011-05-15

    Research highlights: {yields} Taguchi robust design can be applied to study ZnO nanocrystal growth. {yields} Spherical-like and rod-like shaped of ZnO nanocrystals can be obtained from solvothermal method. {yields} [NaOH]/[Zn{sup 2+}] ratio plays the most important factor on the aspect ratio of prepared ZnO. -- Abstract: Zinc oxide (ZnO) nanoparticles and nanorods were successfully synthesized by a solvothermal process. Taguchi robust design was applied to study the factors which result in stronger ZnO nanocrystal growth. The factors which have been studied are molar concentration ratio of sodium hydroxide and zinc acetate, amount of polymer templates and molecular weight of polymer templates. Transmission electron microscopy and X-ray diffraction technique were used to analyze the experiment results. The results show that the concentration ratio of sodium hydroxide and zinc acetate ratio has the greatest effect on ZnO nanocrystal growth.

  3. X-ray pulse preserving single-shot optical cross-correlation method for improved experimental temporal resolution

    SciTech Connect

    Beye, M.; Krupin, O.; Hays, G.; Jong, S. de; Lee, S.; Coffee, R.; Holmes, M. R.; Fry, A. R.; White, W. E.; Bostedt, C.; Schlotter, W. F.; Reid, A. H.; Rupp, D.; Lee, W.-S.; Scherz, A. O.; Chuang, Y.-D.; Cryan, J. P.; Glownia, J. M.; Foehlisch, A.; Durr, H. A.

    2012-03-19

    We measured the relative arrival time between an optical pulse and a soft x-ray pulse from a free-electron laser. This femtosecond cross-correlation measurement was achieved by observing the change in optical reflectivity induced through the absorption of a fraction of the x-ray pulse. The main x-ray pulse energy remained available for an independent pump-probe experiment where the sample may be opaque to soft x-rays. The method was employed to correct the two-pulse delay data from a canonical pump-probe experiment and demonstrate 130 {+-} 20 fs (FWHM) temporal resolution. We further analyze possible timing jitter sources and point to future improvements.

  4. Sorbent, Sublimation, and Icing Modeling Methods: Experimental Validation and Application to an Integrated MTSA Subassembly Thermal Model

    NASA Technical Reports Server (NTRS)

    Bower, Chad; Padilla, Sebastian; Iacomini, Christie; Paul, Heather L.

    2010-01-01

    This paper details the validation of modeling methods for the three core components of a Metabolic heat regenerated Temperature Swing Adsorption (MTSA) subassembly, developed for use in a Portable Life Support System (PLSS). The first core component in the subassembly is a sorbent bed, used to capture and reject metabolically produced carbon dioxide (CO2). The sorbent bed performance can be augmented with a temperature swing driven by a liquid CO2 (LCO2) sublimation heat exchanger (SHX) for cooling the sorbent bed, and a condensing, icing heat exchanger (CIHX) for warming the sorbent bed. As part of the overall MTSA effort, scaled design validation test articles for each of these three components have been independently tested in laboratory conditions. Previously described modeling methodologies developed for implementation in Thermal Desktop and SINDA/FLUINT are reviewed and updated, their application in test article models outlined, and the results of those model correlations relayed. Assessment of the applicability of each modeling methodology to the challenge of simulating the response of the test articles and their extensibility to a full scale integrated subassembly model is given. The independent verified and validated modeling methods are applied to the development of a MTSA subassembly prototype model and predictions of the subassembly performance are given. These models and modeling methodologies capture simulation of several challenging and novel physical phenomena in the Thermal Desktop and SINDA/FLUINT software suite. Novel methodologies include CO2 adsorption front tracking and associated thermal response in the sorbent bed, heat transfer associated with sublimation of entrained solid CO2 in the SHX, and water mass transfer in the form of ice as low as 210 K in the CIHX.

  5. Mathematical formulation of Tmax-Tstop method for LM-OSL and its experimental validation on α-Al2O3:C

    NASA Astrophysics Data System (ADS)

    Soni, Anuj; Mishra, D. R.

    2016-05-01

    A mathematical formulation and its experimental validation on α-Al2O3:C for evaluating the number of OSL components has been described. The method consists of various partial bleaching steps of LM-OSL curve and as a result, the peak position (Tmax) of the resultant curve shifts if the system contains multiple components. However, for single component system the peak position of the resultant curve doesn't change on partial bleaching for a phosphor obeying first order kinetics. The method has been theoretically formulated for single and multiple component system with different order of kinetics and validated experimentally on the commercial α-Al2O3:C OSL phosphor. The slope of the curve between shift in Tmax and bleaching time gives the number of the OSL components and measure of their closeness in terms of photoionization cross-section. Based on this result, the photoionization cross-section of the two embedded peaks in the LM-OSL curve of α-Al2O3:C were found to be 1.51 × 10-18 cm2 and 5.02 × 10-19 cm2 using CW-OSL and NL-OSL method.

  6. Theoretical and experimental study on multi-parameter measurement by ultrasonic method in particle two-phase system

    NASA Astrophysics Data System (ADS)

    Wu, Jian; Su, Mingxu; Cai, Xiaoshu

    2012-03-01

    Measurement technology of muti-parameters in particle two-phase system, which has been paid more attention in recent years, is a great challenge for researchers. However, the parameters of particle two-phase system are showing great importance for further study. Not only the density and concentration but also the particle size distributions of disperse phase in particle two-phase system have been studied in this paper. A novel approach of measuring the density and concentration of particle two-phase system has been developed in this paper, in which the multiple reflection technique is employed to obtain acoustic impedance of the particle two-phase system. Furthermore, the density can be determined by the acoustic impedance combined with the information of sound speed for ultrasonic waves, based on the acoustic theory. As a result, the concentration of particle two-phase system could be achieved by means of a strict derivation from the known densities of the discrete and continuous phase. Experiments have been designed to demonstrate the means with the sample of carborundom (SiC) suspension at the mass concentrations of 14%, 17%, 20%, 25% respectively, in which a group of superb ultrasonic signals (see figure 6, including more than 12 echoes in each one), have been obtained with a high frequency and wide-band ultrasonic transducer (V324-SU, Olympus) at a center frequency of 25MHz. Meanwhile, another wide-band ultrasonic transducer (V312-SU, Olympus) with a lower center frequency (5MHz) is utilized to generate and receive ultrasonic signal, then attenuation spectrum are obtained with the method of pulse echo mode measurement. To extract credible particle size distribution from measured ultrasonic attenuation spectrum, McClement's theoretical model, which is actually a simplified and explicit model for the long wave regime, has been adopted together with BLBL (Bouguer-Lambert-Beer-Law) scattering model. The optimum regularization algorithm is put to use in order to

  7. Evaluating statistical and clinical significance of intervention effects in single-case experimental designs: an SPSS method to analyze univariate data.

