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1

Fast Fourier transform admittance analysis method applied to thickness-shear-mode acoustic wave sensors  

Microsoft Academic Search

A fast Fourier transform admittance analysis (FFT-AA) method, applied to thickness-shear-mode (TSM) acoustic wave sensors, is first proposed and the corresponding theory is presented. Based on the FFT-AA, an oscillatory waveform with the feature of a damped free oscillation is obtained experimentally. It can illustrate dynamically and directly the vibratory characteristics of TSM sensors, which can be considered as an

Huwei Tan; Jinhua Chen; Ronghui Wang; Xiaoli Su; Lihua Nie; Shouzhuo Yao

1997-01-01

2

A comparison of trans-admittance and characteristic impedance as metrics for detection of winding displacements in power transformers  

Microsoft Academic Search

Transfer function signatures are commonly used in condition monitoring analysis to give early indications of winding movement in power transformers. This paper presents a comparison of the use of trans-admittance (frequency response analysis, FRA), presently the industry standard, and characteristic impedance (transmission line diagnostics, TLD), a new method, as signatures for the detection of winding displacements in power transformers. To

A. Singh; F. Castellanos; J. R. Marti; K. D. Srivastava

2009-01-01

3

Implementing transformer nodal admittance matrices into backward\\/forward sweep-based power flow analysis for unbalanced radial distribution systems  

Microsoft Academic Search

This paper proposes a new method to handle distribution transformers of various winding connections in the backward\\/forward sweep-based power flow analysis for unbalanced radial distribution systems. The method takes advantage of available nodal admittance matrices of distribution transformers, and can automatically solve the problem of conductively isolated subnetworks to obtain their equivalent phase-to-reference voltages. In addition, this paper presents a

Zhuding Wang; Fen Chen; Jingui Li

2004-01-01

4

Pulse transformer characterization  

NASA Astrophysics Data System (ADS)

The pulse transformer at TNO PML-Pulse Physics, Delft, is characterized. It constitutes the final step of an energy compression system (Kapitza facility) which can amplify the current up to 24 times, and consists of a primary single layer winding of 24 turns enclosed in a secondary winding. There is a sine wave current source with adjustable frequencies for the characterization. The measurements show that the main inductances decrease and the ohmic resistances increase with increasing frequency, due to differential currents, skin and proximity effect, and parasitic currents induced in the aluminum secondary winding. From the measurements a coupling factor of 0.94 is calculated for 200 Hz, which is slightly below the design specification of 0.98.

Mosterdijk, W. H. P.

1992-12-01

5

A new estimate of the effective elastic thickness of the Canadian shield from admittance analyses using the wavelet transform, and models of flexure and mantle convection  

NASA Astrophysics Data System (ADS)

The flexural rigidity of the Earth's cratonic regions is a topic of much controversy. While many studies have suggested that cratons possess high elastic strength, others maintain that the continental lithosphere is everywhere weak. In this study we focus on the Canadian shield, and show that perceived evidence for weak cratonic lithosphere is compromised by shortcomings of the spectral analysis technique. Here we compare estimates of the admittance between free-air gravity and topography in the spectral domain from wavelet and multitaper methods. We apply particular attention to their long wavelength values, since it is here that the signals from mantle convection, glacial isostatic adjustment (GIA) and flexure are often present together. Our results show that, when used with certain parameter values, the multitaper method has a comparatively poor resolution at long wavelengths, and hence is not always able to distinguish between the harmonics due to convection and flexural processes. This renders it unreliable for estimating the flexural rigidity. We then show that the wavelet method does have the requisite properties to make this distinction, since it is able to correctly resolve a low-admittance dip at long wavelengths in both synthetic and real data. When the observed wavelet admittance of the Canadian shield is inverted against the predictions of a combined flexural, convection and GIA model, we find that the shield possesses a core of high effective elastic thickness (Te), greater than 118 km to 95% confidence, located to the immediate south-west of Hudson Bay.

Kirby, J. F.; Swain, C. J.

2013-12-01

6

Effective Admittivity of Biological Tissues as a Coefficient of Elliptic PDE  

PubMed Central

The electrical properties of biological tissues can be described by a complex tensor comprising a simple expression of the effective admittivity. The effective admittivities of biological tissues depend on scale, applied frequency, proportions of extra- and intracellular fluids, and membrane structures. The effective admittivity spectra of biological tissue can be used as a means of characterizing tissue structural information relating to the biological cell suspensions, and therefore measuring the frequency-dependent effective conductivity is important for understanding tissue's physiological conditions and structure. Although the concept of effective admittivity has been used widely, it seems that its precise definition has been overlooked. We consider how we can determine the effective admittivity for a cube-shaped object with several different biologically relevant compositions. These precise definitions of effective admittivity may suggest the ways of measuring it from boundary current and voltage data. As in the homogenization theory, the effective admittivity can be computed from pointwise admittivity by solving Maxwell equations. We compute the effective admittivity of simple models as a function of frequency to obtain Maxwell-Wagner interface effects and Debye relaxation starting from mathematical formulations. Finally, layer potentials are used to obtain the Maxwell-Wagner-Fricke expression for a dilute suspension of ellipses and membrane-covered spheres.

Kwon, Hyeuknam; Sadleir, Rosalind

2013-01-01

7

Effective admittivity of biological tissues as a coefficient of elliptic PDE.  

PubMed

The electrical properties of biological tissues can be described by a complex tensor comprising a simple expression of the effective admittivity. The effective admittivities of biological tissues depend on scale, applied frequency, proportions of extra- and intracellular fluids, and membrane structures. The effective admittivity spectra of biological tissue can be used as a means of characterizing tissue structural information relating to the biological cell suspensions, and therefore measuring the frequency-dependent effective conductivity is important for understanding tissue's physiological conditions and structure. Although the concept of effective admittivity has been used widely, it seems that its precise definition has been overlooked. We consider how we can determine the effective admittivity for a cube-shaped object with several different biologically relevant compositions. These precise definitions of effective admittivity may suggest the ways of measuring it from boundary current and voltage data. As in the homogenization theory, the effective admittivity can be computed from pointwise admittivity by solving Maxwell equations. We compute the effective admittivity of simple models as a function of frequency to obtain Maxwell-Wagner interface effects and Debye relaxation starting from mathematical formulations. Finally, layer potentials are used to obtain the Maxwell-Wagner-Fricke expression for a dilute suspension of ellipses and membrane-covered spheres. PMID:23710251

Seo, Jin Keun; Bera, Tushar Kanti; Kwon, Hyeuknam; Sadleir, Rosalind

2013-01-01

8

Applications of Admittance Spectroscopy in Photovoltaic Devices Beyond Majority Carrier Trapping Defects: Preprint  

SciTech Connect

Admittance spectroscopy is commonly used to characterize majority-carrier trapping defects. In today's practical photovoltaic devices, however, a number of other physical mechanisms may contribute to the admittance measurement and interfere with the data interpretation. Such challenges arise due to the violation of basic assumptions of conventional admittance spectroscopy such as single-junction, ohmic contact, highly conductive absorbers, and measurement in reverse bias. We exploit such violations to devise admittance spectroscopy-based methods for studying the respective origins of 'interference': majority-carrier mobility, non-ohmic contact potential barrier, minority-carrier inversion at hetero-interface, and minority-carrier lifetime in a device environment. These methods are applied to a variety of photovoltaic technologies: CdTe, Cu(In,Ga)Se2, Si HIT cells, and organic photovoltaic materials.

Li, J. V.; Crandall, R. S.; Repins, I. L.; Nardes, A. M.; Levi, D. H.; Sulima, O.

2011-07-01

9

Derivation of Piezoelectric Losses from Admittance Spectra  

NASA Astrophysics Data System (ADS)

High power density piezoelectrics are required to miniaturize devices such as ultrasonic motors, transformers, and sound projectors. The power density is limited by the heat generation in piezoelectrics, therefore, clarification of the loss mechanisms is necessary. This paper provides a methodology to determine the electromechanical losses, i.e., dielectric, elastic and piezoelectric loss factors in piezoelectrics by means of a detailed analysis of the admittance/impedance spectra. This method was applied to determine the piezoelectric losses for lead zirconate titanate ceramics and lead magnesium niobate-lead titanate single crystals. The analytical solution provides a new method for obtaining the piezoelectric loss factor, which is usually neglected in practice by transducer designers. Finite element simulation demonstrated the importance of piezoelectric losses to yield a more accurate fitting to the experimental data. A phenomenological model based on two phase-shifts and the Devonshire theory of a polarizable-deformable insulator is developed to interpret the experimentally observed magnitudes of the mechanical quality factor at resonance and anti-resonance.

Zhuang, Yuan; Ural, Seyit O.; Rajapurkar, Aditya; Tuncdemir, Safakcan; Amin, Ahmed; Uchino, Kenji

2009-04-01

10

How to measure the strength of the lithosphere without using the admittance or coherence between gravity and topography  

NASA Astrophysics Data System (ADS)

The lithosphere is modeled using a differential equation. As such it is characterized by a set of parameters, at least one of which, under the assumption of elastic behavior, is generally thought of as a proxy for its strength: the flexural rigidity (D), or, by extension, the elastic thickness. This lithospheric 'system' then takes an input: topographic loading by mountain building and other processes, and maps it into an output: the gravity anomaly and the final, measurable, topography. The input is not measurable but some of its properties can be characterized. The outputs are measurable but the relation between them is obfuscated by their stochastic nature and the presence of unmodeled components (such as non-linearity, non-elasticity, non-stationarity etc). Estimating D, most usually in the spectral domain, generally involves an exercise in constructing summaries of gravity and topography. Both admittance and coherence are popular; both are ratios of the cross-spectral density of gravity and topography to the power spectral densities of either, the whole sometimes squared. Despite the fact that neither admittance nor coherence have a Gaussian distribution, estimating D usually comes down to the least-squares fitting of a parameterized curve to the non-Gaussian data, where Gaussian behavior is tacitly, but still incorrectly, assumed. In this two-step procedure, admittance or coherence are first estimated, usually aided by tapering of the spatial input data prior to Fourier transforming (which introduces bias but lowers the estimation variance), and subsequently inverted for the strength parameters. Rarely, if ever, are lithospheric models found that satisfy both coherence and admittance to within their true error. This has led to much handwringing in the literature, ever since the methods were introduced in the eighties. Yet, if models of the lithosphere are 'true', and 'fit' the data, they should fit both representations, i.e. both statistics of it. Why don't they? Poorly characterized errors of admittance and coherence are not the only problems with this procedure. There is also the implicit annihilation of information during the construction of these 'statistics' (coarsely sampled, sometimes squared, ratios, measures of the data as they are) themselves. Then there is the fact that we do not want to know coherence and admittance at all - we want to know properties of the lithosphere! In this presentation, we intend to abandon coherence and admittance studies for good, by proposing an entirely different method of estimating flexural rigidity, which returns it and its confidence interval, as well as a host of tests for the suitability of the assumptions made along the way, and the possible presence of correlated loads and anisotropy in the response. The crux of the method is that it employs a maximum-likelihood formulation that remains very grounded in the data themselves, and which is formulated in terms of variables that do have a Gaussian distribution.

Simons, Frederik J.; Olhede, Sofia C.

2010-05-01

11

Localized Gravity/Topography Admittances on Mars  

NASA Technical Reports Server (NTRS)

Admittances from Mars Global Surveyor (MGS) gravity and topography yield estimates of lithosphere thickness on Mars: central Tharsis > 100 km, Alba Patera = 50 km, southern highlands < 20 km (but south polar cap > 50 km). Alba Patera and Elysium Rise are similar structures.

McGovern, Patrick J.; Solomon, Sean C.; Smith, David E.; Zuber, Maria T.; Neumann, Gregory A.; Head, James W.

2000-01-01

12

Structures that Contribute to Middle-Ear Admittance in Chinchilla  

PubMed Central

We describe measurements of middle-ear input admittance in chinchillas (Chinchilla lanigera) before and after various manipulations that define the contributions of different middle-ear components to function. The chinchilla’s middle-ear air spaces have a large effect on the low-frequency compliance of the middle ear, and removing the influences of these spaces reveals a highly admittant tympanic membrane and ossicular chain. Measurements of the admittance of the air spaces reveal that the high-degree of segmentation of these spaces has only a small effect on the admittance. Draining the cochlea further increases the middle-ear admittance at low frequencies and removes a low-frequency (less than 300 Hz) level dependence in the admittance. Spontaneous or sound-driven contractions of the middle-ear muscles in deeply anesthetized animals were associated with significant changes in middle-ear admittance.

Rosowski, John J.; Ravicz, Michael E.; Songer, Jocelyn E.

2009-01-01

13

Charge injecting layers for admittance spectroscopy  

NASA Astrophysics Data System (ADS)

Admittance spectroscopy is a simple yet powerful tool to determine the carrier mobility of organic compounds. One requirement is to have an Ohmic contact for charge injection. By employing a thin interfacial layer of tungsten oxide or molybdenum oxide we have found a possibility to efficiently inject holes into organic materials with a deep highest occupied molecular orbital level down to 6.3 eV. These results considerably enhance the application range of the admittance spectroscopy method. The measured mobility data are in excellent agreement with data obtained by the time-of-flight technique. To efficiently inject electrons into materials with an ionization potential of up to 2.7 eV we thermally evaporated an intermediate layer of cesium carbonate and discuss the extracted electron mobilities.

Hoping, M.; Schildknecht, C.; Gargouri, H.; Riedl, T.; Tilgner, M.; Johannes, H.-H.; Kowalsky, W.

2008-08-01

14

Characterization of coreless printed circuit board (PCB) transformers  

Microsoft Academic Search

In this paper, coreless printed-circuit-board transformers are characterized. A range of coreless printed circuit board (PCB) transformers with different geometric parameters have been fabricated and tested. Based on a recently reported analytic method, the self inductance of these transformers is calculated. This analytical method is also extended to cover the prediction of the transformers' mutual inductance. All calculated parameters have

S. C. Tang; S. Y. Hui; H. S.-H. Chung

2000-01-01

15

Prediction of payload vibration environments by mechanical admittance test techniques  

NASA Technical Reports Server (NTRS)

A series of experiments were conducted with simple beam and mass launch vehicle and payload models in order to determine the validity of mechanical admittance/impedance techniques applied to development of improved payload vibration tests. Admittance and impedances were measured from tests of the individual components to form matrices which were combined analytically to allow prediction of responses for the complete system. Results were computed for a transmission matrix approach and an admittance matrix approach. Only results for the admittance method appeared to be satisfactory when compared to measurements on the combined system.

Kana, D. D.; Vargas, L. M.

1975-01-01

16

Waveguide Admittance for Radiation into Plasma Layers-Theory and Experiment.  

National Technical Information Service (NTIS)

Measured admittance of an X-band waveguide radiating into dielectric and plasma layers is compared with variationally computed admittance figures. The waveguide admittance measurements for polystyrene sheets of varying thicknesses compared closely with ca...

J. Galejs M. H. Mentzoni

1965-01-01

17

SGEMP-induced transfer admittance coupling in cable bundles  

Microsoft Academic Search

The coupling of energy to the inner wires of an electrical cable bundle exposed to nuclear X-rays which involves the transfer admittance of the inner bundle shields is analyzed. In this coupling mode, the electric field induced by SGEMP between the outer and inner shields couples to the wires via small apertures in the inner shields. The transfer admittance-coupled response

L. C. Nielsen; C. R. Crain

1982-01-01

18

Mechanically Operated Air Admittance Valve with Timing Facilities  

Microsoft Academic Search

A description is given of a simple and cheap air admittance valve for automatic air inlet into turbomolecular pumped UHV system upon (controlled or uncontrolled) power cutoff. The valve is operated by a mechanical timer switch which can be adjusted such that dry air admittance starts just before the turbo pump has finished its pumping action completely. Thus, contamination of

J. Eilander

1973-01-01

19

Antenna admittance determination of electron density.  

NASA Technical Reports Server (NTRS)

A circular-aperture flush-mounted antenna for which a theoretical description of the antenna-plasma interaction has been developed was used to obtain a comparison between theoretical and experimental antenna admittance in the presence of ionized boundary layers of low-collision frequency. The antenna was located in a flat-plate model which was in turn located in the expanding-flow environment of a reflected-shock tunnel. The electron-temperature and electron-density distributions in the plate boundary layer at the antenna location were independently measured using voltage-swept thin-wire Langmuir probes for one of the test conditions. The antenna admittance was measured using a four-probe microwave reflectometer and these measured values were found to be in good agreement with those predicted from the theory. Measurements were also performed with another type of circular-aperture antenna which did not satisfy all of the constraints of the theoretical model, although good agreement was obtained between the calculations and the experimental results.

Dunn, M. G.; Blum, R. J.; Swift, C. T.; Beck, F. B.; Grantham, W. L.

1973-01-01

20

Series expansion of the quantum admittance in mesoscopic systems  

NASA Astrophysics Data System (ADS)

The quantum admittance of an interacting/coupled mesoscopic system and its series expansion are obtained by using the refermionization method. With the help of these nonperturbative results, it is possible to study the dependencies of the admittance according to the applied dc voltage, temperature, and frequency without any restriction on the relative values of these variables. Explicit expressions of the admittance are derived both in the limits of weak and strong interactions/coupling strength, giving clear indication of the inductive or capacitive nature of the mesoscopic system. They help to determine the conditions under which the phase of the current with respect to the ac voltage is positive.

Crépieux, Adeline

2013-04-01

21

Surface acoustic admittance and absorption of highly porous, layered, fibrous materials  

NASA Technical Reports Server (NTRS)

Some acoustic properties of Kevlar-29 - a fine fibered, layered material is investigated. Kevlar is characterized by very high strength, uniform filaments arranged in a parallel batt where most filaments are random in the x-y plane but ordered as planes in the z direction. For experimental purposes, volume porosity, static flow resistance and mean filament diameter are used to identify the material. To determine the acoustic surface admittance of Kevlar, batts of the material are cut into small pads and placed into a standing wave tube terminated by a rigid brass plug. The attenuation and relative phase shift are recorded at each frequency in the range of 50 to 6000 Hz. Normalized conductance and susceptance are combined to form the acoustic absorption coefficient. The data are compared with theory by plotting the normalized admittance and normal incident absorption coefficient versus cyclic frequency.

Tesar, J. S.; Lambert, R. F.

1984-01-01

22

Admittance spectroscopy of copper indium diselenide/cadmium sulfide solar cells  

NASA Astrophysics Data System (ADS)

This dissertation concentrates on admittance spectroscopy of CuInSe2/CdS heterojunction solar cells prepared by chemical spray pyrolysis (CSP) and by multiple-source evaporation (MSE). The primary goal is to examine some of the more important electrical characteristics of these heterojunctions and determine if the spray-pyrolyzed cells behave similar, albeit at a lower efficiency, to higher quality cells prepared by other techniques. The primary analytical tool used in this study is admittance spectroscopy. The theory of admittance spectroscopy is developed using the concept of equivalent circuits. The traditional temperature-swept technique for admittance spectroscopy is shown to be inadequate for measuring most heterojunction samples examined in this study because of the large parallel leakage conductance found in these devices. Instead, a frequency-swept admittance technique is developed and employed to correct for the parallel conductance effect and reveal the true nature of slow charge in the depletion layer. In addition to admittance spectroscopy, the two sets of solar cell diodes are characterized using a variety of measurement techniques including capacitance-voltage, current-voltage over spectral response, capacitance dispersion over wavelength, and solar efficiency. The different pieces of experimental data are discussed to form a self-consistent physical model of the polycrystalline solar cells. Charge transport across the diode junction is dominated by recombination processes within the CuInSe2 depletion layer for both sets of diodes although the large parallel conductance in the CSP diodes often masks this characteristic. The CSP solar cells exhibit a pronounced blue peak in the spectral response indicating that electron collection is the limiting factor in the overall short-circuit quantum efficiency. A large degree of capacitance dispersion is found in both sets of diodes. Supporting measurements indicate that the majority of this dispersion is due to interface traps in the MSE diodes and bulk acceptor traps in the CSP diodes. The high density of bulk acceptor traps in the CuInSe2 are located approximately 0.30 eV above the valence band and exhibit a capture cross section of approximately 5 x 10(exp -18)/sq cm. The dissertation concludes with a summary of the important mechanisms that presently dominate the efficiency of the CuInSe2/CdS solar cells prepared by CSP.

Strifler, Walter A.

23

Automatically Calibrating Admittances in KATE's Autonomous Launch Operations Model.  

National Technical Information Service (NTIS)

This report documents a 1000-line Symbolics LISP program that automatically calibrates all 15 fluid admittances in KATE's Autonomous Launch Operations (ALO) model. (KATE is Kennedy Space Center's Knowledge-based Autonomous Test Engineer, a diagnosis and r...

S. Morgan

1992-01-01

24

Preliminary Admittance Estimates for the Valles Marineris, Mars  

NASA Technical Reports Server (NTRS)

We use the gravity and topography fields derived from Mars Global Surveyor in conjunction with a multi-resolution localization admittance technique to constrain lithospheric structure for the trough system of Valles Marineris on Mars.

Anderson, F. Scott; Banerdt, W. B.

2000-01-01

25

Characterization of the Pulse Transformer (Karakterisering van de Pulstransformator).  

National Technical Information Service (NTIS)

This report treats characterization of the pulse transformer at TNO PML Pulse Physics, Delft. The pulse transformer constitutes the final step of an energy compression system, called the Kapitza facility, and is able to amplify the current up to 24 times....

W. H. Mosterdijk

1992-01-01

26

Acoustic transfer admittance of cylindrical cavities  

NASA Astrophysics Data System (ADS)

The reciprocity calibration method uses two microphones acoustically connected by a coupler, a cylindrical cavity closed at each end by the diaphragms of the transmitting and receiving microphones. The acoustic transfer admittance of the coupler, including the thermal conductivity effect of the fluid, must be modelled precisely to obtain the accurate sensitivity of the microphones from the electrical transfer impedance measurement. It appears that the analytical model quoted in the current standard [International Electrotechnical Commission IEC 61064-2, Measurement Microphones, Part 2: Primary Method for Pressure Calibration of Laboratory Standard Microphones by the Reciprocity Technique, 1992] is not the appropriate one and that it should be revised, as also suggested by a recent EUROMET project report [K. Rasmussen, Datafiles simulating a pressure reciprocity calibration of microphones, EUROMET Project 294 Report PL-13, 2001]. Thus, it is the aim of the paper to investigate analytically the acoustic field inside the coupler, revisiting the assumptions of the earlier work, leading to a coherent description and therefore providing clarity which should facilitate discussion of a possible revised standard.

Guianvarc'h, C.; Durocher, J.-N.; Bruneau, M.; Bruneau, A.-M.

2006-05-01

27

Admittance spectroscopy of sealed secondary batteries  

NASA Astrophysics Data System (ADS)

The admittance of sintered NiCd alkaline and Pb-acid-sealed batteries was investigated in the frequency range 0.01 to 10,000 Hz at 253, 293, and 323 K, with small signals of 1-10 mV amplitude under potentiostatic control to keep the direct current to a minimum value. Fully charged and fully discharged states of these batteries were investigated, the latter corresponding to relatively 'slow' and 'fast' discharges. The spectra of the real and imaginary components of the complex capacitance C(omega) are shown as functions of frequency, and equivalent circuits are derived using as circuit elements resistors and 'universal' dispersive capacitors obeying the power law frequency dependence Cn(omega) = An(i omega)exp n-1 with n in the range 0,1. The results are discussed in terms of known electrochemical reactions in these two types of batteries and assignments are made of the bulk eletrolyte resistance, the interfacial electrochemical reaction, and the transport of ionic species through the pores of the nonconducting matter surrounding the electrodes, as well as a 'structural' inductance term. The analysis shows clear evidence of dispersive processes but no trace of direct current conduction, at least down to 0.01 Hz, which is rather surprising. The results open a number of fundamental questions relating to the processes governing the dynamic response of secondary batteries which are at present not well understood.

Bari, M. A.; Jonscher, A. K.

1986-05-01

28

Anomaly depth detection in trans-admittance mammography: a formula independent of anomaly size or admittivity contrast  

NASA Astrophysics Data System (ADS)

Trans-admittance mammography (TAM) is a bioimpedance technique for breast cancer detection. It is based on the comparison of tissue conductivity: cancerous tissue is identified by its higher conductivity in comparison with the surrounding normal tissue. In TAM, the breast is compressed between two electrical plates (in a similar architecture to x-ray mammography). The bottom plate has many sensing point electrodes that provide two-dimensional images (trans-admittance maps) that are induced by voltage differences between the two plates. Multi-frequency admittance data (Neumann data) are measured over the range 50 Hz-500 kHz. TAM aims to determine the location and size of any anomaly from the multi-frequency admittance data. Various anomaly detection algorithms can be used to process TAM data to determine the transverse positions of anomalies. However, existing methods cannot reliably determine the depth or size of an anomaly. Breast cancer detection using TAM would be improved if the depth or size of an anomaly could also be estimated, properties that are independent of the admittivity contrast. A formula is proposed here that can estimate the depth of an anomaly independent of its size and the admittivity contrast. This depth estimation can also be used to derive an estimation of the size of the anomaly. The proposed estimations are verified rigorously under a simplified model. Numerical simulation shows that the proposed method also works well in general settings.

Zhang, Tingting; Lee, Eunjung; Seo, Jin Keun

2014-04-01

29

Electrical Properties of Prostatic Tissues: II. Spectral Admittivity Properties  

PubMed Central

Purpose The electrical properties of prostate tissues gauged at discrete frequencies provide sufficient contrast to discriminate malignant from benign prostatic tissues. The frequency dependence of these properties is also a function of tissue morphology. We evaluated the potential of this spectral dependence to provide additional diagnostic information for prostate cancer detection. Materials and Methods Electrical conductivity and permittivity were recorded from 50 ex vivo prostates at 31 logarithmically spaced frequencies of 100 Hz to 100 kHz. We used a well established, 4 parameter (??, ??, fc and ?) model to describe individual spectra with each model parameter influenced by tissue morphology. We evaluated these parameters in terms of discriminatory power using ROC curves. Results Of the 4 spectral parameters ?? and fc were significantly greater in cancer than in benign tissues and ?? was significantly more negative in cancer than in benign tissues (each p <0.0001). fc provided the maximum discriminating power with an ROC AUC of 0.821 and 81.5% specificity at 70% sensitivity. Also, ?? and ?? provided high levels of discrimination with an AUC of 0.770 and 0.782, respectively. Conclusions Spectral electrical admittivity properties provide sufficient levels of ex vivo cancer discrimination that may potentially enhance disease localization when prostate cancer is suspected. The development of novel technologies gauging these properties in vivo has the potential to provide new tissue characterizing tools for prostate cancer detection and identification.

Halter, Ryan J.; Schned, Alan; Heaney, John; Hartov, Alex; Paulsen, Keith D.

2009-01-01

30

Admittance spectroscopy study of polymer diodes in small magnetic fields  

NASA Astrophysics Data System (ADS)

We performed a systematic study of bipolar and unipolar organic diodes based on the ?-conjugated polymer, 2-methoxy-5-(2'-ethylhexyloxy) (MEH-PPV), using electronic and magneto-transport measurements with magnetic field in the range 0-180 mT and admittance spectroscopy in the frequency range 1 Hz < f < 10 MHz. The admittance spectra of bipolar devices reveal two relaxation processes with distinct time scales that are influenced by the magnetic field. The slower process, which dominates the device capacitance at f < 10 Hz, is attributed to the trap-assisted monomolecular recombination. The faster process is attributed to the electron-hole bimolecular recombination kinetics. We found that the time scale of this process, ?2, decreases exponentially with the bias voltage. Application of magnetic field, B = 30 mT decreases ?2 by ~30%. We also found that the magneto-conductance, ?G(?,B)/G(?,0), has a characteristic cutoff frequency that shifts to higher frequencies with increasing bias voltage. In particular, the magnetoconductance at 10 MHz in a bipolar device was measured to be 4.5% at B = 30 mT. For bipolar devices we found that the frequency-dependent response of the device admittance to the small magnetic field is identical to the response of the admittance to a small increase in the bias voltage in zero magnetic field. We also found that the admittance of unipolar diodes does not depend on magnetic field.

Djidjou, Thaddee K.; Basel, Tek; Rogachev, Andrey

2012-07-01

31

Admittance spectroscopy study of polymer diodes in small magnetic fields  

NASA Astrophysics Data System (ADS)

We performed a systematic study of bipolar and unipolar diodes based on the pi-conjugated polymer, 2-methoxy-5-(2'-ethylhexyloxy) (MEH-PPV), using electronic and magneto-transport measurements with magnetic field in the range 0 mT- 180 mT and admittance spectroscopy in the frequencies varying from 1 Hz to 10 MHz. The admittance spectra of bipolar devices reveal two relaxation processes with distinct time scales that are influenced by the magnetic field. The slower process, which dominates the device capacitance at frequencies less than 10 Hz, is attributed to the trap-assisted monomolecular recombination. The second faster process is attributed to the electron-hole bimolecular recombination kinetics. When magnetic field of magnitude 30 mT is applied, tau2 decreases by approximately 30 %. We observed that bipolar devices have strong divergent contribution to the device differential capacitance at low frequencies. It is positive at low biases voltages, turns negative at intermediate biases, and becomes positive again at stronger biases. In addition, by carefully selecting bias voltage, we were able to tune some bipolar diodes from the state with the negative capacitance to the state with the positive capacitance just by applying magnetic field. The magneto-conductance has a characteristic cutoff frequency that shifts to higher frequencies with increasing bias voltages. In particular, the magneto-conductance at 10 MHz in a bipolar device was measured to be 4.5 % in the magnetic field of magnitude 30 mT. For bipolar devices, the frequency-dependent response of the device admittance to the small magnetic field is identical to the response of the admittance to the small increase in the bias voltage in zero magnetic field. We found that the response of the admittance on the magnetic field is consistent with the polaron-polaron model of the organic magnetoresistance. The admittance of unipolar diodes did not reveal any magnetic field.

Thaddee, Kamdem Djidjou

32

Transition metal oxides as charge injecting layer for admittance spectroscopy  

NASA Astrophysics Data System (ADS)

Admittance spectroscopy is a simple yet powerful tool to determine the carrier mobility of organic compounds. One requirement is to have an Ohmic contact for charge injection. By employing a thin interfacial layer of tungsten oxide, or molybdenum oxide we have found a possibility to efficiently inject holes into organic materials with a deep highest occupied molecular orbital level down to 6.3 eV. These results considerably enhance the application range of the admittance spectroscopy method. The measured data are in excellent agreement with data obtained by the time-of-flight technique.

Hoping, M.; Schildknecht, C.; Gargouri, H.; Riedl, T.; Tilgner, M.; Johannes, H.-H.; Kowalsky, W.

2008-05-01

33

Validation of the computation of rocket nozzle admittances with linearized euler equations  

NASA Astrophysics Data System (ADS)

High pressure fluctuations coupled with unsteady heat release can affect a rocket engine seriously. Especially when the oscillations match eigenmodes such as T1, T1L1 and T2, T2L1, the acoustic pressure amplitude can reach a critical level. This paper deals with the investigation of the nozzle admittance, which is an important value to characterize the influence of the nozzle on the pressure inside the combustion chamber. Two different nozzle geometries are investigated experimentally at high frequencies. A method to decouple the acoustic modes is presented. The results are compared against an existing theory and simulated data.

Kathan, R.; Morgenweck, D.; Kaess, R.; Sattelmayer, T.

2013-03-01

34

SGEMP-induced transfer admittance coupling in cable bundles  

Microsoft Academic Search

One of the ways energy can couple to the inner wires of an electrical cable bundle exposed to nuclear x-rays involves the transfer admittance of the inner bundle shields; the authors present an analysis of this coupling mode, in which the electric field induced by SGEMP between the outer and inner shields couples to the wires via small apertures in

L. Carlisle Nielsen; Charles R. Crain

1982-01-01

35

Optical Frequency Conductance, Susceptance and Admittance of Quantum Wells  

Microsoft Academic Search

Optical absorption and emission via interband and intersubband transitions in a quantum well can be described by a quantized optical frequency conductance proportional to the fine structure constant. We present a compact physical model based on optical frequency admittance for the interaction of light with quantum wells in photodetectors and semiconductor lasers. HE interaction of light with electrons in quantum

Thomas Szkopek

2011-01-01

36

Techniques for Exploiting the Sparsity or the Network Admittance Matrix  

Microsoft Academic Search

This paper describes some computer programing techniques for taking advantage of the sparsity of the admittance matrix. The techniques are based on two main ideas; (1) determination of a sequence of operations. which results in a near minimum of memory and computing, (2) preservation of these operations for repetition. Use of these techniques makes it possible to obtain significant reductions

Nobou Sato; W. F. Tinney

1963-01-01

37

Frequency-dependent admittance of a short superconducting weak link  

NASA Astrophysics Data System (ADS)

We consider the electromagnetic response of a nanowire connecting two bulk superconductors. Andreev states appearing at a finite phase bias substantially affect the finite-frequency admittance of such wire junction. We evaluate the complex admittance analytically at arbitrary frequency and arbitrary, possibly non-equilibrium, occupation of Andreev levels. Special care is given to the limits of a single-channel contact and a disordered metallic weak link. We also evaluate the quasi-static fluctuations of admittance induced by fluctuations of the occupation factors of Andreev levels. In view of possible qubit applications, we compare properties of a weak link with those of a tunnel Josephson junction of the same normal conductance. Compared to the latter, weak link has smaller low-frequency dissipation. However, because of the deeper Andreev levels, quasi-static fluctuations of the complex admittance in a weak link are exponentially larger than in a tunnel junction. These fluctuations limit the applicability of nanowire junctions in superconducting qubits.

Kos, Filip; Nigg, Simon; Glazman, Leonid

2013-03-01

38

Electrical Properties of Prostatic Tissues: I. Single Frequency Admittivity Properties  

PubMed Central

Purpose Electrical properties of the prostate may provide sufficient contrast for distinguishing malignant and benign formations in the gland. We evaluated how well these electrical properties discriminate cancer from noncancer tissues in the prostate. Materials and Methods Electrical admittivity (conductivity and permittivity) was recorded at 31 discrete frequencies of 0.1 to 100 kHz from each of 50 ex vivo human prostates. A specifically designed admittivity probe was used to gauge these electrical properties from sectioned prostate specimens. The specific tissue area probed was marked to provide precise colocalization between tissue histological assessment and recorded admittivity spectra. Results Adenocarcinoma, benign prostatic hyperplasia, nonhyperplastic glandular tissue and stromal tissue were the primary tissue types probed. Mean cancer conductivity was significantly less than that of glandular and stromal tissues at all frequencies (p <0.05), while mean cancer permittivity was significantly greater than that of all benign tissues at 100 kHz (p <0.0001). ROC curves showed that permittivity at 100 kHz was optimal for discriminating cancer from all benign tissues. This parameter had 77% specificity at 70% sensitivity and an ROC AUC of 0.798. Conclusions The contrast in electrical admittivity properties of different prostate tissues shows promise for distinguishing cancer from benign tissues. Sensitivity and specificity exceed those reported for current prostate specific antigen screening practices at low prostate specific antigen, making this an attractive addition to the clinical armamentarium for identifying prostate cancer.

Halter, Ryan J.; Schned, Alan; Heaney, John; Hartov, Alex; Paulsen, Keith D.

2009-01-01

39

High Frequency Input Admittance of Continuum Regime Langmuir Probe  

NASA Astrophysics Data System (ADS)

Measurement of probe complex input impedance, or admittance, has been suggested as a way to increase the amount of information obtained from Langmuir probes [1]. In this poster, a spherical probe immersed in a weakly ionized homogeneous plasma is considered in the regime in which the probe radius is small compard with the Debye length. When the magnitude of the probe potential exceeds the plasma temperature in volts, the low frequency AC input admittance of the negatively biaed probe is given by the ion conductivity times 4? times the probe radius plus the admittance associated with the probe vacuum capacitance. The real part of the input admittance falls rapidly when the drive frequency exceeds the reciprocal of the time it takes ions to diffuse a distance on the order of the probe radius. An analytic solution to this problem found by applying the method of matched asymptotic expansions to the describing differential equation is given. Probe circuit models and boundary conditions are reviewed.[4pt] [1] D.N. Walker, R.F. Fernsler, D.D. Blackwell, and W.E. Amatucci, Phys. Plasmas 15, 123506 (2008).

Rappaport, H. L.

2010-11-01

40

Derivation of Piezoelectric Losses from Admittance Spectra  

Microsoft Academic Search

High power density piezoelectrics are required to miniaturize devices such as ultrasonic motors, transformers, and sound projectors. The power density is limited by the heat generation in piezoelectrics, therefore, clarification of the loss mechanisms is necessary. This paper provides a methodology to determine the electromechanical losses, i.e., dielectric, elastic and piezoelectric loss factors in piezoelectrics by means of a detailed

Yuan Zhuang; Seyit O. Ural; Aditya Rajapurkar; Safakcan Tuncdemir; Ahmed Amin; Kenji Uchino

2009-01-01

41

SGEMP-induced transfer admittance coupling in cable bundles  

NASA Astrophysics Data System (ADS)

The coupling of energy to the inner wires of an electrical cable bundle exposed to nuclear X-rays which involves the transfer admittance of the inner bundle shields is analyzed. In this coupling mode, the electric field induced by SGEMP between the outer and inner shields couples to the wires via small apertures in the inner shields. The transfer admittance-coupled response is calculated for a generic cable bundle by utilizing an equivalent circuit model, and the results are compared with the direct injection response. The sensitivity of the response to significant cable parameters is examined, and the limitations of the model are noted. It is found that an insulating tape wrap adjacent to the outer shield, usually present as an aid in fabrication, can reduce the response by about an order of magnitude.

Nielsen, L. C.; Crain, C. R.

1982-12-01

42

SGEMP-induced transfer admittance coupling in cable bundles  

SciTech Connect

One of the ways energy can couple to the inner wires of an electrical cable bundle exposed to nuclear x-rays involves the transfer admittance of the inner bundle shields; the authors present an analysis of this coupling mode, in which the electric field induced by SGEMP between the outer and inner shields couples to the wires via small apertures in the inner shields. Using an equivalent circuit model, the transfer admittance-coupled response is calculated for a generic cable bundle, and compared with the direct injection response. Sensitivity of the response to significant cable parameters is investigated, and limitations of the model are discussed. It is shown that an insulating tape wrap adjacent to the outer shield, often present as a fabrication aid, reduces the response by about an order of magnitude.

Nielsen, L.C.; Crain, C.R.

1982-12-01

43

Ultrasonic guided-waves characterization with warped frequency transforms.  

PubMed

Guided wave (GW) dispersion curves can be extracted from a time-transient measurement by means of timefrequency representations (TFRs). Unfortunately, any TFR is subject to the time-frequency uncertainty principle. This, in general, limits the capability of TFRs to characterize closely spaced guided modes over a wide frequency range. To overcome this limitation, we implemented a new warped frequency transform that presents enhanced mode extraction capabilities because of a more flexible tiling of the time-frequency domain. The tiling is designed to match the dispersive spectro-temporal structure of a GW by selecting an appropriate map of the time-frequency plane. The proposed transformation is fast, invertible, and covariant to group delay shifts. An application to Lamb waves propagating in an aluminum plate is presented. Time-transient GWs propagation events obtained both numerically and experimentally are considered. The results show that the proposed warped frequency transform limits the interference patterns which appear with other TFRs and produces a sparse representation of the Lamb wave pattern that can be suitable for identification and characterization purposes. PMID:19942510

De Marchi, Luca; Marzani, Alessandro; Caporale, Salvatore; Speciale, Nicolò

2009-10-01

44

Frequency-dependent admittance of a short superconducting weak link  

NASA Astrophysics Data System (ADS)

We consider the linear and nonlinear electromagnetic responses of a nanowire connecting two bulk superconductors. The Andreev states appearing at a finite phase bias substantially affect the finite-frequency admittance of such a wire junction. Electron transitions involving the Andreev levels are easily saturated, leading to the nonlinear effects in photon absorption for the subgap photon energies. We evaluate the complex admittance analytically at an arbitrary frequency and arbitrary, possibly nonequilibrium, occupation of the Andreev levels. Special care is given to the limits of a single-channel contact and a disordered metallic weak link. We also evaluate the quasistatic fluctuations of admittance induced by fluctuations of the occupation factors of the Andreev levels. In view of possible qubit applications, we compare properties of a weak link with those of a tunnel Josephson junction. Compared to the latter, a weak link has smaller low-frequency dissipation. However, because of the deeper Andreev levels, the low-temperature quasistatic fluctuations of the inductance of a weak link are exponentially larger than of a tunnel junction. These fluctuations limit the applicability of nanowire junctions in superconducting qubits.

Kos, F.; Nigg, S. E.; Glazman, L. I.

2013-05-01

45

Method for measuring transformation energy and quantitative characterization of transformation-induced plasticity  

Microsoft Academic Search

A method for measuring transformation energy (E\\u000a pt) of strain-induced martensite (SIM) and quantitative characterization of transformation-induced plasticity is developed using\\u000a characteristics of the tensile curve of three metastable austenitic stainless steels, 10Cr18.5Ni8.5Mnl.9Si0.9, 19Cr17.5Ni7.4Mn2.3Si1.0,\\u000a and 10Cr16.2Ni11.8Mn1.2Si0.7. The results show that the E\\u000a pt of tested materials at ?196 C is 11.3, 14.7, and 20.1106 J\\/m3, respectively; E\\u000a pt remains constant

W. F. Zhang; Y. M. Chen; J. H. Zhu

2002-01-01

46

Vibration characteristic analysis method for the quartz microgyroscope based on the admittance circle  

NASA Astrophysics Data System (ADS)

The vibration characteristic analysis method for a quartz microgyroscope based on the admittance circle is reported in this paper. Admittance theory is introduced and the admittance circle principle is analysed to study the vibration characteristics of the quartz microgyroscope. The prototype gyroscope was fabricated by micro-electromechanical systems (MEMS) technology. The admittance and phase diagram of the work mode were obtained by vibration mode test systems. Then the admittance circle of the work mode was drawn, and the parameter identification of the transfer function between the voltage and current was completed to analyse the vibration characteristics. Therefore, the vibration characteristic analysis method based on the admittance circle can be used to build the transfer function of the quartz microgyroscope, which is helpful for the design of a high performance quartz microgyroscope.

Wang, Haoxu; Dong, Peitao; Xie, Liqiang; Wu, Xuezhong

2014-03-01

47

Admittance selection for force-guided assembly of polygonal parts despite friction  

Microsoft Academic Search

An important issue in the development of force guidance assembly strategies is the specification of an appropriate admittance control law. This paper identifies conditions to be satisfied when selecting the appropriate admittance to achieve force-guided assembly of polygonal parts for multipoint contact with friction. These conditions restrict the admittance behavior for each of the various one-point and two-point contact cases

Shuguang Huang; Joseph M. Schimmels

2004-01-01

48

Variations in acoustic admittance related to type of ear tip. A plea for a standardized method.  

PubMed

In order to assess the validity of using various ear tips, tympanometry and acoustic admittance were studied in 20 young healthy subjects, and three different types of ear tip used to seal the external auditory canal. Significant variations in the admittance components and tympanometry curves were observed, resulting most probably from changes in the canal volume and the physical nature of the tipe. It appears advisable to develop and adopt an appropriate, standard ear tip for studies of admittance audiometry. PMID:1017930

Himelfarb, M Z; Rapoport, Y; Shanon, E

1976-11-01

49

Admittance of T-stub graphene nanoribbon structure.  

PubMed

In this work, we studied ac responses of T-stub structures that are composed of armchair and zigzag graphene ribbons. Compared with uniform graphene ribbons, the T-stub structures show extraordinary properties. The ac responses of armchair and zigzag T-stub structures show different behaviors for different edge configurations. The imaginary part of admittance can be capacitive or inductive depending on the Fermi energy and structural parameters. These properties provide deeper understanding of dynamic processes of electrons in graphene-based nanodevices. PMID:23187783

Lan, Jin; Ye, En-jia; Sui, Wen-quan; Zhao, Xuean

2013-01-14

50

Discussion of the relevance of transfer admittance and some through elastance measurement results  

Microsoft Academic Search

Transfer admittance for electromagnetic compatibility (EMC) prediction is reviewed. A method for measuring the transfer admittance of cables is presented. Some experimental results are given for coaxial cables. Although the through elastance is not measurable, the authors show that it is at least one order of magnitude smaller than what current theory predicts

F. Broyde; E. Clavelier; D. Givord; P. Vallett

1993-01-01

51

Input Admittance Characteristics of Permanent Magnet Brushless AC Motor Drive Systems  

Microsoft Academic Search

This paper analyzes the input admittance\\/impedance characteristics of a permanent-magnet brushless AC motor drive system, taking account of the influence of both current and speed control loops as well as the motor and inverter losses. It is shown that, if voltage feedforward compensation is not employed, the input admittance of the drive system differs significantly from that of an ideal

J. Wang; A. Griffo; L. Han; D. Howe

2007-01-01

52

High Power Piezoelectric Characterization for Piezoelectric Transformer Development  

NASA Astrophysics Data System (ADS)

The major goal was to develop characterization techniques to identify and define guidelines to manufacture high power density actuators. We particularly aim at improving the strengths of piezoelectric transformers, namely the high efficiency, ease of manufacturing, low electromagnetic noise, and high power to weight ratio resulting in an adaptor application by identifying material limitations, geometrical limitations and offer guidelines to counter drawbacks limiting the power density. There are 3 losses present in piezoelectrics. Namely dielectric, elastic and piezoelectric losses. These losses can be calculated using mechanical quality factors of the resonating piezoelectric actuator. But in order to calculate all three losses, the mechanical quality factor for resonance and anti resonance need to be measured. Although the mechanical quality factor for resonance is conventionally measured, measurements in antiresonance have been ignored. Since there was no unique measurement technique to address antiresonance and resonance Q in one single sweep, in this study constant vibration velocity method was developed. During the constant vibration velocity measurement, the input electrical energy is monitored and significant differences between resonance and antiresonance drives are observed. For the same output work (identical vibration velocity) significant differences in the losses were observed. Thermographic images have shown increasing temperature differences for resonance and antiresonance nodal point temperatures, with higher vibration velocities. The theoretical evaluation identified the difference observed in the mechanical quality factors at resonance and antiresonance to stem from the piezoelectric loss. In order to investigate losses in the absence of thermal effects a transient characterization technique was adopted. The burst technique, originally developed for characterization of the mechanical quality factor at resonance, has been modified with a switch circuit to leave the resonator in an open circuit condition. The newly introduced open circuits burst have resulted in antiresonance quality factor measurements along with resonance quality factors in a "non-heating" sample. In this technique too, resonance and antiresonance losses showed significant difference. Resonance burst mode characterizations at elevated ambient temperatures have shown that the lower vibration velocity mechanical quality factors appear to be more sensitive to the ambient temperature. Design criteria's to produce the most power dense structure were investigated. Common device shapes were investigated to see which one does enhance the power density of the piezoelectric device. Disk shaped piezoelectric actuators have proven to have lower matching impedances and higher, farther persisting mechanical quality factors with respect to vibration velocities. In order to achieve identical power level, plate shaped samples will have been to strain ~3.5 times more than disk shaped samples. Thus the most power dense structure has been concluded to be a disk shape ~1W/cm3 Once the actuators shape was fixed, further design on structure were conducted with (c)ATILA finite element method. For the transformer application, the design considered following key factors; 1-Controlling the output impedance by optimizing number of layers and layer thicknesses of the multilayer and 2- Evaluation of various electrodes and their affect on high power performance was evaluated. As the thickness of active layers decreased, the number of electrode layers increases. This increase in the metal to piezoelectric ratio and the relative increase in the electrode resistance under high current loads, both will have to be accounted for. Thus; with the piezoelectric composition and the device structure optimized, the research input electrical power. Once the actuators shape was fixed, further design on structure were conducted with (c)ATILA finite element method. For the transformer application, the design considered following key factors; 1-Controlling the output imped

Ural, Seyit O.

53

Nontransformed rabbit liver glucocorticoid receptor: purification, characterization and transformation.  

PubMed

The molybdate-stabilized nontransformed form of the glucocorticoid receptor from rabbit liver has been purified approximately 8,000-fold by a three-step procedure. The first step involved protamine sulfate precipitation which allowed a 5-6-fold purification with 85% yield. The second step, affinity chromatography using a N-(12-dodecyl-amino) 9 alpha-fluoro-16 alpha-methyl-11 beta, 17 alpha-dihydroxy-3-oxo-1,4-androstadiene-17 beta-carboxamide substituted Sepharose gel, purified the receptor 1,500-2,000-fold as calculated by specific radioactivity. The third step involved high performance liquid chromatography resulting in overall purification near 8,000-fold. The final glucocorticoid receptor appeared about 60% pure. The purified nontransformed glucocorticoid receptor had a sedimentation coefficient of 9 S in 0.16 M phosphate containing 5-20% sucrose gradients and the Stokes radius was 6.1-6.3 nm as determined by low pressure gel filtration and HPLC. Binding specificity of the purified receptor was identical to that previously reported in crude rabbit liver cytosol. Isoelectricfocusing and ion-exchange chromatography showed that the purification procedure affected the net charge of the receptor protein. This phenomenon could be related to interactions between the glucocorticoid receptor and cytosolic factors. SDS polyacrylamide gel electrophoresis showed a major Mr = 94,000 protein band which is in good agreement with previously reported values for glucocorticoid receptors. Transformation of the purified receptor was achieved after removal of molybdate by exposure at 25 degrees C to 0.4 M KCl. Characterization of the molecular forms was performed by means of incorporation into isolated nuclei, affinity towards polyanionic exchangers and high pressure size exclusion chromatography. Results show that about 40% of the receptor is in the transformed state. PMID:4096908

Lustenberger, P; Blanchardie, P; Denis, M; Formstecher, P; Orsonneau, J L; Bernard, S

1985-12-01

54

Use of paravascular admittance waveforms to monitor relative change in arterial blood pressure  

NASA Astrophysics Data System (ADS)

Non-invasive methods to monitor ambulatory blood pressure often have limitations that can affect measurement accuracy and patient adherence [1]. Minimally invasive measurement of a relative blood pressure surrogate with an implantable device may provide a useful chronic diagnostic and monitoring tool. We assessed a technique that uses electrocardiogram and paravascular admittance waveform morphology analysis to one, measure a time duration (vascular tone index, VTI in milliseconds) change from the electrocardiogram R-wave to admittance waveform peak and two, measure the admittance waveform minimum, maximum and magnitude as indicators of change in arterial compliance/distensibility or pulse pressure secondary to change in afterload. Methods: Five anesthetized domestic pigs (32 ± 4.2 kg) were used to study the effects of phenylephrine (1-5 ug/kg/min) on femoral artery pressure and admittance waveform morphology measured with a quadrapolar electrode array catheter placed next to the femoral artery to assess the relative change in arterial compliance due to change in peripheral vascular tone. Results: Statistical difference was observed (p < 0.05) comparing baseline VTI to phenylephrine VTI (246 ± .05 ms to 320 ± .07 ms) and baseline admittance waveform maximum to phenylephrine admittance waveform maximum (0.0148 ± .002 siemens to 0.0151 ± .002 siemens). Conclusion: Chronic minimally invasive admittance measurement techniques that monitor relative change in blood pressure may be suitable for implantable devices to detect progression of cardiovascular disease such as hypertension.

Zielinski, Todd M.; Hettrick, Doug; Cho, Yong

2010-04-01

55

Surface acoustic admittance of highly porous open-cell, elastic foams  

NASA Technical Reports Server (NTRS)

This work presents a comprehensive study of the surface acoustic admittance properties of graded sizes of open-cell foams that are highly porous and elastic. The intrinsic admittance as well as properties of samples of finite depth were predicted and then measured for sound at normal incidence over a frequency range extending from about 35-3500 Hz. The agreement between theory and experiment for a range of mean pore size and volume porosity is excellent. The implications of fibrous structure on the admittance of open-cell foams is quite evident from the results.

Lambert, R. F.

1983-01-01

56

Characterization of the Adenovirus Type 12-Rat Embryo Transformation System.  

National Technical Information Service (NTIS)

One of the goals of the research is to investigate the transformation of human cells by human virus. Adenovirus type 12, known to be oncogenic in hamsters and rats, is a virus of special interest. Although transformation of hamster, rat, and rabbit cells ...

A. E. Freeman

1966-01-01

57

Admittance of gallium arsenide p+n diodes with lateral base contact  

NASA Astrophysics Data System (ADS)

The frequency dependence of the admittance of a planar p+ gate on an ion-implanted gallium arsenide n-substrate has been evaluated by distributed network analysis to determine capacitance and conductance per unit junction area, and substrate sheet resistance. The experimental data indicate a parasitic, bias dependent admittance shunting the distributed admittance, which we attribute to the spreading of the depletion layer at the gate rim. The magnitude of the sheet resistance in the subthreshold regime and the temperature dependence of the high frequency admittances are ascribed to bulk substrate conduction. The time constant of the product of junction capacitance with underlying sheet resistance is a few seconds, suggesting pronounced electron trapping in the undepleted tail of the implant.

Lehovec, K.; Zuleeg, R.