    PubMed

    Maric, Marija; de Haan, Else; Hogendoorn, Sanne M; Wolters, Lidewij H; Huizenga, Hilde M

    2015-03-01

    Single-case experimental designs are useful methods in clinical research practice to investigate individual client progress. Their proliferation might have been hampered by methodological challenges such as the difficulty applying existing statistical procedures. In this article, we describe a data-analytic method to analyze univariate (i.e., one symptom) single-case data using the common package SPSS. This method can help the clinical researcher to investigate whether an intervention works as compared with a baseline period or another intervention type, and to determine whether symptom improvement is clinically significant. First, we describe the statistical method in a conceptual way and show how it can be implemented in SPSS. Simulation studies were performed to determine the number of observation points required per intervention phase. Second, to illustrate this method and its implications, we present a case study of an adolescent with anxiety disorders treated with cognitive-behavioral therapy techniques in an outpatient psychotherapy clinic, whose symptoms were regularly assessed before each session. We provide a description of the data analyses and results of this case study. Finally, we discuss the advantages and shortcomings of the proposed method.

  8. Experimental and theoretical analysis of the rate of solvent equilibration in the hanging drop method of protein crystal growth

    NASA Technical Reports Server (NTRS)

    Fowlis, William W.; Delucas, Lawrence J.; Twigg, Pamela J.; Howard, Sandra B.; Meehan, Edward J.

    1988-01-01

    The principles of the hanging-drop method of crystal growth are discussed, and the rate of water evaporation in a water droplet (containing protein, buffer, and a precipitating agent) suspended above a well containing a double concentration of precipitating agent is investigated theoretically. It is shown that, on earth, the rate of evaporation may be determined from diffusion theory and the colligative properties of solutions. The parameters affecting the rate of evaporation include the temperature, the vapor pressure of water, the ionization constant of the salt, the volume of the drop, the contact angle between the droplet and the coverslip, the number of moles of salt in the droplet, the number of moles of water and salt in the well, the molar volumes of water and salt, the distance from the droplet to the well, and the coefficient of diffusion of water vapor through air. To test the theoretical equations, hanging-drop experiments were conducted using various reagent concentrations in 25-microliter droplets and measuring the evaporation times at 4 C and 25 C. The results showed good agreement with the theory.

  9. Gravity drainage of activated sludge: new experimental method and considerations of settling velocity, specific cake resistance and cake compressibility.

    PubMed

    Dominiak, Dominik; Christensen, Morten; Keiding, Kristian; Nielsen, Per Halkjær

    2011-02-01

    A laboratory scale setup was used for characterization of gravitational drainage of waste activated sludge. The aim of the study was to assess how time of drainage and cake dry matter depended on volumetric load, SS content and sludge floc properties. It was demonstrated that activated sludge forms compressible cakes, even at the low pressures found in gravitational drainage. The values of specific cake resistance were two to three orders of magnitude lower than those obtained in pressure filtration. Despite the compressible nature of sludge, key macroscopic parameters such as time of drainage and cake solid content showed simple functional dependency of the volumetric load and SS of a given sludge. This suggests that the proposed method may be applied for design purposes without the use of extensive numerical modeling. The possibilities for application of this new technique are, among others, the estimation of sludge drainability prior to mechanical dewatering on a belt filter, or the application of surplus sludge on reed beds, as well as adjustments of sludge loading, concentration or sludge pre-treatment in order to optimize the drainage process.

  10. Using sexually transmitted infection biomarkers to validate reporting of sexual behavior within a randomized, experimental evaluation of interviewing methods.

    PubMed

    Hewett, Paul C; Mensch, Barbara S; Ribeiro, Manoel Carlos S de A; Jones, Heidi E; Lippman, Sheri A; Montgomery, Mark R; van de Wijgert, Janneke H H M

    2008-07-15

    This paper examines the reporting of sexual and other risk behaviors within a randomized experiment using a computerized versus face-to-face interview mode. Biomarkers for sexually transmitted infection (STI) were used to validate self-reported behavior by interview mode. As part of a parent study evaluating home versus clinic screening and diagnosis for STIs, 818 women aged 18-40 years were recruited in 2004 at or near a primary care clinic in São Paulo, Brazil, and were randomized to a face-to-face interview or audio computer-assisted self-interviewing. Ninety-six percent of participants were tested for chlamydia, gonorrhea, and trichomoniasis. Reporting of STI risk behavior was consistently higher with the computerized mode of interview. Stronger associations between risk behaviors and STI were found with the computerized interview after controlling for sociodemographic factors. These results were obtained by using logistic regression approaches, as well as statistical methods that address potential residual confounding and covariate endogeneity. Furthermore, STI-positive participants were more likely than STI-negative participants to underreport risk behavior in the face-to-face interview. Results strongly suggest that computerized interviewing provides more accurate and reliable behavioral data. The analyses also confirm the benefits of using data on prevalent STIs for externally validating behavioral reporting.

  11. Using Sexually Transmitted Infection Biomarkers to Validate Reporting of Sexual Behavior within a Randomized, Experimental Evaluation of Interviewing Methods

    PubMed Central

    Mensch, Barbara S.; de A. Ribeiro, Manoel Carlos S.; Jones, Heidi E.; Lippman, Sheri A.; Montgomery, Mark R.; van de Wijgert, Janneke H. H. M.

    2008-01-01

    This paper examines the reporting of sexual and other risk behaviors within a randomized experiment using a computerized versus face-to-face interview mode. Biomarkers for sexually transmitted infection (STI) were used to validate self-reported behavior by interview mode. As part of a parent study evaluating home versus clinic screening and diagnosis for STIs, 818 women aged 18−40 years were recruited in 2004 at or near a primary care clinic in São Paulo, Brazil, and were randomized to a face-to-face interview or audio computer-assisted self-interviewing. Ninety-six percent of participants were tested for chlamydia, gonorrhea, and trichomoniasis. Reporting of STI risk behavior was consistently higher with the computerized mode of interview. Stronger associations between risk behaviors and STI were found with the computerized interview after controlling for sociodemographic factors. These results were obtained by using logistic regression approaches, as well as statistical methods that address potential residual confounding and covariate endogeneity. Furthermore, STI-positive participants were more likely than STI-negative participants to underreport risk behavior in the face-to-face interview. Results strongly suggest that computerized interviewing provides more accurate and reliable behavioral data. The analyses also confirm the benefits of using data on prevalent STIs for externally validating behavioral reporting. PMID:18525081

  12. Characterization of atomic-level structure in Fe-based amorphous and nanocrystalline alloy by experimental and modeling methods

    SciTech Connect

    Babilas, Rafał

    2015-09-15

    The atomic structure of Fe{sub 70}Nb{sub 10}B{sub 20} alloy in “as-cast” state and after annealing was investigated using high-energy X-ray diffraction (XRD), Mössbauer spectroscopy (MS) and high resolution transmission electron microscopy (HRTEM). The HRTEM observations allowed to indicate some medium-range order (MRO) regions about 2 nm in size and formation of some kinds of short-range order (SRO) structures represented by atomic clusters with diameter ca. 0.5 nm. The Reverse Monte Carlo (RMC) method basing on the results of XRD measurements was used in modeling the atomic structure of Fe-based alloy. The structural model was described by peak values of partial pair correlation functions and coordination numbers determined by Mössbauer spectroscopy investigations. The three-dimensional configuration box of atoms was obtained from the RMC simulation and the representative Fe-centered clusters were taken from the calculated structure. According to the Gonser et al. approach, the measured spectra of alloy studied were decomposed into 5 subspectra representing average Fe–Fe coordination numbers. Basing on the results of disaccommodation of magnetic permeability, which is sensitive to the short order of the random packing of atoms, it was stated that an occurrence of free volume is not detected after nanocrystallization process. - Highlights: • Atomic cluster model of amorphous structure was proposed for studied glassy alloy. • Short range order (ca. 0.5 nm) regions interpreted as clusters were identified by HREM. • Clusters correspond to coordination numbers (N = 4,6,8,9) calculated by using Gonser approach. • Medium-range order (ca. 2 nm) could be referred to few atomic clusters. • SRO regions are able to grow up as nuclei of crystalline bcc Fe and iron borides. • Crystalline particles have spherical morphology with an average diameter of 20 nm.

  13. Effectiveness of Two Methods for Preparation of Autologous Platelet-Rich Plasma: An Experimental Study in Rabbits

    PubMed Central

    Nagata, Maria J. H.; Messora, Michel R.; Furlaneto, Flávia A. C.; Fucini, Stephen E.; Bosco, Alvaro F.; Garcia, Valdir G.; Deliberador, Tatiana M.; de Melo, Luiz G. N.

    2010-01-01

    Objectives: The purpose of this study was to compare the quantity and quality of platelets in platelet-rich plasma (PRP) samples prepared using either the single- or the double-centrifugation protocol. Methods: Ten adult white New Zealand rabbits were used. Ten ml of blood were drawn from each animal via cardiac puncture. Each blood sample was divided into two equal parts for PRP preparation: 5 ml of blood were centrifuged according to a single-centrifugation protocol (Group I), and 5 ml were centrifuged according to a double-centrifugation protocol (Group II). Manual platelet counts were performed on the whole blood and PRP samples of each group. Smears were also done on all samples in order to see the morphology of the platelets. The data obtained in the manual platelet count were submitted to statistical analysis (repeated measures ANOVA, Tukey, P<.05). Results: The average whole blood platelet count was 446,389/μl. The PRP samples in Group II presented an average platelet amount significantly higher than that of Group I (1,986,875 ± 685,020/μl and 781,875 ± 217,693/μl, respectively). The PRP smears from Group II were the only one to present platelets with altered morphology (75% of the smears). A few lymphocytes with increased cytoplasm were observed in the PRP smears of both Groups I (25% of the smears) and II (62.5% of the smears). Conclusions: Within the limits of this study, it can be concluded that the double-centrifugation protocol resulted in higher platelet concentrations than did the single-centrifugation protocol. However, the double-centrifugation protocol caused alterations in platelet morphology and was more sensitive to small processing errors. PMID:20922159

  14. TU-F-BRE-06: Flattening-Filter-Free Beam Quality Correction Factor Determination Using Experimental and Monte Carlo Methods

    SciTech Connect

    Wood, M; Desai, V; Simiele, E; Taneja, S; DeWerd, L

    2014-06-15

    Purpose: To investigate beam quality correction factors for the flattening-filter-free (FFF) energies of the TrueBeam™ accelerator based on a dosimetry formalism for small and nonstandard fields. Methods: Three detectors - an Exradin W1 scintillator, Sun Nuclear EDGE diode, and LiF(Mg,Tl) TLD-100 chips - were investigated to determine their applicability as tools to measure quality correction factors for ionization chambers in the small and nonstandard fields of the TrueBeam™. Volume-averaging effects and energy dependence were observed in fields ranging from 1×1 to 40×40 cm{sup 2} for 6 MV and 10 MV beam energies using both FFF and flattened beam modes. Correction factors were determined for three ionization chambers: an Exradin A12 Farmer-type chamber, an Exradin A1SL scanning chamber, and an Exradin A26 reference-class microchamber. Beam quality corrections were also obtained using a benchmarked model of the TrueBeam™ created with the BEAMnrc user code of EGSnrc. Results: All three detectors demonstrated measureable energy dependence in the megavoltage range. The EDGE diode was deemed the most appropriate tool for beam quality correction factor measurements due to its low energy dependence and small size; however, alanine will be used in the future to reduce energy dependent effects even further. Measured k{sub Qmsr,Q} corrections of up to 4% were found for the 6MV FFF and 10 MV FFF beams, corresponding to a discrepancy of up to 3% compared to TG-51-determined dose. Up to a 10% k{sub Qclin,Qmsr} correction was measured for small fields referenced to a 10×10 cm{sup 2} field of the same energy. Much larger corrections were determined using the Monte Carlo model, and these discrepancies require further investigation. Conclusion: Progress has been made toward determining beam quality correction factors for the small and nonstandard fields of the TrueBeam™ accelerator. Further work must be done to ensure greater accuracy in patient treatments with this new

  15. Experimental and numerical investigation of DNAPL infiltration and spreading in a 2-D sandbox by means of light transmission method

    NASA Astrophysics Data System (ADS)

    Zheng, F.; Shi, X.; Wu, J.; Gao, Y. W.