1984-09-01

58

Prediction of payload vibration environments by mechanical admittance test techniques. [space shuttles/vibration tests  

NASA Technical Reports Server (NTRS)

A series of experiments was conducted with simple beam and mass launch vehicle and payload models in order to determine the validity of mechanical admittance/impedance techniques applied to development of improved payload vibration tests. Admittances and impedances were measured from tests of the individual components to form matrices which were combined analytically to allow prediction of responses for the complete system. Results were computed for a transmission matrix approach and an admittance matrix approach. Both a rigid body and a flexible payload model were considered. The results clearly demonstrate that the transmission matrix method is too sensitive to measurement error to be practical for this application, while the pure admittance matrix method produces quite satisfactory results. The effects of various errors on the final results are demonstrated.

Kana, D. D.; Vargas, L. M.

1975-01-01

59

Plane-Wave Admittance Method and its Applications to Modelling Photonic Crystal Structures  

Microsoft Academic Search

This chapter presents the mathematical basis of the plane-wave admittance method (PWAM), which is a combination of the method\\u000a of lines and plane-wave expansion. In the first part of the chapter the most important equations are derived and the used\\u000a admittance transfer procedure is reviewed. In the second part we show the examples of modelling photonic-crystals-based vertical-cavity\\u000a surface-emitting lasers with

Maciej Dems; Tomasz Czyszanowski; Rafa? Koty?ski; Krassimir Panajotov

2008-01-01

60

Study of frequency-dependent strip admittance in silicon microstrip detectors  

Microsoft Academic Search

We report on detailed interstrip admittance measurements performed on double-sided, AC-coupled and punch-through biased silicon microstrip detectors. The sensors chosen have been fabricated on very high resistivity substrates, which translates in very low depletion voltages, in the range 10–20V. This, together with the absence of bias resistors, allows a careful study of the strip admittance components over a wide range

Gabriele Giacomini; Luciano Bosisio; Irina Rashevskaya; Oleksandr Starodubtsev

2010-01-01

61

A multivariate characterization of crystal transformations of cellulose  

Microsoft Academic Search

A spectroscopic study of cellulose transformation processes, such as alkali treatment and annealing, showed that, in combination with multivariate data analysis techniques, a detailed understanding of the crystalline transformation processes could be reached.13C cross-polarization magic-angle spinning (CPMAS) NMR and near-infrared (NIR) spectroscopy of cotton linters and softwood pulps analysed during the processing revealed information, after data reduction using principal components

Torbjörn Lindgren; Ulf Edlund; Tommy Iversen

1995-01-01

62

Admittance inversion of GPR transmission for crosshole tomography  

NASA Astrophysics Data System (ADS)

We investigated a full waveform inversion algorithm in 2D, that was developed without precise knowledge of the source functions and without any 3D compensation (e.g., point sources) of radar wave propagation. To address this, we proposed a new methodology that measures the electric and magnetic fields generated by a common electric current source, and that inverts the admittance data, the ratio of two mutually orthogonal components of these recorded fields in the frequency domain. To alleviate local minima problems, we devised a data weighting method based on data misfits and data resolution. The developed approach was initially demonstrated by inverting 2D finite-difference time-domain (FDTD) simulation data from a crosshole radar survey. Furthermore, it was demonstrated that numerical data simulated in 3D could be inverted by the developed 2D algorithm. The frequency spectra of the source functions used in the inversion experiments did not agree with the true sources; they were noticeably either higher or lower. The results of the numerical experiments showed that the material property distribution can be calculated with high accuracy, without having accurate source information and without any pre-processing needed to compensate for the characteristics of radar wave propagation in 3D space.

Kim, Jung-Ho; Kobayashi, Takao; Lee, Seong Kon

2012-06-01

63

In-situ characterization of transformation plasticity during an isothermal austenite-to-bainite phase transformation  

SciTech Connect

This paper elucidates the stress-induced variant selection process during the isothermal austenite-to-bainite phase transformation in a tool steel. Specifically, a thorough set of experiments combining electron backscatter diffraction and in-situ digital image correlation (DIC) was carried out to establish the role of superimposed stress level on the evolution of transformation plasticity (TP) strains. The important finding is that TP increases concomitant with the superimposed stress level, and strain localization accompanies phase transformation at all stress levels considered. Furthermore, TP strain distribution within the whole material becomes more homogeneous with increasing stress, such that fewer bainitic variants are selected to grow under higher stresses, yielding a more homogeneous strain distribution. In particular, the bainitic variants oriented along [101] and [201] directions are favored to grow parallel to the loading axis and are associated with large TP strains. Overall, this very first in-situ DIC investigation of the austenite-to-bainite phase transformation in steels evidences the clear relationship between the superimposed stress level, variant selection, and evolution of TP strains. - Highlights: Black-Right-Pointing-Pointer Local variations of strain were observed by DIC throughout the phase transformation. Black-Right-Pointing-Pointer The study clearly established the role of the stress-induced variant selection. Black-Right-Pointing-Pointer Variant selection is a key parameter that governs distortion.

Holzweissig, M.J., E-mail: martinh@mail.upb.de [University of Paderborn, Lehrstuhl fuer Werkstoffkunde (Materials Science), 33095 Paderborn (Germany); Canadinc, D., E-mail: dcanadinc@ku.edu.tr [Koc University, Advanced Materials Group, Department of Mechanical Engineering, 34450 Istanbul (Turkey); Maier, H.J., E-mail: hmaier@mail.upb.de [University of Paderborn, Lehrstuhl fuer Werkstoffkunde (Materials Science), 33095 Paderborn (Germany)

2012-03-15

64

Design, Fabrication, and Characterization of Metamaterials for Transformation Optics and Focusing Applications.  

National Technical Information Service (NTIS)

The research covered four primary areas: manufacture of on-chip transformation optics (metamaterials), metamaterials as superabsorbers, thermal characterization of metamaterials and nanophotonic devices, and use of metamaterials for plasmonic focusing and...

U. Levy

2014-01-01

65

Global Admittance Estimates of Elastic and Crustal Thickness of Venus: Results from Top, Hot Spot, and Bottom Loading Models  

NASA Technical Reports Server (NTRS)

We have calculated admittance spectra using the spatio-spectral method [14] for Venus by moving the central location of the spectrum over a 1 grid, create 360x180 admittance spectra. We invert the observed admittance using top-loading (TL), hot spot (HS), and bottom loading (BL) models, resulting in elastic, crustal, and lithospheric thickness estimates (Te, Zc, and Zl) [0]. The result is a global map for interpreting subsurface structure. Estimated values of Te and Zc concur with previous TL local admittance results, but BL estimates indicate larger values than previously suspected.

Smrekar, S. E.; Anderson, F. S.

2005-01-01

66

Spatial exemplars and metrics for characterizing image compression transform error  

NASA Astrophysics Data System (ADS)

The efficient transmission and storage of digital imagery increasingly requires compression to maintain effective channel bandwidth and device capacity. Unfortunately, in applications where high compression ratios are required, lossy compression transforms tend to produce a wide variety of artifacts in decompressed images. Image quality measures (IQMs) have been published that detect global changes in image configuration resulting from the compression or decompression process. Examples include statistical and correlation-based procedures related to mean-squared error, diffusion of energy from features of interest, and spectral analysis. Additional but sparsely-reported research involves local IQMs that quantify feature distortion in terms of objective or subjective models. In this paper, a suite of spatial exemplars and evaluation procedures is introduced that can elicit and measure a wide range of spatial, statistical, or spectral distortions from an image compression transform T. By applying the test suite to the input of T, performance deficits can be highlighted in the transform's design phase, versus discovery under adverse conditions in field practice. In this study, performance analysis is concerned primarily with the effect of compression artifacts on automated target recognition (ATR) algorithm performance. For example, featural distortion can be measured using linear, curvilinear, polygonal, or elliptical features interspersed with various textures or noise-perturbed backgrounds or objects. These simulated target blobs may themselves be perturbed with various types or levels of noise, thereby facilitating measurement of statistical target-background interactions. By varying target-background contrast, resolution, noise level, and target shape, compression transforms can be stressed to isolate performance deficits. Similar techniques can be employed to test spectral, phase and boundary distortions due to decompression. Applicative examples are taken from ATR practice, with supporting performance analysis of space, time, and computational error associated with measures included in the test suite.

Schmalz, Mark S.; Caimi, Frank M.

2001-12-01

67

TRANSFORMATION  

SciTech Connect

Transformation, which alters the genetic makeup of an individual, is a concept that intrigues the human imagination. In Streptococcus pneumoniae such transformation was first demonstrated. Perhaps our fascination with genetics derived from our ancestors observing their own progeny, with its retention and assortment of parental traits, but such interest must have been accelerated after the dawn of agriculture. It was in pea plants that Gregor Mendel in the late 1800s examined inherited traits and found them to be determined by physical elements, or genes, passed from parents to progeny. In our day, the material basis of these genetic determinants was revealed to be DNA by the lowly bacteria, in particular, the pneumococcus. For this species, transformation by free DNA is a sexual process that enables cells to sport new combinations of genes and traits. Genetic transformation of the type found in S. pneumoniae occurs naturally in many species of bacteria (70), but, initially only a few other transformable species were found, namely, Haemophilus influenzae, Neisseria meningitides, Neisseria gonorrheae, and Bacillus subtilis (96). Natural transformation, which requires a set of genes evolved for the purpose, contrasts with artificial transformation, which is accomplished by shocking cells either electrically, as in electroporation, or by ionic and temperature shifts. Although such artificial treatments can introduce very small amounts of DNA into virtually any type of cell, the amounts introduced by natural transformation are a million-fold greater, and S. pneumoniae can take up as much as 10% of its cellular DNA content (40).

LACKS,S.A.

2003-10-09

68

A Novel Approach to Current Transformer Characterization in the Presence of Harmonic Distortion  

Microsoft Academic Search

The current transformer (CT) performance under distorted waveform conditions is usually characterized by means of the frequency-response test. In this paper, a new way to characterize CTs, closer to real operation conditions, is proposed. The harmonic phase-angle and ratio errors are measured using a nonsinusoidal current composed of fundamental and one harmonic with adjustable phase shift. The new method was

Antonio Cataliotti; Dario Di Cara; Alexander E. Emanuel; Salvatore Nuccio

2009-01-01

69

Characterizing the Hilbert transform by the Bedrosian theorem  

NASA Astrophysics Data System (ADS)

It is proved that a bounded linear translation invariant operator on satisfies the Bedrosian theorem if and only if it is a linear combination of the compositions of the partial Hilbert transforms and the identity operatorE This observation justifies a definition of multidimensional analytic signals in the papers [T. Bulow, G. Sommer, Hypercomplex signals--a novel extension of the analytic signal to the multidimensional case, IEEE Trans. Signal Process. 49 (2001) 2844-2852] and [S.L. Hahn, Multidimensional complex signals with single-orthant spectra, Proc. IEEE 80 (1992) 1287-1300].

Venouziou, Moises; Zhang, Haizhang

2008-02-01

70

Structural Characterization of Carbohydrates by Fourier Transform Tandem Mass Spectrometry  

PubMed Central

Fourier transform tandem mass spectrometry (MS/MS) provides high mass accuracy, high sensitivity, and analytical versatility and has therefore emerged as an indispensable tool for structural elucidation of biomolecules. Glycosylation is one of the most common posttranslational modifications, occurring in ~50% of proteins. However, due to the structural diversity of carbohydrates, arising from non-template driven biosynthesis, achievement of detailed structural insight is highly challenging. This review briefly discusses carbohydrate sample preparation and ionization methods, and highlights recent developments in alternative high-resolution MS/MS strategies, including infrared multiphoton dissociation (IRMPD), electron capture dissociation (ECD), and electron detachment dissociation (EDD), for carbohydrates with a focus on glycans and proteoglycans from mammalian glycoproteins.

Zhou, Wen; Hakansson, Kristina

2012-01-01

71

Effect of nonzero surface admittance on receptivity and stability of compressible boundary layer  

NASA Technical Reports Server (NTRS)

The effect of small-amplitude short-scale variations in surface admittance on the acoustic receptivity and stability of two-dimensional compressible boundary layers is examined. In the linearized limit, the two problems are shown to be related both physically and mathematically. This connection between the two problems is used, in conjunction with some previously reported receptivity results, to infer the modification of stability properties due to surface permeability. Numerical calculations are carried out for a self-similar flat-plate boundary layer at subsonic and low supersonic speeds. Variations in mean suction velocity at the perforated admittance surface can also induce receptivity to an acoustic wave. For a subsonic boundary layer, the dependence of admittance-induced receptivity on the acoustic-wave orientation is significantly different from that of the receptivity produced via mean suction variation. The admittance-induced receptivity is generally independent of the angle of acoustic incidence, except in a relatively narrow range of upstream-traveling waves for which the receptivity becomes weaker. However, this range of angles is precisely that for which the suction-induced receptivity tends to be large. At supersonic Mach numbers, the admittance-induced receptivity to slow acoustic models is relatively weaker than that in the case of the fast acoustic modes. We also find that purely real values for the surface admittance tend to have a destabilizing effect on the evolution of an instability wave over a slightly permeable surface. The limits on the validity of the linearized approximation are also assessed in one specific case.

Choudhari, Meelan

1994-01-01

72

Effect of nonzero surface admittance on receptivity and stability of compressible boundary layer  

NASA Astrophysics Data System (ADS)

The effect of small-amplitude short-scale variations in surface admittance on the acoustic receptivity and stability of two-dimensional compressible boundary layers is examined. In the linearized limit, the two problems are shown to be related both physically and mathematically. This connection between the two problems is used, in conjunction with some previously reported receptivity results, to infer the modification of stability properties due to surface permeability. Numerical calculations are carried out for a self-similar flat-plate boundary layer at subsonic and low supersonic speeds. Variations in mean suction velocity at the perforated admittance surface can also induce receptivity to an acoustic wave. For a subsonic boundary layer, the dependence of admittance-induced receptivity on the acoustic-wave orientation is significantly different from that of the receptivity produced via mean suction variation. The admittance-induced receptivity is generally independent of the angle of acoustic incidence, except in a relatively narrow range of upstream-traveling waves for which the receptivity becomes weaker. However, this range of angles is precisely that for which the suction-induced receptivity tends to be large. At supersonic Mach numbers, the admittance-induced receptivity to slow acoustic models is relatively weaker than that in the case of the fast acoustic modes. We also find that purely real values for the surface admittance tend to have a destabilizing effect on the evolution of an instability wave over a slightly permeable surface. The limits on the validity of the linearized approximation are also assessed in one specific case.

Choudhari, Meelan

1994-08-01

73

Evolute-based Hough transform method for characterization of ellipsoids.  

PubMed

We propose a novel and algorithmically simple Hough transform method that exploits the geometric properties of ellipses to enable the robust determination of the ellipse position and properties. We make use of the unique features of the evolute created by Hough voting along the gradient vectors of a two-dimensional image to determine the ellipse centre, orientation and aspect ratio. A second one-dimensional voting is performed on the minor axis to uniquely determine the ellipse size. This reduction of search space substantially simplifies the algorithmic complexity. To demonstrate the accuracy of our method, we present analysis of single and multiple ellipsoidal particles, including polydisperse and imperfect ellipsoids, in both simulated images and electron micrographs. Given its mathematical simplicity, ease of implementation and reasonable algorithmic completion time, we anticipate that the proposed method will be broadly useful for image processing of ellipsoidal particles, including their detection and tracking for studies of colloidal suspensions, and for applications to drug delivery and microrheology. PMID:23301634

Kaytanli, B; Valentine, M T

2013-03-01

74

Transformers  

NSDL National Science Digital Library

All About Circuits is a website that âÂÂprovides a series of online textbooks covering electricity and electronics.â Written by Tony R. Kuphaldt, the textbooks available here are wonderful resources for students, teachers, and anyone who is interested in learning more about electronics. This specific section, Transformers, is the ninth chapter in Volume II âÂÂAlternating Current (AC). A few of the topics covered in this chapter include: Mutual inductance and basic operation; Step-up and Step-down transformers; Electrical isolation; Phasing; Winding configurations; Voltage Regulation; and finally, Special transformers and applications.. Diagrams and detailed descriptions of concepts are included throughout the chapter to provide users with a comprehensive lesson. Visitors to the site are also encouraged to discuss concepts and topics using the All About Circuits discussion forums (registration with the site is required to post materials).

Kuphaldt, Tony R.

2008-07-03

75

Multiscale characterization of chronobiological signals based on the discrete wavelet transform  

Microsoft Academic Search

To compensate for the deficiency of conventional frequency-domain or time-domain analysis, this paper presents a multiscale approach to characterize the chronobiological time series (CTS) based on a discrete wavelet transform (DWT). We have shown that the local modulus maxima and zero-crossings of the wavelet coefficients at different scales give a complete characterization of rhythmic activities. We further constructed a tree

F. H. Y. Chan; B. M. Wu; E. K. Lam; P. W. F. Poon; A. M. S. Poon

2000-01-01

76

Analysis of the spatial sensitivity of conductance/admittance catheter ventricular volume estimation.  

PubMed

Conductance catheters are known to have a nonuniform spatial sensitivity due to the distribution of the electric field. The Geselowitz relation is applied to murine and multisegment conductance catheters using finite element models to determine the spatial sensitivity in a uniform medium and simplified left ventricle models. A new formulation is proposed that allows determination of the spatial sensitivity to admittance. Analysis of FEM numerical modeling results using the Geselowitz relation provides a true measure of parallel conductance in simplified left ventricle models for assessment of the admittance method and hypertonic saline techniques. The spatial sensitivity of blood conductance (Gb) is determined throughout the cardiac cycle. Gb is converted to volume using Wei's equation to determine if the presence of myocardium alters the nonlinear relationship through changes to the electric field. Results show that muscle conductance (Gm) from the admittance method matches results from the Geselowitz relation and that the relationship between Gb and volume is accurately fit using Wei's equation. Single-segment admittance measurements in large animals result in a more evenly distributed sensitivity to the LV blood pool. The hypertonic saline method overestimates parallel conductance throughout the cardiac cycle in both murine and multisegment conductance catheters. PMID:23559022

Larson, Erik R; Feldman, Marc D; Valvano, Jonathan W; Pearce, John A

2013-08-01

77

Measurement of the acoustic admittance of the burning surface of gunpowder  

Microsoft Academic Search

The acoustic admittance of a burning surface is a fundamental physical property which defines the tendency of gunpowder to acoustic instability of combustion. Under conditions of acoustic instability of combustion of condensed systems, pressure waves are usually intensified at the burning surface of gunpowder in the narrow zone of intense chemical reactions. The characteristic dimensions of this zone are small

A. D. Margolin; I. B. Svetlichnyi; P. F. Pokhil; A. S. Tsirul'nikov

1970-01-01

78

Calculation of Characteristic Admittances and Coupling Coefficients for Strip Transmission Lines  

Microsoft Academic Search

An integral equation technique is presented which may be used to efficiently compute the Maxwellian capacitance matrix, i.e., the coefficients of capacitance and inductance, for any system of zero-thickness strip conductors located parallel to and between two ground planes, The TEM characteristic admittances for various operating modes and the coupling coefficients can then be obtained from the elements of this

D. W. Kammler

1968-01-01

79

Characterization of rare transforming KRAS mutations in sporadic colorectal cancer.  

PubMed

KRAS mutational status has been shown to be a predictive biomarker of resistance to anti-EGFR monoclonal antibody (mAb) therapy in patients with metastatic colorectal cancer. We report the spectrum of KRAS mutation in 1506 patients with colorectal cancer and the identification and characterization of rare insertion mutations within the functional domain of KRAS. KRAS mutations are found in 44.5% (670/1506) of the patients. Two cases are found to harbor double mutations involving both codons 12 and 13. The frequencies of KRAS mutations at its codons 12, 13, 61, and 146 are 75.1%, 19.3%, 2.5%, and 2.7%, respectively. The most abundant mutation of codon 12 is G12D, followed by G12V and G12C while G13D is the predominant mutation in codon 13. Mutations in other codons are rare. The KRAS mutation rate is significantly higher in women (48%, 296/617) than in men (42.1%, 374/889, P = 0.023). Tumors on the right colon have a higher frequency of KRAS mutations than those on the left (57.3% vs. 40.4%, P<0.0001). Two in-frame insertion mutations affect the phosphate-binding loop (codon 10-16) of KRAS are identified. One of them has never been reported before. Compared with wild-type protein, the insertion variants enhance the cellular accumulation of active RAS (RAS-GTP) and constitutively activate the downstream signaling pathway. NIH3T3 cells transfected with the insertion variants show enhanced anchorage-independent growth and in vivo tumorigenicity. Potentially these mutations contribute to primary resistance to anti-EGFR mAb therapy but the clinical implication requires further validation. PMID:24642870

Tong, Joanna Hm; Lung, Raymond Wm; Sin, Frankie Mc; Law, Peggy Py; Kang, Wei; Chan, Anthony Wh; Ma, Brigette By; Mak, Tony Wc; Ng, Simon Sm; To, Ka Fai

2014-06-01

80

On the Congruent Transformation of Electrical Networks for Equivalent Forms.  

National Technical Information Service (NTIS)

In this thesis the generation of equivalent networks by means of a congruent transformation using a variable transformation matrix applied to the admittance matrix of an n+1 node, common datum, network is studied. The ranges of the values of the elements ...

A. Ardalan

1967-01-01

81

Fourier Transform Infrared and Raman Spectroscopy for Characterization of Listeria monocytogenes Strains  

Microsoft Academic Search

The purpose of this study was to characterize the variation in biochemical composition of 89 strains of Listeria monocytogenes with different susceptibilities towards sakacin P, using Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy. The strains were also analyzed using amplified fragment length polymorphism (AFLP) analysis. Based on their susceptibilities to sakacin P, the 89 strains have previously been divided

Astrid Oust; T. Moretro; Kristine Naterstad; Ganesh D. Sockalingum; Isabelle Adt; Michel Manfait; Achim Kohler

2006-01-01

82

Characterization of strain-induced martensitic transformation in a metastable austenitic stainless steel  

Microsoft Academic Search

Kinetics of deformation-induced martensitic transformation in metastable austenitic steel AISI 301 was characterized by several techniques including classical light metallography, scanning electron microscopy, X-ray diffraction, neutron diffraction and electron back scattered diffraction. In situ monitoring of magnetic properties, acoustic emission and temperature increase during tensile tests at different strain rates was also performed. Results obtained by different methods are compared

P. Haušild; V. Davydov; J. Drahokoupil; M. Landa; P. Pilvin

2010-01-01

83

Characterization of fluids involved in the Gneiss-Charnockite transformation in Southern Kerala (India)  

NASA Technical Reports Server (NTRS)

The characterization of fluids involved in the gneiss-charnockite transformation in southern Kerala are discussed. Using a variety of techniques, including microthermometry, Raman laser probe analysis, and mass spectrometry, it was concluded that the CO2-rich, N2-bearing metamorphic fluids in these rocks were internally-derived rather than having been introduced by CO2-streaming.

Klatt, E.; Hoernes, S.; Raith, M.

1988-01-01

84

Validation of admittance computed left ventricular volumes against real-time three-dimensional echocardiography in the porcine heart.  

PubMed

The admittance and Wei's equation is a new technique for ventricular volumetry to determine pressure-volume relations that addresses traditional conductance-related issues of parallel conductance and field correction factor. These issues with conductance have prevented researchers from obtaining real-time absolute ventricular volumes. Moreover, the time-consuming steps involved in processing conductance catheter data warrant the need for a better catheter-based technique for ventricular volumetry. We aimed to compare the accuracy of left ventricular (LV) volumetry between the new admittance catheterization technique and transoesophageal real-time three-dimensional echocardiography (RT3DE) in a large-animal model. Eight anaesthetized pigs were used. A 7 French admittance catheter was positioned in the LV via the right carotid artery. The catheter was connected to an admittance control unit (ADVantage; Transonic Scisense Inc.), and data were recorded on a four-channel acquisition system (FA404; iWorx Systems). Admittance catheterization data and transoesophageal RT3DE (X7-2; Philips) data were simultaneously obtained with the animal ventilated, under neuromuscular blockade and monitored in baseline conditions and during dobutamine infusion. Left ventricular volumes measured from admittance catheterization (Labscribe; iWorx Systems) and RT3DE (Qlab; Philips) were compared. In a subset of four animals, admittance volumes were compared with those obtained from traditional conductance catheterization (MPVS Ultra; Millar Instruments). Of 37 sets of measurements compared, admittance- and RT3DE-derived LV volumes and ejection fractions at baseline and in the presence of dobutamine exhibited general agreement, with mean percentage intermethod differences of 10% for end-diastolic volumes, 14% for end-systolic volumes and 9% for ejection fraction; the respective intermethod differences between admittance and conductance in eight data sets compared were 11, 11 and 12%. Admittance volumes were generally higher than those obtained by RT3DE, especially among the larger ventricles. It is concluded that it is feasible to derive pressure-volume relations using admittance catheterization in large animals. This study demonstrated agreements between admittance and RT3DE to within 10-14% mean intermethod difference in the estimation of LV volumes. Further investigation will be required to examine the accuracy of volumes in largest ventricles, where intermethod divergence is greatest. PMID:23435903

Kutty, Shelby; Kottam, Anil T; Padiyath, Asif; Bidasee, Keshore R; Li, Ling; Gao, Shunji; Wu, Juefei; Lof, John; Danford, David A; Kuehne, Titus

2013-06-01

85

Methods for detection and characterization of signals in noisy data with the Hilbert-Huang transform  

SciTech Connect

The Hilbert-Huang transform is a novel, adaptive approach to time series analysis that does not make assumptions about the data form. Its adaptive, local character allows the decomposition of nonstationary signals with high time-frequency resolution but also renders it susceptible to degradation from noise. We show that complementing the Hilbert-Huang transform with techniques such as zero-phase filtering, kernel density estimation and Fourier analysis allows it to be used effectively to detect and characterize signals with low signal-to-noise ratios.

Stroeer, Alexander; Cannizzo, John K.; Camp, Jordan B.; Gagarin, Nicolas [Laboratory for Gravitational Physics, Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States); Starodub, Incorporated, 3504 Littledale Road, Kensington, Maryland, 20895 (United States)

2009-06-15

86

76 FR 31306 - Admittance to Practice and Roster of Registered Patent Attorneys and Agents Admitted to Practice...  

Federal Register 2010, 2011, 2012, 2013

...DEPARTMENT OF COMMERCE Patent and Trademark Office Admittance to Practice and Roster of Registered Patent Attorneys and Agents Admitted to Practice Before the United States Patent and Trademark Office (USPTO) (Proposed...

2011-05-31

87

Characterization of the transformations of lignocellulosic structures upon degradation in planted soil  

Microsoft Academic Search

Analytical pyrolysis (AP) as well as chemical analysis, ESR, FTIR and UV\\/VIS-spectroscopy has been used to characterize effects of modification of industrial lignins (hydrolysis lignin and kraft lignin) with silicon-containing oligomers on their transformation in soil planted with timothy grass (Phleum pratense). Using Py-GC\\/MS it was shown that carbohydrate-originated admixtures of non-modified hydrolysis lignin were degraded preferentially during the first

G. Telysheva; G. Dobele; D. Meier; T. Dizhbite; G. Rossinska; V. Jurkjane

2007-01-01

88

Simultaneous recovery of admittivity and body shape in electrical impedance tomography: an experimental evaluation  

NASA Astrophysics Data System (ADS)

In this paper, the simultaneous retrieval of the exterior boundary shape and the interior admittivity distribution of an examined body in electrical impedance tomography is considered. The reconstruction method is built for the complete electrode model and it is based on the Fréchet derivative of the corresponding current-to-voltage map with respect to the body shape. The reconstruction problem is cast into the Bayesian framework, and maximum a posteriori estimates for the admittivity and the boundary geometry are computed. The feasibility of the approach is evaluated by experimental data from water tank measurements. The results demonstrate that the proposed method has potential for handling an unknown body shape in a practical setting.

Dardé, Jérémi; Hyvönen, Nuutti; Seppänen, Aku; Staboulis, Stratos

2013-08-01

89

Effect of Different Plasmon Active Metals on Admittance Loci Based Design of a Plasmonic Sensor  

NASA Astrophysics Data System (ADS)

A Kretschmann type plasmonic structure consisting of a fused silica glass prism, plasmon active metal film and dielectric sample has been investigated with the use of admittance loci method in attenuated total internal reflection mode. Different plasmon active metals have been used to study their effect on surface plasmon resonance (SPR) sensing (at 633 nm wavelength of He-Ne light) by admittance loci plots and also by corresponding SPR sensing curves. The performance of the plasmonic structure based on the choice of plasmon active metal has been discussed with the help of sensitivity and figure of merit plots giving emphasis on the dynamic range of the designed plasmonic structure. Simulations have been carried out in MATLAB 7.1 environment.

Brahmachari, Kaushik; Ray, Mina

2014-11-01

90

Development and evaluation of spectral transformation algorithms for analysis and characterization of forest vegetation  

NASA Astrophysics Data System (ADS)

This research reviewed and evaluated some of the most important statistically based spectral transformation algorithms. Two spectral transformation algorithms, canonical discriminant analysis (CDA) and multiple logistic regression (MLR) transformations were developed and evaluated in two independent studies. The objectives were to investigate if the methods are capable of solving the two fundamental questions raised in the beginning: separating spectral overlap and quantifying spatial variability under forest conditions. It was generalized from previous research that spectral transformations are usually performed to complete one or more tasks, with ultimate goal of optimizing data structure for improving visual interpretation, analysis, and classification performance. PCA is the most widely used spectral transformation techniques. Kauth-Thomas Tasseled Cap transformed components are important vegetation indices, and they are developed using sensor and scene physical characteristics and Gram-Schmidt orthogonalization process. A theoretical comparison was conducted to identify major differences among Tasseled Cap, PCA, and CDA transformations in their objectives, prior knowledge requirements, limitations, processes, and variance-covariance usage. CDA was a better "separation" algorithm than PCA in improving overall classification accuracy. CDA was used as a transformation technique to not only increase class separation, but also reduce data dimension and noise. The last two canonical components usually contain largely noise variances, which hold less than 1 percent of the variance found in source variables. A sub-dimension (the first four components) is preferable for final classifications than the whole derived canonical component data sets, as the noise variances associated with the last two components were removed. Comparison of CDA and PCA eigenstructure matrices revealed that there is no distinct pattern in terms of source variable contribution and load signs between the canonical and the principal components. Three-dimensional graphing was a useful tool for the examination of classes which have spectral overlap in multidimensional discriminant space. When comparing dissimilarities of spatial characterizations between using ordinary classification output and probability surface, and when an ordinary classification output was used, spatially varied vegetation communities were sketched as large, homogeneous patches. Inter-class spatial gradients were lost under ordinary membership structure. However, when probability surfaces were combined with ordinary classification output for representation, inter-class and within-class spatial variations were better modeled with certainty. Overall classification accuracies based on MLR images were equivalent to using PCA transformation. The results assured that the MLR transformation can be considered as a "adequate" technique in term of its ability to preserve information for ordinary classification output. The probability surface derived through MLR may also be considered "reliable and predictive" compared to PCA scores.

Zhao, Guang

1998-11-01

91

The determination of carrier mobilities in CIGS photovoltaic devices using high-frequency admittance measurements  

Microsoft Academic Search

We apply a new method to deduce the hole carrier mobilities of Cu(InGa)Se2 (CIGS) polycrystalline films that have been incorporated into working solar cell devices. Our approach extends admittance measurements to frequencies of nearly 100 MHz in order to observe the characteristic dielectric carrier freeze-out and thus deduce the resistivity of the undepleted bulk absorber region in these devices. This

JinWoo Lee; J. David Cohen; William N. Shafarman

2005-01-01

92

Development of a trans-admittance mammography (TAM) using 60×60 electrode array  

NASA Astrophysics Data System (ADS)

We have developed a trans-admittance mammography (TAM) system as a supplementary or alternative method of the X-ray mammography to diagnose the breast cancer. Mechanical structure of the system is similar to the X-ray mammography with the breast placed between two plates. The pair of plates is movable to accommodate breasts with different sizes and rotatable to provide multiple images with different projection angles. Without using ionizing radiation, it acquires a projection image of tissue admittivity values. One plate is a flat solid electrode where we apply a constant sinusoidal voltage with a variable frequency. The other is equipped with 60×60 array of current-sensing electrodes, of which potentials are kept at the signal reference level. The electrode array is connected to six switching modules and each module routes current signals from 600 electrodes to two ammeter modules. Each ammeter module includes six channels of ammeters and each one of them comprises an independent current-to-voltage converter, voltage amplifier, ADC and digital phase-sensitive demodulator. Each ammeter sequentially measures exit currents from 50 electrodes chosen by the corresponding switching module. An FPGA controls six ammeters to collect real- and imaginary-parts of trans-admittance data from 300 electrodes. A separate FPGA arbitrates data and command exchanges between a DSP-based main controller and ammeter modules. It also generates a sinusoidal voltage signal to be applied to the breast. All the 3600 complex current data from 12 ammeter modules are transferred to the main controller, which is interfaced to a PC through an isolated USB. The system is provided with a program to display real- and imaginary-parts of measured trans-admittance maps. The measured maps at multiple frequencies are incorporated into a frequency-difference anomaly detection algorithm. In this paper, we describe the design and construction of the system.

Zhao, Mingkang; Liu, Qin; In Oh, Tong; Woo, Eung Je; Seo, Jin Keun

2010-04-01

93

Impedance and admittance characteristics of Bi2S3 nanowire arrays  

NASA Astrophysics Data System (ADS)

Current studies of the electrical impedance and admittance characteristics of the anodised aluminum oxide (AAO) nanoporous arrays and bismuth sulphide (Bi2S3) nanowire within AAO membranes are presented. The influence of potential and frequency scan rate effect produced on the real, imaginary and complex electrochemical impedance and double layer capacitance of the AAO nanopore and the Bi2S3 nanowire arrays were studied.

Katkevics, J.; Kunakova, G.; Viksna, A.; Holmes, J. D.; Erts, D.

2013-12-01

94

Grading and metastable effects in admittance spectroscopy of CIGS-based solar cells  

Microsoft Academic Search

Cu(In, Ga)Se2-based (CIGS) solar cells have achieved efficiencies up to 20%. Despite these excellent results, the understanding of the underlying mechanisms and the influence of defects on their performance is still incomplete. The determination of the energetic position of the defects and of their density of states is important. Admittance spectroscopy is an adequate technique for this. By varying the

K. Decock; S. Khelifi; F. Pianezzi; A. N. Tiwari; M. Burgelman

2011-01-01

95

Lunar geophysical parameters inversion based on gravity/topography admittance and particle swarm optimization  

NASA Astrophysics Data System (ADS)

This paper presents a FORTRAN computer program. The program as code will be used for lunar parameter inversions based on gravity/topography admittance. This will be done by assuming that the lunar lithosphere is modeled as a thin elastic spherical shell. The parameters discussed here include; load ratio, crustal thickness, subsurface load depth, crustal density and elastic lithosphere thickness. The admittance of the best-fitting model can be found through automatically adjusting misfits between one theoretical admittance and an observed one. The results in this paper indicate that this research’s theoretical model is reasonable for exploring the best-fitting parameters. In addition, this code is not only able to automatically and simultaneously calculate the global optimum solution of the parameters studied, but also performs well in computational speed. The code can be easily modified to include more parameter inversions; such as the inversion for subsurface density anomaly and the case of considering infilling material in some lunar mare basins.

Zhong, Zhen; Li, Fei; Yan, Jianguo; Yan, Peng; Dohm, James M.

2014-08-01

96

Characterisation of defects in p-GaN by admittance spectroscopy  

NASA Astrophysics Data System (ADS)

Mg-doped GaN films have been grown on (0 0 0 1) sapphire using metal organic vapour phase epitaxy. Use of different buffer layer strategies caused the threading dislocation density (TDD) in the GaN to be either approximately 2×109 cm-2 or 1×1010 cm-2. Frequency-dependent capacitance and conductance measurements at temperatures up to 450 K have been used to study the electronic states associated with the Mg doping, and to determine how these are affected by the TDD. Admittance spectroscopy of the films finds a single impurity-related acceptor level with an activation energy of 160±10 meV for [Mg] of about 1×1019 cm-3, and 120±10 eV as the Mg precursor flux decreased. This level is thought to be associated with the Mg acceptor state. The TDD has no discernible effect on the trap detected by admittance spectroscopy. We compare these results with cathodoluminescence measurements reported in the literature, which reveal that most threading dislocations are non-radiative recombination centres, and discuss possible reasons why our admittance spectroscopy have not detected electrically active defects associated with threading dislocations.

Elsherif, O. S.; Vernon-Parry, K. D.; Evans-Freeman, J. H.; Airey, R. J.; Kappers, M.; Humphreys, C. J.

2012-08-01

97

Application of admittance spectroscopy to evaluate carrier mobility in organic charge transport materials  

NASA Astrophysics Data System (ADS)

We examine the feasibility of admittance spectroscopy (AS) and susceptance analysis in the determination of the charge-carrier mobility in an organic material. The complex admittance of the material is analyzed as a function of frequency in AS. We found that the susceptance, which is the imaginary part of the complex admittance, is related to the carrier transport properties of the materials. A plot of the computer-simulated negative differential susceptance versus frequency yields a maximum at a frequency ?r-1. The position of the maximum ?r-1 is related to the average carrier transit time ?dc by ?dc=0.56?r. Thus, knowledge of ?r can be used to determine the carrier mobility in the material. Devices with the structure ITO/4,4',4'' -tris[N, -(3-methylphenyl)-N-phenylamino] triphenylamine/Ag have been designed to investigate the validity of the susceptance analysis in the hole mobility determination. The hole mobilities were measured both as functions of the electric field and the temperature. The hole mobility data extracted by susceptance analysis were in excellent agreement with those independently obtained from time-of-flight (TOF) measurements. Using the temperature dependence results, we further analyzed the mobility data by the Gaussian disorder model (GDM). The GDM disorder parameters are also in good agreement with those determined from TOF.

Tsang, S. W.; So, S. K.; Xu, J. B.

2006-01-01

98

Admittance analysis in (PPE-PPV) polymer (AnE-PVstat) light emitting diodes  

NASA Astrophysics Data System (ADS)

In this work, admittance analysis of organic light emitting diode (OLED) (anode/active layer/cathode) was performed at room temperature within the frequency range of 1 kHz-1MHz to find out transport properties of both injected carriers from each side. Moreover, by proper chosen metals, electron or hole only OLED devices were prepared and the measurement was resumed to identify the governed transport path of injected carrier. Mobility of injected carriers followed the Poole-Frenkel type conduction mechanism and distinguished in the frequency range due to the difference of transit times in admittance measurement. Beginning of light output and onset of negative capacitance took place at the turn-on voltage (or flat band voltage), 1.8 V, which was the difference of energy band gap of polymer and two barrier offsets between metals and polymer. The proposed analytical model for admittance, derived for the frequency dependent space charge limited behavior leading negative capacitance issues, was applied on the measured data for the present OLED device.

Özdemir, Orhan; Mucur, Selin P.; Tekin, Emine; Boudiba, Sameh; Ulbricht, Christoph; Egbe, Daniel A. M.; Deneb Menda, U.; Kavak, Pelin Aydogan; Kutlu, Kubilay

2013-09-01

99

Transient excitation and mechanical admittance test techniques for prediction of payload vibration environments  

NASA Technical Reports Server (NTRS)

Transient excitation forces were applied separately to simple beam-and-mass launch vehicle and payload models to develop complex admittance functions for the interface and other appropriate points on the structures. These measured admittances were then analytically combined by a matrix representation to obtain a description of the coupled system dynamic characteristics. Response of the payload model to excitation of the launch vehicle model was predicted and compared with results measured on the combined models. These results are also compared with results of earlier work in which a similar procedure was employed except that steady-state sinusoidal excitation techniques were included. It is found that the method employing transient tests produces results that are better overall than the steady state methods. Furthermore, the transient method requires far less time to implement, and provides far better resolution in the data. However, the data acquisition and handling problem is more complex for this method. It is concluded that the transient test and admittance matrix prediction method can be a valuable tool for development of payload vibration tests.

Kana, D. D.; Vargas, L. M.

1977-01-01

100

Characterization and immunotherapeutic potential of a monoclonal antibody against a ras oncogene transformed cell line  

SciTech Connect

Transformed cells express cell surface antigens not present, or present in diminished amounts on normal cells. Monoclonal antibodies can be used to identify and biochemically characterize tumor-associated antigens. Monoclonal antibody (MoAb) 45-2D9 was produced by immunization of BALB/c mice with a transformed cell line (45-2D9) induced by transfection of NIH 3T3 cells with a c-H-ras oncogene in DNA isolated from a human lung carcinoma. By immunoperoxidase staining, this antibody binds to the 45-342 cells as well as to the ras transformed primary and 3 secondary transfectants, including the one used to induce 45-342, but not to other ras transformed cell lines. Murine tumors as well as human fetal and most normal adult tissues are not stained. This antibody does bind to a variety of human tumors, including lung adenocarcinomas, as well as breast, colon and esophageal carcinomas. The ability of MoAb 45-2D9 to target ricin toxin A chain (RTA) and radio-isotopes to gp74 expressing cells was investigated. An immunotoxin generated by conjugating RTA to MoAb 45-2D9 inhibits protein and DNA synthesis by the 45-342 cells. Radiolabeled antibody specifically localizes to and can be used to image subcutaneous and pulmonary gp74 expressing tumors in nu/nu mice. Monoclonal antibodies against oncogene transformed cell lines may be useful for the detection and characterization of tumor-associated antigens as well as for the development of new tumor therapeutic and diagnostic reagents.

Ames, R.S. Jr.

1986-01-01

101

Admittance matrix of a trapezoidal piezoelectric heterogeneous bimorph.  

PubMed

Bimorph structures are a standard method for transforming the high force of piezoelectric materials into a large deflection. In micro electromechanical systems (MEMS) applications, it is preferable to use structures consisting of a passive substrate (usually silicon) and one or more piezoelectric layers on the top. Such structures are called heterogeneous bimorphs or enakemesomorphs. In some MEMS applications- for example, for use as acoustic transducers-it is desirable to arrange such heterogeneous bimorphs in a circular shape, which results in trapezoidal cantilever structures. In this paper, an analytic dynamic description of such actuators is obtained. The resulting model is proved to be compatible with existing models for heterogeneous bimorphs with constant width. A comparison to a finite element analysis model of an exemplary layout shows divergences wholly within the same range as found for published models for constant-width structures. PMID:23221226

Schachtele, Jonathan; Goll, Erich; Muralt, Paul; Kaltenbacher, Dominik

2012-12-01

102

Characterization of a case of follicular lymphoma transformed into B-lymphoblastic leukemia  

PubMed Central

Follicular lymphoma (FL) is a common form of non-Hodgkin lymphoma with an ability to transform into a more aggressive disease, albeit infrequently to B-lymphoblastic leukemia/lymphoma. While t(14;18)(q32;q21) has been associated with approximately 90% cases of FL, that alteration alone is insufficient to cause FL and associated mutations are still being elucidated. The transformation of FL to B-lymphoblastic leukemia generally includes the dysregulation of MYC gene expression, typically through IGH rearrangement. Such cases of “double-hit” leukemia/lymphoma with both BCL2 and MYC translocations warrant further study as they are often not identified early, are associated with a poor prognosis, and are incompletely understood in molecular terms. Here we describe a patient with a diagnosis of FL that transformed to B-lymphoblastic leukemia. Detailed cytogenetic characterization of the transformed specimen using karyotype, fluorescence in situ hybridization, microarray and gene rearrangement analyses revealed a complex karyotype comprised principally of whole chromosome or whole arm copy number gains or losses. Smaller, single-gene copy number alterations identified by microarray were limited in number, but included amplification of a truncated EP300 gene and alterations in NEIL1 and GPHN. Analyses defined the presence of an IGH/BCL2 fusion due to a translocation as well as a MYC/IGH fusion due to an insertion, with both rearrangements involving the same IGH allele. The data illustrate the value in characterizing double-hit lymphoma cases with both traditional and novel technologies in the detailed cytogenetic workup.

2013-01-01

103

Characterization of a case of follicular lymphoma transformed into B-lymphoblastic leukemia.  

PubMed

Follicular lymphoma (FL) is a common form of non-Hodgkin lymphoma with an ability to transform into a more aggressive disease, albeit infrequently to B-lymphoblastic leukemia/lymphoma. While t(14;18)(q32;q21) has been associated with approximately 90% cases of FL, that alteration alone is insufficient to cause FL and associated mutations are still being elucidated. The transformation of FL to B-lymphoblastic leukemia generally includes the dysregulation of MYC gene expression, typically through IGH rearrangement. Such cases of "double-hit" leukemia/lymphoma with both BCL2 and MYC translocations warrant further study as they are often not identified early, are associated with a poor prognosis, and are incompletely understood in molecular terms. Here we describe a patient with a diagnosis of FL that transformed to B-lymphoblastic leukemia. Detailed cytogenetic characterization of the transformed specimen using karyotype, fluorescence in situ hybridization, microarray and gene rearrangement analyses revealed a complex karyotype comprised principally of whole chromosome or whole arm copy number gains or losses. Smaller, single-gene copy number alterations identified by microarray were limited in number, but included amplification of a truncated EP300 gene and alterations in NEIL1 and GPHN. Analyses defined the presence of an IGH/BCL2 fusion due to a translocation as well as a MYC/IGH fusion due to an insertion, with both rearrangements involving the same IGH allele. The data illustrate the value in characterizing double-hit lymphoma cases with both traditional and novel technologies in the detailed cytogenetic workup. PMID:23985173

Ning, Yi; Foss, Aubry; Kimball, Amy S; Neill, Nicholas; Matz, Tricia; Schultz, Roger

2013-01-01

104

High-resolution Fourier transform spectrograph for characterization of echelle spectrograph wavelength calibrators  

NASA Astrophysics Data System (ADS)

Wavelength calibrators are a critical component of high precision and accuracy radial velocity measurements. An order of magnitude improvement of the state-of-the-art of calibration of echelle spectrographs is amongst the requirements needed to achieve detection of earth-mass planets around sun-like stars in the habitable zone. We present studies of calibrators using a custom Fourier Transform Spectrograph (FTS) optimized for characterizing broadband, high repetition-rate laser frequency combs ("astro-combs") as well as other calibration sources including Th:Ar lamps and white-light etalons.

Glenday, Alexander G.; Phillips, David F.; Webber, Matthew; Li, Chih-Hao; Furesz, Gabor; Chang, Guoqing; Chen, Li-Jin; Kärtner, Franz X.; Sasselov, Dimitar D.; Szentgyorgyi, Andrew H.; Walsworth, Ronald L.

2012-09-01

105

Characterization of Solid State Phase Transformation in Continuously Heated and Cooled Ferritic Weld Metal  

SciTech Connect

Arc welding processes involve cooling rates that vary over a wide range (1-100 K/s). The final microstructire is thus a product of the heating and cooling cycles experienced by the weld in addition to the weld composition. It has been shown that the first phase to form under weld cooling conditions may not be that predicted by equilibrium calculations. The partitioning of different interstitial/substitutional alloying elements at high temperatures can dramatically affect the subsequent phase transformations. In order to understand the effect of alloying on phase transformation temperatures and final microstructures time-resolved X-ray diffraction technique has been successfully used for characterization. The work by Jacot and Rappaz on pearlitic steels provided insight into austenitization of hypoeutectic steels using a finite volume model. However there is very little work done on the effect of heating and cooling rates on the phase transformation paths in bainitic/martensitic steels and weld metals. Previous work on a weld with higher aluminum content, deposited with a FCAW-S process indicated that even at aluminum levels where the primary phase to solidify from liquid should be delta ferrite, non-equilibrium austenite was observed. The presence of inhomogeneity in composition of the parent microstructure has been attributed to differences in transformation modes, temperatures and microstructures in dual-phase, TRIP steels and ferritic welds. The objectives of the work included the identification of the stability regions of different phases during heating and cooling, differences in the effect of weld heating and cooling rates on the phase transformation temperatures, and the variation in phase fractions of austenite and ferrite in the two phase regions as a function of temperature. The base composition used for the present work is a Fe-1%Al-2%Mn-1%Ni-0.04%C weld metal. A pseudo-binary phase diagram shows the expected solidification path under equilibrium conditions. However, the effect of heating and cooling rates on the phase transformation path due to non-equilibrium partitioning of alloying elements cannot be predicted by equilibrium phase diagrams. Also, it is unclear if there is retention of delta ferrite to room temperature due to compositional or thermal effects. This would dramatically affect the austenite to ferrite transformation due to carbon and nitrogen enrichment in the austenite.

Narayana, B [Ohio State University, The, Columbus; Mills, Michael J. [Ohio State University, The, Columbus; Specht, Eliot D [ORNL; Santella, Michael L [ORNL; Babu, Sudarsanam Suresh [Ohio State University, The, Columbus

2010-12-01

106

Transformation of Sordaria macrospora to hygromycin B resistance: characterization of transformants by electrophoretic karyotyping and tetrad analysis  

Microsoft Academic Search

The ascomycete Sordaria macrospora was transformed using different plasmid molecules containing the bacterial hygromycin B resistance gene (hph) under the control of different expression signals. The highest transformation frequency was obtained with vector pMW1. On this plasmid molecule, expression of the hph gene is directed by the upstream region of the isopenicillin N synthetase gene (pcbC) from the deuteromycete Acremonium

Markus Walz; Ulrich Kiick

1995-01-01

107

Dynamic virtual fixture on the Euclidean group for admittance-type manipulator in deforming environments  

PubMed Central

Background In a deforming anatomic environment, the motion of an instrument suffers from complex geometrical and dynamic constraints, robot assisted minimally invasive surgery therefore requires more sophisticated skills for surgeons. This paper proposes a novel dynamic virtual fixture (DVF) to enhance the surgical operation accuracy of admittance-type medical robotics in the deforming environment. Methods A framework for DVF on the Euclidean Group SE(3) is presented, which unites rotation and translation in a compact form. First, we constructed the holonomic/non-holonomic constraints, and then searched for the corresponded reference to make a distinction between preferred and non-preferred directions. Second, different control strategies are employed to deal with the tasks along the distinguished directions. The desired spatial compliance matrix is synthesized from an allowable motion screw set to filter out the task unrelated components from manual input, the operator has complete control over the preferred directions; while the relative motion between the surgical instrument and the anatomy structures is actively tracked and cancelled, the deviation relative to the reference is compensated jointly by the operator and DVF controllers. The operator, haptic device, admittance-type proxy and virtual deforming environment are involved in a hardware-in-the-loop experiment, human-robot cooperation with the assistance of DVF controller is carried out on a deforming sphere to simulate beating heart surgery, performance of the proposed DVF on admittance-type proxy is evaluated, and both human factors and control parameters are analyzed. Results The DVF can improve the dynamic properties of human-robot cooperation in a low-frequency (0?~?40 rad/sec) deforming environment, and maintain synergy of orientation and translation during the operation. Statistical analysis reveals that the operator has intuitive control over the preferred directions, human and the DVF controller jointly control the motion along the non-preferred directions, the target deformation is tracked actively. Conclusions The proposed DVF for an admittance-type manipulator is capable of assisting the operator to deal with skilled operations in a deforming environment.

2014-01-01

108

Aerodynamic admittance functions and buffeting forces for bridges via indicial functions  

NASA Astrophysics Data System (ADS)

Buffeting forces on bridge decks are commonly modelled by Sears’ function. However, it is well known that Sears’ function is reliable only for very streamlined bridge deck sections and that a complete model would require a suitable formulation of buffeting forces in time domain. In this paper, self-excited and buffeting loads are modelled by means of indicial functions. Corresponding aerodynamic admittance functions are numerically evaluated for rectangular sections and compared with experimental and analytical results. A complete time-domain model for cross-sections including vertical turbulence is presented. Numerical simulations are performed on a sample rectangular section. Comparison with experimental results and relevant flutter analyses are also discussed.

Costa, C.

2007-04-01

109

Optical Fourier transform based in-plane vibration characterization for MEMS comb structure.  