    2013-12-01

    Chlorinated solvents such as trichloroethene (TCE) and tetrachloroethene (PCE) are widespread groundwater contaminants often referred to as dense non-aqueous phase liquids (DNAPLs). Accuracy description of the spreading behavior and configuration for subsurface DNAPL migration is important, especially favourable for design effective remediation strategies. In this study, a 2-D experiment was conducted to investigate the infiltration behavior and spatial distribution of PCE in saturated porous media. Accusand 20/30 mesh sand (Unimin, Le Sueur, MN) was used as the background medium with two 70/80 and 60/70 mesh lenses embedded to simulate heterogeneous conditions. Dyed PCE of 100 ml was released into the flow cell at a constant rate of 2ml/min using a Harvard Apparatus syringe pump with a 50 ml glass syringe for two times, and 5 ml/min water was continuously injected through the inlet at the left side of the sandbox, while kept the same effluent rate at right side to create hydrodynamic condition. A light transmission (LT) system was used to record the migration of PCE and determine the saturation distribution of PCE in the sandbox experiment with a thermoelectrically air-cooled charged-coupled device (CCD) camera. All images were processed using MATLAB to calculate thickness-averaged PCE saturation for each pixel. Mass balance was checked through comparing injected known mounts of PCE with that calculated from LT analysis. Results showed that LT method is effective to delineate PCE migration pathways and quantify the saturation distribution. The relative errors of total PCE volumes calculated by LT analysis at different times were within 15% of the injected PCE volumes. The simulation are conducted using the multiphase modeling software T2VOC, which calibrated by the LT analysis results of three recorded time steps to fit with the complete spatial-temporal distribution of the PCE saturation. Model verification was then performed using the other eight recorded time

  16. Molecular structure, vibrational and 13C NMR spectra of two ent-kaurenes spirolactone type diterpenoids rabdosinate and rabdosin B: A combined experimental and density functional methods

    NASA Astrophysics Data System (ADS)

    Wang, Tao; Wang, Xueliang

    2015-01-01

    The title compounds, rabdosinate and rabdosin B, were isolated from the leaves of Isodon japonica, and characterized by IR-NMR spectroscopy. The molecular geometry, vibrational frequencies and gauge including atomic orbital (GIAO-13C) chemical shift values of the title compounds have been calculated by using DFT/B3LYP method with 6-311++G(d,p) basis set. In addition, obtained results were related to the linear regression of experimental 13C NMR chemical shifts values. The integral equation formalism polarized continuum model (IEFPCM) was used in treating chloroform solvation effects on optimized structural parameters and 13C chemical shifts. Besides, molecular electrostatic potential (MEP), HOMO-LUMO analysis were performed by the B3LYP method.

  17. DETECTORS AND EXPERIMENTAL METHODS: Monte Carlo simulation of the property of a scintillation bar in the multi-neutron correlation spectrometer

    NASA Astrophysics Data System (ADS)

    Song, Yu-Shou; Ye, Yan-Lin; Ge, Yu-Cheng; Lü, Lin-Hui; Faisal, Q.; Jiang, Dong-Xing; Hua, Hui; Zheng, Tao; Li, Zhi-Huan; Li, Xiang-Qing; Lou, Jian-Ling; Lu, Fei; Fan, Feng-Ying; Cao, Zhong-Xin; Li, Qi-Te; Xiao, Jun

    2009-10-01

    To perform a kinematically complete measurement of the dissociation reaction for neutron-rich nuclei, a multi-neutron correlation spectrometer is proposed at Peking University. A Monte Carlo simulation code based on GEANT4 is developed for a single scintillation bar which processes not only the energy deposition but also the light propagation in the scintillator and the light collection and conversion to signal at the end of the bar in a realistic way. The simulating method is described in detail in this paper, and the timing and position resolutions and detector efficiency are studied based on the simulation and compared with the experimental results. A new method of crosstalk rejection has been demonstrated to be important for the design of the whole spectrometer.

  18. Urban upgrading and its impact on health: a "quasi-experimental" mixed-methods study protocol for the BH-Viva Project.

    PubMed

    Friche, Amélia Augusta de Lima; Dias, Maria Angélica de Salles; Reis, Priscila Brandão Dos; Dias, Cláudia Silva; Caiaffa, Waleska Teixeira

    2015-11-01

    There is little scientific evidence that urban upgrading helps improve health or reduce inequities. This article presents the design for the BH-Viva Project, a "quasi-experimental", multiphase, mixed-methods study with quantitative and qualitative components, proposing an analytical model for monitoring the effects that interventions in the urban environment can have on residents' health in slums in Belo Horizonte, Minas Gerais State, Brazil. A preliminary analysis revealed intra-urban differences in age-specific mortality when comparing areas with and without interventions; the mortality rate from 2002 to 2012 was stable in the "formal city", increased in slums without interventions, and decreased in slums with interventions. BH-Viva represents an effort at advancing methodological issues, providing learning and theoretical backing for urban health research and research methods, allowing their application and extension to other urban contexts.

  19. Shear-deformation-potential constant of the conduction-band minima of Si: Experimental determination by the deep-level capacitance transient method

    NASA Astrophysics Data System (ADS)

    Li, Ming-Fu; Zhao, Xue-Shu; Gu, Zong-Quan; Chen, Jian-Xin; Li, Yan-Jin; Wang, Jian-Qing

    1991-06-01

    The shear-deformation-potential constant Ξu of the conduction-band minima of Si has been measured by a method which we called deep-level capacitance transient under uniaxial stress. The uniaxial-stress (F) dependence of the electron emission rate en from deep levels to the split conduction-band minima of Si has been analyzed. Theoretical curves are in good agreement with experimental data for the S0 and S+ deep levels in Si. The values of Ξu obtained by the method are 11.1+/-0.3 eV at 148.9 K and 11.3+/-0.3 eV at 223.6 K. The analysis and the Ξu values obtained are also valuable for symmetry determination of deep electron traps in Si.

  20. Molecular structure, vibrational and 13C NMR spectra of two ent-kaurenes spirolactone type diterpenoids rabdosinate and rabdosin B: a combined experimental and density functional methods.

    PubMed

    Wang, Tao; Wang, Xueliang

    2015-01-25

    The title compounds, rabdosinate and rabdosin B, were isolated from the leaves of Isodon japonica, and characterized by IR-NMR spectroscopy. The molecular geometry, vibrational frequencies and gauge including atomic orbital (GIAO-13C) chemical shift values of the title compounds have been calculated by using DFT/B3LYP method with 6-311++G(d,p) basis set. In addition, obtained results were related to the linear regression of experimental 13C NMR chemical shifts values. The integral equation formalism polarized continuum model (IEFPCM) was used in treating chloroform solvation effects on optimized structural parameters and 13C chemical shifts. Besides, molecular electrostatic potential (MEP), HOMO-LUMO analysis were performed by the B3LYP method. PMID:25123947

  1. Urban upgrading and its impact on health: a "quasi-experimental" mixed-methods study protocol for the BH-Viva Project.

    PubMed

    Friche, Amélia Augusta de Lima; Dias, Maria Angélica de Salles; Reis, Priscila Brandão Dos; Dias, Cláudia Silva; Caiaffa, Waleska Teixeira

    2015-11-01

    There is little scientific evidence that urban upgrading helps improve health or reduce inequities. This article presents the design for the BH-Viva Project, a "quasi-experimental", multiphase, mixed-methods study with quantitative and qualitative components, proposing an analytical model for monitoring the effects that interventions in the urban environment can have on residents' health in slums in Belo Horizonte, Minas Gerais State, Brazil. A preliminary analysis revealed intra-urban differences in age-specific mortality when comparing areas with and without interventions; the mortality rate from 2002 to 2012 was stable in the "formal city", increased in slums without interventions, and decreased in slums with interventions. BH-Viva represents an effort at advancing methodological issues, providing learning and theoretical backing for urban health research and research methods, allowing their application and extension to other urban contexts. PMID:26648363

  2. Charge Transfer Inefficiency in Pinned Photodiode CMOS image sensors: Simple Montecarlo modeling and experimental measurement based on a pulsed storage-gate method

    NASA Astrophysics Data System (ADS)

    Pelamatti, Alice; Goiffon, Vincent; Chabane, Aziouz; Magnan, Pierre; Virmontois, Cédric; Saint-Pé, Olivier; de Boisanger, Michel Breart

    2016-11-01

    The charge transfer time represents the bottleneck in terms of temporal resolution in Pinned Photodiode (PPD) CMOS image sensors. This work focuses on the modeling and estimation of this key parameter. A simple numerical model of charge transfer in PPDs is presented. The model is based on a Montecarlo simulation and takes into account both charge diffusion in the PPD and the effect of potential obstacles along the charge transfer path. This work also presents a new experimental approach for the estimation of the charge transfer time, called pulsed Storage Gate (SG) method. This method, which allows reproduction of a "worst-case" transfer condition, is based on dedicated SG pixel structures and is particularly suitable to compare transfer efficiency performances for different pixel geometries.

  3. Molecular structure, vibrational and 13C NMR spectra of two ent-kaurenes spirolactone type diterpenoids rabdosinate and rabdosin B: a combined experimental and density functional methods.

    PubMed

    Wang, Tao; Wang, Xueliang

    2015-01-25

    The title compounds, rabdosinate and rabdosin B, were isolated from the leaves of Isodon japonica, and characterized by IR-NMR spectroscopy. The molecular geometry, vibrational frequencies and gauge including atomic orbital (GIAO-13C) chemical shift values of the title compounds have been calculated by using DFT/B3LYP method with 6-311++G(d,p) basis set. In addition, obtained results were related to the linear regression of experimental 13C NMR chemical shifts values. The integral equation formalism polarized continuum model (IEFPCM) was used in treating chloroform solvation effects on optimized structural parameters and 13C chemical shifts. Besides, molecular electrostatic potential (MEP), HOMO-LUMO analysis were performed by the B3LYP method.

  4. Experimental and theoretical study on diethyl-(Z)-2-(5,7-diphenyl-1,3,4-oxadiazepin-2-yl)-2-butenedioate using different levels of computational methods.

    PubMed

    Asadi, Z; Asnaashariisfahani, M B; Vessally, E; Esrafili, M D

    2015-04-01

    In this research work, diethyl-(Z)-2-(5,7-diphenyl-1,3,4-oxadiazepin-2-yl)-2-butenedioate, 7, was synthesized and characterized by FT-IR, 1H NMR, 13C NMR spectroscopy, elemental analyses and mass spectra. The reliabilities of various ab initio methods including HF and B3LYP were evaluated. The bond lengths, bond angles, dihedral angles, charge density on atoms at 7 were calculated. The ab initio calculations indicated that the B3LYP method with a 6-311++G(d,p) basis set can give accurate results. The 13C NMR and 1H NMR chemical shifts of 7 calculated and compared with the related experimental data. The HOMO, LUMO, molecular electrostatic potential (MEP) of 7 were investigated. The thermodynamic parameters and physico-chemical properties were calculated.

  5. [Recognition of the potential SF-1 binding sites by SiteGA method, their experimental verification and search for new SF-1 target genes].

    PubMed

    Klimova, N V; Levitskiĭ, V G; Ignat'eva, E V; Vasil'ev, G V; Kobzev, V F; Busygina, T V; Merkulova, T I; Kolchanov, N A

    2006-01-01

    The SF-1 (Steroidogenic Factor-1) is a transcription factor known as a key regulator of the steroidogenic gene expression. SF-1 is required for the development and functioning at all levels of the hypothalamic-pituitary-gonadal and adrenal axis. Also it plays an essential role in sex determination. SF-1 is a member of the nuclear receptor superfamily and it activates gene expression by binding to DNA in a monomeric form. Here, we report the results of potential SF-1 binding sites identification by using the SiteGA recognition method. The SiteGA method was implemented using a genetic algorithm (GA) involving a iterative discriminant analyses of local dinucleotide context characteristics. These characteristics were compiled not only over the core binding sites region but over its flanks as well. Developed SiteGA method is characterized by considerably better recognition accuracy when compared to that for the weight matrix method. The experimental tests demonstrated that 83% of the sites recognized by the SiteGA method in the regulatory regions of steroidogenic genes, indeed, interact with the SF-1 factor. We also estimated the density of predicted sites in regulatory region of genes, the members of different functional groups and developed the criterion to search for new SF-1 target genes in genome sequences.

  6. Comparison of three methods of calculation, experimental and monte carlo simulation in investigation of organ doses (thyroid, sternum, cervical vertebra) in radioiodine therapy.

    PubMed

    Shahbazi-Gahrouei, Daryoush; Ayat, Saba

    2012-07-01

    Radioiodine therapy is an effective method for treating thyroid cancer carcinoma, but it has some affects on normal tissues, hence dosimetry of vital organs is important to weigh the risks and benefits of this method. The aim of this study is to measure the absorbed doses of important organs by Monte Carlo N Particle (MCNP) simulation and comparing the results of different methods of dosimetry by performing a t-paired test. To calculate the absorbed dose of thyroid, sternum, and cervical vertebra using the MCNP code, *F8 tally was used. Organs were simulated by using a neck phantom and Medical Internal Radiation Dosimetry (MIRD) method. Finally, the results of MCNP, MIRD, and Thermoluminescent dosimeter (TLD) measurements were compared by SPSS software. The absorbed dose obtained by Monte Carlo simulations for 100, 150, and 175 mCi administered (131)I was found to be 388.0, 427.9, and 444.8 cGy for thyroid, 208.7, 230.1, and 239.3 cGy for sternum and 272.1, 299.9, and 312.1 cGy for cervical vertebra. The results of paired t-test were 0.24 for comparing TLD dosimetry and MIRD calculation, 0.80 for MCNP simulation and MIRD, and 0.19 for TLD and MCNP. The results showed no significant differences among three methods of Monte Carlo simulations, MIRD calculation and direct experimental dosimetry using TLD.