PubMed

On-line and on-wafer characterizations of mechanical properties of Micro-Electro-Mechanical-System (MEMS) with efficiency are very important to the mass production of MEMS foundry in the near future. However, challenges still remain. In this paper, we present an in-plane vibration characterizing method for MEMS comb using optical Fourier transform (OFT). In the experiment, the intensity distribution at the focal plane was captured to characterize the displacement of the vibrator in the MEMS comb structure. A typical MEMS comb was tested to verify the principle. The shape and the movement of MEMS comb was imitated and tested to calibrate the measurement by using a spatial light modulator (SLM). The relative standard deviations (RSD) of the measured displacements were better than 5%, where the RSD is defined as the ratio of the standard deviation to the mean. It is convinced that the presented method is feasible for on-line and on-wafer characterizations for MEMS with great convenience, high efficiency and low cost. PMID:23482039

Gao, Yongfeng; Cao, Liangcai; You, Zheng; Zhao, Jiahao; Zhang, Zichen; Yang, Jianzhong

2013-02-25

110

Propagation and radiation of sound from flanged circular ducts with circumferentially varying wall admittances. I Semi-infinite ducts. II - Finite ducts with sources  

Microsoft Academic Search

Sound propagation in infinite, semiinfinite, and finite circular ducts with circumferentially varying wall admittances is investigated analytically. The infinite case is considered, and an example demonstrates the effects of wall-admittance distribution on dispersion characteristics and mode shapes. An exact solution is obtained for the semiinfinite case, a circular duct with a flanged opening: sidelobe suppression and circumferential-mode energy scattering leading

C. R. Fuller

1984-01-01

111

Hole transport characteristics in phosphorescent dye-doped NPB films by admittance spectroscopy  

NASA Astrophysics Data System (ADS)

Admittance spectroscopy is a powerful tool to determine the carrier mobility. The carrier mobility is a significant parameter to understand the behavior or to optimize the organic light-emitting diode or other organic semiconductor devices. Hole transport in phosphorescent dye, bis[2-(9,9-diethyl-9H-fluoren-2-yl)-1-phenyl-1Hbenzoimidazol-N,C3] iridium(acetylacetonate [(fbi)2Ir(acac)]) doped into N,N-diphenyl-N,N-bis(1-naphthylphenyl)-1,1-biphenyl-4,4-diamine (NPB) films was investigated by admittance spectroscopy. The results show that doped (fbi)2Ir(acac) molecules behave as hole traps in NPB, and lower the hole mobility. For thicker films(?300 nm), the electric field dependence of hole mobility is as expected positive, i.e., the mobility increases exponentially with the electric field. However, for thinner films (?300 nm), the electric field dependence of hole mobility is negative, i.e., the hole mobility decreases exponentially with the electric field. Physical mechanisms behind the negative field dependence of hole mobility are discussed. In addition, three frequency regions were divided to analyze the behaviors of the capacitance in the hole-only device and the physical mechanism was explained by trap theory and the parasitic capacitance effect.

Wang, Ying; Chen, Jiangshan; Huang, Jinying; Dai, Yanfeng; Zhang, Zhiqiang; Liu, Su; Ma, Dongge

2014-05-01

112

Glycosaminoglycan Characterization by Electrospray Ionization Mass Spectrometry Including Fourier Transform Mass Spectrometry  

PubMed Central

Electrospray ionization mass spectrometry (ESI MS) is a versatile analytical technique in glycomics of glycosaminoglycans (GAGs). Combined with enzymology, ESI MS is used for assessing changes in disaccharide composition of GAGs biosynthesized under different environmental or physiological conditions. ESI coupled with high-resolution mass analyzers such as a Fourier transform mass spectrometer (FTMS) permits accurate mass measurement of large oligosaccharides and intact GAGs as well as structural characterization of GAG oligosaccharides using information-rich fragmentation methods such as electron detachment dissociation. The first part of this chapter describes methods for disaccharide compositional profiling using ESI MS and the second part is dedicated to FTMS and tandem MS methods of GAG compositional and structural analysis.

Laremore, Tatiana N.; Leach, Franklin E.; Solakyildirim, Kemal; Amster, I. Jonathan; Linhardt, Robert J.

2011-01-01

113

Characterization of the Pituitary Tumor Transforming Gene 1 Knockout Mouse Retina  

PubMed Central

Recent gene expression studies on mouse models for retinal degeneration identified deregulation of Pituitary tumor transforming gene 1 (Pttg1) as a potential susceptibility factor involved in photoreceptor cell death. Pttg1 is a transcription regulatory protein involved in sister chromatid segregation, and Pttg1?/? mice exhibit testicular and splenic hypoplasia, thymic hyperplasia, aberrant cell cycle progression, chromosome instability, and impaired glucose homeostasis leading to diabetes, particularly in older males. Due to Pttg1 deregulation in dystrophic retinas, we characterized Pttg1?/? retinas using Hematoxylin and Eosin (H&E) staining, immunohistochemistry (IHC), and electroretinography (ERG). Seven month old Pttg1?/? mice were also examined for a diabetic retinopathy phenotype using Fluorescein Angiography (FA) to test for neovascularization. Our data reveal that up to 9 months of age, Pttg1?/? retinas have a healthy morphology and normal photoreceptor function. This study lays the groundwork for further investigation into the relevance of Pttg1 in retinal dystrophy.

Yetemian, Rosanne M.

2011-01-01

114

Characterization of human tracheal epithelial cells transformed by an origin-defective simian virus 40.  

PubMed Central

To facilitate understanding of the mechanisms underlying pulmonary diseases, including lung cancer and cystic fibrosis, we have transformed and characterized cultures of human tracheal epithelial cells. Cells were transfected by calcium phosphate precipitation with a plasmid containing a replication-defective simian virus 40 (SV40) genome. Colonies of cells with enhanced growth potential were isolated and analyzed for transformation- and epithelial-specific characteristics. Precrisis cells were observed to express the SV40 large tumor antigen, produce cytokeratins, have microvilli, and form tight junctions. After crisis, cells continued to express the SV40 large tumor antigen as well as epithelial-specific cytokeratins and to display the apical membrane microvilli. Apical membrane Cl channels were opened in postcrisis cells exposed to 50 microM forskolin. These channels showed electrical properties similar to those observed in primary cultures. The postcrisis cells have been in culture for greater than 250 generations and are potentially "immortal." In addition to providing a useful in vitro model for the study of ion transport by human airway epithelial cells, the cells can be used to examine stages of neoplastic progression. Images

Gruenert, D C; Basbaum, C B; Welsh, M J; Li, M; Finkbeiner, W E; Nadel, J A

1988-01-01

115

Characterization of chromosome and plasmid transformation in Bacillus subtilis using gently lysed protoplasts  

Microsoft Academic Search

Competent cells of Bacillus subtilis were transformed with DNA from gently lysed protoplasts. Significant linkages among markers separated by distances of approximately 2.3% of the total chromosome were found, which have not been detected for conventional transformation. In comparison to previous reports, enhanced plasmid transformation was observed [4.0×107 transformants per µg DNA (one transformant per 5×104 molecules added)], when competent

T. Akamatsu; J. Sekiguchi

1987-01-01

116

Transformation twinning of Ni-Mn-Ga characterized with temperature-controlled atomic force microscopy  

PubMed Central

The magnetomechanical properties of ferromagnetic shape memory alloy Ni–Mn–Ga single crystals depend strongly on the twin microstructure, which can be modified through thermomagnetomechanical training. Atomic force microscopy (AFM) and magnetic force microscopy (MFM) were used to characterize the evolution of twin microstructures during thermomechanical training of a Ni–Mn–Ga single crystal. Experiments were performed in the martensite phase at 25 °C and in the austenite phase at 55 °C. Two distinct twinning surface reliefs were observed at room temperature. At elevated temperature (55 °C), the surface relief of one twinning mode disappeared while the other relief remained unchanged. When cooled back to 25 °C, the twin surface relief recovered. The relief persisting at elevated temperature specifies the positions of twin boundaries that were present when the sample was polished prior to surface characterization. AFM and MFM following thermomechanical treatment provide a nondestructive method to identify the crystallographic orientation of each twin and of each twin boundary plane. Temperature dependent AFM and MFM experiments reveal the twinning history thereby establishing the technique as a unique predictive tool for revealing the path of the martensitic and reverse transformations of magnetic shape memory alloys.

Reinhold, Matthew; Watson, Chad; Knowlton, William B.; Mullner, Peter

2010-01-01

117

Transformation twinning of Ni-Mn-Ga characterized with temperature-controlled atomic force microscopy.  

PubMed

The magnetomechanical properties of ferromagnetic shape memory alloy Ni-Mn-Ga single crystals depend strongly on the twin microstructure, which can be modified through thermomagnetomechanical training. Atomic force microscopy (AFM) and magnetic force microscopy (MFM) were used to characterize the evolution of twin microstructures during thermomechanical training of a Ni-Mn-Ga single crystal. Experiments were performed in the martensite phase at 25 degrees C and in the austenite phase at 55 degrees C. Two distinct twinning surface reliefs were observed at room temperature. At elevated temperature (55 degrees C), the surface relief of one twinning mode disappeared while the other relief remained unchanged. When cooled back to 25 degrees C, the twin surface relief recovered. The relief persisting at elevated temperature specifies the positions of twin boundaries that were present when the sample was polished prior to surface characterization. AFM and MFM following thermomechanical treatment provide a nondestructive method to identify the crystallographic orientation of each twin and of each twin boundary plane. Temperature dependent AFM and MFM experiments reveal the twinning history thereby establishing the technique as a unique predictive tool for revealing the path of the martensitic and reverse transformations of magnetic shape memory alloys. PMID:20589105

Reinhold, Matthew; Watson, Chad; Knowlton, William B; Müllner, Peter

2010-06-01

118

Sixteen-Year Change in Acoustic-Admittance Measures among Older Adults: Data from a Population-Based Study  

ERIC Educational Resources Information Center

Purpose: The primary purpose of this study was to measure the 16-year change in peak compensated static acoustic admittance (Peak Y[subscript tm]) in a population-based cohort of older adults, and to determine whether age was associated with any observed change in Peak Y[subscript tm]. Other tympanometric measures also were taken and analyzed.…

Nondahl, David M.; Cruickshanks, Karen J.; Wiley, Terry L.; Tweed, Ted S.; Dalton, Dayna S.

2013-01-01

119

Comparison of the Summer Thermal Performance of Three Test Buildings with that Predicted by the Admittance Procedure  

Microsoft Academic Search

This paper details the results of thermal testing carried out on three experimental buildings during the summer of 2007 and compares their performance with that predicted by using the CIBSE Admittance procedure. The buildings, one brick veneer, one mud brick and one of autoclaved aerated concrete wall panels were constructed by the author in Sydney, Australia. The field results were

Kevan Heathcote

2008-01-01

120

Characterizing and overcoming spectral artifacts in imaging Fourier-transform spectroscopy of turbulent exhaust plumes  

NASA Astrophysics Data System (ADS)

The midwave and shortwave infrared regions of the electromagnetic spectrum contain rich information enabling the characterization of hot, rapid events such as explosions, engine plumes, flares and other combustion events. High-speed sensors are required to analyze the content of such rapidly evolving targets. Cameras with high frame rates and non-imaging spectrometers with high data rates are typically used; however the information from these two types of instruments must be later fused to enable characterization of the transient targets. Imaging spectrometers have recently become commercially available for general scientific use, thus enabling simultaneous capture of both spatial and spectral information without co-registration issues. However, their use against rapidly-varying sources has traditionally been considered problematic, for even at moderate spatial and spectral resolutions the time to acquire a single spectrum can be long compared to the timescales associated with combustion events. This paper demonstrates that imaging Fourier-transform spectroscopy (IFTS) can successfully characterize the turbulent combustion exhaust from a turbojet engine. A Telops Hyper-Cam IFTS collected hyperspectral video from a Turbine Technologies SR-30 turbojet engine with a spectral resolution of ?? = 1/cm-1 on a 200×64 pixel sub-window at a rate of 0.3 Hz. Scene-change artifacts (SCAs) are present in the spectra; however, the stochastic fluctuations in source intensity translate into high-frequency "noise." Temporal averaging affords a significant reduction of the noise associated with SCAs. Emission from CO and CO2 are clearly recognized in the averaged spectra, and information about their temperature and relative concentrations is evident.

Moore, Elizabeth A.; Gross, Kevin C.; Bowen, Spencer J.; Perram, Glen P.; Chamberland, Martin; Farley, Vincent; Gagnon, Jean-Philippe; Lagueux, Philippe; Villemaire, André

2009-05-01

121

Protein kinase A phosphorylation characterized by tandem Fourier transform ion cyclotron resonance mass spectrometry.  

PubMed

A microelectrospray ionization tandem Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS(n)) approach for structural characterization of protein phosphorylation is described. Identification of proteolytic peptides is based solely upon mass measurement by high field (9.4 Tesla) FT-ICR MS. The location of the modification within any phosphopeptide is then established by FT-ICR MS(2) and MS(3) experiments. Structural information is maximized by use of electron capture dissociation (ECD) and/or infrared multiphoton dissociation (IRMPD). The analytical utility of the method is demonstrated by characterization of protein kinase A (PKA) phosphorylation. In a single FT-ICR MS experiment, 30 PKA tryptic peptides (including three phosphopeptides) were mass measured by internal calibration to within an absolute mean error of |0.7 ppm|. The location of each of the three sites of phosphorylation was then determined by MS(2) and MS(3) experiments, in which ECD and IRMPD provide complementary peptide sequence information. In two out of three cases, electron irradiation of a phosphopeptide [M + nH](n+) ion produced an abundant charge-reduced [M + nH]((n-1)+*) ion, but few sequence-specific c and z(*) fragment ions. Subsequent IRMPD (MS(3)) of the charge-reduced radical ion resulted in the detection of a large number of ECD-type ion products (c and z ions), but no b or y type ions. The utility of activated ion ECD for the characterization of tryptic phosphopeptides was then demonstrated. PMID:15048979

Chalmers, Michael J; Håkansson, Kristina; Johnson, Robert; Smith, Richard; Shen, Jianwei; Emmett, Mark R; Marshall, Alan G

2004-04-01

122

The effect of flying and low humidity on the admittance of the tympanic membrane and middle ear system.  

PubMed

Many passengers experience discomfort during flight because of the effect of low humidity on the skin, eyes, throat, and nose. In this physiological study, we have investigated whether flight and low humidity also affect the tympanic membrane. From previous studies, a decrease in admittance of the tympanic membrane through drying might be expected to affect the buffering capacity of the middle ear and to disrupt automatic pressure regulation. This investigation involved an observational study onboard an aircraft combined with experiments in an environmental chamber, where the humidity could be controlled but could not be made to be as low as during flight. For the flight study, there was a linear relationship between the peak compensated static admittance of the tympanic membrane and relative humidity with a constant of proportionality of 0.00315 mmho/% relative humidity. The low humidity at cruise altitude (minimum 22.7 %) was associated with a mean decrease in admittance of about 20 % compared with measures in the airport. From the chamber study, we further found that a mean decrease in relative humidity of 23.4 % led to a significant decrease in mean admittance by 0.11 mmho [F(1,8)?=?18.95, P?=?0.002], a decrease of 9.4 %. The order of magnitude for the effect of humidity was similar for the flight and environmental chamber studies. We conclude that admittance changes during flight were likely to have been caused by the low humidity in the aircraft cabin and that these changes may affect the automatic pressure regulation of the middle ear during descent. PMID:23887775

Morse, Robert Peter

2013-10-01

123

Effect of high current density on the admittance response of interface states in ultrathin MIS tunnel junctions  

NASA Astrophysics Data System (ADS)

The effect of a high current density on the measured admittance of ultrathin Metal-Insulator-Semiconductor (MIS) tunnel junctions is investigated to obtain a reliable energy distribution of the density, DS(E), of defects localized at the semiconductor interface. The behavior of admittance Y(V, T, ?) and current density J(V, T) characteristics is illustrated by rectifying Hg//C12H25sbnd Si junctions incorporating n-alkyl molecular layers (1.45 nm thick) covalently bonded to n-type Si(1 1 1). Modeling the forward bias admittance of a nonequilibrium tunnel junction reveals several regimes which can be observed either in C(? ? 0) vs. (J) plots of the low frequency capacitance over six decades in current or in M?(?) plots of the electrical modulus over eight decades in frequency. At low current density, the response of interface states above mid-gap is unaffected and a good agreement is found between the interface states densities derived from the modeling of device response time ?R(V) and from the low-high frequency capacitance method valid for thick MIS devices; the low defect density near mid-gap (DS < 1011 eV-1 cm-2) results from a good passivation of dangling bonds at the C12H25sbnd n Si interface. In the high current density regime (J > 1 mA cm-2), the admittance depends strongly on both the density of localized states and the dc current density, so that the excess capacitance method overestimates DS. For very high current densities (J > 10 mA cm-2), the observation of a linear C(? ? 0) vs. (J) dependence could indicate some Fermi level pinning in a high interface density of states located near the Si conduction band. The temperature-independent excess capacitance C(? ? 0) - C(1 MHz) observed at very small J, not predicted by the admittance model, is attributed to some dipolar relaxation in the molecular junction.

Godet, Christian; Fadjie-Djomkam, Alain-Bruno; Ababou-Girard, Soraya

2013-02-01

124

Localized Gravity/Topography Correlation and Admittance Spectra one the Moon  

NASA Astrophysics Data System (ADS)

Lunar surface and structure can be separate into two parts. The lunar near side crust and far side crust differ remarkably in thickness. This difference probably caused by difference of thermal evolution and state (elastic thickness) and catering history on both side. The correlations and admittance between the topography and gravity anomalies provide important information on the level of isostatic compensation of the lithosphere at the geological timescale, and reflect its thermo-mechanical state. Therefore, localized correlation and admittance analysis is one of the most important studies of selenodesy. A global correlation between topography and gravity of the Moon obtained by Clementine and Lunar Prospector missions, respectively, reveals high value at long wavelength and low value at short wavelength. Such characteristics are distinguished from those of the Earth and other terrestrial planets, whose global correlation between topography and gravity is low at long wavelength. The distinct correlation between topography and gravity of the Moon may indicate that the lunar topography is supported by multiple compensation mechanism. Further, an incomplete coverage of Doppler tracking data prior to Kaguya (SELENE) gravity experiment probably contributed to the correlation. Because the Moon is synchronously rotating with its revolution around the Earth, a spacecraft orbiting over the far side is not visible from ground stations. In either case, it is significant to decompose local correlation from global ones in order to investigate internal structure of the Moon from spherical harmonic model of gravity (LP75G [1]) and topography (GLTM-2 [2]). Japanese lunar exploration Kaguya (SELENE) has two kinds of selenodesical experiments. One is RSAT/VRAD (gravity mapping with direct tracking over far-side) experiment and another is Laser ALTimeter (LALT; topography mapping) experiment. These two experiments enable us to conduct localized analysis for the Moon. Therefore we attempt localized spectral analysis of the Moon first and then apply possible compensation mechanisms to explain the observed admittance. Kaguya mission has been yielding representation of lunar gravity and topography (shape) substantially superior in resolution and accuracy to earlier solutions. For global lunar gravity field, an accurate spherical harmonic model of gravitational potential up to degree and order 100 (SGM100g) was derived from one year tracking (including 4-way Doppler) data [3]. For topography, LALT has obtained more than 6 million altitude measurements with 5 m precision, from which a spherical harmonic expansion of topography to degree and order 359 (STM359_grid-02) has been determined [4]. In this study, we use those new models. We employ the spatio-spectral localization technique [5] to obtain gravity/shape correlation and admittance spectra as function of position on the Moon. In this analysis, we localize harmonic field with axisymmetric windows of constant diameter, described by Lwin zonal harmonic coefficients. This restricts the permissible range of l in the windowed fields at both the low- (l > Lwin) and high-wave number ends (l < Lobs-Lwin, ; Lobs is the maximum degree of observation) . We chose four fixed windows with Lwin = 5, 10, 17, 26 (equivalent to spatial scales 2200, 1100, 640 and 420 km, respectively). These window sizes correspond to huge-, large-, middle-, and small-size of impact basins. For up to degree 50 with Lwin = 5 scale, it is clearly shown that the near-side contains distinct anti-correlation regions whereas the far-side is mostly occupied by high correlation regions. This difference is mainly due to large mascon basins in near-side, such as mare Imbrium. For Lwin = 10 and 17 scales, we can see anti-correlation regions at not only near-side but also far-side. Locations of anti-correlation regions in the far-side correspond to impact basins (Type II basin [6]). However, lots of far side basins (Type I basin [6]) are not indicated by anti-correlations for these window sizes. For Lwin = 26 scale, we can see we

Ishihara, Y.; Namiki, N.; Sugita, S.; Matsumoto, K.; Goossens, S.; Araki, H.; Noda, H.; Sasaki, S.; Iwata, T.; Hanada, H.

2009-04-01

125

Determination of electron mobility in tris(8-hydroxy-quinolinato) aluminum by admittance spectroscopy  

NASA Astrophysics Data System (ADS)

The electron mobilities of tris(8-hydroxy-quinolinato) aluminum (Alq3) thin films at various thicknesses (70-280 nm) have been determined by using admittance spectroscopy measurements. Our results show that the electric field dependence of electron mobilities exhibits different behaviors at different thicknesses of Alq3 films. Clearly, when the thickness of Alq3 film is less than 150 nm, the electron mobilities slightly decrease with increasing the electric field. For the thickness of Alq3 film more than 150 nm, however, the mobilities increase as the electric field increases. The phenomena are well discussed by energetic disorder. Using temperature dependent I-V characteristics, we further calculated the density of traps.

Wang, Yanping; Chen, Jiangshan; Dong, Lisong; Ma, Dongge

2013-09-01

126

Admittance Survey of Type 1 Coronae on Venus: Implications for Elastic Thickness  

NASA Technical Reports Server (NTRS)

Coronae are volcano-tectonic features on Venus which range from 60km to 2600km and are defined by their nearly circular patterns of fractures. Type 1 (regular) coronae are classified as having >50% complete fracture annuli. Previous work has examined the factors controlling the morphology, size, and fracture pattern of coronae, using lithospheric properties, loading signature and geologic characteristics. However, these studies have been limited to Type 2 (topographic) coronae (e.g. coronaes with <50% fracture annuli), and the factors controlling the formation of Type 1 coronae remain poorly understood. In this study, we apply the methodology of to survey the admittance signature for Type 1 coronae to determine the controlling parameters which govern Type 1 coronae formation.

Hoogenboom, T.; Smrekar, S. E.; Anderson, F. S.; Houseman, G.

2003-01-01

127

Development and evaluation of spectral transformation algorithms for analysis and characterization of forest vegetation  

Microsoft Academic Search

This research reviewed and evaluated some of the most important statistically based spectral transformation algorithms. Two spectral transformation algorithms, canonical discriminant analysis (CDA) and multiple logistic regression (MLR) transformations were developed and evaluated in two independent studies. The objectives were to investigate if the methods are capable of solving the two fundamental questions raised in the beginning: separating spectral overlap

Guang Zhao

1998-01-01

128

Faber-Schauder Wavelet Transform, Application to Edge Detection and Image Characterization  

Microsoft Academic Search

The Faber-Schauder wavelet transform is a simple multiscale transformation with many interesting properties in image processing. Some of these properties are: preservation of pixel ranges, arithmetic operations, non requirement of boundary processing, multiscale edge detection, elimination of the constant and the linear correlation, and the use of close neighboring information. In this study we describe this transformation and we propose

H. Douzi; Driss Mammass; Fathallah Nouboud

2001-01-01

129

Stable and efficient reduction of large, multiport RC networks by pole analysis via congruence transformations  

Microsoft Academic Search

A novel technique is presented which employs Pole Analysis via Congruence Transformations (PACT) to reduce RC networks in a well-conditioned manner. Pole analysis is shown to be more efficient than Padé approximations when the number of network ports is large, and congruence transforma- tions preserve the passivity (and thus absolute stability) of the networks. Networks are represented by admittance matrices

Kevin J. Kerns; Andrew T. Yang

1996-01-01

130

A method for determining acoustic-liner admittance in ducts with sheared flow in two-cross-sectional directions  

NASA Technical Reports Server (NTRS)

A method is developed for determining the acoustic admittance of a test liner installed in the wall of a grazing flow impedance tube. The mean flow is permitted flow gradients in both cross-sectional directions of the tube. The unknown admittance value is obtained by solving an eigenvalue problem. This eigenvalue problem results from the application of the finite-element method to the partial differential equation and boundary conditions governing the acoustic field. The credibility of the method is established by comparing results with exact solutions obtained for a constant mean-flow profile and with previous results for cases involving shear in only one cross-sectional direction. Excellent comparisons are obtained in both cases. The analysis is used in conjunction with a limited amount of experimental data and shows that the flow must be accurately modeled in order to determine the acoustic-liner properties.

Watson, W. R.

1985-01-01

131

An Investigation into the Admittance of MIS-Structures Based on MBE HgCdTe with Quantum Wells  

NASA Astrophysics Data System (ADS)

The results of investigations into the complex admittance of the MIS-structures based on heteroepitaxial MBE Hg1- x Cd x Te with quantum wells (QW) in the test-signal frequency range 1 kHz - 2 ?Hz at temperatures 8-300 K are reported. The thickness of single HgTe QWs was 5.6 and 7.1 nm, the content in the 35-nm thick barrier layers - 0.65 and 0.62, respectively.

Dzyadukh, S. M.; Voitsekhovskii, A. V.; Nesmelov, S. N.; Dvoretskii, S. A.; N. Mikhailov, N.; Gorn, D. I.

2013-12-01

132

Biochemical and molecular characterization of Coriolopsis rigida laccases involved in transformation of the solid waste from olive oil production  

Microsoft Academic Search

Two laccase isoenzymes were purified and characterized from the basidiomycete Coriolopsis rigida during transformation of the water-soluble fraction of “alpeorujo” (WSFA), a solid residue derived from the olive oil production\\u000a containing high levels of toxic compounds. Zymogram assays of laccases secreted by the fungus growing on WSFA and WSFA supplemented\\u000a with glucose showed two bands with isoelectric points of 3.3

Rosario Díaz; Mario C. N. Saparrat; Miguel Jurado; Inmaculada García-Romera; Juan Antonio Ocampo; María Jesús Martínez

2010-01-01

133

Hilbert–Huang transform based signal analysis for the characterization of gas–liquid two-phase flow  

Microsoft Academic Search

This paper reports the application of the Hilbert–Huang Transform (HHT) to the dynamic characterization of gas–liquid two-phase flow in a horizontal pipeline. A differential pressure fluctuation signal of gas–liquid two-phase flow is adaptively decomposed into Intrinsic Mode Functions (IMFs) through the use of Empirical Mode Decomposition (EMD) methods. Based on the EMD, the associated time–frequency–energy distribution, i.e., the Hilbert spectrum,

Hao Ding; Zhiyao Huang; Zhihuan Song; Yong Yan

2007-01-01

134

An Admittance Survey of Large Volcanoes on Venus: Implications for Volcano Growth  

NASA Technical Reports Server (NTRS)

Estimates of the thickness of the venusian crust and elastic lithosphere are important in determining the rheological and thermal properties of Venus. These estimates offer insights into what conditions are needed for certain features, such as large volcanoes and coronae, to form. Lithospheric properties for much of the large volcano population on Venus are not well known. Previous studies of elastic thickness (Te) have concentrated on individual or small groups of edifices, or have used volcano models and fixed values of Te to match with observations of volcano morphologies. In addition, previous studies use different methods to estimate lithospheric parameters meaning it is difficult to compare their results. Following recent global studies of the admittance signatures exhibited by the venusian corona population, we performed a similar survey into large volcanoes in an effort to determine the range of lithospheric parameters shown by these features. This survey of the entire large volcano population used the same method throughout so that all estimates could be directly compared. By analysing a large number of edifices and comparing our results to observations of their morphology and models of volcano formation, we can help determine the controlling parameters that govern volcano growth on Venus.

Brian, A. W.; Smrekar, S. E.; Stofan, E. R.

2004-01-01

135

Isolation and characterization of three fungi with the potential of transforming glycyrrhizin.  

PubMed

Three fungi with different types of transformation of glycyrrhizin (GL) were isolated from the soil samples of glycyrrhiza glabra planting area in China. According to their morphologies and 18 S rDNA gene sequence analysis, the three fungi were identified and named as Penicillium purpurogenum Li-3, Aspergillus terreus Li-20 and Aspergillus ustus Li-62. Transforming products analysis by TLC and HPLC-MS indicated that P. purpurogenum Li-3, A. terreus Li-20 and A. ustus Li-62 could stably transform GL into GAMG, GAMG and GA, and GA, respectively. P. purpurogenum Li-3 was especially valuable to directly prepare GAMG for applications in the pharmaceutical industry. PMID:23247917

Wang, Chao; Guo, Xiao-Xiao; Wang, Xiao-Yan; Qi, Feng; Feng, Shi-Jiang; Li, Chun; Zhou, Xiao-Hong

2013-05-01

136

In-Situ Raman Indentation of ??-Eucryptite: Characterization of the Pressure Induced Phase Transformation  

SciTech Connect

A pressure-induced phase transformation in the lithium aluminum silicate -eucryptite was studied with in-situ Raman spectroscopy. Dense -eucryptite composites were made via powder synthesis followed by sintering. The specimens were then subjected to diamond indentation up to applied contact stresses of about 8 GPa, while collecting Raman spectra. The appearance of a Raman peak (~520 cm-1) at a contact stress of about 3 GPa likely corresponds to the reversible phase transformation of -eucryptite to the orthorhombic phase -eucryptite. Loading and unloading in-situ Raman indentation experiments are discussed with regards to this transformation.

Lance, Michael J [ORNL

2009-01-01

137

Isolation and preliminary characterization of a human transforming gene from T24 bladder carcinoma cells  

Microsoft Academic Search

DNA from T24, a cell line derived from a human bladder carcinoma, can induce the morphological transformation of NIH 3T3 cells. Using techniques of gene rescue to clone the gene responsible for this transformation, we have found that it is human in origin, <5 kilobase pairs in size and is homologous to a 1,100-base polyadenylated RNA species found in T24

Mitchell Goldfarb; Kenji Shimizu; Manuel Perucho; Michael Wigler

1982-01-01

138

Characterization of the transformation from calcium-deficient apatite to ?-tricalcium phosphate  

Microsoft Academic Search

The structural changes that occur during the transformation of a Ca-deficient apatite, prepared by a wet chemical method, to ß-TCP were investigated. X-ray diffraction (XRD) analysis of as-prepared samples and samples calcined at temperatures between 500 and 1100 °C showed that the transformation occurs over the temperature range 710–740 °C, under non-equilibrium conditions. The change in crystallite size with increasing

I. R. Gibson; I. Rehman; S. M. Best

2000-01-01

139

Characterization of fossil organic matter with Fourier-Transform Infrared (FTIR) Spectroscopy: an attempt to record extraterrestrial life .  

NASA Astrophysics Data System (ADS)

The characterization of the insoluble macromolecular fraction of organic matter preserved in carbonate sediments allows the identification of fossil organisms otherwise not recognizable. This approach represents a new tool for the detection of extraterrestrial traces of life even in their primitive form, one of the primary goals of exobiological studies on Mars. Considering the deep connection between carbonate sediments and biological activities on Earth, we checked if it was possible to characterize the organic matter remains dispersed within these rocks, with Fourier transform infrared (FTIR) spectroscopy. The experiment was performed on ancient and well preserved carbonates, belonging to the Calcare di Base Formation outcropping in Northern Calabria (Rossano Basin). The origin of these Miocene deposits is problematic, due to the absence of skeletal fossils. The results demonstrate that FTIR is a reliable method for the characterization of the organic matter preserved in carbonates, and generally in all types of sedimentary rocks.

Guido, A.; Mastandrea, A.; Tosti, F.; Demasi, F.; Blanco, A.; D'Elia, M.; Orofino, V.; Fonti, S.; Russo, F.

140

Establishment and characterization of hamster cell lines transformed by restriction endonuclease fragments of adenovirus 5.  

PubMed Central

We have established a library of hamster cells transformed by adenovirus 5 DNA fragments comprising all (XhoI-C, 0 to 16 map units) or only a part (HindIII-G, 0 to 7.8 map units) of early region 1 (E1: 0 to 11.2 map units). These lines have been analyzed in terms of content of viral DNA, expression of E1 antigens, and capacity to induce tumors in hamsters. All cells tested were found to express up to eight proteins encoded within E1A (0 to 4.5 map units) with apparent molecular weights between 52,000 (52K) and 25K. Both G and C fragment-transformed lines expressed a 19K antigen encoded within E1B (4.5 to 11.2 map units), whereas an E1B 58K protein was detected in C fragment-transformed, but not G-fragment-transformed, lines. No clear distinction could be drawn between cells transformed by HindIII-G and by XhoI-C in terms of morphology or tumorigenicity, suggesting that the E1B 58K antigen plays no major role in the maintenance of oncogenic transformation, although possible involvement of truncated forms of 58K cannot be ruled out. Sera were collected from tumor-bearing animals and examined for ability to immunoprecipitate proteins from infected cells. The relative avidity of sera for different proteins was characteristic of the cell line used for tumor induction, and the specificity generally reflected the array of viral proteins expressed by the corresponding transformed cells. However, one notable observation was that even though all transformed lines examined expressed antigens encoded by both the 1.1- and 0.9-kilobase mRNAs transcribed from E1A, tumor sera made against these lines only precipitated products of the 1.1-kilobase message. Thus, two families of E1A proteins, highly related in terms of primary amino acid sequence, appear to be immunologically quite distinct. Images

Rowe, D T; Branton, P E; Yee, S P; Bacchetti, S; Graham, F L

1984-01-01

141

Characterization of Antisense Transformed Plants Deficient in the Tobacco Anionic Peroxidase.  

PubMed Central

On the basis of the biological compounds that they metabolize, plant peroxidases have long been implicated in plant growth, cell wall biogenesis, lignification, and host defenses. Transgenic tobacco (Nicotiana tabacum L.) plants that underexpress anionic peroxidase were generated using antisense RNA. The antisense RNA was found to be specific for the anionic isoenzyme and highly effective, reducing endogenous transcript levels and total peroxidase activity by as much as 1600-fold. Antisense-transformed plants appeared normal at initial observation; however, growth studies showed that plants with reduced peroxidase activity grow taller and flower sooner than control plants. In contrast, previously transformed plants overproducing anionic peroxidase were shorter and flowered later than controls. Axillary buds were more developed in antisense-transformed plants and less developed in plants overproducing this enzyme. It was found that the lignin content in leaf, stem, and root was unchanged in antisense-transformed plants, which does not support a role for anionic peroxidase in the lignification of secondary xylem vessels. However, studies of wounded tissue show some reduction in wound-induced deposition of lignin-like polymers. The data support a possible role for tobacco anionic peroxidase in host defenses but not without a reduction in growth potential.

Lagrimini, L. M.; Gingas, V.; Finger, F.; Rothstein, S.; Liu, TTY.

1997-01-01

142

Characterizing high-frequency effects in transformer windings-a guide to several significant articles  

Microsoft Academic Search

Several papers pertaining to the design and modeling of high-frequency transformer windings are reviewed. Each paper is summarized, stressing its significant contributions and its relationship to the others. The emphases and relative merits of each are discussed, and the understandability and applicability are evaluated

A. M. Urling; V. A. Niemela; G. R. Skutt; T. G. Wilson

1989-01-01

143

Characterization of Herpesvirus saimiri-transformed T lymphocytes from common variable immunodeficiency patients  

PubMed Central

Common variable immunodeficiency (CVID) is a very frequent but heterogeneous syndrome of antibody formation. The primary defect remains unknown, but many reports describe peripheral blood T lymphocyte dysfunctions in a substantial proportion of CVID patients, which may impair T–B cell collaboration. In order to investigate whether such putative defects were intrinsic to T cells or, rather, secondary to quantitative differences in T cell subset distribution, or to other described disorders, we have used Herpesvirus saimiri (HVS) for the targeted transformation of CVID CD4+ and CD8+ T cells and subsequent functional evaluation by flow cytometry of their capacity to generate cell surface (CD154, CD69) or soluble (IL-2, TNF-?, IFN-?) help after CD3 engagement. Unexpectedly, the results showed that 40 different CVID blood samples exposed to HVS gave rise with a significantly increased frequency to transformed CD4+ T cell lines, compared to 40 age-matched controls (27% versus 3%, P ? 0·00002) suggesting the existence of a CVID-specific signalling difference which affects CD4+ cell transformation efficiency. The functional analysis of 10 CD4+ and 15 CD8+ pure transformed T cell lines from CVID patients did not reveal any statistically significant difference as compared to controls. However, half of the CD4+ transformed cell lines showed CD154 (but not CD69) induction (mean value of 46·8%) under the lower limit of the normal controls (mean value of 82·4%, P ? 0·0001). Exactly the same five cell lines showed, in addition, a significantly low induction of IL-2 (P ? 0·04), but not of TNF-? or IFN-?. None of these differences were observed in the remaining CD4+ cell lines or in any of the transformed CD8+ cell lines. We conclude that certain CVID patients show selective and intrinsic impairments for the generation of cell surface and soluble help by CD4+ T cells, which may be relevant for B lymphocyte function. The transformed T cell lines will be useful to establish the biochemical mechanisms responsible for the described impairments.

CABANILLAS, J A; CAMBRONERO, R; PACHECO-CASTRO, A; GARCIA-RODRIGUEZ, M C; MARTIN-FERNANDEZ, J M; FONTAN, G; REGUEIRO, J R

2002-01-01

144

Characterization of corrugated waveguides by modal analysis  

Microsoft Academic Search

A general formulation for the characterization of corrugated waveguides is presented. The formulation is based on modal expansion in the different smooth-walled waveguides which constitute the corrugated structure and on the use of mode matching at discontinuities. The use of an admittance matrix formulation and a suitable root-finding algorithm leads to a rigorous and efficient technique. Dispersion curves are presented

Jaime Esteban; JesGs M. Rebollar

1991-01-01

145

Propagation and radiation of sound from flanged circular ducts with circumferentially varying wall admittances, II: Finite ducts with sources  

NASA Astrophysics Data System (ADS)

The radiation of sound from a flanged duct system containing various hard-walled pressure sources and a finite length of non-uniformly lined duct is considered. Reflection coefficients, transmission losses and the directivity of the radiated field are evaluated. Direct comparisons between the results for the non-uniformly lined ducts, a uniformly lined duct and a hard-walled duct are made for fixed values of admittance, liner length and source distributions. Several interesting wave scattering characteristics which relate to the design of aircraft turbofan inlet liners are uncovered.

Fuller, C. R.

1984-04-01

146

Characterization of the Pituitary Tumor Transforming Gene 1 Knockout Mouse Retina  

Microsoft Academic Search

Recent gene expression studies on mouse models for retinal degeneration identified deregulation of Pituitary tumor transforming\\u000a gene 1 (Pttg1) as a potential susceptibility factor involved in photoreceptor cell death. Pttg1 is a transcription regulatory protein involved\\u000a in sister chromatid segregation, and Pttg1\\u000a ?\\/? mice exhibit testicular and splenic hypoplasia, thymic hyperplasia, aberrant cell cycle progression, chromosome instability,\\u000a and impaired glucose

Rosanne M. Yetemian; Cheryl M. Craft

2011-01-01

147

Characterizing the moisture content of tea with diffuse reflectance spectroscopy using wavelet transform and multivariate analysis.  

PubMed

Effects of the moisture content (MC) of tea on diffuse reflectance spectroscopy were investigated by integrated wavelet transform and multivariate analysis. A total of 738 representative samples, including fresh tea leaves, manufactured tea and partially processed tea were collected for spectral measurement in the 325-1,075 nm range with a field portable spectroradiometer. Then wavelet transform (WT) and multivariate analysis were adopted for quantitative determination of the relationship between MC and spectral data. Three feature extraction methods including WT, principal component analysis (PCA) and kernel principal component analysis (KPCA) were used to explore the internal structure of spectral data. Comparison of those three methods indicated that the variables generated by WT could efficiently discover structural information of spectral data. Calibration involving seeking the relationship between MC and spectral data was executed by using regression analysis, including partial least squares regression, multiple linear regression and least square support vector machine. Results showed that there was a significant correlation between MC and spectral data (r = 0.991, RMSEP = 0.034). Moreover, the effective wavelengths for MC measurement were detected at range of 888-1,007 nm by wavelet transform. The results indicated that the diffuse reflectance spectroscopy of tea is highly correlated with MC. PMID:23012574

Li, Xiaoli; Xie, Chuanqi; He, Yong; Qiu, Zhengjun; Zhang, Yanchao

2012-01-01

148

Characterization of Secondary Structure Transformation of Stretched and Slenderized Wool Fibers with FTIR Spectra  

Microsoft Academic Search

Characterizations of wool fibers were performed with FTIR testing technology for two categories of stretched wool fibers, i.e., the OPTIMTM-Fine wool, and the stretched wool processed on TJGD-ERDOS 02 stretching equipment, developed at College of Textile Engineering, Tianjin Polytechnic University, Tianjin, China. It was observed that the two types of stretched wool fibers could be characterized by the IR transmittance

Jinbo Yao; Yanbo Liu; Suoting Yang; Jianzhong Liu

149

Biochemical and molecular characterization of Coriolopsis rigida laccases involved in transformation of the solid waste from olive oil production.  

PubMed

Two laccase isoenzymes were purified and characterized from the basidiomycete Coriolopsis rigida during transformation of the water-soluble fraction of "alpeorujo" (WSFA), a solid residue derived from the olive oil production containing high levels of toxic compounds. Zymogram assays of laccases secreted by the fungus growing on WSFA and WSFA supplemented with glucose showed two bands with isoelectric points of 3.3 and 3.4. The kinetic studies of the two purified isoenzymes showed similar affinity on 2,6-dimethoxyphenol and 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid), used as phenolic and non-phenolic model substrate, respectively. The molecular mass of both proteins was 66 kDa with 9% N-linked carbohydrate. Physico-chemical properties of the purified laccases from media containing WSFA were similar to those obtained from medium with glucose as the main carbon source. In-vitro studies performed with the purified laccases revealed a 42% phenol reduction of WSFA, as well as changes in the molecular mass distribution. These findings indicate that these laccases are involved in the process of transformation, via polymerization by the oxidation of phenolic compounds present in WSFA. A single laccase gene, containing an open reading frame of 1,488 bp, was obtained in PCR amplifications performed with cDNA extracted from mycelia grown on WSFA. The product of the gene shares 90% identity (95% similarity) with a laccase from Trametes trogii and 89% identity (95% similarity) with a laccase from Coriolopsis gallica. This is the first report on purification and molecular characterization of laccases directly involved in the transformation of olive oil residues. PMID:20607234

Díaz, Rosario; Saparrat, Mario C N; Jurado, Miguel; García-Romera, Inmaculada; Ocampo, Juan Antonio; Martínez, María Jesús

2010-09-01

150

Characterization of gear faults in variable rotating speed using Hilbert-Huang Transform and instantaneous dimensionless frequency normalization  

NASA Astrophysics Data System (ADS)

The objective of this research is to investigate the feasibility of utilizing the instantaneous dimensionless frequency (DLF) normalization and Hilbert-Huang Transform (HHT) to characterize the different gear faults in case of variable rotating speed. The normalized DLF of the vibration signals are calculated based on the rotating speed of shaft and the instantaneous frequencies of Intrinsic Mode Functions (IMFs) which are decomposed by Empirical Mode Decomposition (EMD) process. The faulty gear features on DLF-energy distribution of vibration signal can be extracted without the presence of shaft rotating speed, so that the proposed approach can be applied for characterizing the malfunctions of gearbox system under variable shaft rotating speed. A test rig of gear transmission system is performed to illustrate the gear faults, including worn tooth, broken tooth and gear unbalance. Different methods to determine the instantaneous frequency are employed to verify the consistence of characterization results. The DLF-energy distributions of vibration signals are investigated in different faulty gear conditions. The analysis results demonstrate the capability and effectiveness of the proposed approach for characterizing the gear malfunctions at the DLFs corresponding to the meshing frequency as well as the shaft rotating frequency. The support vector machine (SVM) is then employed to classify the vibration patterns of gear transmission system at different malfunctions. Using the energy distribution at the characteristic DLFs as the features, the different fault types of gear can be identified by SVM with high accuracy.

Wu, T. Y.; Chen, J. C.; Wang, C. C.

2012-07-01

151

Identification and characterization of potential shear transformation zones in metallic glasses.  

PubMed

The stability of local atomic configurations in a Ni-Zr metallic glass is studied by molecular dynamics. It is shown that individual atom displacements induce irreversible atomic rearrangements under different glass relaxation, temperature, and strain conditions. The number of regions with an unstable topology depends on the glass relaxation degree. Their time evolution is governed by thermal activation, the activation energy decreasing with elastic strain. It is also shown that unstable regions are located in correspondence of shear transformation zones operating under plastic deformation. PMID:18643675

Delogu, Francesco

2008-06-27

152

Characterization of oil exhibiting high ?-linolenic acid from a genetically transformed canola strain  

Microsoft Academic Search

The seed oil from a genetically transformed canola (Brassica napus) containing 43% (w\\/w) of ?-linolenic acid (G, 18?3n?6), 22% linoleic acid (L, 18?2n?6), and 16% oleic acid (O, 18?1n?9) was\\u000a evaluated. In this high ?-linolenic acid canola oil (HGCO), the predominant 18?3n?6-containing triacylglycerol (TG) molecular\\u000a species were GGL (23%), GLO (20%), and GGG (11%). In the total TG, approximately 75%

Jim-Wen Liu; Stephen DeMichele; Marti Bergana; Emil Bobik; Christine Hastilow; Lu-Te Chuang; Pradip Mukerji; Yung-Sheng Huang

2001-01-01

153

Characterization of a didehydrobenzoxazine intermediate in a novel carbene-to-carbene transformation.  

PubMed

Irradiation of N(2) matrix-isolated 3-chloro-3-(2-benzoxazolyl)diazirine gives a mixture of syn- and anti-benzoxazolylchlorocarbenes which could be characterized by IR, UV/vis, and B3LYP modeling. Subsequent irradiation of the carbene caused ring opening to the corresponding quinoimine, which was similarly characterized. In turn, the quinoimine photochemically underwent ring-closure to a novel, highly strained cyclic ketenimine. Unrestricted singlet DFT calculations were required to fit the IR spectrum of the ketenimine, suggesting significant diradical character. Photolysis of the ketenimine led to ring cleavage in yet another fashion, to give an isonitrile-phenoxychlorocarbene, whose spectra were similar to those of the previously characterized phenoxychlorocarbene. Finally, at shorter wavelengths, the phenoxycarbene underwent the expected rearrangement to the corresponding benzoyl chloride. PMID:12083916

Nikitina, Asya; Sheridan, Robert S

2002-07-01

154

Genetic and molecular characterization of embryonic mutants identified following seed transformation in Arabidopsis.  

PubMed

Over 5000 transgenic families of Arabidopsis thaliana produced following seed transformation with Agrobacterium tumefaciens were screened for embryonic lethals, defectives, and pattern mutants. One hundred and seventy-eight mutants with a wide range of developmental abnormalities were identified. Forty-one mutants appear from genetic studies to be tagged (36% of the 115 mutants examined in detail). Mapping with visible markers demonstrated that mutant genes were randomly distributed throughout the genome. Seven mutant families appeared to contain chromosomal translocations because the mutant genes exhibited linkage to visible markers on two different chromosomes. Chromosomal rearrangements may therefore be widespread following seed transformation. DNA gel blot hybridizations with 34 tagged mutants and three T-DNA probes revealed a wide range of insertion patterns. Models of T-DNA structure at each mutant locus were constructed to facilitate gene isolation. The value of such models was demonstrated by using plasmid rescue to clone flanking plant DNA from four tagged mutants. Further analysis of genes isolated from these insertional mutants should help to elucidate the relationship between gene function and plant embryogenesis. PMID:8264525

Castle, L A; Errampalli, D; Atherton, T L; Franzmann, L H; Yoon, E S; Meinke, D W

1993-12-01

155

Computational characterization of ketone-ketal transformations at the active site of matrix metalloproteinases.  

PubMed

We modeled the first steps of hydrolysis reactions of a natural oligopeptide substrate of matrix metalloproteinase MMP-2 as well as of a substrate analogue. In the latter, the scissile amide group is substituted by a ketomethylene group which can be transformed to the ketal group upon binding of this compound to the enzyme active site. According to our quantum mechanical-molecular mechanical (QM/MM) calculations, the reaction of the ketone-ketal transformation proceeds with a low energy barrier (3.4 kcal/mol) and a high equilibrium constant (10(4)). The reaction product with the ketal group formed directly at the active site of the enzyme works as an inhibitor that chelates the zinc ion. On the other hand, the oligopeptide mimetic retains molecular groups responsible for binding of this compound to the enzyme active site. This example illustrates a strategy to design MMP inhibitors in situ by using data on binding specificity of substrates to a particular type of MMP and details of the reaction mechanism. PMID:24684684

Khrenova, Maria G; Nemukhin, Alexander V; Savitsky, Alexander P

2014-04-24

156

Monoclonal antibodies as developmental markers to characterize pea floral homeotic transformations  

Microsoft Academic Search

Monoclonal antibodies (mAbs) specific for the different floral organs of the garden pea ( Pisum sativum L.) were raised using two different types of immunization procedures. These antibodies were powerful tools to study the functionality of floral organ identity genes in pea homeotic mutants. The mAbs were used extensively as developmental markers for the immunohistochemical characterization of two pea floral

Luis A. Cañas; Roudeïna Essid; María D. Gómez; José Beltrán

2002-01-01

157

A Method to Detect and Characterize Ellipses Using the Hough Transform  

Microsoft Academic Search

Abstract—In this paper we describe a new technique for detecting and characterizing ellipsoidal shapes automatically from any type of image. This technique is a single pass algorithm which can extract any group of ellipse parameters,or characteristics which can be computed from those parameters,without having to detect all five parameters,for each ellipsoidal shape. Moreover, the method can explicitly incorporate any a

Nick Bennett; Robert Burridge; Naoki Saito

1999-01-01

158

Preparation and characterization of dealuminated metakaolin and its use in the transformation of waste plastics to aromatic hydrocarbons.  

PubMed

Acid activated metakaolins (AAMKs) have been prepared by calcination of the natural clay at 600 degrees C to provide a metakolin which was then leached at 80 degrees C for 3 h using 1M, 2M, 3M, and 6M HCl. These materials were characterized and their ability to transform the off gases from HDPE decomposition into useful aromatic species was evaluated. The amount of adsorbed water and the number of acid sites increased with the severity of acid treatment. Variable temperature DRIFTS spectroscopy of pyridine treated samples revealed that both Brønsted and Lewis acid centers were present until 425 degrees C. Pyridine bonded to the Lewis acid centers was more thermally stable. The AAMKs were all selective to the production of toluene with respectable, but lesser, amounts of xylenes and trimethylbenzenes. This selectivity contrasts with that of acid leached and pillared smectites which are selective toward trimethylbenzene. PMID:16290461

Breen, C; Taylor, S; Burguin, E; Centeno, M

2002-03-01

159

Radial current high power dummy load for characterizing the high power laser triggered transformer-type accelerator.  

PubMed

A radial-current aqueous resistive solution load was applied to characterize a laser triggered transformer-type accelerator. The current direction in the dummy load is radial and is different from the traditional load in the axial. Therefore, this type of dummy load has smaller inductance and fast response characteristic. The load was designed to accommodate both the resistance requirement of accelerator and to allow optical access for the laser. Theoretical and numerical calculations of the load's inductance and capacitance are given. The equivalent circuit of the dummy load is calculated in theory and analyzed with a PSPICE code. The simulation results agree well with the theoretical analysis. At last, experiments of the dummy load applied to the high power spiral pulse forming line were performed; a quasisquare pulse voltage is obtained at the dummy load. PMID:20886974

Yin, Yi; Zhong, Hui-Huang; Liu, Jin-Liang; Ren, He-Ming; Yang, Jian-Hua; Zhang, Xiao-Ping; Hong, Zhi-qiang

2010-09-01

160

Development and testing of a fast Fourier transform high dynamic-range spectral diagnostics for millimeter wave characterization  

NASA Astrophysics Data System (ADS)

A fast Fourier transform (FFT) based wide range millimeter wave diagnostics for spectral characterization of scattered millimeter waves in plasmas has been successfully brought into operation. The scattered millimeter waves are heterodyne downconverted and directly digitized using a fast analog-digital converter and a compact peripheral component interconnect computer. Frequency spectra are obtained by FFT in the time domain of the intermediate frequency signal. The scattered millimeter waves are generated during high power electron cyclotron resonance heating experiments on the TEXTOR tokamak and demonstrate the performance of the diagnostics and, in particular, the usability of direct digitizing and Fourier transformation of millimeter wave signals. The diagnostics is able to acquire 4 GHz wide spectra of signals in the range of 136-140 GHz. The rate of spectra is tunable and has been tested between 200 000 spectra/s with a frequency resolution of 100 MHz and 120 spectra/s with a frequency resolution of 25 kHz. The respective dynamic ranges are 52 and 88 dB. Major benefits of the new diagnostics are a tunable time and frequency resolution due to postdetection, near-real time processing of the acquired data. This diagnostics has a wider application in astrophysics, earth observation, plasma physics, and molecular spectroscopy for the detection and analysis of millimeter wave radiation, providing high-resolution spectra at high temporal resolution and large dynamic range.

Thoen, D. J.; Bongers, W. A.; Westerhof, E.; Oosterbeek, J. W.; de Baar, M. R.; van den Berg, M. A.; van Beveren, V.; Bürger, A.; Goede, A. P. H.; Graswinckel, M. F.; Hennen, B. A.; Schüller, F. C.