  7. Variable viscosity and density biofilm simulations using an immersed boundary method, part II: Experimental validation and the heterogeneous rheology-IBM

    NASA Astrophysics Data System (ADS)

    Stotsky, Jay A.; Hammond, Jason F.; Pavlovsky, Leonid; Stewart, Elizabeth J.; Younger, John G.; Solomon, Michael J.; Bortz, David M.

    2016-07-01

    The goal of this work is to develop a numerical simulation that accurately captures the biomechanical response of bacterial biofilms and their associated extracellular matrix (ECM). In this, the second of a two-part effort, the primary focus is on formally presenting the heterogeneous rheology Immersed Boundary Method (hrIBM) and validating our model by comparison to experimental results. With this extension of the Immersed Boundary Method (IBM), we use the techniques originally developed in Part I ([19]) to treat biofilms as viscoelastic fluids possessing variable rheological properties anchored to a set of moving locations (i.e., the bacteria locations). In particular, we incorporate spatially continuous variable viscosity and density fields into our model. Although in [14,15], variable viscosity is used in an IBM context to model discrete viscosity changes across interfaces, to our knowledge this work and Part I are the first to apply the IBM to model a continuously variable viscosity field. We validate our modeling approach from Part I by comparing dynamic moduli and compliance moduli computed from our model to data from mechanical characterization experiments on Staphylococcus epidermidis biofilms. The experimental setup is described in [26] in which biofilms are grown and tested in a parallel plate rheometer. In order to initialize the positions of bacteria in the biofilm, experimentally obtained three dimensional coordinate data was used. One of the major conclusions of this effort is that treating the spring-like connections between bacteria as Maxwell or Zener elements provides good agreement with the mechanical characterization data. We also found that initializing the simulations with different coordinate data sets only led to small changes in the mechanical characterization results. Matlab code used to produce results in this paper will be available at https://github.com/MathBioCU/BiofilmSim.

  8. Application of ZnO nanorods loaded on activated carbon for ultrasonic assisted dyes removal: Experimental design and derivative spectrophotometry method.

    PubMed

    Ansari, Fatemeh; Ghaedi, Mehrorang; Taghdiri, Mehdi; Asfaram, Arash

    2016-11-01

    A method based on application of ZnO nanorods loaded on activated carbon (ZnO-NRs-AC) for adsorption of Bromocresol Green (BCG) and Eosin Y (EY) accelerated by ultrasound was described. The present material was synthesized under ultrasound assisted wet-chemical method and subsequently was characterized by FE-SEM, TEM, BET and XRD analysis. The extent of contribution of conventional variables like pH (2.0-10.0), BCG concentration (4-20mgL(-1)), EY concentration (3-23mgL(-1)), adsorbent dosage (0.01-0.03g), sonication time (1-5min) and centrifuge time (2-6min) as main and interaction part were investigated by central composite design under response surface methodology. Analysis of variance (ANOVA) was adapted to experimental data and guide the best operational conditions mass by set at 6.0, 9mgL(-1), 10mgL(-1), 0.02g, 4 and 4min for pH, BCG concentration, EY concentration, adsorbent dosage, sonication and centrifuge time, respectively. At these specified conditions dye adsorption efficiency was higher than 99.5%. The suitability and well prediction of optimum point was tested by conducting five experiments and respective results revel that RSD% was lower than 3% and high quality of fitting was confirmed by t-test. The experimental data were best fitted in Langmuir isotherm equation and the removal followed pseudo second order kinetics. The experimentally obtained maximum adsorption capacities were estimated as 57.80 and 61.73mgg(-1) of ZnO-NRs-AC for BCG and EY respectively from binary dye solutions. The mechanism of removal was explained by boundary layer diffusion via intraparticle diffusion. PMID:27245971

  9. Application of ZnO nanorods loaded on activated carbon for ultrasonic assisted dyes removal: Experimental design and derivative spectrophotometry method.

    PubMed

    Ansari, Fatemeh; Ghaedi, Mehrorang; Taghdiri, Mehdi; Asfaram, Arash

    2016-11-01

    A method based on application of ZnO nanorods loaded on activated carbon (ZnO-NRs-AC) for adsorption of Bromocresol Green (BCG) and Eosin Y (EY) accelerated by ultrasound was described. The present material was synthesized under ultrasound assisted wet-chemical method and subsequently was characterized by FE-SEM, TEM, BET and XRD analysis. The extent of contribution of conventional variables like pH (2.0-10.0), BCG concentration (4-20mgL(-1)), EY concentration (3-23mgL(-1)), adsorbent dosage (0.01-0.03g), sonication time (1-5min) and centrifuge time (2-6min) as main and interaction part were investigated by central composite design under response surface methodology. Analysis of variance (ANOVA) was adapted to experimental data and guide the best operational conditions mass by set at 6.0, 9mgL(-1), 10mgL(-1), 0.02g, 4 and 4min for pH, BCG concentration, EY concentration, adsorbent dosage, sonication and centrifuge time, respectively. At these specified conditions dye adsorption efficiency was higher than 99.5%. The suitability and well prediction of optimum point was tested by conducting five experiments and respective results revel that RSD% was lower than 3% and high quality of fitting was confirmed by t-test. The experimental data were best fitted in Langmuir isotherm equation and the removal followed pseudo second order kinetics. The experimentally obtained maximum adsorption capacities were estimated as 57.80 and 61.73mgg(-1) of ZnO-NRs-AC for BCG and EY respectively from binary dye solutions. The mechanism of removal was explained by boundary layer diffusion via intraparticle diffusion.

  10. Estimation of time-varying pollutant emission rates in a ventilated enclosure: inversion of a reduced model obtained by experimental application of the modal identification method

    NASA Astrophysics Data System (ADS)

    Girault, M.; Maillet, D.; Bonthoux, F.; Galland, B.; Martin, P.; Braconnier, R.; Fontaine, J. R.

    2008-02-01

    A method is proposed for the estimation of time-varying emission rates of pollutant sources in a ventilated enclosure, through the resolution of an inverse forced convection problem. Unsteady transport-diffusion of the pollutant is considered, with the assumption of a stationary velocity field remaining unchanged during emission (passive contaminant). The pollutant transport equation is therefore linear with respect to concentration. The source's location is also supposed to be known. As the first step, a reduced model (RM) linking concentrations at a set of control points to emission rates of sources is identified from experimental data by using the modal identification method (MIM). This parameter estimation problem uses transient contaminant concentration measurements made at control points inside the ventilated enclosure, corresponding to increasing and decreasing steps of emission rates. Such experimental modelling allows us to avoid dealing with a CFD code involving turbulence modelling and to get rid of uncertainties about sensors position. In a second step, the identified RM is used to solve an inverse forced convection problem: from contaminant concentration measured at the same control points, rates of sources emitting simultaneously are estimated with a sequential in time algorithm using future time steps.