2009-10-01

161

Long-term batch study of sorption, transformation and extractability to characterize the fate of the veterinary antibiotic sulfadiazine  

NASA Astrophysics Data System (ADS)

The occurrence of veterinary antibiotic substances in various environmental compartments is of growing concern. Once released into the environment (e.g. via manure), these organic substances can cause changes in the composition of microbial populations, provoke the development and spreading of resistance genes and finally reach the food chain. The substance under study is the veterinary antibiotic sulfadiazine (SDZ), which belongs to the chemical group of the sulfonamides. These compounds are widely applied in animal husbandry. There are hardly any studies on the macroscopic sorption and desorption behaviour in combination with transformation processes, particularly investigating the sorbed fraction. We are conducting long-term batch sorption experiments to characterize the partitioning between the liquid and the solid phases as well as formation of transformation products. A sequential extraction procedure enables us to analyse the composition of the various sorbed fractions. We applied 14C-labelled SDZ in aqueous solution to fresh soil, originating from an agricultural field (silty loam). Adsorption and desorption studies are conducted for the duration of 60 d and 80 d, respectively. Unique setups for single time-steps allow us to trace the development of the partition process between the liquid and the solid phase and also partitioning within the solid phase. The composition of these liquid phases concerning the parent substance and the transformation products is analyzed. Using Radio-HPLC we find at least five transformation products: 4-hydroxy-sulfadiazine (4-OH-SDZ), 4-(2-iminopyrimidin-1(2H)-yl)-aniline (An-SDZ) and additionally three yet unknown products. By means of a sequential extraction, differently strong bound fractions of the compound can be distinguished. Extractions consist of a mild method (0.01 M CaCl2-solution; 24 h) followed by a methanol extraction (4 h). Finally, a residual fraction is gained by microwave extraction at an elevated temperature (150°C) and pressure (mixture of water and acetonitril, 4:1). Bound residues are determined by combustion. The course of the kinetic adsorption/desorption processes as well as the partitioning of the compound over the various solid phase fractions is observed. Sorption is time-dependent and strongly non-linear. The topsoil shows a significantly higher sorption affinity than the subsoil. While the amount of radioactivity sorbed to the soil matrix increases with time, the extractability decreases significantly, i. e. at the end of the experimental time there is no yield with mild extraction methods. On the contrary, after 60 d, there is still a considerably mass gained with the microwave extraction. Desorption is very slow due to hysteresis. In the topsoil transformation occurs with higher rates, leading to more detectable transformation products as in the subsoil. With our experimental setup it will be possible to set up a kinetic modell for the partitioning of the solute between the liquid and the solid phase. This description will also include an estimation of the transformation parameters.

Sittig, Stephan; Kasteel, Roy; Groeneweg, Joost; Vereecken, Harry

2010-05-01

162

Fourier transform infrared absorption spectroscopy characterization of gaseous atmospheric pressure plasmas with 2 mm spatial resolution  

SciTech Connect

This paper describes an optical setup built to record Fourier transform infrared (FTIR) absorption spectra in an atmospheric pressure plasma with a spatial resolution of 2 mm. The overall system consisted of three basic parts: (1) optical components located within the FTIR sample compartment, making it possible to define the size of the infrared beam (2 mm Multiplication-Sign 2 mm over a path length of 50 mm) imaged at the site of the plasma by (2) an optical interface positioned between the spectrometer and the plasma reactor. Once through the plasma region, (3) a retro-reflector module, located behind the plasma reactor, redirected the infrared beam coincident to the incident path up to a 45 Degree-Sign beamsplitter to reflect the beam toward a narrow-band mercury-cadmium-telluride detector. The antireflective plasma-coating experiments performed with ammonia and silane demonstrated that it was possible to quantify 42 and 2 ppm of these species in argon, respectively. In the case of ammonia, this was approximately three times less than this gas concentration typically used in plasma coating experiments while the silane limit of quantification was 35 times lower. Moreover, 70% of the incoming infrared radiation was focused within a 2 mm width at the site of the plasma, in reasonable agreement with the expected spatial resolution. The possibility of reaching this spatial resolution thus enabled us to measure the gaseous precursor consumption as a function of their residence time in the plasma.

Laroche, G. [Laboratoire d'Ingenierie de Surface, Centre de Recherche sur les Materiaux Avances, Departement de genie des mines, de la metallurgie et des materiaux, Universite Laval, 1065, avenue de la Medecine, Quebec G1V 0A6 (Canada); Centre de recherche du CHUQ, Hopital St Francois d'Assise, 10, rue de l'Espinay, local E0-165, Quebec G1L 3L5 (Canada); Vallade, J. [Laboratoire Procedes, Materiaux et Energie Solaire, PROMES, CNRS, Technosud, Rambla de la Thermodynamique, F-66100 Perpignan (France); Agence de l'environnement et de la Ma Latin-Small-Letter-Dotless-I -carettrise de l'Energie, 20, avenue du Gresille, BP 90406, F-49004 Angers Cedex 01 (France); Bazinette, R.; Hernandez, E.; Hernandez, G.; Massines, F. [Laboratoire Procedes, Materiaux et Energie Solaire, PROMES, CNRS, Technosud, Rambla de la Thermodynamique, F-66100 Perpignan (France); Nijnatten, P. van [OMT Solutions bv, High Tech Campus 9, 5656AE Eindhoven (Netherlands)

2012-10-15

163

Isolation and characterization of efficient isoxaben-transforming Microbacterium sp strains from four European soils.  

PubMed

Nutrient-agar plates containing isoxaben (500 mg litre(-1)) were used to isolate isoxaben-metabolising bacteria from four European soils incubated with the herbicide under laboratory conditions. In flask experiments, inoculation of a basal salts medium containing nitrogen and [phenyl-U-14C]isoxaben with an isolate (B2b) resulted in 33% recovery of the initial radioactivity as [14C]carbon dioxide after 2 weeks. A major metabolite identified by GC-MS and NMR analysis as 3-(1-ethyl-1-methylpropyl)isoxazol-5-ylamine accumulated both in basal salts and nutrient broth media. 2,6-Dimethoxybenzoic acid, a suspected metabolite of isoxaben, was not detected in either liquid media. However, the capability of the B2b isolate to use 2,6-dimethoxybenzoic acid as a source of carbon was demonstrated. Soil inoculation with the B2b strain resulted in an increase in the recovery of [14C] carbon dioxide from both [phenyl-U-14C] and [isoxazole-5-14C]isoxaben. The metabolite identified as 3-(1-ethyl-1-methylpropyl)isoxazole-5-ylamine only accumulated if the soil was autoclaved before inoculation. This metabolite was rapidly mineralized by the microflora of a natural soil without history of isoxaben treatment. Homology patterns of sequenced 16S rDNA between isoxaben-transforming isolates and reference strains showed that the four isolates identified belonged to the genus Microbacterium. PMID:12476996

Arrault, Sandra; Desaint, Stephane; Catroux, Colette; Sémon, Etienne; Mougin, Christian; Fournier, Jean Claude

2002-12-01

164

Ultrasonic characterization of soft tissue vibrations based on the two-dimensional Fourier transform  

NASA Astrophysics Data System (ADS)

It has recently been demonstrated that soft tissue vibrations in the body, traditionally associated with vascular bruits and cardiac murmurs, can potentially be used for the ultrasonic diagnosis of coronary artery disease and vascular trauma. In this paper, the ultrasonic spectrum of soft tissue vibrations is formulated using the two-dimensional Fourier transform, making full use of the information present in the backscattered ultrasound echoes from vibrating tissue. Parametric simulation studies show that vibrations with amplitude 1 ?m may be detected even with tissue velocity of 20 cm/s and acceleration of 5 m/s2, e.g., during peak cardiac motion. Vibrations with amplitude as low as 0.1 ?m may be detected when the tissue acceleration is negligible, e.g., during mid-diastole. Also, it was found that tissue vibrations in a direction transverse to the ultrasound beam can be detected. In vivo examples of cardiac wall vibrations in patients with coronary artery disease are presented. Tissue vibrations can provide improved sensitivity over conventional duplex ultrasound since the scattering strength from tissue is significantly higher than that from blood. In addition, detection of tissue vibrations has reduced angle dependency and does not require visualization of the vessel lumen, making the exam less dependent on operator skill.

Sikdar, Siddhartha; Kim, Yongmin; Beach, Kirk W.

2005-09-01

165

CT Angiography after 20 Years: A Transformation in Cardiovascular Disease Characterization Continues to Advance.  

PubMed

Through a marriage of spiral computed tomography (CT) and graphical volumetric image processing, CT angiography was born 20 years ago. Fueled by a series of technical innovations in CT and image processing, over the next 5-15 years, CT angiography toppled conventional angiography, the undisputed diagnostic reference standard for vascular disease for the prior 70 years, as the preferred modality for the diagnosis and characterization of most cardiovascular abnormalities. This review recounts the evolution of CT angiography from its development and early challenges to a maturing modality that has provided unique insights into cardiovascular disease characterization and management. Selected clinical challenges, which include acute aortic syndromes, peripheral vascular disease, aortic stent-graft and transcatheter aortic valve assessment, and coronary artery disease, are presented as contrasting examples of how CT angiography is changing our approach to cardiovascular disease diagnosis and management. Finally, the recently introduced capabilities for multispectral imaging, tissue perfusion imaging, and radiation dose reduction through iterative reconstruction are explored with consideration toward the continued refinement and advancement of CT angiography. © RSNA, 2014. PMID:24848958

Rubin, Geoffrey D; Leipsic, Jonathon; Joseph Schoepf, U; Fleischmann, Dominik; Napel, Sandy

2014-06-01

166

Characterization of Low Temperature Ferrite\\/Austenite Transformations in the Heat Affected Zone of 2205 Duplex Stainless Steel Arc Welds  

Microsoft Academic Search

Spatially Resolved X-Ray Diffraction (SRXRD) has been used to identify a previously unobserved low temperature ferrite ()\\/austenite() phase transformation in the heat affected zone (HAZ) of 2205 Duplex Stainless Steel (DSS) welds. In this ''ferrite dip'' transformation, the ferrite transforms to austenite during heating to peak temperatures on the order of 750 C, and re-transforms to ferrite during cooling, resulting

T. A. Palmer; J. W. Elmer; S. S. Babu; J. M. Vitek

2003-01-01

167

Characterization and quantitation of aprepitant drug substance polymorphs by attenuated total reflectance fourier transform infrared spectroscopy.  

PubMed

In this study, we report the use of attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FT-IR) for the identification and quantitation of two polymorphs of Aprepitant, a substance P antagonist for chemotherapy-induced emesis. Mixtures of the polymorph pair were prepared by weight and ATR-FT-IR spectra of the powdered samples were obtained over the wavelength range of 700-1500 cm(-1). Significant spectral differences between the two polymorphs at 1140 cm(-1) show that ATR-FT-IR can provide definitive identification of the polymorphs. To investigate the feasibility of ATR-FT-IR for quantitation of polymorphic forms of Aprepitant, a calibration plot was constructed with known mixtures of the two polymorphs by plotting the peak ratio of the second derivative of absorbance spectra against the weight percent of form II in the polymorphic mixture. Using this novel approach, 3 wt % of one crystal form could be detected in mixtures of the two polymorphs. The accuracy of ATR-FT-IR in determining polymorph purity of the drug substance was tested by comparing the results with those obtained by X-ray powder diffractometry (XRPD). Indeed, polymorphic purity results obtained by ATR-FT-IR were found to be in good agreement with the predictions made by XRPD and compared favorably with actual values in the known mixtures. The present study clearly demonstrates the potential of ATR-FT-IR as a quick, easy, and inexpensive alternative to XRPD for the determination of polymorphic identity and purity of solid drug substances. The technique is ideally suited for polymorph analysis, because it is precise, accurate, and requires minimal sample preparation. PMID:12585491

Helmy, Roy; Zhou, George X; Chen, Yadan W; Crocker, Louis; Wang, Tao; Wenslow, Robert M; Vailaya, Anant

2003-02-01

168

Characterization of a variable angle reflection Fourier transform infrared accessory modified for surface plasmon resonance spectroscopy.  

PubMed

The Harrick AutoSeagull variable angle reflection accessory for Fourier transform infrared (FT-IR) spectrometers provides access to various spectroscopic techniques in a highly flexible platform. In particular, its ability to perform total internal reflection measurements is of interest because it also forms the basis for surface plasmon resonance (SPR) spectroscopy in prism-based configurations. The work presented here discusses the modification of the AutoSeagull to perform SPR spectroscopy, allowing for easy incorporation of the technique into most common FT-IR spectrometers. The wavelength dependency of the dielectric constant of the plasmon-supporting metal (in our case, gold) is largely responsible for the sensitivity attributed to changes in the sample's refractive index (RI) monitored by SPR spectroscopy. Furthermore, the optical properties of gold are such that when near-infrared (NIR) and/or mid-infrared (mid-IR) wavelengths are used to excite surface plasmons, higher sensitivities to RI changes are experienced compared to surface plasmons excited with visible wavelengths. The result is that in addition to instrumental simplicity, SPR analysis on FT-IR spectrometers, as permitted by the modified AutoSeagull, also benefits from the wavelength ranges accessible. Adaptation of the AutoSeagull to SPR spectroscopy involved the incorporation of slit apertures to minimize the angular spread reaching the detector, resulting in sharper SPR "dips" but at the cost of noisier spectra. In addition, discussion of the system's analytical performance includes comparison of dip quality as a function of slit size, tailoring of the dip minima location with respect to incident angle, and sensitivity to bulk RI changes. PMID:20925990

Menegazzo, Nicola; Kegel, Laurel L; Kim, Yoon-Chang; Booksh, Karl S

2010-10-01

169

DNA binding to crystalline silica characterized by Fourier-transform infrared spectroscopy.  

PubMed Central

The interaction of DNA with crystalline silica in buffered aqueous solutions at physiologic pH has been investigated by Fourier-transform infrared spectroscopy (FT-IR). In aqueous buffer, significant changes occur in the spectra of DNA and silica upon coincubation, suggesting that a DNA-silica complex forms as silica interacts with DNA. As compared to the spectrum of silica alone, the changes in the FT-IR spectrum of silica in the DNA-silica complex are consistent with an Si-O bond perturbation on the surface of the silica crystal. DNA remains in a B-form conformation in the DNA-silica complex. The most prominent changes in the DNA spectrum occur in the 1225 to 1000 cm-1 region. Upon binding, the PO2- asymmetric stretch at 1225 cm-1 is increased in intensity and slightly shifted to lower frequencies; the PO2- symmetric stretch at 1086 cm-1 is markedly increased in intensity and the band at 1053 cm-1, representing either the phosphodiester or the C-O stretch of DNA backbone, is significantly reduced in intensity. In D2O buffer, the DNA spectrum reveals a marked increase in intensity of the peak at 1086 cm-1 and a progressive decrease in intensity of the peak at 1053 cm-1 when DNA is exposed to increasing concentrations of silica. The carbonyl band at 1688 cm-1 diminishes and shifts to slightly lower frequencies with increasing concentrations of silica. The present study demonstrates that crystalline silica binds to the phosphate-sugar backbone of DNA.(ABSTRACT TRUNCATED AT 250 WORDS)

Mao, Y; Daniel, L N; Whittaker, N; Saffiotti, U

1994-01-01

170

Characterization of Phase Transformations and Stresses During the Welding of a Ferritic Mild Steel  

NASA Astrophysics Data System (ADS)

The transient stresses and phase evolution have been characterized in the quasi-steady state produced around a gas tungsten arc welding torch in a plain carbon (ASTM 1018) steel using in situ neutron diffraction. A novel method has been developed to isolate the deviatoric or plane stress state in the presence of isotropic contributions to the lattice parameter, such as thermal expansion and solute content. The stress state was found to evolve in the anticipated manner, with compressive stresses ahead of the weld and tensile stresses behind the weld, in the weld and heat-affected zone, and compression in the far field behind the weld. In particular, the region of compression in the heat-affected zone adjacent to and just behind the welding torch expected from weld models was observed. The evolution of phase fraction around the weld was also determined using the technique and the stresses obtained from the ferrite phase.

Dye, D.; Stone, H. J.; Watson, M.; Rogge, R. B.

2014-04-01

171

Characterization of a water-dispersible metal protective coating with Fourier transform infrared spectroscopy, modulated differential scanning calorimetry, and ellipsometry.  

PubMed

An ethylene-methacrylic acid copolymer, formulated by BASF as a waterborne suspension of its alkylammonium salt and used, among other applications, in art conservation as a temporary protective coating was characterized using Fourier transform infrared (FT-IR) spectroscopy aided by modulated differential scanning calorimetry (MDSC) and ellipsometry. The thermal conversion of thin copolymer films from the freshly applied state, where carboxylic acid and carboxylate ion functional groups co-exist, to a purely acidic working state was spectroscopically followed. Transmission mid-infrared data of the working state showed a 1 : 12 ratio of methacrylic acid towards ethylene units. The glass transition temperature (T(g)) in the same state was found at 45 °C. Copolymer films spin-coated on mechanically polished bronze and iron coupons were characterized with transflection infrared spectroscopy and compared to corresponding transmission mid-infrared spectra of copolymer films spin-coated on silicon wafers. In the case of bronze coupons, evidence for interaction of the carboxylate ion with the copper substrate was obtained. The chemical structure and the thermal behavior of the coating, as well as some implications on its protective capability towards iron and copper alloys, is discussed as this material has received considerable attention in the field of metal conservation and coatings. PMID:22524964

Boyatzis, Stamatis C; Douvas, Antonios M; Argyropoulos, Vassilike; Siatou, Amalia; Vlachopoulou, Marilena

2012-05-01

172

A straightforward method for incorporating mutually-coupled circuits into the bus admittance matrix using the concept of artificial branches  

SciTech Connect

Situations frequently exist in which two or more three-phase lines occupy a common right-of-way for a substantial distance. Such lines may be significantly coupled in the zero sequence. Also, the increasing use of phase coordinates in distribution and transmission system analysis mandates the solution of coupled systems. Mutual coupling adds an extra dimension of significant complexity to the development of a classroom understanding of such topics. A method for demonstrating the effects of these couplings readily by inspection is presented. The method, which is computationally stable for all practical cases investigated by the authors, produces no additional buses and retains the topological structure of the prototype except for the addition of some artificial lines. It is demonstrated that the procedure is applicable to a variety of situations and, once the basic principle is understood, can be immediately applied to yield a coupling-free equivalent network whose parameters are directly amenable to inclusion in the bus admittance matrix.

Smolleck, H.A. (New Mexico State Univ., Las Cruces, NM (USA). Dept. of Electrical and Computer Engineering); Shoults, R.R. (Texas Univ., Arlington, TX (USA). Energy Systems Research Center)

1990-05-01

173

Comparison analyses on the 150 × 150 lunar gravity field models by gravity/topography admittance, correlation and precision orbit determination  

NASA Astrophysics Data System (ADS)

We analyzed the 150 × 150 lunar gravity field models, LP150Q, GLGM-3 and SGM150, using the power spectrum on the lunar nearside and farside, the lunar global and localized gravity/topography admittance and correlation, and Chang'E-2 precision orbit determination to investigate which model is a more effective tool to estimate geophysical parameters and determine the lunar satellite precision orbit. Results indicate that all gravity field models can be used to estimate the lunar geophysical parameters of the nearside of the Moon. However, SGM150 is better in such computation of the farside. Additionally, SGM150 is shown to be the most useful model for determining the lunar satellite orbit.

Yan, Jianguo; Zhong, Zhen; Li, Fei; Dohm, James M.; Ping, Jinsong; Cao, Jianfeng; Li, Xie

2013-08-01

174

Athermal compensation of the stress-induced surface deflection of optical coatings using iso-admittance layers.  

PubMed

Mechanical stress in optical thin films can induce surface deflection of optical coatings. In the case of a substrate coated on both sides, a method is proposed which can provide perfect cancellation of this deflection, independently of the deposition process or any other external parameter, such as the temperature sensitivity of the mechanical stress. It is straightforward to implement this method, based on iso-admittance layers, since the thickness of such layers can be used to freely compensate for deflection effects only, without having any influence on the film's optical properties. This method is illustrated by two possible solutions for the design problem B from the Optical Interference Coatings (OIC) 2013 meeting. PMID:24514220

Lemarquis, Frédéric

2014-02-01

175

Characterization of biomass burning: Fourier transform infrared analysis of wood and vegetation combustion products  

NASA Astrophysics Data System (ADS)

The Fourier transform infrared examination of the combustion products of a selection of forest materials has been undertaken in order to guide future detection of biomass burning using satellite remote sensing. Combustion of conifer Pinus strobus (white pine) and deciduous Prunus serotina (cherry), Acer rubrum (red maple), Friglans nigra (walnut), Fraxinus americana (ash), Betula papyrifera (birch), Querus alba (white oak) and Querus rubra (red oak) lumber, in a Meeker burner flame at temperatures of 400 to 900 degrees Fahrenheit produces a broad and relatively flat signal with a few distinct peaks throughout the wavelength spectra (400 to 4000 cm-1). The distinct bands located near wavelengths of 400-700, 1500-1700, 2200-2400 and 3300-3600 cm-1 vary in intensity with an average difference between the highest and lowest absorbing species of 47 percent. Spectral band differences of 10 percent are within the range of modern satellite spectrometers, and support the argument that band differences can be used to discriminate between various types of vegetation. A similar examination of soot and smoke derived from the leaves and branches of the conifer Pinus strobus and deciduous Querus alba (white oak), Querus rubra (red oak), Liquidambar styraciflua (sweetgum), Acer rubrum (maple) and Tilea americana (American basswood) at combustion temperatures of 400 to 900 degrees Fahrenheit produce a similar broad spectrum with a shift in peak location occurring in peaks below the 1700 cm-1 wavelength. The new peaks occur near wavelengths of 1438-1444, 875 and 713 cm-1. This noted shift in wavelength location may be indicative of a fingerprint region for green woods distinguishable from lumber through characteristic biomass suites. Temperature variations during burning show that the spectra of low temperature smoldered aerosols, occurring near 400 to 450 degrees Fahrenheit, may be distinguished from higher temperature soot aerosols that occur above 600 degrees Fahrenheit. A heightened peak intensity of 50 percent is observed throughout the spectra of the lower temperature generated soot and smoke, with respect to the higher temperature generated soot and smoke. These observations suggest the possibility of establishing biomass reduction markers using a ratio method.

Padilla, Diomaris

176

Physical Characterization of human centromeric regions using transformation-associated recombination cloning technology  

SciTech Connect

A special interest in the organization of human centromeric DNA was stimulated a few years ago when two independent groups succeeded in reconstituting a functional human centromere, using constructs carrying centromere-specific alphoid DNA arrays. This work demonstrated the importance of DNA components in mammalian centromeres and opened a way for studying the structural requirements for de novo kinetochore formation and for construction of human artificial chromosomes (HACs) with therapeutic potential. To elucidate the structural requirements for formation of HACs with a functional kinetochore, we developed a new method for cloning of large DNA fragments for human centromeric regions that can be used as a substrate for HAC formation. This method exploits in vivo recombination in yeast (TAR cloning). In addition, a new strategy for the construction of alphoid DNA arrays was developed in our lab. The strategy involves the construction of uniform or hybrid synthetic alphoid DNA arrays by the RCA-TAR technique. This technique comprises two steps: rolling circle amplification of an alphoid DNA dimer and subsequent assembling of the amplified fragments by in vivo homologous recombination in yeast (Figure 1). Using this system, we constructed a set of different synthetic alphoid DNA arrays with a predetermined sequence varying in size from 30 to 140 kb and demonstrated that some of the arrays are competent in HAC formation. Because any nucleotide can be changed in a dimer before its amplification, this new technique is optimal for identifying the structural requirements for de novo kinetochore formation in HACs. Moreover, the technique makes possible to introduce into alphoid DNA arrays recognition sites for DNA-binding proteins. We have made the following progress on the studying of human centromeric regions using transformation-associated recombination cloning technology: i) minimal size of alphoid DNA array required for de novo kinetochore formation was estimated; ii) critical role of CENP-B binding site in do novo kinetochore formation was demonstrated; iii) role of gamma-satellite DNA in functional centromere was elucidated; iv) new generation of HAC with a conditional centromere was constructed for the study of epigenetic control of kinetochore function and for gene expression studies. These studies de novo kinetochore formation may thus provide both a fundamental knowledge and new points of intervention for therapy.

Vladimir Larionov, Ph D

2007-06-05

177

Chemical and photochemical degradation of chlorantraniliprole and characterization of its transformation products.  

PubMed

This study aimed at assessing the photodegradation of the insecticide chlorantraniliprole (CAP) in deionized water and in tap water amended with humic acids and nitrate. Photolysis was carried out under simulated solar or UV-A light. CAP (39 ?M) photodegradation was slightly faster in tap water than in deionized water with half lives of 4.1 and 5.1 days, respectively. Photodegradation rate of CAP was hardly affected by humic acids (up to 100 mg L(-1)) and nitrate. Photodegradation pattern was different in slightly acidic (pH=6.1) deionized water compared to basic (pH=8.0) tap water. Four main degradation products have been isolated and characterized spectroscopically, and crystal structure was recorded for the first two photodegradation products. CAP also degraded in the dark controls, but only at basic pH (23% loss at pH 8.0 in tap water after 6 days), resulting in the formation of one single degradation product. Our study shows that the degradation of chlorantraniliprole in water is a combination of chemical and photochemical reactions, which are highly dependent on the pH of the solution. PMID:24125717

Lavtižar, Vesna; van Gestel, Cornelis A M; Dolenc, Darko; Trebše, Polonca

2014-01-01

178

Secondary organic aerosol (trans)formation through aqueous phase guaiacol photonitration: chemical characterization of the products  

NASA Astrophysics Data System (ADS)

One of the largest primary sources of organic aerosol in the atmosphere is biomass burning (BB) (Laskin et al. 2009); in Europe its contribution to annual mean of PM10 is between 3 and 14 % (Maenhaut et al. 2012). During the process of wood burning many different products are formed via thermal degradation of wood lignin. Hardwood burning produces mainly syringol (2,6-dimetoxyphenol) derivatives, while softwood burning exclusively guaiacol (2-methoxyphenol) and its derivatives. Taking into account physical properties of methoxyphenols only, their concentrations in atmospheric waters might be underestimated. So, their aqueous phase reactions can be an additional source of SOA, especially in regions under significant influence of wood combustion. An important class of compounds formed during physical and chemical aging of the primary BBA in the atmosphere is nitrocatechols, known as strong absorbers of UV and Vis light (Claeys et al. 2012). Very recently, methyl-nitrocatechols were proposed as suitable markers for highly oxidized secondary BBA (Iinuma et al. 2010, Kitanovski et al. 2012). In the present work, the formation of SOA through aqueous phase photooxidation and nitration of guaiacol was examined. The key objective was to chemically characterize the main low-volatility products and further to check their possible presence in the urban atmospheric aerosols. The aqueous phase reactions were performed in a thermostated reactor under simulated sunlight in the presence of H2O2 and nitrite. Guaiacol reaction products were first concentrated by solid-phase extraction (SPE) and then subjected to semi-preparative liquid chromatography.The main product compounds were fractionated and isolated as pure solids and their structure was further elucidated by using nuclear magnetic resonance spectroscopy (1H, 13C and 2D NMR) and direct infusion negative ion electro-spray ionization tandem mass spectrometry (( )ESI-MS/MS). The main photonitration products of guaiacol (4-nitroguaiacol, 6-nitroguaiacol and 4,6-dinitroguaiacol) were examined for their presence in winter aerosol samples by using an optimized HPLC-(?)ESI-MS/MS. 4-nitroguaiacol and 4,6-dinitroguaiacol were unambiguously identified in winter PM10 from Ljubljana, Slovenia, whereas the absence of 6-nitroguaiacol was further explained with the help of long-term reaction monitoring. To our knowledge, our study represents the first report on the identification of 4,6-dinitroguaiacol in ambient aerosols. Laskin, A. et al. (2009) Environ. Sci. Technol. 43, 3764-3771. Maenhaut, W. et al. (2012) Sci. Tot. Environ. 437, 226-236. Claeys, M. et al. (2012) Environ. Chem. 9, 273-284. Iinuma, Y. et al. (2010) Environ. Sci. Technol. 44, 8453-8459. Kitanovski, Z. et al. (2012)J. Chromatogr. A 1268, 35-43.

Grgi?, Irena; Kitanovski, Zoran; Krofli?, Ana; ?usak, Alen

2014-05-01

179

Synthesis and characterization of catalysts for the selective transformation of biomass-derived materials  

NASA Astrophysics Data System (ADS)

The experimental work in this thesis focuses on generating catalysts for two intermediate processes related to the thermal conversion of lignocellulosic biomass: the synthesis and characterization of mesoporous silica supported cobalt catalysts for the Fischer-Tropsch reaction, and an exploration of the reactivity of bulk and supported molybdenum-based nitride catalysts for the hydrodeoxygenation (HDO) of guaiacol, a lignin model compound. The first section of the work details the synthesis of a series of silica-supported cobalt Fischer-Tropsch catalysts with pore diameters ranging from 2-23 nm. Detailed X-ray diffraction measurements were used to determine the composition and particle diameters of the metal fraction, analyzed as a three-phase system containing Cofcc, Cohcp and CoO particles. Catalyst properties were determined at three stages in catalyst history: (1) after the initial calcination step to thermally decompose the catalyst precursor into Co3O4, (2) after the hydrogen reduction step to activate the catalyst to Co and (3) after the FT reaction. From the study, it was observed that larger pore diameters supported higher turnover frequency; smaller pore diameters yielded larger mole fraction of CoO; XRD on post-reduction and post-FTS catalyst samples indicated significant changes in dispersivity after reduction. In the next section, the catalytic behaviors of unsupported, activated carbon-, alumina-, and SBA-15 mesoporous silica-supported molybdenum nitride catalysts were evaluated for the hydrodeoxygenation of guaiacol (2-methoxy phenol) at 300°C and 5 MPa. The nitride catalysts were prepared by thermal decomposition of bulk and supported ammonium heptamolybdate to form MoO 3 followed by nitridation in either flowing ammonia or a nitrogen/hydrogen mixture. The catalytic properties were strongly affected by the nitriding and purging treatment as well as the physical and chemical properties of support. The overall reaction was influenced by the crystalline phase present in the catalyst, dispersion of molybdenum nitride/oxynitride, and the porosity of the support. The hydrodeoxygenation of guaiacol followed two proposed reaction pathways: demethylation (DME) of guaiacol to form catechol, followed by dehydroxylation to form phenol; or a direct demethoxylation (DMO) to form phenol. The selectivity of the reaction was expressed in terms of the phenol/catechol ratio. Phenol was the predominant product for all the catalysts studied, except for the alumina-supported catalysts (an effect of the alumina support). The results from this thesis are encouraging for the application of Mo nitride based catalysts for hydrodeoxygenation of whole pyrolysis oil.

Ghampson, Isaac Tyrone

180

Fate of Transforming Deoxyribonucleic Acid After Uptake by Competent Bacillus subtilis: Phenotypic Characterization of Radiation-Sensitive Recombination-Deficient Mutants  

PubMed Central

A collection of 16 isogenic recombination-deficient strains of Bacillus subtilis isolated on the basis of sensitivity to methyl methane sulfonate (MMS) or mitomycin C (MC) were characterized phenotypically. All were found to be somewhat sensitive to ultraviolet irradiation, MC, and MMS. The mutants were all blocked in “late” steps in the transformation process and were provisionally grouped into four categories on the basis of the various properties examined. Class I mutants were deficient in transformation and heterologous transduction with phage PBS1 but were transducible with homologous donors at nearly the wild-type frequency. They were blocked in donor-recipient complex (DRC) formation but formed essentially normal amounts of double-strand fragments (DSF) and single-strand fragments (SSF). The class IIa strain was deficient in transformation and PBS1 transduction, and formed DRC which was normal by all available physical and biological criteria. Class IIb mutants were deficient in transformation and PBS1 transduction, and failed to form DRC. They did produce DSF and SSF. Class III mutants were deficient in transformation, were normal in PBS1 transduction, and formed DRC which was physically indistinguishable from that of the Rec+ parent although with slightly lowered donor-type transforming activity. Class IV strains were deficient in PBS1 transduction but were transformed at nearly the wild-type efficiency. None of the mutant strains was deficient in the adenosine triphosphate-dependent deoxyribonuclease.

Dubnau, D.; Davidoff-Abelson, R.; Scher, B.; Cirigliano, C.

1973-01-01

181

Bottom-up low molecular weight heparin analysis using liquid chromatography-fourier transform mass spectrometry for extensive characterization.  

PubMed

Low molecular weight heparins (LMWHs) are heterogeneous, polydisperse, and highly negatively charged mixtures of glycosaminoglycan chains prescribed as anticoagulants. The detailed characterization of LMWH is important for the drug quality assurance and for new drug research and development. In this study, online hydrophilic interaction chromatography (HILIC) Fourier transform mass spectrometry (FTMS) was applied to analyze the oligosaccharide fragments of LMWHs generated by heparin lyase II digestion. More than 40 oligosaccharide fragments of LMWH were quantified and used to compare LMWHs prepared by three different manufacturers. The quantified fragment structures included unsaturated disaccharides/oligosaccharides arising from the prominent repeating units of these LMWHs, 3-O-sulfo containing tetrasaccharides arising from their antithrombin III binding sites, 1,6-anhydro ring-containing oligosaccharides formed during their manufacture, saturated uronic acid oligosaccharides coming from some chain nonreducing ends, and oxidized linkage region oligosaccharides coming from some chain reducing ends. This bottom-up approach provides rich detailed structural analysis and quantitative information with high accuracy and reproducibility. When combined with the top-down approach, HILIC LC-FTMS based analysis should be suitable for the advanced quality control and quality assurance in LMWH production. PMID:24905078

Li, Guoyun; Steppich, Julia; Wang, Zhenyu; Sun, Yi; Xue, Changhu; Linhardt, Robert J; Li, Lingyun

2014-07-01

182

Rapid extraction and structural characterization of biomolecules in agarose gels by laser desorption Fourier transform mass spectrometry  

SciTech Connect

A method originally developed for the extraction of biomolecules from agarose gel slices has been utilized as a rapid means of isolating biological compounds from gels for subsequent structural characterization by matrix-assisted laser desorption-ionization Fourier transform mass spectrometry (MALDI/FTMS). This [open quotes]freeze-squeeze[close quotes] extraction method involves pressure extrusion of fluid from frozen gel slices and provides near 50% recovery of analyte in less than 5 min. Experiments were directed at examining the recovery efficiency of the extraction method using [sup 14]C-labeled adenosine monophosphate and investigating the effect of high buffer concentrations on the laser desorption mass spectra. When coupled with this extraction technique, MALDI/FTMS can be used to detect and identify biomolecules at the low picomole level in agarose gel slices. The accurate mass measurements and MS/MS capabilities of the FTMS were exploited to provide detailed structural information at the isomeric level for oligonucleotides electrophoresed into agarose gels. 41 refs., 5 figs., 1 tab.

Dunphy, J.C.; Busch, K.L. (Georgia Inst. of Technology, Atlanta (United States)); Hettich, R.L.; Buchanan, M.V. (Oak Ridge National Lab., TN (United States))

1993-05-15

183

Characterization of Two Soybean (Glycine max L.) LEA IV Proteins by Circular Dichroism and Fourier Transform Infrared Spectrometry  

PubMed Central

Late embryogenesis-abundant (LEA) proteins, accumulating to a high level during the late stages of seed development, may play a role as osmoprotectants. However, the functions and mechanisms of LEA proteins remained to be elucidated. Five major groups of LEA proteins have been described. In the present study, we report on the characterization of two members of soybean LEA IV proteins, basic GmPM1 and acidic GmPM28, by circular dichroism and Fourier transform infrared spectroscopy. The spectra of both proteins revealed limited defined secondary structures in the fully hydrated state. Thus, the soybean LEA IV proteins are members of ‘natively unfolded proteins’. GmPM1 or GmPM28 proteins showed a conformational change under hydrophobic or dry conditions. After fast or slow drying, the two proteins showed slightly increased proportions of defined secondary structures (?-helix and ?-sheet), from 30 to 49% and from 34 to 42% for GmPM1 and GmPm28, respectively. In the dehydrated state, GmPM1 and GmPM28 interact with non-reducing sugars to improve the transition temperature of cellular glass, with poly-l-lysine to prevent dehydration-induced aggregation and with phospholipids to maintain the liquid crystal phase over a wide temperature range. Our work suggests that soybean LEA IV proteins are functional in the dry state. They are one of the important components in cellular glasses and may stabilize desiccation-sensitive proteins and plasma membranes during dehydration.

Shih, Ming-der; Hsieh, Tzung-yang; Lin, Tsai-piao; Hsing, Yue-ie C.; Hoekstra, Folkert A.

2010-01-01

184

Characterization of the dynamic thickness of the aerobic layer during pig manure aerobic composting by Fourier transform infrared microspectroscopy.  

PubMed

A new method for characterizing the aerobic layer thickness in pig manure based on Fourier transform infrared microspectroscopy (FTIRM) is presented to improve the anaerobic/aerobic co-process mechanism, to ensure adequate oxygen supply and, thus, minimize methane emissions during aerobic composting. Freeze-dried manure particles were microtomed into 10 ?m thick sections; the spectral range, spectral resolution, and pixel dimensions in the transmission spectra were 4000-650 cm(-1), 16 cm(-1), and 6.25 × 6.25 ?m, respectively. A mean spectrum of 16 scans was used for the second-derivative analysis with nine smoothing points. This is the first attempt at determining the oxidation profile of composting particles according to the radial variations in second-derivative spectra at 2856 and 1568 cm(-1), which are attributed to the reactants and products of the oxidation, respectively. In addition, an intermediate area is detected between the aerobic layer and anaerobic core. The experimental values of the aerobic layer thickness are consistent with the estimates, and an exponential increase is observed, which is influenced by multiple dynamic factors. However, the contribution of each factor to dynamic variations in the aerobic layer thickness should be investigated using available methods. PMID:24697245

Ge, Jinyi; Huang, Guangqun; Yang, Zengling; Huang, Jing; Han, Lujia

2014-05-01

185

Novel MoO2/carbon hierarchical nano/microcomposites: synthesis, characterization, solid state transformations and thiophene HDS activity.  

PubMed

Novel MoO(2)/C nano/microcomposites were prepared via a bottom-up approach by hydrothermal carbonization of a solution of glucose as a carbon precursor in the presence of polyoxometalates (POMs: phosphomolybdic acid [H(3)PMo(12)O(40)] and ammonium heptamolybdate tetrahydrate [(NH(4))(6)Mo(7)O(24)]·4H(2)O). The structural characterization by FT-IR, XRPD, SEM and TEM analyses revealed the controlled formation of hierarchical MoO(2)/C composites with different morphologies: strawberry-like, based on carbon microspheres decorated with MoO(2) nanoparticles; MoO(2)/C core-shell composites; and irregular aggregates in combination with ring-like microstructures bearing amorphous Mo species. These composites can be fine-tuned by varying reaction time, glucose/POM ratio and type of POM precursor. Subsequent transformations in the solid state through calcinations of MoO(2)/C core-shell composites in air lead to hollow nanostructured molybdenum trioxide microspheres together with nanorods and plate microcrystals or cauliflower-like composites (MoO(2)/C). In addition, the MoO(2)/C composite undergoes a morphology evolution to urchin-like composites when it is calcined under nitrogen atmosphere (MoO(2)/C-N(2)). The MoO(2)/C strawberry-like and MoO(2)/C-N(2) composites were transformed into Mo carbide and nitride supported on carbon microspheres (Mo(2)C/C, MoN/C, and MoN/C-N(2)). These phases were tested as precursors in thiophene hydrodesulphurization (HDS) at 400 °C, observing the following trend in relation to the thiophene steady-state conversion: MoN/C-N(2) > MoN/C > Mo(2)C/C > MoO(2)/C-N(2) > MoO(2)/C. According to these conversion values, a direct correlation was observed between higher HDS activity and decreasing crystal size as estimated from the Scherrer equation. These results suggest that such composites represent interesting and promising precursors for HDS catalysts, where the activity and stability can be modified either by chemical or structural changes of the composites under different conditions. PMID:23243664

Avendaño, Carlos; Briceño, Alexander; Méndez, Franklin J; Brito, Joaquín L; González, Gema; Cañizales, Edgar; Atencio, Reinaldo; Dieudonné, Philippe

2013-02-28

186

Determination of interface states and their time constant for Au/SnO2/n-Si (MOS) capacitors using admittance measurements  

NASA Astrophysics Data System (ADS)

The frequency dependence of admittance measurements (capacitance-voltage (C-V) and conductance-voltage (G/?-V)) of Au/SnO2/n-Si (MOS) capacitors was investigated by taking into account the effects of the interface states (Nss) and series resistance (Rs) at room temperature. Admittance measurements were carried out in frequency and bias voltage ranges of 1 kHz-1 MHz and (-5 V)-(+9 V), respectively. The values of Nss and Rs were determined by using a conductance method and estimating from the admittance measurements of the MOS capacitors. At low frequencies, the interface states can follow the AC signal and yield excess capacitance and conductance. In addition, the parallel conductance (Gp/?) versus log(f) curves at various voltages include a peak due to the presence of interface states. It is observed that the Nss and their time constant (?) range from 1.23 × 1012 eV-1 cm-2 to 1.47 × 1012 eV-1 cm-2 and from 7.29 × 10-5 s to 1.81 × 10-5 s, respectively.

Baran, H. M.; Tataro?lu, A.

2013-04-01

187

Satellite Characterization of Biomass Burning: Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope Study of Combustion Experiments  

NASA Astrophysics Data System (ADS)

Fourier Transform Infrared (FTIR) examination of the combustion products of selected forest materials using a meeker burner flame at temperatures up to 500 degrees Celsius produces a cluster of broad distinct peaks throughout the 400 to 4000 cm-1 wavenumber interval. Distinct bands bracketed by wavenumbers 400-700, 1500-1700, 2200-2400 and 3300-3600 cm-1 show variable intensity with an average difference between the least absorbing and most strongly absorbing species of approximately fifty percent. Given that spectral band differences of ten percent are within the range of modern satellite spectrometers, these band differences are of potential value for discriminating between fires that are impacting a range of vegetation types. Corresponding scanning electron microscope and energy dispersive micro-chemical (SEM/ED) analysis establishes that the evolved soot particles exhibit a characteristic rounded morphology, are carbon rich and host a wide range of adsorbed elements, including calcium, aluminum, potassium, silicon, sulfur and trace nitrogen. Combustion experiments involving leaves and branches as a subset of the biomass experiments at 200-500 degrees Celsius yield a similar broad background, but with peak shifts for maxima residing at less than 1700 cm-1. Additional peaks appear in the ranges 1438-1444, 875 and 713 cm-1. These peak are of potential use for discriminating between hot and smoldering fires, and between soot and smoke yields from green woods and whole-wood or lumber. The spectral shifts noted for low temperature smoldering conditions are in the vicinity of those cited for green vegetation and may not be resolved by present satellite platforms. Nevertheless, the experimental peak data set is of potential use for discriminating between a conflagration or accentuated fire and one characterized by smoldering at low temperature. SEM/ED analysis of the combusted leaf, branch, bark and various crown assemblages yields comparable morphological and geochemical signatures although potassium and light elements are slightly concentrated in effluent from the leafy matrix.

Padilla, D.; Steiner, J. C.

2005-12-01

188

Characterization of the mouse transforming growth factor-beta 1 promoter and activation by the Ha-ras oncogene.  

PubMed Central

We have cloned and sequenced a mouse genomic transforming growth factor beta 1 (TGF-beta 1) DNA fragment that includes the 5' untranslated and regulatory regions of the gene. High-sequence homology with the human TGF-beta 1 gene (66% nucleotide identity in 2.7 kb of DNA upstream of the translational start site) suggested evolutionary conservation of transcriptional regulation for TGF-beta 1. The absence of TATA or CAAT box sequences but the presence of several Sp1-binding and AP-2-like sequences in the promoter region was noted, as previously reported for the human gene. Two transcriptional initiation sites separated by 290 bp were identified by S1 nuclease analysis; these corresponded to transcripts with 866 and 576 nucleotides of 5' untranslated leader sequence. S1 analysis of different mouse tissues indicated that the two transcripts were present in the same ratio even though the total level of TGF-beta 1 mRNA transcripts varied between tissues. Promoter activity adjacent to both transcriptional start sites was demonstrated by using chloramphenicol acetyltransferase fusion genes assayed in mouse AKR-2B fibroblast cells. Transcriptional activation of the promoter by the Ha-ras oncogene was also demonstrated. The minimal promoter constructs (113 and 104 bp 5' of the first and second transcriptional start sites, respectively) were sufficient for induction by Ha-ras. These studies characterize the 5' structure and basal promoter activity of the mouse TGF-beta 1 gene as well as the transcriptional activation of TGF-beta 1 by the Ha-ras oncogene. Images

Geiser, A G; Kim, S J; Roberts, A B; Sporn, M B

1991-01-01

189

Detailed characterization of polar compounds of residual oil in contaminated soil revealed by Fourier transform ion cyclotron resonance mass spectrometry.  

PubMed

Effects of remediation technologies on polar compounds of crude oil in contaminated soils have not been well understood when compared to hydrocarbons. In this study, ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was used to characterize the changes in NSO polar compounds of crude oil and residual oil after long-term natural attenuation, biostimulation and subsequent ozonation following biostimulation of contaminated soils. N1 and O1 species, which were abundant in the crude oil, were selectively biodegraded, and species with higher double bond equivalent values and smaller carbon numbers appeared to be more resistant to microbial alteration. O2-O6 species were enriched by biodegradation and contained a large number of compounds with a high degree of unsaturation. Ozone could react with a variety of polar compounds in residual oil after biodegradation and showed high reactivity with polar species containing aromatic or multi-aliphatic rings, including the residual N1 and O1 species, naphthenic acids and unsaturated O3-O6 compounds. Fatty acids and O3-O8 species dominated by saturated alkyl compounds were resistant to ozonation or the primarily incomplete ozonation products. Principal component analysis of identified peaks in the FT-ICR MS spectra provided a comprehensive overview of the complex samples at the molecular level and the results were consistent with the detailed analysis. Taken together, these results showed the high complexity of polar compounds in residual oils after biodegradation or ozonation in contaminated soil and would contribute to a better understanding of bioremediation and ozonation processes. PMID:21777939

Wang, Jian; Zhang, Xu; Li, Guanghe

2011-10-01

190

Surface carbohydrates of hamster fibroblasts. I. Chemical characterization of surface-labeled glycosphingolipids and aspecific ceramide tetrasaccharide for transformants.  

PubMed

1. Neutral glycosphingolipids of hamster fibroblast NIL cells have been characterized as follows: glucosylceramide, lactosylceramide (betaGall yields 4Glc yields Cer), a digalactosylceramide (alphaGall yields 4betaGal yields Cer), a trihexosylceramide (alphaGall yields 4betaGall yields 4Glc yields Cer), two kinds of ceramide tetrasaccharides (A: alphaGa1NAcl yields 3betaGalNAcl yields 3alphaGall yields 4betaGall yields 1Cer, a new type of Forssman active glycolipid; B: globoside, betaGalNAcl yields 3alphaGall yields 4betaGall yields 4betaGlc yields Cer), and a ceramide pentasaccharide having a classical structure for Forssman antigen (alphaGalNAcl yields 3betaGalNAcl yields 3alphaGall yields 4betaGall yields 4Glc yields Cer). 2. Neutral glycosphingolipids of polyoma virus-transformed NIL cells (NILpy) have been characterized as having an additional ceramide tetrasaccharide which was absent in normal NIL cells. The structure of this specific glycolipid was identified as lacto-N-neotetraosylceramide (betaGall yields 4betaGlc-NAcl yields 3betaGall yields 4Glc yields Cer). Chemical quantities of ceramide tetra- and pentasaccharides in NILpy cells were much lower than in NIL cells. 3. All of these glycolipids, except glucosylceramide and lactosylceramide, were labeled externally by galactose oxidase and tritiated borohydride according to the method previously described (GAHMBERG, C. G, and HAKOMORI, S. (1973) J. Biol. Chem. 248, 4311-4317). The specific activities of the label in glycolipid of NIHpy cells were much greater than that in NIL cells, i.e. reactivity of glycolipids with galactose oxidase in NIHpy cells was much higher than for NIL cells. The surface label in glycolipids was cell cycle-dependent in NIL cells, and a remarkable exposure of a galactosyl residue of a ceramide tetrasaccharide was demonstrated only on the surface of NILpy cells, due to the presence of lacto-N-neotetraosylceramide. PMID:164440

Gahmberg, C G; Hakomori, S

1975-04-10

191

Naylor Transforms of Mellin Type and Applications.  

National Technical Information Service (NTIS)

Some integral transforms introduced by Naylor (1963) are characterized and studied in terms of Mellin transforms. This facilitates the derivation and analysis of transform properties. The transforms are applied to steady-state heat problems in finite circ...

K. A. Patel

1972-01-01

192

Transformational Learners: Transformational Teachers  

ERIC Educational Resources Information Center

Transformational learning, according to Mezirow (1981), involves transforming taken-for-granted frames of reference into more discriminating, flexible "habits of mind". In teacher education, transformative learning impacts on the development of students' action theories, self-efficacy and professional attributes. Although considered imperative to…

Jones, Marguerite

2009-01-01

193

The Transformations of Transformations.  

ERIC Educational Resources Information Center

Harris's original idea of transformations has been changed several times in Chomsky's work. This article explicates these transformations, arguing that though their motivations are highly understandable, these transformations are not necessary for understanding the workings of natural languages. (Author/VWL)

Lin, Francis Y.

2000-01-01

194

Extended microwave-to-optical transformation (MOT) method for electric field analysis of microwave circuits and components  

Microsoft Academic Search

The Microwave-to-Optical Transformation (MOT) method, reported previously, makes use of an optical thin film filter design took known as the Optical Admittance Diagram, the characteristic matrix and the quarter wave rule. Stripline elements are re-configured and modeled as sequential quarter wave optically thin film layers. The previous work was qualitative and mainly focused on the intuitively useful analysis that the

Charmaine C. Franck; Jerome B. Franck; Lewis F. Desandre

1999-01-01

195

Ear-canal acoustic admittance and reflectance effects in human neonates. I. Predictions of otoacoustic emission and auditory brainstem responses  

NASA Astrophysics Data System (ADS)

This report describes the extent to which ear-canal acoustic admittance and energy reflectance (YR) in human neonates (1) predict otoacoustic emission (OAE) levels and auditory brainstem response (ABR) latencies, and (2) classify OAE and ABR responses as present or absent. Analyses are reported on a subset of ears in which hearing screening measurements were obtained previously [Norton et al., Ear. Hear. 21, 348-356 (2000a)]. Tests on 1405 ears included YR, distortion-product OAEs, transient-evoked OAEs, and ABR. Principal components analysis reduced the 33 YR variables to 5-7 factors. OAE levels decreased and ABR latencies increased with increasing high-frequency energy reflectance. Up to 28% of the variance in OAE levels and 12% of the variance in ABR wave-V latencies were explained by these factors. Thus, the YR response indirectly encodes information on inter-ear variations in forward and reverse middle-ear transmission. The YR factors classify OAEs with an area under the relative operating characteristic (ROC) curve as high as 0.79, suggesting that middle-ear dysfunction is partly responsible for the inability to record OAEs in some ears. The YR factors classified ABR responses less well, with ROC areas of 0.64 for predicting wave-V latency and 0.56 for predicting Fsp.

Keefe, Douglas H.; Zhao, Fei; Neely, Stephen T.; Gorga, Michael P.; Vohr, Betty R.

2003-01-01

196

Application of Hilbert-Huang transform to characterize soil liquefaction and quay wall seismic responses modeled in centrifuge shaking-table tests  

Microsoft Academic Search

In this paper, a Hilbert-Huang Transform data-processing technique is successfully used to characterize the seismic responses of soil–quay wall systems using measured data in a series of geotechnical centrifuge shaking-table tests. The predominant frequency of a liquefied deposit shifts down to a low frequency level; however, “de-liquefaction” leads to frequent, local higher-frequency spikes in the time histories of predominant instantaneous

Yu-Chen Wei; Chung-Jung Lee; Wen-Yi Hung; Huei-Tsyr Chen

2010-01-01

197

Microstructure characterization and phase transformation kinetics of ball-milled prepared nanocrystalline Zn 2TiO 4 by Rietveld method  

Microsoft Academic Search

Both the normal and inverse Zn2TiO4 spinel phases have been synthesized by ball milling the mixture of ZnO and anatase TiO2 (2:1mol%) in a high-energy planetary ball mill. Microstructure characterization of unmilled and ball-milled materials has been made by employing the Rietveld’s powder structure refinement methodology using X-ray powder diffraction data. Phase transformation kinetics of ball-milled composites has been studied

S. K Manik; P Bose; S. K Pradhan

2003-01-01

198

The isolation and characterization of growth regulatory factors produced by a herpes simplex virus Type 2 transformed mouse tumor cell line, H238  

SciTech Connect

This study was performed in an attempt to associate HSV-2-transformation with specific growth factors in order to develop a testable model for HSV-2-transformation. We report here the isolation and characterization of four growth regulatory factors produced by H238, an HSV-2-transformed mouse tumor cell line. These factors were separated from the H238-CM by heparin-sepharose affinity chromatography into three peaks of mitogenic activity and a fourth containing inhibitory activity for splenocytes. The three peaks of mitogenic activity have been identified based on physiochemical characteristics: the first supported the anchorage-independent growth of EGF treated NRK-c-49 cells and resembles transforming growth factor-{beta} (TGF-{beta}); the second bound to lectin-coated sepharose beads and was sensitive to trypsin, neuroaminidase, and the reducing agent dithiothreitol (DTT) and, resembled a platelet-derived growth factor (PDGF)-like factor; and the third displaced ({sup 125}I)-labeled basic fibroblast growth factor (bFGF) in a dose-dependent fashion when tested with a radioimmune assay. The fourth peak was inhibitory for a variety of splenocyte function assays. A model for the interaction of these factors in vivo is presented with an emphasis on testability.

Stagg, R.B.

1988-01-01

199

Generation and characterization of soybean and marker-free tobacco plastid transformants over-expressing a bacterial 4-hydroxyphenylpyruvate dioxygenase which provides strong herbicide tolerance.  

PubMed

Plant 4-hydroxyphenylpyruvate dioxygenase (HPPD) is part of the biosynthetic pathway leading to plastoquinone and vitamin E. This enzyme is also the molecular target of various new bleaching herbicides for which genetically engineered tolerant crops are being developed. We have expressed a sensitive bacterial hppd gene from Pseudomonas fluorescens in plastid transformants of tobacco and soybean and characterized in detail the recombinant lines. HPPD accumulates to approximately 5% of total soluble protein in transgenic chloroplasts of both species. As a result, the soybean and tobacco plastid transformants acquire a strong herbicide tolerance, performing better than nuclear transformants. In contrast, the over-expression of HPPD has no significant impact on the vitamin E content of leaves or seeds, quantitatively or qualitatively. A new strategy is presented and exemplified in tobacco which allows the rapid generation of antibiotic marker-free plastid transformants containing the herbicide tolerance gene only. This work reports, for the first time, the plastome engineering for herbicide tolerance in a major agronomic crop, and a technology leading to marker-free lines for this trait. PMID:17207262

Dufourmantel, Nathalie; Dubald, Manuel; Matringe, Michel; Canard, Hélène; Garcon, Frédéric; Job, Claudette; Kay, Elisabeth; Wisniewski, Jean-Pierre; Ferullo, Jean-Marc; Pelissier, Bernard; Sailland, Alain; Tissot, Ghislaine

2007-01-01

200

Photolytic and photocatalytic transformation of methadone in aqueous solutions under solar irradiation: kinetics, characterization of major intermediate products and toxicity evaluation.  

PubMed

The present manuscript describes the transformation and mineralization of methadone (MET) in aqueous solutions (demineralized water (DW) and synthetic municipal wastewater effluent (SWeff)) by natural solar irradiation and two solar photocatalytic processes: heterogeneous photocatalysis with titanium dioxide (TiO2) and homogeneous photocatalysis by photo-Fenton. Direct solar irradiation resulted in almost complete transformation of MET in the investigated matrices after 20 h of normalized irradiation time. MET photocatalytic transformation required shorter illumination times in DW compared to SWeff. Only 16 and 36 min of solar illumination were required during photo-Fenton and photocatalysis with TiO2, respectively, to transform MET completely in SWeff. Mineralization of the dissolved organic carbon took place only during photocatalytic treatments. Kinetics parameters were calculated for processes comparison. Additionally, phototransformation intermediates generated during each treatment were investigated and characterized by means of ultra-performance liquid chromatography coupled to quadrupole-time of flight tandem mass spectrometry (UPLC-QqTOF-MS/MS). The main MET phototransformation pathways were observed to be hydroxylation, and fragmentation and cyclization. According to the Vibrio fischeri bioassay, the acute toxicity of the generated phototransformation products was not relevant, since the observed inhibition percentages of bacterial bioluminescence were always below 30% after 30 min of sample contact. PMID:21767861

Postigo, Cristina; Sirtori, Carla; Oller, Isabel; Malato, Sixto; Maldonado, Manuel Ignacio; López de Alda, Miren; Barceló, Damià

2011-10-15

201

[A profile of admittances to hospital due to non-contagious chronic diseases sensitive to primary health care among chronologically advantaged patients in the southern half of Rio Grande do Sul].  

PubMed

The purpose here established was that of establishing, within the municipalities in the southern part of the Brazilian State of Rio Grande do Sul, the profile of admittances to hospital resulting from Non-Contagious Chronic Diseases Sensitive to Primary Health Care (NCCDSPHC) among chronologically advantaged patients. This is a transversal study with secondary data obtained from the Information Technology Department of the Brazilian Public Health System--SUS (DATASUS), including variables related to admittance to hospital and also the mortality rates in hospitals (according to causes, gender, age, and time spent in hospital). The NCCDSPHC are responsible for 43.99% of hospital admittances for all causes (AAC), with Pulmonary Diseases standing out as the most prevalent single group (18%), followed by Heart Failure (12.28%). The female sex, with the exception of the Pulmonary Disease category, is the one that causes most admittances to hospital through other causes. We also found a linear trend towards an increase in the mortality rate of the NCCDSPHC when grouped together Our conclusion is that, due to the magnitude of the admittances to hospital, as also the increase in the mortality caused by the NCCDSPHC, it is urgent to embark on more in-depth considerations about care to be taken as part of primary care for the chronologically advantaged in this region. PMID:24344594

dos Santos, Vilma Constancia Fioravante; Kalsing, Alice; Ruiz, Eliziane Nicolodi Francescato; Roese, Adriana; Gerhardt, Tatiana Engel

2013-09-01

202

CHARACTERIZATION OF AMBIENT PM2.5 AEROSOL AT A SOUTHEASTERN US SITE: FOURIER TRANSFORM INFRARED ANALYSIS OR PARTICLE PHASE  

EPA Science Inventory

During a field study in the summer of 2000 in the Research Triangle Park (RTP), aerosol samples were collected using a five stage cascade impactor and subsequently analyzed using Fourier Transform Infrared Spectroscopy (FTIR). The impaction surfaces were stainless steel disks....

203

Autofluorescence characterization of DMBA-TPA-induced two-stage carcinogenesis in mouse skin for the early detection of tissue transformation  

NASA Astrophysics Data System (ADS)

The use of autofluorescence technique in the characterization of the sequential tissue transformation process in 7,12-dimethylbenz(a)anthracene and 12-O-tetradecanoylphorbol-13-acetate (DMBA & TPA) induced two-stage mouse skin carcinogenesis model in conjunction with a suitable statistical method is being explored. The fluorescence excitation emission matrix (EEM) from experimental group (n=40; DMBA/TPA application), control group (n=6; acetone application) and the blank group (n=6; no application of DMBA/TPA or acetone) were measured every week using Fluoromax3 spectrofluorometer coupled with a waveguide fiber optic bundle (JY Horiba, NJ). The EEM was recorded for 19 excitation wavelengths from 280 to 460 nm at 10 nm intervals and the fluorescence emission was scanned from 300 to 750 nm. During the tissue transformation the epithelial tissues underwent biochemical and structural changes that are manifested in the tissue fluorescence. To correlate the tissue morphology with the observed fluorescence differences in the fluorescence emission, animals were sacrificed and the tissue biopsies were subjected to histopathological evaluation. The fluorescence emission corresponding to different fluorophores was extracted from the EEM, and the spectral data were used in multivariate statistical algorithm for the earliest diagnosis of the onset of tissue transformation. The intrinsic fluorescence from tryptophan, NADH and prophyrins showed distinct differences in the spectral signature during the tissue transformation, due to the altered metabolic activities of the cells. The statistical analysis of the spectral data corresponding to each excitation wavelength showed better classification accuracy at 280, 320, 350 and 405 nm excitations, corresponding to tryptophan, collagen, NADH and porphyrins with the classification accuracy of 74.3, 68.1, 64.6 and 74.7 % respectively. The variations in the spectral signature and the results of the statistical analysis suggest that porphyrins, tryptophan and NADH can be targeted as potential tumor markers in the early detection of the tissue transformation process.

Diagaradjane, Parmeswaran; Yaseen, Mohammed A.; Yu, Jie; Wong, Michael S.; Anvari, Bahman

2005-04-01

204

Correlation of stability to varied CdCl2 treatment and related defects in CdS/CdTe PV devices as measured by thermal admittance spectroscopy  

NASA Astrophysics Data System (ADS)

A correlation between the CdCl2 treatment and the change in conversion efficiency with light and heat stress indoors (stability) has been shown previously by our group for CdS/CdTe:Cu PV devices. In the present work CdTe devices were fabricated with various CdCl2 treatments and with and without a Cu containing back contact. The electrical characteristics of the defects acting as traps in these devices were studied using thermal admittance spectroscopy (TAS). The activation energy Et-EV, the apparent capture cross section and the densities of state functions (using Walter's method) of the traps in the devices were estimated.

Enzenroth, R. Albert; Barth, K. L.; Sampath, W. S.

2005-11-01

205

Evidences of buried loads in the base of the crust of Borborema Plateau (NE Brazil) from Bouguer admittance estimates  

NASA Astrophysics Data System (ADS)

In the Borborema Province (BP) - northeastern Brazil - two important Cenozoic events occurred at the surface: the Macau magmatism and the Borborema Plateau epeirogenesis. To obtain appropriated-scale geophysical data to explain the deep origins of these two events, different gravimetric/elevation databases were integrated with new surveys. Bouguer admittance estimates reveal that isostatic condition of the BP, especially in the Borborema Plateau, can be explained using elastic models to the lithosphere only if surface and buried loadings are combined. If the buried load is applied in the base of the crust, the ratio between buried and surface weights is circa 15 for a lithosphere with effective elastic thickness around 15 km and crust thickness around 33 km. From an interpretative viewpoint of the buried load, it is assumed that the lower crust under the Borborema Plateau might have an anomalous high value of density. Magmatic underplating might explain this fact as well as the observed surface magmatism and epeirogenesis. Crustal thickening of about 4 km under the Borborema Plateau and intracrustal seismic velocity discontinuity with high Vp/Vs ratio are geophysical facts consistent with magmatic underplating. However, the surface magmatism presents low volume and mainly alkaline composition - facts that are not entirely consistent with the hypothesis of magmatic underplating. Regardless the validity of this hypothesis, Cenozoic-to-present events in BP might be somewhat associated with imbalances in lithosphere-asthenospheric mantle and/or crust-lithospheric mantle systems. The existence of free-air anomalies showing no null integral over area and of an expressive positive geoid anomaly are geophysical evidences of these imbalances. Possibly, the Borborema Plateau is still suffering epeirogenesis. Post-depositional deformation found in Barreiras Formation strata, Late Quaternay fault reactivations, and AFT thermochronology analysis suggesting the existence of a cooling stage between 20 and 0 Ma might be geologic evidences of the continued action of epeirogenesis until the present. In addition, the relatively high level of the present intraplate seismicity recorded in several regions of the BP is another unequivocal geophysical evidence that the crust of the province is still submitted to accommodation processes.

de Oliveira, Roberto Gusmão; de Medeiros, Walter Eugênio

2012-08-01

206

Characterization of solid phases and study of transformation kinetics in m-chlorofluorobenzene by 35Cl nuclear quadrupole resonance.  

PubMed

Polymorphism is of widespread occurrence in the world of molecular crystals. In this work we present experimental results showing the existence of four solid phases in m-chlorofluorobenzene. A glass structure is achieved by quenching the liquid phase at 77 K. This glassy state crystallizes in a disordered phase at T~143 K, which in turn transforms to the high-temperature stable phase (phase I) at T~153 K. Depending on the thermal history of the sample, a different ordered phase (phase III) can be obtained. The disorder is attributed to a molecular orientational disorder. There is no evidence of molecular reorientation in any phase. A study of the disorder-order phase transformation kinetics, using nuclear quadrupole resonance, is presented. The results are analyzed following Cahn's theory. Nucleation seems to take place at grain boundaries. Growth rates for different temperatures have been determined. PMID:22209621

Pérez, Silvina; Wolfenson, Alberto

2012-02-01

207

Fourier transform infrared and Raman spectroscopic characterization of homogeneous solution concentration gradients near a container wall at different temperatures  

NASA Technical Reports Server (NTRS)

Fourier transform infrared (FTIR) and Raman spectroscopic techniques were used to study the solution concentration gradient in succino nitrile-rich and water-rich homogeneous solutions. The spectroscopic data shows significant concentration dependency. Although FTIR-attenuated total reflectance could not yield surface spectra since the evanescent infrared wave penetrated deep into the bulk solution, it showed that water-rich clusters were decreased at higher temperatures. This result is consistent with the calorimetric results reported earlier.

Loo, B. H.; Burns, D. H.; Lee, Y. G. L.; Emerson, M. T.

1991-01-01

208

Characterization of the purified molybdate-stabilized glucocorticoid receptor from rat liver. An in vitro transformable complex.  

PubMed

Rat liver glucocorticoid receptor was purified in the presence of molybdate by a three-step procedure comprising protamine sulfate precipitation, affinity chromatography on a dexamethasone matrix and high-performance size-exclusion chromatography (HPSEC) on a TSK G 3000 SW column. The [3H]triamcinolone-acetonide-receptor complex was obtained in 20% yield with an overall 11 800-fold purification. The dissociation rate constant of this complex was 1.6 X 10(-4) min-1. The purified receptor sedimented at 8.3 S in high-salt and 9.4 S in low-salt sucrose gradients containing molybdate. A 7.0-nm Stokes radius was determined by HPSEC on a TSK G 4000 column in high-salt buffer. The calculated Mr was 278000. Dodecyl sulfate/polyacrylamide gel electrophoresis revealed an almost homogeneous 90 000-Mr band. Three minor bands with Mr of 78 000, 72 000 and 48 000 were also inconstantly seen. An apparent pI = 5.1 was observed for the [3H]steroid complex by isoelectric focusing in agarose gel. Furthermore high-performance ion-exchange chromatography of the purified complex on a DEAE 545 LKB column (DEAE HPLC) yielded a sharp peak eluted at a 315 mM potassium ion concentration. This peak was shown to contain almost all the 90 000-Mr protein. Moreover the purified receptor complex appeared to be transformable to a DNA-binding state after molybdate removal followed by warming 30 min at 25 degrees C in presence of 0.2% bovine serum albumin: 50-78% transformation yield could be demonstrated by DNA-cellulose chromatography. Partial transformation could also be obtained at 0 degrees C in the absence of any added protein and was followed by DEAE HPLC. The transformed complex was eluted by 180 mM potassium. PMID:4065150

Idziorek, T; Formstecher, P; Danze, P M; Sablonniere, B; Lustenberger, P; Richard, C; Dumur, V; Dautrevaux, M

1985-11-15

209

ICAM-1 Expression in a Spontaneously Transformed Human Keratinocyte Cell Line: Characterization by a Simple Cell-ELISA Assay  

Microsoft Academic Search

Interferon gamma (IFN-?) is known to induce ICAM-1 on keratinocytes (KC) in vitro, and its expression in vivo is correlated with epidermal T-cell infiltration in various dermatoses. However, the mechanisms for this cytokine-mediated ICAM-1 expression are essentially unknown. We investigated the induction of ICAM-1 by IFN-? in HaCaT cells, a spontaneously transformed human KC cell line, using an immunoperoxidase-ELISA with

Anthony P. Winiski; Carolyn A. Foster

1992-01-01

210

Characterization of the ?-1,3-glucanase gene in peanut (Arachis hypogaea L.) by cloning and genetic transformation.  

PubMed

Plant ?-1,3-glucanases are commonly involved in disease resistance. This report describes the cloning and genetic transformation of a ?-1,3-glucanase gene from peanut. The gene was isolated from both the genomic DNA and cDNA of peanut variety Huayu20 by polymerase chain reaction (PCR) and reverse transcription PCR (RT-PCR), respectively. The DNA sequence contained 1471 bp including two exons and one intron, and the coding sequence contained 1047 bp that coded for a 348-amino acid protein with a calculated molecular weight of 38.8 kDa. The sequence was registered in NCBI (GenBank accession No. JQ801335) and was designated as Ah-Glu. As determined by BLAST analysis, the Ah-Glu protein has 42-90% homology with proteins from Oryza sativa (BAC83070.1), Zea mays (NP_001149308), Arabidopsis thaliana (NP_200470.1), Medicago sativa (ABD91577.1), and Glycine max (XP_003530515.1). The over-expression vector pCAMBIA1301-Glu containing Ah-Glu was constructed, confirmed by PCR and restriction enzyme digestion, and transformed into peanut variety Huayu22 by Agrobacterium EHA105-mediated transformation. The putative transformed plants (T0) were confirmed by PCR amplification. RT-PCR analysis and ?-glucuronidase (GUS) staining showed that the transferred Ah-Glu was expressed as mRNA and protein. In a laboratory test, the transgenic plants were found to be more resistant to the fungal pathogen Cercospora personata than the non-transgenic plants were. PMID:24668677

Qiao, L X; Ding, X; Wang, H C; Sui, J M; Wang, J-S

2014-01-01

211

Morphometric and biochemical characterization of red beet ( Beta vulgaris L.) hairy roots obtained after single and double transformations  

Microsoft Academic Search

It is known that T-DNA of Agrobacterium rhizogenes affects processes of plant development and activates the synthesis of secondary metabolites in transformed plant cells. In\\u000a the present investigation, we provide evidence that different strains of A. rhizogenes significantly affect morphometric, morphological and functional characteristics of hairy roots of red beet (Beta vulgaris L.). Infection with four strains of A. rhizogenes

R. Thimmaraju; L. Venkatachalam; N. Bhagyalakshmi

2008-01-01

212

Genetic transformation, recovery, and characterization of fertile soybean transgenic for a synthetic Bacillus thuringiensis cryIAc gene  

Microsoft Academic Search

Somatic embryos of Jack, a Glycine max (1.) Merrill cultivar, were transformed using microprojectile bombardment with a syn- thetic Bacillus thuringiensis insecticidal crystal protein gene (Bt crylAc) driven by the 35s promoter and linked to the HPH gene. Approximately 10 g of tissue was bombarded, and three transgenic lines were selected on hygromycin-containing media and converted into plants. The recovered

C. Neal Stewart; Michael J. Adang; H. Roger Boerma; Cuy Cardineau; Donna Tucker; Wayne A. Parrott

1996-01-01

213

Initial characterizations of nontransformed and transformed (/sup 3/H )aldosterone-type I receptor complexes in brain cytosol  

SciTech Connect

Incubation of (/sup 3/H)aldosterone-type I receptor complexes in mouse brain cytosol with the chaotropic anion thiocyanate increased the fraction of receptors retained by DNA-cellulose from less than 10% to over 40%, whereas it decreased the fraction retained by protamine sulfate from more than 90% to less than 10%. Thiocyanate-induced transformation to the DNA-binding species was also accompanied by a 2.1-fold decrease in the rate of (/sup 3/H)aldosterone dissociation from type I receptors as well as by an increase in the apparent positive charge and hydrophobicity of the surface of these receptors, as revealed by DEAE Bio-Gel ion exchange and pentyl agarose hydrophobic interaction chromatography. Sucrose density gradient sedimentation and Sephacryl S-300 gel exclusion chromatography revealed a reduction in the sedimentation coefficient and Stokes radius of the steroid-receptor complex from 9.6S and 8.0 nm before to 4.7S and 6.1 nm after transformation, respectively. These changes in hydrodynamic parameters were found to correspond to a 2.8-fold reduction in the apparent molecular mass from 331,000 before to 120,000 after transformation. In view of these various findings as well as the known differential affinity of protamine sulfate for the 90K heat shock protein, we suggest that thiocyanate-induced transformation is initiated by the dissociation of two molecules of heat shock protein from each steroid/DNA-binding type I receptor subunit.

Luttge, W.G.; Rupp, M.E.; Emadian, S.M.

1989-04-01

214

Identification and Characterization of Plant Genes Involved in Agrobacterium -Mediated Plant Transformation by Virus-Induced Gene Silencing  

Microsoft Academic Search

Genetic transformation of plant cells by Agrobacterium tu- mefaciens represents a unique case of trans-kingdom sex re- quiring the involvement of both bacterial virulence proteins and plant-encoded proteins. We have developed in planta and leaf-disk assays in Nicotiana benthamiana for identifying plant genes involved in Agrobacterium-mediated plant trans- formation using virus-induced gene silencing (VIGS) as a genomics tool. VIGS was

Ajith Anand; Zarir Vaghchhipawala; Choong-Min Ryu; Li Kang; Keri Wang; Olga del-Pozo; Gregory B. Martin; Kirankumar S. Mysore

2007-01-01

215

Characterization of separability and entanglement in (2xD)- and (3xD)-dimensional systems by single-qubit and single-qutrit unitary transformations  

SciTech Connect

We investigate the geometric characterization of pure state bipartite entanglement of (2xD)- and (3xD)-dimensional composite quantum systems. To this aim, we analyze the relationship between states and their images under the action of particular classes of local unitary operations. We find that invariance of states under the action of single-qubit and single-qutrit transformations is a necessary and sufficient condition for separability. We demonstrate that in the (2xD)-dimensional case the von Neumann entropy of entanglement is a monotonic function of the minimum squared Euclidean distance between states and their images over the set of single qubit unitary transformations. Moreover, both in the (2xD)- and in the (3xD)-dimensional cases the minimum squared Euclidean distance exactly coincides with the linear entropy [and thus as well with the tangle measure of entanglement in the (2xD)-dimensional case]. These results provide a geometric characterization of entanglement measures originally established in informational frameworks. Consequences and applications of the formalism to quantum critical phenomena in spin systems are discussed.

Giampaolo, Salvatore M. [Dipartimento di Matematica e Informatica, Universita degli Studi di Salerno, Via Ponte don Melillo, I-84084 Fisciano (Italy); CNR-INFM Coherentia, Naples (Italy); CNISM Unita di Salerno and INFN Sezione di Napoli, Gruppo collegato di Salerno, Baronissi (Italy); Illuminati, Fabrizio [Dipartimento di Matematica e Informatica, Universita degli Studi di Salerno, Via Ponte don Melillo, I-84084 Fisciano (Italy) and CNR-INFM Coherentia, Naples (Italy); CNISM Unita di Salerno and INFN Sezione di Napoli, Gruppo collegato di Salerno, Baronissi (Italy); ISI Foundation for Scientific Interchange, Villa Gualino, Viale Settimio Severo 65, I-10133 Turin (Italy)

2007-10-15

216

Immunological characterization of a major transformation-sensitive fibroblast cell surface glycoprotein. Localization, redistribution, and role in cell shape  

PubMed Central

The major cell surface glycoprotein of chick embryo fibroblasts, cellular fibronectin (formerly known as CSP or LETS protein), was purified and used to produce monospecific antisera. After affinity purification, the anti-fibronectin was used to investigate fibronectin's localization, its transfer from intracellular to extracellular pools, its antibody-induced redistribution on the cell surface, and its role in cell shape. Anti-fibronectin localizes to extracellular fibrils located under and between sparse cells, and to a dense matrix that surrounds confluent cells. Cellular fibronectin is also present in granular intracytoplasmic structures containing newly synthesized fibronectin before secretion. This intracellular staining disappears 2 h after treatment with cycloheximide or puromycin, and returns after removal of these protein synthesis inhibitors. In pulse- chase experiments using cycloheximide, fibronectin was sequentially transferred from the intracellular to the fibrillar extracellular forms. Transformation of chick fibroblasts results in decreases in both extracellular and intracellular fibronectin, and in altered cell shape. Treatment of untransformed chick fibroblasts with anti-fibronectin results in rapid (30 min) alteration to a rounder cell shape resembling that of many transformed cells. These rapid shape changes are followed by a slow, antibody-induced redistribution of fibronectin to supranuclear caplike structures. This "capping" is inhibited by metabolic inhibitors. Reconstitution of cell surface fibronectin onto transformed cells restores a more normal fibroblastic phenotype. The reconstituted fibronectin on these cells organizes into fibrillar patterns similar to those of untransformed cells. As with untransformed cells, treatment of these reconstituted cells with anti-fibronectin also results in cell rounding and "capping" of fibronectin.

1978-01-01

217

Tropomyosin isoforms in chicken embryo fibroblasts: purification, characterization, and changes in Rous sarcoma virus-transformed cells  

PubMed Central

Seven polypeptides (a, b, c, 1, 2, 3a, and 3b) have been previously identified as tropomyosin isoforms in chicken embryo fibroblasts (CEF) (Lin, J. J.-C., Matsumura, F., and Yamashiro-Matsumura, S., 1984, J. Cell. Biol., 98:116-127). Spots a and c had identical mobility on two- dimensional gels with the slow-migrating and fast-migrating components, respectively, of chicken gizzard tropomyosin. However, the remaining isoforms of CEF tropomyosin were distinct from chicken skeletal and cardiac tropomyosins on two-dimensional gels. The mixture of CEF tropomyosin has been isolated by the combination of Triton/glycerol extraction of monolayer cells, heat treatment, and ammonium sulfate fractionation. The yield of tropomyosin was estimated to be 1.4% of total CEF proteins. The identical set of tropomyosin isoforms could be found in the antitropomyosin immunoprecipitates after the cell-free translation products of total poly(A)+ RNAs isolated from CEF cells. This suggested that at least seven mRNAs coding for these tropomyosin isoforms existed in the cell. Purified tropomyosins (particularly 1, 2, and 3) showed different actin-binding abilities in the presence of 100 mM KCl and no divalent cation. Under this condition, the binding of tropomyosin 3 (3a + 3b) to actin filaments was significantly weaker than that of tropomyosin 1 or 2. CEF tropomyosin 1, and probably 3, could be cross-linked to form homodimers by treatment with 5,5'- dithiobis-(2-nitrobenzoate), whereas tropomyosin a and c formed a heterodimer. These dimer species may reflect the in vivo assembly of tropomyosin isoforms, since dimer formation occurred not only with purified tropomyosin but also with microfilament-associated tropomyosin. The expression of these tropomyosin isoforms in Rous sarcoma virus-transformed CEF cells has also been investigated. In agreement with the previous report by Hendricks and Weintraub (Proc. Natl. Acad. Sci. USA., 78:5633-5637), we found that major tropomyosin 1 was greatly reduced in transformed cells. We have also found that the relative amounts of tropomyosin 3a and 3b were increased in both the total cell lysate and the microfilament fraction of transformed cells. Because of the different actin-binding properties observed for CEF tropomyosins, changes in the expression of these isoforms may, in part, be responsible for the reduction of actin cables and the alteration of cell shape found in transformed cells.

1985-01-01

218

Resin characterization in cured graphite fiber reinforced composites using diffuse reflectance-FTIR. [Fourier transform infrared spectroscopy  

NASA Technical Reports Server (NTRS)

The feasibility of using diffuse reflectance in combination with Fourier transform infrared spectroscopy to obtain information on cured graphite fiber reinforced polymeric matrix resin composites was investigated. Several graphite/epoxy, polysulfone, and polyimide composites exposed to thermal or radiation environments were examined. An experimental polyimide-sulfone adhesive tape was also studied during processing. In each case, significant changes in resin molecular structure was observed due to environmental exposure. These changes in molecular structure were correlated with previously observed changes in material properties providing new insights into material behavior.

Young, P. R.; Stein, B. A.; Chang, A. C.

1983-01-01

219

Genetic transformation, recovery, and characterization of fertile soybean transgenic for a synthetic Bacillus thuringiensis cryIAc gene.  

PubMed Central

Somatic embryos of jack, a Glycine max (L.) Merrill cultivar, were transformed using microprojectile bombardment with a synthetic Bacillus thuringiensis insecticidal crystal protein gene (Bt cryIAc) driven by the 35S promoter and linked to the HPH gene. Approximately 10 g of tissue was bombarded, and three transgenic lines were selected on hygromycin-containing media and converted into plants. The recovered lines contained the HPH gene, but the Bt gene was lost in one line. The plasmid was rearranged in the second line, and the third line had two copies, one of which was rear-ranged. The CryIAc protein accumulated up to 46 ng mg-1 extractable protein. In detached-leaf bioassays, plants with an intact copy of the Bt gene, and to a lesser extent those with the rearranged copy, were protected from damage from corn earworm (Helicoverpa zea), soybean looper (Pseudoplusia includens), tobacco budworm (Heliothis virescens), and velvetbean caterpillar (Anticarsia gemmatalis). Corn earworm produced less than 3% defoliation on transgenic plants, compared with 20% on the lepidopteran-resistant breeding line GatIR81-296, and more than 40% on susceptible cultivars. Unlike previous reports of soybean transformation using this technique, all plants were fertile. To our knowledge, this is the first report of a soybean transgenic for a highly expressed insecticidal gene.

Stewart, C N; Adang, M J; All, J N; Boerma, H R; Cardineau, G; Tucker, D; Parrott, W A

1996-01-01

220

EBSD characterization of high-temperature phase transformations in an Al-Si coating on Cr-Mo steel  

SciTech Connect

5Cr-0.5Mo steel was coated by hot-dipping in a molten bath containing Al-10 wt.% Si. The phase transformation in the aluminide layer during diffusion at 750 Degree-Sign C in static air was analyzed by electron backscatter diffraction. The results show the aluminide layer of the as-coated specimen consisted of an outer Al-Si topcoat, a middle layer formed of scattered {tau}{sub 5(C)}-Al{sub 7}(Fe,Cr){sub 2}Si particles and minor plate-shaped {tau}{sub 4}-Al{sub 4}FeSi{sub 2} and {tau}{sub 6}-Al{sub 4}FeSi phases in the Al-Si matrix and an inner continuous {tau}{sub 5(H)}-Al{sub 7}Fe{sub 2}Si layer, respectively from the coating surface to the steel substrate. The formation of FeAl{sub 3} and Fe{sub 2}Al{sub 5} with {tau}{sub 1}-(Al,Si){sub 5}Fe{sub 3} precipitates can be observed with increasing exposure time at 750 Degree-Sign C. After 5 h of exposure, the Al-Si topcoat has been consumed, and the aluminide layer consisted of Fe{sub 2}Al{sub 5} and a few {tau}{sub 1}-(Al,Si){sub 5}Fe{sub 3} precipitates. The FeAl phase not only formed at the interface between Fe{sub 2}Al{sub 5} and the steel substrate, but also transformed from {tau}{sub 1}-(Al,Si){sub 5}Fe{sub 3} after diffusion for 10 h. With prolonged exposure, the aluminide layer comprised only FeAl{sub 2} and FeAl. - Highlights: Black-Right-Pointing-Pointer EBSD can differentiate phases in aluminide layer with similar chemical compositions. Black-Right-Pointing-Pointer Mapping and EBSPs functions in EBSD provide a reliable phase identification. Black-Right-Pointing-Pointer A phase transformation in the aluminide layer has been described in detail. Black-Right-Pointing-Pointer 5 Fe-Al-Si and 4 Fe-Al intermetallic phases are performed during the diffusion. Black-Right-Pointing-Pointer Cubic {tau}{sub 5(C)}-Al{sub 7} (Fe,Cr){sub 2}Si and hexagonal {tau}{sub 5(H)}-Al{sub 7}(Fe,Cr){sub 2}Si are identified.

Cheng, Wei-Jen, E-mail: d9603505@mail.ntust.edu.tw; Wang, Chaur-Jeng

2012-02-15

221

Structural characterization of phospholipids by matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry.  

PubMed

Matrix-assisted laser desorption/ionization (MALDI) Fourier transform ion cyclotron resonance mass spectrometry provides for structural analysis of the principal biological phospholipids: glycerophosphatidylcholine, -ethanolamine, -serine, and -inositol. Both positive and negative molecular or quasimolecular ions are generated in high abundance. Isolated molecular ions may be collisionally activated in the source side of a dual trap mass analyzer, yielding fragments serving to identify the polar head group (positive ion mode) and fatty acid side chains (negative ion mode). Azimuthal quadrupolar excitation following collisionally activated dissociation refocuses productions close to the solenoid axis; subsequent transfer of product ions to the analyzer ion trap allows for high-resolution mass analysis. Cyro-cooling of the sample probe with liquid nitrogen greatly reduces matrix adduction encountered in the negative ion mode. PMID:8633761

Marto, J A; White, F M; Seldomridge, S; Marshall, A G

1995-11-01

222

Experimental geometry for simultaneous beam characterization and sample imaging allowing for pink beam Fourier transform holography or coherent diffractive imaging  

SciTech Connect

One consequence of the self-amplified stimulated emission process used to generate x rays in free electron lasers (FELs) is the intrinsic shot-to-shot variance in the wavelength and temporal coherence. In order to optimize the results from diffractive imaging experiments at FEL sources, it will be advantageous to acquire a means of collecting coherence and spectral information simultaneously with the diffraction pattern from the sample we wish to study. We present a holographic mask geometry, including a grating structure, which can be used to extract both temporal and spatial coherence information alongside the sample scatter from each individual FEL shot and also allows for the real space reconstruction of the sample using either Fourier transform holography or iterative phase retrieval.

Flewett, Samuel; Eisebitt, Stefan

2011-02-20

223

Continuous wavelet-like filter for a spherical surface and its application to localized admittance function on Mars  

Microsoft Academic Search

We have developed a 2D isotropic continuous wavelet-like transform for a spherical surface. The transform is simply defined as the surface convolution between the original field and a kernel, based on the zeroth-order Bessel function with a spherical correction. This spherical correction violates the geometric similarity for the various scales of the kernels, which becomes more apparent at longer wavelengths.

Motoyuki Kido; David A. Yuen; Alain P. Vincent

2003-01-01

224

Group 12 metal monoselenocarboxylates: synthesis, characterization, structure and their transformation to metal selenide (MSe; M = Zn, Cd, Hg) nanoparticles.  

PubMed

Reactions of [MCl2(tmeda)] with potassium salts of monoselenocarboxylic acids gave complexes of the general formula [M(SeCOR)2(tmeda)] (M = Zn, Cd; R = Ph, Tol; Tol = C6H4-p-CH3; tmeda = Me2NCH2CH2NMe2). The analogous mercury complexes were unstable at room temperature and afforded HgSe nanoparticles during the course of reaction. All the complexes were characterized by elemental analysis, IR, UV-vis, NMR (1H, 13C, 77Se, 113Cd) data. The X-ray structural analysis of [Cd(SeCOPh)2(tmeda)] revealed that the complex is a discrete monomer having an approximate tetrahedral coordination environment around the central metal atom with monodentate (Se-bonded) selenocarboxylates. Thermal behavior of these complexes was studied by TG analysis. Pyrolysis in a furnace or in HDA (hexadecylamine) gave MSe nanoparticles, which were characterized by XRD, EDAX, SEM and absorption spectroscopy. PMID:16804584

Kedarnath, Gotluru; Kumbhare, Liladhar B; Jain, Vimal K; Phadnis, Prasad P; Nethaji, Munirathinam

2006-06-14

225

Isolation and characterization of a factor from calf serum that promotes the pigmentation of embryonic and transformed melanocytes  

Microsoft Academic Search

A protein (Mr = 63,000) from calf serum that promotes the pigmentation of cultured chick neural crest and mouse melanoma cells has been partially isolated and characterized in this study. The stimulation of melanin synthesis in cultured cells was used to follow its activity during purification. The pigment-promoting factor was isolated by sequential column chro- matography on dye-agarose matrices followed

JANICE A. JERDAN; HUGH H. VARNER; JUDITH H. GREENBERG; VALERIE I. HORN; GEORGE R. MARTIN

1985-01-01

226

Incomplete nuclear transformation of human spermatozoa in oligo-astheno-teratospermia: characterization by indirect immunofluorescence of chromatin and thiol status  

Microsoft Academic Search

BACKGROUND Sperm heterogeneity in the human, as observed in oligo-astheno-teratozoospermia (OAT), is associated with hypospermatogenesis. METHODS The chromatin of sperm from OAT and normospermic males was characterized with antibodies specific for nucleosomes, the histone H3.1\\/H3.2 isoform, histone TH2B, apoptosis-associated H4 acetylation (KM-2) and protamines. Subsequently, sperm samples were stained with the thiol-specific fluorochrome monobromobimane (mBBr) before and after reduction with

L. Ramos; G. W. van der Heijden; A. Derijck; J. H. M. Berden; J. A. M. Kremer; J. van der Vlag; P. de Boer

2008-01-01

227

Response of Pole-Mounted Distribution Transformer to Lightning Overvoltage Dependent on Rated Capacity  

NASA Astrophysics Data System (ADS)

A pole-mounted transformer on a power distribution line is vulnerable to lightning overvoltages, and is one of the most frequently damaged instruments in Japan. Therefore, the response of transformers to the overvoltage draws great concern. By incorporating the modeling for the secondary windings proposed by Mr. Honda et al., the authors develop equivalent circuits of distribution transformers of 10kVA, 20kVA and 30kVA rated capacity based on modal analysis of measured admittance whereby one can evaluate its response to overvoltages on a low-voltage line as well as on a medium-voltage line. The validity of calculated results obtained by using the developed circuits is demonstrated by comparison with experimental results. The response of transformers made by the same manufacturer to the lightning impulse voltage waveforms is influenced by the rated capacity, and the phase and the degree of such influence is demonstrated.

Michishita, Koji; Hiraiwa, Hideo; Hongo, Yasuji

228

Innovative analytical methodology combining micro-x-ray diffraction, scanning electron microscopy-based mineral maps, and diffuse reflectance infrared fourier transform spectroscopy to characterize archeological artifacts.  

PubMed

Excavations at the 14th century Moorish rampart (Granada, Spain) unearthed a brick oven alongside black ash and bone stratigraphic layers. In situ evidence suggests the oven served to fabricate a wall coating including powdered burnt bones. Original ad hoc analyses improved on conventional methods were used to confirm this hypothesis. These methods enable (i) nondestructive micro-X-ray diffraction (mu-XRD) for fast mineralogical data acquisition (approximately 10 s) and moderately high spatial (approximately 500 microm) resolution and (ii) identification and imaging of crystalline components in sample cross-sections via mineral maps, yielding outstanding visualization of grain distribution and morphology in composite samples based on scanning electron microscopy-energy dispersion X-ray spectrometry (SEM-EDX) elemental maps. Benefits are shown for applying diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) vs transmittance-FT-IR (T-FT-IR) to analyze organic and inorganic components in single samples. Complementary techniques to fully characterize artifacts were gas chromatography/mass spectroscopy (GC/MS), optical microscopy (OM), conventional powder XRD, and (14)C dating. Bone-hydroxyapatite was detected in the coating. Mineralogical transformations in the bricks indicate oven temperatures well above 1000 degrees C, supporting the hypothesis. PMID:19099407

Cardell, Carolina; Guerra, Isabel; Romero-Pastor, Julia; Cultrone, Giuseppe; Rodriguez-Navarro, Alejandro

2009-01-15

229

Improving brain tumor characterization on MRI by probabilistic neural networks and non-linear transformation of textural features.  

PubMed

The aim of the present study was to design, implement and evaluate a software system for discriminating between metastatic and primary brain tumors (gliomas and meningiomas) on MRI, employing textural features from routinely taken T1 post-contrast images. The proposed classifier is a modified probabilistic neural network (PNN), incorporating a non-linear least squares features transformation (LSFT) into the PNN classifier. Thirty-six textural features were extracted from each one of 67 T1-weighted post-contrast MR images (21 metastases, 19 meningiomas and 27 gliomas). LSFT enhanced the performance of the PNN, achieving classification accuracies of 95.24% for discriminating between metastatic and primary tumors and 93.48% for distinguishing gliomas from meningiomas. To improve the generalization of the proposed classification system, the external cross-validation method was also used, resulting in 71.43% and 81.25% accuracies in distinguishing metastatic from primary tumors and gliomas from meningiomas, respectively. LSFT improved PNN performance, increased class separability and resulted in dimensionality reduction. PMID:18053610

Georgiadis, Pantelis; Cavouras, Dionisis; Kalatzis, Ioannis; Daskalakis, Antonis; Kagadis, George C; Sifaki, Koralia; Malamas, Menelaos; Nikiforidis, George; Solomou, Ekaterini

2008-01-01

230

Weathering trend characterization of medium-molecular weight polycyclic aromatic disulfur heterocycles by Fourier transform ion cyclotron resonance mass spectrometry.  

PubMed

Different weathering factors act to change petroleum composition once it is spilled into the environment. n-Alkanes, biomarkers, low-molecular weight polyaromatic hydrocarbons and sulfur heterocycles compositional changing in the environment have been extensively studied by different researchers and many parameters have been used for oil source identification and monitoring of weathering and biological degradation processes. In this work, we studied the fate of medium-molecular weight polycyclic aromatic disulfur heterocycles (PAS2Hs), up to ca. 900Da, of artificially weathered Flotta North Sea crude oil by ultra high-resolution Fourier transform ion cyclotron resonance mass spectrometry. It was found that PAS2Hs in studied crude oil having double bond equivalents (DBE) from 5 to 8 with a mass range from ca 316 to 582Da were less influenced even after six months artificial weathering experiment. However, compounds having DBEs 12, 11 and 10 were depleted after two, four and six months weathering, respectively. In addition, DBE 9 series was more susceptible to weathering than those of DBE 7 and 8. PMID:24997927

Hegazi, Abdelrahman H; Fathalla, Eiman M; Andersson, Jan T

2014-09-01

231

Establishment and characterization of differentiated, nontransformed hepatocyte cell lines derived from mice transgenic for transforming growth factor alpha.  

PubMed

Hepatocytes are extensively used in studies of gene regulation but cannot be maintained in long-term culture as replicating, differentiated cells while remaining nontumorigenic. We have derived two hepatocyte lines from livers of transgenic mice overexpressing transforming growth factor alpha, a potent hepatocyte mitogen, which overcome these limitations. The transgenic hepatocytes were maintained for > or = 2 months in serum-supplemented primary culture and gave rise to cell lines, of which two (AML12 and AML14) have been cultured for > 1.5 years (> 80 passages). Both lines have typical hepatocyte features such as peroxisomes and bile canalicular-like structures, do not grow in soft agar, and are nontumorigenic in nude mice. Like normal hepatocytes, AML cells express high levels of mRNA for serum (albumin, alpha 1-antitrypsin, and transferrin) and gap junction (connexins 26 and 32) proteins, secrete albumin, and contain solely isozyme 5 of lactate dehydrogenase. After extensive passaging, AML12 cells continue to strongly coexpress hepatocyte connexin mRNAs but do not display nonparenchymal cell markers. Although mRNA levels for some serum proteins progressively fall, high expression in late AML12 cultures may be regained by passage in serum-free medium. The AML14 line loses expression of both differentiated markers and transgene mRNA with extended passaging, and hepatocytic traits are only partially restored by passage in serum-free medium. These differentiated, nontumorigenic cell lines should serve as models in which to study hepatocyte growth and differentiation. PMID:7904757

Wu, J C; Merlino, G; Fausto, N

1994-01-18

232

Characterization of a new melanocyte-specific gene (QNR-71) expressed in v-myc-transformed quail neuroretina.  

PubMed Central

Quail neuroretina cells (QNR) infected with the v-myc-expressing retrovirus MC29 become pigmented after several passages in vitro. After differential screening of a cDNA library constructed from these cells, we have isolated a cDNA clone (QNR-71) which identifies an RNA expressed only in the pigmented layer of the retina and in the epidermis. This gene can also be induced in other cell types transformed by MC29, suggesting that QNR-71 may be regulated by the v-myc protein. Sequence analysis showed that the QNR-71 cDNA exhibits stretches of homologies with melanosomal proteins encoding genes. From bacterially expressed QNR-71 peptides we obtained rabbit antisera able to specifically recognize two proteins of 95 and 100 kDa in pigmented retinal cells, but not in the neuroretina. To study the regulation of QNR-71, we used promoter fragments linked to the CAT reporter gene, in transient co-expression assay. We observed an increase in CAT expression with a c-MYC and microphtalmia (mi) expression vectors. Both MYC and mi activate the QNR-71 promoter through direct binding to a CATGTG site present in the promoter fragment. Images

Turque, N; Denhez, F; Martin, P; Planque, N; Bailly, M; Begue, A; Stehelin, D; Saule, S

1996-01-01

233

Structural Characterization of Hydrogen Peroxide-Oxidized Anthracites by X-ray Diffraction, Fourier Transform Infrared Spectroscopy, and Raman Spectra.  

PubMed

The structural characteristics of raw coal and hydrogen peroxide (H2O2)-oxidized coals were investigated using scanning electron microscopy, X-ray diffraction (XRD), Raman spectra, and Fourier transform infrared (FT-IR) spectroscopy. The results indicate that the derivative coals oxidized by H2O2 are improved noticeably in aromaticity and show an increase first and then a decrease up to the highest aromaticity at 24 h. The stacking layer number of crystalline carbon decreases and the aspect ratio (width versus stacking height) increases with an increase in oxidation time. The content of crystalline carbon shows the same change tendency as the aromaticity measured by XRD. The hydroxyl bands of oxidized coals become much stronger due to an increase in soluble fatty acids and alcohols as a result of the oxidation of the aromatic and aliphatic C-H bonds. In addition, the derivative coals display a decrease first and then an increase in the intensity of aliphatic C-H bond and present a diametrically opposite tendency in the aromatic C-H bonds with an increase in oxidation time. There is good agreement with the changes of aromaticity and crystalline carbon content as measured by XRD and Raman spectra. The particle size of oxidized coals (<200 nm in width) shows a significant decrease compared with that of raw coal (1 ?m). This study reveals that the optimal oxidation time is ?24 h for improving the aromaticity and crystalline carbon content of H2O2-oxidized coals. This process can help us obtain superfine crystalline carbon materials similar to graphite in structure. PMID:25014841

Zhang, Yude; Kang, Xiaojuan; Tan, Jinlong; Frost, Ray L

2014-07-01

234

Secretion of neu differentiation factor-like polypeptides by cph-transformed fibroblasts: cloning and characterization of Syrian hamster neuregulin cDNAs.  

PubMed

We reported previously that expression of the cph oncogene in Syrian hamster and mouse cells leads to the secretion of a polypeptide factor or factors structurally and functionally related to neu differentiation factor (NDF) and the establishment of an autocrine loop mediated through the simultaneous overexpression of the erbB4 receptor. To identify the nature of this factor and to characterize its role in the neoplastic conversion of Syrian hamster embryo cells, we cloned cDNAs hybridizing to rat NDF-derived probes by screening a library prepared from neoplastic 81C39 cells, which harbor an activated cph oncogene and secrete active NDF-like polypeptides. Sequence analysis of the isolated clones revealed a high level of homology between the hamster neuregulin and its rat and human counterparts and the existence of various neuregulin cDNA variants in Syrian hamster cells, presumably originating from alternatively spliced RNA species. Interestingly, some of these neuregulin cDNAs were longer (up to 5.5 kb) than those isolated before from any other system, suggesting that the Syrian hamster neuregulin precursor mRNA accumulates at greater concentrations than in other species. We also detected different hamster neuregulin protein isoforms by using in vitro transcription-translation analyses. Peptide sequence analysis identified the major NDF-like polypeptide secreted by 81C39 cells as an alpha2b-neuregulin. Northern blot analyses with the cloned cDNA inserts showed that neuregulin overexpression was commonly associated with the neoplastic conversion of chemically initiated hamster embryo fibroblasts. This, along with the detection of elevated erbB2- or erbB4-specific transcripts in most (six of eight) neoplastic cell lines tested, supports the notion that autocrine neuregulin signaling plays an important role in maintaining the transformed phenotype by providing a growth advantage to cph-transformed cells. PMID:9537646

Velasco, J A; Feijoó, E; Avila, M A; Notario, V

1998-03-01

235

Characterization of phospholipid bilayer formation on a thin film of porous SiO2 by reflective interferometric Fourier transform spectroscopy (RIFTS).  

PubMed

Classical methods for characterizing supported artificial phospholipid bilayers include imaging techniques such as atomic force microscopy and fluorescence microscopy. The use in the past decade of surface-sensitive methods such as surface plasmon resonance and ellipsometry, and acoustic sensors such as the quartz crystal microbalance, coupled to the imaging methods, have expanded our understanding of the formation mechanisms of phospholipid bilayers. In the present work, reflective interferometric Fourier transform spectrocopy (RIFTS) is employed to monitor the formation of a planar phospholipid bilayer on an oxidized mesoporous Si (pSiO(2)) thin film. The pSiO(2) substrates are prepared as thin films (3 ?m thick) with pore dimensions of a few nanometers in diameter by the electrochemical etching of crystalline silicon, and they are passivated with a thin thermal oxide layer. A thin film of mica is used as a control. Interferometric optical measurements are used to quantify the behavior of the phospholipids at the internal (pores) and external surfaces of the substrates. The optical measurements indicate that vesicles initially adsorb to the pSiO(2) surface as a monolayer, followed by vesicle fusion and conversion to a surface-adsorbed lipid bilayer. The timescale of the process is consistent with prior measurements of vesicle fusion onto mica surfaces. Reflectance spectra calculated using a simple double-layer Fabry-Perot interference model verify the experimental results. The method provides a simple, real-time, nondestructive approach to characterizing the growth and evolution of lipid vesicle layers on the surface of an optical thin film. PMID:22486481

Pace, Stéphanie; Seantier, Bastien; Belamie, Emmanuel; Lautrédou, Nicole; Sailor, Michael J; Milhiet, Pierre-Emmanuel; Cunin, Frédérique

2012-05-01

236

Characterization of oil sands naphthenic acids treated with ultraviolet and microwave radiation by negative ion electrospray Fourier transform ion cyclotron resonance mass spectrometry.  

PubMed

Naphthenic acids (NAs) are concentrated in oil sand process water (OSPW) as a result of caustic oil sands extraction processes. There is considerable interest in methods for treatment of NAs in OSPW. Earlier work has shown that the combination of ultraviolet (UV) and microwave treatments in the laboratory was effective in reducing the concentration of classical NAs. Here we apply Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to further characterize NAs treated with (a) UV (254?nm) in the presence of TiO(2) catalyst; and/or (b) microwave irradiation (2.45?GHz). FT-ICR MS was used to characterize the NA fraction before and after treatment. Acidic oxygen-containing classes were most abundant in all samples whereas other heteroatomic classes were least abundant or not present in some samples. For example, the SO(2)-containing species were absent in UV- or combined UV- and microwave-treated samples. The O(2) class was dominant in all samples, indicative of NAs. However, samples treated with UV and microwave radiation have a lower relative abundance of other heteroatomic classes. We observed O(2), S(1)O(2), O(3), S(1)O(3), O(4), O(5), and O(6) classes, whereas the species with relatively high O(n) content, namely, the O(3), O(5), and O(6) classes, were present only in UV- and microwave-treated samples. The relatively high O(n) content is consistent with oxidation of the parent acids in treated samples. There may thus be potential implications for environmental forensics. For example, the monitoring of the ratio of SO(2):O(2) or tracking the relative abundances of O(2), O(3), O(4), O(5), and O(6) classes may provide insights for distinguishing naturally derived oil sands components from those that are process-related in aquatic environments. PMID:20941758

Headley, John V; Peru, Kerry M; Mishra, Sabyasachi; Meda, Venkatesh; Dalai, Ajay K; McMartin, Dena W; Mapolelo, Mmilili M; Rodgers, Ryan P; Marshall, Alan G

2010-11-15

237

Characterization of petroleum products by laser-induced acoustic desorption in a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer  

NASA Astrophysics Data System (ADS)

Many petroleum products, in particular large nonpolar saturated hydrocarbons, have proven difficult to analyze via mass spectrometry due to their low volatility, lack of basic or acidic groups needed for most ionization methods, and low activation energies for fragmentation after ionization. The above limitation has been addressed by using laser-induced acoustic desorption (LIAD) to evaporate nonvolatile and thermally labile petroleum components for analysis in a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer. The gaseous neutral analytes were ionized by electron impact. Model compounds were studied first to test the viability of this method. After that, different types of asphaltenes were characterized successfully. For example, the molecular weight distribution of a North American asphaltene was determined. A comparison between asphaltene samples obtained from different geographical locations showed distinct molecular weight characteristics, possibly allowing for the determination of an unknown asphaltene sample's geographic origin. Asphaltenes were also characterized via electrospray ionization (ESI) in a linear quadrupole ion trap (LQIT). The observed molecular weight distribution had an extended tail past 2000 Da. Collision-activated dissociation (CAD) experiments on isolated ions revealed that water aggregation was present in this analysis. The observed molecular weight distribution of asphaltenes reduced dramatically when water was eliminated from the system. The usefulness of a new chemical ionization reagent, ClMn(H2O) +, is also discussed. This reagent has been shown to ionize hydrocarbons without fragmentation to yield [ClMnR]+, where R is the hydrocarbon, thus providing molecular weight information. CAD of the [ClMnR]+ ions is demonstrated to allow the differentiation of isomeric hydrocarbons. Finally, the LIAD/ClMn(H2O)+ mass spectrometric method was applied to the successful analysis of various petroleum fractions and asphaltene-like compounds.

Pinkston, David S.

238

Transformation Station  

NSDL National Science Digital Library

Shapes are all over the place in geometry. One way we can move these shapes is with transformations. Use these games to help you practice and identify the three types of transformations: reflections, translations, and rotations. Just as a refresher, watch this video about transformational geometry: Gingerbread Transformer! When you are ready...start playing the games!! Take it to the court for Basketball Geometry! Once you type in your name and choose a player, pay attention to the coach for a review on the three types of transformations. While you play, ...

Stroud, Mrs.

2010-09-01

239

A simple and direct isolation of whey components from raw milk by gel filtration chromatography and structural characterization by Fourier transform Raman spectroscopy.  