  11. Collaborative study report: evaluation of the ATCC experimental mycoplasma reference strains panel prepared for comparison of NAT-based and conventional mycoplasma detection methods.

    PubMed

    Dabrazhynetskaya, Alena; Volokhov, Dmitriy V; Lin, Tsai-Lien; Beck, Brian; Gupta, Rajesh K; Chizhikov, Vladimir

    2013-11-01

    The main goal of this collaborative study was to evaluate the experimental panel of cryopreserved mycoplasma reference strains recently prepared by the American Type Culture Collection (ATCC(®)) in order to assess the viability and dispersion of cells in the mycoplasma stocks by measuring the ratio between the number of genomic copies (GC) and the number of colony forming units (CFU) in the reference preparations. The employment of microbial reference cultures with low GC/CFU ratios is critical for unbiased and reliable comparison of mycoplasma testing methods based on different methodological approaches, i.e., Nucleic Acid Testing (NAT) and compendial culture-based techniques. The experimental panel included ten different mycoplasma species known to represent potential human and animal pathogens as well as common contaminants of mammalian and avian cell substrates used in research, development, and manufacture of biological products. Fifteen laboratories with expertise in field of mycoplasma titration and quantification of mycoplasmal genomic DNA participated in the study conducted from February to October of 2012. The results of this study demonstrated the feasibility of preparing highly viable and dispersed (possessing low GC/CFU ratios) frozen stocks of mycoplasma reference materials, required for reliable comparison of NAT-based and conventional mycoplasma detection methods.

  12. Analytical, Numerical, and Experimental Investigation on a Non-Contact Method for the Measurements of Creep Properties of Ultra-High-Temperature Materials

    NASA Technical Reports Server (NTRS)

    Lee, Jonghyun; Hyers, Robert W.; Rogers, Jan R.; Rathz, Thomas J.; Choo, Hahn; Liaw, Peter

    2006-01-01

    Responsive access to space requires re-use of components such as rocket nozzles that operate at extremely high temperatures. For such applications, new ultra-hightemperature materials that can operate over 2,000 C are required. At the temperatures higher than the fifty percent of the melting temperature, the characterization of creep properties is indispensable. Since conventional methods for the measurement of creep is limited below 1,700 C, a new technique that can be applied at higher temperatures is strongly demanded. This research develops a non-contact method for the measurement of creep at the temperatures over 2,300 C. Using the electrostatic levitator in NASA MSFC, a spherical sample was rotated to cause creep deformation by centrifugal acceleration. The deforming sample was captured with a digital camera and analyzed to measure creep deformation. Numerical and analytical analyses have also been conducted to compare the experimental results. Analytical, numerical, and experimental results showed a good agreement with one another.

  13. Application of evolutionary algorithm methods to polypeptide folding: Comparison with experimental results for unsolvated Ac-(Ala-Gly-Gly)5-LysH+

    PubMed Central

    Damsbo, Martin; Kinnear, Brian S.; Hartings, Matthew R.; Ruhoff, Peder T.; Jarrold, Martin F.; Ratner, Mark A.

    2004-01-01

    We present an evolutionary method for finding the low-energy conformations of polypeptides. The application, called foldaway,is based on a generic framework and uses several evolutionary operators as well as local optimization to navigate the complex energy landscape of polypeptides. It maintains two complementary representations of the structures and uses the charmm force field for evaluating the energies. The method is applied to unsolvated Met-enkephalin and Ac-(Ala-Gly-Gly)5-Lys+H+. Unsolvated Ac-(Ala-Gly-Gly)5-Lys+H+ has been the object of recent experimental studies using ion mobility measurements. It has a flat energy landscape where helical and globular conformations have similar energies. foldaway locates several large groups of structures not found in previous molecular dynamics simulations for this peptide, including compact globular conformations, which are probably present in the experiments. However, the relative energies of the different conformations found by foldaway do not accurately match the relative energies expected from the experimental observations. PMID:15123828

  14. Optimization of a liquid chromatography ion mobility-mass spectrometry method for untargeted metabolomics using experimental design and multivariate data analysis.

    PubMed

    Tebani, Abdellah; Schmitz-Afonso, Isabelle; Rutledge, Douglas N; Gonzalez, Bruno J; Bekri, Soumeya; Afonso, Carlos

    2016-03-24

    High-resolution mass spectrometry coupled with pattern recognition techniques is an established tool to perform comprehensive metabolite profiling of biological datasets. This paves the way for new, powerful and innovative diagnostic approaches in the post-genomic era and molecular medicine. However, interpreting untargeted metabolomic data requires robust, reproducible and reliable analytical methods to translate results into biologically relevant and actionable knowledge. The analyses of biological samples were developed based on ultra-high performance liquid chromatography (UHPLC) coupled to ion mobility - mass spectrometry (IM-MS). A strategy for optimizing the analytical conditions for untargeted UHPLC-IM-MS methods is proposed using an experimental design approach. Optimization experiments were conducted through a screening process designed to identify the factors that have significant effects on the selected responses (total number of peaks and number of reliable peaks). For this purpose, full and fractional factorial designs were used while partial least squares regression was used for experimental design modeling and optimization of parameter values. The total number of peaks yielded the best predictive model and is used for optimization of parameters setting.

  15. Sustained prediction ability of net analyte preprocessing methods using reduced calibration sets. Theoretical and experimental study involving the spectrophotometric analysis of multicomponent mixtures.

    PubMed

    Goicoechea, H C; Olivieri, A C

    2001-07-01

    A newly developed multivariate method involving net analyte preprocessing (NAP) was tested using central composite calibration designs of progressively decreasing size regarding the multivariate simultaneous spectrophotometric determination of three active components (phenylephrine, diphenhydramine and naphazoline) and one excipient (methylparaben) in nasal solutions. Its performance was evaluated and compared with that of partial least-squares (PLS-1). Minimisation of the calibration predicted error sum of squares (PRESS) as a function of a moving spectral window helped to select appropriate working spectral ranges for both methods. The comparison of NAP and PLS results was carried out using two tests: (1) the elliptical joint confidence region for the slope and intercept of a predicted versus actual concentrations plot for a large validation set of samples and (2) the D-optimality criterion concerning the information content of the calibration data matrix. Extensive simulations and experimental validation showed that, unlike PLS, the NAP method is able to furnish highly satisfactory results when the calibration set is reduced from a full four-component central composite to a fractional central composite, as expected from the modelling requirements of net analyte based methods.