PubMed

A simple and economical method to isolate whey protein from fresh raw milk is developed by serial defatting, casein eliminating, lactose removing, and separating by gel filtration chromatography. Four major whey components, including immunoglobulin (Ig), bovine serum albumin (BSA), beta-lactoglobulin (beta-Lg) and alpha-lactalbumin (alpha-Lac), and a non-protein of low molecular mass ( approximately 1.7 kDa) but strong absorbance at 280 nm, are detected simultaneously. The small non-protein molecule is rich in aromatic amino acids and thiol groups as supported by the structural characterization with near infrared Fourier transform Raman spectroscopy (FT-Raman). FT-Raman results show that the secondary structure of Ig is dominated by anti-parallel beta-pleated sheet; BSA is mainly in alpha-helix; both beta-form and unordered structure are important in beta-Lg; while alpha-Lac is mostly in alpha-helix coupling with random coil. Differences in the Raman profile for each whey component reflect their intrinsic compositional differences and distinct spatial arrangement. The S-S linkages diverging around 510-540 cm(-1) indicate that the conformation of disulfide bonds in each whey components is different, which may be responsible for their diversified behaviors in solubility, rheological and functional properties. PMID:18970714

Liang, Mong; Chen, Vivin Y T; Chen, Hsiu-Ling; Chen, Wenlung

2006-07-15

240

Structural characterization of polycyclic aromatic hydrocarbon dihydrodiol epoxide DNA adducts using matrix-assisted laser desorption/ionization Fourier transform mass spectrometry  

SciTech Connect

Matrix-assisted laser desorption/ionization (MALDI) Fourier transform ion cyclotron resonance mass spectrometry (FTMS) has been applied for the structural characterization of four polycyclic aromatic hydrocarbon dihydrodiol epoxide (PAH-DE) adducts, including the 5,6-dimethylchrysene DE adduct of 2[prime]-deoxyadenosine, the 5-methyl- and 5,6-dimethylchrysene DE adducts of 2[prime]-deoxyguanosine, and the benzo[a]pyrene-DE adduct of 2[prime]-deoxyguanosyl 3[prime]-phosphate. Measurement of positive and negative ion mass spectra, accurate mass determinations, and CID experiments were carried out using 10-40 ng (20-70 pmol) of sample. An evaluation of five MALDI matrices showed that matrix selection can be used to control the degree of analyte fragmentation. Three MALDI matrices commonly used for the analysis of proteins (sinapinic acid, ferulic acid, 2,5-dihydroxybenzoic acid) gave positive ion adduct mass spectra showing protonated or sodiated molecular ions accompanied by abundant, structurally informative fragment ions. Fragmentation was significantly reduced when working with two matrices used for oligonucleotide analysis (an anthranilic-nicotinic acid mixture and 3-hydroxypicolinic acid). Using the CID capabilities of FTMS, isolation and activation of the MALDI-produced ions was used to provide additional structural information. 68 refs., 9 figs., 2 tabs.

Stemmler, E.A. (Bowdoin College, Brunswick, ME (United States)); Buchanan, M.V.; Hurst, G.B.; Hettich, R.L. (Oak Ridge National Lab, TN (United States))

1994-04-15

241

Fourier-transformed infrared absorption spectroscopy: a tool to characterize the chemical composition of Ar-NH3-SiH4 dielectric barrier discharge  

NASA Astrophysics Data System (ADS)

This study brings initial insight into the characterization of the gas chemical composition in a dielectric barrier discharge (DBD) by Fourier-transformed infrared absorption spectroscopy. Capitalizing on a double path of the IR beam, measurements were performed in 5 cm long, 2 mm gap plasma. As the IR beam cross-section in the plasma was 2 × 2 mm2, a translation system was used to scan the plasma along the direction of the gas flow with a 2 mm spatial resolution. In the case of Ar-SiH4(67 ppm)-NH3(133 ppm) glow-mode DBD, all IR spectra peaks from 6000 to 800 cm-1 are related to vibrations of Si-H from SiH4 and N-H from NH3. Here, the N-H vibration is observable but non-quantifiable. At 50 kHz excitation, the absolute concentration of SiH4 was measured at different positions and different power values in continuous and modulated modes. In the absence of powder formation in the plasma and for an initial density of 1.6 × 1015 cm-3, all the measurements are fitted by the same exponential decay leading to an energy of 38 eV per dissociated molecule of SiH4. The presence of powders in the plasma reduces SiH4 dissociation rate by a factor larger than 4.

Vallade, Julien; Massines, Françoise

2013-11-01

242

Comparing Laser Desorption Ionization and Atmospheric Pressure Photoionization Coupled to Fourier Transform Ion Cyclotron Resonance Mass Spectrometry To Characterize Shale Oils at the Molecular Level  

USGS Publications Warehouse

Laser desorption ionization (LDI) coupled to Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was used to analyze shale oils. Previous work showed that LDI is a sensitive ionization technique for assessing aromatic nitrogen compounds, and oils generated from Green River Formation oil shales are well-documented as being rich in nitrogen. The data presented here demonstrate that LDI is effective in ionizing high-double-bond-equivalent (DBE) compounds and, therefore, is a suitable method for characterizing compounds with condensed structures. Additionally, LDI generates radical cations and protonated ions concurrently, the distribution of which depends upon the molecular structures and elemental compositions, and the basicity of compounds is closely related to the generation of protonated ions. This study demonstrates that LDI FT-ICR MS is an effective ionization technique for use in the study of shale oils at the molecular level. To the best of our knowledge, this is the first time that LDI FT-ICR MS has been applied to shale oils.

Cho, Yunjo; Jin, Jang Mi; Witt, Matthias; Birdwell, Justin E.; Na, Jeong-Geol; Roh, Nam-Sun; Kim, Sunghwan, Kim

2013-01-01

243

Preparation of amorphous calcium-magnesium phosphates at pH 7 and characterization by x-ray absorption and fourier transform infrared spectroscopy  

NASA Astrophysics Data System (ADS)

Amorphous calcium-magnesium phosphates were prepared by precipitation from moderately supersaturated aqueous solutions at pH 7. Chemical analysis of the samples by ion chromatography showed that up to about 50% of the phosphate ions were protonated, the proportion increasing with the magnesium to calcium ion activity ratio in the solution. When left it contact with the supernatant, the amorphous precipitates matured to form the crystalline calcium phosphate brushite (CaHPO 4·2H 2O). The amorphous phases were characterized by X-ray absorption spectroscopy and by Fourier transform infrared spectroscopy and their properties compared with those of a basic amorphous tricalcium phosphate precipitated at pH 10. The X-ray absorption spectra near the K edge of calcium were very similar for all samples but there were differences in the infrared spectra between the basic and the more acidic salts. In the phosphate stretching region, the main band of the more acidic materials occured at higher wavenumber and was broader. Also there was a broad band of medium intensity at about 890 cm -1 whereas there was virtually no absorption band in this region in the spectrum of the amorphous tricalcium phosphate. The acidic amorphous calcium phosphates may be useful as model compounds in describing some complex biological calcium phosphates that form near neutral pH.

Holt, C.; van Kemenade, M. J. J. M.; Harries, J. E.; Nelson, L. S.; Bailey, R. T.; Hukins, D. W. L.; Hasnain, S. S.; De Bruyn, P. L.

1988-10-01

244

Necrotizing lymphadenitis (NEL) is a systemic disease characterized by blastic transformation of CD8+ cells and apoptosis of CD4+ cells.  

PubMed

This clinicopathological, immunohistochemical, electron microscopic, and serological study of 382 cases (148 male, 234 female) of necrotizing lymphadenitis (NEL) in Japan confirms NEL as a self-limited disease with characteristic clinical features: high fever (38-40 °C), painful cervical lymphadenopathy (88.3 %), and leukopenia (under 4,000/mm(3)) without seasonal occurrence. Patient age varied from 5 to 80 years, but 62.8 % was younger than 30 years. There were five recurrent cases and four familial cases. In several cases, elevated serum aminotransaminase and antinuclear antibodies were found. Early in the disease, peripheral blood CD8+ cells were more abundant than CD4+ cells, but CD8+ cells decreased gradually with clinical progression, leading to an increasing ratio of CD4+/CD8+ cells during clinical course. Morphological features of involved lymph nodes are numerous CD8+ large immunoblasts, smaller CD4+ lymphocytes, plasmacytoid dendritic cells, histiocytes, and macrophages, the latter with phagocytized CD4+ apoptotic lymphocytes. Granulocytes are generally absent. These characteristics suggest that NEL is a reactive disease characterized by diploid disrupted CD4+ cells and CD8+ cells transforming to blastic cells. The etiology of the disease remains unknown, although viral infection is suggested, and its pathogenesis might include autoimmunity. Clinical characteristics and cytological and histological findings on lymph node biopsies can improve NEL diagnosis. PMID:24292234

Asano, Shigeyuki; Mori, Kikuo; Yamazaki, Kazuki; Sata, Tetsutaro; Kurata, Atsushi; Sato, Yuko; Odajima, Hajime; Akaike, Yasushi; Wakasa, Haruki; Kojima, Masaru

2014-01-01

245

Surface morphology characterization of pentacene thin film and its substrate with under-layers by power spectral density using fast Fourier transform algorithms  

NASA Astrophysics Data System (ADS)

Surface morphology of pentacene thin films and their substrates with under-layers is characterized by using atomic force microscopy (AFM). The power values of power spectral density (PSD) for the AFM digital data were determined by the fast Fourier transform (FFT) algorithms instead of the root-mean-square (rms) and peak-to-valley value. The PSD plots of pentacene films on glass substrate are successfully approximated by the k-correlation model. The pentacene film growth is interpreted the intermediation of the bulk and surface diffusion by parameter C of k-correlation model. The PSD plots of pentacene film on Au under-layer is approximated by using the linear continuum model (LCM) instead of the combination model of the k-correlation model and Gaussian function. The PSD plots of SiO 2 layer on Au under-layer as a gate insulator on a gate electrode of organic thin film transistors (OTFTs) have three power values of PSD. It is interpreted that the specific three PSD power values are caused by the planarization of the smooth SiO 2 layer to rough Au under-layer.

Itoh, Taketsugu; Yamauchi, Noriyoshi

2007-05-01

246

Physical aspects of the Hartley transform  

Microsoft Academic Search

The close links between Fourier analysis and physics are shared by the Hartley (1942) transform, which represents real data by real transform values, rather than complex, a feature that carries over into optical interferometry. Some objects are characterized by phase as well as brightness. In such cases the Hartley transform acquires an imaginary part while the Fourier transform loses its

R. N. Bracewell

1989-01-01

247

Animating Transformations  

NSDL National Science Digital Library

In most introductory linear algebra courses, prominent applications of transformations or mappings are moving (rotating, reflecting, translating), resizing (contracting, expanding), changing the shape (shearing, projecting) objects in the plane. A typical problem in such courses is to write the matrix of a transformation that changes points in such prescribed ways. The goal of this demo is to help students more easily visualize such transformations on a wide class of plane objects.

Roberts, Lila F.; Hill, David R.

2003-01-24

248

Ear-canal acoustic admittance and reflectance measurements in human neonates. II. Predictions of middle-ear dysfunction and sensorineural hearing loss  

NASA Astrophysics Data System (ADS)

This report describes relationships between middle-ear measurements of acoustic admittance and energy reflectance (YR) and measurements of hearing status using visual reinforcement audiometry in a neonatal hearing-screening population. Analyses were performed on 2638 ears in which combined measurements were obtained [Norton et al., Ear Hear. 21, 348-356 (2000)]. The measurements included distortion-product otoacoustic emissions (DPOAE), transient evoked otoacoustic emissions (TEOAE), and auditory brainstem responses (ABR). Models to predict hearing status using DPOAEs, TEOAEs, or ABRs were each improved by the addition of the YR factors as interactions, in which factors were calculated using factor loadings from Keefe et al. [J. Acoust. Soc. Am. 113, 389-406 (2003)]. This result suggests that information on middle-ear status improves the ability to predict hearing status. The YR factors were used to construct a middle-ear dysfunction test on 1027 normal-hearing ears in which DPOAE and TEOAE responses were either both present or both absent, the latter condition being viewed as indicative of middle-ear dysfunction. The middle-ear dysfunction test classified these ears with a nonparametric area (A) under the relative operating characteristic curve of A=0.86, and classified normal-hearing ears that failed two-stage hearing-screening tests with areas A=0.84 for DPOAE/ABR, and A=0.81 for TEOAE/ABR tests. The middle-ear dysfunction test adequately generalized to a new sample population (A=0.82).

Keefe, Douglas H.; Gorga, Michael P.; Neely, Stephen T.; Zhao, Fei; Vohr, Betty R.

2003-01-01

249

Design and Characterization of a High-power Laser-induced Acoustic Desorption (LIAD) Probe Coupled with a Fourier-transform Ion Cyclotron Resonance Mass Spectrometer  

PubMed Central

We report here the construction and characterization of a high-power laser-induced acoustic desorption (LIAD) probe designed for Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometers to facilitate analysis of non-volatile, thermally labile compounds. This “next generation” LIAD probe offers significant improvements in sensitivity and desorption efficiency for analytes with larger molecular weights via the use of higher laser irradiances. Unlike the previous probes which utilized a power limiting optical fiber to transmit the laser pulses through the probe, this probe employs a set of mirrors and a focusing lens. At the end of the probe, the energy from the laser pulses propagates through a thin metal foil as an acoustic wave, resulting in desorption of neutral molecules from the opposite side of the foil. Following desorption, the molecules can be ionized by electron impact or chemical ionization. Almost an order of magnitude greater power density (up to 5.0 × 109 W/cm2) is achievable on the backside of the foil with the high-power LIAD probe compared to the earlier LIAD probes (maximum power density ~9.0 × 108 W/cm2). The use of higher laser irradiances is demonstrated not to cause fragmentation of the analyte. The use of higher laser irradiances increases sensitivity since it results in the evaporation of a greater number of molecules per laser pulse. Measurement of the average velocities of LIAD evaporated molecules demonstrates that higher laser irradiances do not correlate with higher velocities of the gaseous analyte molecules.

Shea, Ryan C.; Habicht, Steven C.; Vaughn, Weldon E.; Kenttamaa, Hilkka I.

2008-01-01

250

Molecular cloning and characterization of two tropinone reductases in Anisodus acutangulus and enhancement of tropane alkaloid production in AaTRI-transformed hairy roots.  

PubMed

Tropane alkaloids are used medicinally as anticholinergic agents with increasing market demand, so the improvement and production of active components from medicinal plants using molecular biotechnology show great potential for applications that should benefit human healthcare. Two tropinone reductases constitute a branching point in the biosynthesis of tropane alkaloids. In the present paper, we report for the first time the cloning and characterization of two fulllength cDNAs encoding TRI (tropinone reductase I) (GenBank accession number EU424321) and TRII (tropinone reductase II) (GenBank(R) accession number EU424322) from the solanaceous plant Anisodus acutangulus by rapid amplification of cDNA ends. Sequence comparison indicated that AaTRI (A. acutangulus TRI) and AaTRII (A. acutangulus TRII) had high homology with other tropinone reductases from Hyoscyamus niger, Datura stramonium etc., but AaTRI and AaTRII showed identity of only 60.8%. Phylogenetic-tree analysis showed that AaTRI and AaTRII belong to different clusters and have the closest relationship with H. niger TRI and TRII respectively. Expression-pattern analysis showed that AaTRI and AaTRII were expressed in all tissues tested, including root, stem and leaf, but the transcript level of AaTRI was much lower than AaTRII. Expression of AaTRI and AaTRII could be enhanced by methyl jasmonate, with a weak effect for AaTRI and a strong effect for AaTRII. AaTRI-transformed hairy-root lines were accompanied by a mean 1.87-fold higher level of hyoscyamine and a mean 8-fold higher level of scopolamine compared with control roots, indicating that AaTRI is a promising target for genetic engineering to increase tropane alkaloid in A. acutangulus. PMID:19751215

Kai, Guoyin; Li, Li; Jiang, Yuxin; Yan, Xiangming; Zhang, Yan; Lu, Xuan; Liao, Pan; Chen, Jianbo

2009-11-01

251

Phospholipids chiral at phosphorus. Characterization of the subgel phase of thiophosphatidylcholines by use of X-ray diffraction, Phosphorus-31 nuclear magnetic resonance, and Fourier transform infrared spectroscopy  

SciTech Connect

A recent study using differential scanning calorimetry (DSC) showed that the thermotropic phase behavior of 1,2-dipalmitoyl-sn-glycero-3-thiophosphocholine (DPPsC) is sensitive to the configuration at phosphorus and that the R/sub P/ isomer displayed only a broad transition at 45.6/sup 0/C. The authors have employed x-ray diffraction, /sup 31/P NMR, and Fourier transform infrared (FT-IR) spectroscopy to characterize various phases of the isomers of DPPsC, to compare the structural differences between 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and isomers of DPPsC, and to identify structural factors responsible for the unique behavior of the R/sub P/ isomer. The results from all three techniques support the previous proposal based on DSC studies that (S/sub P/)- and (R/sub P/ + S/sub P/)-DPPsC undergo a subtransition, a pretransition, and a main transition analogous to those of DPPC, while (R/sub P/)-DDPsC is quite stable at the subgel phase and undergoes a direct subgel ..-->.. liquid-crystalline transition at 46/sup 0/C. Quantitative differences between DPPC and DPPsC in the subgel phase have also been observed in the chain spacing, the motional averaging, and the factor group splitting. In particular, DPPsC isomers are motionally rigid and show enhanced factor group splitting in the subgel phase. These results suggest that DPPsC is packed in different subcells relative to DPPC in the subgel phase. Two unique structural features of (R/sub P/)-DPPsC have also been observed in the subgel phase: The bilayer spacing is small,and the C=O stretching band is asymmetric. These features could be responsible for the unusual stability of the subgel phase of (R/sub P/)-DPPsC.

Sarvis, H.E.; Loffredo, W.; Dluhy, R.A.; Hernqvist, L.; Wisner, D.A.; Tsai, M.T.

1988-06-28

252

Characterization of low molecular weight dissolved natural organic matter along the treatment trait of a waterworks using Fourier transform ion cyclotron resonance mass spectrometry.  

PubMed

Dissolved natural organic matter (DOM), particularly the low molecular weight DOM, can affect the performance of water treatment processes and serve as a main precursor of disinfection by-products (DBPs) during chlorination. In this study, electrospray ionization coupled to Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) was used to characterize the low molecular weight DOM along the treatment trait of a conventional drinking water treatment plant. The ESI FT-ICR MS data showed that various C, H, O-only class species were the major components in the source water. According to the van Krevelen diagram analysis, lignin- and tannin-like compounds were the most abundant components. Within an isobaric group, the DOM molecules with a high degree of oxidation (high O/C value) were preferentially removed during coagulation, while those with low degree of oxidation were found to be more reactive toward chlorine. In addition, 357 one-chlorine containing products and 199 two-chlorine containing products formed during chlorination were detected in the chlorination effluent sample at a high confidence level. The chlorinated products can be arranged into series, suggesting that they were originated from C, H, O-only precursor compounds, which were in series related by the replacement of CH(4) against oxygen. For the first time, this study explored the behavior of low molecular weight DOM along a drinking water treatment trait on the molecular level, and revealed the presence of abundant unknown chlorinated products, which are probably rich in carboxylic and phenolic groups, in drinking water. PMID:22853975

Zhang, Haifeng; Zhang, Yahe; Shi, Quan; Ren, Shuoyi; Yu, Jianwei; Ji, Feng; Luo, Wenbin; Yang, Min

2012-10-15

253

Optical characterization of free electron concentration in heteroepitaxial InN layers using Fourier transform infrared spectroscopy and a 2 × 2 transfer-matrix algebra  

NASA Astrophysics Data System (ADS)

Fourier Transform Infrared (FTIR) reflectance spectroscopy has been implemented as a non-destructive, non-invasive, tool for the optical characterization of a set of c-plane InN single heteroepitaxial layers spanning a wide range of thicknesses (30-2000 nm). The c-plane (0001) InN epilayers were grown by plasma-assisted molecular beam epitaxy (PAMBE) on GaN(0001) buffer layers which had been grown on Al2O3(0001) substrates. It is shown that for arbitrary multilayers with homogeneous anisotropic layers having their principal axes coincident with the laboratory coordinates, a 2 × 2 matrix algebra based on a general transfer-matrix method (GTMM) is adequate to interpret their optical response. Analysis of optical reflectance in the far and mid infrared spectral range has been found capable to discriminate between the bulk, the surface and interface contributions of free carriers in the InN epilayers revealing the existence of electron accumulation layers with carrier concentrations in mid 1019 cm-3 at both the InN surface and the InN/GaN interface. The spectra could be fitted with a three-layer model, determining the different electron concentration and mobility values of the bulk and of the surface and the interface electron accumulation layers in the InN films. The variation of these values with increasing InN thickness could be also sensitively detected by the optical measurements. The comparison between the optically determined drift mobility and the Hall mobility of the thickest sample reveals a value of rH = 1.49 for the Hall factor of InN at a carrier concentration of 1.11 × 1019 cm-3 at 300° ?.

Katsidis, C. C.; Ajagunna, A. O.; Georgakilas, A.

2013-02-01

254

Optical characterization of free electron concentration in heteroepitaxial InN layers using Fourier transform infrared spectroscopy and a 2 Multiplication-Sign 2 transfer-matrix algebra  

SciTech Connect

Fourier Transform Infrared (FTIR) reflectance spectroscopy has been implemented as a non-destructive, non-invasive, tool for the optical characterization of a set of c-plane InN single heteroepitaxial layers spanning a wide range of thicknesses (30-2000 nm). The c-plane (0001) InN epilayers were grown by plasma-assisted molecular beam epitaxy (PAMBE) on GaN(0001) buffer layers which had been grown on Al{sub 2}O{sub 3}(0001) substrates. It is shown that for arbitrary multilayers with homogeneous anisotropic layers having their principal axes coincident with the laboratory coordinates, a 2 Multiplication-Sign 2 matrix algebra based on a general transfer-matrix method (GTMM) is adequate to interpret their optical response. Analysis of optical reflectance in the far and mid infrared spectral range has been found capable to discriminate between the bulk, the surface and interface contributions of free carriers in the InN epilayers revealing the existence of electron accumulation layers with carrier concentrations in mid 10{sup 19} cm{sup -3} at both the InN surface and the InN/GaN interface. The spectra could be fitted with a three-layer model, determining the different electron concentration and mobility values of the bulk and of the surface and the interface electron accumulation layers in the InN films. The variation of these values with increasing InN thickness could be also sensitively detected by the optical measurements. The comparison between the optically determined drift mobility and the Hall mobility of the thickest sample reveals a value of r{sub H} = 1.49 for the Hall factor of InN at a carrier concentration of 1.11 Multiplication-Sign 10{sup 19} cm{sup -3} at 300 Degree-Sign {Kappa}.

Katsidis, C. C. [Department of Materials Science and Technology, University of Crete, P.O. Box 2208, 71003 Heraklion-Crete (Greece); Ajagunna, A. O.; Georgakilas, A. [Microelectronics Research Group, IESL, FORTH, P.O. Box 1385, 71110 Heraklion-Crete (Greece); Physics Department, University of Crete, P.O. Box 2208, 71003 Heraklion-Crete (Greece)

2013-02-21

255

Identification and characterization of a novel Terrabacter ginsenosidimutans sp. nov. beta-glucosidase that transforms ginsenoside Rb1 into the rare gypenosides XVII and LXXV.  

PubMed

A new beta-glucosidase from a novel strain of Terrabacter ginsenosidimutans (Gsoil 3082(T)) obtained from the soil of a ginseng farm was characterized, and the gene, bgpA (1,947 bp), was cloned in Escherichia coli. The enzyme catalyzed the conversion of ginsenoside Rb1 {3-O-[beta-D-glucopyranosyl-(1-2)-beta-D-glucopyranosyl]-20-O-[beta-D-glucopyranosyl-(1-6)-beta-D-glucopyranosyl]-20(S)-protopanaxadiol} to the more pharmacologically active rare ginsenosides gypenoside XVII {3-O-beta-D-glucopyranosyl-20-O-[beta-D-glucopyranosyl-(1-6)-beta-D-glucopyranosyl]-20(S)-protopanaxadiol}, gypenoside LXXV {20-O-[beta-v-glucopyranosyl-(1-6)-beta-D-glucopyranosyl]-20(S)-protopanaxadiol}, and C-K [20-O-(beta-D-glucopyranosyl)-20(S)-protopanaxadiol]. A BLAST search of the bgpA sequence revealed significant homology to family 3 glycoside hydrolases. Expressed in E. coli, beta-glucosidase had apparent K(m) values of 4.2 +/- 0.8 and 0.14 +/- 0.05 mM and V(max) values of 100.6 +/- 17.1 and 329 +/- 31 micromol x min(-1) x mg of protein(-1) against p-nitrophenyl-beta-D-glucopyranoside and Rb1, respectively. The enzyme catalyzed the hydrolysis of the two glucose moieties attached to the C-3 position of ginsenoside Rb1, and the outer glucose attached to the C-20 position at pH 7.0 and 37 degrees C. These cleavages occurred in a defined order, with the outer glucose of C-3 cleaved first, followed by the inner glucose of C-3, and finally the outer glucose of C-20. These results indicated that BgpA selectively and sequentially converts ginsenoside Rb1 to the rare ginsenosides gypenoside XVII, gypenoside LXXV, and then C-K. Herein is the first report of the cloning and characterization of a novel ginsenoside-transforming beta-glucosidase of the glycoside hydrolase family 3. PMID:20622122

An, Dong-Shan; Cui, Chang-Hao; Lee, Hyung-Gwan; Wang, Liang; Kim, Sun Chang; Lee, Sung-Taik; Jin, Fengxie; Yu, Hongshan; Chin, Young-Won; Lee, Hyeong-Kyu; Im, Wan-Taek; Kim, Song-Gun

2010-09-01

256

Transforming Schools.  

ERIC Educational Resources Information Center

Transforming the school as an organization requires change in all its components. More important, transformation connects the technical components with the human elements to create fundamental changes in the ways people perceive, think, and behave. With the community, a Wisconsin school board adopted a school district value statement to be used as…

Goens, George A.; Clover, Sharon I. R.

1992-01-01

257

Transformative Education.  

ERIC Educational Resources Information Center

The authors present the essential aspects composing the framework of transformative education. They discuss the general ends it promotes, the psychosocial theory upon which it is based, and the processes through which transformations are realized. Critical questions and educational virtues that serve as guidelines for implementation of…

Boyd, Robert D.; Myers, J. Gordon

1988-01-01

258

[Transformation toughening  

SciTech Connect

In NiAl, we have succeeded in determining the complete Ginzburg-Landau strain free energy function necessary to model the cubic to tetragonal martensite transformation in a sample of any size. We believe that this is the first time that the parameters of a Ginzburg-Landau functional and the complete strain spinodal for any three-dimensional displacive transformation were used in simulating the transformation near a crack tip under Mode I loading; the transformation pattern and toughening are different from standard transformation toughening theories. Furthermore, the strain spinodal has an approximately conical shape which can be specified by two material dependent experimentally accessible parameters, rather than the ellipsoidal shape in standard theories. Stress induced martensitic transformation in a polycrystalline sample of NiAl was simulated. In the ZrO[sub 2] system, first principles calculations to determine the semi-empirical potentials for simulating the cubic-tetragonal and tetragonal-monoclinic transformations have been started by doing a more elaborate total energy calculation.In the Al[sub 2]0[sub 3] system, we have discovered that the first principles calculations and semi-empirical potentials have just been completed byanother group in England which we will use instead to base our molecular dynamics simulations on.

Rafa, M.J.

1993-04-19

259

Backlund Transformations as Canonical Transformations.  

National Technical Information Service (NTIS)

Toda and Wadati as well as Kodama and Wadati have shown that the Backlund transformations, for the exponential lattice equation, sine-Gordon equation, K-dV (Korteweg de Vries) equation and modified K-dV equation, are canonical transformations. It is shown...

A. Villani A. H. Zimerman

1977-01-01

260

Triple transformation  

NASA Astrophysics Data System (ADS)

A new business plan that enables policy transformation and resource mobilization at the national and international level, while improving access to resources, will allow the Green Climate Fund to integrate development goals and action on climate change.

Khan, Farrukh I.; Schinn, Dustin S.

2013-08-01

261

Transformation Golf  

NSDL National Science Digital Library

In this game students use the isometric transformations (sliding, flipping and turning) to sink a golf ball into a cup. There are nine holes in the course and learners are challenged to meet or break a par score.

2011-01-01

262

Fluorescence excitation-emission matrix combined with regional integration analysis to characterize the composition and transformation of humic and fulvic acids from landfill at different stabilization stages.  

PubMed

Fluorescence excitation-emission matrix spectroscopy (EEMs) combined with fluorescence regional integration (FRI) analysis was used to investigate the composition and transformation of humic acid (HA) and fulvic acid (FA) from landfill. The EEMs of HAs at different landfill ages were characterized by two typical fluorescence chromophores with Ex/Em pairs at Ex=420-470 nm/Em=490-530 nm and Ex=345-375 nm/Em=450-465 nm. EEMs of FA were featured by other two distinctly different fluorophores with Ex/Em pairs at Ex=315-335 nm/Em=420-440 nm and Ex=255-275 nm/Em=425-455 nm. The results show that HA extracted from the refuse disposed in the year of 1989 was formed by connecting small-condensed aromatic structures with protein-like chains. Compared with HA extracted from the refuse disposed in the year of 1992, HA extracted from the refuse of 1996 had a higher fluorescence intensity and lower r(()(B)(,)(A)()) (the ratio of the fluorescence intensities of peak B and peak A) value. It contained low molar mass components, low aromatic condensation degree, and more easily oxidized substituents. This indicates that the landfill time strongly affects the EEMs characteristics of HA, and that the humification degree of HA increases with the landfill time. A red shift to a longer wavelength region and an increase of fluorescence intensity were observed when the concentration of HA was increased, suggesting that concentration had a great influence on the fluorescence characteristics of HAs. pH (2-12) also had significant effects on the fluorescence intensity, although it exerted no effect on the peak position of fluorescence of HA and FA. The results of FRI show that increasing concentration lead to more interactions among various structure components and that small molecular weight units tend to aggregate or be masked into more complicated and larger structures. The pH influence on the fluorescence intensity of HA seems mainly through molecular configuration, while the fluorescence intensity change with pH may be due to various substituents of FA. PMID:22104617

Xiaoli, Chai; Guixiang, Liu; Xin, Zhao; Yongxia, Hao; Youcai, Zhao

2012-03-01

263

Transformation toughening  

Microsoft Academic Search

The critical stress-intensity factor,Kc, of materials containing tetragonal ZrO2 was found to decrease with increasing temperature and CeO2 alloying additions, as predicted by theory. The temperature dependence ofKc was related to the temperature dependence of the chemical free-energy change associated with tetragonal-monoclinic transformation. Good agreement with thermodynamic data available for pure ZrO2 was obtained when the size of the transformation

F. F. Lange

1982-01-01

264

Admittance-based pressure-volume loops versus gold standard cardiac magnetic resonance imaging in a porcine model of myocardial infarction  

PubMed Central

Abstract A novel admittance?based pressure–volume system (AS) has recently been developed and introduced. Thus far, the new technique has been validated predominantly in small animals. In large animals it has only been compared to three?dimensional echocardiography (3DE) where the AS showed to overestimate left ventricular (LV) volumes. To fully determine the accuracy of this device, we compared the AS with gold standard cardiac magnetic resonance imaging (CMRI) in a porcine model of chronic myocardial infarction (MI). Fourteen pigs were subjected to 90 min closed chest balloon occlusion of the left anterior descending artery. After 8 weeks of follow up, pigs were consecutively subjected to LV volume measurements by the AS, CMRI, and 3DE under general anesthesia. The AS overestimated end diastolic volume (EDV; +20.9 ± 30.6 mL, P = 0.024) and end systolic volume (ESV; +17.7 ± 29.4 mL, P = 0.042) but not ejection fraction (EF; +2.46 ± 6.16%, P = NS) compared to CMRI. Good correlations of EDV (R = 0.626, P = 0.017) and EF (R = 0.704, P = 0.005) between the AS and CMRI were observed. EF measured by the AS and 3DE also correlated significantly (R = 0.624, P = 0.030). After subjection of pigs to MI, the AS very moderately overestimates LV volumes and shows accurate measurements for EF compared to CMRI. This makes the AS a useful tool to determine cardiac function and dynamic changes in large animal models of cardiac disease.

van Hout, Gerardus P. J.; Jansen, Sanne J.; Gho, Johannes M. I. H.; Doevendans, Pieter A.; van Solinge, Wouter W.; Pasterkamp, Gerard; Chamuleau, Steven A. J.; Hoefer, Imo E.

2014-01-01

265

Transformation of Anaplasma phagocytophilum  

PubMed Central

Background Tick-borne pathogens cause emerging zoonoses, and include fastidious organisms such as Anaplasma phagocytophilum. Because of their obligate intracellular nature, methods for mutagenesis and transformation have not been available. Results To facilitate genetic manipulation, we transformed A. phagocytophilum (Ap) to express a green fluorescent protein (GFP) with the Himar1 transposase system and selection with the clinically irrelevant antibiotic spectinomycin. Conclusion These transformed bacteria (GFP/Ap) grow at normal rates and are brightly fluorescent in human, monkey, and tick cell culture. Molecular characterization of the GFP/Ap genomic DNA confirmed transposition and the flanking genomic insertion locations were sequenced. Three mice inoculated with GFP/Ap by intraperitoneal injection became infected as demonstrated by the appearance of morulae in a peripheral blood neutrophil and re-isolation of the bacteria in culture.

Felsheim, Roderick F; Herron, Michael J; Nelson, Curtis M; Burkhardt, Nicole Y; Barbet, Anthony F; Kurtti, Timothy J; Munderloh, Ulrike G

2006-01-01

266

Fractional Transforms in Optical Information Processing  

Microsoft Academic Search

In this paper we review the progress achieved in optical information processing during the last decade by applying fractional linear integral transforms. The fractional Fourier transform and its applications for phase retrieval, beam characterization, space-variant pattern recognition, adaptive filter design, encryption, watermarking, etc., is discussed in detail. A general algorithm for the fractionalization of linear cyclic integral transforms is introduced

Tatiana Alieva; Martin J. Bastiaans; Maria Luisa Calvoy

2005-01-01

267

SHARP transformation  

NASA Astrophysics Data System (ADS)

The U.S. Navy"s SHAred Reconnaissance Pod (SHARP) employs the Recon/Optical, Inc. (ROI) CA-279 dual spectral band (visible/IR) digital cameras operating from an F-18E/F aircraft to perform low-to-high altitude reconnaissance missions. SHARP has proven itself combat worthy, with a rapid transition from development to operational deployment culminating in a highly reliable and effective reconnaissance capability for joint forces operating in Operation Iraqi Freedom (OIF). The U.S. Navy"s intelligence, surveillance and reconnaissance (ISR) roadmap transforms the SHARP system from being solely an independent reconnaissance sensor to a node in the growing Joint ISR network. ROI and the U.S. Navy have combined their resources to ensure the system"s transformation continues to follow the ISR road map. Pre-planned product improvements (P3I) for the CA-270 camera systems will lead the way in that transformation.

Wyatt, Stephan

2004-08-01

268

Phase transformation of \\  

Microsoft Academic Search

Specimens of poled and unpoled ''chem-prep'' PNZT ceramic from batch HF1035 were tested under hydrostatic, uniaxial, and constant stress difference loading conditions at -55, 25, and 75 C. The objective of this experimental study was to characterize the mechanical properties and conditions for the ferroelectric (FE) to antiferroelectric (AFE) phase transformations of this ''chem-prep'' PNZT ceramic to aid grain-scale modeling

Stephen Tedford Montgomery; Moo Yul Lee; Diane A. Meier; John H. Hofer

2006-01-01

269

Transformational leadership.  

PubMed

Rapid changes in the health care system have caused competition among institutions, as organizations are restructured to increase client satisfaction, resulting in the need for a new style of leadership. The transformational leader communicates the mission and vision of the organization and empowers others to effectively resolve conflicts that may arise with change. The health care team that can cope with changes and conflicts views restructuring as a positive transaction and approaches client satisfaction with energy and motivation. Institutions with transformational leadership are the ones that will survive the transition. PMID:8945261

Taccetta-Chapnick, M

1996-01-01

270

DC Transformer.  

National Technical Information Service (NTIS)

A component level dc transformer is described in which no alternating currents or voltages are present. It operates by combining features of a homopolar motor and a homopolar generator, both de devices, such that the output voltage of a de power supply ca...

C. M. Ihlefeld R. C. Youngquist S. O. Starr

2013-01-01

271

Transforming Defense.  

National Technical Information Service (NTIS)

From April 17-20, 2001, the U.S. Army War College sponsored a major conference to examine the many issues and questions surrounding the transformation of the U.S. Armed Forces from a Cold War paradigm into a defense establishment ready to meet the complex...

C. C. Crane

2001-01-01

272

Exploring Transformations  

NSDL National Science Digital Library

In this activity, students will explore transformations of an absolute value function. Step by step instructions guide students in using graphing calculators to examine the effect that stretching and translating has on the coordinates of the graph. Teacher notes and a worksheet are also included to aid in teaching this lesson.

2011-11-25

273

FOURIER TRANSFORM INFRARED PHOTOACOUSTIC SPECTROSCOPY CHARACTERIZATION OF SULFUR-OXYGEN SPECIES RESULTING FROM THE REACTION OF SO2 WITH CAO AND CACO3  

EPA Science Inventory

Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS) has been used to investigate the reaction of SO2 in He with CaO and CaCO3 particles at temperatures between 25 and 900 C. SO2 reacts with CaC at 25 C, while the reaction of Ca-CO3 with SO2 is first evident at 550 C ...

274

Characterization of Potential Weapon Component Materials by Combined Gas Chromatography/Mass Spectrometry and Gas Chromatography/Fourier Transform Infrared Spectroscopy.  

National Technical Information Service (NTIS)

A commercial accelerator for curing epoxy systems, Cordova ATC-3, was examined by combined gas chromatography/mass spectrometry (GC/MS) and gas chromatography/Fourier transform infrared spectroscopy (GC/FT-IR). Over 20 different chemical compounds were se...

A. B. Nease R. O. Yelton

1984-01-01

275

Characterization of Japanese color sticks by energy dispersive X-ray fluorescence, X-ray diffraction and Fourier transform infrared analysis  

Microsoft Academic Search

This work comprises the use of energy dispersive X-ray fluorescence (EDXRF), X-ray diffraction (XRD) and Fourier transformed infrared (FTIR) techniques for the study of the composition of twentieth century traditional Japanese color sticks. By using the combination of analytical techniques it was possible to obtain information on inorganic and organic pigments, binders and fillers present in the sticks. The colorant

M. Manso; S. Valadas; S. Pessanha; A. Guilherme; I. Queralt; A. E. Candeias; M. L. Carvalho

2010-01-01

276

High-temperature superconducting transformer evaluation  

SciTech Connect

The advancing development of high-temperature superconducting (HTS) materials is encouraging the evaluation of many practical applications. This paper summarizes a study that examined the future potential of HTS power transformers in the 30-MVA to 1000-MVA capacity range. Transformer performance was characterized on the basis of potentially achievable HTS materials capabilities and dominant transformer design parameters. Life-cycle costs were estimated and compared with those of conventional transformers to evaluate the economic viability and market potential of HTS designs. HTS transformers are projected to have both capital and energy cost advantages attributable to their ability to be intrinsically smaller and lighter than conventional transformers of comparable capacity.

DeSteese, J.G.; Dagle, J.E.; Dirks, J.A.

1995-04-01

277

Transformations Journal  

NSDL National Science Digital Library

Different forms of communication have always had a tendency to transform interactions and everyday life in ways that have surprised people from many different backgrounds. Academics have long been interested in such dynamic transformations, and this electronic journal represents one of the responses to such processes. As their site notes, this journal is "dedicated to the exploration of ideas, issues and debates emerging out of contemporary global culture." Visitors to the site can read the complete version of every issue on the site, and they will be pleased to find such intriguing titles as "Rethinking Regionality", "Accidental Environments", and "Fleeing the City". Interested parties can also consult the site to learn about the journal's editorial board, their calls for papers, submission guidelines, and related links.

278

Establishment and characterization of equine fibroblast cell lines transformed in vivo and in vitro by BPV-1: Model systems for equine sarcoids  

SciTech Connect

It is now widely recognized that BPV-1 and less commonly BPV-2 are the causative agents of equine sarcoids. Here we present the generation of equine cell lines harboring BPV-1 genomes and expressing viral genes. These lines have been either explanted from sarcoid biopsies or generated in vitro by transfection of primary fibroblasts with BPV-1 DNA. Previously detected BPV-1 genome variations in equine sarcoids are also found in sarcoid cell lines, and only variant BPV-1 genomes can transform equine cells. These equine cell lines are morphologically transformed, proliferate faster than parental cells, have an extended life span and can grow independently of substrate. These characteristics are more marked the higher the level of viral E5, E6 and E7 gene expression. These findings confirm that the virus has an active role in the induction of sarcoids and the lines will be invaluable for further studies on the role of BPV-1 in sarcoid pathology.

Yuan, Z.Q.; Gault, E.A.; Gobeil, P.; Nixon, C.; Campo, M.S. [Institute of Comparative Medicine, University of Glasgow Faculty of Veterinary Medicine, Bearsden Road, Glasgow G61 1QH (United Kingdom); Nasir, L. [Institute of Comparative Medicine, University of Glasgow Faculty of Veterinary Medicine, Bearsden Road, Glasgow G61 1QH (United Kingdom)], E-mail: l.nasir@vet.gla.ac.uk

2008-04-10

279

Pulse transformers  

Microsoft Academic Search

Pulse transformers capable of transmitting substantially rectangular voltage pulses, with durations of less than one microsecond, were developed for radar applications during World War II. Their primary functions were to match the impedances of high-power microwave radio-frequency electron-tube generators to electronic pulse generators and coaxial transmission cables, and to provide polarity reversal and impedance matching functions within pulse generator circuitry.

H. Lord

1971-01-01

280

Characterization of poly-L-lysine adsorption onto alkanethiol-modified gold surfaces with polarization-modulation Fourier transform infrared spectroscopy and surface plasmon resonance measurements  

Microsoft Academic Search

The electrostatic adsorption of poly-L-lysine molecules onto a vapor-deposited gold film modified with a carboxylic acid-terminated alkanethiol monolayer is monitored with the spectroscopic techniques of polarization-modulation Fourier transform infrared (PM-FTIR) spectroscopy and surface plasmon resonance (SPR). The PM-ITIR spectrum of a monolayer of poly-L-lysine (PL) adsorbed onto a self-assembled monolayer of 11-mercaptoundecanoic acid (MUA) indicates that the lysine residues and

Claire E. Jordan; Brian L. Frey; Steven Kornguth; Robert M. Corn

1994-01-01

281

An X-ray diffraction (XRD) and Fourier transform infrared spectroscopic (FT-IR) characterization of the speciation of arsenic (V) in Portland cement type-V  

Microsoft Academic Search

The speciation of As(V) bearing oxyanions (AsO43?) in cementitious environment has been investigated by X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR). The hydration of Portland cement type-V(OPC-V) was found to be retarded in presence of AsO43?, and the retardation was caused mainly by the formation of highly insoluble calcium arsenate on the surface of hydrating cement particles. Arsenate

M. Yousuf A. Mollah; Felix Lu; David L. Cocke

1998-01-01

282

Molecular characterization of a stably transformed Bombyx mori cell line: identification of alternative transcriptional initiation sites of the A3 cytoplasmic actin gene  

Microsoft Academic Search

We have isolated a stably transformed Bombyx mori cell line containing a novel selectable marker gene, puromycin N-acetyl transferase, under control of transcriptional regulatory signals from the A3 cytoplasmic actin gene. By using this\\u000a cell line we have identified alternative transcriptional initiation sites for the A3 actin gene. One of these start sites\\u000a is located ?35 bp upstream from the

K. Fatyol; K. Illes; T. Praznovszky; W. H. R. Langridge; G. Hadlaczky; A. A. Szalay

1998-01-01

283

Laplace-Transform Deep-Level Spectroscopy Characterization of the Intrinsic and Deep-Level States in Self-Assembled InAs Quantum-Dot Structures  

SciTech Connect

The electron emission from the intrinsic and deep-level states in self-assembled InAs/GaAs quantum-dot structures is probed using the Laplace-transform deep-level transient spectroscopy. The technique shows sufficient resolution to resolve electron emission from the singly and doubly occupied QD s states. By applying an appropriate set of voltage pulses across the Schottky-diode structure, we identify the electron distribution profile in the quantum-dot intrinsic states.

Lin, S. W. [School of Electrical and Electronic Engineering, University of Manchester, Manchester M60 1QD (United Kingdom); School of Materials Science and Chemical Engineering, Hainan University, Haikou 570228 (China); Song, A. M.; Peaker, A. R. [School of Materials Science and Chemical Engineering, Hainan University, Haikou 570228 (China)

2010-01-04

284

Subsurface characterization of an oxidation-induced phase transformation and twinning in nickel-based superalloy exposed to oxy-combustion environments  

SciTech Connect

In the integration of oxy-fuel combustion to turbine power generation system, turbine alloys are exposed to high temperature and an atmosphere comprised of steam, CO{sub 2} and O{sub 2}. While surface and internal oxidation of the alloy takes place, the microstructure in the subsurface region also changes due to oxidation. In this study, bare metal coupons of Ni-base superalloys were exposed in oxy-fuel combustion environment for up to 1000 h and the oxidation-related microstructures were examined. Phase transformation occurred in the subsurface region in Ni-based superalloy and led to twinning. The transformation product phases were analyzed through thermodynamic equilibrium calculations and various electron microscopy techniques, including scanning electron microscopy (SEM), orientation imaging microscopy (OIM) and transmission electron microscopy (TEM). The mechanism by which the phase transformation and the formation of the microstructure occurred was also discussed. The possible effects of the product phases on the performance of the alloy in service were discussed.

Zhu, Jingxi; Holcomb, Gordon R.; Jablonski, Paul D.; Wise, Adam; Li, Jia; Laughlin, David E.; Sridhar, Seetharaman

2012-07-30

285

Construction and characterization of a plant transformation-competent BIBAC library of the black Sigatoka-resistant banana Musa acuminata cv. Tuu Gia (AA).  

PubMed

A plant transformation-competent binary bacterial artificial chromosome (BIBAC) library was constructed from Musa acuminata cv. Tuu Gia (AA), a black Sigatoka-resistant diploid banana. After digestion of high-molecular-weight banana DNA by HindIII, several methods of DNA size selection were tested, followed by ligation, using a vector/insert molar ratio of 4:1. The library consists of 30,700 clones stored in 80 384-well microtiter plates. The mean insert size was estimated to be 100 kb, and the frequency of inserts with internal NotI sites was 61%. The majority of insert sizes fell into the range of 100+/-20 kb, making them suitable for Agrobacterium-mediated transformation. Only 1% and 0.9% of the clones contain chloroplast and mitochondrial DNA, respectively. This is the first BIBAC library for banana, estimated to represent five times its haploid genome (600 Mbp). It was demonstrated by hybridization that the library contains typical members of resistance gene and defense gene families that can be used for transformation of disease susceptible banana cultivars for banana genetic improvement. PMID:15650812

Ortiz-Vázquez, E; Kaemmer, D; Zhang, H-B; Muth, J; Rodríguez-Mendiola, M; Arias-Castro, C; James, Andrew

2005-02-01

286

Synthesis and characterization of combined cross-linked laccase and tyrosinase aggregates transforming acetaminophen as a model phenolic compound in wastewaters.  

PubMed

Laccase (EC 1.10.3.2) and tyrosinases (EC 1.14.18.1) are ubiquitous enzymes present in nature as they are known to originate from bacteria, fungi, plants, etc. Both laccase and tyrosinase are copper-containing phenoloxidases requiring readily available O2 without auxiliary cofactor for their catalytic transformation of numerous phenolic substrates. In the present study, laccase and tyrosinase have been insolubilized as combined crosslinked enzyme aggregates (combi-CLEA) using chitosan, a renewable and biodegradable polymer, as crosslinker. The combi-CLEA, with specific activity of 12.3U/g for laccase and 167.4U/g for tyrosinase, exhibited high enzymatic activity at pH5-8 and temperature at 5-30°C, significant resistance to denaturation and no diffusional restriction to its active site based upon the Michaelis-Menten kinetic parameters. Subsequently, the combi-CLEA was applied to the transformation of acetaminophen as a model phenolic compound in samples of real wastewaters in order to evaluate the potential efficiency of the biocatalyst. In batch mode the combi-CLEA transformed more than 80% to nearly 100% of acetaminophen from the municipal wastewater and more than 90% from the hospital wastewater. UPLC-MS analysis of acetaminophen metabolites showed the formation of its oligomers as dimers, trimers and tetramers due to the laccase and 3-hydroxyacetaminophen due to the tyrosinase. PMID:24867811

Ba, Sidy; Haroune, Lounes; Cruz-Morató, Carles; Jacquet, Chloé; Touahar, Imad E; Bellenger, Jean-Phillipe; Legault, Claude Y; Jones, J Peter; Cabana, Hubert

2014-07-15

287

GC and GC-MS characterization of crude oil transformation in sediments and microbial mat samples after the 1991 oil spill in the Saudi Arabian Gulf coast.  

PubMed

The massive oil discharge in the Saudi Arabian coast at the end of the 1991 Gulf War is used here as a natural experiment to study the ability of microbial mats to transform oil residues after major spills. The degree of oil transformation has been evaluated from the analysis of the aliphatic and aromatic hydrocarbons by gas chromatography (GC) and GC coupled to mass spectrometry (GC-MS). The oil-polluted microbial mat samples from coastal environments exhibited an intermediate degree of transformation between that observed in superficial and deep sediments. Evaporation, photo-oxidation and water-washing seemed to lead to more effective and rapid elimination of hydrocarbons than cyanobacteria and its associated microorganisms. Furthermore, comparison of some compounds (e.g. regular isoprenoid hydrocarbons or alkylnaphthalenes) in the oil collected in the area after the spill or in the mixtures retained by cyanobacterial growth gave rise to an apparent effect of hydrocarbon preservation in the microbial mat ecosystems. PMID:16095784

Garcia de Oteyza, T; Grimalt, J O

2006-02-01

288

Down-regulation of lysyl oxidase-induced tumorigenic transformation in NRK-49F cells characterized by constitutive activation of ras proto-oncogene.  

PubMed

Several investigations have suggested a putative tumor suppressor role for lysyl oxidase because it is down-regulated in many human and oncogene-induced tumors. To address this issue we down-regulated the enzyme in normal rat kidney fibroblasts by stable transfection of its cDNA in an antisense orientation. The selected clones revealed an absence of lysyl oxidase and dramatic phenotypic changes, interpretable as signs of transformation. The antisense lysyl oxidase clones showed, indeed, loose attachment to the plate and anchorage-independent growth and were highly tumorigenic in nude mice. Moreover, we found an impaired response of the PDGF and IGF-1 receptors to their ligands. In particular, the transformed cells showed a down-regulation of both PDGF receptors and expressed the 105-kDa isoform of the IGF-1 beta receptor, which was not present in the normal control cells. The lack of response to PDGF-BB has been described as a feature of many ras-transformed phenotypes. Therefore, we looked at the status of the p21(ras). Indeed, we found a significantly higher level of active p21(ras) both during steady-state growth and prolonged starvation. Our data reveal new evidence for a tumor suppressor activity of lysyl oxidase, highlighting its particular role in controlling Ras activation and growth factor dependence. PMID:11323426

Giampuzzi, M; Botti, G; Cilli, M; Gusmano, R; Borel, A; Sommer, P; Di Donato, A

2001-08-01

289

Recent advances in transformation optics  

NASA Astrophysics Data System (ADS)

Within the past a few years, transformation optics has emerged as a new research area, since it provides a general methodology and design tool for manipulating electromagnetic waves in a prescribed manner. Using transformation optics, researchers have demonstrated a host of striking phenomena and devices; many of which were only thought possible in science fiction. In this paper, we review the most recent advances in transformation optics. We focus on the theory, design, fabrication and characterization of transformation devices such as the carpet cloak, ``Janus'' lens and plasmonic cloak at optical frequencies, which allow routing light at the nanoscale. We also provide an outlook of the challenges and future directions in this fascinating area of transformation optics.

Liu, Yongmin; Zhang, Xiang

2012-08-01

290

Cloning and characterization of a novel stress-responsive WRKY transcription factor gene (MusaWRKY71) from Musa spp. cv. Karibale Monthan (ABB group) using transformed banana cells.  

PubMed

WRKY transcription factor proteins play significant roles in plant stress responses. Here, we report the cloning and characterization of a novel WRKY gene, MusaWRKY71 isolated from an edible banana cultivar Musa spp. Karibale Monthan (ABB group). MusaWRKY71, initially identified using in silico approaches from an abiotic stress-related EST library, was later extended towards the 3' end using rapid amplification of cDNA ends technique. The 1299-bp long cDNA of MusaWRKY71 encodes a protein with 280 amino acids and contains a characteristic WRKY domain in the C-terminal half. Although MusaWRKY71 shares good similarity with other monocot WRKY proteins the substantial size difference makes it a unique member of the WRKY family in higher plants. The 918-bp long 5' proximal region determined using thermal asymmetric interlaced-polymerase chain reaction has many putative cis-acting elements and transcription factor binding motifs. Subcellular localization assay of MusaWRKY71 performed using a GFP-fusion platform confirmed its nuclear targeting in transformed banana suspension cells. Importantly, MusaWRKY71 expression in banana plantlets was up-regulated manifold by cold, dehydration, salt, ABA, H2O2, ethylene, salicylic acid and methyl jasmonate treatment indicating its involvement in response to a variety of stress conditions in banana. Further, transient overexpression of MusaWRKY71 in transformed banana cells led to the induction of several genes, homologues of which have been proven to be involved in diverse stress responses in other important plants. The present study is the first report on characterization of a banana stress-related transcription factor using transformed banana cells. PMID:21110110

Shekhawat, Upendra K Singh; Ganapathi, Thumballi R; Srinivas, Lingam

2011-08-01

291

Hamlet's Transformation.  

NASA Astrophysics Data System (ADS)

William Shakespeare's Hamlet has much evidence to suggest that the Bard was aware of the cosmological models of his time, specifically the geocentric bounded Ptolemaic and Tychonic models, and the infinite Diggesian. Moreover, Shakespeare describes how the Ptolemaic model is to be transformed to the Diggesian. Hamlet's "transformation" is the reason that Claudius, who personifies the Ptolemaic model, summons Rosencrantz and Guildenstern, who personify the Tychonic. Pantometria, written by Leonard Digges and his son Thomas in 1571, contains the first technical use of the word "transformation." At age thirty, Thomas Digges went on to propose his Perfit Description, as alluded to in Act Five where Hamlet's age is given as thirty. In Act Five as well, the words "bore" and "arms" refer to Thomas' vocation as muster-master and his scientific interest in ballistics. England's leading astronomer was also the father of the poet whose encomium introduced the First Folio of 1623. His oldest child Dudley became a member of the Virginia Company and facilitated the writing of The Tempest. Taken as a whole, such manifold connections to Thomas Digges support Hotson's contention that Shakespeare knew the Digges family. Rosencrantz and Guildenstern in Hamlet bear Danish names because they personify the Danish model, while the king's name is latinized like that of Claudius Ptolemaeus. The reason Shakespeare anglicized "Amleth" to "Hamlet" was because he saw a parallel between Book Three of Saxo Grammaticus and the eventual triumph of the Diggesian model. But Shakespeare eschewed Book Four, creating this particular ending from an infinity of other possibilities because it "suited his purpose," viz. to celebrate the concept of a boundless universe of stars like the Sun.

Usher, P. D.

1997-12-01

292

Light-induced catalytic transformation of ofloxacin by solar Fenton in various water matrices at a pilot plant: mineralization and characterization of major intermediate products.  

PubMed

This work investigated the application of a solar driven advanced oxidation process (solar Fenton), for the degradation of the antibiotic ofloxacin (OFX) in various environmental matrices at a pilot-scale. All experiments were carried out in a compound parabolic collector pilot plant in the presence of doses of H2O2 (2.5 mg L(-1)) and at an initial Fe(2+) concentration of 2 mg L(-1). The water matrices used for the solar Fenton experiments were: demineralized water (DW), simulated natural freshwater (SW), simulated effluent from municipal wastewater treatment plant (SWW) and pre-treated real effluent from municipal wastewater treatment plant (RE) to which OFX had been spiked at 10 mg L(-1). Dissolved organic carbon removal was found to be dependent on the chemical composition of the water matrix. OFX mineralization was higher in DW (78.1%) than in SW (58.3%) at 12 mg L(-1) of H2O2 consumption, implying the complexation of iron or the scavenging of hydroxyl radicals by the inorganic ions present in SW. On the other hand, the presence of dissolved organic matter (DOM) in SWW and RE, led to lower mineralization per dose of H2O2 compared to DW and SW. The major transformation products (TPs) formed during the solar Fenton treatment of OFX, were elucidated using liquid chromatography-time of flight-mass spectrometry (LC-ToF-MS). The transformation of OFX proceeded through a defluorination reaction, accompanied by some degree of piperazine and quinolone substituent transformation while a hydroxylation mechanism occurred by attack of the hydroxyl radicals generated during the process leading to the formation of TPs in all the water matrices, seven of which were tentatively identified. The results obtained from the toxicity bioassays indicated that the toxicity originates from the DOM present in RE and its oxidation products formed during the photocatalytic treatment and not from the TPs resulted from the oxidation of OFX. PMID:23712114

Michael, I; Hapeshi, E; Aceña, J; Perez, S; Petrovi?, M; Zapata, A; Barceló, D; Malato, S; Fatta-Kassinos, D

2013-09-01

293

Transformations - Dilation  

NSDL National Science Digital Library

In this interactive simulation, students are able to visualize and manipulate objects to understand dilation transformations. Students are able to adjust the center of dilation, rotate and move figures, change the scale factor to see what effect it has on the figures, add their own figures, and more. Across the top of the page, visitors will find links to activities to guide students as they explore the site, and more advanced activities involving computation are available in the Parent/Teacher section. The Instructions sections has detailed information for students and teachers alike on how to use the manipulative.

2003-01-01

294

Rotary Transformer  

NASA Technical Reports Server (NTRS)

None given. From first Par: Many spacecraft (S/C) and surface rovers require the transfer of signals and power across rotating interfaces. Science instruments, antennas and solar arrays are elements needing rotary power transfer for certain (S/C) configurations. Delivery of signal and power has mainly been done by using the simplest means, the slip ring approach. This approach, although simple, leaves debris generating noise over a period of time...The rotary transformer is a good alternative to slip rings for signal and power transfer.

McLyman, Colonel Wm. T.

1996-01-01

295

Production and characterization of bacterial polyhydroxyalkanoate copolymers and evaluation of their blends by fourier transform infrared spectroscopy and scanning electron microscopy  

Microsoft Academic Search

Rhizobium meliloti produced a copolymer of short chain length polyhydroxyalkanoate (scl-PHA) on sucrose and rice bran oil as carbon substrates.\\u000a Recombinant Escherichia coli (JC7623ABC1J4), bearing PHA synthesis genes, was used to synthesize short chain length-co-medium chain length PHA (scl-co-mcl-PHA)\\u000a on glucose and decanoic acid. Fourier transform infrared spectroscopy (FTIR) spectra of the PHAs indicated strong characteristic\\u000a bands at 1282, 1723,

T. R. Shamala; M. S. Divyashree; Reeta Davis; K. S. Latha Kumari; S. V. N. Vijayendra; Baldev Raj

2009-01-01

296

Mutational analysis of the DEAD-box RNA helicase eIF4AII characterizes its interaction with transformation suppressor Pdcd4 and eIF4GI  

Microsoft Academic Search

Eukaryotic initiation factor (eIF) 4A unwinds secondary and tertiary structures in the 5-untranslated region of mRNA, permit- ting translation initiation. Programmed cell death 4 (Pdcd4) is a novel transformation suppressor and eIF4A-binding partner that inhibits eIF4A helicase activity and translation. To elucidate the regions of eIF4A that are functionally significant in binding to Pdcd4, we generated point mutations of eIF4A.

HALINA ZAKOWICZ; HSIN-SHENG YANG; CRISTI STARK; ALEXANDER WLODAWER; NICOLE LARONDE-LEBLANC; NANCY H. COLBURN

2005-01-01

297

Physical aspects of the Hartley transform  

NASA Astrophysics Data System (ADS)

The close links between Fourier analysis and physics are shared by the Hartley (1942) transform, which represents real data by real transform values, rather than complex, a feature that carries over into optical interferometry. Some objects are characterized by phase as well as brightness. In such cases the Hartley transform acquires an imaginary part while the Fourier transform loses its Hermitian property. The interrelation between the two complex planes suggests an instrumental means for object phase determination starting from only amplitude information in the transform domain.

Bracewell, R. N.

1989-10-01

298

Expression and Functional Characterization of the Agrobacterium VirB2 Amino Acid Substitution Variants in T-pilus Biogenesis, Virulence, and Transient Transformation Efficiency  

PubMed Central

Agrobacterium tumefaciens is a phytopathogenic bacterium that causes crown gall disease by transferring transferred DNA (T-DNA) into the plant genome. The translocation process is mediated by the type IV secretion system (T4SS) consisting of the VirD4 coupling protein and 11 VirB proteins (VirB1 to VirB11). All VirB proteins are required for the production of T-pilus, which consists of processed VirB2 (T-pilin) and VirB5 as major and minor subunits, respectively. VirB2 is an essential component of T4SS, but the roles of VirB2 and the assembled T-pilus in Agrobacterium virulence and the T-DNA transfer process remain unknown. Here, we generated 34 VirB2 amino acid substitution variants to study the functions of VirB2 involved in VirB2 stability, extracellular VirB2/T-pilus production and virulence of A. tumefaciens. From the capacity for extracellular VirB2 production (ExB2+ or ExB2?) and tumorigenesis on tomato stems (Vir+ or Vir?), the mutants could be classified into three groups: ExB2?/Vir?, ExB2?/Vir+, and ExB2+/Vir+. We also confirmed by electron microscopy that five ExB2?/Vir+ mutants exhibited a wild-type level of virulence with their deficiency in T-pilus formation. Interestingly, although the five T-pilus?/Vir+ uncoupling mutants retained a wild-type level of tumorigenesis efficiency on tomato stems and/or potato tuber discs, their transient transformation efficiency in Arabidopsis seedlings was highly attenuated. In conclusion, we have provided evidence for a role of T-pilus in Agrobacterium transformation process and have identified the domains and amino acid residues critical for VirB2 stability, T-pilus biogenesis, tumorigenesis, and transient transformation efficiency.

Wu, Hung-Yi; Chen, Chao-Ying; Lai, Erh-Min

2014-01-01

299

Herbicide Transformation  

PubMed Central

A strain of Fusarium solani isolated from soil by enrichment techniques used propanil (3?, 4?-dichloropropionanilide) as a sole source of organic carbon and energy for growth in pure culture. The primary product of the transformation of propanil by F. solani was isolated and identified as 3,4-dichloroaniline (DCA). This compound accumulated in the medium to a level (80 ?g/ml) which stopped further herbicide utilization. Herbicide utilization by F. solani was influenced by various environmental and nutritional factors. It was more sensitive to acid than alkaline pH. Added glucose and yeast extract increased the rate of propanil decomposition, and the reduced aeration retarded growth of the fungus and herbicide utilization. The growth of F. solani on propionate was inhibited by added DCA. Images

Lanzilotta, R. P.; Pramer, David

1970-01-01

300

Characterization of Japanese color sticks by energy dispersive X-ray fluorescence, X-ray diffraction and Fourier transform infrared analysis  

NASA Astrophysics Data System (ADS)

This work comprises the use of energy dispersive X-ray fluorescence (EDXRF), X-ray diffraction (XRD) and Fourier transformed infrared (FTIR) techniques for the study of the composition of twentieth century traditional Japanese color sticks. By using the combination of analytical techniques it was possible to obtain information on inorganic and organic pigments, binders and fillers present in the sticks. The colorant materials identified in the sticks were zinc and titanium white, chrome yellow, yellow and red ochre, vermillion, alizarin, indigo, Prussian and synthetic ultramarine blue. The results also showed that calcite and barite were used as inorganic mineral fillers while Arabic gum was the medium used. EDXRF offered great potential for such investigations since it allowed the identification of the elements present in the sample preserving its integrity. However, this information alone was not enough to clearly identify some of the materials in study and therefore it was necessary to use XRD and FTIR techniques.

Manso, M.; Valadas, S.; Pessanha, S.; Guilherme, A.; Queralt, I.; Candeias, A. E.; Carvalho, M. L.

2010-04-01

301

Characterization of ancient glass excavated in Enez (Ancient Ainos) Turkey by combined Instrumental Neutron Activation Analysis and Fourier Transform Infrared spectrometry techniques  

NASA Astrophysics Data System (ADS)

Ancient glass fragments excavated in the archaeological district Enez (Ancient Ainos)-Turkey were investigated by combined Instrumental Neutron Activation Analysis (INAA) and Fourier Transform Infrared (FTIR) spectrometry techniques. Multi-elemental contents of 15 glass fragments that belong to Hellenistic, Roman, Byzantine, and Ottoman Periods, were determined by INAA. The concentrations of twenty six elements (Na, K, Ca, Sc, Cr, Mn, Fe, Co, Cu, Zn, As, Rb, Sr, Sb, Cs, Ba, Ce, Sm, Eu, Tb, Yb, Lu, Hf, Ta, Au and Th), which might be present in the samples as flux, stabilizers, colorants or opacifiers, and impurities, were examined. Chemometric treatment of the INAA data was performed and principle component analysis revealed presence of 3 distinct groups. The thermal history of the glass samples was determined by FTIR spectrometry.

Akyuz, Sevim; Akyuz, Tanil; Mukhamedshina, Nuranya M.; Mirsagatova, A. Adiba; Basaran, Sait; Cakan, Banu

2012-05-01

302

Characterization of Cancer Stem-Like Cells Derived from Mouse Induced Pluripotent Stem Cells Transformed by Tumor-Derived Extracellular Vesicles  

PubMed Central

Several studies have shown that cancer niche can perform an active role in the regulation of tumor cell maintenance and progression through extracellular vesicles-based intercellular communication. However, it has not been reported whether this vesicle-mediated communication affects the malignant transformation of normal stem cells/progenitors. We have previously reported that the conditioned medium derived from the mouse Lewis Lung Carcinoma (LLC) cell line can convert mouse induced pluripotent stem cells (miPSCs) into cancer stem cells (CSCs), indicating that normal stem cells when placed in an aberrant microenvironment can give rise to functionally active CSCs. Here, we focused on the contribution of tumor-derived extracellular vesicles (tEVs) that are secreted from LLC cells to induce the transformation of miPSCs into CSCs. We isolated tEVs from the conditioned medium of LLC cells, and then the differentiating miPSCs were exposed to tEVs for 4 weeks. The resultant tEV treated cells (miPS-LLCev) expressed Nanog and Oct3/4 proteins comparable to miPSCs. The frequency of sphere formation of the miPS-LLCev cells in suspension culture indicated that the self-renewal capacity of the miPS-LLCev cells was significant. When the miPS-LLCev cells were subcutaneously transplanted into Balb/c nude mice, malignant liposarcomas with extensive angiogenesis developed. miPS-LLCevPT and miPS-LLCevDT, the cells established from primary site and disseminated liposarcomas, respectively, showed their capacities to self-renew and differentiate into adipocytes and endothelial cells. Moreover, we confirmed the secondary liposarcoma development when these cells were transplanted. Taken together, these results indicate that miPS-LLCev cells possess CSC properties. Thus, our current study provides the first evidence that tEVs have the potential to induce CSC properties in normal tissue stem cells/progenitors.

Yan, Ting; Mizutani, Akifumi; Chen, Ling; Takaki, Mai; Hiramoto, Yuki; Matsuda, Shuichi; Shigehiro, Tsukasa; Kasai, Tomonari; Kudoh, Takayuki; Murakami, Hiroshi; Masuda, Junko; Hendrix, Mary J. C.; Strizzi, Luigi; Salomon, David S.; Fu, Li; Seno, Masaharu

2014-01-01

303

Use of wavelet-packet transforms to develop an engineering model for multifractal characterization of mutation dynamics in pathological and nonpathological gene sequences  

NASA Astrophysics Data System (ADS)

This study uses dynamical analysis to examine in a quantitative fashion the information coding mechanism in DNA sequences. This exceeds the simple dichotomy of either modeling the mechanism by comparing DNA sequence walks as Fractal Brownian Motion (fbm) processes. The 2-D mappings of the DNA sequences for this research are from Iterated Function System (IFS) (Also known as the ``Chaos Game Representation'' (CGR)) mappings of the DNA sequences. This technique converts a 1-D sequence into a 2-D representation that preserves subsequence structure and provides a visual representation. The second step of this analysis involves the application of Wavelet Packet Transforms, a recently developed technique from the field of signal processing. A multi-fractal model is built by using wavelet transforms to estimate the Hurst exponent, H. The Hurst exponent is a non-parametric measurement of the dynamism of a system. This procedure is used to evaluate gene- coding events in the DNA sequence of cystic fibrosis mutations. The H exponent is calculated for various mutation sites in this gene. The results of this study indicate the presence of anti-persistent, random walks and persistent ``sub-periods'' in the sequence. This indicates the hypothesis of a multi-fractal model of DNA information encoding warrants further consideration. This work examines the model's behavior in both pathological (mutations) and non-pathological (healthy) base pair sequences of the cystic fibrosis gene. These mutations both natural and synthetic were introduced by computer manipulation of the original base pair text files. The results show that disease severity and system ``information dynamics'' correlate. These results have implications for genetic engineering as well as in mathematical biology. They suggest that there is scope for more multi-fractal models to be developed.

Walker, David Lee

1999-12-01

304

Hough Transform from the Radon Transform  

Microsoft Academic Search

An appropriate special case of a transform developed by J. Radon in 1917 is shown to have the major properties of the Hough transform which is useful for finding line segments in digital pictures. Such an observation may be useful in further efforts to generalize the Hough transform. Techniques for applying the Radon transform to lines and pixels are developed

Stanley R. Deans

1981-01-01

305

Polycyclic aromatic hydrocarbons (PAHs) in ambient aerosols from Beijing: characterization of low volatile PAHs by positive-ion atmospheric pressure photoionization (APPI) coupled with Fourier transform ion cyclotron resonance.  

PubMed

Aromatic fractions derived from aerosol samples were characterized by gas chromatography and mass spectrometry (GC-MS), high temperature simulated distillation (SIMDIS), and positive-ion atmospheric pressure photoionization (APPI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), respectively. It was found that about 27 wt % compounds in aromatic fractions could not be eluted from a GC column and some large molecule PAHs were neglected in GC-MS analysis. APPI FT-ICR MS was proven to be a powerful approach for characterizing the molecular composition of aromatics, especially for the large molecular species. An aromatic sample from Beijing urban aerosol was successfully characterized by APPI FT-ICR MS. Results showed that most abundant aromatic compounds in PM2.5 (particles with aerodynamic diameter ? 2.5 ?m) were highly condensed hydrocarbons with 4-8 aromatic rings and their homologues with very short alkyl chains. Furthermore, heteroatom-containing hydrocarbons were found as the significant components of the aromatic fractions: O1, O2, N1, and S1 class species with 10-28 DBEs (double bond equivalents) and 14-38 carbon numbers were identified by APPI FT-ICR MS. The heteroatom PAHs had similar DBEs and carbon number distribution as regular PAHs. PMID:24702199

Jiang, Bin; Liang, Yongmei; Xu, Chunming; Zhang, Jingyi; Hu, Miao; Shi, Quan

2014-05-01

306

Combining Fourier transform-ion cyclotron resonance/mass spectrometry analysis and Kendrick plots for silicon speciation and molecular characterization in petroleum products at trace levels.  

PubMed

A new method combining FT-ICR/MS analysis and Kendrick plots for the characterization of silicon species at trace levels in light petroleum products is presented. The method provides efficient instrumental detection limits ranging from 80 ng/kg to 5 ?g/kg and reliable mass accuracy lower than 0.50 ppm for model silicon molecules in spiked gasoline. More than 3000 peaks could be detected in the m/z 50-500 range depending on the nature of the gasoline sample analyzed. An in-house software program was used to calculate Kendrick plots. Then, an algorithm searched, selected, and represented silicon species classes (O(2)Si, O(3)Si, and O(4)Si classes) in Kendrick plots by incorporating model molecules' information (i.e., exact mass and intensity). This procedure allowed the complete characterization of more than 50 new silicon species with different degrees of unsaturation in petroleum products. PMID:22482428

Chainet, Fabien; Ponthus, Jérémie; Lienemann, Charles-Philippe; Courtiade, Marion; Donard, Olivier François Xavier

2012-05-01

307

Characterization of Water and CO2 Adsorption by Stores 3A Desiccant Samples Using Thermal Gravimetric Analysis and Fourier Transform Infrared Spectroscopy  

Microsoft Academic Search

Two lots of manufactured Type 3a zeolite samples were compared by TGA\\/IR analysis. The first lot, obtained from Davidson Chemical, a commercial vendor, was characterized during the previous study cycle for its water and water-plus-COâ uptake in order to determine whether COâ uptake prevented water adsorption by the zeolite. It was determined that COâ did not hamper water adsorption using

DION A. RIVERA; M. KATHLEEN ALAM; LAURA MARTIN; JASON R. BROWN

2003-01-01

308

Micro-heterogeneity of human saliva Peptide P-C characterized by high-resolution top-down Fourier-transform mass spectrometry.  

PubMed

Top-down proteomics characterizes protein primary structures with unprejudiced descriptions of expressed and processed gene products. Gene sequence polymorphisms, protein post-translational modifications, and gene sequence errors can all be identified using top-down proteomics. Saliva offers advantages for proteomic research because of availability and the noninvasiveness of collection and, for these reasons, is being used to search for disease biomarkers. The description of natural protein variants, and intra- and inter-individual polymorphisms, is necessary for a complete description of any proteome, and essential for the discovery of disease biomarkers. Here, we report a striking example of natural protein variants with the discovery by top-down proteomics of two new variants of Peptide P-C. Intact mass measurements, and collisionally activated-, infrared multiphoton-, and electron capture-dissociation, were used for characterization of the form predicted from the gene sequence with an average mass 4371 Da, a form postulated to result from a single nucleotide polymorphism of mass 4372 Da, and another form of mass 4370 Da postulated to arise from a novel protein sequence polymorphism. While the biological significance of such subtle variations in protein structure remains unclear, their importance cannot be assigned without their characterization, as is reported here for one of the major salivary proteins. PMID:20185333

Halgand, Frédéric; Zabrouskov, Vlad; Bassilian, Sara; Souda, Puneet; Wong, David T; Loo, Joseph A; Faull, Kym F; Whitelegge, Julian P

2010-05-01

309

Physical transformations in solvated pharmaceuticals  

Microsoft Academic Search

Understanding the properties of solid-state compounds, especially solvated drugs, is very important during process\\/product development. The stability and performance of such solvated drugs can vary drastically with variations in processing and storage conditions. Therefore, it becomes imperative to properly document and control the crystal form present in the formulation. A systematic attempt to characterize phase transformations in solvates and hydrates

Vidya Joshi

1998-01-01

310

Identification and Characterization of a Ginsenoside-Transforming ?-Glucosidase from Pseudonocardia sp. Gsoil 1536 and Its Application for Enhanced Production of Minor Ginsenoside Rg2(S)  

PubMed Central

The ginsenoside Rg2(S), which is one of the pharmaceutical components of ginseng, is known to have neuroprotective, anti-inflammation, and anti-diabetic effects. However, the usage of ginsenoside Rg2(S) is restricted owing to the small amounts found in white and red ginseng. To enhance the production of ginsenoside Rg2(S) as a 100 gram unit with high specificity, yield, and purity, an enzymatic bioconversion method was developed to adopt the recombinant glycoside hydrolase (BglPC28), which is a ginsenoside-transforming recombinant ?-glucosidase from Pseudonocardia sp. strain Gsoil 1536. The gene, termed bglPC28, encoding ?-glucosidase (BglPC28) belonging to the glycoside hydrolase family 3 was cloned. bglPC28 consists of 2,232 bp (743 amino acid residues) with a predicted molecular mass of 78,975 Da. This enzyme was overexpressed in Escherichia coli BL21(DE3) using a GST-fused pGEX 4T-1 vector system. The optimum conditions of the recombinant BglPC28 were pH 7.0 and 37°C. BglPC28 can effectively transform the ginsenoside Re to Rg2(S); the Km values of PNPG and Re were 6.36±1.10 and 1.42±0.13 mM, respectively, and the Vmax values were 40.0±2.55 and 5.62±0.21 µmol min?1 mg?1 of protein, respectively. A scaled-up biotransformation reaction was performed in a 10 L jar fermenter at pH 7.0 and 30°C for 12 hours with a concentration of 20 mg/ml of ginsenoside Re from American ginseng roots. Finally, 113 g of Rg2(S) was produced from 150 g of Re with 84.0±1.1% chromatographic purity. These results suggest that this enzymatic method could be usefully exploited in the preparation of ginsenoside Rg2(S) in the cosmetics, functional food, and pharmaceutical industries.

Park, Sung Chul; Kim, Jin-Kwang; Yu, Hong-Shan; Jin, Feng-Xie; Sun, Changkai; Kim, Sun-Chang; Im, Wan-Taek

2014-01-01

311

Contribution made by multivariate curve resolution applied to gel permeation chromatography-Fourier transform infrared data for an in-depth characterization of styrene-butadiene rubber blends.  

PubMed

We evaluate the contribution made by multivariate curve resolution-alternating least squares (MCR-ALS) for resolving gel permeation chromatography-Fourier transform infrared (GPC-FT-IR) data collected on butadiene rubber (BR) and styrene butadiene rubber (SBR) blends in order to access in-depth knowledge of polymers along the molecular weight distribution (MWD). In the BR-SBR case, individual polymers differ in chemical composition but share almost the same MWD. Principal component analysis (PCA) gives a general overview of the data structure and attests to the feasibility of modeling blends as a binary system. MCR-ALS is then performed. It allows resolving the chromatographic coelution and validates the chosen methodology. For SBR-SBR blends, the problem is more challenging since the individual elastomers present the same chemical composition. Rank deficiency is detected from the PCA data structure analysis. MCR-ALS is thus performed on column-wise augmented matrices. It brings very useful insight into the composition of the analyzed blends. In particular, a weak change in the composition of individual SBR in the MWD's lowest mass region is revealed. PMID:18935830

Ruckebusch, C; Vilmin, F; Coste, N; Huvenne, J P

2008-07-01

312

Connecting Environment and Genome Plasticity in the Characterization of Transformation-Induced SOS Regulation and Carbon Catabolite Control of the Vibrio cholerae Integron Integrase  

PubMed Central

The human pathogen Vibrio cholerae carries a chromosomal superintegron (SI). The SI contains an array of hundreds of gene cassettes organized in tandem which are stable under conditions when no particular stress is applied to bacteria (such as during laboratory growth). Rearrangements of these cassettes are catalyzed by the activity of the associated integron integrase. Understanding the regulation of integrase expression is pivotal to fully comprehending the role played by this genetic reservoir for bacterial adaptation and its connection with the development of antibiotic resistance. Our previous work established that the integrase is regulated by the bacterial SOS response and that it is induced during bacterial conjugation. Here, we show that transformation, another horizontal gene transfer (HGT) mechanism, also triggers integrase expression through SOS induction, underlining the importance of HGT in genome plasticity. Moreover, we report a new cyclic AMP (cAMP)-cAMP receptor protein (CRP)-dependent regulation mechanism of the integrase, highlighting the influence of the extracellular environment on chromosomal gene content. Altogether, our data suggest an interplay between different stress responses and regulatory pathways for the modulation of the recombinase expression, thus showing how the SI remodeling mechanism is merged into bacterial physiology.

Baharoglu, Zeynep; Krin, Evelyne

2012-01-01

313

The Prosodic Component: Lacuna in Transformational Theory.  

National Technical Information Service (NTIS)

Two contradictory tendencies have characterized the treatment within the framework of transformational theory of the prosodic features of English. On the one hand much prosodic variation has been excluded from the linguist's immediate purview as being 'ab...

R. Vanderslice

1968-01-01

314

Enterprise transformation :lessons learned, pathways to success.  

SciTech Connect

In this report, we characterize the key themes of transformation and tie them together in a ''how to'' guide. The perspectives were synthesized from strategic management literature, case studies, and from interviews with key management personnel from private industry on their transformation experiences.

Slavin, Adam M.; Woodard, Joan Brune

2006-05-01

315

Biosynthesis of homoeriodictyol from eriodictyol by flavone 3'-O-methyltransferase from recombinant Yarrowia lioplytica: Heterologous expression, biochemical characterization, and optimal transformation.  

PubMed

In this work, we attempted to synthesize homoeriodictyol by transferring one methyl group of S-adenosyl-L-methionine (SAM) to eriodictyol using flavone 3'-O-methyltransferase ROMT-9, which was produced by recombinant Yarrowia lipolytica. Specifically, the ROMT-9 gene from rice was synthesized and cloned into the multi-copy integrative vector pINA1297, and was further expressed in Y. lipolytica with a growth phase-dependent constitutive promoter hp4d. The highest ROMT-9 activity reached 5.53 U/L after 4 days of culture in shake flask. The optimal pH and temperature of the purified ROMT-9 were 8.0 and 37 °C, respectively. The purified enzyme was stable up to 40 °C, and retained more than 80% of its maximal activity between pH 6.5 and 9.0. The recombinant ROMT-9 did not require Mg²? for catalysis, while was completely inhibited in the presence of 5 mM Zn²?, Cu²?, Ba²?, Al³?, or Ni²?. The purified ROMT-9 was used to synthesize homoeriodictyol, and the maximal transformation ratio reached 52.4% at 16 h under the following conditions: eriodictyol 0.2 g/L, ROMT-9 0.16 g/L, SAM 0.2 g/L, CH?OH 6% (v/v), temperature 37 °C, and pH 8.0. This work provides an alternative strategy for efficient synthesis of homoeriodictyol and compared to the traditional plant extraction or chemical synthesis, the biotransformation approach generates less environmental pollution and has a great potential for the sustainable production of homoeriodictyol. PMID:23906843

Liu, Qingtao; Liu, Long; Zhou, Jingwen; Shin, Hyun-Dong; Chen, Rachel R; Madzak, Catherine; Li, Jianghua; Du, Guocheng; Chen, Jian

2013-09-20

316

Evaluate and characterize mechanisms controlling transport, fate, and effects of army smokes in the aerosol wind tunnel: Transport, transformations, fate, and terrestrial ecological effects of hexachloroethane obscurant smokes  

SciTech Connect

The terrestrial transport, chemical fate, and ecological effects of hexachloroethane (HC) smoke were evaluated under controlled wind tunnel conditions. The primary objectives of this research program are to characterize and assess the impacts of smoke and obscurants on: (1) natural vegetation characteristic of US Army training sites in the United States; (2) physical and chemical properties of soils representative of these training sites; and (3) soil microbiological and invertebrate communities. Impacts and dose/responses were evaluated based on exposure scenarios, including exposure duration, exposure rate, and sequential cumulative dosing. Key to understanding the environmental impacts of HC smoke/obscurants is establishing the importance of environmental parameters such as relative humidity and wind speed on airborne aerosol characteristics and deposition to receptor surfaces. Direct and indirect biotic effects were evaluated using five plant species and two soil types. HC aerosols were generated in a controlled atmosphere wind tunnel by combustion of hexachloroethane mixtures prepared to simulate normal pot burn rates and conditions. The aerosol was characterized and used to expose plant, soil, and other test systems. Particle sizes of airborne HC ranged from 1.3 to 2.1 {mu}m mass median aerodynamic diameter (MMAD), and particle size was affected by relative humidity over a range of 20% to 85%. Air concentrations employed ranged from 130 to 680 mg/m{sup 3}, depending on exposure scenario. Chlorocarbon concentrations within smokes, deposition rates for plant and soil surfaces, and persistence were determined. The fate of principal inorganic species (Zn, Al, and Cl) in a range of soils was assessed.

Cataldo, D.A.; Ligotke, M.W.; Bolton, H. Jr.; Fellows, R.J.; Van Voris, P.; McVeety, B.D.; Li, Shu-mei W.; McFadden, K.M.

1989-09-01

317

Complex BIFORE transform  

Microsoft Academic Search

Complex BIFORE (Binary FOurior REpresentation) transform belongs to the family of discrete orthogonal transformations and is analogous to discrete Fourier transform (DFT) when dealing with complex inputs. For real inputs, complex BIFORE transform (CBT) reduces to BIFORE or Hadamard transform (BT or HT) whose bases are Walsh functions. BT has been applied in several phases of information processing and sequency

K. R. RAO; N. AHMED

1971-01-01

318

Fast Polar Harmonic Transforms  

Microsoft Academic Search

Polar Harmonic Transform (PHT) is termed to represent a set of transforms those kernels are basic waves and harmonic in nature. PHTs consist of Polar Complex Exponential Transform (PCET), Polar Cosine Transform (PCT) and Polar Sine Transform (PST). They are proposed to represent invariant image patterns for two dimensional image retrieval and pattern recognition tasks. They are demonstrated to show

Zhuo Yang; Sei-ichiro Kamata

2010-01-01

319

Synthesis, structure characterization, and reversible transformation of a cobalt salt of a dilacunary ?-Keggin silicotungstate and sandwich-type di- and tetracobalt-containing silicotungstate dimers.  

PubMed

A cobalt salt of a ?-Keggin dilacunary silicotungstate, {CoL5}2[?-SiW10O34L2] [Co-SiW10; L = N,N-dimethylformamide (DMF) or H2O], could be synthesized by the cation-exchange reaction of TBA4[?-H4SiW10O36] (TBA = tetra-n-butylammonium) with 2 equiv of Co(NO3)2 with respect to TBA4[?-H4SiW10O36] in a mixed solvent of DMF and acetone (97% yield). Each Co-SiW10 was linked by water molecules via a hydrogen-bonding network. Besides Co-SiW10, various kinds of isostructural M-SiW10 could be synthesized via the same procedure as that for Co-SiW10 (M = Mn(2+), Fe(2+), Ni(2+), Cu(2+), Zn(2+), and Cd(2+)). By the reaction of Co-SiW10 with 1 equiv of TBA6[?-H2SiW10O36] in acetone, a silicotungstate dimer pillared by two cobalt cations with a significantly slipped dimer configuration, TBA6[Co2(?-H3SiW10O36)2]·3H2O (Co2), could be synthesized. By the reaction of Co-SiW10 with 3 equiv of TBAOH in acetone, a tetracobalt-containing sandwich-type silicotungstate, TBA6[{Co(H2O)}2(?3-OH)2{Co(H2O)2}2(?-H2SiW10O36)2]·5H2O (Co4), could be synthesized. Compound Co4 possessed the tetracobalt-oxygen core, [{Co(H2O)}2(?3-OH)2{Co(H2O)2}2](6+), identical with those of previously reported Weakley-type sandwich polyoxometalates, [Co4(H2O)2(XM9O34)2](n-) (X = P(5+), Si(4+), Ge(4+), As(5+) or V(5+); M = Mo(6+) or W(6+)). The reversible transformation between these three compounds (Co-SiW10 ? Co2, Co-SiW10 ? Co4, and Co2 ? Co4) took place by the addition and/or subtraction of required components in appropriate solvents, affording the desired products in high yields (71-93% yields). PMID:23834162

Kikukawa, Yuji; Suzuki, Kosuke; Yamaguchi, Kazuya; Mizuno, Noritaka

2013-08-01

320

Biocompatible, pH-sensitive AB(2) Miktoarm Polymer-Based Polymersomes: Preparation, Characterization, and Acidic pH-Activated Nanostructural Transformation.  

PubMed

Motivated by the limitations of liposomal drug delivery systems, we designed a novel histidine-based AB(2)-miktoarm polymer (mPEG-b-(polyHis)(2)) equipped with a phospholipid-mimic structure, low cytotoxicity, and pH-sensitivity. Using "core-first" click chemistry and ring-opening polymerization, mPEG(2kDa)-b-(polyHis(29kDa))(2) was successfully synthesized with a narrow molecular weight distribution (1.14). In borate buffer (pH 9), the miktoarm polymer self-assembled to form a nano-sized polymersome with a hydrodynamic radius of 70.2 nm and a very narrow size polydispersity (0.05). At 4.2 µmol/mg polymer, mPEG(2kDa)-b-(polyHis(29kDa))(2) strongly buffered against acidification in the endolysosomal pH range and exhibited low cytotoxicity on a 5 d exposure. Below pH 7.4 the polymersome transitioned to cylindrical micelles, spherical micelles, and finally unimers as the pH was decreased. The pH-induced structural transition of mPEG(2kDa)-b-(polyHis(29kDa))(2) nanostructures may be caused by the increasing hydrophilic weight fraction of mPEG(2kDa)-b-(polyHis(29kDa))(2) and can help to disrupt the endosomal membrane through proton buffering and membrane fusion of mPEG(2kDa)-b-(polyHis(29kDa))(2). In addition, a hydrophilic model dye, 5(6)-carboxyfluorescein encapsulated into the aqueous lumen of the polymersome showed a slow, sustained release at pH 7.4 but greatly accelerated release below pH 6.8, indicating a desirable pH sensitivity of the system in the range of endosomal pH. Therefore, this polymersome that is based on a biocompatible histidine-based miktoarm polymer and undergoes acid-induced transformations could serve as a drug delivery vehicle for chemical and biological drugs. PMID:23002330

Yin, Haiqing; Kang, Han Chang; Huh, Kang Moo; Bae, You Han

2012-09-28

321

Hough transform from the radon transform.  

PubMed

An appropriate special case of a transform developed by J. Radon in 1917 is shown to have the major properties of the Hough transform which is useful for finding line segments in digital pictures. Such an observation may be useful in further efforts to generalize the Hough transform. Techniques for applying the Radon transform to lines and pixels are developed through examples, and the appropriate generalization to arbitrary curves is discussed. PMID:21868933

Deans, S R

1981-02-01

322

Co(OH)3 nanobelts: synthesis, characterization and shape-preserved transformation to pseudo-single-crystalline Co3O4 nanobelts  

NASA Astrophysics Data System (ADS)

In this paper, we demonstrated a facile hydrothermal route leading to the generation of a new cobalt hydroxide, Co(OH)3, nanobelt. This new product of Co(OH)3 nanobelts was well characterized and identified by SEM, TEM, XRD, EDX, XPS, EXAFS, Raman, TGA and SQUID. Additionally, through systematic investigations on morphological evolution, it was found that the size and shape of Co(OH)3 nanobelts were adjustable in large scale, e.g. from 50 to 1.5 µm in length and 5 µm to 20 nm in width, by means of fine experimental parameter control. Furthermore, the unique pseudo-single-crystalline Co3O4 nanobelts were produced from Co(OH)3 precursors via heating treatment. This is the first synthesis of Co(OH)3 with tunable shapes and sizes, which may find important applications as gas sensors, catalysts, and electrode materials, owing to the specific large surface-to-volume ratio and other unique properties endowed by typical 1D nanobelts.

Yang, Jinhu; Hyodo, Hiroshi; Kimura, Kaoru; Sasaki, Takehiko

2010-01-01

323

Mechanism of drug resistance, characterization of plasmid-borne determinants and transformation study in P. aeruginosa from burn and ICU units-its susceptibility pattern.  

PubMed

The transfer of drug resistance between hospital pathogens has led to alarming increase of multidrug resistant strains imposing therapeutic challenges. These resistant isolates harbor various mechanisms to counteract the drugs administered and have been reported to deliver these factors to sensitive strains in hostile environment. The present study aimed to screen for multidrug resistant Pseudomonas aeruginosa strains for the production of extended-spectrum ?-lactamases, metallo-?-lactamases, AmpC ?-lactamase, drug efflux phenotypes and co-transfer the resistance for cephalosporin and other non-beta lactam antibiotics in CaCl2 treated drug sensitive E. coli strains. From the 87 samples processed about 23 isolates of P. aeruginosa were ESBL and MBL positive, 5 (20%) were found to be AmpC ?-lactamase producers, efflux mechanism was observed in 8 isolates, 15 isolates had MIC of 16 ?g/ml. A putative efflux mechanism was observed in 8 out of 23 isolates that showed decrease in the MIC of meropenem with reserpine. The plasmid profile was characterized for all the common isolates obtained from burn and ICU units. About 69.66% of E. coli recombinants scored positive for both beta lactam and non-beta lactam antibiotics is due to co transfer of resistant plasmid obtained from P. aeruginosa. PMID:22980776

Shanthi, J; Pazhanimurugan, R; Gopikrishnan, V; Balagurunathan, R

2013-06-01

324

Formation and characterization of iron-oligonucleotide complexes with matrix-assisted laser desorption/ionization fourier transform ion cyclotron resonance mass spectrometry.  

PubMed

Iron-containing oligonucleotide negative ions can be generated by matrix-assisted laser desorption/ionization from a stainless steel target disk (by either defocusing the laser beam or by mixing iron salts such as FeCl3 with the matrix compound during the sample preparation). High resolution mass measurements reveal the presence of both Fe2+ (as M + Fe - 3H)- and Fe3+ (as M + Fe - 4H)- in the metal-oligonucleotide ions. The presence of Fe3+ is unexpected, and must involve replacement of protons from the nucleic bases or ribose groups as well as the phosphate groups of the oligonucleotides. Inspection of a range of small oligonucleotides and mononucleotides reveals that the presence of both Fe2+ and Fe3+ in the iron-biomolecule complexes is dependent on the number of acidic hydrogens that can be replaced in the oligonucleotide or nucleotide. Collisional dissociation of several metal-tetranucleotide ions revealed that the presence of the iron ion alters the fragmentation observed. The iron atom was observed to be present in all of the fragment ions, and, whenever possible, seemed to enhance the abundance of fragment ions containing both iron and a guanine nucleic base. These results suggest that iron may serve as a useful probe for characterizing phosphorylated biomolecules. PMID:10497807

Hettich, R L

1999-10-01

325

Army Maintenance System Transformation.  

National Technical Information Service (NTIS)

The first official use of the term 'transformation' is often attributed to the document 'Joint Vision 2010,' which was published in 1996. Logistics, an integral component of this transformation, is adjusting as well. As a part of logistics transformation,...

F. V. Gilbertson

2006-01-01

326

Characterization of Water and CO2 Adsorption by Stores 3A Desiccant Samples Using Thermal Gravimetric Analysis and Fourier Transform Infrared Spectroscopy  

SciTech Connect

Two lots of manufactured Type 3a zeolite samples were compared by TGA/IR analysis. The first lot, obtained from Davidson Chemical, a commercial vendor, was characterized during the previous study cycle for its water and water-plus-CO{sub 2} uptake in order to determine whether CO{sub 2} uptake prevented water adsorption by the zeolite. It was determined that CO{sub 2} did not hamper water adsorption using the Davidson zeolite. CO{sub 2} was found on the zeolite surface at dewpoints below -40 C, however it was found to be reversibly adsorbed. During the course of the previous studies, chemical analyses revealed that the Davidson 3a zeolite contained calcium in significant quantities, along with the traditional counterions potassium and sodium. Chemical analysis of a Type 3a zeolite sample retrieved from Kansas City (heretofore referred to as the ''Stores 3a'' sample) indicated that the Stores sample was a more traditional Type 3a zeolite, containing no calcium. TGA/IR studies this year focused on obtaining CO{sub 2} and water absorbance data from the Stores 3a zeolite. Within the Stores 3a sample, CO{sub 2} was found to be reversibly absorbed within the sample, but only at and below -60 C with 5% CO{sub 2} loading. The amount of CO{sub 2} observed eluting from the Stores zeolite at this condition was similar to what was observed from the Davidson zeolite sample but with a greater uncertainty in the measured value. The results of the Stores 3a studies are summarized within this report.

RIVERA, DION A.; ALAM, M. KATHLEEN; MARTIN, LAURA; BROWN, JASON R.

2003-02-01

327

Establishment and characterization of a line of adipose-derived human microvascular endothelial cells (HADMEC-5) transformed by simian virus 40 large T antigen expression: application to endotoxin research.  

PubMed

This paper reports the establishment and initial characterization of an immortalized line of human, adipose tissue-derived microvascular endothelial cells. Transfection of primary endothelial cell cultures was accomplished by the introduction of a plasmid, which contained simian virus 40 large T antigen DNA as well as a Rous sarcoma viral promoter region. One emergent colony, termed HADMEC-5, was isolated and has been passaged 45 times to date. The cells express simian virus 40 large T antigen protein, are immunohistochemically positive for factor VIII-related antigen, bind Ulex europaeus lectin, and accumulate Dil-labeled acetylated low density lipoprotein. The HADMEC-5 line demonstrates a highly proliferative growth rate in the absence of supplemental growth factors, when compared with primary cultures of nontransformed endothelial cells. HADMEC-5 growth remains serum dependent, but exhibits a lower serum requirement than nontransformed cells. The transformed cells grow well upon a variety of matrix compounds and in a variety of growth media. When grown upon Matrigel, the HADMEC-5 cells form three dimensional tube-like structures. The HADMEC-5 line was also tested for its ability to produce eicosanoids in response to bacterial lipopolysaccharide. The transformed cells, tested at passages 7 and 45, displayed a dose-dependent production of prostaglandin E2 in response to lipopolysaccharide in a manner similar to that seen in primary cell cultures. Threshold sensitivity to lipopolysaccharide was 10 pg/mL of media. The HADMEC-5 cell line represents a unique model in which to investigate lipopolysaccharide interactions with microvessel-derived endothelial cells and is of potential value in the study of other aspects of endothelial cell physiology. PMID:9249912

Flynn, J T; Westbrooks, M; Lucas, K A

1997-07-01

328

Co-fired magnetoelectric transformer  

NASA Astrophysics Data System (ADS)

In this study, we demonstrate a co-fired magnetoelectric (ME) laminate consisting of piezoelectric/magnetostrictive/piezoelectric layers with unipoled piezoelectric transformer structure. The ME transformer was characterized by quantifying the voltage gain variation and resonance frequency shift as a function of applied DC magnetic field. We delineate the magnetic tunability feature by considering the magnetoelectric coupling and delta-E effect, where E represents the modulus of magnetic material. The ME response of the composite structure was found to be 473 mV/cm.Oe exhibiting DC field sensitivity of 100 nT under AC field of 1 Oe at 1 kHz. At a magnetic bias of 60 Oe, the transformer exhibited large frequency tunability of the order of 1.4 Hz/Oe. These results present significant advancement towards developing on-chip magnetic-field-tunable devices.

Zhou, Yuan; Yan, Yongke; Priya, Shashank

2014-06-01

329

Admittance and subthreshold characteristics of atomic-layer-deposition Al2O3 on In0.53Ga0.47As in surface and buried channel flatband metal-oxide-semiconductor field effect transistors  

NASA Astrophysics Data System (ADS)

The admittances and subthreshold characteristics of capacitors and MOSFETs on buried and surface In0.53Ga0.47As channel flatband wafers, with a dielectric of Al2O3 deposited on In0.53Ga0.47As, are reported. The admittance characteristics of both wafers indicate the presence of defect states within the oxide, in common with a number of other oxides on In0.53Ga0.47As. The two wafers studied have not been hydrogen annealed, but do show some similar features to FGA treated oxides on n+ substrates. We discuss how the possible presence of residual hydroxyl ions in as-grown Al2O3 may explain these similarities and also account for many of the changes in the properties of FGA treated n+ samples. The issues around the comparison of subthreshold swing (SS) results and the impact of transistor design parameters on the energy portion of the defect state distribution affecting efficient device switching are discussed. The interface state model is applied to low source-drain voltage SS data to extract an effective interface state density (Dit) that includes interface and oxide traps. The logarithmic gate voltage sweep rate dependence of the SS Dit is used to extract an oxide trap density (Dot) and a simple method is used to estimate the Fermi level position within the band gap, Et. The Al2O3 Dit(Et) and Dot(Et) distributions are found to be similar to each other and to the results of our analysis of Gd0.25Ga0.15O0.6/Ga2O3 and HfO2/Al2O3 on In0.53Ga0.47As, adding weight to the suggestion of there being a common defect state distribution and perhaps a common cause of defects states for a number of oxides on In0.53Ga0.47As.

Paterson, G. W.; Bentley, S. J.; Holland, M. C.; Thayne, I. G.; Ahn, J.; Long, R. D.; McIntyre, P. C.; Long, A. R.

2012-05-01

330

Hadamard transform image coding  

Microsoft Academic Search

The introduction of the fast Fourier transform algorithm has led to the development of the Fourier transform image coding technique whereby the two-dimensional Fourier transform of an image is transmitted over a channel rather than the image itself. This devlopement has further led to a related image coding technique in which an image is transformed by a Hadamard matrix operator.

W. K. Pratt; J. Kane; H. C. Andrews

1969-01-01

331

RM2: Transform operations  

NASA Technical Reports Server (NTRS)

The two-dimensional transform used in the research TV source encoder, RM2 is discussed. It is shown that both conceptually and in terms of the number of required computations, the RM2 transform is considerably simpler than the Fast Hadamard Transform. The latter can in fact be generated by extending the RM2 transform.

Rice, R. F.

1974-01-01

332

Fast Discrete Curvelet Transforms  

Microsoft Academic Search

This paper describes two digital implementations of a new mathematical transform, namely, the second generation curvelet transform (12, 10) in two and three dimensions. The first digital transformation is based on unequally-spaced fast Fourier transforms (USFFT) while the second is based on the wrapping of specially selected Fourier samples. The two implementations essentially dier by the choice of spatial grid

Emmanuel Cande?s; Laurent Demanet; David Donoho; Lexing Ying

2006-01-01

333

Transform domain LMS algorithm  

Microsoft Academic Search

The concept of transform domain adaptive filtering is introduced. In certain applications, filtering in the transform domain results in great improvements in convergence rate over the conventional time-domain adaptive filtering. The relationship between several existing frequency domain adaptive filtering algorithms is established. Applications of the discrete Fourier transform (DFT) and the discrete cosine transform (DCT) domain adaptive filtering algorithms in

S. Narayan; A. M. Peterson; M. J. Narasimha

1983-01-01

334

Discrete Cosine Transform  

Microsoft Academic Search

A discrete cosine transform (DCT) is defined and an algorithm to compute it using the fast Fourier transform is developed. It is shown that the discrete cosine transform can be used in the area of digital processing for the purposes of pattern recognition and Wiener filtering. Its performance is compared with that of a class of orthogonal transforms and is

N. Ahmed; T. Natarajan; K. R. Rao

1974-01-01

335

Assessing the Hartley transform  

Microsoft Academic Search

The fast algorithm for the (real) Hartly transform is discussed in relation to the established fast algorithm for the (complex) Fourier transform. The two transforms are compared by timing comparably written programs on a given machine, and the discipline of timing is discussed as an adjunct to complexity analysis. With real data, one Hartley transform program can economically replace such

R. N. Bracewell

1990-01-01

336

[Differentiation and characterization of yeasts pathogenic for humans (Candida albicans, Exophiala dermatitidis) and algae pathogenic for animals (Prototheca spp.) using Fourier transform infrared spectroscopy (FTIR) in comparison with conventional methods].  

PubMed

Due to the Fourier-Transform Infrared Spectroscopy (FT-IR) of strain specific traits demonstrated to be a suitable and efficient method for diagnostic and epidemiological determinations for the yeasts Candida albicans, Exophiala dermatitidis and the chlorophylless algae of the genus Prototheca. FT-IR leads in a rapid and economical way to reproducible results according to the spectral differences of intact cells (IR-fingerprints). Different genera, species and sub-species respectively, different strains can be recognized and grouped into different clusters and subclusters. The FT-IR analysis of Candida albicans isolates (n = 150) of 22 newborns-at-risk of an intensive care unit showed, that 86% of the children were colonised with several (2-4) different strains in the oral cavities and faeces. Stationary cross-infections could definitely be determined. Exophiala dermatitidis isolates (n = 31), mostly isolated repetitively within a period of 3 years from sputa of patients suffering from cystic fibrosis could be characterized and grouped patient-specifically over the total sampling period. Of 6 from 8 patients (75%) their individual strains remain the same and could be tracked over the three years. Cross-infections during the stationary treatment could be clearly identified by FT-IR. The Prototheca isolate (n = 43) from live-stock and farm environment showed clear distinguishable clusters differentiating the species P. wickerhamii, P. zopfii and P. stagnora. In addition, the biotypes of P. zopfii could be distinguished, especially the subclusters of variants II and III. It could be demonstrated, that FT-IR is suitable for the routine identification and differentiation of yeasts and algae. However, in spite of the gain of knowledge by using FT-IR for the characterization of microorganisms, the conventional phenotyping and/or genetic analysis of yeast or algae strains cannot be replaced completely. For a final taxonomic classification a combination of conventional methods on FT-IR together with more sophisticated molecular genetic procedures is necessary. PMID:9717390

Schmalreck, A F; Tränkle, P; Vanca, E; Blaschke-Hellmessen, R

1998-01-01

337

On the Mechanism of Integration of Transforming Deoxyribonucleate  

Microsoft Academic Search

The characteristics of the intermediates in the reaction, between DNA and pneumococcus, that results in genetic transformation are described in so far as they have been characterized. Transformation with DNA isolated from bacteria carrying in addition to genetic markers 8a2 as a radioactive label and 2H and 'IN as density labels has permitted the characterization of the prod- uct of

MAURICE S. FOX

1966-01-01

338

Transforming the Way We Teach Function Transformations  

ERIC Educational Resources Information Center

In this article, the authors discuss "function," a well-defined rule that relates inputs to outputs. They have found that by using the input-output definition of "function," they can examine transformations of functions simply by looking at changes to input or output and the respective changes to the graph. Applying transformations to the input…

Faulkenberry, Eileen Durand; Faulkenberry, Thomas J.

2010-01-01

339

Transformation of the diamond /110/ surface  

NASA Technical Reports Server (NTRS)

The diamond surface undergoes a transformation in its electronic structure by a vacuum anneal at approximately 900 C. This transformation is characterized by the appearance of a feature in the band gap region of the energy loss spectrum. The kinetics of the transformation on the (110) surface is studied by observing the growth of this feature with time and temperature. The transformation is found to be consistent with first-order kinetics with an activation energy of 4.8 eV. It is also found that the band gap feature could be removed by exposure of the transformed surface to excited hydrogen. The results are consistent with the polished diamond (110) surface being covered with hydrogen which removes the band gap states and can be thermally desorbed at approximately 900 C.