  16. Experimental measurements of out-of-plane vibrations of a simple blisk design using Blade Tip Timing and Scanning LDV measurement methods

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

    The study of dynamic properties of rotating structures, such as bladed discs, can be conveniently done using simple bladed discs where the blades do not have staggering angles. Simplified design, although not truly representative of real structures, can be easy and economic to manufacture and, still, very helpful for studying specific dynamic properties. An example of this can be called as mass mistune blisk study. Experimental measurements of vibrations of bladed discs under rotating conditions can be performed using Scanning Laser Doppler Vibrometer (SLDV) systems. However, in the aerospace industry, the vibrations of complex bladed discs must be measured under operating conditions which are more hostile than laboratory simulations. The Blade Tip Timing (BTT) measurement method is a measurement technique, which can be used to measure vibrations of bladed discs of an engine aircraft under operating conditions. However, the BTT technique is ineffective when used with a flat bladed disc whose blade vibrations cannot be measured. This can be detrimental when the use of controlled dynamic parameters, such as those obtained from a simple bladed disc design, can improve the confidence for the validation of post-processing software. This paper presents a work about experimental measurements of a simple bladed disc design whose vibrations were measured synchronously by Scanning LDV and BTT measurement systems. A rotating test rig and its mechanical modifications for the installation of the BTT probes are introduced. Implications of rotating a specimen inconsistently are presented so as solutions to obtained constant revolving speed. The experimental comparisons of forced response vibrations measured synchronously at one blade are presented and explained.

  17. Methods for the experimental characterization and analysis of the efficiency and speed of chromatographic columns: A step-by-step tutorial.

    PubMed

    Andrés, Axel; Broeckhoven, Ken; Desmet, Gert

    2015-09-24

    Due to the developing insights in the theory of chromatography, column manufacturers of any kind (industrial, academic) nowadays have a broad array of experimental column testing tools at their disposal. The present tutorial aims at helping the novice in the field getting an overview of these tools and provides a fixed procedure to carry out the subsequent steps in the column quality analysis (guided via an Excel template file). After some brief introduction about the main equations, the reader is taken step by step through the theories underlying the measurement methods for the different column and performance parameters. In the final section, the reader is taken through the different items in the Excel template.

  18. Experimental and theoretical methods to study structural phase transition mechanisms in K{sub 3}WO{sub 3}F{sub 3} oxyfluoride

    SciTech Connect

    Krylov, A.S.; Sofronova, S.N.; Kolesnikova, E.M.; Ivanov, Yu.N.; Sukhovsky, A.A.; Goryainov, S.V.; Ivanenko, A.A.; Shestakov, N.P.; Kocharova, A.G.; Vtyurin, A.N.

    2014-10-15

    The results of structural phase transitions mechanisms study in K{sub 3}WO{sub 3}F{sub 3}oxyfluoride are represented by different experimental and theoretical methods. The structural phase transition anomalies at T{sub 1}=452 K and T{sub 2}=414 K of Raman and IR spectra have been analyzed. Using vibrational spectroscopy methods, the NMR-experiment has been done to clarify the nature of found phase transitions: displacive types or order-disorder types. The model of “disordered” crystal was proposed, and the results of lattice dynamics calculation in frameworks of the generalized Gordon–Kim method of ordered (R3) and “disordered” crystals were compared. The high pressure phases were studied by the Raman technique too. - Graphical abstract: (1) Two possible configuration of octahedra. (2). All phases Raman lines of octahedra. (3) All phases IR lines of octahedra. (4) NMR spectra of all phases. - Highlights: • The results of study oxyfluoride K{sub 3}WO{sub 3}F{sub 3} are represented by Raman, IR, NMR technique. • The high pressure phases were studied by the Raman technique. • The anionic octahedra [WO{sub 3}F{sub 3}]{sup 3−} are not ordered below the both phase transitions. • The ferroelectric phase is realized due to the shift of atoms without F/O ordering. • Both of found phase transitions are close to the second order.

  19. Essential Experimental Methods for Identifying Bonghan Systems as a Basis for Korean Medicine: Focusing on Visual Materials from Original Papers and Modern Outcomes.

    PubMed

    Kim, Hoon-Gi; Lee, Byung-Cheon; Lee, Ki-Bog

    2015-01-01

    In the 1960s, through studies on Korean Medicine, Bonghan Kim proposed the Bonghan systems (BS) as the anatomical reality of the acupuncture meridians based on various experimental data. Since 2002, several groups, mainly led by a team at Seoul National University, who renamed the BS as the primo vascular system (PVS), have published around 70 papers showing biological structures corresponding to the BS. However, it is still difficult for other researchers to find them, especially under the skin, which Bonghan Kim first reported as acupuncture points, due to similar-looking biological tissues, for example, the lymphatic vessels, and such artifacts as blood clots or fascia debris. To solve these drawbacks, we examined the main methods for identifying the BS by comparing the original papers with the modern outcomes in terms of the common physical/chemical characteristics of the BS. In addition, effective methods of staining and microscopic observations discovered by modern teams are synthetically explained using visual materials such as diagrams and photos. Through the essentially organized methods in this review paper, we suggest that one can find the BS under the skin as putative acupuncture points by tracing the intraexternal BS, from which a new Korean Medicine will be born.

  20. A Method for Serial Tissue Processing and Parallel Analysis of Aberrant Crypt Morphology, Mucin Depletion, and Beta-Catenin Staining in an Experimental Model of Colon Carcinogenesis

    PubMed Central

    2010-01-01

    The use of architectural and morphological characteristics of cells for establishing prognostic indicators by which individual pathologies are assigned grade and stage is a well-accepted practice. Advances in automated micro- and macroscopic image acquisition and digital image analysis have created new opportunities in the field of prognostic assessment; but, one area in experimental pathology, animal models for colon cancer, has not taken advantage of these opportunities. This situation is primarily due to the methods available to evaluate the colon of the rodent for the presence of premalignant and malignant pathologies. We report a new method for the excision and processing of the entire colon of the rat and illustrate how this procedure permitted the quantitative assessment of aberrant crypt foci (ACF), a premalignant colon pathology, for characteristics consistent with progression to malignancy. ACF were detected by methylene blue staining and subjected to quantitative morphometric analysis. Colons were then restained with high iron diamine–alcian blue for assessment of mucin depletion using an image overlay to associate morphometric data with mucin depletion. The subsequent evaluation of ACF for beta-catenin staining is also demonstrated. The methods described are particularly relevant to the screening of compounds for cancer chemopreventive activity. PMID:21406072