Pepper, S. V.

1982-01-01

340

Direct Current Transformer.  

National Technical Information Service (NTIS)

A direct current transformer was built in which the primary consists of an elongated strip of superconductive material, across the ends of which is applied a direct current potential. Parallel and closely spaced to the primary is positioned a transformer ...

E. W. Urban S. M. Khanna

1977-01-01

341

Equations For Rotary Transformers  

NASA Technical Reports Server (NTRS)

Equations derived for input impedance, input power, and ratio of secondary current to primary current of rotary transformer. Used for quick analysis of transformer designs. Circuit model commonly used in textbooks on theory of ac circuits.

Salomon, Phil M.; Wiktor, Peter J.; Marchetto, Carl A.

1988-01-01

342

The Adaptive Hough Transform  

Microsoft Academic Search

We introduce the Adaptive Hough Transform, AHT, as an efficient way of implementing the Hough Transform, HT, method for the detection of 2-D shapes. The AHT uses a small accumulator array and the idea of a flexible iterative \\

John Illingworth; Josef Kittler

1987-01-01

343

Pulse Transformer Design Study.  

National Technical Information Service (NTIS)

This final report describes the design, development of fabrication techniques, fabrication, and testing of two uniform field, air core pulse transformers. The described transformer design minimizes the volume of dielectric material, which provides turn-to...

H. Aslin

1977-01-01

344

Transformations in Solidified Gases.  

National Technical Information Service (NTIS)

Transformations in solidified gases have been studied in very few laboratories yet they are governed by factors of wide scientific interest, some of which are very different from those involved in the commonly studied transformations of metallic substance...

C. S. Barrett

1968-01-01

345

Evaluate and characterize mechanisms controlling transport, fate and effects of Army smokes in the aerosol wind tunnel: Transport, transformations, fate, and terrestrial ecological effects of red phosphorus-butyl rubber and white phosphorus obscurant smokes: Final report  

SciTech Connect

An evaluation of the terrestrial transport, transformations and ecological effects of phosphorus (red phosphorus-butyl rubber (RP/BR)) smoke obscurant was performed at Pacific Northwest Laboratory. A similar evaluation using white phosphorus (WP) smoke/obscurant is currently proceeding. The objective is to characterize the effects of smokes and obscurants on: (1) natural vegetation characteristic of US Army training sites in the United States; (2) physical and chemical properties of representative of soils of those sites; and (3) soil microbiological communities. The influence and interactions of smoke/obscurant concentration, relative humidity (25%, 60%, 90% and simulated rain) and wind speed of 0.22 to 4.45 m/s by smoke is assessed. Five plant species and four soils were exposed to both single and repeated doses of RP/BR smokes in the Pacific Northwest Laboratory ''P-3'' rated recirculating environmental wind tunnel. Detailed results for RP/BR and limited results for WP are presented. Toxicity symptoms for plants exposed for 2, 4, 6, and 8 hours to concentrations of RP/BR ranging from 200 mg/m/sup 3/ included leaf tip burn, leaf curl, leaf abscission and drop, floral abortion, chlorosis, neucrotic spotting, wilting, desiccation and dieback. Grass and bushbean were the most sensitive. The intensity and duration of these effects varied. Soils effects data suggest that there is an increase in the mobility of selected trace elements after exposure; however, this effect appears to be ameliorated with time. Soil microbial community effects show a reduction in the production of nitrate after soil is exposed to RP/BR smoke. Most of the plant, soil and soil microbial effects are transient in nature and are somewhat less intense resulting from repeated exposures; however, there is evidence that some of these environmental impacts may be persistent. 43 refs., 44 figs., 67 tabs.

Van Voris, P.; Ligotke, M.W.; McFadden, K.M.; Li, S.M.W.; Thomas, B.L.; Cataldo, D.A.; Garland, T.R.; Fredrickson, J.K.; Bean, R.M.; Carlile, D.W.

1987-10-01

346

Discrete radon transform  

Microsoft Academic Search

This paper describes the discrete Radon transform (DRT) and the exact inversion algorithm for it. Similar to the discrete Fourier transform (DFT), the DRT is defined for periodic vector-sequences and studied as a transform in its own right. Casting the forward transform as a matrix-vector multiplication, the key observation is that the matrix-although very large-has a block-circulant structure. This observation

GREGORY BEYLKIN

1987-01-01

347

Optical Hartley transforms  

Microsoft Academic Search

The two-dimensional Hartley transform is of particular interest not only as a tool for analysis and processing of images and other two-dimensional functions, but because it can be implemented optically without introducing the phase ambiguities associated with intensity-only observations of Fourier transforms. The Hartley transform property of producing real transforms from real inputs means that square law detection introduces only

J. D. Villasenor

1994-01-01

348

Golden Hadamard Transform Matrices  

Microsoft Academic Search

Here is introducing a new transform known as the Golden Hadamard Transform whose kernel contains just the Golden Mean. An analytical comparison is made with the Walsh-Hadamard Transform to use in various applications such as coding, error correction codes etc.

Sos Agaian; Hakob Sarukhanyan; Jaakko Astola

349

Stationary Hadamard Transform Spectrometry  

Microsoft Academic Search

Two novel applications of a stationary electro -optic shutter have been successfully developed for use in Hadamard transform spectrometry. The first of these combines interferometric and Hadamard transform techniques for a spectrometric instrument offering advantages over conventional spectrometers. A Hadamard transform encoding mask is incorporated into a multiple-beam Fizeau interferometer design, allowing the use of a single detector element rather

James David Tate

1991-01-01

350

The pulse sorting transform  

Microsoft Academic Search

A modification of conventional Fourier transforms is presented. This modification is called the pulse sorting transform (PST) and is useful in extracting information from signals comprised of interleaved pulse trains. A brief derivation of the PST from the conventional transform is presented, followed by theorems that describe the PST's properties. Several examples of how the PST can be an effective

K. C. Overman; D. F. Mix; J. A. Lookadoo

1990-01-01

351

Transformer Core Clamp.  

National Technical Information Service (NTIS)

This report describes a transformer core clamp that increases both the clamping force applied to a center leg of the transformer core and the shock resistance of the transformer core. The clamp is constructed with opposed clamp plates on the outward facin...

B. Allen N. Williams

1980-01-01

352

Transformations - Composition (NLVM)  

NSDL National Science Digital Library

This Java applet enables learners to explore compositions of two transformations (among sliding, flipping and turning) both informally and within a coordinate system. Students select and compose shapes and manipulate the transformations to see the effect on a transformed image. Links to instructions, activities and teacher/parent information are included.

2011-01-01

353

The Transformation of Suffering  

Microsoft Academic Search

This article offers reflections on The Passion of the Lord, edited by James A. Noel and Matthew V. Johnson. The title “The Transformation of Suffering” refers not only to the transformations emerging from the epic suffering endured by Jesus and by peoples of the African diaspora, but to the ways each of us may be spiritually transformed by the crucible

Liza J. Rankow

2006-01-01

354

On SYZ mirror transformations  

Microsoft Academic Search

In this expository paper, we discuss how Fourier-Mukai-type transformations, which we call SYZ mirror transformations, can be applied to provide a geometric understanding of the mirror symmetry phenomena for semi-flat Calabi-Yau manifolds and toric Fano manifolds. We also speculate the possible applications of these transformations to other more general settings.

Kwokwai Chan; Naichung Conan Leung

2008-01-01

355

Characterization of nonlocal gates  

Microsoft Academic Search

A nonlocal unitary transformation of two-qubits occurs when some Hamiltonian interaction couples them. Here we characterize the amount, as measured by time, of interaction required to perform two-qubit gates, when also arbitrarily fast, local unitary transformations can be applied on each qubit. The minimal required time of interaction, or interaction cost, defines an operational notion of the degree of nonlocality

K. Hammerer; G. Vidal; J. I. Cirac

2002-01-01

356

Note: Tesla transformer damping.  

PubMed

Unexpected heavy damping in the two winding Tesla pulse transformer is shown to be due to small primary inductances. A small primary inductance is a necessary condition of operability, but is also a refractory inefficiency. A 30% performance loss is demonstrated using a typical "spiral strip" transformer. The loss is investigated by examining damping terms added to the transformer's governing equations. A significant alteration of the transformer's architecture is suggested to mitigate these losses. Experimental and simulated data comparing the 2 and 3 winding transformers are cited to support the suggestion. PMID:22852736

Reed, J L

2012-07-01

357

Note: Tesla transformer damping  

NASA Astrophysics Data System (ADS)

Unexpected heavy damping in the two winding Tesla pulse transformer is shown to be due to small primary inductances. A small primary inductance is a necessary condition of operability, but is also a refractory inefficiency. A 30% performance loss is demonstrated using a typical ``spiral strip'' transformer. The loss is investigated by examining damping terms added to the transformer's governing equations. A significant alteration of the transformer's architecture is suggested to mitigate these losses. Experimental and simulated data comparing the 2 and 3 winding transformers are cited to support the suggestion.

Reed, J. L.

2012-07-01

358

Fractional finite Fourier transform  

NASA Astrophysics Data System (ADS)

We show that a fractional version of the finite Fourier transform may be defined by using prolate spheroidal wave functions of order zero. The transform is linear and additive in its index and asymptotically goes over to Namias's definition of the fractional Fourier transform. As a special case of this definition, it is shown that the finite Fourier transform may be inverted by using information over a finite range of frequencies in Fourier space, the inversion being sensitive to noise. Numerical illustrations for both forward (fractional) and inverse finite transforms are provided.

Khare, Kedar; George, Nicholas

2004-07-01

359

Analyses of temperature-dependent interface states, series resistances, and AC electrical conductivities of Al/p—Si and Al/Bi4Ti3O12/p—Si structures by using the admittance spectroscopy method  

NASA Astrophysics Data System (ADS)

In this study, Al/p—Si and Al/Bi4Ti3O12/p—Si structures are fabricated and their interface states (Nss), the values of series resistance (Rs), and AC electrical conductivity (?ac) are obtained each as a function of temperature using admittance spectroscopy method which includes capacitance—voltage (C—V) and conductance—voltage (G—V) measurements. In addition, the effect of interfacial Bi4Ti3O12 (BTO) layer on the performance of the structure is investigated. The voltage-dependent profiles of Nss and Rs are obtained from the high-low frequency capacitance method and the Nicollian method, respectively. Experimental results show that Nss and Rs, as strong functions of temperature and applied bias voltage, each exhibit a peak, whose position shifts towards the reverse bias region, in the depletion region. Such a peak behavior is attributed to the particular distribution of Nss and the reordering and restructuring of Nss under the effect of temperature. The values of activation energy (Ea), obtained from the slope of the Arrhenius plot, of both structures are obtained to be bias voltage-independent, and the Ea of the metal-ferroelectric-semiconductor (MFS) structure is found to be half that of the metal—semiconductor (MS) structure. Furthermore, other main electrical parameters, such as carrier concentration of acceptor atoms (NA), built-in potential (Vbi), Fermi energy (EF), image force barrier lowering (? ?b), and barrier height (?b), are extracted using reverse bias C-2—V characteristics as a function of temperature.

Mert, Y?ld?r?m; Perihan, Durmu?; ?emsettin, Alt?ndal

2013-10-01

360

Analysis and transformation of image using spectral transformation technique  

Microsoft Academic Search

Image processing is a rapidly growing field. There are several transforms that do image transformation i.e image enhancement and segmentation. Among all the transformations spectral transformation is the simplest one because it is similar to the commonly used geometric coordinate transformation except that the geometric coordinate are replaced with the spectral bands. I can perform spectral transformation by different algorithms,

V. Singh; M. Singh

2010-01-01

361

A Catalan Transform and Related Transformations on Integer Sequences  

NASA Astrophysics Data System (ADS)

We introduce and study an invertible transformation on integer sequences related to the Catalan numbers. Transformation pairs are identified among classical sequences. A closely related transformation which we call the generalized Ballot transform is also studied, along with associated transformations. Results concerning the Fibonacci, Jacobsthal and Pell numbers are derived. Finally, we derive results about combined transformations.

Barry, Paul

2005-09-01

362

Shape description using sequency-ordered complex Hadamard transform  

NASA Astrophysics Data System (ADS)

Sequency-ordered complex Hadamard transform (SCHT) is a novel discrete orthogonal transform and has been applied to spectrum analysis and image watermarking. In this paper, a novel SCHT based shape descriptors, termed SCHDs, is proposed and applied to image retrieval. SCHDs first expresses the shape boundary as a 1-D complex signal, and SCHT is then applied to it. The resulting transform coefficients are used to characterize the shapes. This description scheme is applied to shape based image retrieval, and the experimental results show that the proposed SCHDs outperforms Fourier descriptors (FDs) and wavelet transform combined with Fourier transform based method (WFDs).

Wang, Bin; Wu, Jiasong; Shu, Huazhong; Luo, Limin

2011-06-01

363

Fourier-transform optical microsystems  

NASA Technical Reports Server (NTRS)

The design, fabrication, and initial characterization of a miniature single-pass Fourier-transform spectrometer (FTS) that has an optical bench that measures 1 cm x 5 cm x 10 cm is presented. The FTS is predicated on the classic Michelson interferometer design with a moving mirror. Precision translation of the mirror is accomplished by microfabrication of dovetailed bearing surfaces along single-crystal planes in silicon. Although it is miniaturized, the FTS maintains a relatively high spectral resolution, 0.1 cm-1, with adequate optical throughput.

Collins, S. D.; Smith, R. L.; Gonzalez, C.; Stewart, K. P.; Hagopian, J. G.; Sirota, J. M.

1999-01-01

364

Evaluate and Characterize Mechanisms Controlling Transport, Fate and Effects of Army Smokes in the Aerosol Wind Tunnel: Transport, Transformations, Fate, and Terrestrial Ecological Effects of Red Phosphorus-Butyl Rubber and White Phosphorus Obscurant Smokes: Final Report.  

National Technical Information Service (NTIS)

An evaluation of the terrestrial transport, transformations and ecological effects of phosphorus (red phosphorus-butyl rubber (RP/BR)) smoke obscurant was performed at Pacific Northwest Laboratory. A similar evaluation using white phosphorus (WP) smoke/ob...

P. Van Voris M. W. Ligotke K. M. McFadden S. M. W. Li B. L. Thomas

1987-01-01

365

The LMT Transformational System  

Microsoft Academic Search

We present a newly designed transformational system for the MT system LMT, consisting of a transformational formalism, LMT-TL,\\u000a and an algorithm for applying transformations written in this formalism. LMT-TL is both expressive and simple because of the\\u000a systematic use of a powerful pattern matching mechanism that focuses on dependency trees. LMT-TL is a language in its own\\u000a right, with no

Michael C. Mccord; Arendse Bernth

1998-01-01

366

The Cascaded Hough Transform  

Microsoft Academic Search

When using the original slope-intercept parameterisationfor the Hough transform, the resulting parameterspace actually corresponds to the dual space. Indeed,lines are transformed into points, and for everypoint there is also a corresponding line. This paperpresents a way of exploiting this special property, bythe introduction of the Cascaded Hough Transform, orCHT for short. This allows to look for the overallstructure in an

Tinne Tuytelaars; Marc Proesmans; Luc Van Gool

1998-01-01

367

Nanosecond Pulse Transformers  

Microsoft Academic Search

The transmission-line approach to the design of transformers yields a unit with no first-order rise-time limit since this approach uses distributed rather than lumped constants. The total time delay through the transmission-line-type transformer may exceed the rise time by a large factor, unlike conventional transformers. The extra winding length can be employed to improve the low-frequency response of the unit.

C. Norman Winningstad

1959-01-01

368

Magnetically Controlled Variable Transformer  

NASA Technical Reports Server (NTRS)

Improved variable-transformer circuit, output voltage and current of which controlled by use of relatively small current supplied at relatively low power to control windings on its magnetic cores. Transformer circuits of this type called "magnetic amplifiers" because ratio between controlled output power and power driving control current of such circuit large. This ratio - power gain - can be as large as 100 in present circuit. Variable-transformer circuit offers advantages of efficiency, safety, and controllability over some prior variable-transformer circuits.

Kleiner, Charles T.

1994-01-01

369

An extension of the Laplace transform to Schwartz distributions  

NASA Technical Reports Server (NTRS)

A characterization of the Laplace transform is developed which extends the transform to the Schwartz distributions. The class of distributions includes the impulse functions and other singular functions which occur as solutions to ordinary and partial differential equations. The standard theorems on analyticity, uniqueness, and invertibility of the transform are proved by using the characterization as the definition of the Laplace transform. The definition uses sequences of linear transformations on the space of distributions which extends the Laplace transform to another class of generalized functions, the Mikusinski operators. It is shown that the sequential definition of the transform is equivalent to Schwartz' extension of the ordinary Laplace transform to distributions but, in contrast to Schwartz' definition, does not use the distributional Fourier transform. Several theorems concerning the particular linear transformations used to define the Laplace transforms are proved. All the results proved in one dimension are extended to the n-dimensional case, but proofs are presented only for those situations that require methods different from their one-dimensional analogs.

Price, D. R.

1974-01-01

370

PPS electrical properties for power transformers  

Microsoft Academic Search

In order to find a material that can be used as wrapped insulating film in the power transformer industry, we have tested polyphenylene sulfone which is film characterized by a high thermal resistance, a high chemical resistance and an outstanding mechanical strength. The thermal degradation study is of major importance in this application, so thermal aging test in the presence

M.-B. Fatmi; A. Bui; C. Boisdon; P. Vuarchex

1998-01-01

371

Fingerprint Anti-Spoofing Using Ridgelet Transform  

Microsoft Academic Search

This paper proposes a new ridgelet transform-based method to detect spoof fingerprint attacks in fingerprint biometric systems. It uses differences in textural characteristics observed in real and spoof fingerprints for spoof detection. Textural measures based on ridgelet energy signatures and ridgelet co-occurrence signatures are used to characterize fingerprint texture. Principal component analysis with ranker search is used to reduce dimensionalities

ShankarBhausaheb Nikam; Suneeta Agarwal

2008-01-01

372

Color Space Transformation from RGB to CIELAB Using Neural Networks  

Microsoft Academic Search

Transformations in digital color imaging from RGB to CIELAB are compared between conventional ICC profiles and a newly developed\\u000a neural network model. The accuracy of the transformations are computed in terms of Delta E and a comparison is made between\\u000a the ICC profile and a neural network implemented in MATLAB. The transformations are used to characterize and test the color

Nawar Fdhal; Matthew J. Kyan; Dimitri Androutsos; Abhay Sharma

2009-01-01

373

Two Different Squeeze Transformations  

NASA Technical Reports Server (NTRS)

Lorentz boosts are squeeze transformations. While these transformations are similar to those in squeezed states of light, they are fundamentally different from both physical and mathematical points of view. The difference is illustrated in terms of two coupled harmonic oscillators, and in terms of the covariant harmonic oscillator formalism.

Han, D. (Editor); Kim, Y. S.

1996-01-01

374

Pathways to Transformation.  

ERIC Educational Resources Information Center

The ubiquitous use of the term "transformation" in experiential education has blurred its specific meaning in any given case. Designing an effective curriculum requires instructors to determine what kind of transformation they would like to generate. A review of two research projects provides insights about different types of personal change and…

Henderson, Bob; Cushing, Pamela

375

Direct current transformer  

NASA Technical Reports Server (NTRS)

A direct current transformer in which the primary consists of an elongated strip of superconductive material, across the ends of which is direct current potential is described. Parallel and closely spaced to the primary is positioned a transformer secondary consisting of a thin strip of magnetoresistive material.

Khanna, S. M.; Urban, E. W. (inventors)

1979-01-01

376

Operating Transformers by Temperature  

Microsoft Academic Search

This paper discusses a proposal, sponsored by the Transformer Subcommittee of the Committee on Electrical Machinery, which is intended to serve as a guide in operating transformers by temperature rather than in accordance with their nameplate ratings. There is a real difference between ``rating standards'' and ``recommendations for operation;'' one simply specifies the measure of a machine under a definite

W. M. Dann

1930-01-01

377

Human Dimension of Transformation.  

National Technical Information Service (NTIS)

The transformation of the U.S. military and the Department of Defense represents a complex process which has been evolving since the end of the Cold War. Successful transformation will require a cultural change that focuses on producing forces that when i...

R. E. Scurlock

2004-01-01

378

TRANSFORMS, ALGORITHMS AND APPLICATIONS  

Microsoft Academic Search

Fourier transforms and other related transforms are an essential tool in applications of science, engineering and technology. In fact, much of the work currently being done in mathematics, physics and engineering has its roots in Fourier's pioneering idea of representing an arbitrary function as the sum of a trigonometric series. The main purpose of these notes is to give a

M. J. Soares

379

The Discrete Pulse Transform  

Microsoft Academic Search

We investigate a recent algorithm, here called a discrete pulse transform (DPT), for the multiresolution analysis of a sequence. A DPT represents a sequence as a sum of pulses, where a pulse is a sequence which is zero everywhere except for a certain number of consecutive elements which have a constant nonzero value. Unlike the discrete Fourier and wavelet transforms,

C. H. Rohwer; D. P. Laurie

2006-01-01

380

Transformational Plasmon Optics  

Microsoft Academic Search

Transformation optics has recently attracted extensive interest, since it provides a novel design methodology for manipulating light at will. Although transformation optics in principle embraces all forms of electromagnetic phenomena on all length scales, so far, much less efforts have been devoted to near-field optical waves, such as surface plasmon polaritons (SPPs). Due to the tight confinement and strong field

Yongmin Liu; Thomas Zentgraf; Guy Bartal; Xiang Zhang

2010-01-01

381

Biochemical transformation of coals  

DOEpatents

A method of biochemically transforming macromolecular compounds found in solid carbonaceous materials, such as coal is provided. The preparation of new microorganisms, metabolically weaned through challenge growth processes to biochemically transform solid carbonaceous materials at extreme temperatures, pressures, pH, salt and toxic metal concentrations is also disclosed. 7 figs.

Lin, M.S.; Premuzic, E.T.

1999-03-23

382

Support Principals, Transform Schools  

ERIC Educational Resources Information Center

The Transformational Coaching Team in Oakland Unified School District provides differentiated, sustained, job-embedded support to the district's school leaders. In this article, members of the team describe how they work with principals to transform the culture of schools. Student achievement data show above-average improvement in schools in which…

Aguilar, Elena; Goldwasser, Davina; Tank-Crestetto, Kristina

2011-01-01

383

Genetic Transformation of Bacteria.  

ERIC Educational Resources Information Center

An activity in which students transform an ampicillin-sensitive strain of E. coli with a plasmid containing a gene for ampicillin resistance is described. The procedure for the preparation of competent cells and the transformation of competent E. coli is provided. (KR)

Moss, Robert.

1991-01-01

384

Role of Oocyte Loss in Ovarian Surface Mesothelial Cell Transformation.  

National Technical Information Service (NTIS)

Three Specific Aims (SA) were proposed to test in mice if accelerated oocyte loss caused by Bclw deficiency or Bax gain-of-function drives ovarian surface mesothelial cell (OSMC) transformation: (1) characterize preneoplastic changes in OSMC of Bclw(-/-)1...

J. L. Tilly

2003-01-01

385

Role of Oocyte Loss in Ovarian Surface Mesothelial Cell Transformation.  

National Technical Information Service (NTIS)

Three Specific Aims (SA) were proposed to test in mice the hypothesis that accelerated oocyte loss caused by Bclw deficiency or Bax gain-of-function drives ovarian surface mesothelial cell (OSMC) transformation: (1) characterize preneoplastic changes in O...

J. L. Tilly G. R. MacGregor

2002-01-01

386

Parameter extraction of ferrite transformers using S-parameters  

Microsoft Academic Search

A characterization of ferrite transformers based on S-parameters measurement using vector network analyzer and specially developed PCB test fixture is presented. Ferrite transformers are realized with commercially available ferrite component. In addition, in order to verify the measurement procedure, we have tested the same component using impedance analyzer, and compared the results with VNA measurement procedure. It is shown that

Mirjana Damnjanovic; Ljiljana Zivanov; Goran Radosavljevic; Andrea Maric; Aleksandar Menicanin

2010-01-01

387

Transformational Development of User Interfaces with Graph Transformations  

Microsoft Academic Search

In software engineering transformational development aims at developing software systems by transforming a coarse-grained specification to final code (or to a detailed specification) through a sequence of small transformation steps. Transformational development is known to bring benefits such as: correctness-preserving of the development cycle, explicit mappings between development steps, reusability and reversibility of transformations. No piece of literature provides a

Quentin Limbourg; Jean Vanderdonckt

2004-01-01

388

The martensitic transformation in ceramics — its role in transformation toughening  

Microsoft Academic Search

This paper reviews the current knowledge and understanding of martensitic transformations in ceramics — the tetragonal to monoclinic transformation in zirconia in particular. This martensitic transformation is the key to transformation toughening in zirconia ceramics. A very considerable body of experimental data on the characteristics of this transformation is now available. In addition, theoretical predictions can be made using the phenomenological

Patrick M. Kelly; L. R. Francis Rose

2002-01-01

389

New geometrical approach for new Hough-like transforms  

NASA Astrophysics Data System (ADS)

Hough Transform, an important tool in image processing, does not use the analytical or geometrical properties of its basic objects, sine curves. Their replacement by other curves, namely circles, has led us to the discovery and the autonomous study of two families of transforms, named Circle and Envelope Transforms. These transforms, internal to the plane of study, are divided into three classes: parabolic, elliptic and hyperbolic, in connection with the Euclidean and the two non-Euclidean geometries. They are shown to be equivalent to Hough Transform. Three 'classical geometry' transforms interplay with envelope transforms: reciprocal polar transform, inversion transform and pedal transform. A unified view is brought by the introduction of the 'space of circles' equipped with a special quadratic form. This set of transforms can be applied successfully to conic curves in view of their characterization and detection. Almost every concept in this model is generalizable to 3D in a straightforward manner. Generalization is also promising for gray-level images in the direction of Radon Transform.

Becker, Jean-Marie

1998-10-01

390

Fourier transform differences and averaged similarities in diatoms.  

PubMed

Phase contrast photographs of diatoms are characterized from their Fourier transform taken through an optical diffractometer. The system output is placed on line to a PDP11/40 providing digital subtraction of two output spectral distributions due to different species. Differences obtained in this manner are used for characterizing various species. An average Fourier transform taken through coherent additions is also analyzed to find common features in a given set of diatoms. PMID:20212908

Almeida, S P; Fujii, H

1979-05-15

391

The Practice of Transformative Pedagogy  

ERIC Educational Resources Information Center

The author examined the practice of transformative pedagogy in an undergraduate teacher education program. The research was guided by two questions: What is the impact of transformative pedagogy on fostering preservice teachers' transformative learning? and What practices of transformative pedagogy impact student transformative learning?…

Ukpokodu, Omiunota

2009-01-01

392

Transformer design tradeoffs  

NASA Technical Reports Server (NTRS)

Material was presented to assist transformer designers in the transition from long-used English units to the less familiar metric equivalents. A coordination between the area product numbers ap (product of window and core cross-section areas) and current density J was developed for a given regulation and temperature rise. Straight-line relationships for Ap and Volume, Ap and surface area At and, Ap and weight were developed. These relationships can now be used as new tools to simplify and standardize the process of transformer design. They also made it possible to design transformers of small bulk and volume or to optimize efficiency.

Mclyman, W. T.

1976-01-01

393

Fourier Transform Interferometry.  

National Technical Information Service (NTIS)

The basic Michelson interferometer, as used for Fourier transform spectroscopy, is analyzed in this report. The principles of operation are explained, and its inherent limitations are shown. An original analysis of apodization, for the case of an off-axis...

D. R. Hearn

1999-01-01

394

Proof in Transformation Geometry  

ERIC Educational Resources Information Center

The first of three articles showing how inductively-obtained results in transformation geometry may be organized into a deductive system. This article discusses two approaches to enlargement (dilatation), one using coordinates and the other using synthetic methods. (MM)

Bell, A. W.

1971-01-01

395

A Classical Science Transformed.  

ERIC Educational Resources Information Center

Describes how satellites and other tools of space technology have transformed classical geodesy into the science of space geodynamics. The establishment and the activities of the French Center for Geodynamic and Astronomical Research Studies (CERGA) are also included. (HM)

Kovalevsky, Jean

1979-01-01

396

Pulse Transformer Design Study.  

National Technical Information Service (NTIS)

The design of a compact, lightweight, high average power, air-core pulse transformer to satisfy the electrical and physical requirements of a developmental power conditioning system is presented. (Author)

H. Aslin P. Chao

1975-01-01

397

The Laguerre Transform.  

National Technical Information Service (NTIS)

A novel transform is presented which maps continuum functions (such as probability distributions) into discrete sequences and permits rapid numerical calculation of convolutions, multiple convolutions, and Neumann expansions for Volterra integral equation...

J. Keilson W. Nunn U. Sumita

1980-01-01

398

Transformational Grammars Again.  

National Technical Information Service (NTIS)

The note presents some criticisms of Chomsky's theory of Transformational Grammar, and in particular of his most recent attempt to demarcate syntax from semantics by means of the distinction between selectional and subcategorization rules. I argue that, a...

Y. Wilks

1967-01-01

399

Generic quantum Fourier transforms  

Microsoft Academic Search

The quantum Fourier transform (QFT) is the principal ingredient of most efficient quantum algorithms. We present a generic framework for the construction of efficient quantum circuits for the QFT by \\

Cristopher Moore; Daniel N. Rockmore; Alexander Russell

2004-01-01

400

Fiber optics transforms  

Microsoft Academic Search

We give fiber or planar lightwave circuit (PLC) architectures to implement the discrete Fourier transform (DFT) and the discrete Hartley transform (DHT) directly in the optical domain. In both cases, we present a recursive approach for the decimation-in-frequency algorithm, considering parallel and serial input configurations. We also describe PLC devices for high-speed optical filtering and data compression, based on discrete

Michela Svaluto Moreolo; Gabriella Cincotti

2008-01-01

401

Plant transformation technology  

Microsoft Academic Search

Plant transformation has its roots in the research on Agrobacterium that was being undertaken in the early 1980s. The last two decades have seen significant developments in plant transformation\\u000a technology, such that a large number of transgenic crop plants have now been released for commercial production. Advances\\u000a in the technology have been due to development of a range of Agrobacterium-mediated

Christine A. Newell

2000-01-01

402

Series Transmission Line Transformer  

DOEpatents

A series transmission line transformer is set forth which includes two or more of impedance matched sets of at least two transmissions lines such as shielded cables, connected in parallel at one end ans series at the other in a cascading fashion. The cables are wound about a magnetic core. The series transmission line transformer (STLT) which can provide for higher impedance ratios and bandwidths, which is scalable, and which is of simpler design and construction.

Buckles, Robert A. (Livermore, CA); Booth, Rex (Livermore, CA); Yen, Boris T. (El Cerrito, CA)

2004-06-29

403

Transformation superplasticity of zirconium  

SciTech Connect

A tensile strain of 270% was achieved for coarse-grained zirconium subjected to transformation superplasticity condition, where strain increments are accumulated upon repeated thermal cycling around the allotropic transformation temperature under the biasing effect of a uniaxial tensile stress. The strain increment per cycle was found to consist of two equal contributions from transformations on heating and cooling and to increase linearly with the applied stress. The measured strain increments are in good quantitative agreement with predictions based on the average internal stress during the transformation, which was determined independently from experimental transformation times. As the cycling frequency is raised, the average strain rate increases (a maximum value of 1.3 {times} 10{sup {minus}4} s{sup {minus}1} was measured), but the strain increment per cycle decreases above a critical cycling frequency, for which the sample gage section undergoes only a partial phase transformation. The resulting reduction in internal mismatch and increase in internal stress are modeled using the experimental observation that {beta}-Zr deforms by a mixture of diffusional and dislocation creep in the stress range of interest.

Zwigl, P. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Materials Science and Engineering; Dunand, D.C. [Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering

1998-10-01

404

Floral Transformation of Wheat  

NASA Astrophysics Data System (ADS)

A method is described for the floral transformation of wheat using a protocol similar to the floral dip of Arabidopsis. This method does not employ tissue culture of dissected embryos, but instead pre-anthesis spikes with clipped florets at the early, mid to late uninucleate microspore stage are dipped in Agrobacterium infiltration media harboring a vector carrying anthocyanin reporters and the NPTII selectable marker. T1 seeds are examined for color changes induced in the embryo by the anthocyanin reporters. Putatively transformed seeds are germinated and the seedlings are screened for the presence of the NPTII gene based on resistance to paromomycin spray and assayed with NPTII ELISAs. Genomic DNA of putative transformants is digested and analyzed on Southern blots for copy number to determine whether the T-DNA has integrated into the nucleus and to show the number of insertions. The non-optimized transformation efficiencies range from 0.3 to 0.6% (number of transformants/number of florets dipped) but the efficiencies are higher in terms of the number of transformants produced/number of seeds set ranging from 0.9 to 10%. Research is underway to maximize seed set and optimize the protocol by testing different Agrobacterium strains, visual reporters, vectors, and surfactants.

Agarwal, Sujata; Loar, Star; Steber, Camille; Zale, Janice

405

Kinetics of phase transformations  

SciTech Connect

This volume contains papers presented at the Materials Research Society symposium on Kinetics of Phase Transformations held in Boston, Massachusetts from November 26-29, 1990. The symposium provided a forum for research results in an exceptionally broad and interdisciplinary field. Presentations covered nearly every major class of transformations including solid-solid, liquid-solid, transport phenomena and kinetics modeling. Papers involving amorphous Si, a dominant topic at the symposium, are collected in the first section followed by sections on four major areas of transformation kinetics. The symposium opened with joint sessions on ion and electron beam induced transformations in conjunction with the Surface Chemistry and Beam-Solid Interactions: symposium. Subsequent sessions focused on the areas of ordering and nonlinear diffusion kinetics, solid state reactions and amorphization, kinetics and defects of amorphous silicon, and kinetics of melting and solidification. Seven internationally recognized invited speakers reviewed many of the important problems and recent results in these areas, including defects in amorphous Si, crystal to glass transformations, ordering kinetics, solid-state amorphization, computer modeling, and liquid/solid transformations.

Thompson, M.O. (Cornell Univ., Ithaca, NY (United States)); Aziz, M.J. (Harvard Univ., Cambridge, MA (United States)); Stephenson, G.B. (International Business Machines Corp., Yorktown Heights, NY (United States). Thomas J. Watson Research Center)

1992-01-01

406

Characterization of a Transforming N-ras Gene in the Human Hepatoma Cell Line Hep G2: Additional Evidence for the Importance of c-myc and ras Cooperation in Hepatocarcinogenesis  

Microsoft Academic Search

The expression of the c-myc gene has previously been shown to be elevated and deregulated in the human hepatoma cell line Hep G2 (B. E. Huber and S. S. Thorgeirsson, Cancer Res., 47: 3414-3420, 1987). We now report that the Hep G2 N-ras gene is activated to a dominant- acting, transforming gene by a missense mutation in codon 61. Hep

Cynthia A. Richards; Steven A. Short; Snorri S. Thorgeirsson; Brian E. Huber

1990-01-01

407

Alterations in the antigen processing-presenting machinery of transformed plasma cells are associated with reduced recognition by CD8+ T cells and characterize the progression of MGUS to multiple myeloma.  

PubMed

We hypothesized that progression of monoclonal gammopathy of undetermined significance (MGUS) to multiple myeloma (MM) reflects the escape of transformed plasma cells from T-cell recognition because of impaired antigen processing-presenting machinery (APM). We studied plasma cells and CD8(+) T cells from bone marrow of 20 MGUS patients, 20 MM patients, and 10 control patients. Immunofluorescence and flow cytometry revealed significantly different patterns of APM component expression in plasma cells from the 3 groups. Compared with control patients, MM samples had lower expression of proteasome subunits and peptide transporters and greater expression of chaperones, considering both percentages of stained cells and molecular equivalents of soluble fluorochrome. MGUS samples had intermediate percentages of stained cells but molecular equivalents of soluble fluorochrome similar to control patients. Real-time polymerase chain reaction documented that APM changes occurred at the transcriptional level. Cytotoxicity assays demonstrated that MGUS CD8(+) T cells lysed autologous transformed plasma cells more than MM CD8(+) T cells did. MGUS progression correlated directly with calnexin, calreticulin, and tapasin and indirectly with delta, LMP2, and LMP10 expression levels; MM disease status did not correlate with APM levels. APM changes may allow transformed plasma cells to elude immunesurveillance in the MGUS-MM pathogenetic sequence. PMID:20008301

Racanelli, Vito; Leone, Patrizia; Frassanito, Maria Antonia; Brunetti, Claudia; Perosa, Federico; Ferrone, Soldano; Dammacco, Franco

2010-02-11

408

Recombinant human adenoviruses containing hybrid adenovirus type 5 (Ad5)/Ad12 E1A genes: characterization of hybrid E1A proteins and analysis of transforming activity and host range.  

PubMed Central

Hybrid adenovirus type 12 (Ad12)/Ad5 E1A genes were constructed by homologous recombination in Escherichia coli, a technique which offers several advantages over conventional mutagenesis for genetic analysis of proteins. In particular, functional differences between the proteins can be mapped by correlating the replacement of specific sequences with the acquisition of new properties, and there is no requirement for common unique restriction sites or polymerase chain reaction strategies to construct the hybrids. Recombinant adenoviruses expressing these hybrid E1A proteins were capable of replicating efficiently in HeLa cells, with the exception of one construct which contained a hybrid transactivation domain. The transforming activity of the hybrid E1A constructs was assayed by DNA transfection of primary baby rat kidney cells. Plasmids containing Ad12 E1 were approximately 20-fold less efficient at transformation than those with E1 of Ad5, and it was found that two regions in exon 1 of E1A mediate this difference. No differences were found in the abilities of any hybrid E1A proteins to bind to cellular proteins previously determined to be important for transformation by E1A. Images

Jelinek, T; Graham, F L

1992-01-01

409

Transforming Growth Factors: Isolation of Polypeptides from Virally and Chemically Transformed Cells by Acid \\/ Ethanol Extraction  

Microsoft Academic Search

Polypeptides characterized by their ability to confer a transformed phenotype on an untransformed indicator cell have been isolated directly from tumor cells growing both in culture and in the animal, by using an acid \\/ ethanol extraction procedure. Assay of these polypeptides is based on their ability to induce normal rat kidney fibroblasts to form colonies in soft agar. Peptides

Anita B. Roberts; Lois C. Lamb; Dianne L. Newton; Michael B. Sporn; Joseph E. de Larco; George J. Todaro

1980-01-01

410

Solid-state current transformer  

NASA Technical Reports Server (NTRS)

A signal transformation network which is uniquely characterized to exhibit a very low input impedance while maintaining a linear transfer characteristic when driven from a voltage source and when quiescently biased in the low microampere current range is described. In its simplest form, it consists of a tightly coupled two transistor network in which a common emitter input stage is interconnected directly with an emitter follower stage to provide virtually 100 percent negative feedback to the base input of the common emitter stage. Bias to the network is supplied via the common tie point of the common emitter stage collector terminal and the emitter follower base stage terminal by a regulated constant current source, and the output of the circuit is taken from the collector of the emitter follower stage.

Farnsworth, D. L. (inventor)

1976-01-01

411

Precise Semantics of EMF Model Transformations by Graph Transformation  

Microsoft Academic Search

Model transformation is one of the key activities in model-driven soft- ware development. An increasingly popular technology to define modeling lan- guages is provided by the Eclipse Modeling Framework (EMF). Several EMF model transformation approaches have been developed, focusing on different transformation aspects. To validate model transformations wrt. functional behav- ior and correctness, a formal foundation is needed. In this

Enrico Biermann; Claudia Ermel; Gabriele Taentzer

2008-01-01

412

Initial Biochemical Characterization of Cells Derived from Human Periodontium and Their In vitro Response to Platelet-Derived Growth Factor, Epidermal Growth Factor and Transforming Growth Factor-Beta.  

National Technical Information Service (NTIS)

Periodontal disease is characterized by a loss of connective tissue attachment to teeth. One of the goals of periodontal therapy is to regenerate the destroyed periodontal attachment apparatus. Currently, this is not a predictable procedure. The aim of th...

J. E. Piche'

1988-01-01

413

Shape transformation for polyhedral objects  

Microsoft Academic Search

Techniques that transform one two-dimensionaf image into another have gained widespread use m recent yeara. Extending these tech- niques to transform pairs of 3D objects, as opposed to 2D images of the objects, providea several advsntagea, including the ability to sn- imate the objects independently of the transformation. This paper presents an algorithm for computing such transformations. The al- gorithm

James R. Kent; Wayne E. Carlson; Richard E. Parent

1992-01-01

414

Stationary Hadamard Transform Spectrometry.  

NASA Astrophysics Data System (ADS)

Two novel applications of a stationary electro -optic shutter have been successfully developed for use in Hadamard transform spectrometry. The first of these combines interferometric and Hadamard transform techniques for a spectrometric instrument offering advantages over conventional spectrometers. A Hadamard transform encoding mask is incorporated into a multiple-beam Fizeau interferometer design, allowing the use of a single detector element rather than the more problematic linear detector arrays in the near-infrared region. The instrument can be made small, inexpensive, and compatible with harsh industrial environments. The second application of the stationary encoding mask is in conjunction with a Hadamard transform (HT) Raman spectrometer for use in the near-infrared spectral region. This spectral region is important to the practicing Raman spectroscopist since problems associated with fluorescence in the visible spectral region are reduced significantly. However, on going to the near-infrared region, a sacrifice is made in terms of adequate Raman signal resulting in poorer signal -to-noise ratio. As such, there is a need for multiplexing spectrometers to recover the loss associated with the near -infrared spectral region. The Hadamard transform Raman spectrometer using a stationary encoding mask offers this multiplex advantage. Both instruments share some special features such as the ability to perform spectral subtraction. However, the stationary encoding masks used in both instruments have some disadvantages (e.g. less than 100% modulation efficiency). One disadvantage associated with the electro -optic encoding masks is the finite mask response time. The finite mask response time, in addition to increasing data acquisition time, has deleterious effects on the recovered spectrum following a Hadamard transform To a large extent, the problem has been alleviated by a special correction procedure which when applied to spectral results actually compensates for the spectral error associated with the finite mask response time. The use of this correction procedure, in effect, allows the user to acquire spectral data at accelerated rates relative to conventional acquisition schemes.

Tate, James David

415

Modelling of Diffusive and Massive Phase Transformation  

Microsoft Academic Search

Diffusion in multi-component alloys can be characterized (a) by the vacancy mechanism for substitutional components, (b) by\\u000a the existence of sources and sinks for vacancies, and (c) by the motion of atoms of interstitial components. The description\\u000a of diffusive and massive phase transformation of a multi-component system is based on the principle of maximum dissipation\\u000a rate by Onsager; the finite

Ji?í Vala

416

Residential market transformation: National and regional indicators  

SciTech Connect

A variety of programs are underway to address market barriers to the adoption of energy-efficient residential technologies and practices. Most are administered by utilities, states, or regions that rely on the Energy Star as a consistent platform for program marketing and messaging. This paper reviews regional and national market transformation activities for three key residential end-uses -- air conditioning, clothes washing, and lighting -- characterizing current and ongoing programs; reporting on progress; identifying market indicators; and discussing implications.

Van Wie McGrory, Laura L.; McNamara, Maureen; Suozzo, Margaret

2000-06-01

417

Toothpicks and Transformations  

NSDL National Science Digital Library

In this math lesson, learners explore transformations and quadratic functions through toothpick patterns. Learners examine the mathematical pattern that emerges as they build a geometric design with toothpicks. The pattern is quadratic, and the learners determine the mathematical model in several different forms. Learners investigate the recursive nature of the relationship. An explicit model for the relation is developed, and a third model is developed by examining the scatterplot and determining the equation from the transformations. Finally, the group uses graphing calculators to develop another model and to verify that all of the models--factored form, vertex form, and general form--are equivalent.

Pbs

2012-01-01

418

Evolved image compression transforms  

NASA Astrophysics Data System (ADS)

State-of-the-art image compression and reconstruction schemes utilize wavelets. Quantization and thresholding are commonly used to achieve additional compression, but cause permanent, irreversible information loss. This paper describes an investigation into whether evolutionary computation (EC) may be used to optimize forward (compression-only) transforms capable of matching or exceeding the compression capabilities of a selected wavelet, while reducing the aggregate error in images subsequently reconstructed by that wavelet. Transforms are independently trained and tested using three sets of images: digital photographs, fingerprints, and satellite images.

Aldridge, Shawn; Babb, Brendan; Moore, Frank; Peterson, Michael

2010-04-01

419

Wavelet transforms for optical pulse analysis.  

PubMed

An exploration of wavelet transforms for ultrashort optical pulse characterization is given. Some of the most common wavelets are examined to determine the advantages of using the causal quasi-wavelet suggested in Proceedings of the LEOS 15th Annual Meeting (IEEE, 2002), Vol. 2, p. 592, in terms of pulse analysis and, in particular, chirp extraction. Owing to its ability to distinguish between past and future pulse information, the causal quasi-wavelet is found to be highly suitable for optical pulse characterization. PMID:16396051

Vázquez, Javier Molina; Mazilu, Michael; Miller, Alan; Galbraith, Ian

2005-12-01

420

The general quadratic Radon transform  

NASA Astrophysics Data System (ADS)

The general quadratic Radon transform in two dimensions is investigated. Whereas the classical Radon transform of a smooth function represents the integration over all lines, the general quadratic Radon transform integrates over all conic sections. First, the parabolic isofocal Radon transform, i.e. the restriction of the general quadratic Radon transform to all parabolae with focus in the origin, is defined and illustrated. We show its intense relation to the classical Radon transform, deduce a support theorem, formulate an extension of the support theorem and derive an inversion formula. The natural extension to a more general class of isofocal quadratic Radon transforms is outlined. We show how the general quadratic Radon transform can be derived from the integrals over all parabolae by solving the related Cauchy problem. Finally, we introduce an entirely geometrical definition of a generalized Radon transform, the oriented generalized Radon transform.

Denecker, Koen; Van Overloop, Jeroen; Sommen, Frank

1998-06-01

421

Thermal evaporation and characterization of superstrate CdS/Sb2Se3 solar cells  

NASA Astrophysics Data System (ADS)

Sb2Se3 is a very promising absorber material for thin film photovoltaics because of its ideal band gap, strong optical absorption, and non-toxic and earth-abundant constituents. However, only until this year Sb2Se3 solar cell was reported. Here, we present the fabrication and characterization of thermally evaporated superstrate CdS/Sb2Se3 solar cell. Our device achieved a power conversion efficiency of 1.9% (Voc = 300 mV, Jsc = 13.2 mA/cm2, and FF = 48%) and showed good stability. Moreover, using current-voltage measurement, admittance spectroscopy, capacitance-voltage profiling, and drive level capacitance profiling, device characteristics and performance limiting factors are revealed and discussed.

Luo, Miao; Leng, Meiying; Liu, Xinsheng; Chen, Jie; Chen, Chao; Qin, Sikai; Tang, Jiang

2014-04-01

422

Comparative study of Hilbert–Huang transform, Fourier transform and wavelet transform in pavement profile analysis  

Microsoft Academic Search

This study employs the Hilbert–Huang transform (HHT), the wavelet transform and the Fourier transform to analyse the road surface profiles of three pavement profiles. The wavelet and Fourier transforms have been the traditional spectral analysis methods, but they are predicated on a priori selection of basis functions that are either of infinite length or have fixed finite widths. The central

A. Y. Ayenu-Prah; N. O. Attoh-Okine

2009-01-01

423

Winthrop College Transformed Curriculum.  

ERIC Educational Resources Information Center

Dealing with the issue of a changing society and recognizing that teacher education has remained basically unchanged for 100 years, the faculty of the Winthrop College School of Education agreed to take the risk involved with transforming the teacher education curriculum. Three interdisciplinary teams have identified curriculum to be taught to…

Hawisher, Margaret F.

424

Fourier Transform I  

NSDL National Science Digital Library

Created by Lang Moore for the Connected Curriculum Project, the purpose of this module is to study the Fourier transform and use it to describe solutions of the heat equation on an infinite rod. This is one of a much larger set of learning modules hosted by Duke University.

Moore, Lang

2010-07-02

425

Transforming Data into Knowledge  

ERIC Educational Resources Information Center

School systems can be data rich and information poor if they do not understand and manage their data effectively. The task for school leaders is to put existing data into a format that lends itself to answering questions and improving outcomes for the students. Common barriers to transforming data into knowledge in education settings often include…

Mills, Lane

2006-01-01

426

Transforming Education with Technology  

ERIC Educational Resources Information Center

In this EL interview, Karen Cator, the director of the Office of Educational Technology at the U.S. Department of Education, talks about ways to realize the potential of technology to transform education. She discusses what students need: their own digital devices for classroom use, the ability to use the information they access, the skills to…

Scherer, Marge

2011-01-01

427

Fourier transform deflection mapping  

Microsoft Academic Search

In a previous paper in 1992, we presented a flow visualization technique based on deflection mapping. We now present a new method for the interpretation of deflection mapping of small angles obtained by Ronchi gratings. In this method, a Fourier transform is operated on the transmission pattern of the Ronchi grating and the individual sine terms are then obtained by

Arie Dahan; Gabi Ben-Dor; Ezra Bar-Ziv

1993-01-01

428

Transformative Mixed Methods Research  

ERIC Educational Resources Information Center

Paradigms serve as metaphysical frameworks that guide researchers in the identification and clarification of their beliefs with regard to ethics, reality, knowledge, and methodology. The transformative paradigm is explained and illustrated as a framework for researchers who place a priority on social justice and the furtherance of human rights.…

Mertens, Donna M.

2010-01-01

429

Hadamard transform imaging  

Microsoft Academic Search

We have constructed a Hadamard transform Raman microscopic imaging system, and have developed it to a high definition (64K pixel) technique. We have demonstrated multispectral Raman imaging and developed the first three-dimensional (digital confocal) Raman imaging. We have explored the systematic errors in Hadamard multiplexing techniques and developed corrections. We have used our Raman microscope techniques to explore defect distributions

1992-01-01

430

Hexagonal Parallel Pattern Transformations  

Microsoft Academic Search

The concept of the two-dimensional (2-D) parallel computer with square module arrays was first introduced by Unger. It is the purpose of this paper to discuss the relative merits of square and hexagonal module arrays, to propose an operational symbolism for the various basic hexagonal modular transformations which may be performed by these comupters, to illustrate some logical circuit implementation,

M. J. E. Golay

1969-01-01

431

Leaders lost in transformation  

Microsoft Academic Search

Purpose – To examine why most Lean transformations achieve only modest favorable results, despite years of effort. Design\\/methodology\\/approach – Comparative\\/evaluative discussion of efforts made by senior managers to implement the Lean management system, with commentary on a published example. Findings – Presents common obstacles and identifies common implementation errors that must be avoided in order to realize the full benefits

M. L. Emiliani; D. J. Stec

2005-01-01

432

Fourier Transform Mass Spectrometry.  

ERIC Educational Resources Information Center

Discusses the nature of Fourier transform mass spectrometry and its unique combination of high mass resolution, high upper mass limit, and multichannel advantage. Examines its operation, capabilities and limitations, applications (ion storage, ion manipulation, ion chemistry), and future applications and developments. (JN)

Gross, Michael L.; Rempel, Don L.

1984-01-01

433

Migration by Fourier transform  

Microsoft Academic Search

Wave equation migration is known to be simpler in principle when the horizontal coordinate or coordinates are replaced by their Fourier conjugates. Two practical migration schemes utilizing this concept are developed. One scheme extends the Claerbout finite difference method, greatly reducing dispersion problems usually associated with this method at higher dips and frequencies. The second scheme effects a Fourier transform

R. H. Stolt

1978-01-01

434

Transforming Primary Mathematics  

ERIC Educational Resources Information Center

What is good mathematics teaching? What is mathematics teaching good for? Who is mathematics teaching for? These are just some of the questions addressed in "Transforming Primary Mathematics", a highly timely new resource for teachers which accessibly sets out the key theories and latest research in primary maths today. Under-pinned by findings…

Askew, Mike

2011-01-01

435

Beyond Reform: Transformation  

ERIC Educational Resources Information Center

The Coalition of Essential Schools (CES) is not a reform movement. To reform is to make a thing again; reformation implies a stasis that doesn't deliver enough for the educational future. This issue of Horace demonstrates that Essential schools and the districts and networks that support them are at various points in the journey of transformation,…

Davidson, Jill

2007-01-01

436

Leading System Transformation  

ERIC Educational Resources Information Center

This article outlines progress made towards education transformation in Wales. It explores the way in which tri-level reform is guiding system level change in Wales and looks at the implementation of the School Effectiveness Framework, which is at the heart of the reform process. It describes the way in which professional learning communities are…

Harris, Alma

2010-01-01

437

Transformations: Reflection (NLVM)  

NSDL National Science Digital Library

This Java applet enables learners to explore the reflection transformation both informally and within a coordinate system. Students select and compose shapes and manipulate the axis of symmetry (the mirror) to see the effect on a reflected image. Links to instructions, activities and teacher/parent information are included.

2011-01-01

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